Fernando Rodriguez

Energy Storage Systems for Automotive Applications

The fuel efficiency and performance of novel vehicles with electric propulsion capability are largely limited by the performance of the energy storage system (ESS). This paper reviews state-of-the-art ESSs in automotive applications. Battery technology options are considered in detail, with emphasis on methods of battery monitoring, managing, protecting, and balancing. Furthermore, other ESS candidates such as ultracapacitors, flywheels and fuel cells are also discussed. Finally, hybrid power sources are considered as a method of combining two or more energy storage devices to create a superior power source.

Power Management of an Ultracapacitor/Battery Hybrid Energy Storage System in an HEV

To overcome the power delivery limitations of batteries and energy storage limitations of ultracapacitors, hybrid energy storage systems, which combine the two energy sources, have been proposed. A comprehensive review of the state of the art is presented. In addition, a method of optimizing the operation of a battery/ultracapacitor hybrid energy storage system (HESS) is presented. The goal is to set the state of charge of the ultracapacitor and the battery in a way which ensures that the available power and energy is sufficient to supply the drivetrain. By utilizing an algorithm where the states of charge of both systems are tightly controlled, we allow for the overall system size to reduce since more power is available from a smaller energy storage system

A Novel Digital Control Technique for Brushless DC Motor Drives

Brushless DC (BLDC) motor drives are continually gaining popularity in motion control applications. Therefore, it is necessary to have a low cost, but effective BLDC motor speed/torque regulator. This paper introduces a novel concept for digital control of trapezoidal BLDC motors. The digital controller was implemented via two different methods, namely conduction-angle control and current-mode control. Motor operation is allowed only at two operating points or states. Alternating between the two operating points results in an average operating point that produces an average operating speed. The controller design equations are derived from Newtons second law. The novel controller is verified via computer simulations and an experimental demonstration is carried out with the rapid prototyping and real-time interface system dSPACE.

A novel digital control technique for brushless DC motor drives: conduction-angle control

Brushless DC (BLDC) motor drives are continually gaining popularity in motion control applications. Therefore, it is necessary to have a low cost, but effective BLDC motor speed/torque regulator. This paper introduces a novel concept for digital control of trapezoidal BLDC motors: conduction-angle control. The controller is very simple to implement in a cost effective application-specific-integrated-circuit (ASIC). The controller design equations are derived from Newtons 2nd law. The novel controller is verified via computer simulations and an experimental demonstration is carried out with the rapid prototyping and real-time interface system, dSPACE

A novel, low-cost, high-performance single-phase adjustable-speed motor drive using PM brush-less DC machine: IIT's design for 2003 future energy challenge

This paper presents a novel, low-cost, high-performance single-phase adjustable-speed motor drive by using a three-phase permanent magnet brush-less DC (BLDC) machine. This system has been designed and implemented by the multidisciplinary student team of Illinois Institute of Technology (IIT) for the 2003 IEEE/DOE/DOD international future energy challenge and won the first prize overall award for the motor competition. Machine configurations and driver topologies have been investigated to develop a low-cost innovative system. To satisfy the requirements of the challenge, a commercially available motor has been selected and redesigned including the stator winding and permanent magnet rotor. The redesigned motor has been fabricated and tested successfully. For the designed power electronic driver, the main goal was to achieve high performance and reliability at low cost. Simulation and experimental results are provided to verify the proposed approach.

A Novel Digital Control Technique for Brushless DC Motor Drives: Steady State and Dynamics

This paper introduces a novel digital control for trapezoidal back-emf brushless DC (BLDC) motor drives. First, the over all concept is outlined followed by the steady state analysis and design procedure that is derived from Newtons 2nd law of motion. Second, transient operation is presented, which makes use of a state observer. The state observer is used to estimate the load torque, which is necessary for the digital controller to calculate the appropriate control parameters. The design equations for the state observer are derived. Finally, a BLDC motor drive model is created in the MATLAB/Simulink environment to validate the developed control algorithm. The simulation results will show that the proposed controller is able to accurately track a commanded speed despite time varying torque disturbances

Adaptive control for hybrid electric vehicles

Existing controllers of hybrid electric vehicles (HEV) are mostly tuned to achieve higher fuel economy for specific driving conditions. In this paper, a brief review of control strategies is presented followed by new approaches to implementing an optimisation based controller. First, a control strategy based on stochastic dynamic programming that can be used for real time applications is presented. This strategy achieves about 10% increase in fuel efficiency in most drive cycles over a rule-based control strategy. The second analysis uses an artificial neural network (ANN) to develop an optimised control strategy. Several existing hybrid control strategies are used to model a base for city and highway driving. Elite simulation data was extracted to form a training set for the ANN. The training set was then used to develop a new ANN control strategy that was superior to all the existing strategies used to develop the training set.