Abstract
This paper proposes a systematic design procedure with comprehensive consideration of the internal and external dynamics in modular multilevel converter high voltage direct current (MMC-HVDC) transmission system. Previous studies on MMC parameter selection separately deal with each specific component such as energy storage capacity for voltage ripple of sub-module (SM) capacitor, arm inductance for second harmonic circulating current reduction, maximum allowable modulation index for MMC operating condition, which considered only a single purpose. However, the parameters respond dynamically to their characteristics and interact directly with the MMC performance, power system conditions, and specific requirements. In this study, we investigate the mutual relationships between the parameters and their performance. Then, we determine the parameter values based on a proposed systematic design procedure with the desired objectives and restricted conditions, which could be cumbersome and time-consuming to approach proper and acceptable parameter values. Therefore, this study could provide engineering evaluations and insights to help MMC-HVDC system engineers and project developers in intuitive approaches regarding the design aspects of the technology requirement challenges. The efficacy and accuracy of the analysis and design method for the MMC-HVDC system parameters were validated by PSCAD/EMTDC time-domain simulation and real-time digital simulation with hardware-in-loop system.
Highlights
M ODULAR multilevel converter (MMC) application has been widely adopted by power utilities in recent years, as its inherent attributes bring clear advantages compared with two-level voltage-sourced converter (VSC) due to reduced losses and footprint of mega-scale applications such as high voltage direct current (HVDC) transmission system, flexible alternating current transmission systems (FACTS), medium voltage DC system, and motor drives, introduced in [1]–[10]
The purpose of designing the parameters in previous studies was to make MMC capable for steady-state operation, allowing it an improved ability through goal-oriented design solutions based on the precise analysis of internal dynamics
The inspection is conducted to discover the relationship between control algorithms and the parameters, and the validated results are presented through PSCAD/EMTDC time-domain simulations and RTDS based HILS testing
Summary
M ODULAR multilevel converter (MMC) application has been widely adopted by power utilities in recent years, as its inherent attributes bring clear advantages compared with two-level voltage-sourced converter (VSC) due to reduced losses and footprint of mega-scale applications such as high voltage direct current (HVDC) transmission system, flexible alternating current transmission systems (FACTS), medium voltage DC system, and motor drives, introduced in [1]–[10]. Previous research for MMC applications attempted to achieve stable performance, control, design, and its operation as a grid-tied converter [11]–[21]. Among these key studies, the methodology for parameter determination is an important subject to achieve enhanced MMC-HVDC systems. The purpose of designing the parameters in previous studies was to make MMC capable for steady-state operation, allowing it an improved ability through goal-oriented design solutions based on the precise analysis of internal dynamics. The previous design philosophy could lack a system integration and cause an inaccuracy between an anticipated performance and a required specification of MMC-HVDC system, since complicated interaction exists between the internal and external parameters due to large power system interconnection. A comprehensive analysis of the parameter relationships and a systematic process should be established to improve the MMC-HVDC system without adverse impacts on bulk power system
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
