【作者】 余浩；

【导师】 熊健；

【作者基本信息】 华中科技大学 ， 电力电子与电力传动， 2007， 硕士

【摘要】 本文致力于单相不间断电源(UPS)的数字化控制。随着数字控制芯片功能的日益完善,不间断电源的数字化控制已经是大势所趋。本文主要从单相逆变器的数字化波形控制和数字化过程中由于采样和控制延时带来的问题及解决方案这两方面进行研究。在把负载电流视为扰动输入的前提下,建立了逆变器的连续状态空间模型和离散状态空间模型,并在MATLAB环境下建立了包含死区的精确仿真模型,为以后的分析设计奠定了基础。分析了理想状况下逆变器输出电压谐波情况,并指出实际情况下造成输出电压波形畸变的主要原因:死区效应和非线性负载扰动。探讨无差拍控制原理在逆变器波形控制中的应用,并从极点配置的角度,分析和比较了两种无差拍控制方案的异同,优劣势。指出逆变器控制系统应该对系统的所有极点同时进行适当的配置,而不是仅着眼于部分极点。通过仿真和试验验证了相关结论。从控制系统数字化过程中,遇到的采样和控制延时的实际问题出发。通过控制理论分析,指出采样和控制延时给控制系统带来影响的原因。并从观测器,改进型的PWM脉冲产生方式和考虑延时的逆变器建模三个方向上,探讨解决采样和控制延时的方法。针对经典的观测器法,分析了模型参数误差对观测器带来的影响。详细的介绍了改进型的PWM脉冲产生方式在解决采样控制延时方面的应用和考虑延时的逆变器建模的推导。更多还原

【Abstract】 This dissertation is focused on the research of the digital control technologies for uninterruptible power supply (UPS). With the popularity of micro-processor, digital controller are widely used in uninterruptible power supply (UPS).The digital control technologies to the output voltage waveform of UPS inverters and the problems caused by the time-delay in digital control are discussed.Assuming the current of load as disturbance input, continuous state-space model and discrete state-space model of inverter are established. A precise simulation model taking into account dead-time effect is also established with MATLAB software. These models are the bases of farther analysis. The harmonic component of output voltage is studied. It is analyzed that causing the waveform distortion including dead-time effect and nonlinear load disturbing. Essentiality of the waveform correction technology is pointed out.Two different kinds of deadbeat control methods for waveform control technique of single phase uninterruptible power supply (UPS) inverters with only feedback of output voltage are analysed based on pole-placement. The drawbacks of the method which makes only one state-variable (output voltage) achieve a deadbeat dynamic response are pointed out. In addition, the design of a novel deadbeat controller for single phase UPS inverters based on pole-placement method is presented. With this method, all close-loop poles of system are placed at origin with output voltage feedback for achieving fast dynamic response. Furthermore, the feedforward of load current is designed so as to reduce the voltage distortion introduced by load current. The method of design and the results of experiments are given by examples.The reason of the problems caused by the time-delay in digital control is analysed. There are three methods concerning are discussed, which are state observer, modified pulsewidth modulation (PWM) and discrete state-space model of inverter with time-delay.更多还原