Motor drive control device, fan unit, and motor start-up control method

Abstract

To enable quick and stable start by correctly determining an anomalous state when the drive of a single-phase two system drive motor is started from a stopped state.SOLUTION: A motor drive control device includes: two motor drive circuits 10_1, 10_2 that are provided in correspondence with coils 6_1 and 6_2 of two systems for driving one motor 3 based on a drive command signal Sca and perform control for energizing the coils of the corresponding systems; and a drive control circuit 20 that outputs a drive command signal Sca to at least one of the two motor drive circuits 10_1, 10_2. At the time of starting, the drive control circuit 20 performs a primary determination for determining whether each system is anomalous or not, based on a detection result of a frequency of level changes of FG signals Fg_1, Fg_2 of each system input when a drive command signal Sca is output to at least one of the two motor drive circuits 10_1, 10_2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a motor drive control device, a fan unit, and a motor startup control method, and more particularly to a motor drive control device having two motor drive circuits compatible with dual-system drive, a fan unit, and a motor startup control method. [Background technology]

[0002] Generally, in a fan (hereinafter also referred to as a "fan motor") for cooling the inside of an electronic device such as a server, if a failure in the drive circuit that drives the motor makes it impossible to rotate the motor in the specified direction (forward rotation), an external force may act and the motor may be forced to rotate in the opposite direction to the forward rotation (reverse rotation).

[0003] For example, in a server with multiple fan motors installed inside its housing, if one fan motor fails, the air generated by the rotation of the other fan motors may flow into the failed fan motor, causing the failed fan motor to rotate in reverse. If one fan motor in a server rotates in reverse, the internal pressure of the server will drop, reducing its cooling function and potentially adversely affecting the server's operation. For this reason, fan motors installed in electronic devices such as servers are required to continue rotating in the forward direction as long as possible.

[0004] To solve the above-mentioned problems, motor drive control devices with two drive systems are known. For example, Patent Document 1 discloses a motor drive control device for driving a motor with two coil systems, which is provided with two motor drive circuits that independently drive the coils of each system of the motor. With this motor drive control device, even if one drive circuit fails, it is possible to continue driving the motor using the other drive circuit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-054187 Summary of the Invention [Problem to be solved by the invention]

[0006] In a single-phase two-system drive such as that disclosed in Patent Document 1, when a microcontroller (MCU) outputs a drive command signal to two motor drive units, the inverter circuit is driven based on the drive command signal, causing the motor to rotate, and the two motor drive units output FG signals, which are motor position and speed signals, at one pulse per electrical angle cycle to the MCU. The MCU calculates the motor rotation speed from the two input FG signals and the number of poles, and detects an abnormality if each FG signal does not switch over for longer than the abnormality detection time, determining that a rotor lock has occurred if an abnormality is detected in both systems, and that an FG failure has occurred if an abnormality is detected in either one of the systems.

[0007] In this case, when the motor is started from a stopped state, if the motor voltage is low or the drive command signal is at a low rotation speed, or if one of the two motor drive systems has a Hall sensor failure (which makes it impossible to switch the current direction as the motor rotates), the power supply voltage and stopped position may cause the motor to hold (hold state) or chatter (reciprocating motion) due to insufficient drive force or drive interference, resulting in the motor being erroneously diagnosed as having an FG failure when it is in a normal state, or as having a rotor lock when it is in an FG failure state, resulting in the motor not starting up stably.

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to enable a quick and stable start-up of a single-phase two-system drive motor by correctly determining abnormal conditions such as rotor lock and FG failure when starting the motor from a stopped state. [Means for solving the problem]

[0009] A motor drive control device according to a representative embodiment of the present invention comprises two motor drive circuits that correspond to two systems of coils that drive one motor based on a drive command signal and control the flow of electricity to the coils of the corresponding systems, and a drive control circuit that outputs the drive command signal to at least one of the two motor drive circuits, and is characterized in that, at startup, the drive control circuit performs a primary determination to determine whether or not there is an abnormality in each system based on the detection result of the number of level changes of the FG signal of each system that is input when the drive command signal is output to at least one of the two motor drive circuits. [Effects of the Invention]

[0010] According to the motor drive control device of the present invention, when starting a single-phase two-system drive motor from a stopped state, an abnormal state can be correctly determined, thereby enabling quick and stable start-up. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a block diagram showing a configuration of a motor drive control system according to an embodiment of the present invention; [Figure 2] FIG. 2 is a circuit diagram showing a configuration example of a detection voltage output circuit. [Figure 3] FIG. 2 is a block diagram showing the functional configuration of a drive control circuit. [Figure 4] FIG. 2 is a circuit diagram illustrating a configuration example of a signal blocking circuit. [Figure 5A] 10 is a circuit diagram schematically showing a first current-carrying state in the inverter circuit when a PWM signal is turned on and the gate is not blocked. FIG. [Figure 5B] 10 is a circuit diagram schematically showing a second current-carrying state in the inverter circuit when the PWM signal is turned on and the gate is not blocked. FIG. [Figure 6A] 10 is a circuit diagram schematically showing a first current-carrying state in the inverter circuit when the PWM signal is turned off and the gate is not blocked. FIG. [Figure 6B]10 is a circuit diagram schematically showing a second current-carrying state in the inverter circuit when the PWM signal is turned off and the gate is not blocked. FIG. [Figure 7A] 10 is a circuit diagram schematically showing a first current-carrying state in the inverter circuit when the PWM signal is turned off and the gate is blocked. FIG. [Figure 7B] 10 is a circuit diagram schematically showing a second current-carrying state in the inverter circuit when the PWM signal is turned off and the gate is blocked. FIG. [Figure 8] FIG. 4 is a diagram showing a determination sequence in the motor drive control system according to the present embodiment. [Figure 9] FIG. 10 is a diagram showing an outline of the determination conditions in the dual system startup mode in the primary determination. [Figure 10] FIG. 10 is a diagram showing an outline of the determination conditions in the first system startup mode in the primary determination. [Figure 11] FIG. 10 is a diagram showing an outline of the determination conditions in the second system startup mode in the primary determination. [Figure 12] FIG. 10 is a diagram showing an outline of the determination conditions in each rotation delay mode in the secondary determination. [Figure 13] 5A and 5B are diagrams illustrating the driving and detection states of each system in each driving mode. [Figure 14] 10 is a timing chart showing an example of a signal waveform up to the two-system drive mode. [Figure 15] 10 is a timing chart showing an example of signal waveforms up to a rotor lock mode. [Figure 16] 10 is a timing chart showing an example of signal waveforms up to the second system drive mode. [Figure 17] 10 is a timing chart showing an example of signal waveforms up to the first system drive mode. [Figure 18] 10 is a timing chart showing an example of a signal waveform from chattering of the first system to a two-system drive mode. [Figure 19] 10 is a timing chart showing an example of a signal waveform from chattering of the second system to a two-system drive mode. [Figure 20] 10 is a timing chart showing an example of a signal waveform from inertial rotation to a dual-system drive mode. [Figure 21] 5 is a flowchart showing an example of a processing flow when power is turned on in the motor drive control system according to the present embodiment. [Figure 22] 5 is a flowchart showing an example of a processing flow when determining whether a rotor is locked in the motor drive control system according to the present embodiment. [Figure 23] 5 is a flowchart showing an example of the flow of a dual-system startup mode process in the motor drive control system according to the present embodiment. [Figure 24] 10 is a flowchart showing an example of the flow of a two-system rotation wait mode process in the motor drive control system according to the present embodiment. [Figure 25] 5 is a flowchart showing an example of the flow of a dual-system drive mode process in the motor drive control system according to the present embodiment. [Figure 26] 5 is a flowchart showing an example of the flow of a first system startup mode process in the motor drive control system according to the present embodiment. [Figure 27] 6 is a flowchart showing an example of the flow of a first-system rotation wait mode process in the motor drive control system according to the present embodiment. [Figure 28] 5 is a flowchart showing an example of the flow of a first system drive mode process in the motor drive control system according to the present embodiment. [Figure 29] 5 is a flowchart showing an example of the flow of a second system startup mode process in the motor drive control system according to the present embodiment. [Figure 30] 6 is a flowchart showing an example of the flow of a second-system rotation wait mode process in the motor drive control system according to the present embodiment. [Figure 31] 5 is a flowchart showing an example of the flow of a second system drive mode process in the motor drive control system according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] 1. Overview of the embodiment First, a typical embodiment of the invention disclosed in this application will be outlined. In the following description, for example, reference numerals in the drawings corresponding to components of the invention are written in parentheses.

[0013] [1] A motor drive control device (1) according to a representative embodiment of the present invention comprises two motor drive circuits, each corresponding to two systems of coils that drive one motor based on a drive command signal, for controlling the energization of the coils of the corresponding systems, and a drive control circuit that outputs the drive command signal to at least one of the two motor drive circuits, wherein the drive control circuit, at startup, performs a primary determination to determine whether or not there is an abnormality in each system based on the detection result of the number of level changes of the FG signal of each system that is input when the drive command signal is output to at least one of the two motor drive circuits.

[0014] [2] In the motor drive control device described in [1] above, the drive control circuit may perform a secondary judgment to determine whether or not there is an abnormality in each system based on the detection result of the number of level changes of the FG signal of each system input when the drive command signal is output to at least one of the two motor drive circuits, and the detection result of the number of rotations of the motor calculated from the time for each level of the FG signal, depending on the judgment result of the primary judgment.

[0015] [3] In the motor drive control device described in [2] above, the drive command signal may be output to both of the two motor drive circuits to perform the primary judgment, and if the primary judgment determines that there is no abnormality in either system, the drive command signal may be output to both of the two motor drive circuits to perform the secondary judgment.

[0016] [4] In the motor drive control device described in [2] or [3] above, the drive control circuit may detect the number of level changes of the FG signals of each system input when the drive command signal is output to both of the two motor drive circuits while the motor is being driven, and perform a tertiary judgment to determine whether or not there is an FG failure based on the difference in the number of level changes.

[0017] [5] In the motor drive control device described in any one of [1] to [4] above, at startup, before performing the primary judgment, if the drive control circuit detects an idling state of the motor from the detection result of the number of level changes of the FG signal of each system input from both of the two motor drive circuits and the detection result of the motor rotation speed calculated from the time for each level of the FG signal, and if the motor rotation speed is equal to or greater than a predetermined minimum rotation speed, the drive control circuit may not perform the primary judgment and instead output the drive command signal to both of the two motor drive circuits to start two-system drive.

[0018] [6] In the motor drive control device described in any one of [1] to [4] above, the drive control circuit may perform the primary judgment by determining whether or not there is an abnormality in each system based on a detection result of the number of level changes of the FG signal of each system input when the drive command signal is output to at least one of the two motor drive circuits, and if the judgment determines that at least one motor drive circuit is abnormal, enabling operation of one motor drive circuit and stopping operation of the other motor drive circuit according to the judgment result, and judging whether or not there is an abnormality in each system based on the detection result of the number of level changes of the FG signal input from one of the motor drive circuits.

[0019] [7] In the motor drive control device according to any one of [1] to [4] and [6] above, each of the two motor drive circuits comprises an inverter control circuit that generates a drive control signal based on the drive command signal input from the drive control circuit and a position detection signal generated in accordance with the rotation of the motor, and outputs an FG signal having a frequency corresponding to the actual rotation speed of the motor to the drive control circuit, an inverter circuit that drives the coil based on the drive control signal, and a signal blocking circuit that switches between inputting and blocking the drive control signal from the inverter control circuit to the inverter circuit in accordance with control from the drive control circuit, and the drive control circuit performs the primary judgment by and if the determination indicates that at least one motor drive circuit is abnormal, the signal blocking circuit of one of the two motor drive circuits may be controlled according to the determination result to enable input of the drive control signal from the inverter control circuit of one system to the inverter circuit, and to stop input of the drive control signal from the inverter control circuit of the other system to the inverter circuit, thereby determining whether or not there is an abnormality in each system based on the detection result of the number of level changes of the FG signal input from one of the systems.

[0020] [8] In the motor drive control device according to any one of [6] to [7] which cite [4] and [4] above, the drive control circuit has an abnormality determination unit which sequentially performs the primary determination, the secondary determination, and the tertiary determination, and a drive command signal generation unit which generates the drive command signal to at least one system of the two motor drive circuits according to the determination results of the primary determination and the secondary determination, and the drive command signal generation unit outputs the drive command signal corresponding to either a two-system drive which drives both of the two motor drive circuits, a first-system drive which drives the motor drive circuit of the first system of the two motor drive circuits, or a second-system drive which drives the motor drive circuit of the second system of the two motor drive circuits, and in the primary determination at the time of startup, the motor drive control circuit operates in the two-system drive. the first-system start-up mode in which the motor operates in the first-system drive mode, and the second-system start-up mode in which the motor operates in the second-system drive mode; and in the second determination after the first determination, the motor may be adapted to operate in any one of the two-system rotation wait mode in which the motor operates in the dual-system drive mode, the first-system rotation wait mode in which the motor operates in the first-system drive mode, and the second-system rotation wait mode in which the motor operates in the second-system drive mode, depending on the determination result of the first determination; and in driving after the second determination, the motor may be adapted to operate in any one of the two-system drive mode in which the motor operates in the dual-system drive mode, the first-system drive mode in which the motor operates in the first-system drive mode, and the second-system drive mode in which the motor operates in the second-system drive mode, depending on the determination result of the second determination; and after the first determination or the second determination, the drive command signal corresponding to the operation mode may be generated.

[0021] [9] In the motor drive control device described in [8] above, the abnormality determination unit generates a determination result in the dual-system startup mode based on the number of level changes of the FG signal of each system in a predetermined period, such that if the number of level changes in both systems does not reach a predetermined number, it tentatively determines that the rotor is locked, if the number of level changes in both systems does not reach a predetermined number, it tentatively determines that the first system is normal if the number of level changes in only the first system reaches the predetermined number, it tentatively determines that the second system is normal if the number of level changes in only the second system reaches the predetermined number, or it tentatively determines that the two systems are normal if the number of level changes in both systems reach the predetermined number, and the drive command signal generation unit generates the drive command signal corresponding to one of the operation modes of the first system startup mode based on the tentative rotor lock determination, the first system startup mode based on the tentative first system normal determination, the second system startup mode based on the tentative second system normal determination, and the two-system rotation wait mode based on the tentative two-system normal determination, according to the determination result generated by the abnormality determination unit.

[0022]

[10] In the motor drive control device described in [9] above, the abnormality determination unit may generate a determination result in the following manner: in the first system startup mode, the first system is tentatively determined to be normal when the number of level changes of the FG signal of the first system in a predetermined period reaches a predetermined number; in the first system startup mode based on the rotor lock tentative determination, the first system is tentatively determined to be rotor locked when the number of level changes of the FG signal of the first system in a predetermined period does not reach a predetermined number; and in the first system startup mode based on the first system normal tentative determination, the first system is tentatively determined to be FG fault when the number of level changes of the FG signal of the first system in a predetermined period does not reach a predetermined number; and the drive command signal generation unit may generate the drive command signal corresponding to one of the operation modes of the first system rotation waiting mode based on the first system temporary normal determination, the second system startup mode based on the rotor lock tentative determination, and the rotor lock mode based on the first system FG fault tentative determination, according to the determination result generated by the abnormality determination unit in the first system startup mode.

[0023]

[11] In the motor drive control device described in [8] above, the abnormality judgment unit may generate a judgment result in which, in the second system startup mode, the second system is provisionally judged to be normal when the number of level changes of the FG signal of the second system in a predetermined period reaches a predetermined number, and the second system is provisionally judged to be a rotor lock judgment or a second system FG failure judgment when the number of level changes does not reach the predetermined number, and the drive command signal generation unit may generate the drive command signal corresponding to one of the operation modes of the second system rotation waiting mode based on the second system provisional normality judgment and the rotor lock mode based on the rotor lock judgment or the second system FG failure provisional judgment, depending on the judgment result generated by the abnormality judgment unit in the second system startup mode.

[0024]

[12] In the motor drive control device according to any one of [8] to

[11] above, the abnormality determination unit, in the two-system rotation waiting mode, determines a second system FG failure provisionally when the rotation number reaches a minimum rotation number and the number of level changes of only the first system reaches a predetermined number based on the rotation number of the motor based on the FG signal and the number of level changes of the FG signal of each system in a predetermined period, determines a first system FG failure provisionally when the rotation number reaches a minimum rotation number and the number of level changes of only the second system reaches a predetermined number, and determines a second system FG failure provisionally when the rotation number reaches a minimum rotation number and the number of level changes of only the second system reaches a predetermined number, and determines a second system FG failure provisionally when the rotation number reaches a minimum rotation number and the number of level changes of both systems reaches a predetermined number. a determination result in which a first-system FG drive mode is determined to be normal if the rotation speed does not reach the minimum rotation speed, and a rotor lock determination is determined if the rotation speed does not reach the minimum rotation speed; and the drive command signal generation unit may generate the drive command signal corresponding to one of the operation modes of the first-system drive mode or the rotor lock mode based on the second-system FG failure provisional determination, the second-system drive mode or the rotor lock mode based on the first-system FG failure provisional determination, the dual-system drive mode based on the two-system normal determination, and the rotor lock mode based on the rotor lock determination, in accordance with the determination result generated by the abnormality determination unit, in the dual-system rotation wait mode.

[0025]

[13] In the motor drive control device described in any one of [8] to

[11] above, the abnormality determination unit, in the first system rotation waiting mode, determines a second system FG fault when the rotation speed reaches a minimum rotation speed and the number of level changes of only the first system reaches a predetermined number based on the rotation speed of the motor based on the FG signal and the number of level changes of the FG signal of each system in a predetermined period, and determines a first system FG fault when the rotation speed reaches a minimum rotation speed and the number of level changes of only the second system reaches a predetermined number, and determines a first system FG fault when the rotation speed reaches a minimum rotation speed and the number of level changes of only the second system reaches a predetermined number, and determines a first system FG fault when the rotation speed reaches a minimum rotation speed and the number of level changes of both systems reaches a predetermined number. The drive command signal generating unit may generate a determination result in which the two systems are determined to be normal when the number of times reaches a predetermined number, and the rotor is locked when the rotation speed does not reach a minimum rotation speed, and in the first system rotation waiting mode, the drive command signal generating unit may generate the drive command signal corresponding to one of the operation modes of the first system drive mode based on the second system FG failure determination, the rotor locked mode based on the first system FG tentative failure determination, the two system drive mode based on the two system normal determination, and the rotor locked mode based on the rotor locked determination, according to the determination result generated by the abnormality determination unit.

