Abstract:
At present, the methods of optimizing busbar structure parameters, changing gate drive resistance and designing absorption circuit are commonly used to suppress the peak voltage of insulated gate bipolar transistor (IGBT) in mine-used inverter caused by stray inductance. But the existing research has not revealed the coordination and unification relationship between the methods and their coordination and optimization criteria. In order to solve this problem, taking BPJ5-630-1140 type mine-used four-quadrant inverter as the research object, based on the analysis of the influence of stray inductance on the electric-thermal performance of IGBT, a coordinated optimization method of IGBT peak voltage suppression is proposed. ① The method analyzes the influence of busbar structure parameters and grid drive resistance on IGBT peak voltage and power loss. The results show that the peak voltage and power loss of IGBT increase with the AC busbar length increase and the AC busbar width decrease. With the increase of gate drive resistance, IGBT peak voltage decreases and power loss increases. ② The diode clamped absorption circuit is designed, which is verified by experiments to reduce the peak voltage and power loss of IGBT. ③ Considering that the AC busbar width has no effect on the layout and heat dissipation performance of IGBT, the gate drive resistance and the AC busbar length are selected as decision variables. The BP neural network and elitist non-dominated sorting genetic algorithm (BP-NSGAⅡ) are used to achieve multi-objective optimization of IGBT peak voltage, the maximum IGBT temperature and the maximum temperature of radiator surface. The experimented results show that when the maximum temperature of radiator surface is 55-65 ℃ and the maximum IGBT temperature is 74-80 ℃, the minimum IGBT peak voltage is 1861 V. The corresponding grid drive resistance is 5 Ω, the AC busbar length is 300 mm, and the AC busbar width is 200 mm. The optimized IGBT peak voltage of BPJ5-630-1140 type inventer is 1 856 V, which is 35% lower than 2 856 V before optimization. The IGBT peak voltage is effectively suppressed, and the operation reliability of the mine-used inverter is improved.