Abstract

FERNANDEZ, Herman; HERNANDEZ, Iván  and  MONTILLA, Francisco. HARMONICS REDUCTION AND IMPROVE ISOLATION CAPABILITY OF THE WOUND ROTOR AC INDUCTION MOTOR DRIVES . uct [online]. 2008, vol.12, n.49, pp.255-262. ISSN 1316-4821.

This work presents technical improvements in the pulse generator circuit of wound rotor AC induction motor drive installed in a crane system. The three-phase pulse generator produces six output pulses, each displaced 60 electrical degrees to provide gate firing signals to AC thyristor controller. This original circuit exhibits two drawbacks: employs resistors in series for provide impedance isolation from 460VAC voltage inputs directly connected to printed circuit board. Additionally, the control have an excessive minimalshift- phase pulse for the activation of the thyristors, which produces current and voltage harmonics into utility system and AC motor terminals respectively. An efficient control circuit has been designed and constructed. The main advantages of the proposed pulse generator as compared with conventional system are: power reactive reduction and improve method for electric isolation.

Keywords : AC drives; AC-AC controller; Thyristors /VCO.