News Details

JY-180kVA/60kV Series Resonance Withstand Voltage Test 

Variable frequency series resonance is suitable for AC withstand voltage tests of various large power transformers, power cables, steam and hydro generators, and other capacitive equipment, which must be strictly carried out periodically according to test regulations. Under power frequency conditions, due to the large capacitance of the test object or the high test voltage requirements, the power capacity of the test device is correspondingly high. Traditional power frequency withstand voltage devices often have large single-piece volume, heavy weight, are inconvenient for on-site handling, and are not easy to combine arbitrarily, resulting in poor flexibility.

JY-180kVA/60kV Series Resonance Withstand Voltage Test DeviceTechnical Solution

1. Basic Principle of Variable Frequency Series Resonance:

The variable frequency series resonance withstand voltage test uses the inductance of the reactor and the capacitance of the test object to form an LC series circuit. By adjusting the output voltage frequency of the variable frequency power supply, series and parallel resonance is achieved, obtaining high voltage on the test object. It is a new method of high voltage testing, highly praised by experts, and has been widely used domestically and internationally.

2. Characteristics of the Variable Frequency Series Resonance Test Device:

The variable frequency series resonance test device has large output capacity, high output voltage, and can arbitrarily combine reactors for AC withstand voltage tests on different test objects.

The variable frequency series resonance test device is small in size, light in weight, with each piece not exceeding 50kg, especially convenient for field tests.

The variable frequency series resonance test device has good protection functions, including overvoltage protection, overcurrent protection, time protection, flashover protection, overtemperature protection, module protection, etc.

The variable frequency series resonance test device is extremely simple to operate and has both manual and automatic modes.

The variable frequency series resonance test device adopts a large screen, making test data clear at a glance, and can print test results.

The variable frequency series resonance test device has no risk of overvoltage after test object breakdown, causing minimal damage to the test object.

The power capacity required for the test with the variable frequency series resonance test device is small, only a fraction of that required for power frequency transformer tests, solving the problem of difficult on-site power supply.

3. Scope of Application:

Suitable for AC withstand voltage test of 400mm2/35kV cross-linked cable with a length of 2000m.

4. Operating Environmental Conditions:

1 Ambient temperature: -10℃～40℃

2 Relative humidity: not greater than 90%

3 Altitude: below 2500 meters

5. Standards Referenced and Implemented for Equipment Manufacturing

1 DL/T849.6—2004     High Voltage Resonant Test Devices;

2 GB 6450—1986        Dry-type Power Transformers;

3 DL/T848.2—2004     Test Transformers;

4 GB/10229—1988      Reactors;

5 GB/T11920—1989     General Technical Conditions for Control Devices;

6 GB/T16927.1—1997   High Voltage Test Techniques;

7 IEC358—1990           Coupling Capacitors and Capacitor Dividers.

6. Equipment Configuration List

7. Main Functions and Parameters:

7．1 System Parameters of the Variable Frequency Resonant Test Device

7.1.1. Instrument input voltage: 220V±10%   50Hz;

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

7.1.2. Rated output voltage adjustment range: 0 ~ 50kV;

7.1.3. Maximum test capacity: 300kVA;

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

7.1.5. Output voltage instability: ≤0.5%;

7.1.6. Output frequency range: 25～320Hz;

7.1.7. Frequency adjustment resolution: 0.01Hz;

7.1.8. Quality factor Q value: not less than 50 under rated load;

7.1.9. Insulation level: 1.2 times rated voltage for 1 minute;

7.1.10. Continuous operation time at rated current not less than 30 minutes;

7.1.11. Voltage measurement accuracy: Class 1;

7.1.12. Noise: ≤45dB;

7.1.13. 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 is displayed on a large screen, with Chinese menu, printable output, and the printer is embedded.

7.2 Variable Frequency Power Supply: 

7.2.1. Rated output capacity: 15kVA;

7.2.2. Instrument power: 220V±10%  50Hz;

                   Power supply: 380V±10%  50Hz;

7.2.3. Rated input current: 39.5A;

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

7.2.5. Rated output current: 44A;

7.2.6. Frequency adjustment range: 25～320Hz;

7.2.7. Continuous operation at rated capacity: temperature rise ≤60K within specified working time;

7.2.8. Displays the following parameters:

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

b. Overvoltage protection voltage value, which can be arbitrarily set. When the output voltage of the complete device reaches the protection setting, the complete device can be automatically cut off;

c. Overcurrent protection: When the output current of the variable frequency power supply reaches the protection setting value, the complete device can be automatically cut off;

d. Breakdown protection: When a ground flashover occurs on the high-voltage side, the complete device can be automatically cut off. The device is equipped with isolation devices to ensure that equipment and personnel are not harmed;

e. Has full voltage output protection. During voltage regulation, if voltage regulation loses control, the variable frequency power supply immediately locks;

7.2.9. The following operations can be achieved:

a. Frequency adjustment, with coarse and fine adjustment for rising and falling frequency, and automatic search for the test resonance point, ensuring that the resonance frequency does not drift during the entire test;

b. With set voltage and set time, the voltage automatically rises to the set value and stops, and timing starts automatically;

c. With setting buttons for various protection functions, various protection values can be set on the panel;

d. With manual test function and automatic test function;

e. With test data printing function.

7.3 Excitation Transformer 

7.3.1. Structure: dry-type;

7.3.2. Input voltage: 340V;

7.3.3. Output voltage: 2.5kV/5kV;

7.3.4. Rated capacity: 15kVA;

7.3.5. Rated output current: 6A/3A;

7.3.6. Working frequency: 30～300Hz;

7.3.7. Continuous operation at rated capacity: within specified working time, the temperature rise of the coil to air is not greater than 60K;

7.4 High Voltage Reactor 25kV/3A 

7.4.1. Structure: dry-type, epoxy cast;

7.4.2. Rated capacity: 75kVA;

7.4.3. Rated voltage: 25kV;

7.4.4. Rated current: 3A;

7.4.5. Rated inductance: 40H;

7.4.6. Working frequency: 30～300Hz;

7.4.7. Continuous operation at rated capacity: within specified working time, the temperature rise of the reactor to air is not greater than 60K;

7.4.8. Performance and characteristics: The reactor is designed as dry-type, epoxy cast, and can be freely and conveniently stacked. The epoxy resin insulating cylinder shell has sufficient electrical and mechanical strength, necessary heat dissipation capability, and margin for thermal expansion and contraction. The upper and lower covers of the shell are orange-red.

7.5 Capacitive Voltage Divider 

7.5.1. Structure: capacitive;

7.5.2. Rated voltage: 50kV;

7.5.3. Rated capacitance: 1000pF;

7.5.4. Working frequency: 30～300Hz;

7.5.5. Measurement accuracy: ≤1.0%;

7.5.6. Performance and characteristics:

         a. Can operate continuously for 2 hours at rated voltage.

         b. Within the range of 30～300Hz, its accuracy and stability remain unchanged.

         c. At 20℃, the dielectric loss value of the capacitive voltage divider is ≤0.0025

         d. Voltage measurement is carried out through a special test lead to the variable frequency power supply.

7.5 Compensation Capacitor 

7.5.1. Structure: capacitive;

7.5.2. Rated voltage: 50kV;

7.5.3. Rated capacitance: 12500pF;

7.5.4. Working frequency: 30～300Hz;

7.5.6. Working time: can operate continuously for 2 hours at rated voltage.