JP7238424B2 - electric motor drive - Google Patents

Description

The present invention relates to an electric motor drive device that drives an electric motor with two inverters.

2. Description of the Related Art Conventionally, a technique of driving one AC motor provided between two power sources and two inverters is known. For example, the AC motor drive system disclosed in Patent Document 1 has a configuration in which one of the two power sources is a variable voltage capacitor power source to eliminate interference between the generated motor torque (output) control and capacitor voltage control. Stabilize drive.

JP 2015-73373 A

In the prior art of Patent Document 1, three parameters, the output of the AC motor and the power of the two inverters (or the power of the two power sources), are determined according to the drive state of the two inverters to which the two power sources are connected. Ultimately, one is voltage control, so not only the power of each inverter, but also the efficiency.

Further, in the prior art of Patent Document 1, in the two-power-supply two-inverter system, interference is eliminated by increasing the output of one inverter to the maximum output and controlling the voltage of the other inverter, which assumes a capacitor. However, the object to be stabilized by this technique is only the torque, and there is no mention of stabilizing the inverter power that reflects the power supply state such as SOC. In particular, there is a relationship between the inverter output, torque, and each power, and if you try to satisfy only one parameter (for example, torque), the other elements (for example, power) are determined by chance. As a result, the efficiency is In addition, it destabilizes the stability and output state.

Furthermore, in a configuration in which one power supply is not a capacitor (output type power supply) and both power supplies are batteries (capacitance type power supply), dual power supply management is required and low power consumption (that is, low loss) is also required. , no mention is made of a technique for realizing the driving state. In addition, if the prior art is applied to a configuration in which both power sources are batteries, there is a risk that voltage control may not be able to achieve even the torque determined by the energized current, let alone the power of each power source, depending on the operating conditions.

The present invention has been created in view of the above-mentioned problems, and its object is to provide an appropriate drive according to the priority element so as to reduce the loss while managing the torque of the electric motor with the configuration of two power sources and two inverters. To provide a motor driving device capable of selecting a pattern.

A motor driving device according to the present invention uses two inverters to which two power sources are individually connected, and a motor (80) having two or more phase windings (81, 82, 83) whose end points are open. control the drive of This motor drive device includes a first inverter (60), a second inverter (70), and a control section (300). The first inverter receives DC power from a first power supply (11), has a plurality of first switching elements (61 to 66) provided corresponding to each phase of the winding, and is connected to one end of the winding. be done. The second inverter receives DC power from the second power supply (12), has a plurality of second switching elements (71 to 76) provided corresponding to each phase of the winding, and Connected.

Based on the torque command, the control unit includes a first inverter control circuit (301) that generates a first voltage command that is an output voltage command to the first inverter, and a second voltage that is an output voltage command to the second inverter. It has two inverter control circuits, a second inverter control circuit (302), which generates commands. At least one of the first inverter control circuit and the second inverter control circuit operates as a "torque management circuit" that manages the torque of the electric motor by torque feedback control.

Each inverter control circuit has a PWM control mode that outputs a plurality of pulses according to the carrier frequency in one electrical cycle based on the comparison between the voltage command and the carrier wave, and a rectangular wave control mode that outputs one pulse in one electrical cycle. It can drive an inverter.

The control unit has a "large degree of freedom pattern" in which both inverters are driven in PWM control mode, and a "high efficiency pattern" in which one of the two inverters is driven in rectangular wave control mode and the other is driven in PWM control mode. , and a "maximum output pattern" in which both inverters are driven in the rectangular wave control mode. The pattern selection unit selects a drive pattern according to a request for the degree of freedom of power adjustment, a request for system loss reduction, or a request for output of the electric motor.

A large degree of freedom pattern in which a PWM control mode with a large number of switching is also used has a large degree of freedom in power adjustment and is suitable for SOC adjustment of two power sources. A high-efficiency pattern combining the PWM control mode and the square wave control mode is effective in reducing system loss. Also, when a high output (torque) is required for the electric motor, a maximum output pattern in which a rectangular wave control mode is used is suitable. The electric motor driving device of the present invention stably realizes the electric motor torque to be controlled and the electric power state of the two power sources as required, and at least according to the priority factor selected from electric power flexibility, loss reduction, and electric motor output. Three drive patterns are selected. Therefore, adaptability to the operating conditions at that time is improved.

In the first aspect of the present invention, the control unit has a state transition unit (306) that makes a state transition to the selected drive pattern when the current drive pattern is different from the drive pattern selected by the pattern selection unit. In addition to the voltage utilization rate, which is the ratio of the voltage applied to each inverter or motor to the input voltage from each power supply, the state transition section also includes a power distribution ratio or a required amount of power, or a control mode or The state is changed based on the voltage command vector. As a result, it is possible to stably transition the state without disturbing the control.

In the second aspect of the present invention, one of the first inverter control circuit and the second inverter control circuit operates as a torque management circuit, and the other of the first inverter control circuit and the second inverter control circuit has two inverter control circuits. It operates as a power management circuit that manages the power distribution ratio or the amount of power supplied to the inverters.

Also, the PWM control mode includes a sine wave control mode and an overmodulation control mode according to the output of the motor and the amount of electric power of each inverter. The pattern selector has nine combinations of sine wave control mode, overmodulation control mode, or square wave control mode by each inverter control circuit, and the torque control circuit and power control circuit by the first inverter control circuit and the second inverter control circuit. One of a total of 18 driving patterns obtained by multiplying two types of role settings is selected. As a result, it is possible to achieve the desired performance more appropriately with respect to power adjustment, loss reduction, and motor output requirements.

1 is an overall configuration diagram of a system to which an electric motor drive device according to one embodiment is applied; FIG. FIG. 2 is a schematic configuration diagram of a control unit according to one embodiment; FIG. 2 is a block diagram showing control configurations of first and second inverter control circuits; 4 is a block diagram showing configurations of a pattern selector and a state transition unit; FIG. Current line diagram for maximum torque minimum current. FIG. 4 is a diagram for comparing effects of (a) PWM+PWM mode, (b) rectangular+PWM mode, and (c) rectangular+rectangular mode. 4A and 4B are diagrams for explaining switching from a rectangular wave control mode to a PWM control mode in (a) a one-power-supply one-inverter system and (b) a two-power-supply two-inverter system; FIG. 5 is a diagram showing control mode transitions in a driving example in a scene in which the accelerator is released from full throttle; (a) A diagram of switching example 1, (b) a diagram supplementing FIG. 9 (a). (a) Diagram of switching example 2, (b) Diagram of switching example 3, (c) Diagram of switching example 4. FIG. FIG. 4 is a conceptual diagram for explaining role replacement of torque management and power management by the first and second inverter control circuits; (a) Figure of role replacement example 1, (b) Figure of role replacement example 2, (c) Figure of role replacement example 3. FIG. 11 is a diagram of role exchange example 4; FIG. 4 is a diagram showing control mode combinations of “torque management by FB control” and “power management by FF control+power control”; FIG. 5 is a diagram showing control mode transitions in an example of driving in a combination of a rectangular wave control mode and a PWM control mode; 4 is a flow chart illustrating the basic concept of processing according to one embodiment. 4 is a detailed flow chart of processing according to one embodiment. FIG. 5 is a diagram showing control mode combinations between "torque management by FB control";

(one embodiment)
An embodiment of the electric motor drive device will be described below with reference to the drawings. The electric motor drive device of the present embodiment is a device that controls the drive of the MG, which is a three-phase AC motor, in a system that drives a motor generator (hereinafter referred to as "MG"), which is the power source of hybrid vehicles and electric vehicles. "MG" and "MG control device" in the embodiments correspond to "electric motor" and "electric motor driving device".

