Control device, power conversion device, control method, and program

Abstract

To make an output voltage of a capacitor charged by a charger close to a desired voltage.SOLUTION: A control device is a device for controlling a startup voltage regulation circuit including a capacitor, a coil, a resistor, a first switch, a second switch and a third switch. The control device comprises an acquisition unit and a control unit. The acquisition unit acquires a detection result of switching of an ON state and an OFF state of the second switch. Based on the detection result, the control unit controls the third switch into an ON state until the lapse of a predetermined first time from bringing the third switch into the ON state. Otherwise, the control unit controls the third switch into the ON state until the lapse of a second time, which is longer than the first time, from bringing the third switch into the ON state.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] An embodiment of the present invention relates to a control device, a power conversion device, a control method, and a program. [Background technology]

[0002] 2. Description of the Related Art In a circuit in which a capacitor for smoothing a voltage is connected to the output of a DC power supply, the capacitor may be charged using a charging device at start-up. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-205257 A [Patent Document 2] Japanese Patent Application Publication No. 05-146066 [Patent Document 3] Patent Publication No. 2021-044971 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a control device, a power conversion device, a control method, and a program that can bring the output voltage of a capacitor charged by a charging device closer to a desired voltage. [Means for solving the problem]

[0005] The control device according to the embodiment includes: a first switch that is connected in series to a path for charging the capacitor from a DC power source and that switches between an on state and an off state depending on whether the coil is excited or not, a second switch that is connected in series to the coil and in parallel to the resistor and that switches between an on state and an off state depending on whether the coil is excited or not, and a third switch that is connected in series to the resistor and the second switch and that switches between an on state and an off state depending on whether the coil is excited or not in response to a control signal, wherein the capacitor and the first switch that are connected in series control a starting voltage adjustment circuit that is connected in parallel to the coil, the resistor, and the third switch, whereby a control device that charges the capacitor through a path through which a current flows from the DC power source to the first switch even if a resistor is broken, the control device comprising: an acquisition unit that acquires a detection result of switching between an on state and an off state of the second switch; a determination unit that determines whether the resistor is broken; and a control unit that controls the third switch to an on state for a period until a predetermined first time has elapsed since the third switch was turned on when the determination unit determines that the resistor is not broken based on the detection result, and controls the third switch to an on state for a period until a second time longer than the first time has elapsed since the third switch was turned on when the determination unit determines that the resistor is broken based on the detection result. . [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram showing an example of a configuration of a power conversion device according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing an example of the configuration of a control device according to the embodiment. [Diagram 3]FIG. 4 is a diagram showing an example of a processing flow of the control device according to the embodiment. [Figure 4] FIG. 1 is a schematic block diagram illustrating the configuration of a computer according to at least one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, a control device, a power conversion device, a control method, and a program according to the embodiments will be described with reference to the drawings. Note that the drawings are schematic or conceptual, and the allocation of functions of each part is not necessarily the same as in reality.

[0008] In the following description, components having the same or similar functions are denoted by the same reference numerals, and redundant descriptions of those components may be omitted. In the embodiment, "connected" includes being electrically connected. "Based on XX" means "based on at least XX" and may include the case of being based on another element in addition to XX. "Based on XX" is not limited to the case of directly using XX, but may also include the case of being based on XX that has been calculated or processed. "XX or YY" is not limited to either one of XX and YY, but may also include both XX and YY. This also applies to the case of three or more selective elements. "XX" and "YY" are any element (for example, any information). "Inverter" is a power converter that outputs AC, and includes, for example, a DC / AC converter. "Motor" is a rotating electric machine such as an induction motor driven by AC power. "Detection" is not limited to directly sensing the physical quantity of the target, but may also include the case of directly or indirectly acquiring other physical quantities related to the physical quantity of the target, and estimating or identifying the physical quantity of the target from the other acquired physical quantities. "Acquisition" is not limited to directly receiving the target itself, but may also include the case of performing calculations or processing on the directly received object to become the target.

[0009] <Embodiment> (Configuration of power conversion device) Fig. 1 is a diagram showing an example of the configuration of a power conversion device 1 according to an embodiment. As shown in Fig. 1, the power conversion device 1 includes a DC power supply 10, a switch 20, a capacitor 30, a voltage detection device 40, a power converter 50, a motor 60, a charging device 70, and a control device 80.

