Damping Optimum-Based Design of Control Strategy Suitable for Battery/Ultracapacitor Electric Vehicles

Abstract

This contribution outlines the design of electric vehicle direct-current (DC) bus control system supplied by a battery/ultracapacitor hybrid energy storage system, and its coordination with the fully electrified vehicle driveline control system. The control strategy features an upper-level DC bus voltage feedback controller and a direct load compensator for stiff tracking of variable (speed-dependent) voltage target. The inner control level, comprising dedicated battery and ultracapacitor current controllers, is commanded by an intermediate-level control scheme which dynamically distributes the upper-level current command between the ultracapacitor and the battery energy storage systems. The feedback control system is designed and analytical expressions for feedback controller parameters are obtained by using the damping optimum criterion. The proposed methodology is verified by means of simulations and experimentally for different realistic operating regimes, including electric vehicle DC bus load step change, hybrid energy storage system charging/discharging, and electric vehicle driveline subject to New European Driving Cycle (NEDC), Urban Driving Dynamometer Schedule (UDDS), New York Certification Cycle (NYCC) and California Unified Cycle (LA92), as well as for abrupt acceleration/deceleration regimes.

Adaptive Constant-Current/Constant-Voltage Charging of a Battery Cell Based on Cell Open-Circuit Voltage Estimation

“…Precise energy management is needed to achieve dynamic power allocations between different power sources and the continuity of power delivery under varied dynamic disturbance scenarios [16]. Thus, the hybrid power source power allocation strategy needs to be tested under different realistic operating conditions, especially when vehicular implementation is considered [17].…”

An Overview of Current Challenges and Emerging Technologies to Facilitate Increased Energy Efficiency, Safety, and Sustainability of Railway Transport

“…Owing to their exceptionally long cycle life of over 10 6 charge-discharge cycles characterised by deep discharges and large discharge rates [67], ultracapacitors have shown great potential in terms of supplementing batteries and hydrogen fuel cells for high-power/shortduration (pulsed) loading regimes [68]. This has been illustrated for both stationary energy storage systems in microgrids [69] and those with potential use in transportation applications [70], wherein LiFePO 4 batteries are considered as good candidates in terms of energy density and operational safety [48]. Moreover, it seems that the energy densities of the next generation of commercial ultracapacitors are approaching the energy densities of electrochemical batteries, thus allowing for prolonged loading compared to ultracapacitors from just a decade ago [67].…”

Internal Combustion Engine Starting and Torque Boosting Control System Design with Vibration Active Damping Features for a P0 Mild Hybrid Vehicle Configuration

“…traces in the middle and bottom plot in Figure 16). This sequence of commands was due to the action of the vehicle driver model aimed at achieving zero velocity tracking error, as discussed in [5], which, in turn, tried to reach the fixed vehicle velocity target of 80 km/h in the minimum time by commanding the maximum driveline torque (see top plot in Figure 16). In order to fulfill this task, the BSG drive performed torque boosting with the maximum available torque (characterized by its torque limit value of 75 Nm) The above results of the MATLAB/Simulink co-simulation with the EXCITE-based FEAD model showed that the active damping tuning or the BSG electrical drive PI speed controller also resulted in favorable behavior of the overall FEAD system characterized by the realistic timing belt slippage effects, i.e., it did not excite timing belt vibrations due to belt compliance effects.…”

“…traces in the middle and bottom plot in Figure 16). This sequence of commands was due to the action of the vehicle driver model aimed at achieving zero velocity tracking error, as discussed in [5], which, in turn, tried to reach the fixed vehicle velocity target of 80 km/h in the minimum time by commanding the maximum driveline torque (see top plot in Figure 16). In order to fulfill this task, the BSG drive performed torque boosting with the maximum available torque (characterized by its torque limit value of 75 Nm) throughout the vehicle acceleration process, i.e., from 10 km/h to 80 km/h, finally reaching the desired vehicle velocity within 8 s (time frame between 15 s and 23 s).…”

“…(1) increasing the transport system's energy efficiency, (2) accelerating the deployment of low-GHG emission technologies and alternative energy sources in the transport sector, and (3) gradually moving towards zero-emission vehicles, i.e., those with fully electrified power trains, such as battery-based electric vehicles [5], and hydrogen fuel cell electric vehicles [6].…”