HXKP Biased Arc Suppression Coil Intelligent Compensation Device

1. Product introduction

HXKP bias magnetic arc suppression coil intelligent compensation device uses additional DC excitation current to change the magnetic permeability of the iron core and realize the change of inductance. There are many types of arc suppression coils. According to the different excitation methods, they can be divided into two types: separately-excited and self-excited. The DC-biased arc suppression coil is a kind of arc suppression coil that can continuously adjust the inductance. Its interior is a fully static structure with no moving parts and high working reliability. The response speed is fast, and the inductance value can be adjusted when the arc suppression coil is subjected to high voltage. The ratio of the upper and lower limits of the compensation current can reach 6:1. The device is jointly developed with the China University of Mining and Technology, and has achieved satisfactory results since the product was put into industrial operation. The new type of bias arc suppression coil has been greatly improved in terms of structure and performance.

2. Performance characteristics

1. The adjustment accuracy is high, and the electronic control is stepless and continuously adjustable. The magnetic resistance of the iron core is changed by applying a DC excitation current, so as to achieve the purpose of continuously adjusting the reactance value of the arc suppression coil. It can adjust the inductance at a high voltage and electric speed. Value, fast response speed, compensation response time does not exceed 20ms;

2. High reliability, long service life, fully static structure, without any moving parts inside, and the whole device without any contacts;

3. Online real-time monitoring of grid voltage, neutral point voltage and current, and automatic tracking of changes in grid parameters;

4. Large adjustment range, wide adjustment range of compensation current, the ratio of upper and lower limits can be 6~10 times; dynamic compensation, no damping resistance;

5. High measurement accuracy, automatic measurement of the power grid line-to-ground capacitance current, neutral point displacement voltage, and the measurement error is less than 2%;

6. The control system has complete functions. A. It has RS232 and RS485 serial interfaces, which can communicate with the host computer, and transmit the power grid capacitance current, neutral point voltage, device self-check information in real time, and transmit compensation current after a ground fault occurs in the power grid. Current and other information; B. Automatic manual control mode switching function; C. Two units can be operated in parallel, and the capacity of the parallel arc suppression ring can be allocated reasonably to ensure the safety and reliability of the equipment; D. The capacitor current can be displayed in real time, and the residual current after compensation is available. Capacitance current recall function and ground fault recall function, with printing function.

3. Technical parameters

1. Voltage level: 6-10kV;

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

3. Ground residual current: less than 2A;

4. System frequency: 50Hz

4. Working principle

        The magnetic resistance of the iron core is changed by applying direct excitation, so as to achieve the purpose of changing the reactance value of the arc suppression coil. The device can adjust the inductance value at an electric speed with high voltage. When the power grid is operating normally, the excitation current is not applied to adjust the arc suppression to Keep away from the resonance point to avoid the possibility of series resonance over-voltage and various resonance over-voltages. When the power grid has a ground fault, Uº rises, and the microcomputer controller turns on the excitation system pulse output. The excitation current rises to the required value within 3ms, the arc suppression coil is compensated, and an alarm signal and data communication are sent out at the same time. When the fault disappears completely, it exits the excitation and returns to the original state. The microcomputer controller conducts self-inspection regularly, and then conducts self-inspection on the entire dynamic compensation system to ensure the normal operation of the compensation system. If there is a failure, an alarm signal will be issued.

5. Device composition

The device is composed of a microcomputer control panel, a grounding transformer, an excitation power supply system, and an arc suppression coil.

1. Microcomputer control panel: The microcomputer control panel is the core control component of the whole set of equipment. It collects and processes the Uº, Uab and neutral point current Iº of the entire power supply system and the zero sequence current of each high-voltage outlet in real time, so as to calculate the compensation The value of the capacitor current controls the working state of the arc suppression coil and waits for the occurrence of a ground fault. When a ground fault occurs in the power grid, Uº rises, and the microcomputer controller turns on the pulse output of the excitation system. The excitation current rises to the required value within 3ms, the arc suppression coil is compensated, and an alarm signal and data communication are sent out at the same time. When the fault disappears completely, it exits the excitation and returns to the original state. The external dimensions of the microcomputer control panel is the same as that of the volume-adjusting device control panel. For the hardware structure and detailed information, please refer to the instruction manual of our company "HXK Series Arc Suppression Coil Intelligent Compensation Device".

2. Grounding transformer: the grounding transformer is the same as the grounding transformer in the capacitive arc suppression coil device.

3. Excitation power supply system: The structure of the excitation power supply system has its main circuit composed of a power transformer, a silicon controlled full-wave bridge rectifier circuit, a fast fuse, a shunt and a resistance-capacitance protection circuit; the control circuit is triggered by a synchronous transformer and a full-wave rectifier It consists of pulse forming circuit, pulse amplifying circuit, regulator, low-pass filter, amplifier and Hall current sensor. The excitation pulse signal is sent by the microcomputer controller. The design capacity of the power transformer is 2-3 times larger than the magnetization capacity required by the bias arc suppression coil, which greatly improves the excitation current response speed. The measured results show that the excitation current rises from 0 to 75A, and the time is less than 3ms. The excitation current adopts a closed loop. After control, its magnitude corresponds linearly to the given voltage Ur, and after calibration, Ur represents the magnitude of the excitation current.

4. Magnetic-biased arc suppression coil: The magnetic-biased arc suppression coil is an electronically controlled stepless and continuously adjustable arc suppression coil with a fully static structure. There are no moving parts inside. The arc suppression coil uses the excitation power system to apply a DC excitation current to the arc suppression coil to change the magnetic resistance of the iron core, thereby achieving the purpose of changing the reactance value of the arc suppression coil.

Biased arc suppression coils are divided into two types: oil-immersed and insulated dry-type.

6. System wiring and overall dimension layout installation of complete equipment

For the system wiring and overall dimensions of the complete set of equipment, please refer to the instruction manual of our company "HXK Arc Suppression Coil Intelligent Compensation Device".

    7. Device installation form 

8. Ordering instructions

      When placing an order, the user needs to provide the following parameters:

      1. Voltage level, grounding transformer capacity, current adjustment range;

      2. Control mode: capacity adjustment type, turn adjustment type or magnetic bias type, arc suppression coil capacity;

      3. The type of arc suppression coil and grounding transformer, dry or oil-immersed, with line selection function, determine the number of zero-sequence current transformers;

      4. Device installation type: outdoor or indoor, combined box type or decentralized type.