JP2021078284A - Control device of ac rotating machine - Google Patents

Abstract

To provide a control device of an AC rotating machine which can determine abnormality in a current detection circuit that detects a field current, and suppress heat generation of the current detection circuit.SOLUTION: A control device of an AC rotating machine includes a bus current detection circuit 6 that detects a bus current, a common path current detection circuit 7 that detects a field current, a converter switching control unit 31 that switches between a power supply path and a return path of a converter 9, a current calculation unit 32 that detects a field current If_det by the common path current detection circuit 7, detects a bus current by the bus current detection circuit 6, and calculates a field current estimated value on the basis of the bus current, and an abnormality determination unit 33 that compares the field current If_det with the field current estimated value, and determines abnormality of one or both of the bus current detection circuit 6 and the common path current detection circuit 7.SELECTED DRAWING: Figure 2

Description

The present application relates to a control device for an AC rotating machine.

The electronic control device of Patent Document 1 drives a DC motor by an H-bridge circuit, and detects the motor current by using the first current detection circuit and the second current detection circuit. Further, the abnormality is determined by mutually comparing the signal of the first current detection circuit and the signal of the second current detection circuit.

JP-A-2018-182798

In Patent Document 1, since a current detection circuit is provided in each of the two connection paths connecting the H-bridge circuit and the motor, current always flows through the two current detection circuits while the motor current is flowing. .. As in Patent Document 1, in many cases, the current detection circuit uses a shunt resistor, so that the shunt resistor generates heat while the current is flowing. Therefore, since the motor current always flows through the two current detection circuits, the heat generated in the H bridge becomes large.

Therefore, in an AC rotating machine having an AC armature winding and a field winding, it is possible to determine an abnormality in the current detection circuit that detects the field current, and it is possible to suppress heat generation in the current detection circuit. A control device is desired.

The control device for the AC rotor according to the present application is a control device for the AC rotor that controls the AC rotor having an AC armature winding and a field winding.
A power supply path that has a switching element and allows a current to flow from a DC power supply to the field winding by turning the switching element on and off, and a recirculation path that recirculates the current in the converter and allows a recirculation current to flow through the field winding. However, with the converter that switches,
A bus current detection circuit that detects a bus current, which is a current flowing through a connection path between the DC power supply and the converter, and a bus current detection circuit.
A common path current detection circuit that detects a current flowing through a common path between the power supply path and the return path, and a common path current detection circuit.
A converter switching control unit that switches the power supply path and the reflux path by turning on and off the switching element of the converter.
The field current flowing through the field winding is detected based on the output signal of the common path current detection circuit, the bus current is detected based on the output signal of the bus current detection circuit, and the detected bus current is used as the detected bus current. Based on this, a current calculation unit that calculates a field current estimated value, which is an estimated value of the current flowing through the field winding, and a current calculation unit.
An abnormality determination unit that compares the field current with the field current estimated value and determines an abnormality of one or both of the bus current detection circuit and the common path current detection circuit.
It is equipped with.

According to the control device of the AC rotating machine according to the present application, when the field current is detected by the common path current detection circuit capable of detecting the field current in both the power supply path and the recirculation path, and the field current is switched to the power supply path. Only in, the field current estimated value is calculated by the bus current detection circuit that can detect the field current, and the field current and the field current estimated value are compared, and one of the bus current detection circuit and the common path current detection circuit. Alternatively, both abnormalities can be determined. Further, in the bus current detection circuit, the current flows only when the power supply path is switched, and no current flows when the bus current detection circuit is switched to the reflux path, so that the heat generation of the bus current detection circuit can be suppressed. ..

It is a schematic block diagram of the AC rotary machine and the control device of the AC rotary machine which concerns on Embodiment 1. FIG. It is a schematic block diagram of the controller which concerns on Embodiment 1. FIG. It is a hardware block diagram of the controller which concerns on Embodiment 1. FIG. It is a figure explaining the voltage vector of the converter control which concerns on Embodiment 1. FIG. It is a figure explaining the current path of the voltage vector Vf0 which concerns on Embodiment 1. FIG. It is a figure explaining the current path of the voltage vector Vf1 which concerns on Embodiment 1. FIG. It is a figure explaining the current path of the voltage vector Vf2 which concerns on Embodiment 1. FIG. It is a figure explaining the current path of the voltage vector Vf3 which concerns on Embodiment 1. FIG. It is a time chart explaining the control behavior of the converter which concerns on Embodiment 1. FIG. It is a schematic diagram of the AC rotary machine which was made into the generator motor for the vehicle which concerns on Embodiment 1. FIG. It is a schematic block diagram of the AC rotary machine and the control device of the AC rotary machine which concerns on Embodiment 2. FIG. It is a figure explaining the voltage vector of the inverter control which concerns on Embodiment 2. FIG. It is a time chart explaining the control behavior of the inverter which concerns on Embodiment 2. FIG. It is a time chart explaining the control behavior of the inverter which concerns on Embodiment 2. FIG. It is a time chart explaining the control behavior of the converter which concerns on Embodiment 3. FIG.

1. 1. Embodiment 1
The control device 11 (hereinafter, simply referred to as the control device 11) of the AC rotary machine according to the first embodiment will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of an AC rotating machine 1 and a control device 11 according to the present embodiment.

1-1. AC rotating machine The AC rotating machine 1 includes a stator 18 and a rotor 14 arranged inside the stator 18 in the radial direction. The AC rotating machine 1 is a field winding type synchronous rotating machine. The AC armature winding 12 is wound around the stator 18. A field winding 4 is wound around the rotor 14, and an electromagnet is provided.

In the present embodiment, the AC armature winding 12 is a U-phase, V-phase, and W-phase three-phase AC armature winding Cu, Cv, and Cw. The three-phase AC armature windings Cu, Cv, and Cw may be star-connected or delta-connected.

The rotor 14 is provided with an angle detection circuit 15 for detecting the rotation angle (rotation angle) of the rotor 14. The output signal of the angle detection circuit 15 is input to the controller 30. Various sensors are used in the angle detection circuit 15.

In the present embodiment, the AC rotary machine 1 is a generator motor for a vehicle. The rotating shaft of the rotor 14 of the AC rotating machine 1 is connected to the internal combustion engine 54 via a connecting mechanism. Further, the rotating shaft of the AC rotating machine 1 is connected to the wheel 52 via a connecting mechanism. For example, as shown in FIG. 10, the rotating shaft of the AC rotating machine 1 is connected to the crankshaft of the internal combustion engine 54 via a pulley and a belt mechanism 53. The rotating shaft of the AC rotating machine 1 is connected to the wheels 52 via the internal combustion engine 54 and the transmission 55. The AC rotating machine 1 rotates only in one direction and does not rotate in the other direction.

1-2. DC power supply 2
The DC power supply 2 outputs a power supply voltage Vdc to the inverter 5 and the converter 9. As the DC power supply 2, any device that outputs a DC voltage, such as a battery, a DC-DC converter, a diode rectifier, and a PWM rectifier, is used. A smoothing capacitor 3 is connected in parallel to the DC power supply 2. A voltage detection circuit 17 for detecting the power supply voltage Vdc is provided. The output signal of the voltage detection circuit 17 is input to the controller 30.

1-3. Inverter 5
The inverter 5 has a switching element and performs power conversion between the DC power supply 2 and the AC armature winding 12. The inverter 5 is a three-phase series circuit in which a switching element on the positive electrode side connected to the positive electrode side of the DC power supply 2 and a switching element on the negative electrode side connected to the negative electrode side of the DC power supply 2 are connected in series. Three sets are provided corresponding to the phase AC armature winding. The connection points of the two switching elements in each series circuit are connected to the corresponding phase AC armature windings.

Specifically, in the U-phase series circuit, the switching element SPu on the positive electrode side of the U phase and the switching element SNu on the negative electrode side of the U phase are connected in series, and the connection points of the two switching elements are U-phase AC electric machines. It is connected to the child winding Cu. In the V-phase series circuit, the switching element SPv on the positive electrode side of the V phase and the switching element SNv on the negative electrode side of the V phase are connected in series, and the connection point of the two switching elements becomes the V-phase AC armature winding Cv. It is connected. In the W-phase series circuit, the switching element SPw on the positive electrode side of W and the switching element SNw on the negative electrode side of W phase are connected in series, and the connection point of the two switching elements is connected to the AC armature winding Cw of W phase. Has been done.

