Effect of road gradient on regenerative braking energy in a pure electric vehicle

Abstract

A regenerative brake system significantly improves the energy efficiency of electric vehicles, but road gradient can adversely affect fuel economy and vehicle control. This study seeks to explore the effects of road gradient on the regenerative brake system on the basis of driving information collected by global positioning systems (GPS) and inertial sensors, including road gradient and vehicle speed. Then optimization is made of conventional parallel control strategy, serial control strategy with fixed front–rear brake force allocation, and serial control strategy with optimal energy recovery. By calculating the contribution ratio to energy consumption reduction in each of the three strategies based on a model of pure electric vehicle’s energy flow, the roles that road gradient plays are carefully investigated. Simulation results show that our proposal for taking road gradient into account helps to design more efficient strategies of regenerative braking systems.

Analysis of regenerative braking efficiency in an electric vehicle through experimental tests

“…En relación con el consumo de energía, estos factores requieren un mejor desempeño de las baterías en los vehículos eléctricos, especialmente en rutas de montaña. En este sentido, la pendiente de la carretera es un factor que no puede ser ignorado cuando se diseñan estrategias para optimizar el frenado regenerativo [7,8].…”

Advisor Based Modelling of Regenerative Braking Performance of Electric Vehicles at Different Road Slopes

“…Yang et al, in their study on electric scooter, have stated that regenerative energy recovery is more suitable for current systems included in electric vehicles [17]. In a simulation of electric vehicles, made for recovery of energy lost during braking, it has been foreseen that an energy saving of 25% can be made by KERS for intra-city usage [18]. The road slope is very important for electric vehicles in terms of vehicle control and fuel economy.…”

Truck mass estimation method based on the on-board sensor

“…Similarly, sensor-based estimation methods also require the global positioning system (GPS) and inertial navigation system (INS) to estimate the road gradient. 14–16…”

“…Similarly, sensor-based estimation methods also require the global positioning system (GPS) and inertial navigation system (INS) to estimate the road gradient. [14][15][16] The current main research methods are Kalman filtering (KF), 17,18 least squares (LS) [19][20][21] and adaptive parameter estimation. Kim et al 22 developed road grade and mass estimation methods for commercial vehicle using the recursive least square method (RLS) and the in-vehicle sensors.…”