A Critical Review of the Various Energy-Saving Models Used in Hydrostatic Power Transmission Drives for Enhancing the Efficiency of Chairlift Transport System

This paper critically reviews various energy-saving models used for enhancing the energy efficiency of hydrostatic power transmission drives. The system layout, component design, and controllers used are discussed in detail in its sub-category. Based on the detailed review of various energy-saving models, a novel energy-efficient hydrostatic power transmission drive of the chairlift transport system (CTS) is proposed. The rise in fluid temperature in the existing hydraulic arrangement of the CTS, owing to its continuous recirculation, is controlled by incorporating the flushing valve, while the boost pump replenishes the fluid volume loss. However, because of its loading nature, the CTS’s existing power transmission drive encounters energy losses and uncontrolled fluid cooling. In the present study, the hydraulic circuit design of the existing power transmission drive of the CTS is modified to reduce energy losses. Using a variable displacement auxiliary pump in the system helps minimize the energy losses through the pressure relief valve. Also, the proposed design enhances the cooling efficiency of the flushing valve unit controlled through a suitably designed Fuzzy logic controller having a dependency on fluid temperature. The simulation model is made in MATLAB/ Simulink® environment, and the result shows that, with the increase in speed, the orifice area opening of the proportional flow control valve increases to prevent oil temperature from exceeding the operating range and the same decreases for a reduced speed. Furthermore, the proposed system exhibits a significant energy saving of 32 kJ over 300 s, demonstrating its improved efficiency compared to the existing system.