JP3955891B2 - Inspection method for digital protective relay - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inspection method for a digital protection relay device that determines the quality of a device using the amount of electricity taken from an electric power system, and in particular, electrical quantity data obtained from a plurality of digital protection relay devices by a common calculation technique. The present invention relates to an inspection method for a digital protective relay device in which a determination is made by taking
[0002]
[Prior art]
Conventionally, when checking a digital protective relay device in a power system, an amount of electricity that is clearly higher than the power flow level of the system is manually input, and in particular, the analog input processing unit and other input processing units are checked for quality. Therefore, it took a lot of work and time.
[0003]
In particular, when inspecting digital protective relays installed in remote mountainous substations, workers regularly visit the site to input inspection inputs and perform inspections. It was. During the inspection period, it was necessary to lock the device and temporarily stop operation.
[0004]
[Problems to be solved by the invention]
Thus, it is not efficient to go to the inspection work of the digital protective relay device at a substation installed in a remote area such as a mountainous area, instead of making the worker spend a lot of time and effort. For this reason, there has been a long-awaited development of an inspection system that enables inspection work of digital protective relay devices without going to substations.
[0005]
Even during normal operation at a remote substation, etc., the present invention can perform periodic inspection work without taking time and labor by sucking up the data of the relay device from a remote location and performing the pass / fail judgment processing of the device. The purpose of the present invention is to obtain a digital protection relay inspection system that can simplify and improve efficiency.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention of the digital protection relay inspection system according to claim 1 converts an analog electric quantity input from the power system into a digital quantity by sampling at a constant period, and further performs a filtering process. after, the digital protective relay electrical location for protecting computing a plurality prepared based on the protective operation program set in advance, the relay determining unit and the input electric outputs a protection operation result to each of the digital protective relay device An electric quantity sending unit that outputs the result of calculating the quantity by the same calculation method is provided, and the electric quantity sent from these electric quantity sending parts is collected by a common data collecting means via the signal transmission path, and this collected In the inspection method of the digital protection relay device in which data is input to the pass / fail judgment unit and the pass / fail judgment is made based on the following judgment formula ,
Switch from the power system to the simulated input device based on the operation output of the insufficient electricity quantity detection unit, the simulated input device, and the insufficient electricity quantity detection unit that operates when the amount of analog electricity input from the power system is a predetermined value or less. An inspection method for a digital protective relay device, characterized by comprising input switching means that operates so as to capture a simulated input.
｜ IAmax−IBmax | ≧ ε + k (| IAmax | + | IBmax |)
here,
ε: fixed error,
k (| IAmax | + | IBmax |): proportional error,
k: proportional error factor,
IAmax = MAX (IAm to Iam-i) (i: 0 to n for n seconds) Maximum value for n seconds.
IBmax = MAX (IBm to IBm-i) (i: n seconds from 0 to n) Maximum value for n seconds.
IAmax: Maximum amount of electricity of digital protective relay device DigRy1 for n seconds.
IBmax: The maximum amount of electricity of the digital protective relay DigRy2 for n seconds.
| IAmax−IBmax |: (difference between the maximum values of the A device and the B device for n seconds).
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a configuration diagram according to a first embodiment of a digital protection relay device inspection system according to the present invention.
[0010]
In FIG. 1, DigRy1 and DigRy2 are digital protection relay devices, and both analog voltage and current (system electrical quantity) measured by PT and CT installed at the terminals of transmission line TL that are the same protection target. Then, the signal is input to the analog / digital conversion unit 2 through the input converter 1, where it is converted into a digital quantity suitable for digital calculation and then input to the digital processor 3.
[0011]
The digital processor 3 includes hardware such as a buffer memory for storing A / D converted digital data, a program memory for storing a program, a CPU for calculating according to the contents of the program memory, a setting memory for storing set values, and an output circuit. The function is as shown in the block diagram of FIG.
[0012]
That is, the digital electricity quantity introduction unit 3-1 takes in the A / D converted digital data, performs a filtering process, and then outputs it to the input processing unit 3-2. The input processing unit 3-2 calculates instantaneous value data using the input digital quantity. The electrical quantity sending unit 3-3 sends the instantaneous value data calculated by the input processing unit 3-2 to the signal transmission path 4 such as an external LAN. Relay judgment unit 3-4 uses the output digital quantity of input processing unit 3-2 to perform relay operation according to a predetermined program, and outputs a disconnection command to a circuit breaker (not shown) when the relay operating conditions are met To do.
