ENGINE DRIVE UNIT

Abstract

Motor drive device (1) comprising: a drive unit (2) configured to drive a starter / generator (4) which is directly connected to a motor via a rotating shaft by performing on / off control of each of the switching elements (UH, UL, VH, VL, WH, WL) in a bridge circuit (23) to drive a motor; and a drive control (3) designed to control a drive operation performed by the drive unit (2) for the starter / generator (4), wherein the drive unit (2) is configured to control a motor drive voltage for the starter / generator (4) by changing the ON time period of the switching elements (UH, UL, VH, VL, WH, WL) of the bridge circuit (23) and to perform an active freewheeling operation to raise a backfeed voltage generated by the starter / generator (4) by alternately switching on the predetermined switching element and a complementary switching element within a period in which a gate drive signal for a predetermined switching element is at a low level, thereby forming a current path caused by a backfeed voltage and wherein the drive control (3) is configured to instruct the drive unit (2) to control the motor drive voltage and the switching on and off of the active freewheel on the basis of a battery voltage.

Description

Technical field

[0001] The present invention relates to a motor drive device for driving a starter of a motor. background

[0002] In general, a motor is used to drive a load and serves as a generator to produce regenerative energy.

[0003] For example, the publication of Japanese patent application JP 2001-271729 A discloses a technique relating to a control device for a motor that serves as a starter and generator.

[0004] If the starter motor acts as a generator, an additional device is / are required to charge a battery or similar with renewable energy. A voltage booster / step-down converter or a motor speed increaser mechanism, which is assumed to be this additional device, is comparatively large, resulting in an increase in the size, weight, and cost of the motor drive system.

[0005] In light of the above, the present invention proposes a motor drive device capable of precisely controlling a motor / generator without requiring an additional device of comparatively large size.

[0006] DE 11 2014 006 489 T5 relates to a control device and a control method for the sensorless determination of the switching of a power supply mode in a three-phase, brushless motor. EP 2 706 657 B1 relates to a device for controlling a brushless motor, which is configured to perform drive control of a brushless three-phase motor and to perform rectification and phase control of AC output voltages from the brushless three-phase motor in order to charge a battery, in a case where the brushless three-phase motor is driven by an internal combustion engine and is operated as a three-phase AC power generator. Summary

[0007] In accordance with one aspect of the present invention, a motor drive device is provided comprising: a drive unit configured to drive a starter / generator directly connected to a machine via a rotating shaft by performing an on / off control of each of the switching elements in a bridge circuit for driving a motor; and a drive control configured to control a drive operation for the starter / generator performed by the drive unit.The drive unit is configured to control a motor drive voltage for the starter / generator by changing the ON-time of the bridge circuit's switching elements and to perform active freewheeling operation to boost a backfeed voltage generated by the starter / generator. This is achieved by alternately switching on the predetermined switching element and a complementary switching element within a period when a gate drive signal for a predetermined switching element is at a low level, thereby creating a current path caused by a back EMF. Furthermore, the drive control is configured to instruct the drive unit to control the motor drive voltage and the on / off switching of the active freewheeling operation based on a battery voltage.

[0008] In other words, in a configuration where the starter / generator is directly connected to the machine via the rotating shaft, the motor drive unit can be provided in such a way that the starter / generator is adapted to properly provide the motor starting function for the machine and the regenerative energy function for charging the battery. Here, the motor drive voltage is controlled and the regenerative voltage is boosted by controlling the switching elements of the bridge circuit.

[0009] Furthermore, the motor drive unit can be designed to instruct the drive unit to control the motor drive voltage and the switching on / off of the active freewheeling operation using a PWM signal.

[0010] For example, the control content can be set based on an H period (“H” indicates the high level of the pulse) or an L period (“L” indicates the low level of the pulse) of the PWM signal.

[0011] Furthermore, the drive control in the motor drive device can be designed to supply the drive unit with an initial signal and a motor start signal by using a single PWM signal.

[0012] For example, the initial signal and the motor start signal can be further supplied to the drive unit based on the H-period or the L-period of the PWM signal.

[0013] Furthermore, the drive control in the motor drive unit can be designed to instruct the drive unit to perform the on / off control of the active freewheeling operation in response to machine rotation information or operating information.

[0014] For example, if the machine's speed is reduced, it may be possible to stop the active freewheeling operation, or it may be possible to stop the active freewheeling operation in response to a user action.

[0015] In accordance with the aspect of the present invention, it is possible to provide the motor drive device for driving the starter / generator, which can be miniaturized at low cost without the need for an additional up / down switching, a mechanism for increasing the motor speed or the like. Brief description of the drawings

[0016] The objectives and features of the present invention will become apparent from the following description of embodiments, which is given in conjunction with the accompanying drawings: Fig. Figure 1 is a block diagram of a motor drive device and its peripheral parts according to one embodiment; Fig. 2 explains a PWM control signal according to one embodiment; Fig. 3 is a block diagram of an internal configuration of a drive unit according to an embodiment; The Fig. Figures 4 to 6 explain the operation of a three-phase FET bridge according to one embodiment; Fig. 7 explains a gate voltage waveform according to one embodiment; Fig. Figure 8 explains a gate voltage waveform in the case of switching on an active freewheeling circuit according to one embodiment; The Fig. 9A and Fig. 9B explain an electromotive force of a motor coil; Fig. 10 explains a relationship between the rotational speed of a motor and a voltage; The Fig. 11A and Fig. 11B are flowcharts of the implementation of a drive control and a drive unit according to one embodiment; Fig. 12 explains the device setting according to one embodiment; Fig. 13 explains the case where a load is increased according to an embodiment; Fig. 14 explains the case in which an engine speed is reduced according to an embodiment; Fig. 15 explains the case where a throttle valve is opened according to an embodiment; and Fig. 16 describes a hybrid operating range and a charging range according to one embodiment. Detailed description<Ausgestaltung eines Antriebssystems, das eine Motorantriebseinrichtung enthält>

[0017] The following describes a design and process of one embodiment with reference to the drawings.

