Wireless-Parallel Of Inverter Modules Based On DSP

As the Industries' demand to the power supply is more and more higher, especially the security and the dependability, the Module Integration System has become more and more popular. Because of the redundancy, the system can improve the securi ty greatly and also supply higher quali ty power than the Centralized Supply. In the field, the AC Module Integration System is applied more abroad and more difficult than DC Module Integrat ion System. Among the AC Module Integration System, the parallel is a very important field. To paral lel successful ly the output ' s phase and amplitude must be accord with each other. And the parallel technology can be divided into two parts by whether there is a wire among modules. If there is a wire among modules, the technology is called wire-parallel, whereas it ' s called wireless-parallel, and the wireless-parallel is more redundant. Nowadays it ' s often control the phase and the amplitude through the active-power and reactive-power of the load, which is called basic droop-theory.The task of the paper is the inverters wireless-parallel based on DSP, and the control theory is developed from the basic droop-theory. In the new theory, the output phase and amplitude is correlative with both the active-power and react ive-power, that is to say, the phase and the amplitude is controlled by active-power and reactive-power together. On the other hand, to improve the dynamic response, the theory added derivative arithmetic. In the theory, the parameters are very important, which affect the stability directly. But the parameters affected each other, the designing is very difficult. In the paper, We analyze the influence of each parameters, and find that the parameter related with the phase and the act ive-power is the most important. So We design it first and then get other parameter from it. The experiment indicates the correction of the theory.Another important problem is how to get the active-power and reactive-power. In the paper, We compare two methods, one is the voltage and current shift-phase method, and the other is two-table method. Considering of the dynamic response, Wechoose the two-table method.In the parallei system, every inverter connects to a PC by a CAN-BUS, so we can control it through the monitor software in the computer.The experiment results show that the control theory is successful, which can assure the stability and the dynamic response. In the experiment, the stability-error is small, and the current-share error is 5 percent. When a new inverter joins or a inverter exits the system, or the load changes, it will take two to four periods to achieve the new stable state.