US 9,866,109 B2Granted

Methods and devices for power compensation

AssigneeABB Schweiz AG

InventorsJean-Philippe Hasler, Marcio De Oliveira

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Abstract

A method is performed in a control device for controlling a power compensation arrangement including a voltage source converter and one or more power compensation branches, each power compensation branch including a thyristor controlled reactor, a thyristor switched reactor or a thyristor controlled capacitor. The voltage source converter and the one or more power compensation branches are connected to a same busbar. The method includes: detecting a request in an electrical power system to which the power compensation arrangement is connected; determining, based on the request, a need for reactive power supply to the electrical power system; providing reactive power by means of the voltage source converter and/or by one or more of the power compensation branches; and compensating, by means of the voltage source converter, any disturbances caused by the power compensation branches when providing the reactive power to the electrical power system. Corresponding devices are also disclosed.

Claims15

Dependent claims

A method performed in a control device for controlling a power compensation arrangement comprising a voltage source converter and one or more power compensation branches, each power compensation branch comprising a thyristor controlled reactor, a thyristor switched reactor or a thyristor switched capacitor, the voltage source converter and the one or more power compensation branches being connected to a same busbar, wherein at least one of the one or more power compensation branches comprises a thyristor switched capacitor, the method comprising the steps of:

detecting a request in an electrical power system to which the power compensation arrangement is connected, wherein the request indicates a need of change in reactive power output of the power compensation arrangement;
determining, based on the request, whether the need of change in reactive power output of the power compensation arrangement is larger than a reactive power capacity of the voltage source converter;
providing reactive power by the voltage source converter and by one or more of the power compensation branches when it is determined that the need of change in reactive power output of the power compensation arrangement is larger than the reactive power capacity of the voltage source converter;
and
compensating, by the voltage source converter, any disturbances caused by the power compensation branches when providing the reactive power to the electrical power system, wherein the compensating of disturbances comprises the steps of:
measuring a current and voltage of the thyristor switched capacitor, and a bus voltage;
and
compensating, by the voltage source converter, based on the measured current and voltages and a switching time instance giving a minimal voltage of the thyristor switched capacitor, for the sum of transient currents of the thyristor switched capacitor and the voltage source converter.

5 more elements

A control device for controlling a power compensation arrangement comprising a voltage source converter and one or more power compensation branches, each power compensation branch comprising a thyristor switched reactor, a thyristor switched reactor or a thyristor controlled capacitor, at least one of the one or more power compensation branches comprising a thyristor switched capacitor, the voltage source converter and the one or more power compensation branches being connected to a same busbar, the control device being configured to:

detect a request in an electrical power system to which the power compensation arrangement is connected, wherein the request indicates a need of change in reactive power output of the power compensation arrangement;
determine, based on the request, whether the need of change in reactive power output of the power compensation arrangement is larger than a reactive power capacity of the voltage source converter;
provide reactive power by the voltage source converter and by one or more of the power compensation branches when the control device determines that the need of change in reactive power output of the power compensation arrangement is larger than the reactive power capacity of the voltage source converter;
and
compensate, by the voltage source converter, any disturbances caused by the power compensation branches when providing the reactive power to the electrical power system, by:
measuring a current and voltage of the thyristor switched capacitor, and a bus voltage;
and
compensating, by the voltage source converter, based on the measured current and voltages and a switching time instance giving a minimal voltage of the thyristor switched capacitor, for the sum of transient currents of the thyristor switched capacitor and the voltage source converter.

5 more elements

A computer program for a control device configured to control a power compensation arrangement comprising a voltage source converter and one or more power compensation branches, each power compensation branch comprising a thyristor controlled reactor, a thyristor switched reactor or a thyristor switched capacitor, at least one of the one or more power compensation branches comprising a thyristor switched capacitor, the voltage source converter and the one or more power compensation branches being connected to a same busbar, the computer program comprising computer program code, which, when run on the control device causes the control device to:

detect a request in an electrical power system to which the power compensation arrangement is connected, wherein the request indicates a need of change in reactive power output of the power compensation arrangement;
determine, based on the request, whether the need of change in reactive power output of the power compensation arrangement is larger than a reactive power capacity of the voltage source converter;
provide reactive power by the voltage source converter and by one or more of the power compensation branches when the control device determines that the need of change in reactive power output of the power compensation arrangement is larger than the reactive power capacity of the voltage source converter;
and
compensate, by the voltage source converter, any disturbances caused by the power compensation branches when providing the reactive power to the electrical power system, by:
measuring a current and voltage of the thyristor switched capacitor, and a bus voltage;
and
compensating, by the voltage source converter, based on the measured current and voltages and a switching time instance giving a minimal voltage of the thyristor switched capacitor, for the sum of transient currents of the thyristor switched capacitor and the voltage source converter.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/903,245Filed 19 Jul 2013
Published: US 2016/0149481 A126 May 2016
Granted: 9 Jan 2018
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

H02M 1/4208
Circuits or arrangements for compensating for or adjusting power factor in converters or inverters: arrangements for improving power factor of AC…
H02J 3/16
Arrangements for adjusting voltage in AC networks by changing a characteristic of the network load: by adjustment of reactive power
H02J 3/1857
Having reactive elements actively controlled by bridge converters, e.g. active filters or static compensators [STATCOM]: the bridge converters…
H02J 3/1864
With stepless control: using reactive elements connected in series with semiconductor switches, e.g. static VAR compensators [SVC],…