CN103532819B - A kind of intelligent bridge - Google Patents

Abstract

A kind of intelligent bridge, belong to technical field of telecommunications, its technical scheme is, it includes the isolation of medium voltage side signal and transmission circuit, low-side signal isolation and transmission circuit and signal processing and transmission control circuit, the signal of communication of medium voltage power line delivers to the input of signal processing and transmission control circuit through the isolation of medium voltage side signal and transmission circuit, signal processing be coupled to low-voltage power line through low-side signal isolation with transmission circuit after processing with transmission control circuit；The signal of communication of low-voltage power line delivers to the input of signal processing and transmission control circuit through low-side signal isolation and transmission circuit, signal processing be coupled to medium voltage power line through the isolation of medium voltage side signal with transmission circuit after processing with transmission control circuit.Present invention achieves medium voltage power line channel to be connected with the network of low voltage power line communication channel, solve the remote technical barrier uploaded in real time of a large amount of low pressure adapted electrical information.

Description

A kind of intelligent bridge

Technical field

The present invention relates to the intelligent bridge of pressure/low voltage power line communication channel network interconnection function during a kind of energy realizes, belong to Communication technical field.

Background technology

Deepening continuously and developing along with intelligent grid construction, possesses the intelligent terminal of telecommunication and observing and controlling function in a large number Equipment needs to be arranged on electrical network, to realize electric line key node temperature, insulator dielectric level, switch contact temperature The electrical equipment parameters such as degree, distribution transformer and running status and user power utilization information etc. are monitored, transmit or control, and A large amount of low pressure adapted electrical information are uploaded to transformer station in real time comprehensively analyze and process.

Fiber optic communication no doubt has that capacity is big, real-time good, high reliability, but due to fiber optic communication facility investment High, great in constructing amount, construction period length and very flexible, limit its application in intelligent grid particularly power distribution network.GPRS Although motility is strong, but poor real and its operating cost high (charging by communication flows), therefore which is also difficult to meet intelligence The requirement of energy electrical network.Compared with other communication mode, power line communication can make full use of the existing physical network of electrical network, it is achieved Measurement and control center and the direct information exchange of each distant place detection and control terminal equipment, apply this communication mode to need not exclusively carry out communication work Cheng Jianshe, has the advantages such as investment little, motility is strong, network reliability is high, the construction period is short, the wide network coverage, is to realize Rural power grids, particularly remote mountain areas circuit adapted electrical information gather one of most effective mode with transmission.Along with adapted electrical network is automatic Change, intellectuality is constantly carried out with informatization work, and power line communication technology is widely used.

Distribution transformer is the Unique Device connecting medium voltage power lines with low-voltage power line, at whole adapted electric network In serve transmission power frequency energy important function.But, to high-frequency communication signal, distribution transformer but has the strongest decay Effect, i.e. has the strongest iris action to medium voltage power line communication channel and low-voltage power line communication channel.Therefore, distribution becomes Depressor prevents the network between medium-voltage power line communication and low-voltage power line communication to connect, and limits medium voltage electricity information with low Information sharing between piezoelectric forces.

At present, people once attempted being joined directly together passive middle pressure bonder with passive low-voltage bonder, set up mesolow The network interconnection of power line channel.But due to low voltage power line communication channel and the frequency characteristic of medium voltage power line channel, impedance operator, All there is the biggest difference, particularly low voltage power line communication channel characteristic and there is the most serious frequency selective fading in noise characteristics etc. And stronger time variation feature, the method is the most successful.In a word, it is achieved the network between middle pressure/low voltage power line communication channel is mutual Connection and intercommunication, be to perplex one of wide variety of difficult problem of power line communication for many years, the most also do not have one well Solution.

Summary of the invention

Present invention aims to the drawback of prior art, it is provided that a kind of can realize in pressure/low voltage power line communication channel The intelligent bridge of network interconnection function, is connected with the network of low voltage power line communication channel realizing medium voltage power line channel, solves The remote of a large amount of low pressure adapted electrical information uploads problem in real time.

