Three phase medium voltage power conversion system for coupling a power source to a utility grid

1. A three phase Medium-Voltage (MV) power conversion system ( 43 ) that couples a power source ( 11 ) to a utility grid ( 15 ), the system comprising:

a power converter ( 51 ) that comprises a rectifier ( 61 ) coupled to the power source ( 11 ), a DC-Link ( 63 ), and an inverter ( 65 );

a Notch-Filter ( 53 ) coupled to output nodes of the inverter ( 65 ); and

a switching control system ( 67 ) that controls the inverter ( 65 ) based on Selective Harmonic Elimination-Pulse Width Modulation (SHE-PWM) patrons;

wherein

the Notch-Filter ( 53 ) is tuned to attenuate a frequency of a first harmonic of the inverter that the switching control system ( 67 ) of the inverter ( 65 ) cannot attenuate and is configured with damping means that smooths a resonance frequency of the Notch-Filter ( 53 ) without affecting a notch frequency.

2. The three phase MV power conversion system ( 43 ) according to claim 1 , wherein the number of switching transitions of the SHE-PWM patrons within the first quarter cycle of the fundamental period is set at X angles, X being comprised between 5-15.

3. The three phase MV power conversion system ( 43 ) according to claim 1 , wherein said damping means are a RC parallel damper that is in parallel with a notch branch of the Notch-Filter ( 53 ).

4. The three phase MV power conversion system ( 43 ) according to claim 1 , further comprising a transformer ( 25 ) coupled to output nodes of the Notch-Filter ( 53 ).

5. The three phase MV power conversion system ( 43 ) according to claim 1 , wherein the power source ( 11 ) is a wind turbine.