In the radiation aspect , the features o radiation sources in power converters are discussed . the radiation models of dm current and cm current in cables and radiative characteristics of cables and high frequency current loops in the converter are also discussed 在功率变换器辐射emi方面，系统地讨论了功率变换器各辐射源的特点，重点分析了共模电流和差模电流在电缆中的辐射模型，功率变换器中电缆与高频电流回路的辐射性能。
The mathematical models of ac pmsm is founded at first , then the simulation research based on matlab is completed , such as rotor magnetic field - oriented vector control , svpwm , the adjustment of current and speed , which validates the feasibility of control theory and provides the theory basis for the realization and debugging of real system 论文首先建立了交流永磁同步电机系统的数学模型,并对转子磁链定向矢量控制、空间矢量pwm波形的产生、电流回路和速度回路的调节等控制方法进行了matlab仿真研究,验证了这些实现方法的可行性,为实际系统的实现和调试提供了理论依据。
This thesis is founded on the investigation of the ion migration of 500kv dc ceramic support insulators for the production of the 500kv dc ceramic support insulators . in the test system , we added the grounding switch for each circuit and the mutual switch , prescribed the four status of the current measuring program , making the measurement system more stabile 在对离子迁移试验研究的过程中，对原有离子迁移试验测量系统进行了改进，通过为每路泄漏电流回路设置接地开关及公共测量开关，并在软件上为测量回路设定4种状态，提高了测量系统的稳定性。