As the switching element of the inverter 5, an IGBT (Insulated Gate Bipolar Transistor) in which diodes are connected in antiparallel, a bipolar transistor in which diodes are connected in antiparallel, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), and the like are used. The gate terminal of each switching element is connected to the controller 30 via a gate drive circuit or the like. Therefore, each switching element is turned on or off by the switching signal output from the controller 30.

1-4. Converter 9
The converter 9 has a switching element and performs power conversion between the DC power supply 2 and the field winding 4. The converter 9 has a power supply path 20 for passing a current from the DC power supply 2 to the field winding by turning the switching element on and off, and a recirculation path 21 for recirculating the current in the converter 9 and passing a recirculating current to the field winding 4. And switch.

In the present embodiment, the converter 9 is a series circuit in which a switching element on the positive electrode side connected to the positive electrode side of the DC power supply 2 and a switching element on the negative electrode side connected to the negative electrode side of the DC power supply 2 are connected in series. It is said to be an H-bridge circuit provided with two sets. The connection point between the positive electrode side switching element SP1 and the negative electrode side switching element SN1 in the first set of series circuit 28 is connected to one end of the field winding 4, and the positive electrode side switching in the second set of series circuit 29 The connection point between the element SP2 and the switching element SN2 on the negative electrode side is connected to the other end of the field winding 4.

As the switching element of the converter 9, an IGBT in which diodes are connected in antiparallel, a bipolar transistor in which diodes are connected in antiparallel, a MOSFET, and the like are used. The gate terminal of each switching element is connected to the controller 30 via a gate drive circuit or the like. Therefore, each switching element is turned on or off by the switching signal output from the controller 30.

As shown in FIG. 6, which will be described later, when the switching element of the converter 9 is turned on and off, the converter 9 switches to the power supply path 20. On the other hand, as shown in FIG. 5 or FIG. 8 described later, when the switching element of the converter 9 is turned on and off, the converter 9 switches to the reflux path 21. In this embodiment, the field winding 4 is designed on the premise that a current flows only in the first direction from the series circuit 28 side of the first set to the series circuit 29 side of the second set.

1-5. Armature current detection circuit 8
The armature current detection circuit 8 is a current detection circuit that detects the current flowing through the AC armature windings Cu, Cv, and Cw of each phase. In the present embodiment, the armature current detection circuit 8 is provided on the electric wire connecting the series circuit of the switching elements of each phase and the AC armature winding. The output signal of the armature current detection circuit 8 of each phase is input to the controller 30. The armature current detection circuit 8 is a non-contact current sensor such as a Hall element. The armature current detection circuit 8 may be a shunt resistor connected in series to a series circuit of switching elements of each phase.

1-6. Bus current detection circuit 6
The bus current detection circuit 6 is a current detection circuit that detects the bus current Idc, which is the current flowing through the connection path between the DC power supply 2 and the converter 9. In the present embodiment, the bus current detection circuit 6 is a connection path between the DC power supply 2 and the converter 9, and is a current flowing through a portion that is not common to the connection path between the DC power supply 2 and the inverter 5. The bus current Idc is detected. The bus current detection circuit 6 is provided in a connection path connecting the converter 9 and the negative electrode side of the DC power supply 2. The bus current detection circuit 6 may be provided in a connection path connecting the converter 9 and the positive electrode side of the DC power supply 2.

The output signal of the bus current detection circuit 6 is input to the controller 30. When a shunt resistor is used for the bus current detection circuit 6, if the wire is broken due to heat generation, power cannot be supplied from the DC power supply 2 to the converter 9. Therefore, it is preferable that a non-contact current sensor such as a Hall element is used for the bus current detection circuit 6. Even if an abnormality occurs in the non-contact current sensor, there is no effect on the power supply system. A shunt resistor may be used in the bus current detection circuit 6 as long as the heat dissipation is ensured and the heat generating surface is not hindered.

1-7. Common path current detection circuit 7
The common path current detection circuit 7 is a current detection circuit that detects a current flowing through a common path between the power supply path 20 and the return path 21. In the present embodiment, as will be described later, the power supply path 20 is the path in the case of the voltage vector Vf1 shown in FIG. 6, and the reflux path 21 is the path in the case of the voltage vector Vf0 shown in FIG. Therefore, the common path current detection circuit 7 is provided in a common path portion between the power supply path 20 of FIG. 6 and the reflux path 21 of FIG. In this example, the common path current detection circuit 7 is provided on the connection line on the negative electrode side of the switching element SN2 on the negative electrode side of the second set of series circuits 29. The common path current detection circuit 7 may be provided in any portion as long as it is a common path portion between the power supply path 20 and the return path 21, and the field winding 4 and the first set may be provided. It may be provided on the connecting line connecting the series circuit 28 or the connecting line connecting the field winding 4 and the switching element SN2 on the negative side of the second set of the series circuit 29.

The output signal of the common path current detection circuit 7 is input to the controller 30. A shunt resistor, a Hall element, or the like is used in the common path current detection circuit 7.

1-8. Controller 30
The controller 30 controls the AC rotating machine 1 via the inverter 5 and the converter 9. As shown in FIG. 2, the controller 30 includes functional units such as a converter switching control unit 31, a current calculation unit 32, an abnormality determination unit 33, and an inverter switching control unit 34. Each function of the controller 30 is realized by a processing circuit provided in the controller 30. Specifically, as shown in FIG. 3, the controller 30 includes an arithmetic processing unit 90 (computer) such as a CPU (Central Processing Unit), a storage device 91 for exchanging data with the arithmetic processing unit 90, as a processing circuit. The arithmetic processing unit 90 includes an input circuit 92 for inputting an external signal, an output circuit 93 for outputting a signal from the arithmetic processing unit 90 to the outside, a communication circuit 94 for data communication with the external device, and the like.

The arithmetic processing device 90 is provided with an ASIC (Application Specific Integrated Circuit), an IC (Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), various logic circuits, various signal processing circuits, and the like. You may. Further, as the arithmetic processing unit 90, a plurality of the same type or different types may be provided, and each processing may be shared and executed. As the storage device 91, a RAM (Random Access Memory) configured to be able to read and write data from the arithmetic processing unit 90, a ROM (Read Only Memory) configured to be able to read data from the arithmetic processing unit 90, and the like are used. It is equipped. The input circuit 92 is connected to various sensors and switches such as an angle detection circuit 15, a voltage detection circuit 17, an armature current detection circuit 8, a bus current detection circuit 6, and a common path current detection circuit 7. It is provided with an A / D converter or the like that inputs an output signal to the arithmetic processing device 90. The output circuit 93 includes an electric load such as a gate drive circuit that drives the switching elements of the inverter 5 and the converter 9 on and off, and a drive circuit or the like that outputs a control signal from the arithmetic processing device 90 to these electric loads. The communication circuit 94 communicates with an external device such as the vehicle integrated control device 27.

Then, in each function of the control units 31 to 34 and the like included in the controller 30, the arithmetic processing unit 90 executes software (program) stored in the storage device 91 such as ROM, and the storage device 91 and the input circuit 92. , And other hardware of the controller 30 such as the output circuit 93. The setting data such as the determination value used by each of the control units 31 to 34 and the like is stored in a storage device 91 such as a ROM as a part of the software (program). Hereinafter, each function of the controller 30 will be described in detail.

1-8-1. Inverter switching control unit 34
The inverter switching control unit 34 applies a voltage to the AC armature windings Cu, Cv, and Cw of each phase by turning on and off the switching element of the inverter 5. The inverter switching control unit 34 calculates a three-phase voltage command applied to the AC armature winding of each phase. The inverter switching control unit 34 calculates a three-phase voltage command using known vector control or V / f control.

