DISCRETE INPUT DETERMINING CIRCUIT AND METHOD

    公开(公告)号:US20190107565A1

    公开(公告)日:2019-04-11

    申请号:US15726809

    申请日:2017-10-06

    摘要: A discrete input determining circuit is disclosed, which includes an input biasing network connected to a discrete input for providing a first input voltage, a voltage divider network for dividing the first input voltage into a second input voltage and a third input voltage, a first comparator, wherein a non-inverting input terminal of the first comparator receives the second input voltage, and a second comparator, wherein an inverting input terminal of the second comparator receives the third input voltage, wherein an inverting input terminal of the first comparator and a non-inverting input terminal of the second comparator receive a reference voltage, and an output terminal of the first comparator and an output terminal of the second comparator are configured to provide a logic output. A discrete input determining method is also disclosed.

    Electrical machine component failure detection apparatus and method

    公开(公告)号:US10082531B2

    公开(公告)日:2018-09-25

    申请号:US15347499

    申请日:2016-11-09

    申请人: ROLLS-ROYCE plc

    摘要: A rectifier diode failure detection apparatus for an electrical machine (10), the electrical machine (10) comprising an exciter armature winding (28a-c), a rotor main field winding (24) and first and second rectifiers (34a, 34b) arranged in parallel, each rectifier (34a, 34b) comprising at least first and second diodes (38a, 38b), each rectifier being configured to independently supply the rotor main field winding (24) with DC electrical current, the failure detection apparatus comprising:a controller (40) comprising at least two current sensors (42a, 42b), each current sensor (42a, 42b) being configured to measure output current (If1, If2) of a respective one of the rectifiers (34a, 34b), and the controller (40) being configured to determine a harmonic of the measured rectifier output currents; the controller (40) being further configured to determine a ratio of the magnitude of the first rectifier (34a) output current harmonic to the magnitude of the second rectifier (34b) output current harmonic, wherein the controller (40) is configured to determine that a fault has occurred in one of the rectifier diodes (38a, 38b) where the ratio exceeds a threshold value.