[0018] It is assumed that a drive system with a motor drive unit 1 according to an embodiment is mounted on a movable body, e.g. a radio-controlled aircraft (radio-controlled drone, small helicopter or other aircraft), a vehicle or the like.

[0019] Fig. Figure 1 shows an example design of a drive system that can be used for a moving body such as a drone or similar. Fig. Figure 1 shows a motor drive unit 1, a starter / generator 4, a machine or motor 5, a battery 6, a receiver 8 and a transmitter 9.

[0020] The starter / generator 4 contains, for example, a brushless motor.

[0021] Machine 5 and starter / generator 4 are directly connected by a rotating shaft 7. Starter / generator 4 transmits motor drive power to machine 5 to act as its starter. Additionally, starter / generator 4 transmits motor drive power to machine 5 as an auxiliary function, i.e., a so-called hybrid operation.

[0022] The driving force of machine 5 is transferred to the starter / generator 4 and used to generate regenerative energy. This regenerative energy is used to charge battery 6.

[0023] The battery 6 supplies a drive current as direct current to the motor drive unit 1. The motor drive unit 1 generates a three-phase drive current from the drive current and supplies the generated three-phase drive current to the starter / generator 4 to drive the motor.

[0024] On the other hand, current generated by the starter / generator 4 is supplied as charging current to the battery 6 via the motor drive unit 1.

[0025] The motor drive unit 1 is divided into a starter drive control device and a rectifier for regulating power generation. The motor drive unit 1 includes a drive unit 2 and a drive control unit 3.

[0026] The drive unit 2, controlled by the drive controller 3, generates the drive current for the three-phase motor and drives the starter / generator 4. As described later, the drive unit 2 contains a three-phase FET bridge, a gate driver for a FET that serves as a switching element for the three-phase FET bridge, or similar components, and generates the three-phase motor drive current.

[0027] In addition, the drive unit 2 can perform an active freewheeling operation, which will be described later, by controlling the three-phase FET bridge to increase a regenerative voltage.

[0028] The drive control unit 3 contains, for example, a microcomputer and controls the drive unit 2 in response to various inputs.

[0029] The drive control 3 and the drive unit 2 are connected to each other via three lines, i.e. a supply voltage line (Vcc), a ground line (GND) and a PWM control signal PS2.

[0030] The drive control 3 uses the PWM control signal PS2 to supply an initial signal and a motor start signal to the drive unit 2 and to perform speed control as well as the on / off control of the active freewheel.

[0031] The transmitter 9 is a radio-controlled device for a moving body, such as a drone or the like, and sends a signal (operating information) in response to an operator action. The operating information is received by the receiver 8, and the operating content of the information is recognized by the drive controller 3.

[0032] The receiver 8 and the drive control 3 are connected via three lines, i.e. a power supply voltage line (Vcc), a ground line (GND) and a PS1 line for the PWM control signal.

[0033] The receiver 8 transmits the operating information from the transmitter 9 to the drive control 3 as a PWM control signal PS1.

[0034] The operator using transmitter 9 can, for example, perform an engine start procedure, throttle actuation (changing the throttle valve opening degree), on / off control of an active freewheel, or similar actions.

[0035] The active freewheeling operation is carried out in the motor drive unit 1 in a suitable manner without the operator's knowledge. The operator can detect this operation, for example, in a switch-on mode. As described later, the active freewheeling operation causes a load on the motor 5. Therefore, if the operator requests that the motor be switched on, the drive control unit 3 may interpret this as a request to switch off the active freewheeling operation.

[0036] The drive control unit 3, which has received the operating information as a PWM control signal PS1 from the receiver 8, generates the PWM control signal PS2 in response to the operating information and transmits the PWM control signal PS2 to the drive unit 2. In particular, the operating information includes a motor start command, a throttle valve opening degree control command, an on / off control command for active freewheeling operation, or similar.

[0037] The throttle valve opening control command controls the carburetor opening degree of engine 5 via an engine drive system (not shown). At this point, the engine speed (e.g., the number of revolutions) is also controlled.

[0038] Therefore, the drive control unit 3 for the drive unit 2 not only controls the supply of the motor start signal, the speed control and the on / off control of the active freewheel, but also the supply of the start signal for the motor start according to the operating information. This is implemented by a PWM control signal PS2.

[0039] The drive control 3 monitors a terminal voltage Vb (battery voltage) of battery 6.

[0040] A machine / engine speed signal S1 (ignition signal) from the machine or engine 5 is fed to the drive control unit 3. The engine speed signal S1 is a Hall sensor signal, e.g., a signal representing a pulse for one engine revolution. Before the engine 5 is started, the starter / generator 4 is rotated at, for example, 500 revolutions per minute. After the engine 5 has started, the starter / generator 4 rotates at approximately 2000 rpm. Therefore, the drive control unit 3 can determine, based on the engine speed signal S1, whether the engine 5 has started or not, and it can detect an increase in the load on the engine 5.

