Method and device for separating positive sequence component and negative sequence component of grid voltage or current

A technology of positive sequence components and negative sequence components, applied in the direction of circuit devices, electrical components, AC network circuits, etc., can solve the problems of complex calculation process and long time consumption, achieve simple implementation, enhance system control accuracy, and improve system dynamic response Effect
CN103117544BActive Publication Date: 2015-08-05四川科陆新能电气有限公司
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
四川科陆新能电气有限公司
Publication Date
2015-08-05

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Abstract

The invention discloses a method and a device for separating a positive sequence component and a negative sequence component of network voltage or current, relates to control technology of a three-phase converter of an electric power system, and aims to provide a simpler method for separating the positive sequence component and the negative sequence component and a device corresponding to the method. The technical scheme mainly includes that the method includes a negative sequence component extracting step and a positive sequence component extracting step, wherein the negative sequence component extracting step includes the steps: N1, converting a three-phase electric vector including the voltage or the current of a power network into a first vector in a two-phase static coordinate system; N2, delaying the first vector and then rotating the phase position of the first vector to obtain a second vector; and N3, adding the first vector and the second vector to obtain the negative sequence component; the positive sequence component extracting step includes the steps: P1, delaying the first vector and then rotating the phase position of the first vector to obtain a third vector; and P2, adding the first vector and the third vector to obtain the positive sequence component.
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Description

technical field

[0001] The invention relates to the control technology of a three-phase converter in a power system, in particular to a method for separating positive sequence components and negative sequence components of grid voltage / current. Background technique

[0002] In the power system, voltage / current imbalance is unavoidable when the electronic converter is running. Especially when wind power, photovoltaic and other converters are running, three-phase voltage / current low voltage imbalance is more common. At present, the country has put forward clear requirements for the limitation of unbalanced faults in low-voltage ride-through of wind power, photovoltaic and other converters.

[0003] For an ideal power system, due to the voltage / current three-phase symmetry, there are only positive sequence components. When the system fails, the three-phase voltage / current becomes asymmetrical, and there will be positive sequence components and negative sequence components at ...

Claims

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