WO2018056381A1

WO2018056381A1 - Biaxial inverter device

Info

Publication number: WO2018056381A1
Application number: PCT/JP2017/034172
Authority: WO
Inventors: 明生中島
Original assignee: Ntn株式会社
Priority date: 2016-09-23
Filing date: 2017-09-21
Publication date: 2018-03-29
Also published as: JP2018050431A; JP6755763B2

Abstract

Provided is a biaxial inverter device in which abnormality determination for identifying whether there is an abnormality in either of two normal use resolver-to-digital (RD) converters can be performed by adding one monitoring RD converter, abnormalities in excitation circuits and detection circuits can be determined, and alternation of detection and alternation of excitation can be distinguished and performed. The present invention is provided with: a first change-over switch (28) which switches between two resolvers (25, 25) and connects one of the resolvers to the detection side of a monitoring RD converter (1C), to cause detection signals of the connected resolver (25) to be inputted into the monitoring RD converter (1C); and two second change-over switches (31, 31) which are respectively connected to the resolvers (25) corresponding to the excitation side of the monitoring RD converter (1C), and which switch the excitation signal inputted into the connected resolver (25), from the excitation signal outputted by the corresponding normal use RD converter (1A(1B)), to the excitation signal outputted by the monitoring RD converter (1C).

Description

2-axis inverter

Related applications

This application claims the priority of Japanese Patent Application No. 2016-185808 filed on September 23, 2016, which is incorporated herein by reference in its entirety.

The present invention relates to a two-shaft inverter device that drives two motors and the like that respectively drive left and right drive wheels in an electric vehicle, and more particularly to abnormality detection and redundancy of the RD converter.

In an electric vehicle, an inverter device connected to a lower level of an ECU (also referred to as VCU) that performs overall control of the entire vehicle is used to drive a motor for traveling. The inverter device includes a drive circuit configured by an inverter that converts a direct current of the battery into a three-phase alternating current, and a motor control circuit that monitors the rotation of the motor and controls the output and efficiency of the motor.

As such an inverter device, an electric vehicle equipped with a motor that individually drives left and right drive wheels, such as using an in-wheel motor drive device, includes a drive circuit and a motor control circuit for the left and right motors in one housing. A two-shaft inverter device is also used. In the biaxial inverter device, the motor control circuits for the left and right motors are generally provided in one microcomputer.

Fig. 8 shows the basic structure of the 2-axis inverter device. The motor control means 21 comprising a microcomputer in the inverter device 101 drives the motors 4 by controlling the left and right motor drive circuits 22 based on commands from the ECU (VCU). At that time, the rotational position of the motor 4 is detected by the resolver 25 and is taken into the motor control circuit 21 using the RD converters (resolver / digital converter) 1A, 1B. The

RD converters

1A and 1B are interfaces for taking an analog rotational position signal of the resolver 25 into a control circuit, and may be abbreviated as RDC. Various other rotation detectors can be used to detect the rotational position of the motor 4, but a resolver is often used because of excellent rotation detection accuracy.

RD converters

1A and 1B are important parts in the inverter device 101, and in the case of a failure, a serious problem occurs such that the vehicle cannot operate. Therefore, failure detection and a redundant circuit have been proposed (for example, Patent Documents 1 to 3). In

Patent Documents

2 and 3, a plurality of resolvers with different resolutions are attached to improve accuracy and reliability.

Japanese Patent Laid-Open No. 9-072758 JP-A-11-064039 JP 2001/082982 A

In Patent Document 1, an AD converter input of a microcomputer is used as a redundant circuit of an RD converter. Although this configuration depends on the processing speed of the microcomputer, the processing cannot catch up with a motor having a high rotational speed such as that used in an in-wheel motor system with a speed reducer, which is not suitable. Further, depending on the situation, it cannot be determined whether the RD converter is faulty or the AD converter is faulty.

Therefore, in the case of a motor with a high rotational speed, an RD converter is used as a backup, but two expensive RD converters are required for one motor, and the rotational position data is compared. Even if there is a difference, it is often impossible to determine which RD converter has failed. For this reason, even if preparations are made for switching to backup in the event of a failure, the judgment necessary for switching cannot be made.

Fig. 9 shows an example of a two-axis inverter equipped with a constant monitoring circuit.

