高频UPS在绿色数据中心应用的改进（上）

The Improved Applications of High Frequency UPS in Green Datacenters（I）

当前的高频UPS与现代的工频UPS比较，仍具有一些优点：可以双向四象限工作、体积小、重量轻等。但也仍然存在一些不足：开关损耗及输入输出谐波含量偏大、可靠性差、带不对称负载能力有待进一步提高等。文中针对上述不足提出了扬长补短的几种改进方法：用并联级联叠加法减少输入输出谐波、利用中性点形成变压器提高带不对称负载能力、减少开关损耗的SPWM节能控制法。这一切对于高频UPS提高使用性能都是有显著作用的。改进后的高频UPS很适合于绿色数据中心供电系统的应用。

Compared to power frequency UPS, high frequency UPS has some advantages such as the ability of four-quadrant bi-directional operation control and its small size and light weight. But the switching loss and the output THD of high frequency UPS is high and its reliability and unsymmetrical load capacity is low. This paper proposes some improvement methods to cover the shortages of high frequency UPS. The parallel cascade control will decrease the output THD. The unsymmetrical load capacity will be improved with the neutral point forming a transformer. The SPWM energy-saving control will reduce the switching loss. These methods mentioned above improves the performance of high frequency UPS significantly. The improved high frequency UPS is applicable for the power supply system of green datacenters.