The Research Of Switching Control For The Isolated Wind-solar Complementary Micro Grid System

This paper does research about the domestic and foreign status of isolated micro grid and analyzes the difference between microgrid and the traditional power supply mode.Then,it reserches in the full utilization of renewable energy and new challenges brought by the access of storage device to the isolated micro grid furtherly.This paper comparises the mirco grid based on the diesel generator as the main control and the mirco grid based on the battery as the main control,comsidering of the isolated micro grid stratified control method of the different time scales as a starting point,and then puts forward the micro grid energy management model based on improved particle swarm optimization algorithm to solve the global optimization.Firstly,this paper gives the model of the wind-solar-diesel micro grid structure and the mathematical model of every distributed generation,achieve the none steady state error system voltage and frequency stablity control of isolated micro grid with the long-time scale and big net load fluctuations through the proportional integral controller and auxiliary reactive power compensation device.Then,a new diesel engine optimization strategy is raised to reduce fuel consumption on the basis of the full use of diesel generator system,referring to the changes of the external environment,the diesel engine running economy,and achieve smooth switching between large and small power diesel generators according to the power of diesel generators.It is verified by experiments.This paper adds battery as the main power sypply on the basis of the wind-solar-diesel micro grid to deal with the short time scale and small net load fluctuations and improve the system stability of voltage and frequency with a new battery inverter controller through the improvement of battery system P-f and Q-V droop controller.Then,a new energy management optimization scheduling model for microgrid is established according to the constraints of pollutant handling costs,operation and maintenance costs and fuel costs of each disturbed generators.it updates the weight of the particle swarm optimization algorithm and constantly adjusts the accelerated particle.Finally,the simulation data of several experiments prove that the strategy that canimprove the reliability and economy of the system effectively,and improve the global optimal value search and shrinkage speed.