KR200288277Y1 - Digital Ground Overvoltage relay - Google Patents

Abstract

The present invention relates to a digital ground overvoltage relay that is designed to protect a distribution line against ground faults. More specifically, it is possible to select and change a CPU unit for performing control operations throughout the apparatus, and various functions and setting values. A keyboard consisting of a plurality of keys, a fault detection information storage unit that stores information on a fault voltage detection, a RAM unit that stores relay system information (correction value), a computer, and a SCADA A relay having a communication module for communication connection with the system, a display that electrically connects the CPU but displays the operation status of the device by numbers or letters, and a function of connecting the power supply to operate each driver according to the selected function. An output unit, an analog filter unit for filtering harmonics mixed in the input signal, and a continuous analog signal is converted into encoded digital signals. The A / D conversion unit is connected to the CPU by an electrical combination, and it is not only able to accurately identify the cause of the accident, but also to read and write the set values necessary for operation through the communication device. It is easy to check the voltage value and various status information.

Description

Digital Ground Overvoltage Relay

The present invention relates to a digital ground overvoltage relay that is designed to protect a distribution line against ground faults. In particular, a fault recorder is built into the relay to record recent fault data, so that the cause of accident analysis can be accurately identified and communication can be obtained. The present invention relates to a digital ground overvoltage relay that can read and write the set values required for operation through an apparatus and can easily check the current voltage value and various status information.

In general, when a problem occurs in a distribution line and a ground fault or a short circuit occurs, a ground detector is used to detect it. Such a detector is an apparatus used for detecting the first ground fault of a high-voltage distribution line, and two types of electrostatic and electronic types are used. The former detects ground faults by an unbalance of electrostatic forces acting between three fixed electrodes connected to a high voltage line and three grounded starting electrodes, and the latter uses a ground transformer. In both cases, when a ground fault is detected, the circuit breaker is tripped by a ground (ground fault) protection relay (O.V.G.R S.G.R D.G.R) to open the line.

In the conventional ground fault detector, when a ground (ground) or short circuit accident occurs in a line, only the role of detecting and opening the line is not displayed, and it is impossible to know the instantaneous maximum voltage at the time of the accident.

Therefore, the present invention was created in view of the above-mentioned matters, and its purpose is to operate the video voltage generated in the event of a ground fault, and can be used for instantaneous and temporary operation functions, alarms and trips, as well as any abnormality of the relay. It is to provide a digital ground fault overvoltage relay with multi-function, including the ability to monitor.

In addition, another object of the present invention is to incorporate a fault recording device inside the relay, to record the recent fault data to accurately determine the cause of the accident, as well as the set value required for operation using RS-232, RS-484 communication The present invention provides a digital ground overvoltage relay that can read and write externally and easily check the current voltage value and status information.

1 is an exemplary view showing the appearance of the present invention ground fault overvoltage relay,

Figure 2 is an internal configuration diagram of a digital ground overvoltage relay to which the present invention is applied.

<Description of the symbols for the main parts of the drawings>

34: key input, 35: DSP,

47: analog input unit, 48: A / D conversion unit,

49: digital input (DI), 50: digital output (DO),

34, 51, 52: external display and key input section, A: program memory section,

B: communication control unit.

The present invention for achieving the above object is a digital ground voltage relay that can monitor and protect the distribution line failure, the CPU unit to perform a control operation throughout the device, and can change various functions and setting values A keyboard consisting of a number of keys, a fault detection information storage unit that stores information on fault voltage detection, a RAM unit that stores relay system information (correction values), a computer, and a SCADA Communication module for the communication connection with the system, the CPU electrically connected, the display showing the operating status of the device by the number or letters, and the function to connect the power supply to operate each driver according to the selected function Analog filter for filtering harmonics mixed in the relay output and input signal, and A / D for converting continuous analog signals into coded digital It is characterized by connecting the converter to the CPU in an electrical combination.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exemplary view showing the appearance of the digital ground fault overvoltage relay of the present invention, Figure 2 is an internal configuration of the digital ground overvoltage relay to which the present invention is applied.