Monitoring RD converters

1D and 1D are provided in parallel to the left and

right RD converters

1A and 1B, respectively. In comparison of rotational position data between the left RD converter 1A and the monitoring RD converter 1D connected in parallel and between the right RD converter 1B and the monitoring RD converter 1D connected in parallel, there is a difference. If not, both RD converters are determined to be normal. If there is a difference, one of them is judged as a failure. The criterion for determining the difference is determined, for example, by multiplying the allowable error of the RD converter by a safety factor. Since each

RD converter

1A, 1B, 1D has a self-diagnosis function, if there is a problem in the diagnosis, the use of the RD converter is stopped.

However, when the

monitoring RD converters

1D and 1D are provided in parallel with the left and

right RD converters

1A and 1B as shown in the same figure, the number of RD converters increases as described above, and the cost increases. When the converter is normal by self-diagnosis, it is difficult to determine which one has failed.

In the above example, the two-axis inverter device for controlling the motor for driving the electric vehicle has been described. However, the above problem also applies to the two-axis inverter device for controlling another motor of the electric vehicle.

The object of the present invention is to add an additional RD converter for monitoring and to determine which of the two normally used RD converters is abnormal. The motor drive can be continued by the alternative use of the RD converter, and further, it can be determined whether the abnormality is in the excitation circuit or the detection circuit of the normal use RD converter, and the alternative can be performed depending on which one is abnormal. A two-axis inverter device is provided.

The two-axis inverter device according to one configuration of the present invention includes two

drive circuits

22 and 22 each having an inverter and driving the corresponding motor 4 of the two

motors

4 and 4. 22, 22, a motor control circuit 21 that controls the

drive circuits

22 and 22, and two

resolvers

25 and 25, each of which corresponds to one of the two

motors

4 and 4 when an excitation signal is input. The two

resolvers

25 and 25 for detecting the rotation of the motor 4 and two normally used

RD converters

1A and 1B, respectively, and an excitation signal is sent to the corresponding resolver 25 of the two

resolvers

25 and 25, respectively. Two normally used RD converters 1A that output and digitize the detection signal of the resolver 25 and input it as output data to the motor control circuit 21. B and a monitoring RD converter 1C that monitors the two normally used

RD converters

1A and 1B, and outputs an excitation signal to the resolver 25 connected on the excitation side of the two

resolvers

25 and 25. The monitoring RD converter 1C that digitizes the detection signal of the resolver connected on the detection side of the two

resolvers

25, 25 and inputs it as output data to the motor control circuit 21; and the monitoring RD converter 1C The first changeover switch 28 for switching and connecting the two

resolvers

25, 25 to the detection side, and inputting a detection signal of the connected resolver 25 to the monitoring RD converter 1C, and two second The change-

over switches

31 and 31 are respectively connected to the two resolvers 2 on the excitation side of the monitoring RD converter 1C. , 25 is connected to the corresponding resolver 25, and the excitation signal input to the connected resolver is output by the corresponding normal use RD converter 25 of the two normal

use RD converters

25, 25. Two second change-over switches 31 are provided for switching from the signal to the excitation signal output from the monitoring RD converter 1C.

According to this configuration, the single monitoring RD converter 1C and the changeover switch 28 are provided, and the detection signals of the

resolvers

25 and 25 of the two

motors

4 and 4 are switched by the changeover switch 28, so that the one monitoring use is performed. Since it is possible to input to the RD converter 1C, it is possible to perform abnormality diagnosis by specifying which of the two normally used

RD converters

1A and 1B is abnormal while making the additional number of RD converters one. In some cases, the motor drive can be continued by using the monitoring RD converter 1C as an alternative. Further, the excitation signal output from the corresponding normal use RD converter 1A (1B) of the two normal

use RD converters

1A and 1B is switched to the excitation signal output from the monitoring RD converter 1C. Since the second two changeover switches 31 and 31 for inputting to the resolver 25 are provided, it is possible to determine which of the excitation circuit 3 and the detection circuit 2 of the normally used

RD converters

1A and 1B is abnormal. Alternatives can be made depending on which is abnormal. In this way, by adding a simple configuration, it is possible to make a reliable abnormality determination by distinguishing which one of the excitation circuit 3 and the detection circuit 2 of the

RD converters

1A, 1B, and 1C is abnormal. The drive of the

motors

4 and 4 can be continued by alternative use corresponding to the abnormality of the excitation circuit 3 and the detection circuit 2.

The two normally used

RD converters

1A and 1B and the monitoring RD converter 1C respectively digitize the excitation signal that generates and outputs the excitation signal and the detection signal of the resolver connected on the detection side. And a self-diagnosis means 32 for diagnosing whether or not the

RD converters

1A, 1B, and 1C are abnormal based on the detection signal. When the self-diagnosis unit 32 is provided, it is easy to determine abnormality in the motor control circuit 21, and by providing the first and

second changeover switches

28 and 31, switching to alternative use of the monitoring RD converter 1C is possible. it can.

