AC Resonant Test Set , High Voltage Cable Testing Equipment , AC
Withstand Voltage Test Set
I. Application :
AC resonant test set is a kind of high voltage cable testing
equipments for applied withstand voltage , which can be classified
as variable frequency and variable inductance resonant test system.
The former is tuned to resonance by regulating test frequency and
the latter is by adjustable inductance. Different regulation modes
lead to the same objective, that is, large capacity output on test
object can be obtained by inputting small capacity power supply.
For large capacity test objects like XLPE HV cable, the biggest
difficulty for adopting power frequency or approach power frequency
AC voltage withstand test as acceptance test for XLPE insulating
cable, is that it needs power supply and equipments with large
capacity. For instance, given a 630mm2, 110kV XLPE cable with
capacitance of 0.188uF/kM, the test parameter of each cable is
2.9MVA/128kV/22.7A if cable length is 3kM. Then there has a
conclusion that it is impossible to do field test in traditional
way. However, in variable frequency resonant test system, by
dropping test frequency on one hand, and with a high quality factor
(Q) on the other, the required capacity of input power supply is
1/Q of that of test power, thus dramatic reductions in volume and
weight of test equipments are available, ideal for field test.
Fanke company owns many years of manufacturing experience in this
type of testing equipment, customized types of such equipment
according to the test needs of different customers, including OEM services, The components of the sets can also be
II. Main Components of AC Resonant Test Set With Variable Frequency
1. Isolation transformer
2. Variable frequency power source
3. Excitation transformer
4. HV test reactor group(resonant inductor)
5. Voltage divider
6. Optional part
6.1 Load capacitor
6.2 HV damping blocking inductor
1).Load capacitor can be optional when small load line is tesing or
need analog load to control test frequency.
2).Test reactor can be produced to be 130KV,150KV,155KV,200KV,
250KV, 300KV, 350KV, 400KV for each piece rated voltage according
to different tested object scope or customer requried. The max.
rated current of each HV reactor can be 1~5A,10A,15A,20A,25A,30A.
3). Test cir circuit is as following
VF: Variable Frequency Power Supply Source which is control and
measurement part in the test circuit.
T : Excitation Transformer which provide the exciting voltage for
HV test reactor
L : Test Reactor which is resonant inductance in the LC circuit and
produce the test voltage
Cx: Tested Equipment
MOA1: Lightning Arrestor is protection part on the excitation
C1,C2: Voltage divider(C1 is high voltage arm,C2 is low voltage arm
) which is HV voltage measurement part
III. Test Object Range Applied
- 110kV~400kV long-distance cables
- 110kV~500kV HV GIS
- 110kV~220kV HV coupling condenser
- 110kV~500kV Capacitor Voltage Transformer(CVT)
Advantage and Features:
- Cordwood design to expand capacitance
- Large thermal capacitance for a long continuous running hour
- Quality Factor:Q≥100(at f=30Hz)
- Small size and light weight is easy for field test.
- Working frequency range:20-300Hz
Field test figure
Note: 750KV/5A AC resonant test set with variable frequency from
Fanke High-voltage is performed withstand voltage on 500KV power