基于逆阻型IGCT器件的固态式直流断路器设计及研制

直流系统是支撑高比例新能源接入与灵活高效用能的重要技术方向。固态式直流断路器(solid state DC circuit breaker,SSCB)具有开断速度极快、无电弧、寿命长等优点,在中低压直流系统的故障保护中得到广泛应用。随着电力电子器件的发展,固态式直流断路器的拓扑结构、工作性能也在不断进步。为此基于逆阻型集成门极换流晶闸管(intergated gate commutate thyristor,IGCT),提出了一种新型的固态式直流断路器结构及设计方法,通流支路采用逆阻IGCT反并联结构实现双向通流,缓冲支路采用金属氧化物避雷器(metal oxide varistor,MOV)-电容结构来抑制过电压,吸能支路采用MOV吸收系统能量。进一步地,给出了关键元器件的参数设计方法,并验证了有效性;设计了性能良好的重力热管散热器,单个模块散热功率可达700 W;提出了主被动结合的控保策略,提高断路器的保护性能。最后,研制了固态式直流断路器样机,可用于750 V以内的低压直流系统,额定通流可达2 kA,可在百微秒内开断10 kA故障电流,成本低、体积小、高可靠,具有良好的应用前景。

混合式直流断路器的发展现状及展望

混合式直流断路器是直流电网中实现直流电流开断和故障隔离最为理想的选择之一,该文总结了混合式直流断路器的发展现状。首先,根据直流断路器的拓扑结构梳理其技术路线,并进行对比分析。然后,针对混合式直流断路器的关键技术,围绕换流方式、电力电子开关、快速机械开关、控制保护和供能、能量吸收等方面进行综述。针对大容量直流开断这一世界性难题,国内外学者已开展广泛研究,提出了创新型拓扑结构,突破了高可控高可靠的故障换流、毫秒级超快速高效斥力机构、高裕度高稳定性电力电子开关、低残压快响应的耗能装置等关键技术。接着,对混合式直流断路器的应用场景进行分析,介绍了混合式直流断路器的典型应用。中国实现了世界上首套混合式高压直流断路器和首套三端口直流断路器的工程应用,并开展了世界上电压等级最高、开断能力最强的混合式直流断路器工程应用。最后,对混合式直流断路器的发展趋势进行展望与总结,为未来混合式直流断路器的技术发展、应用拓展提供参考。

基于柔性直流配电网的城市能源互联网

为推动城市能源互联网的发展,满足城市能源变革的新需求,首先提出了构建基于柔性直流配电网的城市能源互联网;接着,对城市能源互联网物理基础层的核心网络——柔性直流配电网进行了关键技术分析,建立了包含规划设计、关键设备研制、运行控制、故障保护等多端柔性直流配网的成套技术体系,为推进柔性直流配电网的规划建设提供了强有力的技术保障;最后,开展了柔性直流配电网示范工程的设计及分析,提出了工程总体建设方案,并成功投运世界容量最大、电压等级最多的珠海唐家湾三端柔性直流配电网工程,为推进柔性直流配电技术在中国落地、运行奠定了坚实基础,为城市能源互联网的发展以及建设国际化能源变革城市提供支撑。

中压配电网柔性互联示范工程技术方案设计

结合东莞松山湖地区中压配电网的实际问题和工程示范规划,对中压柔性直流互联在该地区中压配电网中的应用方案进行研究。对系统的主接线方式、联接变压器配置和接地方式进行了论证;对系统中模块化多电平换流器和电力电子直流变压器进行了初步设计,确定了关键设备主要技术要求;仿真分析了系统过电流和过电压特性,提出了系统的过流耐受和绝缘配合要求;设计了系统总体控制架构和保护配置,明确了系统的控制保护策略。文章对示范工程所采用的新型主回路拓扑进行了论证,提出并采用了高纹波紧凑化的设备设计方案,提出了交流故障协调响应策略,并对这些新技术进行了论证和仿真验证,可为后续相关研究和工程实践提供参考。

Precise multi‐dimensional temperature‐rise characterisation of switchgear based on multi‐conditional experiments and LPTN model for high‐capacity application

As the power load increases, the capacity of switchgear becomes larger so the problem of overheating of switchgears becomes more significant. Whether the switchgears operate safely and reliably affects the reliability and economy of the entire power system. Different methods have been tried to study the thermal problems of switch-gears. However, there are few experimental studies on the switchgear entity. In this study, a series of temperature rise tests were carried out on medium‐voltage high‐ca-pacity switchgear to explore laws of temperature rise. First, five groups of multi‐con-ditional experiments were carried out including changes of the load current, ventilation conditions and loop resistance. Then, multi‐dimensional temperature‐rise characterisa-tion was analysed based on the experimental results and the relating theory. Finally, a circuit‐based lumped‐parameter thermal network (LPTN) model was developed by analysing the heat dissipation in switchgear and used to determine the steady‐state temperature distribution of the switchgear. The model is verified by comparing the simulation results with the experimental results.

Zero-pole cancellation for identity-based aggregators:a constant-size designated verifier-set signature

In this paper we present a designated verifier-set signature(DVSS),in which the signer allows to designate many verifiers rather than one verifier,and each designated verifier can verify the validity of signature by himself.Our research starts from identity-based aggregator(IBA)that compresses a designated set of verifier’s identities to a constant-size random string in cryptographic space.The IBA is constructed by mapping the hash of verifier’s identity into zero or pole of a target curve,and extracting one curve’s point as the result of aggregation according to a specific secret.Considering the different types of target curves,these two IBAs are called as zeros-based aggregator and poles-based aggregator,respectively.Based on them,we propose a practical DVSS scheme constructed from the zero-pole cancellation method which can eliminate the same elements between zeros-based aggregator and poles-based aggregator.Due to this design,our DVSS scheme has some distinct advantages:(1)the signature supporting arbitrary dynamic verifiers extracted from a large number of users;and(2)the signature with short and constant length.We rigorously prove that our DVSS scheme satisfies the security properties:correctness,consistency,unforgeability and exclusivity.This is a preview of subscription content,log in to check access.