CN104280632B - Automatic detecting and early warning method for relay protection device and fault recorder - Google Patents

Abstract

Disclosed is an automatic detecting and early warning method for a relay protection device and a fault recorder. The method comprises the steps of acquiring data, calculating effective values, unifying the calculated effective values to the primary side, ranking the effective values, calculating the average value, determining a failure and the like. The method has the advantages that failures of the relay protection device and the fault recorder in an electric system can be found in time, the defect of the prior art that potential safety hazards can be caused by failure checking lag during periodical check can be overcome, and then the frequency of grid failures caused by failures of a device itself can be reduced greatly.

Description

A method for automatic detection and early warning of relay protection device and fault recorder

technical field

The invention belongs to the technical field of automatic detection and early warning of electric power protection devices, in particular to a method for automatic detection and early warning of relay protection devices and fault recorders.

Background technique

The power grid safety automatic device is an automatic protection device commonly used in the power grid to prevent the power grid from losing stability and avoiding large-scale blackouts when the power system fails or operates abnormally.

The safety automatic device is when the power components in the power system (such as generators, lines, etc.) or the power system itself break down and endanger the safe operation of the power system, it can send a warning signal to the operation duty personnel in time, or directly send a warning signal to the control center. An automated device in which a circuit breaker issues a trip command to terminate the development of an event. The fault recorder is an important safety automatic device that can improve the safe operation of the power system. When the power system fails or oscillates, it can automatically and accurately record the changes of various electrical quantities in the process before and after the fault. Through the analysis and comparison of these electrical quantities, personnel can analyze and deal with accidents and judge whether the relay protection device is operating correctly, so it plays an important role in improving the safe operation level of the power system. Since the relay protection device and fault recorder are crucial to the safe operation of the power system, it is generally necessary to regularly check the relay protection device and fault recorder in power supply practice in order to detect the relay protection in time. The possible faults of the device and the fault recorder can be repaired or replaced, so as to ensure that they always play a reliable role in the power system. However, the disadvantage of regular calibration is that it is impossible to detect possible faults in time. Assuming that after the relay protection device itself fails and before the fault is detected and repaired, the power system has an operating fault, then the relay protection device may Failure to make a correct response, which further expands the operating fault and causes serious losses; or the fault recorder fails and the fault has not been detected and repaired, which will no longer be able to accurately record the operating data of the power system, thus affecting the power system. Analysis and research on the operation of the system. Therefore, how to discover the faults of the relay protection device or the fault recorder in real time and give early warning in time, so as to ensure that the relay protection device and the fault recorder always play a normal and reliable role in the power system It is of great significance to solve the disadvantages of experience, ensure the safe operation of the power system, and prevent the large-scale expansion of faults, and also makes the solution of this problem have great theoretical, social and economic value.

Contents of the invention

In order to solve the above problems, the object of the present invention is to provide a method for automatic detection and early warning of relay protection devices and fault recorders. This method can automatically and timely and accurately find the faults of safety automatic devices, and at the same time send early warning signals to the staff.

In order to achieve the above object, the relay protection device and fault recorder automatic detection and early warning method provided by the present invention include the following steps performed in order:

Step 1) Collect data: According to the communication protocol of various safety automatic devices, collect the outgoing current and bus line from each device at the same time or adjacent time, and the sampling time is 10 milliseconds, which is a half cycle or 20 milliseconds, which is a cycle Instantaneous data of voltage;

Step 2) Calculate the effective value: Based on the instantaneous data of the above-mentioned devices, calculate the root mean square effective value C _M within the sampling time interval, M is the safety value of the same primary equipment or interval transformer connected to the substation. The number of the automatic device, M=1,2,3..., the algorithm of the root mean square effective value C _M is the sum of the squares of the instantaneous sampling data in a cycle or half cycle divided by the number of samples and then taking the square root, Among them, N is the number of sampling, and A _Mi is the instantaneous value of sampling:

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\sqrt{{\mathrm{<span\; class="notranslate">\; N</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; N</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$

Step 3) Unify the above calculated effective values to the primary side: C _M1 is the primary effective value of No. M device, C _M2 is the secondary effective value of No. M device, and K _B is the primary and secondary transformation ratio;

C _M1 ＝C _M2 ×K _B

Step 4) Sorting of effective values: sorting the primary effective values of all devices to find out the maximum and minimum values;

