并网式光伏配电线的距离保护

发布时间：2021-05-26 11:53

　　随着新能源发电的规模不断扩大,集中式大规模新能源并网消纳的问题开始变得突出。分布式新能源发电以其与负荷联系紧密,对电网冲击小,在近年来受到了广泛的关注。分布式光伏发电相对风电等技术来说有更好的应用场景,但其对配网潮流的改变以及逆变器控制策略,也会给继电保护等传统领域带来新的问题。距离保护和过流保护是配电网通用保护,由光伏电源提供的短路电流受到并网逆变器的限制,与常规电源提供的电流叠加,对距离保护的测量和动作会产生影响。研究含光伏电站的配电网保护的特性和整定方法也是亟需解决的问题。本文论述了将光伏电站（PVPP）连接到电网的电力线的保护;它分析了并网光伏系统（GCPV）对常规距离保护的影响。由于通常存在故障转换电阻,这会误导距离保护的操作。特别是对于并网光伏系统的配电网络,测得的阻抗将更加不准确并且导致保护误动。电网侧的过电流保护和PVPP侧的距离保护之间的特定协调用于消除这种影响。这种协调需要延迟距离保护并保持逆变器与电网连接,这是通过故障穿越（FRT）功能和故障状态下的逆变器控制实现的。使用在距离PV侧10km处的BC相间故障来研究仿真,其中在0.8s处具有2Ω故障电阻。首先,在没有... 

【文章来源】：华北电力大学(北京)北京市 211工程院校 教育部直属院校

【文章页数】：55 页

【学位级别】：硕士

【文章目录】：
摘要
Abstract
Chapter 1 Background and Introduction
    1.1 Background and Introduction
    1.2 Research Objectives
    1.3 Plan
    1.4 Tools and Simulation
        1.4.1 Model and simulate electrical power systems
        1.4.2 Key Features
        1.4.3 Simscape Platform Capabilities
        1.4.4 Simulation and Analysis
        1.4.5 Simulation Methods
        1.4.6 Power Transmission
        1.4.7 Transformers
        1.4.8 Power Converters
        1.4.9 Specialized Technology
    1.5 Thesis Layout
Chapter 2 Literature Review
    2.1 General Control Targets of Photovoltaic Systems
    2.2 More Power Electronics and Advanced Controls
    2.3 Control of Three-Phase Photovoltaic Systems
        2.3.1 Advanced Control of Three-Phase PV Systems under Grid Faults
        2.3.2 Unity Power Factor Control Strategy
    2.4 Fault Ride-Through Strategies
        2.4.1 DC Braking Chopper (BC)
        2.4.2 Avoiding of the MPPT Operation (AV-MPPT)
        2.4.3 Dumping the Energy in Energy Storage Systems (DEESS)
        2.4.4 AC Side Strategies:
    2.5 Power System Protection: Introduction
        2.5.1 Fundamentals of Protection Practice
        2.5.2 Protective Relays
        2.5.3 Numerical Relay Structure
    2.6 Distance Relays
        2.6.1 Zones of protection
        2.6.2 Effect of fault Resistance on relay coverage
        2.6.3 Mho Relay Model Algorithm
        2.6.4 Other Impedance Planes
        2.6.5 Under Reach of Distance Relay
    2.7 The impact of the PV System on the protection of the distributed network
        2.7.1 The impact on the overcurrent protection
        2.7.2 The Impact on Distance Protection
Chapter 3 Methodology and Simulation
    3.1 BUILDING DISTANCE RELAY MODEL
        3.1.1 Fault Detection Block
        3.1.2 Impedance Measurement Block
        3.1.3 Zone Protection Coordination
        3.1.4 Building Shape Mho Characteristics
        3.1.5 Fault Detection Block
    3.2 Fault Resistance and Its Amplification
        3.2.1 The Proposed Coordination Method
        3.2.2 Proposed Grid Tied System
        3.2.3 Study Cases
    3.3 The Proposed Coordination Method
Chapter 4 Results and Discussion
    4.1 Introduction
    4.2 The implemented Grid-tie PV system
    4.3 The Proposed Coordination Method Result
        4.3.1 Case 1
        4.3.2 Case 2
Chapter 5 Conclusion
    5.1 Introduction
    5.2 Conclusion
    5.3 Research Contribution
    5.4 Achieved Research Objectives
    5.5 Future Work
References
ACKNOWLEDGEMENT



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