[0026]

[14] In the motor drive control device described in any one of [8] to

[11] above, the abnormality determination unit, in the second system rotation waiting mode, determines a second system FG failure provisionally when the rotation speed reaches a minimum rotation speed and the number of level changes of only the first system reaches a predetermined number based on the rotation speed of the motor based on the FG signal and the number of level changes of the FG signal of each system in a predetermined period, determines a first system FG failure when the rotation speed reaches a minimum rotation speed and the number of level changes of only the second system reaches a predetermined number, and determines a first system FG failure when the rotation speed reaches a minimum rotation speed and the number of level changes of only the second system reaches a predetermined number, a determination result in which the two-system is determined to be normal when the number of rotations reaches a predetermined number, and the rotor is determined to be locked when the rotation speed does not reach a minimum rotation speed, and the drive command signal generation unit may generate the drive command signal corresponding to one of the operation modes of the rotor locked mode based on the second-system FG tentative failure determination, the second-system drive mode based on the first-system FG failure determination, the two-system drive mode based on the two-system normal determination, and the rotor locked mode based on the rotor lock determination, in accordance with the determination result generated by the abnormality determination unit, in the second-system rotation wait mode.

[0027]

[15] A fan unit according to a representative embodiment of the present invention is characterized by comprising a motor drive control device described in any one of [1] to

[14] above, the motor, and an impeller that rotates by the rotational force of the motor.

[0028]

[16] A motor startup control method according to a representative embodiment of the present invention is a motor startup control method using a motor drive control device that includes two motor drive circuits that are provided corresponding to two systems of coils that drive one motor based on a drive command signal and that control the energization of the coils of the corresponding systems, and a drive control circuit that outputs the drive command signal to the two motor drive circuits, and is characterized in that the steps in which the drive control circuit controls the motor at startup include a primary judgment step in which the presence or absence of an abnormality in each system is determined based on a detection result of the number of level changes of the FG signal of each system that is input when the drive command signal is output to at least one of the two motor drive circuits, and a secondary judgment step in which the presence or absence of an abnormality in each system is determined based on the detection result of the number of level changes of the FG signal of each system that is input when the drive command signal is output to at least one of the two motor drive circuits, depending on the judgment result of the primary judgment step, and on the detection result of the number of rotations calculated from the time for each level of the FG signal.

[0029] 2. Specific examples of embodiments Hereinafter, specific examples of embodiments of the present invention will be described with reference to the drawings. In the following description, components common to the embodiments will be designated by the same reference numerals, and repeated description will be omitted.

[0030] FIG. 1 is a diagram showing a configuration of a motor drive control system according to an embodiment.

[0031] The motor drive control system 100 shown in FIG. 1 includes a motor 3 as a load to be driven, a motor drive control device 1 that drives the motor 3, and a higher-level device 2 that controls the motor drive control device 1.

[0032] Motor drive control system 100 is used, for example, in an electrical equipment system, and constitutes a fan system in which the operation of multiple fans is controlled by a single control device to send air to multiple cooling targets.Motor drive control system 100 according to this embodiment is placed, for example, in a closed space within a server, and constitutes a cooling system that cools various electronic components that make up the server.

[0033] For example, an impeller (impeller wheel) 4 is connected to the output shaft (not shown) of the motor 3, and the motor 3 and the impeller 4 form a single fan (fan motor) 5 that generates wind by rotating the impeller 4 with the rotational force of the motor 3.

[0034] The fan 5 and the motor drive control device 1 constitute one fan unit 101. Note that, as an example, only one fan unit 101 is shown in Fig. 1, but the number of fan units 101 included in the motor drive control system 100 is not particularly limited.

[0035] The higher-level device 2 (host device) is, for example, a program processing device such as a CPU in a server equipped with a fan 5. The higher-level device 2 controls the rotation of the motor 3 via the motor drive control device 1 by outputting a speed command signal Sc to the motor drive control device 1, and also acquires a motor drive information signal So relating to the drive state of the motor 3 (fan 5) from the motor drive control device 1 to monitor the operation of the motor 3 (fan 5).

[0036] The speed command signal Sc is a signal including a command related to the driving of the motor 3. The speed command signal Sc includes, for example, a command indicating a target rotation speed (target number of rotations) of the motor 3. For example, the speed command signal Sc is a PWM (pulse width modulation) signal with a duty ratio corresponding to the target rotation speed of the motor 3. Note that the speed command signal Sc may be a signal in another format, such as a PFM signal having a frequency corresponding to the target rotation speed or a torque command signal indicating a target value of motor torque.

[0037] The motor 3 is, for example, a brushless DC motor. For example, the motor 3 is a single-phase brushless motor including two systems of coils (windings) 6_1 and 6_2 wound around teeth (not shown). Position detectors 7_1 and 7_2 are provided around the coils 6_1 and 6_2, respectively.

[0038] The position detectors 7_1 and 7_2 are devices that output position detection signals according to the position of the rotor of the motor 3. Each of the position detectors 7_1 and 7_2 includes, for example, a Hall element that outputs a signal according to the magnetic flux of the magnet of the rotor. Each of the Hall elements outputs two signals with different phases as position detection signals. For example, each outputs a Hall signal Vhp having a positive polarity and a Hall signal Vhn having a negative polarity.

[0039] The position detector 7_1 is disposed at a position corresponding to the coil 6_1 and outputs Hall signals (position detection signals) Vhp and Vhn to an inverter control circuit 11_1 of a motor drive circuit 10_1, which will be described later. Similarly, the position detector 7_2 is disposed at a position corresponding to the coil 6_2 and outputs Hall signals (position detection signals) Vhp and Vhn to an inverter control circuit 11_2 of a motor drive circuit 10_2, which will be described later. At this time, the position detector 7_1 and the position detector 7_2 are arranged at positions where their relative positions are, for example, an electrical angle of π / 2 (90 degrees).

[0040] The motor drive control device 1 is a device for controlling the rotation of the motor 3. The motor drive control device 1 rotates the motor 3 by periodically supplying drive current to two single-phase coils 6_1 and 6_2 that constitute the motor 3 via inverter circuits 12_1 and 12_2.

[0041] The motor drive control device 1 is supplied with a DC power supply voltage Vdc from the outside, and the circuits within the motor drive control device 1 are configured to be operable by the power supply voltage Vdc.

[0042] The motor drive control device 1 drives the motor 3 in accordance with the speed command signal Sc output from the higher-level device 2. The motor drive control device 1 also outputs information relating to the state of the motor 3 to the higher-level device 2. For example, the motor drive control device 1 outputs a composite FG signal Fg corresponding to the actual rotation speed (actual number of rotations) of the motor 3 and a signal indicating an abnormal state of the motor 3 as a motor drive information signal So to the higher-level device 2. This allows the higher-level device 2 to know the rotation state of the motor 3, the presence or absence of an abnormality in the motor 3, etc.

[0043] The motor drive control device 1 includes, for example, two motor drive circuits 10_1 and 10_2 that respectively drive two coils 6_1 and 6_2 of the motor 3, a drive control circuit 20 that controls the operation of the two motor drive circuits 10_1 and 10_2, a power supply circuit 23, two detection voltage output circuits 24_1 and 24_2, and an alarm circuit 25. The detection voltage output circuit 24_1 is provided corresponding to the coil 6_1, and the detection voltage output circuit 24_2 is provided corresponding to the coil 6_2. In addition to the circuits described above, the motor drive control device 1 may also include, for example, a protection circuit for suppressing inrush current or preventing circuit failure due to reverse connection of a power supply.

[0044] A power supply voltage Vdc (DC voltage) is supplied to a power supply terminal Pv of the motor drive control device 1 as a main power supply for driving the motor 3 and the motor drive control device 1. The power supply voltage Vdc is supplied from the power supply terminal Pv to a power supply line Lp. The power supply line Lp is a power supply path that supplies power for driving the motor 3 via the motor drive circuits 10_1 and 10_2.

[0045] The power supply circuit 23 is a circuit that generates a power supply voltage to be supplied to some of the circuits in the motor drive control device 1. The power supply circuit 23 is realized by, for example, a series regulator or a switching regulator. The power supply circuit 23, for example, steps down the power supply voltage Vdc supplied to the power supply terminal Pv to generate a DC voltage, and supplies the DC voltage to the drive control circuit 20.

[0046] The detection voltage output circuits 24_1 and 24_2 are circuits that output two systems of detection voltages Vs_1 and Vs_2, respectively, used to detect abnormal states such as breaks in the windings of the motor 3 or voltage abnormalities. Specifically, the detection voltage output circuit 24_1 generates a voltage corresponding to a voltage (winding midpoint voltage) Vm_1 at the midpoint of the coil (winding) 6_1 and outputs it as the detection voltage Vs_1, and the detection voltage output circuit 24_2 generates a voltage corresponding to a voltage (winding midpoint voltage) Vm_2 at the midpoint of the coil (winding) 6_2 and outputs it as the detection voltage Vs_2. Hereinafter, the detection voltages Vs_1 and Vs_2 are also referred to as "winding midpoint detection voltages Vs." The winding midpoint voltages Vm_1 and Vm_2 of the coils 6_1 and 6_2 will be described in detail later.

[0047] Fig. 2 is a diagram showing a configuration example of the detection voltage output circuit 24_1 of the first system. Note that the detection voltage output circuit 24_2 of the second system is configured similarly to the detection voltage output circuit 24_1 shown in Fig. 3, so only the detection voltage output circuit 24_1 will be described here, and description of the detection voltage output circuit 24_2 will be omitted.

[0048] As shown in FIG. 2, the detection voltage output circuit 24_1 includes, for example, a voltage-dividing circuit 240, a resistor R21, a capacitor C21, and a rectifying element D21. The voltage-dividing circuit 240 divides and outputs a winding midpoint voltage Vm_1 of the coil 6_1 input from an input terminal Pm1_1. The voltage-dividing circuit 240 includes, for example, two resistors Ra1 and Rb1 connected in series between the midpoint of the winding of the coil 6_1 and a ground potential (GND) serving as a reference potential. The detection voltage output circuit 24_1 divides the winding midpoint voltage Vm_1 of the coil 6_1 based on a voltage division ratio determined by the resistors Ra1 and Rb1, and outputs the divided voltage as a winding midpoint detection voltage Vs_1 from an output terminal Pm2_1 via the rectifying element D21. The winding midpoint detection voltage Vs_1 output from the detection voltage output circuit 24_1 is input to the drive control circuit 20.

[0049] The winding midpoint detection voltage Vs_1 is held by the capacitor C21. The capacitor C21 is charged by the switching (on-duty) of the inverter circuit 12_1 from the voltage dividing circuit 240 via the rectifying element D21 and discharged by the resistor R21. At this time, the rectifying element D21 adjusts the charging speed of the capacitor C21 to be faster than the discharging speed, taking advantage of the fact that the discharging due to the switching (off-duty) of the inverter circuit 12_1 does not affect the capacitor C21.

[0050] The notification circuit 25 is a circuit for externally notifying the drive control circuit 20 of an abnormality in the motor 3 when the abnormality is detected by the drive control circuit 20. For example, as shown in Fig. 1, the notification circuit 25 includes a control terminal connected to the signal output terminal P3 of the drive control circuit 20, and a switch element (for example, a bipolar transistor) Qc connected between a signal line for transmitting the motor drive information signal So output from the output terminal P2 of the drive control circuit 20 to the higher-level device 2 and ground potential (GND).

[0051] The drive control circuit 20 is a circuit that comprehensively controls the operation of the motor drive control device 1. The drive control circuit 20 operates when a power supply voltage is supplied from a power supply circuit 23. In this embodiment, the drive control circuit 20 is a program processing device, for example, a microcontroller (MCU: Micro Controller Unit), having a configuration in which a processor such as a CPU, various storage devices such as RAM, ROM, and flash memory, and peripheral circuits such as a counter (timer), an A / D conversion circuit, a clock generation circuit, and an input / output interface circuit are connected to each other via a bus or dedicated lines.

[0052] In this embodiment, the drive control circuit 20 is packaged as a single semiconductor device (IC: Integrated Circuit), but the present invention is not limited to this.

[0053] The drive control circuit 20 has a plurality of external terminals for transmitting and receiving signals to and from the outside (such as the higher-level device 2 and the two systems of motor drive circuits 10_1 and 10_2). In Fig. 1, as examples of the plurality of external terminals, a power supply terminal VDD to which a power supply voltage is supplied, an input terminal P1, an output terminal P2, signal output terminals P3, P4, P5, P6, and P7, and signal input terminals P8, P9, P10, and P11 are shown with reference numerals.

[0054] FIG. 3 is a block diagram showing the functional configuration of the drive control circuit 20. As shown in FIG.

[0055] The drive control circuit 20 has, as its main functions, a drive control function for controlling the operations of the motor drive circuits 10_1 and 10_2, and an abnormality determination function for determining the presence or absence of rotor lock or an abnormality in the two motor drive circuits 10_1 and 10_2. Specifically, as shown in Fig. 3, the drive control circuit 20 has a state control unit 21 and a monitoring unit 22 as functional units for realizing the above functions.

[0056] The state control unit 21 further has a speed command duty ratio calculation unit 211, an operation mode control unit 212, a drive command duty ratio output unit 213, a first system drive command signal generation unit 214, and a second system drive command signal generation unit 215.

[0057] The monitoring unit 22 further has a first system FG signal measuring unit 221, a second system FG signal measuring unit 222, a rotation speed measuring unit 223, an abnormality determination unit 224, an FG signal generating unit 225, a measurement selecting unit 226, and a voltage measuring unit 227.

[0058] The respective configurations of the state control unit 21 and the monitoring unit 22 are realized, for example, in a program processing device constituting the drive control circuit 20, by a processor executing various arithmetic processing in accordance with programs stored in memory and controlling peripheral circuits such as counters, signal capture circuits, and A / D conversion circuits.

[0059] The monitoring unit 22 is a functional unit that monitors the operating status of the motor 3 (fan 5) and each system. The monitoring unit 22 determines whether or not there is an abnormality in the motor 3 and the two systems of motor drive circuits 10_1 and 10_2, measures the number of rotations, and generates an FG signal to be sent to the higher-level device 2. Specifically, based on a change in the level of FG signals Fg_1 and Fg_2 input from the two systems of motor drive circuits 10_1 and 10_2 to signal input terminals P8 and P9, the monitoring unit 22 generates the number of rotations and a determination result, and also generates a composite FG signal Fg by combining the FG signals Fg_1 and Fg_2. The generated number of rotations and determination result are passed to the state control unit 21, and the composite FG signal Fg is output from the output terminal P2 and input to the higher-level device 2. The monitoring unit 22 also detects an abnormality in the motor 3 based on the winding midpoint detection voltages Vs_1 and Vs_2 input from the detection voltage output circuits 24_1 and 24_2 to the signal input terminals P10 and P11.

[0060] Here, a level change of the FG signals Fg_1, Fg_2 refers to, for example, a change between two states, that is, a state in which the FG signals Fg_1, Fg_2 are at a "high" level and a state in which the FG signals Fg_1, Fg_2 are at a "low" level. Making a determination based on a level change includes the concept of making a determination by detecting the number of state changes of the FG signals Fg_1, Fg_2 and the time for each state. In this embodiment, the primary determination is made based on the number of times the FG signals Fg_1, Fg_2 have changed between a "high" level and a "low" level, and in the secondary determination, the rotation speed calculated from the time for each state is also detected and used for determination.

[0061] The first system FG signal measuring unit 221 receives the FG signal Fg_1 from the inverter control circuit 11_1 of the first system motor drive circuit 10_1, measures the number of level changes of the FG signal Fg_1 and the time for each level from the changes in the level of the FG signal Fg_1, and detects the rotation speed of the motor 3.

[0062] The second system FG signal measuring unit 222 receives the FG signal Fg_2 from the inverter control circuit 11_2 of the second system motor drive circuit 10_2, measures the number of level changes of the FG signal Fg_2 and the time for each level from the changes in the level of the FG signal Fg_2, and detects the rotation speed of the motor 3.

[0063] The rotation speed measurement unit 223 calculates the rotation speed of the motor 3 from the time for each level of the FG signal Fg_1 measured by the first system FG signal measurement unit 221 and the FG signal Fg_2 measured by the second system FG signal measurement unit 222. The FG signals Fg_1 and Fg_2 are signals that change by one pulse per electrical angle period in accordance with changes in the magnetic poles in the respective systems.

[0064] Specifically, the rotation speed measurement unit 223 uses the FG switching time (e.g., t1, t2) measured by the FG signal measurement units 221, 222 of each system when the levels of the FG signals Fg_1, Fg_2 change, as the time measured by the elapsed timers of the monitoring unit 22. The elapsed timer is a counter that periodically counts up at a predetermined time, sets a flag at the upper limit, and cycles, operating as a clock. The rotation speed measurement unit 223 determines the period of the electrical angle based on the relationship between the system whose FG signal level changed immediately before and the system whose FG signal level changed this time. Here, the period of the electrical angle is determined as 1 / 2 of the electrical angle when the same system continues (e.g., t1a → t1b or t2a → t2b), and as 1 / 4 of the electrical angle when switching to a different system (e.g., t1a → t2a, t2a → t1b, and t1b → t2b). The rotation speed measurement unit 223 also calculates the period (e.g., txb-txa) during which two FG switching times occurred from the FG switching time immediately before the elapsed timer (e.g., txa, where x is 1 or 2 and represents the FG signal system, and a represents the rising edge of the FG signal) and the FG switching time of the current elapsed timer (e.g., txb, where x is 1 or 2 and represents the FG signal system, and b represents the falling edge of the FG signal).The rotation speed measurement unit 223 further calculates the rotation speed during the period during which the two FG switching times occurred on the elapsed timer, using the identified period of the electrical angle and the number of poles of the motor 3.At this time, in the case of the first system drive mode or the second system drive mode in which one system is determined to have an FG failure, it is not necessary to use the time during which the level of the FG signal from the system on the failed side changed.

[0065] The abnormality determination unit 224 performs abnormality determination for each system in multiple stages, including a primary determination, a secondary determination, and a tertiary determination. The abnormality determination unit 224 performs the primary determination, the secondary determination, and the tertiary determination in sequence.

[0066] The monitoring unit 22 has a standby timer for measuring the FG standby time and the rotation standby time, a constraint protection timer for measuring the constraint protection time, and an elapsed timer for measuring the FG switching time of each system and the threshold time from the FG switching time. The abnormality determination unit 224 makes each determination while using the timer timing as necessary. The FG standby time of the standby timer is the time required for the primary determination. The rotation standby time of the standby timer is the time required for the secondary determination. The threshold time from the FG switching time of the elapsed timer is the time during which the rotation speed of the motor 3 is treated as zero because, for example, t1a → t1b or t2a → t2b do not occur within the threshold time. The constraint protection time is the time until the rotor lock is released.

[0067] In the primary judgment, the abnormality judgment unit 224 judges whether or not there is an abnormality in each system based on the detection result of the number of level changes of the FG signals Fg_1, Fg_2 of each system that are input when a drive command signal Sca (Sca_1, Sca_2) is output to at least one of the two motor drive circuits 10_1, 10_2 at startup.

[0068] In the secondary judgment, the abnormality judgment unit 224 judges whether or not there is an abnormality in each system based on the detection result of the number of level changes of the FG signals Fg_1, Fg_2 of each system that are input when a drive command signal Sca (Sca_1, Sca_2) is output to at least one of the two motor drive circuits 10_1, 10_2, depending on the judgment result of the primary judgment, and the detection result of the rotation speed calculated from the time for each level of the FG signals Fg_1, Fg_2.