The motor control circuit 21 includes a sequential monitoring switching unit 29 having a switch switching unit 29a, an abnormality determination unit 29b, and a used RD converter switching unit 29c.
The switch switching unit 29a switches the first and

second changeover switches

28 and 31 alternately according to a predetermined rule. As a combination of the changeovers, the switch changeover unit 29a is configured to switch the 2nd changeover switch 29a to one of the

second changeover switches

31 and 31. Of the two normally used

RD converters

1A and 1B, the excitation signal of the corresponding normally used RD converter 1A (1B) is switched to the corresponding resolver 25, and the first changeover switch 28 A combination in which the detection signal of the resolver 25 to which excitation signals of the normally used

RD converters

1A and 1B are input is input to the monitoring RD converter 1C and one of the

second changeover switches

31 and 31. Therefore, the excitation signal of the monitoring RD converter 1C corresponds to the corresponding resolver of the two

resolvers

25, 25. 25, and a combination in which the detection signal of the resolver 25 is a switching state input to the corresponding normal use RD converter 25 among the two normal

use RD converters

25, 25. Including
The abnormality determination unit 29b uses the diagnosis result by the self-diagnosis means 32 of each of the

RD converters

1A, 1B, and 1C in each combination of the first and

second changeover switches

28 and 31 to perform the normal use. Determining which of the detection circuit 2 and the excitation circuit 3 is abnormal in any one of the

RD converters

1A, 1B, and 1C among the

monitoring RD converters

1A, 1B, and 1C;
The used RD converter switching unit 29c is based on the rules determined according to the determination of the abnormality determination unit 29b, and the monitoring RD converter switching unit 29c is operated during normal operation of the motor 4 except during diagnosis of the

RD converters

1A and 1B. The detection circuit 2 and / or the excitation circuit 3 of the RD converter 1C is used in place of the detection circuit 2 and / or one of the excitation circuits 3 of the two normally used

RD converters

1A and 1B. As described above, even if the switch switching unit 29a selects the combination of the first and second changeover switches 28, 31, 31 and the

detection circuits

2A, 2B, 2C used for the operation of the motor 4 are selected. Good.

The basic combination by the switch switching unit 29a is a switching state in which excitation signals of the normally used

RD converters

1A and 1B are input to the

resolvers

25 and 25, respectively, with respect to the excitation side changeover switches 31 and 31. The detection-side changeover switch 28 is also in a switching state in which the detection signals of the

resolvers

25 and 25 are input to the normally used

RD converters

1A and 1B, respectively.

By including the sequential monitoring switching means 29 having such a function, an abnormality determination for specifying which of the two normally used

RD converters

1A and 1B is abnormal by adding one monitoring RD converter 1C. When the motor 4 can be operated and is abnormal, the drive of the motor 4 can be continued with the alternative use of the monitoring RD converter 1C, and any abnormality in the excitation circuit and the detection circuit of the normal

use RD converters

1A and 1B. Can be used, and alternative use according to which one is abnormal can be performed.

The motor control circuit 21 may include a microcomputer (microcomputer) in which one RD converter is incorporated, and the built-in RD converter may be the monitoring RD converter 1C. By using a microcomputer incorporating one RD converter as described above, the configuration of the two-axis inverter device is simplified.

The motor control circuit 21 includes a microcomputer with two built-in RD converters, the two built-in RD converters are the two normally used

RD converters

1A and 1B, and the monitoring RD converter 1C has It may be provided outside the microcomputer. By using a microcomputer incorporating two RD converters as described above, the configuration of the two-axis inverter device is further simplified.

The two

motors

4 and 4 may be motors for driving the left and

right wheels

52 and 52 in the electric vehicle, respectively. When the two-shaft inverter device 20 is applied to an electric vehicle, even if an abnormality occurs in the normally used

RD converters

1A and 1B, the vehicle can continue to travel for the time being until it is retracted to a safe place. Will improve.

Any combination of at least two configurations disclosed in the claims and / or the specification and / or drawings is included in the present invention. In particular, any combination of two or more of each claim in the claims is included in the present invention.