Problem of the present invention realizes with following technical proposals:

A kind of intelligent bridge, composition includes that the isolation of medium voltage side signal and transmission circuit, low-side signal are isolated and receive Power Generation Road and signal processing and transmission control circuit, the signal of communication of medium voltage power line is through the isolation of medium voltage side signal and transmitting-receiving electricity The input of signal processing and transmission control circuit is delivered on road, signal processing believe through low-pressure side after processing with transmission control circuit Number isolation with transmission circuit be coupled to low-voltage power line；The signal of communication of low-voltage power line is through low-side signal isolation and transmitting-receiving electricity The input of signal processing and transmission control circuit is delivered on road, signal processing believe through medium voltage side after processing with transmission control circuit Number isolation with transmission circuit be coupled to medium voltage power line.

Above-mentioned intelligent bridge, medium pressure side signal isolation with transmission circuit include middle pressure bonder, middle pressure high frequency receive/ Send out Hair Fixer in isolating transformer, Phototube Coupling and send pressure reception amplifier and middle crimping collection of letters road in power amplifier, Phototube Coupling Impedance matching network, medium pressure high frequency transmits/receives isolating transformer and arranges 3 groups of coils, and wherein, transmit-receive sharing coil one terminates Ground, presses bonder to connect medium voltage power line in the warp of one end, and its receiving coil one terminates DC power cathode, and one end is in Phototube Coupling Pressure reception amplifier connects the input of signal processing and transmission control circuit, and in described Phototube Coupling, Hair Fixer send power amplifier Input termination signal processing and the outfan of transmission control circuit, press high frequency to transmit/receive the transmission of isolating transformer in outfan warp Coil connects DC power cathode；Described low-side signal isolation with transmission circuit include low voltage couplers, low-voltage high-frequency transmit/receive every Channel impedance is received from transformator, Phototube Coupling low pressure transmit power amplifier, Phototube Coupling low pressure reception amplifier and low pressure Matching network, described low-voltage high-frequency transmits/receives isolating transformer and arranges 3 groups of coils, wherein, transmit-receive sharing coil one end ground connection, and one End connects low-voltage power line through low voltage couplers, and its receiving coil one terminates DC power cathode, and one end is through the low crimping of Phototube Coupling Receive amplifier and connect the input of signal processing and transmission control circuit, the input of described Phototube Coupling low pressure transmit power amplifier Termination signal processes the outfan with transmission control circuit, and outfan transmits/receives the transmission coil of isolating transformer through low-voltage high-frequency Connect DC power cathode.

Above-mentioned intelligent bridge, described signal processing and transmission control circuit include that digital signal processor, DDS directly count Word frequency synthesizer and analog switch, SPISIMOA, SPISOMIA, SPICLKA, SPISIEA of described digital signal processor With SPISO, SPISI, CLK, EN and R/W end that R/W port connects DDS Direct Digital Frequency Synthesizers respectively, its ADCINAO and ADCINBO port connects respectively presses reception amplifier and the outfan of Phototube Coupling low pressure reception amplifier in Phototube Coupling, numeral PWM1～the PWM6 port of signal processor connects Hair Fixer in Phototube Coupling respectively and send power amplifier and Phototube Coupling low pressure to send Control end, C2, C1 end of analog switch and the middle crimping collection of letters road impedance matching network of power amplifier and low pressure receive letter Road impedance matching network controls end, and the D port of described analog switch connects the SOUT end of DDS Direct Digital Frequency Synthesizers, its S1, S2 end connects Hair Fixer in Phototube Coupling respectively and send power amplifier and the input of Phototube Coupling low pressure transmit power amplifier.

Above-mentioned intelligent bridge, medium pressure bonder includes high-frequency coupling high-voltage capacitor, high frequency secondary coupled high voltage Capacitor, power frequency lead coil, critesistor, varistor and stabilivolt, high-frequency coupling high-voltage capacitor and high frequency secondary coupling Close a termination medium voltage power line after high-voltage capacitor is connected in series, a termination is pressed high frequency transmit/receive the transmitting-receiving of isolating transformer altogether Use coil；Power frequency lead coil, critesistor, varistor and stabilivolt are connected in parallel rear one end ground connection, a termination height Frequently the concatenating a little of coupled high voltage capacitor and high frequency secondary coupled high voltage capacitor.

