Chao Feng Electric Co., Ltd., Henan

Ultra (ultra front front man Gao Pinlu) development

14 years ago, a chance to join the high industry, 14 years be conscientious and do one’s best, I did not dare laches, in order to high-frequency cause takeoff, super Feng who have been working hard,development of super Feng electrical as you witness the high frequency in recent 20 years!!!

Overview of the development of high frequencyinduction heating equipment, there are four periods: the development of period - mature application -Application - improve the performance period, the following four stages were described. In 120th Century 70 many units involved in the research and development stage in our country with thedevelopment history of intermediate frequencyinduction heating power supply, we can put its development summarized as 70′s research and development period, eighty’s, ninety’s mature periodof extended period, the late twentieth Century to improve performance. Application of power semiconductor devices developed in China with high frequency power supply of induction heating inhistory can be traced back to the nineteen seventies, accompanied by the 1963 China’s firstthyristor advent, in 1970 our country develop fast thyristor, around 1972 many of our units havestarted to research the thyristor medium frequency power supply can say, the domestic firstintermediate frequency heat off the stage of development of the many units involved in thenineteen seventies. Intermediate frequency furnace heat of this period mainly engaged in research and development in the field of units, the period of the application of the core device for fast thyristor,the control circuit is a plug-in box structure is composed of a plurality of control board manydiscrete components, at the same time as thethyristor production technology constraints, thestructure of main circuit for thyristor blockingvoltage is not high enough, but two thyristor or three thyristor inverter bridge arm, the number of applications of the thyristor is 8 or 12, thusinevitably accompanied by pressure are network fastthyristor, at the same time we should see this period because of the thyristor turn off time is not too short, so determines the output frequency is notthe medium frequency power supply high; secondly,because of the dynamic parameters dv/dt and di/dt of the thyristor is not very high, cause the system tolimit dv/dt and di/dt networks are large and complex; third, at this stage because of the thyristor reliability is not very ideal (at that time, dubbed the “terrible silicon”), which is determined by the stage of intermediate frequency power supply is laboratory products, is rarely used in the industry.

2, nineteen eighties mature application period

After 1980, with the considerable progress made inthe manufacturing process of thyristor, theintroduction of technology reform and opening-up of our country, the thyristor reliability obtainedgreat progress, thus gradually High frequency furnace  high frequencyinduction heating medium frequency power supply has bid farewell to the laboratory to use in industrial production, during this period the thyristor medium frequency power inverter has gradually from the fastthyristor series transition to the single thyristor,but the output frequency is not very high, muchbelow 2.5kHz, the output frequency to be 4kHz or 8kHz still had to use multiplication of complex control technology. And should see the startingprogram of this period of Thyristor Medium frequency power supply for charging links with ramming specialstarting scheme, the plug-in box type structure and the control plate into a plurality of small controlboard. In general the whole control system is composed of twelve blocks of control board (six rectifier trigger board, two inverter pulse plate, apower board, a negative power supply board, a guard plate, an adjusting plate), and during this period the fast thyristor domestic level off the fastest time is 35 µ about s, and the blocking voltage does not exceed the maximum 1600V, average on state current up to 500A, which determines the induction heating power capacity of more than 350kW by medium frequency power supply to the fast thyristorparallel scheme.