The present invention will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are for illustration and description only and should not be used to define the scope of the present invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same reference numerals in a plurality of drawings indicate the same or corresponding parts.
It is explanatory drawing which shows the conceptual structure of an example of the electric vehicle carrying the 2 axis type inverter apparatus which concerns on 1st Embodiment of this invention. It is a block diagram which shows the outline of a conceptual structure of the biaxial inverter apparatus of FIG. It is explanatory drawing of the conceptual structure of the RD converter with which the biaxial inverter apparatus of FIG. 1 is equipped, and the resolver of the analysis object. FIG. 2 is a block diagram showing a simplified conceptual configuration of each RD converter and its redundancy means in the two-axis inverter device of FIG. 1. FIG. 2 is a block diagram specifically illustrating a conceptual configuration of an RD converter and each means for redundancy in the two-axis inverter device of FIG. 1. It is a block diagram which shows the outline of a conceptual structure of the 2-axis type inverter apparatus which concerns on 2nd Embodiment of this invention. It is a block diagram which shows the outline of a conceptual structure of the 2-axis type inverter apparatus which concerns on 3rd Embodiment of this invention. It is a block diagram which shows the basic composition of the conventional 2 axis type inverter apparatus. It is a block diagram of the redundant structure example which concerns on the proposal example made into the continuous monitoring type | mold of a 2-axis type inverter apparatus.

A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a conceptual configuration of an electric vehicle. In this electric vehicle, the left and

right wheels

52, 52 at the rear of the vehicle 51 are driven wheels that are individually driven by the

electric motors

4, 4, and the

wheels

53, 53 that are front wheels are steered by the steering device 6. It is a rear-wheel two-wheel drive vehicle which is a driven wheel. Each motor 4 constitutes an in-wheel motor drive device 5 together with a wheel bearing and a speed reducer (not shown) that transmits the rotation of the motor 4 to the wheel 52 at a reduced speed. Each motor 4 is mounted on a chassis (not shown) of a vehicle 51 without constituting an in-wheel motor drive device 5, and is an on-board type that transmits drive to a corresponding wheel 52 via a drive shaft. Also good. Each motor 4 is a three-phase AC motor such as a permanent magnet type synchronous motor. A brake 7 is provided for each of the

wheels

52 and 53.

Explain the control system. An ECU (electric control unit) 8 is provided as a means for overall control of the entire vehicle 51. The ECU 8 is also referred to as a VCU (vehicle control unit). The ECU 8 includes an accelerator input that is an operation amount of the accelerator operation means 9 such as an arsel pedal, a brake input that is an operation amount of the brake operation means 10 such as a brake pedal, and a steering amount of the steering operation means 11 such as a steering handle. A certain steering input is input. The ECU 8 outputs a torque command for driving the left and

right motors

4 and 4 to the two-shaft inverter device 20 from the accelerator input, the brake input, and the steering input according to a predetermined rule.

The biaxial inverter device 20 is a device that individually drives the left and

right motors

4 and 4 according to the left and right torque commands, and uses a battery 12 as a power source. The biaxial inverter device 20 is an inverter device in which means for driving and controlling the two

motors

4 and 4 are housed in one housing (not shown). Instead, two independent inverter devices may be housed in one housing. The battery 12 is used as a power source for the entire vehicle 51.

As shown in FIG. 2, the two-axis inverter device 20 includes two

drive circuits

22 and 22 that respectively drive the left and

right motors

4 and 4, and one motor control circuit that controls the

drive circuits

22 and 22. 21. Each drive circuit 22 is a power circuit, and is configured by a brib circuit or the like of a semiconductor switching element such as an IGBT. The inverter converts the DC power of the battery 12 into three-phase AC power for driving the motor 4, and the inverter The semiconductor switching element is configured by a driver circuit (not shown) such as a PWM driver that performs opening / closing control of the semiconductor switching element by pulse width control or the like.

In this embodiment, the motor control circuit 21 includes a one-chip or one-board microcomputer and a program executed on the microcomputer. The microcomputer includes a CPU (Central Processing Unit) and various electronic circuits such as a memory and an I / O port. The motor control circuit 21 has two individual

motor control units

23 and 23 for controlling two

drive circuits

22 and 22 respectively corresponding to the left and

right motors

4 and 4, and controls the left drive circuit 22 and its control. The left inverter unit 24L is conceptually configured by one motor control unit 23, and the right inverter unit 24R is conceptually configured by the right drive circuit 22 and one motor control unit 23 that performs control thereof. ing. The two individual

motor control units

23 and 23 may be conceptually divided into two, for example, may be configured by one microcomputer and its program. Instead, the left and right

inverter device sections

24L and 24R may be composed of independent circuit elements and programs. “Left side” and “right side” correspond to the left wheel and the right wheel, respectively, and do not indicate the position.