Above-mentioned intelligent bridge, described low voltage couplers includes high pressure resonant capacitance, series resonance inductor and transfiguration two pole Pipe, after they are connected in series, one terminates low-voltage power line, and a termination low-voltage high-frequency transmits/receives the transmit-receive sharing line of isolating transformer Circle.

Above-mentioned intelligent bridge, medium pressure receives channel impedance matching network and low pressure receives channel impedance matching network Circuit identical, all include compound key decoder, low pass filter, digital potentiometer, varactor, reactance transformer, institute The D/U end stating compound key decoder receives the serial composite coding that PWM5 or the PWM6 end of digital signal processor exports, its B1 ～B4 termination digital potentiometer control end, the low-pass filtered device of Carry out end connect in Phototube Coupling press reception amplifier or The input of Phototube Coupling low pressure reception amplifier；One termination of described digital potentiometer press high frequency to transmit/receive isolating transformer Or low-voltage high-frequency transmits/receives the receiving coil of isolating transformer, another termination Phototube Coupling presses reception amplifier or Phototube Coupling The input of low pressure reception amplifier via varactor and reactance transformer the line build-out reactor ground connection being connected into.

Above-mentioned intelligent bridge, during in described Phototube Coupling, Hair Fixer send power amplifier, Phototube Coupling press reception amplifier, Phototube Coupling low pressure transmit power amplifier is identical with the circuit of Phototube Coupling low pressure reception amplifier, all includes linear light thermocouple Closing preamplifier and tri-state integrated power amplifier, the output termination tri-state of described linear photoconductor coupling preamplifier is integrated The input of power amplifier.

The present invention constitutes and is erected at medium voltage power line channel together to the " signal bridge between low voltage power line communication channel Beam ", it utilizes impedance match technique, channel Power estimation and balancing technique, digital frequency conversion technology, and take high frequency transceiver insulation, The effective measures such as linear photoconductor coupling amplification and Surge suppression, not only overcome mesolow power line channel characteristic inconsistent and The communication performance deterioration problem caused, but also it is effectively increased the safety and reliability of bridger.This intelligent bridge is real Show medium voltage power line channel to be connected with the network of low voltage power line communication channel, solve the remote of a large amount of low pressure adapted electrical information The technical barrier uploaded in real time.

Accompanying drawing explanation

The invention will be further described below in conjunction with the accompanying drawings.

Fig. 1 is the structural representation of intelligent bridge；

Fig. 2 is the electrical schematic diagram of intelligent bridge；

Fig. 3 be in the electrical schematic diagram of (or low) crimping collection of letters road impedance matching network；

Fig. 4 is the electrical schematic diagram of each power amplifier；

Fig. 5 is the block diagram of channel Power estimation and equalization algorithm；

Fig. 6 is that 10kV/220V adapted electric network information transmits the block diagram of system.

Figure is respectively numbered: U1, digital signal processor；U2, DDS Direct Digital Frequency Synthesizers；U3, analog switch； CTRL, signal processing and transmission control circuit；OT1, middle pressure bonder；OT2, low voltage couplers；TR1, middle pressure high frequency transmit/receive every From transformator；TR2, low-voltage high-frequency transmit/receive isolating transformer；In OP1, Phototube Coupling, Hair Fixer send power amplifier；OP2, photoelectricity Isolation is pressed reception amplifier；OP3, Phototube Coupling low pressure transmit power amplifier；OP4, Phototube Coupling low pressure reception amplifier； M1, middle crimping collection of letters road impedance matching network；M2, low pressure receive channel impedance matching network；C1, high-frequency coupling high-voltage capacitance Device；C2, high frequency secondary coupled high voltage capacitor；C3, high pressure resonant capacitance；L1, power frequency lead coil；L2, series resonance inductor； Rt, critesistor；RV, varistor；D1, stabilivolt；D2, varactor；L-B-2, low pressure coupling electrode；M-B-1, middle pressure Coupling electrode；DCODER, compound key decoder；LPF, low pass filter；VCR, digital potentiometer；VC, varactor； LC, reactance transformer；O1, linear photoconductor coupling preamplifier；O2, tri-state integrated power amplifier.

