CN203759134U - High-voltage line carrier communication coupling capacitor online monitoring instrument - Google Patents

Abstract

The utility model relates to a high-voltage line carrier communication coupling capacitor online monitoring instrument, and belongs to the field of electrical engineering. The high-voltage line carrier communication coupling capacitor online monitoring instrument is used for monitoring the capacitance of a coupling capacitor Cx online and characterized in that a jaw of a clamp type current transformer T1 is clamped with a wire which connects the coupling capacitor Cx to carrier wave communication equipment so as to act as a primary coil of the current transformer T1, two ends of a secondary coil of the current transformer T1 are connected to a point P1 and a point P2 respectively, the point P2 is connected to a ground wire of a power supply of a measuring instrument, circuits N1-N8 are integrated, and a universal operational amplifier is selected and used, wherein the circuit N1 forms an amplification circuit, the circuit N2, the circuit N3 and the circuit N4 form a 50Hz frequency selecting circuit so as to eliminate interferences from other signals, the circuit N5 and the circuit N6 form a full-wave rectification circuit, the circuit N7 forms a filtering circuit, the circuit N8 forms an amplification circuit, and direct-current voltage Vo is outputted at a point P14, and the direct-current voltage Vo is in direct proportion to the capacitance of the coupling capacitor Cx.

Description

Hi-line carrier communication coupling condenser on-line monitoring instrument

Technical field

The utility model belongs to electrotechnics technical field.

Background technology

In hi-line carrier communication loop, all use coupling condenser Cx, one termination hi-line, the other end connects the input end of carrier telecommunication equipment, and the effect of coupling condenser has two, 1) for carrier communication provides information channel, 2) by Cx from hi-line for carrier telecommunication equipment provides low-tension supply, therefore, the quality of coupling condenser not only affects the work of carrier communication, also relevant with the safe operation of electrical network, so extremely important to the measurement of coupling condenser Cx; Conventional measuring method is, between the low pressure end and ground of coupling condenser, be connected in series an alternating current ammeter, by formula Ix=2 π fUCx, measure Cx, wherein f is work frequency, U is the voltage between hi-line and ground, although this method is simple, in the time measuring, carrier telecommunication equipment will be removed from circuit, inconvenient operation, nor be on-line measurement truly; In 110kV hi-line carrier communication loop, the value of Cx is about 6000PF, Ix value is about 120mA, the power frequency impedance Zc ≈ 530k Ω of coupling condenser Cx, the equivalent power frequency impedance Za ≈ 2.5k Ω of carrier telecommunication equipment, therefore,, in the time measuring hi-line, coupling condenser Cx, carrier telecommunication equipment to electric current I x in the loop on ground, can ignore the impact of the power frequency impedance of carrier telecommunication equipment.

Summary of the invention

Technical problem to be solved in the utility model is: a kind of instrument is provided, can detects online the numerical value of hi-line carrier communication coupling condenser Cx.

The utility model adopts following technical scheme: the jaw of hook type current transformer T1, clamp together at coupling condenser Cx and receive on the electric wire of carrier telecommunication equipment, elementary as current transformer T1, the two ends of T1 secondary coil are connected on respectively on P1 and P2 point, P2 point connects the ground wire of measurement instrument power supply, integrated circuit N1～N8, select universal operational amplifier, wherein, N1 forms amplifying circuit, N2, N3 and N4 composition 50Hz frequency selection circuit, to get rid of the interference of other signals, N5 and N6 composition full-wave rectifying circuit, N7 forms filtering circuit, N8 forms amplifying circuit, at P14 point output dc voltage Vo, Vo is proportional to the capacitance of coupling condenser Cx, diode D1 and D2 reverse parallel connection, its two end is connected on P1 and P2 point, two ends of capacitor C1 are connected on P1 and P2 point, the two ends of resistor R1 are also connected on P1 and P2 point, the in-phase input end of operational amplifier N1 connects P1 point by resistor R3, and the inverting input of N1 connects P2 point by resistor R2, the inverting input of a termination N1 of resistor R4, another termination P3 point of R4, the output termination P3 point of N1, the two ends of resistor R5 are connected on respectively on P3 and P4 point, the two ends of resistor R6 are connected on respectively on P4 and P2 point, the in-phase input end of operational amplifier N2 connects P2 point, the anti-phase input termination P5 point of N2, the output termination P6 point of N2, the two ends of capacitor C2 connect respectively P5 and P6 point, the two ends of resistor R7 are connected on respectively on P6 and P7 point, the in-phase input end of operational amplifier N3 connects P4 point, the anti-phase input termination P7 point of N3, the output termination P8 point of N3, the two ends of resistor R8 are connected on respectively on P7 and P8 point, the two ends of resistor R9 are connected on respectively on P8 and P9 point, the anti-phase input termination P9 point of operational amplifier N4, the in-phase input end of N4 connects P2 point, the output termination P10 point of N4, the two ends of capacitor C4 connect respectively P9 and P10 point, the two ends of resistor R10 are connected on respectively on P4 and P10 point, resistor R11 and be connected into variable-resistance potentiometer Rp1 series connection, two end points is connected on respectively on P5 and P10 point, the in-phase input end of operational amplifier N5 connects P2 point by resistor R12, the inverting input of N5 is by resistor R13 and be connected into variable-resistance potentiometer Rp2 and be concatenated on P10 point, the positive pole of diode D4 connects the inverting input of N5, the negative pole of D4 connects the output terminal of N5, the positive pole of diode D3 connects the output terminal of N5, the negative pole of D3 connects P11 point, the inverting input of a termination N5 of resistor R14, its another termination P11 point, the in-phase input end of operational amplifier N6 connects P10 point by resistor R15, the positive pole of diode D6 connects the inverting input of N6, the negative pole of D6 connects the output terminal of N6, the positive pole of diode D5 connects the output terminal of N6, the negative pole of D3 connects P11 point, the inverting input of a termination N6 of resistor R16, its another termination P11 point, the two ends of resistor R17 connect respectively P11 and P12 point, the in-phase input end of operational amplifier N7 connects P2 point, a termination P12 point of capacitor C6, the inverting input of another termination N7 of C6, a termination P12 point of capacitor C7, the output terminal of another termination N7 of C7, the output termination P13 point of N7, a termination P13 point of resistor R18, the inverting input of another termination N7, the in-phase input end of operational amplifier N8 connects P12 point by resistor R20, the two ends of resistor R19 connect respectively P12 and P2 point, a termination P2 point of resistor R21, the inverting input of another termination N8, the output termination P14 point of N8, potentiometer Rp3 is connected into variable resistor, the inverting input of one termination N8, the other end is connected in series with resistor R22, another termination P14 point of R22, P14 point output dc voltage Vo, Vo is proportional to the capacitance of coupling condenser Cx.

