Research On Wind Storage Frequency Regulation Strategy Of High Permeability Renewable Energy Grid

Facing increasingly severe climate and environmental problems,energy development must change the original mode of production and consumption.In the power supply system,achieving clean energy,low carbon and sustainable development has become the general trend.In the traditional power system,the frequency regulation is mainly a hydro or thermal power frequency regulation unit.By changing the power output,the load fluctuation is suppressed,and the grid frequency is stabilized.One of the main problems of renewable energy power generation is that it is not as schedulable as traditional energy sources such as thermal power and hydraulic power.At the same time that it randomly and intermittently increases the frequency regulation requirements,the lack of traditional frequency regulation power sources will also reduce the frequency regulation reserve of the grid.The energy storage system has unique advantages in climbing speed and response time:it can use the droop control of power electronics in the microgrid to simulate the once-frequency power frequency characteristics of the traditional wind turbine generator system to adjust its charge and discharge.Achieve stable frequency of microgrid with high proportion of renewable energy.The command signal of automatic power generation control can also be used as the command of secondary frequency regulation,so as to achieve the local consumption of renewable energy and reduce the dependence of grid frequency on traditional frequency regulated units.On the basis of summarizing the existing research in this field,the paper first summarizes the background and significance of the topic,the current status of research at home and abroad,and the main problems.Then it studies the high proportion of renewable energy droop control in the microgrid frequency control,and finally capacity planning for scenarios where power-to-gas(P2G)participates in frequency regulation in a centralized wind farm.This article mainly completed the following two aspects of work:Research on microgrid frequency regulation with renewable energy and energy storage equipment,microgrid can provide enough equipment to integrate renewable energy into large grid,and a high proportion of renewable energy based on power electronics has become the main component of microgrid However,as an independent power system,its inertia and grid support are small,and frequency deviation is easy to occur.Therefore,firstly,the principle of traditional droop control to support the frequency of microgrid is introduced systematically,and the microgrid,inverter model and improved droop control scheme are introduced.Finally,the support provided by improved droop control for microgrid frequency is provided.Simulation verification was carried out.Through this part,the frequency control scheme in the future with a high proportion of renewable energy distributed microgrids was introduced.Secondly,the phenomenon of abandoning wind in a centralized wind farm under a high proportion of renewable energy is analyzed.P2G is introduced to absorb the abandoned wind at night.At the same time,gas storage equipment is used to store the natural gas converted by P2G,and then the nature-gas-generator-unit(NGGU)adjusts the output for secondary frequency regulation according to instructions issued by the Automatic Generation Control(AGC)in the Energy Management System(EMS),and establishes a P2G-gas storage-NGGGU combined frequency regulation system,then introduced the operating strategy of each device in the combined frequency regulation system,the market rules for participating in the frequency regulation service,and the differences in the power generation characteristics of the NGGU and traditional thermal frequency regulation units in the set-up scenario.A method for determining the NGGU frequency regulation instruction was proposed.Then,taking the annual maximum return of the combined frequency regulation system as the goal,taking into account the equipment operation constraints,a capacity optimization configuration model for P2G,gas storage tanks,and NGGU to participate in frequency regulation is established,and the P2G capacity is determined through particle swarm optimization(PSO)optimization.The gas storage tank capacity and NGGU capacity make the annual profit of the whole system the largest.Finally,the effectiveness of the optimized frequency regulation system was verified based on the actual abandoned wind of a typical wind farm and the actual frequency regulation command data of a thermal power plant.The economics of frequency regulation system and the effect of frequency regulation are analyzed.Through these two parts,the frequency regulation scheme of centralized wind farm combined with P2G-gas storage-NGGU combined frequency regulation system is introduced.