[0010] A first terminal of the DC power supply 10 is connected to a first terminal of the switch 20 and a first terminal of the charging device 70. A second terminal of the DC power supply 10 is connected to a second terminal of the switch 20 and a second terminal of the charging device 70. A third terminal of the switch 20 is connected to a first terminal of the capacitor 30, a first terminal of the voltage detection device 40, a first terminal of the power converter 50, and a third terminal of the charging device 70. A fourth terminal of the switch 20 is connected to a second terminal of the capacitor 30, a second terminal of the voltage detection device 40, a second terminal of the power converter 50, and a fourth terminal of the charging device 70. A fifth terminal of the switch 20 is connected to a first terminal of the control device 80. A third terminal of the voltage detection device 40 is connected to a second terminal of the control device 80. A third terminal of the power converter 50 is connected to a third terminal of the control device 80. A fourth terminal of the power converter 50 is connected to a first terminal of the motor 60. A fifth terminal of the power converter 50 is connected to a second terminal of the motor 60. A sixth terminal of the power converter 50 is connected to a third terminal of the motor 60. A fifth terminal of the charging device 70 is connected to a fourth terminal of the control device 80. A sixth terminal of the charging device 70 is connected to a fifth terminal of the control device 80. The capacitor 30 and the charging device 70 are an example of a starting voltage adjustment circuit.

[0011] When the power conversion device 1 is started up, the DC power supply 10 applies a DC voltage to the capacitor 30 via the charging device 70. The capacitor 30 is charged by this DC voltage. Furthermore, the DC power supply 10 applies a DC voltage to the power converter 50 via the switch 20 when the power conversion device 1 is in a steady state. This DC voltage is a voltage smoothed by the capacitor 30.

[0012] The switch 20 includes a switch 20a and a switch 20b. The switch 20a and the switch 20b are both turned off or both turned on in response to the control of their respective third terminals by the control device 80. For example, the switch 20a and the switch 20b are turned off in response to the control by the control device 80 at the start of the power conversion device 1. Furthermore, the switch 20a and the switch 20b are turned on in response to the control by the control device 80 when the power conversion device 1 is in a steady state. Examples of the switch 20a and the switch 20b include semiconductor switches such as MOS (Metal Oxide Semiconductor) transistors.

[0013] A first terminal of the switch 20a is connected to a first terminal of the switch 20. A second terminal of the switch 20a is connected to a third terminal of the switch 20. A first terminal of the switch 20b is connected to a second terminal of the switch 20. A second terminal of the switch 20b is connected to a fourth terminal of the switch 20. A third terminal of the switch 20a and a third terminal of the switch 20b are connected to a fifth terminal of the switch 20.

[0014] The capacitor 30 is a capacitor that smoothes the output voltage of the DC power supply 10. The voltage detection device 40 is a device that detects the voltage smoothed by the capacitor 30. The power converter 50 converts the voltage smoothed by the capacitor 30 into a voltage that drives the motor 60. The power converter 50 is, for example, an inverter that generates AC power from DC power. The motor 60 is a motor that operates according to the output voltage of the power converter 50. The motor 60 is, for example, a three-phase AC motor.

[0015] The charging device 70 is a circuit that charges, i.e., pre-charges, the capacitor 30 at the time of start-up of the power conversion device 1. The charging device 70 includes a relay 701, a resistor 702 (an example of a resistor), a switch 703 (an example of a third switch), and a resistor 704.

[0016] The relay 701 includes a coil 701a, a switch 701b, a switch 701c (an example of a first switch), and a switch 701d (an example of a second switch). The coil 701a is excited when a current flows and generates a magnetic field. The coil 701a is not excited when no current flows and does not generate a magnetic field.

[0017] Each of the switches 701b, 701c, and 701d is a switch that switches between an off state and an on state depending on whether or not a current flows through the coil 701a. When no current flows through the coil 701a, the switches 701b and 701c are in the off state. When a current flows through the coil 701a, the switches 701b and 701c are in the on state due to a magnetic field generated by excitation.

