兆瓦级风机接入10kV馈线的兼容性分析与主动适应性控制

Megawatt wind turbines connected to 10kV feeder is a kind of distributed wind power generation mode. It faces many compatibility problems to directly access to megawatt wind turbines on 10kV feeder. 10kV feeder prone to have three-phase imbalance, harmonic, voltage drop, voltage surge and other extreme circumstance, which are serious threats to the safe operation of the grid wind turbines. At the same time, currently the cooperation technology still has defects of 10kV feeder's protection, automatic reclosing device and the grid wind turbines, besides the poor coordination with the wind turbines and distribution. To solve these problems, based on active control idea we carry out the following researches: (1) the stability behavior of 10kV non-ideal distribution system in the grid wind turbines; (2) the voltage regulation methods of megawatt wind turbines connected to 10kV feeder; (3) the compatibility and coordination mechanism of the protection system of megawatt wind turbines and 10kV feeder fan; (4) the stable operation technology of megawatt wind turbines connected to 10kV feeder (5) the development of semi-physical verification and experimental platform of "the system solution". The research of this topic theoretically solves the problems of power quality of megawatt wind turbines connected to 10kV feeder and reliability and overall stability of the system, at the same time invents semi-physical experimental platform on the condition of testing technique which can effectively verify the central part of grip wind turbines.

兆瓦级风机接入10kV馈线属于分布式风电接入模式，在10kV馈线上接入兆瓦级风机存在较多兼容性难题。10kV馈线易出现三相不平衡、谐波、电压跌落和电压骤升等异常现象，这些现象严重威胁并网风机的安全运行，同时10kV线路继电保护与并网风机的配合技术尚有缺陷，风机和配电网协调性差。本项目分别从风机角度和配网角度分析二者的兼容性，提出双馈风机主动适应非理想环境的控制思想并开展以下研究：①10kV非理想馈电系统中并网风机的行为特点；②兆瓦级风机接入10kV馈线条件下的电压调节方法；③兆瓦级风机与10kV馈线保护系统的兼容性与协调机制；④含兆瓦级风机的10kV馈线孤岛稳定运行技术；⑤开发"系统解决方案"的半实物验证与试验平台。本课题研究成果可解决兆瓦级风机接入非理想10kV馈线的电能质量、可靠性和系统整体稳定性等问题，同时在试验技术上发明一套可有效验证风机并网核心环节的半实物试验平台。

随着大量分布式电源（DG）如兆瓦级双馈风机接入配电网，传统配电网变为有源配电网，配电网和分布式电源之间存在兼容性问题，非理想的配电网对风机有影响，而风机又会反作用配电网，同时兆瓦级风机的接入，对配电自动化（DA）及供电可靠性提出了新的更高的要求。DG对配电保护的影响取决于其在配电网中的位置、渗透水平和类型。基于通讯网络的DA技术，在隔离馈线故障段的同时使DG孤岛运行。而不同步的重合将可能毁坏DG以及负载，导致合闸失败。为了使双馈风力发电机（DFIG）在配电网故障段跳闸暂态具备不脱网能力以及适应联络开关安全合闸，项目研究了含DFIG的配电自动化控制策略。首先，分析了现有典型馈线自动化(FA)技术与DFIG的矛盾；然后，提炼出FA与DFIG相互兼容的关键问题并给出了解决方案；其次，提出了FA与DFIG相互兼容的具体技术，包括：基于电压矢量定向的DFIG快速负载恒压、恒频、相位独立控制技术、附加速度控制技术、DFIG与现有FA GOOSE 报文通讯实现和智能配电终端（STU）模拟信号预处理传输机制；最后，研究了DFIG在各个方面与配电网的兼容性和主动适应性的控制策略，并通过仿真证实其有效性。