Design And Control Research On Modular Stator Permanent Magnet Generator Based On IPOS-SAB Isolated DC/DC Converter

Wind power is a renewable,clean and pollution-free resource.The development and utilization of wind power can effectively alleviate the energy shortage in the advancement of human civilization.Compared to the onshore wind power generation,the offshore wind farm can provide stable power output without causing land occupation and noise disturbance.In addition,wind power can be efficiently utilized because offshore wind farms are usually located closer to industrial load centers.In the future,the development of wind energy resources will be exploited onshore,offshore along coastal sea as well as abysmal sea.The operation environment of offshore wind farms requires that the electric generators have distinctive characteristics such as high reliability,convenient transportation and installation.Moreover,all-DC transmission of offshore wind farms is promising compared to traditional high voltage AC transmission because the excessive cable capacitance of the latter causes reactive power problems.In order to address the bulk volume size and poor heat dissipation capability problems of traditional direct drive rotor permanent magnet generator,a modular stator permanent magnet generator(MSPMG)with 72/72 poles is designed so as to effectively solve the problem of heat dissipation of the permanent magnets,transportation and assembly of the generator.The sizing equation of the MSPMG is deduced based on the analysis of its operation characteristics.The design scheme of the MSPMG including the determination of size parameters and materials is implemented.The curves depicting the interactions between flux linkage,winding current and rotor position angle are computed based on finite element method.Aimed at a wind power generation control system,the topologies of AC/DC converter in the generator side,the isolated DC/DC converter based on IPOS-SAB,the optimized power control based on variational principle,the voltage balance control of LVDC bus in generator side,and voltage sharing control of SABC modules are proposed and designed.The simulation results verify the correctness and effectiveness of MSPMG and its control strategy.