Power conversion device

Abstract

A power conversion device (10) is provided with: a first power converter (13a) that converts an alternating current generated by a first rotating electrical machine (8a) coupled to an internal combustion engine into a direct current; a second power converter (13b) that converts the direct current into an alternating current and supplies the alternating current to a second rotating electrical machine (8b) coupled to the drive wheel (17); a DC power converter (12) that changes the voltage of the battery (2); a first current sensor (4) that measures the current between the first power converter (13a) and the first rotating electrical machine (8a); a second current sensor (5) that measures the current between the second power converter (13b) and the second rotating electrical machine (8b); a current sensor (3) for a DC power converter that measures a current between the battery (2) and the DC power converter (12); a first sensor power supply (15a) that supplies power to the first current sensor (4) and the current sensor (3) for the DC power converter; and a second sensor power supply (15b) that supplies power to the second current sensor (5).

Description

Technical Field

[0001] The present application relates to a power conversion device. Background Art

[0002] Hybrid vehicles that use an internal combustion engine to drive a generator to generate electricity and use the generated power to drive an electric motor to provide power to the drive wheels have been put into practical use. The hybrid vehicle has a battery, and when the internal combustion engine is stopped, power is supplied from the battery to provide power to the drive wheels of the vehicle. When the internal combustion engine is running, the battery is charged with power from the generator driven by the internal combustion engine. In addition, even when the internal combustion engine is running, the power supplied from the battery can be added to the power generated by the generator to drive the electric motor more strongly when necessary.

[0003] As the driving motor of a hybrid vehicle, an AC motor represented by a three-phase brushless motor is often used. The current generated by the generator is converted into a DC current as a DC power supply for charging the battery. Then, a DC-AC converter (power converter) is used to generate an AC current from the DC power supply to drive the AC motor.

[0004] In such a hybrid vehicle, the primary current of the motor is vector-controlled by the DC-AC converter to generate a target drive output. Then, the output of the internal combustion engine is controlled to generate the power required by the output of the DC-AC converter. At this time, a technology has been proposed to accurately control the supply current by measuring the output current of the generator and the supply current from the battery by a current sensor (for example, Patent Document 1). Prior art literature Patent Literature

[0005] Patent Document 1: Japanese Patent Laid-Open No. 5-146008 Summary of the invention Technical problem to be solved by the invention

[0006] In order to control the driving output of a hybrid vehicle with higher accuracy, a current sensor can be used to measure the output current of the DC-AC converter used to supply power to the electric motor driving the driving wheels. The current sensor that measures the output current of the generator, the current sensor that measures the supply current from the battery, and the current sensor that measures the output current of the DC-AC converter that drives the electric motor are all important sensors. In the case where all the power sources used to operate these sensors are common, if the sensor power source is lost, all current sensors cannot be used and current control becomes difficult. As a result, it becomes difficult to drive the hybrid vehicle. Regarding the countermeasures to this problem, there is no record in Patent Document 1.

[0007] When a part of the vehicle fails, it is required to be able to travel for emergency evacuation even with limited performance. This function is called limp home mode. Limp home mode is a function that allows you to reach your home even when driving at a low speed.

[0008] For the sensor power supplies of various current sensors, as long as all independent sensor power supplies are ensured, even if any sensor power supply fails, other sensors can continue to be used through other sensor power supplies. However, when all sensor power supplies are set up independently, the increase in sensor power supplies and sensor power supply wiring will lead to a larger power conversion device, an increase in weight, and an increase in cost. Equipment mounted on vehicles is required to be lightweight, miniaturized, and low-cost. Therefore, it is required to find the best balance between fault tolerance and improvements in lightweight, miniaturized, and low-cost.

[0009] The present application is completed to solve the above-mentioned technical problems in a power conversion device, and its purpose is to obtain a power conversion device that can cope with the failure of sensor power supplies of various current sensors to ensure the limp mode function and minimize the number of sensor power supplies. Technical means for solving technical problems

[0010] The power conversion device disclosed in this application includes: a first power converter for converting an alternating current generated by a first rotating electric machine coupled to an output shaft of the internal combustion engine into a direct current and outputting the direct current from the direct current terminal; a second power converter that converts a DC current connected to the DC terminal into an AC current and supplies the AC current to a second rotating electric machine coupled to the drive wheel; A DC power converter that connects between the battery and the DC terminals and changes the voltage; a first current sensor measuring a current flowing between the first power converter and the first rotating electric machine; a second current sensor for measuring a current flowing between the second power converter and the second rotating electric machine; a current sensor for a DC power converter that measures a current flowing between a battery and the DC power converter; A first sensor power supply for supplying power to the first current sensor and the current sensor for the DC power converter; and A second sensor power supply provides power to the second current sensor. Effects of the Invention