Each individual motor control unit 23 of the motor control circuit 21 controls the magnitude of a current command or the like given from the ECU 8 to the corresponding drive circuit 22 according to the magnitude of the torque command to the corresponding motor 4. In addition, the detection signal of the resolver 25 that is a rotation detection sensor of the corresponding motor 4 is monitored, and phase control such as vector control for improving the driving efficiency of the motor 4 is performed. Therefore, high accuracy is required for the rotation detection sensor, and the resolver 25 is used as the rotation detection sensor.

Since the output of the resolver 25 is an analog signal, the detection signals of the

resolvers

25 and 25 are digitized and input to the motor control circuit 21 so that the motor control circuit 21 can handle them. 1A, 1B) (when there is no need to individually distinguish a plurality of RD converters, they may be simply referred to as “RD converter 1”).

As shown in FIG. 3, the resolver 25 has an outer ring 34 fixed to a frame (not shown) and an inner ring 35 mechanically connected to the rotating shaft of the motor 4 (see FIG. 2). The resolver 25 detects two rotation signals of a detection coil 38 that detects the SIN wave (sine wave) and a detection coil 39 that detects the COS wave (cosine wave), which are induced from the excitation coil 37 to rotate the inner ring 25. Output as.

The RD converter 1 has an excitation circuit 3 for sending an excitation signal to the excitation coil 37 and a detection circuit 2. The detection circuit 2 analyzes the SIN wave and COS wave detection signals output as analog voltage signals from the resolver 25 to detect the rotational position of the inner ring 35, digitizes it, and outputs it as a rotation detection signal. At the time of the analysis, the detection circuit 2 performs an analysis based on the excitation signal (reference signal REF) from the excitation circuit 3 that drives the excitation coil 37 of the resolver 25. The excitation circuit 3 may be provided independently outside the IC constituting the detection circuit 2.

In the two-axis inverter device 20 having the above basic configuration, in this embodiment, redundancy of the

RD converters

1A and 1B is achieved as shown in FIG. That is, the two-shaft inverter device 20 includes a monitoring RD converter 1C separately from the left and

right RD converters

1A and 1B, which are normally used RD converters, and the monitoring RD converter 1C with the two resolvers 25, Two excitation signals output by the two normally used

RD converters

1A and 1B, and the excitation signal output by the detection-side changeover switch 28 that enables input by switching 25 detection signals and the RD converter 1C for monitoring. Two excitation-side change-over

switches

31 and 31 that can be input to the two

resolvers

25 and 25 by switching from signals are provided. Sequential monitoring in which the motor control circuit 21 of the two-shaft inverter device 20 determines abnormality of the normally used

RD converters

1A, 1B, etc., and uses the monitoring RD converter 1C instead of the RD converter determined to be abnormal. Switching means 29 is provided.

Further, as shown in FIG. 5, each of the

RD converters

1A, 1B, 1C has a self-diagnosis means 32. The self-diagnosis means 32 determines whether or not the RD converter 1 is abnormal. For example, since the relationship of sin ² + cos ² = 1 holds between the sine detection signal and the cosine detection signal, if the magnitude of sin ² + cos ² is somewhat smaller than 1, the drive circuit 22 (see FIG. 2) is abnormal. It is also considered that the detection circuit 2 (2A, 2B, 2C) is abnormal. In this embodiment, when the sine detection signal and the cosine detection signal have a value of sin ² + cos ² of the detection signal of sin and cos that is equal to or less than a predetermined threshold value, it is determined as abnormal.

As shown in FIG. 4 in a simplified manner, the detection-side changeover switch 28 switches one common terminal Tc between the two switch terminals Ta and Tb for each of the three systems of

switch portions

28a, 28b and 28c. The

switches

28a, 28b, 28c can be simultaneously switched to the same side by a control signal input to a control terminal (not shown). The changeover switch 28 may be a semiconductor switch or a contact switch. The three common terminals Tc of the changeover switch 28 are connected to the sine output terminal, cosine output terminal and reference signal input terminal of the monitoring RD converter 1C, and the switch terminals Ta and Tb are connected to the left and

right resolvers

25 and 25, respectively. The sine detection signal output terminal, the cosine detection signal output terminal, and the excitation signal input terminal are connected. Note that the wiring of each system in the three systems is actually two on each of the high side and the low side as shown in FIG. 3 and FIG. 5, but in FIG. To display. Similarly, there are actually two terminals Ta, Tb, and Tc of each of the three

switch sections

28a, 28b, and 28c of the changeover switch 28, and the connection of the two switches in the same manner at the same time.