[0013]
Reference numeral 5 denotes a data processing device (hereinafter referred to as a personal computer) such as a personal computer installed at a location different from the digital protection relay devices DigRy1 and DigRy2, and is connected to the signal transmission path 4. The personal computer includes a printer in addition to a monitor (not shown).
[0014]
As an internal function of the personal computer 5, a data collecting unit 5-1 that collects data such as instantaneous values output from both the digital protective relay devices DigRy1 and DigRy2 through an interface, and a predetermined calculation for the collected data A pass / fail judgment unit 5-2 that performs pass / fail judgment of the devices of the protective relay devices DigRy1 and DigRy2 by substituting into the equation is provided.
[0015]
In this pass / fail judgment unit 5-2, for example, the following judgment formula (1) is used, and when this judgment formula (1) is satisfied, it is judged that the digital protection relay devices DigRy1 and DigRy2 are defective.
[0016]
| IAmax−IBmax | ≧ ε + k (| IAmax | + | IBmax |) (1)
here,
ε: fixed error,
k (| IAmax | + | IBmax |): proportional error,
k: proportional error factor,
IAmax = MAX (IAm to Iam-i) (i: 0 to n for n seconds) Maximum value for n seconds.
IBmax = MAX (IBm to IBm-i) (i: n seconds from 0 to n) Maximum value for n seconds.
IAmax: Maximum amount of electricity of digital protective relay device DigRy1 for n seconds.
IBmax: The maximum amount of electricity of the digital protective relay DigRy2 for n seconds.
| IAmax−IBmax |: (difference between the maximum values of the A device and the B device for n seconds).
[0017]
The above judgment formula (1) means that the amount of electricity in the transmission lines input to a plurality of digital protection relay devices DigRy1 and DigRy2 installed for one transmission line is the same (instrumental transformation Assuming that the amount of electricity taken in via the PT or current transformer CT is the same), the maximum amount of electricity data collected by the data collection unit 5-1 from the digital protection relay devices DigRy1 and DigRy2 for n seconds The value is taken into the pass / fail judgment unit 5-2, and the absolute value of the difference between the electric quantities of the two devices DigRy1 and DigRy2 is obtained by multiplying the sum of the fixed component error and the electric quantity data of the two devices by the proportional error factor. If it is larger than the sum of the minute error, it is determined that one of the two devices is defective.
[0018]
According to the present embodiment, the digital protection relay capable of detecting defects such as the phase characteristics of the electric quantity input circuit (analog input processing unit) of each digital protection relay device without being affected by the power system side. An inspection method for electric devices can be provided.
[0019]
(Second Embodiment)
FIG. 2 is a block diagram of the digital protection relay device according to the second embodiment of the present invention. The same parts as those in FIG. The transformer PT is not shown for the sake of space. The same applies to the following embodiments. In this embodiment, three or more digital protection relay devices DigRy1, DigRy2, DigRy3,... Are installed, data is taken into the personal computer 5 from each of these digital relay devices DigRy1, DigRy2, DigRy3,. This is a method in which data comparison for defect determination is performed with data of three or more devices.
According to this embodiment, it is possible to specify which device is a defective device.
[0020]
(Third embodiment)
FIG. 3 is a block diagram of an inspection system for a digital protection relay device according to the third embodiment of the present invention. The same parts as those in FIG. The transformer (PT) is omitted for reasons of space.
[0021]
In the present embodiment, an insufficient electricity quantity detection unit 3-5 that operates when the actual input of the power system falls below a predetermined value is provided, and the input switch 6 is connected to the power system by the output of the insufficient electricity quantity detection unit 3-5. Instead of the actual input, the electric quantity of the simulation input device 7 is applied.
[0022]
According to the present embodiment, even when the input level of the actual system electric quantity is small and the detection error when detecting the failure of the analog input processing unit becomes large, by switching to the simulated input device, the digital protection relay Device defects can be detected.
[0023]
(Fourth embodiment)
FIG. 4 is a configuration diagram of an inspection system for a digital protective relay device according to a fourth embodiment of the present invention.
[0024]
This embodiment stores the past data of the determination value obtained by the determination formula in the pass / fail determination unit 5-2 in the data storage means 5-3 newly provided in the configuration diagram shown in FIG. A new trend calculator 5-4 compares the current judgment value with the judgment value at the time of previous (for example, previous) inspection, and detects a defect or a sign of failure based on the trend of the judgment data. It is a thing. A device failure is detected by substituting the electric quantity data into the determination formula (2).
[0025]
Xi = | IAmax−IBmax | / (k + | IAmax | + | IBmax |)
| Xn-Xn-1 | ≧ *% (2)
However, Xn: judgment value this time
Xn-1: Previous determination value According to the present embodiment, it is possible to roughly predict when a device will be defective.
