Design And Application Of Filter Compensator For Medium Frequency Induction Heating System

With the development of the modern industrial production technology,more and more power electronic devices have been used into actual production.But large number of non-linear loads have been put into the grid.It has seriously caused the quality of electric energy detriment.The contradiction between these two aspects makes the harmonic problem aroused more and more attention in our society.Researchers both at home and abroad have devoted themselves to research it widely and deeply and proposed a large number of design scheme of filtering devices.Each country has put forward standard for harmonic wave restrictions.This paper is based on the medium frequency induct ion heating equipment which have produced a large number of harmonic in their process of production.Through the studies of intermediate frequency induction heating equipment working principle,operation,harmonic characteristics fully determined that it has the advantages of simple and effective and low cost by using passive filter to filter harmonic in medium frequency furnace.In this paper,according to the structure and basic principle of single tuned filter,and its constraints and the matters needing attention in the design process,etc.I have designed low pressure dynamic filter by using thyristor switched capacitor(TSC)and reactive power compensation device.The final measurement results show that after the filter was put into operation,the 5,7,11 harmonics current generated by the medium frequency induction heating equipment have been suppressed effectively.Harmonic current,harmonic voltage of power network are both satisfied with the requirements of the 'Power quality Utility grid harmonic' GB/T14549-93.Filter compensation device provides a clean power environment for producing equipment.And it makes the power supply system more secure,stable and efficient.At the same time the device is also provided reactive power compensation to power grid,the power factor has increased.The design of the filter reduced the energy consumption.The company's investment benefit is remarkable.