[0041] The drive control 3 controls the drive unit 2 in response to the terminal voltage Vb of the battery 6 or the motor speed signal S1, which is also realized by the PWM control signal PS2.

[0042] Fig. Figure 2 shows an example of the PWM control signal PS2, which is output by the drive controller 3.

[0043] To control the rotational speed, the H-period of the PWM pulse is varied. For example, the motor's rotational speed is controlled by varying the H-period by a width of 1.3 ms to 2.0 ms.

[0044] For example, transmitter 9 displays throttle position information with a H-period width of 0.8 ms to 2.0 ms. The minimum H-period is 0.8 ms, and the maximum H-period is 2.0 ms.

[0045] The drive control 3 uses a period with a width of 1.3 ms to 2.0 ms for controlling the motor drive voltage.

[0046] The initial signal is expressed by setting the H-period of the PWM pulse to 0.8 ms, and the motor start signal is expressed by setting the H-period of the PWM pulse to 1.2 ms. This is an example with a pulse length that does not correspond to the length of 1.3 ms to 2.0 ms described above.

[0047] One L-period of the PWM pulse is used to control the active freewheeling on / off function. For example, if the L-period is 4 ms, the active freewheeling is switched off. If the L-period is 2 ms, the active freewheeling is switched on.

[0048] For example, as in the example described above, the drive controller 3 transmits the control contents to the drive unit 2 using a PWM control signal PS2.

[0049] Fig. Figure 3 shows the design of drive unit 2.

[0050] The drive unit 2 includes a gate control 21, a gate driver 22, a three-phase FET bridge 23, an active freewheeling drive unit 25 and a detection unit for detecting the motor-induced voltage 26.

[0051] The gate controller 21 contains a microcomputer, receives the PWM control signal PS2 from the drive controller 3, analyzes the command content and controls the gate driver 22 or the active freewheel drive unit 25.

[0052] In addition, the gate control 21 monitors the magnet position data DM from the detection unit 26 for the motor-induced voltage and sets a gate driver timing for switching elements of the three-phase FET bridge 23.

[0053] The gate driver 22 generates and outputs a gate driver signal PS3 for switching control of the individual FETs, which are the switching elements of the three-phase FET bridge 23, based on the timing control of the gate controller 21.

[0054] The active freewheel drive unit 25 controls the gate drive signal PS3 from the gate driver 22, so that the active freewheel operation is switched on / off in response to an on / off setting signal SFF from the gate control 21.

[0055] The three-phase FET bridge 23 generates motor drive currents for U-phase, V-phase and W-phase of the motor coil 41 of the starter / generator 4.

[0056] The motor-induced voltage detector 26 detects the motor-induced voltage from the three-phase FET bridge 23, generates the magnet position data DM and delivers the magnet position data DM to the gate controller 21.

[0057] The Fig. Figures 4 to 6 show the three-phase FET bridge 23 and the motor coil 41. Fig. Figures 4 to 6 each show current paths during an ON time interval of the switching elements.

[0058] The three-phase FET bridge 23 is, for example, as shown in Fig. Figure 4 shows a bridge circuit in which, for example, six N-type MOSFETs serve as switching elements between a voltage V1 and ground.

[0059] In the case of the U-phase, the switching elements UH and UL are connected in series, and the connection point is connected to the U-phase winding of the motor coil 41.

[0060] In the case of the V-phase, the switching elements VH and VL are connected in series, and the connection point is connected to the V-phase coil of the motor coil 41.

[0061] In the case of the W-phase, the switching elements WH and WL are connected in series, and the connection point is connected to the W-phase coil of the motor coil 41.

[0062] Gate pulses UHg, ULg, VHg, VLg, WHg and WLg from gate driver 22 are applied to the gates of the switching elements UH, UL, VH, VL, WH and WL. Accordingly, the switching elements VH, VL, WH and WL are switched on / off.

[0063] The gate driver signal PS3 described above refers in total to these gate pulses UHg, ULg, VHg, VLg, WHg and WLg.

[0064] Fig. Figure 7 is a timing diagram of the gate pulses of the gate control signal PS3. One cycle is performed in the time intervals t1 to t6. The pulse width, the number of pulses, and similar parameters are shown schematically.

[0065] During the time interval t1 in Fig. 7. The H pulses PG appear intermittently in the gate pulses UHg and VLg, so that the switching elements UH and VL are intermittently switched on simultaneously. At this time, a motor drive current flows, which is represented by a dashed line d1 in Fig. 4 is displayed.

[0066] During the time interval t2 in Fig. 7. The H-pulses PG appear intermittently in the gate pulses UHg and WLg, so that the switching elements UH and WL are intermittently switched on simultaneously. At this time, a motor drive current flows, which is represented by a dashed line d2 in Fig. 4 is displayed.

[0067] During the time period t3 in Fig. 7. The H-pulses PG appear intermittently in the gate pulses VHg and WLg, so that the switching elements VH and WL are intermittently switched on simultaneously. At this time, a motor drive current flows, which is represented by a dashed line d3 in Fig. 5 is displayed.

[0068] During the time period t4 in Fig. 7. The H-pulses PG appear intermittently in the gate pulses VHg and ULg, so that the switching elements VH and UL are intermittently switched on simultaneously. At this time, a motor drive current flows, which is represented by a dashed line d4 in Fig. 5 is displayed.

[0069] During the time period t5 in Fig. 7. The H-pulses PG appear intermittently in the gate pulses WHg and ULg, so that the switching elements WH and UL are intermittently switched on simultaneously. At this time, a motor drive current flows, which is represented by a dashed line d5 in Fig. 6 is displayed.

