AC line reactor is an instrument used on the load side of the VFD, three phase input or output. The line reactor coil has good insulation performance, high overall mechanical strength and good moisture resistance. The coils are F and H insulation grades, which greatly improves the reliability of long-term operation. ATO sells line reactors at the best price, with power ranges from 2 hp to 150 hp input/output.
AC input line reactor can restrain the harmonic current, improve the power factor and weaken the impact of surge voltage and current in the input circuit, weaken the influence of the power supply voltage imbalance, use it to limit the voltage mutation of the power grid and the current impact caused by overvoltage, smooth the peak pulse contained in the voltage of the power supply, and effectively protect the frequency conversion. AC line reactor can not only prevent interference from power grid, but also reduce the pollution caused by harmonic current generated by rectifier unit.
The role of AC input reactor
The role of AC output reactor
For the industrial control automation industry, the AC reactor at the input end of the inverter can absorb the surge of the power grid and the operating overvoltage to protect the equipment behind the inverter, and at the same time suppress the power frequency harmonic current of the inverter and improve the power factor.
The rated AC current is the long-term operating current of the reactor designed from the aspect of heat generation, while sufficient high harmonic components should be considered. The current value must be greater than or equal to the rated value of the motor.
The voltage drop is the actual voltage drop across the reactor coil at 50HZ corresponding to the actual rated current. The rated voltage drop of the incoming reactor, UN is the line voltage voltage, UP is the phase voltage, and the voltage drop is usually chosen to be around 4V~8V.
Restrict the short-circuit current
When the power system has short circuit, it will generate a very high short-circuit current. In order to guarantee the dynamic stability and thermal stability of the electrical equipment, the reactor is usually connected to the outgoing breaker in series, so as to increase the short-circuit impedance and restrict the short-circuit current. Because of the application of the reactor, the voltage drop on the reactor is high in case of a short circuit. It also plays the role of maintaining the voltage of the busbar, ensuring the small voltage fluctuation of the busbar and guaranteeing the operation stability of the electrical equipment on the non-fault line.
Restrict the higher harmonic
Because a large amount of power electronic devices have been used in the power system, especially high-power DC and frequency conversion equipment, which generate plentiful harmonics, the compensating capacitor is frequently damaged, and in serious conditions, the compensating capacitor is unable to be put into operation. When the harmonic is rather low, the harmonic suppressor can be used. When the harmonic in the power system is rather higher, the reactor in series can be adopted. The higher harmonic in the power grid can be restricted through connecting the capacitor in serious or parallel in the water filter.
Reactive balance is very important in enhancing the economic benefit of the power system and improving the power supply quality. Meanwhile, it is required to conduct dynamic regulation, and provide more capacitive reactiveness in load peak, so as to satisfy the reactive demand of the industrial and mining enterprises, stabilize the system voltage. On the other hand, it should be able to provide sensible reactiveness, so as to balance the charging power of the cables in fractional loading, ensuring the not too high voltage of the system. LC series circuit constituted by the capacitor and reactor in series has the function of restraining a certain frequency harmonic. Usually, the low-voltage series reactor is used to restrain the harmonics for three, four and five times.
Arc extinguish reactor
Arc extinguish reactor is connected between the neutral point and ground of the three-phase transformer. When one phase of the three-phase power grid is connected with the ground, the induction current can be supplied, so as to compensate the capacitive current flowing through the earthing point, enabling the nonflamability of the arc, so as to avoid having overvoltage caused by the repeated ignition of the arc. The arc extinguish reactor is widely used for the resonance earthing system of 6kV~10kV.
Phase shifting function
Phase shifting means that the waveform of the AC signal fails to change as the original angle and presents an angle change. The function of phase shifting reactor is to reduce the influence of the harmonic current and voltage generated by the semiconductor converter device and non-linear load to the power supply system. It is a new method for the converter power supply system to restrain the harmonic wave. Because in the three-phase symmetrical power supply system, generally the 5th, 7th, 11th, and 13th harmonics have greater contents and more serious influence to the system, the phase shifting electric reactor is designed to weaken these harmonics.
Input line reactor is mainly used in the industrial automation control to restrain the surge voltage and current generated by the frequency converter and speed regulator, so as to decay the high-frequency and distorted harmonics in the system to the greatest extent, limit the current impact caused by power grid voltage mutation and overvoltage operation.
Output line reactor is also called as the motor reactor. It is mainly used in the industrial automation system, especially occasions with frequency converter, to extend the valid transmission distance of the frequency converter, effectively restrain the transient high voltage in switching on/off the IGBT module of the frequency converter. It is suitable for compensating the distributed capacitance, restraining the output harmonic current, effectively protecting the frequency converter and improving the power factor, with an expectation to reduce the pollution of the harmonic current generated by the rectification unit to the power grid.