创新型的基于软开关的X射线电源系统

自动X射线检测(AXI)已经成为检测和评估复杂微机电系统(MEMS)和微光电子机械系统(MOEMS)的基本方法,在医疗、考古等领域也有了广泛应用,而稳定可靠高效的直流高压电源是AXI的核心组件。一般的高压直流电源为定值输出,它们在X射线管这样的宽负载变化范围下的稳态和暂态响应不能满足AXI的要求。基于AXI的需要,本文介绍了一种最新研制的可调高压电源,创新型的主电路拓扑结构由PFC(功率因数校正)模块、Buck模块、逆变电路、高频变压器和倍压电路组成。电源利用变压器的寄生参数谐振工作,利用软形状技术实现了ZCS低损耗。PFC模块能使此电源系统适用于国内外市场并且可减小对电网的谐波污染。电源的控制电路采用基于DSP的PI调解器,并基于RS232实现与PC的通信,从而实现本地控制和远程管理。

A Novel Topology of Series-parallel Resonant ZOS-PWM DO-DO Converter for X-ray Generator

AXI has heen becoming the dispensable and essential method for detecting and evaluating features in complex micro electromechanical (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.