Detailed description of the invention

(1) technical characterstic of the present invention

The intelligent bridge of the present invention is connected with the network of low voltage power line communication channel for realizing medium voltage power line channel, from And solve the remote of a large amount of low pressure adapted electrical information and upload problem in real time.This intelligent bridge has a characteristic that

First, it is provided with and includes power frequency isolation, Surge suppression, high frequency transceiver insulation transformator, linear photoconductor coupling isolation The multiple isolation such as amplifier and protective measure, effectively prevent high pressure power frequency component and strong glitch signal passes through bridger, Improve the safety and reliability of this intelligent bridge.

Its two, be provided with and include that mesolow receives channel impedance matching network, medium/low pressure channel Power estimation and channel equalization Deng measure, effectively overcome and cause due to the factor such as mesolow power line channel frequency characteristic, impedance operator be inconsistent Problem of signal attenuation, is effectively increased the effectiveness of this intelligent bridge.

Its three, be provided with and include the measure such as downlink transfer self-adapting frequency conversion, uplink self-adapting frequency conversion, it is possible to achieve in The automatic carrier frequency of low voltage power line communication channel selects function, is effectively increased the antagonism frequency-selective decline of this intelligent bridge Performance.

(2) composition of the present invention and the principle of each unit part

Intelligent bridge proposed by the invention is achieved through the following technical solutions.It is illustrated in figure 1 the present invention The structural representation of the intelligent bridge proposed.It is illustrated in figure 2 the electrical schematic diagram of intelligent bridge proposed by the invention. Intelligent bridge involved in the present invention specifically includes that middle pressure bonder OT1, middle pressure high frequency transmit/receive isolating transformer TR1, light Reception amplifier is pressed during Hair Fixer send power amplifier OP1, middle crimping collection of letters road impedance matching network M1, Phototube Coupling in electric isolution OP2, low voltage couplers OT2, low-voltage high-frequency transmit/receive isolating transformer TR2, Phototube Coupling low pressure transmit power amplifier OP3, low Crimping collection of letters road impedance matching network M2, Phototube Coupling low pressure reception amplifier OP4, digital signal processor TMS320F2812, DDS Direct Digital Frequency Synthesizers AD9854 and mesolow signal send the composition such as the element circuit that selects analog switch SW1.

Said units and circuit are first passed through High-Voltage Insulation silicone rubber and carries out disposal vacuum encapsulation, the most again by not Rust steel packed by metal casing together, externally draws three electrodes, respectively M-B-1: middle pressure coupling electrode, L-B-2: low pressure coupling Composite electrode, and GND: phase-ground coupling earth lead.Additionally, the common ground shell that stainless steel metal shell is middle pressure and low pressure, It is connected with distribution transformer ground wire, to improve signal shielding effect.

The present invention relates to can realize in intelligent bridge each of pressure/low voltage power line communication channel network interconnection function Part composition and principle are as follows.

1. in, pressure bonder is the essential elements of this intelligent bridge, and it is by high-frequency coupling high-voltage capacitor C1, high frequency two Secondary coupling high-voltage capacitor C2 and the Surge suppression being made up of critesistor, varistor, power frequency lead coil, stabilivolt etc. Leadage circuits etc. form.The reliability of invention intelligent bridge in order to improve, whole middle pressure bonder is encapsulated by vacuum insulation Inside the insulator cavities being made up of electrically insulating silicone rubber.The top of high-frequency coupling high-voltage capacitor C1 by high voltage insulated cable with The high-voltage connection terminal of distribution transformer is connected, and its lower end is connected with Surge suppression leadage circuit part, and leads to as high frequency The input of letter signal and lead-out terminal, receive high frequency and transmit/receive the signal end of isolating transformer TR1.Surge suppression leadage circuit by Stabilivolt, varistor, critesistor, inductance coil etc. form.The other end of Surge suppression leadage circuit is ground terminal, logical It is often that the shell with distribution transformer is connected.Whole middle pressure coupled circuit portions typically uses phase-ground coupling mode and 10kV The middle phase of medium-voltage line and ground wire are connected, and use which to reduce and want the pressure of high-frequency coupling high-voltage capacitor C1 Ask, and then improve the safety and reliability of intelligent bridge.