[0070] During the time interval t6 in Fig. 7. The H-pulses PG appear intermittently in the gate pulses WHg and VLg, so that the switching elements WH and VL are intermittently switched on simultaneously. At this time, a motor drive current flows, which is represented by a dashed line d6 in Fig. 6 is displayed.

[0071] The starter / generator 4 is set in rotation by the supply of the motor drive current, as described above.

[0072] Here, the motor drive voltage is changed as an average voltage depending on the H-periods (or duty cycles) of the gate pulses UHg, ULg, VHg, VLg, WHg, and WLg as gate driver signal PS3. The gate controller 21 can control the motor speed by applying the motor drive voltage, which corresponds, for example, to the operator's throttle opening control, the charging process, or the hybrid operation described later, by changing the H-periods (or duty cycle) of the gate pulses UHg, ULg, VHg, VLg, WHg, and WLg in response to the speed specified by the PWM control signal PS2.

[0073] In the description above, the gate driver signal PS3 was used when the active freewheel is switched off. Fig. Figure 8 shows the gate drive signal PS3 when the active freewheel is switched on.

[0074] During the time periods t1 to t6 in Fig. In step 8, the H-pulses PG, which form the motor drive current paths (d1 to d6), have the same timings as in Fig. 7 is shown. In addition, the instantaneous H impulses PH appear as in Fig. 8 shown.

[0075] During the time interval t1 in Fig. 8. The instantaneous H-pulses PH appear intermittently as the gate pulses ULg and VHg within the L-periods of the gate pulses UHg and VLg, so that the switching elements UL and VH are intermittently switched on simultaneously. At this time, the current caused by an electromotive force back EMF flows, as shown by a dashed line k1 in Fig. 4 is displayed.

[0076] During the time interval t2 in Fig. 8. The instantaneous H-pulses PH appear intermittently as the gate pulses ULg and WHg within the L-periods of the gate pulses UHg and WLg, so that the switching elements UL and WH are intermittently switched on simultaneously. At this time, the current caused by the electromotive force back EMF flows, as shown by a dashed line k2 in Fig. 4 shown.

[0077] During the time period t3 in Fig. 8. The instantaneous H-pulses PH appear intermittently as the gate pulses VLg and WHg within the L-periods of the gate pulses VHg and WLg, so that the switching elements VL and WH are intermittently switched on simultaneously. At this time, the current caused by the electromotive force back EMF flows, as shown by a dashed line k3 in Fig. 5 shown.

[0078] During the time period t4 in Fig. 8. The instantaneous H-pulses PH appear intermittently as the gate pulses VLg and UHg within the L-periods of the gate pulses VHg and ULg, so that the switching elements VL and UH are intermittently switched on simultaneously. At this time, the current caused by the electromotive force back EMF flows, as shown by a dashed line k4 in Fig. 5 shown.

[0079] During the time period t5 in Fig. 8. The instantaneous H-pulses PH appear intermittently as the gate pulses WLg and UHg within the L-periods of the gate pulses WHg and ULg, so that the switching elements WL and UH are intermittently switched on simultaneously. At this time, the current caused by the electromotive force back EMF flows, as shown by a dashed line k5 in Fig. 6 shown.

[0080] During period t6 in Fig. 8. The instantaneous H-pulses PH appear intermittently as the gate pulses WLg and VHg within the L-periods of the gate pulses WHg and VLg, so that the switching elements WL and VH are intermittently switched on simultaneously. At this time, the current caused by the electromotive force flows, as shown by a dashed line k6 in Fig. 6 shown.

[0081] In other words, in active freewheeling mode, the gate pulse ULg is switched on immediately when the chopping drive of the gate pulse UHg becomes a low level; the gate pulse VHg is switched on immediately when the chopping drive of the gate pulse VLg becomes a low level; and the gate pulse WHg is switched on immediately when the chopping drive of the gate pulse WLg becomes a low level.

[0082] Accordingly, the currents caused by the electromotive force flow through the switching elements, and the boost process is carried out.

[0083] Fig. Figure 9A shows the relationship between the motor drive current (dashed line d1) and the electromotive back EMF in a single-phase section (operation during time interval t1) of the motor driver circuit. The U-phase and V-phase coils of the motor coil 41 and the switching elements UH, UL, VH, and VL are extracted.

[0084] Fig. Figure 9B shows a boost circuit of a general DC / DC converter, which Fig. 9A corresponds to the switching element VL, which corresponds to a switching element of the general DC / DC converter. The switching element VH corresponds to a diode of the general DC / DC converter. The coil 101 in Fig. 9B corresponds to the U- and V-phase coils of the motor coil 41 in Fig. 9A. Additionally, a power supply 100 and a load resistor 102 are shown.

[0085] In Fig. A current of 9A flows through the FETs as the switching elements UH and VL. This current corresponds to the current flowing through the coil 101 and the switching element VL, as shown by a dashed dotted line d1' when the switching element VL is switched on. Fig. 9B is displayed.

[0086] In Fig. A discharge current of 9A, caused by the electromotive force (represented by a dashed line k1), flows through the FETs acting as switching elements UL and VH. This current corresponds to the current discharged through the coil 101 and the switching element VH, as indicated by a dashed line k1', when the switching element VH is in Fig. 9B is switched on.

[0087] In summary, it can be said that the active freewheeling operation is due to the factors relating to Fig. The described regulation enables the same boosting process as that of the DC / DC converter.