[0011] According to the power conversion device involved in the present application, since a first sensor power supply is provided to supply power to a current sensor of a first power converter that converts an AC current generated by a first rotating motor driven by an internal combustion engine into a DC current, a current sensor that measures the current of a DC power converter that boosts a battery voltage, and a second sensor power supply that supplies power to a current sensor of a second power converter that supplies an AC current to a second rotating motor coupled to a driving wheel, a power conversion device that can cope with a failure of a sensor power supply to ensure a limp home mode function and minimize the number of sensor power supplies can be obtained. As a result, the number of sensor power supplies of the power conversion device can be reduced, and miniaturization, lightness, and cost reduction can be promoted. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a configuration diagram of a power conversion device according to Embodiment 1. Figure 2 This is a hardware configuration diagram of the control device for the power conversion device according to the first embodiment. Figure 3 1 is a circuit diagram showing a first power converter of the power conversion device according to the first embodiment. Figure 4 1 is a circuit diagram showing a second power converter of the power conversion device according to the first embodiment. Figure 5 This is a diagram showing power supply when the sensor power supply of the power conversion device according to the first embodiment is normal. Figure 6 This is a first diagram showing power supply when a first sensor power supply of the power conversion device according to the first embodiment fails. Figure 7 This is a second diagram showing power supply when the first sensor power supply of the power conversion device according to the first embodiment fails. Figure 8 This is a diagram showing power supply when the second sensor power supply of the power conversion device according to the first embodiment fails. Fig. 9 This is a diagram showing power supply when the second sensor power supply of the power conversion device according to the second embodiment fails. DETAILED DESCRIPTION

[0013] Hereinafter, embodiments of the power conversion device according to the present application will be described with reference to the drawings.

[0014] 1. Implementation Method 1 <Structure of power conversion device> Figure 11 is a structural diagram of a power conversion device 10 according to Embodiment 1. The power conversion device 10 is electrically connected to a battery 2 of a vehicle 1, a first rotating motor 8a mechanically coupled to an output shaft of an internal combustion engine 6, and a second rotating motor 8b mechanically coupled to a drive wheel 17. Here, the mechanical coupling may be direct coupling of a main shaft, coupling through a reduction gear and a clutch, or coupling through a rotation transmission mechanism via a belt. Figure 1 In FIG. 1 , the internal combustion engine 6 is represented by ENG, the first rotating electric machine 8 a is represented by M1 , and the second rotating electric machine 8 b is represented by M2 .

[0015] The first rotating motor 8a and the second rotating motor 8b may be three-phase AC rotating motors having a U-phase winding, a V-phase winding, and a W-phase winding. The first rotating motor 8a and the second rotating motor 8b may drive a load to rotate, and may regenerate the rotational energy of the load into electric energy. The first rotating motor 8a and the second rotating motor 8b may be motors having a permanent magnet on the rotor, motors having an electromagnet on the rotor, brush motors, brushless motors, and the like.

[0016] The power conversion device 10 includes a first power converter 13a, a second power converter 13b, a DC power converter 12, a control device 14, a sensor power supply 15, a first current sensor 4, a second current sensor 5, and a DC power converter current sensor 3. The first rotating electric machine 8a is driven by the output of the internal combustion engine 6 mounted on the vehicle 1 to generate electricity, and the AC current generated by the first power converter 13a is converted into DC and output from the positive side DC terminal 23a and the negative side DC terminal 23b.

[0017] The second power converter 13b supplied with direct current from the positive-side DC terminal 23a and the negative-side DC terminal 23b converts the direct current into alternating current, rotates the second rotating electric machine 8b, and drives the driving wheel 17. The DC power converter 12 changes the voltage of the battery 2 mounted on the vehicle 1, and transmits and receives direct current with the positive-side DC terminal 23a and the negative-side DC terminal 23b. Current is supplied from the battery 2 to the positive-side DC terminal 23a and the negative-side DC terminal 23b as needed, and current is received from the positive-side DC terminal 23a and the negative-side DC terminal 23b when charging the battery 2.

[0018] The current passing through the first power converter 13a, the second power converter 13b, and the DC power converter 12 is detected by the first current sensor 4, the second current sensor 5, and the DC power converter current sensor 3. The first current sensor 4 and the DC power converter current sensor 3 receive power from the first sensor power supply 15a via the first sensor power supply line 9a. The second current sensor 5 receives power from the second sensor power supply 15b via the second sensor power supply line 9b. Figure 1In the embodiment, the first sensor power supply 15a and the second sensor power supply 15b are built in the sensor power supply 15. However, the first sensor power supply 15a and the second sensor power supply 15b may also be independently provided at different positions.

[0019] The control device 14 inputs the detection signal of the first current sensor 4 from the input terminal I1, the detection signal of the second current sensor 5 from the input terminal I2, and the detection signal of the DC power converter current sensor 3 from the input terminal IC. The control device 14 controls the second power converter 13b from the control terminal C2. Thus, the control device 14 can control the current amount of the second rotating electric machine 8b according to the driving force required by the vehicle 1.