2. pressing high-frequency isolation coupling transformer TR1 to have three ports in, three ports have the strongest electric each other Isolation effect.Its port I is connected with middle pressure bonder OT1, and it is a bi-directional signal interface.Both medium voltage power line can have been received The signal of communication that channel gets off；Signal of communication can be sent again on 10kV medium voltage power line channel.Its port II and photoelectricity every Send power amplifier OP1 to be connected from middle Hair Fixer, the signal of communication preparing to send on 10kV medium voltage power line channel is passed through High-frequency isolation coupling transformer TR1, is loaded on 10kV medium voltage power line channel.Its port III with in crimp receipts channel impedance Distribution network M1 is connected, and the signal of communication received is delivered to middle crimping receive channel impedance on 10kV medium voltage power line channel On matching network M1.Using signal cancellation technology, port II and the port III of high-frequency isolation coupling transformer TR1 also meet signal The feature of isolation, ensure that transmitting-receiving signal of communication does not interfere with each other.

3. in Phototube Coupling, Hair Fixer send power amplifier OP1, by tri-state integrated power amplifier OPA528, linear photoconductor Bonder collectively constitutes.Its input and mesolow signal send select analog switch SW1 to being connected, its output and high frequency receive/ The port II sending out isolating transformer TR1 is connected, and completes to amplify the purpose of signal of communication transmit power.In order to reduce photoelectricity further In isolation, Hair Fixer send the quiescent dissipation of power amplifier OP1, when not sending signal, passes through digital signal processor The PWM1 signal output of TMS320F2812 controls tri-state power amplifier OPA528, is allowed to be in high-impedance state.The most also may be used Transmit/receive the impedance of isolating transformer port III side with increase high frequency, make it easier to reception upper and lower from 10kV medium voltage power line channel The signal of communication come.

4. affected by factors such as loads due to the line impedance of 10kV medium voltage power line channel, its channel impedance characteristic Present certain time variation and randomness, have impact on received signal power and signal to noise ratio.In order to overcome the time-varying of channel impedance Property and randomness, circuit is provided with middle crimping collection of letters road impedance matching network M1 and low pressure and receives channel impedance matching network M2, the two structure is identical, all includes compound key decoder DCODER, low pass filter LPF, digital potentiometer VCR and by becoming Hold the line build-out reactor of the composition such as diode VC, reactance transformer LC.Compound key decoder DCODER receives digital signal The serial composite coding of the PWM5 output of processor, is demodulated two paths of signals.One is used for controlling digital potentiometer VCR's Resistance value, its two through low pass filter LPF filter after be used for control circuit compensation reactor with change receive loop reactance Value.When the resistance value of impedance matching network and the reactance value of compensation reactor realize conjugate impedance match with the equiva lent impedance of channel, I.e. can obtain maximal received power.

5., in order to improve reliability and the electrical isolation effect of intelligent bridge further, Phototube Coupling crimps Receive amplifier OP2 and achieve the further electrical isolation of the centering crimping collection of letters number.Avoid wearing of high voltage surge interference signal More.

6. low-voltage high-frequency transmits/receives isolating transformer TR2 to transmit/receive isolating transformer TR1 function with middle pressure high frequency similar.Light Electric isolution low pressure transmit power amplifier OP3 send power amplifier OP1 function similar with Hair Fixer in Phototube Coupling.Low pressure receives letter Road impedance matching network M2 is similar with middle crimping collection of letters road impedance matching network M1 function.Phototube Coupling low pressure reception amplifier OP4 is similar with pressure reception amplifier OP2 function in Phototube Coupling.Here repeat no more.

Its principle is analyzed as a example by Hair Fixer send power amplifier in Phototube Coupling below.Its composition includes that linear photoconductor couples Preamplifier O1 and tri-state integrated power amplifier O2.Linear photoconductor coupling preamplifier O1 realizes the electricity sending signal Pressing big, tri-state integrated power amplifier O2 realizes the amplification sending signal power.When needs send signal, digital signal It is effective that the PWM1 of processor controls to send enable signal, is transmitted.When need not send signal, digital signal processor PWM1 controls to send enable invalidating signal, makes power amplification circuit be in high-impedance state, in order to not affect the reception impedance of circuit.

