Design Of The Test Platform For Press Pack IGBT's Switching Characteristics

Currently,flexible HVDC in the world,especially in China,are developing into higher voltage and larger capacity,which certainly require higher standards for the key equipments—converter valve and DC hybrid circuit breaker.Meanwhile,as the key switching device for converter valve and broker,IGBT should have stricter requirements for packaging and electrical performance.Bond wired IGBT in the past has gradually failed to meet the requirements of the current power system and was replaced by a new press pack IGBT,which is becoming a preferred device for flexible HVDC with significant advantages in power level,switching speed and so on.Therefore,it is of practical significance to test the switching characteristic of press pack IGBT.The main work of this thesis is as follows.Firstly,in this thesis,theoretical formula is combined with simulation to complete the design of constant current charging device.In order to change bus capacitance charging shortcomings--low efficiency,difficult to control the capacitor voltage,forbid short circuit which is caused by the way of charging that is by the commercial power,the voltage regulator,and then through the transformer,and finally by the bridge rectifier with the charging resistor,this thesis designs a set of constant current charging system based on LC resonant principle,and is proved by MATLAB simulation.Then,on the basis of simulation results,according to the theoretical analysis and the actual characteristics of the device,the components involved in the system are selected,and the actual construction of constant current charging equipment is completed.The equipment should not only select the capacitor,inductance,transformer,rectifier silicon and other main circuit devices,but also control and protect devices.The reliability and practicability of the whole equipment are verified from the actual charging effect.Finally,finish the design that is based on double pulse test principle of switching characteristic test platform according to StakPak IGBT of ABB Company.During the operation of the test platform,the charging equipment is actually applied to the pre charging link of the test to verify the current and voltage target of the device to meet the requirements of the test platform.For the switching characteristics of IGBT devices,the method of MATLAB simulation and field measurement is also used to give relevant conclusions.