[0026]
In addition, if the judgment value X0 for the first time is used as the judgment value for the past, it is possible to know the degree of deterioration of the analog input processing unit particularly from the initial stage of delivery of the device based on the trend of the judgment data.
| Xn−X ₀ | ≧ *% (3)
However, X ₀ : Initial determination value, Xn: Current determination value
(Embodiment 5)
Compared with the fourth embodiment shown in FIG. 4, this embodiment stores past data of determination values obtained by the determination formula for defect determination in the pass / fail determination unit 5-2 in the data storage unit 5-3. If the trend calculation prediction unit 5-5 predicts the future judgment value based on the trend (trend) of the judgment data at the previous or previous inspection, and it is determined that the judgment value will deviate from the predetermined value in the future, It is configured to issue an alarm when a defect is determined.
According to this embodiment, it is possible to reduce the time during which the apparatus cannot be operated, for example, by exchanging the parts before the apparatus becomes defective, and to improve the operating rate of the system.
[0028]
(Sixth embodiment)
In this embodiment, a device having a larger zero-phase component among the electric quantities transmitted from two digital relay devices is determined to be defective.
According to this embodiment, it is possible to determine which of the two devices is defective.
[0029]
(Seventh embodiment)
In this embodiment, a device having a larger trend change in the failure determination data among the amounts of electricity transmitted from the two digital relay devices is determined to be defective by the pass / fail determination unit 5-2b. .
According to this embodiment, even when it is difficult to determine whether the zero-phase component is good or bad due to the influence of the system phenomenon, it can be determined which of the two devices is defective.
[0030]
(Eighth embodiment)
In this embodiment, the personal computer 5 collects data using an intelligent mobile agent (software that performs processing by repeatedly moving between computers and various devices connected via a network) agent, In this system, the quality of the electric device is determined, and the agent displays the device inspection result and the failure determination result in a format of a report on the operation screen.
[0031]
According to the present embodiment, it is possible to perform the inspection work and detect a defect of a device only by performing a patrol instruction operation on the intelligent mobile agent without a human being accessing each device each time.
[0032]
In addition, data is collected without human access to each individual device, and device failure detection and reports are automatically created in a pre-specified format, so they can be sent as email attachments or printed out. Can be quickly distributed to the relevant places.
In addition to the above-described embodiments, some of the embodiments can be modified as follows.
[0033]
(Modification (1))
In the first embodiment, the instantaneous value of the electric quantity is used for the defect determination, but it is not necessary to limit to only the instantaneous value, and the defect determination may be performed using the effective value. When the effective value is used, strict time synchronization between devices on the order of several microseconds is not necessary, and it is possible to check the amount of electricity between devices of different manufacturers with different specifications of the analog input processing unit.
[0034]
(Modification (2))
The digital protection relay device may be divided into two lines, data may be taken in between the two lines, and data comparison for device determination may be performed. As described above, when data comparison is performed between two systems, a device failure can be detected more strictly.
[0035]
(Modification (3))
You may make it use the data at the time of a power system failure as an input source for a check of a digital protection relay device. If the amount of electricity at the time of accident is adopted, the amount of electricity is large and various frequencies are included, so the characteristics of the analog input processing unit can be analyzed without artificially applying a high level inspection input, Device defects can be detected.
[0036]
(Modification 4)
The data collection unit 5-1 may be configured such that the acquisition time of the electric quantity data between the plurality of devices can be changed to an arbitrary value. In this case, even if the amount of electricity in the system fluctuates at a certain time interval, the data acquisition time can be adjusted to the fluctuation period, so that a device failure can be detected.
[0037]
(Modification (5))
The data collection unit 5-1 may be configured such that the acquisition interval of the electrical quantity data between a plurality of devices can be changed to an arbitrary value. In this case, even if the amount of electricity in the system fluctuates at certain time intervals, the data acquisition cycle is matched with the fluctuation cycle, so there is no need to acquire more data than necessary, and the hardware involved in data collection This makes it possible to construct a system with little risk of squeezing the memory capacity and storage capacity.
[0038]
(Modification (6))
As shown in FIG. 2, there are three or more digital protection relay devices installed, and the common quality judgment unit 5-4 performs the failure judgment. If the device data is clearly different from the determination data of most other device groups, the device is determined to be defective.
According to this embodiment, it is possible to determine which device is defective.
[0039]
(Modification 7)
This is different from the configuration diagram shown in FIG. 4 in that the data when the data captured by the personal computer 5 is captured at the previous time or when the past data is captured is stored, and the trend (trend) of the captured data is stored. The calculation is such that when the trend changes greatly and the rate of change exceeds a predetermined value, it is determined as defective.
