CN-116298678-B - High frequency signal detection system

Abstract

The invention provides a high-frequency signal detection system which comprises a Rogowski coil type current sensor, a first circuit, a second circuit and a delay circuit, wherein one end of the first circuit comprises a first resistor, one end of the first resistor is connected with a coil of the Rogowski coil type current sensor, the other end of the first resistor is grounded, the second circuit comprises the delay circuit and a second resistor, one end of the delay circuit is connected with one end of the first resistor, the other end of the delay circuit is connected with one end of the second resistor, the other end of the second resistor is grounded, one end of the first resistor serves as a first output end of the high-frequency signal detection system, one end of the second resistor serves as a second output end of the high-frequency signal detection system, and the pressure difference between the first output end and the second output end serves as an output signal, and the high-frequency signal is acquired according to the output signal. The invention can exactly filter the power frequency by using a proper delay circuit and the electromagnetic wave difference before and after delay without affecting the output of the high-frequency signal, thereby conveniently obtaining the high-frequency signal to be analyzed.

Inventors

• CHANG SHUAI
• LUO JIAOHONG
• YANG KAIDI
• ZHAO CHUJUN
• ZHANG FEIYUN
• WANG QING
• XIA TIANLEI
• GAO JIAPING
• HUANG TAO
• Ni Xiaoru
• GE XIN
• CAI FEI
• ZHANG LEI

Assignees

• 国网江苏省电力有限公司常州供电分公司
• 国网江苏省电力有限公司
• 国家电网有限公司

Dates

Publication Date

20260512

Application Date

20230222

Claims (1)

1. 1. A high frequency signal detection system, comprising: A rogowski coil type current sensor; The first circuit comprises a first resistor, one end of the first resistor is connected with a coil of the rogowski coil type current sensor, and the other end of the first resistor is grounded; The second circuit comprises a delay circuit and a second resistor, wherein one end of the delay circuit is connected with one end of the first resistor, the other end of the delay circuit is connected with one end of the second resistor, and the other end of the second resistor is grounded; one end of the first resistor is used as a first output end of the high-frequency signal detection system, one end of the second resistor is used as a second output end of the high-frequency signal detection system, the pressure difference between the first output end and the second output end is used as an output signal, and the high-frequency signal is acquired according to the output signal; the delay time T of the delay circuit is set according to the following formula: ; Wherein, T is the delay time of the delay circuit, f 0 is the power frequency of the output signal of the Rogowski coil type current sensor, and f is the high frequency of the output signal of the Rogowski coil type current sensor; the delay circuit consists of a capacitance inductance chain; the resistance value of the second resistor is equal to the wave impedance of the delay circuit; The resistance value of the first resistor is equal to the wave impedance of the delay circuit; the wave impedance of the delay circuit meets the self-integrating circuit condition of the Rogowski coil type current sensor in the high frequency range.

Description

High frequency signal detection system Technical Field The invention relates to the technical field of electricity, in particular to a high-frequency signal detection system. Background At present, in the power grid, the off-line detection method cannot meet the requirements of the current power grid on safety and reliability, and on-line monitoring is imperative. One of the important problems encountered in on-line monitoring is how to accurately acquire the frequency response signal. In the related art, a current sensor is generally adopted to collect current signals for on-line monitoring, and the power frequency interference of the field test environment is large, and the current signals collected by the current sensor are superposition of power frequency signals and high-frequency signals of 1kHz-1MHz, so that high-pass filtering is needed to obtain the high-frequency signals of 1kHz-1MHz required by research. In the related art, an active filtering mode is generally adopted to perform high-pass filtering, and the power frequency voltage input to the filter in the mode exceeds the power voltage of the active filter, so that the active filter cannot work normally, and further high-frequency signals cannot be obtained effectively. Disclosure of Invention In order to solve the technical problems, the invention provides a high-frequency signal detection system. The technical scheme adopted by the invention is as follows: The embodiment of the invention provides a high-frequency signal detection system, which comprises a Rogowski coil type current sensor, a first circuit, a second circuit and a delay circuit, wherein one end of the first circuit is connected with a coil of the Rogowski coil type current sensor, the other end of the first resistor is grounded, the second circuit comprises the delay circuit and the second resistor, one end of the delay circuit is connected with one end of the first resistor, the other end of the delay circuit is connected with one end of the second resistor, the other end of the second resistor is grounded, one end of the first resistor is used as a first output end of the high-frequency signal detection system, one end of the second resistor is used as a second output end of the high-frequency signal detection system, the differential pressure between the first output end and the second output end is used as an output signal, and the high-frequency signal is acquired according to the output signal. The high-frequency signal detection system provided by the invention can also have the following additional technical characteristics: According to one embodiment of the invention, the delay time T of the delay circuit is set according to the following formula: Wherein T is the delay time of the delay circuit, f 0 is the power frequency of the output signal of the Rogowski coil type current sensor, and f is the high frequency of the output signal of the Rogowski coil type current sensor. According to one embodiment of the invention, the delay circuit is composed of a capacitive-inductive chain. According to one embodiment of the present invention, the second resistor has a value equal to the wave impedance of the delay circuit. According to one embodiment of the present invention, the first resistor has a value equal to the wave impedance of the delay circuit. According to one embodiment of the invention, the wave impedance of the delay circuit satisfies the self-integrating circuit condition of the high frequency range of the rogowski coil type current sensor. The invention has the beneficial effects that: The invention can exactly filter the power frequency by using a proper delay circuit and the electromagnetic wave difference before and after delay without affecting the output of the high-frequency signal, thereby conveniently obtaining the high-frequency signal to be analyzed. The delay of electromagnetic waves can be completed through the capacitor inductance chain formed by a plurality of capacitors and inductors under the condition of short line length, so that the space is saved, and the feasibility of a detection scheme is improved. In addition, the capacitor and the inductor selected by the delay circuit can be purchased in the market, and special customization is not needed, so that the cost is greatly reduced. Drawings Fig. 1 is a circuit topology diagram of a high frequency signal detection system according to a first embodiment of the present invention; fig. 2 is a schematic diagram of a delay circuit according to a first embodiment of the present invention. Detailed Description The present invention was made based on the study and knowledge of the following problems: In the test, the power frequency signal is extremely strong, and another method for eliminating the power frequency magnetic field is to apply a power frequency load to the sensor, so that the nonlinear characteristic of the load is required to be very outstanding, the impedance is almost zero at the