JPH04308412A - Composite relay - Google Patents

Abstract

PURPOSE:To easily perform post-accident troubleshooting by providing a data inputting, commanding, and holding means and holding data after abnormality occurs. CONSTITUTION:A CPU 6 which works as a commanding means respectively outputs a data holding or discarding command signal, display driving command signal, and output driving command signal to a data hold circuit 8, display drive circuit 10, and output drive circuit 12 on the basis of input data from a data input circuit 4 and the setting of a setting circuit 14. The circuit 8 is provided with storing areas 1-100 and respectively stores 50 pieces of data before abnormality and 1 piece of data at the time of abnormality in the areas 1-50 and 51 when the abnormality occurs in data. After a driving command is given, the section 8 stores 49 pieces of data after the abnormality in the areas 52-100. As a result, the cause of the abnormality can be examined and analyzed from the 100 pieces of data and troubleshooting can be easily performed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite relay suitable as a protective relay for a generator that detects an abnormality in an electrical system and opens a circuit breaker.

0002

[Prior Art] Conventional protective relays for generators have a set value necessary to protect the electrical system, and open the circuit breaker when the current or voltage in the electrical system exceeds or falls below the set value. It is designed to operate and isolate the point of failure.

0003

[Problem to be solved by the invention] Although this protective relay can serve the purpose of detecting an accident in the electrical system and isolating the failure point, it does not contribute to providing materials for investigating the cause after an accident. It is difficult to say, for example, whether the accident was caused by an accident on the power distribution line or by a malfunction of a circuit breaker, and the analysis required very troublesome work.

[0004] Therefore, in the present invention, by making it possible to retain data necessary for analyzing the cause of an accident even after the accident, it is possible to easily take countermeasures against the failure based on the retained data after the accident. It was made so that it could be done.

[0005]

[Means for Solving the Problems] The composite relay of the present invention has a data input means, a command means, and a data holding means, and the data input means converts input from an electrical system into data. The command means outputs a first command to store and discard data at predetermined time intervals, and a second command to hold data before and after the occurrence of abnormal data in response to input of abnormal data. The data holding means stores and discards data in the storage area in response to the first command, and holds data before and after the occurrence of abnormal data in the storage area in response to the second command. It is characterized by being

[0006]

[Operation] When abnormal data is input, the data before and after the input of the abnormal data is held in the data holding means, so the composite relay can detect an accident in the electrical system and isolate the fault point. After an accident, based on the abnormality data, it is easy to investigate and analyze whether the cause of the accident is in the electrical system or the circuit breaker, and if it is in the electrical system, where the cause is located. Therefore, it is possible to easily take measures against failures after an accident.

[0007]

Embodiments Hereinafter, embodiments of the present invention will be explained in detail with reference to FIGS. 1 to 3.

Referring to FIG. 1, a composite relay 1 according to an embodiment of the present invention is applied to protect a generator. For the distribution line 2 consisting of phases, first and second current transformers CT1,
CT2, voltage detection transformer PT, zero-phase current transformer ZCT,
and are connected via a zero-phase voltage detection device ZPD.

Here, the first and second current transformers CT1, C
T2 measures the load current in the three-phase distribution line 2, voltage detection transformer PT measures the load voltage in the three-phase distribution line 2, and zero-phase current transformer ZCT measures the zero-phase current in the three-phase distribution line 2. , the zero-phase voltage detection device ZPD detects the zero-phase voltage within the three-phase distribution line 2, and outputs the detected value to the composite relay 1.

[0010] The present composite relay 1 is roughly divided into two components: a data input circuit 4, a CPU 6 as a command means,
In addition to the data holding circuit 8, the display drive circuit 10, the output drive circuit 12, the setting circuit 14, and the data transmission circuit 16 are also included.

[0011] The data input circuit 4 has three
It takes in the load current, load voltage, zero-sequence current, zero-sequence voltage, and others given from the phase distribution line 2 as data, processes each of these data as appropriate, and outputs it to the CPU 6. I will explain its structure below.

That is, the first and second current transformers CT1,
The load currents in the three-phase distribution line 2 detected by CT2 are further transformed by internal current transformers 4-1 and 4-2, and then transformed into three-phase distribution lines by over-input protection circuits 4-3 and 4-4. The intrusion surge component from the electric line 1 is absorbed, and the rectifier circuit 4
-5, 4-6, then level conversion circuit 4-7
, 4-8, the signal is converted to a DC level and given to the A/D conversion terminals 6-1, 6-2 of the CPU 6 as R-phase and T-phase load current signals.

