AC-DC Hybrid Electric Power Systems

一个多世纪以来，电力系统已经演变成一个完全以交流(AC)形式产生和分配能量的系统；尽管高压直流(HVDC)输电已在特定情况下使用，但输电系统仍以交流为主。这是因为，尽管爱迪生早期的直流电力系统有其优点，但它在这场战斗中输给了交流电力系统，主要是因为缺乏“直流变压器”，从而导致了远距离部署的高得令人望而却步的能量损失。然而，近年来，高效电子能量转换的进步重新引起了人们对直流电力系统的兴趣，以补充现有的交流系统。当涉及到海底电力传输时，例如来自海上风电场的直流电是更好的选择。此外，大多数储能设备和现代发电机(如光伏系统、风力涡轮机和燃料电池)可以更方便、更高效地与直流基础设施连接。此外，电能的消耗主要是以直流形式进行的。另一方面，交流电力具有明显的优点，是现有电力基础设施和设备的基础。因此，相信未来的电力系统将受益于直流电和交流电的结合。因此，拟议研究的总体目标是研究交流和直流共存的混合电力系统。更具体地说，这项研究将发展和确定：

For more than a century, the electric power system has evolved into one in which energy is generated and distributed exclusively in the Alternating Current (AC) form; even though High-Voltage Direct Current (HVDC) transmission has been used in specific cases, the transmission system is nonetheless predominantly AC. This is because, despite its merits, Edison's early DC electric power system lost the battle to its AC counterpart, mainly due to the lack of a "DC transformer" and consequent prohibitively large energy losses for long-distance deployment. In recent years, however, advancements in efficient electronic energy conversion have renewed interests in DC electric power systems to supplement the existing AC system. DC power is superior when it comes to sub-sea power transmission, from offshore wind farms for example. Moreover, most energy storage devices and modern electric power generators (such as photovoltaic systems, wind turbines, and fuel cells) can more conveniently and efficiently be interfaced with a DC infrastructure. Furthermore, the consumption of electric energy primarily takes place in the DC form. On the other hand, AC power possesses distinct merits and is the foundation of the existing electric power infrastructure and equipment. Hence, it is believed that the power system of the future will benefit from a combination of both DC and AC powers. The overall objective of the proposed research is thus to study hybrid electric power systems in which AC and DC coexist. More specifically, the research will develop and identify: