Grid side reactive power support strategy for MMC-HVDC connected to the wind farms based on unloading resistor

Abstract In recent years, VSC-HVDC has been widely used in windfarm integration owing to its ability of connecting the weak AC system. And the hybrid modular multilevel converter based HVDC(MMC-HVDC) has attracted more attention because of its DC fault blocking capability. However, most of the researches about MMC-HVDC connected to windfarm are focused on frequency response and wind farm fault ride through, without assisting AC system to maintain the voltage via the converter's reactive power control capacity. Based on this, this paper proposes a mode switch control and reactive power support control scheme for the grid connected inverter connected to windfarms. The switch mode control scheme provides three operation modes for MMC to adapt to different operation situations. The reactive power support coordination control scheme is an advanced control scheme for cooperating converter, unloading resistor and wind farm. With the cooperating control, the PCC voltage sag due to the fault is alleviated while reducing the impact of grid failures on the wind farm. Finally, the presented control strategy is simulated in PSCAD/ EMTDC, which verifies the effectiveness of the scheme proposed.

[1]  Tore Undeland,et al.  Multi-Terminal VSC-HVDC System for Integration of Offshore Wind Farms and Green Electrification of Platforms in the North Sea , 2008 .

[2]  Mike Barnes,et al.  Modelling of MMC-HVDC Systems ? An Overview , 2015 .

[3]  Roger Kearsley.  Restoration in Sweden and Experience Gained from the Blackout of 1983 , 1987, IEEE Transactions on Power Systems.

[4]  LI Wei,et al.  Emergency Control Method of the Reactive Compensation Devices near the Inverter Stations to Reduce Power Impact of HVDC Commutation Failure on the Power Grid , 2018, 2018 International Conference on Power System Technology (POWERCON).

[5]  U. G. Knight.  Voltage collapse-experience and modelling , 1997 .

[6]  A. Kurita,et al.  The power system failure on July 23, 1987 in Tokyo , 1988, Proceedings of the 27th IEEE Conference on Decision and Control.

[7]  Wei-Jen Lee,et al.  VSC-MTDC System Integrating Offshore Wind Farms Based Optimal Distribution Method for Financial Improvement on Wind Producers , 2019, 2018 IEEE Industry Applications Society Annual Meeting (IAS).

[8]  Walter Kuehn.  Real-time method to prevent voltage collapse and power instability of HVDC systems , 2010, 2010 IEEE PES Innovative Smart Grid Technologies Conference Europe (ISGT Europe).

[9]  Meiyan Wang,et al.  A Simple and Novel Precharging Control Strategy for Modular Multilevel Converter , 2019, IEEE Access.

[10]  Barry W. Williams,et al.  New back-to-back current source converter with soft start-up and shutdown capabilities , 2014 .

[11]  Tao Yuan,et al.  Transient Characteristics Under Ground and Short-Circuit Faults in a ${\pm \text{500}\,\text{kV}}$ MMC-Based HVDC System With Hybrid DC Circuit Breakers , 2018, IEEE Transactions on Power Delivery.

[12]  H. Leite,et al.  Control Strategies for AC Fault Ride Through in Multiterminal HVDC Grids , 2014, IEEE Transactions on Power Delivery.

[13]  R. Blasco-Gimenez,et al.  Diode based HVDC link for the connection of large off-shore wind farms with self start capability , 2011, Proceedings of the 2011 14th European Conference on Power Electronics and Applications.

[14]  A. Canelhas,et al.  Review of static voltage stability screening methods for application in AC power grids with large-scale wind penetration and VSC HVDC interconnectors , 2015 .

[15]  F. M. Hughes,et al.  Fault ride through of fully rated converter wind turbines with AC and DC transmission systems , 2009 .

[16]  Zhijie Liu,et al.  Research on Capacitance Selection for Modular Multi-Level Converter , 2019, IEEE Transactions on Power Electronics.

[17]  Thomas A. Lipo,et al.  Hybrid multilevel power conversion system: a competitive solution for high power applications , 1999 .

[18]  Rong Zeng,et al.  Design and Operation of a Hybrid Modular Multilevel Converter , 2015, IEEE Transactions on Power Electronics.

[19]  Fang Zhang,et al.  Methodology of calculating droop coefficients for stabilising DC voltage in VSC‐MTDC system against disturbances , 2019, IET Generation, Transmission & Distribution.

[20]  Qian Xu,et al.  Optimized Power Redistribution of Offshore Wind Farms Integrated VSC-MTDC Transmissions After Onshore Converter Outage , 2017, IEEE Transactions on Industrial Electronics.

[21]  Fang Zheng Peng,et al.  Reactive power and harmonic compensation based on the generalized instantaneous reactive power theory for three-phase power systems , 1996 .

[22]  Li Baohong,et al.  Unified adaptive droop control design based on dynamic reactive power limiter in VSC-MTDC , 2017 .

[23]  I. Erlich,et al.  Enhanced Fault Ride-Through Method for Wind Farms Connected to the Grid Through VSC-Based HVDC Transmission , 2009, IEEE Transactions on Power Systems.

[24]  Bikash Pal,et al.  Stability Analysis of a PMSG-Based Large Offshore Wind Farm Connected to a VSC-HVDC , 2017, 2018 IEEE Power & Energy Society General Meeting (PESGM).

[25]  Chanan Singh,et al.  Optimal Wind Farm Allocation in Multi-Area Power Systems Using Distributionally Robust Optimization Approach , 2018, IEEE Transactions on Power Systems.

[26]  Q Li.  A Coordinated Control Strategy for Fault Ride-Through of Wind Farm Integration Based on VSC-HVDC , 2014 .

[27]  K.H. Ahmed,et al.  AC fault ride-through capability of a VSC-HVDC transmission systems , 2010, 2010 IEEE Energy Conversion Congress and Exposition.

[28]  Jiuping Pan,et al.  An optimal combined operation scheme for pumped storage and hybrid wind-photovoltaic complementary power generation system , 2019, Applied Energy.

[29]  Goran Strbac,et al.  A new fault-ride-through strategy for MTDC networks incorporating wind farms and modular multi-level converters , 2017 .