# Dynamic Test Measurements and Simulation on a Series Wound DC Motor
## 1 Introduction  
The different types of electric- and hybrid-powered vehicles have a rapidly increasing role in modern road transport. Thus, research on electric powertrains applied in them is becoming more and more important, not only in vehicle industry but also in research institutes and universities [1, 2, 3]. In Reference [1], a general review of modern vehicle powertrains and their modelling and simulation in MATLAB/Simulink is presented, while in References [2, 3], a comprehensive review is given on hybrid electric vehicles and electric vehicle drives. In the framework of the Thematic Excellence Programme--launched by the Hungarian Ministry of Innovation and Technology in 2019--a research group was established in the field of automotive industry. The research group has long-term experience in vehicle dynamics, modeling, and the simulation of prototype race cars designed and constructed by student teams at the University of Debrecen Faculty of Engineering [4, 5, 6]. In Reference [4], the dynamic model and simulation program for a pneumobile is presented, while in References [5, 6], an electric race car is presented, driven by a series wound DC motor (SWDCM) [5] and a brushless DC motor (BLDCM) [6], respectively. These teams participate in different competitions for vehicles with alternative (usually pneumatic or electric) drives (Pneumobile Race, Shell Eco-maranthon, Szechenyi Race, MVM Energy Race) [5, 7, 8]. In reference [5, 7], information about the MVM Energy Race and Shell Eco-maranthon is presented respectively, while in reference [8], a review about the participation of our Faculty in the Pneumobile competitions is presented. As a part of the above activity, a program for vehicle dynamics simulation has been realised in MATLAB/Simulink [5] which is applicable for calculating the driving dynamics functions (e.g., covered distance-, velocity- and acceleration-time functions) of a vehicle from its technical data and characteristics, including the ones of itspowertrain. Applying the above simulation program--complementing it with an optimising procedure--the optimal technical parameters and characteristics of a vehicle can be computed for a given task [9]. An important part of the program above is the modelling and simulation of the electric (or pneumatic) motor. In references [1,10], a general review of the modelling and simulation of different types of electric motors (SWDCM, BLDCM, IM, SM, SRM) is presented. In References [11-15] and [16], examples are given for the modelling and simulation of series wound DC motors. In the last few years, models and simulation programs have been developed by us for different electric motor types [6,11,17]. In References [6,11,16], models and simulation programs for a SWDC motor, while in reference [6] for a BLDC motor, is presented. One of the analysed motors was a 4 kW SWDC motor [11] which was applied in the drive system of the prototype race car that was the winner of the MVM race in 2015 [5]. For this motor, a dynamic model and simulation program had been developed in MATLAB/Simulink, seen in [11]. Our motor simulation program for SWDC motors can calculate the torque and angular speed of the motor, as well as the intensity of electric current through it, from its dynamic and electromagnetic characteristics (moment of inertia of the rotor, loading torque on the rotor, bearing friction, electric resistances and inductances of the windings, brush voltage) as a function of time. The electromagnetic characteristics of the motor (electric resistances, self- and mutual-dynamic inductances of the windings, brush voltage), which serve as the input characteristics of the simulation program were also measured [11]. Additionally, locked rotor response measurements were performed on the motor [11] to test the accuracy of the determined electromagnetic characteristics and the appropriate operation of the program in the given static situation.