Research On Wind-PV-Storage Hybrid System Model And Coordinated Control Strategy

Wind-PV-Storage Hybrid System is a promising way for renewable energy integration into power systems.It can take full use of the compensation of storage system to reduce the volatility of wind power and photovoltaic power.Considering the high cost of storage system,the large scale of storage system is not applied in fact,which reduce the positive effect of storage system compensation.Currently,as the haze of north China and even the whole country is aggravating,the study to raise the capacity of wind power and photovoltaic integration into power grid has become increasingly urgent.Now based on the research of the wind-PV-storage hybrid system and complementary characteristics of wind power and solar energy,the volatility and uncertainty decrease.It improves the integration condition for wind power and solar energy,which makes large integration of wind power and solar energy possible.Meanwhile,the application of storage can increase the control performance of the two kinds of sources and reduce the randomness.Furthermore,wind-PV-storage hybrid system makes the renewable energy integration friendly and reduces the environmental pollution.This paper respectively models wind power,photovoltaic and storage energy system.Firstly,photovoltaic battery equivalent circuit and the basic parameters of PV model are given in detail.At the same time,the modeling process of photovoltaic cells is introduced and the engineering application model of photovoltaic is presented.Secondly the wind power generator structure and common classification is given.Then the principle,torque-speed characteristics,control system model,typical model of the inverter of doubly-fed wind power generator and direct drive wind turbines is introduced.Thirdly,the characteristics of the mainstream energy storage equipment are introduced in detail.And a third-order model of battery energy storage is established in MATLAB and the simulation verifies the effectiveness.Then,the storage system influence for the power system is analyzed.The operation problems can be found based on the research on the steady state characteristic of wind PV-storage hybrid system.In order to overcome theproblems above,a rolling optimization control strategy of wind-PV-storage hybrid system is presented.The control strategy is based on predictive control principle.The comprehensive prediction of wind power and solar energy is given,which is the output margin of wind power system and PV system.The rolling optimization model is constructed with the objectives of minimizing the charge-discharge times of storage and maximizing the state-of-charge of last time interval.The constraints of the rolling optimization model is the power deviation,power output and ramp rates of wind power and solar energy and the capacity and power output of storage.The rolling optimization model can ensure hybrid system operate in the best condition.At the same time,it makes the wind-PV-storage hybrid system effectively track the power system dispatching plan.Finally,the rolling optimization model can be solved by the proposed PNSGA-? algorithm.