[0069] In the tertiary determination, the abnormality determination unit 224 detects the number of level changes of the FG signals Fg_1 and Fg_2 of each system that are input when drive command signals Sca_1 and Sca_2 are output to both of the two motor drive circuits 10_1 and 10_2, respectively, while the motor 3 is being driven, and determines whether or not there is an FG failure based on the difference in the number of level changes in the FG signals Fg_1 and Fg_2 of the two systems. The tertiary determination is a determination that is performed after the secondary determination is completed.

[0070] At startup, before performing a primary determination, the abnormality determination unit 224 may detect an idling state of the motor 3 from the detection results of the number of level changes of the FG signals Fg_1 and Fg_2 of each system that are input when drive command signals Sca_1 and Sca_2 are output to both of the two motor drive circuits 10_1 and 10_2, respectively, and the detection results of the rotation speed calculated from the time for each level of the FG signals Fg_1 and Fg_2. The idling state is a state in which the motor 3 is rotating even though it is not being driven. If the abnormality determination unit 224 detects that the motor 3 is in an idling state and the rotation speed of the motor 3 is equal to or greater than a predetermined minimum rotation speed, the primary determination is not performed.

[0071] The determination made by the abnormality determination unit 224 will be described in detail later.

[0072] The FG signal generating unit 225 generates a composite FG signal Fg to be output to the higher-level device 2 .

[0073] The measurement selection unit 226 selects to measure either the winding midpoint detected voltage Vs_1 or Vs_2.

[0074] The voltage measurement unit 227 measures the winding midpoint detection voltages Vs_1 and Vs_2 selected for measurement, and inputs the measured values ​​to the abnormality determination unit 224.

[0075] The state control unit 21 appropriately generates a first system drive command signal Sca_1 and a second system drive command signal Sca_2 that instruct the motor 3 to drive, based on the speed command signal Sc input to the input terminal P1 from the higher-level device 2 and the rotation speed and determination results received from the monitoring unit 22, and outputs them from signal output terminals P6 and P7. The output drive command signals Sca_1 and Sca_2 are input to the motor drive circuits 10_1 and 10_2.

[0076] Here, the drive command signals Sca_1 and Sca_2, like the speed command signal Sc described above, include commands indicating the target rotational speed (target rotation number) of the motor 3, and are, for example, PWM signals having a duty ratio corresponding to the target rotational speed of the motor 3.

[0077] The state control unit 21 outputs, for example, drive command signals Sca_1, Sca_2 with a duty ratio of 0% when instructing the motor 3 to stop rotating, and outputs drive command signals Sca_1, Sca_2 with a duty ratio of 100% when instructing the motor 3 to rotate at the settable maximum rotation speed. In this way, the drive control circuit 20 instructs the motor drive circuits 10_1, 10_2 on the control details of the motor 3 by changing the duty ratio of the drive command signals Sca_1, Sca_2.

[0078] In the state control unit 21 , a speed command duty ratio calculation unit 211 calculates a speed command duty from a speed command signal Sc input from the higher-level device 2 and the rotation speed of the motor 3 .

[0079] The operation mode control unit 212 determines the operation mode (start-up mode, rotation waiting mode, drive mode) and operation system (two-system, first system, second system) based on the judgment result received from the monitoring unit 22, and also sets various flags.

[0080] The flags set in this embodiment include, but are not limited to, a "rotor lock provisional determination flag," a "rotor lock flag," a "first system failure flag," and a "second system failure flag."

[0081] The operation mode control unit 212 sets a flag according to the determination result received from the monitoring unit 22. The operation mode control unit 212 controls the drive command duty ratio output unit 213 to operate in an operation mode according to the current operation mode and the set flag. The operation modes will be described later.

[0082] The drive command duty ratio output unit 213 outputs drive command duty ratios to the first system drive command signal generation unit 214 and the second system drive command signal generation unit 215 as appropriate based on the determined operation mode. The drive command duty ratio is a duty corresponding to the determined operation mode, and is either a speed command duty or a zero duty. The speed command duty is a duty ratio calculated from the speed command signal Sc. The zero duty is a duty ratio used during standby or when the rotor is locked. In the event of a failure, a predetermined duty ratio, a failure duty, may be used.

[0083] Based on the determined operation mode, the drive command duty ratio output unit 213 instructs the first system drive command signal generation unit 214 and the second system drive command signal generation unit 215 to generate control signals St_1 and St_2 that switch between input and cut-off of the drive control signal as appropriate.

[0084] In the state control unit 21, a first system drive command signal generation unit 214 and a second system drive command signal generation unit 215 generate a first system drive command signal Sca_1 and a second system drive command signal Sca_2, respectively, based on the drive command duty ratio received from the drive command duty ratio output unit 213. At this time, the control signals St_1 and St_2 are generated based on the instruction to generate the control signals St_1 and St_2 received from the drive command duty ratio output unit 213.

[0085] The first-path drive command signal generator 214 outputs the generated first-path drive command signal Sca_1 from a signal output terminal P6, and the second-path drive command signal generator 215 outputs the generated second-path drive command signal Sca_2 from a signal output terminal P7. The drive command signal Sca_1 is input to the motor drive circuit 10_1 of the first path. Similarly, the drive command signal Sca_2 is input to the motor drive circuit 10_2 of the second path. The control signals St_1 and St_2 output from the first-path drive command signal generator 214 and the second-path drive command signal generator 215 are input to the signal blocking circuits 13_1 and 13_2, respectively.

[0086] The drive command signals Sca_1 and Sca_2 may be signals in other formats, such as PFM signals with a frequency corresponding to the target rotation speed.

[0087] The motor drive circuits 10_1 and 10_2 are circuits that control the energization of the motor 3 based on drive command signals Sca_1 and Sca_2, respectively. The motor drive circuits 10_1 and 10_2 are configured to be operable by receiving power (power supply voltage Vdc) from a power supply line Lp.

[0088] The motor drive circuit 10_1 of the first system includes, for example, an inverter control circuit 11_1, an inverter circuit 12_1 that energizes the coil 6_1 based on the control of the inverter control circuit 11_1, and a signal blocking circuit 13_1. Similarly, the motor drive circuit 10_2 of the second system includes, for example, an inverter control circuit 11_2, an inverter circuit 12_2 that energizes the coil 6_2 based on the control of the inverter control circuit 11_2, and a signal blocking circuit 13_2.

[0089] The motor drive circuit 10_1 of the first system has a fuse F1, one end of which is connected to a power supply line Lp. A power supply voltage Vdc is supplied from the power supply line Lp via the fuse F1 to a power supply terminal VCC of the inverter circuit 12_1 and the inverter control circuit 11_1 that constitute the motor drive circuit 10_1 of the first system. Similarly, the motor drive circuit 10_2 of the second system has a fuse F2, one end of which is connected to the power supply line Lp. A power supply voltage Vdc is supplied from the power supply line Lp via the fuse F2 to a power supply terminal VCC of the inverter circuit 12_2 and the inverter control circuit 11_2 that constitute the motor drive circuit 10_2 of the second system.

[0090] The inverter control circuits 11_1 and 11_2 are each realized using, for example, a commercially available general-purpose integrated circuit (IC) for motor drive control. Note that the inverter control circuits 11_1 and 11_2 are not limited to being configured using a general-purpose IC, and may be configured using, for example, a microcontroller (MCU).

[0091] The inverter circuit 12_1 of the first system drives the coil 6_1 of the motor 3 connected to the load drive terminals 16_1 and 17_1 based on the first drive control signal Sda_1 and the second drive control signal Sdb_1 output from the inverter control circuit 11_1. Similarly, the inverter circuit 12_2 of the second system drives the coil 6_2 of the motor 3 connected to the load drive terminals 16_2 and 17_2 based on the first drive control signal Sda_2 and the second drive control signal Sdb_2 output from the inverter control circuit 11_2. The first drive control signals Sda_1 and Sda_2 and the second drive control signals Sdb_1 and Sdb_2 will be described in detail later.

[0092] The inverter circuits 12_1 and 12_2 are, for example, H-bridge circuits including a plurality of transistors as switch elements. Specifically, the first inverter circuit 12_1 and the second inverter circuit 12_2 are connected in parallel between a power supply line Lp, to which a power supply voltage Vdc is supplied, and a ground potential (GND). The first inverter circuit 12_1 is connected in series between the power supply line Lp and the ground potential, and includes high-side switch elements Q1 and Q2 that perform a switching operation based on a first drive control signal Sda_1 and low-side switch elements Q3 and Q4 that perform a switching operation based on a second drive control signal Sdb_1. The second inverter circuit 12_2 is connected in series between the power supply line Lp and the ground potential, and includes high-side switch elements Q1 and Q2 that perform a switching operation based on a first drive control signal Sda_2 and low-side switch elements Q3 and Q4 that perform a switching operation based on a second drive control signal Sdb_2.

[0093] The switching elements Q1 to Q4 are, for example, transistors. More specifically, the high-side switching elements Q1 and Q2 are, for example, P-channel MOSFETs, and the low-side switching elements Q3 and Q4 are, for example, N-channel MOSFETs. Note that the switching leg consisting of the switching elements Q1 and Q3 and the switching leg consisting of the switching elements Q2 and Q4 may be connected to ground potential via a current detection resistor Rs, as shown in FIG.

[0094] Furthermore, inverter circuit 12_1 has load drive terminals 16_1 and 17_1 for driving coil 6_1 as a load, and inverter circuit 12_2 has load drive terminals 16_2 and 17_2 for driving coil 6_2 as a load. Load drive terminals 16_1 and 16_2 are nodes where switch elements Q1 and Q3 of inverter circuits 12_1 and 12_2 are commonly connected, and are connected to one ends of coils 6_1 and 6_2, respectively. Load drive terminals 17_1 and 17_2 are nodes where switch elements Q2 and Q4 of inverter circuits 12_1 and 12_2 are commonly connected, and are connected to the other ends of coils 6_1 and 6_2, respectively.

[0095] The switching elements Q1 to Q4 constituting the inverter circuits 12_1 and 12_2 are controlled to be on or off by a first drive control signal Sda and a second drive control signal Sdb output from the inverter control circuits 11_1 and 11_2.

[0096] The first-system inverter control circuit 11_1 generates a first drive control signal Sda_1 and a second drive control signal Sdb_1 based on the drive command signal Sca_1 supplied from the drive control circuit 20 and the Hall signals Vhp, Vhn output from the position detector 7_1, and drives the inverter circuit 12_1. The inverter control circuit 11_1 has output terminals Pd1 to Pd4 that output the generated first drive control signal Sda_1 and second drive control signal Sdb_1.

[0097] Similarly, the second-system inverter control circuit 11_2 generates a first drive control signal Sda_2 and a second drive control signal Sdb_2 based on the drive command signal Sca_2 supplied from the drive control circuit 20 and the Hall signals Vhp, Vhn output from the position detector 7_2, and drives the inverter circuit 12_2. The inverter control circuit 11_2 has output terminals Pd1 to Pd4 that output the generated first drive control signal Sda_2 and second drive control signal Sdb_2.

[0098] Specifically, the inverter control circuit 11_1 determines the direction of current flow through the coil 6_1 based on the Hall signals (position detection signals) Vhp and Vhn, and outputs a first drive control signal Sda_1 having a duty ratio according to the drive command signal Sca_1 input from the drive control circuit 20, and a second drive control signal Sdb_1 synchronized with the Hall signals Vhp and Vhn. For example, the first drive control signal Sda_1 is directly supplied to the control electrodes (gate electrodes) of the high-side switch elements Q1 and Q2 of the inverter circuit 12_1, and the second drive control signal Sdb_1 is supplied to the control electrodes (gate electrodes) of the low-side switch elements Q3 and Q4 of the inverter circuit 12_1 via a signal blocking circuit 13_1, which will be described later.

[0099] Similarly, the inverter control circuit 11_2 determines the direction of current flow through the coil 6_2 based on the Hall signals (position detection signals) Vhp and Vhn, and outputs a first drive control signal Sda_2 having a duty ratio according to the drive command signal Sca_2 input from the drive control circuit 20, and a second drive control signal Sdb_2 synchronized with the Hall signals Vhp and Vhn. For example, the first drive control signal Sda_2 is directly supplied to the control electrodes (gate electrodes) of the high-side switch elements Q1 and Q2 of the inverter circuit 12_2, and the second drive control signal Sdb_2 is supplied to the control electrodes (gate electrodes) of the low-side switch elements Q3 and Q4 of the inverter circuit 12_2 via a signal blocking circuit 13_2, which will be described later.

[0100] The inverter control circuit 11_1 of the first system generates a first drive control signal Sda_1 and a second drive control signal Sdb_1 so that the direction of current flowing through the coil 6_1 of the motor 3 alternates at timings according to the Hall signals Vhp and Vhn, thereby controlling the energization of the coil 6_1. Similarly, the inverter control circuit 11_2 of the second system controls the energization of the coil 6_2.

[0101] For example, the first-system inverter control circuit 11_1 generates a second drive control signal Sdb_1 to turn on the low-side switch element Q4 and turn off the low-side switch element Q3 in accordance with the switching timing of the Hall signals Vhp and Vhn output from the position detector 7_1, and generates a first drive control signal Sda_1 to turn off the high-side switch element Q2 and PWM-drive the high-side switch element Q1. Furthermore, the inverter control circuit 11_1 generates a second drive control signal Sdb_1 to turn on the low-side switch element Q3 and turn off the low-side switch element Q4 in accordance with the next switching timing of the Hall signals Vhp and Vhn, and generates a first drive control signal Sda_1 to turn off the high-side switch element Q1 and PWM-drive the high-side switch element Q2.

[0102] In this way, the inverter control circuit 11_1 of the first system switches between the low-side switch element to be turned on and the high-side switch element to be PWM-driven so as to switch the direction of the current flowing through the coil 6_1 in accordance with the switching timing of the Hall signals Vhp, Vhn output from the position detector 7_1. Similarly, the inverter control circuit 11_2 of the second system switches between the low-side switch element to be turned on and the high-side switch element to be PWM-driven so as to switch the direction of the current flowing through the coil 6_2 in accordance with the switching timing of the Hall signals Vhp, Vhn output from the position detector 7_2.

[0103] The inverter control circuit 11_1 of the first system further generates and outputs an FG (Frequency Generator) signal Fg_1, which is a rotational speed signal having a frequency corresponding to the actual rotational speed (actual rotational speed) of the motor 3, based on the Hall signals Vhp and Vhn from the position detector 7_1. Similarly, the inverter control circuit 11_2 of the second system generates and outputs an FG (Frequency Generator) signal Fg_2, which is a rotational speed signal having a frequency corresponding to the actual rotational speed (actual rotational speed) of the motor 3, based on the Hall signals Vhp and Vhn from the position detector 7_2.

[0104] The FG signals Fg_1 and Fg_2 are, for example, rectangular wave signals having a predetermined duty ratio. For example, the FG signals Fg_1 and Fg_2 are binary signals (digital signals) that have a frequency corresponding to the actual rotation speed of the motor 3 and are generated so that the duty ratio is 50% when the rotation speed is constant. Using these FG signals Fg_1 and Fg_2, the drive control circuit 20 generates a composite FG signal Fg that corresponds to the actual rotation speed (actual rotation number) of the motor 3 and outputs it from the output terminal P2.

[0105] The signal blocking circuit 13_1 is a circuit that switches between inputting and blocking the second drive control signal Sdb_1 from the inverter control circuit 11_1 to the low-side switch elements Q3 and Q4 of the inverter circuit 12_1 in response to a control signal St_1 output from the drive control circuit 20. As shown in Fig. 1, the signal blocking circuit 13_1 is provided between output terminals Pd3 and Pd4, from which the second drive control signal Sdb_1 in the inverter control circuit 11_1 is output, and the control electrodes (gate electrodes) of the low-side switch elements Q3 and Q4 of the inverter circuit 12_1.

[0106] Similarly, the signal blocking circuit 13_2 is a circuit that switches between inputting and blocking the second drive control signal Sdb_2 from the inverter control circuit 11_2 to the low-side switch elements Q3 and Q4 of the inverter circuit 12_2 in response to the control signal St_2 output from the drive control circuit 20. As shown in Fig. 1, the signal blocking circuit 13_2 is provided between output terminals Pd3 and Pd4, from which the second drive control signal Sdb_2 in the inverter control circuit 11_2 is output, and the control electrodes (gate electrodes) of the low-side switch elements Q3 and Q4 of the inverter circuit 12_2.

[0107] Fig. 4 is a diagram showing a configuration example of the signal blocking circuit 13_1. Note that, since the signal blocking circuit 13_2 is also configured in the same manner as the signal blocking circuit 13_1 shown in Fig. 4, only the signal blocking circuit 13_1 will be described here, and description of the signal blocking circuit 13_2 will be omitted.

[0108] The signal blocking circuit 13_1 has terminals Ps1 to Ps5. The terminals Ps1 and Ps2 are connected to output terminals Pd3 and Pd4, respectively, from which the second drive control signal Sdb_1 of the inverter control circuit 11_1 is output. The terminal Ps3 is connected to the control electrode (gate electrode) of the low-side switch element Q3 of the inverter circuit 12_1, and the terminal Ps4 is connected to the control electrode (gate electrode) of the low-side switch element Q4 of the inverter circuit 12_1. The terminal Ps5 is connected to a signal output terminal P4 from which the control signal St_1 of the drive control circuit 20 is output.

[0109] 4, the signal cutoff circuit 13_1 has cutoff switch elements Q11 and Q12 and changeover switch elements Q13 and Q14. The cutoff switch element Q11 is connected between an output terminal Pd3 of the inverter control circuit 11_1 and a control electrode (gate electrode) of the low-side switch element Q3 of the inverter circuit 12_1. The cutoff switch element Q12 is connected between an output terminal Pd4 of the inverter control circuit 11_1 and a control electrode (gate electrode) of the low-side switch element Q4 of the inverter circuit 12_1.

[0110] The cutoff switch elements Q11 and Q12 are, for example, PNP type bipolar transistors, and the changeover switch elements Q13 and Q14 are, for example, NPN type bipolar transistors.

[0111] A first main electrode (e.g., emitter electrode) of the changeover switch element Q13 is connected to the ground potential, and a second main electrode (e.g., collector electrode) of the changeover switch element Q13 is connected to the control electrode (base electrode) of the cutoff switch element Q11. A first main electrode (e.g., emitter electrode) of the changeover switch element Q14 is connected to the ground potential, and a second main electrode (e.g., collector electrode) of the changeover switch element Q14 is connected to the control electrode (base electrode) of the cutoff switch element Q12.

[0112] The control electrodes (base electrodes) of the changeover switch elements Q13 and Q14 are connected to a signal output terminal P4 from which a control signal St_1 of the drive control circuit 20 is output via a terminal Ps5.

[0113] 4, a resistor may be connected to the electrode of each of the transistors serving as the cutoff switch elements Q11, Q12 and the selector switch elements Q13, Q14. For example, in each transistor, a resistor may be connected to the base electrode, and a resistor may be connected between the emitter electrode and the base electrode.

[0114] In the signal cutoff circuit 13_1, the on / off switching of the cutoff switch elements Q11 and Q12 is controlled by a control signal St_1 from the drive control circuit 20.