[0018] The switch 701d is in an ON state when no current flows through the coil 701a. When a current flows through the coil 701a, the switch 701d is in an OFF state due to a magnetic field generated by excitation. The resistor 702 is a resistor for suppressing the current flowing through the coil 701a. The resistor 702 is determined so that a current that allows the coil 701a to continue to be excited flows even when the current flowing through the coil 701a is suppressed. In other words, the coil 701a can continue to be excited even when the current is limited by the resistor 702.

[0019] The switch 703 is a switch that is switched between an off state and an on state under the control of the control device 80. Specifically, when the switch 703 is on, the charging device 70 is in an operable state and charges the capacitor 30 from the DC power source 10 via the switches 701b, 701c, and the resistor 704. When the switch 703 is off, the charging device 70 is in an inoperable state and does not charge the capacitor 30. An example of the switch 703 is a semiconductor switch such as a MOS transistor. The resistor 704 is a resistor that performs a soft start to suppress the magnitude of the inrush current when the charging device 70 charges the capacitor 30.

[0020] A first terminal of the coil 701a is connected to a first terminal of the switch 701d and a first terminal of the resistor 702. A second terminal of the coil 701a is connected to a second terminal of the charging device 70 and a first terminal of the switch 701b. A second terminal of the switch 701b is connected to a fourth terminal of the charging device 70. A first terminal of the switch 701c is connected to a first terminal of the resistor 704. A second terminal of the switch 701c is connected to a first terminal of the charging device 70 and a first terminal of the switch 703. A second terminal of the switch 701d is connected to a second terminal of the resistor 702 and a second terminal of the switch 703. A third terminal of the switch 703 is connected to a fourth terminal of the charging device 70. A second terminal of the resistor 704 is connected to a third terminal of the charging device 70.

[0021] The sixth terminal of the charging device 70 is a terminal for outputting information for the control device 80 to detect the off state and on state of the switch 701d to the control device 80. For example, the sixth terminal of the charging device 70 may detect the current flowing through the switch 701d by a current transformer CT (not shown), and if the detected current is continuous, it may be determined that the switch 701d is in the on state, and if the detected current is discontinuous, it may be determined that the switch 701d is in the off state. In addition, for example, an auxiliary contact (not shown) (i.e., a switch similar to the switch 701d) linked to the switch 701d may be provided, and the current flowing through the auxiliary contact may be converted into a voltage by, for example, a resistor. Then, if the voltage is zero volts, it may be determined that the switch 701d is in the off state, and if the voltage is other than zero volts, it may be determined that the switch 701d is in the on state. However, as long as the control device 80 can correctly detect the off state and on state of the switch 701d, any kind of information may be output from the terminal, and the terminal for outputting the information may be connected to the sixth terminal of the charging device 70.

[0022] FIG. 2 is a diagram showing an example of the configuration of the control device 80 of the embodiment. As shown in FIG. 2, the control device 80 includes an acquisition unit 801, a determination unit 802, a control unit 803, a processing unit 804, a notification unit 805, and a storage unit 806. The control device 80 is a device that controls a starting voltage adjustment circuit including a capacitor, a coil, a resistor connected in series to the coil, a first switch that is in series with a path that charges the capacitor from a DC power source and switches between an on state and an off state depending on whether the coil is excited, a second switch that is connected in series with the coil and in parallel with the resistor and switches between an on state and an off state depending on whether the coil is excited, and a third switch that is connected in series with the resistor and the second switch and switches between an on state and an off state depending on a control signal. Specifically, the control device 80 is a device that controls at least the charging device 70.

[0023] The acquiring unit 801 acquires a detection result of switching between an on state and an off state of the switch 701d (an example of a second switch). For example, the acquiring unit 801 detects a current flowing through the switch 701d by a current transformer CT (not shown), and acquires information indicating the detected current (hereinafter, referred to as a “detected current”) from the charging device 70.

[0024] When the detected current is zero, it means that no current flows through switch 701d, i.e., switch 701d is in the off state. When the detected current is not zero, it means that a current flows through switch 701d, i.e., switch 701d is in the on state. Therefore, acquiring the detected current by acquisition unit 801 is equivalent to acquiring a detection result of switching between the on state and the off state of switch 701d by acquisition unit 801.

[0025] Moreover, the acquiring unit 801 acquires the detection result of the voltage smoothed by the capacitor 30 from the voltage detecting device 40 .

