INVESTIGATION OF THE CURRENT SPACE VECTOR CORRECTION OF 3P3W VOLTAGE INVERTER

Abstract

The article presents a solution to the problem of asymmetry of a three-phase voltage inverter output currents for the trajectory correction vector currents to a wheel form. The solution uses the layout described using the fuzzy logic equations. Test results apply to verify a system operation in terms of the asymmetric load. It was examined in the form of a circular trajectory of the vector output currents in case of resistant or induction asymmetry. Also not harmonics components of load currents are included. They simulate the vibrations of mechanical loads or mechanical resonance. After verification by simulations the laboratory prototype control system of inverter with equalizer in the FPGA was performed. The investigations were done on the system created for this purpose, using the field programmable gate arrays of EP3SL150F type. This system performs the task of correcting space vector of the inverter currents and, at the same time, the process of modulation waveforms. In parallel with the controlling tasks the inverter model was running in real time. The waveforms of inverter model were observed using a Signal Tap II utility or after processing into an analog signal using an oscilloscope. Observed trajectories of the currents' space vector were adjusted to the circular form in addition to the type of load asymmetry.