Overvoltage of distribution network is usually superimposed on the power frequency voltage

therefore

to simulate the actual overvoltage situation in the electrical power system

a test device of controllable phase for synergy of the power frequency voltage and the impulse voltage was designed. The coupling capacitor between the power frequency voltage generating circuit and impulse voltage generator can make the impulse voltage to superimpose on the power frequency voltage

and the automatic ignition device can control the phase of the power frequency voltage superimposed the impulse voltage. Moreover

the circuit principle of the device was analyzed and was simulated by using the ATP-EMTP software.The simulation results show that coupling capacitance value will affect the power frequency voltage and impulse voltage waveforms and efficiency. The experimental results show that the hardware delay time of the device is 1.4 ms

the superimposed phase of the power frequency voltage and the impulse voltage is controllable

and the superimposed waveforms are similar to the measured overvoltage waveforms which can simulate the actual overvoltage.