[0020] The control device 14 controls the first power converter 13a from the control terminal C1. Thus, the control device 14 can control the amount of current driving the first rotating electric machine 8a according to the driving force required by the vehicle 1. The control device 14 can adjust the output of the internal combustion engine 6 according to the signal from the control terminal CE. The control device 14 can control the generated current of the first rotating electric machine 8a by adjusting the output of the internal combustion engine 6 and controlling the rotation speed of the internal combustion engine 6.

[0021] The DC power converter 12 boosts the voltage of the battery 2 to the voltage of the positive DC terminal 23a and the negative DC terminal 23b. The supply current from the battery 2 or the charging current to the battery 2 is transmitted to the input terminal IC of the control device 14 as a signal of the DC power converter current sensor 3.

[0022] <Hardware structure of control device> Figure 2 1 is a hardware configuration diagram of the control device 14 according to Embodiment 1. Each function of the control device 14 is implemented by a processing circuit included in the control device 14. Specifically, the control device 14 is configured as follows: Figure 2 As shown, as a processing circuit, it includes an operation processing device 90 (also called a processor) such as a CPU (Central Processing Unit), a storage device 91 for exchanging data with the operation processing device 90, an input circuit 92 for inputting external signals to the operation processing device 90, and an output circuit 93 for outputting signals from the operation processing device 90 to the outside.

[0023] The operation processing device 90 may include an ASIC (Application Specific Integrated Circuit), an IC (Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), various logic circuits, and various signal processing circuits. In addition, the operation processing device 90 may include a plurality of the same or different operation processing devices to share the execution of various processes.

[0024] In the control device 14, as a storage device 91, a RAM (Random Access Memory) configured to read and write data from the operation processing device 90, a ROM (Read Only Memory) configured to read data from the operation processing device 90, etc. can be provided. The storage device 91 can also be built in the operation processing device 90. The input circuit 92 is connected to input signals, sensors, switches, and includes an A / D converter that inputs these input signals, sensors, and switch signals to the operation processing device 90. Specifically, the signals of the first current sensor 4, the second current sensor 5, and the current sensor 3 for the DC power converter are input. The output circuit 93 is connected to an electric load such as a gate drive circuit that drives the switching element to turn on and off, and includes a drive circuit that outputs a control signal from the operation processing device 90 to these electric loads. Specifically, the output signal that drives the switching element of the first power converter 13a, the second power converter 13b, and the DC power converter 12 is output.

[0025] The various functions of the control device 14 are realized by executing the software (program) stored in the storage device 91 such as ROM by the arithmetic processing device 90, and cooperating with other hardware of the control device 14 such as the storage device 91, the input circuit 92 and the output circuit 93. The setting data such as the threshold value and the judgment value used by the control device 14 are stored in the storage device 91 such as ROM as part of the software (program). The various functions of the control device 14 can be constituted by software modules respectively, or can be constituted by a combination of software and hardware.

[0026] <DC power converter> Figure 1The DC power converter 12 has a function as a voltage conversion device that converts the voltage of the battery 2 and the voltage between the positive side DC terminal 23a and the negative side DC terminal 23b. The DC power converter 12 is also called a DC-DC converter. The DC power converter 12 includes a reactor 7, a positive side switching element 16b, a negative side switching element 16a, and a DC power converter current sensor 3 that detects the reactor current.

[0027] The DC power converter 12 is connected to a low voltage side smoothing capacitor 21 for smoothing a low voltage side voltage and a high voltage side smoothing capacitor 22 for smoothing a high voltage side voltage. The positive side switching element 16b and the negative side switching element 16a are controlled by the control device 14.

[0028] The positive side switching element 16b and the negative side switching element 16a are connected in series to form a switching circuit in the DC power converter 12. The negative side switching element 16a may be formed by connecting a plurality of switching elements in parallel. The positive side switching element 16b may also be formed by connecting a plurality of switching elements in parallel.

[0029] The positive side switch element 16b and the negative side switch element 16a are switched by gate signals from the control terminals G1 and G2 of the control device 14. The positive side switch element 16b and the negative side switch element 16a are each composed of, for example, an IGBT (Insulated Gate Bipolar Transistor) in which a freewheeling diode is connected in reverse parallel. As a switch element, in addition to this, a FET (Field Effect Transistor) having a parasitic diode connected in reverse parallel can also be used. In addition, as a switch element, a normal bipolar transistor having a reversely connected diode can also be used.

[0030] The DC power converter 12 boosts the voltage of the DC power output from the battery 2 and supplies it to the first power converter 13a and the second power converter 13b. In addition, there is also a case where the AC current generated by the first rotating electric machine 8a is converted into a DC current in the first power converter 13a, and the voltage at this time is stepped down by the DC power converter 12 to charge the battery 2. That is, the DC power converter 12 functions as a boost converter or a step-down converter.

[0031] <First power converter> Figure 3 1 is a circuit diagram of the first power converter 13a of the power conversion device 10 according to Embodiment 1. The first power converter 13a functions as an AC-DC converter that converts the three-phase AC current output from the first rotating electrical machine 8a into a DC current.

