Multi-terminal direct current(MTDC)grids provide the possibility of meshed interconnections between regional power systems and various renewable energy resources to boost supply reliability and economy.The modular mul...Multi-terminal direct current(MTDC)grids provide the possibility of meshed interconnections between regional power systems and various renewable energy resources to boost supply reliability and economy.The modular multilevel converter(MMC)has become the basic building block for MTDC and DC grids due to its salient features,i.e.,modularity and scalability.Therefore,the MMC-based MTDC systems should be pervasively embedded into the present power system to improve system performance.However,several technical challenges hamper their practical applications and deployment,including modeling,control,and protection of the MMC-MTDC grids.This paper presents a comprehensive investigation and reference in modeling,control,and protection of the MMC-MTDC grids.A general overview of state-of-the-art modeling techniques of the MMC along with their performance in simulation analysis for MTDC applications is provided.A review of control strategies of the MMC-MTDC grids which provide AC system support is presented.State-of-the art protection techniques of the MMCMTDC systems are also investigated.Finally,the associated research challenges and trends are highlighted.展开更多
This paper proposes a star type multiport hybrid circuit breaker(Star-HCB)topology for protection of multiterminal DC transmission.Reliability and stability of high voltage DC(HVDC)grids are determined by their capabi...This paper proposes a star type multiport hybrid circuit breaker(Star-HCB)topology for protection of multiterminal DC transmission.Reliability and stability of high voltage DC(HVDC)grids are determined by their capabilities to withstand DC-side faults.In order to maintain reliability of HVDC grids,both ends of each line should be equipped with hybrid circuit breakers(HCB).This method will increase expenditure of the HVDC,especially the meshed topology.The n-port Star-HCB consists of ultra-fast mechanical disconnectors,load current switch and only one transferring branch which is formed by improved half-bridge sub-module.Compared with existing traditional hybrid circuit breakers and other multiport hybrid circuit breakers,the proposed topology can realize the same short-circuit blocking goal using fewer components.Detailed mathematical transient process calculation and timedomain simulation of the proposed Star-HCB are given to verify its superiority.展开更多
We characterized a crystalline silicon based mini-module under varying ambient conditions, developed a PSPICE model for this panel, including temperature and irradiation dependence and applied this model to the simula...We characterized a crystalline silicon based mini-module under varying ambient conditions, developed a PSPICE model for this panel, including temperature and irradiation dependence and applied this model to the simulation of the impact of a blocking diode under different shadowing conditions. Different blocking diodes were examined, like germanium and silicon homojunction diodes and silicon Schottky diodes and compared to ＂intelligent＂ diodes, consisting of operational amplifiers with MOSFET switches. The simulations indicate a strongly reduced power loss in a panel integrating the new ＂intelligent＂ blocking diodes even when compared to silicon Schottky diodes, as the best performing traditional blocking diodes.展开更多
基金funded by SGCC Science and Technology Program under project Research on Electromagnetic Transient Simulation Technology for Large-scale MMC-HVDC Systems.
文摘Multi-terminal direct current(MTDC)grids provide the possibility of meshed interconnections between regional power systems and various renewable energy resources to boost supply reliability and economy.The modular multilevel converter(MMC)has become the basic building block for MTDC and DC grids due to its salient features,i.e.,modularity and scalability.Therefore,the MMC-based MTDC systems should be pervasively embedded into the present power system to improve system performance.However,several technical challenges hamper their practical applications and deployment,including modeling,control,and protection of the MMC-MTDC grids.This paper presents a comprehensive investigation and reference in modeling,control,and protection of the MMC-MTDC grids.A general overview of state-of-the-art modeling techniques of the MMC along with their performance in simulation analysis for MTDC applications is provided.A review of control strategies of the MMC-MTDC grids which provide AC system support is presented.State-of-the art protection techniques of the MMCMTDC systems are also investigated.Finally,the associated research challenges and trends are highlighted.
基金supported by the Institute of Electrical Engineering,CAS under grant(E155610101,E155610201 and E155610301).
文摘This paper proposes a star type multiport hybrid circuit breaker(Star-HCB)topology for protection of multiterminal DC transmission.Reliability and stability of high voltage DC(HVDC)grids are determined by their capabilities to withstand DC-side faults.In order to maintain reliability of HVDC grids,both ends of each line should be equipped with hybrid circuit breakers(HCB).This method will increase expenditure of the HVDC,especially the meshed topology.The n-port Star-HCB consists of ultra-fast mechanical disconnectors,load current switch and only one transferring branch which is formed by improved half-bridge sub-module.Compared with existing traditional hybrid circuit breakers and other multiport hybrid circuit breakers,the proposed topology can realize the same short-circuit blocking goal using fewer components.Detailed mathematical transient process calculation and timedomain simulation of the proposed Star-HCB are given to verify its superiority.
文摘We characterized a crystalline silicon based mini-module under varying ambient conditions, developed a PSPICE model for this panel, including temperature and irradiation dependence and applied this model to the simulation of the impact of a blocking diode under different shadowing conditions. Different blocking diodes were examined, like germanium and silicon homojunction diodes and silicon Schottky diodes and compared to ＂intelligent＂ diodes, consisting of operational amplifiers with MOSFET switches. The simulations indicate a strongly reduced power loss in a panel integrating the new ＂intelligent＂ blocking diodes even when compared to silicon Schottky diodes, as the best performing traditional blocking diodes.
