Energy Saving Control Strategy for the High-Frequency Start-up Process for Electric Mining Haul Trucks

Electric mining haul trucks (EMHTs) used for “short distance” mining transportation undergo a high-frequency of start-ups which can be highly energy consuming. This paper proposes an energy saving control (ESC) strategy for the high-frequency start-up process of EMHTs. To design the ESC strategy, a system model is established based on the characteristics of the power transfer mechanism of the EMHT drive system. With this model, the ESC strategy is designed using optimal control theory. The Hamilton function is reconstructed and the Pontryagin minimum principle is used to formulate the ESC strategy by taking the energy consumption and the response time into account. Based on this strategy, an ESC-strategy-based control algorithm for EMHT is designed by selecting the switching time according to the system boundary condition. To verify the ESC strategy performance, the simulation model of dc drive 154t EMTH is built with MATLAB. Compared with the constant power control and the driver's manual control, the ESC strategy enjoys better dynamic performances and a lower energy consumption in the start-up process.