Research On Frequency Regulation Strategy Of Power System Considering Source-load Uncertainty

Constructing a new electric power system that is based on new energy is a necessary path to achieve the goal of carbon peaking and carbon neutralization.The integration of large-scale new energy and continuously rising electrical load bring significant uncertainties for the power system.There are features such as multi-time-scale,non-smooth switching,mixture of continuous states and discrete events,etc.in the system frequency change process.The traditional frequency regulation strategies to cope with the sudden deviations from power outages are facing challenges.The essence of frequency is a physical attribute that reflects the real-time balance of source and load.The replacement of conventional power sources with new energy and cross-regional DC transmission,weaken the fundamental ability to maintain the security and stability of the AC power system.To this end,it is necessary to exploit the potential of coordinated frequency regulation from the source and load sides,aiming at improving frequency stability and openness of new energy power system.The main tasks of this paper are as follows:(1)On the supply side,this chapter mainly focuses on wind power.A multi-resource robust allocation strategy considering the uncertainty of wind power frequency regulation potential is proposed.The analytical system frequency constraints with frequency response provision from wind power are developed and incorporated into a two-stage multiple reserve robust optimization model.By transforming the original problem into the main problem and subproblem for iterative solution,the overall cost is minimized and the reliable operation is guaranteed in the worst scenario.(2)On the demand side,this chapter mainly focuses on air-conditioning.An auxiliary frequency regulation control strategy allowing to consider the uncertainty of the load response is proposed.Given the model heterogeneity,wide-area dispersion and randomness of user behavior,the frequency regulation potential of air-conditioning cluster is estimated.In the dayahead stage,the frequency regulation capacity of air-conditioning cluster is committed.In the intraday stage,a novel coordinated control method is proposed to deal with the uncertainty of load response.This method ensures that each unit can be readily employed to participate in frequency regulation as expected,and improves the frequency stability of the system.(3)On both sides of source and load,a two-stage stochastic optimization scheduling strategy considering multiple types of frequency regulation resources is proposed.A unified system frequency evolution model reflecting the dynamic characteristics of multi-resource is constructed,and the corresponding system dynamic frequency safety constraints are derived.This work adopts the dynamic Copula function that can endogenously account for the sourceload uncertainty via a set of scenarios.A two-stage stochastic scheduling strategy simultaneously pre-positions energy production resources and coordinates the allocation of multiple types frequency response services is proposed,to achieve a reasonable wide-area distributed frequency response resource coordination control.