[0032] The first power converter 13a has positive-side switching elements 16d, 16f, 16h of the U phase, V phase, and W phase connected to the positive-side DC terminal 23a, and negative-side switching elements 16c, 16e, 16g of the U phase, V phase, and W phase connected to the negative-side DC terminal 23b. These switching elements are composed of IGBTs and the like and have return diodes connected in reverse parallel, similarly to the positive-side switching element 16b and the negative-side switching element 16a of the DC power converter 12. The positive-side switching element of each phase is called an upper arm, and the negative-side switching element is called a lower arm. The upper arm and the lower arm of each phase are connected in series, and the three-phase AC current of the U phase, V phase, and W phase is transferred from each connection point.

[0033] The connection points of each phase are connected to the windings of the first rotating electric machine 8a, respectively, and the current passing through each phase is detected by the first current sensors 4a, 4b, 4c of each phase. Figure 1 14, the detection current of the first current sensor 4 is input from the input terminal I1 of the control device 14. Actually, the three input terminals for inputting the detection values ​​of the first current sensors 4a, 4b, and 4c of the U-phase, V-phase, are collectively represented by the input terminal I1.

[0034] The switching elements of the first power converter 13a are controlled by control terminals C11 to C16 of the control device 14. Figure 1 , the control terminals C11 to C16 are collectively referred to as the control terminal C1. The control device 14 monitors the measured value of the first current sensor 4 measuring the output current, and controls the output of each switching element and the internal combustion engine 6 so that the output current of the first power converter 13a becomes the target value. That is, the first current sensor 4 is provided in order to allow the controller 14 to feedback control the output of the first power converter 13a.

[0035] The three-phase AC current supplied to the first power converter 13a is rectified by the switching element and converted into a DC current, and supplied to the positive DC terminal 23a and the negative DC terminal 23b. The first rotating electric machine 8a sometimes functions as a generator to supply current, and sometimes is supplied with current to function as a motor. The first power converter 13a sometimes functions as an AC-DC converter, and sometimes functions as a DC-AC converter. When the internal combustion engine is stopped, the first power converter 13a converts the DC current whose voltage is converted from the battery 2 by the DC power converter 12 into an AC current, drives the first rotating electric machine 8a, and starts the internal combustion engine 6.

[0036] <Second power converter> Figure 41 is a circuit diagram of the second power converter 13b of the power conversion device 10 according to Embodiment 1. The second power converter 13b functions as a DC-AC converter that converts a DC current supplied from the positive DC terminal 23a and the negative DC terminal 23b into a three-phase AC current for driving the second rotating electrical machine 8b.

[0037] The second power converter 13b has positive-side switching elements 16j, 16l, 16n of the U phase, V phase, and W phase connected to the positive-side DC terminal 23a, and negative-side switching elements 16i, 16k, 16m of the U phase, V phase, and W phase connected to the negative-side DC terminal 23b. These switching elements are composed of IGBTs and the like and have return diodes connected in reverse parallel, similarly to the positive-side switching elements 16b, 16d, 16f, 16h and negative-side switching elements 16a, 16c, 16e, 16g of the DC power converter 12 and the first power converter 13a. The positive-side switching element of each phase is called an upper arm, and the negative-side switching element is called a lower arm. The upper arm and the lower arm of each phase are connected in series, and the three-phase AC current of the U phase, V phase, and W phase is transferred from each connection point.

[0038] The connection points of each phase are connected to the windings of the second rotating electric machine 8b, respectively, and the current passing through each phase is detected by the second current sensors 5a, 5b, 5c of each phase. Figure 1 In the figure, it is explained that the detection current of the second current sensor 5 is input from the input terminal I2 of the control device, but in fact, the collective terminology of the three terminals for inputting the detection values ​​of the second current sensor 5a of the U phase, the second current sensor 5b of the V phase, and the second current sensor 5c of the V phase is represented as the input terminal I2.

[0039] The switching elements of the second power converter 13b are controlled by the control terminals C21 to C26 of the control device 14. Figure 1 In the embodiment, the control terminals C21 to C26 are collectively referred to as the control terminal C2. The control device 14 monitors the measured value of the second current sensor 5 measuring the output current, and controls the output of each switching element and the internal combustion engine 6 so that the output current of the second power converter 13b becomes the target value. That is, the second current sensor 5 is provided so that the control device 14 can feedback control the output of the second power converter 13b.

[0040] The DC current supplied to the second power converter 13b is converted into a three-phase AC current by the switching element through duty cycle control, and supplied to the coils of the U-phase, V-phase, and W-phase of the second rotating electric machine 8b. The second rotating electric machine 8b sometimes functions as a motor and is driven by current supplied, and sometimes functions as a generator and supplies current. The second power converter 13b sometimes functions as a DC-AC converter, and sometimes functions as an AC-DC converter. When the vehicle 1 is decelerated, the second rotating electric machine 8b is driven by the drive wheel 17 and functions as a generator, and the second power converter 13b converts the regenerative power into AC-DC to charge the battery 2.

