US 5,296,764 A · Reduction of disturbances in a power network

Abstract

A method and a device in an electric power network (1), comprising an active filter (4) controllable via a control input (41), for reducing disturbances generated by a disturbance source (6) located in and/or connected to the power network. A control member (8) is adapted, in dependence on the control deviation (DU) from a desired value (Y2iR) of at least one state variable (Y2i) sensed in the power network (1), to generate a control signal (C1) which is supplied to the control input (41). The control member (8) is adapted to transform the control deviation (DU) in a filter device (93) with a transfer function (FI) which simulates the inverse of the transfer function (F1') from the control signal (C1) to the control deviation (DU) and/or to filter the output signal of the controller in a filter device (943, 953, 956) without any phase shift. (FIGS. 1 and 10)

Claims49

Dependent claims

A method in an electric power network, which network comprises at least one output line and an active filter controllable via a control input, for reducing disturbances on said output line generated by a disturbance source located in or connected to the power network, comprising the steps of:

sensing at least one state variable in the power network and supplying said state variable to a controller;
forming an output signal from the controller in dependence on the control deviation of said at least one state variable form a desired value as a sequence of values repeated with a period T', said values being formed in dependence on the control deviation;
generating a control signal in dependence on the output signal and supplied to the control input;
and
said step of forming the output signal of the controller including the step of carrying out a transformation dependent on non-minimum phase properties of the transfer function from the output signal of the controller to the control deviation.

2 more elements

A device in an electric power network (1), comprising at least one output line (31, 32) and an active filter (4) controllable via a control input (41), for reducing on the output line (31, 32) disturbances generated by a disturbance source (6) located in or connected to the power network, at least one state variable (Y2i) being sensed in the power network (1) and a controller forming, in dependence on the control deviation (DU) of the state variable (Y2i) from a desired value (Y2iR), an output signal (C1") as a sequence (SC14) of values (C14n) repeated with a period (T'), the values (C14n) being formed in dependence on the control signal (C1"), a control signal (C1) which is supplied to the control input (41), wherein the controller comprises a filter device (93) for carrying out a transformation dependent on non-minimum phase properties of the transfer function (F1') from the output signal (C1") of the controller to the control deviation (DU).

Dependencies are inferred from the claim text.

Reduction of disturbances in a power network

Life of this patent

Reduction of disturbances in a power network

Life of this patent

Abstract

Claims49