The inverter switching control unit 34 detects the rotation angle and the rotation angular velocity of the rotor 14 based on the output signal of the angle detection circuit 15. The inverter switching control unit 34 detects the three-phase armature current flowing through the AC armature winding of each phase based on the output signal of the armature current detection circuit 8. The inverter switching control unit 34 detects the power supply voltage based on the output signal of the voltage detection circuit 17.

When vector control is used, the inverter switching control unit 34 calculates a three-phase voltage command based on a torque command, an armature current detection value, a rotation angle, a rotation angular velocity, a power supply voltage, and the like. The torque command may be configured to be transmitted from the vehicle integrated control device 27 or the like, or may be configured to be calculated in the controller 30. Specifically, the inverter switching control unit 34 calculates the dq-axis current command based on the torque command, the rotation angle speed, the power supply voltage Vdc, and the like, and based on the detected value and the rotation angle of the three-phase armature current. Calculate the dq-axis current detection value, perform current feedback control on the dq-axis coordinate system based on the dq-axis current command and dq-axis current detection value, calculate the dq-axis voltage command, and calculate the dq-axis voltage command and rotation. The three-phase voltage command is calculated based on the angle. The inverter switching control unit 34 executes feedforward control for changing the d-axis voltage command and the q-axis voltage command by using the specifications of the AC rotating machine based on the dq-axis current command without using the current detection value. You may. Then, the inverter switching control unit 34 converts the dq-axis voltage command into a three-phase voltage command based on the rotation angle. The inverter switching control unit 34 may apply modulation such as space vector modulation and two-phase modulation so that the line voltage does not change to the three-phase voltage command.

When V / f control is used, the inverter switching control unit 34 determines the amplitude V of the voltage command based on the rotation frequency command f of the AC rotating machine transmitted from the vehicle integrated control device 27 or the like. Then, the inverter switching control unit 34 calculates the three-phase voltage command based on the phase obtained by integrating the amplitude V of the voltage command and the rotation frequency command f.

The inverter switching control unit 34 turns on and off a plurality of switching elements by PWM (Pulse Width Modulation) control based on a three-phase voltage command. The inverter switching control unit 34 generates a switching signal for turning on / off the switching element of each phase by comparing each of the three-phase voltage commands with the carrier wave. The carrier wave is a triangular wave having an amplitude of a power supply voltage Vdc and oscillating at a carrier frequency. The inverter switching control unit 34 turns on the switching signal when the voltage command exceeds the carrier wave, and turns off the switching signal when the voltage command falls below the carrier wave. The switching signal is transmitted to the switching element on the positive electrode side as it is, and the switching signal obtained by inverting the switching signal is transmitted to the switching element on the negative electrode side. Each switching signal is input to the gate terminal of each switching element of the inverter 5 via a gate drive circuit to turn each switching element on or off.

1-8-2. Converter switching control unit 31
The converter switching control unit 31 applies a voltage to the field winding 4 by turning on and off the switching element of the converter 9. The converter switching control unit 31 turns on / off the switching element of the converter 9 to switch between the power supply path 20 and the reflux path 21.

In the present embodiment, the converter switching control unit 31 turns on / off the switching element of the converter 9 based on the voltage command of the field winding applied to the field winding 4. The converter switching control unit 31 performs current feedback control that changes the voltage command of the field winding so that the field current detection value If_det calculated by the current calculation unit 32, which will be described later, approaches the field current command. The converter switching control unit 31 calculates the field current command based on the torque command or the like. The torque command may be configured to be transmitted from the vehicle integrated control device 27 or the like, or may be configured to be calculated in the controller 30.

As shown in FIG. 4, there are four on / off patterns of the four switching elements of the converter 9 as the H-bridge circuit. In FIG. 4, "0" indicates that the corresponding switching element is off, and "1" indicates that the corresponding switching element is on. The four on / off patterns are referred to as voltage vectors Vf0, Vf1, Vf2, and Vf3.

<Voltage vector Vf0>
As shown in FIGS. 4 and 5, in the voltage vector Vf0, the switching element SP1 on the positive electrode side of the first set is set to “0” (off), and the switching element SN1 on the negative electrode side of the first set is “1”. (On), the switching element SP2 on the positive electrode side of the second set is set to "0" (off), and the switching element SN2 on the negative electrode side of the second set is set to "1" (on). In the voltage vector Vf0, the power supply voltage Vdc is not applied to the field winding 4, the current recirculates in the converter 9, and the recirculated current flows through the field winding 4. When the voltage vector Vf1 is set immediately before, a current flows through the field winding 4 in the first direction as shown in FIG. On the other hand, when the voltage vector Vf2 is set immediately before, a current flows in the second direction of the field winding 4 in the direction opposite to that of FIG. The voltage vector Vf0 is a zero vector in which no current flows between the DC power supply 2 and the converter 9.

<Voltage vector Vf1>
As shown in FIGS. 4 and 6, in the voltage vector Vf1, the switching element SP1 on the positive electrode side of the first set is set to “1” (on), and the switching element SN1 on the negative electrode side of the first set is set to “0”. (Off), the switching element SP2 on the positive electrode side of the second set is set to "0" (off), and the switching element SN2 on the negative electrode side of the second set is set to "1" (on). In the voltage vector Vf1, the power supply voltage Vdc is applied to the field winding 4, and a current flows from the DC power supply 2 to the field winding 4. Further, a current flows through the field winding 4 in the first direction from the series circuit 28 side of the first set to the series circuit 29 side of the second set. In the present embodiment, the AC rotating machine 1 is designed on the premise that the current flows only in the first direction, and the voltage vector Vf2 in which the current flows in the second direction, which will be described later, is not used. The voltage vector Vf0 is an effective vector in which a current flows between the DC power supply 2 and the converter 9.

<Voltage vector Vf2>
As shown in FIGS. 4 and 7, in the voltage vector Vf2, the switching element SP1 on the positive electrode side of the first set is set to “0” (off), and the switching element SN1 on the negative electrode side of the first set is “1”. (On), the switching element SP2 on the positive electrode side of the second set is set to "1" (on), and the switching element SN2 on the negative electrode side of the second set is set to "0" (off). In the voltage vector Vf2, the power supply voltage Vdc is applied to the field winding 4, and a current flows from the DC power supply 2 to the field winding 4. Further, a current flows through the field winding 4 in the second direction from the side of the series circuit 29 of the second set to the side of the series circuit 28 of the first set. In the present embodiment, the AC rotating machine 1 is designed on the premise that no current flows in the second direction. The voltage vector Vf2 is also an effective vector in which a current flows between the DC power supply 2 and the converter 9, but it is not used in the present embodiment.

<Voltage vector Vf3>
As shown in FIGS. 4 and 8, in the voltage vector Vf3, the switching element SP1 on the positive electrode side of the first set is set to “1” (on), and the switching element SN1 on the negative electrode side of the first set is set to “0”. (Off), the switching element SP2 on the positive electrode side of the second set is set to "1" (on), and the switching element SN2 on the negative electrode side of the second set is set to "0" (off). In the voltage vector Vf3, the power supply voltage Vdc is not applied to the field winding 4, the current recirculates in the converter 9, and the recirculated current flows through the field winding 4. When the voltage vector Vf1 is set immediately before, a current flows through the field winding 4 in the first direction as shown in FIG. On the other hand, when the voltage vector Vf2 is set immediately before, a current flows in the second direction of the field winding 4 in the direction opposite to that of FIG. The voltage vector Vf3 is a zero vector in which no current flows between the DC power supply 2 and the converter 9, but it is not used in the present embodiment.

<Switching voltage vector by PWM control>
As shown in FIG. 9, the converter switching control unit 31 generates a PWM signal having an on-duty ratio, which is a ratio obtained by dividing the voltage command of the field winding by the power supply voltage Vdc, and based on the PWM signal, the converter 9 generates a PWM signal. Turn the switching element on and off.

For example, the converter switching control unit 31 compares the voltage command of the field winding with the carrier wave (triangular wave) that vibrates between 0 and the power supply voltage Vdc in the PWM cycle, and when the voltage command exceeds the carrier wave. Turns on (1) the PWM signal, and turns off (0) the PWM signal when the voltage command falls below the carrier wave. Alternatively, the converter switching control unit 31 may simply generate a PWM signal having an on-duty ratio.