[0041] <Sensor power supply> The first current sensor 4, the second current sensor 5, and the current sensor 3 for the DC power converter receive the supply of sensor power from the sensor power supply 15. In-vehicle equipment is required to be small, lightweight, and low-cost. Therefore, for the sensor power supply, it is also desired to share and minimize the power supply setting and wiring to the sensor.

[0042] like Figure 1 As shown, in the power conversion device 10 involved in the first embodiment, three current sensors are included, namely, the first current sensor 4, the second current sensor 5, and the current sensor 3 for the DC power converter. The operating power supplies of these sensors are set to the first sensor power supply 15a and the second sensor power supply 15b, and the wiring for providing power is set to the first sensor power supply line 9a and the second sensor power supply line 9b, while trying to improve the fault resistance, while promoting miniaturization, lightness, and low cost. The components of the multiple sensors measuring the current can be the same, but different sensor components can also be used.

[0043] <Current flow when sensor power supply is normal> Figure 5 1 is a diagram showing the power supply of the sensor power supply of the power conversion device according to Embodiment 1 when the power is normal. The transmission of power applied to the first rotating electric machine 8a driven by the internal combustion engine 6 is indicated by white arrows. The alternating current generated by the first rotating electric machine 8a is converted into direct current by the first power converter 13a.

[0044] The converted DC current is then converted into AC current by the second power converter 13b to drive the second rotary motor 8b. The flow of this series of currents is indicated by arrows. The transmission of power applied to the drive wheel 17 driven by the second rotary motor 8b is indicated by white arrows. Figure 5 In the figure, the current detected by the first current sensor 4 is represented as I1, the current detected by the second current sensor 5 is represented as I2, and the current detected by the DC power converter current sensor 3 is represented as IC.

[0045] The battery 2 exchanges the DC current with the DC power converter 12, and the DC power converter 12 exchanges the DC current with the first power converter 13a and the second power converter 13b. Figure 5 In the diagram, a converter group using a current sensor operated by a first sensor power supply 15a for feedback control is shown in range 20a. A converter group using a current sensor operated by a second sensor power supply 15b for feedback control is shown in range 20b.

[0046] <Current Flow When the First Sensor Power Supply Fails> Figure 6 This is a first diagram showing power supply when the first sensor power supply 15a fails in the power conversion device 10 according to Embodiment 1. If the first sensor power supply 15a or the first sensor power supply line 9a fails, the first current sensor 4 and the DC power converter current sensor 3 lose power for sensor operation and cannot detect current.

[0047] In this case, the control device 14 cannot perform current feedback control on the first power converter 13a and the DC power converter 12. This means that the first power converter 13a cannot be driven normally, and the DC power converter 12 cannot perform voltage step-up and voltage step-down operations.

[0048] The DC power converter 12 cannot use the DC power converter current sensor 3, so the step-up and step-down operations become difficult. In this case, the control device 14 keeps the positive side switch element 16b on and keeps the negative side switch element 16a off through the gate signal output from the control terminals G1 and G2, so that the DC terminal can be directly connected to the battery 2.

[0049] The driving state of the DC power converter at this time is called direct drive. Through direct drive, current can be provided from the battery 2 to the second power converter 13b. The flow of current at this time is indicated by an arrow. In this case, when the second sensor power supply 15b is normal, the output current of the second power converter 13b can be detected by the second current sensor. Therefore, the second rotating motor 8b can be subjected to current feedback control.

[0050] Figure 7 This is a second diagram showing power supply when the first sensor power supply of the power conversion device involved in embodiment 1 fails. The first power converter 13a cannot be driven normally and stops driving. However, even if the first power converter 13a is stopped, it can function as a three-phase full-wave rectifier circuit through the return diode connected in reverse parallel to each switching element.

[0051] At this time, the speed of the internal combustion engine 6 can be increased according to the command from the control device 14. As a result, the induced voltage generated by the first rotating motor 8a can be controlled to be larger than the voltage of the battery 2. As a result, the current generated by the first rotating motor 8a driven by the internal combustion engine 6 can be supplied to the second power converter 13b and the battery 2 through three-phase full-wave rectification. The current flow at this time is Figure 7 Indicated by arrows.

[0052] The voltage of the battery 2 is, for example, 14.7 V, and the speed of the internal combustion engine 6 at which the induced voltage of the first rotating electric machine 8a exceeds this voltage can be measured and specified in advance. The control device 14 can also control the internal combustion engine 6 to be above this speed. In addition, a battery voltage sensor for detecting the voltage of the battery 2 can also be provided. The control device 14 can also control the internal combustion engine 6 to reach a speed at which an induced voltage exceeding the detection value of the battery voltage sensor is generated.

