HXKC Capacity-adjusting Arc Suppression Coil Intelligent Compensation Device

1. Product overview

The HXKC capacitance-adjusting arc suppression coil intelligent compensation device developed by our company adopts the principle of transformer and impedance transformation. The arc suppression coil is equipped with a secondary winding, and at the same time, a capacitor controlled by a thyristor (or vacuum switch) is connected in parallel to the secondary winding. Group, adjust the inductance current of the primary side of the arc suppression coil by adjusting the size of the parallel capacitance of the secondary winding, that is, adjust the compensation current when the power supply system is single-phase grounded.

The device uses an imported industrial computer as the acquisition control core, and the data acquisition device uses a high-precision (16-bit) chip to ensure data acquisition and control accuracy. At the same time, the device has the characteristics of fast adjustment speed, wide adjustment range, small residual current, etc., and has extremely high anti-interference ability.

The device has a built-in grounding line selection module, and adopts the residual current adjustment method to select the ground fault line. The line selection is fast and accurate, which solves the problem of low accuracy of single-phase grounding fault line selection in the power supply system.

2. Performance characteristics

1. The controller adopts industrial computer system, which is stable and reliable in operation and strong in anti-interference ability;

2. It adopts color liquid crystal display in Chinese, parameter display, setting and query are convenient and intuitive;

3. Accurate adjustment, fast speed, and wide adjustment range, which can be adjusted in the full range of 0~100% rated current;

4. The built-in high-voltage grounding line selection module adopts the residual current adjustment method to make line selection fast and accurate;

5. Equipped with RS232 and RS485 communication interfaces, which can realize the communication with the upper computer and achieve the long-distance signal transmission;

6. It has dual functions of automatic control and manual control;

7. Alarm display can be realized;

8. No harmonic pollution to the power grid;

9. With grounding information printing function (printer is optional);

10. It has the function of one controller to control two arc suppression coils.

3. Technical parameters

 1. Voltage level: 6kV~66kV;

2. Capacitance current measurement error: less than 2%;

3. Number of adjustable gears: 16 gears/32 gears;

4. Gear shift time: less than 20ms;

5. Ground residual current: less than 2A;

6. Controller power supply: 220V 50Hz;

7. Number of selected routes: less than 42 routes;

8. Communication interface: RS232/RS485.

4. Working principle

The arc suppression coil is an adjustable inductance coil installed at the neutral point of the distribution network. When a single-phase grounding fault occurs in the power grid, the function of the arc suppression coil is to provide an inductive current to compensate for the capacitive current of the single-phase grounding and make the capacitance The current is reduced to below the specified value; at the same time, the voltage recovery speed at both ends of the fault phase grounding arc is reduced, and the purpose of automatically extinguishing the arc is achieved.

This complete set of devices is a capacity-adjustable arc suppression coil device. First, according to the operation mode and development of the system, determine the rated capacity of the arc suppression coil under over-compensation conditions to determine the inductive current that can be provided in the event of a ground fault. Add an arc suppression coil secondary capacitor load winding, and at the same time connect several (usually four to five) low-voltage capacitors in parallel to the arc suppression coil secondary winding, and adjust the arc suppression by controlling the input capacitance of the secondary capacitor through the controller The magnitude of the secondary capacitive reactance of the coil, thereby changing the magnitude of the inductance current on the primary side of the arc suppression coil.

The outstanding feature of this device is that its grounding line selection accuracy rate is very high, and the residual current adjustment method is used to judge the line selection when the ground fault occurs. Its working principle is to adjust the compensation current of the arc suppression coil when a ground fault occurs (that is, adjust the residual current). ), by collecting and comparing the changes in the zero sequence current of each line to determine the grounding line.

5. Device composition

(1) Microcomputer control screen

The function of the microcomputer control panel is to collect and process the Uº, Uab, and neutral point current Iº from the voltage transformer in real time, and the zero sequence current of each high-voltage line, so as to calculate the value of the capacitance current to be compensated, thereby determining the capacitance The capacitor bank of the regulating cabinet is in an ideal compensation position. When a ground fault occurs, the capacitor current is first quickly compensated and alarmed, and the residual current is adjusted after the system is stable. The grounding line is selected by comparing the changes in the zero sequence current of each line.