[0026] The determination unit 802 determines whether the resistor 702 is disconnected based on the detection result (e.g., detected current) acquired by the acquisition unit 801. For example, the control device 80 controls the switch 703 to the on state, and the determination unit 802 repeatedly determines whether the detected current acquired by the acquisition unit 801 is zero within the error range until a first time has elapsed. "Zero within the error range" refers to a current within a range that can be considered as not flowing, taking into account noise, measurement error, detection error, and the like.

[0027] When the switch 703 is on and the resistor 702 is not disconnected, a current flows from the DC power source 10 to the coil 701a through the switch 703 and the switch 701d. In this case, the coil 701a is excited and a magnetic field is generated. Then, the switch 701d is switched from an on state to an off state by the generated magnetic field. When the switch 701d is turned off, a current flows from the DC power source 10 to the coil 701a through the switch 703 and the resistor 702. In this case, a current flows to the coil 701a through the resistor 702 until the switch 703 is in an off state. In other words, when the switch 703 is on and the resistor 702 is not disconnected, a current continues to flow to the coil 701a and a magnetic field continues to be generated until the switch 703 is turned off, so that the switch 701d remains in an off state. As a result, no current flows through the switch 701d, and the detection current acquired by the acquisition unit 801 becomes zero.

[0028] On the other hand, even if the switch 703 is on and the resistor 702 is disconnected, a current flows from the DC power supply 10 to the coil 701a via the switch 703 and the switch 701d. In this case, the coil 701a is excited and a magnetic field is generated. Then, the switch 701d is switched from the on state to the off state by the generated magnetic field. When the switch 701d is turned off, since the resistor 702 is disconnected, there is no path for current to flow to the coil 701a, the coil 701a is not excited, and a magnetic field is not generated. In this case, the switch 701d is turned on. As a result, a current flows again from the DC power supply 10 to the coil 701a via the switch 703 and the switch 701d. In other words, when the switch 703 is on and the resistor 702 is disconnected, a period in which a current flows through the coil 701a and a period in which a current does not flow through the coil 701a are alternately repeated until the switch 703 is turned off. That is, switch 701d alternates between periods in an on state and periods in an off state, and the detection current acquired by acquisition unit 801 is both zero and another value until the first time has elapsed. The first time is a predetermined time sufficient for charging device 70 to charge capacitor 30 if resistor 702 is not disconnected, and is the time during which determination unit 802 can execute a process of determining that resistor 702 is disconnected.

[0029] That is, the determination unit 802 determines that the resistor 702 is not open-circuited until the detection current acquired by the acquisition unit 801 is determined to be non-zero within the error range until the first time has elapsed. Furthermore, when the determination unit 802 determines that the detection current acquired by the acquisition unit 801 is non-zero within the error range until the first time has elapsed, it determines that the resistor 702 is open-circuited.

[0030] The control unit 803 controls the power converter 50 so as to generate a voltage for driving the motor 60 during normal operation. For example, the control unit 803 drives the motor 60 by controlling the power converter 50 by PWM control (Pulse Width Modulation control). The control unit 803 can perform control to stop the operation of the entire power conversion device 1. Furthermore, the control unit 803 controls the charging device 70 to suppress inrush current.

[0031] For example, based on the detection result (e.g., the detected current) acquired by the acquisition unit 801, the control unit 803 controls the switch 703 to be in the on state for a predetermined first time period after the switch 703 is turned on, or controls the switch 703 to be in the on state for a second time period longer than the first time period after the switch 703 is turned on.

[0032] More specifically, when the determination unit 802 determines that the resistor 702 is not disconnected, the control unit 803 controls the switch 703 to be in the on state until a predetermined first time has elapsed since the switch 703 was turned on. Also, when the determination unit 802 determines that the resistor 702 is disconnected, the control unit 803 controls the switch 703 to be in the on state until a second time longer than the first time has elapsed since the switch 703 was turned on.

[0033] Furthermore, when the determination unit 802 determines that the resistor 702 is not disconnected and a predetermined first time has elapsed since the switch 703 was turned on, the control unit 803 controls the switches 20a and 20b to the on state and controls the switch 703 to the off state. When the determination unit 802 determines that the resistor 702 is disconnected and a predetermined second time has elapsed since the switch 703 was turned on, the control unit 803 controls the switches 20a and 20b to the on state and controls the switch 703 to the off state.

