直流微电网监测与保护系统研究
发布时间：2019-06-10 06:16
【摘要】：随着全球经济的发展,能源需求快速增长,尤其是对电力的需求更加凸显,环境问题也日益严重。在能源需求和环境保护的双重压力下,分布式发电应运而生。为了最大限度了发掘分布式发电的价值,微电网的概念逐渐成为了当下的一大热点。直流微电网具有变换环节少、控制简单和便于分布式电源接入的优势。随着电力电子技术的不断发展,直流微电网的发展迎来了曙光。本文基于直流环状微电网,对其监测和保护系统进行研究,为推广直流微电网的工程应用提供技术支持。 文章以电压等级为400V,容量为80kW的直流环网系统为例,分析了系统的组网方式、组成部分和运行特点。系统采用双向DC/DC变流器的组网方式,这使得系统在潮流控制、系统保护和供电可靠性方面都具有明显优势。文章详细介绍了各组成部分的型号选型,同时对系统的控制策略、运行方式、备用方式和故障诊断等进行了阐述。基于该直流微电网的结构和运行特点,展开对于监测方法和保护策略的研究。 根据保护的需要,对直流微电网的电压、电流幅值及方向、功率、温度和电池SOC(State of Charge)等参数进行实时监测。文章对监测系统的结构和设备选型进行了介绍,同时设计了相应的硬件电路。采用以RS-485为底层通信和以工业以太网为上层通信的双层通信方式,有效地提高了通信系统的抗干扰能力,同时也解决了通信距离长带来的通信难题。电池SOC是电池管理和保护的重要参数。文章提出了一种改进的按时积分法对储能设备SOC进行监测,大大地提高了SOC的估算精度。 结合该直流微电网的运行方式,基于直流系统电流方向的特征,采用了以电流方向保护策略为主,电流速断保护和定时限电流以及定时限电压保护为辅的继电保护方案,同时还考虑了热过负荷保护和电池过充过放电保护。文章还对各保护策略的保护算法进行了详细介绍。该保护方案保护范围大,能有效地保护系统的全线路,并能进行快速的故障诊断和选择性保护。
[Abstract]:With the development of the global economy, the energy demand is growing rapidly, especially the demand for electricity is more prominent, and the environmental problems are becoming more and more serious. Under the dual pressure of energy demand and environmental protection, distributed power generation emerges as the times require. In order to maximize the value of distributed power generation, the concept of microgrid has gradually become a hot spot. DC microgrid has the advantages of less conversion links, simple control and easy access to distributed power supply. With the continuous development of power electronics technology, the development of DC microgrid ushered in the dawn. In this paper, based on DC annular microgrid, its monitoring and protection system is studied, which provides technical support for popularizing the engineering application of DC microgrid. Taking the DC loop network system with voltage level of 400V and capacity of 80kW as an example, this paper analyzes the networking mode, components and operation characteristics of the system. The system adopts the networking mode of bidirectional DC/DC converter, which makes the system have obvious advantages in power flow control, system protection and power supply reliability. This paper introduces the model selection of each component in detail, and expounds the control strategy, operation mode, standby mode and fault diagnosis of the system. Based on the structure and operation characteristics of the DC microgrid, the monitoring method and protection strategy are studied. According to the need of protection, the voltage, current amplitude and direction, power, temperature and battery SOC (State of Charge) of DC microgrid are monitored in real time. In this paper, the structure and equipment selection of the monitoring system are introduced, and the corresponding hardware circuits are designed. The double layer communication mode with RS-485 as the bottom layer and industrial Ethernet as the upper layer is adopted, which effectively improves the anti-interference ability of the communication system and solves the communication problem caused by the long communication distance. Battery SOC is an important parameter of battery management and protection. In this paper, an improved time integration method is proposed to monitor the SOC of energy storage equipment, which greatly improves the estimation accuracy of SOC. Combined with the operation mode of the DC microgrid, based on the characteristics of the current direction of the DC system, a relay protection scheme is adopted, which is mainly based on the current direction protection strategy, supplemented by the current fast break protection, the fixed time limit current and the fixed time limit voltage protection. At the same time, thermal overload protection and battery overcharge and discharge protection are also considered. The protection algorithms of each protection strategy are also introduced in detail. The protection scheme has a wide protection range, can effectively protect the whole line of the system, and can carry out fast fault diagnosis and selective protection.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM77
[Abstract]:With the development of the global economy, the energy demand is growing rapidly, especially the demand for electricity is more prominent, and the environmental problems are becoming more and more serious. Under the dual pressure of energy demand and environmental protection, distributed power generation emerges as the times require. In order to maximize the value of distributed power generation, the concept of microgrid has gradually become a hot spot. DC microgrid has the advantages of less conversion links, simple control and easy access to distributed power supply. With the continuous development of power electronics technology, the development of DC microgrid ushered in the dawn. In this paper, based on DC annular microgrid, its monitoring and protection system is studied, which provides technical support for popularizing the engineering application of DC microgrid. Taking the DC loop network system with voltage level of 400V and capacity of 80kW as an example, this paper analyzes the networking mode, components and operation characteristics of the system. The system adopts the networking mode of bidirectional DC/DC converter, which makes the system have obvious advantages in power flow control, system protection and power supply reliability. This paper introduces the model selection of each component in detail, and expounds the control strategy, operation mode, standby mode and fault diagnosis of the system. Based on the structure and operation characteristics of the DC microgrid, the monitoring method and protection strategy are studied. According to the need of protection, the voltage, current amplitude and direction, power, temperature and battery SOC (State of Charge) of DC microgrid are monitored in real time. In this paper, the structure and equipment selection of the monitoring system are introduced, and the corresponding hardware circuits are designed. The double layer communication mode with RS-485 as the bottom layer and industrial Ethernet as the upper layer is adopted, which effectively improves the anti-interference ability of the communication system and solves the communication problem caused by the long communication distance. Battery SOC is an important parameter of battery management and protection. In this paper, an improved time integration method is proposed to monitor the SOC of energy storage equipment, which greatly improves the estimation accuracy of SOC. Combined with the operation mode of the DC microgrid, based on the characteristics of the current direction of the DC system, a relay protection scheme is adopted, which is mainly based on the current direction protection strategy, supplemented by the current fast break protection, the fixed time limit current and the fixed time limit voltage protection. At the same time, thermal overload protection and battery overcharge and discharge protection are also considered. The protection algorithms of each protection strategy are also introduced in detail. The protection scheme has a wide protection range, can effectively protect the whole line of the system, and can carry out fast fault diagnosis and selective protection.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM77
【参考文献】
中国期刊全文数据库 前10条
1 吴红杰;齐铂金;郑敏信;刘永U，
本文编号：2496240
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