According to national test standards, the induced test voltage for power transformers and voltage transformers is approximately 2-3 times the maximum working phase voltage. As is well known, when a transformer operates at rated frequency and rated voltage, the iron core is close to saturation. If a test voltage higher than the rated voltage is applied across the windings of the transformer under test using a power frequency source, the no-load excitation current will increase sharply to an unacceptable level. From the relationship of induced electromotive force, it can be seen that in order to apply a test voltage higher than the rated voltage without saturating the iron core, the method of increasing the power supply frequency can be adopted, and a frequency multiplier power generator must be used. It is simple to operate, reliable in performance, and can well meet the needs of induced withstand voltage tests for transformers and instrument transformers.

【Operating Environment】

1. Power supply conditions: three-phase 380V/50Hz

2. Output voltage: 50—500V (max 750V), 150Hz;

100—1000V (max 1500V), 150Hz;

3. Capacity: 1-1000KVA;

4. Waveform: sine wave, distortion less than 1%;

5. Load characteristics: resistive, inductive, capacitive all acceptable;

Product Structure




It consists of a three-phase five-limb transformer (or three single-phase transformers), a single-phase voltage regulator, reactors, and a control part. According to user requirements, the appearance can be integral or split push-type.

 

Purpose




1. Widely used for frequency multiplier induced withstand voltage tests on voltage transformers.

2. Perform phase-by-phase frequency multiplier induced withstand voltage tests on power transformers.

3. Perform frequency multiplier induced withstand voltage tests on other inductive coil-type electrical products.

Configuration Table




Technical Parameters
Model DF3003 DF3005 DF3010 DF3015
Output Power 3kVA 5kVA 10kVA 15kVA
Output Frequency 45HZ-300HZ frequency continuously adjustable, adjustment step 0.1HZ. (Frequency adjustment range can be customized)
Output Voltage 0V-400V sine wave, continuously adjustable, adjustment step 0.1V. (Voltage output range can be customized)
Waveform Distortion Rate Pure sine wave, distortion rate ≤2%
Output Isolation Input and output completely isolated, isolation voltage not less than AC3kV, 1min
Output Voltage Stability Automatic voltage stabilization, voltage stability ≤1%
Minimum Voltage Resolution 0.1V
Minimum Current Resolution 0.01A
Measurement Accuracy +-0.5%
Instrument Weight 20Kg 15+25Kg 18+30Kg 20+33Kg





Capacity: 3～1000kVA.

Input voltage: AC 380V 50HZ three-phase.

Output voltage: 200～1000V 150HZ single-phase.

Output waveform: sine wave, distortion less than 2%.

Load characteristics: load can be resistive, inductive, capacitive.

Partial discharge: less than 2PC at full voltage.

Usage Method




1. With voltage regulator (3kVA～10kVA)

1) Connect according to the wiring diagram, then adjust the overcurrent protection current value according to the test object.

2) Set the voltage regulator to the lowest position, close the power switch, the zero position indicator light is on, check for phase loss, and start the test bench.

3) Adjust the voltage regulator so that the triple frequency output voltage reaches the test voltage, use an oscilloscope to measure the output voltage waveform, frequency, and output voltage value to meet the test requirements of the test object.