Optimization of TSPWM for Common-Mode Voltage Reduction in Vehicular Electric Drive System

Common-mode voltage can be reduced effectively by optimized modulation methods without increasing additional costs. However, the existing methods cannot satisfy the requirements of the vehicular electric-drive application. This paper optimizes the tri-state voltage modulation method to reduce the common-mode voltage for vehicular electric drive system applications. Firstly, the discontinuous switching issue during sector transition is analyzed. Under the limit of two switching times in one period, multiple alignments combination is proposed to address that issue. Secondly, the zero-voltage time intervals in different modulation ranges are explored. This paper proposes an unsymmetric translation method to reconstruct the voltage vector, and then the minimum zero-voltage time interval is controlled to enough value for safe switching. Finally, the proposed methods have been validated through experiments on a vehicular electric drive system. The results show that the common-mode voltage can be reduced effectively in the whole range with the optimized tri-state voltage modulation method.

COMPARATIVE ANALYSIS OF CONTROL SYSTEMS FOR A VOLTAGE SOURCE INVERTERS FOR AC DRIVES

The brief survey of electric drives implicated in both industry and transport are carried out. The results of comparison of control systems of a voltage source inverters included in an electric drive system with an asynchronous or synchronous motor are presented. The results were obtained by means of Matlab.

Influence of the Final Ratio on the Consumption of an Electric Vehicle under Conditions of Standardized Driving Cycles

Electric vehicles must improve their electric drive system efficiency and effectively use their limited energy to become a viable means of transportation. As such, these technologies have undergone substantial improvements from their initial conception. More efficient powertrains, together with improved storage technologies, have enabled more extended autonomy. However, from an engineering perspective, these systems are still a key area of research and optimization. This work presents a powertrain optimization methodology, developing energy savings and improving the performance of the electric vehicle by focusing on the differential. The proposed methodology includes a study of the dynamics of the electric vehicle and the generation of a mathematical model that represents it. By simulating the vehicle and varying the final ratio of the differential, a significant optimization for energy savings is obtained by developing a standardized driving cycle. In this case, NEDC, WLTC-2, and WLTC-3 test cycles are used. The results show that a short ratio improves performance, even if this implies a larger torque from the prime mover. Depending on the operating cycle used, an energy-saving between 3% and 8% was registered. An extended energy autonomy and an increment in the life-cycle of the batteries are expected in real driving scenarios.

Model of a prototype vehicle powered by a hybrid hydrogen system

The paper presents a physical mathematical model of the movement of a prototype vehicle equipped with an electric drive system powered by two sources of hydrogen fuel cell and supercapacitors. The model is based on the analysis of the forces acting on the vehicle during motion, taking into account both resistance to motion and propulsion. The model also considers the flow of electrical energy from two sources: a hydrogen fuel cell and supercapacitors, taking into account energy buffering. The aim of the model was to develop a tool to analyse fuel consumption at different control strategies of energy flow in a vehicle. The paper also presents the results of model identification for the Hydros prototype vehicle developed at Lublin University of Technology for the Shell Eco Marathon competition. Model validation was performed for a selected run during the 2019 London competition. High agreement of the model with the results of the actual vehicle was obtained.

Method for assessing the current and additional load on the parallel kinematic structure mechanisms electric drive system

Introduction. The problem of the load on an electric drive system in a parallel kinematic structure is considered. The task of developing a fault-tolerant system that provides performing a given process in case of a failure of one or more drives is described. The work objective is to create a method for estimating the current and additional load on each drive of the mechanism of a parallel kinematic structure. The solution enables to correct the operating mode when performing a given process without compromising serviceable drives.Materials and Methods. Previously, a diagnostic method was developed. It is based on the calculation and analysis of the coefficients of straight lines that approximate the envelopes of the values of the wavelet transform coefficients of electric motor current signals, taking into account the characteristic scales. This makes it possible to determine the current technical condition of the electric motor and find malfunctions. The logical continuation of this approach is the proposed method for assessing the current and additional load. It provides finding the current load on the drive based on the coefficients of the lines approximating the envelopes of the wavelet coefficients of the current signal. To calculate the additional load, the number and location of faulty drives are taken into account.Results. For each scale of the wavelet coefficients, the relative coefficients and the current load on each drive are determined. The possibility of redistributing the load to two adjacent jacks was checked; the behavior of the system in this case was investigated. The load moved by the faulty jack is redistributed to two adjacent jacks in equal shares — 14.76 % each. The total load on the drives is 44.28 %, which is safe for the servo. The load on the drive of the fourth jack does not change (29.52 %). The drives have a sufficient safety margin. It is established that all three operating modes are acceptable for the studied servo drive, and they do not cause dynamic overloads and premature failure.Discussion and Conclusions. The experimental studies on the method of assessing the current and additional load have shown its adequacy and high efficiency. It was found that when the drives were disconnected from one of the racks of the mechanism, the system performed a load redistribution on the drives. Thus, it was possible to avoid their dynamic overloads and premature failure. This means that the solution is able to ensure the reliable functioning of the complex at the time of renovation work.

