Voltage Synthesis Using Dual Virtual Quadrature Sources - A New Concept in AC Power Conversion

Dynamic control of amplitude and phase of AC line voltage will allow node voltage and branch current in meshed systems. This has traditionally required the use of inverters with energy storage, and/or AC/AC converters with multiple phases. This paper presents a novel concept wherein dual virtual quadrature sources are used to synthesize both a direct and quadrature component of the line voltage so as to realize arbitrary amplitude and phase angle control. This approach results in simple low-cost AC converters that are robust, have minimal component count, and can realize phase shift and/or harmonic control without requiring multiple sources or energy storage elements. The approach is seen to have simple implementation and can realize potentially useful devices such as phase and amplitude controllable transformers and inverter-less active filters.