UHV transmission line electronic current mutual inductor and corona loss measurement mechanism thereof
Technical field
The invention belongs to transmission line high-tension measurement field, relate to a kind of corona loss measurement mechanism, relate in particular to UHV transmission line corona loss measurement mechanism, it is applicable to the long term monitoring of the corona loss of 1000kV electric pressure transmission line, also be applicable to the measurement and the evaluation of 1000kV electric pressure transmission line energy loss, also significant to the leads of ultra-high voltage power transmission lines structure model selection simultaneously.
Background technology
When electric field strength surpassed the air breakdown field intensity around the transmission line wire, near the air the adjacent wires produced ionization and forms corona discharge.The charged ion that produces because of corona discharge under the alternating voltage effect around lead back and forth movement, be accompanied by air ionization and also can produce light and radio interference, the energy that these effects consume is referred to as corona loss.
When definite 1000kV leads of ultra-high voltage power transmission lines structure, not only to consider the resistance loss when lead passes through electric current, and will consider the corona loss under the different conductor structural condition.Under some specific condition, link tester is crossed the local climate very severe, and it is very big that rain, snow, frost, greasy weather gas account for annual ratio, and the electric energy total losses that corona loss causes may become main governing factor.
Last century six the seventies, states such as the U.S., the former Soviet Union, Canada, Italy, France, Japan have set up the test line segment in succession for the construction of various countries' transmission line, have carried out the measurement Research of corona loss.Because be subjected to the restriction of various countries' transmission voltage grade, the corona loss study limitation that most countries is carried out is in extra high voltage network, only the correlation test of ultra high voltage test circuit was done by a handful of countries such as the U.S., the former Soviet Union and Italy.Up to the present, abroad the time of this class ultra high voltage corona loss test duration meteorological condition short, the test experience also not thorough, cause test data very incomplete, need further carry out long test and measurement research.
Before early stage NORTHWEST CHINA area 330kV circuit builds up,, successively set up corresponding test line segment, the measurement Research of having carried out corona loss in Qinghe, Beijing and lake, Yunnan head in order to obtain the design considerations of corona loss.And Qinghe 330kV line segment is reconstructed into the 500kV line segment carried out 500kV line corona loss measurement.Wuhan High Voltage Research Institute has been built 1km500kV test line segment the eighties in Wuhan, and carries out the corona loss measurement of circuit.But up to the present, the corona loss of UHV TRANSMISSION LINES IN CHINA is measured and not carried out substantially, and the correlation computations of ultra high voltage corona loss is basic with reference to external related data, and this class can be with reference to measured data seldom, and is very incomplete.
China is carrying out the research of ultra high voltage technical elements at present energetically, transmission line corona loss research is one of key technology of China 1000kV extra-high voltage electric transmission and transformation engineering, presses for development and can accurately measure the device of UHV transmission line corona loss for a long time.Early stage corona loss is measured often to use and is carried out through being adapted as self balancing Schering bridge, and needs reversal connection, electric bridge to be in the high potential district when the measurement of testing line segment.There is certain potential safety hazard in this method of measurement inconvenient operation to the person and equipment, is difficult to realize that the real-time online under the long-time different weather conditions detects.
Traditional high-voltage current measurement adopt electromagnetic current transducer based on electromagnetic induction principle (CurrentTransformer, CT).It adopts iron-core coil to be used to measure passage, but adopts sieve Paderewski coil to be used to protect passage.The precision that traditional electromagnetic type CT measures steady-state current can reach ten thousand/and several even higher, yet, along with the continuous increase of electric power system capacity, the improving constantly of electric pressure, electromagnetic type CT is because the defective on self principle, and more and more is difficult to satisfy the power system development needs.Under the short trouble situation, serious magnetic saturation phenomenon can appear in iron-core coil, causes the serious distortion of secondary output current wave, the transient process in the time of can not accurately reflecting short circuit.And take place at current waveform under the situation of distortion, but the accuracy of sieve Paderewski coil is not high enough.So adopt traditional electromagnetic type CT when current waveform distorts, can not reflect current information very exactly.