[0115] For example, when the control signal St_1 is at a high level, the changeover switch elements Q13 and Q14 are turned on, which turns on the cutoff switch elements Q11 and Q12, allowing the second drive control signal Sdb output from the output terminals Pd3 and Pd4 of the inverter control circuit 11_1 to be input to the control electrodes of the switch elements Q3 and Q4.

[0116] On the other hand, when the control signal St_1 is at a low level or at a high impedance, the changeover switch elements Q13 and Q14 are turned off, which turns off the cutoff switch elements Q11 and Q12, cutting off the input of the second drive control signal Sdb_1 output from the output terminals Pd3 and Pd4 of the inverter control circuit 11_1 to the control electrodes of the switch elements Q3 and Q4.

[0117] Here, the operation modes of the inverter circuits 12_1 and 12_2 when the motor 3 is in a normal state or when the Hall sensor is faulty will be described. In this description, there is basically no difference between the first system and the second system. In the description using Fig. 5 to Fig. 7, for parts that do not differ between the first system and the second system, the subscripts (_1, _2) for identifying the system are omitted, and the first system and the second system are expressed without any particular distinction.

[0118] First, the operation of the inverter circuit 12 when the drive control circuit 20 outputs the drive command signal Sca but does not output the control signal St will be described. In this control, the PWM signal is on and there is no gate blocking.

[0119] 5A and 5B are circuit diagrams that schematically show a first conduction state and a second conduction state, respectively, in the inverter circuit 12 when the PWM signal is on and there is no gate blocking.

[0120] 5A and 5B show cases where the inverter control circuit 11 outputs the first drive control signal Sda and the second drive control signal Sdb in response to the drive command signal Sca and the Hall signals Vhp and Vhn when the signal blocking circuit 13 allows signals to be input to the low-side switch elements Q3 and Q4 (no signal blocking).

[0121] 5A and 5B, the arrows indicate the direction of current flow through coil 6 based on Hall signals Vhp and Vhn, and current Im indicates the current flowing through inverter circuit 12. Fig. 5A shows the case where current Im flows from high-side switching element Q1 through coil 6 to low-side switching element Q4 (current flow direction: Q1 → Q4), and Fig. 5B shows the case where current Im flows from high-side switching element Q2 through coil 6 to low-side switching element Q3 (current flow direction: Q2 → Q3).

[0122] For example, when the motor 3 is normal, when the coil 6 is energized by the first drive control signal Sda and the second drive control signal Sdb, which are drive command PWM signals, the rotor rotates and the direction of energization is switched between the first energization state of FIG. 5A and the second energization state of FIG. 5B by the Hall signals Vhp and Vhn, thereby driving the motor 3.

[0123] In the event of a Hall sensor failure, the rotor rotates when the coil 6 is energized by the first drive control signal Sda and the second drive control signal Sdb, which are drive command PWM signals. However, if a failure occurs, the Hall signals Vhp and Vhn do not switch the energization direction between the first energization state in Fig. 5A and the second energization state in Fig. 5B, and energization in one direction is maintained. As a result, strong braking occurs in the motor 3.

[0124] Now, consider the winding midpoint detection voltage Vs of the inverter circuit 12 in this state. For example, when the motor 3 is normal, as shown in FIG. 5A, if the inverter control circuit 11 turns off the low-side switch element Q3, turns on the switch element Q4, and turns off the high-side switch element Q2, and PWM-drives the switch element Q1 (current flow direction: Q1 → Q4), a current Im flows from the power supply voltage Vdc through the fuse F1 (F2), the switch element Q1, the coil 6_1 (6_2), and the switch element Q4. If the current detection resistor Rs is ignored because its resistance is sufficiently small, the winding midpoint voltage Vm of the coil 6 is the voltage obtained by dividing the power supply voltage (DC voltage) Vdc by the two resistance components Rc / 2 of the coil 6, i.e., "Vm = Vdc / 2." In this case, the detection voltage output circuit 24 outputs a winding midpoint detection voltage Vs (=Vdc / 2 × voltage division ratio) which is the magnitude of the winding midpoint voltage Vm (=Vdc / 2) of the coil 6 multiplied by the voltage division ratio based on the resistors Ra1 and Rb1.

[0125] 5B, when the inverter control circuit 11 turns off the low-side switch element Q4, turns on the switch element Q3, turns off the high-side switch element Q1, and PWM-drives the switch element Q2 (current flow direction: Q2 → Q3), a current Im flows from the power supply voltage Vdc through the fuse F1, switch element Q2, coil 6, and switch element Q3. In this case, as in the case of FIG. 4A, the winding midpoint voltage Vm of coil 6 becomes "Vdc / 2," and the detection voltage output circuit 24 outputs a winding midpoint detection voltage Vs (= Vdc / 2 × voltage division ratio) that is obtained by multiplying the winding midpoint voltage Vm (= Vdc / 2) of coil 6 by a voltage division ratio based on the resistors Ra1 and Rb1.

[0126] Therefore, when the signal cutoff circuit 13 allows signals to be input to the low-side switch elements Q3 and Q4 (no signal cutoff), if the motor 3 is normal, the winding midpoint detection voltage Vs is "Vdc / 2 × voltage division ratio."

[0127] Next, a description will be given of the operation of the inverter circuit 12 when the drive control circuit 20 controls to output neither the drive command signal Sca nor the control signal St. In this control, the PWM signal is off and there is no gate blocking.

[0128] 6A and 6B are diagrams each schematically showing a first conduction state and a second conduction state in the inverter circuit 12 when the PWM signal is off and there is no gate blocking.

[0129] 6A and 6B show a case where the inverter control circuit 11 does not output the first drive control signal Sda and the second drive control signal Sdb, which are drive command PWM signals, when the signal blocking circuit 13 allows signals to be input to the low-side switch elements Q3 and Q4 (no signal blocking).

[0130] When inverter control circuit 11 does not output the first drive control signal Sda and second drive control signal Sdb, which are drive command PWM signals, both high-side switch elements Q1 and Q2 of inverter circuit 12 are always open. Also, signal blocking circuit 13 enables signal input to low-side switch elements Q3 and Q4 (no signal blocking), so on the low-side switch elements Q3 and Q4 side of inverter circuit 12, a free-wheeling circuit is formed by the on state of one of switch elements Q3 and Q4 due to coil 6 and position detector 7 and the parasitic diode of the other.

[0131] For example, when the motor 3 is normal, the Hall signals Vhp and Vhn cause switching between the first energization state shown in FIG. 6A and the second energization state shown in FIG. 6B. When the motor 3 is rotated by an external force, a reverse induced voltage is generated in the freewheel circuit, causing a weak brake to be applied to the motor 3. When the motor 3 continues to be rotated by an external force, the Hall signals Vhp and Vhn from the position detector 7 cause switching of the energization direction, but the freewheel circuit also reverses, causing a continuous weak brake to be applied to the motor 3.

[0132] In the event of a Hall sensor failure, the motor will always be in either the first energization state shown in Figure 6A or the second energization state shown in Figure 6B, and no switching will occur. When the motor 3 is rotated by external force, an induced voltage is generated in the freewheel circuit in either the reverse or forward direction. When an induced voltage is generated in the reverse direction in the freewheel circuit, a weak brake will be generated in the motor 3, and when an induced voltage is generated in the forward direction in the freewheel circuit, no brake will be generated in the motor 3. When the motor 3 continues to be rotated by external force, the Hall sensor failure will prevent the Hall signals Vhp and Vhn from switching the energization direction, and the freewheel circuit will be maintained, resulting in a continuous weak brake or no brake in the motor 3.

[0133] Next, an operation mode of the inverter circuit 12 when the drive control circuit 20 does not output the drive command signal Sca but outputs the control signal St will be described. In this control, the PWM signal is off and the gate is blocked.

[0134] 7A and 7B are diagrams each schematically illustrating a first conduction state and a second conduction state in an inverter circuit when the PWM signal is off and there is gate blocking.

[0135] 7A and 7B show a case where the inverter control circuit 11 does not output the first drive control signal Sda and the second drive control signal Sdb, which are drive command PWM signals, when the signal blocking circuit 13 prevents signals from being input to the low-side switch elements Q3 and Q4 (signal blocking occurs).

[0136] When the inverter control circuit 11 does not output the first drive control signal Sda and the second drive control signal Sdb, which are drive command PWM signals, both high-side switch elements Q1 and Q2 of the inverter circuit 12 are always open. Furthermore, the signal blocking circuit 13 prevents signals from being input to the low-side switch elements Q3 and Q4 (signal blocking), so both low-side switch elements Q3 and Q4 of the inverter circuit 12 are always open. In other words, all switch elements Q1, Q2, Q3, and Q4 are always open, and the motor 3 is free. At this time, no brake that affects the rotation of the motor 3 is generated.

[0137] For example, when the motor 3 is normal, the Hall signals Vhp and Vhn cause switching between the first energization state shown in Fig. 7A and the second energization state shown in Fig. 7B. When the motor 3 is rotated by external force, the Hall signals Vhp and Vhn cause switching of the energization direction, but the high-side switch elements Q1 and Q2 and the low-side switch elements Q3 and Q4 of the inverter circuit 12 are all maintained open.

[0138] In the event of a Hall sensor failure, the Hall sensor failure always results in either the first energization state shown in Fig. 7A or the second energization state shown in Fig. 7B, and no switching occurs. When the motor 3 is rotated by external force, the Hall signals Vhp and Vhn do not switch the energization direction due to the failure, and all of the high-side switch elements Q1 and Q2 and the low-side switch elements Q3 and Q4 of the inverter circuit 12 remain open.

[0139] The determination sequence executed in the motor drive control system according to this embodiment will be described.

[0140] FIG. 8 is a diagram showing a determination sequence in the motor drive control system according to this embodiment.

[0141] The motor drive control system of this embodiment performs three stages of judgment: primary judgment, secondary judgment, and tertiary judgment.

[0142] The primary determination includes a dual-system startup mode S1000, a first-system startup mode S1100, and a second-system startup mode S2200. The secondary determination includes a dual-system rotation wait mode S2000, a first-system rotation wait mode S2100, and a second-system rotation wait mode S2200. The tertiary determination includes a dual-system drive mode S3000, a first-system drive mode S3100, and a second-system drive mode S3200.

[0143] The motor drive control system of this embodiment operates in an operation mode included in the primary determination, then in an operation mode included in the secondary determination, and then in an operation mode included in the tertiary determination.

[0144] In addition to the primary, secondary, and tertiary determinations, the motor drive control system of this embodiment may also perform a rotor lock mode S4000. The rotor lock mode is a mode to which the system is transitioned when it is determined that the rotor is locked in any of the operating modes.

[0145] In the operating modes included in the primary, secondary and tertiary judgments, an abnormality is judged for at least one of the motor drive circuit 10_1 of the first system and the motor drive circuit 10_2 of the second system by detecting the number of level changes of the FG signals Fg_1, Fg_2 output from the inverter control circuits 11_1, 11_2 of each system in a predetermined driving state.

[0146] Each operation mode in the determination sequence explained above will be further explained with reference to FIGS.

[0147] FIG. 9 is a diagram showing an outline of the determination conditions in the dual system startup mode in the primary determination.

[0148] In the two-system startup mode shown in FIG. 9, when both the first system drive command signal Sca_1 and the second system drive command signal Sca_2 are output to drive the motor 3, the determination is made by detecting the number of level changes of the FG signals Fg_1 and Fg_2 output from the inverter control circuits 11_1 and 11_2 of each system.

[0149] As shown in Figure 9, if it is determined that there is no switching of the FG signals Fg_1 and Fg_2 in both systems, a rotor lock provisional determination is made and the system transitions to the first system startup mode. If it is determined that only the FG signal Fg_1 of the first system has switched, a first system normal determination is made and the system transitions to the first system startup mode. If it is determined that only the FG signal Fg_2 of the second system has switched, a second system normal determination is made and the system transitions to the second system startup mode. If it is determined that there is switching of the FG signals Fg_1 and Fg_2 in both systems, a second system normal determination is made and the system transitions to the second system rotation waiting mode.

[0150] Specifically, in the two-system startup mode, the determination of whether or not the FG signals Fg_1 and Fg_2 are switched is made such that, for systems where the number of level changes (FG switching count) of the FG signals Fg_1 and Fg_2 of each system during a specified FG waiting time exceeds a specified threshold count, it is determined that "FG switching has occurred," and for systems where the number of level changes does not exceed the specified threshold count, it is determined that "FG switching has not occurred."

[0151] FIG. 10 is a diagram showing an outline of the determination conditions in the first system startup mode in the primary determination.

[0152] In the first system startup mode shown in Figure 10, when only the first system drive command signal Sca_1 is output to drive the motor 3, judgment is made by detecting the number of level changes of the FG signal Fg_1 output from the first system inverter control circuit 11_1.

[0153] As shown in Fig. 10, if it is determined that the FG signal Fg_1 of the first system has switched, a tentative determination that the first system is normal is made, and the system transitions to the first system rotation waiting mode. If it is determined that the FG signal Fg_1 of the first system has not switched, the rotor lock tentative determination flag is checked, and if the rotor lock tentative determination flag is set, a rotor lock tentative determination is made, and the system transitions to the second system startup mode. Furthermore, if the rotor lock tentative determination flag is checked and not set (cleared), a tentative determination that the first system FG has failed is made, and the system transitions to the rotor lock mode.

[0154] Specifically, the determination of whether or not the FG signal Fg_1 has been switched in the first system startup mode is made by determining that "first system FG switching has occurred" if the number of level changes (FG switching count) of the first system Fg_1 during a specified FG waiting time exceeds a specified threshold count, and determining that "first system FG switching has not occurred" if the number of times does not exceed the specified threshold count.

[0155] FIG. 11 is a diagram showing an outline of the determination conditions in the second system startup mode in the primary determination.

[0156] In the second system startup mode shown in Figure 11, when only the second system drive command signal Sca_2 is output to drive the motor 3, judgment is made by detecting the number of level changes of the FG signal Fg_2 output from the second system inverter control circuit 11_2.

[0157] As shown in Fig. 11, if it is determined that the second system FG signal Fg_2 has switched, a temporary determination that the second system is normal is made, and the system transitions to the second system rotation waiting mode. If it is determined that the second system FG signal Fg_2 has not switched, the rotor lock temporary determination flag is checked, and if the rotor lock temporary determination flag is set, a rotor lock determination is made, and the system transitions to the rotor lock mode. Also, if the rotor lock temporary determination flag is checked and not set (cleared), a temporary determination that the second system FG has failed is made, and the system transitions to the rotor lock mode.

[0158] Specifically, the determination of whether or not the FG signal Fg_2 has been switched in the second system startup mode is made as follows: if the number of level changes (number of FG switches) of the second system FG signal Fg_2 during a specified FG waiting time exceeds a specified threshold number, it is determined that "second system FG switching has occurred," and if the number of times does not exceed the specified threshold number, it is determined that "second system FG switching has not occurred."

[0159] FIG. 12 is a diagram showing an outline of the determination conditions in each rotation delay mode in the secondary determination.

[0160] FIG. 12 shows conditions for determination in the two-system rotation wait mode, the first-system rotation wait mode, and the second-system rotation wait mode.

[0161] First, in the two-system rotation waiting mode, when both the first system drive command signal Sca_1 and the second system drive command signal Sca_2 are output to drive the motor 3, the number of level changes of the FG signals Fg_1 and Fg_2 output from the inverter control circuits 11_1 and 11_2 of each system is detected, and the number of rotations calculated from the time for each level of the FG signals Fg_1 and Fg_2 is detected to make a judgment.

[0162] As shown in Figure 12, in the dual-system rotation waiting mode, if the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed and it is determined that only the first system has switched over in the FG signal Fg_1, a second-system FG failure is determined, and the system transitions to the first-system drive mode. In the dual-system rotation waiting mode, if the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed and it is determined that only the second system has switched over in the FG signal Fg_2, a first-system FG failure is determined, and the system transitions to the second-system drive mode. In the dual-system rotation waiting mode, if the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed and it is determined that both systems have switched over in the FG signals Fg_1 and Fg_2, it is determined that the two systems are normal, and the system transitions to the dual-system drive mode. In the dual-system rotation waiting mode, if it is determined that the rotation speed of the motor 3 is less than the minimum rotation speed, a rotor lock is determined, and the system transitions to the rotor lock mode.

[0163] Specifically, in the two-system rotation waiting mode, the determination of whether or not the FG signals Fg_1 and Fg_2 are switched is made such that if the number of level changes (FG switching count) of the FG signals Fg_1 and Fg_2 of each system during a specified FG waiting time exceeds a specified threshold count, the system is determined to have had an FG switch, and if the number of level changes does not exceed the specified threshold count, the system is determined to have had an FG switch.

[0164] In the first system rotation waiting mode, when only the first system drive command signal Sca_1 is output to drive the motor 3, the number of level changes of the FG signals Fg_1 and Fg_2 output from the inverter control circuits 11_1 and 11_2 of each system is detected, and the number of rotations calculated from the time for each level of the FG signals Fg_1 and Fg_2 is detected to make a judgment.

[0165] As shown in Figure 12, in the first-system rotation waiting mode, if the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed and it is determined that only the first system has switched over to the FG signal Fg_1, a second-system FG failure is determined and the system transitions to the first-system drive mode. In the first-system rotation waiting mode, if the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed and it is determined that only the second system has switched over to the FG signal Fg_2, a first-system FG failure is tentatively determined and the system transitions to the rotor lock mode. In the first-system rotation waiting mode, if the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed and it is determined that both systems have switched over to the FG signals Fg_1 and Fg_2, the two-system normality is determined and the system transitions to the two-system drive mode after the winding midpoint voltage wait time has elapsed. In the first-system rotation waiting mode, if it is determined that the rotation speed of the motor 3 is less than the minimum rotation speed, a rotor lock is determined and the system transitions to the rotor lock mode.

[0166] Specifically, the determination of whether or not the FG signals Fg_1, Fg_2 are switched in the first system rotation waiting mode is made by determining that "FG switching has occurred" for a system in which the number of level changes (FG switching count) of the FG signals Fg_1, Fg_2 of each system during a specified FG waiting time exceeds a specified threshold count, and determining that "FG switching has not occurred" for a system in which the number of level changes does not exceed the specified threshold count.

[0167] In the second system rotation waiting mode, when the motor 3 is driven by outputting only the second system drive command signal Sca_2, the number of level changes of the FG signals Fg_1 and Fg_2 output from the inverter control circuits 11_1 and 11_2 of each system is detected, and the number of rotations calculated from the time for each level of the FG signals Fg_1 and Fg_2 is detected to make a judgment.

[0168] As shown in FIG. 12, in the second-system rotation waiting mode, if the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed and it is determined that only the first system has switched over in the FG signal Fg_1, a second-system FG failure is provisionally determined, and the system transitions to the rotor lock mode. In the second-system rotation waiting mode, if the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed and it is determined that only the second system has switched over in the FG signal Fg_2, a first-system FG failure is determined, and the system transitions to the second-system drive mode. In the second-system rotation waiting mode, if the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed and it is determined that both systems have switched over in the FG signals Fg_1 and Fg_2, the two-system normality is determined, and the system transitions to the two-system drive mode after the winding midpoint voltage wait time has elapsed. In the second-system rotation waiting mode, if it is determined that the rotation speed of the motor 3 is less than the minimum rotation speed, a rotor lock is determined, and the system transitions to the rotor lock mode.

