Advanced electronic control systems for electric vehicles
The characteristics and relative advantages of several types of electric vehicle control systems are discussed. An advanced electronic control system for a separately excited dc motor is described. Performance characteristics of an electric vehicle using this control are discussed and recommendations for future systems are given.
ELECTROCHEMICAL POWER FOR TRANSPORTATION
The use of electrochemical power in transportation vehicles is an old concept that has a good probability of again playing a significant role in the transportation industry. It is interesting to note that this is occurring almost a century after its initial success in the late 1800s and early 1900s. It is appropriate to include in this section some historical background of the rise and fall and subsequent rebirth of the electric vehicle, as well as a brief discussion of current transportation needs, and environmental and energy utilization issues that resulted in the renewed interest in applying electrochemical energy conversion technology to electric vehicle applications. Although energy utilization has become the most significant and important issue, the environmental issue will be discussed first in this section only because of its chronological occurrence.
TORQUE CONVERTERS MAKE ELECTRIC VEHICLES COMPETITIVE
The Hobbs Torque Converter has recently been applied to electric vehicles to reduce the cost premium associated with such vehicles. The main claimed advantages of the unit are listed; these include a cost saving through simplification of the motor controls, provision of regenerative braking and a much improved performance which is comparable with that of internal combustion engines. It is suggested that the cost premium associated with electric vehicles in their present state limits their penetration of the motor vehicle market. Apart from the batteries, the electric motor and control equipment are the components for which costs are high. An alternative to sophisticated control equipment has been the use of automatic transmission, but conventional units have high power losses, mainly in the torque converter. The hobbs torque converter has both lower power losses and a higher starting ratio than conventional units, and its application to electric vehicles is described. Experimental vehicles incorporating the unit are claimed here to have a range of 50 miles in towns, a maximum speed of 50 mile/h and are likely to produce savings of around 30 per cent over petrol vehicles. It is also suggested that to bring electric vehicles into the market, the refinements associated with petrol vehicles must be included. /TRRL/