Modelling of the permanent magnet synchronous motor (PMSM) torque ripple and PMSM current harmonics controlling technology are important branches of PMSM research. Based on the existing linear PMSM ...model derived from magnetic co-energy, this study considers the variation of PMSM parameters (inductance, permanent magnet flux and cogging torque) caused by magnetic saturation. Then, the harmonic coupling models including flux–current coupling model, voltage–current coupling model and torque–current coupling model are deduced. In these harmonic coupling models, the PMSM parameters no longer vary with rotor position but only with current amplitude and phase. Based on the torque–current coupling model, a novel method of obtaining the required injecting currents which could suppress torque ripple is proposed. The validity of the harmonic coupling models and the injecting current solution method is verified by finite-element method.
In this article, a minimum-copper-loss fault-tolerant control scheme is proposed for open-phase fault and open-switch fault of dual three-phase permanent magnet synchronous motor (DT-PMSM) drives. ...Both the winding configurations of isolated neutral points and connected neutral points are studied in this article. In conventional minimum-copper-loss fault-tolerant control schemes, the constraints of sinusoidal phase currents result in insufficient copper-loss reduction. Different from them, the current references with the theoretically lowest copper losses are first derived and applied for different fault cases of DT-PMSM drives without using any unnecessary constraints in the proposed fault-tolerant control scheme. Thus, all phase currents in the proposed minimum-copper-loss fault-tolerant control scheme are optimized to be nonsinusoidal waveforms. Besides, the copper losses are further reduced by fully utilizing the remaining healthy switch in the faulty inverter leg for the open-switch fault of DT-PMSM drives with the proposed scheme. It has been theoretically and experimentally proved that the proposed fault-tolerant control scheme can reduce copper losses than all existing fault-tolerant schemes for both open-phase fault and open-switch fault in typical two-level voltage-source-inverter-fed DT-PMSM drives.
The design of permanent magnet synchronous motor (PMSM) is a constrained multi-objective problem, and there are often conflicts between the goals. Aiming at the complexity of PMSM optimisation and a ...large number of variables, multi-objective optimisation design of PMSM using a multi-objective comprehensive teaching algorithm (MCTA) is proposed. This algorithm is improved based on the teaching–learning-based optimisation algorithm and can better adapt to large-scale sample space and multivariate optimisation. Also, based on a magnetic equivalent circuit, a static electromagnetic model of the radial magnetic field PMSM is derived, and the design requirements and goals of the PMSM are analysed. In the two PMSM multi-objective optimisation calculation processes, the optimal solution was calculated based on the composite fitness function and Pareto front, respectively. The results of the MCTA were compared with other natural optimisation algorithms. Finally, according to the optimisation results of two sets of experiments, the correctness of the optimal solution of the algorithm was verified by finite element analysis and actual measurement of the prototype. The analysis of results shows the effectiveness, simplicity, and inspiration of MCTA in the PMSM multi-objective structure optimisation design.
Abstract
This paper deal with comparative evaluation of control techniques of Permanent magnet synchronous motor (PMSM) drive in automotive application is investigated. The FOC, DTC and proposed ...SVM-DTC with LC-Snubber circuit are presented. In SVM-DTC, this reduces low torque ripple by using space vector modulated. The parameters of FOC, DTC and proposed SVM-DTC with LC-Snubber method are studied by simulation. The simulation analysis of control method is investigated in terms of speed, current and torque ripples It was observed that the proposed method upgrade the performance of PMSM drive in respect to speed, current ripples, and torque responses
Interest in permanent magnet synchronous machines (PMSMs) is continuously increasing worldwide, especially with the increased use of renewable energy and the electrification of transports. This book ...contains the successful submissions of fifteen papers to a Special Issue of Energies on the subject area of “Permanent Magnet Synchronous Machines”. The focus is on permanent magnet synchronous machines and the electrical systems they are connected to. The presented work represents a wide range of areas. Studies of control systems, both for permanent magnet synchronous machines and for brushless DC motors, are presented and experimentally verified. Design studies of generators for wind power, wave power and hydro power are presented. Finite element method simulations and analytical design methods are used. The presented studies represent several of the different research fields on permanent magnet machines and electric drives.
