# Dynamic Simulation and Control of a New Parallel Hybrid Power System
## 1 Introduction  
Vehicles with internal combustion engines produce greenhouse gases [1; 2; 3]. However, pure electric vehicles have issues in terms of endurance, cost, charging time, and reliability of the lithium battery itself [4; 5; 6; 7]. Therefore, hybrid power vehicles can meet the needs of consumers at this stage. The electric motor works at low speed, while the internal combustion engine of a hybrid power vehicle is set to operate in the high-energy conversion efficiency area. That may significantly reduce the fuel consumption and air pollution [8; 9; 10]. According to the architecture of power control, hybrid electric vehicles can be divided into series and parallel configurations [11; 12]. In the series configuration, only one power source provides the driving force required by the vehicle, while in the parallel configuration, two or more power sources are used to provide the driving force required by the vehicle [13; 14; 15]. The parallel configuration has better efficiency than the series configuration, because in the former configuration, the internal combustion engine and electric motor can operate simultaneously, and hence, greater power is synthesized through the power integration and distribution mechanism to drive the vehicle. Moreover, when the output power of the internal combustion engine exceeds the power required by the vehicle, the battery can be charged by driving the generator, which serves as an electric power source when the electric motor operates. When the vehicle starts and runs at a low speed, the internal combustion engine does not move and is powered by the motor. In addition, a fuzzy logic controller has been proposed to improve the energy efficiency of hybrid vehicles with parallel configuration [16; 17; 18]. The basic theme of fuzzy rules is to optimize the operating efficiency of all components as a system. Simulation results have been used to evaluate the controllers. A forward-facing hybrid vehicle model is used for implementing and simulating the controller. Compared to other controllers, the use of fuzzy logic improves the fuel economy and maximizes the engine efficiency. The innovation and improvement of the control system allows the vehicle with a parallel hybrid power system to obtain better power output. [PERSON] and [PERSON] [19] used a logic-based switching control system to convert the drive torque control of the internal combustion engine into an auxiliary control, for the purpose of achieving better torque output through the vehicle's electronic throttle control device. [PERSON] and [PERSON] [20] used fuzzy logic and neuro-fuzzy logic to establish fuzzy control rules, so that the control system can have self-learning ability in addition to its automation function. [PERSON] et al. [21] proved the effectiveness of decision-making using a fuzzy logic controller, to improve the driving performance through a vehicle road test, which also improves the battery-charging mechanism while reducing NOx emissions. [PERSON] et al. [22] developed an integrated power transmission system for parallel hybrid electric vehicles using mathematical models and computer control software. [PERSON] et al. [23] used fuzzy logic control to establish vehicle operation strategies with high and low loads and verified the feasibility of this control design through simulation. [PERSON] et al. [24] developed a simulation tool for hybrid electric trucks, which comprised feed forward control, dynamic equations of subsystem modules, and basic vehicle features. [PERSON] et al. [25] proposed an optimal control theory, based on rules that exhibited lower computational complexity compared to other methods. [PERSON] and [PERSON] [26] summarized the power flow control methods of parallel hybrid power and electric vehicle systems, and explained that the optimal energy efficiency can be obtained by controlling the internal combustion engine in the minimum fuel consumption area and the maximum torque area. [PERSON] et al.