1,721,084 research outputs found
Synchronous Adaptive Resolver-to-Digital Converter for FPGA-Based High-Performance Control Loops
No full textThis paper deals with a gain scheduling synchronous demodulation scheme useful to obtain speed and position measurements from resolver position sensors. The proposed algorithm is devoted to a field-programmable gate array implementation in order to provide the elaborated information for very low latency control loops. The presented design allows getting accurate estimations in a wide range of rotational speeds without requiring costly off-the-shelf integrated circuits and leads to higher accuracy at low speed if compared to commercial solutions. To this purpose, the resolver excitation circuit has been simplified working directly with a square wave signal, and the resolver frequency behavior due to the nonsinusoidal excitation has been considered
Digital Deadbeat and Repetitive Combined Control for a Stand-Alone Four-Leg VSI
No full textThis paper deals with a newly conceived combined control topology. Deadbeat and repetitive controllers are proposed to operate jointly in a four-leg voltage-source inverter for stand-alone applications. In such a mode of operation, a dedicated controller has to regulate the inverter output voltages, which are measured at the output of the power filter. In the proposed combined control, the deadbeat rapidly compensates the output voltage variations due to load changes, whereas the repetitive control provides the required harmonic compensation capabilities that are mandatory to comply with the standards when balanced and unbalanced nonlinear loads have to be fed. As a consequence, high dynamic performance is assured, as well as harmonics in the output voltages are almost absent. In fact, the achieved experimental tests have verified that resulting output voltage total harmonic distortion is around 0.5%, and in the case of highly unbalanced and nonlinear loads, compensating also the distortion introduced by the switches' deadtime. © 1972-2012 IEEE
High Reliable Near Z Speed Control for sinusoidal Zero PMSM Drives with Low Resolution position Sensors
No full textIn this paper a back-EMF-based method is used in conjunction with three very low-cost integrated circuits based on the Hall-effect to estimate the rotor position of direct-drive PMSMs to be used for traction purpose of an electric wheelchair. A speed estimator based on rotor frame machine model (SERF) has been implemented for the PMSM drives, and then the rotor position estimation is achieved by means of a discrete integration of the estimated speed. The three Hall effect sensors are used to detect the rotor initial position as well to reset the error on the rotor position estimation every 60 electrical degrees. Start-up and near-zero speed operations for the drive, equipped with the speed estimation algorithm, have been investigated by means of simulations and an extensive experimental test campaign
Medium-Voltage Seven-Level Multiplexed Converter for AC Applications
Full text linkAfter several decades of technological evolution, power electronics applications have become extremely important for electric/hybrid propulsion systems, smart grids, renewable energy systems, energy saving, and bulk energy storage, besides the typical applications in industrial automation and high-efficiency energy systems. In all these applications, a power conversion system with high efficiency and power density is required without sacrificing the system's power quality. The paper describes the specific characteristics and the scalar modulation strategy of a new multi-level multiplexed inverter topology for medium-voltage AC applications. The proposed power converter configuration is intended for high-power applications aiming to reduce the active device's voltage rating and losses exhibiting a resulting low switching frequency of the power switches. The proposed modulation strategy aims to reduce the computational burden and simplify the implementation process, which are at the basis of any possible industrial adoption. Simulation results and full Hardware-In-the-Loop verification support the analysis. The Hardware-In-the-Loop assessment has enabled the development of a suitable modulation strategy, and the testing of the power converter is a safe environment
Design of SiC-Si Hybrid Interleaved 3-Phase 5-Level E-Type Back-to-Back Converter
Full text linkIn modern applications, such as variable frequency electric drives, aircraft propulsion, electric vehicles, and uninterruptible power supply units, high power-dense, and efficient AC-AC power converters are the key to reducing power losses, thus limiting the overall costs, and improving the system's reliability. Power electronic equipment can be enhanced thanks to the continuous evolution of conversion topologies and advancements in power semiconductor technology. The design and the optimization strategy of the AC-AC 5-Level converter, called Interleaved 3-Phase 5-Level E-Type Back-to-Back Converter (I3Φ5L BTB E-Type Converter), has been proposed in this paper. The converter is analyzed and experimentally characterized to prove the configuration's high efficiency and high-power density. An introduction to the characteristics of the I-3Φ5L BTB E-Type Converter is described, and afterward, the optimization methodology to design the multilevel converter is presented. The converter prototype is illustrated, which achieves a peak efficiency of 98.2% and a total weight of 6.18 kg using hybrid technology for power semiconductor
Design and implementation of reduced grid impact charging station for public transportation applications
Full text linkThis paper deals with the complete design procedure, implementation and control software realization for a multi-converter charging station with reduced grid impact due to local electromechanical energy storage. In particular, energy storage is accomplished by a dedicated flywheel designed and built for this purpose. The proposed charging station was designed for ultra-fast charging procedures presenting a strongly reduced impact on the electrical grid. Modes of operations are described with reference to pure electric buses in public transportation applications
Resonant-Repetitive Combined Control for Stand-Alone Power Supply Units
No full textThis paper investigates a combined resonant-repetitive (RR) control structure for a three-phase four-leg dc/ac converter power supply. The RR control configuration is composed by a resonant controller tuned at the system fundamental frequency working in conjunction with a plug-in-type repetitive controller. The resonant part of the control scheme is used to assure prompt tracking of the inverter output voltage and to achieve as fast as possible system response to load variations; to this purpose, it is tuned at the fundamental frequency. At the same time, the resonant controller is able to stabilize the system without the necessity of any further additional controller; the repetitive part of the scheme is implemented for the fine regulation at the system harmonic frequencies. The proposed control configuration is used to regulate the power supply output voltage, providing very good tracking of the output voltage reference even in the presence of a nonlinear load. Experimental validation from a 40-kVA converter prototype is presented to validate the operation of the proposed converter and control. © 1972-2012 IEEE
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