Summary of the invention
The objective of the invention is at the existing defective of traditional measurement corona loss method of measurement, a kind of UHV transmission line electronic current mutual inductor and corona loss measurement mechanism thereof are provided, its accuracy of measurement height, there is not Insulation Problems, easy to operate, there is not potential safety hazard, and can realizes long-time on-line measurement the UHV transmission line corona loss.
Technical solution of the present invention is: a kind of UHV transmission line electronic current mutual inductor, it is characterized in that: it comprises resistance sampling unit 2.1, distant place module 2.2, optical fiber composite insulator 2.7 and local module 2.8, resistance sampling unit 2.1 distant place modules 2.2 are electrically connected, and distant place module 2.2 is connected with local module 2.8 light by optical fiber composite insulator 2.7;
Described resistance sampling unit 2.1 comprises preceding conductive copper rod 3.1, Copper Foil 3.2, circuit board 3.3, accurate noninductive resistance 3.4 and the back conduction copper rod 3.1 that is electrically connected successively;
Described distant place module 2.2 comprises the high-pressure side A/D modular converter 2.3 and the electricity/light conversion module 2.5 of electrical connection, and photoelectricity can be electrically connected with high-pressure side A/D modular converter 2.3 and electricity/light conversion module 2.5 respectively by modular converter 2.6;
Described local module 2.8 comprises signal processing circuit and D/A modular converter 2.9, light/electric conversion module 2.10, laser 2.11, power supply 2.12, drive circuit 2.13; Light/electric conversion module 2.10 is electrically connected with D/A modular converter 2.9 with signal processing circuit, drive circuit 2.13 is electrically connected with laser 2.11, and power supply 2.12 provides electric energy for signal processing circuit and D/A modular converter 2.9, light/electric conversion module 2.10, drive circuit 2.13 and laser 2.11;
The high-pressure side A/D modular converter 2.3 of the two ends output voltage signal of accurate noninductive resistance 3.4 in the distant place module 2.2 in the resistance sampling unit 2.1.
A kind of UHV transmission line corona loss measurement mechanism that adopts above-mentioned UHV transmission line with electronic current mutual inductor is characterized in that: it comprises electronic current mutual inductor 1.3, ultra high voltage capacitance type potential transformer 1.4, second divided voltage iron-core coil 1.9 and industrial computer;
Described electronic current mutual inductor 1.3 comprises resistance sampling unit 2.1, distant place module 2.2, optical fiber composite insulator 2.7 and local module 2.8, resistance sampling unit 2.1 distant place modules 2.2 are electrically connected, and distant place module 2.2 is connected with local module 2.8 light by optical fiber composite insulator 2.7; The output of local module 2.8 and the DAQ-2006 data acquisition card connection of industrial computer;
The resistance sampling unit 2.1 and the distant place module 2.2 of electronic current mutual inductor 1.3 are suspended on phase conductor top;
Ultra high voltage capacitance type potential transformer 1.4 is installed in extra-high voltage transformer 1.1 sleeve pipe leading-out terminals, the secondary winding binding post of ultra high voltage capacitance type potential transformer 1.4 intermediate transformers and second divided voltage are electrically connected with iron-core coil 1.9, second divided voltage carries out electricity/light conversion with iron-core coil 1.9 output signals, pass to the local module 2.8 that voltage measurement is used with optical cable, gathered by the DAQ-2006 data collecting card of industrial computer then.
Aforesaid UHV transmission line corona loss measurement mechanism is characterized in that: industrial computer is electrically connected with air velocity transducer 1.5, Temperature Humidity Sensor 1.6 and instantaneous rainfall gauge 1.7 respectively.