[0034] When the resistor 702 is disconnected, as described above, the period during which the current flows through the coil 701a and the period during which the current does not flow are repeated alternately until the switch 703 is turned off. In this case, like the switch 701d, the switches 701b and 701c also alternate between the period during which the current is on and the period during which the current is off. In addition, during the period during which the switch 701d is turned on, the switches 701b and 701c are turned off. In addition, during the period during which the switch 701d is turned off, the switches 701b and 701c are turned on. When the resistor 702 is not disconnected, the switches 701b and 701c are always turned on, so that the charging device 70 can continuously charge the capacitor 30. However, when the resistor 702 is disconnected, the charging device 70 can charge the capacitor 30 during the period during which the switches 701b and 701c are turned on. In other words, the charging time of the capacitor 30 by the charging device 70 when the resistor 702 is disconnected is longer than when the resistor 702 is not disconnected, but charging is possible if time is taken. The second time is the time during which the charging device 70 can charge the capacitor 30 even when the resistor 702 is disconnected.

[0035] As shown in FIG. 2, the processing unit 804 includes a first processing unit 804a and a second processing unit 804b. The first processing unit 804a can perform a first process when the voltage across the capacitor 30 is less than a specified value when the determining unit 802 determines that the resistor 702 is not disconnected and a first time has elapsed since the switch 703 was turned on. For example, the first processing unit 804a compares a voltage value obtained by the obtaining unit 801 from the voltage detection device 40 when the first time has elapsed with a specified value stored in the storage unit 806. Then, the first processing unit 804a performs a first process when the obtained voltage value is less than the specified value. The specified value is a voltage value with a margin for the minimum voltage that needs to be supplied to the power converter 50. Examples of the first process include a process of making the notifying unit 805 notify that the voltage output from the capacitor 30 is not equal to or greater than the desired specified value, and a process of making the control unit 803 stop the operation of the power conversion device 1.

[0036] In addition, when the judgment unit 802 judges that the resistor 702 is broken, the first processing unit 804a is capable of not performing the first processing until a second time has elapsed since the switch 703 was turned on, and of performing the first processing after the second time has elapsed.

[0037] The second processing unit 804b can perform the first processing if the determination unit 802 determines that the resistor 702 is not disconnected and the voltage across the capacitor 30 is less than a specified value when a first time has elapsed since the switch 703 was turned on. For example, the second processing unit 804b compares the voltage value acquired from the voltage detection device 40 by the acquisition unit 801 when the first time has elapsed with a specified value stored in the storage unit 806. Then, the second processing unit 804b performs the first processing if the acquired voltage value is less than the specified value.

[0038] Furthermore, when the determination unit 802 determines that the resistor 702 is disconnected, the second processing unit 804b can reduce the specified value based on the reduction amount stored in the storage unit 806, and perform the first processing if the reduced specified value is less than the reduced specified value when a first time has elapsed since the switch 703 was turned on. Note that it is assumed that the margin in the specified value before the value is reduced is large, and that a margin exists even in the specified value after the value is reduced.

[0039] When the determination unit 802 determines that the resistor 702 is disconnected, the notification unit 805 outputs a fault signal indicating the occurrence of a malfunction to, for example, a higher-level device (not shown) of the power conversion device 1. The storage unit 806 is a storage unit that stores various information required for the processing performed by the control device 80. For example, the storage unit 806 stores the specified value of the voltage between both ends of the capacitor 30, the reduction amount of the specified value, the specified value after reduction, and the like.

[0040] (Processing performed by the control device) Next, a process performed by the control device 80 of the embodiment will be described. Fig. 3 is a diagram showing an example of a process flow of the control device 80 of the embodiment. Here, the process performed by the control device 80 will be described with reference to the process flow shown in Fig. 3.

[0041] The acquiring unit 801 acquires a detection result of switching between an on state and an off state of the switch 701d (an example of a second switch) (step S1). For example, the acquiring unit 801 detects a current flowing through the switch 701d by a current transformer CT (not shown), and acquires the detected current from the charging device 70. The acquiring unit 801 also acquires a detection result of a voltage smoothed by the capacitor 30 from the voltage detection device 40.

