Cascaded DC Power Multi-level Inverter Control Strategy And Achieve

Modern inverter technology has become an indispensable technology in the process of people to produce life, his main role is to the mains electricity grid has been polluted AC power, or batteries, fuel cells, solar cells unstable electricity transform into high-quality, harmonic pollution to meet the user requirements for voltage and frequency. This technique is mainly used in AC motor frequency control, uninterruptible power supplies, active filters, reactive power compensation of the mains, where DC need to be able to transform the place of the AC power.Accompanied by social development, industrial technology continues to improve, more and more electrical equipment connected to the grid, these devices, most of will causing serious harmonic pollution on the grid, making the original electricity power line can not meet the people The high-quality AC power demand. This electrical energy must be processed in order for the normal use.So modern inverter technology will play an important role in the process.There are two main directions inverter reduces the output voltage harmonic, first is two-level inverter,used soft-switching technology, high-frequency to reduce the harmonic pollution. The other is the multi-level inverter technology. The first method is to increase the switching frequency to reduce the harmonic content of output. This approach is to improve the switching device costs at the expense of the EMI large switching loss, can only improve the write wave frequency can not eliminate harmonics, but the regulator convenient. Another is by increasing the number of output level toreduce the output harmonic content. This method is based on increasing the number of switching devices to expense the EMI small, the switching loss, low harmonic content, the circuit is simple, low cost, but not the regulator.IN this paper, a method of combining above the two methods, using the DC power structure of the cascade, design an inverter used in high voltage high power occasion. And use the mathlab theoretical simulation.. And under laboratory conditions to build an experimental platform, the platform to the carrier triangular wave cascade method for the control strategy, the use of a digital signal processor (DSP) and programmable logic devices (FPGA) combination of the control circuit. On the basis of experimental platform described in detail the composition and characteristics of the control system hardware and software. The carrier phase shift method, the carrier triangular wave reverse cascade method of control experiments to verify the correctness of the theory...