A New Dual Polarity Direct AC-AC Voltage Regulator Ensuring Voltage Step-Up and Step-Down Capabilities

Abstract

The problem of voltage sag and swell is one of the major reasons for low-quality power in the distribution system. Normally, it results from the system’s faults, including line-to-ground and line-to-line, non-linear characteristics of loads and sources. Its effect is very serious for the critical loads as their performance is very sensitive to the variation in voltage. The stabilization of voltage is a mandatory requirement in such a situation. The correction of such problems requires the addition and subtraction of the voltage once the line voltage is decreased and increased. This behavior of the correcting voltage is ensured by the use of voltage controllers that can convert a constant input voltage into a non-inverted and inverted variable form. Their voltage gains depend on the depth level of the problem. The voltage buck and boost capabilities of the AC voltage stabilizers can tackle the problems having any depth level. The smartness of such a system depends on the number of electronic devices as they are the key elements in the power conversion system. Therefore, this research proposes a new AC voltage controller with fewer solid-state devices. Its overall impact is low volume and cost. The validation of the introduced approach is ensured with the help of simulation modeling and results gained from the practical setup.

A Transformerless AC-AC Converter with Improved Power Quality Employed to Step-Down Power Frequency at Output

“…The instantaneous values of the voltage and current may regard constant as their variation can be ignored at high switching frequencies. The value of switching losses for the existing circuits of [23,25,26] and the proposed topology in Equations ( 41)-( 44) respectively may be realized with the procedure as detailed in [28,29].…”

“…The main source of the conversion losses consists of conduction losses (especially for diode and thyristors) and line frequency input transformer. The conduction losses in the topologies reported in [23,25,26] and the developed circuit are calculated from Equations ( 45)-( 48) respectively by following the procedure adopted in [29]. In these equations, the notation V f is used to represent the value of the forward voltage of a diode or a thyristor.…”

A Direct Single-Phase to Three-Phase AC/AC Power Converter

“…Because of this, the lifespan of the DC-link AC/AC power converter device prematurely shortens due to the usage of the most prevalent electrolytic capacitors [18][19][20]. For the aforementioned reasons, environmental and operational factors impacting the longevity of power converters, particularly high-power ones, are given special consideration, with a focus on DC-link capacitors [21]. An intriguing way to lower the price and size of power converters is to produce them without huge capacitors in their design (DC-link) [22,23].…”