[0042] The determination unit 802 determines whether the resistor 702 is disconnected based on the detection result (e.g., the detected current) acquired by the acquisition unit 801 (step S2). For example, the determination unit 802 determines that the resistor 702 is not disconnected until it is determined that the detected current acquired by the acquisition unit 801 is non-zero within the error range until the first time has elapsed. Furthermore, if the determination unit 802 determines that the detected current acquired by the acquisition unit 801 is non-zero within the error range even once until the first time has elapsed, it determines that the resistor 702 is disconnected.

[0043] Based on the detection result (e.g., the detected current) acquired by the acquisition unit 801, the control unit 803 controls the switch 703 to be in the on state for a predetermined first time period after the switch 703 is turned on, or controls the switch 703 to be in the on state for a second time period longer than the first time period after the switch 703 is turned on.

[0044] For example, when the determination unit 802 determines that the resistor 702 is not disconnected (NO in step S2), the control unit 803 controls the switch 703 to be in the on state until a predetermined first time has elapsed since the switch 703 was turned on (step S3). In this case, the capacitor 30 is charged from the DC power source 10 via the switch 701b, the switch 701c, and the resistor 704. Regardless of whether the resistor 702 is disconnected or not, when the capacitor 30 is being charged, the resistor 704 suppresses an increase in inrush current. When the determination unit 802 determines that the resistor 702 is not disconnected and a predetermined first time has elapsed since the switch 703 was turned on, the control unit 803 controls the switches 20a and 20b to be in the on state and controls the switch 703 to be in the off state.

[0045] Furthermore, when the determination unit 802 determines that the resistor 702 is disconnected (YES in step S2), the control unit 803 controls the switch 703 to be in an on state until a second time longer than the first time has elapsed since the switch 703 was turned on (step S4). In this case, the capacitor 30 is charged from the DC power source 10 via the switch 701b, the switch 701c, and the resistor 704. At this time, since the average current is further reduced compared to when the resistor 702 is not disconnected, an increase in the inrush current is suppressed by the resistor 704. Then, when the determination unit 802 determines that the resistor 702 is disconnected and a predetermined second time has elapsed since the switch 703 was turned on, the control unit 803 controls the switches 20a and 20b to be in an on state and controls the switch 703 to be in an off state. Note that the startup processing is performed before switches 20a and 20b are controlled to the on state and switch 703 is controlled to the off state, and the steady state processing is performed after switches 20a and 20b are controlled to the on state and switch 703 is controlled to the off state.

[0046] The control unit 803 controls the switches 20a and 20b to the on state and the switch 703 to the off state, and then controls the power converter 50 to generate a voltage for driving the motor 60. For example, the control unit 803 drives the motor 60 by controlling the power converter 50 by PWM control.

[0047] In addition, the first processing unit 804a may perform the first processing when the judgment unit 802 judges that the resistor 702 is not broken and the voltage across the capacitor 30 is less than a specified value when a first time has elapsed since the switch 703 was turned on.

[0048] In addition, when the judgment unit 802 judges that the resistor 702 is broken, the first processing unit 804a may not perform the first processing until a second time has elapsed since the switch 703 was turned on, and may perform the first processing after the second time has elapsed.

[0049] The second processing unit 804b may perform a first processing when the judgment unit 802 judges that the resistor 702 is not broken and the voltage across the capacitor 30 is less than a specified value when a first time has elapsed since the switch 703 was turned on.

[0050] Furthermore, the second processing unit 804b may perform a first process when the determining unit 802 determines that the resistor 702 is disconnected, by lowering the specified value based on the reduction amount stored in the storage unit 806, and when a first time has elapsed since the switch 703 was turned on, the specified value after the reduction is less than the specified value. Examples of the first process include a process of causing the notifying unit 805 to notify that the voltage output from the capacitor 30 is not equal to or greater than the desired specified value, and a process of causing the control unit 803 to stop the operation of the power conversion device 1.