[System configuration]
FIG. 1 shows the overall configuration of a system in which "two power sources and two inverters", that is, two power sources 11, 12 and two inverters 60, 70 are used. The MG 80 is a permanent magnet synchronous three-phase AC motor having a U-phase winding 81 , a V-phase winding 82 and a W-phase winding 83 . When applied to a hybrid vehicle, the MG80 functions as an electric motor that generates torque for driving the drive wheels, and as a generator capable of generating power by being driven by the kinetic energy of the vehicle transmitted from the engine and the drive wheels. have a function.

The MG 80 of this embodiment has an open winding configuration in which the end points of the three-phase windings 81, 82, and 83 are not coupled. Each phase output terminal of the first inverter 60 is connected to one ends 811, 821, 831 of the three-phase windings 81, 82, 83, and each phase output terminal of the second inverter 70 is connected to the three-phase windings 81, 82 and 83 are connected to the other ends 812 , 822 and 832 . The rotation angle sensor 85 is composed of a resolver or the like, and detects the mechanical angle θm of the MG80. The mechanical angle θm is converted into an electrical angle θe by the electrical angle calculator 87 of the controller 300 .

The first power source 11 and the second power source 12 are two independent power sources that are insulated from each other, and each of them is a chargeable/dischargeable power storage device such as a secondary battery such as nickel metal hydride or lithium ion, or an electric double layer capacitor. . For example, an output type lithium ion battery may be used for the first power source 11 and a capacity type lithium ion battery may be used for the second power source 12 . The power of the power supplies 11 and 12 is represented by SOC (State Of Charge). Also, the voltages of the power supplies 11 and 12 may be the same or different.

The two inverters 60 and 70 receive DC power from the two power sources 11 and 12 individually. First power supply 11 can exchange power with MG 80 via first inverter 60 , and second power supply 12 can exchange power with MG 80 via second inverter 70 . The output of the first inverter 60 is equal to the power of the first power supply 11 and the output of the second inverter 70 is equal to the power of the second power supply 12 .

The MG 80 is supplied with power from the first power supply 11 via the first inverter 60 and is supplied with power from the second power supply 12 via the second inverter 70 . A U-phase voltage VU1, a V-phase voltage VV1, and a W-phase voltage VW1 are applied to the three-phase windings 81, 82, and 83 on the first inverter 60 side. A U-phase voltage VU2, a V-phase voltage VV2, and a W-phase voltage VW2 are applied to the three-phase windings 81, 82, and 83 on the second inverter 70 side.

For example, a current sensor 84 is provided in the power path from first inverter 60 to MG 80 to detect phase currents flowing through three-phase windings 81 , 82 , 83 . In the example of FIG. 1, V-phase current Iv and W-phase current Iw are detected, but any two-phase or three-phase current may be detected. Further, current sensor 84 may be provided in the power path from second inverter 70 to MG 80 or may be provided in both paths of first inverter 60 and second inverter 70 .

The first capacitor 16 is connected between the high potential side wiring P1 and the low potential side wiring N1, and the second capacitor 17 is connected between the high potential side wiring P2 and the low potential side wiring N2. The first voltage sensor 18 detects an input voltage VH1 input from the first power supply 11 to the first inverter 60 . The second voltage sensor 19 detects an input voltage VH2 input from the second power supply 12 to the second inverter 70 . The ratio of the voltage applied to the inverters 60, 70 or MG80 to the input voltages VH1, VH2 from the respective power supplies 11, 12 is the "voltage utilization rate".

The MG control device 100 includes a first inverter 60 , a second inverter 70 , a control section 300 and drive circuits 67 and 77 . The first inverter 60 has six first switching elements 61 to 66 which are provided corresponding to the respective phases of the windings 81, 82, 83 and are bridge-connected. Switching elements 61, 62, and 63 are upper arm switching elements of the U, V, and W phases, respectively, and switching elements 64, 65, and 66 are lower arm switching elements of the U, V, and W phases, respectively. element. The second inverter 70 has six second switching elements 71 to 76 which are provided corresponding to the respective phases of the windings 81, 82, 83 and are bridge-connected. Switching elements 71, 72, and 73 are upper arm switching elements of the U, V, and W phases, respectively, and switching elements 74, 75, and 76 are lower arm switching elements of the U, V, and W phases, respectively. element.

Each of the switching elements 61 to 66 and 71 to 76 is composed of, for example, an IGBT, and is connected in parallel with a free wheel diode that allows a current flowing from the low potential side to the high potential side. In order to prevent a short circuit between the high potential side wirings P1, P2 and the low potential side wirings N1, N2, the upper arm element and the lower arm element of each phase should not be turned on at the same time, but turned on and off complementarily. , is controlled so that when one is on, the other is off.

The control unit 300 is configured by a microcomputer or the like, and includes a CPU, ROM, I/O (not shown), bus lines connecting these components, and the like. The control unit 300 performs software processing by executing a program pre-stored in a physical memory device such as a ROM (that is, a non-temporary readable tangible recording medium) by the CPU, and hardware processing by a dedicated electronic circuit. Perform control by processing.

The control unit 300 controls a first inverter control circuit 301 that generates a first voltage command, which is an output voltage command to the first inverter 60, based on information on the torque command trq ^* and the detected value, and an output to the second inverter. It has a second inverter control circuit 302 that generates a second voltage command that is a voltage command. Information such as the electrical angle θe and the input voltages VH1 and VH2 are input to the inverter control circuits 301 and 302, respectively. First drive circuit 67 outputs a gate signal based on the first voltage command generated by first inverter control circuit 301 to first inverter 60 . Second drive circuit 77 outputs a gate signal based on the second voltage command generated by second inverter control circuit 302 to second inverter 70 .

[Configuration of control unit]
FIG. 2 shows a schematic configuration of the control section 300. As shown in FIG. In the following figures, the inverter is described as "INV". The first inverter control circuit 301 and the second inverter control circuit 302 drive the first inverter 60 and the second inverter 70, respectively, by dq control (that is, vector control on dq axis coordinates). The inverter control circuits 301 and 302 may be provided in separate microcomputers, respectively, or may be provided in one common microcomputer. Each inverter control circuit 301, 302 generates an independent and coordinated voltage command in order to drive as a system of two power supplies and two inverters.

As the information acquired by the control unit 300, since the MG80 is common, the detected values of the angle (specifically, the electrical angle θe) and the three-phase current may be common. However, as indicated by broken lines, a plurality of current sensors 84 and rotation angle sensors 85 may be provided, and the respective inverter control circuits 301 and 302 may acquire corresponding detection values. Further, when performing feedforward control, the second inverter control circuit 302 does not need to acquire the detected values of the three-phase currents as indicated by the dashed lines.

By the way, the dq control for the inverter control circuits 301 and 302 to drive the inverters 60 and 70 is independent. 70 power (and power supply SOC). As a result, even the amount of energized current and the switching state of the inverters 60 and 70 are changed, which affects the system loss. Therefore, in the present embodiment, each inverter control circuit 301, 302 is set to play a role of torque management and power management, and the control mode for driving each inverter 60, 70 is appropriately selected to prioritize control elements. Realization of drive according to

The control unit 300 of this embodiment operates as a torque management circuit in which at least one inverter control circuit manages the torque of the MG 80 by torque feedback control. In the configuration of FIG. 2, one first inverter control circuit 301 serves as a torque management circuit and realizes torque through feedback control. Also, the other second inverter control circuit 302 serves as a power management circuit and manages power by feedforward control and power distribution control. In the following figures, "feedback" is written as "FB", and "feedforward" is written as "FF". Also, in the following specification, power distribution control is also simply referred to as "power control". Note that the roles of the first inverter control circuit 301 and the second inverter control circuit 302 may be exchanged.

In this configuration, the first inverter control circuit 301 corrects disturbance suppression so that the torque follows the command, while the second inverter control circuit 302 controls the inverters 60 and 70 by feedback control uniquely determined by the command. of power is managed. In this way, while the power management circuit adjusts the inverter power, the torque management circuit corrects disturbance suppression through feedback control so that the required torque is achieved. Realization with each power source is compatible.

