Method in frequency converter provided with voltage intermediate circuit, and frequency converter
First Claim
1. A method in a frequency converter provided with a voltage intermediate circuit in connection with interference in a network to be supplied, the frequency converter comprising a network converter part and an inverter part and a DC intermediate circuit between them, the method comprising controlling the intermediate circuit voltage at the beginning of network interference by limiting the torque on the inverter side, detecting interference in the network voltage, setting a torque reference to a predetermined value in response to the network interference, detecting network voltage recovery, and controlling the torque reference to a normal value in response to the network voltage recovery.
2 Assignments
0 Petitions
Accused Products
Abstract
A method in a frequency converter provided with a voltage intermediate circuit in connection with interference in a network (5) to be supplied and a frequency converter (2), which comprises a network converter part (4) and an inverter part (3) and a DC intermediate circuit (7) between them. The method comprises steps of controlling the intermediate circuit voltage at the beginning of network interference by limiting the torque on the inverter side, detecting interference in the network voltage, setting a torque reference to a predetermined value in response to the network interference, detecting network voltage recovery, and controlling the torque reference to a normal value in response to the network voltage recovery.
-
Citations
14 Claims
-
1. A method in a frequency converter provided with a voltage intermediate circuit in connection with interference in a network to be supplied, the frequency converter comprising a network converter part and an inverter part and a DC intermediate circuit between them, the method comprising
controlling the intermediate circuit voltage at the beginning of network interference by limiting the torque on the inverter side, detecting interference in the network voltage, setting a torque reference to a predetermined value in response to the network interference, detecting network voltage recovery, and controlling the torque reference to a normal value in response to the network voltage recovery.
-
10. A frequency converter provided with a voltage intermediate circuit and comprising a network inverter part and an inverter part and a DC intermediate circuit between them, the frequency converter comprising
means for controlling the DC intermediate circuit voltage, means for detecting interference in the network voltage, means responsive to the network voltage interference for setting a torque reference to a predetermined value, means for controlling the torque of the inverter part and limiting the current of the network converter, means for noticing network voltage recovery, and means responsive to the network voltage recovery for controlling the torque reference to a normal value.
Specification