Then, the converter switching control unit 31 turns on / off the switching element of the converter 9 so as to become the power supply path 20 when the PWM signal is on (1), and returns the return path when the PWM signal is off (0). The switching element of the converter 9 is turned on and off so as to be 21. In the present embodiment, the converter switching control unit 31 turns on / off the switching element of the converter 9 in the on / off pattern of the voltage vector Vf1 when the PWM signal is on (1), and when the PWM signal is off (0). , The switching element of the converter 9 is turned on and off according to the on / off pattern of the voltage vector Vf0.

1-8-3. Current calculation unit 32
As shown in FIG. 9, the field current If flowing through the field winding 4 increases monotonically when it is switched to the power supply path 20, and decreases monotonically when it is switched to the reflux path 21. .. The bus current detection circuit 6 is configured to detect the bus current Idc flowing in the connection path between the DC power supply 2 and the converter 9. Therefore, as shown in FIGS. 9 and 6, when the power supply path 20 is switched, the field current If flows through the location where the bus current detection circuit 6 is arranged, so that the field current If is increased by the bus current Idc. Can be detected. On the other hand, as shown in FIGS. 9 and 5, when the return path 21 is switched, the field current If does not flow through the location where the bus current detection circuit 6 is arranged, so that the bus current Idc becomes zero. The field current If cannot be detected. Therefore, when the bus current detection circuit 6 is used, it is necessary to detect the field current If in consideration of switching between the power supply path 20 and the return path 21.

On the other hand, the common path current detection circuit 7 detects the current flowing through the common path between the power supply path 20 and the return path 21, and flows through the field winding 4 as shown in FIGS. 9, 5, and 6. The field current If can be constantly detected.

The current calculation unit 32 detects the field current If_det (hereinafter, referred to as the field current detection value If_det) flowing through the field winding 4 based on the output signal of the common path current detection circuit 7. The current calculation unit 32 detects the bus current Idc_det (hereinafter, referred to as the bus current detection value Idc_det) based on the output signal of the bus current detection circuit 6. The current calculation unit 32 calculates the field current estimated value If_est, which is an estimated value of the current flowing through the field winding 4, based on the bus current detected value Idc_det.

In the present embodiment, the current calculation unit 32 uses the field current estimated value If_est1 based on the bus current detection value Idc_det1 at the time of power supply, which is the bus current detection value detected when the power supply path 20 is switched. Is calculated.

According to this configuration, the field current estimated value If_est can be calculated accurately based on the bus current detected value Idc_det1 at the time of power supply, which is equal to the field current If.

<Compensation for offset of bus current detection circuit 6>
An offset may occur in the output signal of the bus current detection circuit 6. When the offset does not occur, the bus current detection value Idc_det2 at the time of reflux becomes zero, but when the offset occurs, the bus current detection value Idc_det2 at the time of reflux shifts from zero by the offset.

Therefore, the current calculation unit 32 subtracts the bus current detection value Idc_det2 at the time of reflux, which is the bus current detection value Idc_det detected when the return path 21 is switched, from the bus current detection value Idc_det1 at the time of power supply. , Calculate the bus current detection value Idc_det1off at the time of power supply after offset adjustment. Then, the current calculation unit 32 may calculate the field current estimated value If_est based on the bus current detected value Idc_det1off at the time of power supply after the offset adjustment.

The offset of the bus current detection circuit 6 is often caused by temperature drift, and since the time constant of the temperature change is large, it changes sufficiently later than the PWM cycle. Therefore, it is not necessary to detect the bus current detection value Idc_det2 at the time of reflux for each PWM cycle.

Therefore, the current calculation unit 32 may make the detection frequency of the bus current detection value Idc_det2 at the time of reflux lower than the detection frequency of the bus current detection value Idc_det1 at the time of power supply. For example, the current calculation unit 32 may detect the bus current detection value Idc_det1 at the time of power supply for each PWM cycle, and may detect the bus current detection value Idc_det2 at the time of reflux for each of a plurality of PWM cycles. Further, the current calculation unit 32 subtracts the average value of the bus current detection value Idc_det2 at the time of reflux detected in the past a plurality of times from the bus current detection value Idc_det1 at the time of power supply, and at the time of power supply after offset adjustment. The bus current detection value Idc_det1off may be calculated.

<Detection timing>
As shown in FIG. 9, the current calculation unit 32 detects the bus current detection value Idc_det1 at the time of power supply by the bus current detection circuit 6 at the central timing (time t3) of the period of switching to the power supply path 20. .. According to this configuration, the center value of the field current If that is monotonically increasing can be detected during the switching period to the power supply path 20, and the average value of the field current If in the PWM cycle is detected. be able to. Therefore, the accuracy of the field current estimated value If_est can be improved. Further, the period of switching to the power supply path 20 can be reduced to the limit where the current can be detected.

Further, the current calculation unit 32 detects the bus current detection value Idc_det2 at the time of reflux by the bus current detection circuit 6 at the central timing (time t1, time t5) of the period of switching to the reflux path 21. According to this configuration, it is less likely to be affected by the current due to the on / off of the switching element, so that the accuracy of the field current detection value If_det can be improved. In addition, the period of switching to the reflux path 21 can be reduced to the limit at which the current can be detected.

In the present embodiment, the current calculation unit 32 detects the current at the timing of the peaks and valleys of the carrier wave.

Since the common path current detection circuit 7 can always detect the field current If, the current calculation unit 32 can detect the field current at an arbitrary timing. However, in order to reduce the number of detections in the PWM cycle, the central timing of the period of switching to the power supply path 20 (time t3) and the central timing of the period of switching to the reflux path 21 (time t1, time). The field current detection value If_det may be detected by the common path current detection circuit 7 in one or both of t5). The current calculation unit 32 may detect the field current detection value If_det a plurality of times within the PWM cycle, and calculate the average value of them as the final field current detection value If_det.

1-8-4. Abnormality determination unit 33
<Abnormality judgment when supplying current>
The abnormality determination unit 33 compares the field current detection value If_det with the field current estimation value If_est, and determines one or both of the bus current detection circuit 6 and the common path current detection circuit 7.

For example, in the abnormality determination unit 33, as shown in the following equation, when the absolute value of the deviation between the field current detection value If_det and the field current estimation value If_est becomes larger than the preset determination value threshold value THF. Determine if an abnormality has occurred.
| If_det-If_est |> THF ... (1)

For example, when the abnormality determination unit 33 determines that the current detection circuit is abnormal, the converter switching control unit 31 stops the current feedback control using the field current detection value If_det, and stops the field current command and the field winding. The voltage command of the field winding may be set in a feed-forward manner based on the resistance value of the wire. Alternatively, if the abnormality determination unit 33 determines that one of the bus current detection circuit 6 and the common path current detection circuit 7 is normal by another abnormality determination method, the bus current detection circuit 6 and the common path current It may be determined that the other side of the detection circuit 7 is abnormal. When the common path current detection circuit 7 is abnormal and the bus current detection circuit 6 is determined to be normal, the converter switching control unit 31 sets the field current estimated value If_est to approach the field current command. Current feedback control that changes the voltage command of the field winding may be performed.

<Setting of switching period>
There is a response delay between turning on or off the switching element and stabilizing the current flowing through the switching element. If the on-period or off-period of the switching element is too short, the current cannot be detected in a stable state after the switching element is turned on or off, and the current detection accuracy deteriorates.

When the power supply path 20 continues for a current stabilization period or longer until the current stabilizes, the bus current detection value Idc_det1 at the time of power supply is detected. After the switching element is turned on or off, the current can be detected in a stable state, and the accuracy of the field current estimated value If_est can be improved. Therefore, the abnormality determination by the equation (1) can be performed accurately. When the return path 21 continues for a current stabilization period or longer until the current stabilizes, the offset error included in the output signal of the bus current detection circuit 6 is detected by detecting the bus current detection value Idc_det2 at the time of power supply. Can be obtained with high accuracy.