[0053] Furthermore, a first rotating motor voltage sensor for detecting the output voltage of the first rotating motor 8a may be provided to detect the induced voltage generated by the first rotating motor 8a. When the control device 14 detects an abnormality in the first sensor power supply 15a, it adjusts the rotation speed of the internal combustion engine so that the induced voltage detected by the first rotating motor voltage sensor is greater than the battery voltage detected by the battery voltage sensor. Thus, the current generated by the first rotating motor 8a driven by the internal combustion engine 6 is more reliably supplied to the second power converter 13b and the battery 2 through three-phase full-wave rectification.

[0054] Even when the first sensor power supply 15a fails, the second power converter 13b can be driven normally. Since the second current sensor 5 operates by receiving the sensor power supply from the second sensor power supply 15b, the control device 14 can perform feedback control on the second power converter 13b. The second power converter 13b can drive the second rotating motor 8b with high precision by the current from the battery 2 provided by the direct-connected driving DC power converter 12 and the current supplied by the three-phase full-wave of the first power converter 13a.

[0055] Thus, even when the first sensor power supply 15a fails, the vehicle 1 can control the second rotating motor 8b. By direct control of the DC power converter 12, the voltage of the DC terminal is reduced, and the drive current of the second rotating motor 8b by the second power converter 13b is limited. However, the vehicle 1 can be driven by the drive wheel 17, and the limp home mode function can be ensured. Furthermore, by increasing the rotation speed of the internal combustion engine 6, the battery 2 can also be charged with the generated current of the first rotating motor 8a. Thus, the drivable time and drivable distance of the vehicle 1 based on the charge amount of the battery 2 at that time can be extended.

[0056] <Current Flow When the Second Sensor Power Supply Fails> Figure 8 This diagram shows power supply when the second sensor power supply 15a fails in the power conversion device 10 according to Embodiment 1. If the second sensor power supply 15b or the second sensor power supply line 9b fails, the second current sensor 5 loses power supply for sensor operation and cannot detect current.

[0057] In this case, the control device 14 cannot perform current feedback control on the second power converter 13b. However, for the driving current required by the second rotating motor 8b, the control device 14 can predictably drive the second rotating motor 8b by performing PWM (Pulse Width Modulation) control on the switching element of the second power converter 13b with a pulse width predetermined in accordance with the required current. Thus, although the high-precision feedback control of the output current using the second current sensor 5 cannot be performed, the limp home mode function can be ensured.

[0058] Since the first current sensor 4 of the first power converter 13a and the first sensor power supply 15a for supplying power to the DC power converter current sensor 3 and the second sensor power supply 15b for supplying power to the second current sensor 5 of the second power converter 13b are provided, it is possible to obtain a power conversion device 10 that can both ensure the limp home mode function in response to a failure of the sensor power supply and minimize the number of sensor power supplies. As a result, the number of sensor power supplies of the power conversion device 10 can be reduced, and miniaturization, weight reduction, and cost reduction can be promoted. 2. Implementation Method 2 Fig. 9 1 is a diagram showing power supply when the second sensor power supply 15b of the power conversion device 10a according to Embodiment 2 fails. The structure of the power conversion device 10a according to Embodiment 2 is different from the structure of the power conversion device 10 according to Embodiment 1 in that a third power converter 13c is added. The control device 14a controls the switching element of the third power converter 13c in addition to the first power converter 13a and the DC power converter 12 (the control device 14a is not shown).

[0060] The vehicle 1a equipped with the power conversion device 10a according to the second embodiment includes a third rotating electrical machine 8c. Figure 1, the third rotating motor 8c is represented by M3. The third rotating motor 8c is used as a rear motor for driving the rear wheel 17a. The object driven by the third rotating motor 8c can also be the driving wheel 17. The third rotating motor 8c is driven by the third power converter 13c providing current. In addition to the above points, the power conversion device 10a involved in the second embodiment is the same as the power conversion device 10 involved in the first embodiment.

[0061] <Current Flow When the Second Sensor Power Supply Fails> If the second sensor power supply 15b or the second sensor power supply line 9b fails, the second current sensor 5 loses the power supply for sensor operation and cannot detect the current. In this case, the control device 14a cannot perform current feedback control on the second power converter 13b.

[0062] Even in this case, the third power converter 13c can be driven normally. The current provided to the DC terminal by the DC power converter 12 after the power of the battery 2 is converted into a voltage, and the current provided to the DC terminal by the first power converter after the power generated by the first rotating motor 8a is provided to the third power converter 13c. Therefore, the control device 14a controls the third power converter 13c to provide current to the third rotating motor 8c, so that the rear wheel 17a can be driven to travel.

[0063] At this time, the second power converter 13b stops driving. The second rotating motor 8b is pulled and rotated by the driving wheel 17. The second rotating motor 8b rotates and generates a back electromotive force. The second rotating motor 8b functions as a generator, and generates a direct current through the rectification action of the return diode connected in reverse parallel to the switching element of the second power converter 13b in which the driving is stopped. This current interferes with the control of the third power converter 13c. As the speed of the driving wheel 17 increases, the induced voltage of the second rotating motor 8b increases. Therefore, in order to suppress the induced voltage of the second rotating motor 8b, the driving speed in the limp home mode cannot be increased to more than the specified speed.

