Research on the dynamic power control strategy of the two-mode electro-mechanical variable transmission

The two-mode electro-mechanical variable transmission (EVT) system can realize the power transmitting variable transmission by the split and couple of the electric and mechanical power. The electric and mechanical power is limited by the coupled restriction, and its distribution and dynamic control is quite difficult. Based on the power management strategy which is optimal fuel curve of engine-based and widely used, the affect to the system operating and power distributing of the efficiency model used to the calculation of power distribution and the response delay of the power components especially the engine is analyzed by the power balance equation and the test data. The engine speed based cooperation strategy of electric and mechanical power and the bus voltage based cooperation strategy of electric-driving power are proposed, which can ensure the system stability and electric power balance by the closed-loop control based on the measured variables. The EVT system test bench is established and the bench test results indicate that the researched dynamic power control strategy can realize the precise control and regulation of the multi-power by the closed-loop control, which can realize the optimal tradeoff of the regulation of the static-state target and the dynamic torque output required by the dynamic performance index, and ensure the system stable operation and the electric power balance.