System Efficiency Improvement for Electric Vehicles Adopting a Permanent Magnet Synchronous Motor Direct Drive System

Abstract

To improve the endurance mileage of electric vehicles (EVs), it is important to decrease the energy consumption of the Permanent Magnet Synchronous Motor (PMSM) drive system. This paper proposes a novel loss optimization control strategy named system efficiency improvement control which can optimize both inverter and motor losses. A nonlinear power converter loss model is built to fit the nonlinear characteristics of power devices. This paper uses double Fourier integral analysis to analytically calculate the fundamental and harmonic components of motor current by which the fundamental motor loss and harmonic motor loss can be accurately analyzed. From these loss models, a whole-frequency-domain system loss model is derived and presented. Based on the system loss model, the system efficiency improvement control method applies the genetic algorithm to adjust the motor current and PWM frequency together to optimize the inverter and motor losses by which the system efficiency can be significantly improved without seriously influence on the system stability over the whole operation range of EVs. The optimal effects of system efficiency is verified by the experimental results in both Si-IGBT-based PMSM system and SiC-MOSFET-based system.

Fast and Accurate Model of Interior Permanent-Magnet Machine for Dynamic Characterization

“…where stator flux linkage is preserved as state-variable. The full FLM set of equations is defined by Equations (2), (3), (14), and (16).…”

Determining electrical losses of the traction drive of electric train based on a synchronous motor with excitation from permanent magnets

“…Papers [19,20] determine losses in the inverter and in the engine comprehensively. Author of [19] proposed analytical formulae for determining losses in the engine from the main frequency and higher harmonics of phase current, as well as losses in the inverter's transistors.…”

“…Papers [19,20] determine losses in the inverter and in the engine comprehensively. Author of [19] proposed analytical formulae for determining losses in the engine from the main frequency and higher harmonics of phase current, as well as losses in the inverter's transistors. In [20], losses in the inverter are determined using a simulation of the inverter, while losses in the traction motor are calculated by the finite element method.…”

“…The shortcoming of procedures given [19,20] is the calculation of losses in transistor using averaged formulae that do not make it possible to take into account the dependence of energy of enabling and disabling the transistors, energy of the antiparallel diode reverse recovery, and other reference characteristics of transistors, on the current that passes through them.…”

Digital Control of an Interleaving Operated Buck-Boost Synchronous Converter Used in a Low-Cost Testing System for an Automotive Powertrain

“…Current Source Inverters require a current source. For all types of DC-AC converters, the analysis has to be performed regarding harmonic distortion and related issues [13][14][15][16][17]. Well-known testing systems setups are shown in Figure 1 [4][5][6].…”