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In this study, a switch-mode three-phase active tracking AC-AC voltage regulator based on the boost converter is proposed with a moderate number of active and passive elements used in the topology. A robust hybrid control, where a novel designed feedforward controller supports the closed-loop PID controller, is proposed for the control of the regulator apart from similar studies in the literature. Active tracking response of the reference output phase voltages is augmented by the proposed hybrid control method. Thus nearly close to sine-wave output phase voltages can be obtained, whether the input AC phase voltages are ideal pure sine or not. Also, the modular structure of the regulator topology enables independent control for each output phase. Thus, the supply of balanced/unbalanced wye-connected three-phase loads or independent single-phase loads with nearly close to ideal sine wave voltages can be achieved by the modularity of the regulator. Both experimental and simulation test studies are performed for the proposed regulator system. A laboratory set-up for the regulator is designed for 0-200 Vp input phase voltages (50 Hz), and 0-300 Vp output phase voltages, and 1.8 kW output power. The achieved results for both simulation and experimental tests verify the proposed switch-mode boost-type regulator’s ability to provide output phase voltages nearly close to sine wave with total harmonic distortion (THD) values under 5%. [ABSTRACT FROM AUTHOR]

In this paper, a single-phase switch-mode buck-type AC-AC voltage regulator is presented with reduced numbers of elements which are used in the topology. Apart from similar studies in the literature, a new hybrid control method which is structured by the closed-loop PID controller and a new enhanced feedforward controller is used for the control of the regulator. The hybrid controller improves the active tracking capability of the reference to achieve an output voltage as close to the sine-wave with high quality. The input AC voltage may be an ideal sine wave or it may include harmonics. Both simulation and experimental tests are applied for the proposed regulator controlled by this control method. The experimental set-up for the regulator is designed for 0-200 Vp input voltage (50 Hz), 0-100 Vp output voltage, and 0.6 kW output power. The results proved the capability of the proposed buck-type switch-mode regulator to achieve the requested output voltage as near as possible to sine wave. The obtained output voltages for different load conditions and input-output parameters have less than 5% THD (total harmonic distortion) and high quality. [ABSTRACT FROM AUTHOR]

In this article, a new buck-boost converter topology based 3-phase AC voltage regulator is proposed. The proposed regulator circuit has a simple structure including only two bidirectional active switches, one inductor and one capacitor for each phase, and does not require a coupling transformer. The regulator controls each phase independently. Therefore, it can be efficiently used for 3-phase systems and independent three single-phases. Closed-loop regulator circuit operation is supported with a control law depending on the instantaneous values of the real input and the desired output voltages of the regulator in order to improve the controller efficiency. The control law provides efficient pulse width modulation switching duty ratio for the desired output voltage when the input voltage has fast fluctuations and the output load is changed. A simulation model has been implemented for the proposed 3-phase AC voltage regulator in MATLAB (The MathWorks, Natick, Massachusetts, USA)-Simulink. An experimental laboratory setup has also been built for the proposed voltage regulator. The results of both the simulation and experimental studies have demonstrated that the proposed topology is capable of and efficient for both bucking and boosting the input 3-phase AC voltage to a high-quality output voltage with a low total harmonic distortion at different input voltage and load conditions. [ABSTRACT FROM PUBLISHER]

Light emitting diodes (LEDs) can be used for many lightning applications in offices, in homes, and in streets. A special converter with limited duty cycle for driving LEDs is treated. The basic analysis is done resulting in dimensioning equations of the converter. The basic analyses have to be done with idealized components (that means no parasitic resistors, no switching losses) and for the continuous mode in steady (stationary) state. A mathematical model based on state-space description is derived. Some experimental results are shown. The converter is useful for street, home, and automotive lightning applications. [ABSTRACT FROM AUTHOR]

The use of a tapped inductor in the classical sepic converter leads to a high step-down ratio thus avoiding the extreme duty cycles of the active switch and the high peak currents in the active and passive switches. The function and some stress data of such a converter are summarized and the flux density and the current through the inductor during start-up are measured and simulated by the energetic model of ferromagnetic hysteresis and the magnetic losses of the inductors are calculated. [ABSTRACT FROM AUTHOR]

Presents a study which describes a high-efficiency direct current-to-alternating current inverter for stand-alone and direct alternating current mains connection. Description of the inverter; Model of the inverter; Measurement results; Comparison of the losses; Conclusion.