The direct-quadrature-zero transformation or zero-direct-quadrature transformation is a tensor that rotates the reference frame of a three-element vector or a three-by-three element matrix in an effort to simplify analysis. The direct-quadrature-zero (DQZ or DQ0 or DQO, sometimes lowercase) transformation or zero-direct-quadrature (. A space vector and its time rate of change are attached to an αβ coordinate system rotating at the speed. The Park Transform block converts the time-domain components of a three- phase system in an abc reference frame to direct, quadrature, and zero components. The abc to dq0 block performs a Park transformation in a rotating reference frame. abc to dq0 transform is used frequently while making matlab models for.