Constant-voltage transformer (CVT) harmonic testing method based on capacitance currents

A technology of capacitive current and testing method, which is applied in the field of electric power, can solve problems such as inability to accurately reflect the proportion of high-order harmonics, narrow bandwidth, etc., and achieve the effect of suppressing harmonic interference and improving power quality

Inactive Publication Date: 2013-04-24
NORTH CHINA ELECTRIC POWER UNIV (BAODING) +1
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  • Abstract
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AI Technical Summary

Problems solved by technology

This method of directly applying the harmonic analyzer to carry out the test can accurately obtain the harmonic components of the secondary side of the connected capacitor voltage transformer CVT, but the capacitor voltage transformer CVT and other transformers are designed to test the 50Hz fundamental voltage current for the purpose, its narrow bandwidth
Relevant research carried out abroad shows that the transformation ratio of capacitor voltage transformer CVT varies greatly at different frequencies, and the existing test methods that directly use harmonic analyzers cannot accurately reflect the composition ratio of high-order harmonics

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  • Constant-voltage transformer (CVT) harmonic testing method based on capacitance currents
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  • Constant-voltage transformer (CVT) harmonic testing method based on capacitance currents

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Embodiment Construction

[0017] The preferred embodiments will be described in detail below in conjunction with the accompanying drawings. It should be emphasized that the following description is only exemplary and not intended to limit the scope of the invention and its application.

[0018] (1) Connect each module correctly according to the electrical wiring diagram to form a test system:

[0019] The current sensor (measurement range 0~30A, accuracy to 1mA, error is ±1%), data acquisition card (each channel is not lower than 25kHz sampling rate, 12-bit resolution, 4-channel data acquisition card with synchronous sampling function ), computer (installed with harmonic analysis software) and capacitive voltage transformer CVT according to the electrical wiring diagram to form a test system. Such as figure 1 and figure 2 .

[0020] (2) Measure the low-voltage capacitor C flowing through the current sensor respectively 2 The capacitive current I 2 (jω) and flow through the high voltage capacitor...

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Abstract

The invention discloses a constant-voltage transformer (CVT) harmonic testing method based on capacitance currents and belongs to the technical field of electric power. According to the technical scheme, capacitance current I 2 (j omega) of a low-voltage capacitor C2 and capacitance current I 1 (j omega) of a high-voltage capacitor C1 are measured through an electric current transducer, and voltage U 1 (j omega) of each frequency point on primary side of the CVT is directly obtained by calculating of a harmonic analysis system, and harmonic analysis is carried out. The CVT harmonic testing device based on the capacitance currents has the advantages that elements of higher harmonic can be obtained accurately, harmonic interference can be restrained effectively through guiding harmonic treatment measures, and quality of electric energy is improved.

Description

technical field [0001] The invention belongs to the technical field of electric power, and in particular relates to a CVT harmonic test method based on capacitive current. Background technique [0002] The quality of power supply is a hot spot that both users and power companies pay close attention to. With the development of the power grid, the construction of DC projects and new energy projects, switching power supplies, thyristor devices, wind turbines, etc. are more and more used in the power grid. On the one hand, these devices have improved people's utilization efficiency of electric energy, and on the other hand, they have formed a large number of harmonic currents in the power grid. The consequence is that other electronic products in the same power grid will be disturbed, and the harmonic current will also cause the overload of the neutral line current of the power grid, which will affect the power transmission capacity of the power grid. In addition, the phase co...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01R23/16
Inventor 赵志斌曹敏王昕毕志周刘清蝉靳晓军
Owner NORTH CHINA ELECTRIC POWER UNIV (BAODING)
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