Device and method for measuring reactor inductance in active power filter

Abstract

The invention provides a device and a method for measuring the inductance value of an electric reactor in an active power filter. The device is so structured that the input end of a voltage regulator is connected to a power source, while the output end of the voltage regulator is connected to the input end of a transformer, the output end of the transformer is connected to the input end of a rectifier, and a first capacitor and a second capacitor are connected in series and then connected in parallel to the positive output end and the negative output end of the rectifier; the output ends of the rectifier are connected to the input end of an inverter; the voltage regulator is used for realizing linear adjustment of power voltage; the transformer is used for boosting the voltage output by the voltage regulator; the rectifier is used for rectifying the alternating-current voltage output by the transformer into direct-current voltage; the inverter is used for inverting the direct-current voltage into the alternating-current voltage for output; the two ends of a tested electric reactor are connected to the positive output end and the negative output end of the rectifier, respectively; the frequency of the pulsed voltage output by the inverter is the actual working frequency of the tested electric reactor. The device is capable of measuring high-frequency inductance value, loading to the rated power and superposing the direct-current component.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a device and method for measuring the inductance of a reactor in an active power filter. Background technique [0002] Active Power Filter (APF, ActivePowerFilter) is a power electronic device that can dynamically suppress harmonics and perform reactive power compensation. [0003] see Figure 1a , which is a schematic diagram of an APF in the prior art. [0004] Among them, APF is equivalent to a controllable current source, which is connected in parallel with the power grid. [0005] Among them, U dc As a DC power supply, APF detects the harmonic current of the grid load, generates a current equal to the harmonic current of the load, and injects a current in the opposite direction into the grid, so that the current on the grid side is a sine wave. specifically by controlling Figure 1a The switching status of Q1 and Q2 in the middle makes the APF inject current int...

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Problems solved by technology

[0019] However, the reactors used in power electronic equipment such as APF have both power frequency current and high frequency current in their actual work. The power frequency voltammetry test cannot measure the actual working inductance and the saturation degree of the reactor. Some people By increasing the current to 2-3 times the rated current equivalent high-frequency inductance, it is obvious that this approximate estimate is unreasonable

[0020] There is another method in the prior art (Chinese application number CN103312188) by simulating the working environment of the APF, adding a reactor and testing whether the reactor can meet the requirements according to the actual operating conditions of the APF. Although this method can be used according to the final operation However, it is impossible to accurately measure the inductance of the reactor, and it is impossible to quantitatively optimize the design of the reactor, that is, the parameters of the reactor are easily over-designed.

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