Abstract: To solve the problems of poor steering feeling and high energy consumption in the hydraulic power steering system of a heavy vehicle, a winding type permanent magnet coupler (WTPMC)-based electronically controlled hydraulic power steering (W-ECHPS) system is proposed in this paper. The structural principles of W-ECHPS and WTPMC are introduced, the operating parameters of WTPMC under different driving conditions are determined to provide the basis for its design and performance study based on driving condition. Finite element simulations on WTPMC using Ansoft Maxwell software are conducted to study its steady-state performances, including electromagnetic, speed-regulating and slip power recovery performances. On the basis of simulation results meeting requirements, WTPMC prototype is manufactured and bench tests are carried out with their results compared with simulation ones in respects of line back-EMF in no-load condition, duty ratio of IGBT and terminal voltage of ultracapacitor. The results show that the outcomes of simulation basically agree with test data, WTPMC has good electromagnetic performance, can meet the requirement of operating limits, and can operate in different driving conditions by regulating the duty ratio of IGBT. In addition, it has good slip power recovery performance, with a slip power recovery rate between 67.4% and 72.5%.

Key words: winding type permanent magnet coupler, electronically controlled hydraulic power steering, finite element simulation, steady-state performance, slip power recovery