Power Quality Improvement of Smart Microgrids

智能微电网是一种很有前途的解决方案，可以将可再生能源(RESS)整合到公用电网中，并允许用户参与能源企业。在不久的将来，智能微电网将为客户提供负担得起的电力，并将为依赖零排放能源铺平道路。智能微电网通常分为交流型、直流型和交/直流型混合电网，与传统电力系统相比具有许多优点，如提高了可靠性、安全性和效率，允许通过分布式发电(DG)单元开发RESS，降低了损耗，有利于健康、气候和世界经济。尽管它们具有优势，但与智能微电网的有效设计和使用相关的技术挑战仍然存在。其中一些主要挑战是公用电网的电能质量(PQ)下降，以及由于RESS和负载变化的间歇性性质而产生的稳定性问题。此外，配电网中非线性和不平衡负荷的扩散导致了智能微网的PQ和稳定性问题。不良的电能质量会给电网和用户带来大量的问题，例如，电力损失、敏感设备故障、电力中断、负载性能差、安全问题，并产生巨大的成本。例如，EPRI-CEIDS进行的一项调查显示，北美经济每年因各种PQ问题而损失超过240亿美元。 在这个探索计划中，我们的目标是克服与电能质量以及交流和混合交流/直流微电网的稳定性相关的一些挑战。更具体地说，在拟议的研究中，我们将处理以下任务： ·提出高性能稳健的分散控制器，用于改善交流微电网的电能质量，包括电子和直接耦合的机基分布式发电机组， ·开发并网变流器分布式发电机组的多功能控制策略，以补偿非整数次谐波， ·在存在不确定的非线性和/或不平衡负载的情况下，提出鲁棒控制器以提高孤岛交流/直流混合微电网的鲁棒稳定性和PQ；以及 ·为交直流混合微电网互联变流器设计非线性鲁棒控制器，以保证电压稳定和改善电能质量。 拟议中的发现计划将有助于可再生能源和智能微电网技术的发展。此外，通过拟议的计划，我们将为加拿大工业界和学术界对HQP的培训做出贡献。

Smart microgrids are promising solutions to integrate renewable energy sources (RESs) into the utility grid and allow the customers to participate in the energy enterprise. In the near future, smart microgrids will contribute to affordable electricity for customers, and will pave the path to rely on an emission-free form of energy. Smart microgrids are usually categorized into ac, dc and hybrid ac/dc, and provide several advantages over conventional power systems, e.g., they provide increased reliability, security, efficiency, allow the exploitation of the RESs through distributed generation (DG) units, reduce losses, and are beneficial for health, the climate, and the world economy. Despite their advantages, there exist several technical challenges associated with the efficient design and use of smart microgrids. Some of the main challenges are power quality (PQ) degradation of the utility grid, and stability issues due to the intermittent nature of the RESs and load variations. Moreover, the proliferation of nonlinear and unbalanced loads in distribution networks results in a number of PQ and stability problems for smart microgrids. Poor PQ results in a multitude of problems for both utility grid and consumers, e.g., power losses, malfunction of sensitive equipment, power interruptions, poor performance of the loads, safety issues, and incur huge costs. For example, a survey conducted by EPRI-CEIDS shows that the North American economy loses more than 24 billion dollars per year due to various PQ problems. In this Discovery program, we aim to overcome some of the challenges associated with PQ and stability of ac and hybrid ac/dc microgrids. More specifically, in the proposed research, we will tackle the following tasks: • Proposing high performance robust decentralized controllers for PQ improvement of ac microgrids with electronically- and directly-coupled machine-based DG units, • Developing multifunctional control strategies for grid-connected converter-based DG units in order to compensate for non-integer harmonics, • Proposing robust controllers to improve robust stability and PQ of islanded hybrid ac/dc microgrids in the presence of uncertain nonlinear and/or unbalanced loads, and • Designing nonlinear robust controllers for the interlinking converters of a grid-connected hybrid ac/dc microgrid to guarantee voltage stability and improve PQ. The proposed Discovery program will contribute to the development of renewable energy and smart microgrids technologies. Moreover, through the proposed program, we will contribute to the training of HQP which are in high demand by Canadian industries and academia.