JP2771222B2 - Inverter device with fault trace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an inverter device having a trip function at the time of an abnormal operation such as a power failure, and is particularly suitable for driving an AC motor such as an induction motor. It relates to an inverter device.

[Conventional technology]

In general, an inverter device is provided with a so-called trip function for automatically stopping operation in order to protect the inverter device itself and load devices when an operation abnormality such as a power failure or overload occurs.

Thus, as a result, a certain degree of satisfaction can be obtained in terms of protection of the equipment, but when such a trip function is activated, it is necessary to know the reason why the trip worked, except for external factors such as a power failure. There is.

Therefore, as described in Japanese Patent Application Laid-Open No. 63-114594, the conventional apparatus includes, at the time of occurrence of a failure, a sampling result of variables and logic signals indicating the operating state m times before the failure and a result of the failure occurrence (n- and m) sampling results (n> m) are recorded in the nonvolatile storage element.

[Problems to be solved by the invention]

In the above prior art, although the transition of the operating state before and after the occurrence of the failure can be reproduced for the time being, it is possible to determine the failure occurrence time and various failure factors (for example, overcurrent, overvoltage, overload, ground fault, etc.). Insufficient voltage, excessive temperature rise, instantaneous power failure, runaway of control microcomputer, etc.), and failure to determine the frequency of failures are not sufficiently considered. For example, when an inverter is installed as an unmanned system However, there is a problem that a trouble may be hindered in a failure investigation at the time of repair when a failure occurs.

SUMMARY OF THE INVENTION An object of the present invention is to provide an inverter device with a fault trace that can accurately investigate the cause at the time of trip operation and can always provide accurate repair.

[Means for solving the problem]

The above object is achieved by storing data representing time and data representing trip factors during trip operation.

[Action]

Since the trip time and the event that caused the trip are sequentially stored, the cause of the failure can be easily and accurately determined by the failure investigation after the trip.

For example, data related to the time of tripping after a certain period of time after the start of operation or tripping at a specific time can be obtained. Instead, trips due to external factors (power failure, lightning strike, change in power supply conditions, load fluctuations in the same power supply system, etc.) can also be determined.

〔Example〕

Hereinafter, an inverter device with a fault trace according to the present invention will be described in detail with reference to the illustrated embodiment.

FIG. 1 shows an embodiment of the present invention, in which 1 is a commercial power supply, 2 is an inverter device, 3 is an AC motor, and a constant voltage and a constant frequency AC power from the commercial power supply 1 are supplied to the inverter device 2. A power system is configured to convert the AC voltage into a variable voltage and a variable frequency AC power, thereby driving an AC motor such as an induction motor at a variable speed.

The inverter device 2 includes a converter 2A and a capacitor 2
B, a power conversion system including an inverter unit 2C, and an inverter control unit 4 having a microcomputer as a main unit. Normally, the microcomputer of the inverter control unit 4 executes a predetermined program set therein. Therefore, data is taken in from various sensors and data input / output devices (not shown), and control data necessary for controlling the converter unit 2A and the inverter unit 2C is calculated, whereby the variable speed driving of the AC motor 3 is performed. Necessary control is performed.

In parallel with this, the inverter control unit 4 monitors the occurrence of an abnormality based on data from the various sensors described above, and determines predetermined abnormality determination conditions, for example, a voltage abnormality on the power supply side, an overvoltage on the output side. The inverter device is tripped by the occurrence of overcurrent, abnormal temperature rise of the equipment, etc., and performs the protection function. By the way, the above operation is the same as that of the known inverter device.
A non-volatile memory 5 called a non-volatile random access memory (M), a clock circuit 6 for timekeeping, and a display device 7 for monitoring are added. Further, a power supply backup device (not shown) supplies power from the commercial power supply 1. Even when the power supply is cut off, the inverter control unit 4 is operable for a while, and the clock circuit 6 is configured so that the clocking operation can be continued for a considerable period of time. As a result, as the nonvolatile memory 5,
Ordinary RAM, which can always hold data irrespective of the power supply state of the entire system by the power supply backup, may be used.

 Next, the operation of this embodiment will be described.

As described above, the inverter control unit 4 including the microcomputer is configured to always execute the control of the inverter when the system is operating and to be provided with a trip function at the time of abnormality. As described above, during normal operation, the time data given from the clock circuit 6 and the data representing the operation state of the inverter are sequentially written into the RAM inside the microcomputer at predetermined sampling periods. And,
When the power of the system is turned on, the data of the cumulative number of failures previously written in the nonvolatile memory 5 is transferred to the RAM in the microcomputer.

