三相电压型SVPWM整流器控制策略研究毕业设计（论文）.docVIP

毕业设计（论文） 三相电压型SVPWM整流器控制策略研究 摘要 常规整流环节广泛采用的二极管整流电路和晶闸管相控整流电路对电网注入了大量谐波，给电网造成污染。三相电压型PWM整流器具有输出PWM整流器的工作原理，建立了基于三相静止坐标系以及两相坐标系的低频和高频数学模型，并选择了三相电压型PWM整流器作为本文主要研究对象。电压空间矢量调制(SVPWM)控制方法能够获得更高的电压利用率，同时可使可有效减小电流谐波。文中对三相电压空间矢量的原理和如何实现作了详细的分析，选择了谐波含量相对小的矢量排序策略。 在电流控制方案上，提出了dq坐标系下的固定开关频率的直接电流控制策略，同时在控制中实现电流的解耦控制，以及输入电网电压的前馈，使得系统具有更好的动态性能和稳定性，并通过进行闭环系统的仿真验证了方案的可行性。 在进行三相电压型PWM整流器系统的仿真研究中，建立主电路、空间电压矢量PWM控制模块及PI控制调节器的仿真模型，并深入对三相电压型PWM整流器的谐波含量进行分析，研究主电路参数对系统跟随性和稳定性的影响。 关键字：PWM整流；SVPWM调制；直接电流控制；仿真研究 Research on Control Strategy of the Three-phase Voltage SVPWM Abstract The conventional rectifier section widely consists of diode-rectifier circuit and phase-control thyristor rectifier,which injects large amounts of harmonics into the power networks and produces much contamination.The three-phase voltage-source PWM reetifier(VSR) have the characteristics of constant direet voltage,high power factor,small harmonic pollution,bidirectional power flow，so they have more and more application perspective in active filteringreaetive-load compensation and motor control systems. The principle of single-phase voltage-source PWM rectifier was introduced in details,constructing the high and low-frequency mathematical model based on the three-phase static coordinate system and the two-phase synchronous rotating coordinate system from the poinit of the topology of the main circuit,and select the three-phase voltage-source PWM rectifier as this major study.With the voltage space vectors pulsewidth modulation,we can get higher usage of the voltage,at the same time it can effectively reduce the current harmonics.In this paper,the principle of three- phase voltage space vector and the specific implementation were analyzed in details,choosing the vector sequencing strategy with relatively small harmonic content. As to the current control scheme,this paper propose a directly current control scheme,which with fixed switching frequency in dq rotation reference frame.And also,