A test system and method for access impedance of broadband power line carrier channel

Abstract

The invention provides a testing system and method for the broadband power line carrier channel access resistance. The testing system comprises a PC, a signal generator, amplifiers, directional couplers, a power line coupler, a signal conditioning circuit and a data acquisition card. The PC, the signal generator, the amplifiers, the directional couplers, the signal conditioning circuit and the data acquisition card are sequentially connected, the data acquisition card is connected with the PC, and a broadband power line is connected with the directional couplers through the power line coupler. According to the testing system and method, a frequency sweeping method is adopted, the resolution of the access resistance to the frequency is improved, and the accuracy of measured data is higher; meanwhile, the testing system is easy and convenient to use, and site testing can be easily carried out. The modulus of the broadband power line carrier channel access resistance can be obtained through testing, and the phase information of the resistance can also be obtained; meanwhile, the measuring result is accurate, and the testing system and method can be conveniently applied to site measurement and are of great significance in further development research of power line communication.

Description

technical field [0001] The invention belongs to the technical field of electric power communication, and in particular relates to a test system and method for access impedance of a broadband power line carrier channel. Background technique [0002] At present, the frequency bands in existing test power line carrier communication systems and devices at home and abroad are divided into narrowband (30kHz-500kHz) and broadband (2MHz-20MHz) communication, and the middle frequency band (500kHz-2MHz) is not used, so it is not used. Measurement. Moreover, the existing impedance measuring instruments can only measure the impedance of the power line when it is not charged. Even if there is an instrument that can measure the impedance when it is charged, it needs to be equipped with an impedance adapter. This is not a direct measurement of the impedance of the power line, so the measurement results are not very accurate. [0003] Power line carrier communication refers to a communicat...

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Problems solved by technology

[0005] 1) The ratio method can only measure the modulus value of the impedance, but cannot obtain the phase information of the impedance;

[0006] 2) The resonance method can only measure the impedance value of a single frequency point, and cannot obtain the impedance characteristics of the continuous spectrum;

[0007] 3) Although the dual current probe method can measure the modulus and phase information of the low-voltage power line impedance, due to the low frequency resolution of the network analyzer used, the accuracy of the measured results is not very high, and the on-site test is not convenient

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