Refine
Labor/Institute
Keywords
- Elektrische Maschine (5) (remove)
Document Type
Language
- English (5)
Has Fulltext
- no (5)
This paper will present different modulation schemes for optimizing the efficiency of low-voltage traction drives.
The converter of the vehicle automatically has to select the most suitable modulation or control scheme depending
on the present operating point in order to maximize the efficiency of the complete drive train. Furthermore, the
functional principles and algorithms of the individual modulation schemes will be presented, as well as the transition
between those schemes. Finally, the performance of the different schemes will be proved by dynamic and
stationary tests through fully automatized measurement analysis.
This contribution presents an innovative approximation method for the estimation of power quantities, fundamental waveforms, and RMS values of inverter-fed electrical machines. Typically, all these parameters are calculated as cyclically linked to the fundamental cycle of the voltages and currents of the inverter output or machine input. In order to increase the dynamic of this calculation, a suitable evaluation method based on the inverter switching cycle has been presented in previous publications. The present paper extends this switching frequency-based analysis by introducing additional quantities such as apparent and reactive power. Moreover, the paper describes the utilization of this analysis method for a power control of a dual two-level inverter-fed application.
In this contribution, a highly dynamic calculation method of power quantities and additional electrical quantities, such as RMS values and fundamental waveforms, is presented. Typically, these quantities are calculated periodically based on the fundamental cycle of the electrical voltages and currents. Hence, they are well defined during steady state conditions for ideal periodical waveforms. During dynamic balancing processes, electrical signals are non-periodic. In a strict sense, the fundamental cycle-based definitions, which are well known from the literature, are not valid for these transient signals. However, this paper presents a novel definition for the calculation of cycle-based quantities based on the switching cycle of the inverter output voltages. This definition delivers instantaneous results during transient balancing processes, whereby it approximates the conventional fundamental cycle-based definitions during the steady state.
This paper aims to present an optimized inverter topology, based on the dual two-level inverter, for feeding an open-end winding electrical machine with superconductive stator windings and a superconductive rotor. In order to achieve a high torque density, the stator windings are built of several superconducting tapes being in parallel. One inverter of the dual two-level inverter is equipped with powerful IGBT semiconductors and supplies the machine with energy. The second inverter is a low voltage MOSFET inverter that monitors the superconductor resistance (quench detection) and balances the current on the parallel superconductive tapes for guaranteeing an optimum operation with respect to the superconductive losses.
Advanced Control Methods for High Performance Dual Two-Level Inverter for Traction Application
(2021)
The topology of the dual two-level inverter in combination with an electrical machine with open-end winding is an optimal
solution for the realization of high requirements from the automotive sector for high-performance traction drives. In this
publication, methods for extending the operating range and improving output voltage and current quality are presented
for synchronous as well as asynchronous PWM methods for the entire operating range for this system configuration.
Emphasis is placed on symmetrical power sharing between the inverters to maximize the power range. Optimal integration
of the system is achieved by the topology-related possibility of DC fast charging of the energy storages from a DC grid
without an additional charging unit.