7. much lower due to the impedance of the impedance ratio medium-voltage line of 220V low-voltage circuit, in order to improve low-voltage signal coupling Closing efficiency, low voltage couplers OT2 is made up of series resonance inductor, varactor D2 and high pressure resonant capacitance C3 etc., to logical Letter signal composition series resonance, improves coupled power and the efficiency of low voltage communication signal.

8. the digital signal processor TMS320F2812 in this intelligent bridge is the core of whole system, and it is except complete In Phototube Coupling, Hair Fixer send power amplifier OP1, middle crimping collection of letters road impedance matching network M1, Phototube Coupling low pressure to send in pairs Power amplifier OP3, low pressure receive channel impedance matching network M2, DDS Direct Digital Frequency Synthesizers AD9854 and in low Pressure signal sends outside the control selecting the element circuits such as analog switch SW1, and it achieves mesolow channel also by software Estimate in real time and equalization function, effectively overcome the frequency selective fading of mesolow channel, be effectively increased this bridger Receptivity.This technology is one of key core technology of this intelligent bridge.In order to improve digital signal processor The interference free performance of TMS320F2812, PW1～the PWM6 control signal of its output is all by photoelectrical coupler and by control circuit Realize electrical isolation.

9. owing to no matter being medium voltage power line channel, or low voltage power line communication channel, all there is certain time variation and relatively For serious frequency selective fading point, and the frequency selective fading frequency of mesolow channel differs often.For Avoiding using deep fading's frequency to communicate, this intelligent bridge is also additionally arranged downstream transmission self-adapting frequency conversion function. This partial function is jointly to be completed with digital signal processor TMS320F2812 by DDS Direct Digital Frequency Synthesizers AD9854 's.The principle of this part is: first realized the estimation to the mesolow characteristic of channel by digital signal processor TMS320F2812, Then software realizes self-adapting frequency conversion, finally by the signal after the output frequency conversion of DDS Direct Digital Frequency Synthesizers AD9854.So that Avoid using deep frequency decline point carrier frequency transmission signal of communication, improve the reliability of communication.TMS320F2812 with The communication of AD9854 have employed SPI synchronous data transmission mode, and transfer rate between the two can reach 300Mbps.

10. mesolow signal sends and selects analog switch SW1 is analogue signal distribution switch, by digital signal processor PWM3 and the PWM4 signal of TMS320F2812 controls.When control signal PWM3=1 and PWM4=0, switch S1 end output signal, Being now in medium-voltage power line communication sending mode, the signal that DDS chip AD9854 exports is delivered to middle pressure transmit power and is put by it Big device OP1 carries out power amplification, in order to be sent on medium-voltage line.When control signal PWM4=1 and PWM3=0, switch S2 end Output signal, is now in low-voltage power line communication sending mode, and the signal that DDS chip AD9854 exports is delivered to low Hair Fixer by it Power amplifier OP3 is sent to carry out power amplification, in order to be sent on low-voltage circuit.

11. use half-duplex application model, therefore this intelligent bridge due to electric line communication system majority at present In mesolow channel spectrum estimate that in real time with the function etc. such as Jun Heng and self-adapting frequency conversion be all by same set of Digital Signal Processing Device TMS320F2812, DDS Direct Digital Frequency Synthesizers AD9854 and mesolow signal send and select analog switch SW1 altogether With complete, the selection of channel and the downstream transmission of signal are then realized control by software.

(3) this intelligent bridge core technology algorithm principle is analyzed

In sum, composition and the operation principle thereof of each component units circuit are analyzed.Below by this intelligence of selective analysis The channel Power estimation of energy bridger and Channel Equalization Algorithm.Owing to mesolow channel Power estimation method and equalization algorithm principle are classes As, as a example by middle pressure channel Power estimation and channel equalization, carry out the principle of parser below.It is channel Power estimation as shown in Figure 5 And the block diagram of equalization algorithm.

