CN101907653B - Signal acquisition and transmission device for high-voltage DC transmission converter valve - Google Patents
Signal acquisition and transmission device for high-voltage DC transmission converter valve Download PDFInfo
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- CN101907653B CN101907653B CN201010214618.XA CN201010214618A CN101907653B CN 101907653 B CN101907653 B CN 101907653B CN 201010214618 A CN201010214618 A CN 201010214618A CN 101907653 B CN101907653 B CN 101907653B
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Abstract
The invention belongs to the technical field of measurement and testing, and in particular relates to a signal acquisition and transmission device for a high-voltage DC transmission converter valve, which comprises a sensor and a transmitter which are connected through a transmitter probe, wherein the sensor is a current measurement device or a voltage measurement device; the transmitter comprises a luminotron packaged in a shielding shell IV, an amplifier and a power supply unit; a cover of the shielding shell IV is provided with an insulating post; an inner core of the insulating post is provided with the transmitter probe; the power supply unit supplies power to the luminotron and the amplifier; and the sensor transmits the detected electric signals to the amplifier in the transmitter for power amplification, and the electric signals are superposed with direct current bias to make the luminotron to illuminate. The signal acquisition and transmission device has the advantages of high reliability, high stability, simple operation, convenient maintenance and installation, small volume and light weight, and can meet requirements of various fields of high voltage.
Description
Technical field
The invention belongs to measurement technical field of measurement and test, relate in particular to a kind of signals collecting dispensing device for high voltage direct current transmission converter valve.
Background technology
HVDC converter valve belongs to hoisting structure, when carrying out the tests such as excess current, superpotential, triggering non-periodic, in valve, measure the sensor of the electric parameters such as valve main circuit current, damping circuit electric current, valve module terminal voltage, the above-said current signal recording need be reached to ground through transmitter.Because converter valve is positioned at noble potential, electromagnetic environment is very severe in valve, traditional cable type signals collecting sending method run into set up, the bottleneck problem such as ground connection, outer shielding, can not meet the needs of on-the-spot test.
The analog electrical signal that first existing signals collecting radiating circuit collects sensor is converted to digital signal by voltage controlled oscillator (or A/D converter), luminous by driver drives luminotron, complete electric light conversion by passed to the receiving circuit on ground by cable, with regard to radiating circuit, this mode needs control circuit and the analog to digital conversion circuit of more complicated, particularly when measurement frequency band is higher, analog to digital conversion circuit complex, if measure frequency band, reach 20MHz, the switching rate of analog to digital conversion circuit need to reach the precision of 60MSPs guarantee signal, if add again high measurement accuracy, the requirements such as changeable fluid, its circuit will be more complicated, extremely difficult realization.
Main circuit current in prior art in definite described valve layer above and the method for damping circuit electric current are only confined to simulation calculation, but in test, converter valve is positioned at noble potential, its electromagnetic environment of living in is very severe, and the stray capacitance between being subject to layer by layer, between layer ground, the impact of inductance, therefore often there is larger error in simulation calculation, can not meet the actual needs of engineering.In process of the test, in converter valve major loop, by the excess current that flows through thousands of amperes, when so large electric current is flowed through thyristor, may burn thyristor, have great potential safety hazard.Therefore, in the urgent need to inserting major loop in converter valve layer and the current measuring device of damping circuit.
In prior art, measure described valve module terminal voltage above and conventionally adopt capacitance-resistance voltage divider principle in parallel to record, as shown in Figure 1, its feature is R to its equivalent electrical circuit
1/ R
2=C
2/ C
1time, RC divider is not subject to frequency band limits, can be from direct current to very high frequency, between electric capacity and resistance, needn't coordinate.Because tested voltage reaches tens thousand of volts, the high-voltage arm resistance of voltage divider and electric capacity not only need to consider insulation, dispel the heat and prevent the series of problems such as corona, and the impact that needs consideration to produce circuit-under-test, thereby often need to adopt very large high-voltage arm resistance (as 10M Ω) and minimum high-voltage arm electric capacity (as 0.5pF), reducing impact on circuit-under-test, reduce the power of voltage divider, but minimum high-voltage arm capacitance pole is difficult, obtain.The people such as the Zhao Zhongyuan of domestic Xi'an Communications University, local records have developed a kind of voltage measuring apparatus as shown in Figure 2, the high-voltage arm 45 of this device is placed in plexiglass tent 42, plexiglass tent 42 overcoats have an aluminium cover 46, the outside of aluminium cover is provided with low-field electrode lead end 44, the left end of high-voltage arm connects high-field electrode lead end 41, right-hand member connects low-voltage arm 47, by being connected to the measurement extension line 48 of low-voltage arm right-hand member, measuring-signal is exported, wherein the outside of high-voltage arm 45 is with umbrella shape shading ring 43, and low-voltage arm 47 is cylindric.This device has been studied the impacts of parameter on divider performance such as the diameter, the degree of depth, angle of high-voltage arm shading ring 43, and has done optimal design.But because the high-voltage arm in this device belongs to oil immersed type structure, can produce easy oil leakage, difficult in maintenance, bulky defect, the voltage on high-voltage arm distributes still inhomogeneous, and the voltage on high-voltage arm distributes as shown in Figure 3.
Summary of the invention
The technical problem to be solved in the present invention is to provide the signals collecting dispensing device for high voltage direct current transmission converter valve that a kind of volume is little, measurement range is wide, error is little, highly sensitive, reliable and stable.
For solving the problems of the technologies described above, the present invention proposes a kind of signals collecting dispensing device for high voltage direct current transmission converter valve, comprise by the connected sensor of transmitter probe and transmitter, described sensor adopts current measuring device or voltage measuring apparatus, described transmitter comprises the luminotron being encapsulated in shielding case IV, amplifier and power supply unit, described power supply unit is luminotron and amplifier power supply simultaneously, the electric signal that described sensor is recorded is passed to the amplifier power amplification in addition in transmitter, and be superimposed with direct current biasing, make luminotron luminous, the lid of described shielding case IV is provided with an insulation column, the inner core of described insulation column is provided with a transmitter probe.
