Power grid operation data acquisition system

Abstract

The invention discloses a power grid operation data acquisition system, which is characterized in that an overload detection circuit detects the current flowing through a primary side coil of a current sensor; in case of overload, the harmonic frequency is calculated by a divider IC1; the harmonic impedance is obtained by multiplication of a multiplying unit IC2; one path of the harmonic impedanceis connected to a feedback resistor of an operational amplifier AR1 in parallel; the current of a power grid cable is attenuated and then connected into a primary coil of a current sensor T1 in a windowing regulating circuit; the other path triggers a triode Q1 and a triode Q2 to be conducted; the number of turns of the primary coil of the current sensor T1 is changed; the measurement accuracy isimproved; the current of a secondary coil of the current sensor T1 is converted into voltage and subjected to amplitude limiting amplification through an operational amplifier AR2; the voltage is transmitted to a frequency modulation transmitting circuit under a sampling clock of a switch SW3 to ensure the integrity of signals; the frequency modulation transmitting circuit adopts a frequency modulation circuit taking a triode Q7 as a core to carry out preliminary frequency modulation; and then a controllable frequency multiplication circuit taking a triode Q6 as a core carries out frequency multiplication on the preliminary frequency modulation and add the preliminary frequency modulation to a transmitter, so that the relative frequency offset is increased, and the transmission anti-interference capability is improved.

Description

technical field [0001] The invention relates to the technical field of power grid data collection, in particular to a power grid operation data collection system. Background technique [0002] The grid operation data acquisition system is an important part of the State Grid Corporation of China to build a smart grid. Whether the grid operation data can be collected accurately in real time is the key to the grid operation data acquisition system. The electrical parameters of the grid operation data mainly include current, voltage and power. The collection of data is usually collected by corresponding sensors on site, and then transmitted to the collection terminal through wired or wireless methods. The collection terminal transmits the data to the terminal server of the smart grid through the communication network. Abnormalities such as nonlinear loads will cause large grid harmonics, and harmonic oscillations will generate large harmonic currents. The harmonic currents are o...

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Problems solved by technology

[0004] In view of the above situation, in order to overcome the defects of the prior art, the object of the present invention is to provide a power grid operation data acquisition system, which effectively solves the problem of low measurement accuracy when the rated value of the current sensor is not close to the value to be measured

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