JPS59169320A - Protecting 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] [Technical Field of the Invention] The present invention relates to a protective relay device, particularly a protective relay device that detects a fault in an electric power system by calculating the amount of operation and the amount of suppression obtained through a filter. The present invention relates to a protective relay device that prevents unnecessary responses due to differences in response times of filters that occur during the occurrence and recovery of an accident.

[Technical background of the invention]

The first example is a ratio differential relay device that protects the power system.
This will be explained below using figures. A current 11 at each end obtained through a two-terminal power transmission system 3 and an auxiliary transformer 1 shown in FIG.
After vector synthesis in the +Ize adder circuit 4A, it is introduced into the filter circuit 5A, and the operating amount 1 is passed through the full-wave rectifier circuit 6A.
Get Idl. On the other hand, the suppression amount IIresl is obtained through the rear arithmetic circuit 4B and the filter circuit 5B, which rectify the currents Il and I2 at each end in the half-wave rectifier circuit 6B. Operation amount II
al, the suppression amount IIresl is introduced into the level detection circuit 7A together with the DC suppression amount, l Id l:>l
When I res l +KO is established, the level detection circuit 7
A works. After that, the waveform expansion circuit 8 is applied, t1
Time will be delayed when returning. FIG. 2 shows an example of the ratio characteristics obtained with the above configuration.

[Problems with background technology]

In the ratio differential relay device having the above configuration, the response of the filter circuit should ideally have the following relationship when a power system fault occurs and is recovered, but it is impossible to satisfy terms (1) to 6iD. A waveform stretching circuit 8 is used as a countermeasure against unnecessary responses due to inability to coordinate filter response times.
A method has been adopted in which timer 9 (timer time t2) is inserted after , but this causes an unnecessary delay in operating time in the event of an internal accident.

On coordination of filter response times.

(1) When an internal accident occurs 'r, (T2) (11) When an external accident occurs T1) T2 (iiD When recovering from an external accident TI<T2 Tl: Operation amount derivation filter 5A response time T2: Suppression amount derivation filter 5B response time, e.g. Figure 3 shows the waveforms of various parts when an external accident occurs when TI<T2.l Ia
l, l Ires l are each T1+ until they reach a constant value
Since it takes T2 hours, during that time l Id l ) l
A portion where Ires 1+Ko is established occurs, and an output appears in the waveform expansion circuit 8. Therefore, the timer 9 prevents mistrips due to its output.

[Purpose of the invention]

The present invention has been made with the aim of solving the above problems, and provides a highly reliable protective relay that reduces delay in operation time as much as possible and prevents unnecessary responses at the time of accident occurrence and recovery. The purpose is to provide equipment.

[Summary of the invention]

In the present invention, the input/output terminal of the filter circuit that generates the operating amount is connected to the adder circuit 2, and even if the input changes, when the input to the filter circuit and the output after the filter response time are equal, the adder circuit When the output becomes zero and there is a difference in the magnitude of the input and output signals when the input changes, this difference occurs after the filter response time, and this is used as a lock signal to prevent unnecessary responses. It is something to do.

[Embodiments of the invention]

The entire embodiment will be explained below with reference to the drawings. FIG. 4 is a configuration diagram of an embodiment of the protective relay device according to the present invention.

In the figure, the input and output of the operation amount deriving filter circuit 5A are introduced into the adder circuit 4C, and the DC electricity amount is 1 and the filter response delay of the filter circuit 5A is calculated by the level detection circuit 7B through the full-wave rectifier circuit 6C. To detect. The output of the level detection circuit 7B is introduced into an AND circuit 11 together with the output of the level detection circuit 7A via a NOT circuit 10, and is configured to become the final protective relay device output via a waveform expansion circuit 8. . In FIG. 4, the same symbols as in FIG. 1 indicate similar circuit configurations.

The operation of the protective relay device configured as above will be explained below. When an external accident occurs in the power system and the power system recovers, the output of the filter circuit 5A is as shown in FIG. This is because the output of the adder circuit 4C becomes zero when the input and output of the filter circuit 5A are equal (after the filter response time), but when the input changes, the filter circuit 5AK has a response delay, so the magnitude of the output signal is This is because since the input signal is followed after a certain time delay, a difference in the magnitude of the output signal occurs in the adder circuit 4C. When the output obtained from the adder circuit 4C via the full-wave rectifier circuit 6C'z exceeds a predetermined amount of DC electricity, the level detection circuit 7B operates. That is, the level detection circuit 7B will output at the time of accident occurrence and recovery. By this output, NOT circuit 10, AND circuit 1
1, by locking the output of the level detection circuit 7A, it becomes possible to appropriately prevent an external accident from occurring and unnecessary response during recovery. In addition, in the event of an internal accident, please refer to Figure 5 (b).
), the operation time delay when an accident occurs is a problem, but since unnecessary responses can be locked without including the waveform extension time (1,), the operation time is reduced by the equivalent of t1 time compared to the conventional technology. can. In addition, in the present invention, the timer 9 is not required, which facilitates short-term cooperation.

The above explanation is based on the method of adding the input and output of the filter to detect the response error at the time of recovery from an accident, but the following method can also be applied as long as it detects the amount of change in the input. In Fig. 6, if a filter 5C having the characteristics as shown in Fig. 7 is used as the input of the operation amount deriving filter 5A, the output of the filter 5C is generated only during a transient response when the input is at a predetermined frequency fo; The fo acid component is almost attenuated and not generated.

〔Effect of the invention〕

According to the present invention described above, it is possible to reliably prevent unnecessary responses due to differences in response times of filters, and to shorten the response time overall, thereby providing highly reliable protection with a quick p1 operation time. Relay equipment can be provided.

[Brief explanation of the drawing]

Fig. 1 is a diagram of a conventional ratio differential relay, Fig. 2 is a characteristic example diagram of a ratio differential relay, Fig. 3 is an external fault response diagram of the relay shown in Fig. 1, and Fig. 4 is a diagram of a conventional ratio differential relay. A diagram of a ratio differential relay device according to the present invention, FIG. 5 is an internal and external fault response diagram of the relay device shown in FIG. 4, FIG. 6 is a diagram of another embodiment according to the present invention, and FIG.
FIG. 7 is a characteristic diagram of the filter used in FIG. 6; ■... Current transformer 2... Breaker 3...
Power transmission system 4A, 4B, 4C...Addition circuit 5A, 58.5C...Filter circuit 6A, 6C...Full wave rectifier circuit 6B...Half wave current circuit 7A, 7B...Level detection circuit 8 ...Waveform extension circuit 9...Timer 10...
Not circuit 11...And circuit (7317) Agent Patent attorney Noriyuki Chika (and 1 other person) Figure 2

Claims (1)

[Claims] AC electricity quantity f from the power system: By deriving it through each of the first and second filters, the electricity quantity by the first filter is used as the operating quantity, and the electricity quantity by the second filter is the suppression quantity. In a protective relay device that detects a power system failure by comparing an operation amount and a suppression amount, the change in the input electrical amount of a first filter circuit that derives the operation amount reaches a predetermined level after a filter response time? A protective relay device characterized in that it outputs a lock signal for an amount of operation when the amount of operation exceeds the amount of operation.