As shown in FIG. 1, the external voltage (1) configuration of the inventive digital voltage relay is a large display for viewing various types of information of the relay, and the power and relay fail (10) of the relay, which is a relay output unit, is shown in FIG. (13), CPU error (24), forward seat 11, one seat 12, DC Power Fail (20), when the alarm occurs, LED is used to visually inform with the display.

In addition, as a keyboard part that can freely set the relay's correction values as a key signal, MENU (15), UP (18), DOWN (17), SET (19), SEL (16), and CPU Reset (25). ), Target Reset key (21) (22), etc., 25 is a short-range communication port having a function of connecting the computer as a RS-232 communication port and the failure analysis and correction of the relay operation value.

On the other hand, the self-diagnosis function displays various statuses and errors of the device. Alarms are provided through the display as numerical values and characters, and the error is displayed only when malfunctions are returned. In addition, it is desirable to have a WATCH DOG function in order to increase the safety and reliability of the system.

FIG. 2 is a diagram illustrating the internal configuration of FIG. 1, and reference numeral 48 denotes an analog input unit (AI). Since a calculation algorithm of the relay is based on a sine wave of a power system fundamental frequency (60 Hz), frequency components other than the sine wave are input. If it is included in the waveform, an error occurs in the calculation result and it is difficult to accurately determine the failure. Therefore, an analog filter is used to cut off some frequencies except the sine wave.

47 is an A / D converter that converts an input analog signal into a digital signal. This relay uses a 16-bit A / D converter. In the sample hold circuit inside the A / D converter, analog filter is used. Sample the output analog value at regular time interval and read the line voltage.

49 is a digital input unit (DI) for inputting external contact information. When the contact information input is activated as a "ON" signal, a constant DC voltage is supplied. The input signal is duplicated digital information. It is supplied to the relay algorithm described later.

The 50 is a digital output and consists of 6 channels isolated by photocouplers. One DO output is 30A / 24V excitation relay for trip output and the other five DO outputs are alarm output, one-sheet alarm, forward seat alarm, relay fail. It is composed of 5A / 24V excitation relay for power fail.

34, 51, and 52 are external displays and key input units, and have the same configuration as described in FIG. 1, but have a large-capacity liquid crystal panel and are designed to easily read various numerical values and correction values. It is equipped for easy operation while watching the display.

A is a program memory unit, which is connected to a 32-bit data bus by using two high-speed 16-bit SRAMs 38, and uses command code data or table data by using one 8-bit flash memory 39 for storing data. Used for storage. The data of the flash memory 39 is used after being moved to the SRAM area by a boot operation or the like.

In addition, it is another memory in which data is retained by data backup even when the power is off, and is connected to a 16-bit data bus using two high-speed 8-bit SRAMs 37.

B is a communication control unit, which controls two communication methods such as two-channel type RS-232 (44) and RS-485 (43) as a communication device, and RS-485 communication (43) is a network for DNP communication (SCADA system). 45) It turns on / off the relay in case of overvoltage accident and trip according to the received command, and 44 has RS-232 communication for external and remote communication function to read or store all the information of this relay using a computer. have. In particular, it reads FAULT RECODER information of this relay and enables accurate failure cause identification and analysis using the failure analysis program of this relay.

The digital arithmetic processing unit (CPU) uses a 32-bit floating-point DSP 35 operating in 400MHZ clicks with a central processing unit, and a CPU that stores the CPU and its operation procedure (PROGRAM). A / D conversion data from the analog input unit and RAM for temporarily storing data are connected to each other by a line for transmitting data control information such as a bus. Here, as the input signal, a system voltage, a state signal of a peripheral circuit, a correction value, and the like are received, and relay operation processing is performed, and the result is output to a memory unit or an output unit.

Unexplained reference numeral 40 denotes a decoder circuit, and 32 denotes a real-time clock part. Therefore, the date and time must be calculated and maintained even when the power is turned off. Therefore, it is preferable to use the backup power of the battery backup circuit in the same manner as the RAM. Do.

The digital ground overvoltage relay of the present invention configured as described above has a number of functions. Firstly, the ground fault overvoltage relay operates at the image voltage generated when the ground fault of AC occurs. It is available. Here, it is a matter of course that the user can operate through various keyboard keys with a constant instantaneous and time-limited operation correction range.