2. Embodiment 2
Next, the AC rotating machine 1 and the control device 11 according to the second embodiment will be described. The description of the same components as in the first embodiment will be omitted. The basic configuration of the AC rotating machine 1 and the control device 11 according to the present embodiment is the same as that of the first embodiment, but the arrangement position of the bus current detection circuit 6 is different from that of the first embodiment. FIG. 11 is a schematic configuration diagram of the AC rotating machine 1 and the control device 11 according to the present embodiment.

In the present embodiment, the bus current detection circuit 6 is a current flowing through a common path between the connection path between the DC power supply 2 and the converter 9 and the connection path between the DC power supply 2 and the inverter 5. Is detected as the bus current.

Therefore, the bus current Idc detected by the bus current detection circuit 6 is the converter current Icn, which is the current flowing between the DC power supply 2 and the converter 9, and the inverter, which is the current flowing between the DC power supply 2 and the inverter 5. The current Iin and the combined current are obtained. Therefore, in order to obtain the field current estimated value, it is necessary to extract only the converter current Icn from the bus current Idc.

<Inverter on / off pattern where the inverter current becomes zero>
When the inverter current Iin is not flowing, the bus current Idc becomes equal to the converter current Icn. Therefore, the on / off pattern of the switching element of the inverter 5 in which the inverter current Iin becomes zero will be described.

As shown in FIG. 12, there are eight on / off patterns of the six switching elements of the inverter 5. In FIG. 12, "0" indicates that the corresponding switching element is off, and "1" indicates that the corresponding switching element is on. The eight on / off patterns are referred to as voltage vectors V0 to V7.

In the voltage vector V0, the switching elements SNu, SNv, and SNw on the negative electrode side of the U phase, V phase, and W phase are all turned on, and the switching elements SPu, SPv, and SPw on the positive electrode side of the U phase, V phase, and W phase are turned on. All are turned off, and the terminals of the three-phase AC armature windings Cu, Cv, and Cw are connected to each other via the electric wire on the negative electrode side. In this voltage vector V0, the current circulates between the three-phase AC armature winding and the inverter, the inverter current Iin becomes zero, and no current flows between the DC power supply 2 and the inverter 5. Become in a state.

In the voltage vector V7, the switching elements SPu, SPv, and SPw on the positive electrode side of the U phase, V phase, and W phase are all turned on, and the switching elements SNu, SNv, and SNw on the negative electrode side of the U phase, V phase, and W phase are turned on. All are turned off, and the terminals of the three-phase AC armature windings Cu, Cv, and Cw are connected to each other via the electric wire on the positive electrode side. In this voltage vector V7, the current circulates between the three-phase AC armature winding and the inverter, the inverter current Iin becomes zero, and no current flows between the DC power supply 2 and the inverter 5. Become in a state.

In the other voltage vectors V1 to V6, the inverter currents Iin become armature currents Iu, Iv, and Iw flowing through the U-phase, V-phase, and W-phase AC armature windings. In these voltage vectors V1 to V6, the inverter current Iin does not become zero, and the current is in an effective vector state in which the current flows between the DC power supply 2 and the inverter 5.

As described in the first embodiment, the inverter switching control unit 34 compares each of the three-phase voltage commands Vu, Vw, and Vw with the carrier wave Ca to turn on and off the switching element of each phase. To generate. FIG. 13 shows the three-phase voltage commands Vu, Vw, Vw, the carrier wave Ca, and the switching signals of each switching element in the PWM period Tc. As shown in this figure, the voltage vector V0 is switched to V8 in the PWM cycle Tc. At times t1 to t2 and times t6 to t7, the voltage vector V7 is a zero vector. Therefore, even in the state of PWM control in which a voltage is applied to the AC armature winding 12, there is a zero vector period in which the inverter current Iin becomes zero in the PWM cycle, and the bus current in the zero vector period. Therefore, the converter current Icn can be detected.

<Calculation of field current estimate at zero vector>
Therefore, the current calculation unit 32 is based on the bus current detection value Idc_det detected when the current is switched to the power supply path 20 in the state of a zero vector in which no current flows between the DC power supply 2 and the inverter 5. The magnetic current estimated value If_est is calculated.

The current calculation unit 32 detects the bus current detection value Idc_det1 at the time of power supply and the bus current detection value Idc_det2 at the time of reflux in the state of the zero vector of the inverter 5. Then, as in the first embodiment, the current calculation unit 32 calculates the field current estimated value If_est based on the bus current detection value Idc_det1 at the time of power supply. Further, the current calculation unit 32 draws a field based on the bus current detection value Idc_det1off at the time of power supply after offset adjustment calculated by subtracting the bus current detection value Idc_det2 at the time of recirculation from the bus current detection value Idc_det1 at the time of power supply. The magnetic current estimated value If_est may be calculated.

<Calculation of field current estimate at effective vector>
On the other hand, depending on the PWM control method, there may be no zero vector period in the PWM cycle. FIG. 14 shows an example in the case where the zero vector does not exist. In this example, the first carrier wave Ca1 is compared with the U-phase voltage command Vu and the V-phase voltage command Vv, and the second carrier wave Ca2, which is opposite to the first carrier wave Ca1, is the W-phase voltage command. Compared to Vw. As shown in FIG. 14, in the PWM period Tc, the periods of the voltage vectors V1, V2, and V6 which are effective vectors exist, but the voltage vectors V0 and V7 which are zero vectors do not exist.

Even in that case, as shown in FIG. 12, the inverter current Iin becomes equal to any of the three-phase armature currents Iu, Iv, and Iw depending on each of the voltage vectors V1 to V6 which are effective vectors. For example, in the voltage vector V1, the inverter current Iin becomes equal to the U-phase armature current Iu. In the voltage vector V2, the inverter current Iin becomes equal to the sign inversion value (−Iw) of the W-phase armature current Iw. In this way, even if it is an effective vector, the inverter current Iin is calculated from the armature current of a specific phase according to the type of the effective vector, and the inverter current Iin is subtracted from the bus current Idc to obtain the converter current Icn. Can be extracted.

Therefore, the current calculation unit 32 detects the armature current based on the output signal of the armature current detection circuit 8, and the bus current detection value Idc_det and the armature current detection value detected at the same time, and the armature at the time of current detection. The field current estimated value If_est is calculated based on the on / off pattern of the switching element of 5.

The current calculation unit 32 switches between the DC power supply 2 and the inverter 5 based on the armature current detection value of a specific phase determined based on the on / off pattern (voltage vector) of the switching element of the inverter 5 at the time of current detection. The inverter current detection value Iin_det, which is the flowing current, is calculated. At the time of this determination, the current calculation unit 32 determines the on / off pattern (voltage vector) of the switching element of the inverter 5 and the information of the armature current of the specific phase equal to the inverter current Iin and the code of the current as shown in FIG. Information on the presence or absence of inversion refers to a preset data table. When the on / off pattern (voltage vector) of the switching element of the inverter 5 is a zero vector of the voltage vectors V0 and V7, the current calculation unit 32 may set the inverter current detection value Iin_det to zero.

The armature current detection timing may be adjusted to the same bus current detection timing as in the first embodiment.

Then, the current calculation unit 32 subtracts the inverter current detection value Iin_det from the bus current detection value Idc_det detected at the same time as the armature current detection value of the specific phase, calculates the converter current detection value Icn_det, and calculates the converter. The field current estimated value If_est is calculated based on the current detected value Icn_det.

Further, as in the first embodiment, the current calculation unit 32 detects the inverter current from the bus current detection value Idc_det (bus current detection value Idc_det1 at the time of power supply) detected when the power supply path 20 is switched. Iin_det is subtracted to calculate the converter current detection value Icn_det1 at the time of power supply, and the field current estimated value If_est is calculated based on the converter current detection value Icn_det1 at the time of power supply. Further, the current calculation unit 32 subtracts the inverter current detection value Iin_det from the bus current detection value Idc_det (bus current detection value Idc_det2 at the time of recirculation) detected when the recirculation path 21 is switched, and the converter at the time of recirculation The current detection value Icn_det2 is calculated, and the converter current detection value Icn_det1 at the time of power supply is calculated by subtracting the converter current detection value Icn_det2 at the time of recirculation from the converter current detection value Icn_det1 at the time of power supply. The magnetic current estimated value If_est may be calculated.