Here, data representing the operation state of the inverter, for example, data such as the output frequency, voltage, and current may be obtained from the outputs of the various sensors at the time of sampling.

Further, when the inverter control section 4 detects the occurrence of an abnormality such as an overheated state of the inverter by the trip function, it is written in the RAM as described above, as shown in FIG. Are transferred to the non-volatile memory 5 for saving. Further, at this time, a factor of a failure that caused the trip function to be activated is detected, and the detected data is stored as non-volatile data as predetermined data. The process of storing the data in the predetermined storage area of the volatile memory 5 and the above-described data of the cumulative number of failures are read out from the RAM, and when this is set to n, 1 is added to this data to obtain the new cumulative data of the number of failures (n + 1). Memory 5
And a process of saving the data to the server.

By the way, when the trip function is activated as described above, the power of the entire system is turned off. However, as described above, the inverter control unit 4 also operates independently of the power state of the entire system for a predetermined period. Since it is configured to be backed up, the nonvolatile memory 5
Until the saving of the various data described above is completed, the operation of the inverter control unit 4 is guaranteed and can be operated without any problem.

Therefore, each time the inverter device is tripped, the above-mentioned predetermined data is stored in the nonvolatile memory 5. As a method of storing the data at this time, the data may be updated for each trip or may be sequentially accumulated.

On the other hand, although not shown, the inverter control unit 4 is provided with a predetermined input device such as a push button switch, which enables a built-in microcomputer to operate in a data display mode as described below. Is configured to be executed.

Therefore, it is assumed that the inverter control unit 4 is set to the data display mode by the input device such as the switch at a maintenance process after a trip or at a predetermined maintenance point.

Then, the microcomputer of the inverter control unit 4 executes a process of taking out predetermined data from the non-volatile memory 5 and displaying the data on the display device 7 as a predetermined message. In addition to various data representing the operating status of the inverter at the fault occurrence time (trip occurrence time) described above, the fault occurrence time itself, the cause of the fault, and the cumulative number of faults are displayed in characters, symbols, and figures. As a result, the cause of the trip can be clarified with higher accuracy than when the inverter is operated only from the operating state.
Accurate responses can always be made to trips, and high reliability can be easily maintained.

In the above embodiment, the trip time is stored. However, the time data supplied from the clock circuit 6 is reset every time the system is powered on, thereby providing the power supply. The elapsed time from the time of insertion to the trip may be stored.

〔The invention's effect〕

According to the present invention, for each trip operation, the trip time, the trip factor, and the cumulative number of trips are stored in addition to the data indicating the operating state of the inverter such as frequency, voltage, and voltage. Can be easily and accurately obtained.
Precise maintenance can always be performed, and high reliability can be maintained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of an inverter device with a fault trace according to the present invention, and FIG. 2 is an explanatory diagram of processing in one embodiment of the present invention. 1 ... commercial power supply, 2 ... inverter device, 2A ... converter unit, 2B ... capacitor, 2C ... inverter unit, 3 ...
... AC motor, 4 ... Inverter control unit, 5 ... Non-volatile memory, 6 ... Clock circuit, 7 ... Display device.

Continued on the front page (72) Inventor Koji Hara 7-1-1 Higashi Narashino, Narashino-shi, Chiba Inside the Narashino Plant of Hitachi, Ltd. (72) Inventor Satoshi Ibori 7-1-1 Higashi-Narashino, Narashino-shi, Chiba Hitachi, Ltd. (56) References JP-A-59-117469 (JP, A) JP-A-63-114594 (JP, A) JP-A-63-92273 (JP, A) JP-A-63-257468 (JP) , A) (58) Field surveyed (Int.Cl. ⁶ , DB name) H02M 7/42-7/98

Claims (1)

(57) [Claims] In an inverter device having a trip function at the time of abnormal operation, a trip detecting means for detecting the occurrence of a trip signal by the trip mechanism, and data capable of constantly storing data regardless of the operation of the inverter device. A memory means, a clocking means for providing time data, and a trip factor analyzing means for analyzing a cause of occurrence of a trip signal are provided. When a trip signal is detected, the time data given from the clocking means and the trip factor analyzing means are provided. An inverter device with a fault trace, wherein the applied trip factor data is stored in the data storage means.