Inverter Mode of operation in single phase fully controlled converter
Inverter Mode of Operation:
- The expression for average dc voltage from a single phase fully controlled converter in continuous conduction mode was
- For α < π/2, Vd > 0. Since the thyristors conducts current only in one direction I0 > 0 always. Therefore power flowing to the dc side P = V0I0 > 0 for α < π/2. However for α > π/2, V0 < 0. Hence P < 0.
- This may be interpreted as the load side giving power back to the ac side and the converter in this case operates as a line commutated current source inverter.
- To supply power, the load EMF source can be utilized. if an attempt is made to supply power to the ac side (by making α > π/2) the energy stored in the load inductor will be exhausted and the current will become discontinuous.
- Therefore for sustained inverter mode of operation the connection of E must be reversed.