Research And Design Of Three-phase Online High-power UPS

High-tech products can be found everywhere in life.These high-tech products require a stable and reliable power supply system,and the power supply of the power grid often fails to meet its requirements.Uninterruptible Power System(Uninterruptible Power System),referred to as UPS,can provide safe and reliable high-quality power for the load,and is widely used in power occasions with high power quality requirements.However,due to the limitations of power devices and the choice of circuit topology,UPS is difficult to apply to some high-power occasions.This paper aims at the problem that UPS is difficult to be applied in high-power power consumption occasions.The research and design of three-phase online high-power UPS are carried out to solve the application problem of UPS in high-power power consumption occasions.This paper mainly studies the circuit topology and control strategy of the rectification and inverter links of the three-phase online high-power UPS,as well as the key technologies of UPS parallel current sharing.In order to improve the output power of UPS,VIENNA rectifier is selected as the rectification part of UPS.The mathematical model of three-phase VIENNA rectifier is established and its working principle is analyzed,and the space vector pulse width modulation method for VIENNA rectifier is designed.Adopt voltage and current double closed-loop control strategy.A VIENNA rectifier simulation model was built on the MATLAB \ Simulink platform to analyze its steady-state and dynamic performance.A mathematical model of three-phase voltage inverter is established,a simplified SVPWM modulation method is proposed,and the feasibility of the simplified SVPWM modulation method is verified.Design voltage and current double closed-loop control strategy,build a simulation model,and analyze its steady-state dynamic performance.In order to meet the high-power operation of UPS,considering the parallel operation of multiple UPS,the key technologies used in it include phase-locked loop and droop control method.In this paper,the principles of traditional phase-locked loop(PLL),synchronous rotating reference coordinate system phase-locked loop(SRF-PLL)and sinusoidal tracking algorithm(STA)are analyzed and compared.Phase loop technology.The principle of droop control is analyzed,the traditional droop control method is improved,and the robustness of the droop control method is improved.Research and design the UPS machine.According to the design requirements of high-power UPS,the selection of power devices in the circuit is carried out.The other components of UPS and the working mode of UPS are introduced,and the whole UPS is simulated and analyzed.Based on the designed circuit,a three-phase online UPS experiment platform was built.In the experiment,the load test of the UPS was carried out,and the different power output of the UPS when the resistive load was tested was tested.Experiments show that the circuit topology and control strategy designed in this paper are feasible and correct.The three-phase online high-power UPS has good output performance and can be used in high-power power applications.