Second, the automatic constant monitoring function is provided to monitor the abnormality of the relay. The monitoring range includes CPU, memory (ROM, RAM) and correction unit, digital signal input / output unit, A / D conversion unit, power circuit. do.

Third, it monitors the state change with respect to the digital input of the external information contact signal and converts it to the data desired by the user for various events, and when the event state changes, the corresponding data including time information is used as the communication device. send. The monitoring elements include ground overvoltage protection (instantaneous / temporary) and relay fail. In particular, a value obtained by converting an analog signal obtained from a power facility into a digital signal should be transmitted. The measurement element is a ground voltage.

Fourth, the relay is provided with a record for storing the fault record in case of system failure, in which case the newest record is deleted and the new record is stored. The relay must be able to store more than a certain number of fault records for fault analysis, and the minimum length of each fault record is at least 1 second. The fault record contains all analog and digital inputs and outputs for the relay. If the power supply of the relay is interrupted, the fault data stored in case of failure should be kept for a minimum period of time from the point of interruption of the DC supply, and the relay correction values, etc., are not permanently changed. Here, the software for fault analysis can be installed in a personal computer or HMI device for fault analysis, harmonic analysis of analog signals, voltage and current magnitude and phase analysis (including before and after breakdown), relay element operation time analysis, and various Includes the ability to convert event records, relay failures, and fault records to Comtrade files.

Fifth, it has HMI and telecommunication function. It can be used by directly connecting RS-232C to relay status, fault data acquisition, analysis and correction using a portable PC, and relay period through RS-485 port. It can be used for interlock application through.

The above description is only one embodiment of the present invention and can be changed and modified as much as possible within the scope of the present invention.

As described above, the present invention operates on an image voltage generated in a ground fault, and can be used for instantaneous and timed operation functions, alarms, and trips, as well as monitoring the abnormality of the relay at all times.

In addition, the relay self-diagnosis function, FAULT RECODER function to store the detected fault voltage, communication function with SCADA system, RS-232 communication function for computer control and failure analysis of the relay internal system at a short distance, relay Built-in test function provides convenience of interlock test. Even if the power supply for the relay control is temporarily cut off, the relay memorizes the correction value and current time, and if the power is normalized, the protection mission before power failure occurs without human intervention. Can be done.

In particular, with the introduction of the Human Machine Interface (HMI) function, the user's convenience is further improved compared to the conventional technology, and digital signal processing technology improves the reliability of the measurement and protection mission much more accurately than the existing relay.

Claims (1)

Digital ground voltage relay that operates on video voltage generated when a ground fault occurs and can be used for alarms and trips, and employs an analog filter to cut off some frequencies except sinusoids. A / D converter that converts analog signal to digital signal, and analog input unit (AI) that samples line voltage by sampling the analog value output from analog filter at a certain time interval in the sample hold circuit inside this A / D converter. And A / D conversion units 47 and 48, A digital input unit 49 for inputting contact information by supplying a constant DC voltage when the contact information input is activated as a contact activated by an "ON" signal, It is composed of 6 channels insulated by photocoupler, one DO output is 30A / 24V excitation relay for trip output and the other five DO outputs are alarm output, one seat alarm, pure seat alarm, relay fail, 5A for power fail Digital output unit 50 composed of / 24V excitation relay, A large-capacity liquid crystal panel is adopted to design various readings and corrections, and the KEY operation is provided with an external display and key input unit 34, 51, 52 for easy operation while looking at the upper display. It is composed of ROM embedded in the CPU which stores the operation procedure through the input unit, A / D conversion data in the analog input unit, RAM which temporarily stores the data, and the like. A CPU 35 which receives a state signal, a correction value, etc. of a peripheral circuit, executes relay arithmetic processing, and outputs the result to a memory unit or an output unit; It uses two high-speed 16Bit SRAMs connected to a 32-bit data bus and uses one 8-bit flash memory for data storage to store command code data or table data. A program memory section A having another memory for storing data by RS-485 communication performs DNP communication in SCADA system through network, and relays on / off in case of overvoltage accident and trip occurrence according to received command, and it is equipped with remote communication function through RS-232 communication to relay information using computer. Digital ground overvoltage relay, characterized in that consisting of a communication control unit (B) that can read or store all.