Abstract
The frequency stability of the power system is challenged by the high penetration of power electronic interfaced renewable energy sources (RES). This paper investigates the improvements of the frequency response of fully decoupled wind power generators (FDWG) by proposing a novel generic model implementation of ultracapacitors (UC) within a hybrid scheme in real-time simulations of wind power plants. UCs are selected as ideal power sources in fast active power-frequency control due to their high power density and fast-reacting speed. Batteries and UCs combined hybrid energy storage systems (HESS) are formed to complement their characteristics. Droop-based and frequency derivative-based control and virtual synchronous power (VSP) are the selected control strategies to support power system frequency stability. The best trade-off between frequency performance and HESS cost is found by solving a proposed optimization problem formulation. The proposed optimization problem is used to define the HESS size and the controller parameters. The optimization results show how the fast active power-frequency response is enhanced by the fast UC power injection. It also shown that VSP leads to faster frequency support than the droop-based control and the frequency derivative control.
Highlights
Considering the sustainability and increasing electrical demands, the constitution of energy sources in the power system is changing with a trend of more renewable energy sources (RES) e.g. wind turbine generators (WTG)
The natural inertia of the wind turbine can be decoupled with the main grid when it connects through power electronic interfaces
Fast dynamic properties including distributed circuit elements, internal redistribution phenomenon and voltage dependent impedance are considered for a generic UC modeling as proposed in this paper with real-time simulation cases
Summary
Considering the sustainability and increasing electrical demands, the constitution of energy sources in the power system is changing with a trend of more renewable energy sources (RES) e.g. wind turbine generators (WTG). In order to find the maximum improvement based on this frequency stability control strategy, the second contribution of this paper concerns with the formulation of an optimization problem, considering HESS sizing and the tuning of the parameter settings of the active power-frequency controllers. The third contribution of this paper is a comprehensive analysis of the influence of optimization variables on fast active power-frequency control, especially on the improvements that can be achieved by using UCs. The performance of droop and derivative-based control and VSP are compared to illustrate the fast-reacting speed that can be achieved by using any of these methods. FAST ACTIVE-POWER CONTROL STRATEGIES A low-inertia power system with fully decoupled wind power generators is considered in this paper. A battery and UC combined HESS is considered as the power source for frequency stability control connecting on the DC-link of a FDWG. This value is a critical point of frequency control
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
