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In this paper, in order to replace a conventional electric linear actuator which is consist of rotary PM machine and ball screw, a novel double-sided five-phase modular linear permanent magnet synchronous machine (MLPMSM) is proposed and designed with the same volume. The basic structure of the machine is firstly described and the major dimensions of one module are then optimized to acquire the largest...
Multilevel inverters are high voltage, high power devices with wide electrical applications due to their lower output harmonic component and device stress management capabilities. Manifold control strategies have been proposed and implemented for MLIs and fundamental frequency switching strategies are especially suited due to their ability to provide for higher efficiency. This paper proposes a hybrid...
In this paper, we investigate rotor and stator designs of interior permanent synchronous motors for variable speed/load applications to reduce the carrier harmonic losses caused by pulse width modulated inverters. The rotor core and magnet shapes are determined by an automatic optimization method using electromagnetic field analysis that considers the inverter carrier. Appropriate stator-winding configurations...
Permanent magnet synchronous machines (PMSMs) have been used in many applications due to their outstanding advantages such as high torque/power density, high efficiency, light weight and good reliability. However the emerging field of electrical traction gave arise to issues which were in general hardly considered in the past Yet, even though well established methods for eDrive control are available,...
This paper further develops the concept of very large size flash-memory-based pulse-width-modulation (PWM) with the implementation of an over-modulation algorithm for a three-phase inverter. The compensation of voltage for linearization is incorporated within the same flash memory with a multi-optimal PWM generator. Using flash memory demonstrates a low cost alternative to advanced processors. This...
Today's three-phase Adjustable Speed Drive (ASD) systems still employ Diode Rectifiers (DRs) and Silicon-Controlled Rectifiers (SCRs) as the front-end converters due to structural and control simplicity, small volume, low cost, and high reliability. However, the uncontrollable DRs and phase-controllable SCRs bring side-effects by injecting high harmonics to the grid, which will degrade the system...
A model predictive control system for delta-connected modular multilevel converter is proposed in this paper. The control system is based on offline computed optimal pulse patterns, which are modified online using model predictive control. Optimized pulse patterns facilitate the shaping of the grid current spectrum at low switching frequencies. Unlike conventional control methods with optimal pulse...
To help mitigate some of the challenges associated with the wide spread adoption of the stochastic wind power, wind turbine with full-scale power converter (Type D) is preferred. Since full power is processed by the power converter in a type D wind turbine, it is important to improve its efficiency and reduce the cost per kW to achieve lower cost of energy. The power produced by the wind turbine varies...
In the operation of grid-connected photovoltaic power stations, a large amount of harmonic current is injected into distribution network, which reduces the power quality of distribution network. In the paper, the Static Var Generator (SVG) is added to the outlet of the photovoltaic power station, by using the feedforward control strategy for the voltage, SVG can effectively suppress the harmonic current...
A hybrid modulation approach is proposed in this work, which allows to modulate the switches of the five level neutral point clamped inverter (5LANPC) with different switching frequencies. Some of the switches are controlled with a low switching frequency using six-step modulation and Optimized Pulse Patterns (OPPs), whereas the rest are modulated with a high switching frequency using Carrier-Based...
The multiobjective allocation optimization of single tuned passive power filters for decreasing the power losses and harmonic mitigation in distribution networks is presented in the paper. The Pareto definition of the multiobjective problems is used in the paper. The two objectives problem consists of the two technical objective functions, the real power losses and the total harmonic distortion, is...
This paper presents a multiphysics modeling approach to design an electric powertrain assembly in order to predict its NVH performance and perform optimization to minimize noise while keeping weight under control. The powertrain assembly contains two components — synchronous motor and a geartrain. Numerical simulation approach involves three steps; 1. A two-dimensional (2D) finite element electromagnetic...
The problem studied in this paper and described in the literature is determining the fundamental frequency of a non-trivial signal in real-time. Using the gradient-descent algorithm, a new optimized method for fundamental frequency evaluation was proposed. The comparison between the two methods, classic and optimized, was carried out by utilizing a sine, square and amplitude modulated wave as input...
The paper focuses on optimal current quality (minimal Total Harmonic Distortion — THD) for a single-phase three-level inverter modulation. Previous works addressed optimal THD problem in frequency domain accounting for a limited number of harmonics. The uniqueness of this work is in its time-domain formulation of minimal current THD problem, which facilitates optimization accounting for all harmonics...
Interleaving (ILV) operation is often used for parallel-connected voltage source converters (VSC) since it provides a better harmonic spectrum which enables a smaller filter realization. To investigate the performance limitations and the impact of ILV operation on the LCL filter, a comprehensive LCL filter and intercell transformer (ICT) optimization procedures for two-interleaved VSCs is presented...
A novel decentralized method for harmonics detection and suppression is proposed. Compared with the traditional centralized style, harmonics optimal estimation task in micro-grid system is scattered to smart phasor measurement unit (PMU) nodes without a monitoring host. Similar to the structure, mechanism and characteristics of biological communities, a smart PMU can communicate with adjacent nodes...
Customers may have different power quality requirements, thus, the economic operational strategy can try to provide them with distinctive quality levels as customized service. An optimization based method is proposed in this paper to realize this functionality, offering the possibility that the customers can flexibly set and adjust their requirements. Converter interfaced distributed generators are...
The traditional particle swarm optimization (PSO) algorithm has been used to optimize inverter controller parameters. However, there are some disadvantages when the quantity and optimization interval of inverter controller parameters increase, such as easily falling into local optimum, and optimization convergence problems. An improved PSO algorithm with multi-swarm and multi-velocity (MMPSO) is proposed...
The objective of this project is the performance optimization of an electrical drive system, which consists of a two-level Voltage Source Inverter (VSI) and a Permanent Magnet Synchronous Motor (PMSM) with high magnetic anisotropy. To this end, the concept of Synchronous Optimal Modulation (SOPWM) is employed for inverter control and the optimal inverter switching angles are defined for an isotropic...
Second harmonic imaging relies on the double the transmit frequency being generated as the waves propagate into the tissue. The method requires good control over the transmit system, to suppress 2nd harmonics transmitted from the transducer. These transmitted harmonics may originate from both linear, e.g. sidebands in the transmit spectrum, and nonlinear effects in the transducer and transmitting...
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