創新型的基于軟開關的X射線電源系統

摘要： AXI（自動X射線檢測）已經成為檢測和評估復雜MEMS（微機電系統）和MOEMS（微光電子機械系統）的基本方法，并且在醫療，考古等領域的也有了廣泛的應用，而穩定可靠高效的直流高壓電源是AXI的核心組件。一般的高壓直流電源為定值輸出，它們在X射線管這樣的寬負載變化范圍下的穩態和暫態響應不能滿足AXI的要求。基于AXI的要求本文介紹了一種最新研制的可調高壓電源，創新的主電路的拓撲結構由PFC（功率因數校正）模塊、BUCK模塊、逆變電路、高頻變壓器和倍壓電路組成。電源利用變壓器的寄生參數諧振工作，利用軟開關技術實現了ZCS低損耗。PFC模塊能使此電源系統使用與國內和國外市場并且減小對電網的諧波污染。電源的控制電路采用基于DSP的PI調解器，并基于RS232實現與PC的通信從而實現本地控制和遠程管理。 敘詞：AXI，軟開關，PI調解器，DSP，PFC，諧振，倍壓 Abstract： AXI has been becoming the dispensable and essential method for detecting and evaluating features in complex micro-electro-mechanical (MEMS) and micro-opto-electro-mechanical (MOEMS) devices and the high-voltage DC power supply is the very important component. In general, high-voltage DC power supplies are implemented for constant value control schemes but particularly their good transient and steady-state performances can not be achieved under wide load variations involved in an X ray tube. This paper introduces a new-developed high-voltage power supply designed for an X ray generator application, which has a novel topology comprised a PFC module, a BUCK circuit and a series-parallel transformer， multiplier voltage. A constant on-time/fixed frequency control scheme inverter using the parasitic parameter of special-designed high-frequency high-voltage transformer implements ZCS. At the same time introducing the PFC module can greatly cuts down the harmonic current and adapt to various line voltage ratings even the unsteadily voltage. The control system of the power is the digital PID adjuster based on DSP.