For example, when the voltage vector is V6 at the time of current detection, the current calculation unit 32 refers to a data table as shown in FIG. 12 to determine the V phase as a specific phase, and as shown in the following equation, the V phase electric machine. The sign inversion value (-Iv_det) of the child current detection value Iv_det is set to the inverter current detection value Iin_det. Then, as shown in the following equation, the current calculation unit 32 subtracts the inverter current detection value Iin_det from the bus current detection value Idc_det detected at the same time as the V-phase armature current detection value Iv_det to detect the converter current. Calculate the value Icn_det. When the bus current detection value Idc_det is detected, if the power supply path 20 is switched to, the converter current detection value Icn_det1 at the time of power supply is set. The detected value is Incn_det2.
Iin_det = -Iv_det
Icn_det = Idc_det-Iin_det ... (2)

<Judgment of short circuit abnormality of inverter 5>
When the positive electrode side and negative electrode side switching elements of the same phase of the inverter 5 are turned on at the same time due to a short circuit abnormality of the switching element of the inverter 5, the positive electrode side and the negative electrode side of the DC power supply 2 are short-circuited, and an excessive inverter current Iin flows. .. In the present embodiment, the bus current detection circuit 6 is arranged so as to detect the inverter current Iin, so that an excessive inverter current Iin due to a short circuit of the inverter 5 can be detected. In particular, when the armature current detection circuit 8 is arranged between the AC armature winding and the inverter, it is not possible to directly detect the large current flowing through the bus, which is preferable.

Therefore, the abnormality determination unit 33 determines that a short-circuit abnormality has occurred in the inverter 5 when the bus current detection value Idc_det deviates from the normal current range. For example, in the abnormality determination unit 33, when the field current detection value If_det detected by the common path current detection circuit 7 is in the normal range and the bus current detection value Idc_det becomes larger than the preset short-circuit determination value. , It is determined that a short circuit abnormality has occurred in the inverter 5. When it is determined that a short-circuit abnormality has occurred in the inverter 5, the inverter switching control unit 34 stops the normal on / off control and performs on / off control at the time of the short-circuit abnormality such as turning off all the switching elements of the inverter 5.

3. 3. Embodiment 3
Next, the AC rotating machine 1 and the control device 11 according to the third embodiment will be described. The description of the same components as in the first embodiment will be omitted. The basic configuration of the AC rotating machine 1 and the control device 11 according to the present embodiment is the same as that of the first embodiment, but is different from the first embodiment in that a low-pass filter process is performed in detecting the current.

<Detection of field current after low-pass filter processing>
In the present embodiment, the current calculation unit 32 performs a low-pass filter process in detecting the field current, and detects the field current detection value If_detflt after the low-pass filter process as the field current detection value If_det. The cutoff frequency of the low-pass filter processing in the detection of the field current is equal to or lower than the on / off frequency of the converter switching control unit 31. Here, the on / off frequency is the reciprocal of the PWM cycle of the converter switching control unit 31.

The low-pass filter processing of the field current may be performed by passing the output signal of the common path current detection circuit 7 through the low-pass filter circuit, or the output signal of the common path current detection circuit 7 may be converted to an A / D value. On the other hand, it may be performed by performing a low-pass filter processing by software. When it is performed by software, A / D conversion is performed in a sampling cycle sufficiently shorter than the PWM cycle, and low-pass filter processing is performed.

As shown in FIG. 15, the field current If before the filter has a waveform in which a multiple order component of 1 kHz is superimposed when the PWM cycle is 1 ms. At this time, the amplitude can be attenuated to about 10% by passing it through a low-pass filter having a cutoff frequency of 100 Hz, and the amplitude can be attenuated to about 1% by passing it through a low-pass filter having a cutoff frequency of 10 Hz. Therefore, since the field current detection value If_detflt after the low-pass filter processing is stable at any timing of the PWM cycle, the field current detection value If_det can be detected regardless of the current detection timing.

<Detection of bus current after low-pass filter processing>
The current calculation unit 32 performs low-pass filter processing in detecting the bus current, and detects the bus current detection value Idc_detflt after the low-pass filter processing as the bus current detection value Idc_det. The cutoff frequency of the low-pass filter processing in the detection of the bus current is equal to or lower than the on / off frequency of the converter switching control unit 31. Here, the on / off frequency is the reciprocal of the PWM cycle of the converter switching control unit 31.

The low-pass filter processing of the bus current may be performed by passing the output signal of the bus current detection circuit 6 through the low-pass filter circuit, or the output signal of the bus current detection circuit 6 may be A / D converted. It may be performed by performing low-pass filtering by software. When it is performed by software, A / D conversion is performed in a sampling cycle sufficiently shorter than the PWM cycle, and low-pass filter processing is performed.

As shown in FIG. 15, the bus current Idc_flt after the low-pass filter processing has a value obtained by averaging the bus current Idc in the PWM cycle. The bus current Idc matches the field current If when switched to the power supply path 20, but becomes zero when switched to the reflux path 21. Therefore, the bus current Idc_flt after the low-pass filter processing is lower than the average value of the field current If, and the ratio of the bus current Idc_flt after the low-pass filter processing to the average value If_ave of the field current If in the PWM cycle is as follows. As shown in the above, the ratio of the switching period to the power supply path 20 to the total period of the switching period to the power supply path 20 and the switching period to the return path 21, that is, is proportional to the on-duty ratio Don.
Idc_flt = If_ave × Don ... (3)

Therefore, the current calculation unit 32 uses the on-duty ratio Don, which is the ratio of the switching period to the power supply path 20 to the total period of the switching period to the power supply path 20 and the switching period to the return path 21, and the low-pass filter processing. The field current estimated value If_est is calculated based on the later bus current detection value Idc_detflt.

For example, the current calculation unit 32 calculates the field current estimated value If_est by dividing the bus current detection value Idc_detflt after the low-pass filter processing by the on-duty ratio Don, as shown in the following equation.
If_est = Idc_detflt / Don ... (4)

As shown in FIG. 15, since the bus current detection value Idc_detflt after the low-pass filter processing is stable at any timing of the PWM cycle, the bus current detection value Idc_detflt after the low-pass filter processing is set regardless of the current detection timing. It can be detected and the field current estimated value If_est can be calculated.

4. Embodiment 4
Next, the AC rotating machine 1 and the control device 11 according to the third embodiment will be described. The description of the same components as in the first embodiment will be omitted. The basic configuration of the AC rotating machine 1 and the control device 11 according to the present embodiment is the same as that of the first embodiment, but the arrangement position of the bus current detection circuit 6 is the same as that of the second embodiment. However, it is different from the first embodiment.

Similar to the second embodiment, as shown in FIG. 11, the bus current detection circuit 6 includes a connection path between the DC power supply 2 and the converter 9, a connection path between the DC power supply 2 and the inverter 5. The current flowing through the common path between the two is detected as the bus current.

Similar to the third embodiment, the current calculation unit 32 performs the low-pass filter processing in the detection of the bus current, and detects the bus current detection value Idc_detflt after the low-pass filter processing as the bus current detection value Idc_det. The cutoff frequency of the low-pass filter processing in the detection of the bus current is not less than the on / off frequency of the converter switching control unit 31 and not more than the on / off frequency of the inverter switching control unit 34. Here, the on / off frequency in the converter switching control unit 31 is the inverse number of the PWM cycle of the converter switching control unit 31, and the on / off frequency in the inverter switching control unit 34 is the inverse number of the PWM cycle of the inverter switching control unit 34. The PWM cycle of the inverter switching control unit 34 is set shorter than the on / off frequency of the converter switching control unit 31.

