CN106896290A - A kind of substation's electricity consumption leak current fault detection means - Google Patents

Abstract

An electric leakage fault detection device used in a substation, comprising a phase voltage sensor, a phase voltage signal sampling circuit, a phase voltage A/D circuit, a phase current sensor, a phase current signal sampling circuit, a phase current A/D circuit, Leakage current sensor, total leakage current sampling circuit, total leakage current A/D circuit, feeder leakage current sensor, feeder leakage current sampling circuit, feeder leakage current A/D circuit, CPU, keyboard circuit, communication circuit, data storage circuit, Alarm circuit, liquid crystal display, pairing terminals, device power supply; real-time monitoring of electric leakage fault detection used in substations, realizing online fault location and clear fault point.

Description

An electric leakage fault detection device used in a substation

technical field

The invention belongs to the field of substation equipment monitoring devices, in particular to a device for detecting electric leakage faults used in substations.

Background technique

The substation of the power system concentrates various power equipment and is the most important link and place of the power transmission and transformation network. Power transmission, current and voltage conversion, and control of power transmission and blackout are all completed by substations. The electricity used in the substation is mainly for the lighting of the substation, the power supply of the main transformer cooler system, the energy storage of the circuit breaker, the dehumidification and heating of outdoor equipment, the air conditioner in the control room, the power supply of the charging device of the DC system, the maintenance power supply, and the production and domestic electricity of the substation. Therefore, the electricity used in the substation has a wide range of power supply, many electrical equipment, and many power supply links. The electricity used in the substation is used in all aspects of the substation, especially the electricity used by the cooling system of the main transformer. The failure of the electricity used will pose an important danger to the safety of the power system. In order to improve the safety of the power supply used in the substation, the substation is powered by two transformers installed to ensure the reliability of power consumption. Due to dust, pollution, heat generation, insulator flashover, miswiring, disconnection and other reasons of long-term electrified operation, the leakage of electricity used in substations must be caused. In order to improve the reliability of the electricity used in the substation, leakage protection switches are only added to the terminals of the electricity used in the substation. Many circuits have leakage faults, and ground faults are determined by workers' trial pull and trial stop. At present, there is no automatic The device for locating the leakage fault of the electric circuit used seriously affects the work efficiency.

Contents of the invention

Aiming at possible leakage faults of electricity used in substations, and real-time monitoring of the operation status and leakage fault information of the electric feeder circuit used, the present invention provides a detection device specially for the leakage faults of electricity used in substations.

The technical scheme adopted in the present invention:

An electric leakage fault detection device used in a substation is characterized in that it includes a phase voltage sensor, a phase voltage signal sampling circuit, a phase voltage A/D circuit, a phase current sensor, a phase current signal sampling circuit, a phase current A/D circuit, Total leakage current sensor, total leakage current sampling circuit, total leakage current A/D circuit, feeder leakage current sensor, feeder leakage current sampling circuit, feeder leakage current A/D circuit, CPU, keyboard circuit, communication circuit, data Storage circuit, alarm circuit, liquid crystal display, connecting terminal, device power supply; phase voltage sensor and phase voltage signal sampling circuit are connected in series, and then connected to phase voltage A/D circuit; phase current sensor and phase current signal sampling circuit are connected in phase connected in series, and then connected to the phase current A/D circuit; the total leakage current sensor used is connected to the total leakage current sampling circuit, and then connected to the total leakage current A/D circuit; the feeder leakage current sensor is connected to the leakage current sampling circuit in phase Then connect to the feeder leakage current A/D circuit; the four A/D circuit outputs are connected to the CPU input; the CPU output is connected to the alarm circuit; the CPU input is connected to the data storage circuit; the CPU output is connected to the LCD display Connected; the phase current sensor is connected in series to the output circuit of the electricity used, the phase voltage sensor is connected in parallel to the total output A, B, and C three-phase electricity of the electricity used by the substation, and the voltage and current signals of the three-phase electricity used are passed through the phase current The sampling circuit and the phase voltage signal sampling circuit are converted and sent to each corresponding A/D circuit; the total leakage current sensor of the electricity used is installed on the power transmission cable of the total output terminal of the electricity used or the switch cabinet, and the total leakage current sampling circuit samples and After conversion, the total leakage current is sent to the A/D circuit; the feeder leakage current sensor is installed on each output feeder of the electricity used, and the signal of the leakage current sensor of each feeder is sent to the leakage current sampling circuit for monitoring, and the leakage current sampling circuit performs 0- The 5V voltage is converted and sent to the feeder leakage current A/D circuit; the four A/D circuits complete the conversion of the information and data of each sampling circuit, and then the digital signal is sent to the CPU for processing, and the CPU converts various parameters and the set parameters Comparing and calculating, the CPU completes the measured signal through the keyboard circuit through the communication interface circuit and substation monitoring communication to realize the receiving and sending of TCP/UDP messages in the substation. When an alarm fault occurs, it is output by the alarm circuit, and the measured data is stored with the data. On the storage circuit, all parameter signals measured by the CPU, alarm signals, and information of each feeder circuit are displayed through the liquid crystal display circuit.