Principle of the present invention is: current signal extracts part, adopts electronic current mutual inductor, as current sensor, can guarantee that resistance itself can not destroyed by transient voltage and electric current with powerful accurate noninductive resistance like this.Resistance string is connected in the leads of ultra-high voltage power transmission lines, and because the resistance precision is noninductive, current flowing resistance in the lead, produce and the synchronous voltage signal of current in wire at the resistance two ends, guarantee not distortion of waveform, can reflect current information accurately, change by electric light, use the Optical Fiber Transmission current signal, in the control room,, realize the measurement accurately and reliably of UHV transmission line electric current by opto-electronic conversion reduction current signal; Voltage signal extracts part, adopts 1000kV capacitance type potential transformer (CVT), through second divided voltage, by the electric light conversion, uses the Optical Fiber Transmission voltage signal, by opto-electronic conversion recovery voltage signal, realizes the measurement accurately and reliably of voltage in the control room.Adopt the DAQ-2006 data collecting card to gather the voltage and current signal, develop software, calculate corona loss in real time based on virtual instrument technique.
The present invention has following beneficial effect:
1, when distortion takes place electric current, reflects current information very exactly
Powerful accurate noninductive resistance is as current sensor, can guarantee that like this resistance itself can not destroyed by transient voltage and electric current, accurate noninductive resistance series connection is inserted in the leads of ultra-high voltage power transmission lines, current flowing resistance in the lead, produce voltage signal at the resistance two ends, because the resistance precision is noninductive, the voltage signal of generation and current in wire signal are synchronous, guarantee that the secondary distortion can not take place waveform.Because the earth-free and equipotential of high-pressure side, data message is by Optical Fiber Transmission, and insulation is simple, anti-electromagnetic interference capability is strong, compact conformation, volume is little, in light weight, integrated cost is low.Electronic current mutual inductor satisfies 0.2 grade of requirement of stipulating in the IEC standard, can accurately measure the UHV transmission line electric current.
2, easy to operate, there is not potential safety hazard
Voltage and current signal passes through Optical Fiber Transmission, thereby makes high-pressure side and low-pressure end not have electrical link, does not have the problem of electric insulation, carries out software operation in master-control room on the industrial computer, and is easy to operate, do not have potential safety hazard.
3, can realize long-time on-line measurement
Package unit can round-the-clock running, by 1000kV capacitance type potential transformer and real-time measuring voltage of electronic current mutual inductor and current signal, the data that collect are carried out real-time calculation and analysis, draw the corona loss result, thereby realize long-time on-line measurement.And can preserve the corona loss monitoring result automatically, from now on can be in conjunction with meteorologic parameter at that time, for the further further investigation of UHV transmission line corona loss rule lays the foundation.
Description of drawings
The UHV transmission line corona loss measurement mechanism structural representation of Fig. 1, the embodiment of the invention.
The structural representation of the electronic current mutual inductor 1.3 of Fig. 2, the embodiment of the invention.
The structural representation of resistance sampling unit 2.1 among Fig. 3, Fig. 2.
The structure chart of circuit board 3.3 among Fig. 4, Fig. 3.
Fig. 5, resistance sampling unit 2.1 electrical connection diagrams.
Fig. 6,1000kV capacitance type potential transformer.
Fig. 7, software flow block diagram.
Fig. 8, corona loss monitoring result.
Embodiment
The explanation of mark among Fig. 1: 1.1-extra-high voltage transformer; 1.2-extra high voltage line; 1.3-electronic current mutual inductor; 1.4-condenser type current transformer; 1.5-air velocity transducer; 1.6-Temperature Humidity Sensor; 1.7-instantaneous rainfall gauge; 1.8-industrial computer.
The explanation of mark among Fig. 2: 2.1-resistance sampling unit; 2.2-distant place module; 2.3-high-pressure side A/D modular converter; 2.4-high-pressure side digital signal; 2.5-electricity/light conversion module; 2.6-photoelectricity energy modular converter; 2.7-optical fiber meets insulator; 2.8-local module; 2.9-signal processing circuit and D/A module; 2.10-light/electric conversion; 2.11-laser; 2.12-power supply; 2.13-drive circuit; 2.14-output port.