In each of the excitation side change-over

switches

31 and 31, the high-side and low-side input wirings of the excitation signal of the corresponding resolver 25 are respectively connected to the excitation circuit 3 A (3 B) of the normally used RD converter 1 A (1 B). A switch for switching between a state connected to the two output wirings and a state connected to the two output wirings of the excitation circuit 3C of the monitoring RD converter 1C. The switch is switched for each of the high side and low side wirings. It has a switching terminal Td. Each excitation-side change-over switch 31 may be a semiconductor switch or a contact switch similarly to the detection-side change-over switch 28.

The sequential monitoring switching means 29 provided in the motor control circuit 21 includes a command for switching the detection-side and excitation-side change-over

switches

28, 31, and 31, judgment of abnormality of the RD converter 1, and judgment result of this abnormality. And a command for alternative use by the monitoring RD converter 1C according to the above, according to a predetermined rule. The sequential monitoring switching unit 29 includes a switch switching unit 29a, an abnormality determination unit 29b, and a used RD converter switching unit 29c. Individual functions of the units 29a to 29c will be described later. First, the function of the sequential monitoring switching unit 29 as a whole will be described.

The sequential monitoring switching means 29 specifically performs switching, abnormality determination, and switching to alternative use shown in the following Tables 1 and 2. Table 1 shows the judgment and switching performed between the normal use RD converter 1A and the monitoring RD converter 1C. Table 2 shows the decision between the normal use RD converter 1B and the monitoring RD converter 1C. The judgment and switching to be performed are shown respectively. The items in both Tables 1 and 2 are the same except for the left side or the right side.

The sequential monitoring switching means 29 uses the self-diagnosis means 32 of the RD converter 1 (1A, 1B, 1C). After the self-diagnosis of the normally used

RD converters

1A, 1B, the detection circuit 2 (2A, 1 2B) is switched to the monitoring side. If any one of the self-diagnosis means 32 of the normally used RD converter 1A (1B) and the self-diagnosis means 32 of the monitoring RD converter 1C is determined to be abnormal, the RD converter 1 (1A, 1B, It is determined that the detection circuit 2 of 1C) is abnormal. For the RD converter 1A (1B) in which the detection circuit 2A (2B) is determined to be abnormal, in order to increase the reliability, the excitation circuit 3 of the RD converter 1 is replaced with the normally used RD converter 1A ( The excitation circuit 3A (3B) of 1B) is switched to the excitation circuit 3C of the monitoring RD converter 1C to check whether the detection circuit 2 (2A, 2B) has the same result.

When it is determined that both of the self-diagnostic means 32 are abnormal, it is determined that the excitation circuit 3 in the RD converter 1 is abnormal. In order to increase the reliability, the excitation circuit 3 (3A to 3C) is switched from the excitation circuit 3A (3B) of the normally used RD converter 1A (1B) to the excitation circuit 3C of the monitoring RD converter 1C by the changeover switch 31 on the excitation side. It is confirmed that the self-diagnostic means 32 of both the normally used RD converter 1A (1B) and the monitoring RD converter 1C are determined to be abnormal. The excitation circuit 3 or the detection circuit 2 of the RD converter 1 determined to be abnormal is not used until the repair is completed.

The series of processing by the sequential monitoring switching means 29 may be performed a plurality of times, for example, at the time of initial diagnosis, or may be performed every fixed time, for example, every second during the operation of the two-shaft inverter device 20. Good.

The above series of switch switching, abnormality judgment, and alternative use will be described with specific examples. The excitation circuit 3A of the left-side normally used RD converter 1A drives the excitation coil 37 of the resolver 25, and includes a detection coil 38 for detecting a SIN wave (sine wave) and a detection coil 39 for detecting a COS wave (cosine wave). The detection circuit 2A receives the signal.

When the changeover switch 28 on the detection side is switched to the left side, the monitoring RD converter 1C receives signals from the detection coil 38 that detects the SIN wave of the left resolver 25 and the detection coil 39 that detects the COS wave. The rotational position data from the left resolver 25 is received. Then, the rotational position data measured by the monitoring RD converter 1C is compared with the rotational position data obtained by the left-side normally used RD converter 1A. When the detection side changeover switch 28 is switched to the right side, signals from the detection coil 38 for detecting the SIN wave of the right resolver 25 and the detection coil 39 for detecting the COS wave are received, and the signals from the right resolver 25 are received. Measure rotational position data. Then, the rotational position data measured by the monitoring RD converter 1C is compared with the rotational position data obtained by the right-side normal use RD converter 1B. In these cases, the excitation circuit 3C of the monitoring RD converter 1C is not used.

