Optimum design and research on novel vehicle hybrid excitation synchronous generator

Hybrid excitation is an organic combination of permanent magnet excitation and electric excitation. Hybrid excitation synchronous generator (HESG) both has the advantages of light quality, less losses and high efficiency like permanent magnet generator and the advantages of good magnetic field adjusting performance like electric excitation generator, so it is very suitable for the vehicle application. This paper presented a novel vehicle HESG which has skew stator core, permanent magnet rotor and both armature winding and field winding in the stator. Using ANSYS software, simulating the electric excitation field and the magnetic field, and finally the main parameters of HESG were designed. The simulation and the test results both show that the novel vehicle PMSG has the advantages of small cogging torque, high efficiency, small harmonic component output voltage and low waveform aberration, so as to meet the design requirements fully

Repetitive control-based phase voltage modulation amendment for FOC-based five-phase PMSMs under single-phase open fault

This article investigates the most elementary phase voltage modulation (PVM) for a more generic five-phase permanent magnet synchronous motor drive under a single-phase open fault. Most works on this topic are intended for some specific motor types, and in most cases, it assumes the inverter can still be treated as a linear switching-mode power amplifier. This article figures out that due to an oscillating neutral, the phase voltage is unable to be linearly modulated, which is to say the simplest sinusoidal pulsewidth modulation is problematic to fit a newly developed well-decoupled model under single-phase open fault. To this end, a nonlinear transform incorporating the faulty phase voltage is theoretically proposed, which alleviates the influence of oscillating neutral on PVM, and several approaches to cancel the need for phase voltage sensors are comparatively investigated. Accordingly, the PVM with repetitive control and back electromotive force compensation is put forward to fix the “faulty inverter” in practice. Plausible PVM approaches are tested experimentally, and the superiority of the proposed PVM is confirmed by experimental results

Freewheeling Current-Based Sensorless Field-Oriented Control of Five-Phase Permanent Magnet Synchronous Motors Under IGBT Failures of a Single Phase

Model-based sensorless field-oriented control (FOC) suffers from overparameterization and can be laborious to use for a five-phase permanent magnet synchronous motor. On the other hand, insulated gate bipolar transistor (IGBT) frequently fails in an electric drive. Under IGBT failure, a freewheeling current is observed, and, above all, it carries the failed phase back electromotive force information. Based on this observation, this article presents the design of a brand new sensorless FOC by exploiting the freewheeling current to accommodate both IGBT and position sensor failures, which is expected to further enhance the drive's fault-tolerant capability. The mathematical model of this current is first established to provide a theoretical basis and a comprehensive understanding of the presented sensorless FOC. By virtue of this model, a second-order generalized integrator with a frequency-locked loop can be used as a simple and elegant way to extract position/speed estimates. Experimental results are provided to validate the proposed sensorless FOC philosophy

Observer Based Improved Position Estimation in Field-Oriented Controlled PMSM with Misplaced Hall-Effect Sensors

Low resolution Hall-effect sensors have been commonly applied in PMSM drives for the reason of cost and volume. Generally, rotor speed and position are estimated inaccurately due to the installation error of the sensors. The inaccurate position degrades the performance of current control and also increases torque ripples, which aggravates mechanical vibration and noise. An improved dual observer is proposed in this paper to suppress the impact of misplaced Hall-effect sensors and improve estimation accuracy. By a cascading dual Luenberger observer and combining feedback decoupling control, the low-order noises produced by the deviation of Hall signals are effectively suppressed. The effectiveness of the proposed method is verified by experimental results