The explanation of mark: 3.1-conduction copper rod among Fig. 3; 3.2-Copper Foil; 3.3-circuit board; 3.4-accurate noninductive resistance; 3.5-screw; 3.6-epoxy resin board.
The accurate noninductive resistance of the explanation of mark: 3.4-among Fig. 4; 4.1-apply copper; 4.3-Transient Voltage Suppressor; 4.4-piezo-resistance; 4.5-precision resistance seal in end; 4.6-the measuring junction of precision resistance; 4.7-measurement terminal.
The explanation of mark among Fig. 5: 5.1-sub-conductor; 5.2-insulation yoke plate; 5.3-trap; 3.4-accurate noninductive resistance.
The explanation of mark among Fig. 6: 6.1-high-voltage capacitance; 6.2-middle piezoelectricity holds; 6.3-compensation reactor; 6.4-damping device; 6.5-protective device; 6.6-carrier communication terminal; 6.7-intermediate voltage transformer; 6.8-the intermediate voltage terminal of capacitor voltage divider; 6.9-the primary voltage terminal of calutron; 6.10-secondary winding binding post; 6.11-residual voltage winding connection terminal and damper winding terminal; 6.12-the low-voltage terminal of compensation reactor.
The present invention is further detailed explanation below in conjunction with accompanying drawing.
It is applicable to the long term monitoring of the corona loss of 1000kV electric pressure transmission line the present invention, also is applicable to the measurement and the evaluation of 1000kV electric pressure transmission line energy loss.
As shown in Figure 1, the basic structure of the embodiment of the invention is mainly extracted part by current signal, voltage signal extracts part, three parts composition is calculated in corona loss, can expand devices such as being aided with air velocity transducer 1.5, Temperature Humidity Sensor 1.6, instantaneous rainfall gauge 1.7 simultaneously and obtain corresponding meteorologic parameter.
As Fig. 2, Fig. 3, shown in Figure 4; the resistance sampling unit 2.1 design circuit plates 3.3 of applying electronic formula current transformer 1.3; accurate noninductive resistance 3.4 series connection of customization are inserted in the resistance sampling unit 2.1; gold utensil by resistance sampling unit 2.1 shields; install Transient Voltage Suppressor (Transient Voltage Suppressor simultaneously additional; TVS) 4.3 and piezo-resistance 4.4, protection UHV transmission line corona loss measurement mechanism.In conjunction with advantages such as the high-insulativity of fiber optic transmission system, anti-electromagnetic interference, extract current signal at high-pressure side, be modulated into digital electric signal through high-pressure side A/D modular converter 2.3, be converted into digital optical signal by electricity/light conversion module 2.5 again, optical fiber in optical fiber composite insulator 2.7 is sent to low-pressure end and changes digital electric signal into by light/electric conversion module 2.10, revert to and the proportional weak electric signal of electric current to be measured by signal processing circuit and 2.9 demodulation of D/A module then, and obtain current amplitude and phase information.Signal is transferred in the master-control room, by the data collecting card collection that is installed in the industrial control computer.Adopt DAQ-2006 high-precision multi-path high-speed synchronous data acquiring card, its performance parameter is as follows: 4 tunnels analogies input (AI) synchronous acquisition, 16 of sampling resolutions, Gain Adjustable, sample range is ± 1.25V ± 2.5V, ± 5V, ± 10V, high sampling rate 250KS/s
The resistance sampling unit 2.1 of the electronic current mutual inductor 1.3 of limit phase and remote end module 2.2 are by the machanical fastener of processing, be suspended in the mouse cage wire jumper, the resistance sampling unit 2.1 of the electronic current mutual inductor 1.3 of middle phase and remote end module 2.2 are suspended in the grading ring by the machanical fastener of processing.The conduction copper rod 3.1 of resistance sampling unit 2.1 seals in the phase conductor 5.1 by trap 5.3 and (to see accompanying drawing 5).