FIG. 3 simply shows the control configuration of the inverter control circuits 301 and 302 . The first inverter control circuit 301 includes a torque subtractor 32 and a controller 33 . A torque subtractor 32 calculates a torque deviation Δtrq between a torque command trq ^* input from a host ECU or the like and the actual torque. The actual torque trq may be detected directly, or an estimated value may be calculated based on the detected value of the dq-axis current. The controller 33 PI-calculates the voltage phase so as to bring the torque deviation Δtrq close to 0, and outputs the first voltage command together with the separately calculated current amplitude.

The second inverter control circuit 302 includes a power control section 50 . The power control unit 50 receives the first voltage command generated by the first inverter control circuit 301, the second voltage command generated by the second inverter control circuit 302, the input powers VH1 and VH2 of the inverters 60 and 70, and the target A target power distribution ratio or a target power amount is input as a power command. The distribution adjustment amount generated by the power control unit 50 based on these pieces of information is added to the second voltage command output by the feedforward calculation unit 34 in the adjustment amount adder 36 . As a result, the target power distribution is achieved for the power amounts of the inverters 60 and 70 .

Then, the control unit 300 controls the inverters 60 and 70 by the inverter control circuits 301 and 302 so that the system loss is minimized according to the MG output, the electric energy (SOC) of each power supply, or the magnitude relationship thereof. Set the control mode to drive. There are three control modes: sine wave control mode, overmodulation control mode and rectangular wave control mode. The definition of each control mode and the relationship with the voltage utilization rate are well-known techniques in the motor control technical field, and hence description thereof is omitted.

In addition, since the PWM control mode includes a sine wave control mode and an overmodulation control mode according to the output of the MG 80 and the power amount of each inverter 60, 70, the sine wave control mode and the overmodulation control mode are is treated as PWM control mode. In the PWM control mode, each inverter control circuit 301, 302 outputs a plurality of pulses corresponding to the carrier wave frequency in one electrical cycle based on the comparison between the voltage command and the carrier wave. The inverters 60 and 70 are driven by outputting pulses. In the following figures, the PWM control mode is described as "PWM", and the rectangular wave control mode is described as "rectangle".

As shown in FIG. 4, the control section 300 of the present embodiment includes a pattern selection section 305 and a state transition section 306 as components for appropriately setting control modes for driving the inverters 60 and 70 . Information such as an MG output request, a power adjustment request, a loss reduction request, and a power supply SOC is input to the pattern selection unit 305 . These pieces of information may be input via inverter control circuits 301 and 302, as indicated by dashed lines. Based on this information, the pattern selection unit 305 selects either one of three major drive patterns or eighteen minor drive patterns, as will be described later.

When the current drive pattern is different from the drive pattern selected by the pattern selection unit 305, the state transition unit 306 causes the state transition to the selected drive pattern without varying the torque or power. The state transition unit 306 acquires information on the voltage utilization rate, the power distribution ratio, or the required value of the electric energy, the control mode of each inverter control circuit 301, 302, or the voltage command vector, and changes the state based on this information. . This avoids the maintenance of improper rectangular stagnation and achieves the aim condition when needed. The meaning of "rectangular stagnation" will be described later.

Further, the state transition unit 306 switches the roles of the torque management circuit and the power management circuit by the first inverter control circuit 301 and the second inverter control circuit 302 based on the selected drive pattern, thereby changing the possible next drive state. come true. Furthermore, the state transition unit 306 changes the role of the torque management circuit and the power management circuit at the timing determined based on the power amount of each inverter 60, 70, or the control mode or voltage command vector of each inverter control circuit 301, 302. Replace.

[High-efficiency drive principle]
Next, with reference to FIGS. 5 and 6, the high-efficiency drive principle in MG drive will be described. The first high-efficiency driving principle is to realize the command torque with the maximum torque and the minimum current, as shown in FIG. As is well known, the maximum torque minimum current line is drawn as a line that rises from the origin and connects the minimum current points on the equal torque line in the region of Id<0, Iq>0 on the dq-axis current coordinates. A current command vector is determined along the maximum torque/minimum current line according to the required torque, so that the required torque is realized at the minimum current. This reduces MG copper loss and inverter loss due to switching and conduction.

The second high-efficiency drive principle is to achieve a minimum current with a small number of switching times. If the number of switching times is small, the switching loss of the inverter will be small. The third high-efficiency driving principle is multi-level (multi-stage) MG applied voltage. For example, Japanese Unexamined Patent Application Publication No. 2017-175700 discloses a voltage multilevel technology that combines the operations of two three-phase inverters to switch winding end voltages of five levels. Multi-leveling is achieved by the two inverters 60, 70 outputting pulses that are asymmetrical, ie, not fully inverted. As the voltage applied to the MG 80 becomes multi-level, the pulse waveform of the applied voltage becomes closer to a sine wave and the current ripple is reduced. When the ripple is reduced, the harmonic components are reduced and the MG core loss is reduced.

In this embodiment, high-efficiency driving of the MG 80 is realized according to the selection of the control mode for driving the two inverters 60 and 70 . In this embodiment, for convenience of explanation, the control mode is selected on the assumption that the power supply voltages of both power supplies 11 and 12 are the same. However, in other embodiments, the power supply voltage relationship is not limited to the same. Here, there are three control modes for realizing the current amount and characteristics to be energized, sine wave control mode, overmodulation control mode, and rectangular wave control mode, for each inverter 60 and 70. Two inverters 60, A total of 9 drive patterns can be created by combining 70 control modes. Furthermore, including the replacement of the roles of the torque control circuit and the power control circuit by the two inverter control circuits 301 and 302, in the two power supply two inverter system configuration, (9 x 2 =) a total of 18 drive patterns can be used. is.

Also, the sine wave control mode and the overmodulation control mode can be collectively treated as the PWM control mode. If the combination of the PWM control mode and the rectangular wave control mode is arranged, the driving patterns of the two inverters 60 and 70 are broadly divided into the following three patterns.
(1) Pattern in which both of the two inverters 60 and 70 are driven in PWM control mode (2) Pattern in which one of the two inverters 60 and 70 is driven in rectangular wave control mode and the other is driven in PWM control mode (3 ) A pattern in which both inverters 60 and 70 are driven in rectangular wave control mode

In the following description, when a distinction is necessary, the three drive patterns will be referred to as "three major drive patterns" and the eighteen drive patterns will be referred to as "eighteen minor drive patterns" for convenience. There are 8 drive patterns in the major category (1), 8 drive patterns in the major category (2), and 2 minor categories in the drive pattern in the major category (3). Subsequently, the characteristics and selection of the three broadly classified drive patterns will be described, and then switching to the selected drive pattern will be described based on two options, the PWM control mode and the rectangular wave control mode. At the end of the specification, the PWM control mode is divided into the sine wave control mode and the overmodulation control mode, and the performance comparison of the 18 sub-classification drive patterns will be explained. In this specification, the verbs "switch" and "replace" are written with okurigana, and the nouns "switch" and "replace" are written without okurigana.

<Large degree of freedom pattern>
FIG. 6(a) shows a pattern in which both inverters 60 and 70 are driven in PWM control mode. The PWM control mode has a large number of switching times (“SW times” in the figure), but allows fine adjustment of power distribution, and can change the power magnitude relationship, specifically, the magnitude relationship of the SOC of the power supply. That is, the degree of freedom of power adjustment is large. Therefore, this drive pattern is called a "large degree of freedom pattern". The large-degree-of-freedom pattern is effective when prioritizing SOC adjustment of the two power sources 11 and 12, for example, when using power equally.