The individual functions of the switch switching unit 29a, the abnormality determination unit 29b, and the used RD converter switching unit 29c of the sequential monitoring switching unit 29 will be described. The switch switching unit 29a switches the detection-side and excitation-side change-over

switches

28 and 31 alternately according to a predetermined rule. As a combination of this switching, the excitation switch of the first normal use RD converter 1A is in a switching state in which the excitation signal is input to the first resolver 25 and the detection switch is switched. 28, the combination in which the detection signal of the first resolver 25 is input to the monitoring RD converter 1C and the switching in which the excitation signal of the monitoring RD converter 1C is input to the first resolver 25 And a combination in which the detection signal of the first resolver 25 is switched to be input to the first normally used RD converter 1A (1B). The basic combination is a switching state in which the excitation signal of the first normally used RD converter 1A (1B) is input to the first resolver 25 for the excitation side changeover switch 31, and the detection side The changeover switch 28 is also in a switching state in which the detection signal of the first resolver 25 is input to the first normally used RD converter 1A (1B).

The abnormality determination unit 29b performs the normal use based on the combination of the diagnosis results of the self-diagnosis unit 32 of the

RD converters

1A, 1B, and 1C in each combination of the detection side and excitation side changeover switches 28 and 29. Then, it is determined which of the detection circuit 2 and the excitation circuit 3 is abnormal in any of the

RD converters

1A, 1B, and 1C for monitoring.

The used RD converter switching unit 29c is configured to monitor the normal operation of the motor 4 excluding the diagnosis of the RD converter 1 based on a predetermined rule according to the result of the abnormality determination by the abnormality determination unit 29b. The switch switching unit 29a is used so that the detection circuit 2 and the excitation circuit 3 of the RD converter 1C for use are replaced with the detection circuit 2 and the excitation circuit 3 of the normally used

RD converters

1A and 1B, respectively. The selection of the combination of the switching states of the detection side and excitation side changeover switches 28 and 31 and the selection of the detection circuit 2 used for the operation of the motor 25 are performed.

The sequential monitoring switching means 29 includes the switch switching unit 29a, the abnormality determination unit 29b, and the used RD converter switching unit 29c having such functions, so that according to the two-axis inverter device 20, one monitoring unit can be used. With the addition of the RD converter 1C, an abnormality determination can be made to identify which of the two normally used

RD converters

1A and 1B is abnormal, and if it is abnormal, the motor can be replaced with the monitoring RD converter 1C. The driving can be continued, and it is possible to determine which abnormality of the excitation circuit 3 and the detection circuit 2 of the normally used

RD converters

1A and 1B, and to perform alternative use according to which abnormality is present.

According to the two-axis inverter device 20 having the above configuration, as described above, the monitoring RD converter 1C and the changeover switch 28 are provided, and detection signals of the

resolvers

25 and 25 of the two

motors

4 and 4 are sent to the changeover switch. 28, the monitoring RD converter 1C can be input to the monitoring RD converter 1C, so that it is possible to identify which of the two normally used

RD converters

1A and 1B is abnormal while the additional number of RD converters is one. Thus, abnormality diagnosis can be performed, and when the abnormality is detected, the motor driving can be continued using the monitoring RD converter 1C instead.

Further, the excitation signal output from the monitoring RD converter 1C is switched from the two excitation signals output from the two normally used

RD converters

1A and 1B, and input to the two

resolvers

25 and 25. Therefore, it is possible to determine which abnormality of the excitation circuit 3 and the detection circuit 2 of the normally used

RD converters

1A and 1B, and which one is abnormal. Alternatives can be made accordingly.

The first embodiment has been described with respect to the case where the microcomputer constituting the motor control circuit 21 is a type that does not have an RD converter. However, as shown in the second and third embodiments described below, respectively. When the microcomputer constituting the motor control circuit 21 has one or two RD converters, the following configuration can be adopted. The second and third embodiments are the same as those of the first embodiment shown in FIGS. 1 to 5 except for matters to be specifically described.

In the second embodiment shown in FIG. 6, the microcomputer constituting the motor control circuit 21 has one RD converter. In this embodiment, the built-in RD converter is used as the monitoring RD converter 1C. By using a microcomputer incorporating one RD converter as described above, the configuration of the two-axis inverter device 20 is simplified.

In the third embodiment shown in FIG. 7, the microcomputer constituting the motor control circuit 21 has two RD converters. In this embodiment, two built-in RD converters are used as

RD converters

1A and 1B for normal use, and the monitoring RD converter 1C is externally attached to the microcomputer. In the case of a microcomputer incorporating two RD converters, the configuration of the two-axis inverter device 20 is further simplified by adopting the above configuration.

