Design, development and characterisation of a FPGA platform for multi-motor electric vehicle control

Abstract

Abstract-Two three-phase squirrel-cage induction motors are used as a propulsion system of an electric vehicle (EV). A simple XC3S1000 FPGA is used to simultaneously control both electric motors, with field oriented control and space vector modulation techniques. To electronically distribute the torque between the two electric motors, a simple, yet effective, strategy based on a uniform torque distribution has been implemented. Experimental results obtained with a multi-motor EV prototype demonstrate the proper operation of the proposed system.

FPGA Based Powertrain Control for Electric Vehicles

“…Note that in a multi-motor configuration each motor is free to rotate at any speed, and can be seen as an independent system: all motors receive equal value of acceleration/braking torque, but the load torque experience by each motor is different, especially during cornering manoeuvres, which naturally leads to different wheel speeds. These observations are corroborated by the experimental results obtained in the multi-motor uCar prototype (de Castro et al, 2009b) and allow us to employ a simple and low cost torque allocation to operate the EV.…”

“…Although important, this block is still under internal development by our team (de Castro, 2010) and we are planning to incorporate it, as soon as possible, in the powertrain library. Nevertheless, while this block is not completely developed we are employing a simple constant torque allocation (de Castro et al, 2009b), whose features will be discussed in a later section.…”

“…3, was designed using polar coordinates, represented in the stationary reference frame (α, β), having as inputs the normalized magnitude (m) and angle (θ) of the desired voltage vector to be applied to the motor. Based on this information, and employing simple trigonometric relations (de Castro et al, 2009b), the SVPWM calculates the duty cycles to be applied to each arm in the inverter. Before generating the final PWM signals, dead-times are inserted in the switching signals, as a mean to prevent upper and lower arm short-circuits, and pulses less than a minimum width (2 times the inverter dead-times) are dropped to ensure the proper operation of the inverter when high modulation indexes are requested.…”

Robust DC-Link Control in EVs With Multiple Energy Storage Systems

“…As future work, we intend to validate the DC-Link controller in one of our full-scale EV prototypes [44], [51] and address the VEM layer. …”

DC link control for multiple energy sources in electric vehicles

“…The former objective, the constant DC bus voltage, represents a typical requirement in the EMS of EVs, given the nature of the loads connected to the converter output, e.g. the voltage source inverter(s) of the electric motors [13,14]. Regarding the second objective, the SC SOC (indirect) control, this is a strategic component to optimize the power sharing between the two energy sources and reduce the overall losses.…”