The controller in the control panel adopts an imported industrial computer (PC104) as the host, and the circuit board design adopts a multi-layer board structure, which has strong anti-interference ability and is suitable for harsh industrial environments. The controller acquisition device uses a high-precision 16-bit AD chip with high resolution, thus ensuring the measurement and control accuracy of the device.

The standard size of the control panel is 2260mmx800mm×600mm, and two controllers can be installed on one control panel. In addition to the controller, the control panel is also equipped with low-voltage electrical appliances such as ammeters, voltmeters and various relays. The control panel is equipped with wiring terminals for grounding compensation and line selection. For details, please refer to the company's "HXK Series Arc Suppression Coil Intelligent Compensation Device" manual and the company's supporting drawings.

(2) Capacitor adjustment cabinet

The capacitance adjustment cabinet is composed of capacitors, thyristors (or vacuum switches) and so on. The controller automatically tracks and adjusts the capacity of the secondary side capacitor according to the sampling of the grid-to-ground capacitive current, thereby automatically compensating for the single-phase ground current of the system.

There are several capacitors in the capacitor control cabinet, and the capacity configuration ratio is: C1 C2 C3 C4 C5=1 2 4 8 16. According to the principle of binary combination, 4 capacitors have 16 combinations, that is, 16-speed adjustment is achieved; 5 capacitors have 32 combinations, that is, 32-speed adjustment is achieved. The adjustment switch adopts thyristor (or vacuum switch), and the adjustment speed is fast. The capacitor is a self-healing capacitor with a rated voltage of 1000V.

External dimensions of the capacitor control cabinet: 1400mm×800mmx600mm

(3) Grounding transformer

The arc suppression coil system must have a power neutral point when it is connected, and the arc suppression coil should be connected to the neutral point. The function of the grounding transformer is to use the grounding transformer to construct the neutral point of the system when the neutral point of the power system is delta-type wiring or Y-type wiring is not drawn. The grounding transformer can also carry a secondary load.

The capacity of the grounding transformer is selected. When the grounding transformer has no electric load, the capacity is equal to the capacity of the arc suppression coil; when the grounding transformer has an electric load, the capacity is equal to the sum of the arc suppression coil and the electric load.

Grounding transformers are divided into oil-immersed type and resin-insulated dry type.

(4) Adjustable capacitance type arc suppression coil

The arc suppression coil is a kind of adjustable reactor connected between the neutral point and the ground. Its function is to compensate the single-phase grounding capacitive current (inductance current) of the power supply system when a single-phase grounding fault occurs. Reduce the ground fault current and eliminate the effect of arc grounding.

The difference between the capacity-adjustable arc suppression coil and the ordinary arc suppression coil is that a secondary capacitor load winding is added to the arc suppression coil. Connect several groups of capacitors with thyristor (or vacuum switch) on and off in parallel on the secondary side to adjust the capacitive reactance value of the secondary side capacitance. According to the impedance conversion principle, adjusting the capacitance of the secondary side can meet the requirement of changing the inductor current on the primary side. There are many different permutations and combinations for the size and number of capacitors to meet the requirements of adjustment range and accuracy.

The capacity-adjustable arc suppression coil is divided into oil-immersed and insulated resin dry arc suppression coils.

Yichang Hengyuan Technology Co., Ltd. is a professional manufacturer of European-style cable connectors, plug connectors, cable branch boxes, American elbows, high-voltage vacuum circuit breakers, high-voltage load switches, lightning arresters, zinc oxide arresters, tank arresters, overvoltage protectors, Counters, monitors, heat-shrinkable cable accessories, cold-shrinkable cable accessories, T-shaped heads, wall bushings, European cable accessories, American cable connectors, transformer neutral point protection devices, fuses, isolation switches, PT cable heads, elbows Manufacturers of type cable joints, 10kV outdoor terminals, switch cabinets, cable intermediate joints, cable accessories and other products