[0169] Specifically, the determination of whether or not the FG signals Fg_1, Fg_2 are switched in the second system rotation waiting mode is made by determining that "FG switching has occurred" for a system in which the number of level changes (FG switching count) of the FG signals Fg_1, Fg_2 of each system during a specified FG waiting time exceeds a specified threshold count, and determining that "FG switching has not occurred" for a system in which the number of level changes does not exceed the specified threshold count.

[0170] The details of the determination conditions will be described later using timing charts and flowcharts.

[0171] FIG. 13 is a diagram showing the driving and detection states of each system in each driving mode.

[0172] FIG. 13 shows the driving and detection of each system performed in each of the standby mode, the two-system driving mode, the first-system driving mode, the second-system driving mode, and the rotor lock mode.

[0173] In the standby mode, neither the first system drive command signal Sca_1 nor the second system drive command signal Sca_2 is output, and neither rotor lock detection nor fault detection is performed. Note that in the standby mode, it may be possible to detect that the rotor is rotating idly at a rotation speed equal to or greater than a predetermined number of rotations before startup, i.e., that the rotor is rotating by inertia.

[0174] In the dual-system drive mode, both the first system drive command signal Sca_1 and the second system drive command signal Sca_2 are output to drive the motor 3, and rotor lock detection and fault detection are performed for both systems. In the dual-system drive mode, the values ​​of the speed command duty are output as the first system drive command signal Sca_1 and the second system drive command signal Sca_2.

[0175] In the first-system drive mode, a drive command signal Sca_1 of the first system is output to drive the motor 3, and rotor lock detection of the first system is performed. In the first-system drive mode, a value of a failure duty may be output as the drive command signal Sca_1 of the first system instead of the speed command duty.

[0176] In the second system drive mode, a second system drive command signal Sca_2 is output to drive the motor 3, and rotor lock detection for the second system is performed. In the second system drive mode, a fault duty value may be output as the second system drive command signal Sca_2 instead of the speed command duty.

[0177] In the rotor lock mode, neither the first system drive command signal Sca_1 nor the second system drive command signal Sca_2 is output, nor is detection performed.

[0178] Next, the transition of the operation mode when the motor 3 is started will be described in detail.

[0179] FIG. 14 is a timing chart showing an example of signal waveforms from when a stopped motor in a normal state is started to when the motor enters the dual-system drive mode.

[0180] 14 shows, from top to bottom, waveforms of a speed command signal Sc, each signal in the inverter control circuit 11_1 of the first system, a winding midpoint detection voltage Vs_1 in the detection voltage output circuit 24_1 of the first system, each signal in the inverter control circuit 11_2 of the second system, and a winding midpoint detection voltage Vs_2 in the detection voltage output circuit 24_1 of the second system. For the inverter control circuit 11_1 of the first system, waveforms of a drive command signal Sca_1 of the first system, a control signal St_1 of the first system, gate signals and an FG signal Fg_1 of switch elements Q1 to Q4 of an inverter circuit 12_1 of the first system, and an FG switching count which is the number of level changes are shown. For the inverter control circuit 11_2 of the second system, waveforms of a drive command signal Sca_2 of the second system, a control signal St_2 of the second system, gate signals and an FG signal Fg_2 of switch elements Q1 to Q4 of an inverter circuit 12_2 of the second system, and an FG switching count which is the number of level changes are shown. The horizontal axis represents time, and the vertical axis represents the voltage of each signal.

[0181] Figure 14 shows the waveforms of each signal when the system starts from standby mode, goes through dual-system start-up mode, and then transitions to dual-system drive mode via dual-system rotation wait mode. Figure 14 shows that the dual-system start-up mode continues for the FG wait time, and the dual-system rotation wait mode continues for the rotation wait time.

[0182] In the example shown in Fig. 14, in the dual-system startup mode, both the drive command signal Sca_1 of the first system and the drive command signal Sca_2 of the second system are output, and switching of both the FG signals Fg_1 and Fg_2 has occurred more than the threshold number of times. According to the judgment table in Fig. 9, from "FG switching has occurred in both systems," a provisional judgment is made that the two systems are normal, and the system transitions to the dual-system rotation waiting mode.

[0183] During the FG standby time in this dual-system startup mode, if the driving force of a normal motor 3 is weak, or if a brake applied to a faulty motor 3 causes the motor 3 to hold (hold state) or chatter (reciprocating motion), the number of rotations of the motor 3 calculated by the FG signals Fg_1 and Fg_2 may not be an accurate value. Therefore, the number of FG switches, which is the number of level changes of the FG signals Fg_1 and Fg_2 during the FG standby time, is counted, but the elapsed timer is not used for counting. In other words, in dual-system startup mode, the FG switch times of the FG signals Fg_1 and Fg_2 for each system and the number of rotations of the motor 3 are not updated within the threshold time measured by the elapsed timer. In this case, since the number of FG switches in both systems exceeds the threshold number, it is provisionally determined that the motor 3 is rotating normally.

[0184] Next, in order to operate in the two-system rotation waiting mode, both the first system drive command signal Sca_1 and the second system drive command signal Sca_2 are output. At this time, the rotation speed of the motor 3 is detected based on the time for each level of the FG signals Fg_1 and Fg_2, and is equal to or greater than the minimum rotation speed. Since both the FG signals Fg_1 and Fg_2 have been switched more than the threshold number of times, according to the determination table in Fig. 12, it is determined that the two systems are normal from "FG switching has occurred in both systems," and the system transitions to the second-system drive mode.

[0185] During the rotation waiting time in this two-system rotation waiting mode, an elapsed timer is used to update the FG switching time of the FG signals Fg_1 and Fg_2 of each system and the rotation speed of the motor 3. At this time, the number of FG switches in the two systems exceeds the threshold number of times, and the motor 3 exceeds the minimum rotation speed, so it is determined that the motor 3 is rotating normally.

[0186] From the above, it can be determined that the motor 3 is rotating normally based on the number of FG switches during the FG standby time in dual-system startup mode, and the number of FG switches and rotation speed during the rotation standby time in dual-system rotation standby mode. Also, by starting both systems from the beginning rather than starting each system individually, startup under normal conditions is faster.

[0187] Figure 15 is a timing chart showing an example of signal waveforms from when a motor in a rotor-locked state due to an external factor is started until it enters rotor-lock mode. Figure 15 also shows waveforms for each signal similar to those in Figure 14.

[0188] Fig. 15 shows the waveforms of each signal when the motor starts in standby mode, then transitions to rotor lock mode via primary and secondary startup modes. Fig. 15 shows that the dual-system startup mode, primary and secondary startup modes each last for an FG standby time, and that there is a startup standby time between the dual-system startup mode and primary startup mode, and between the primary and secondary startup modes. The startup standby time indicates that the control signal St is turned off after the drive command signal Sca is turned off, but the drive command signal Sca and the control signal St may be turned off simultaneously.

[0189] In the example shown in Fig. 15, in the dual-system startup mode, even though both the drive command signal Sca_1 for the first system and the drive command signal Sca_2 for the second system are being output, neither of the FG signals Fg_1 nor Fg_2 has switched more than the threshold number of times. According to the determination table in Fig. 9, a provisional rotor lock determination is made from "no FG switching in either system," and the system transitions to the dual-system startup mode.

[0190] During the FG standby time in this dual-system startup mode, the number of rotations of the motor 3 due to the FG signals Fg_1 and Fg_2 may not reach the correct value, so the number of FG switches is used. In this case, since the number of FG switches for both systems does not exceed the threshold number, a rotor lock is provisionally determined.

[0191] Next, to operate in the first-system startup mode, only the drive command signal Sca_1 of the first system is output, and the gate of the second system is shut off. However, since the number of times that the FG signal Fg_1 has been switched does not exceed the threshold number of times, a rotor lock tentative determination is made according to the determination table in Figure 10, based on "no first-system FG switching and the rotor lock tentative determination flag is set," and the system transitions to the second-system startup mode.

[0192] During the FG standby time in this primary system startup mode, the drive of the secondary system is turned off and the gate is blocked to prevent braking, which would affect the rotation of the motor 3 if the secondary system were to fail. However, the rotation speed of the motor 3 according to the FG signal Fg_1 may not be the correct value. Therefore, the number of FG switches is used for judgment in the primary system startup mode. In this case, since the number of FG switches in both systems does not exceed the threshold number, a rotor lock is provisionally judged.

[0193] After that, to operate in the second-system startup mode, only the drive command signal Sca_2 of the second system is output, and the gate of the first system is shut off. However, since the number of times that the FG signal Fg_2 is switched does not exceed the threshold number, a rotor lock determination is made according to the determination table in Figure 11, based on "no second-system FG switching and the rotor lock tentative determination flag is set," and the system transitions to rotor lock mode.

[0194] During the FG wait time in this second-system startup mode, the drive of the first system is turned off and the gate is blocked to prevent braking, which would affect the rotation of the motor 3 if the first system were to fail, but the rotation speed of the motor 3 due to the FG signal Fg_2 may not be the correct value. Therefore, the number of FG switches is used for judgment in the second-system startup mode. In this case, since the number of FG switches in both systems does not exceed the threshold number, a rotor lock is provisionally determined, and rotor lock is determined to have occurred because this provisional rotor lock judgment continues in all startup modes of the second system, the first system, and the second system.

[0195] From the above, by determining rotor lock in the order of the two systems, the first system, and the second system, erroneous determination due to the occurrence of a hold (hold state) in the motor 3 will not occur.

[0196] Figure 16 is a timing chart showing an example of signal waveforms from when a stopped motor with a first system FG failure is started to when it enters the second system drive mode. Figure 16 also shows waveforms for each signal similar to those in Figure 14.

[0197] Figure 16 shows the waveforms of each signal when the system starts from standby mode in dual-system startup mode, passes through second-system startup mode and second-system rotation wait mode, and then transitions to second-system drive mode. Figure 16 shows that the dual-system startup mode and second-system startup mode each last for an FG wait time, the second-system rotation wait mode lasts for a rotation wait time, and there is a startup wait time between the dual-system startup mode and the second-system startup mode.

[0198] In the example shown in Fig. 16, in the dual-system startup mode, even though both the drive command signal Sca_1 of the first system and the drive command signal Sca_2 of the second system are being output, switching of only the FG signal Fg_2 has occurred more than the threshold number of times. According to the determination table in Fig. 9, from "FG switching only in the second system," a provisional determination is made that the second system is normal, and the system transitions to the dual-system startup mode.

[0199] During the FG standby time in this dual-system startup mode, the number of rotations of the motor 3 due to the FG signals Fg_1 and Fg_2 may not be the correct value, so the number of FG switches is used for judgment. At this time, since the number of FG switches occurred in the second system only exceeded the threshold number, it cannot be determined whether the motor 3 is faulty, but it is provisionally determined that at least the second system is normal.

[0200] Next, to operate in the second-system startup mode, only the drive command signal Sca_2 of the second system is output, and the gate of the first system is shut off. At this time, since the number of switching of the FG signal Fg_2 has exceeded the threshold number of times, according to the judgment table in Figure 11, a provisional judgment is made that the second system is normal from "second-system FG switching has occurred," and the system transitions to the second-system rotation waiting mode.

[0201] During the FG standby time in this second-system startup mode, the drive of the first system is turned off and the gate is blocked to prevent braking, which would affect the rotation of the motor 3 if the first system were to fail. However, the rotation speed of the motor 3 according to the FG signal Fg_2 may not be the correct value. Therefore, the number of FG switches is used for judgment in the second-system startup mode. In this case, because the number of FG switches in the second system alone exceeded the threshold number, it cannot be determined whether the motor 3 is faulty, but it is provisionally determined that at least the second system is normal.

[0202] After that, in order to operate in the second system rotation waiting mode, only the drive command signal Sca_2 of the second system is output and the gate of the first system is shut off. At this time, the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed, and switching of only the FG signal Fg_2 has occurred more than the threshold number of times, so according to the judgment table in Figure 12, it is judged that there is an FG failure in the first system from "FG switching only in the second system", and the system transitions to the second system drive mode.

[0203] During the rotation standby time in this second system rotation standby mode, in order to prevent braking that would affect the rotation of motor 3 if the first system were to fail, the drive of the first system is turned off and the gate is blocked, and an elapsed timer is used to update the FG switching times of the FG signals Fg_1 and Fg_2 of each system and the rotation speed of motor 3. At this time, the number of FG switches in only the second system exceeds the threshold number of times, and since the motor 3 exceeds the minimum rotation speed, it is determined that there is an FG failure in the first system.

[0204] From the above, a primary system FG failure can be determined from the number of FG switches during the FG standby time in dual system startup mode, the number of FG switches during the FG standby time in secondary system startup mode, and the number of FG switches and rotation speed during the rotation standby time in secondary system rotation standby mode.

[0205] Fig. 17 is a timing chart showing an example of signal waveforms from when a stopped motor with a faulty FG in the second system is started to when it enters the first system drive mode. Fig. 17 also shows waveforms for each signal similar to those in Fig. 14.

[0206] Figure 17 shows the waveforms of each signal when the system starts from standby mode in dual-system startup mode, passes through primary-system startup mode and primary-system rotation wait mode, and then transitions to primary-system drive mode. Figure 17 shows that the dual-system startup mode and primary-system startup mode each last for an FG wait time, the primary-system rotation wait mode lasts for a rotation wait time, and there is a startup wait time between the dual-system startup mode and the primary-system startup mode.

[0207] In the example shown in Fig. 17, in the dual-system startup mode, even though both the drive command signal Sca_1 of the first system and the drive command signal Sca_2 of the second system are being output, switching of only the FG signal Fg_1 has occurred more than the threshold number of times. According to the determination table in Fig. 9, from "FG switching only in the first system", a provisional determination is made that the first system is normal, and the system transitions to the first-system startup mode.

[0208] During the FG standby time in this dual-system startup mode, the number of rotations of the motor 3 due to the FG signals Fg_1 and Fg_2 may not reach the correct value, so the number of FG switches is used for judgment. In this case, since the number of FG switches occurred in the first system only exceeded the threshold number, it cannot be determined whether the motor 3 is faulty, but it is provisionally determined that at least the first system is normal.

[0209] Next, to operate in the first-system startup mode, only the drive command signal Sca_1 of the first system is output, and the gate of the second system is shut off. At this time, since only the switching of the FG signal Fg_1 has occurred more than the threshold number of times, according to the judgment table in Figure 10, a provisional judgment is made that the first system is normal from "first-system FG switching has occurred," and the system transitions to the first-system rotation waiting mode.

[0210] During this FG standby time in the first system startup mode, the drive of the second system is turned off and the gate is blocked to prevent braking, which would affect the rotation of the motor 3 if the second system were to fail. However, the rotation speed of the motor 3 according to the FG signal Fg_1 may not be the correct value. Therefore, the number of FG switches is used for judgment in the first system startup mode. In this case, because the number of FG switches in the first system alone exceeded the threshold number, it cannot be determined whether the motor 3 is faulty, but it is provisionally determined that at least the first system is normal.

[0211] After that, in order to operate in the first system rotation waiting mode, only the drive command signal Sca_1 of the first system is output and the gate of the second system is shut off. At this time, the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed, and switching of only the FG signal Fg_1 has occurred more than the threshold number of times, so according to the judgment table in Figure 12, it is judged that there is an FG failure in the second system from "FG switching only in the first system", and the system transitions to the first system drive mode.

[0212] During the rotation standby time in this system 1 rotation standby mode, in order to prevent braking that would affect the rotation of motor 3 if system 2 fails, the drive of system 2 is turned off and the gate is blocked, and an elapsed timer is used to update the FG switching times of the FG signals Fg_1 and Fg_2 of each system and the rotation speed of motor 3. At this time, the number of FG switches in system 1 only exceeds the threshold number of times, and motor 3 exceeds the minimum rotation speed, so it is determined that there is an FG failure in system 2.

[0213] From the above, a second system FG failure can be determined from the number of FG switches during the FG standby time in dual system startup mode, the number of FG switches during the FG standby time in first system startup mode, and the number of FG switches and rotation speed during the rotation standby time in first system rotation standby mode.

[0214] Fig. 18 is a timing chart showing an example of signal waveforms from when a stopped motor in a normal state is started, through chattering in the first system, to when the motor enters the dual system drive mode. Fig. 18 also shows waveforms for each signal similar to those in Fig. 14.

[0215] Fig. 18 shows the waveforms of each signal when the inverter starts in standby mode, goes through second-system startup mode and second-system rotation wait mode, and then transitions to second-system drive mode. Fig. 18 shows that the dual-system startup mode and second-system startup mode each last for the FG wait time, the second-system rotation wait mode lasts for the rotation wait time and the winding midpoint voltage wait time, and there is a startup wait time between the dual-system startup mode and the second-system startup mode.

[0216] In the example shown in Fig. 18, in the dual-system startup mode, even though both the drive command signal Sca_1 of the first system and the drive command signal Sca_2 of the second system are output, chattering occurs in the first system, so switching does not occur in the FG signal Fg_1, and switching occurs only in the FG signal Fg_2 more than the threshold number of times. According to the judgment table in Fig. 9, from "FG switching only in the second system", a provisional judgment is made that the second system is normal, and the system transitions to the dual-system startup mode.

[0217] During the FG standby time in this dual-system startup mode, the number of rotations of the motor 3 due to the FG signals Fg_1 and Fg_2 may not be the correct value, so the number of FG switches is used for judgment. At this time, since the number of FG switches occurred in the second system only exceeded the threshold number, it cannot be determined whether the motor 3 is faulty, but it is provisionally determined that at least the second system is normal.

[0218] Next, to operate in the second-system startup mode, only the drive command signal Sca_2 for the second system is output, and the gate of the first system is shut off. At this time, chattering in the first system has converged, and switching has occurred in both the FG signals Fg_1 and Fg_2 more than the threshold number of times. However, since the second-system startup mode only monitors switching of the Fg signal Fg_2 for the second system, a provisional determination is made that the second system is normal according to the determination table in FIG. 11, and the system transitions from "second-system FG switching has occurred" to second-system rotation waiting mode.

[0219] During the FG standby time in this second-system startup mode, the drive of the first system is turned off and the gate is blocked to prevent braking, which would affect the rotation of the motor 3 if the first system were to fail. However, the rotation speed of the motor 3 according to the FG signal Fg_2 may not be the correct value. Therefore, the number of FG switches is used for judgment in the second-system startup mode. In this case, because the number of FG switches in the second system alone exceeded the threshold number, it cannot be determined whether the motor 3 is faulty, but it is provisionally determined that at least the second system is normal.

