Matrix Converter And Its Applications In Induction Heating

Matrix converter is considered as a "green" frequency converter with a lot of merits. It permits frequency conversion in a single-stage processing without large reactive energy storage components. It draws sinusoidal input currents and allows the input fundamental displacement factor to be set at unity or freely varied regardless of the load power factor. Besides these, it is capable of performing frequency conversion with sinusoidal output voltages and currents at the desired output frequency and allows bi-directional power flow.Combined with computer simulation and prototype experiment, its application in the induction heating, was deeply investigated in this dissertation.According to compare all kinds of current commutation algorithms, the most conformable current commutation algorithm are confirmed. But there is a serious problem brought by the multi-step commutation, the multi-step commutation made the output voltage distorted, and the output voltage error is calculated, all of the works is ready for the improvement in the future;Compared all kinds of 3 × 1 matrix converter circuit topologies, the most fitted 3×1 matrix converter circuit topology are confirmed. On the basis of the scheme, the main circuit and its control system were built, in which the combinations of MOSFETs and the safeguard were adopted due to the lack of the true bi-directional switches at present. The design principle of input filter and its affection to input and output performance were discussed, a design method of asymmetry load input filter was applied and a modulation method with power factor correction was presented. Applying the matrix converter in the induction heating for the first time, and integrated both of them's characteristics;a conformable control method was presented. Emphasis on analyzing several power regulation methods of matrix converter, the pulse frequency method is considered the easiest and the most simpleness method. At last, all the feasibility of the theories mentioned above is validated by computer simulation and experimental investigation.This dissertation mainly discussed principal issues of the matrix converter such as realization and application. By the theoretical analysis, computer simulation and experimental investigation, some valuable experiences and significant conclusions were given, which found the technological basis for the matrix converter's further practical studies.