The electrical leakage fault detection device used in a substation is further characterized in that it adopts a unit plug-in structure, which consists of a display panel, a main CPU control board, a current and voltage sampling board, a total leakage current sampling board, a feeder leakage current sampling board, The wiring board consists of 6 circuit boards; the display panel includes: LCD screen, keyboard circuit; the main CPU control board includes: CPU, storage current, ventilation current, alarm circuit; the current and voltage sampling board includes: phase voltage signal sampling circuit, Phase voltage signal A/D circuit, phase current signal sampling circuit, phase current A/D circuit; total leakage current sampling board includes: total leakage current sampling circuit of electricity used, total leakage current A/D sampling current; feeder leakage current sampling The board includes: feeder leakage current sampling circuit, feeder leakage current A/D circuit; after wiring, the board includes: phase voltage sensor and phase voltage sampling circuit terminal, phase current sensor and current signal sampling circuit. The connection terminals for the total leakage current sensor and the total leakage current sampling circuit, the connection terminals for the feeder leakage current sensor and the feeder leakage current sampling circuit, the connection terminals for the external communication of the communication circuit, and the connection terminals for the external alarm of the alarm circuit.

The electric leakage fault detection device used in a substation adopts multiple A/D sampling converters, the measurement can be carried out simultaneously, and an alarm circuit and a communication circuit are externally provided, and actions, alarms, abnormalities, voltages and currents can be uploaded to the outside Information such as measurement: the beneficial effect of the present invention lies in.

The device has a simple structure, high integration, multiple A/D sampling, will not interfere with each other and realizes the same field sampling, and has the characteristics of high precision and fast response.

The device has storage, memory, alarm output, data TCP/UDP transmission, upper computer data information upload, and has strong environmental adaptability.

The unit plug-in structure is adopted, the device is easy to debug, the fault maintenance is simple, the rear panel wiring is clear, and the independent logic processing is simple and efficient.

Description of drawings

Fig. 1 is a block diagram of the working principle of the circuit of the present invention.

Fig. 2 is a schematic diagram of the overall structure of the present invention.

detailed description

Below in conjunction with accompanying drawing and embodiment case, the present invention will be further described

