By hvhipot 
The frequency conversion series resonance test device may sometimes fail due to factors such as personnel operation or equipment loss after long-term testing. Some common and simple faults of the variable frequency series resonance test device can be eliminated and repaired by comparing the following articles.
One The frequency conversion series resonance testing device cannot boost to the test voltage.
Phenomenon:
1. The tuning curve is a low peak straight line;
During the testing process, the voltage was high but the high voltage was low. Even if it has not risen to the test voltage, the primary voltage has already reached the rated voltage, and the circuit will automatically step down;
reason:
1. The capacitance of the reactor does not match the capacitance of the sample, and the resonance point cannot be found accurately;
2. High sample loss and low system Q value;
3. The high voltage output voltage of the excitation transformer is low;
4. The high-voltage connecting wire is too long or the high-voltage corona discharge wire is not used.
Methods for eliminating frequency conversion series resonance:
1. Connect the compensation capacitor in parallel to the test circuit to increase the circuit capacitance;
2. Connect as many reactors as possible in series to increase the inductance of the circuit;
3. Increase the output voltage of the excitation transformer;
4. Dry the sample to improve its insulation strength and reduce active losses in the circuit;
5. Generally, when the equipment outputs high voltage, high-voltage corona discharge wires are used, or ordinary high-voltage output wires are changed to shorter connecting wires, usually less than 5 meters.
II It is impossible to complete the automatic tuning of the variable frequency series resonance test device and find the resonance point.
Phenomenon:
The tuning curve is completely a straight line, indicating that the instrument has no resonance point after tuning.
reason:
The circuit grounding is poor, the test circuit wiring is incorrect, and one of the instruments in the device is open circuit.
Methods for eliminating frequency conversion series resonance:
1. Check if the grounding device is reliable and if there are any open circuit points in the grounding connection wire;
2. Check the continuity of the high and low voltage coils of the excitation transformer; (Low voltage winding resistance; each output end of the high voltage winding resistance is opposite to the high voltage tail)
3. Check the switches of each reactor for frequency conversion series resonance; (Resistance of each winding)
4. Check the continuity of the voltage divider signal line; (High and low voltage capacitors)
5. Check the continuity of the high and low voltage capacitor arms of the voltage divider; (Core 1 hole, shell 2 holes are respectively conductive; single hole to double hole are disconnected)
6. When boosting, the device itself does not have a resonance point, and it is necessary to check the on/off of the compensation capacitor
HV Hipot Electric Co., Ltd. specializes in producing series resonance (also known as power frequency withstand voltage test equipment) and has been engaged in the electrical measurement industry for many years. Its products have first-class quality and welcome customers to come and purchase.