Wherein, described sensor adopts current measuring device, this current measuring device comprises the shielding case being formed by shielding case I and shielding case II docking, in described shielding case I, be provided with the magnetic core I that is being wound around coil I, in described shielding case II, be provided with the magnetic core II that is being wound around coil II, integrating circuit, voltage divider and elastic piece structure, described integrating circuit input end is all connected with coil II with shielding case II, described integrating circuit output terminal connects voltage divider, described voltage divider output terminal connects an elastic piece structure, described elastic piece structure is comprised of spring and copper sheet, the end cap of described shielding case II is provided with a through hole passing for insulation column.
Wherein, described magnetic core I and magnetic core II all adopt U-shaped or C shape FERRITE CORE, are provided with the magnetic core fixing device I that magnetic core I is fixed in described shielding case I, are provided with the magnetic core fixing device I I that magnetic core II is fixed in shielding case II.
Wherein, be provided with fastening plug-in unit in described shielding case, described coil I is connected with fastening plug-in unit respectively with coil II.
Wherein, on described magnetic core I and magnetic core II, be arranged with respectively insulating supporting.
Wherein, described shielding case I and shielding case II all adopt U-shaped or C shape structure, after the openend docking of described shielding case I and shielding case II, by external fastening, be fixed into a ring shielding shell, the interior ring center line of this ring shielding shell is provided with slot, embeds the insulation cover pad being useful on testee insulation isolation in described slot.
Wherein, described sensor adopts voltage measuring apparatus, this measurement mechanism comprises the upper disc electrode connecting successively from top to bottom, high-voltage arm resistance, lower disc electrode and low-voltage arm, described upper disc electrode, high-voltage arm resistance and lower disc electrode form the symmetrical disc electrode structure of work type, described high-voltage arm resistance and upper, space electric capacity between lower disc electrode is as high-voltage arm electric capacity, the upper end of described high-voltage arm resistance is provided with high-voltage connection end, its lower end is arranged with insulation cushion cover, described lower disc electrode is insulated and is connected with high-voltage arm resistance by insulation cushion cover, described low-voltage arm comprises with cylindrical shape shielding shell III and is placed in circuit board and the elastic piece structure in shielding case III, described shielding case III is fixed in the lower end of lower disc electrode, the upper end of described circuit board is connected with the bottom of high-voltage arm resistance by lead-in wire, the lower end of described circuit board is connected with elastic piece structure, described elastic piece structure is comprised of spring and copper sheet, the bottom end cover of described shielding case III is provided with a through hole passing for insulation column.
Wherein, on described circuit board, be packaged with low-voltage arm resistance parallel with one another and low-voltage arm electric capacity.
Wherein, described low-voltage arm resistance adopts four Chip-Rs, and low-voltage arm electric capacity adopts four electric capacity, and each Chip-R all becomes four groups of capacitance-resistance structures with a Capacitance parallel connection, and described four groups of capacitance-resistance structures are parallel with one another and be symmetrically distributed on disc type circuit board.
Wherein, the model of described luminotron is HFBR-1414, and described amplifier adopts AD812 chip, and described power supply unit comprises power supply and holding circuit, and described power supply is in series and is powered by two lithium batteries.
Beneficial effect of the present invention is: the reliability of this signals collecting dispensing device is high, good stability, simple to operate, safeguard easy for installationly, there is in addition little, the lightweight advantage of volume, can meet the demand in various high pressure field.
Accompanying drawing explanation
Fig. 1 is the equivalent circuit diagram of RC divider in prior art;
Fig. 2 is the structural representation of valve module voltage measuring apparatus in prior art; Wherein, 41-high-voltage motor lead end, 42-plexiglass tent, 43-shading ring, 44-low-field electrode lead end, 45-high-voltage arm, 46-aluminium cover, 47-low-voltage arm, 48-measures extension line;
Fig. 3 is the ohmically voltage distribution plan of the mesohigh of measurement mechanism shown in Fig. 2 arm;
Fig. 4 is the structural representation of signals collecting dispensing device in the embodiment of the present invention 1;
Fig. 5 is the equivalent circuit diagram of voltage measuring apparatus;
Fig. 6 is the ohmically voltage distribution plan of high-voltage arm;
Fig. 7 is low-voltage arm resistance and the connection diagram of low-voltage arm electric capacity on circuit board;
Fig. 8 is from integration type Rogowski coil equivalent circuit diagram;
Fig. 9 is the installation site schematic diagram of current measuring device in embodiment 2;
Figure 10 is the outside drawing of signals collecting dispensing device in embodiment 2;
Figure 11 is the inner structure schematic diagram of signals collecting dispensing device in embodiment 2;
Figure 12 is the installation site schematic diagram of signals collecting dispensing device in embodiment 3;
Figure 13 is the inner structure schematic diagram of signals collecting dispensing device in embodiment 3;
Figure 14 is the circuit theory diagrams of amplifier;
In figure, 11-shielding case, 11a-shielding case I, 11b-shielding case II, 12a-magnetic core I, 12b-magnetic core II, 13-integrating circuit, 14-voltage divider, 14a-high-voltage arm, 14b-low-voltage arm, 15a-coil I, 15b-coil II, 16a-magnetic core fixing device I, 16b-magnetic core fixing device I I, the fastening plug-in unit of 17-, 17a-contact pin, 17b-slot, 18-external fastening, 19-slot, 110-insulating supporting, 111-spring, 112-end cap, 113-voltage divider output terminal, 114-copper sheet;
The upper disc electrode of 21-, 22-high-voltage arm resistance, disc electrode under 23-, 24-high-voltage connection end, 25-circuit board, 26-low-voltage arm resistance, 27-low-voltage arm electric capacity, 28-shielding case III, the 29-cushion cover that insulate, 210-bottom end cover;
3-transmitter, 31-shielding case IV, 32-luminotron, 33-amplifier, 34-power supply unit, 35-battery charge port, 36-power switch, 37-lid; 4-transmitter probe, 5-insulation column.