As shown in Figure 1, an electric leakage fault detection device used in a substation is characterized in that it includes a phase voltage sensor, a phase voltage signal sampling circuit, a phase voltage A/D circuit, a phase current sensor, a phase current signal sampling circuit, a phase Current A/D circuit, total leakage current sensor used, total leakage current sampling circuit, total leakage current A/D circuit, feeder leakage current sensor, feeder leakage current sampling circuit, feeder leakage current A/D circuit, CPU, keyboard circuit, communication circuit, data storage circuit, alarm circuit, liquid crystal display, connecting terminal, device power supply; the phase voltage sensor and the phase voltage signal sampling circuit are connected in series, and then connected to the phase voltage A/D circuit; the phase current sensor and The phase current signal sampling loop is connected in series, and then connected to the phase current A/D circuit; the total leakage current sensor used is connected to the total leakage current sampling circuit, and then connected to the total leakage current A/D circuit; the feeder leakage current sensor It is connected with the leakage current sampling circuit, and then connected with the feeder leakage current A/D circuit; the output of the four A/D circuits is connected with the CPU input; the CPU output is connected with the alarm circuit; the CPU input is connected with the data storage circuit; The CPU output is connected to the LCD display; the phase current sensor is connected in series to the output circuit of the electricity used, and the phase voltage sensor is connected in parallel to the total output of the electricity used by the substation A, B, C three-phase electricity, the voltage of the three-phase electricity used , The current signal is sent to each corresponding A/D circuit after being converted by the phase current sampling circuit and the phase voltage signal sampling circuit; The leakage current sampling circuit samples and converts the total leakage current to the A/D circuit; the feeder leakage current sensor is installed on each output feeder of the electricity used, and the signal of the leakage current sensor of each feeder is sent to the leakage current sampling circuit for monitoring. The current sampling circuit converts the voltage of 0-5V and sends it to the feeder leakage current A/D circuit; the four A/D circuits complete the conversion of the information and data of each sampling circuit and send the digital signal to the CPU for processing. The parameters are compared and calculated with the set parameters, and the measured signal is completed by the CPU through the keyboard circuit through the communication interface circuit and the substation monitoring communication to realize the receiving and sending of the TCP/UDP message of the substation. When an alarm fault occurs, the alarm circuit outputs and measures On the data storage and data storage circuit, all the parameter signals measured by the CPU, the alarm signal, and the information of each feeder circuit are displayed through the liquid crystal display circuit.

The number of on-site feeder loops determines the number of feeder leakage current sensors. When there is a leakage current in a certain feeder, the total leakage current sensor installed on the output end of the electricity used or the output cable of the switch cabinet will sense the leakage current of the current used. The leakage current of electricity consumption; the signals sampled by each leakage current sensor installed in each branch feeder circuit can be calculated by the feeder leakage current sampling circuit to obtain the leakage current status information of each branch circuit, and all the measured information is stored in the CPU. Under the calculation, it is displayed through the liquid crystal display value; the communication circuit uploads the data including: total leakage current, each phase voltage, current, each feeder current and other information, and the alarm circuit outputs signals through the dry contact circuit and the contact relay. The management personnel just can be clear which route loop has gone out the electric leakage fault.

The phase voltage sensor adopts the N100 core-type current transformer produced by Shaanxi Yixing Electric Co., Ltd., and the phase current is installed through the open type through the core, and there is no need for power failure. The installation is convenient and the original wiring needs to be changed from time to time, which is safe, reliable and convenient.

The total leakage current sensor and the leakage current sensor of each feeder adopt passive zero-sequence current sensors, which are set outside the insulation layer of the output terminal of the power used or the output cable of the switch cabinet. Certainly, the open installation does not require a power outage.

The chip of current signal sampling circuit, voltage signal sampling circuit, total leakage current sampling circuit and feeder leakage current sampling circuit adopts LF412, and each voltage and current signal is converted into 0-5V voltage signal and sent to A/D circuit;

The main chip of each A/D circuit uses MC14433, which is a 13-bit A/D converter produced by American AD Company.

The chip used in the CPU circuit is a 32-bit single-chip microcomputer of the FT 430 type produced by the American INTEL company. It has 4 address interfaces, has the characteristics of good stability, and is easy to use, and is cheap and high-quality.

The keyboard circuit is equipped with 6 keys such as reset, up, down, left, right, and OK. It can be operated according to on-site reading data and on-site parameter setting.

The communication circuit is composed of two independent interfaces, RS232 and RS485, and the software adopts the MOBUS protocol for users to choose.

The data storage circuit has a 1024-bit data storage, which records the fault circuit, and the alarm information can be read at any time.

The liquid crystal display is provided by Shenzhen Huaxin Company, the model is FL320X240, which can display data parameters and circuit status information and fault information in real time.