The low-pass filter processing of the bus current may be performed by passing the output signal of the bus current detection circuit 6 through the low-pass filter circuit, or the output signal of the bus current detection circuit 6 may be A / D converted. It may be performed by performing low-pass filtering by software. When it is performed by software, A / D conversion is performed in a sampling cycle sufficiently shorter than the PWM cycle, and low-pass filter processing is performed.

As described in the second embodiment, the bus current detected by the bus current detection circuit 6 is the converter current Icn, which is the current flowing between the DC power supply 2 and the converter 9, and the DC power supply 2 and the inverter 5. The combined current is the inverter current Iin, which is the current flowing between them. Therefore, it is necessary to extract only the converter current Icn from the bus current.

The average value of the inverter current in the PWM cycle, Iin_ave, is obtained by dividing the voltage commands Vu, Vw, and Vw of the corresponding phases by the power supply voltage Vdc for each of the three-phase armature currents Iu, Iv, and Iw, as shown in the following equation. It can be expressed by the sum of the values obtained by multiplying the on-duty ratios Du, Dv, and Dw of each phase. Therefore, the converter current Icn_flt after the low-pass filter processing can be calculated by subtracting the average value Iin_ave of the inverter current from the bus current detection value Idc_detflt after the low-pass filter processing.
Iin_ave = Iu x Vu / Vdc + Iv x Vv / Vdc + Iw x Vw / Vdc
= (Iu x Vu + Iv x Vv + Iw x Vw) / Vdc
= Iu x Du + Iv x Dv + Iw x Dw
... (5)

Therefore, the current calculation unit 32 calculates the average value Iin_ave of the inverter current, which is the current flowing between the DC power supply 2 and the inverter 5, based on the armature current. In the present embodiment, the current calculation unit 32 calculates the average value Iin_ave of the inverter current based on the product of the three-phase armature current detection values Iu, Iv, Iw and the three-phase voltage commands Vu, Vw, Vw. calculate. As shown in the equation (5), the current calculation unit 32 totals the values obtained by multiplying each of the three-phase armature current detection values Iu, Iv, and Iw by the voltage commands Vu, Vw, and Vw of the corresponding phases. Then, the value obtained by dividing the total value by the power supply voltage Vdc is calculated as the average value Iin_ave of the inverter current.

The current calculation unit 32 calculates the field current estimated value If_est based on the subtraction value obtained by subtracting the average value Iin_ave of the inverter current from the bus current detection value Idc_detflt after the low-pass filter processing and the on-duty ratio Don. Here, the on-duty ratio Don is the ratio of the switching period to the power supply path 20 to the total period of the switching period to the power supply path 20 and the switching period to the reflux path 21. As shown in the following equation, the current calculation unit 32 divides the subtraction value obtained by subtracting the average value of the inverter current Iin_ave from the bus current detection value Idc_detflt after the low-pass filter processing by the on-duty ratio Don, and divides the field current. Calculated as the estimated value If_est.
If_est = (Idc_detflt-Iin_ave) / Don
... (6)

By this subtraction value (Idc_detflt-Iin_ave), only the converter current Icn_flt after the low-pass filter can be extracted from the bus current Idc_flt after the low-pass filter. Then, similarly to the equation (4) of the third embodiment, the field current estimated value If_est can be calculated by dividing the converter current Icn_flt after the low-pass filter by the on-duty ratio Don.

Since the bus current detection value Idc_detflt after the low-pass filter processing is stable at any timing of the PWM cycle, the converter current Icn_flt after the low-pass filter can be detected regardless of the current detection timing, and the field current can be estimated. The value If_est can be calculated.

[Other embodiments]
Finally, other embodiments of the present application will be described. The configurations of the respective embodiments described below are not limited to those applied independently, and can be applied in combination with the configurations of other embodiments as long as there is no contradiction.

(1) In each of the above embodiments, the case where the AC rotating machine 1 includes a three-phase AC armature winding has been described as an example. However, the AC rotating machine 1 may include a plurality of phases of AC armature windings other than the three-phase, or may include a plurality of sets of a plurality of sets of a plurality of phases of the AC armature windings.

(2) In each of the above embodiments, the case where the AC rotary machine 1 is a generator motor for a vehicle has been described as an example. However, the AC rotary machine 1 may be an AC rotary machine for various purposes other than the generator motor for vehicles.

(3) In each of the above embodiments, the case where the converter switching control unit 31 sets the voltage vector Vf0 as the zero vector for switching to the reflux path 21 has been described as an example. However, the converter switching control unit 31 may set the voltage vector Vf3 as the zero vector for switching to the return path 21, or may periodically switch between the voltage vector Vf0 and the voltage vector Vf3. In this case, the common path current detection circuit 7 is a connection line connecting the field winding 4 and the first set of series circuits 28, or the field winding 4 so that the return current can be detected in the voltage vector Vf3. Is provided on the connection line connecting the and the switching element SN2 on the negative side of the second set of series circuits 29.

(4) In each of the above embodiments, the case where the converter 9 is an H-bridge circuit has been described as an example. However, when the converter switching control unit 31 switches to the return path 21, when only the voltage vector Vf0 shown in FIG. 5 is set, the switching element SP2 on the positive electrode side of the second set is always turned off, so that the second set The circuit portion of the switching element SP2 on the positive electrode side of the above may not be provided and may be unconnected, or only an antiparallel diode may be provided. Further, in this case, since the switching element SN2 on the negative electrode side of the second set is always on, the circuit portion of the switching element SN2 on the negative electrode side of the second set may be configured by a connecting line. The resistance of the switching element SN1 on the negative electrode side of the first set can be reduced as compared with the antiparallel diode by turning it on in the case of the return path 21, but if there is a margin in the amount of heat generated, the switching element on the negative electrode side of the first set The circuit portion of the SN1 may be only an antiparallel diode.

On the other hand, as described in the other embodiment 3, when the converter switching control unit 31 switches to the recirculation path 21 and sets only the voltage vector Vf3 in FIG. 8, switching on the negative electrode side of the first set. Since the element SN1 is always off, the circuit portion of the switching element SN1 on the negative electrode side of the first set may not be provided and may be disconnected, or only the antiparallel diode may be provided. Further, in this case, since the switching element SP1 on the positive electrode side of the first set is always on, the circuit portion of the switching element SP1 on the positive electrode side of the first set may be configured by a connecting line. The resistance of the switching element SP2 on the positive electrode side of the second set can be reduced as compared with the antiparallel diode by turning it on in the case of the reflux path 21, but if there is a margin in the amount of heat generated, the switching element on the positive electrode side of the second set The circuit portion of SP2 may be only an antiparallel diode.

Although the present application describes various exemplary embodiments and examples, the various features, embodiments, and functions described in one or more embodiments are applications of a particular embodiment. It is not limited to, but can be applied to embodiments alone or in various combinations. Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed herein. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

1 AC rotating machine, 2 DC power supply, 4 field winding, 5 inverter, 6 bus current detection circuit, 7 common path current detection circuit, 8 armature current detection circuit, 9 converter, 11 AC rotation machine control device, 12 AC armature winding, 20 power supply path, 21 return path, 31 converter switching control unit, 32 current calculation unit, 33 abnormality determination unit, 34 inverter switching control unit

The control device for the AC rotor according to the present application is a control device for the AC rotor that controls the AC rotor having an AC armature winding and a field winding.
A power supply path that has a switching element and allows a current to flow from a DC power supply to the field winding by turning the switching element on and off, and a recirculation path that recirculates the current in the converter and allows a recirculation current to flow through the field winding. However, with the converter that switches,
A bus current detection circuit that detects a bus current, which is a current flowing through a connection path between the DC power supply and the converter, and a bus current detection circuit.
A common path current detection circuit that detects a current flowing through a common path between the power supply path and the return path, and a common path current detection circuit.
A converter switching control unit that switches the power supply path and the reflux path by turning on and off the switching element of the converter.
The field current flowing through the field winding is detected based on the output signal of the common path current detection circuit, the bus current is detected based on the output signal of the bus current detection circuit, and the detected bus current is used as the detected bus current. Based on this, a current calculation unit that calculates a field current estimated value, which is an estimated value of the current flowing through the field winding, and a current calculation unit.
An abnormality determination unit that compares the field current with the field current estimated value and determines an abnormality of one or both of the bus current detection circuit and the common path current detection circuit.
An inverter that has a switching element and performs power conversion between the DC power supply and the AC armature winding.
An inverter switching control unit that turns on and off the switching element of the inverter and applies a voltage to the AC armature winding is provided.
The bus current detection circuit detects a current flowing through a common path between the DC power supply and the converter and the connection path between the DC power supply and the inverter as the bus current. And
The current calculation unit estimates the field current based on the bus current detected when the current is switched to the power supply path in a zero vector state in which no current flows between the DC power supply and the inverter. It calculates the value.