[0088] In other words, the regenerative voltage can be increased and drawn off through active freewheeling operation.

[0089] The control of the generated voltage will now be described.

[0090] Fig. Figure 10 simply shows the relationship between the motor drive voltage Vd and the motor speed. An electromotive motor force (electromotive motor voltage) e satisfies the condition "e=Ke×N". Ke represents an electromotive force constant (Vd / rpm) and N a speed (rpm). The electromotive voltage of the motor is proportional to the rotational speed. Wiring resistance of the motor or similar is ignored.

[0091] In the case of Vd>e, the current flows into a positive pole of the motor, as indicated by an arrow i1, and the motor is accelerated.

[0092] In the case of Vd=e, the rotation of the motor is constant. In the case of Vd <e fließt der Strom vom Pluspol des Motors, wie durch einen Pfeil i2 angezeigt, und der Motor dient als Generator (unter der Annahme, dass der Motor durch eine externe Kraft, z.B. den Motor, angetrieben wird).

[0093] If the motor is driven, for example, at idle by a certain motor drive voltage Vd, the speed of the motor will become a speed at which the motor drive voltage Vd is equal to the electromotive voltage e of the motor.

[0094] When the motor drive voltage Vd is increased, the speed of the motor is increased and stabilized at a level where the motor drive voltage Vd is equal to the electromotive motor voltage e.

[0095] In other words, the current flowing through the motor coil is determined by the difference between the motor drive voltage Vd and the electromotive motor voltage e.

[0096] The case in which the motor is rotated by an external force (at constant speed) will now be described. (1) When the motor is turned by the external force and the difference between the motor drive voltage Vd and the electromotive motor voltage e is small, a small amount of current flows through the motor coil (when a load is applied to the regenerative voltage) and the electromotive back E voltage is reduced. (2) When the motor is turned by the external force and the difference between the motor drive voltage Vd and the electromotive motor voltage e is large, a large amount of current flows through the motor coil (when a load is applied to the regenerative voltage) and the electromotive back EMF is increased.

[0097] From the above statements (1) and (2) it is clear that if the motor is driven by the external force, the voltage of the electromotive force of the motor can be adjusted by changing the motor drive voltage Vd.

[0098] In the present embodiment, the regenerative voltage generated by the starter / generator 4 can be adjusted by controlling the motor drive voltage for the starter / generator 4. This shows that the regenerative voltage can be set as an average voltage by controlling the motor drive voltage, wherein the motor drive voltage depends on the H-periods (or pulse duty cycles) of the gate pulses UHg, ULg, VHg, VLg, WHg and WLg as gate control signal PS3, which is applied by the gate driver 22 to the three-phase FET bridge 23.

[0099] Furthermore, it can be considered that the motor drive voltage can be adjusted via the PWM control signal PS.

[0100] By increasing the electromotive back EMF of the motor in the active freewheeling operation described above, a regenerative power with sufficient voltage can be generated, even if the speed of the external force (i.e., of the motor 5) for driving the starter / generator 4 is low.

[0101] Furthermore, when active freewheeling is deactivated, the motor's generated voltage will be greater than or equal to the supply voltage at a speed greater than or equal to the supply voltage's no-load speed. In this case, the voltage is controlled to ensure the motor speed matches the machine's speed, making precise control difficult. Conversely, when active freewheeling is activated, the generated voltage can be increased even at low motor speeds and low generated voltages. Therefore, it is possible to precisely control the charging voltage by increasing the generated voltage to a level at which charging can occur. <Example of the design of drive control and drive unit>

[0102] Based on the design described above, the following will be used: Fig. 11A and Fig. Section 11B describes a concrete example of the implementation of the drive control 3 and the drive unit 2. As in Fig. As shown in 11A, the execution of drive control 3 comprises steps S101 to S107, and as in Fig. As shown in Figure 11B, the execution of the gate control 21 of the drive unit 2 comprises steps S201 to S211.

[0103] As described above, the drive controller 3 receives the PWM control signal PS1 from the receiver 8, and the drive controller 3 monitors the motor rotation signal S1 or the terminal voltage Vb of the battery 6.

[0104] In step S101, a predetermined trigger is detected and the drive control 3 is switched on. The drive control 3 performs a switch-on process and checks the supply voltage.

[0105] When switched on, the drive control 3 gives an initial signal in step S102 (see Fig. 2) using the PWM control signal PS2 for drive unit 2.

[0106] Then, in step S103, the drive control unit 3 sends a motor start signal (see Fig. 2) using the PWM control signal PS2.

[0107] In step S104, the drive control 3 sends an instruction to stop the active freewheel via the PWM control signal PS2 (see Fig. 2) out.

[0108] In step S201, the gate controller 21 of the drive unit 2 performs a switch-on process in response to a predefined trigger. Then, in step S202, the gate controller 21 checks the PWM control signal PS2, which is an input signal. In step S202, the gate controller 21 waits for the input signal. In other words, the gate controller 21 waits until the high period of the PWM control signal PS2 is 0.8 ms.

[0109] After the initial signal has been verified, gate controller 21 proceeds to step S203 and checks the motor start signal. In other words, gate controller 21 waits until the high period of the PWM control signal PS2, which is an input signal, is 1.2 ms.

[0110] After the motor start signal has been checked, the gate controller 21 proceeds to step S204 and checks the active freewheeling command by checking the L-period of the PWM control signal PS2, which is the input signal.

[0111] If the L-period is 2 ms, the gate controller 21, in response to a command to start the active freewheeling, transitions to step S205 and executes the control to start the active freewheeling (output of the gate control signal PS3 in Fig. 8).

