Study On Reactive Power Control Of Active Distribution Network Containing Storage And PV Distributed Generation

With the proportion of photovoltaic(PV), wind power and many other renewable energy increasing as well as consciousness of environmental protection, it is a new problem for stable operation of distribution network as the uncertainty of new energy. Active distribution network(ADN) can efficiently settle problems of the interactions between smart grid and chargeable facilities, control of renewable energy generations and intelligent grid operation. Therefore, the key problems need to be addressed containing smart power equipment research, development and implementation of reactive power compensation and voltage regulation, harmonic governance, gridding of renewable energy for the power electronic equipment. This paper has discussed the technologies of how to dynamic control the pause width modulation(PWM) converter to optimize energy conversion and improve power quality of ADN system. At the same time, signal detection, self-theory analysis, simulation, experimental test, implementation of detailed procedure code, power analysis, control means of exploration and mathematical modeling have been carried out as a result of laying the foundation of intelligent electricity power equipment research and manufacture for active power distribution network in technology and theory. Main contents are as follows:(1)The mathematical modules and calculating power was build. The mathematical model of three-phase PWM converter in abc coordinates system was determined by use of switching function description method. The abc static coordinate power calculation formula was derived based on the instantaneous power theory. Then, the transformation and equivalent transformation power in stationary coordinate and dq synchronous rotating coordinate system was calculated by means of coordinate transformation analysis.(2)PWM converter was reasonable controlled based on its inverter and rectifier function. By considering reactive power and instantaneous active power control in power system, a new direct power control method was worked out. Power flow was strictly controlled based on internal current protection consist of external power loop and internal current loop. Meanwhile, the achievement of high-quality and dynamic power control for PWM converter systems was proved by simulation results.(3)A natural coordinate PWM control method were raised up based on abc coordinate including the control method without voltage sensors, direct current control method and direct power control. The flux linkage value of each phase was calculated by the AC side phase voltage of PWM converter and integral to replace differential method. The target was achieved relying on flux estimation and phase voltage estimation module in the absence of AC voltage sensor control. The direct power control strategy in the natural coordinates was completed based on new concept of direct power control consist of power loop and current loop.