Development Of The Power Unit For The Air Cooling High Voltage Inverter

With China's high voltage inverter market size continues to expand, thecorrelation value increased from1.1billion Yuan in2005to3.9billion Yuan in2009,the year compound increase rate is up to37%. Therefore, in order to increase thecompetitiveness of the company high voltage inverter, companies need to developgreater capacity of high voltage frequency converter, in order to perfect companysystem of products, and strive for greater market share. Therefore, research anddevelopment of new490A power unit and the capacity expansion of existingproducts which can reach10kV/6800kW level, has become the aim of this research.This thesis focuses on points that the power unit is easy to maintain and easy todevelop following models, and adopts using a novel split type power unit design.The power unit function modular subdivide, thereby effectively dispersed unitweight, decreased the electrolytic capacitor portion of the environment temperatureand prolonging the service life. However, this scheme needs to solve the difficultiesupon the power unit cooling design and laminated bus bars low inductance designIn the thermal design, it uses the calculation of thermal resistance and thermalsimulation, and the radiator section dimensions for radiator thermal resistance effects.By optimizing the power unit of the radiator section size, the radiator thermalresistance increased in7.23%while the cooling radiator fin volume reduced39.7%,this coordinated contradiction between the cooling performance and production cost.Through the research of the low inductance laminated busbar technology theory andfrom the flat section laminated busbar calculation formula, as well as through theoptimization of bus row size, it reduces the direct current bus bar inductance value,effectively reducing the insulated gate bipolar transistor (IGBT--Insulated GateBipolar Transistor) impact current when powered off, and improving productreliability. The results show that temperature rise test results and simulation resultsare basically identical, and electrical de-rating test also verified the bus row size onstray inductance effect. Therefore, the power units of the thermal design andlaminated bus bars design have achieved the expected goal. Thus, this new type of split type power unit design scheme is feasible, and haveapplied for and obtained a utility model patent.