Embodiment
Below in conjunction with accompanying drawing, signals collecting dispensing device of the present invention is further described in detail.
The signals collecting dispensing device for high voltage direct current transmission converter valve described in this example comprises sensor and the transmitter 3 being connected by transmitter probe 4, this transmitter probe 4 is arranged on by insulation column 5 on the lid 37 of shielding case IV of transmitter 3, and top, the upper end of transmitter probe 4 presses copper sheet 114, its lower end to be connected with the amplifier 33 in transmitter 3.
(1) sensor
Sensor in this example adopts voltage measuring apparatus, as shown in Figure 4, this voltage measuring apparatus comprises upper disc electrode 21, high-voltage arm resistance 22, lower disc electrode 23 and the low-voltage arm connecting successively from top to bottom, and described upper disc electrode 21, high-voltage arm resistance 22 and lower disc electrode 23 form work type symmetrical structure.The upper end of high-voltage arm resistance is provided with a high-voltage connection end 24, its lower end is arranged with insulation cushion cover 29, lower disc electrode 23 is insulated and is connected with high-voltage arm resistance 22 by insulation cushion cover 29, the lower end of high-voltage arm resistance 22 is connected with the circuit board in low-voltage arm by lead-in wire, circuit board lower end is connected with the spring 111 in being located at shielding case III 28, the lower end of spring connects a copper sheet 114, finally by bottom end cover 210 sealings.The bottom end cover 210 of shielding case III 28 is provided with a through hole passing for insulation column 5, and the top, upper end of transmitter probe 4 is pressed on copper sheet 114, and spring 111 is compressed, and the setting of this copper sheet is in order to increase the contact area of spring 111 and transmitter probe 4.
This measurement mechanism is based on capacitance-resistance voltage divider principle in parallel, adopt work type symmetrical expression disc electrode structure, its schematic diagram and equivalent electrical circuit are as shown in Figure 4 and Figure 5, roomy upper disc electrode 21 and lower disc electrode 23 have increased the electric capacity between itself and high-voltage arm resistance 22, compensated the ground capacitance of high-voltage arm resistance, thereby the ohmically voltage of high-voltage arm is evenly distributed, the ingenious space capacitor C of utilizing high-voltage arm resistance 22 and upper and lower disc electrode 21,23
11, C
12as high-voltage capacitance, thereby obtain the high-voltage arm electric capacity of about 0.3pF, solved an extremely difficult difficult problem of obtaining minimum electric capacity.
High-voltage arm resistance 22 is selected column glass-film glaze resistance, and its resistance 10M Ω, limiting voltage 75kV, capacity 75W, the highest power-frequency voltage of withstand long term exposure (effective value) are 27.4kV, effectively insulated lengths 200mm, diameter 25mm, temperature coefficient are less than 150 * 10
-6/ ℃.High-voltage arm resistance is exposed in air, and resistance edge flashing voltage (peak value) is 60kV, therefore, resistance internal breakdown and edge flashing can not occur, safe and reliable.For 50kV surge voltage, ohmically power consumption is 12.5mJ, without particular design cooling system, easy to maintenance.It is 5mm that upper and lower disc electrode is designed to thickness, diameter is the stainless steel disk of 100mm, and its edge is processed into arc, lower disc electrode 23 is connected with high-tension resistive by the insulation cushion cover 29 of a diameter 40mm, thick 15mm, and this insulation cushion cover 29 is sheathed on the bottom of high-voltage arm resistance 22.As calculated, the frequency breakdown voltage of said structure (peak value) is 68kV, there will not be corona discharge in process of the test.As shown in Figure 6, adopt the measurement mechanism of above-mentioned design under the surge voltage of 50kV, on high-voltage arm resistance, the voltage of each point distributes very even.
Low-voltage arm comprises with the shielding case III 28 of bottom end cover 210 and is placed in circuit board 25, spring 111 and the copper sheet 114 in shielding case III, is packaged with low-voltage arm resistance parallel with one another 26 and low-voltage arm electric capacity 27 on this circuit board.Low-voltage arm resistance 26 in this example is designed to 300 Ω, by 4 1.2k Ω Chip-Rs, is formed in parallel, and symmetric packages, on disc type circuit board 25, has been eliminated the impact of stray inductance.Low-voltage arm electric capacity 27 is designed to the parallel-connection structure of 10000pF, 1000pF, 100pF, tetra-electric capacity of 20pF, and also symmetric packages is on disc type circuit board, with decentralized capacitance electric current and overcome the lower shortcoming of large capacitance measurement frequency band.As shown in Figure 7, being encapsulated in low-voltage arm resistance 26 on circuit board 25 and the optimum structure of low-voltage arm electric capacity 27 is: by the Chip-R of each 1.2k Ω respectively with four groups of capacitance-resistance structures of low-voltage arm electric capacity 27 formation in parallel, and then by these four groups of capacitance-resistance structures parallel with one another and symmetric packages on disc type circuit board 25.Adopt structure shown in above-mentioned Fig. 7, can make the voltage that this measurement mechanism is exported just meet the input voltage ± 1.5V of rear end-receiver (signaling for receiving this device).
In addition, this device has designed the low pressure end stainless steel cylinder type shielding case III28 of thick 2mm, diameter 40mm, this shielding case has been avoided the impact of outside electromagnetic interference on chip circuit, has guaranteed authenticity and the accuracy of output signal, and described circuit board 25 can be selected pcb board.Bottom end cover, with a bottom end cover 210, is first opened when mounted in the bottom of this shielding case III, circuit board 25 and elastic piece structure is placed in to shielding case III and by lead-in wire, circuit board 25 is connected with high-voltage arm bottom, finally by bottom end cover 210 sealings.
