A single phase multi-string PV inverter with minimal bus capacitance
- John Schonberger
- 2009 13th European Conference on Power…
The use of switches within a photovoltaic arrays architecture is gaining recognition as an optimal solution to the partial shading problem because it allows the array to behave in a flexible manner which is ideal for rapid response to unpredictable shading environments. Although that has been the driving force behind recent research, an interesting alternative reason for implementing a dynamic array is that it is able to exhibit complex behaviours. One such behaviour is the ability to directly synthesize an alternating current by the switching of DC cells in a controlled sequence. Voltage inversion is a very well researched field and commercial inverters can achieve very high efficiencies (typically over 95%). However, high powered models are expensive and are often the cause of system failure. This paper discusses the concept of AC synthesis through the switching of PV sources and looks at the similarities with the conventional cascaded H bridge multilevel inverter. A basic Alternating current dynamic photovoltaic array (AC-DPVA) is disclosed and a theoretical solution to extracting maximum power is discussed. Many interesting new features are evident and implementing a PV array like this can ultimately remove the need for and inverter altogether.