Testing and Evaluation of the Electric Drive System on the Vehicle Level

In order to obtain the performance of the electric drive system (EDS) on the vehicle level correctly and effectively, the authors carried out research on the testing and evaluation technology. Firstly, the typical control strategy and its influence and limitations regarding the EDS performance were discussed in detail. Secondly, a test system on four-wheel dynamometers with a high-performance data acquisition and analysis system was introduced. A dedicated test was performed. Further analysis of the results was introduced. It is proved that the method introduced here is feasible and effective, which is beneficial to benchmarking and evaluation of the EDS used in electric vehicles.

Algorithm for improving energy efficient wheel motor for electric vehicles

In accordance with the tendency to reduce the number of mechanical assemblies in electric driven machines and mechanisms, attempts are made to bring the electric motor and the actuator of the mechanism into a single whole. Thereby increasing the quality and productivity of the machines. A motor-wheel is a kind of a driving wheel, an actuator of a traction electric drive system of a pneumatic-wheeled transport vehicle. The work is devoted to the modernization of urban electric transport by equipping it with high-energy efficiency motor wheels, based on the frequency converter system - asynchronous motor. This paper describes the improvement algorithm and technological features.

Fuel Selections for Electrified Vehicles: A Well-to-Wheel Analysis

Electrified vehicles (xEV), especially the battery electric vehicle (BEV), are burgeoning and growing fast in China, aimed at building a sustainable, carbon-neutral future. This work presents an overview and quantitative comparison of the carbon-neutral vehicles fuel options based on the well-to-wheel (WTW) analysis. A more intuitionistic figure demonstrates the fuel options for greenhouse gas (GHG) emissions and describes the sustainability. Electricity and hydrogen shift the tailpipe emissions to the upstream process, forming larger WTW emissions from a fuel cycle view. The electricity WTW GHG emission reaches as much as twice that of gasoline. However, the high efficiency of the electric drive system improves the WTW emission performance from a vehicle view, making the lowest WTW emission of BEV. The fuel options’ technical and environmental perspectives are presented. Finally, long-term carbon-neutral vehicle development is discussed.

TRAINING OF PRACTICAL ENGINEERING SKILLS IN THE CONTEXT OF THE COVID-19 PANDEMIC

This paper proposes a solution for carrying out laboratory work in the strict conditions of the Covid - 19 pandemic. The traditional laboratory can be replaced by the virtual laboratory or the remote laboratory, depending on the requirements of the course and the skills required for the training of engineers. The environment for performing alternative laboratory work (Virtual or Remote Laboratory) is the Multisim software from National Instruments. The student with the help of this software can make the electrical circuits provided in the curriculum of the discipline of General Electrical Engineering. This paper presents four examples of alternative laboratory works for the field of electrical engineering, namely, three-phase electrical circuits, static electrical converters, asynchronous motor and electric drive system. The student can simulate the required regimes in the laboratory guide and is free to simulate other regimes at his own initiative. The paper ends with the proposal of a step-by-step algorithm, which can be a guide for any teacher who wants to organize alternative laboratory work.

Research on Electromagnetic-Radiated Emission of Multi-in-One Electric Drive System

The strong electromagnetic interference produced by the electric drive system is the main factor that leads to the strong radiated emission of electric vehicles. It is very important to study the influence of the electric drive system on vehicle-radiated emission by taking the common-mode current of the electric drive system as the interference source. In this paper, the conducted emission model of the electric drive system is proposed, and the common-mode current is calculated by this model. The influence of filter on the common-mode interference current of HVDC cables is calculated and analyzed, and then the radiating antenna effect model of HVDC cables is established. Based on this, a vehicle-level radiated emission simulation model including an electric drive system and DC cables was established. The effectiveness of the conducted emission model was verified by experiments. The effects of different shielding structures on the shielding efficiency of HVDC cables were compared. Quantitative guidance for EMI suppression design of multi-in-one electric drive system design can be provided by the model in this paper.