<High efficiency pattern>
FIG. 6(b) shows a pattern in which one of the two inverters 60 and 70 is driven by the rectangular wave control mode and the other is driven by the PWM control mode. The combination of the rectangular wave control mode and the PWM control mode has a smaller switching frequency, higher efficiency, and lower loss than the large degree of freedom pattern. Therefore, this drive pattern is called a "high efficiency pattern". The power of the inverter driven in square wave control mode is greater than the power of the inverter driven in PWM control mode. In other words, the power magnitude relationship is uniquely determined, so the degree of power freedom is small.

The high-efficiency pattern is effective when priority is given to efficiency, for example, when the SOC of one power supply has a margin and a large amount of power can be used on the one side. In addition, regarding the point that the power magnitude relationship is uniquely determined, it is also possible to use it so as to equalize the power over the long term while alternately switching between the inverter driven in the rectangular wave control mode and the inverter driven in the PWM control mode. It is possible. However, it is premised on allowing temporary power imbalance. Also, in the high-efficiency pattern that combines the rectangular wave control mode and the PWM control mode, both inverters always output different pulses, which is effective for multi-leveling.

<Maximum output pattern>
FIG. 6(c) shows a pattern in which both inverters 60 and 70 are driven in the rectangular wave control mode. This drive pattern is called the "maximum output pattern" because the number of times of switching is the minimum and the MG80 can output the maximum torque. The maximum output pattern is effective when driving the MG80 in a high output range.

As described above, the pattern selection unit 305 of the present embodiment selects a large degree of freedom pattern when the power adjustment degree of freedom request is prioritized, a high efficiency pattern when the system loss reduction request is prioritized, and a high power range pattern. One of the three drive patterns is selected, such as the maximum output pattern when the MG output request is prioritized.

[Problem specific to 2 power supply 2 inverter system - Rectangular stagnation]
Next, with reference to FIGS. 7 and 8, a problem peculiar to the two-power-supply two-inverter system that occurs when switching from the rectangular wave control mode to the PWM control mode in one inverter control circuit will be described. First, for comparison, FIG. 7(a) shows the switching behavior from the rectangular wave control mode to the PWM control mode when the MG output demand decreases in the one-power-supply one-inverter system. A command line indicated by a solid line on the dq-axis current coordinates is a maximum torque minimum current line. The switching line indicated by the dashed line is the line for switching to the PWM control mode because the output voltage in the rectangular wave control mode becomes excessive and the rectangular output is no longer necessary, and is set to the retard side by the margin with respect to the command line.

In the one-power-supply-one-inverter system, since there is a relationship of "MG output=inverter output=power supply power", the control mode of sine wave, overmodulation, and rectangular wave is uniquely determined by the drive state of MG80. In the rectangular wave control mode, the inverter current is controlled to be positioned on the advance side of the command line in a field-weakening state, and when the MG output demand decreases, it moves to the retard side, that is, closer to the command line. . When the output of the rectangular one-pulse voltage exceeds the required voltage, the actual current temporarily crosses the command line and changes from the field-weakening state to the retarding side of the field-strengthening state. Then, when it is determined that the actual current reaches the switching line, the rectangular wave control mode is switched to the PWM control mode.

On the other hand, as shown in FIG. 7B, in the two-power supply two-inverter system, the output and control of the first inverter 60 and the second inverter 70 are independent. Not necessarily in control mode. Also, the timing of control mode switching does not necessarily match. For example, it is assumed that the first inverter control circuit 301 operates in a rectangular wave control mode using a torque feedback control method, and the second inverter control circuit 302 operates in a PWM control mode using a current feedback control method.

Since the PWM control mode has more switching pulses than the rectangular wave control mode, it is excellent in control flexibility and responsiveness. Therefore, the second inverter control circuit 302 traces the current command line regardless of whether the other first inverter control circuit 301 is operating in the square wave control mode. Due to this, an event occurs in which the first inverter control circuit 301 cannot transition from the rectangular wave control mode to the PWM control mode even if the MG output request decreases. Thus, when one inverter control circuit operates in the PWM control mode by the current feedback control method, the other inverter control circuit operating in the rectangular wave control mode cannot transition to the PWM control mode, and the rectangular wave The event of stagnation in control mode is called "rectangular stagnation".

The first specific factor for the rectangular stagnation is due to variations in control and equipment, that is, actual differences between the two inverters 60 and 70 . For example, due to the configuration of two microcomputers, interrupt timing, inverters, and variations in multiple sensors, even if the current is ideally shared, the rectangle of the inverter on the side whose response is delayed during switching may be the switching line. You may not be able to cross over.

In FIG. 7(b), the recognition values of the first inverter current and the second inverter current are not always common due to the influence of variations in control and equipment. For example, assume that the first inverter current crosses the command line and reaches the switching line before the second inverter current. Then, in the first inverter control circuit 301, the switching determination from the rectangular wave control mode to the PWM control mode is established, and the control is shifted to the control along the command line. On the other hand, since the first inverter control circuit 301 shifts to control on the command line before the second inverter current reaches the switching line, the second inverter control circuit 302 determines switching from the rectangular wave control mode to the PWM control mode. does not hold. This behavior is shown in the (*) part of FIG. 7(b).

Thus, as long as one inverter control circuit continues to maintain the command line in the PWM control mode based on the current feedback control method, the inverter side driven in the rectangular wave control mode loses the opportunity to reach the switching line, and the rectangular wave It becomes impossible to return from the control mode to the PWM control mode. In this way, if the rectangular wave control mode is maintained unintentionally, the rectangular output voltage will be canceled when the torque and rotation speed decrease to a level where one of the rectangular outputs is not required for the MG output. current feedback control works. At that time, if the output voltage cannot be canceled due to the difference in the applied voltage, an overcurrent will occur, which will lead to torque fluctuations and equipment failure.

The second specific factor of the rectangular stagnation is bias in the output of each inverter (or power supply power) due to how the MG drive system is used. Even if torque feedback control causes the torque to follow the command and the MG output is achieved as requested, the SOC of the power from the two power sources may be adjusted. When adjusted to decrease the SOC on the first power supply 11 side and increase the SOC on the second power supply 12 side (SOC1<SOC2), the torque management circuit is feedback control, and the power management circuit is feedforward control and power control. 2, the output of the second inverter 70 is boosted to enter the rectangular wave control mode again. In that state, if the first inverter 60 is driven in the PWM control mode by the current feedforward control method, the second inverter current will have no chance to reach the switching line because it is controlled by the command line.

FIG. 8 shows control mode transitions in an example of operation in a scene in which the accelerator is released from the fully open state. In phase I, the first inverter 60 and the second inverter 70 are driven between square wave control modes, with maximum output and power equalization. At this time, if the equal power of each inverter 60, 70 is Peq, the MG power is equivalent to twice Peq. In Phase II, the MG output drops and both inverters 60, 70 transition to PWM control mode while maintaining power equality.

In phase III the MG output is further reduced. At this time, when the output of the second inverter 70 is boosted by adjusting the SOC, the second inverter 70 side enters the rectangular wave control mode again, resulting in an excessive voltage state. However, as mentioned above, the second inverter current misses the opportunity to reach the switching line, so overcurrent may occur.

[Switch control mode]
At the time of switching the control mode, the process of escaping from the rectangular stagnation described above and switching from the rectangular wave control mode to the PWM control mode is called "rectangular escape". The state transition unit 306 transitions the drive state so as to "exit from the rectangle" when necessary, even if the inverter control circuit operating in the rectangular wave control mode is constantly controlled by the command line.

9 and 10 list examples of switching methods for switching the inverter control circuit operating in the rectangular wave control mode from the maximum torque and minimum current to the PWM control mode. 9 and below, [1] indicates the first inverter 60 or the first inverter control circuit 301, and [2] indicates the second inverter 70 or the second inverter control circuit 302. FIG.

The state transition unit 306 transitions the drive state based on the voltage utilization rate, the control mode of each inverter control circuit 301, 302, the power distribution ratio or the required value of the power amount, or the voltage command vector. In each switching example, the second inverter control circuit 302 operates in the PWM control mode by the current feedback control method, and the first inverter control circuit 301 exits the rectangular wave control mode and switches to the PWM control mode.

