180kVA/60kV Series Resonance Withstand Voltage Test Device



1. It has large output capacity, high output voltage, and can arbitrarily combine reactors for AC withstand voltage tests on different test objects.

2. It is small in size and light in weight, especially convenient for field tests.

3. It has good protection functions, including overvoltage protection, overcurrent protection, time protection, flashover protection, overtemperature protection, module protection, etc.

4. It is extremely simple to operate and has both manual and automatic modes.

5. It uses a large screen to make test data clear at a glance, and can print test results.

6. It has no risk of overvoltage after test object breakdown, causing relatively little damage to the test object.

7. The power capacity required for the test is small, only a fraction of that required for power frequency transformer tests, solving the problem of difficulty in finding power sources on site.



Scope of Application of the Equipment



References and Standards for Equipment Manufacturing



DL/T849.6—2004     High Voltage Resonant Test Device

GB 6450—1986        "Dry-type Power Transformer"

DL/T848.2—2004      "Test Transformer" 

GB/10229—1988       "Reactor" 

GB/T11920—1989      "General Technical Conditions for Control Devices"

GB/T16927.1—1997    "High Voltage Test Techniques"

IEC358—1990         "Coupling Capacitors and Capacitor Dividers"

GB311.1              "Insulation Coordination for High Voltage Transmission and Transformation Equipment"

DL/T846—2004        "General Technical Conditions for High Voltage Test Equipment"

Q/CSG10007—2004     "Regulations for Preventive Tests of Power Equipment"

GB7328—87           "Measurement of Sound Level of Transformers and Reactors"

DL474.4—1992       "AC Withstand Voltage Test"



Specific Configuration of the Equipment



1 Test requirements:

  1.1. AC withstand voltage test for 300mm2/10kV cable, length 3 km. Test time 5min, test voltage 22kV, test frequency 30-300Hz, equivalent capacitance 0.418uF/km.

2 Design of the reactor:

  2.1. AC withstand voltage test for 300mm2/10kV cable, length 3 km. Test time 5min, test voltage 22kV, test frequency 30-300Hz, equivalent capacitance 1.254uF. When frequency is 35Hz.

Test current I=ωCXUtest=2×3.14×35×1.254×22×10-3=6A

Corresponding reactor inductance L=1/ω2C =16.5H

3 Configuration of the reactor:

  3.1. For AC withstand voltage test of 300mm2/10kV cable, length 3 km, maximum test voltage 22kV, for easy transportation, the reactor is divided into three sections, each section with voltage 30kV, current 2A, and inductance 50H.

Verification:

1) AC withstand voltage test for 300mm2/10kV cable, length 3 km. Test time 5min, test voltage 22kV, test frequency 30-300Hz, equivalent capacitance 1.254uF. Use three reactors in parallel, with rated inductance 16.6H, rated voltage 30kV, rated current 6A.

Test frequency: f=1/2π√LC = 34.8Hz

Test current I=ωCXUtest=2×3.14×34.8×1.254×22×10-3=6A

4 Configuration of the excitation transformer:

  4.1. Since the quality factor Q value is not less than 20 under rated load, the excitation transformer is the total capacity of the reactor 180KVA, divided by the quality factor 20 to get 10KVA.

  4.2. The configured excitation transformer specification is YHXZB—10KVA/1.5kv/3kv.

5 Configuration of the frequency conversion power supply:

  5.1. The capacity of the frequency conversion power supply is equal to or greater than the capacity of the excitation transformer, take 10kvA.

  5.2. The configured frequency conversion power supply specification is YHXZB—10kvA.

6 Configuration of the capacitive voltage divider:

  6.1. Since the maximum test voltage is 22kV, the capacitive voltage divider voltage is 30kV, capacitance 10000PF.

  6.2. Configure 1 unit of capacitive voltage divider with specification FRC—30kv/0.01uF.



Description of Each Component of the Device



1. System parameters:

 1.1. Instrument input voltage: 220v±10%   50Hz;

      Power input voltage: 380v ±10%   50Hz;

 1.2. Rated output voltage adjustment range: 0 ~30kv;

 1.3. Maximum test capacity: 180kvA;

 1.4. Resonant voltage waveform: sine wave, distortion rate: ≤0.5%;

 1.5. Output voltage instability: ≤0.5%;

 1.6. Output frequency range: 25～320Hz;

 1.7. Frequency adjustment resolution: 0.01Hz;

 1.8. Quality factor Q value: not less than 20 under rated load;

 1.9. Insulation level: 1.2 times rated voltage withstand for 1min;

 1.10. Continuous operation time at rated current: intermittent operation time 60 min;

 1.11. Voltage measurement accuracy: class 1;

 1.12. Noise: ≤45dB;

 1.13. The device is equipped with the following protection functions:

    The equipment has manual test, automatic tuning and automatic test;

    Overvoltage protection, overcurrent protection, discharge protection, power-off protection, zero-start protection.

    Test data displayed on large screen, Chinese menu, printable output, printer is embedded.



2. Frequency conversion power supply parameters:



 2.1. Rated output capacity: 10kvA;

 2.2. Instrument power: 220v±10%  50Hz;

       Power supply: 220v or 380v ±10%  50Hz;

 2.3. Rated input current: 26.3A;

 2.4. Rated output voltage: 0-340v adjustable, single phase, output voltage instability 0.05%;

 2.5. Rated output current: 29.4A;

 2.6. Frequency adjustment range: 25～320Hz;

 2.7. Continuous operation at rated capacity for 60min, maximum temperature rise ≤60K;

 2.8. Display the following parameters:

    a. Frequency, voltage, current after frequency conversion output;



3 Excitation transformer parameters



 3.1. Structure form: single-phase dry type;

 3.2. Rated capacity: 10kvA;

 3.3. Input voltage: 340V;

 3.4. Output voltage: 1.5kv/3kv;

 3.5. Rated output current: 6.67A/3.33A;

 3.6. Operating frequency: 30～300Hz;

 3.7. Temperature rise: under rated capacity for 60min, the temperature rise of coil to air is not greater than 60K;



4 Single high-voltage reactor parameters

 4.1. Structure form: dry type, epoxy casting;

 4.2. Rated capacity: 60kvA;

 4.3. Rated current: 2A;

 4.4. Rated voltage: 30kv;

 4.5. Rated inductance: 50H;

 4.6. Operating frequency: 30～300Hz;

 4.7. Temperature rise: under rated current for 60min, the temperature rise of reactor to air is not greater than 60K;



5 Capacitive voltage divider parameters

 5.1. Rated voltage 30kv;

 5.2. High voltage body 1 section, each section rated voltage 30kv/0.01uF;

 5.3. The low voltage arm capacitor uses the same material as the high voltage body, with small temperature coefficient and low dielectric loss;



Basic Principle



It uses the inductance of the reactor and the capacitance of the test object to form an LC series circuit, adjusts the output voltage frequency of the frequency conversion power supply, realizes series-parallel resonance, and obtains high voltage on the test object. It is a new method of high voltage testing, highly praised by experts, and has been widely used at home and abroad.



Keywords: 180kVA/60kV Series Resonance Withstand Voltage Test Device, 180kVA/60kV Series Resonance Withstand Voltage Test Device