[0112] If the L-period is 4 ms, the gate controller 21 proceeds to step S206 in response to a command to stop the active freewheeling and performs a drive control to stop the active freewheeling (output of the gate control signal PS3 in Fig. 7).

[0113] Since in the example of the Fig. 11A and Fig. If, in step S104, the drive control 3 issues a command to stop the active freewheel in the initial state, the operation is carried out in step S206. However, the drive control 3 can issue an instruction to start the active freewheel operation in the initial state.

[0114] In step S207, the gate controller 21 begins outputting the gate control signal PS3 and supplies a motor control voltage to the starter / generator 4 to start the motor 5. In other words, the starting process is carried out.

[0115] Then the gate control 21 proceeds to step S208 and checks the active freewheel instruction by checking the L-period of the PWM control signal PS2.

[0116] In step S105, the drive control 3 waits for the motor or machine 5 to start. In other words, the drive control 3 monitors the motor speed signal S1.

[0117] When the motor speed signal S1 confirms that the motor 5 has been started, the drive control 3 proceeds to step S106 and issues a command to start the active freewheel using the PWM control signal PS2.

[0118] The drive control unit 3 then executes the control process in step S107. For example, the following processes Pa to Pf are carried out. (Process Pa) Control of the charging voltage (feedback voltage) and on / off control of the charging in response to the terminal voltage Vb of the battery 6 (Process Pb) On / Off control of the active freewheel depending on the terminal voltage Vb of the battery 6 (Process PC) Control of the motor drive voltage to support the motor in response to the motor speed signal S1 (Process Pd) On / Off control of active freewheeling operation in response to the motor speed signal S1 (Process Pe) Control of the motor drive voltage in response to the PWM control signal PS1 from receiver 8 (Process Pf) On / Off control of the active freewheeling operation in response to the PWM control signal PS1 from receiver 8

[0119] In response to these processes, the drive control 3 outputs the PWM control signal PS2.

[0120] The gate control 21 of the drive unit 2 executes processes following step S208 in response to the PWM control signal PS2.

[0121] In other words, in step S208, the gate controller 21 checks the L-period of the PWM control signal PS2 and verifies the instruction for active freewheeling.

[0122] In response to the instruction from the drive control 3 to start the active freewheeling operation in step S106, after the motor has been started in step S207, the gate control 21 first proceeds quickly from step S208 to S209 and executes the output control of the gate control signal PS3 to start the active freewheeling operation.

[0123] If, afterwards, a command to stop the active freewheeling operation is received from the drive control 3, the processing continues from step S208 to S210, and the gate control 21 executes the output control of the gate drive signal PS3 to stop the active freewheeling.

[0124] Next, the active freewheel is switched on / off by the drive unit 2 in response to the instruction from the drive control 3.

[0125] In step S211, the gate controller 21 sets the motor drive voltage. At this point, the gate driver signal PS3 is variably controlled in response to changes in the H-period of the PWM control signal PS2 between 1.3 ms and 2.0 ms. In other words, the motor drive voltage is controlled by varying the H-periods of the gate pulses UHg, ULg, VHg, VLg, WHg, and WLg as the average voltage.

[0126] By repeating the execution of the drive control 3 in step S107 and the execution of the gate control 21 in steps S208 to S211, the adjustment of the motor drive voltage or the on / off control of the active freewheel is carried out in response to the circumstances or the operator's action as follows.

[0127] In the process Pa described above, the drive controller 3 monitors the terminal voltage Vb of battery 6 to charge battery 6 using the regenerative current and variably controls the motor drive voltage by adjusting the H-period of the PWM control signal PS2 within a range of 1.3 ms to 2.0 ms to obtain a desired regenerative voltage. The motor drive voltage is controlled so that the charging process stops when battery 6 is fully charged.

[0128] In the process Pb described above, the drive control 3 manages the active freewheeling operation so that it is stopped when the terminal voltage Vb of battery 6 is greater than or equal to a reference voltage. This is because, if charging is not taking place, the active freewheeling operation to increase the regenerative voltage is not necessary.

[0129] In the process Pc described above, when the load on motor 5 increases and the motor speed decreases, the motor drive voltage is controlled so that the motor-assisting operation of the starter / generator 4 is carried out.

[0130] The engine support mode (hybrid mode) will be described later.

[0131] In the process Pd described above, the drive control 3 stops the active freewheeling operation when the motor speed drops below a certain threshold. Active freewheeling increases the load on the motor 5 (such as when the brake is applied to the motor). Therefore, if the motor speed decreases, the motor can be stopped. Accordingly, the monitored motor speed is checked, and if it falls below a certain threshold, active freewheeling is stopped and the charging process is terminated.

[0132] The speed limit is determined taking into account the torque characteristic curve and charging current of motor 5 and an environment in which motor 5 is used.

[0133] In the process Pe described above, the motor drive voltage is varied in response to the operator's throttle actuation. The speed of the starter / generator 4 is controlled by setting the H-period of the PWM control signal PS2 to a range of 1.3 ms to 2.0 ms and variably controlling the motor drive voltage within this range.

[0134] In the process Pf described above, the operator stops the active freewheeling operation when power is required. For example, if the operator performs an operation such as a power-on mode or similar, the drive control 3 stops the active freewheeling operation.

