Current source back to back converter for wind energy conversion systems

This paper proposes a new back-to-back current source converter (BTB-CSC) suitable for mediumvoltage high power wind energy conversion systems (WECS). It employs a dual three-phase permanent magnet synchronous generator and two current source inverters with a phase-shift transformer at the grid side. The proposed BTB-CSC has the following advantages: reduced power circuit and control complexity; low switching losses (zero switching losses at the inverter side); and independent control of active and reactive power. PSCAD/EMTDC simulations are used as to assess the steady-state and dynamic behaviour of the proposed system under different operating conditions. It is shown that the proposed WECS can ride-through ac faults. Experimental results from scaled prototype of the proposed WECS are used to validate the simulations.