HTXZ series variable frequency power supply

With the rapid development of China's power industry, more and more high-voltage electrical equipment will be used in the power grid. After the installation of electrical equipment is completed, various high-voltage equipment must undergo AC withstand voltage tests before being put into use to determine whether they can be put into normal operation. The series resonant system is different from traditional power frequency test transformers. When conducting withstand voltage tests on high-voltage equipment, a high voltage and large capacity test power supply is required, making the equipment appear particularly bulky and not suitable for on-site testing. Therefore, adopting a series resonance test system is of great significance. Series resonance is mainly used 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 variable frequency power supply is an important component of the series resonant system.

As the core part of the series resonant withstand voltage test system, the variable frequency power supply independently regulates voltage and frequency, with an output voltage of 0-400 V and a frequency of 30-300 Hz. It outputs pure PWM wave signals with high stability and strong anti-interference ability in the field environment.

In the early development of frequency and voltage regulation control technology, PAM method was often used. Therefore, the AC voltage waveform output by the inverter of the variable frequency power supply can only be a square wave. Changing the effective value of the square wave can only be achieved by changing the amplitude of the square wave, that is, the amplitude of the intermediate DC voltage. With the emergence of fully controlled fast switching devices such as GTR, IGBT, MOSFET, etc., it gradually developed into PWM mode. Due to the fact that adjusting the duty cycle of the PWM wave can regulate the voltage amplitude, the inverter can simultaneously complete voltage and frequency regulation tasks, eliminating the need for rectifier control. The equipment structure is simpler and the control is more convenient. The output voltage has been improved from a square wave to a PWM wave, reducing the low order harmonic content of the output voltage.

Product nickname: Variable frequency power supply, series resonant variable frequency power supply