Owing to having adopted such scheme, in the situation that not changing original circuit wiring, can detect online the numerical value of hi-line carrier communication coupling condenser Cx.

Brief description of the drawings: Fig. 1 is electrical schematic diagram of the present utility model.

Embodiment: below in conjunction with accompanying drawing, the utility model is described further.In circuit, get R5=R7=R8=R10=51k Ω 0.1%, R11=27k Ω, R9=27K Ω, Rp1=5k Ω C2=C4=0.1 μ FCBB, in the time having the input of 50Hz signal, adjusts Rp1, the voltage maximum that P10 is ordered, get C6=C7=0.47 μ F, R18=1M Ω, integrated circuit N1～N8 gets general operational amplifier.

Claims (1)

1. hi-line carrier communication coupling condenser on-line monitoring instrument, for the capacitance of on-line monitoring coupling condenser Cx, it is characterized in that: the jaw of hook type current transformer T1, clamp together at coupling condenser Cx and receive on the electric wire of carrier telecommunication equipment, elementary as current transformer T1, the two ends of T1 secondary coil are connected on respectively on P1 and P2 point, P2 point connects the ground wire of measurement instrument power supply, integrated circuit N1～N8, select universal operational amplifier, wherein, N1 forms amplifying circuit, N2, N3 and N4 composition 50Hz frequency selection circuit, N5 and N6 composition full-wave rectifying circuit, N7 forms filtering circuit, N8 forms amplifying circuit, diode D1 and D2 reverse parallel connection, its two end is connected on P1 and P2 point, two ends of capacitor C1 are connected on P1 and P2 point, the two ends of resistor R1 are also connected on P1 and P2 point, the in-phase input end of operational amplifier N1 connects P1 point by resistor R3, and the inverting input of N1 connects P2 point by resistor R2, the inverting input of a termination N1 of resistor R4, another termination P3 point of R4, the output termination P3 point of N1, the two ends of resistor R5 are connected on respectively on P3 and P4 point, the two ends of resistor R6 are connected on respectively on P4 and P2 point, the in-phase input end of operational amplifier N2 connects P2 point, the anti-phase input termination P5 point of N2, the output termination P6 point of N2, the two ends of capacitor C2 connect respectively P5 and P6 point, the two ends of resistor R7 are connected on respectively on P6 and P7 point, the in-phase input end of operational amplifier N3 connects P4 point, the anti-phase input termination P7 point of N3, the output termination P8 point of N3, the two ends of resistor R8 are connected on respectively on P7 and P8 point, the two ends of resistor R9 are connected on respectively on P8 and P9 point, the anti-phase input termination P9 point of operational amplifier N4, the in-phase input end of N4 connects P2 point, the output termination P10 point of N4, the two ends of capacitor C4 connect respectively P9 and P10 point, the two ends of resistor R10 are connected on respectively on P4 and P10 point, resistor R11 and be connected into variable-resistance potentiometer Rp1 series connection, two end points is connected on respectively on P5 and P10 point, the in-phase input end of operational amplifier N5 connects P2 point by resistor R12, the inverting input of N5 is by resistor R13 and be connected into variable-resistance potentiometer Rp2 and be concatenated on P10 point, the positive pole of diode D4 connects the inverting input of N5, the negative pole of D4 connects the output terminal of N5, the positive pole of diode D3 connects the output terminal of N5, the negative pole of D3 connects P11 point, the inverting input of a termination N5 of resistor R14, its another termination P11 point, the in-phase input end of operational amplifier N6 connects P10 point by resistor R15, the positive pole of diode D6 connects the inverting input of N6, the negative pole of D6 connects the output terminal of N6, the positive pole of diode D5 connects the output terminal of N6, the negative pole of D3 connects P11 point, the inverting input of a termination N6 of resistor R16, its another termination P11 point, the two ends of resistor R17 connect respectively P11 and P12 point, the in-phase input end of operational amplifier N7 connects P2 point, a termination P12 point of capacitor C6, the inverting input of another termination N7 of C6, a termination P12 point of capacitor C7, the output terminal of another termination N7 of C7, the output termination P13 point of N7, a termination P13 point of resistor R18, the inverting input of another termination N7, the in-phase input end of operational amplifier N8 connects P12 point by resistor R20, the two ends of resistor R19 connect respectively P12 and P2 point, a termination P2 point of resistor R21, the inverting input of another termination N8, the output termination P14 point of N8, potentiometer Rp3 is connected into variable resistor, the inverting input of one termination N8, the other end is connected in series with resistor R22, another termination P14 point of R22, P14 point output dc voltage Vo, Vo is proportional to the capacitance of coupling condenser Cx.