The DC withstand voltage test and DC leakage current test of the water-cooled generator voltage tester are conducted without external blowing or water supply conditions. Their respective advantages and disadvantages are compared as follows:
 
Conduct experiments while blowing water
Advantages: It can be tested with a general DC high-voltage tester, which is lightweight, easy to operate, accurate in reading, and not affected by water quality conditions.
Disadvantage: Due to the structure of the generator unit, it is difficult to dry the accumulated water at the bottom. Therefore, it is very time-consuming, and the water blowing time can even last for more than a week. Extended the downtime for major repairs. If the water is not thoroughly blown, it will not only cause measurement errors, but also pose a risk of damaging the winding if it causes internal arcing during the test.
 
Conduct experiments under water conditions
Advantages: No need for water blowing equipment, saving time for blowing water.
Disadvantages: Currently, AC trial transformers (or resonant transformers) are used in combination with silicon stacks and capacitors, and additional devices are required for polarization compensation of the water collection pipes. The equipment is bulky, scattered, and the wiring is complex. The test results are affected by water quality, and the microampere meter fluctuates greatly, making it difficult to read.
 
Considering the above situation, in order to overcome both shortcomings, it is necessary to solve the problem of using a complete set of specialized equipment for testing under the premise of being lightweight, simple, and accurate when water is flowing. Our company has developed a specialized leakage current tester for water-cooled generators based on the principle of "low voltage shielding method", which basically meets this requirement. Its main features are:
The entire device consists only of a control box and a voltage multiplier, and the wiring is very simple.
2. Adopting electronic control and tuning, easy and comfortable operation; Voltage, current, etc. are directly read on the panel meter without the need for conversion.
3. One minute timer and prompt function, set according to the requirements of the test procedure.
4. Comprehensive overvoltage and overcurrent protection function, with an external zinc oxide overvoltage protection device.

The leakage current testing device for water-cooled generators is a new generation of LCD screen display and intelligent specialized testing instrument developed by our company based on the principle of "low voltage shielding" on the basis of the previous generation product.
 
It adopts a high-power DC high voltage generator, replacing a series of single component combination test tools such as traditional test transformers, high-voltage silicon stacks, stabilizing capacitors, rectifying capacitors and inductors, DC high voltage dividers, regulators, mA meters, μ A meters, and polarization potential compensation devices. All of them are integrated into one high voltage (generating) unit and one control box, reducing the number of single components in the complete test device, lowering the weight of the test equipment, reducing the workload of the test personnel, simplifying the test wiring, making the test more convenient, efficient, and reliable.
 
At the same time, it has electronic voltage regulation, automatic polarization compensation, and rich protection functions, making the test operation easier and safer; The use of intermediate frequency voltage doubling makes the test voltage more suitable, the test data more accurate and stable, and the results more reliable.
 
1. Adopting an intermediate frequency voltage doubling circuit, applying PWM pulse width modulation technology and high-power IGBT devices, and based on electromagnetic compatibility theory, adopting special shielding, isolation, and grounding measures, the instrument achieves high quality, portability, and can withstand rated voltage discharge without damage.
 
2. Adopting voltage feedback greatly improves voltage stability. At the same time, the inverter frequency was increased, and the volume and weight of the instrument and the voltage doubler were reduced. More convenient to carry.

Output voltage (kV): 60,80,90100
Output current (mA): 80120200300
Output power (kW): 4.8, 7.2, 12, 18
Voltage measurement error: 1.0% ± 2 words
Total current measurement error: 1.0% ± 2 words
Leakage current measurement error: ± 2.0% (full scale)
Overvoltage setting error: ≤ 1%
Voltage stability: 1.0% (random fluctuations, power supply voltage changes ± 10%)
Working mode: rated load, continuous operation for ≤ 5 minutes at a time
Environmental temperature: -10 ℃~40 ℃
Relative humidity: not greater than 90% when the temperature is 25 ℃ (no condensation)
Altitude: below 2000 meters