Tatsuo Teratani

Development of Toyota Mild Hybrid System (THS-M) with 42V PowerNet

For the first time ever a hybrid system using a 42-V power supply system has been developed for better fuel economy, lower emissions and urban environment. And Toyota Mild Hybrid System (THS-M), which is the first mass production vehicle with dual voltage(42V/14V) has been launched to the Japanese market In August, 2001. This paper introduces the system configuration, features and gives actual vehicle evaluation results. The system has a motor generator (hereinafter M/G) connected to the engine crankshaft via a belt, in place of the alternator on a conventional vehicle. The electronic control of the M/G has five functions: restarting the stopped engine, driving the vehicle when starting, driving auxiliaries when the engine Is stopped, power generation during ordinary traveling and regenerative braking on deceleration braking. By restarting the engine via a belt with motor driving control, a smooth starting without discomfort is achieved. Furthermore, using this motor to drive auxiliaries during Idle increases the number of idle stop opportunities. Installing this system on a direct injection 3.0 liter engine with a 5-speed automatic transmission improves fuel economy by about 40% in the Japanese standard urban mode, when compared to the average fuel consumption of vehicles in the same class without the system.

Power Consumption and Conversion of EPS Systems

Recently, the EPS increases as one of the items of the fuel efficiency equipped with the vehicle. To compare and verify the electric power consumption for the 14 V drive EPS and the 42 V drive EPS using simulation with EPS models on computers, and assess the advantages of the higher voltage system quantitatively.

EPS System Analysis using Multi Domain Simulation for Power Network Design in a Vehicle

An EPS system requires large electrical power depending on steering torque. Recently, the required steering torque is getting larger especially for luxury sedans and large Sports Utility Vehicles. In heavy vehicles, the steering without driving and the emergency steering are becoming a very heavy load for a conventional 12 V battery system. Therefore, it is important to estimate the battery power management and the voltage behavior using the multi domain simulation for concept planning. The purpose of this research is to show that multi domain simulation is effective to discuss power electronics system and power network in the vehicle. This paper describes modeling method for an EPS system using VHDL-AMS. Static steering and dynamic steering results were validated in comparison with experimental data.

EPS system analysis using multi domain simulation for conventional 12V power network design in a vehicle

An EPS system requires large electrical power depending on steering torque. Recently, the required steering torque is getting larger especially for luxury sedans and large Sports Utility Vehicles. In heavy vehicles, the steering without driving and the emergency steering are becoming a very heavy load for a conventional 12V battery system. Therefore, it is important to estimate the battery power management and the voltage behavior using the multi domain simulation for concept planning. The purpose of this research is to show that multi domain simulation is effective to discuss power electronics system and power network in the vehicle. This paper describes modeling method for an EPS system using VHDL-AMS [1] [2]. Static steering and dynamic steering results were validated in comparison with experimental data