In switching example 1 shown in FIG. 9A, the state transition unit 306 determines switching based on the voltage utilization rate and the power request value of each inverter 60 and 70 . Assuming that the ratio of the required power values of the first inverter 60 and the second inverter 70 before switching is X:Y and the voltage utilization rate of the second inverter 70 is Vuf2, the voltage utilization rate Vuf_MG of the MG 80 is "{(X+Y) /Y}×Vuf2". Note that the power request value may be a power command or a computable actual power amount.

When the MG voltage utilization rate Vuf_MG decreases and falls below the rectangular exit determination threshold, the state transition unit 306 determines that the rectangular wave control mode does not need to be continued, and switches the first inverter control circuit 301 to the PWM control mode. Here, in order to prevent hunting in control, it is preferable to set a margin for the determination threshold. That is, when the voltage utilization rate Vuf_MG of the MG falls below the value obtained by subtracting the margin from the determination threshold, the state transition unit 306 determines that there is no risk of hunting during switching, and switches from the rectangular wave control mode to the PWM control mode. Execute switching.

Here, referring to FIG. 9B, switching example 1 will be supplemented from the viewpoint of the power modulation degree of the first inverter 60 . Before switching, the control modulation degrees of the first inverter 60 and the second inverter 70 are both values of the rectangular wave control mode. The output request decreases during MG driving, and the control modulation index of the second inverter 70 starts decreasing at the timing tr when the rectangular output from both the inverters 60 and 70 becomes unnecessary. On the other hand, the first inverter 60 is in a state of rectangular stagnation.

After that, at the timing tx when the power modulation degree of the first inverter 60 has decreased to the PWM switching threshold, the state transition unit 306 switches the first inverter control circuit 301 from rectangular stagnation to PWM control mode. The "first inverter power modulation factor" after timing tx indicates the modulation factor when power distribution control is executed after switching from rectangular stagnation to PWM control mode. Even if the power distribution request is realized by the power control after switching, the first inverter 60 is prevented from switching from the PWM control mode to the rectangular wave control mode and stagnating, which is inappropriate control.

In short, the state transition unit 306 prevents the first inverter 60 from switching from the PWM control mode to the rectangular wave control mode again. Therefore, the state transition unit 306 determines that the first inverter 60 on the rectangular stagnation side is It is determined whether or not there is a possibility of switching to the square wave control mode again with the amount of electric power that will be borne at present or immediately thereafter.

In switching example 2 shown in FIG. 10A, the state transition unit 306 determines switching based on the control mode of each inverter control circuit 301 and 302 and the voltage utilization rate of each inverter 60 and 70 . Before switching, the voltage utilization rate of the first inverter 60 driven in the rectangular wave control mode is maintained at a constant value Vuf0, and the voltage utilization rate of the second inverter 70 driven in the PWM control mode is reduced to MG output reduction. It gradually decreases from Vuf0 accordingly. Then, at the timing tx when the voltage utilization rate of the second inverter 70 reaches the threshold Vuf_th, the first inverter control circuit 301 is switched from the rectangular wave control mode to the PWM control mode. The voltage utilization rate threshold Vuf_th is set to a limit value at which the voltage becomes excessive when the first inverter 60 is driven in the rectangular wave control mode beyond that.

In switching example 3 shown in FIG. The behavior before and after the switching timing tx is the same as in the second switching example. The power amount of the second inverter 70 gradually decreases from Pwr0, and the first inverter control circuit 301 is switched from the rectangular wave control mode to the PWM control mode at the timing tx when the power amount threshold value Pwr_th is reached. The power amount threshold Pwr_th is set to, for example, a sufficiently small value including zero or a negative value.

Here, the output voltage from the viewpoint of inverters 60 and 70 and the output voltage from the viewpoint of MG 80 are distinguished and their relationship will be described. In the present embodiment, one MG 80 is the object of control, so the viewpoint is adjusted to the object of control, and the inverters 60 and 70 are controlled by the control method from the MG viewpoint. However, due to the characteristics of this technology, it is not necessary to limit the viewpoint. In other words, the inverters 60 and 70 may be controlled from the viewpoint of the inverter instead of the viewpoint of the MG to be controlled. In that case, it becomes unnecessary to use the correction ratio for calculating the inverter power, which will be described below, and the correction ratio for various determination means, which will be described later.

The output voltage from the viewpoint of the inverter is a value synonymous with the voltage amplitude Vamp1, Vamp2 of each inverter 60, 70, or a value multiplied by a conversion factor. Therefore, the output voltage Vamp1 of the first inverter 60 and the output voltage Vamp2 of the second inverter 70 are calculated based on the input voltages VH1 and VH2 input from the power supplies 11 and 12, respectively, as shown in equations (1.1) and (1.2). can be grasped by |Vdq1| and |Vdq2| are the output voltages from the viewpoint of MG 80 corresponding to the first inverter 60 and the second inverter 70, respectively, when the total input voltage is (VH1+VH2). Also, the denominator (VH1+VH2) is the maximum applied voltage from the viewpoint of the MG 80, and the numerators VH1 and VH2 are the maximum voltages applied by the inverters 60 and 70 themselves. The fractional part is defined as the correction ratio K1, K2 of each inverter 60,70.

Also, the power Pwr1 of the first inverter 60 and the power Pwr2 of the second inverter 70 are represented by the product of the voltage, the current and the power factor according to equations (2.1) and (2.2). In the formula, Vamp1 and Vθ1 are the voltage amplitude and voltage phase of the first inverter 60, and Vamp2 and Vθ2 are the voltage amplitude and voltage phase of the second inverter . Iamp, Iθ are common current amplitude and current phase. The difference (Vθ1−Iθ) and (Vθ2−Iθ) between the voltage phase and the current phase corresponds to the power factor angle. Power Pwr_MG of MG 80 is represented by the sum of power Pwr1 of first inverter 60 and power Pwr2 of second inverter 70 according to equation (2.3).

Further, the powers Pwr1 and Pwr2 of the inverters 60 and 70 are the correction ratios K1 and K2, the dq-axis currents Id and Iq, the dq-axis voltages Vd1 and Vq1 of the first inverter 60, the dq-axis voltage Vd2 of the second inverter 70, Based on Vq2, it is represented by formulas (3.1) and (3.2). Therefore, the power of each inverter 60, 70 can be grasped from the relationship between the equations (2.1), (2.2) and the equations (3.1), (3.2).

In switching example 4 shown in FIG. 10C, the state transition unit 306 determines switching based on the relationship between the voltage command vectors of the inverter control circuits 301 and 302 . When the output decreases from the state shown on the left side and the output voltage of the rectangular wave control by the first inverter control circuit 301 becomes excessive, the voltage command vector of the second inverter control circuit 302 behaves to cancel out the excessive voltage of the rectangular wave control. , the d-axis voltage Vd is positive or the q-axis voltage Vq is negative. At this time, occurrence of an inflection point at which the voltage phase is reversed is detected and used for switching determination.

[Replacement of roles of inverter control circuit]
Next, with reference to FIG. 11, the switching of the roles of the torque management circuit and the power management circuit by the first inverter control circuit 301 and the second inverter control circuit 302 will be described. When the SOC of the first power supply 11 is higher than the SOC of the second power supply 12 and the power of the first inverter 60 has a margin, as shown in the upper side of the figure, the first inverter control circuit 301 is the torque management circuit and the second inverter The control circuit 302 is role set as a power management circuit. On the other hand, when the SOC of the second power supply 12 is higher than the SOC of the first power supply 11 and the power of the second inverter 70 has a margin, as shown in the lower part of the figure, the first inverter control circuit 301 is the power management circuit, The role of the second inverter control circuit 302 is set as a torque management circuit.

