Improving energy performance and mains voltage quality by means of power electronics

Abstract

The possibilities of improving energy performance of valve inverters in phase regulation and high-and low-frequency pulse modulation are considered. In some cases, the use of circuit design and special methods of control and artificial switching considerably reduced reactive power consumption, but did not make it possible to a sufficient degree to solve the higher harmonics problem and ensure the consumption of sine current from the mains. Particular attention is paid to the use of the active voltage rectifier. Devices that ensure power supply to any customers together with improving the energy performance of the entire power supply system and the quality of its voltage are called “active rectifying compensators of passive power.” The way these devices are controlled ensures that the total mains current consumed by all customers approaches the optimal level, i.e., it is sine current with voltage-relative shift angle φ (for example, φ = 0). Mains voltage fluctuations can be reduced by making the control over a group of ac converters with low-frequency pulse modulation and active load depend on mains current changes. The advantages of the combined ac/dc power supply system are presented.