JPS6091816A - Protective relaying device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention monitors the entire transport status of transport at both ends of the protected area 101, mutually sends and receives status signals representing the monitoring results, and when an abnormality occurs, The present invention relates to a protective relay device that interrupts.

Conventionally, a single power supply loop type transmission system is used, that is, as shown in FIG. In a power transmission system arranged in a ring, a protection zone is defined for each predetermined transmission section, and relay devices 5A, 5B, 6A are installed at both ends of the protection zone.
, 6B, 7A, and 7B, respectively, and pilot wires 5C and 6C.

Detection at the other end received from the relay device at the other end via 7C
If the difference between the F4L current value (or phase) and the detected current value (or phase) at the own end is a certain value or more, it is determined that an abnormality has occurred, and the circuit breaker 5D at both ends in the insurance section,
A protective relay system is used in which the insured section is released from the power transmission line 2 by activating the relays 5E, 6D, 6g, 7D, and 7E. Similarly, in a one-source or two-source power transmission system as shown in Figure 1, a protection zone is defined for each predetermined transmission section, and a relay device 8A is installed at both ends of this protection zone.
, 8B is placed, and the transmission equipment +! Detected current value (or phase) at the other end received from the relay device at the other end via sc and sD
If the difference between the detected g-flow value (or phase) at the own end exceeds a certain value, the circuit breakers 8E, 8F at both ends of the river in the conservation area 111f are operated to
: A protective relay system is used in which the power transmission 1 is released from the glue path 9.

However, in the Bao Zhao Jitun force method, the transmission capacity of the pilot wires 5C to 7C or the transmission device 8C28D is limited, so when trying to transmit a large number of signals related to the protection of the power transmission system, it is necessary to increase the number of FW. The disadvantage was that transmission lines had to be installed in parallel, which increased costs in terms of installation and maintenance costs for the transmission lines.

In this case, the number of transmission spaces can be increased by increasing the transmission speed, but this increases the cost of the transmission equipment, and especially in the case of wired transmission, the transmission quality decreases due to the increase in transmission loss, which increases the cost. In addition to this, it is also undesirable because of the risk of transmission quality.

The present invention has been made to solve such problems, and its purpose is to provide a protective relay system that can transmit a large number of transmission signals related to power transmission system maintenance without reducing the transmission speed and transmission quality. It's about doing.

The non-invention is a transmission means for compressing a state signal (current value or phase, etc.) representing the transmission state and transmitting it from one relay device 6 to the other relay device, and The above object has been achieved by providing receiving means for expanding and demodulating the received signals in accordance with the compressed signal characteristics.

Hereinafter, the invention will be described in detail based on the illustrated embodiments.

FIG. 2 is a block diagram showing an embodiment of the main parts of the present invention, which can be roughly divided into a transmission M section 10 that compresses and encodes a monitoring point detection signal and transmits it, and a transmission line 11. and a receiving section 12 that decompresses and demodulates the received information from the other relay device received via the relay device.

The sending section (1) 0 includes a zangle hold circuit 10A, a pressurizer 10B, an encoder 1sc, an fs signal 10. [ ), and the detected current at the monitoring point is sampled at a predetermined period in the sample-and-hold circuit IOA. This sample value is sent to the compressor 10B, where it is compressed according to a non-violent input/output characteristic as shown in Figure 3a. The thus compressed sample value is converted from an analog value to a digital value by the encoder 10C, and then sent to the transmission line 11 (optical transmission line, wired or wireless transmission line) by the transmitter 10D.

That is, since the detection signal of the monitoring point is compressed according to the characteristics shown in Fig. 3a, it can be quantized finely where the input level is low, and coarsely quantized where the Mll level is high, resulting in a transmission rate of %11. transmitted to. In this way, since the signal is compressed and transmitted, quantization noise can be reduced regardless of the input level.

The signal on the transmission line 11 is input to a receiving section 12 .

The receiving section 12 consists of a receiver 12A, an expander 12B, and a relay operation calculation section 12c, and the received signals received from the transmission path 11 in the receiver 12A are sent to the expander 12B, where the signals shown in FIG. The nonlinear input-output property Ka is expanded. The expansion result is then processed by a relay operation calculator 1 consisting of a microcomputer or the like.
2c, where the circuit breaker tripping relay 1
3 is to be driven. Based on this determination result, the relay 13 is activated.

In the above embodiment, the compressor 10B and the encoder ioc were explained as being divided into two circuits, but a compressor H+f that simultaneously performs compression encoding may also be used.

In addition to configuring the above embodiment, when digitally transmitting a conventional system through a transmission line, many bits are required and the word of the transmission format becomes long, so it is difficult to compress it. Since the number of bits can be reduced, the word length can be shortened. As a result, the transmission speed can be lowered, allowing the conventionally used pilot key cable to be used as is, making it possible to transmit a large number of analog IF signals. Furthermore, by reducing the transmission capacity, it becomes possible to perform high-speed sampling. In other words, the -f function is achieved by eliminating the restriction due to the transmission speed. Furthermore, in general, input information has a small probability of having a high amplitude, so it is not necessary to know the waveform finely with high amplitude amplitude, but low-level input information is quantized finely. There is.

As is clear from the above explanation, in the present invention, the power transmission status signal at the monitoring point is compressed and transmitted, and the receiving side expands and demodulates the received signal 4. The transmission capacity is reduced, and it becomes possible to transmit many types of signals through one transmission path. In addition, in areas where the area of the power transmission status signal is small,
On the other hand, since large areas are quantized with a coarse interval, quantization noise can be reduced regardless of the size of the power transmission status signal, and malfunctions of relays etc. due to quantization noise can be prevented, and transmission It is also possible to improve product quality. As a result, a large number of signals related to the maintenance of the six transmission lines were
Jl: With the pilot wires that have been used since then, it will be possible to transmit even one song without any deterioration in transmission quality, and if the power transmission system can be used in complex protective relay systems. The effect is extremely large.

[Brief explanation of drawings]

The first is a system configuration diagram of the protective relay system that has been used in the past, and the second is the centralization characteristic and extension characteristic of the main part of the present invention.
, 5B-7B... relay device, 5D-7D, s E
~7E...Breaker, 10...Transmission unit, 11...Transmission line, 12...Reception unit, IOA...Sample hold circuit, LOB...Compressor, 10C...Code vessel,
1. OD...Transmitter, 12A...Receiver, 12B.
...Extender, 12C...Relay operation calculator. Figure 1(a) 1stvA(b) ? 3A 8B Figure 2 X force → X force 1111

Claims (1)

[Claims] In a protective relay device that mutually transmits and receives status signals representing the results of monitoring the power transmission status of the power transmission line at both ends of a protection zone, and shuts off the protection zone when an abnormality occurs, the above status signals are compressed and transmitted to one side of the protection zone. The present invention further includes a transmission means for transmitting data from the relay device to the other relay device, and a receiving means for expanding and demodulating the signal received from the other relay device in accordance with the characteristics of the compressed signal. Features of protective relay device.