[0220] Then, to operate in the second-system rotation waiting mode, only the second-system drive command signal Sca_2 is output, and the first-system gate is shut off. At this time, the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed, and switching has occurred in both the FG signals Fg_1 and Fg_2 more than the threshold number of times. Therefore, according to the determination table in FIG. 12, "FG switching has occurred in both systems" is determined to be normal for both systems, and the system transitions to the second-system drive mode after the winding midpoint voltage wait time has elapsed. Note that waiting for the winding midpoint voltage wait time to elapse is necessary when using the detection voltage output circuit 24 to determine a fault from the winding midpoint voltage during operation, and the FG signal for the stop side is restored during rotation waiting in one system at startup.

[0221] During the rotation standby time in this second system rotation standby mode, in order to prevent the generation of a brake that would affect the rotation of the motor 3 if the first system were to fail, the drive of the first system is turned off and the gate is blocked, and an elapsed timer is used to update the FG switching times of the FG signals Fg_1 and Fg_2 of each system and the rotation speed of the motor 3. At this time, the number of FG switches that occurred in both systems exceeded the threshold number of times, and the motor 3 exceeded its minimum rotation speed, so it is determined that both systems are normal.

[0222] From the above, the number of FG switches during the FG standby time in the dual-system startup mode, the number of FG switches during the FG standby time in the second-system startup mode, and the number of FG switches and rotation speed during the rotation standby time in the second-system rotation standby mode prevent erroneous determination due to chattering (reciprocating motion) in the motor 3.

[0223] Fig. 19 is a timing chart showing an example of signal waveforms from when a stopped motor in a normal state is started, through chattering in the second system, to when the motor enters the dual-system drive mode. Fig. 19 also shows waveforms for each signal similar to those in Fig. 14.

[0224] Fig. 19 shows the waveforms of each signal when the inverter starts in standby mode, goes through primary startup mode and primary rotation wait mode, and then transitions to dual drive mode. Fig. 19 shows that the dual startup mode and primary startup mode each last for the FG wait time, the primary rotation wait mode lasts for the rotation wait time and the winding midpoint voltage wait time, and there is a startup wait time between the dual startup mode and primary startup mode.

[0225] In the example shown in Fig. 19, in the dual-system startup mode, even though both the drive command signal Sca_1 of the first system and the drive command signal Sca_2 of the second system are output, chattering occurs in the second system, so that switching of the FG signal Fg_2 does not occur more than the threshold number of times, and switching of only the FG signal Fg_1 occurs. According to the judgment table in Fig. 9, from "FG switching only in the first system", a provisional judgment is made that the first system is normal, and the system transitions to the first-system startup mode.

[0226] During the FG standby time in this dual-system startup mode, the number of rotations of the motor 3 due to the FG signals Fg_1 and Fg_2 may not reach the correct value, so the number of FG switches is used for judgment. In this case, since the number of FG switches occurred in the first system only exceeded the threshold number, it cannot be determined whether the motor 3 is faulty, but it is provisionally determined that at least the first system is normal.

[0227] Next, to operate in the first-system startup mode, only the drive command signal Sca_1 of the first system is output, and the gate of the second system is shut off. At this time, chattering in the second system has converged, and switching has occurred in both the FG signals Fg_1 and Fg_2 more than the threshold number of times. However, since the first-system startup mode only monitors switching of the Fg signal Fg_1 of the first system, according to the judgment table in Figure 10, a provisional judgment is made that the first system is normal from "first-system FG switching has occurred," and the system transitions to the first-system rotation waiting mode.

[0228] During the FG standby time in this first-system startup mode, the drive of the second system is turned off and the gate is blocked to prevent braking, which would affect the rotation of the motor 3 if the second system were to fail. However, the rotation speed of the motor 3 based on the FG signals Fg_1 and Fg_2 may not be the correct value. Therefore, the number of FG switches is used for judgment in the first-system startup mode. In this case, because the number of FG switches in the first system alone exceeded the threshold number, it cannot be determined whether the motor 3 is faulty, but it is provisionally determined that at least the first system is normal.

[0229] After that, to operate in the first system rotation waiting mode, only the drive command signal Sca_1 of the first system is output, and the gate of the second system is shut off. At this time, the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed, and switching has occurred in both the FG signals Fg_1 and Fg_2 more than the threshold number of times, so according to the judgment table in Figure 12, from "FG switching occurred in both systems," it is judged that the two systems are normal, and after the winding midpoint voltage waiting time, the system transitions to the two-system drive mode.

[0230] During the rotation standby time in this second system rotation standby mode, in order to prevent braking that would affect the rotation of motor 3 if the second system were to fail, the drive of the second system is turned off and the gate is blocked, and an elapsed timer is used to update the FG switching times of the FG signals Fg_1 and Fg_2 of each system and the rotation speed of motor 3. At this time, the number of FG switches that occurred in both systems exceeded the threshold number of times, and motor 3 exceeded the minimum rotation speed, so it is determined that both systems are normal.

[0231] From the above, the number of FG switches during the FG standby time in the dual-system startup mode, the number of FG switches during the FG standby time in the primary system startup mode, and the number of FG switches and rotation speed during the rotation standby time in the primary system rotation standby mode prevent erroneous judgment due to chattering (reciprocating motion) in the motor 3.

[0232] Fig. 20 is a timing chart showing an example of signal waveforms from when a motor in a normal state rotating by inertia is started until it enters the dual-system drive mode. Fig. 20 also shows waveforms for each signal similar to those in Fig. 14.

[0233] Figure 20 shows the waveforms of each signal when a coasting motor transitions from standby mode to dual-drive mode without going through dual-start mode. This transition occurs when it is determined that the motor 3 is in an idling state before startup and that its rotation speed is equal to or greater than the minimum rotation speed. In the case of coasting, even though the motor 3 is not being driven, some force is causing the motor 3 to rotate idly at a rotation speed equal to or greater than a predetermined rotation speed. In this case, the motor 3 is not in a hold state or chattering (reciprocating motion), so it can transition to dual-drive mode without going through dual-start mode.

[0234] FIG. 21 is a flowchart showing an example of the processing flow when power is turned on in the motor drive control system according to this embodiment.

[0235] 21, for example, when the drive control circuit 20 is started, an initialization process is executed (step S1). For example, the drive control circuit 20 initializes registers and the like within the microcomputer. The drive control circuit 20 also stops the output of drive command signals Sca_1 and Sca_2 (sets them to low level), sets control signals St_1 and St_2 to high level, and switches to standby mode by enabling input of second drive control signals Sdb_1 and Sdb_2 to low-side switch elements Q3 and Q4 (no signal interruption) (step S2). At this time, the motor 3 becomes free.

[0236] Next, after switching to the standby mode (step S2), the drive control circuit 20 initializes the FG switching time, which is the time for each level of the FG signal of each system, the number of rotations, and starts the elapsed timer (step S3).

[0237] Next, the drive control circuit 20 determines whether or not there is a switch in the first system of FG signal Fg_1 in order to detect the idling state of the motor (step S4). If it is determined that there is a switch in the first system of FG signal Fg_1 (step S4: YES), the drive control circuit 20 updates the FG switch time and rotation speed of the first system of FG signal Fg_1 from the elapsed timer (step S5).

[0238] Next, the drive control circuit 20 determines whether or not there is a switch in the second system FG signal Fg_2 (step S6). If it determines that there is a switch in the second system FG signal Fg_2 (step S6: YES), it updates the FG switch time and rotation speed of the second system FG signal Fg_2 from the elapsed timer (step S7).

[0239] Next, the drive control circuit 20 determines whether or not the elapsed time timer from at least one of the FG switching times exceeds the threshold time (step S8). If it determines that the elapsed time timer from at least one of the FG switching times exceeds the threshold time (step S8: YES), it initializes the FG switching time and rotation speed of each system (step S9).

[0240] Next, the drive control circuit 20 determines whether or not a speed command signal Sc has been input (step S10). If it is determined that a speed command signal Sc has not been input (step S10: NO), the process returns to step S4. By repeating steps S4 to S10, if the motor 3 is rotating by inertia during the period when the speed command signal Sc is not being input, the rotation speed is updated, and unlike when the motor 3 is started from a stopped state, no holding or chattering occurs in the motor 3. Therefore, (if the determination is YES in step S11, which will be described later) it is possible to transition to each drive mode without passing through each start-up mode.

[0241] If it is determined that the speed command signal Sc has been input (step S10: YES), the drive control circuit 20 determines whether the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed (step S11). If the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed, it can be said that the motor 3 is rotating by inertia (is in an idling state).

[0242] If it is determined that the rotation speed is equal to or greater than the minimum rotation speed (step S11: YES), it is determined whether or not the second system failure flag is set (step S12). If it is determined that the second system failure flag is set (step S12: YES), the mode is shifted to the first system drive mode.

[0243] If it is determined that the second system failure flag is not set (step S12: NO), the drive control circuit 20 determines whether the first system failure flag is set (step S13).If it is determined that the first system failure flag is set (step S13: YES), the drive control circuit 20 transitions to the second system drive mode.

[0244] If it is determined that the first system failure flag is not set (step S13: NO), the mode shifts to the dual system drive mode.

[0245] In step S11, if it is determined that the rotation speed is less than the minimum rotation speed (step S11: NO), it is determined whether or not the second system failure flag is set (step S14).If it is determined that the second system failure flag is set (step S14: YES), the system transitions to the first system startup mode.

[0246] If it is determined that the second system failure flag is not set (step S14: NO), the drive control circuit 20 determines whether the first system failure flag is set (step S15).If it is determined that the first system failure flag is set (step S15: YES), the drive control circuit 20 transitions to the second system startup mode.

[0247] If it is determined that the first system failure flag is not set (step S15: NO), the mode shifts to the two-system startup mode.

[0248] FIG. 22 is a flowchart showing an example of the processing flow when determining whether rotor lock occurs in the motor drive control system according to this embodiment.

[0249] In the motor drive control system 100 according to this embodiment, when a rotor lock determination is made, the rotor lock mode is executed. In the rotor lock mode, first, a counting operation by the constraint protection timer is started (step S20). It is determined whether the constraint protection timer has elapsed the constraint protection time (step S21). If the constraint protection timer determines that the constraint protection time has elapsed (step S21: YES), the rotor lock flag is cleared (step S22), and the process proceeds to step S2 in FIG. 21. If the constraint protection timer determines that the constraint protection time has not elapsed (step S21: NO), the process of step S21 is repeated.

[0250] FIG. 23 is a flowchart showing an example of the flow of the dual-system startup mode process in the motor drive control system according to this embodiment.

[0251] In the two-system startup mode, the drive control circuit 20 first initializes the number of FG switches and the rotor lock tentative determination flag for each system and starts counting the standby timer (step S101), and then turns on the PWM outputs of the two systems to output the first drive command signal Sca_1 and the second drive command signal Sca_2 (step S102).

[0252] Thereafter, the drive control circuit 20 determines whether or not there is a switch in the FG signal Fg_1 of the first system (step S103). If it is determined that there is a switch in the FG signal Fg_1 of the first system (step S103: YES), the drive control circuit 20 increments the number of FG switches in the first system (step S104).

[0253] Next, the drive control circuit 20 determines whether or not there is a switch in the FG signal Fg_2 of the second system (step S105). If it is determined that there is a switch in the FG signal Fg_2 of the second system (step S105: YES), the drive control circuit 20 increments the number of FG switches in the second system (step S106).

[0254] Next, the drive control circuit 20 determines whether the FG standby time has elapsed (step S107). If the standby timer determines that the FG standby time has not elapsed (step S107: NO), the process returns to step S103.

[0255] If the standby timer determines that the FG standby time has elapsed (step S107: YES), the drive control circuit 20 determines whether the conditions that the number of FG switches of the first system FG signal Fg_1 is less than a threshold and the number of FG switches of the second system FG signal Fg_2 is also less than a threshold are met (step S108).

[0256] If it is determined that the condition that the number of FG switches of the FG signal Fg_1 of the first system is less than the threshold value and the number of FG switches of the FG signal Fg_2 of the second system is also less than the threshold value is met (step S108: YES), a rotor lock tentative determination is made (step S109), a rotor lock tentative determination flag is set (step S110), the two-system PWM output is turned off (step S111), the standby timer starts counting (step S112), and after waiting for the standby timer to elapse the startup standby time (step S113), the system transitions to the first system startup mode.

[0257] If it is determined that the condition that the number of FG switches of the FG signal Fg_1 of the first system is less than the threshold value and the number of FG switches of the FG signal Fg_2 of the second system is also less than the threshold value is not met (step S108: NO), the drive control circuit 20 determines whether the condition that the number of FG switches of the FG signal Fg_1 of the first system is equal to or greater than the threshold value and the number of FG switches of the FG signal Fg_2 of the second system is less than the threshold value is met (step S114).

[0258] If it is determined that the condition that the number of FG switches of the FG signal Fg_1 of the first system is equal to or greater than the threshold value and the number of FG switches of the FG signal Fg_2 of the second system is less than the threshold value is met (step S114: YES), a tentative determination that the first system is normal is made (step S115), and the processing of steps S111 to S113 is executed to transition to the first system startup mode.

[0259] If it is determined that the condition that the number of FG switches of the FG signal Fg_1 of the first system is greater than or equal to the threshold value and the number of FG switches of the FG signal Fg_2 of the second system is less than the threshold value is not met (step S114: NO), the drive control circuit 20 determines whether the condition that the number of FG switches of the FG signal Fg_1 of the first system is less than the threshold value and the number of FG switches of the FG signal Fg_2 of the second system is greater than or equal to the threshold value is met (step S116).

[0260] If it is determined that the condition that the number of FG switches of the FG signal Fg_1 of the first system is less than the threshold value and the number of FG switches of the FG signal Fg_2 of the second system is equal to or greater than the threshold value is met (step S116: YES), a provisional determination is made that the second system is normal (step S118), the two-system PWM output is turned off (step S119), the standby timer starts counting (step S120), and the standby timer waits for the startup standby time to elapse (step S121). Once the startup standby time has elapsed (step S121: YES), the system transitions to the second system startup mode.

[0261] If it is determined that the condition that the number of FG switches of the FG signal Fg_1 of the first system is less than the threshold value and the number of FG switches of the FG signal Fg_2 of the second system is not met (step S116: NO), a provisional determination is made that the two systems are normal (step S122), and the system transitions to the two-system rotation waiting mode.

[0262] FIG. 24 is a flowchart showing an example of the flow of the two-system rotation wait mode process in the motor drive control system according to this embodiment.

[0263] In the two-system rotation waiting mode, the drive control circuit 20 first initializes the number of FG switches for each system, the FG switch time for each system, and the rotation speed, and starts counting the elapsed timer and the standby timer (step S201).

[0264] Thereafter, the drive control circuit 20 determines whether or not there is a switch in the FG signal Fg_1 of the first system (step S202). If it determines that there is a switch in the FG signal Fg_1 of the first system (step S202: YES), it increments the number of FG switches of the first system and updates the FG switch time and rotation speed of the first system from the elapsed timer (step S203).

[0265] Next, the drive control circuit 20 determines whether or not there is a switch in the FG signal Fg_2 of the second system (step S204). If it determines that there is a switch in the FG signal Fg_2 of the second system (step S204: YES), it increments the number of FG switches of the second system and updates the FG switch time and rotation speed of the second system from the elapsed timer (step S205).

[0266] Next, the drive control circuit 20 determines whether or not the elapsed timer since at least one of the FG switching times has exceeded the threshold time (step S206). If it determines that the elapsed timer since at least one of the FG switching times has exceeded the threshold time (step S206: YES), it initializes the number of FG switching times, the FG switching time, and the rotation speed of each system (step S207).

[0267] Next, the drive control circuit 20 determines whether the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed (step S208). If it is determined that the rotation speed is equal to or greater than the minimum rotation speed (step S208: YES), it further determines whether the condition that the number of FG switching times of the first system is equal to or greater than the threshold and the number of FG switching times of the second system is less than the threshold is met (step S209).

[0268] If it is determined that the condition that the number of FG switches of the first system is equal to or greater than the threshold value and the number of FG switches of the second system is less than the threshold value is met (step S209: YES), a second system FG failure determination is made (step S210), a second system failure flag is set (step S211), the second system PWM output is turned off, and the second system gate blocking signal (control signal St_2) is turned on (step S212), and the system transitions to the first system drive mode.

[0269] If it is determined that the condition that the number of FG switching times of the first system is greater than or equal to the threshold and the number of FG switching times of the second system is less than the threshold is not met (step S209: NO), it is further determined whether the condition that the number of FG switching times of the first system is less than the threshold and the number of FG switching times of the second system is greater than or equal to the threshold is met (step S213).

[0270] If it is determined that the condition that the number of FG switching times of the first system is less than the threshold value and the number of FG switching times of the second system is equal to or greater than the threshold value is met (step S213: YES), a first system FG failure determination is made (step S214), a first system failure flag is set (step S215), the first system PWM output is turned off, and the first system gate blocking signal (control signal St_1) is turned on (step S216), and the system transitions to the second system drive mode.

[0271] If it is determined that the condition that the number of FG switching times of the first system is less than the threshold value and the number of FG switching times of the second system is greater than or equal to the threshold value is not met (step S213: NO), a two-system normality determination is made (step S217), and the system transitions to two-system drive mode.

[0272] Returning to step S208, if it is determined that the rotation speed is not equal to or greater than the minimum rotation speed (step S208: NO), it is further determined whether the standby timer has elapsed the rotation standby time (step S218). If the standby timer has determined that the rotation standby time has not elapsed (step S218: NO), the process returns to step S202. Note that the determination in step S208 may be made after the determination in step S218.

[0273] If the standby timer determines that the rotation standby time has elapsed (step S218: YES), a rotor lock determination is made (step S219), the rotor lock flag is set (step S220), the dual-system PWM output is turned off (step S221), and the system transitions to rotor lock mode.

[0274] FIG. 25 is a flowchart showing an example of the flow of the two-system drive mode process in the motor drive control system according to this embodiment.

[0275] In the two-system drive mode, the drive control circuit 20 first initializes the FG switching count difference, which is the difference in the number of level changes between the FG signals Fg_1 and Fg_2, the FG switching time and rotation speed of each system, and starts counting the elapsed timer (step S301).

[0276] Thereafter, the drive control circuit 20 turns on two systems of PWM output to output the first drive command signal Sca_1 and the second drive command signal Sca_2 (step S302).

[0277] The drive control circuit 20 determines whether or not there is a switch in the FG signal Fg_1 of the first system (step S303). If it determines that there is a switch in the FG signal Fg_1 of the first system (step S303: YES), it increments the FG switch count difference by "1" and updates the FG switch time and rotation speed of the first system from the elapsed timer (step S304).

[0278] Next, the drive control circuit 20 determines whether or not there is a switch in the FG signal Fg_2 of the second system (step S305). If it determines that there is a switch in the FG signal Fg_2 of the second system (step S305: YES), it decrements the FG switch count difference by "1" and updates the FG switch time and rotation speed of the second system from the elapsed timer (step S306).

[0279] When the motor is rotating normally, FG switching of the second system occurs after FG switching of the first system occurs, so the difference in the number of FG switches will alternate between 0 and +1 or 0 and -1 and will never exceed ±1. However, if an FG failure occurs in the second system and no FG switching occurs, only FG switching of the first system will occur continuously, so the difference in the number of FG switches will increase by a positive value. Also, if an FG failure occurs in the first system and no FG switching occurs, FG switching of the second system will occur continuously, so the difference in the number of FG switches will increase by a negative value.