In addition, although each said embodiment demonstrated about the example applied to the biaxial inverter apparatus in which the two

inverter apparatus parts

24L and 24R were accommodated in the same housing | casing, as a reference example, two

inverter apparatus parts

24L and 24R The present invention can also be applied to a pair of inverter devices including two in the same manner as the two-axis inverter device of the present invention.

As described above, the preferred embodiments have been described with reference to the drawings, but various additions, changes, or deletions can be made without departing from the spirit of the present invention. Therefore, such a thing is also included in the scope of the present invention.

DESCRIPTION OF

SYMBOLS

1A, 1B ... Normal use RD converter 1C ... Monitoring RD converter 4 ... Motor 20 ... Two-shaft type inverter device 21 ... Motor control circuit 22 ... Drive circuit 25 ... Resolver 28 ... First changeover switch (switch on detection side) switch)
31 ... Second changeover switch (excitation side changeover switch)

Claims

Two drive circuits, each having an inverter, and two drive circuits for driving the corresponding motors of the two motors;
A motor control circuit for controlling these drive circuits;
Two resolvers, each of which receives an excitation signal, two resolvers for detecting the rotation of the corresponding motor among the two motors;
Two normally used RD converters, each of which outputs an excitation signal to a corresponding resolver among the two resolvers, digitizes the detection signal of the resolver, and inputs it to the motor control circuit as output data A normal use RD converter;
A monitoring RD converter that monitors the two normally used RD converters, and outputs an excitation signal to a resolver connected on an excitation side of the two resolvers, and connected on a detection side of the two resolvers. A monitoring RD converter that digitizes the detected signal of the resolver and inputs it as output data to the motor control circuit;
A first changeover switch for switching and connecting the two resolvers to the detection side of the monitoring RD converter and inputting a detection signal of the connected resolver to the monitoring RD converter;
Two second change-over switches, each of which connects an excitation side of the monitoring RD converter to a corresponding resolver of the two resolvers, and an excitation signal input to the connected resolver, A two-axis inverter device comprising two second changeover switches for switching from an excitation signal output from a corresponding normal use RD converter to an excitation signal output from the monitoring RD converter among two normal use RD converters .
2. The two-axis inverter device according to claim 1, wherein the two normally used RD converters and the monitoring RD converter are respectively connected to an excitation circuit that generates and outputs the excitation signal on a detection side. A two-shaft inverter device having a detection circuit for digitizing the detection signal of the resolver and self-diagnosis means for diagnosing whether or not the RD converter is abnormal from the detection signal.
The two-axis inverter device according to claim 2, wherein the motor control circuit includes a sequential monitoring switching unit having a switch switching unit, an abnormality determination unit, and a used RD converter switching unit,
The switch changeover unit alternately switches the first and second changeover switches in accordance with a predetermined rule. As a combination of the changeovers, one of the second changeover switches has the two normally used RD converters. The detection signal of the resolver in which the excitation signal of the corresponding normal use RD converter is input to the corresponding resolver and the excitation signal of the normal use RD converter is input to the first changeover switch. Are input to the monitoring RD converter and the excitation signal of the monitoring RD converter is input to the corresponding resolver of the two resolvers for one of the second changeover switches. The resolver detection signal is in the switching state, and the resolver detection signal is one of the two normally used RD converters. And a combination is a switching state that is input to the normal use of the RD converter response,
The abnormality determination unit uses any of the RD converters for normal use and monitoring by using a result of diagnosis by the self-diagnosis unit of each RD converter in each combination of the first and second changeover switches. In the RD converter, it is determined which of the detection circuit and the excitation circuit is abnormal,
The used RD converter switching unit is configured to detect the monitoring RD converter during normal operation of the motor except for diagnosis of the RD converter based on a predetermined rule according to the determination of the abnormality determination unit. The first and second switches by the switch switching unit so that the circuit and / or the excitation circuit is used in place of one of the two normally used RD converters and one or both of the excitation circuits. A two-axis inverter device that selects a combination of switching states of the changeover switch and selects the detection circuit used for operating the motor.
4. The two-shaft inverter device according to claim 1, wherein the motor control circuit includes a microcomputer in which one RD converter is incorporated, and the built-in RD converter is used for the monitoring. A two-axis inverter device that is an RD converter.
4. The two-shaft inverter device according to claim 1, wherein the motor control circuit includes a microcomputer in which two RD converters are built, and the two built-in RD converters are A two-axis inverter device, which is two normally used RD converters, wherein the monitoring RD converter is provided outside the microcomputer.
6. The two-shaft inverter device according to claim 1, wherein the two motors are motors respectively driving left and right wheels of an electric vehicle.