JPS6035887B2 - Inspection and monitoring device for computerized protective relays - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a computer-based system protection device, and particularly to a computer-based protection relay inspection and monitoring device suitable for a large-scale system protection device that requires high reliability.

Since computers are designed as general-purpose products, they have the disadvantage that even when used for control purposes, they cannot operate as fast as dedicated hardware.

In particular, when introducing a computer for protection relays, the calculation speed required to complete the number of program steps required for accident detection is approximately the same as the calculation speed limit due to the performance of current computers. It is extremely difficult to allocate a large amount of regular calculation time to hard checks, that is, constant monitoring, which have been performed with dedicated hardware relays. For this reason, it is possible to secure time for accident detection calculations that are constantly performed by a computer based on input data from the grid, and to ensure that hardware inspections are carried out without any negative impact, without eating into this time too much. It is desirable to derive a method for performing this, and unless this method is established, there is a concern that reliability will decline due to a decline in the ability to detect the presence or absence of hardware failures compared to the case of conventional dedicated hardware methods.

- The purpose of the present invention is to eliminate the above-mentioned drawbacks of the conventional system and provide an inspection and monitoring device for a computerized protective relay that reliably inspects and monitors hardware without compressing the operating time of the protective relay. .

The above object of the present invention is to inspect the hardware of a computer by running a hardware inspection program during the margin time in each sampling period, which is obtained by subtracting the calculation time required for a protective relay to detect an accident for each sample data from the sampling period. This can be achieved by the inspection and monitoring device for computerized protective relays according to the present invention, which allows monitoring to be carried out periodically on-line.

Furthermore, when the above-mentioned margin time is short, the inspection monitoring device according to the present invention divides the execution of the above-mentioned hardware inspection program into a plurality of times. It is characterized by constant hardware monitoring. Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing an inspection and monitoring device for a computerized protective relay according to the present invention.

In Fig. 1, 1-1 to 1-m indicate m bus bars or transmission lines, and from the bus bars or transmission lines 1-1 to 1-m, an amount proportional to the primary amount of the system is connected to the current transformer 2-1. ~21m respectively. Current transformer 2-1~2-
The outputs of m are converted into digital quantities proportional to their respective outputs by analog-to-digital converters 3-1 to 3-m, respectively. These analog-digital converters 3-1~
3-m converts each input amount at that time into a corresponding digital amount when there is a conversion command CK, ~CKm from the data bus control device 4, which will be described later, and outputs the digital amount CD.
, ~CDm are applied to the data bus control device 4 via the output line. In order to share data for a large number of different types of computerized relays within a system that are to be inspected and monitored, it is necessary to easily understand the relative temporal relationship of data in each computerized relay. It is necessary to do so.

For this reason, the conversion commands CK, -CKm are issued at exactly the same time. Therefore, each analog-to-digital converter 3-
The outputs CD, -CDm of 1 to 3-m arrive at the input end of the data bus control device 4 at practically the same time. The data bus control device 4 receives these data and sends common data to the computer relay group onto the data bus 5 in a time-sharing cyclic manner. At this time, an address word and a parity bit for data identification are added so that each of the computer protection relays 6-1 to 6-k in the computer group can take in only necessary data. A large number (k in FIG. 1) of computerized protection relays 6-1 to 6-k are connected to this data bus 5 in order to protect systems in different ranges, respectively.

These computer-operated protective relays 6-1 to 6-k do not necessarily need to adopt the same accident detection principle, but in order to select and import only the system data necessary for accident detection for each protection target, each The input/output control circuits 8-1 to 81M provided inside the relays 6-1 to 61k are an address setting circuit for required data and a parity check circuit (
(not shown) is provided. The address setting circuit consists of a comparison circuit between the address word on the data bus 5 and its own set address, and only when the two match, the data word of that address is taken in and the central processing unit 7-
It performs the function of giving 1 to 71 k'. Further, when the address setting circuit takes required data into the computer from the data bus 5, the parity check circuit checks the parity bit added to the data word based on the required data, and reads the data as well as the computer central processing unit 7--. 1-7-
It performs the function of giving W. Already filed patent application 1977-13617
According to No. 5 (Japanese Patent Application Laid-Open No. 50-186649), the computer central processing unit of each computer-type protective relay, regardless of whether it has one input or multiple inputs, such as a Morau relay, a reactance relay, a differential current relay, a phase comparison relay, etc. This can be realized by accident detection calculation using .

FIG. 2 shows a general operation flow of the computer-operated protective relay that uses the principle of integration calculation as an accident detection calculation according to the above-mentioned application. FIG. 3 shows the operation flow of the computer-operated protective appliance inspection and monitoring device according to the present invention.

In the flowchart of FIG. 3, after the fifth means of the maintenance relay routine shown in FIG. A routine 101 for determining the contents of
A divided inspection calculation routine 102 that performs inspection calculations to be executed at the sample time according to the results determined by the routine 101, and a routine 103 that determines the calculation results for the inspection data are added. Hereinafter, the operation in the embodiment of the present invention will be explained according to each step shown in FIG.

