Control of inverter-based distributed generation in low-inertia power systems

在减少温室气体排放、改善空气质量和应对气候变化的需求驱动下，可再生能源在电网中的渗透率多年来一直在上升。与传统的同步发电机不同，大多数可再生能源通过电力转换器连接到电网。控制策略已被设计成允许它们集成到网络中，并使它们适应传统同步发电机的众所周知的和完善的控制和稳定性规则。由于不同类型的功率转换器、它们的灵活性和大量的制造商，为每个功率转换器设计的控制器可以彼此非常不同。尽管迄今为止，通过使转换器适应同步电机的规则来集成转换器在维持系统稳定性方面是有效的，但随着可再生能源发电比例的增加，可能会威胁网络稳定性和供应安全。此外，由于可再生能源的渗透率预计将继续增加，这可能导致电力系统很少甚至没有同步发电机。本项目将研究稳定性，并试图找到新的控制设计规则的电力变换器在电力电子为主/只。因此，该项目与EPSRC的能源主题内的能源网络研究领域保持一致。该工作将开始，首先回顾以前对功率转换器控制器进行的稳定性分析。然后，一个稍微简化的电力网络与不同比例的电力提供通过功率转换器将模拟与各种控制策略。功率转换器与彼此的相互作用时，控制不同的策略将进行分析研究。从模拟和理论分析，一些控制设计规则将被列举，可以提高整体的稳定性，如果适用于所有的功率转换器。一个缩小的实验原型转换器可以建立在一个电源硬件在环的安排，以验证仿真结果。

Driven by the need to reduce greenhouse gas emissions, improve air quality and address climate change, the penetration of renewables into the electrical network has risen over the years. Unlike traditional synchronous generators, most renewables are connected to the power network through power converters. Control strategies have been designed to allow their integration into the network and adapt them to the well-known and well-established control and stability rules of the traditional synchronous generators. Due to the different types of power converters, their flexibility and the high number of manufacturers, the controllers designed for each power converter can be very different to each other. Although integration of converters by adapting them to the rules of the synchronous machines has been effective so far in maintaining the stability of the system, renewable generation could threaten the network stability and security of supply as its proportion increases. Besides, since the penetration of renewables is expected to keep increasing, it could lead to a power system with few or even no synchronous generators. This project will study the stability and will attempt to find new control design rules for power converters in electrical networks with power electronics mainly/only. The project is, therefore, aligned with EPSRC's Energy Networks research area within the Energy theme.The work will begin by reviewing previous stability analyses conducted on power converter controllers. Then, a somewhat simplified electrical network with different proportions of power provided through power converters will be simulated with various control strategies. The interaction of power converters with each other when controlled with different strategies will be analytically studied. From the simulations and theoretical analyses, some control design rules will be enumerated that could improve the overall stability if applied to all power converters. A down-scaled experimental prototype converter could be built in a power-hardware-in-the-loop arrangement to verify simulation results.