Considering environmental conditions and reduced fuel availability, electric cars (ECs) play a vital role in many applications such as consumer cars and short-distance transportation. This paper proposes a detailed dynamic modelling of battery, motor, and inverter developed for the design of an EC. In addition, an improved controller is developed with a different geometrical method using the sensitivity gain of the current sensor and tachometer to assure the optimal performance of the EC. For achieving linear vehicle operation and improved stability, a system transfer function model is designed by considering various uncertainties such as force acting on the car, wheel, road, and wind speed conditions. To offer better regulation and excellent tracking operation of the EC, a combined proportional-integral-derivative controller-based outer-speed and innercurrent control approach is suggested to regulate the nonlinear parameters for different driving profile applications. The proposed designed control approach and system model are tested using two input conditions such as step and driving profile inputs through MATLAB/Simulink software, and performance is analysed through various open-loop and closed-loop test scenarios.
| INTRODUCTIONConsidering environmental conditions and greater awareness about energy conservation, researchers have been paying more attention to the design of zero-polluting electric cars (ECs) of late. Recently, improvements in EC/hybrid-EC modelling have attracted greater interest at an augmented pace [1]. Particularly, lesser-weight ECs are becoming popular for many applications such as patrol and short-distance transportation cars. Many EC modelling techniques have been suggested to offer a longer driving range and linear operation [2]. Generally, EC modelling is designed by considering two subsystems, such as electric motors (EMs) for the drive system with a car platform, as shown in Figure 1. The main components of ECs are battery energy storage (BES) devices, central control structures, a tachometer, and a voltage source converter to convert DC-AC power. A single EM is used to drive each wheel [3]. However, with increasing costs and complex modelling, [4] the EC can lose its attraction for real-time applications. To achieve greater simplicity and easier control action, the DC EM is popularly selected for the traction of ECs [5]. In addition, DC motors also supply high starting torque. Therefore, to develop a robust/light, high-efficiency, reduced-cost EC, it is necessary to derive an appropriate mathematical model of ECs and EMs for different driving profile operations.Simple EC design leads to a simple control strategy that decreases the overall cost of the vehicle. However, the development of the simple EC model is difficult because of uncertainty and non-linearity in the environment and wheel and road conditions [6,7]. Mostly, disturbances are categorised into two types: (1) parametric uncertainty and (2) inner/outer disturbances. The first type of disturbance is caused by a lack of appr...