[0135] During the execution of the Fig. 11A and Fig. In 11B, the drive control unit 3, for example, automatically starts active freewheeling mode when the motor 5 is started, in order to charge the battery. At this point, a portion of the motor power is used for the charging process. The operator performs the start-up mode procedure if necessary. In this case, the drive control unit 3 stops active freewheeling mode because starting up is more important than charging. <hybridbetrieb>

[0136] The following describes hybrid operation. Here, hybrid operation refers to an operation in which the starter / generator 4 supports the motor 5.

[0137] In other words, if the engine speed falls below a certain value relative to the throttle position due to a load or similar, the starter / generator 4 automatically assists the engine 5 with a torque proportional to the reduced speed.

[0138] First, the device settings are described. In the following description of hybrid operation, starter / generator 4 is simply referred to as "motor 4".

[0139] When the carburetor is fully open (position a in Fig. 12) If the speed at which motor 4 begins to assist motor 5 is set to Ra and the voltage applied to motor 4 is set to Va, then motor 4 must be selected with a KV value (speed per 1V) k that satisfies the condition k = Ra / Va. It is therefore assumed that motor 4 must be selected with speed Ra at voltage Va. In other words, speed Ra indicates the speed at which motor 4 does not produce any external torque.

[0140] The opening degree of the carburetor, the input signal to the drive unit 2 (PWM control signal PS2) and the motor drive voltage are linked together.

[0141] For example, a linear interpolation is performed between the fully open position a and the position in which the carburetor is fully closed, and the voltage V0 applied to motor 4 is set to 0 (V). The carburetor opening degree and the voltage applied to motor 4 indicate the Fig. The relationship shown is 12.

[0142] The procedure in the event of a load increase is explained based on the assumption described above.

[0143] Initially, it is assumed that the carburetor opening degree in the operating state before the load increase is... Fig. 12 b is; the voltage Vb applied to the motor 4 is and the rotational speed Rb satisfies a condition Rb=k*Vb.

[0144] The operating state is located at a point b in Fig. 13, and the amount of energy generated and the torque to support motor 5 are zero.

[0145] A first case of increased load will now be described.

[0146] When the load is increased and the speed of motor 5 is set to “Rb1” in Fig. As 14 decreases, the operating state moves to a point b1.

[0147] The voltage Vb applied to motor 4 remains unchanged. However, since motor 4 and motor 5 are connected, the rotational speed is reduced by ΔR=(Rb-Rb1) and the torque generated by motor 4 is increased, thus assisting motor 5.

[0148] A second instance of load increase will now be described. This occurs when the operator operates (opens) the throttle valve.

[0149] If in Fig. 12. The carburetor opening degree is set to "c" by opening the throttle valve in a state where a carburetor opening degree b, a voltage Vb applied to the motor 4 and a rotational speed Rb satisfy a condition Rb=k*Vb. The voltage "Vc" applied to the motor 4 then changes, and the operating state moves from point b to point c. Fig. 15.

[0150] Since the applied voltage is increased without a change in speed, the torque generated by motor 4 increases, thus supporting motor 5.

[0151] Whether the operation in the present embodiment takes place in the “hybrid operating range” or in the Fig. The “charging range” shown in section 16 is determined by the ratio between “motor speed (= rotational speed of the motor)” and “motor drive voltage”.

[0152] If the process is on a diagonal line in Fig. If step 16 is performed, charging will not be carried out and the motor will not be supported.

[0153] If the motor speed is reduced in a state with constant motor drive voltage, operation takes place in the hybrid operating range (example of the first case).

[0154] If the motor drive voltage becomes greater than the voltage corresponding to the motor's speed, operation is carried out in the hybrid operating range (example of the second case).

[0155] On the other hand, in the charging area, charging is carried out using regenerative energy.

[0156] In this embodiment, the switching between operation in the hybrid mode and operation in the charging mode is not specifically controlled.

[0157] Drive control 3 generally activates the freewheeling mode, operates primarily in the charging range, and automatically switches to hybrid mode depending on the circumstances. In other words, the motor speed is monitored in the above process (PC), and the movement is controlled to switch to hybrid operation if necessary.

[0158] In the process Pd described above, the active freewheeling operation increases the load on motor 5 (braking the motor). Therefore, the active freewheeling operation is controlled to stop when it becomes difficult for motor 5 to operate. <zusammenfassung>

[0159] In the embodiment described above, the motor drive device 1 comprises the drive unit 2 for driving the starter / generator 4, which is directly connected to the motor 5 via the rotating shaft, by performing the on / off control of the switching elements in the bridge circuit (three-phase FET bridge 23) for driving the motor, and the drive control 3 for controlling the drive of the starter / generator 4 by the drive unit 2.

[0160] The drive unit 2 controls the motor drive voltage for the starter / generator 4 by changing the ON-times of the switching elements of the three-phase FET bridge 23. Furthermore, the drive unit 2 performs, as shown in Fig. Figure 8 shows the active freewheeling operation for increasing the regenerative voltage using the starter / generator 4 by switching on a predetermined switching element of the three-phase FET bridge 23 at a predetermined time of the H-pulse PH. The drive control 3 can issue the motor drive voltage command and the on / off command for active freewheeling operation to the drive unit 2 based on the battery voltage (terminal voltage Vb of battery 6).

[0161] According to this motor drive unit 1, it is possible to control a motor (starter / generator 4) that serves as a starter and a motor for generating charging power accordingly. In other words, the operation of the motor that serves as a starter and assists the motor and the operation for generating electricity to charge the battery 6 are automatically switched.