Through experimental verification, adopt the high-voltage direct-current power transmission valve assembly voltage measuring apparatus of said structure to there is the advantages such as volume is little, reliability is high, good stability, easy maintenance, can reach ± 50kV of its measurement range, frequency band 0～10MHz, actual measurement intrinsic standoff ratio 33464: 1, measuring maximum error is 2.48%, can meet the measurement needs of converter valve experiments completely.
(2) transmitter 3
As shown in Figure 4, the profile of the transmitter in this example is the rectangular parallelepiped shielding case IV 31 of 40mm * 25mm * 30mm, its inside is packaged with luminotron 32, amplifier 33 and power supply unit 34, power supply unit is luminotron and amplifier power supply simultaneously, amplifier 33 receives the analog electrical signal that transmits by transmitter probe 4 and to the in addition power amplification of this electric signal, and be superimposed with direct current biasing, make luminotron 32 luminous; Direct current biasing provides DC current to luminotron 32, makes the central point of luminotron 32 in linear working range, and the current waveform corresponding with signal is superimposed upon on bias current, and light intensity is changed.
Shielding case IV 31: adopt pure red copper to make, profile is 40mm * 25mm * 30mm, the thick 3mm of shell, can fall electromagnetic interference shield complicated in valve.In order to prevent corona discharge, rounding processing is carried out in the corner, outside of this shielding case IV.On launcher shell, be reserved with battery charge port 35, convenient to lithium cell charging.One insulation column 5 is installed on the lid 37 of shielding case IV upper end, at the inner core place of insulation column, insert a transmitter probe 4, the upper end of insulation column is through being arranged on the through hole on shielding case III 28 bottom end covers 210, the setting of this insulation column 5 is for transmitter probe 4 and bottom end cover 210 and lid 37 are insulated mutually, the lower end of transmitter probe 4 is connected with the amplifier 33 in shielding case IV, its upper end is stretched into top in shielding case III and is pressed on copper sheet 114, and spring 111 is compressed.
Luminotron 32: adopt HFBR-1414 type luminotron in this example, its luminescence efficiency is high, good reliability.From the volt-ampere characteristic of HFBR-1414, the forward conduction voltage of HFBR-1414 and electric current keep good linear relationship between 20mA～100mA.Therefore, the best effort scope of this luminotron is 20mA～100mA, and central task point is 60mA, and corresponding operating voltage is 1.5V～1.85V, and central task voltage is about 1.7V.In addition, this luminotron is without biasing in advance in the situation that, and the rise time is 4ns, meets the requirement of measured signal far away.
Amplifier 33: because luminotron drive current is 20mA～100mA, consider that measured signal has positive-negative polarity, thereby elect the zero input service point of luminotron as 60mA, make it there is identical range to positive signal and negative signal.So large electric current can affect for measuring the operating characteristic of the sensor of electric signal, and far beyond the load capacity of voltage sensor.Therefore, amplifier becomes essential parts, and the circuit structure of amplifier 33 as shown in figure 14, its role is to electric signal to carry out power amplification, and direct current biasing is provided, and by luminotron with for measuring the sensor of electric signal, keep apart.Consider the factor in many ways such as frequency, power consumption, input impedance, output power, power supply, the present invention selects AD812 chip to design amplifier, and 33 pairs of electric signal of amplifier carry out power amplification and direct current biasing is provided.As calculated, amplifier current-limiting resistance is 7.8 Ω, and input voltage range is ± 1.5V.
Power supply unit 34: comprise power supply and holding circuit; the chargeable cellular li-ion battery series connection that power supply is 1380mAh by two 3.7V, capacity is powered; holding circuit adopts Seiko Instr Inc (SII) protection chip that produce, that model is S-8232NTFT-T2-G; this chip for the voltage by power supply is overcharged, overdischarge and overcurrent protection, by power switch 36, control the break-make of power supply.
Embodiment 2
The structure of this routine described device, connected mode and principle of work are same as embodiment 2 substantially, have difference only and are:
(1) sensor
Sensor of the present invention adopts current measuring device, this current measuring device is connected with the amplifier 33 in transmitter 3 by transmitter probe 4, this transmitter probe 4 is arranged on by insulation column 5 on the lid 37 of shielding case IV of transmitter 3, the left end of transmitter probe 4 top be pressed in copper sheet 114 by spring 111 compress, its right-hand member is connected with the amplifier 33 in transmitter 3.
As shown in Figure 9, this current measuring device is arranged in the major loop rectangular copper bar in converter valve layer, so configuration design becomes counterpart formula structure, and this structural volume is little, easy for installation.
This current measuring device 1 of measuring main circuit current adopts from integration type Rogowski coil principle, its equivalent electrical circuit as shown in Figure 1, coiling L on the skeleton around tested electric current
0, coil two ends can induce the induced potential e (t) being directly proportional to the derivative di/dt of tested electric current, and induced potential is by coil L
0the integrating circuit R that two ends connect
rinstitute's integration, integrating circuit R
rthe voltage waveform U at two ends
out(t) consistent with the waveform of tested electric current.Described C
0for coil L
0and the electric capacity producing between shielding case, described R
0for coil L
0and the resistance producing between shielding case.