[0051] (advantage) The power conversion device 1 of the embodiment has been described above. In the power conversion device 1, the control device 80 is a device that controls a starting voltage adjustment circuit including a capacitor, a coil, a resistor connected in series to the coil, a first switch that is in series with a path that charges the capacitor from a DC power source and switches between an on state and an off state depending on whether the coil is excited or not, a second switch that is connected in series with the coil and in parallel with the resistor and switches between an on state and an off state depending on whether the coil is excited or not, and a third switch that is connected in series with the resistor and the second switch and switches between an on state and an off state depending on a control signal. Specifically, the control device 80 is a device that controls at least the charging device 70. The acquisition unit 801 acquires a detection result of switching between an on state and an off state of a switch 701d (an example of a second switch). Based on the detection result (e.g., detected current) acquired by the acquisition unit 801, the control unit 803 controls the switch 703 to be in the on state until a predetermined first time has elapsed since the switch 703 was switched on, or controls the switch 703 to be in the on state until a second time longer than the first time has elapsed since the switch 703 was switched on. When the resistor 702 is disconnected, it takes longer to charge the capacitor 30 than when the resistor 702 is not disconnected. Therefore, when the resistor 702 is not disconnected, the output voltage of the capacitor 30 may not reach the desired voltage under the control of the control device 80. On the other hand, the control device 80 can make the output voltage of the capacitor charged by the charging device approach the desired voltage.

[0052] In another embodiment, the control device that controls the charging device 70 and the control device that controls the power converter 50 may be independent of each other.

[0053] In another embodiment, the switch 20 may be a relay. In this case, the switch 20 has a coil like the relay 701, and the switch 20a and the switch 20b are turned on or off depending on whether or not a current flows through the coil.

[0054] In another embodiment, the switch 703 may be a relay. In this case, the switch 703 has a coil like the relay 701, and the switch 703 is turned on or off depending on whether or not a current flows through the coil.

[0055] In another embodiment, the resistor 702 may be included in the relay 701 .

[0056] In the above embodiment, the coil 701a, the switch 701b, the switch 701c, and the switch 701d are described as being included in one relay 701. However, in another embodiment, the coil 701a, the switch 701b, the switch 701c, and the switch 701d do not have to be included in one relay, so long as the switches 701b, 701c, and 701d are each in a desired on or off state depending on whether or not a current flows through the coil 701a.

[0057] It should be noted that the order of the processes in the embodiment may be changed as long as appropriate processes are performed.

[0058] Although the embodiment has been described, the above-mentioned control device 80, the power conversion device 1, and other control devices may have a computer system inside. The above-mentioned process steps are stored in a computer-readable recording medium in the form of a program, and the above-mentioned process is performed by the computer reading and executing the program. Specific examples of computers are shown below. FIG. 4 is a schematic block diagram illustrating a configuration of a computer according to at least one embodiment. As shown in FIG. 4, the computer 5 includes a CPU 6 (including a vector processor), a main memory 7, a storage 8, and an interface 9. For example, the above-mentioned control device 80, the power conversion device 1, and the other control devices are each implemented in a computer 5. The operations of the above-mentioned processing units are stored in the storage 8 in the form of a program. The CPU 6 reads the program from the storage 8, loads it in the main memory 7, and executes the above-mentioned processing in accordance with the program. The CPU 6 also secures storage areas in the main memory 7 corresponding to the above-mentioned storage units in accordance with the program.

[0059] Examples of the storage 8 include a hard disk drive (HDD), a solid state drive (SSD), a magnetic disk, a magneto-optical disk, a compact disc read only memory (CD-ROM), a digital versatile disc read only memory (DVD-ROM), and a semiconductor memory. The storage 8 may be an internal medium directly connected to the bus of the computer 5, or an external medium connected to the computer 5 via an interface 9 or a communication line. In addition, when the program is distributed to the computer 5 via a communication line, the computer 5 that receives the program may load the program into the main memory 7 and execute the above-mentioned process. In at least one embodiment, the storage 8 is a non-transitory tangible storage medium.

[0060] The program may also realize some of the functions described above. Furthermore, the program may be a file that can realize the functions described above in combination with a program already recorded in the computer system, that is, a so-called differential file (differential program).