For the two types of role setting, three types of driving patterns are switched according to the priority element. When power flexibility is prioritized, the torque management circuit performs feedback control in the PWM control mode, and the power management circuit performs feedforward power distribution control in the PWM control mode. When high efficiency (ie, low losses) is a priority, the torque management circuit operates in square wave control mode and the power management circuit performs feedforward power distribution control in PWM control mode. When maximum output is prioritized, both the torque management circuit and the power management circuit operate in square wave control mode.

A double-headed solid line arrow on the left side of the figure indicates an operation of switching the roles of the two inverter control circuits between the "rectangular-rectangular" drive patterns. Also, the double-headed dashed arrow indicates an operation of switching the roles of the two inverter control circuits between the "PWM-PWM" drive patterns. In this way, by switching the roles of the two inverter control circuits according to the driving state of the inverter, 18 kinds of driving patterns can be realized. As a result, in a state where one inverter control circuit operates in the square wave control mode and the other inverter control circuit operates in the PWM control mode, it is possible to perform control so as to maintain the command line for maximum torque and minimum current.

FIGS. 12 and 13 show an example of a replacement method in which the state transition unit 306 switches the roles of the torque management circuit and the power management circuit, and drives the inverters 60, 70 and MG 80 stably without fluctuation at the moment of switching. Enumerate. In the figure, "torque" means the torque management circuit, and "power" means the power management circuit. As shown in the following example, the state transition unit 306 changes the torque management circuit at timing determined based on the power amount of each inverter 60, 70, or the control mode or voltage command vector of each inverter control circuit 301, 302. and swap the roles of the power management circuit.

In replacement example 1 shown in FIG. 12A, the first inverter control circuit 301 operates as a torque management circuit and the second inverter control circuit 302 operates as a power management circuit in both PWM control modes before replacement. The power amount of the first inverter 60 gradually decreases from A[W], and the power amount of the second inverter 70 gradually increases from B[W] (<A[W]). Then, at timing txx when the power amounts of the inverters 60 and 70 are both equal to (A+B)/2 [W], the roles are switched, the first inverter control circuit 301 is the power management circuit, and the second inverter control circuit 302 is the power management circuit. It becomes a torque control circuit. In replacement example 1, the instantaneous power of inverters 60, 70 and MG 80 is guaranteed.

In replacement example 2 shown in FIG. 12B, before replacement, the first inverter control circuit 301 operates as a torque management circuit and the second inverter control circuit 302 operates as a power management circuit in both PWM control modes. The output of the first inverter control circuit 301 increases, and at timing txx when the PWM control mode is switched to the rectangular wave control mode, the roles are switched, and the second inverter control circuit 302 becomes the torque management circuit. The first inverter control circuit 301 may operate as either a power management circuit or a torque management circuit. In replacement example 2, a measure is realized that maintains the command line even when one is in the square wave control mode.

In replacement example 3 shown in FIG. 12C, before replacement, the first inverter control circuit 301 operates as a torque management circuit and the second inverter control circuit 302 operates as a power management circuit in both rectangular wave control modes. The power amount A [W] of the first inverter 60 and the power amount B [W] of the second inverter 70 are equivalent. At a certain timing txx during operation, the roles are switched based on the SOC magnitude of each of the power supplies 11 and 12, the first inverter control circuit 301 becomes the power management circuit, and the second inverter control circuit 302 becomes the torque management circuit.

Also, when the MG output drops from a certain timing tdn, the power amount of the second inverter 70 drops from B [W] to BB [W], and the second inverter control circuit 302 switches to the PWM control mode. On the other hand, the electric energy of the first inverter 60 changes from A [W] to AA [W], and the first inverter control circuit 301 operates in the rectangular wave control mode. As described above, in the replacement example 3, the roles are switched as a preliminary preparation after escaping from the rectangular wave control mode.

In the replacement example 4 shown in FIG. 13, the voltage command vectors of the inverter control circuits 301 and 302 are always shared, and the state transition unit 306 exchanges the command at an arbitrary timing, whereby the inverter control circuits 301 and 302 replace the role of In exchange example 4, roles can be forcibly exchanged.

[Performance comparison of control mode combinations]
In FIG. 14, the first inverter control circuit 301 performs feedback control as a torque management circuit, and the second inverter control circuit 302 performs feedforward control and power control as a power management circuit. Show the difference in performance. The symbol "⊚" in the figure means very good, "○" means good, "Δ" means inferior, and "×" means very inferior. “=” and “>” express superiority or inferiority of performance with an equal sign or an inequality sign. The upper right column and the lower left column are symmetrical with respect to the diagonal line connecting the upper left and lower right of the figure.

The sine wave control mode is selected when the output of the first inverter 60 (=the power of the first power supply 11) is small, the overmodulation control mode when it is medium, and the rectangular wave control mode when it is large. The sine wave control mode is selected when the output of the second inverter 70 (=the power of the second power supply 12) is small, the overmodulation control mode when it is intermediate, and the rectangular wave control mode when it is large.

The combination of sine wave control modes has a large degree of power freedom and the largest number of switching times. The combination of the sine wave control mode and the overmodulation control mode has a medium degree of power freedom and a small number of switching times. The combination of the sine wave control mode and the rectangular wave control mode and the combination of the overmodulation control modes have a small degree of power freedom and a small number of switching times. In the combination of the overmodulation control mode and the square wave control mode, there is almost no power flexibility and the number of switching times is almost the minimum.

In the combination of square wave control modes, there is no power degree of freedom and the number of switching times is the minimum. Supplementally, in the combination of the rectangular wave control modes, the outputs of both the first inverter 60 and the second inverter 70 are large, and the MG output is maximized. However, since the command current is set in the field-weakening region on the advance side of the maximum torque minimum current line, the required current for torque does not become the minimum.

FIG. 15 shows control mode transitions in an example in which the first inverter 60 is driven in the rectangular wave control mode and the second inverter 70 is driven in the PWM control mode. In phase I, the first inverter 60 and the second inverter 70 are driven between PWM control modes and the output power is in a state of equality. At this time, if the equal power of each inverter 60, 70 is Peq, the MG power is equivalent to twice Peq.

In phase II, the second inverter control circuit 302 performs power control in PWM control mode such that the first inverter 60 is in square wave control mode. As a result, the output of the first inverter 60 increases and the output of the second inverter 70 decreases accordingly. In Phase III, MG output is reduced. At this time, the second inverter control circuit 302 performs power control so that the first inverter 60 maintains the rectangular wave control mode even if the MG output changes.

[Processing flowchart]
The flowchart of FIG. 16 shows the basic concept of processing by the control unit 300 of this embodiment. In the description of the flowchart, the symbol "S" means step. In S01, the control unit 300 grasps the driving state of the MG80. Specifically, the role of each inverter 60, 70, MG output, control current and voltage, control state, etc. are grasped. These pieces of information may be substituted with information on the amount of control used for normal control. In S02, as a priority element in MG drive control, which one of (1) large degree of freedom related to power adjustment of two power sources, (2) high efficiency (that is, low loss), and (3) realization of maximum output is given priority? It is determined.

In S03, the pattern selection unit 305 selects one of the 18 drive patterns obtained by multiplying 9 combinations of control modes and 2 combinations of the role settings of the torque management circuit and the power management circuit by the inverter control circuits 301 and 302. Choose a pattern. In S04, if the current drive pattern is different from the drive pattern selected by the pattern selection unit 305, the state transition unit 306 causes the state transition to the selected drive pattern.

Details of the processing are shown in the flowchart of FIG. In S11, the control unit 300 acquires the required torque for the MG 80 from a higher-level vehicle control circuit or the like. The subsequent steps S12 to S20 are steps in which the pattern selection unit 305 selects one of the 18 drive patterns. (x1), (x4), and (x2) in S13, S15, S17, and S18 indicate the number of control mode combination patterns defined at that step.

