Power Advance Prediction to Improve the Energy Utilization Efficiency of Motor-Driven System Considering Multilink Time-Delay

In the motor-driven system, the utilization of a supercapacitor (SC) energy storage unit (ESU) contributes to energy saving. However, the multilink time-delay in the system makes the SC unable to immediately track and respond to the sharp change in motor power. This will cause a large dc bus voltage fluctuation, the peak current at the power grid side, and unnecessary energy loss. In this article, a power advance prediction control strategy considering multilink time-delay is proposed. The multilink time-delay mechanism in the system is analyzed, in particular for the different conditions of motor power change. Afterward, with the motor speed, torque, and the inverter acceleration/deceleration rate obtained in advance, the motor steady power and power change rate are predicted. In the dynamic process, by adjusting the tracking rate in real time, the motor reference power function is derived. The reference current of the SC is given online, so as to match the power between the motor and the ESU. Both simulation and experimental results verify the rationality and validity of the proposed control strategy. In the dynamic process, the system stability and energy utilization are successfully improved in comparison with multiparameter collaborative power prediction control and double closed-loop control.