As shown in Figure 1, use 1000kV capacitance type potential transformer (CVT) and measure the UHV transmission line phase voltage.
Software flow as shown in Figure 7.Measured voltage signal and current signal are transferred in the master-control room by optical cable, by local module 2.8 demodulation of electronic current mutual inductor that are integrated in the industrial control computer cabinet.On industrial control computer,, adopt virtual instrument technique, use DAQ-2006 high-precise synchronization data collecting card, realize accurate, the synchro measure of voltage signal, current signal based on " software is equipment " thought.Use the UHV transmission line corona loss monitoring system of LabVIEW software development, the intrinsic error of the method bucking-out system by software improves the certainty of measurement of UHV transmission line corona loss.Extract the power frequency component of voltage signal, current signal, adopt sinusoidal wave algorithm, judge and phasing by quadrant voltage signal, current signal initial phase, can accurately try to achieve the initial phase of voltage signal, current signal, thereby obtain the power-factor angle of voltage signal and current signal power frequency component, and then calculate the corona loss value.
The course of work of the embodiment of the invention is: accurate noninductive resistance 3.4 series connection insert in the leads of ultra-high voltage power transmission lines, electric current in the lead flows through accurate noninductive resistance 3.4, produce voltage signal at accurate noninductive resistance 3.4 two ends, voltage signal is an analog signal herein, be transferred to high-pressure side A/D modular converter 2.3 by signal conductor, be converted to digital electric signal, pass through electricity/light conversion module 2.5 then, change digital optical signal into.Resistance sampling unit 2.1 and the high-pressure side A/D modular converter 2.3 that is arranged on high-tension side distant place module, electricity/light conversion module 2.5 and photoelectricity energy modular converter 2.6 all are installed in the shielding gold utensil.The digital optical signal of digital current signal, be transferred to the local module 2.8 of the master-control room that is positioned at low-pressure side by signal optical fibre, change digital electric signal into by light/electric conversion module 2.10, be reduced to the analog signal of UHV transmission line electric current then by signal processing circuit and D/A modular converter 2.9, this signal is gathered by the DAQ-2006 data collecting card of industrial computer.
Powerful accurate noninductive resistance 3.4 is as current sensor, can guarantee that like this resistance itself can not destroyed by transient voltage and electric current, accurate noninductive resistance series connection is inserted in the leads of ultra-high voltage power transmission lines, because accurate noninductive resistance 3.4 precisions are noninductive, so the voltage signal and the current in wire signal same-phase that produce, so just guaranteed that the secondary distortion can not take place waveform, thereby can reflect current information accurately.To photoelectricity energy modular converter 2.6, photoelectricity can modular converter 2.6 be electric energy with transform light energy to energy optical fiber then, is high-pressure side A/D modular converter 2.3 and electricity/light conversion module 2.5 energy supplies with electric energy transmitting.
Ultra high voltage capacitance type potential transformer 1.4 is installed in extra-high voltage transformer 1.1 sleeve pipe leading-out terminals, the secondary winding binding post of ultra high voltage capacitance type potential transformer 1.4 intermediate transformers is connected with iron-core coil 1.9 with second divided voltage, voltage signal is through behind the second divided voltage, and the modulation of signal, transmission and demodulation are identical with the principle that current signal extracts part.Through behind the second divided voltage, be transferred to high-pressure side A/D modular converter 2.3 at the high side voltage signal, be converted to digital electric signal, pass through electricity/light conversion module 2.5 then, change digital optical signal into by signal conductor.In the process of carrying out A/D conversion and electricity/light conversion, high-pressure side A/D modular converter 2.3 and electricity/light conversion module 2.5 all needs electric energy, energy optical fiber arrives photoelectricity energy modular converter 2.6 with electric energy transmitting, photoelectricity can modular converter 2.6 be electric energy with transform light energy then, is high-pressure side A/D modular converter 2.3 and electricity/light conversion module 2.5 energy supplies.Second divided voltage iron-core coil 1.9, high-pressure side A/D modular converter 2.3, electricity/light conversion module 2.5, and photoelectricity energy modular converter 2.6 all are positioned at the high-pressure side, are installed in the aluminium alloy transfer box.The digital optical signal of digital voltage signal, be transferred to the local module 2.8 of the master-control room that is positioned at low-pressure side by signal optical fibre, change digital electric signal into by light/electric conversion module 2.10, be reduced to the analog signal of phase voltage then by signal processing circuit and D/A modular converter 2.9, voltage signal collects industrial computer by the DAQ-2006 data collecting card.