[0064] However, even in this case, the interference caused by the induced voltage of the second rotating electric machine 8b can be suppressed by causing the DC power converter 12 to perform a boost operation through the control device 14a. Therefore, a reasonable boost voltage higher than the boost voltage of the DC power converter 12 under normal circumstances can be predetermined. Then, the control device 14a causes the DC power converter 12 to perform a boost operation until the boost voltage is determined in advance. Alternatively, the voltage may be boosted to the rated maximum voltage of the DC power converter 12.

[0065] When the third power converter 13c is used to drive the third rotating motor 8c, a third current sensor for detecting the output current of the third power converter 13c can also be provided to implement current feedback control with higher accuracy. In this case, the sensor power supply of the third current sensor can be received from the first sensor power supply 15a. Thus, even if the second sensor power supply 15b or the second sensor power supply line 9b fails, the current feedback control of the third power converter 13c can be performed with high accuracy from the control device 14a. Fig. 9 In FIG. 1 , the current detected by the third current sensor is represented as I3.

[0066] In the second embodiment, when the first sensor power supply 15a or the first sensor power supply line 9a fails, the control device 14a stops driving the first power converter 13a and directly controls the DC power converter 12. In this case, it is possible to deal with it in the same way as in the first embodiment, and the limp home mode function can be ensured, so the description is omitted.

[0067] As described above, according to the power conversion device 10a involved in Embodiment 2, it is possible to obtain a power conversion device 10a that can cope with the failure of the sensor power supply to ensure a sufficient limp home mode function while minimizing the number of sensor power supplies. As a result, the number of sensor power supplies of the power conversion device 10a can be reduced, and miniaturization, weight reduction, and cost reduction can be promoted.

[0068] Although the present application describes various exemplary embodiments and examples, the various features, methods and functions described in one or more embodiments are not limited to the application of specific embodiments and can be applied to the embodiments individually or in various combinations. Therefore, it can be considered that countless variations that are not illustrated are also included in the technical scope disclosed in the present application specification. For example, it is set to include the case where at least one structural element is deformed, added or omitted, and the case where at least one structural element is extracted and combined with the structural elements of other embodiments. The power conversion device as described in any one of Supplementary Notes 1 to 9 outputs to the terminal.

[0069] Hereinafter, each aspect of the present disclosure will be collectively described as a supplementary note.

[0070] (Supplementary Note 1) A power conversion device comprising: a first power converter for converting an alternating current generated by a first rotating electric machine coupled to an output shaft of the internal combustion engine into a direct current and outputting the direct current from the direct current terminal; a second power converter connected to the DC terminal and converting the DC current into AC current to provide the AC current to a second rotating electric machine coupled to the driving wheel; a DC power converter connected between the battery and the DC terminal for changing the voltage; a first current sensor for measuring a current flowing between the first power converter and the first rotating electric machine; a second current sensor for measuring a current flowing between the second power converter and the second rotating electric machine; a DC power converter current sensor for measuring a current flowing between the battery and the DC power converter; A first sensor power supply for supplying power to the first current sensor and the current sensor for the DC power converter; and A second sensor power supply provides power to the second current sensor. (Supplement 2) The power conversion device as described in Supplement 1, comprising a control device for controlling the DC power converter, The DC power converter comprises a positive-side switching element, a negative-side switching element and a reactor. When the control device detects that the power supply of the first sensor is abnormal, the control device directly drives the DC power converter. (Supplementary Note 3) The power conversion device as described in Supplementary Note 2, When the control device detects that the first sensor power supply is abnormal, the control device turns on the positive electrode side switching element and turns off the negative electrode side switching element. (Supplement 4) The power conversion device as described in Supplement 2 or 3, comprising: a battery voltage sensor for detecting a voltage of the battery; and a first rotating electrical machine voltage sensor for detecting an output voltage of the first rotating electrical machine, The control device adjusts the rotation speed of the internal combustion engine so that the induced voltage detected by the first rotating electrical machine voltage sensor becomes larger than the battery voltage detected by the battery voltage sensor when an abnormality in the first sensor power supply is detected. (Supplement 5) A power conversion device as described in any one of Supplements 2 to 4, When the first sensor power supply and the second sensor power supply are normal, the control device controls the first power converter according to the current value detected by the first current sensor, controls the second power converter according to the current value detected by the second current sensor, and controls the DC power converter according to the current value detected by the DC power converter current sensor, and when an abnormality is detected in the second sensor power supply, the control device does not use the current value detected by the second current sensor to control the second power converter for the second power sensor. (Supplement 6) A power conversion device as described in any one of Supplements 2 to 5, A third power converter is provided, which is connected to the DC terminal and converts the DC current into AC current, and provides the AC current to the third rotating electric machine coupled to the driving wheel. When the control device detects that the second sensor power supply is abnormal, the control device stops driving the second power converter and controls the first power converter, the third power converter, and the DC power converter. (Supplementary Note 7) The power conversion device as described in Supplementary Note 6, including a third current sensor for measuring a current flowing between the third power converter and the third rotating electric machine, The third current sensor receives power supply from the first sensor power supply. (Supplementary Note 8) The power conversion device as described in Supplementary Note 6 or 7, When the control device detects that the second sensor power supply is abnormal, the control device increases the voltage of the DC terminal to a predetermined voltage higher than a normal voltage when the second sensor power supply is normal, using the DC power converter. (Supplementary Note 9) The power conversion device as described in Supplementary Note 8, When the control device detects that the second sensor power supply is abnormal, the control device increases the voltage of the DC terminal to a rated maximum voltage through the DC power converter. (Supplement 10) A power conversion device as described in any one of Supplements 1 to 9, When the internal combustion engine is started, the first power converter converts the DC current supplied from the DC terminal into AC current and drives the first rotating electrical machine. The second power converter converts the AC current generated by the second rotating electric machine into a DC current during power regeneration, and outputs the DC current to the DC terminal. Description of symbols 2 battery, 3 current sensor for DC power converter, 4 first current sensor, 5 second current sensor, 6 internal combustion engine, 8a first rotating electrical machine, 8b second rotating electrical machine, 8c third rotating electrical machine, 10, 10a power conversion device, 12 DC power converter, 13a first power converter, 13b second power converter, 13c third power converter, 14, 14a control device, 15a first sensor power supply, 15b second sensor power supply, 16a negative electrode side switching element, 16b positive electrode side switching element, 17 driving wheel, 17a rear wheel.

