Design And Research On Three-Phase Inverter In Electric Gyrocompass

Drifting, life-span and accuracy of Electric Gyroscope is directly affected by voltage, frequency and waveform of Three-phase Inverter, which is one of the most important components in Inertial Navigation System. We plan to provide Electric Gyroscope with Sine-wave Inverter of CFCV to make it run smoothly, that can reduce the fluctuation of drifting parameters and prolong the life-span of Gyroscope.First, Modern inverting technology, the Hysteresis Synchronized Motor and unbalanced loads of an Electric Compass are analyzed, and then schemes and parameters of Three-phase Insulated Inverter of 110V/400Hz are given in the thesis. Second, discussion on topology of modern inverter and SPWM theory is carried out. The circuit topology of Three-phase Inverter along with its rectifier filter and output filter are designed and simulated quantitatively.Decoupling Control for Multi-variable System is applied for unbalanced loads of Inverter here, based on topology of Inverter. The Open-loop Model of the Three-phase Inverter is built, the Decoupling Control algorithm is deduced and the Simulation of PID algorithm is carried out, too. Finally, all the theory above is successfully carried out on hardware of three-phase Inverter, in which MSP430 mixed signals controller is take as controlling core and IPM of Fuji Co. is used as inverter bridge.Electricity with stable voltage, accuracy frequency and good wave is successfully output from the Inverter. The simulation and experiment results show the feasibility of the system. The research in the dissertation, to some extend, has paved a way for the further research, improvement and application in Electric Compass.