An intelligent energy management strategy for an off‐road plug‐in hybrid electric tractor based on farm operation recognition

Abstract

Due to the growing emergence of vehicle electrification, agricultural tractor developers are launching hybrid powertrains in which energy management strategy (EMS) assumes a prominent role. This work mainly aims at developing an EMS for a plug-in hybrid electric tractor (PHET) to minimise fuel consumption and increase the operating range. The developed off-road PHET power sources are composed of a biogas-fuelled Internal Combustion Engine Generator (Bio-Gen), a photovoltaic system, and a battery pack. To control the power flow among different sources, a two-layer EMS is formulated. In this regard, initially, the farm operating mode is recognised by means of classification of a working cycle's features. Then, a control strategy based on a multi-mode fuzzy logic controller (MFLC) is employed to manage the power flow. At each sequence, the classifier identifies the farm operation condition and accordingly activates the relative mode of the MFLC to meet the requested power from the Bio-Gen. The performance of the proposed EMS has been evaluated based on three real-world typical agricultural working cycles. The results demonstrate the successful performance of the proposed intelligent EMS under farm conditions by maintaining the energy sources' operation in a highefficiency zone which can lead to the extension of the working range and decrease fuel consumption.

An Efficiency Based Approach for the Energy Management in HEVs

“…Other works analyze, from an electric and mechanical perspective, specific hybrid configurations, e.g., parallel tractors with electric motors mounted on the main shaft [25] or directly in wheels [26]. Only a few works propose EMS for hybrid tractors: [27] and [28] approach the EMS problem using a backward modeling paradigm, where the driving-cycle is known in advance and can be perfectly tracked; [29], on the other side, does consider the speed profile tracking problem but assumes the possibility of controlling both the ICE and the electric motor torque, as in traditional parallel hybrid electric vehicles.…”

An Add-On Model Predictive Control Strategy for the Energy Management of Hybrid Electric Tractors

“…Other works analyze, from an electric and mechanical perspective, specific hybrid configurations, e.g., parallel tractors with electric motors mounted on the main shaft [27] or directly in wheels [28]. Only a few works propose EMS for hybrid tractors: [29] and [30] approach the EMS problem using a backward modeling paradigm, where the driving-cycle is known in advance and can be perfectly tracked; [31], on the other side, does consider the speed profile tracking problem but assumes the possibility of controlling both the ICE and the electric motor torque, as in traditional parallel hybrid electric vehicles.…”

Simultaneous Energy Management and Speed Control in a Hybrid Tractor With Experimental Validation

“…Indeed, even feasibility studies are very recent as [22], or [23] and [24] which analyze different hybrid architectures with on-shaft or in-wheel EMs. The energy management problem for tractors, e.g., [25], [26], [27], is in a very early stage with respect to the advanced techniques developed for standard vehicles. Finally, in [28] a specific strategy for agricultural operations is proposed.…”