Claims

1. A power conversion device, characterized in that: include: a first power converter for converting an alternating current generated by a first rotating electric machine coupled to an output shaft of the internal combustion engine into a direct current and outputting the direct current from the direct current terminal; a second power converter connected to the DC terminal and converting the DC current into AC current to provide the AC current to a second rotating electric machine coupled to the driving wheel; a DC power converter connected between the battery and the DC terminal and changing the voltage; a first current sensor for measuring a current flowing between the first power converter and the first rotating electric machine; a second current sensor for measuring a current flowing between the second power converter and the second rotating electric machine; a DC power converter current sensor for measuring a current flowing between the battery and the DC power converter; A first sensor power supply for supplying power to the first current sensor and the current sensor for the DC power converter; and A second sensor power supply provides power to the second current sensor.

2. The power conversion device according to claim 1, characterized in that: comprising a control device for controlling the DC power converter, The DC power converter includes a positive-side switching element, a negative-side switching element, and a reactor. When the control device detects that the first sensor power supply is abnormal, the control device directly drives the DC power converter.

3. The power conversion device according to claim 2, characterized in that: When the control device detects that the first sensor power supply is abnormal, the control device turns on the positive electrode side switching element and turns off the negative electrode side switching element.

4. The power conversion device according to claim 2 or 3, characterized in that: include: a battery voltage sensor for detecting a voltage of the battery; as well as a first rotating electrical machine voltage sensor for detecting an output voltage of the first rotating electrical machine, The control device adjusts the rotation speed of the internal combustion engine so that the induced voltage detected by the first rotating electrical machine voltage sensor becomes larger than the battery voltage detected by the battery voltage sensor when an abnormality in the first sensor power supply is detected.

5. The power conversion device according to any one of claims 2 to 4, characterized in that: When the first sensor power supply and the second sensor power supply are normal, the control device controls the first power converter according to the current value detected by the first current sensor, controls the second power converter according to the current value detected by the second current sensor, and controls the DC power converter according to the current value detected by the DC power converter current sensor. When the second sensor power supply is detected to be abnormal, the control device does not use the current value detected by the second current sensor to control the second power converter.

6. The power conversion device according to any one of claims 2 to 5, characterized in that: A third power converter is provided, which is connected to the DC terminal and converts the DC current into AC current, and provides the AC current to the third rotating electric machine coupled to the driving wheel. When the control device detects that the second sensor power supply is abnormal, the control device stops driving the second power converter and controls the first power converter, the third power converter, and the DC power converter.

7. The power conversion device according to claim 6, characterized in that: including a third current sensor for measuring a current flowing between the third power converter and the third rotating electric machine, The third current sensor receives power supply from the first sensor power supply.

8. The power conversion device according to claim 6 or 7, characterized in that: When the control device detects that the second sensor power supply is abnormal, the control device increases the voltage of the DC terminal to a predetermined voltage higher than a normal voltage when the second sensor power supply is normal, using the DC power converter.

9. The power conversion device according to claim 8, characterized in that: When the control device detects that the second sensor power supply is abnormal, the control device increases the voltage of the DC terminal to a rated maximum voltage through the DC power converter.

10. The power conversion device according to any one of claims 1 to 9, characterized in that: When the internal combustion engine is started, the first power converter converts the DC current supplied from the DC terminal into AC current to drive the first rotating electrical machine. The second power converter converts the AC current generated by the second rotating electric machine into a DC current during power regeneration, and outputs the DC current to the DC terminal.

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