The load voltage of the three-phase power distribution line 2 detected by the voltage detection transformer PT is further converted to a lower voltage by the low voltage transformer 4-9, and then the load voltage of the three-phase power distribution line 2 detected by the voltage detection transformer PT is further converted to a lower voltage by the low voltage transformer 4-9.
The intrusion surge is absorbed.

The load voltage passing through one of the over-input protection circuits 4-10 is changed from an AC waveform to a rectangular waveform (changes ± with the ground potential as the center) using the zero-crossing points of the AC waveform in the zero-crossing circuit 4-12. ) is converted into
Then, the waveform shaping circuit 4-13 shapes the waveform so that it changes from the ground potential to the + side, and generates a clock pulse (CPU 6
measures one cycle from the rise to the fall of the clock pulse and uses it to check the frequency of the load voltage), and then interrupts the interrupt terminal 6 of the CPU 6.
At the same time, it is amplified by an amplifier circuit 4-14, converted from an effective value to a DC level by an RMS/DC conversion circuit 4-15, and then sent to the A/3 of the CPU 6.
It is given to the D conversion terminal 6-4 as data for determining undervoltage and overvoltage.

The load voltage that passes through the other over-input protection circuit 4-11 is converted from voltage to frequency by a voltage/frequency (V/F) conversion circuit 4-16, and then multiplied to obtain the power value. It is applied to one input section of the circuit 4-17.

The load current from the first current transformer CT1 is also:
After being further current-transformed by an internal current transformer 4-18, it is applied to the other input section of the multiplication circuit 4-17 via an over-input protection circuit 4-19.

The load voltage and load current applied to each input section of the multiplication circuit 4-17 are multiplied here to obtain a power value, and then the multiplication output in a pulse state is converted to DC in an integration circuit 4-20. A/ of CPU6 is integrated for
It is given as a power (reverse power) signal to the D conversion terminal 6-5.

The zero-sequence current detected by the zero-sequence current transformer ZCT is further transformed by an internal current transformer 4-21, passed through an over-input protection circuit 4-22, and then transformed by a gain adjustment circuit 4-23. The gain is adjusted for the gain of the stage amplifier circuit, and further subjected to harmonic removal and amplification in the filter amplifier circuit 4-24, and then passed through the level conversion circuit 4-25 to the A/D conversion terminal 6-6 of the CPU 6. is given as a zero-sequence current signal.

Here, the output of the filter amplifier circuit 4-24 is also given to one input section of the phase discrimination circuit 4-26.

The zero-phase voltage detected by the zero-phase voltage detection device ZPD is further transformed by an internal current transformer 4-27, and then sent to an over-input protection circuit 4-28 and a filter amplifier circuit 4-2.
9 to the other input section of the phase discrimination circuit 4-26.

The zero-sequence current and zero-sequence voltage applied to each input section of the phase discrimination circuit 4-26 are subjected to phase discrimination to determine whether the ground fault is an on-premises or off-premises fault. After receiving the signal, it is applied to the I/O terminals 6-7 of the CPU 6 as a signal indicating whether the phase is an operating phase or an inactive phase. Here, the zero-phase voltage that has passed through the filter amplifier circuit 4-29 is sent to the CPU via the level conversion circuit 4-30.
It is given to the A/D conversion terminal 6-8 of No. 6 as a DC zero-phase voltage signal.

Based on the input data from the data input circuit 4 and the setting value of the setting circuit 14, which are input to each terminal, the CPU 6 controls the data holding circuit 8 (where data is stored, discarded, and held). will be described later.), the display drive circuit 10 sends a command signal to retain or discard data.
A display drive command signal (a signal indicating that one of the relay elements has operated, in response to which the display drive circuit 10 drives the corresponding display) is sent to the output drive circuit 12. On the other hand, the output drive command signal (a signal output from the CPU 6 after a set time has elapsed when an accident input is applied to a relay element and exceeds the set value, and the output drive circuit 12 responds to the required signal) (drives circuit breaker)
are output respectively.

The CPU 6 also transmits data to the personal computer connected to the relay 1 via the data transmission circuit 16 so that the data is useful for data confirmation and accident analysis on the personal computer. Commands such as data deletion are given from the personal computer via the data transmission circuit 16.