As shown in Figure 10,11, this current measuring device mainly comprises A, B two parts:
A part mainly comprises U-shaped shielding case I 11a and U-shaped magnetic core I 12a.Symmetrical two magnetic core fixing device I 16a and two insulating supportings 110 that are useful on fixed magnetic core I 12a in shielding case I 11a, magnetic core fixing device I 16a and insulating supporting 110 are adhered in shielding case I 11a by insulating gel, before magnetic core fixing device I 16a, be arranged side by side a fastening plug-in unit 17, fastening plug-in unit is comprised of contact pin 17a and slot 17b, and in this example, the contact pin 17a of fastening plug-in unit is adhered in shielding case I 11a by insulating gel; With the winding of a copper enameled wire, on magnetic core I 12a, the coil I 15a being wound around on magnetic core I 12a after coiling is uniformly distributed.Open the end cap 112 in shielding case I left side, the magnetic core I that is wound with coil I is stretched in shielding case I, and two long limits of this magnetic core I are passed to insulating supporting 110 and magnetic core fixing device I 16a successively, by two coil I joints of copper enameled wire head and the tail respectively be bonded in shielding case I in two contact pin 17a be connected, then by 112 sealings of the end cap in shielding case I left side.
B part mainly comprises U-shaped shielding case II 11b, U-shaped magnetic core II 12b, integrating circuit 13 and voltage divider 14.Symmetrical two magnetic core fixing device I I 16b and two insulating supportings 110 that are useful on fixed magnetic core I in shielding case II 11b, magnetic core fixing device I I 16b and insulating supporting 110 by insulating gel bonding with shielding case II 11b in, in this example, the slot 17b of fastening plug-in unit is adhered in shielding case II 11b by insulating gel; With the symmetrical winding of two copper enameled wires, on magnetic core II 12b, the coil II 15b being wound around on magnetic core II 12b after coiling is uniformly distributed.Open the end cap 112 on shielding case II right side, the magnetic core II that is wound with coil II is stretched in shielding case II, and two long limits of this magnetic core II are passed to insulating supporting 110 and magnetic core fixing device I I 16b successively, two coil II joints of two copper enameled wire head ends are connected with two slot 17b respectively, again two coil II joints of two copper enameled wire ends are connected with shielding case II with integrating circuit input end respectively, integrating circuit output terminal connects the high-voltage arm 14a of voltage divider, the low-voltage arm 14b of voltage divider is connected with the end cap of shielding case II, voltage divider output terminal 113 is connected with the front end of spring 111, the rear end of spring connects a copper sheet 114, finally by end cap 112 sealings.The right side end cap 112 of shielding case II is provided with a through hole passing for insulation column 5, and the left end top of transmitter probe 4 is pressed on copper sheet 114 spring 111 is compressed, and the setting of this copper sheet is in order to increase the contact area of spring 111 and transmitter probe 4.
Shielding case I 11a and shielding case II 11b adopt duralumin to make, and the thick 3mm of shell can fall extraneous complicated electromagnetic interference shield.In this example, on the interior ring center line of ring shielding shell 11, have a circle slot 19, when practical application, first in the slot 19 of shielding case I and shielding case II, respectively embed after the insulation cover pad that a 3mm is thick (not shown in FIG.), again above-mentioned mounted A, B two parts are nested in major loop rectangular copper bar, the contact pin 7a of fastening plug-in unit is inserted in slot 7b, A, B two parts are played and connected and fixation, finally pass through two external fastenings 18 by A, the fastening of B two parts.After fastening, after shielding case I and shielding case II docking, form a ring shielding shell 11, after magnetic core I and magnetic core II docking, form a toroidal core.The effect of slot 19 is: the one, and the magnetic field that guarantees to can be good at coil in shielding case being coupled main circuit current excites; The 2nd, cut off the induction circulation on shielding case; The 3rd, for providing, insulation cover pad embeds position.Magnetic core fixing device I I16a and magnetic core fixing device I I 16b are the ring texture that insulating material is made, and adopt epoxy resin ring in this example.
The design of coil: this measurement mechanism design frequency band is 40Hz～6MHz, depends primarily on the space capacitor C between coil and shielding case from integration type Rogowski coil high-frequency by frequency
0, space electric capacity is less, and high frequency is higher by frequency; Its low frequency depends primarily on the ratio of integrating circuit and coil inductance by frequency.Therefore, the number of turn of coil can not be too many, otherwise space capacitor C between coil and shielding case
0excessive, high frequency characteristics is bad; Coil turn can not be very little, otherwise electric current on coil is too large, and coil will generate heat, and the resistance that requires integrating circuit to produce is minimum.When coil turn is less, its low frequency be difficult for to reduce by frequency, therefore take soft magnetic ferrites as magnetic core to increase inductance.As calculated, the definite U-iron ferrite core of selecting of the present invention forms framed structure, and wherein the diameter of section of magnetic core I and magnetic core II is 15.5mm, relative permeability 2000.Coil I, II all adopt copper enameled wire, with the coil turn of copper enameled wire coiling on magnetic core I, are 34 circles: on two long limits of magnetic core I, be wound with respectively and on 14 circle coil I, minor face, be wound with 6 circle coil I; With the symmetrical coiling on magnetic core II of two copper enameled wires, be wound with altogether 26 circle coil II: first copper enameled wire is wound around and on 10 circle coil II, minor face, is wound around 3 circle coil II on a long limit of magnetic core II, second copper enameled wire is wound around and on 10 circle coil II, minor face, is wound around 3 circle coil II on another long limit of magnetic core II 2b; Coil I 115a and coil II 115b all carry out coiling in the same direction, and the turn-to-turn of coil I and coil II is apart from being the even coiling of 8mm, and the spacing of coil I and shielding case I and coil II are 5mm with the spacing of shielding bridge II.
The design of integrating circuit 13: if adopt the minimum resistance of resistance to be difficult to processing, and it is larger affected by stray inductance, therefore as calculated, this Array selection is by 10 0.1 Ω resistance and be unified into the integrating circuit of 0.01 Ω, and this integrating circuit can effectively be eliminated the impact of stray inductance.
The design of voltage divider 14: described voltage divider consists of the resistance of two series connection, one of them resistance is connected with integrating circuit 13 as high-voltage arm 14a, and another resistance is connected with shielding case II as low-voltage arm 14b.