[0061] The computer 5 may be a software function unit realized by one or more hardware processors such as a CPU (Central Processing Unit) executing a computer program, or may be realized by hardware (e.g., a circuit unit; circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a PLD (Programmable Logic Device). All or a part of the control unit 803 may be realized by a combination of a software function unit and hardware. [Explanation of symbols]

[0062] 1...power conversion device, 5...computer, 6...CPU, 7...main memory, 8...storage, 9...interface, 10...DC power supply, 20, 20a, 20b, 701b, 701c, 701d...switch, 30...capacitor, 40...voltage detection device, 50...power converter, 60...motor, 70...charging device, 80...control device, 701a...coil, 702, 704...resistor.

Claims

1. a first switch that is connected in series to the coil and in parallel with the resistor and that switches between an on state and an off state depending on whether the coil is excited or not; a second switch that is connected in series to the coil and in parallel with the resistor and that switches between an on state and an off state depending on whether the coil is excited or not; and a third switch that is connected in series to the resistor and the second switch and that switches between an on state and an off state depending on a control signal; an acquisition unit that acquires a detection result of switching between an on state and an off state of the second switch; A determination unit for determining whether the resistor is broken; a control unit that controls the third switch to an on state for a period until a predetermined first time has elapsed since the third switch was turned on when the determination unit determined that the resistor is not broken based on the detection result, and controls the third switch to an on state for a period until a second time longer than the first time has elapsed since the third switch was turned on when the determination unit determined that the resistor is broken based on the detection result; A control device comprising:

2. a processing unit that performs a first process when the determination unit determines that the resistor is not broken and when the first time has elapsed since the third switch was turned on, the voltage between both ends of the capacitor is less than a specified value, and when the determination unit determines that the resistor is broken, the first processing unit does not perform the first process until the second time has elapsed since the third switch was turned on, and performs the first processing after the second time has elapsed; The control device according to claim 1 .

3. a processing unit that performs a first processing when the determination unit determines that the resistor is not broken and when the first time has elapsed since the third switch was turned on, the processing unit performs the first processing when the determination unit determines that the resistor is broken, lowering the specified value, and when the first time has elapsed since the third switch was turned on, the processing unit performs the first processing when the voltage between both ends of the capacitor is less than a specified value after the determination unit determines that the resistor is broken, The control device according to claim 1 or 2, comprising:

4. a notification unit that outputs a fault signal indicating that a malfunction has occurred when the determination unit determines that the resistor is disconnected; The control device according to any one of claims 1 to 3, comprising:

5. a power converter to which the power smoothed by the capacitor is supplied; The control device according to any one of claims 1 to 4, which controls the power converter; A power conversion device comprising:

6. a first switch that is connected in series to the coil and in parallel to the resistor and that switches between an on state and an off state depending on whether the coil is excited or not; a second switch that is connected in series to the coil and in parallel to the resistor and that switches between an on state and an off state depending on whether the coil is excited or not; and a third switch that is connected in series to the resistor and the second switch and that switches between an on state and an off state depending on a control signal; Obtaining a detection result of switching between an on state and an off state of the second switch; when it is determined based on the detection result that the resistor is not open-circuited, controlling the third switch to an on state for a period until a predetermined first time has elapsed since the third switch was turned on, and when it is determined based on the detection result that the resistor is open-circuited, controlling the third switch to an on state for a period until a second time longer than the first time has elapsed since the third switch was turned on. A control method performed by a control device including the above.

7. a first switch that is connected in series to the coil and in parallel to the resistor and that switches between an on state and an off state depending on whether the coil is excited or not; a second switch that is connected in series to the coil and in parallel to the resistor and that switches between an on state and an off state depending on whether the coil is excited or not; and a third switch that is connected in series to the resistor and the second switch and that switches between an on state and an off state depending on a control signal, wherein the capacitor and the first switch that are connected in series control a starting voltage adjustment circuit that is connected in parallel to the coil, the resistor, and the third switch, thereby charging the capacitor along a path through which a current flows from the DC power supply to the first switch even when the resistor is disconnected; Obtaining a detection result of switching between an on state and an off state of the second switch; when it is determined based on the detection result that the resistor is not open-circuited, controlling the third switch to an on state for a period until a predetermined first time has elapsed since the third switch was turned on, and when it is determined based on the detection result that the resistor is open-circuited, controlling the third switch to an on state for a period until a second time longer than the first time has elapsed since the third switch was turned on. A program that executes the following.

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