The series resonance test device is divided into frequency modulation and inductance modulation types, generally consisting of a variable frequency power supply, excitation transformer, reactor, and capacitive voltage divider. The tested product is connected in series resonance with the capacitor of the reactor, and the voltage divider is connected in parallel with the tested product to measure the resonance voltage on the tested product and generate an overvoltage protection signal.
In a series circuit composed of resistors, inductors, and capacitors, when the capacitance reactance xc is equal to the inductance xl, i.e. xc=xl, the voltage u and current i in the circuit are the same, and the circuit behaves as a resistor. This phenomenon is called series resonance; When a series resonance occurs in the circuit, the impedance Z=R ^ 2 (XC-XL) ^ 2 ≤ R, the total impedance is minimized, and the current reaches its maximum value.
The series resonance test device has the following technical advantages:
(1) The series resonance test device has overvoltage, overcurrent, zero start, system detuning (flashover), segmented voltage output, independent preset test time for each voltage segment, 7-inch true color touch screen, real-time printing and data storage, output circuit with contactor, touch output line without triggering the safety of electric parking, eliminating safety hazards.
(2) Overvoltage, overcurrent, any preset time, standard sine wave output, frequency output range of 30 ≤ 300 Hz, fast response of flashover protection.
(3) Wide voltage range input, wide frequency input, 50 Hz frequency adaptive. The generator and industrial power supply can work normally.
(4) Fully automatic working mode.
(5) One variable frequency power supply can simultaneously control the output of multiple variable frequency power supplies, and only one of them needs to be operated. Customers can purchase a small capacity set first, and if it is not enough, they can purchase multiple sets for parallel use later. The price is favorable and the use is more flexible.
(6) The capacity demand for cables of 110 kV and above is relatively high. Musen Electric adopts hollow core reactors, multiple series parallel replacement methods, how many series parallel modes are required, one person operation, easy disassembly and assembly, and mobility, solving the problems of weight and utilization.
The series resonance test device is suitable for AC withstand voltage testing of 10kV, 35kV, 110kV, 220kV, and 500kV polyethylene cross-linked power cables, AC withstand voltage testing of GIS (fully enclosed insulated substation), handover and preventive testing of large capacity high-voltage capacitive testing products, and power frequency withstand testing. Voltage testing of large transformers and generator sets, induction withstand voltage testing of power transformers.