Saeid Haghbin

Grid-Connected Integrated Battery Chargers in Vehicle Applications: Review and New Solution

For vehicles using grid power to charge the battery, traction circuit components are not engaged during the charging time, so there is a possibility to use them in the charger circuit to have an onboard integrated charger. The battery charger can be galvanically isolated or nonisolated from the grid. Different examples of isolated or nonisolated integrated chargers are reviewed and explained. Moreover, a novel isolated-high-power three-phase battery charger based on a split-phase permanent-magnet motor and its winding configuration is presented in this paper. The proposed charger is a bidirectional high-power charger with a unity power factor operation capability that has high efficiency.

Integrated chargers for EV's and PHEV's: examples and new solutions

The battery is an important component in an electric vehicle (EV) or a plug-in hybrid electric vehicle (PHEV) and it should be charged from the grid in a cost efficient, preferably fast and definitely safe way. The charger could be an on board or an off board charger. For an on board charger it is possible to use available hardware of the traction system, mainly the inverter and the electric motor, in the charger circuit. This is called an integrated charger. In this paper, different examples of integrated chargers are reviewed and explained. Additionally, other possible solutions of integrated chargers are described.

An Isolated High-Power Integrated Charger in Electrified-Vehicle Applications

For electric and hybrid vehicles that use grid power to charge the battery, traction circuit components are not normally engaged during the charging time; hence, there is a possibility of using the traction circuit components in the charger circuit to have an onboard integrated charger. An isolated high-power integrated charger based on a special electrical machine with a double set of stator windings is described. Through the reconfiguration of the motor stator windings in the charging mode, a six-terminal machine is achieved. The so-called motor/generator acts as an isolated three-phase power source after synchronization with the utility grid in the charging mode. This rotary isolated power source constitutes a three-phase boost rectifier (battery charger) with full utilization of the inverter. The motor windings are reconfigured by a relay-based switching device for the charging and traction modes. This paper presents the mathematical model of the motor/generator and explains the systems functionality for the traction and charging modes. Furthermore, the charger grid synchronization and charge control are described. Finally, the simulation results are presented for a practically designed system with a traction power of 25 kW and a possible charge power of 12.5 kW.

An Integrated 20-kW Motor Drive and Isolated Battery Charger for Plug-In Vehicles

For vehicles using grid power to charge the battery, traction circuit components are not normally engaged during the charging time, so there is a possibility to use them in the charger circuit to have an on-board integrated motor drive and battery charger. An isolated high-power three-phase integrated motor drive and charger based on a split-phase permanent magnet motor is presented in this paper. The motor winding connections are reversible by a relay-based switching device for traction and battery charging. In traction mode, the motor is a classical three-phase motor, but in charging mode it is a rotating isolating transformer providing a three-phase voltage source for the inverter to charge the battery. A mathematical model of the motor with six stator windings is presented for an arbitrary phase shift in windings. For the charging mode, the split-phase motor grid synchronization process and charge control are explained including the developed controller. A 20 -kW system is designed and implemented to verify the proper operation of the proposed system. Simulation and practical results are provided to show the system performance in terms of functionality, dynamic response, and efficiency. Moreover, some discussions, recommendations, and limitations are provided to give more practical insights.

An integrated charger for plug-in hybrid electric vehicles based on a special interior permanent magnet motor

For a plug-in hybrid electric vehicle (PHEV), the battery needs to be charged from the grid while the vehicle is parked. The traction system components are normally not engaged during the charging time so there is a possibility to use them in the charger system to develop an integrated charger. An innovative high power isolated three-phase bi-directional integrated charger with unit power factor operation is introduced for PHEVs based on a special configuration of the ac motor. The winding of the machine is re-arranged in charging mode to have a three-phase boost based high power battery charger. The system configuration, the device model (machine with multiple windings), traction and charging system functionality and charger control are presented in this paper.