Step 5) Fault judgment: When the difference between the maximum value and the minimum value is greater than 10% of the minimum value, it is considered that there is a sampling fault, and C _Max and C _Min are respectively the maximum primary effective value and the minimum primary effective value of the device;

$\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}}}<span\; class="notranslate">\; ></span>\mathrm{<span\; class="notranslate">\; 10</span>}\mathrm{<span\; class="notranslate">\; \%</span>}$

Step 6) calculate the average value: calculate the average value of all samples again;

Step 7) Fault confirmation: If the difference between the maximum sampled value and the average value is greater than the difference between the minimum sampled value and the average value, then it is considered that the device corresponding to the maximum sampled value has a device fault, otherwise it is considered that the device corresponding to the minimum sampled value has a device fault, and is determined by The computer-controlled early-warning device sends out an early-warning signal.

The effect of the automatic detection and early warning method of the relay protection device and the fault recorder provided by the present invention: the faults existing in the relay protection device and the fault recorder in the power system can be found in time, and the existing regular calibration will cause fault troubleshooting Lag has the disadvantage of potential safety hazards, which can greatly reduce the number of power grid failures caused by the failure of the device itself.

Description of drawings

Fig. 1 is a flow chart of the automatic detection and early warning method for a relay protection device and a fault recorder provided by the present invention.

detailed description

The automatic detection and early warning method of the relay protection device and the fault recorder provided by the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, the relay protection device provided by the present invention and the automatic detection and early warning method of the fault recorder are completed in the substation computer of the substation relay protection information remote transmission system, which includes the following steps performed in order:

Step 1) Collect data: According to the communication protocol of various safety automatic devices, collect the outgoing current and Instantaneous data of busbar voltage;

Step 2) Calculate the effective value: Based on the instantaneous data of the above-mentioned devices, calculate the root mean square effective value C _M within the sampling time interval, M is the safety value of the same primary equipment or interval transformer connected to the substation. The number of the automatic device, M=1,2,3..., the algorithm of the root mean square effective value C _M is the sum of the squares of the instantaneous sampling data in a cycle or half cycle divided by the number of samples and then taking the square root, Among them, N is the number of sampling, and A _Mi is the instantaneous value of sampling:

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\sqrt{{\mathrm{<span\; class="notranslate">\; N</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; N</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$

Step 3) Unify the above calculated effective values to the primary side: Considering that the conversion ratios of different devices are different, the calculated effective values of all devices should be unified to the primary value for easy comparison. C _M1 is the primary effective value of the M device, C _M2 is the secondary effective value of No. M device, and K _B is the primary and secondary transformation ratio;

C _M1 ＝C _M2 ×K _B

Step 4) Sorting of effective values: sorting the primary effective values of all devices to find out the maximum and minimum values;

Step 5) Fault judgment: When the difference between the maximum value and the minimum value is greater than 10% of the minimum value, it is considered that there is a sampling fault, and C _Max and C _Min are respectively the maximum primary effective value and the minimum primary effective value of the device;

$\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}}}<span\; class="notranslate">\; ></span>\mathrm{<span\; class="notranslate">\; 10</span>}\mathrm{<span\; class="notranslate">\; \%</span>}$

Step 6) calculate the average value: calculate the average value of all samples again;

Step 7) Fault confirmation: If the difference between the maximum sampled value and the average value is greater than the difference between the minimum sampled value and the average value, then it is considered that the device corresponding to the maximum sampled value has a device fault, otherwise it is considered that the device corresponding to the minimum sampled value has a device fault, and is determined by The computer-controlled early-warning device sends out an early-warning signal.

In the above technical scheme, by obtaining the current and voltage data in the relay protection, safety automatic device, and fault recorder connected to the same primary equipment or bay transformer in the substation and comparing the significance of the difference, if the significance of the difference If it is greater than a certain preset value, it means that at least one of the relay protection device and the fault recorder has a device failure, and an early warning signal is issued. The sampling and comparison of the above-mentioned current and voltage are completed by a computer. When an early warning is required, the computer controls the alarm device. action. The method can timely discover the faults of the relay protection device and the fault recorder in the electric power system, and overcomes the drawbacks of the existing periodic checks that cause lagging faults and potential safety hazards.