The operation of the CPU 6 will be explained with reference to flowcharts 1 and 2 of FIG. 2 and a memory map of FIG. 3.

Step n in flowchart part 1
1, various data are taken in from the data input circuit 4. In step n2, among the various data taken in by the CPU 6, the load current, load voltage, and power required for accident analysis are collected in steps n2-1, n2-2, and n2-3 according to part 2 of the flowchart. It is stored in the holding circuit 8, transferred, and discarded. Here, the data holding circuit 8 is
As shown in FIG. 3(a), it has storage areas 1 to 100. Then, in step n2-1, a 10 mS timer is started, and when the timer expires in step n2-2, data 1 is first stored in storage area 1 in step n2-3. Next, the process returns to step n3 to determine whether the stored data is abnormal. If there is no abnormality, data 2 is stored in storage area 2 in step n2. In this way, if the data is not abnormal, 10 mS x 100 is applied to all storage areas 1 to 100, that is,
100 pieces of data 1 to 1 as shown in Figure 3(a) in 1 second
00 will be stored.

Note that in step n2-3, since the data is stored in the storage area 100, in order to be able to store new data, the oldest data 1 stored in the storage area 1 is The data in each storage area is migrated to the previous storage area, thereby
A storage area 100 is made an empty area so that the latest data can be stored there. In this way, data 1 to 100 for one second are stored in each storage area of the data holding circuit 8.

Next, in step n3, it is determined whether the data stored in the storage area exceeds or falls below a set value, that is, whether the data is abnormal or not, and if it is not abnormal, step n2 is performed as described above. If there is an abnormality, the duration of the abnormal state is monitored to determine whether it is just a change in voltage, or whether it is an actual abnormality. Therefore, in step n4, a timer for monitoring the duration is started. This timer determines whether the abnormal state of the data continues for one second, which is set as the settling time.If it does not continue for one second, it is not abnormal, that is, the abnormal state is temporary. , it is determined that there is no problem. Therefore, step n5
and n6, it is determined whether the above state is continuing during that 1 second, and if the time is up while it is continuing, it is determined that there is an abnormality in the electrical system or relay, etc., and the output is sent to the display drive circuit 10 in step n7. A drive command is output to each of the drive circuits 12, and necessary operations such as lighting a display or operating a circuit breaker are performed. Then, in steps n8 and n9, the same processing as in steps n1 and n2 is performed to store data, and in step n10, the number of data stored after the drive command is 49 (these are stored in storage areas 52 to 100). It is determined whether or not the data has exceeded the specified data, and if it has, in step n11, 51 pieces of data before the drive command (these are data stored in storage areas 1 to 51) and 49 data after the drive command are stored. The data holding circuit 8 is caused to hold the memory. As a result, as shown in FIG. 3(b), in the data holding circuit 8, when data is abnormal, 50 pieces of data ab1 to ab50 before the abnormality are stored in the storage area 1.
~50, one piece of data a1 at the time of abnormality is stored in area 5.
1, after the drive command, 49 pieces of data aa1 after the abnormality
~aa49 will be held in storage areas 52-100.

As a result, in this embodiment, the cause of the accident can be easily investigated and analyzed from the 100 pieces of data.

In the above embodiment, the command means is C.
Although the PU 6 and the data holding circuit are configured with a memory separate from the CPU 6, the memory built into the CPU 6 may be used as the data holding circuit, and the present invention includes such a data holding circuit configuration.

[0030]

[Effects of the Invention] According to the present invention, when abnormal data is input, the data before and after the input of the abnormal data is held in the data holding means. Based on this, it is possible to easily investigate and analyze whether the cause of the accident is in the electrical system, the circuit breaker, or if it is in the electrical system, where the cause is located. Failure countermeasures can be easily taken.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a composite relay according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation.

FIG. 3 is a diagram showing a memory map.

[Explanation of symbols]

1. Composite relay 2 3-phase distribution line 4 Data input circuit 6 CPU 8 Data retention circuit

Claims (1)

[Claims] Claim 1: Data input means (4) and command means (
6) and data holding means (8), the data input means (4) converts input from the electrical system (2) into data and outputs the data, and the command means (6) includes: The data holding means (8
) is characterized in that it stores and discards data in the storage area in response to the first command, and retains data before and after the occurrence of abnormal data in the storage area in response to the second command. Composite type relay.