Multiple Medium Voltage AC Drives Fed from a Common AC Bus for Single or Multi Motor Conveyor Applications

AC Drive conveyor applications can be very challenging. The proposed scheme is to connect a medium voltage (2.4kV to 7.2kV) AC drive system to a common AC bus feeding either single or multiple motors. This system exhibits the following advantages: meeting the line side harmonic requirements use of only one isolation transformer per conveyer system (not per drive) inherent regeneration to the main power source, attractive for down hill conveyor applications. These advantages improve system efficiency, size and allow for the ability to run more than one motor per drive if the need arises. Various identical multi-motor mechanically coupled cases are investigated and motors with differing characteristics supplying separate loads (i.e. mechanically uncoupled). The field experimental results for three different applications of 6.6kV and 4.16kVdrives are presented.