Bidirectional Nonisolated Fast Charger Integrated in the Electric Vehicle Traction Drivetrain

Abstract

Electric vehicles present an opportunity to reduce the substantial global footprint of road transportation. Cost and range anxiety issues, however, remain major roadblocks to their widespread adoption. One of the simplest ways to reduce cost is to remove components from the vehicle via novel topologies, estimation and control; to reduce range anxiety, charging infrastructure needs to be simplified and the power electronics in the vehicle made more efficient. This thesis proposes a bidirectional non-isolated fast charger integrated in the traction drivetrain of an electric vehicle that is enabled by a modular power electronic converter topology called the autoconverter module. The autoconverter module is an evolution of previous modular power electronic concepts with the goal of a highly integrated, high performance converter capable of being used in a number of applications through simple parallelization. By simplifying system design through the use of one base power conversion block, overall system cost can be reduced.Key to the realization of the power module is state estimation. To enable high performance operation of the system, low noise state information must be provided to the controller. State estimation is capable of filtering measurement noise to achieve this goal. However, conventional estimation techniques typically have low bandwidth and a convergence time associated with them, limiting the overall control system's performance. Higher performance techniques, such as receding horizon estimation, offer near-instantaneous estimation with noise rejection capabilities,

An electric vehicle integrated battery charger with high utilization rate of the three‐phase open‐winding permanent‐magnet‐synchronous‐motor

“…To restrain the leakage current, filter capacitors C f (8 μF) and common mode inductor L CM (4 mH) can be introduced into the topology, as shown in Figure 16A. The principle is described in Eull et al 38 and is not repeated here. We can see in Figure 16B that the amplitude of the common mode voltage is below 100 V and the RMS value of the leakage is reduced to 17 mA.…”

“…Leakage current path and simulation results with suppress method in Eull et al 38 (A) Leakage current path. (B) Waveforms of the common mode voltage and leakage current…”

Comprehensive review of battery charger structures of EVs and HEVs for levels 1–3

“…[55][56][57][58][59][60][61][62][63][64][65][66][67] And integrated chargers are one of those solutions where, in most cases, they use the traction system's electric machine to interface between the external AC source and the vehicle's batteries. [68][69][70][71][72][73][74][75] These integrated chargers into the electric motor have been attracting many interests in the industry, and they are becoming the trend for the new generation development of EVs and HEVs in the next decade, due to the performance of more than one functionality, for example, using multi-phase machines. [76][77][78] Chargers that use resonant topologies have also aroused great interest for application in OBCs, which operate through the exchange of energy between an inductor and a capacitor (LC tank circuit) when resonance occurs, producing sinusoidal voltages or currents, enabling operation with high switching frequencies.…”

“…In addition, the project is not being optimized to act as a motor and charger, as it leads to reduced system efficiency when it is necessary to extract more power in the recharging process. A similar strategy is adopted by Eull et al, 75 where only one three-phase full-bridge inverter is used. F I G U R E 6 (A) Topology of the isolated charger incorporating a symmetrical six-phase machine.…”

Vehicle-to-Grid Fleet Service Provision considering Nonlinear Battery Behaviors

“…Battery power rating and efficiency are sensitive to the SoC, and the charge or discharge power must be carefully controlled to ensure battery thermal security and reduce degradation rates [21]. A common protocol for EV charging management is the CC-CV (constant currentconstant voltage) method [22]- [24], that the battery charges with constant current until reaching a high SoC level and then gradually reduces the current to maintain a constant charging voltage to prevent over-voltage damages. Modeling battery characteristics such as CC-CV protocols in V2G management is critical to maximize cost savings and ensure battery security, but it requires representing battery power and efficiencies as functions of SoC instead of using constant values, which introduces significant computation complexities [13], [25]- [28].…”