【作者】 刘炜；

【导师】 卢伟国；

【作者基本信息】 重庆大学 ， 电气工程， 2017， 硕士

【摘要】 PWM整流器由于具有输入电流正弦化与功率因数可控的特点而广泛应用于电能变换系统中作为交流到直流功率的转换单元,其性能直接决定了变换器前后级的电能质量,特别是在新能源发电和电动汽车充电领域中,输入与负载随机性大范围波动,对其稳态性能与稳定性要求更高,如此对PWM整流器的控制提出了新的设计要求。基于此,本论文主要研究单相PWM整流器dq坐标变换的控制策略,探索一种模拟电路实现的控制方式以改善系统的稳态性能,此外,分别从控制方式和控制策略的角度出发以改进单相PWM整流器dq坐标变换的控制,使系统其具有更佳的工作性能,具体完成的主要研究工作及成果归纳如下。首先,对于单相PWM整流器的控制结构,通常采用数字控制的方式以实现dq坐标变换,由此引入了AD采样的量化误差和计算延时从而影响系统控制性能。基于此,设计了一种坐标变换的模拟实现电路,由全通滤波器实现周期正弦信号的延时,结合运算放大器构成的运算电路实现坐标变换,应用该电路实现了单相PWM整流器dq坐标系下的双环控制,进一步分析了系统模型与控制结构并给出了补偿器参数的设计方法。最后,通过仿真实验验证了模拟电路设计的有效性。所提的模拟坐标变换电路具有普遍性,同样适用于其它坐标变换的控制策略中,为在dq坐标系下所构建的控制策略提供了一种简单有效的模拟电路实现方案法。其次,由于数字控制具有结构简单,易于改变控制参数与控制结构而设计了单相PWM整流器的数字控制系统,以DSP处理器TMS320F28335为主控芯片,并给出了系统具体的硬件电路设计和软件设计方法,实现了单相PWM整流器dq变换双环模拟控制的数字化。最后,通过实验验证了单相PWM整流器dq变换双环数字控制的可行性。本部分工作所设计的数字控制系统为单相PWM整流器的一般系统,可更加灵活的调整控制参数和控制结构。最后,针对单相PWM整流器双闭环控制结构当负载大范围波动时会对系统稳态性能带来较大影响甚至出现不稳定的情况提出了单相PWM整流器dq变换Lyapunov控制策略,将Lyapunov稳定性理论应用到单相PWM整流器中,构建了dq坐标系下系统的能量差函数并导出具体的控制结构以满足系统的大范围渐进稳定。最后进行了相应的仿真分析并搭建了实验样机,验证所提控制结构的正确性,本部分研究工作有效的解决了负载扰动对PWM整流器系统性能的影响。更多还原

【Abstract】 PWM rectifier as ac to dc power conversion unit with the characteristics of the sinusoidal input current and power factor control is widely used in power transformation system,its performance directly determines the power quality of the front and back,especially,it requires higher stablility in the field of new energy power generation and electric vehicle charging for the input and load randomness wide fluctuations,hence,it is desired to put forward a new designed requirement for the control of PWM rectifier.Based on this,this thesis mainly studies the control strategy based on dq coordinate transformation for the single-phase PWM rectifier,and explores a kind of analog circuits to realize the control to improve the steady state performance of the system,in addition,improves the control based on dq coordinate transformation of single-phase PWM rectifier respectively from the perspective of control mode and control strategy to make it has better performance.The main research work and achievements are summarized as follows:First of all,in view of the control structure usually introduce dq coordinate transformation for the single-phase PWM rectifier,it will bring the the AD sampling quantization error and sampling time delay when digital control be used.This article designed a kind of analog circuit realize the coordinate transformation,it combines the cycle delay unit constituted by all-pass filter with the operational circuit consisted by operational amplifier,based on the circuit,the double-loop control on dq coordinate system of the single-phase PWM rectifier is realized.Furthermore,it analyzes the system model and control structure,the design method of the compensator parameters is given.Finally,the validity of the circuit design and the correctness of the compensator parameter design are verified by simulation and experiment.The proposed analog coordinate transform circuit are universal and applicable for other control strategies of coordinate transformation,which provides a simple and effective analog implementation method for the control strategy based on dq coordinates.Secondly,single-phase PWM digital control system of the rectifier is designed because it has some advantages such as simple structure,easy to change the control parameters and control structure.control.In the control system,the main control chip of DSP processor TMS320F28335 be used and the detailed methods of hardware circuit design with software design be gived.It comes ture single-phase PWM rectifier dq transform the double closed loop digital.Finally,the feasibility of the double closed loop digital PI control based on dq transform for single-phase PWM rectifier is verified by experiments.This part of the research work furtherly improves the double loop control base on dq transform of the single-phase PWM rectifier,in addition,the digital control system design for the single-phase PWM rectifier is a general system,which can easily adjust the control parameters and control structure.Finally,when the load varying in a broad range,the performance of the single-phase PWM rectifier under the double closed loop PI control will be changed greatly and even instable,the Lyapunov control strategy based on dq transform is therefore proposed in this paper.In fact,the Lyapunov stable ility theory is applied to the single-phase PWM rectifier,and the energy function of dq coordinate system is built by the Lyapunov direct method,similarly,the control equations for system convergence are derived,likewise,the Lyapunov control structure based on dq transform of the single-phase PWM rectifier is given to meet the needs of a wide range of system asymptotical stablitity.Finally,the corresponding simulation analysis and experimental prototype is built,which verifies the correctness of the proposed control method.This part of the research can effectively reduce the influence of load disturbance on the performance of the PWM rectifier system.更多还原