Real-time measurement of d- and q-axis currents using Rogowski coil

The control process of many inverter-based systems requires having d- and q-axis currents which have been calculated through a microprocessor-based system. This paper presents a new technique able to direct measure those currents through a non-magnetic current sensor called a Rogowski coil. The basic idea behind this technique is to design a suitable integrator circuit for the coil to convert the actual current passing through it into a proper voltage that indicates the values of its d- and q-axis components. The proposed configuration of the coil and its associated integrator circuit is analyzed and discussed in detail in this paper. A simulation study proves how the proposed method could provide real-time measurement capability.