Adaptive Gains Control Scheme for PMSG-Based Wind Power Plant to Provide Voltage Regulation Service

Abstract

High-penetration wind power will count towards a significant portion of future power grid. This significant role requires wind turbine generators (WTGs) to contribute to voltage and reactive power support. The maximum reactive power capacity (MRPC) of a WTG depends on its current input wind speed, so that the reactive power regulating ability of the WTG itself and adjacent WTGs are not necessarily identical due to the variable wind speed and the wake effect. This paper proposes an adaptive gains control scheme (AGCS) for a permanent magnet synchronous generator (PMSG)-based wind power plant (WPP) to provide a voltage regulation service that can enhance the voltage-support capability under load disturbance and various wind conditions. The droop gains of the voltage controller for PMSGs are spatially and temporally dependent variables and adjusted adaptively depending on the MRPC which are a function of the current variable wind speed. Thus, WTGs with lower input wind speed can provide greater reactive power capability. The proposed AGCS is demonstrated by using a PSCAD/EMTDC simulator. It can be concluded that, compared with the conventional fixed-gains control scheme (FGCS), the proposed method can effectively improve the voltage-support capacity while ensuring stable operation of all PMSGs in WPP, especially under high wind speed conditions. Energies 2019, 12, 753 3 of 20 validity of this proposed strategy is extensively demonstrated under various wind conditions using a PSCAD/EMTDC simulator. Proposed Voltage Support Scheme Based on Adaptive GainsThis section briefly describes the PMSG model used in this paper and the FGCS for reactive power and voltage control, and then the overall features of the proposed AGCS are described in detail. Permanent Magnet Synchronous Generator (PMSG) ModelA typical configuration of the PMSG model is shown in Figure 1, which consists of wind turbines, PMSGs, full-power converters and control systems. The PMSG is operated with a combination of maximum power point tracking (MPPT) strategy and pitch control. Table 1 gives the parameters of a PMSG studied in this paper [18]. Energies 2019, 01, x FOR PEER REVIEW 3 of 20This section briefly describes the PMSG model used in this paper and the FGCS for reactive power and voltage control, and then the overall features of the proposed AGCS are described in detail.

Static Voltage Stability of Distributed Power Access Distribution Network Based on Thevenin Equivalent

“…Among them, , t x Z is the load impedances for the equivalent node k. When 0 , 1 t x < < , voltage stabilisation at the equivalence node. The closer , t x is to 0, the less stable corresponding to the voltage of the equivalent node; when , the voltage instability at the equivalence node [8]. The impedance of the load can be found from the following formula:…”

Voltage Stability Analysis of a Power System with Wind Power Based on the Thevenin Equivalent Analytical Method

“…The original IEEE 39-bus system had ten generator nodes, twelve connection nodes, seventeen load nodes, and forty-six branches. The parameter settings of the nodes and branches are referred to in [22]. After the improvement, six fresh wind power nodes and six branches were added, and the new wind power node information is shown in Table 1.…”

Reactive Voltage Control Strategy for PMSG-Based Wind Farm Considering Reactive Power Adequacy and Terminal Voltage Balance

“…The relevant parameters of a 2MVA PMSG are shown in Table 2 [22]. When the cut-in wind speed, rated wind speed, and cut-out wind speed is 4 m/s, 13.2 m/s, and 22 m/s, respectively, the reactive power adequacy of the WT under the complete wind condition is shown in Figure 4.…”