The external wiring terminal adopts T 5.8 wiring terminal, and all the wiring from each current sensor to the host machine passes through this interface, which realizes the characteristics of simple wiring and convenient engineering installation.

As shown in Figure 2, an electric leakage fault detection device used in a substation is also characterized in that it adopts a unit plug-in structure, and consists of a display panel, a main CPU control board, a current and voltage sampling board, a total leakage current sampling board, and a feeder leakage current The sampling board and wiring board are composed of 6 circuit boards; the display panel includes: LCD screen, keyboard circuit; the main CPU control board includes: CPU, storage current, ventilation current, alarm circuit; the current and voltage sampling board includes: phase voltage signal Sampling circuit, phase voltage signal A/D circuit, phase current signal sampling circuit, phase current A/D circuit; total leakage current sampling board includes: total leakage current sampling circuit of electricity used, total leakage current A/D sampling current; feeder Leakage current sampling board includes: feeder leakage current sampling circuit, feeder leakage current A/D circuit; after wiring, the board includes: phase voltage sensor and phase voltage sampling circuit terminal, phase current sensor and current signal sampling circuit connection terminal, The connection terminals for the total leakage current sensor of the electricity used and the total leakage current sampling circuit, the connection terminals for the feeder leakage current sensor and the feeder leakage current sampling circuit, the connection terminals for the external communication of the communication circuit, and the connection terminals for the external alarm of the alarm circuit.

The electric leakage fault detection device used in a substation adopts multiple A/D sampling converters, the measurement can be carried out simultaneously, and an alarm circuit and a communication circuit are externally provided, and actions, alarms, abnormalities, voltages and currents can be uploaded to the outside measurement and other information.

Claims (2)

1. A kind of electrical leakage fault detection device used in substation, it is characterized in that: comprise phase voltage sensor, phase voltage signal sampling circuit, phase voltage A/D circuit, phase current sensor, phase current signal sampling circuit, phase current A/D Circuit, total leakage current sensor, total leakage current sampling circuit, total leakage current A/D circuit, feeder leakage current sensor, feeder leakage current sampling circuit, feeder leakage current A/D circuit, CPU, keyboard circuit, communication circuit , data storage circuit, alarm circuit, liquid crystal display, connecting terminal, device power supply; phase voltage sensor and phase voltage signal sampling circuit are connected in series, and then connected to phase voltage A/D circuit; phase current sensor and phase current signal sampling The loop phases are connected in series, and then connected to the phase current A/D circuit; the total leakage current sensor used is connected to the total leakage current sampling circuit, and then connected to the total leakage current A/D circuit; the feeder leakage current sensor and leakage current sampling The circuit is connected, and then connected to the leakage current A/D circuit of the feeder; the output of the four A/D circuits is connected to the input of the CPU; the output of the CPU is connected to the alarm circuit; the input of the CPU is connected to the data storage circuit; the output of the CPU is connected to the LCD The monitors are connected. 2. The electrical leakage fault detection device used in a substation is characterized in that it also adopts a unit plug-in structure, which is composed of a display panel, a main CPU control board, a current and voltage sampling board, a total leakage current sampling board, and a feeder leakage current sampling board. Board and wiring board are composed of 6 circuit boards; the display panel includes: LCD screen, keyboard circuit; the main CPU control board includes: CPU, storage current, ventilation current, alarm circuit; the current and voltage sampling board includes: phase voltage signal sampling Circuit, phase voltage signal A/D circuit, phase current signal sampling circuit, phase current A/D circuit; total leakage current sampling board includes: total leakage current sampling circuit of electricity used, total leakage current A/D sampling current; feeder leakage The current sampling board includes: feeder leakage current sampling circuit, feeder leakage current A/D circuit; after wiring, the board includes: phase voltage sensor and phase voltage sampling circuit terminal, phase current sensor and current signal sampling circuit connection terminal, all The connection terminal of the total leakage current sensor of electricity consumption and the total leakage current sampling circuit, the connection terminal of the feeder leakage current sensor and the feeder leakage current sampling circuit, the connection terminal of the communication circuit for external communication, and the connection terminal of the alarm circuit for external alarm.