Research On The Dsp Based Controlled Method For Frequency-variable High Voltage Device

In energy saving filed, the application of the high-voltage cascaded multilevel inverter become more and more wide, its control requirements increase, and it has become to a hotspot in the industry of power electronic. Based on the series cell multi-levels topology structure, this paper takes the controller as the research object, and redesign and debug a DSP central control panel and CPLD pulse expansion board. A novel space vector phase-shifted control method , which is introduced in this paper,and be used in experiment combined with optimization V/F control method. The tested system can be controlled and run in safe and stableFirst, the paper analyzed and compared the features of several different multi-level circuit topology structures, and summary that the cascaded multilevel topology is easy-to-digital controlled and has almost sine wave of output and suitable for the high-voltage vary Frequency Control System. Specially the series cell multi-level topology structure, hardware circuit and power cell is introduced in detailSecond, we compared several sampling methods and modulating methods by simulations, for example carrier level phase-shift modulating and carrier vertical phase-shift modulating. According to the results of the simulations, it shows that we can promote the equal switching frequency by the method of carrier level phase-shift modulating, and increase the numbers of the level of output wave, and make the output wave good. But its DC utilization is not high and dynamic performance need to be further improved.This paper introduces a novel space vector phase-shifted width modulation method (N-SVPWM) adapting to DSP digital realization for Cascaded Multilevel Inverter, which combines the advantage of sinusoid carrier phase-shifting modulation technique(SPWM) and voltage space vector modulation (SVM),the result of simulation through MATLAB/simulink test verified its feasibility, its output voltage advantages in less harmonics and a higher usage rate of the dc voltageThis article has finished the hardware and software design of the central control panel and the pulse expansion circuit board. The hardware design include the DSP board, CPLD plus extension board, A/D converter circuits, Isolation circuit, photoelectric conversion circuit and other auxiliary circuits. For the software design, the paper introduced the concept of functional block and time gap. It include the optimization V/F control method model, realizing the real time computing of the N-SVPWM pulse width in detail model and voltage compurgation which is handled by DSPFinally, we tested the developed controller for the high voltage inverter device. The result of the testing verified that this controller can complete the control of the frequency variable and speed adjusting, and feasibility of the N-SVPWM modulating method, and has laid the foundation for further research.