Confirmation of the High Frequency Model for Conducted EMI in Passive Components ─ Simulation and Measurements

• Main Authors: Hong-bin Du, 杜弘彬
• Other Authors: Nan-Ming Chen
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/88848474019545321219

碩士 === 國立臺灣科技大學 === 電機工程系 === 97 === The purpose of this thesis is to investigate the generalization of the conducted EMI model developed earlier by Lin [1]. Both measurements and simulation for conducted EMI are performed to verity the high frequency model proposed earlier by Lin [1]. The application circuit is that of boost power factor correctors. Experiment steps: (1) simulation of a boost power factor corrector in operation to identify low frequency problems, (2) including high frequency characteristics in low frequency component models to account for the 150 kHz ~ 30 MHz frequency range of conducted EMI in practical measurements. First, measurements and simulation for each separate component are conducted to verify their impedances and phase curves. The model is included in the circuit to simulate conducted EMI. Finally, simulation and measured EMI noises are compared to investigate whether the model is suitable for the frequency range of conducted EMI or not. The problematic electromagnetic interference can be predicted. Thus, time and cost of circuit design can be reduced. Considering the results of applying high-frequency model by Lin [1], the comparison results show that the EMI of different circuits will have different influence factors, including circuit structure, component characteristics, circuit design, PCB layout, and so on. Therefore, the high-frequency model should be concerned about more parameters, such as working temperatures of components, the permeability of magnetic components, and so on, for designing a further complete high-frequency model. In addition, the factors influencing EMI also include some environmental problems, such as the testing cables of measuring instruments, noise value, and so on. Thus, if the condition mentioned above can be considered, the model will facilitate EMI simulations of circuits.