Opportunities and challenges of electrohydraulic control systems in the electrification era of non-road mobile machinery

Electrification of Non-road mobile machinery (NRMM) is more and more urgent due to the demand of pollution reduction and energy conservation. In electrified NRMMs, electrohydraulic control system is still irreplaceable in many working conditions owing to its high power density and shock resistance performance. Meanwhile, electrohydraulic control systems are facing many opportunities to improve its energy efficiency by novel component and circuit design if the internal combustion engines (ICEs) and fossil fuel are replaced by electric motors (EMs) and energy storage devices. However, there are also a lot of challenges about controllability, compactness, lifetime and so on, due to the frequent variable load characteristic and wide speed regulation range of NRMMs. In this study, the technical opportunities and challenges of electrohydraulic control systems are reviewed and summarized in the electrification era of NRMM. Finally, the future directions are considered to improve the energy efficiency and electrification level of NRMMs.