Small Generator Control System Based On Dsp Design

As a mobile and separate power supply,the traditional medium-small petrol generator has unique advantage in the situation in need of standby power supply and fluid operation.but due to the mid-frequency of the generator,its frequency and voltage are different from the power supply for common use and don't fit most electrical equipments' requirements.With the digitalization and intelligence of inverter,the inverter based on medium-small petrol generator is becoming popular in the market.According to this type of the small mid-frequency petrol generator, its control system is mainly investigated and designed in this dissertation.The dissertation first introduces the composition of control system for small petrol generator,including three-phase semicontrol rectifier, single-phase inverter,throttle control system with a stepping motor,ignitor and fault display system.The principle,relationship and function of each part in the control system are expatiated in detail.After analyzing the characteristics of common trigger circuits, a new intergrated trigger circuit is designed for three-phase semicontrol rectifier of the small petrol generator.three-phase synchronous signals for the trigger circuit are obtained directly from the input of rectifier instead of synchronous transformer,and the phase of each trigger signal is adjusted by resistance-sampling method and PI adjustor.in addition,the dc voltage can be protected by blocking the trigger signals.The circuit is proved to be easy to debug,stable,low-cost and practicable by experiment.The principle and topologies of SPWM inverter are introduced,and then the single-phase inverter is chosen to be the research subject.Three control strategies including bipolar SPWM,unipolar SPWM and unipolar SPWM with double frequency are expatiated in detail and modeled by the sampling method of asymmetric rule.In addition the hardware of the single-phase inverter is designed,which is based on TMS320LF2407A DSP and a power module called IPM.After introducing the normal PI control and its existing problems, a new PI control which can avoid integral saturation is brought forward,and the software of several SPWMs control introduced before is designed, its efficiency is verified by experiment,and the experiment results illustrates that the control system for small petrol generator is practical.