I. Equipment Composition
A set of 150kVA/10kV AC withstand voltage equipment, based on its technical principle, can be divided into two types: power frequency test transformer and series resonance test device. It is mainly used as the series resonance device for cable tests, with its core components as follows:
Power control section
Generally integrated in the control console or frequency conversion power supply box, it can adjust the 380V power frequency supply on site and perform frequency conversion processing, providing adjustable power for subsequent voltage increase, and integrating overvoltage and overcurrent protection circuits, with voltage and current display functions.
Excitation transformer
Its main function is to complete impedance and voltage matching between the power supply and the high-voltage reactor.
High-voltage reactor
As the core component of the equipment, it is usually composed of multiple sections and can be connected in series or parallel according to the test requirements. This equipment with a 150kVA capacity and 10kV voltage level can theoretically achieve a larger output current of up to 15 amperes; in the resonant state, the inductance of the reactor and the capacitance of the tested item form a resonant condition, and a high voltage can be generated under a smaller power load.
Capacitive divider
It is used to accurately measure the output voltage at the high-voltage end in real time and feed the signal back to the control system to achieve voltage stabilization and protection functions, ensuring measurement accuracy.
Auxiliary cables
Including high-voltage leads, grounding wires, and various necessary connection lines.
II. AC Withstand Voltage Test Equipment — Voltage Selection for Test
The test voltage must be strictly determined according to relevant national standards. For 10kV voltage level power equipment, the test voltage values for different tested items vary significantly:
10kV power transformer: The交接试验 usually follows the factory test voltage at 80% – 85%， and the commonly used test voltage is 28kV – 30kV， with a duration of 1 minute.
10kV high-voltage switchgear， circuit breakers， transformers： The rated insulation level is relatively high， and the AC withstand voltage test voltage usually requires 42kV， with a duration of 1 minute.
10kV power cable： When conducting the交接试验 using power frequency or variable frequency resonance methods， the common main insulation test voltage for 8.7/10kV cables is generally 17.4kV， and it should be sustained for 1 hour or more according to the regulations； short cables can also be tested with a 21.7kV voltage for 5 minutes.
10kV lightning arresters： Generally， AC withstand voltage tests are not conducted， and only DC reference voltage tests are performed.
Special note： If the equipment’s maximum output voltage is only 10kV， it cannot meet the withstand voltage requirements of 10kV transformers and switchgear， as the required test voltage is much higher than 10kV. This voltage level is more suitable for 6kV motor and generator equipment tests， or as a component of the 10kV cable resonant test system， and the voltage needs to be raised to above 17.4kV through the resonant principle. If the equipment’s higher output is limited by electronics or mechanics at 10kV， it cannot be applied in this scenario.
III. Application Scope
Combined with the 150kVA capacity and 10kV voltage output limit， the applicable scenarios of this equipment are clear：
It is mainly used for AC withstand voltage tests of 10kV and below power cables， and by leveraging the series resonance characteristic， it can conduct variable frequency resonance withstand voltage tests on medium-length 10kV cables， detecting the reliability of the main insulation. The prerequisite is that the device can raise the voltage to above 17.4kV through resonance， and if the equipment’s higher output is limited by electronics or mechanics at 10kV， it cannot be applied in this scenario.
It is suitable for the withstand voltage tests of 6kV voltage level motors and generators. The AC withstand voltage test voltage for 6kV motors is usually between 10kV and 16kV， which is in line with the equipment’s output capacity.
It can be used for withstand voltage tests of the neutral point of transformers， or for segment insulation verification tests of GIS， transformers， and bushings in the 35kV system.
It can complete the preventive withstand voltage tests of 10kV level insulating rods， insulating boots， and insulating gloves as power safety tools.
Post time: Feb-27-2026