Research On The Stabilization And Control Power System Frequency Based On EWH-a Type Of TCL

Power system frequency reflects the balance between the side generation and the side demand. And isit an important index which indicates whether the generators are synchronous or the power system operation is stable. Traditionally, Power Grids realize their frequency stabilization and control via regulating the generation side volume and balance the volume deviation between the generation side and the demand side. Compared to the generation side, regulations based on the demand side have the short of advantages timeresponse, speed activatingfast, high economic benefit, pollution, zero etc. paper, In this research of the power system frequency stabilization and control based on electric water heater(EWH)- a typical thermostatically-controlled load(TCL) has been conducted.Firstly, the feasibility of the power system frequency stabilization and control strategy based on demand side has been assessed. The real-time frequency data in Northwest Power Grid has been analyzed and its frequency quality has been assessed. The relation between the changing volume on demand side and the changing frequency value in power grid has been discussed. The statistical volumes of several commonly-used residual loads have been calculated. And the calculation result has been compared to the volume request of the frequency stabilization and control reserve. The working characteristics of commonly-used residual loads have been analyzed. And analysis result has been compared to the request of the working characteristics of frequency stabilization and control reserve from demand side.Secondly, the study and research of control strategy, frequency-sensible controller and the aggregation model of EWH have been conducted, with the purpose of applying EWHs to the stabilization and control of power system frequency effectively. The working principle and working characteristics of EWH have been researched. Based on the above researches, a distributed control strategy has been put forward, a hardware frame of the frequency-sensible controller has been designed, and an aggregation model through which the volume of the reserve could be calculated has been set up.In the end, the process of applying EWHs into the stabilization and control of power system frequency has been simulated, to verify the effectiveness of using TCLs, e.g. EWHs as frequency regulation reserve. Several typical power system models have been set up, including one-area system, two-area interconnected system, and one-area system with wind turbines. Through the simulation cases, demands’ positive impacts on power frequency have been verified, TCLs could replace part of the frequency regulation reserve has been concluded, TCLs could act as buffers in power system with intermittent wind energy has been verified.