In S12, it is determined whether or not the MG 80 is driven in the high output range. If YES, the process proceeds to S13, and if NO, the process proceeds to S14. At S13, realization of the maximum output is selected by one combination of "[1]: rectangle, [2]: rectangle". In S14, it is determined whether there is a priority request for power adjustment, that is, whether there is a priority request for adjustment so as to equalize the SOCs of the two power sources. If YES in S14, the process proceeds to S15, and if NO, the process proceeds to S16. In S15, aggressive power adjustment is selected by a combination of "[1]: PWM, [2]: PWM". There are four combinations of "[1]: PWM, [2]: PWM" because the sine wave control mode or overmodulation control mode is selected for each inverter.

In S16, it is determined whether or not there is a request for preferential use of power from the first power supply 11 . If the SOC of the first power supply 11 is greater than the SOC of the second power supply 12 and the power of the first power supply 11 is preferentially used, the determination is YES, and the process proceeds to S17. Conversely, when the SOC of the second power supply 12 is greater than the SOC of the first power supply 11 and the power of the second power supply 12 is preferentially used, the determination is NO, and the process proceeds to S18.

High efficiency operation is selected by a combination of "[1]: rectangular, [2]: PWM" in S17 and by a combination of "[1]: PWM, [2]: rectangular" in S18. In other words, the inverter control circuit on the power supply side with power margin operates in the square wave control mode that uses more power, and the power supply side inverter control circuit with no power margin operates in the PWM control mode and overruns. Adjust for deficiencies. Combinations of "[1]: Rectangular, [2]: PWM" and "[1]: PWM, [2]: Rectangular" select either sine wave control mode or overmodulation control mode as the PWM control mode. There are two ways. Up to this point, a total of nine drive patterns are selected.

In S19, it is determined whether or not there is a request for torque management in feedback control in the first inverter control circuit 301 . In the case of YES in S19, the pattern selection unit 305 sets the role of the first inverter control circuit 301 to the torque management circuit and the role of the second inverter control circuit 302 to the power management circuit in S20. If NO in S19, the pattern selection unit 305 sets the role of the first inverter control circuit 301 to the power management circuit and the role of the second inverter control circuit 302 to the torque management circuit in S21. In this way, a total of 9 patterns defined up to S18 are multiplied by 2 patterns for setting the role of the inverter control circuit, resulting in a total of 18 patterns.

Next, in S22, the state transition section 306 executes the state transition to the selected drive pattern. At S23, the control unit 300 calculates the voltage command so as to achieve the request and generates an inverter drive signal. As described above, in the present embodiment, while stably realizing the MG torque to be controlled and the power state of the two power sources as required, there is a large degree of power freedom according to the priority element from among a plurality of drive patterns. A pattern or a pattern that minimizes loss can be selected.

[Modified Example of Role Configuration of Inverter Control Circuit]
In the basic embodiment described above, one inverter control circuit operates as a torque management circuit and the other inverter control circuit operates as a power management circuit, and the combination of control modes in that configuration is described in FIG. On the other hand, FIG. 18 shows a combination of control modes in a role configuration in which both inverter control circuits perform feedback control as torque management circuits. Symbols in the figure conform to FIG.

Here, the combination of the sine wave control mode or the overmodulation control mode, which is the PWM control mode, is selected mainly for the purpose of power adjustment. That is, it is excluded because it is based on feedback control and power control, not on feedback control. In the case of two rectangular wave control modes, at least one of them needs to be feedback control in order to realize torque. Also, the combination of rectangular wave control modes is selected mainly for the purpose of maximum output, and may be either "feedback control + power control" or feedback control. In either case, the number of switching times is minimized.

In the combination of sine wave control mode and square wave control mode, the power is commensurate and the number of switching times is small. In the combination of overmodulation control mode and square wave control mode, the power is commensurate and the switching times are minimal. In these combinations, if the power supply voltage is the same, the rectangular wave control mode consumes more power. Further, even if the power supply voltages are different, it is possible to compare the amounts of electric power according to the actual situation by correcting the ratio of both power supply voltages.

Here, the implications of the configuration of "torque management by feedback control" will be described. Control responsiveness is improved in the PWM control mode (especially in the sine wave control mode) compared to the rectangular wave control mode due to the large number of switching times in one electrical cycle and the difference in control cycle. Using this characteristic, the control unit 300 uses feedback control in the PWM control mode for high-speed control so that an optimum (for example, minimum torque) current command can be obtained even if the rectangular wave control mode side is feedback control. , we intentionally generate “rectangular stagnation”. As a result, while satisfying the required torque, it is possible to continue to automatically realize the optimum current by feedback control in the PWM control mode while driving one inverter in the rectangular wave control mode. In other words, it is possible to take advantage of the "rectangular stagnation" phenomenon unique to two power sources and two INVs.

(Other embodiments)
(a) Specific means for switching the control mode by the state transition unit 306 or switching the roles of the two inverter control circuits is not limited to the means illustrated in FIGS. may be used. Further, if MG torque or power fluctuation at the time of control mode switching does not matter, the state transition unit 306 may not be provided, and the drive pattern selected by the pattern selection unit 305 may always be forcibly switched.

(b) In the configuration using two independent power sources, each power source is not limited to a configuration in which both are secondary batteries represented by batteries or capacitors. For example, one power source may be a secondary battery, and the other power source may be configured by a fuel cell or a generator.

(c) The number of phases of the open windings of the electric motor is not limited to three, and may be four or more. Alternatively, a configuration in which two-phase open windings are bridge-connected may be used.

(d) The 2-power source 2-inverter type electric motor drive device is suitable for pure electric vehicles such as electric vehicles and fuel cell vehicles, PHVs (plug-in hybrids), hybrid power trains such as range extenders that are rich in electricity, and furthermore, It is applied to light electric vehicles such as 12-48V ISG (Integrated Starter Generator). This technology is based on voltage-type circuit topology that can be applied to applications that realize high output with high efficiency by serializing the power supply voltage without using any booster circuit using a reactor, which is known as conventional technology. . This technology is suitable for applications in vehicles that require high output even in areas where conventional boost circuits and high-current inverters are thermally difficult to achieve, enabling more efficient operation than conventional powertrains. .

As described above, the present invention is by no means limited to the above embodiments, and can be embodied in various forms without departing from the spirit of the present invention.

11... First power supply, 12... Second power supply,
300... control section,
301... First inverter control circuit,
302... second inverter control circuit,
305... Pattern selection unit, 306... State transition unit,
60... first inverter, 61 to 66... first switching element,
70 ... second inverter, 71 to 76 ... second switching element,
80... MG (motor generator, electric motor),
81, 82, 83... 3 phase windings.

