Ouyang Minggao

Study on direct torque control of permanent magnet synchronous motor in electric vehicle drive

In order to improve efficiency of electric drive system and dynamic performance of electric vehicle (EV) driven by permanent magnet synchronous motor (PMSM), a novel direct torque control (DTC) strategy in EV drive is proposed. Based on operating mode of PMSM, different space voltage vectors are chosen to acquire both quick dynamic torque response of PMSM and reduced switching loss of inverter. An optimization control method about stator flux linkage is presented to improve system efficiency. Simulation and experiment results prove the proposed strategy

Distributed control system based on CAN bus for fuel cell/battery hybrid vehicle

A distributed control system comprising a TTCAN (Time Triggered Controller Area Network) and a J1939 CAN (Controller Area Network) is proposed for a PEM (Proton Exchange Membrane) fuel cell / Ni-MH battery hybrid vehicle. A current-regulated DC/DC (Direct Current to Direct Current converter) is used to control the output power of the fuel cell. The work of the hybrid power train is coordinated by the TTCAN network, incorporating an optimal energy management strategy and a brake energy regeneration algorithm. In order to keep the vehicle safe, another CAN network based on the SAE (Society of Automotive Engineers) J1939 protocol is designed to coordinate the work of the braking energy regeneration algorithm and the ABS. Results of the city bus in the “China typical city bus cycle” are presented.

Improved direct torque control of permanent magnet synchronous motor in electric vehicle drive

In order to improve dynamic performance and reduce switching loss of permanent magnet synchronous motor system in electric vehicle drive, a self-adjusting direct torque control strategy is proposed. Based on the analyses of zero voltage vector in DTC, fuzzy control rules with zero voltage vector are presented to acquire both quick dynamic torque response of PMSM and reduced switching loss of inverter. Simulation and experiment results prove the proposed strategy.

Vehicle Powertrain Technology

In China, the internal-combustion engine accounts for over 99 % of vehicle power technology, and over 99 % passenger cars and 73 % commercial vehicles are powered by gasoline and diesel engines, respectively; the diesel-powered passenger cars are mainly SUVs and gasoline commercial vehicles mainly consist of mini-trucks, light trucks, and buses. The vehicle’s power system is in the initial stage of electrification, but over 50 % of two-wheeled motor are electrified.

Development and validation of emissions and fuel economy test procedures for heavy duty hybrid electric vehicle

Chassis dynamometer based test procedures were developed to benchmark the emissions and fuel economy performance of heavy duty hybrid electric vehicles (HEVs). And a hybrid electric bus (HEB) was tested according to the presented procedures to make a validation and get a picture of the HEB performance on the fuel economy, cold and hot start running emissions. Results show that the presented procedure is practical for heavy duty HEVs evaluation, and exhibited satisfying reproducibility.

Scenario Analyses of China’s Vehicle Ownership and Vehicle Traffic Services

A hybrid vehicle ownership model, which comprises three sub-models (private passenger vehicle population model, public traffic vehicle population model, and other vehicle population model), was established to simulate the growth of China’s vehicle population.

Integration of fuel cell hybrid powertrain based on dynamic testbed

An experimental research platform based on dynamic testbed is developed and applied for fuel cell hybrid powertrain test and integration. Driver brake model is added to dynamic testbed to simulate brake process of electric vehicle. Test methods of sub systems and whole hybrid powertrain are investigated. Characteristic curve of sub parts and energy flow chart of hybrid powertrain are acquired through experiments on this testbed. Configuration of fuel cell hybrid powertrain is investigated. This platform provides a powerful tool for fuel cell powertrain research and development.

Feedback linearization based air pressure and mass flow rate regulation for PEMFCs

In Polymer Electrolyte Membrane Fuel Cells (PEMFCs), precise regulation of air pressure and flow rate is critical to the performance and durability of fuel cell systems. This study is based on a 20-kW fuel cell engine. Based on physical interpretation and data, a nonlinear model of the cathode of the fuel cell system is presented in this paper. By utilizing the basic idea of differential geometry, the nonlinear model is further exactly linearized via coordinate transformation. Optimal controller design methodology is then adopted to construct a Linear Quadratic Regulator (LQR) for air pressure and flow rate regulation. Finally, the effectiveness of the controller is validated by the experimental results.

Electronic inertia design for in-wheel-drive system to improve off-road dynamic performance

Due to the low inertia, low damp, and high stiffness, in-wheel-drive system has vibration problems, especially under off-road conditions. Mechanical approaches such as applying additional inertia to wheels can effectively reduce the torsional vibration, however, that increases unsprung mass and brings more severe vertical vibration. In this article, electronic inertia is designed for the system to realize the same function of mechanical inertia. Joint simulation is conducted between Carsim and Matlab/Simulink, which shows that this method can suppress the torsional vibration to a satisfying level without extra cost.

Hydrogen and Fuel-Cell Vehicle Technology

The hydrogen production and utilization and thus the flow chart are analyzed, and the fuel-cell vehicle technology and its demonstration activities are summarized; based on the analysis of government policies and vehicle development scenario, the hydrogen fuel-cell vehicle development pathway is suggested and recommended.