Variable Frequency Series Resonance Test Wiring Diagram and Test Procedure

 Variable frequency series resonance integrates voltage regulation, frequency regulation, control, and protection functions, effectively solving the constraints on field testing caused by insufficient power supply capacity. Below,Guodian Zhongxing introduces the wiring and steps for the variable frequency series resonance test.

I. Variable Frequency Series Resonance Test Wiring

The test wiring is shown in the figure below:

FC - Variable frequency power supply; T - Excitation transformer; L - Resonant reactor; CX - Test object; C1, C2 - High and low voltage arm capacitors of the capacitive voltage divider

II. Variable Frequency Series Resonance Test Procedure

1. Reasonably arrange the test equipment and check whether the resonant reactor is placed stably. Ground the excitation transformer, resonant reactor, the enclosure of the test object, and the grounding terminal of the voltage divider.

2. Before the test, measure the insulation resistance of the test object, then wire according to the diagram, and check the wiring and the gear of the voltage divider.

3. Check that the capacity of the test power supply meets the test requirements. First close the test power switch, then close the control power and working power switches of the variable frequency power supply. After stabilization, close the main circuit switch of the variable frequency power supply, and set the protection voltage to 1.1 to 1.2 times the test voltage.

4. Start boosting the voltage, which must be increased uniformly from zero at the specified rate. First rotate the voltage adjustment button to adjust the output power ratio to 2% or 3-5% of the test voltage. Then rotate the frequency adjustment button to change the system frequency, and observe the values of the excitation voltage and the test voltage. When the excitation voltage is at its minimum and the test voltage is at its maximum, this frequency is the resonant frequency of the system.

5. After the system resonates, uniformly adjust the voltage to the test voltage as required. During the voltage increase, closely monitor the high-voltage circuit and listen for any abnormal sounds from the test object. After the test duration is reached, reduce the voltage to zero, cut off the main circuit, control circuit, and working power switches, open the test power switch, discharge the test object, and the test is completed.