Through many experiments, verify, more than the main circuit current measuring device of design has good shielding, little on the field strength distribution impact in change of current valve body, there is the advantages such as volume is little, the linearity good, reliability is high, good stability, this device frequency band is 40Hz～6MHz, sensitivity is 150mV/kA, and maximum error is 1.22%.Adopt the current measuring device measurement range of said structure to be ± 10kA, can make to measure range enough wide, can meet actual measurement demand.
As shown in figure 11, one insulation column 5 is installed on the lid 37 of shielding case IV upper end, at the inner core place of insulation column, insert a transmitter probe 4, the left end of insulation column is through being arranged on the through hole on shielding case II right side end cap 112, the right-hand member of transmitter probe 4 is connected with the amplifier 33 in shielding case IV, its left end stretches into top in shielding case II 11b and is pressed on copper sheet 114, and spring 111 is compressed.
The structure of this routine described device, connected mode and principle of work are same as embodiment 2 substantially, have difference only and are:
(1) sensor
Sensor of the present invention adopts current measuring device, this current measuring device is connected with the amplifier of transmitter by transmitter probe 4, this transmitter probe 4 is arranged on by insulation column 5 on the lid 37 of shielding case IV of transmitter 3, and the left end of transmitter probe 4 top is pressed on copper sheet 114 spring 111 is compressed, its right-hand member is connected with the amplifier 33 in transmitter 3.As shown in figure 12, current measuring device of the present invention is arranged on the thyristor damping return wire in converter valve layer, so configuration design becomes counterpart formula structure, and this structural volume is little, easy for installation.As shown in figure 13, this current measuring device mainly comprises A, B two parts:
A part mainly comprises C shape shielding case I 11a and C shape magnetic core I 12a.In shielding case I 11a, be provided with two for the magnetic core fixing device I 16a of fixed magnetic core I 2a, this magnetic core fixing device I is adhered in shielding case I by insulating gel symmetry, before magnetic core fixing device I 6a, be arranged side by side a fastening plug-in unit 17, fastening plug-in unit is comprised of contact pin 17a and slot 17b, and in this example, the contact pin 7a of fastening plug-in unit is adhered in shielding case I 11a by insulating gel; With the winding of a copper enameled wire, on magnetic core I 12a, the coil I 15a being wound around on magnetic core I 12a after coiling is uniformly distributed.Open the end cap 112 in shielding case I left side, the magnetic core I that is wound with coil I is stretched in shielding case I, and two minor faces of this magnetic core I are fixed through magnetic core fixing device I 16a, by two coil I joints of copper enameled wire head and the tail respectively be bonded in shielding case I in two contact pin 17a be connected, then by 112 sealings of the end cap in shielding case I left side.
B part mainly comprises C shape shielding case II 11b, C shape magnetic core II 12b, integrating circuit 13 and voltage divider 14.In shielding case II 1b, be provided with two for two magnetic core fixing device I I 16b of fixed magnetic core I 12a, this magnetic core fixing device I I is by insulating gel symmetrical bonding and shielding case II 11b, and in this example, the slot 17b of fastening plug-in unit is adhered in shielding case II 11b by insulating gel; With the symmetrical winding of two copper enameled wires, on magnetic core II 12b, the coil II 15b being wound around on magnetic core II 12b after coiling is uniformly distributed.Open the end cap 112 on shielding case II right side, the magnetic core II that is wound with coil II is stretched in shielding case II, and two minor faces of this magnetic core II are passed to magnetic core fixing device I I 16b, two coil II joints of two copper enameled wire head ends are connected with the slot 17b of two fastening plug-in units respectively, again two coil II joints of two copper enameled wire ends are connected with shielding case II with integrating circuit input end respectively, integrating circuit output terminal connects the high-voltage arm 14a of voltage divider, the low-voltage arm 14b of voltage divider is connected with the end cap of shielding case II, voltage divider output terminal 113 is connected with the front end of spring 111, the rear end of spring connects a copper sheet 114, finally by end cap 112 sealings.The right side end cap 112 of shielding case II is provided with a through hole passing for insulation column 5, and the left end top of transmitter probe 4 is pressed on copper sheet 114 spring 111 is compressed, and the setting of this copper sheet is in order to increase the contact area of spring 111 and transmitter probe 4.
Shielding case I 1a and shielding case II 1b adopt duralumin to make, and the thick 3mm of shell can fall extraneous complicated electromagnetic interference shield.In this example, on the interior ring center line of ring shielding shell 11, have a circle slot 19, when practical application, first in the slot 19 of shielding case I and shielding case II, respectively embed after the insulation cover pad that a 3mm is thick (not shown in FIG.), again above-mentioned mounted A, B two parts are nested on thyristor damping return wire, the contact pin 17a of fastening plug-in unit is inserted in slot 17b, A, B two parts are played and connected and fixation, finally pass through two external fastenings 18 by A, the fastening of B two parts.After fastening, after shielding case I and shielding case II docking, form a ring shielding shell 11, after magnetic core I and magnetic core II docking, form a toroidal core.The effect of slot 19 is: the one, guarantee that the coil in shielding case can be good at the magnetic field that Coupling Damping loop current excites; The 2nd, cut off the induction circulation on shielding case; The 3rd, for providing, insulation cover pad embeds position.Magnetic core fixing device I I16a and magnetic core fixing device I I 16b are the ring texture that insulating material is made, and adopt epoxy resin ring in this example.