According to the present embodiment, even when there is no target to be compared or when the device data to be compared cannot be collected for some reason, it is possible to detect a defect by using only the device.
[0040]
(Modification 8)
This is a system in which the personal computer 5 is installed at a location away from the digital relay devices DigRy 1 and 2, a general-purpose Internet browser is moved on the device, and the results of remote operation and device failure determination are displayed. is there.
According to the present embodiment, it is not necessary to develop dedicated communication software for displaying the result of remote operation of the device and the determination of failure, so that the cost of system construction can be reduced.
[0041]
【The invention's effect】
As described above, the present invention pays attention to the fact that the amount of electricity of the transmission line input to a plurality of digital protection relay devices installed in one protection target is the same, and the plurality of devices By collecting the amount of electricity input by the remote and comparing it with a failure judgment formula, it is possible to detect defects such as changes in the characteristics of the electricity input circuit of each digital protection relay device without being affected by the system side. As before, the inspection system for the digital protective relay device can be realized at low cost and with labor saving and system construction by using the grid electricity quantity in normal times without human going to the site. Can be provided.
[Brief description of the drawings]
FIG. 1 is a configuration diagram for explaining a first embodiment of the present invention relating to an inspection method for a digital protective relay device.
FIG. 2 is a configuration diagram for explaining a second embodiment of the present invention relating to an inspection method for a digital protective relay device.
FIG. 3 is a configuration diagram for explaining a third embodiment of the present invention relating to an inspection method for a digital protective relay device.
FIG. 4 is a configuration diagram for explaining a fourth embodiment of the present invention relating to an inspection method for a digital protective relay device;
FIG. 5 is a configuration diagram for explaining a fifth embodiment of the present invention relating to an inspection method for a digital protective relay device;
FIG. 6 is a configuration diagram for explaining a sixth embodiment of the present invention relating to an inspection method for a digital protective relay device;
FIG. 7 is a configuration diagram for explaining a seventh embodiment of the present invention relating to an inspection method for a digital protective relay device;
FIG. 8 is a configuration diagram for explaining an eighth embodiment of the present invention relating to an inspection method for a digital protective relay device;
[Explanation of symbols]
DigRy1, DigRy2 ... Digital protection relay device, 1 ... Input converter, 2 ... Analog / digital conversion unit, 3 ... Digital processor, 3-1 ... Digital electricity introduction unit, 3-2 ... Input processing unit, 3-3 ... Electric quantity sending part, 3-4 ... Relay judgment part, 3-5 ... Insufficient electricity quantity detection part, 4 ... Signal transmission path, 5 ... Data processing device, 5-1 ... Data collection part, 5-2 ... Good / bad judgment 5-3, data storage unit, 5-4, trend calculation unit, 5-5, trend calculation prediction unit, 6 ... input switch, 7 ... simulated input device, agent ... intelligent mobile agent.

Claims (1)

Converted into a digital amount by sampling the analog quantity of electricity input from a power system at a constant period, further after performing the filtering process, a plurality of digital protective relay electrical location for performing protection operation based on the protective operation program set in advance Each of the digital protection relay devices includes a relay determination unit that outputs a protection calculation result and an electric quantity sending unit that outputs a result obtained by calculating the input electric quantity using the same calculation method. Digital protection that collects the amount of electricity sent from the common data collection means via the signal transmission path, and inputs the collected data to the quality judgment unit to make a quality judgment based on the following judgment formula In the inspection method of the relay device ,
Switch from the power system to the simulated input device based on the operation output of the insufficient electricity quantity detection unit, the simulated input device, and the insufficient electricity quantity detection unit that operates when the amount of analog electricity input from the power system is a predetermined value or less. An inspection method for a digital protective relay device, characterized by comprising input switching means that operates so as to capture a simulated input.
｜ IAmax−IBmax | ≧ ε + k (| IAmax | + | IBmax |)
here,
ε: fixed error,
k (| IAmax | + | IBmax |): proportional error,
k: proportional error factor,
IAmax = MAX (IAm to Iam-i) (i: 0 to n for n seconds) Maximum value for n seconds.
IBmax = MAX (IBm to IBm-i) (i: n seconds from 0 to n) Maximum value for n seconds.
IAmax: Maximum amount of electricity of digital protective relay device DigRy1 for n seconds.
IBmax: The maximum amount of electricity of the digital protective relay DigRy2 for n seconds.
| IAmax−IBmax |: (difference between the maximum values of the A device and the B device for n seconds).

Images