Dynamic analysis and controller design for a center-point-clamped ac-ac converter

Bhowmik, Pankaj; Yellapragada, Sushma; Manjrekar, Madhav

doi:10.1109/apec.2015.7104401

Cited by 9 publications

(3 citation statements)

References 12 publications

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“…The desired output voltage is generated with the required output voltage, frequency, and phase by comparing the desired sine wave and the synchronous voltage wave to determine the generation time of the trigger pulses applied to trigger the thyristors. However, because thyristors are unidirectional conduction devices [7], the positive and negative half waves of the sinusoidal output current are output by the thyristors in the positive and negative groups, respectively. A risk for short circuit exists because a thyristor in the positive group is turned on before all the thyristors in the negative group are turned off or vice versa.…”

Section: Traditional Ac/ac Frequency Conversion and Its Disadvantagesmentioning

confidence: 99%

Thyristor-based “phase hopping” frequency conversion technique

Xu¹,

Zhang²,

Yi³

et al. 2019

Turk J Elec Eng & Comp Sci

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This study proposes a new AC/AC "phase hopping" frequency conversion method based on the analyses of the disadvantages of the conventional cosine wave-crossing method. The advantages of this new method include no circulating current, no dead time, and an output frequency close to the power frequency. This study also introduces the basic principles of the "phase hopping" method and analyzes these principles combined with the voltage phase-changing comparison to that of the cosine wave-crossing method. The "phase hopping" principles are used to analyze the generation of thyristor trigger pulses, including the generation time and duration. A simulation is conducted in MATLAB, and the simulation output waveform and harmonic analysis results are then obtained. The proposed approach is verified on an experimental platform. Consequently, the results are in good agreement with those of the theoretical and simulation analyses.

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Section: Traditional Ac/ac Frequency Conversion and Its Disadvantagesmentioning

confidence: 99%

Thyristor-based “phase hopping” frequency conversion technique

Xu¹,

Zhang²,

Yi³

et al. 2019

Turk J Elec Eng & Comp Sci

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“…A simplified circuit schematic of the proposed static reactive power compensator based on center-point-clamped acac conversion [11] approach is shown in fig. 4.…”

Section: Switched Reactance Based Reactive Power Compensator Witmentioning

confidence: 99%

“…But the employment of the VAr compensator topologies that have been reported in the literature remains challenging due to nonavailability of power semiconductor devices rated at utility scale voltage and power levels. The topology of Center-Point-Clamped AC-AC Reactive Power Compensator [11] that has been introduced in this paper uses power semiconductor devices rated at half the utility scale voltages.…”

Section: Introductionmentioning

confidence: 99%

State space analysis and duty cycle control of a switched reactance based center-point-clamped reactive power compensator

Bhowmik

Essakiappan

Manjrekar

2016

2016 IEEE Applied Power Electronics Conference and Exposition (APEC)

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A new approach for static reactive power compensation has been presented in this paper. Conventional thyristor controlled Static VAr Compensators (SVC) have inherent disadvantages like slow response times and poor harmonic performance as these FACTS devices are based on slow switching power electronics devices. Alternately, Pulse Width Modulated (PWM) dc-ac inverters and direct ac-ac converter structures offer higher bandwidth and push the spectral content to higher switching frequencies that are easier to filter. However, the application space of this approach is limited by the low voltage blocking capability of power devices employed in these converters. A center-point-clamped ac-ac direct power converter has been reported recently in literature which operates on the principle of neutral-point-clamped dc-ac inverter. By clamping the grid voltage to its mid-point, the center-pointclamped converter structure reduces voltage stress on the bidirectional switches by 50%. Compared to the conventional twolevel and multilevel dc-ac inverters, the proposed compensator based on direct ac-ac conversion has a simpler structure and control. The operating principle as well as dynamic analysis for the proposed VAr compensation approach has been presented in the paper. A feedback controller has been designed for closed loop control. Simulation results presented in the paper verify that proposed converter offers better control of reactive power, retrofit capability, and reduced voltage stress on the bidirectional switches. Furthermore, it has been shown that leading and lagging reactive compensation can be accomplished with a smooth control of the reactance through duty cycle modulation.

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