Multiphase machines are well known for their fault-tolerant capability. Star-connected multiphase machines have fault tolerance in an open circuit. For an inverter switch short-circuit fault, it is ...possible to keep a smooth torque of a permanent magnet synchronous machine if the currents of the faulty phases are determined and their values are acceptable. This paper investigates fault-tolerant operations of an open-end five-phase drive, i.e., a multiphase machine fed with a dual-inverter supply. Inverter switch short-circuit fault is considered and handled with a simple solution. Original theoretical developments are presented. Simulation and experimental results validate the proposed strategy.
In this paper, three control schemes with variable switching frequencies are proposed and analyzed for the paralleled voltage source inverters (VSIs) fed permanent magnet synchronous motor (PMSM) ...drive. The proposed schemes could be applied in the low-speed operation region of high-power drive system, where the frequency modulation index is high. First, the field-oriented control (FOC) with phase-shifted chaotic space vector modulation (SVM) under synchronous frame and the FOC with phase-shifted chaotic sinusoidal pulse width modulation under stationary frame is proposed for the paralleled VSIs fed PMSM drive. The proposed phase-shifted chaotic PWM schemes not only eliminate specific switching harmonics completely but also suppress all remaining switching harmonic peaks in the spectrum. The avoidance of inherent circulating current is also considered in designing these two schemes. Second, the direct torque control (DTC) for the paralleled VSIs fed PMSM drive is proposed with circulating current suppression. Besides inheriting the advantages of DTC, the output currents of paralleled VSIs are kept balanced. The working principles of these three methods are presented in detail. Experimental results on a laboratory prototype are given to verify the validity of the three proposed control schemes for the paralleled VSIs fed PMSM with variable switching frequencies.
This paper deals with optimal control strategies robustified by a decoupling super-twisting sliding mode control (ST-SMC) for permanent magnet synchronous machines (PMSM). In general, ST-SMC is a ...robust method for controlling systems and guarantees asymptotic convergence in cases where the upper bound of model uncertainties such as disturbances and parametric uncertainties is not known a priori, if the upper bound of the derivative is known. The proposed optimal control strategy is designed for a constant torque reference whose control is implemented in two control regions: maximum torque per ampere (MTPA) and flux-weakening control. In the proposed analysis, the operating point of the motor can also be in the saturation region, which makes the estimation of Ld and Lq in the proposed optimization procedure of particular interest and also important for the decoupling control implemented with ST-SMC. To compensate for typical parameter variations, adaptive parameter estimation is introduced into the control system using an extended Kalman filter (EKF) in combination with a bivariate polynomial. In order to be able to make an assessment of the control performance of the ST-SMC, a comparison with a conventional PI controller is shown at the end of the paper. Measured results using hardware in the loop (HIL) to validate the results and their detailed discussion and analysis are included.
To make full use of the advantages of dual three-phase PMSM (DTP-PMSM) and three-phase open-winding PMSM (OW-PMSM), this paper proposed a novel typology of motor drive which can switch between dual ...three-phase (DTP) structure and three-phase open-winding (OW) structure online. On this basis, the basic control and fault-tolerant control are studied to explore the superiority of the proposed typology. Under healthy conditions, no adjustment is required for the modulation method of the proposed control scheme when switching between DTP mode and OW mode. By using two bidirectional thyristors, smooth switching between the two modes can be guaranteed. Besides, the power weight of two inverters can be adjusted by changing the current ratio in DTP mode and changing the voltage ratio in OW mode. For the fault-tolerant control, when an open-phase fault occurs, DTP mode will be used to provide sufficient dimensions of current control and the fault-tolerant scheme can be realized through current compensation without changing the control framework. When an open-switch fault or short-switch fault occurs, OW mode will be adopted to guarantee symmetrical phase currents, and the remaining healthy switches in the faulty inverter are fully used to share the loss of the healthy inverter. The experiment has been conducted to prove the feasibility and superiority of the proposed typology and control scheme.
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