This manuscript analyzes the operation of an interior permanent magnet (IPM) machine working as a permanent magnet synchronous generator (PMSG). The partial demagnetization operation is analyzed. To obtain more accurate voltages and currents of the machine, finite element analysis (FEA) is used in co-simulation with the full converter and the converter’s control algorithm. Direct field oriented control (DFOC) shows robustness by maintaining the speed even with a 25% demagnetized PMSG. Also, an analysis of the rotating reference frame DQ signals is done to asses demagnetization.
Grzegorz Iwański, Paweł Maciejewski and Tomasz Łuszczyk
One of the currently investigated problems in power electronics-based electrical energy conversion is proper operation of electronic converters during grid voltage imbalance and harmonics. In classic control methods, it introduces oscillations of variables, resulting in the necessity to improve control systems with signals filtration and usually by application of resonant terms as part of current controllers. The paper presents a new approach to grid-connected inverter control based on transformation to a non-Cartesian frame, the parameters of which are correlated with grid voltage asymmetry. The proposed method results in resignation from resonant terms used as controllers and their replacement with proportional–integral terms for which anti-wind-up structures are significantly simpler than for oscillatory terms. The paper presents new transformation principles, features and some simulation results showing the waveforms of signals transformed to the new non-Cartesian frame.
Grzegorz Iwański, Paweł Maciejewski and Tomasz Łuszczyk
The paper presents a control method for the three-phase power converter operating under unbalanced grid voltage conditions. The method uses a new transformation to the non-Cartesian frame, which makes the controlled current vector components balanced in this frame even if originally the three-phase current is referenced as unbalanced. Furthermore, Park’s transformation makes the controlled variables constant, which allows to apply proportional–integral terms as current controllers independent of the required control target. Several control targets known from literature have been analyzed with regard to the required new transformation parameters, and the transformation parameters for all targets have been found. Simulation results are shown to prove the theoretical analysis, and the experimental test results are presented as practical validation of the proposed use of the non-Cartesian frame in control.
Amira Mohamed, Shady S. Refaat and Haitham Abu-Rub
Smart grid (SG) is the solution to solve existing problems of energy security from generation to utilization. Examples of such problems are disruptions in the electric grid and disturbances in the transmission. SG is a premium source of Big Data. The data should be processed to reveal hidden patterns and secret correlations to extrapolate the needed values. Such useful information obtained by the so-called data analytics is an essential element for energy management and control decision towards improving energy security, efficiency, and decreasing costs of energy use. For that reason, different techniques have been developed to process Big Data. This paper presents an overview of these techniques and discusses their advantages and challenges. The contribution of this paper is building a recommender system using different techniques to overcome the most obstacles encountering the Big Data processes in SG. The proposed system achieves the goals of the future SG by (i) analyzing data and executing values as accurately as possible, (ii) helping in decision-making to improve the efficiency of the grid, (iii) reducing cost and time, (iv) managing operating parameters, (v) allowing predicting and preventing equipment failures, and (vi) increasing customer satisfaction. Big Data process enables benefits that were never achieved for the SG application.
Motion control is facing an increasing popularity in the present research activities. Owing to the expected wide spreading of motion control applications, it can be predicted that the advancements in the field of electric motor drives will have a high level of influence on the new results in the field of motion control. The synchronous reluctance motor drives mean an excellent and yet cost-effective solution for actuators in motion control applications. In this article, the direct torque control with space vector modulation is analysed as a possible candidate for synchronous reluctance motor motion control applications. Its torque-control performance is investigated as a function of torque-control sample time, and a comparison of the torque ripples is made with other torque-control algorithms by an FFT analysis.
Boris Reznikov, Alexander Ruderman and Valentina Galanina
The paper considers a discrete state-space model for transients in a three-level flying capacitor DC–DC converter. A transition matrix is obtained for a pulse width modulation (PWM) period. The matrix elements are expanded into a power series using a selected small parameter. The matrix eigenvalues that determine the natural balancing dynamics transients are presented in the form of power series as well. Four separate transients are constructed based on four possible PWM period initial states (topologies). Inductor current and capacitor voltage transients are found for the voltage source power-up as the arithmetic average of the four separate transients. The discrete solutions are replaced by continuous ones. The resulting transients that are elementary functions of the circuit parameters, PWM period, and voltage reference demonstrate good agreement with the simulation results.
Synchronous reluctance motor drives are one of the most attractive alternatives of permanent magnet synchronous motor drives and induction motor drives in the field of conventional industrial and household applications. This tendency is expected to be continued in the case of motion control applications as well. This article investigates two torque-control algorithms that are possible candidates for motion control synchronous reluctance motor applications. The examined torque-control algorithms are direct torque control (DTC) and hysteresis current vector control (HCVC).
This paper proposes a multiobjective improved particle swarm optimisation (IPSO) for placing and sizing the series modular multilevel converter-based unified power flow controller (MMC-UPFC) FACTS devices to manage the transmission congestion and voltage profile in deregulated electricity markets. The proposed multiobjective IPSO algorithm is perfect for accomplishing the close ideal distributed generation (DG) sizes while conveying smooth assembly qualities contrasted with another existing algorithm. It tends to be reasoned that voltage profile and genuine power misfortunes have generous upgrades along ideal speculation on DGs in both the test frameworks. The proposed system eliminates the congestion and the power system can be easily used to solve complex and non-linear optimisation problems in a real-time manner.
Rao Anand, Nihal Vishnu Vantagodi, Kartik A Shanbhag and Mahesh M
Material handling and logistics management that involve transportation of work pieces on production floor are important aspects to manufacturing that affect productivity and efficiency. Tow vehicles that are manually driven are currently used for this purpose. These processes can be better performed through automation. Automated guided vehicle (AGV) is an apt solution. AGVs are unmanned autonomous vehicles that can be programmed to perform versatile tasks. AGVs available in market are imported and hence have high capital cost and increased lead time for spare parts. Proposed AGV is built with a capital cost that is less than half of the existing AGVs. Its design is made indigenously, with most of its parts locally sourced. It can achieve a speed of 0.83 m/s, with a pulling capacity of 1,300 kg. Its rechargeable batteries sustain four hours of continuous operation for one complete discharge. It has been tested and found to effectively replace tow vehicles.
Single-stage energy converters, in particular, the Z-Source Inverter (ZSI) or impedance source inverter, has gained significant attention in the recent years. ZSI ensures flexible energy conversions (dc–dc, dc–ac, ac–ac and ac–dc) because of its unique ability to boost the output voltage in typical renewable energy systems. The impedance network integrated between the energy source and the load contributes to the unique functionality of the ZSI. As substantial research has been conducted on the ZSI, this article provides a review on the operation of ZSI. The article initially examines the various topologies commonly adopted for the application of the ZSI. Subsequently, details of the various modulation methods that are commonly used to obtain the voltage boosting using ZSI are documented. Additionally, the phenomenon of neutral point formation, which is an important impediment to the adoption of multilevel ZSIs and the limitation of the modulation methods, is explained.