基于虚拟直流母线结构的轴向磁场永磁电机小电容驱动系统

Small-capacitor Drive System of Axial Flux PM Motor Based on Virtual DC Bus Structure

该文提出一种新的有源功率解耦电路及瞬时电压控制策略,基于此构建轴向磁场永磁电机(axialfieldpermanent magnet,AFPM)的小电容驱动系统。该有源功率解耦电路在电网、直流母线之间构建2套功率供给通道,增加了电网脉动功率控制自由度和灵活性。控制解耦电容电压跟踪虚拟直流母线电压脉动量变化,有效抑制电网脉动功率对直流母线电压的影响。将瞬时电压控制策略引入到小电容AFPM电机驱动系统直流母线电压抑制环节,进一步将直流母线电压波动控制在较小的范围内,实现静、动态工况下小电容AFPM驱动系统高性能运行。分析该有源功率解耦电路的工作机理,对其数学模型进行推导,详述电路关键参数的设计思路。最后,通过原理样机验证该解耦电路及对应小电容驱动系统的有效性。

An active power decoupling circuit and instantaneous voltage control strategy applied to axial flux PM motors were proposed.The active power decoupling circuit constructed two power flow paths between the grid and the DC-bus,which significantly increased the control degree and flexibility of grid pulsating power processing under the same power switching frequency.The decoupling capacitor voltage was controlled to track the virtual DC-bus voltage,so the influence of the grid pulsating power on the DC-bus voltage was effectively suppressed.In addition,the instantaneous voltage control strategy was applied in the DC-bus pulsating voltage suppression,and the DC-bus pulsating voltage was limited to a small range to achieve high performance operation of the small capacitor drive system under static and dynamic conditions.The operating mechanism of the new active power decoupling circuit was analyzed,and its mathematical model was deduced.The design of key parameters of the circuit was detailed.Finally,the effectiveness of the decoupling circuit and the corresponding small capacitor drive system was verified by a prototype.