[0280] Next, the drive control circuit 20 determines whether the difference in the number of FG switching times is greater than a positive value of the threshold number of times (positive threshold number of times), which is the allowable number of times of chattering (step S307). If it is determined that the difference in the number of FG switching times is greater than the positive value of the threshold number of times (step S307: YES), a second-system FG failure is determined (step S308), a second-system failure flag is set (step S309), the second-system PWM output is turned off, and the second-system gate blocking signal (control signal St_2) is turned on (step S310), and the drive mode is switched to the first-system drive mode.

[0281] If it is determined that the difference in the number of FG switching times is not greater than the value at the threshold number of times (step S307: NO), it is further determined whether or not the difference in the number of FG switching times is smaller than the negative value of the threshold number of times (negative threshold number of times), which is the allowable number of times of chattering (step S311).If it is determined that the difference in the number of FG switching times is smaller than the negative value of the threshold number of times (step S311: YES), a first-system FG failure is determined (step S312), a first-system failure flag is set (step S313), the first-system PWM output is turned off, and the first-system gate blocking signal (control signal St_1) is turned on (step S314), and the system transitions to the second-system drive mode.

[0282] If it is determined that the difference in the number of FG switching times is not smaller than the negative value of the threshold number of times (step S311: NO), the drive control circuit 20 determines whether or not the elapsed timer since at least one of the FG switching times has exceeded the threshold time (step S315).If it is determined that the elapsed timer since at least one of the FG switching times has exceeded the threshold time (step S315: YES), a rotor lock determination is made (step S316), a rotor lock flag is set (step S317), the dual PWM output is turned off (step S318), and the system transitions to rotor lock mode.

[0283] If it is determined that the elapsed timer since at least one of the FG switching times has not exceeded the threshold time (step S315: NO), the drive control circuit 20 determines whether or not there is a speed command (step S319). If it is determined that there is a speed command (step S319: YES), the process returns to step S302, where the duty of the PWM output is changed in accordance with the change in the speed command. If it is determined that there is no speed command (step S319: NO), the PWM output of both systems is turned off (step S320), and the process returns to step S2 in FIG. 22.

[0284] FIG. 26 is a flowchart showing an example of the flow of the first system startup mode process in the motor drive control system according to this embodiment.

[0285] In the first system startup mode, the drive control circuit 20 first initializes the number of FG switching times for each system and starts counting the standby timer (step S401), and then turns on the PWM output of the first system to output the first drive command signal Sca_1 and turns on the second system gate blocking signal (control signal St_2) (step S402).

[0286] The drive control circuit 20 determines whether or not there is a switch in the FG signal Fg_1 of the first system (step S403). If it determines that there is a switch in the FG signal Fg_1 of the first system (step S403: YES), it increments the number of FG switches in the first system by "1" (step S404).

[0287] Next, the drive control circuit 20 determines whether or not there is a switch in the FG signal Fg_2 of the second system (step S405). If it is determined that there is a switch in the FG signal Fg_2 of the second system (step S405: YES), the drive control circuit 20 increments the number of FG switches in the second system by "1" (step S406).

[0288] Next, the drive control circuit 20 determines whether the FG standby time has elapsed (step S407). If the standby timer determines that the FG standby time has not elapsed (step S407: NO), the process returns to step S403.

[0289] If the standby timer determines that the FG standby time has elapsed (step S407: YES), it is further determined whether the number of FG switches in the first system is equal to or greater than a threshold (step S408).If it is determined that the number of FG switches in the first system is equal to or greater than the threshold (step S408: YES), a tentative determination is made that the first system is normal (step S409), and the system transitions to the first system rotation waiting mode.

[0290] If it is determined that the number of FG switching times of the first system is not equal to or greater than the threshold value (step S408: NO), the PWM output of the first system is turned off, and the second system gate blocking signal (control signal St_2) is turned off (step S410). After that, it is determined whether the rotor lock tentative determination flag is set (step S411).

[0291] If it is determined that the rotor lock tentative determination flag is set (step S411: YES), a rotor lock tentative determination is made (step S412), the standby timer starts counting (step S413), and after waiting for the standby timer to elapse the startup standby time (step S414), the system transitions to the second system startup mode.

[0292] If it is determined that the rotor lock tentative determination flag is not set (step S411: NO), a tentative determination of a first system FG failure is made (step S415), the rotor lock flag is set (step S416), and the system transitions to rotor lock mode.

[0293] FIG. 27 is a flowchart showing an example of the flow of the first system rotation wait mode process in the motor drive control system according to this embodiment.

[0294] In the first system rotation waiting mode, the drive control circuit 20 first initializes the number of FG switches for each system, the FG switch time for each system, and the rotation speed, and starts counting the elapsed timer and the standby timer (step S501).

[0295] Thereafter, the drive control circuit 20 determines whether or not there is a switch in the FG signal Fg_1 of the first system (step S502). If it determines that there is a switch in the FG signal Fg_1 of the first system (step S502: YES), it increments the number of FG switches of the first system and updates the FG switch time of the first system and the rotation speed from the elapsed timer (step S503).

[0296] Next, the drive control circuit 20 determines whether or not there is a switch in the FG signal Fg_2 of the second system (step S504). If it determines that there is a switch in the FG signal Fg_2 of the second system (step S504: YES), it increments the number of FG switches of the second system and updates the FG switch time and rotation speed of the second system from the elapsed timer (step S505).

[0297] Next, the drive control circuit 20 determines whether the elapsed time count from the FG switching time of the first system has exceeded the threshold time (step S506). If it determines that the elapsed time count from the FG switching time of the first system has exceeded the threshold time (step S506: YES), it initializes the number of FG switching times, the FG switching time, and the rotation speed of each system (step S507).

[0298] Next, the drive control circuit 20 determines whether the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed (step S508). If it is determined that the rotation speed is equal to or greater than the minimum rotation speed (step S508: YES), it further determines whether the condition that the number of FG switching times of the first system is equal to or greater than the threshold and the number of FG switching times of the second system is less than the threshold is met (step S509).

[0299] If it is determined that the condition that the number of FG switches of the first system is equal to or greater than the threshold value and the number of FG switches of the second system is less than the threshold value is met (step S509: YES), a second system FG failure determination is made (step S510), a second system failure flag is set (step S511), and the system transitions to the first system drive mode.

[0300] If it is determined that the condition that the number of FG switching times of the first system is greater than or equal to the threshold and the number of FG switching times of the second system is less than the threshold is not met (step S509: NO), it is further determined whether the condition that the number of FG switching times of the first system is less than the threshold and the number of FG switching times of the second system is greater than or equal to the threshold is met (step S512).

[0301] If it is determined that the condition that the number of FG switching times of the first system is less than the threshold value and the number of FG switching times of the second system is equal to or greater than the threshold value is met (step S512: YES), a tentative determination of a first system FG failure is made (step S519), the rotor lock flag is set (step S520), the first system PWM output is turned off, and the second system gate blocking signal (control signal St_2) is turned off (step S521), and the system transitions to rotor lock mode.

[0302] If it is determined that the condition that the number of FG switching times of the first system is less than the threshold and the number of FG switching times of the second system is equal to or greater than the threshold is not met (step S512: NO), a two-system normality determination is made (step S513), the second-system PWM output is turned on and the second-system gate blocking signal (control signal St_2) is turned off (step S514), the standby timer starts counting (step S515), and when the standby timer has elapsed the startup standby time (step S516: YES), the system transitions to two-system drive mode.

[0303] Returning to step S508, if it is determined that the rotation speed is not equal to or greater than the minimum rotation speed (step S508: NO), the drive control circuit 20 determines whether the standby timer has elapsed the FG standby time (step S517). If the standby timer has determined that the FG standby time has not elapsed (step S517: NO), the process returns to step S502. Note that the determination in step S508 may be made after the determination in step S517.

[0304] If the standby timer determines that the FG standby time has elapsed (step S517: YES), a rotor lock determination is made (step S518), a rotor lock flag is set (step S520), the first system PWM output is turned off, and the second system gate blocking signal (control signal St_2) is turned off (step S521), and the system transitions to rotor lock mode.

[0305] FIG. 28 is a flowchart showing an example of the flow of the first system drive mode process in the motor drive control system according to this embodiment.

[0306] In the first-system drive mode, the drive control circuit 20 first initializes the FG switching time and rotation speed of the first system and starts counting the elapsed timer (step S601), and then turns on the second-system gate blocking signal (control signal St_2) (step S602). This process frees the second system, and no braking that would affect the rotation of the motor 3 is generated by the second system. Next, the PWM output of the first system is turned on with the speed command duty (step S603). At this time, the failure duty may be used instead of the speed command duty.

[0307] Thereafter, the drive control circuit 20 determines whether or not there is a switch in the FG signal Fg_1 of the first system (step S604). If it determines that there is a switch in the FG signal Fg_1 of the first system (step S604: YES), it updates the FG switch time and rotation speed of the first system from the elapsed timer (step S605).

[0308] Next, the drive control circuit 20 determines whether the elapsed time count from the FG switching time of the first system has exceeded the threshold time (step S606). If it is determined that the elapsed time count from the FG switching time of the first system has exceeded the threshold time (step S606: YES), a rotor lock determination is made (step S607), a rotor lock flag is set (step S608), the PWM output of the first system is turned off, the second system gate blocking signal (control signal St_2) is turned off (step S609), and the system transitions to rotor lock mode.

[0309] If it is determined that the elapsed timer from the FG switching time of the first system has not exceeded the threshold time (step S606: NO), it is determined whether or not there is a speed command (step S610). If it is determined that there is a speed command (step S610: YES), the process returns to step S603, and the duty of the PWM output may be changed in step S603 according to the change in the speed command. If it is determined that there is no speed command (step S610: NO), the PWM output of the first system is turned off, and the second system gate blocking signal (control signal St_2) is turned off (step S611), and the process returns to step S2 in FIG. 21. At this time, the motor becomes free.

[0310] FIG. 29 is a flowchart showing an example of the flow of the second system startup mode process in the motor drive control system according to this embodiment.

[0311] In the second system startup mode, the drive control circuit 20 first initializes the number of FG switching times for each system and starts counting the standby timer (step S701), turns on the PWM output of the second system, and turns on the first system gate blocking signal (control signal St_1) (step S702).

[0312] Thereafter, the drive control circuit 20 determines whether or not there is a switch in the FG signal Fg_1 of the first system (step S703). If it is determined that there is a switch in the FG signal Fg_1 of the first system (step S703: YES), the drive control circuit 20 increments the number of FG switches in the first system by "1" (step S504).

[0313] Next, the drive control circuit 20 determines whether or not there is a switch in the FG signal Fg_2 of the second system (step S705). If it is determined that there is a switch in the FG signal Fg_2 of the second system (step S705: YES), the drive control circuit 20 increments the number of FG switches in the second system by "1" (step S706).

[0314] Next, the drive control circuit 20 determines whether the standby timer has exceeded the FG standby time (step S707). If it is determined that the standby timer has not exceeded the FG standby time (step S707: NO), the process returns to step S703.

[0315] If the standby timer determines that the FG standby time has elapsed (step S707: YES), the drive control circuit 20 determines whether the number of FG switches in the second system is equal to or greater than a threshold (step S708).If the number of FG switches in the second system is equal to or greater than the threshold (step S708: YES), a provisional determination is made that the second system is normal (step S709), and the system transitions to a second system rotation waiting mode.

[0316] If it is determined that the number of FG switches of the second system is not equal to or greater than the threshold value (step S708: NO), the drive control circuit 20 turns off the PWM output of the second system and turns off the first system gate blocking signal (control signal St_1) (step S710), and determines whether the rotor lock tentative determination flag is set (step S711).If it is determined that the rotor lock tentative determination flag is set (step S711: YES), a rotor lock determination is made (step S712), the rotor lock flag is set (step S714), and the system transitions to rotor lock mode.

[0317] If it is determined that the rotor lock tentative determination flag is not set (step S711: NO), a tentative determination of a second system FG failure is made (step S713), the rotor lock flag is set (step S714), and the system transitions to rotor lock mode.

[0318] FIG. 30 is a flowchart showing an example of the flow of the second system rotation wait mode process in the motor drive control system according to this embodiment.

[0319] In the second system rotation waiting mode, the drive control circuit 20 first initializes the number of FG switches for each system, the FG switch time for each system, and the rotation speed, and starts counting the elapsed timer and the standby timer (step S801).

[0320] Thereafter, the drive control circuit 20 determines whether or not there has been a switch in the FG signal Fg_1 of the first system (step S802). If it determines that there has been a switch in the FG signal Fg_1 of the first system (step S802: YES), it increments the number of FG switches of the first system by "1" and updates the FG switch time and rotation speed of the first system from the elapsed timer (step S803).

[0321] Next, the drive control circuit 20 determines whether or not there is a switch in the FG signal Fg_2 of the second system (step S804). If it determines that there is a switch in the FG signal Fg_2 of the second system (step S804: YES), it increments the number of FG switches of the second system by "1" and updates the FG switch time and rotation speed of the second system from the elapsed timer (step S805).

[0322] Next, the drive control circuit 20 determines whether the elapsed time count from the FG switching time of the second system has exceeded the threshold time (step S806). If it determines that the elapsed time count from the FG switching time of the second system has exceeded the threshold time (step S806: YES), it initializes the FG switching count, FG switching time, and rotation speed of each system (step S807).

[0323] Next, the drive control circuit 20 determines whether the rotation speed of the motor 3 is equal to or greater than the minimum rotation speed (step S808). If it is determined that the rotation speed is equal to or greater than the minimum rotation speed (step S808: YES), it further determines whether the condition that the number of FG switching times of the first system is equal to or greater than the threshold and the number of FG switching times of the second system is less than the threshold is met (step S809).

[0324] If it is determined that the condition that the number of FG switches of the first system is equal to or greater than the threshold value and the number of FG switches of the second system is less than the threshold value is met (step S809: YES), a provisional determination of a second system FG failure is made (step S810), the rotor lock flag is set (step S818), the second system PWM output is turned off, and the first system gate blocking signal (control signal St_1) is turned off (step S819), and the system transitions to rotor lock mode.

[0325] If it is determined that the condition that the number of FG switching times of the first system is greater than or equal to the threshold and the number of FG switching times of the second system is less than the threshold is not met (step S809: NO), it is further determined whether the condition that the number of FG switching times of the first system is less than the threshold and the number of FG switching times of the second system is greater than or equal to the threshold is met (step S811).

[0326] If it is determined that the condition that the number of FG switches of the first system is less than the threshold value and the number of FG switches of the second system is greater than or equal to the threshold value is met (step S811: YES), a first system FG failure is determined (step S820), a first system failure flag is set (step S821), and the system transitions to the second system drive mode.

[0327] If it is determined that the condition that the number of FG switching times of the first system is less than the threshold and the number of FG switching times of the second system is not equal to or greater than the threshold is not met (step S811: NO), a two-system normality determination is made (step S812), the first-system PWM output is turned on and the first-system gate blocking signal (control signal St_1) is turned off (step S813), the standby timer starts counting (step S814), and after waiting for the standby timer to elapse the startup standby time (step S815), the system transitions to two-system drive mode.

[0328] Returning to step S808, if it is determined that the rotation speed is not equal to or greater than the minimum rotation speed (step S808: NO), the drive control circuit 20 determines whether the standby timer has elapsed the FG standby time (step S816). If the standby timer has determined that the FG standby time has not elapsed (step S816: NO), the process returns to step S802. Note that the determination in step S808 may be made after the determination in step S816.

[0329] If the standby timer determines that the FG standby time has elapsed (step S816: YES), a rotor lock determination is made (step S817), a rotor lock flag is set (step S818), the second system PWM output is turned on, and the first system gate blocking signal (control signal St_1) is turned off (step S819), and the system transitions to rotor lock mode.

[0330] FIG. 31 is a flowchart showing an example of the flow of the second system drive mode process in the motor drive control system according to this embodiment.

[0331] In the second-system drive mode, the drive control circuit 20 first initializes the FG switching time and rotation speed of the second system and starts counting the elapsed timer (step S901), then turns on the first-system gate blocking signal (control signal St_1) (step S902). This process frees the first system, and no braking that would affect the rotation of the motor is generated by the first system. Next, the PWM output of the second system is turned on with the speed command duty (step S903). At this time, the failure duty may be used instead of the speed command duty.

[0332] Thereafter, the drive control circuit 20 determines whether or not there is a switch in the FG signal Fg_2 of the second system (step S904). If it is determined that there is a switch in the FG signal Fg_2 of the second system (step S904: YES), the drive control circuit 20 updates the FG switch time and rotation speed of the second system from the elapsed timer (step S905).

[0333] Next, the drive control circuit 20 determines whether the elapsed time count from the FG switching time of the second system has exceeded the threshold time (step S906). If it is determined that the elapsed time count from the FG switching time of the second system has exceeded the threshold time (step S906: YES), a rotor lock determination is made (step S907), a rotor lock flag is set (step S908), the PWM output of the second system is turned off, and the first system gate blocking signal (control signal St_1) is turned off (step S909), and the system transitions to rotor lock mode.

[0334] If it is determined that the elapsed timer from the FG switching time of the second system has not exceeded the threshold time (step S906: NO), it is determined whether or not there is a speed command (step S910). If it is determined that there is a speed command (step S910: YES), the process returns to step S903, and the duty of the PWM output may be changed in step S903 according to the change in the speed command. If it is determined that there is no speed command (step S910: NO), the PWM output of the second system is turned off, and the first system gate blocking signal (control signal St_1) is turned off (step S911), and the process returns to step S2 in FIG. 21. At this time, the motor becomes free.

[0335] In this way, the motor drive control device 1 according to the embodiment can accurately determine abnormal conditions such as rotor lock and FG failure when starting the drive of the single-phase two-system driven motor 3 from a stopped state, thereby enabling quick and stable start-up.

[0336] Furthermore, before starting, it is determined that the motor is in an idling state, and if it is rotating at or above the minimum rotation speed, drive control is performed in dual-system drive mode without going through the start-up mode, so drive control of motor 3 can be performed without making unnecessary determinations.

[0337] <<Extension of Embodiment>> The invention made by the inventor has been specifically described above based on an embodiment, but it goes without saying that the invention is not limited thereto and can be modified in various ways without departing from the spirit of the invention.

[0338] For example, the configurations of the motor drive control system, the detection voltage output circuit, the drive control circuit, and the signal cutoff circuit are not limited to those shown in the drawings. For example, if the gate signal controlled by the Hall signal can be cut off, the signal cutoff circuits 13_1 and 13_2 are not essential components and can be omitted.

[0339] In the above-described embodiment, the timing charts shown in FIGS. 14 to 20 and the flowcharts shown in FIGS. 8 and 21 to 31 are merely specific examples, and the present invention is not limited to these.

[0340] At the time of startup, instead of the speed command duty, a startup duty, which is a predetermined duty ratio used at startup, may be temporarily used.

