Design And Realization Of Three-phase Energy Storage Invter

The traditional power supply networks are only supported by a very large power generation system, which is difficult to guarantee the safety and reliability. To solve this problem, distributed generation system came into being. However, the distributed generation system still has some inherent disadvantages, such as the impact against the main electric network, control complexity, etc. As a result, a micro-grid system is purposed, which combines the distributed generation systems and controllable load together. Storage inverter is the core of the micro-grid system energy conversion, and the key link to the function" peak load shaving and regulate the surplus and deficiency" of the micro-grid system. Energy storage inverter technology research and development is of great significance to improve the technical level of the micro-grid power system.The energy storage inverter topology and working principle is researched deeply in this paper, and a mathematical model of the energy storage inverter system is also established. The brief introd uctions of the grid-connected control algorithm respectively under the rectification working status and inverter working status is gave acorrding to the mathematical model. The researches and designs of the energy storage inverter power circuit, detection circuit and control circuit are respectively proposed in the paper at the same time.Considering different SVM sequences, a new method to calculate the high frequency voltage ripple on the DC capacitor in the three-phase half-bridge VSC system is proposed in this paper. The paper focus on research and design of the main power supply of the system, detailedly analyzes the working principle of non-destructive LCD absorption circuit in the flyback switching power supply, derives the feedback loop transfer function of the main power supply system under the TL431+optocoupler feedback mode and intermittent mode, then simulates the phase margin by Simulink software to verify the stability of the feedback loop under different load conditions.Based on the above, the model machine design of5kW energy storage inverter is completed. First of all, the functions of system power board and control board are verified through single board debugging test. Then, according to the rectifier and inverter working status, the working efficiency, power factor and exchanges side current harmonic content of the energy storage inverter system under output power is respectively recorded. Under the rated power, the system efficiency up to93%, the power factor up to0.998, and the AC side current harmonic content is as low as1.8%, all the parameters of the indicators meet the design requirements.