[0162] Therefore, the motor assistance operation and the charging process can be carried out appropriately without a user noticing, e.g., an operator using a transmitter 9. In particular, the drive control 3 controls the drive unit 2 by monitoring the terminal voltage Vb of the battery 6 and issuing the motor drive control command as well as the on / off command for active freewheeling operation. Accordingly, the motor assistance operation and the charging operation are carried out accordingly (see S107 and S208 to S211 in Fig. 11B).

[0163] In the motor drive unit 1, the motor drive voltage is controlled by the gate on / off control of the switching elements UH, UL, VH, VL, WH and WL of the three-phase FET bridge 23 and the active freewheeling operation is carried out.

[0164] Therefore, it is possible to regulate the motor drive voltage and the feedback voltage and to perform the boost process using active freewheeling or similar mechanisms, without requiring an additional step-up / step-down switch, a mechanism to increase the motor speed, or similar components. In other words, motor support operation and the charging process can be carried out efficiently without increasing the circuit size.

[0165] Typically, a control unit for the starter drive and a rectifier for regulating power generation were required separately. Therefore, the load was high when installed on a small mobile engine.

[0166] The motor drive unit 1 of the present embodiment can reduce the weight by sharing the power generation control rectifier with the starter drive control device.

[0167] Furthermore, the motor 5 and the starter / generator 4 are directly connected to each other, so that a starter mechanism or drive unit for power generation is not required.

[0168] A permanent magnet generator produces a voltage in response to the rotational speed of a motor. Therefore, a semiconductor control element with high voltage capability was typically used. If the rotational speed was low, it had to be increased to ensure a sufficient charging voltage.

[0169] In accordance with the motor drive unit 1 of the present embodiment, the voltage generated by the permanent magnet generator can be regulated. Therefore, the generated voltage can be reduced when the required voltage is high and increased when the required voltage is low. Accordingly, the voltage suitable for charging the battery 6 can be achieved over a wide speed range, and it is not necessary to increase the speed of the generator or the high-voltage semiconductor element.

[0170] Due to the active freewheeling operation, a relatively high regenerative voltage can be achieved even at low speeds, which enables efficient charging.

[0171] In active freewheeling mode, no regenerative current path through a body diode of a FET, which is a switching element, is used. Therefore, it is advantageous that the efficiency or accuracy is not degraded compared to the case where the body diode is used.

[0172] In this embodiment, the drive controller 3 controls the drive unit 2 by issuing the command for the motor drive voltage and the command for active freewheeling operation using the PWM control signal PS2, which is a PWM signal.

[0173] In other words, in the example above, the motor drive voltage was regulated by setting the high period of the PWM control signal PS2 to between 1.3 ms and 2.0 ms, and the switching on / off of the active freewheel was controlled by setting the low period to 2 ms or 4 ms. Accordingly, motor support operation and charging can be adequately performed with a single PWM signal. In other words, control can be achieved with a single PWM signal, just like with a conventional motor drive device.

[0174] The in Fig. The specific time period shown, the tax content and the like are merely examples.

[0175] In this embodiment, the drive controller 3 controls the drive unit 2 by providing the initial signal and starting the motor with the PWM control signal PS2, which is a PWM signal.

[0176] The initial signal, or motor start signal, is set by the H-period of the PWM control signal PS2. Accordingly, the drive controller 3 performs the overall control of the drive unit 2 using a PWM signal. The connecting line simply comprises three wires: a power wire, a ground wire, and a PWM signal wire.

[0177] In this embodiment, the drive control 3 can perform the on / off control of the active freewheel in response to the motor speed signal S1 or the operating information (PWM control signal PS1 from receiver 8).

[0178] For example, if the engine speed is reduced, it is possible to stop the active freewheeling operation, or it is possible to stop the active freewheeling operation in response to an action by a user.

[0179] Accordingly, it is possible to determine the priority between the charging process and the motor assistance process. If power is needed to propel a drone or similar device, the active freewheeling operation can be stopped to reduce the load on the motor. In this way, the priority can be determined according to the circumstances.< / zusammenfassung> < / hybridbetrieb>

Claims

[1] Motor drive device (1) comprising: a drive unit (2) configured to drive a starter / generator (4) which is directly connected to a motor via a rotating shaft by performing on / off control of each of the switching elements (UH, UL, VH, VL, WH, WL) in a bridge circuit (23) to drive a motor; and a drive control (3) designed to control a drive operation performed by the drive unit (2) for the starter / generator (4), wherein the drive unit (2) is configured to control a motor drive voltage for the starter / generator (4) by changing the ON time period of the switching elements (UH, UL, VH, VL, WH, WL) of the bridge circuit (23) and to perform an active freewheeling operation to raise a backfeed voltage generated by the starter / generator (4) by alternately switching on the predetermined switching element and a complementary switching element within a period in which a gate drive signal for a predetermined switching element is at a low level, thereby forming a current path caused by a backfeed voltage and wherein the drive control (3) is configured to instruct the drive unit (2) to control the motor drive voltage and the switching on and off of the active freewheel on the basis of a battery voltage. [2] Motor drive device (1) according to claim 1, wherein the drive control (3) is configured to instruct the drive unit (2) to control the motor drive voltage and the switching on / off of the active freewheeling operation using a PWM signal. [3] Motor drive device (1) according to claim 2, wherein the drive control (3) is configured to provide the drive unit (2) with an initial signal and a motor start signal using a single PWM signal. [4] Motor drive device (1) according to any one of claims 1 to 3, wherein the drive control (3) is configured to instruct the drive unit (2) to perform the on / off control of the active freewheeling operation in response to motor rotation information or operating information.

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