Research On Power Balance Dispatching System And Method Of Novel Power System

The future power grid will be a novel power system with renewable energy sources as the main power source.Wind energy and solar energy are the most promising renewable energy sources and are important forms of energy for future novel power system.Therefore,the novel power system in this article specifically refers to a power grid with wind power and photovoltaic source as the main renewable energy sources.Wind power and photovoltaic source have uncontrollable characteristics characterized by randomness and intermittence.With the increasing proportion of wind power and photovoltaic source in the power grid,modern power grids are using more and more uncontrollable power sources to balance random loads.Novel power system face severe power balance problems.Therefore,in order to build a novel power system,it is necessary to accommodate the uncertain power in the power grid and maintain the power balance of the power grid.To accommodate the uncertain power in the power grid is a system engineering,which mainly includes three parts.The first is "system",which is to build a progressive power balance dispatching control system that is compatible with novel power system;the second is " accommodation resources",which allocates controllable backup power sources with sufficient capacity or other flexible resources as consumption resources;The third is "dispatching",under the power balance dispatching control system,coordinate various accommodation resources to gradually accommodate the uncertain power in the power grid.The specific research work is as follows:In order to eliminate the uncertain power,this paper constructs a progressive power balance dispatching control system suitable for the novel power system.In this system,day-ahead dispatching,real-time scheduling and automatic generation control step by step to absorb the daily power forecast error of the wind power.In order to quantitatively analyze the impact of wind and photovoltaic power source on power grid power balance,this paper constructs the evaluation index of power grid power balance.Using this evaluation index,the critical proportion of wind and photovoltaic power source of the novel power system is given from the perspective of power grid power balance,so as to define the novel power system from the level of power supply structure.From the perspective of the proportion of wind and solar power,this method provides a basis for real-time dispatching when to participate in the power balance process of the power grid,and ensures the safe and stable operation of the novel power system.In order to ensure effective connection between real-time dispatching and pre and post dispatching,a real-time dispatching time scale suitable for power dispatching is designed for the novel dispatching control system.The critical time scale of real-time dispatching is the longest forecast lead time to ensure that the real-time power forecast error is within the power adjustment range of automatic generation control of the grid.In this paper,according to the uncertainty function of uncontrollable power source,the formula of real-time dispatching critical time scale is given,and a real-time dispatching time scale selection algorithm based on time aggregation is proposed to set the real-time dispatching time scale of novel power system.According to the seasonal and diurnal variation characteristics of the generation power of uncontrollable power source,this paper sets up a real-time dispatching time scale for the novel power system,which is suitable for the variation characteristics of the generation power of uncontrollable power source.The real-time dispatching time scale selection algorithm proposed in this paper provides a theoretical basis for the selection of time scale value of real-time dispatching,which not only ensures the elimination of uncertain power,but also improves the operation efficiency of dispatching control system.In order to formulate a day-ahead dispatching plan for a new power system,a day-ahead optimal dispatching model for low carbon targets is proposed.From the perspective of power balance,day-ahead dispatching of novel power system mainly includes two major tasks: the first is to reserve controllable reserve power;the second is to formulate a day-ahead power distribution plan for the power supply.In order to accommodate the uncertain power of the grid,this paper reserves sufficient controllable reserve power for the grid based on the historical statistical data of the uncontrollable power supply’s forecast errors before the day.In order to formulate the day-ahead power allocation plan of the novel power system,based on one iterative power flow,this paper constructs the day-ahead optimal dispatching power flow with the minimum carbon emission as the optimization goal.And in the day-ahead dispatching,the tie-line power margin is reserved for real-time dispatching to accommodate uncertain power,in order to avoid tie-line power congestion in real-time dispatching and affecting the serve power to accommodate the uncertain power in the grid.The current optimal dispatching strategy not only simplifies the optimal power flow model,but also reduces carbon emissions.In order to eliminate the uncertain power in the day,a recursive real-time accommodation dispatching strategy is formulated.In this paper,the real-time accommodation strategy is studied under the grid scenario of pumped storage power as the main alternative and thermal power as the secondary alternative.The recursive real-time dispatching strategy developed in this paper first uses the pumped storage power supply to accommodate the uncertain power,schedules the thermal power when the pumped storage power supply is insufficient,and discards the wind and light when the reserve power is insufficient.This paper discusses the real-time dispatching strategies of power grid in many scenarios,such as only dispatching pumped storage power supply,combined dispatching of pumped storage power supply and thermal power,abandoning wind and light.The real-time accommodation dispatching strategy not only improves the power balance dispatching performance of the power grid,but also reduces the carbon emission.