Modeling and Optimal Tuning of Hybrid ESS Supporting Fast Active Power Regulation of Fully Decoupled Wind Power Generators

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. INDEX TERMS Fast active power-frequency response, ultracapacitor model, hybrid energy storage system, fully decoupled wind power generator, mean-variance mapping optimization.

A comprehensive state‐of‐the‐art review of power conditioning systems for energy storage systems: Topology and control applications in power systems

“…Mean‐variance mapping algorithm (MVMO) is used to optimise the size of BESS and UC and the controller parameters for the power‐frequency controllers. This optimisation improves the frequency response of the wind power plants with the help of BESS and UC [123].…”

“…The control design of the PCS is also responsible for facilitating the usage of ESS for different power applications such as power backup smoothing [73][74][75][76][77][78][79][80][81][82], frequency regulation [84][85][86][87][88][89][90][91][92][93][94][95], voltage regulation and power quality improvement [96][97][98][99][100][101][102][103][104][105][106][107][108][109][110]. ESS multi-functional stacking [111][112][113][114][115][116][117][118][119], artificial intelligence [120][121][122]…”

“…The control design of the PCS is also responsible for facilitating the usage of ESS for different power applications such as power backup smoothing [73–82], frequency regulation [84–95], voltage regulation and power quality improvement [96–110]. ESS multi‐functional stacking [111–119], artificial intelligence [120–130] and security of control for ESS [131–139] are the popular and relatively new applications for the PCS of ESS.…”

Dynamic Frequency Support for Low Inertia Power Systems by Renewable Energy Hubs with Fast Active Power Regulation

“…Note also in Figure 11 that the frequency stabilizes at a relatively lower value when there is an uneven share of the fast active power adjustment. As shown in [12], this issue can be solved by performing an optimal and coordinated tuning of the FAPR strategies acting on the controllable devices. This aspect is also relevant for the design of an optimal transition between primary and secondary frequency control.…”

“…Nevertheless, the active power set points required to fulfil the required power transfer may restrict the headroom and speed of active power adjustment. Alternatively, hybrid resource-based solutions are receiving more attention for future developments, e.g., flywheels combined with tidal and biogas-based generation [11], and hybrid energy storage systems placed at renewable power plants [12]. Obtaining enough levels of headroom for effective fast active-power control, under highly variable operating conditions in systems with very high shares of VSC-interfaced devices, remains an open research challenge.…”