The design of coil: this measurement mechanism design frequency band is 40Hz～20MHz, depends primarily on the space capacitor C between coil and shielding case from integration type Rogowski coil high-frequency by frequency
0, space electric capacity is less, and high frequency is higher by frequency; Its low frequency depends primarily on the ratio of integrating circuit and coil inductance by frequency.Therefore, the number of turn of coil can not be too many, otherwise space capacitor C between coil and shielding case 1
0excessive, high frequency characteristics is bad; Coil turn can not be very little, otherwise electric current on coil is too large, and coil will generate heat, and the resistance that requires integrating circuit to produce is minimum.When coil turn is less, its low frequency be difficult for to reduce by frequency, therefore take soft magnetic ferrites as magnetic core to increase inductance.As calculated, the definite C shape FERRITE CORE of selecting of the present invention forms framed structure, and wherein the diameter of section of C shape FERRITE CORE I and magnetic core II is 15.5mm, relative permeability 2000.Coil I, II all adopt copper enameled wire, with the coil turn of copper enameled wire coiling on magnetic core I, are 5 circles: on two minor faces of magnetic core I 2a, be wound with respectively on 1 circle coil I, long limit and be wound with 3 circle coil I; With the symmetrical coiling on magnetic core II of two copper enameled wires, be wound with altogether 5 circle coil II: first copper enameled wire is wound around on 1 circle coil II, long limit and is wound around 2 circle coil II on a minor face of magnetic core II, second copper enameled wire is wound around respectively 1 circle coil II at another minor face of magnetic core II with growing on limit; The turn-to-turn of coil I and coil II is apart from being the even coiling of 8mm, and the spacing of the spacing of coil I and shielding case I and described coil II and shielding case II is 5mm.
The design of integrating circuit 13: if adopt the minimum resistance of resistance to be difficult to processing, and it is larger affected by stray inductance, therefore as calculated, this Array selection is by 10 1 Ω resistance and be unified into the integrating circuit of 0.1 Ω, and this integrating circuit can effectively be eliminated the impact of stray inductance.
The design of voltage divider 14: described voltage divider 4 consists of the resistance of two series connection, one of them resistance is connected with integrating circuit 3 as high-voltage arm 4a, and another resistance is connected with shielding case II 1b as low-voltage arm 4b.
Through many experiments, verify, more than the damping circuit current measuring device of design has good shielding, little on the field strength distribution impact in change of current valve body, there is the advantages such as volume is little, the linearity good, reliability is high, good stability, the measurement range of this device is ± 300A, frequency band is 40Hz～20MHz, and sensitivity is 10mV/kA, and maximum error is 0.48%.
This measurement mechanism in use, need first by fastening plug-in unit, whole device to be nested on the thyristor damping return wire in converter valve layer, again the copper bar of converter valve is inserted in the interior ring of ring shielding shell 11, copper bar touches mutually with the insulation cover pad embedding in slot 19, can realize this device to manage the monitoring of electric current in damping circuit by respecting ancestral, when the electric current of this measurement device surpasses the scope that thyristor can bear, just starting protection device is protected thyristor, the excess current that generally flows through thyristor damping loop is ± 5Ka, the structural design of this measurement mechanism makes its measurement range be ± 300A, can greatly extend the serviceable life of this measurement mechanism.
Finally should be noted that: above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit, although the present invention is had been described in detail with reference to above-described embodiment, those of ordinary skill in the field are to be understood that: still can modify or be equal to replacement the specific embodiment of the present invention, and do not depart from any modification of spirit and scope of the invention or be equal to replacement, it all should be encompassed in the middle of claim scope of the present invention.
Claims (8)
1. the signals collecting dispensing device for high voltage direct current transmission converter valve, this device comprises by the connected sensor of transmitter probe (4) and transmitter (3), described sensor adopts current measuring device (1) or voltage measuring apparatus (2), described current measuring device comprises by shielding case I(11a) and shielding case II(11b) shielding case (11) that forms of docking, described shielding case I(11a) in, be provided with and be wound around coil I(15a) magnetic core I(12a), described shielding case II(11b) in, be provided with and be wound around coil II(15b) magnetic core II(12b), described transmitter comprise be encapsulated in shielding case IV(31) in luminotron (32), amplifier (33) and power supply unit (34), described power supply unit is that luminotron and amplifier are powered simultaneously, it is characterized in that:
The electric signal that described sensor is recorded is passed to the power amplification be superimposed with direct current biasing in addition of amplifier in transmitter, make luminotron luminous, the lid of described shielding case IV (37) is provided with an insulation column (5), and the inner core of described insulation column is provided with a transmitter probe (4);
The shielding case II(11b of described current measuring device) in, be also provided with integrating circuit (13), voltage divider (14) and elastic piece structure, described integrating circuit input end and shielding case II(11b) all with coil II(15b) be connected, described integrating circuit output terminal connects voltage divider (14), described voltage divider output terminal (113) connects an elastic piece structure, described elastic piece structure is comprised of spring (111) and copper sheet (114), and the end cap of described shielding case II (112) is provided with a through hole passing for insulation column (5);
Described voltage measuring apparatus comprises the upper disc electrode (21) connecting successively from top to bottom, high-voltage arm resistance (22), lower disc electrode (23) and low-voltage arm, described upper disc electrode (21), high-voltage arm resistance (22) and lower disc electrode (23) form the symmetrical disc electrode structure of work type, described high-voltage arm resistance (22) is with upper, lower disc electrode (21, 23) the space electric capacity between is as high-voltage arm electric capacity, the upper end of described high-voltage arm resistance is provided with high-voltage connection end (24), its lower end is arranged with insulation cushion cover (29), described lower disc electrode (23) is insulated and is connected with high-voltage arm resistance (22) by insulation cushion cover (29), described low-voltage arm comprises with cylindrical shape shielding shell III(28) and be placed in circuit board (25) and the elastic piece structure in shielding case III, described shielding case III is fixed in the lower end of lower disc electrode, the upper end of described circuit board is connected with the bottom of high-voltage arm resistance by lead-in wire, the lower end of described circuit board is connected with elastic piece structure, described elastic piece structure is comprised of spring (111) and copper sheet (114), the bottom end cover of described shielding case III (210) is provided with a through hole passing for insulation column (5).
