Medium Voltage DC Systems in Electricity Distribution Networks

EPSRC产品组合领域：储能，太阳能技术描述：太阳能光伏和储能系统已被广泛认为是解决能源和环境问题的最有效方法之一。需要几个电力电子转换器来管理从太阳能光伏板到储能和电网的功率流。因此，这种转换器可以确定整体性能，例如，近来已经提出了许多控制方法、拓扑结构和调制策略来提高转换器的功率密度、效率、可靠性和成本。然而，两大挑战仍然是进一步推进这些进程的关键障碍。第一个挑战是用于降低电压纹波的笨重电解电容器，这是转换器中最脆弱的组件。它们可以引起约30%的故障，并在小型功率转换器中占据83%的体积。第二个挑战是用于隔离泄漏电流的隔离变压器效率低下且体积庞大。在6千瓦的光伏逆变器中，此类变压器可以占系统功率损失的约3%、重量的60%以上和体积的50%以上。在本项目中，我们的目标是开发一个5千瓦的高效，可靠和小型化的转换器系统的太阳能光伏储能系统，通过1）先进的电源拓扑设计，以消除隔离变压器和电解电容器; 2）高频电感的设计，以减少系统的尺寸和重量; 3）控制系统的设计，以提高系统的动态性能; 4）对所研制的功率变换器进行了仿真和实验验证。在Solar Ready Solutions的承诺下，开发的转换器的商业化路线将作为该项目的一部分。

EPSRC Portfolio Areas: Energy storage, Solar technologyDescription:Solar PV and energy storage systems have been widely recognised as one of most effective ways to address energy and environmental issues. Several power electronic converters are required to manage the power flow from solar PV panels to energy storage and power grid. As a result, such converters can determine the overall performance, e.g., efficiency and power density, of the solar energy storage system.Numerous control methods, topologies, and modulation strategies have been recently proposed to improve power density, efficiency, reliability, and costs of the converters. However, two major challenges remain as critical obstacles to further advance these. The first challenge is the bulky electrolytic capacitors used to reduce voltage ripples, which are the most vulnerable components in the converters. They can cause about 30% of failures, and occupy 83% of the volume in a small power converter. The second challenge is the inefficient and bulky isolation transformers used to isolate leakage currents. Such transformers can account for about 3% of system power losses, over 60% of weight, and over 50% of volume in a 6 kW PV inverter. In this project, we aim to develop a 5 kW highly efficient, reliable and small-sized converter system for solar PV energy storage systems through 1) advanced design of power topologies to remove isolation transformers and electrolytic capacitors; 2) design of high-frequency inductors to reduce system size and weight; 3) control system design to improve system dynamics; 4) simulation and experimental verification of the developed power converters. With the commitment from Solar Ready Solutions, routes to commercialization of the developed converters will be included as a part of this project.