The current signal of UHV transmission line and phase voltage signal collect industrial computer by the DAQ-2006 data collecting card that is positioned at the low-pressure side master-control room.The DAQ-2006 data collecting card is installed in the PCI slot of industrial computer, industrial computer, and UPS uninterrupted power supply, and two local modules 2.8 that are used for demodulation current signal and voltage signal are installed in the industry control rack of standard.Industrial computer is equipped with the corona loss monitoring of software based on the virtual instrument technique exploitation, uses sinusoidal wave algorithm, can calculate the corona loss result in real time at voltage signal that collects and current signal, and realizes the result who monitors is preserved automatically.
Practical measuring examples of the present invention is as follows:
Used this system at present, the limit phase of the single time test in Wuhan High Voltage Research Institute Of State Grid extra-high-voltage alternating current proving ground line segment and the corona loss of middle phase study line segment have been carried out the monitoring of a period of time.In master-control room, open the industry control rack, the power-on switch, electronic current mutual inductor and optical fiber transport channel bring into operation, and start industrial computer, operating software, input account name and password land and move the corona loss monitoring system.Voltage signal and current signal pass through distant place module 2.2 opto-electronic conversion in the high-pressure side, change light signal into, be transferred to the master-control room that is positioned at low-pressure side by optical cable, by local module 2.8, demodulation is reduced to the analog signal of voltage signal and current signal, gather through DAQ-2006 synchronous data collection card, system begins monitoring voltage waveform and current waveform.Background program passes through digital filtering, extract the first-harmonic composition of voltage signal and current signal, the sampled point of the first-harmonic of migration current signal carries out digital phase shift to the first-harmonic composition of current signal, thereby reduce the intrinsic error of system as far as possible, improved the certainty of measurement of system.First-harmonic composition at voltage signal and current signal adopts the sine wave parameter method to calculate the corona loss value in real time.The computational methods of sine wave parameter method are as follows:
If corona current i (t)=I
mSin (ω t+ φ
i), phase voltage u (t)=U
mSin (ω t+ φ
i), current i (t) and voltage u (t) is deployable is then
i(t)=D
0sinωt+D
1cosωt (1)
u(t)=C
0sinωt+C
1cosωt (2)
In the formula, D
0=I
mCos φ
i, D
1=I
mSin φ
i, C
0=U
mCos φ u, C
1=U
mCos φ
u
According to orthogonality of trigonometric function, can calculate to derive and calculate D
0, D
1, C
0, C
1Formula:
Can get thus:
φ
i=tan
-1(D
1/D
0),φ
u=tan
-1(C
1/C
0) (7)
Calculating can get
The effective value of transmission line phase voltage and phase conductor electric current is measured in real time by program, then according to the corona loss formula
Just can calculate the result of UHV transmission line corona loss in real time.Automatically preserve the corona loss monitoring result, so that from now on the rule of the corona loss of UHV transmission line is done further further investigation and analyze.
On January 13rd, 2008 to January 15, the proving ground has experienced twice snowfall, corona loss monitoring result at that time as shown in Figure 8.