Open Access

ARTICLE

Heavy-Load Start-Up Compensation for an IPMSM-Driven Gravity Energy Storage Hoisting Unit

Zheng Cao, Wei Li^*, Teng Li
School of Automation and Electrical Engineering, Lanzhou University of Technology, Lanzhou, China
* Corresponding Author: Wei Li. Email:

Energy Engineering https://doi.org/10.32604/ee.2026.085812

Received 19 May 2026; Accepted 08 July 2026; Published online 15 July 2026

Abstract

The hoisting unit is a key electromechanical energy-conversion component in a hoisting-based gravity energy storage system (GESS). Under heavy-load start-up conditions, an interior permanent magnet synchronous motor (IPMSM)-driven hoisting unit may suffer from start-up rollback, delayed torque buildup, and low-speed current fluctuation, which reduce start-up reliability. This paper develops a torque-balance-based adaptive gravity feedforward (AGF) compensation framework for improving the heavy-load start-up performance of an IPMSM-driven GESS hoisting unit. An electromechanically coupled model is established to describe the interaction among the IPMSM drive, transmission mechanism, inclined load, and nonlinear friction. Based on the model, the proposed AGF provides physically matched feedforward compensation for the dominant start-up disturbances while retaining the conventional cascaded feedback structure. Comparative simulations are conducted under conventional proportional-integral (PI) control, fixed feedforward, basic AGF, and improved AGF. Under the 4.8 t full-load condition, conventional PI control produces a maximum start-up rollback of approximately 9.1 mm, while fixed feedforward reduces it to approximately 6.1 mm but introduces a pronounced transient current peak. The improved AGF further reduces the maximum rollback to approximately 0.1 mm and improves low-speed current smoothness. Under the 2.4 t half-load condition, adaptive gravity reconstruction avoids fixed-feedforward overcompensation. Simulations with the motor rotor inertia varied by ±20% around its nominal value show that the proposed strategy retains satisfactory start-up performance under moderate plant-side rotor-inertia variation. The proposed framework provides a practical control approach for improving the heavy-load start-up reliability of IPMSM-driven GESS hoisting equipment without changing the basic hardware topology.

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Keywords

Gravity energy storage system (GESS); IPMSM drive; hoisting unit; heavy-load start-up; adaptive gravity feedforward (AGF)

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