Variable frequency series resonant withstand voltage test device? Wuhan UHV specializes in the production of series resonance, with a wide range of product selection and professional electrical testing. To find series resonance, choose Wuhan UHV.
The variable frequency series resonant withstand voltage test device adopts the method of adjusting the frequency of the power supply to achieve resonance between the reactor and the tested capacitor, and obtain high voltage and high current on the tested object. It is a new method and trend of high voltage testing, which has been widely used at home and abroad.
Working principle of frequency conversion series resonance withstand voltage test device
Connect to AC220V or AC380V power supply, output a voltage with adjustable frequency of 30-200HZ through the frequency conversion control unit, and send it to the excitation transformer for boosting to 0-5000V. After passing through the resonant reactor L and the test sample CX, a high-voltage main harmonic circuit is formed. The capacitive voltage divider is pure capacitive and used to measure the test voltage. Firstly, the variable frequency control unit sends a lower voltage Ue to the main resonant circuit through the excitation transformer, and adjusts the output frequency of the variable frequency control unit. When the frequency meets the condition Ω L=1/Ω C, the circuit reaches the resonant state. At this time, under a smaller excitation voltage Ue, a voltage UCX several tens of times greater than Ue can be generated on the test sample CX. The resonance point is achieved by adjusting the frequency of the frequency converter to the natural frequency of the series resonant circuit. After circuit resonance, the output voltage waveform is a pure sine wave, and the frequency of the system depends on the L-C parameter of the circuit. The reactance value of the reactor is adjustable, and the frequency of the system depends on the size of the load capacitance, as shown in the above equation. The inductance L value of the reactor can be adjusted appropriately according to the size of CX, so that the resonant frequency is fixed within a required range. The variable frequency series resonant withstand voltage test device can meet the requirements for conducting AC withstand voltage tests on test samples under power frequency conditions.
The working characteristics of the variable frequency series resonance withstand voltage test device:
1. The higher the quality factor of the variable frequency series resonance withstand voltage test device, the smaller the required power capacity.
2. The resonant reactor L is in a resonant state with the tested power CX, forming a good filtering circuit. Therefore, the output voltage UCX has a good sine waveform.
3. When the tested cable of the frequency conversion series resonance withstand voltage test device breaks down, the resonance condition is lost, and the current of the high-voltage circuit and low-voltage power supply circuit decreases instead. Therefore, the arc at the insulation breakdown point will not expand the fault point, making it easier for maintenance.
Precautions for frequency conversion series resonance withstand voltage test device:
1. The frequency conversion series resonance withstand voltage test device should be used by high-voltage testing professionals. Before use, the user manual should be carefully read and repeatedly operated and trained.
2. There should be no less than 2 operators. Strictly follow the safety operation regulations of our unit regarding high-voltage testing when using it.
3. In order to ensure the safety and correctness of the test, in addition to being familiar with the product manual, it is also necessary to strictly follow the relevant national standards and regulations for the test operation.
4. Each connecting wire must not be connected incorrectly, especially the grounding wire must not be connected incorrectly. Otherwise, it may cause damage to the testing device
5. When using the frequency conversion series resonance withstand voltage test device, the output is high voltage or ultra-high voltage, and it must be reliably grounded, paying attention to operational safety.
6. When the power is turned on and the voltage still cannot be increased after returning to zero, please press the reset button for a long time (about 10 seconds) and make the indicator lights on the control box panel normal, that is, no other red lights are on except for "high voltage", and then start normal operation.