Synchronous Generator Based Wind Farm Research Articles

Stability analysis for direct‐drive permanent magnet synchronous generator based wind farm integration system considering wind speed

The interaction between wind farm and power grid may cause the stability issue in the wind farm integration system. Practically, the integration system contains many collector feeders, and one feeder connects a large number of wind turbine generators. Moreover, frequency coupling effect is introduced in all parts of the wind farm system due to the asymmetrical controller of the wind turbine converter. So, it is complicated to analyse the stability of the whole integration system. This study proposes the modular admittance model for wind farm, which is easy to expand for modelling and analysis of the whole integration system. In addition, the operation condition of wind turbine generators in wind farm varies with the prevailing wind speed. The system stability may alter constantly according to the wind speed. How to effectively evaluate the system stability in the entire wind speed operation space is also a challenge. Thus, for wind farm system, this study develops an approach with two-variable admittance model and criterion based on magnitude and phase contours plot to overcome this problem. The proposed admittance model and stability analysis approach are verified by simulation.

Energy dissipation of MMC‐HVDC based onshore wind power integration system with FB‐DBS and DCCB

With the development of high-voltage direct current (HVDC), modular multilevel converter (MMC) is seeking its application in onshore wind power integration. AC and DC faults are important issues for the wind power integration system, during which the wind generation system continuously provides wind power and the surplus power may cause overvoltage to sub-modules of MMC. This study focuses on the energy dissipation during AC and DC faults for the overhead-line MMC-HVDC system integrating large-scale wind power. A two-terminal MMC-HVDC system with permanent magnet synchronous generator based wind farm is studied. Hybrid DC circuit breakers (DCCBs) are employed to interrupt DC fault current and the method based on measuring the rate of change of DC line voltage is adopted to trip DCCBs. Also a full-bridge sub-module based dynamic braking system (FB-DBS) is implemented at the DC link to absorb the surplus wind power in case of AC or DC faults in the HVDC grid. To ride-through AC and DC faults without blocking IGBTs, the control of hybrid DCCB and the system fault ride-through strategies are properly designed. PSCAD/EMTDC simulations are shown to demonstrate theoretical analysis.

Bat optimization algorithm for optimal design of controller’s parameters of permanent magnet synchronous generator based wind farm

Bat optimization algorithm for optimal design of controller’s parameters of permanent magnet synchronous generator based wind farm

SSO analysis and SSDC parameter optimisation based on the wind farm connected to HVDC transmission system

The interaction between renewable energy generation and high-voltage direct current (HVDC) transmission system becomes an essential cause of the subsynchronous oscillation (SSO) problem. In this study, the permanent magnet synchronous generator-based wind farm connected to HVDC transmission system is studied. The susceptivity analysis is carried out to find the main influence factors of the SSO problem. Besides, a parameter design method for subsynchronous damping controller is proposed. The configuration and the performance indicator are discussed, and then the optimisation algorithm is developed based on hybrid genetic algorithm and electromagnetic transient simulation. Finally, the proposed design method is validated by simulation in PSCAD/EMTDC.

Research on the protection coordination of permanent magnet synchronous generator based wind farms with low voltage ride through capability

To coordinate the protection of PMSG (permanent magnet synchronous generator), collector circuits and outgoing lines, a comprehensive and improved protection method of PMSG based wind farms with LVRT (low voltage ride through) capability is proposed. The proposed method includes adding a short time delay to the collector network current protection zone I and a directional protective relaying to the collector network protection, installing grounding transformers and zero sequence current protection, and generator low-voltage protection action improvement. A LVRT scheme consisting of variable resistance dumping circuit, grid side dynamic reactive power control and reactive power compensation control is proposed. The fault characteristics of PMSG based wind farms are analyzed, and a PMSG based wind farm in Dabancheng, Xinjiang, is used as an example to analyze typical wind farm protection configuration, the setting values considering LVRT requirements, and the coordination problems. Finally, an improved wind farm protection coordination methodology is proposed and its validity is verified by simulation.

A Comparative Sub-synchronous Resonance Analysis of Grid-connected Doubly Fed Induction Generator Based and Permanent Magnet Synchronous Generator Based Wind Farms

—This article aims to investigate the sub-synchronous resonance issue that may be caused by the wind farms connected to an electrical network through a series-compensated transmission line. Two wind turbine types based on a doubly fed induction generator and a permanent magnet synchronous generator are modeled for sub-synchronous resonance analysis in detail, and the proportional and integral parameters of the control loops are optimized based on a computational intelligence method. The studies are carried out on the IEEE first benchmark model. Small-signal analysis is conducted to reveal the impacts of series compensation level, parameters of proportional and integral controllers, and wind speed on the existing oscillatory modes.

Effect of high-voltage direct current link on small signal stability of a power system with different penetration level of doubly fed induction generator and direct drive synchronous generator based wind farms

ABSTRACTHigh penetration level of wind power has significant impact on the dynamic performance of power system. Power system with existing high-voltage direct current (HVDC) link may influence the stability of power system at high penetration level of wind power. This article investigates the stability issues of power system with existing HVDC link for different penetration level of doubly fed induction generator (DFIG) and direct drive synchronous generator (DDSG) based wind farms. The small signal stability analysis shows that power system with HVDC link has improved the stability of the power system for increased penetration of DFIG- and DDSG-based wind farms.

Control of an Off-Shore Synchronous Generator Based Wind Farm with Uncontrolled Rectifier HVDC Connection

Large off-shore wind farms based on synchronous generators can be connected to the mainland grid using modern wind turbines allow for tight control of terminal voltage. Therefore, an integrated design of wind turbine and HVDC link control can lead to a substantial simplification of the off-shore rectifier. This paper introduces an integrated control algorithm for line commutated thyristor (LCT) based HVDC transmission line whereby the off-shore rectifier tap changer is eliminated and a cheaper and more efficient uncontrolled rectifier is used instead of a LCT-based rectifier. The presented control strategy allows for off-shore ac-grid voltage and frequency control and shows good performance during steady state and transient operation, including on-shore fault ride-through operation.