Research On Input Series Output Parallel Combination Converter And Its Control Strategy

With the rapid development of the global economy,the demand for energy is rising rapidly.As a clean energy,electric energy plays a more and more important role in the modern production and life.As the important carrier of electric energy storage,the battery is more and more widely used.The large capacity battery is more and more indispensable in the production and life.This has a higher requirement for the voltage level,power grade and the flexibility of the power expansion.Input series and output parallel(ISOP)combination system can fully utilize the advantages of low voltage devices through the series a nd parallel connection of standard charging units.It is suitable for high power applications with medium and high voltage input.It deeply studies its control strategy to achieve stable system operation and control of various modules.It is of great signi ficance to be independent and to increase the flexibility of the power and pressure rating through deeply studying its control strategy to achieve stable system operation and control of various modules.On the basis of analyzing the basic working principle of ISOP system,it is concluded that the control strategy can only be further designed by controlling the input pressure of each module.On the control strategy,aimed at the background of the constant current charging the battery pack,the output current feedback control is used in the main module,the module on the basis of the output current feedback control and joined the input pressure control,so as to realize the module pressure single input,output constant current and control the function of the i ndependent,improved the control strategy of the main module at the same time,the unity on the achieved all modules in the control.The simulation model is built with Plecs software,which proves that the strategy can make the system have good performance under static and dynamic conditions.Compensator in the design parameters,the first to establish small signal model of a single module,which has been generalized to consists of two modules of ISOP small signal model of combination system after the system transfer function is obtained respectively for the main module and the module design compensation system,improve the stability of the system and make the system has the ability of fast response at the same time.Combination system of the main components for the design,selection,set up by the two files is given priority to with the whole bridge structure of the circuit module combination system,load chose by two pieces of the rated voltage of 12 v lead-acid batteries in series connection of the battery pack.In a stable state,the input voltage mutation,start,and standby for the combined system under the condition of experiment,the experimental results show that the control strategy is adopted in this paper can realize the stable operation of the sys tem and resistant to some external disturbances,and the effect is good.