The specific working process of the relay protection device and fault recorder automatic detection and early warning method provided by the present invention is as follows:

1. The relay protection information sub-station of the substation has established a communication channel for connecting data with each relay protection device and fault recorder in the station, and collects the same A piece of current or voltage data of a unified channel at a time or adjacent time, the time window is generally 20 milliseconds, and it is converted into effective value data, and the effective value calculation adopts the integral effective value algorithm, that is, the square sum of each sampling point is divided Prescribing is based on the number of samples;

2. Then unify all the effective values to the primary value, and sort them by voltage and current respectively, and compare the maximum and minimum values. When the difference between the maximum value and the minimum value is greater than 10% of the minimum value, it is considered that there is a sampling failure. C _Max and C _Min are the maximum primary effective value and the minimum primary effective value of the device respectively;

$\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}}}<span\; class="notranslate">\; ></span>\mathrm{<span\; class="notranslate">\; 10</span>}\mathrm{<span\; class="notranslate">\; \%</span>}$

3. If the difference between the maximum and minimum values of the current exceeds 10% of the minimum value, the average value of all current samples is calculated. If the difference between the maximum sample value and the average value is greater than the difference between the minimum sample value and the average value, the maximum sample value is considered The device corresponding to the value has a device fault, otherwise it is considered that the device corresponding to the minimum sampling value has a device fault;

4. If the difference between the maximum and minimum values of the voltage exceeds 10% of the minimum value, the average value of all voltage samples is calculated. If the difference between the maximum sampled value and the average value is greater than the difference between the minimum sampled value and the average value, the maximum sampled value is considered The device corresponding to the value has a device fault, otherwise it is considered that the device corresponding to the minimum sampling value has a device fault;

5. When an alarm is required, the computer sends a signal to the early warning device, such as a buzzer or a light emitting device.

At present, devices such as relay protection devices, safety automatic devices, fault recorders, and information remote transmission system substations have been widely used in power systems. Therefore, this method plays a vital role in the safe, reliable and stable operation of power systems. important role.

The relay protection device and fault recorder automatic detection and early warning method provided by the present invention discloses a relay protection device, a safety automatic device, a fault recorder self-acquisition or a detection and early warning method for transformer faults. Connected to the relay protection of the same primary equipment (or interval) transformer in the substation, compare the instantaneous data of the safety automatic device and the fault recorder, analyze whether the difference exceeds the set range, and judge whether the device has its own collection Failure or transformer failure, and timely warning.

This embodiment is only an illustration of the conception and realization of the present invention, and is not intended to limit it. Under the conception of the present invention, technical solutions without substantial changes are still within the scope of protection.

Claims (1)

1. A relay protection device and fault recorder automatic detection and early warning method, is characterized in that: it comprises the following steps that are carried out in order: Step 1) Collect data: According to the communication protocol of various safety automatic devices, collect the outgoing current and bus line from each device at the same time or adjacent time, and the sampling time is 10 milliseconds, which is a half cycle or 20 milliseconds, which is a cycle Instantaneous data of voltage; Step 2) Calculate the effective value: Based on the instantaneous data of the above-mentioned devices, calculate the root mean square effective value C _M within the sampling time interval, M is the safety value of the same primary equipment or interval transformer connected to the substation. The number of the automatic device, M=1,2,3..., the algorithm of the root mean square effective value C _M is the sum of the squares of the instantaneous sampling data in a cycle or half cycle divided by the number of samples and then taking the square root, Among them, N is the number of sampling, and A _Mi is the instantaneous value of sampling: ${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\sqrt{{\mathrm{<span\; class="notranslate">\; N</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; N</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$ Step 3) Unify the above calculated effective values to the primary side: C _M1 is the primary effective value of No. M device, C _M2 is the secondary effective value of No. M device, and K _B is the primary and secondary transformation ratio; C _M1 ＝C _M2 ×K _B Step 4) effective value sorting: sort the primary effective values of all devices to find out the maximum value and the minimum value; Step 5) Fault judgment: When the difference between the maximum value and the minimum value is greater than 10% of the minimum value, it is considered that there is a sampling fault, and C _Max and C _Min are respectively the maximum primary effective value and the minimum primary effective value of the device; $\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}}}<span\; class="notranslate">\; ></span>\mathrm{<span\; class="notranslate">\; 10</span>}\mathrm{<span\; class="notranslate">\; \%</span>}$ Step 6) calculate the average value: calculate the average value of all samples again; Step 7) Fault confirmation: If the difference between the maximum sampled value and the average value is greater than the difference between the minimum sampled value and the average value, then it is considered that the device corresponding to the maximum sampled value has a device fault, otherwise it is considered that the device corresponding to the minimum sampled value has a device fault, and is determined by The computer-controlled early-warning device sends out an early-warning signal.