Demand-side behavior in the smart grid environment

Recent developments in traditional power systems which involve emerging smart technologies and widely employing of communication will convert the present electricity grids into the smart grids. The future smart and efficient power systems will treat completely different compare with the existing power systems. This paper discusses the effect of emerging smart grids on the consumers behavior. It investigates the responses of different types of consumers to the spot electricity price and the price elasticity of demand in the smart grid environment. Smart technologies could bring all of the consumers with any level of demand to the market actively, and results in increasing the efficiency of the market in a fully competitive electricity market. This paper also describes the effect of Demand Response (DR) on some electricity market issues like short-term load and price forecasting, generation expansion, and imperfect competition, in the smart grid environment. The qualitative discussions show that by emerging the smart grids the market efficiency, costumers benefits, and Demand Response of the power system are improved and the ability of strategic players to exert market power will be reduced.

Design and performance analysis of a permanent-magnet assisted synchronous reluctance machine for an integrated charger application

In a plug-in hybrid electric vehicle equipped with an integrated charger, the electric machine and the inverter, which in traction mode are used to propel the vehicle and recover energy during braking, are also used to charge the battery from the grid while the vehicle is at rest [1]. This paper studies the design and performance of a permanent-magnet assisted synchronous reluctance machine (PMaSynRM) both in traction and charging mode. Designing a PMaSynRM in order to obtain optimal reluctance and magnetic torque components is a complex task since rotor dimensioning for one torque component (magnet or reluctance torque) limits the possibility to optimize the other torque component. This paper identifies and relates the design parameters that influence these torque components and the performance of the machine using simulations based on the finite element method. The results are compared based on developed torque, torque ripple and relative values of the resulting magnet and reluctance torque.

Electromagnetic design considerations for a 50,000 rpm 1kW Switched Reluctance Machine using a flux bridge

The Switched Reluctance Machine (SRM) is a robust machine and is a candidate for ultra high speed applications. Until now the area of ultra high speed machines has been dominated by permanent magnet machines (PM). The PM machine has a higher torque density and some other advantages compared to SRMs. However, the soaring prices of the rare earth materials are driving the efforts to find an alternative to PM machines without significantly impacting the performance. At the same time significant progress has been made in the design and control of the SRM. This paper reviews the progress of the SRM as a high speed machine and proposes a novel rotor structure design to resolve the challenge of high windage losses at ultra high speed. It then elaborates on the path of modifying the design to achieve optimal performance. The simulation result of the final design is verified on FEA software. Finally, a prototype machine with similar design is built and tested to verify the simulation model. The experimental waveform indicates good agreement with the simulation result. Therefore, the performance of the prototype machine is analyzed and presented at the end of this paper.

Integrated motor drive and non-isolated battery charger based on the torque cancelation in the motor

For a plug-in vehicle, the traction circuit components like electric motor, inverter, and sensors are not used during the battery charging. So there is a possibility to use them in the battery charger circuit that is called an integrated motor drive and battery charger which can be galvanically isolated or non-isolated from the grid utility. A novel integrated motor drive and non-isolated battery charger is presented and described. The drive system is based on a split-phase PM motor that has a double set of stator windings. The motor windings are reconfigured by a relay for the traction and charging operation. One important challenge to use the motor as three inductors in charger circuit is to have it in stand-still during the battery charging. Simulation and experimental results are provided to verify proper operation of the system. The results shows that the system has a good performance and the developed torque is negligible during the battery charging.

Field-oriented control of a PMSM drive system using the dSPACE controller

Field-oriented control (FOC) of the permanent magnet synchronous motor (PMSM) is one of the widely used scheme in drive system application. Moreover, in some high performance applications, the rotor position information is needed that can be measured by a resolver for example. A drive system is designed and explained based on the FOC of a PMSM using the dSPACE controller. A resolver sensor is used for the position measurement in the system. Simulation and practical implementation results are presented to verify the proper operation of the drive system that is a speed controller in this case.