Modular UPS Several Key Technology Research

Uninterrupted Power Supply(UPS),as a kind of energy storage,energy conversion and power purification functions such as power equipment,has been widely used in Banks,hospitals,airports,railways,government and other important places.The human made a more and more high ask to the reliability and efficiency of UPS.Modular UPS as UPS for the future development direction,developing modular UPS with more efficient and better reliability will have a very high economic value.UPS inverter topology has a significant effect on the efficiency of UPS,and parallel is the key technology of UPS reliability ascension,at the same time also has a lot of ascension in the UPS application efficiency and reliability of the UPS system operation mode.So this article will from the three aspects of in-depth research,promoting the comprehensive performance of UPS.In this paper,the main contents are the following:This paper introduces the structure and working principle of a diode clamping three-level half-bridge inverter,established a three-level half bridge inverter control model based on double loop control.This paper also gives a three level inverter PWM drive scheme,analysis of the logic of PWM drive half cycle switch and current limit at the time of the PWM inverter drive logic.Parallel control technology is a key technology of the modular UPS,the wireless parallel control technology for its higher flexibility and reliability has been widely used.But the output voltage and current sampling precision will affect the performance of UPS.The affect with the difference between inverter is larger.At the same time,the steady index of performance is not ideal.This article introduced the basic principles of the wireless parallel control technology.Analysis the influence of the output voltage sampling accuracy to the parallel UPS system,and proposes the corresponding improvement strategy;through experiment verify its feasibility.A control scheme is given in this paper to realize the economic model in a scattered bypass modular UPS.The main technical points of the intelligent resting management is studied,at the same time analyzed the principle of synchronous control between two independent UPS;presents a synchronization control scheme to eliminates the single point of failure.