Frequency modulation series resonant equipment has many significant advantages in GIS equipment withstand voltage testing.
① Small size and light weight: Compared to traditional voltage testing equipment, frequency modulated series resonant devices have smaller size and lighter weight. This makes it more convenient for transportation and on-site layout, reducing labor and material costs. For example, in some testing sites with limited space, a smaller volume can better adapt to the site environment, making it easier for operators to arrange and operate.
② Easy to use: The device is relatively simple to operate and easy to get started with. After receiving certain training, operators can quickly master the use of equipment and improve work efficiency. At the same time, it has a high degree of intelligence and can automatically adjust and control some key parameters, reducing human errors in operation.
③ Small capacity of power equipment: The frequency modulation series resonant AC withstand voltage test system uses a variable frequency and variable voltage power supply to achieve resonant boosting of the test circuit. Due to the resonant characteristics, the required capacity of the power equipment is relatively small. This is of great significance in practical applications, as it can reduce equipment costs and minimize the occupation of power resources.
④ Good communication equivalence: This device can provide good communication equivalence and simulate the electrical state of GIS equipment more realistically in actual operation. This helps to more accurately detect the insulation performance of GIS equipment and identify potential issues.
⑤ Automatic frequency modulation function: It can continuously frequency modulate within the range of 30-300Hz and automatically search for the resonant frequency. Real time sampling of capacitor voltage amplitude is used to determine the series resonance state, and after reaching resonance, the resonance frequency is kept constant and the output voltage amplitude is automatically adjusted. The entire process utilizes unipolar sine pulse width modulation (SPWM) to control the inverter power supply, enabling its output to automatically track the resonant frequency and ultimately control the capacitor voltage to reach the set value, meeting the requirements of the withstand voltage test.
⑥ Good dynamic performance: By using the variable parameter average digital PI control method, the voltage of the test sample is regulated and controlled, ensuring no overshoot of the voltage. The frequency characteristics of the system indicate that the voltage phase of the test sample is a nonlinear function of frequency. By using the small deviation method to linearize the phase frequency characteristics, an incremental linear model of the phase frequency characteristics at the resonant frequency point was obtained, which improved the dynamic performance of the system.
⑦ High waveform quality: The segmented synchronous unipolar SPWM method is used for waveform modulation of the frequency modulation power supply, ensuring that there are few low order harmonics and high waveform sinuosity during the large-scale frequency conversion and voltage regulation process of the power supply. Adopting a simplified switching mode during steady-state resonance operation can avoid dead zone effects, achieve ideal unipolar SPWM effects, and minimize switching losses.
The ZCVF-A series variable frequency series resonant withstand voltage test device adopts the method of adjusting the power supply frequency to achieve resonance between the reactor and the tested capacitor, thereby obtaining high voltage and high current on the tested object. Due to its low required power supply, light weight and small size, it has been widely praised and applied at home and abroad, and is a new method and trend of high voltage testing. This device is mainly designed for AC withstand voltage testing of cross-linked cables, hydroelectric generators, main transformers, busbars, GIS, etc. It has a wide range of applications and is an ideal withstand voltage equipment for high-voltage testing departments and power installation and maintenance engineering units at the local, municipal, and county levels. The equipment mainly consists of a variable frequency control power supply, an excitation transformer, a reactor, a capacitive voltage divider, and a compensation capacitor (optional).
Kvtester Electronics Technology Co.,Ltd. is a high-tech enterprise specializing in power testing, testing, research and development, production, and sales of testing equipment. It has been engaged in the electrical testing industry for many years, and its products are of high quality. We welcome customers to come and purchase. Service hotline: 0086-27-81778799, to learn more, visit the official website: www.kvtester.com
