大容量中压混合型直流真空断路器限流分断技术研究

The vessel integrated power systems are characterized with heavy rated current and when short-circuit faults occurred the current rises very fast to high prospective value. The hybrid dc vacuum current circuit breaker(HDCVCB) based on forced commutation principle, which has both the characteristics of vacuum switch interrupting technology and active commutation, has been one development direction of the high capacity MVDC switchgear. The HDCVCB have to act fast，correspondly，the arcing time is short during interruption. Thereby, the interruption capability of VCB is low. A novel HDCVCB based on the combination of zero voltage switching and zero current switching principle was developed. When protection against fault is requested, the current of VCB is firstly divvied to the static branch before finally interrupted under low-level. This project would focus on the reliability of the high current commutation from the vacuum circuit breaker to the static branch and the turn-off characteristic of SCR under high current conditions, as well the interruption characteristic of VCB under short arcing time conditions. On the basis of breakthroughs in these key technologies, the integration optimization design methods of the high capacity medium voltage HDCVCB will be bring forward as well. This project would promote the realization of HDCVCB and the application of the vessel integrated power systems.

舰船综合电力系统具有额定电流大、短路电流上升快、预期峰值高的特点。基于强迫换流原理的混合型直流真空断路器兼具真空开关分断技术和有源换流技术两者特性，是大容量中压直流断路器的发展方向之一。直流真空断路器限流分断过程中燃弧时间短，真空开关分断能力不足。本项目提出了改进的混合型直流真空断路器方案。该方案集成了零电压开关技术和零电流开关技术的两种技术，通过在真空开关两端并联固态开关进行分流，降低真空开关的分断压力，增强了混合型直流真空断路器整机的分断能力。该项目将围绕大短路电流下并联支路分流特性、晶闸管组件浪涌电流冲击下关断特性、真空开关短燃弧时间条件下分断特性等开展研究。上述关键技术的突破，有利于大容量中压混合型直流真空断路器的集成设计和工程实现，为舰船综合电力系统应用奠定坚实的基础。

基于强迫换流原理的混合型直流真空断路器兼具真空开关分断技术和有源换流技术两者特性，是大容量中压直流断路器的发展方向之一。直流真空断路器限流分断过程中燃弧时间短，真空开关分断能力不足。本项目提出了ZVS-ZCS联合型直流真空断路器方案，通过在真空开关两端并联固态开关进行分流，降低真空开关的分断压力，提升混合型直流真空断路器整机的分断能力。本项目开展了大短路电流下并联支路分流特性、晶闸管组件浪涌电流冲击下关断特性的分析与试验测试，验证了上述方案解决大电流保护难题的可行性，开展了不同触头结构真空灭弧室短燃弧时间条件下引燃特性与分断特性研究。基于上述成果，研制了5kV直流真空断路器样机，并在实验室条件下进行了短路分断特性试验。