Similar to conventional computer relays, the first means takes in system information from the computer central processing units 6-1 to 6-6, and the second
Preprocessing is performed based on this data using the following means. The third and fourth means perform a product operation and a filtering operation on the output of the second means. The fifth means determines the accident detection calculation result of the fourth means, and issues a predetermined shearing command when an accident is detected. After completing each step above, step 10
Count value n of the inspection calculation program selection counter at 0
Add 11 to , proceed to step 11, determine the content of n, and if n = 1, proceed to step 21 and calculate the first 1/m (in this case m = 5) of the inspection calculations. , moves to the next sampling period, sets t←t+to (ra=sampling period), and proceeds to the next step.

In the next sampling period, first to fifth means are performed in the same way, and the process proceeds to step 10.

At this point, the count value n is added by 11 from the previous time, and n=
If it is 2, the process proceeds from step 11 to step 12, and then jumps to step 22, where the second 1/m calculation of the inspection calculation, which is a continuation of step 21, is executed, and t←t+to is set in preparation for the next sampling. As a result, 2/5 of the series of inspection calculations are executed. In exactly the same way,
For the next sample, the process advances to step 23 based on the determination in step 13, and for the next sample, the process advances to step 24 based on the determination in step 14, where the third 1/m and fourth 1/m of the inspection calculations are executed. be done. At the time of the next sample, the process proceeds to step 31 of the routine 103, where the last 1/m of the inspection calculation, that is, the input for inspection (
Previous steps 21, 22, 23, 2 according to known)
It is determined whether the calculation result of step 4 matches a preset expected answer. If they match, it means that the inspection calculations have been performed correctly so far.
That is, in order to show that there is no defect in the computer hardware, in step 33, it is notified to the outside that the computer central processing unit (hardware) is normal. Furthermore, step 3
4, the count value n of the inspection calculation program selection counter
Set to 0, prepare for the next inspection, and set t←t+
The following sample data is handled as to. Further, if the value does not match the planned value in step 31, it is determined that the computer central processing unit (hardware) is not normal, and in step 32, the computer is notified to the outside and the computer is stopped.
Instruct external parties to search for hardware failures, repair, etc. In the embodiments described so far, the inspection calculation is performed in each step 2.
1 to 24 and 31, but it goes without saying that this division can be arbitrarily selected in consideration of the margin time tR.

FIG. 4 shows an operation time chart in the above embodiment. In Fig. 4, a is the time T of the first to fifth means of relay electricity calculation.
, ~ the relationship between T5 and the margin time TR, b is step 21
24 and 31 are shown, respectively. Thus, in the embodiment of FIG. 3, each sample period t.

Steps 21 to 24 and 31 are executed sequentially for each time, and the same inspection calculation is performed again after m sample periods (mxt.) have elapsed. Generally, in a protective relay, the electrical angle of the AC signal is 30
Since the processing shown in FIG. 3 is performed by sampling once every (degree), the result of step 31 will be displayed and output once every 150 degrees (electrical angle). In Fig. 5, since there is no need for frequent inspections, inspections are carried out once every appropriate number of times.For example, in step 11, the count number n=10, and in step 12, n=20, step 13 n=30, step 14 n=40, step 15 n=
It is assumed that it is determined that the number is 50. By doing so, step 21 is executed when 10 sample periods have elapsed since n=0, and thereafter steps 22, 23, 24, and 31 are executed every 10 sample periods.
When the sample period does not match the count value n, the process moves from step 100 to steps 11-12-13-14-15;
t. When the time has elapsed, the process returns to the process of the first means, which is the first process in FIG. The other configuration in FIG. 5 is exactly the same as the flow in FIG. 3. FIG. 6 shows an operation time chart corresponding to the flowchart of the embodiment shown in FIG. As is clear from the above explanation, according to the present invention, the presence or absence of a hardware failure can be determined, so a protective relay system with high operational reliability can be realized. Since the calculation is carried out during the spare time of the accident detection calculation, instead of being carried out separately, highly accurate and reliable accident detection can be realized.

Further, the device according to the present invention can arbitrarily select the calculation time for determining the presence or absence of a hardware failure, and can be used for both constant monitoring and automatic inspection.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an inspection and monitoring device for a computerized protective relay according to an embodiment of the present invention. Figure 2 shows the calculation flow for a computerized protective relay. FIG. 3 is an operational flow showing one embodiment of the present invention, and the fourth
The figure shows its operation time chart. FIG. 5 shows an operation flow of another embodiment of the present invention, and FIG. 6 shows its operation time chart. Explanation of symbols 1... Bus bar or power transmission line, 2... Current transformer, 3... Analog-to-digital converter, 4... Data bus control device, 5... ...Data bus, 6...Computer-type protective relay, 7...Central processing unit, 8...
・Input circuit, 100...count step,
101... Count judgment step, 102...
...Arithmetic routine for split inspection, 103...Inspection judgment routine. Tsutomu 2 figure hair 3 figure 1 figure 5 leopard 4 figure hair 6 figure

Claims (1)

[Claims] 1. A device that obtains a digital quantity proportional to the primary quantity of the system sent from the bus or transmission line via a transformer and an analog-to-digital converter, and a computer that takes in this digital quantity, performs fault detection calculations, and makes an accident determination. A computer-operated protective relay inspection and monitoring device comprising: after the accident determination processing of the computer, the hardware of each computer is divided for each sampling or at an appropriate sampling time within the margin time for the accident detection calculation in each sampling period. An inspection and monitoring device for a computer-type protective relay, which is characterized by executing a wear inspection and monitoring routine and reporting the results to the outside.