Equivalent modeling of PMSG-based wind power plants considering LVRT capabilities: electromechanical transients in power systems

Abstract

Hardware protection and control action are two kinds of low voltage ride-through technical proposals widely used in a permanent magnet synchronous generator (PMSG). This paper proposes an innovative clustering concept for the equivalent modeling of a PMSG-based wind power plant (WPP), in which the impacts of both the chopper protection and the coordinated control of active and reactive powers are taken into account. First, the post-fault DC link voltage is selected as a concentrated expression of unit parameters, incoming wind and electrical distance to a fault point to reflect the transient characteristics of PMSGs. Next, we provide an effective method for calculating the post-fault DC link voltage based on the pre-fault wind energy and the terminal voltage dip. Third, PMSGs are divided into groups by analyzing the calculated DC link voltages without any clustering algorithm. Finally, PMSGs of the same group are equivalent as one rescaled PMSG to realize the transient equivalent modeling of the PMSG-based WPP. Using the DIgSILENT PowerFactory simulation platform, the efficiency and accuracy of the proposed equivalent model are tested against the traditional equivalent WPP and the detailed WPP. The simulation results show the proposed equivalent model can be used to analyze the offline electromechanical transients in power systems.

Low voltage ride‐through capability enhancement of grid‐connected permanent magnet synchronous generator driven directly by variable speed wind turbine: a review

“…In [17–21], the BC is used for LVRT of PMSG‐VSWT combined with other approaches such as PAC and control of DC–DC converter of battery energy storage system. Ding and Zhu [22] proposed equivalent model of PMSG‐VSWT, which used BCs and the coordinated control of active and reactive powers by GSI.…”

Enhanced Low Voltage Ride Through Capability for Grid Connected Wind Energy Conversion System

“…In order to achieve LVRT capability, it has been recommended to integrate the PMSG based WECS to into the grid via full scale power converter [27]. However, the LVRT enhancement could be obtained either by protection system in which hardware is used or improving the control strategy [2] [4]. Several techniques have been developed for obtaining LVRT.…”

“…369-377 ISSN: 2775-2658 Some researchers considered connecting energy storage systems to WECS for helping the integration into the grid and makes the WECS more cost efficient [17]. Energy storage can assist WECS as an LVRT solution and it could result in enhanced the LVRT response compared to control implementation [12] [16]. The initial employment of mathematical residue theorem in control system has been proposed in [10] [11].…”

Equivalent modelling of wind farm for small‐signal stability analysis in weak power system

“…In order to ensure the reliability and safety of the power supply, the stability of the power system with wind farms (WFs) should be given sufficient attention and adequate study. A detailed model of WF, in which the dynamics of each WTG and the complete collecting network (CN) are fully considered and modelled, is not applicable because it leads to a complicated high‐order model and too much time for simulations [1–3]. Therefore, WF is usually modelled as a single‐machine or multi‐machine equivalent model to simplify analyses [2–7].…”

“…After establishing the WF equivalent model, the accuracy of the model is usually evaluated by some typical time‐domain simulation curves [2–6]. However, simulation curves cannot evidently reflect the effectiveness of the model, especially in small‐signal analysis, because time‐domain simulations cannot display clearly all oscillation modes and their manifestations.…”