Impact of ASD settings in its LVRT behaviour

A common matter of concern in industrial installations is that adjustable-speed drives (ASD) trip due to voltage sags. ASD manufacturers are including more and more in these devices settings related to control strategies (e.g. allowable DC voltage levels, etc) in order to improve their Low Voltage Ride Through (LVRT). These settings must be carefully adjusted in each installation in order to prevent any interference with the process where ASDs are used. In this paper, a method to establish the setting values to achieve a determined LVRT level has been done. A voltage sag generator developed by the part of the authors has been used to test several setting values and its impact on the process. Two commercial ASD installed in a factory were used during tests.