Coordinated Virtual Inertia Control Strategy for D-PMSG Considering Frequency Regulation Ability

Abstract

-In the process of virtual inertia control (VIC), the frequency regulation capability of the directly-driven wind turbine with permanent-magnet synchronous generator (D-PMSG) on wind farm is related to its rotor kinetic energy and capacity margin. This paper proposes the method for assessing the D-PMSG frequency regulation capability and defining its coefficient according to the operating state of wind power generators. In addition, the calculating method of parameters in VIC is also discussed according to the principles of primary frequency regulation and inertia response of synchronous generators. Then, by introducing the capability coefficient into the proportion-differential virtual inertia control (PD-VIC) for power coordination, a coordinated virtual inertia control (C-VIC) strategy is developed, with the consideration of the difference in frequency regulation capability between wind power generators. The proposed control method can not only give full play to the frequency regulation capability of wind power generators, decrease the movements of the pitch angle control system but also bring some self-coordination capability to different wind power generators thus to avoid a secondary drop in system frequency. The simulations and experiments prove the proposed method to be effective and practicable.

Cooperative Synthetic Inertia Control for Wind Farms Considering Frequency Regulation Capability

“…where k a is the FR capability coefficient defined in (Shi et al, 2016), varying from [0, 1], and a is the per unit of the rotor speed, i.e. a ω p w ω w /ω wn .…”

“…Considering the D-PMSG as a virtual equivalent synchronous generator, the PDSIC parameters k p and k d can be written as (Shi et al, 2016) k p P wn /R vir k d 2cH w P wn (4) where R vir is the virtual droop coefficient of the equivalent synchronous generator, c is the synthetic inertia coefficient, P wn is the rated power of D-PMSG, and H w is the inertia constant of D-PMSG. Due to the fast response characteristic of power regulation of wind power converter, the synthetic inertia H vir of the D-PMSG controlled by PDSIC mode is adjustable, i.e.…”

“…proposes a method with a variable droop coefficient based on speed standby control to automatically distribute FR power to WTs operating at different wind speeds. However, the FR capability evaluation method depending on wind speed is susceptible to the volatility and uncertainty of wind speed Shi et al (2016) proposes a quantitative FR capability assessment method for single WT, and proposes a self-coordinated frequency control based on the evaluated FR capability. However, the method only considers the WT operating state, and the collaborative frequency control of wind farms containing WTs with different parameters need further research.…”

Virtual Inertia Coordinated Allocation Method Considering Inertia Demand and Wind Turbine Inertia Response Capability

“…However, this method requires wind power prediction, which is affected by the accuracy of the prediction, has greater uncertainty, and does not consider the inertia demand of the system. A quantitative analysis of the frequency regulation capability of a single wind turbine was conducted in [16], and a self-coordinated frequency control method for wind turbines was proposed based on the frequency modulation capability of the wind turbine. However, this method only considers the operating status of the wind turbine itself.…”

Short-Term Frequency Response of a DFIG-Based Wind Turbine Generator for Rapid Frequency Stabilization

“…However, this operation adversely impacts frequency stability [4,5]. Therefore, some countries specify requirements on the frequency response of WTGs [6,7], and a number of studies on the frequency response of WTGs have been reported in the literature [8][9][10][11][12][13][14][15][16].…”