Claims (18)

A control device for an AC rotating machine that controls an AC rotating machine having an AC armature winding and a field winding.
A power supply path that has a switching element and allows a current to flow from a DC power supply to the field winding by turning the switching element on and off, and a recirculation path that recirculates the current in the converter and allows a recirculation current to flow through the field winding. However, with the converter that switches,
A bus current detection circuit that detects a bus current, which is a current flowing through a connection path between the DC power supply and the converter, and a bus current detection circuit.
A common path current detection circuit that detects a current flowing through a common path between the power supply path and the return path, and a common path current detection circuit.
A converter switching control unit that switches the power supply path and the reflux path by turning on and off the switching element of the converter.
The field current flowing through the field winding is detected based on the output signal of the common path current detection circuit, the bus current is detected based on the output signal of the bus current detection circuit, and the detected bus current is used as the detected bus current. Based on this, a current calculation unit that calculates a field current estimated value, which is an estimated value of the current flowing through the field winding, and a current calculation unit.
An abnormality determination unit that compares the field current with the field current estimated value and determines an abnormality of one or both of the bus current detection circuit and the common path current detection circuit.
Control device for AC rotating machine equipped with. The control device for an AC rotor according to claim 1, wherein the current calculation unit calculates the field current estimated value based on the bus current detected when the power supply path is switched. An inverter that has a switching element and performs power conversion between the DC power supply and the AC armature winding.
Further provided with an inverter switching control unit that turns on and off the switching element of the inverter and applies a voltage to the AC armature winding.
The bus current detection circuit detects a current flowing through a common path between the connection path between the DC power supply and the converter and the connection path between the DC power supply and the inverter as the bus current. The control device for an AC rotary machine according to claim 1. The current calculation unit estimates the field current based on the bus current detected when the current is switched to the power supply path in a zero vector state in which no current flows between the DC power supply and the inverter. The control device for an AC rotary machine according to claim 3, wherein the value is calculated. An armature current detection circuit for detecting an armature current, which is a current flowing through the AC armature winding, is further provided.
The current calculation unit detects the armature current based on the output signal of the armature current detection circuit, the bus current and the armature current detected at the same time, and the switching element of the inverter at the time of current detection. The control device for an AC rotating machine according to claim 3 or 4, wherein the field current estimated value is calculated based on the on / off pattern of the above. An armature current detection circuit for detecting an armature current, which is a current flowing through the AC armature winding, is further provided.
The current calculation unit detects the armature current based on the output signal of the armature current detection circuit, and determines the armature of a specific phase based on the on / off pattern of the switching element of the inverter at the time of current detection. Based on the current, the inverter current, which is the current flowing between the DC power supply and the inverter, is calculated.
The inverter current is subtracted from the bus current detected at the same time as the armature current to calculate the converter current, which is the current flowing between the DC power supply and the converter, and the converter current is calculated based on the converter current. The control device for an AC rotating machine according to any one of claims 3 to 5, which calculates an estimated field current. The control device for an AC rotor according to claim 5 or 6, wherein the armature current detection circuit detects a current flowing through a connection path between the inverter and the AC armature winding. The control device for an AC rotor according to any one of claims 3 to 7, wherein the abnormality determination unit determines that a short-circuit abnormality has occurred in the inverter when the bus current deviates from the normal current range. The current calculation unit
A low-pass filter process is performed in the detection of the bus current, and the bus current after the low-pass filter process is detected as the bus current.
Based on the on-duty ratio, which is the ratio of the switching period to the power supply path to the total period of the switching period to the power supply path and the switching period to the reflux path, and the bus current after the low-pass filter processing. , Calculate the field current estimate,
The control device for an AC rotor according to claim 1, wherein the cutoff frequency of the low-pass filter processing in detecting the bus current is equal to or lower than the on / off frequency in the converter switching control unit. The current calculation unit performs low-pass filter processing in detecting the bus current, and detects the bus current after the low-pass filter processing as the bus current.
The AC rotor according to claim 3, wherein the cutoff frequency of the low-pass filter processing in the detection of the bus current is equal to or lower than the on / off frequency of the converter switching control unit and equal to or lower than the on / off frequency of the inverter switching control unit. Control device. An armature current detection circuit for detecting an armature current, which is a current flowing through the AC armature winding, is further provided.
The current calculation unit detects the armature current based on the output signal of the armature current detection circuit, and based on the armature current, is an inverter current which is a current flowing between the DC power supply and the inverter. Calculate the average value of
Switching to the power supply path for the total period of the subtraction value obtained by subtracting the average value of the inverter current from the bus current after the low-pass filter processing and the switching period to the power supply path and the switching period to the return path. The control device for an AC rotary machine according to claim 10, wherein the field current estimated value is calculated based on the on-duty ratio, which is the ratio of the periods. The inverter switching control unit turns on / off the switching element of the inverter based on the voltage command applied to the AC armature winding.
The control device for an AC rotor according to claim 11, wherein the current calculation unit calculates an average value of the inverter current based on the product of the armature current and the voltage command. The control device for an AC rotor according to claim 11 or 12, wherein the armature current detection circuit detects a current flowing through a connection path between the inverter and the AC armature winding. The current calculation unit performs a low-pass filter process in detecting the field current, and detects the field current after the low-pass filter process as the field current.
The control device for an AC rotor according to claim 9 or 10, wherein the cutoff frequency of the low-pass filter processing in the detection of the field current is equal to or lower than the on / off frequency in the converter switching control unit. The converter is provided with two sets of a series circuit in which a power semiconductor on the positive side connected to the positive side of the DC power supply and a power semiconductor on the negative side connected to the negative side of the DC power supply are connected in series. The connection point between the power semiconductor on the positive side and the power semiconductor on the negative side in the series circuit of the set is connected to one end of the field winding, and the power semiconductor on the positive side in the series circuit of the second set. The connection point between the power semiconductor and the power semiconductor on the negative side is connected to the other end of the field winding, and at least the power semiconductor on the positive side in the series circuit of the first set and the power semiconductor in the series circuit of the second set. The control device for an AC rotary machine according to any one of claims 1 to 14, wherein the power semiconductor on the negative electrode side is a switching element. The power semiconductor on the negative electrode side in the first set of the series circuit is a switching element.
The converter switching control unit
When switching to the power supply path, the switching element on the positive electrode side in the series circuit of the first set is turned on, the switching element on the negative electrode side is turned off, and the switching element on the negative electrode side in the series circuit of the second set is turned on. Turn on and
When switching to the return path, the switching element on the positive electrode side in the series circuit of the first set is turned off, the switching element on the negative electrode side is turned on, and the switching element on the negative electrode side in the series circuit of the second set is turned on. The control device for an AC rotating machine according to claim 15, which is turned on. The power semiconductor on the positive electrode side in the second set of the series circuit is a switching element.
The converter switching control unit
When switching to the power supply path, the switching element on the positive electrode side in the series circuit of the first set is turned on, the switching element on the positive electrode side in the series circuit of the second set is turned off, and the switching element on the negative electrode side is turned off. Turn on and
When switching to the return path, the switching element on the positive electrode side in the series circuit of the first set is turned on, the switching element on the positive electrode side in the series circuit of the second set is turned on, and the switching element on the negative electrode side is turned on. The control device for an AC rotating machine according to claim 15. The control device for an AC rotary machine according to any one of claims 1 to 17, wherein the AC rotary machine is a generator motor for a vehicle.

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