| According to the request of high-field asymmetric waveform ion mobility spectrum technology to non-symmetric high frequency and high voltage pulse waveform, this thesis proposes and designs a novel kind of high-pressure non-symmetric high-frequency square wave pulse power which adopts power MOSFET as its key component.The thesis firstly analyses the ion detector power currently being used in developed western countries and then the domestic status quo on the FAIMS, finally determines to adopt the asymmetric high frequency and high voltage square wave pulse. Compared with the realistic approach of pulse source, the author adopted as far as possible the technical solutions that not only satisfy technical requirements but is relatively mature. And he designed the asymmetric square wave pulse circuit based on half-bridge structure with MOSFET series connection as switch in order to meet the requirements of high-voltage pulse. For the characteristics of half-bridge circuit, he designed a two-way driver output circuit that can produce adjustable dead zone. On the basis of deep understanding of MOSFET structural parameters and principle, this thesis has solved the key synchronous open and shutdown technology of MOSFET series connection and implemented the effective isolation of driven signal and high-voltage pulse circuits with the method of power suspension and Optocoupler isolation. At the same time to design the hardware circuit, this thesis adopted the PSPICE 9.2 software of ORCAD Company to itemize all parts with simulative analysis. Through the simulation result, it further proves the rationality of pulsed power supply design and supplies significant references and basis for hardware circuit design. Eventually, the author actually produced the power and made tests. The experiment met the design requirement: continuously tunable output voltage pulse 0-2000 V, frequency of output pulse up to 100 kHz, adjustable pulse duty cycle and adjustable asymmetric pulse waveform. |
PDF Full Text Request