The Optimizal Design And Reliability Of Power Conditioning Unit Based On S3R Topology

Considering the space Power Conditioning Unit(PCU) needs high reliable design,especially for it works in harsh environment, a robust design and optimal method is proposed. In circuit design, each functional module of the circuit was simulated and tested, realize accurate control of the bus voltage,use the LCR technology, the technology of current high-end sampled. Considering the reliability of the circuit design, doing the following aspects to the circuit: sensitivity analysis, parameter analysis, worst case analysis, stress analysis, failure mode analysis.Firstly,the mathematical model of sequential switching shunt regulator(S3R) is shown to be suitable for regulated bus power systems. Secondly, optimize the bus capacitor parameter by the parameter sweep analysis. Thirdly, when all the components change simultaneously in the worst case, the performance of the S3 R circuit meets the design requirements and the shunt component meets the derating requirements in the monte carlo analysis and stress analysis. Finally, simulate two failure modes: the load changes in pulse mode and the current supply of the second-stage solar array is zero,the simulation results show that the output of the bus voltage is stable and ripples in the specified range.Secondly, do frequency characteristic analysis to the superbuck circuit, and do simulation analysis to the current sampling circuit, the main error amplifier circuit, the proportional integral circuit, pulse forming current, the driving circuit, the output over-current protection circuit, and the global BCR circuit. The simulation results show that the battery control circuit can charge the battery in constant current.