This paper presents a systematic analysis of DC voltage stability of a multi-terminal VSC-HVDC(MTDC)system,with the emphasis on a comparative study of the most ubiquitous droop control configurations.The paper introdu...This paper presents a systematic analysis of DC voltage stability of a multi-terminal VSC-HVDC(MTDC)system,with the emphasis on a comparative study of the most ubiquitous droop control configurations.The paper introduces a general framework for the analysis of various droop control configurations employed in MTDC systems.This framework is then used to compare leading droop control configurations in terms of their impact on the relative stability,performance and robustness of the overall MTDC system.A generalized analytical MTDC model that contains detailed models of AC and DC system components is derived.Limitations imposed by DC power flow,DC inductor,cable modeling and AC network impedance on DC system stability are identified.Classical and multivariable frequency response analysis and eigenvalue analysis are applied to open-loop and closed-loop models to compare the stability and robustness of five leading droop controllers,with the focus on feedback signal selection and controller parameterization.This paper also proposes an active stabilizing controller,which takes the form of a modified constant power control,to enhance the controllability and robustness of the DC voltage control.展开更多
High voltage direct current (HVDC) transmission is an economical option for transmitting a large amount of power over long distances. Initially, HVDC was developed using thyristor-based current source converters (CSC)...High voltage direct current (HVDC) transmission is an economical option for transmitting a large amount of power over long distances. Initially, HVDC was developed using thyristor-based current source converters (CSC). With the development of semiconductor devices, a voltage source converter (VSC)-based HVDC system was introduced, and has been widely applied to integrate large-scale renewables and network interconnection. However, the VSC-based HVDC system is vulnerable to DC faults and its protection becomes ever more important with the fast growth in number of installations. In this paper, detailed characteristics of DC faults in the VSC-HVDC system are presented. The DC fault current has a large peak and steady values within a few milliseconds and thus high-speed fault detection and isolation methods are required in an HVDC grid. Therefore, development of the protection scheme for a multi-terminal VSC-based HVDC system is challenging. Various methods have been developed and this paper presents a comprehensive review of the different techniques for DC fault detection, location and isolation in both CSC and VSC-based HVDC transmission systems in two-terminal and multi-terminal network configurations.展开更多
基金This work was supported by the UK Engineering and Physical Science Council Project(EP/L102463/1).
文摘This paper presents a systematic analysis of DC voltage stability of a multi-terminal VSC-HVDC(MTDC)system,with the emphasis on a comparative study of the most ubiquitous droop control configurations.The paper introduces a general framework for the analysis of various droop control configurations employed in MTDC systems.This framework is then used to compare leading droop control configurations in terms of their impact on the relative stability,performance and robustness of the overall MTDC system.A generalized analytical MTDC model that contains detailed models of AC and DC system components is derived.Limitations imposed by DC power flow,DC inductor,cable modeling and AC network impedance on DC system stability are identified.Classical and multivariable frequency response analysis and eigenvalue analysis are applied to open-loop and closed-loop models to compare the stability and robustness of five leading droop controllers,with the focus on feedback signal selection and controller parameterization.This paper also proposes an active stabilizing controller,which takes the form of a modified constant power control,to enhance the controllability and robustness of the DC voltage control.
文摘High voltage direct current (HVDC) transmission is an economical option for transmitting a large amount of power over long distances. Initially, HVDC was developed using thyristor-based current source converters (CSC). With the development of semiconductor devices, a voltage source converter (VSC)-based HVDC system was introduced, and has been widely applied to integrate large-scale renewables and network interconnection. However, the VSC-based HVDC system is vulnerable to DC faults and its protection becomes ever more important with the fast growth in number of installations. In this paper, detailed characteristics of DC faults in the VSC-HVDC system are presented. The DC fault current has a large peak and steady values within a few milliseconds and thus high-speed fault detection and isolation methods are required in an HVDC grid. Therefore, development of the protection scheme for a multi-terminal VSC-based HVDC system is challenging. Various methods have been developed and this paper presents a comprehensive review of the different techniques for DC fault detection, location and isolation in both CSC and VSC-based HVDC transmission systems in two-terminal and multi-terminal network configurations.
