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The paper proposes a method to analyze a trade-off between IC engine and electric battery sizes which is the essential issue of plugin hybrid and range extended electric vehicle design. This method implies a set of maps to be elaborated from batch simulations of hybrid vehicle running a driving cycle. Said maps establish relationships between ICE power, fuel consumption, electric energy consumption, and driving range of a vehicle. From these, one can choose a combination of ICE power and battery energy content meeting specific requirements for fuel economy and driving range. Mathematical model of the vehicle and the hybrid powertrain adopted for driving cycle simulations is described. Besides vehicle dynamics and drivetrain’s powerflows, it addresses battery’s current and voltage restrictions, which define performance of an electric drivetrain and have to be taken into account when selecting ICE power.

The paper gives a short description of the University's developments in the field of hybrid electric powertrains and vehicles as well as a survey of theoretical instruments utilized in these works for elaboration of powertrains control strategies. At the present, two units fitted with hybrid powertrains are in operation. These are the four-wheel-drive SUV and the powertrain test rig. Both allow to test different powertrain configurations. Prior to implementing a certain configuration in the rig, a theoretical research of powertrain is conducted to reveal its properties and find a way to control it optimally. The basic tool adopted for that purpose is R.Bellman's dynamic programming (DP). The paper gives an example of applying DP to explore a potential of decreasing fuel consumption and pollutant emissions of a light commercial vehicle by converting its powertrain into hybrid one. During this study, a contradiction has emerged between minimizing fuel consumption and emissions of NOx.