Compensating current detection method based on instant space voltage vector orientation

A space voltage vector, compensation current technology, applied in the direction of reactive power/actual component measurement, etc., can solve the problem that PLL is difficult to accurately lock equals

Inactive Publication Date: 2016-08-03
SHANDONG JIANZHU UNIV +1
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] In order to solve the above problems, the present invention proposes a compensation current detection method based on instantaneous space voltage vector orientation. The present invention overcomes the problem that PLL is difficult to lock phase accurately under high voltage distortion rate, and the obtained positioning information includes voltage distortion information, can achieve the effect of separating the harmonic current caused by the distorted voltage, and solve the shortcomings of the traditional method applied to the parallel active power filter

Method used

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  • Compensating current detection method based on instant space voltage vector orientation
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  • Compensating current detection method based on instant space voltage vector orientation

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Embodiment 1

[0076] like Figure 4 The application of a compensation current detection method based on instantaneous space voltage vector orientation in a three-phase three-wire system.

[0077] Let the instantaneous values ​​of the three-phase voltage and current in the three-phase circuit be e, respectively a , e b , e c and i a , i b , i c . First, the three-phase instantaneous voltage e a , e b , e c Perform three-phase to two-phase coordinate transformation to obtain e α , e β , passing e in the αβ coordinate system α , e β Calculate the phase angle θ of the three-phase composite rotating voltage vector e e Corresponding sinusoidal signal sinθ e and cosine signal cosθ e , and use it as the orientation basis of the synchronous rotating coordinate system to transform the three-phase current coordinate to obtain i α , i β .

[0078] e α ...

Embodiment 2

[0100] like Figure 5 As shown, the application of the method described in Embodiment 1 in a single-phase system:

[0101] For a single-phase system, the single-phase voltage and single-phase current can be regarded as the A-phase voltage and A-phase current in the three-phase circuit. In order to meet the requirements of the present invention i p -i q The use conditions of the compensation current detection method are to construct the B and C phase voltages and currents according to the principle of three-phase symmetry, and then process the A, B, C three-phase voltages and three-phase currents according to the conventional algorithm, and the calculated A-phase current detection The result is the detection result corresponding to the single-phase circuit.

[0102] remember e s and i s are the instantaneous values ​​of voltage and current of a single-phase circuit, respectively, and are denoted by e s and i s Construct a three-phase system and set e a , e b , e c and ...

Embodiment 3

[0113] like Image 6 As shown, the application of the method described in Embodiment 1 in a three-phase four-wire system:

[0114] Compared with the three-phase three-wire system, the zero-sequence current component should be dealt with correspondingly in the command current detection of the three-phase four-wire system. Referring to the processing idea of ​​the traditional dq0 method, the zero axis perpendicular to the coordinate plane is added to the αβ coordinate system and the dq coordinate system respectively, and the coordinate transformation operation process is adjusted accordingly.

[0115] The operation method of transforming the abc coordinate system to the αβ0 coordinate system is as follows:

[0116] i α i β i ...

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Abstract

The invention discloses a compensating current detection method based on instant space voltage vector orientation .The compensating current detection method based on instant space voltage vector orientation comprises the steps that an on-voltage instant value and an on-current instant value are collected, coordinate transformation from three phases to two phases is carried out respectively, and two-phase instant voltage and two-phase instant current are obtained; a sinusoidal signal and a cosine signal corresponding to a phase angle of a three-phase composite rotational voltage vector are calculated through the two-phase instant voltage, the projection of the two-phase instant current value on the voltage vector is solved, and instant active current and instant reactive current are obtained; direct-current components of the instant active current and the instant reactive current are separated, a fundamental wave positive sequence current component is solved, coordinate transformation from two phases to three phases is carried out on the fundamental wave positive sequence current component, and a fundamental wave current component in three-phase current is obtained; three-phase compensating current is obtained by subtracting the fundamental wave current component from the three-phase current instant value .A compensating current instruction obtained with the method includes fundamental wave negative sequence current and harmonic current elements, and the ideal effects of suppressing harmonic waves and balancing three-phase loads can be achieved at the same time .

Description

technical field [0001] The invention relates to a compensation current detection method based on instantaneous space voltage vector orientation. Background technique [0002] Active power filtering technology and equipment (APF) provides an effective way to achieve harmonic control and reactive power compensation in the power grid. The accuracy and real-time detection of compensation command current play a decisive role in the final compensation and filtering performance. influences. In order to achieve fast and accurate harmonic current detection, domestic and foreign scholars have proposed a variety of harmonic detection methods based on different theories. Among them, the p-q method based on the instantaneous reactive power theory, the i p -i q method and dq0 method are the most representative. [0003] figure 1 The operation flow of the traditional p-q method is given in . The traditional p-q method has a large amount of calculation and the detection result is easily...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01R19/06
CPCG01R19/06
Inventor 尹春杰段培永丁绪东张玫王芳石磊
Owner SHANDONG JIANZHU UNIV
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