Claims (9)

A motor driving device for controlling the driving of a motor (80) having two or more phase windings (81, 82, 83) whose ends are open, using two inverters to which two power sources are individually connected. and
DC power is input from a first power supply (11), a plurality of first switching elements (61 to 66) are provided corresponding to each phase of the winding, and the first switching element is connected to one end of the winding. 1 inverter (60);
DC power is input from a second power supply (12), and it has a plurality of second switching elements (71 to 76) provided corresponding to each phase of the winding, and is connected to the other end of the winding. a second inverter (70);
Based on the torque command, a first inverter control circuit (301) that generates a first voltage command that is an output voltage command to the first inverter, and a second voltage command that is an output voltage command to the second inverter. a control unit (300) having two inverter control circuits, a second inverter control circuit (302) for generating;
with
at least one of the first inverter control circuit and the second inverter control circuit operates as a torque management circuit that manages the torque of the electric motor by torque feedback control;
Each inverter control circuit has a PWM control mode that outputs a plurality of pulses corresponding to the carrier wave frequency in one electrical cycle based on the comparison between the voltage command and the carrier wave, and a rectangular wave control mode that outputs one pulse in one electrical cycle. can drive the inverter by
The control unit has a large degree of freedom pattern in which both of the two inverters are driven in PWM control mode, a high efficiency pattern in which one of the two inverters is driven in rectangular wave control mode and the other is driven in PWM control mode, and a maximum output pattern for driving both of the two inverters in a rectangular wave control mode. a state transition unit (306) that, when different from the drive pattern selected by the pattern selection unit, causes a state transition to the selected drive pattern;
The pattern selection unit selects a drive pattern according to a request for power adjustment flexibility, a request for system loss reduction, or a request for output of the electric motor ,
In addition to the voltage utilization rate, which is the ratio of the voltage applied to each inverter or the motor to the input voltage from each power supply, the state transition unit also controls a power distribution ratio or a required amount of power, or controls each of the inverters. A motor drive device that changes state based on the circuit control mode or voltage command vector . A motor driving device for controlling the driving of a motor (80) having two or more phase windings (81, 82, 83) whose ends are open, using two inverters to which two power sources are individually connected. and
DC power is input from a first power supply (11), a plurality of first switching elements (61 to 66) are provided corresponding to each phase of the winding, and the first switching element is connected to one end of the winding. 1 inverter (60);
DC power is input from a second power supply (12), and it has a plurality of second switching elements (71 to 76) provided corresponding to each phase of the winding, and is connected to the other end of the winding. a second inverter (70);
Based on the torque command, a first inverter control circuit (301) that generates a first voltage command that is an output voltage command to the first inverter, and a second voltage command that is an output voltage command to the second inverter. a control unit (300) having two inverter control circuits, a second inverter control circuit (302) for generating;
with
Either the first inverter control circuit or the second inverter control circuit operates as a torque management circuit that manages the torque of the electric motor by torque feedback control, and the first inverter control circuit or the second inverter control circuit The other operates as a power management circuit that manages the power distribution ratio or power amount supplied to the two inverters,
Each inverter control circuit has a PWM control mode that outputs a plurality of pulses corresponding to the carrier wave frequency in one electrical cycle based on the comparison between the voltage command and the carrier wave, and a rectangular wave control mode that outputs one pulse in one electrical cycle. can drive the inverter by
The control unit has a large degree of freedom pattern in which both of the two inverters are driven in PWM control mode, a high efficiency pattern in which one of the two inverters is driven in rectangular wave control mode and the other is driven in PWM control mode, and a pattern selection unit (305) for selecting one of three drive patterns: a maximum output pattern for driving both of the two inverters in a rectangular wave control mode;
The electric motor driving device, wherein the pattern selecting unit selects a driving pattern according to a request for a degree of freedom of power adjustment, a request for system loss reduction, or a request for output of the electric motor. The PWM control mode includes a sine wave control mode and an overmodulation control mode according to the output of the electric motor and the power amount of each inverter,
The pattern selection unit
Nine combinations of sine wave control mode, overmodulation control mode, or rectangular wave control mode by each inverter control circuit, roles of the torque management circuit and the power management circuit by the first inverter control circuit and the second inverter control circuit 3. The electric motor driving device according to claim 2, wherein one of a total of 18 drive patterns obtained by multiplying two settings is selected. The control unit has a state transition unit (306) that makes a state transition to the selected drive pattern when the current drive pattern is different from the drive pattern selected by the pattern selection unit,
4. The motor drive according to claim 3 , wherein the state transition unit switches roles of the torque management circuit and the power management circuit by the first inverter control circuit and the second inverter control circuit based on the selected drive pattern. Device. The state transition unit switches roles of the torque management circuit and the power management circuit at timing determined based on the power amount of each inverter, or the control mode or voltage command vector of each inverter control circuit. 5. The electric motor drive device according to 4 . In addition to the voltage utilization rate, which is the ratio of the voltage applied to each inverter or the motor to the input voltage from each power supply, the state transition unit also controls a power distribution ratio or a required amount of power, or controls each of the inverters. 6. The electric motor driving device according to claim 4, wherein the state is changed based on the control mode of the circuit or the voltage command vector. The motor drive device according to any one of claims 1 to 6, wherein the pattern selection section selects the drive pattern based on the power amounts of the two inverters or the SOCs of the two power sources. A motor driving device for controlling the driving of a motor (80) having two or more phase windings (81, 82, 83) whose ends are open, using two inverters to which two power sources are individually connected. A program of
The electric motor drive device
DC power is input from a first power supply (11), a plurality of first switching elements (61 to 66) are provided corresponding to each phase of the winding, and the first switching element is connected to one end of the winding. 1 inverter (60);
DC power is input from a second power supply (12), and it has a plurality of second switching elements (71 to 76) provided corresponding to each phase of the winding, and is connected to the other end of the winding. a second inverter (70);
Based on the torque command, a first inverter control circuit (301) that generates a first voltage command that is an output voltage command to the first inverter, and a second voltage command that is an output voltage command to the second inverter. a control unit (300) having two inverter control circuits, a second inverter control circuit (302) for generating;
with
at least one of the first inverter control circuit and the second inverter control circuit operates as a torque management circuit that manages the torque of the electric motor by torque feedback control;
Each inverter control circuit has a PWM control mode that outputs a plurality of pulses corresponding to the carrier wave frequency in one electrical cycle based on the comparison between the voltage command and the carrier wave, and a rectangular wave control mode that outputs one pulse in one electrical cycle. can drive the inverter by
For the control unit,
A large degree of freedom pattern in which both of the two inverters are driven in PWM control mode, a high efficiency pattern in which one of the two inverters is driven in square wave control mode and the other is driven in PWM control mode, and the two inverters maximum output pattern in which both inverters are driven in rectangular wave control mode, any one of three drive patterns, depending on the power adjustment degree of freedom request, system loss reduction request, or the output request of the electric motor operate to select, and
When the current drive pattern is different from the drive pattern selected by the pattern selection unit, in addition to the voltage utilization rate, which is the ratio of the voltage applied to each inverter or motor to the input voltage from each power supply, the power A program that causes a state transition to the selected drive pattern based on the distribution ratio or the required value of the electric energy, or the control mode or voltage command vector of each of the inverter control circuits. A motor driving device for controlling the driving of a motor (80) having two or more phase windings (81, 82, 83) whose ends are open, using two inverters to which two power sources are individually connected. A program of
The electric motor drive device
DC power is input from a first power supply (11), a plurality of first switching elements (61 to 66) are provided corresponding to each phase of the winding, and the first switching element is connected to one end of the winding. 1 inverter (60);
DC power is input from a second power supply (12), and it has a plurality of second switching elements (71 to 76) provided corresponding to each phase of the winding, and is connected to the other end of the winding. a second inverter (70);
Based on the torque command, a first inverter control circuit (301) that generates a first voltage command that is an output voltage command to the first inverter, and a second voltage command that is an output voltage command to the second inverter. a control unit (300) having two inverter control circuits, a second inverter control circuit (302) for generating;
with
Either the first inverter control circuit or the second inverter control circuit operates as a torque management circuit that manages the torque of the electric motor by torque feedback control, and the first inverter control circuit or the second inverter control circuit The other operates as a power management circuit that manages the power distribution ratio or power amount supplied to the two inverters,
Each inverter control circuit has a PWM control mode that outputs a plurality of pulses corresponding to the carrier wave frequency in one electrical cycle based on the comparison between the voltage command and the carrier wave, and a rectangular wave control mode that outputs one pulse in one electrical cycle. can drive the inverter by
For the control unit,
A large degree of freedom pattern in which both of the two inverters are driven in PWM control mode, a high efficiency pattern in which one of the two inverters is driven in square wave control mode and the other is driven in PWM control mode, and the two inverters maximum output pattern in which both inverters are driven in rectangular wave control mode, any one of three drive patterns, depending on the power adjustment degree of freedom request, system loss reduction request, or the output request of the electric motor A program that acts as a selection.

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