公开(公告)号：EP2671315A2

公开(公告)日：2013-12-11

申请号：EP11724925.0

申请日：2011-06-03

Applicant: ABB Inc. ,  ABB OY

Inventor： GOKHALE, Kalyan, P. ,  KARRAKER, Douglas, W. ,  PAJARI, Ilkka, T. ,  JUSSILA, Matti, T.

IPC: H02M7/48 ,  H01H47/00

CPC classification number: H02M1/32

Abstract: A system for the detection of welded contacts in a circuit of a line converter system has a plurality of inverter switches, a plurality of utility switches in which a pair of utility switches is connected in series through a line to a utility, a voltage detector, an electronic controller, and a DC input source. The line converter system converts incoming DC power into AC output power that is delivered to the utility grid. The voltage detector measures the voltage across a first node and a second node of the circuit and provides an output that is interpreted by an electronic controller for each step performed during a method of detection of welded contacts. The detection method has a sequence of test steps in which at least one switch is opened and/or closed, a DC bus of the inverter or the utility grid is used as a stimulus voltage, and the voltage is measured. If a voltage is not detected across the first and second nodes, the test sequence is continued until a welded contact is detected or the electronic controller determines that none of the contacts are welded. If the controller determines that none of the contacts are welded, the line converter system is permitted to connect and supply AC power to the utility.

公开(公告)号：EP2577859A2

公开(公告)日：2013-04-10

申请号：EP11724919.3

申请日：2011-06-02

Applicant: ABB Inc. ,  ABB OY

Inventor： KARRAKER, Douglas, W. ,  GOKHALE, Kalyan, P. ,  JUSSILA, Matti, T.

IPC: H02M7/487 ,  H02M1/38

CPC classification number: H02M7/487 ,  H02J3/383 ,  Y02E10/563

Abstract: A full-bridge, NPC inverter uses pulse width modulation (PWM) to convert the DC voltage from a solar panel array to an AC voltage at the output of the inverter that is acceptable for connection to a utility. The PWM control unit has a predetermined carrier frequency. The carrier unit uses for each carrier period either positive or negative values of a reference voltage to generate a predetermined number of signals to control the switching on and off of each of the eight inverter switching elements in a predetermined pattern for a predetermined period of the carrier frequency period to thereby produce the acceptable alternating current voltage at the inverter output and not produce between the inverter input and earth ground a carrier frequency component.