I recently designed a bidirectional DC-DC charger for an Electric Vehicle (EV) battery.
I would like to focus on the inverter control. In this application, I designed the inverter to have unitary power factor (cosφ=1 , Q=0, S=P). I have read that in an application like this, it is possible to make use of the capacitors in order to offer voltage regulation to the grid. In other words, we can offer reactive power to the grid.
So, let's say that I redesign the topology: S=P/coφ in order to have the ability to transfer reactive power as well. So, the maximum power that we can offer to the grid is :
So, in case there is no active power transferred (P=0), the maximum reactive power is Qmax=P. I would like to ask if something like this is realistic. Are there any undesired consequences in the system? Should I take into consideration some parameters (for instance, the capacitor size) during the design methodology?
Also, almost the same topology is used in order to connect photovoltaic panels to the grid. In this case, it is also possible to use the capacitor to offer reactive power. However, in the most cases, I noticed that unitary power factor is desired. I would like to ask why is this happening since topologies like that seem like good solutions for local voltage regulation.