2. signals collecting dispensing device according to claim 1, it is characterized in that: described magnetic core I(12a) and magnetic core II(12b) all adopt U-shaped or C shape FERRITE CORE, described shielding case I(11a) in, be provided with magnetic core I(12a) the magnetic core fixing device I (16a) that is fixed, shielding case II(11b) in be provided with magnetic core II(12b) the magnetic core fixing device I I(16b that is fixed).
3. signals collecting dispensing device according to claim 2, is characterized in that: in described shielding case (11), be provided with fastening plug-in unit (17), described coil I(15a) with coil II(15b) be connected with fastening plug-in unit (17) respectively.
4. signals collecting dispensing device according to claim 3, is characterized in that: described magnetic core I(2a) and magnetic core II(2b) on be arranged with respectively insulating supporting (10).
5. signals collecting dispensing device according to claim 4, it is characterized in that: described shielding case I(11a) and shielding case II(11b) all adopt U-shaped or C shape structure, described shielding case I(11a) and shielding case II(11b) openend docking after by external fastening (18), be fixed into a ring shielding shell (11), the interior ring center line of this ring shielding shell (11) is provided with slot (19), embeds the insulation cover pad being useful on testee insulation isolation in described slot (19).
6. signals collecting dispensing device according to claim 1, is characterized in that: on described circuit board (25), be packaged with low-voltage arm resistance parallel with one another (26) and low-voltage arm electric capacity (27).
7. signals collecting dispensing device according to claim 6, it is characterized in that: described low-voltage arm resistance (26) adopts four Chip-Rs, low-voltage arm electric capacity (27) adopts four electric capacity, each Chip-R all becomes four groups of capacitance-resistance structures with a Capacitance parallel connection, and described four groups of capacitance-resistance structures are parallel with one another and be symmetrically distributed on disc type circuit board (25).
8. signals collecting dispensing device according to claim 1; it is characterized in that: the model of described luminotron (32) is HFBR-1414; described amplifier (33) adopts AD812 chip; described power supply unit (34) comprises power supply and holding circuit, and described power supply is in series and is powered by two lithium batteries.
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| CN201010214618.XA CN101907653B (en) | 2010-06-25 | 2010-06-25 | Signal acquisition and transmission device for high-voltage DC transmission converter valve |
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| CN201010214618.XA CN101907653B (en) | 2010-06-25 | 2010-06-25 | Signal acquisition and transmission device for high-voltage DC transmission converter valve |
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| CN103513081B (en) * | 2012-10-15 | 2016-05-18 | 上海市计量测试技术研究院 | A kind of resistor-type impulse voltage divider of high accuracy fast-response |
| CN106158077B (en) * | 2016-06-22 | 2018-01-19 | 西北核技术研究所 | A kind of radial direction three board transmission line of Transmission Convergence pulse current |
| CN106503338B (en) * | 2016-10-24 | 2020-06-16 | 上海华力微电子有限公司 | Anti-electromagnetic interference crystal oscillator resonant circuit |
| CN112290899B (en) * | 2020-10-26 | 2024-02-06 | 杭州爱华仪器有限公司 | Preamplifier of measuring circuit |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4374359A (en) * | 1979-10-04 | 1983-02-15 | IREQ--Institut de Recherche de l'Hydro-Quebec | System and method of sensing current in high voltage transmission lines utilizing the transmission of digital information by optical fibers |
| CN1584607A (en) * | 2004-05-31 | 2005-02-23 | 席世友 | Overvoltage on-line sampler for 6-35 KV electric power system |
| CN201075123Y (en) * | 2007-09-10 | 2008-06-18 | 中国电力科学研究院 | Device for measuring high potential current |
| CN201130234Y (en) * | 2007-12-21 | 2008-10-08 | 西安电力机械制造公司 | Circuit structure of voltage monitoring plate of DC transmission thyristor flow-exchanging valve |
| CN101382568A (en) * | 2008-10-24 | 2009-03-11 | 陕西电力科学研究院 | Optical fiber type voltage measurement method and measuring set thereof |
| CN201355371Y (en) * | 2009-02-20 | 2009-12-02 | 国网电力科学研究院 | Impulse voltage divider |
| CN101650403A (en) * | 2009-09-15 | 2010-02-17 | 重庆大学 | Current sensor for polluted insulator leakage of AC high-voltage electric transmission line |
| CN101713793A (en) * | 2009-12-04 | 2010-05-26 | 中国西电电气股份有限公司 | Gas insulation-based DC high voltage measuring device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07218538A (en) * | 1994-01-31 | 1995-08-18 | Sony Tektronix Corp | Probe for floating measurement |
-
2010
- 2010-06-25 CN CN201010214618.XA patent/CN101907653B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4374359A (en) * | 1979-10-04 | 1983-02-15 | IREQ--Institut de Recherche de l'Hydro-Quebec | System and method of sensing current in high voltage transmission lines utilizing the transmission of digital information by optical fibers |
| CN1584607A (en) * | 2004-05-31 | 2005-02-23 | 席世友 | Overvoltage on-line sampler for 6-35 KV electric power system |
| CN201075123Y (en) * | 2007-09-10 | 2008-06-18 | 中国电力科学研究院 | Device for measuring high potential current |
| CN201130234Y (en) * | 2007-12-21 | 2008-10-08 | 西安电力机械制造公司 | Circuit structure of voltage monitoring plate of DC transmission thyristor flow-exchanging valve |
| CN101382568A (en) * | 2008-10-24 | 2009-03-11 | 陕西电力科学研究院 | Optical fiber type voltage measurement method and measuring set thereof |
| CN201355371Y (en) * | 2009-02-20 | 2009-12-02 | 国网电力科学研究院 | Impulse voltage divider |
| CN101650403A (en) * | 2009-09-15 | 2010-02-17 | 重庆大学 | Current sensor for polluted insulator leakage of AC high-voltage electric transmission line |
| CN101713793A (en) * | 2009-12-04 | 2010-05-26 | 中国西电电气股份有限公司 | Gas insulation-based DC high voltage measuring device |
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