JPH01291682A - Fault diagnostic device for motor controller - Google Patents

Abstract

PURPOSE:To discriminate the cause of faults by estimating the disturbance torque of a motor in different aspects respectively based on the voltage, current and speed signals and by estimating the faulted region from each estimate. CONSTITUTION:A speed regulator(ASR) 7 outputs a current command I* in accordance with the deviation between a speed actual value N and a speed command N*. A current regulator(ACR) gives a voltage command V* in accordance with the deviation between a current actual value l and a current command I* to a striking pulse regulator 9. On the other hand, a state observer 10 estimates a plurality of disturbance torque mutually different taud1, taud2, taud3 based on the current actual value I, a speed actual value N and a voltage command V*. A fault diagnoser 11 detects the deviation between each disturbance torque taud1-taud3 and discriminates the fault state in accordance with these deviated states.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a control device that supplies power to a load including an electric motor via a static power converter and controls the torque, rotational speed, etc. of the electric motor, particularly its control device. The present invention relates to a failure diagnosis device.

[Conventional technology]

As a conventional device for this purpose, for example, the rationality of each control system, that is, the voltage command value and the actual voltage, is calculated from the digital signals for each control system calculated inside the digital control device, and the actual measured current, voltage, and speed during motor operation. The value is proportional to the voltage actual value.

Fault detection that checks whether a certain relationship holds between the motor's back electromotive force, main circuit resistance, main circuit inductance, and main circuit current, and outputs a fault signal when the rationality is not satisfied. Device (Unexamined Japanese Patent Publication No. 57-6868
No. 9) is known.

[Problem to be solved by the invention]

Although such devices can detect failures,
For example, if the actual voltage value and the command value are not proportional, it may be possible to detect the failure, but it may not be possible to determine whether the cause lies in the detection unit or the drive unit such as a phase shifter. There is a 9th problem.

Therefore, an object of the present invention is to provide a fault diagnosis device that can determine the cause of a fault when it is detected.

[Means to solve the problem]

Multiple types of states in which voltage, current, and speed signals, which serve as control signals, are selectively input to a motor control device that controls the motor via a static power converter, and the disturbance torque of the motor is estimated in different ways. An observation device and a failure diagnosis device for estimating a failure location from each estimated value are provided.

[Effect]

Focusing on the fact that most of the causes of failures in digital control devices are in the hardware, such as the current, voltage, speed detection section, and drive section including power converters, we Voltage.

Diagnose abnormal operation of the control signal, which is the input signal of the condition observation device, from multiple condition observation devices with different configurations that estimate the disturbance torque of the motor using current and speed signals, and the operation of these estimated values. By providing a failure diagnostic device, the cause of the failure can be determined and reliability is improved.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of the present invention, FIGS. 2A to 2C are block diagrams showing different specific examples of the state observation device in FIG. 1, and FIG. 3 shows the operation of FIG. 1. It is a flow chart for explanation.

In FIG. 1, 1 is a static power converter constructed by connecting thyristors in antiparallel, and 2 is a load such as a DC motor. 3 is a current detector that detects the current flowing through the load, 4 is a rectifier, 5 is a speed detector that detects the rotational speed N of the motor, N is a speed command value, and 7 is an actual speed value N that is equal to the speed command N
8 is a current regulator (ACR), 9 is a point at which an ignition pulse is output to the static power converter 1 based on the voltage command [v* which is the output of ACR 8]. It is an arc pulse regulator. 10 is a state observation device,
Here, as shown in Fig. 2A, the actual current value i and the actual speed value N,
As shown in Fig. 2B, the current actual value 1 and voltage command value v9, 2nd C
As shown in the figure, a so-called minimum dimension observation device is provided which estimates the disturbance torque τd1°τd2yτd5 from the actual speed value N and the voltage command value V, respectively.

FIG. 6 is a flowchart of a program that is executed at regular intervals.The operation of the failure diagnosis apparatus will be explained below based on this flowchart.

First, the voltage command value v*, the actual current value i, and the actual speed value N are read. Then, using these values,
Perform calculations for the observation device in diagram C. For example, the calculation algorithm for the case of Fig. 2A is as follows:
Estimated disturbance torque value before knee, W(k+1), W(k)
: Variable for performing integral calculations.

The estimated value τd of the disturbance torque can be found from the above equation (
Estimated values are indicated with a “△” mark). Figure 2B.

Similarly, the deviation between the disturbance torque values is calculated from the observation device in Fig. 2C, and from the behavior of these deviations, the estimated disturbance torque value that behaves differently is detected and is normal.

Determine abnormality. The determination of normality and abnormality is made as follows.

C&) If the total deviation is less than a certain value, it is determined to be normal due to disturbance.

If it is below, it can be determined that the estimated disturbance torque value τd is likely to behave differently from other estimated values. By comparing the input signals of the observation devices in Figures 2A to 2C, the voltage command value V
*The operation of the current is actually ri! i p Since it can be determined that the movement of the actual speed value N is unrelated, that is, the actual voltage value applied to the motor 2 and the voltage command value V* are different, the ignition pulse regulator 9. The drive unit such as static power converter 1 is determined to be abnormal.

In this case, it can be determined that the estimated disturbance torque value τ exhibits a behavior different from other estimated values. Comparing the input signals of the observation devices shown in FIGS. 2A to 2C reveals that the operation of the speed sensor N is abnormal, so it is determined that the speed detector is abnormal.

(d) If only the deviation between τd and τ intuition is less than a certain value, it can be determined that the current detector is abnormal using the same determination method as in (c) above.

Note that the above determination method cannot be used when multiple failures occur simultaneously in different hardware. However, since it is rare for another hardware to fail at the same time, there is no problem at all in practice.

〔Effect of the invention〕

According to this invention, a plurality of condition observation devices are provided that estimate the disturbance torque of the '-E+ motor at the load using the voltage, current, and speed signals that are the control signals of the control device, and a failure occurs based on the operation of these estimated values. Since it is possible to detect the cause of the failure, it is possible to determine the cause of the failure. In addition, the state observation device measures not only the disturbance torque but also the actual current and the estimated value of the actual speed value (speed estimation i n in Fig. 2B, current estimation [ia] in Fig. 2C).
), this provides advantages such as the ability to continue operating the control device using the estimated value even if the detector becomes abnormal.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIGS. 2A to 2C are block diagrams showing different specific examples of the state observation device in FIG. 1, and FIG. 3 shows the operation of FIG. 1. It is a flow chart for explanation. Description of symbols 1... Static power converter, 2... Electric motor, 3... Song tfL detector, 4... Rectifier, 5...
・Surface speed detector, 7...Speed regulator (ASR)
, 8... Current regulator (ACR), 9...
・Ignition pulse regulator, 1o...Status observation device, 1
1...Fault diagnosis device, 21.24...Integrator, 22...Cutting torque calculator, 25.26-29...
... Proportional gain element, 25 ... Main circuit resistance voltage calculator, 60 ... Motor back electromotive force calculator. Agent Patent Attorney Akio Namiki Agent Patent Attorney Kiyoshi Matsuzaki Figure 1 Figure 2A Figure 2B Figure 20 Figure 3

Claims (1)

[Claims] For a motor control device that controls a motor via a static power converter, voltage, current, and speed signals serving as control signals are selectively input to the motor control device to control the disturbance torque of the motor in different modes. 1. A failure diagnosis device for a motor control device, comprising: a plurality of types of state observation devices that estimate the respective estimated values; and a failure diagnosis device that estimates a failure location from each of the estimated values.