[0341] In the above embodiment, an example has been described in which the signal blocking circuits 13_1 and 13_2 block signals to the high-side switch elements Q1 and Q2 of the inverter circuits 12_1 and 12_2. However, the present invention is not limited to this example, and the side from which the signal is blocked in the signal blocking circuits 13_1 and 13_2 may be either the high-side switch elements Q1 and Q2 or the low-side switch elements Q3 and Q4, as long as it is the side controlled by the position detection signal. Furthermore, if the inverter control circuit 11 can block the gate on the side controlled by the position detection signal, the signal blocking circuit 13 may not be provided.

[0342] In the above embodiment, the above-mentioned determination is made by monitoring the FG signals Fg_1 and Fg_2, but the method of fault detection is not limited to this. For example, a fault or voltage abnormality may be determined from the winding midpoint voltage during operation using the detection voltage output circuit 24. In this case, however, when the FG signal of the stopped side is restored due to a waiting period for rotation of one system at start-up, the winding midpoint voltage difference must be eliminated using the winding midpoint voltage waiting time in response to the winding midpoint voltage that rises due to the side that is driven later.

[0343] When the drive control circuit 20 detects an abnormality in the motor 3, the notification circuit 25 notifies the outside. In this case, an alarm output circuit (not shown) may be used to notify the upper device 2 of the abnormal state of the motor 3 as a motor drive information signal So instead of the rotation state of the motor 3. [Explanation of symbols]

[0344] 1...motor drive control device, 2...host device, 3...motor, 4...impeller (impeller wheel), 5...fan (fan motor), 6, 6_1, 6_2...coil (winding), 7, 7_1, 7_2...position detector, 10_1, 10_2...motor drive circuit, 11, 11_1, 11_2...inverter control circuit, 12, 12_1, 12_2...inverter circuit, 13, 13_1, 13_2...signal interruption circuit, 16_1, 16_2, 17_1, 17_2...load drive terminal, 20...drive control circuit, 21...state control unit, 211...speed command duty ratio calculation unit, 212 ...Operation mode control unit, 213...Drive command duty ratio output unit, 214...First system drive command signal generation unit, 215...Second system drive command signal generation unit, 22...Monitoring unit, 221...First system FG signal measurement unit, 222...Second system FG signal measurement unit, 223...Rotation speed measurement unit, 224...Abnormality determination unit, 225...FG signal generation unit, 226...Measurement selection unit, 227...Voltage measurement unit, 23...Power supply circuit, 24, 24_1, 24_2...Detection voltage output circuit, 25...Alarm circuit, 100...Motor drive control system, 101...Fan unit, 240...Voltage division circuit, C21... Capacitor, F1, F2... fuse, Fg... composite FG signal, Fg_1, Fg_2... FG signal, Lp... power line, Pv... power terminal, Pm1_1, Pm1_2... input terminal, Pm2_1, Pm2_2... output terminal, P1... input terminal, P2... output terminal, P3, P4, P5, P6, P7... signal output terminal, P8, P9, P10, P11... signal input terminal, Pd1 to Pd4... output terminal, Ps1 to Ps5... terminal, Q1 to Q4, Qc... switch element, Q11, Q12... cut-off switch element, Q13, Q14... change-over switch element, Ra1, Rb 1, R21...resistor, D21...rectifier element, Rs...current detection resistor, Sc...speed command signal, Sca, Sca_1, Sca_2...drive command signal, Sda, Sda_1, Sda_2...first drive control signal, Sdb, Sdb_1, Sdb_2...second drive control signal, So...motor drive information signal, St_1, St_2...control signal, VDD, VCC...power supply terminal, Vdc...power supply voltage, Vhn, Vhp...Hall signal (an example of a position detection signal), Vm, Vm_1, Vm_2...winding midpoint voltage, Vs, Vs_1, Vs_2...winding midpoint detection voltage (detection voltage).

Claims

1. two motor drive circuits provided corresponding to two systems of coils that drive one motor, and that control energization of the coils of the corresponding systems based on a drive command signal; a drive control circuit that outputs the drive command signal to at least one of the two motor drive circuits, The drive control circuit, upon startup, a primary determination is made to determine whether or not there is an abnormality in each system based on a result of detecting the number of level changes of the FG signal of each system input when the drive command signal is output to at least one of the two motor drive circuits; The drive control circuit includes: At startup, before the primary determination is made, if an idling state of the motor is detected from the detection result of the number of level changes of the FG signals of each system input from both of the two motor drive circuits and the detection result of the number of rotations of the motor calculated from the time for each level of the FG signal, and if the number of rotations of the motor is equal to or greater than a predetermined minimum number of rotations, the primary determination is not made, and the drive command signal is output to both of the two motor drive circuits to start two-system drive. Motor drive control device.

2. 2. The motor drive control device according to claim 1, The drive control circuit includes: In response to the result of the primary determination, a secondary determination is made to determine whether or not there is an abnormality in each system based on the result of detecting the number of level changes of the FG signal of each system input when the drive command signal is output to at least one of the two motor drive circuits and the result of detecting the number of rotations of the motor calculated from the time for each level of the FG signal. Motor drive control device.

3. 3. The motor drive control device according to claim 2, The drive command signal is output to both of the two motor drive circuits to perform the primary determination, and if it is determined in the primary determination that there is no abnormality in either system, the drive command signal is output to both of the two motor drive circuits to perform the secondary determination. Motor drive control device.

4. 4. The motor drive control device according to claim 2, wherein: The drive control circuit includes: During the driving of the motor, the number of level changes of the FG signals of each system input when the drive command signal is output to both of the two motor drive circuits is detected, and a tertiary determination is made to determine whether or not there is an FG failure based on the difference in the number of level changes. Motor drive control device.

5. Two motor drive circuits provided corresponding to two systems of coils that drive one motor based on a drive command signal, and controlling the energization of the coils of the corresponding systems; a drive control circuit that outputs the drive command signal to at least one of the two motor drive circuits, The drive control circuit includes: an abnormality determination unit that sequentially performs a primary determination, a secondary determination, and a tertiary determination; a drive command signal generation unit that generates the drive command signal for at least one of the two motor drive circuits in accordance with the results of the primary determination and the secondary determination; A motor drive control device having The drive control circuit, upon startup, the primary determination is made to determine whether or not there is an abnormality in each system based on a detection result of the number of level changes of the FG signal of each system input when the drive command signal is output to at least one of the two motor drive circuits; The drive control circuit includes: In response to the result of the primary determination, a secondary determination is made to determine whether or not there is an abnormality in each system based on a detection result of the number of level changes of the FG signal of each system input when the drive command signal is output to at least one of the two motor drive circuits and a detection result of the number of rotations of the motor calculated from the time for each level of the FG signal; detecting the number of level changes of the FG signals of each system input when the drive command signals are output to both of the two motor drive circuits while the motor is being driven, and performing the tertiary determination of determining whether or not there is an FG fault based on the difference in the number of level changes; The drive command signal generation unit outputting the drive command signal corresponding to one of a two-system drive for driving both of the two motor drive circuits, a first-system drive for driving the motor drive circuit of a first system of the two motor drive circuits, and a second-system drive for driving the motor drive circuit of a second system of the two motor drive circuits; the primary determination at the time of startup corresponds to a dual-system startup mode in which the engine operates using the dual-system drive, a first-system startup mode in which the engine operates using the first-system drive, and a second-system startup mode in which the engine operates using the second-system drive; In the secondary determination after the primary determination, depending on the determination result of the primary determination, the system is operated in one of a dual-system rotation wait mode in which the system operates in the dual-system drive mode, a first-system rotation wait mode in which the system operates in the first-system drive mode, and a second-system rotation wait mode in which the system operates in the second-system drive mode; During driving after the secondary determination, the driving mode corresponds to one of a dual-system driving mode in which the vehicle operates using the dual-system driving, a first-system driving mode in which the vehicle operates using the first-system driving, and a second-system driving mode in which the vehicle operates using the second-system driving, depending on the determination result of the secondary determination; After the primary or secondary determination, the drive command signal corresponding to the rotor lock mode is generated. Motor drive control device.

6. In the motor drive control device according to claim 5, The drive control circuit performs the primary determination by: determining whether or not there is an abnormality in each system based on a result of detecting the number of level changes of the FG signal of each system input when the drive command signal is output to at least one of the two motor drive circuits; If the determination indicates that at least one motor drive circuit is abnormal, then, depending on the determination result, one of the motor drive circuits is enabled to operate and the other motor drive circuit is stopped to operate, and a determination is made as to whether or not there is an abnormality in each system based on the detection result of the number of level changes of the FG signal input from the one of the motor drive circuits. Motor drive control device.

7. The motor drive control device according to claim 5 or 6, The two motor drive circuits each include: an inverter control circuit that generates a drive control signal based on the drive command signal input from the drive control circuit and a position detection signal generated in response to rotation of the motor, and outputs an FG signal having a frequency corresponding to the actual rotation speed of the motor to the drive control circuit; an inverter circuit that drives the coil based on the drive control signal; a signal blocking circuit that switches between inputting and blocking the drive control signal from the inverter control circuit to the inverter circuit in response to control from the drive control circuit; The drive control circuit performs the primary determination by: determining whether or not there is an abnormality in each system based on a result of detecting the number of level changes of the FG signal of each system input when the drive command signal is output to both of the two motor drive circuits; 、 If it is determined that at least one motor drive circuit is abnormal, the signal cutoff circuit of one of the two motor drive circuits is controlled in accordance with the determination result to enable input of the drive control signal from the inverter control circuit of one system to the inverter circuit, and to stop input of the drive control signal from the inverter control circuit of the other system to the inverter circuit, and to determine whether or not there is an abnormality in each system based on the detection result of the number of level changes of the FG signal input from one system. Motor drive control device.

8. The motor drive control device according to any one of claims 5 to 7, the abnormality determination unit generates a determination result in the dual-system startup mode based on the number of level changes of the FG signal of each system within a predetermined period, whereby it makes a tentative determination of a rotor lock when the number of level changes of both systems does not reach a predetermined number, it makes a tentative determination of a first system normal when the number of level changes of only the first system reaches a predetermined number, it makes a tentative determination of a second system normal when the number of level changes of only the second system reaches a predetermined number, and it makes a tentative determination of a two-system normal when the number of level changes of both systems reaches a predetermined number; The drive command signal generation unit generates the drive command signal corresponding to any one of the operation modes: the first system startup mode based on the rotor lock tentative determination, the first system startup mode based on the first system normal tentative determination, the second system startup mode based on the second system normal tentative determination, and the two system rotation waiting mode based on the two system normal tentative determination, depending on the determination result generated by the abnormality determination unit. Motor drive control device.

9. 9. The motor drive control device according to claim 8, the abnormality determination unit generates a determination result in which, in the first system startup mode, it is determined that the first system is temporarily normal when the number of level changes of the FG signal of the first system in a predetermined period reaches a predetermined number; in the first system startup mode based on the rotor lock determination, it is determined that the rotor is locked when the number of level changes of the FG signal of the first system in a predetermined period does not reach a predetermined number; and in the first system startup mode based on the first system temporary normal determination, it is determined that the first system is temporarily abnormal when the number of level changes of the FG signal of the first system in a predetermined period does not reach a predetermined number; The drive command signal generating unit generates the drive command signal corresponding to one of the operation modes of the first system rotation waiting mode based on the first system temporary normality determination, the second system startup mode based on the rotor lock temporary determination, and the rotor lock mode based on the first system FG failure temporary determination, in accordance with the determination result generated by the abnormality determining unit, in the first system startup mode. Motor drive control device.

10. The motor drive control device according to any one of claims 5 to 7, the abnormality determination unit generates a determination result in which, in the second system startup mode, when the number of level changes of the FG signal of the second system in a predetermined period reaches a predetermined number, the second system is tentatively determined to be normal, and when the number of level changes does not reach the predetermined number, the abnormality determination unit generates a determination result in which the second system is tentatively determined to be rotor locked or a second system FG failure; The drive command signal generating unit generates the drive command signal corresponding to one of the operation modes of the second system rotation waiting mode based on the second system temporary normality determination and the rotor lock mode based on the rotor lock determination or the second system FG failure temporary determination in accordance with the determination result generated by the abnormality determining unit in the second system startup mode. Motor drive control device.

11. 11. The motor drive control device according to claim 5, the abnormality determination unit generates a determination result in the two-system rotation waiting mode based on the number of rotations of the motor based on the FG signal and the number of level changes of the FG signal of each system in a predetermined period, whereby it determines that the second system has a FG failure if the number of rotations reaches a minimum number of rotations and the number of level changes of only the first system has reached a predetermined number, it determines that the first system has a FG failure if the number of rotations reaches the minimum number of rotations and the number of level changes of only the second system has reached a predetermined number, it determines that the two systems are normal if the number of rotations reaches the minimum number of rotations and the number of level changes of both systems has reached a predetermined number, and it determines that a rotor is locked if the number of rotations does not reach the minimum number of rotations; The drive command signal generating unit generates the drive command signal corresponding to one of the operation modes of the first system drive mode or the rotor lock mode based on the second system FG failure provisional determination, the second system drive mode or the rotor lock mode based on the first system FG failure provisional determination, the two system drive mode based on the two system normal determination, and the rotor lock mode based on the rotor lock determination, in accordance with the determination result generated by the abnormality determining unit, in the dual system rotation wait mode. Motor drive control device.

12. 11. The motor drive control device according to claim 5, the abnormality determination unit generates a determination result in the first system rotation waiting mode based on the rotation speed of the motor based on the FG signal and the number of level changes of the FG signal of each system in a predetermined period, determining that the second system has an FG failure when the rotation speed reaches a minimum rotation speed and the number of level changes of only the first system has reached a predetermined number, determining that the first system has a FG failure tentatively when the rotation speed reaches the minimum rotation speed and the number of level changes of only the second system has reached a predetermined number, determining that the two systems are normal when the rotation speed reaches the minimum rotation speed and the number of level changes of both systems has reached a predetermined number, and determining that the rotor is locked when the rotation speed does not reach the minimum rotation speed; The drive command signal generating unit generates the drive command signal corresponding to any one of the operation modes of the first system drive mode based on the second system FG failure determination, the rotor lock mode based on the first system FG failure tentative determination, the dual system drive mode based on the dual system normal determination, and the rotor lock mode based on the rotor lock determination, in accordance with the determination result generated by the abnormality determining unit in the first system rotation waiting mode. Motor drive control device.

13. 11. The motor drive control device according to claim 5, the abnormality determination unit generates a determination result in the second system rotation waiting mode based on the rotation speed of the motor based on the FG signal and the number of level changes of the FG signal of each system in a predetermined period, whereby it determines that the second system has a tentative FG failure when the rotation speed reaches a minimum rotation speed and the number of level changes of only the first system has reached a predetermined number, it determines that the first system has an FG failure when the rotation speed reaches the minimum rotation speed and the number of level changes of only the second system has reached a predetermined number, it determines that the two systems are normal when the rotation speed reaches the minimum rotation speed and the number of level changes of both systems has reached a predetermined number, and it determines that the rotor is locked when the rotation speed does not reach the minimum rotation speed; The drive command signal generating unit generates the drive command signal corresponding to any one of the operation modes of the rotor lock mode based on the second system FG failure tentative determination, the second system drive mode based on the first system FG failure determination, the dual system drive mode based on the dual system normal determination, and the rotor lock mode based on the rotor lock determination, in accordance with the determination result generated by the abnormality determining unit, in the second system rotation waiting mode. Motor drive control device.

14. The motor drive control device according to any one of claims 1 to 13; the motor; an impeller that rotates by the rotational force of the motor; Fan unit.

15. two motor drive circuits provided corresponding to two systems of coils that drive one motor, and that control energization of the coils of the corresponding systems based on a drive command signal; a drive control circuit that outputs the drive command signal to the two motor drive circuits, The step of the drive control circuit controlling the motor at startup includes: a primary determination step of determining whether or not there is an abnormality in each system based on a result of detecting the number of level changes of the FG signal of each system input when the drive command signal is output to at least one of the two motor drive circuits; a secondary determination step of determining whether or not there is an abnormality in each system based on a detection result of the number of level changes of the FG signal of each system input when the drive command signal is output to at least one of the two motor drive circuits, and a detection result of the number of rotations calculated from the time for each level of the FG signal, in accordance with the determination result of the primary determination step; The drive control circuit includes: At startup, before the primary determination step is performed, if an idling state of the motor is detected from the detection result of the number of level changes of the FG signals of each system input from both of the two motor drive circuits and the detection result of the number of rotations of the motor calculated from the time for each level of the FG signal, and if the number of rotations of the motor is equal to or greater than a predetermined minimum number of rotations, the primary determination step is not performed, and the drive command signal is output to both of the two motor drive circuits to start two-system drive. Motor start control method.

16. Two motor drive circuits provided corresponding to two systems of coils that drive one motor based on a drive command signal, and controlling the energization of the coils of the corresponding systems; a drive control circuit that outputs the drive command signal to at least one of the two motor drive circuits, The drive control circuit includes: an abnormality determination unit that sequentially performs a primary determination step, a secondary determination step, and a tertiary determination step; a drive command signal generating unit that generates the drive command signal for at least one of the two motor drive circuits in accordance with the determination results of the primary determination step and the secondary determination step; A motor start-up control method using a motor drive control device having The step of the drive control circuit controlling the motor at startup includes: the primary determination step of determining whether or not there is an abnormality in each system based on a result of detecting the number of level changes of the FG signal of each system input when the drive command signal is output to at least one of the two motor drive circuits; a secondary determination step in which, depending on the determination result of the primary determination step, the presence or absence of an abnormality in each system is determined based on a detection result of the number of level changes of the FG signal of each system input when the drive command signal is output to at least one of the two motor drive circuits and a detection result of the number of rotations of the motor calculated from the time for each level of the FG signal; the tertiary determination step of detecting the number of level changes of the FG signals of each system input when the drive command signals are output to both of the two motor drive circuits while the motor is being driven, and determining whether or not there is an FG failure based on a difference in the number of level changes; The drive command signal generation unit outputting the drive command signal corresponding to one of a two-system drive for driving both of the two motor drive circuits, a first-system drive for driving the motor drive circuit of a first system of the two motor drive circuits, and a second-system drive for driving the motor drive circuit of a second system of the two motor drive circuits; the primary determination step at the time of startup corresponds to a dual-system startup mode in which the engine operates using the dual-system drive, a first-system startup mode in which the engine operates using the first-system drive, and a second-system startup mode in which the engine operates using the second-system drive; In the secondary determination step following the primary determination step, depending on the determination result of the primary determination step, the system is operated in one of a dual-system rotation wait mode in which the system operates in the dual-system drive mode, a first-system rotation wait mode in which the system operates in the first-system drive mode, and a second-system rotation wait mode in which the system operates in the second-system drive mode; During driving after the second determination step, the vehicle operates in one of a dual-system drive mode in which the vehicle operates in the dual-system drive mode, a first-system drive mode in which the vehicle operates in the first-system drive mode, and a second-system drive mode in which the vehicle operates in the second-system drive mode, depending on the determination result of the second determination step; After the primary determination step or the secondary determination step, the drive command signal corresponding to the rotor lock mode is generated. Motor drive control method.

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