3 phase online ups uninterruptible power supply electrical Circuit knowledge
Provide knowledge of UPS uninterruptible power supply, understand the classification of UPS uninterruptible power supply and UPS electrica Circuit, etc.
For the constant switching frequency and constant on-time (Ton) SPWMPFC rectifier introduced earlier, the 5th harmonic content of the mains input current is still on the high side. In 1995, Q. Huang proposed a variable control method of Ton. The method is to inject the 6th harmonic to change the duty cycle d, so as…
Most of the SCR polyphase phase-controlled rectifiers used in three-phase high-power power frequency UPS use 12-phase rectifiers or 12-phase rectification + 11th harmonic passive filters, which have become a typical power frequency UPS circuit mode, which can Meet the requirements of the national standard GB/T 7260.3 for the harmonic content of the mains input current….
The three-phase half-bridge SPWM inverter is the most widely used inverter in three-phase UPS. Regardless of whether it is a power frequency UPS or a high frequency UPS, whether it is a UPS with an isolation transformer or a UPS without an isolation transformer, this inverter is used as the output of the UPS. 1….