If reception signalIt is the output signal pressing reception amplifier OP2 in Phototube Coupling, this signal is delivered to The analog-digital converter ADCINA0 passage of digital signal processor TMS320F2812, through its inner high speed A/D converter, by mould Intend signalBe converted to discrete data.IfIt it is the middle pressure that receives of receiving terminal The of power line channelGroup data block；It is the discrete impulse response of electric lines of force reception channel,It is the discrete noise of channel, ifCorresponding transmission data block is, then

(1)

In order to make designed channel Power estimation and Channel Equalization Algorithm have versatility, it is allowed to be applicable to various ways Multicarrier application channel.For ofdm system, in order to eliminate intersymbol interference when receiving, generally when sending data, increase Cyclic Prefix, increase Cyclic Prefix another one effect also reside in linear convolution " * " is converted into cyclic convolution "”.For General multiple carrier channel, generally by interpolation zero padding measure linear convolution " * " can also be converted into cyclic convolution "”。 So that fast Fourier transform.

(2)

RightSeek discrete Fourier transform DFT, then

Here,,,。

1. fast signal analysis of spectrum

In order to quickly realize channel equalization, the real-time of Fourier transformation is most important, and this intelligent bridge have employed zero Postpone SIFT(Sample Integrated Fourier Transform) algorithm.The core of this algorithm is to pass through iterative manner By concentration, the calculating of Fourier transformation is carried out be converted into distribution carry out, make that each sampled point can be independent to fourier coefficient Produce contribution, and each sampled point is that instant carrying out processes, it is thus possible to continuous print computing.Fourier coefficient is along with adopting The arrival of sampling point and real-time update, sampled point is i.e. no longer necessary to after having been processed, and therefore need not store again, thus can To reduce the use of memory space.Formula (4) and formula (5) are i.e. iterative formulas.

(4)

(5)

By formula (4) and formula (5) it will be seen that all coefficientsWithPart I component, be all by the first point Sampled dataThe contribution produced；Equally, all coefficientsWithPart II component, be all second point sampled dataThe contribution produced；The like.

Obviously, as long as acquiring the first point data, it is possible to start to calculate all coefficientsWithPart 1 component. If able to before the 2nd sampled data arrives, calculated and stored the results of intermediate calculations of all coefficients, then, when the 2nd When point data arrives, it is possible to calculate Part II component, and the packing coefficient that real-time update is original.As procedure described above, one During until N-1 point data arrives, all of coefficientWithJust all calculate, it is possible to all real parts of Sequential output CoefficientWith imaginary part coefficient.The outstanding advantages of above-mentioned algorithm, is available with pipelining algorithm and uses less hardware money Source i.e. can realize DFT computing, is therefore particularly suited for realizing with hardware.

2. Fast Channel Power estimation, channel equalization and self-adapting frequency conversion

For output, owing to input information and channel information are all unknown, therefore, want from the information received, Correctly estimate transmission information, need exist for relying on the correct estimation of channel condition information and the efficient balance to channel. Part in Fig. 2 dotted line frame feeds back judgement channel equalizer exactly.In view of the feature of power line channel, equalizer have employed judgement Feedback equalizer.The output of equalizerIt is i.e. according to Channel Received Signal, the frequency spectrum sending signal estimated, then Obtain through ISIFT conversion, by the output signal of D/A converterI.e. can be by middle pressure or the reception of low pressure channel Device is demodulated.

Although power line channel has time variation, but owing to the time-varying speed of channel is well below signal two adjacent-symbol Between transfer rate, therefore two adjacent symbol times interval in, channel may be considered smoothly.Objective deposit based on this , the thought of decision feedback equalization algorithm is: use the calculated channel estimation value of previous moment Channel Received Signal to go all The weighing apparatus next one receives signal, forms a closed loop feedback judgement and equalizing system.Owing to the method need not additionally increase pilot tone Signal, and continuous channel estimation and equilibrium can be carried out, substantially increase the real-time of algorithm.The flow process of algorithm is as follows:

(1) channel estimation and equalization initializes

First the training sequence of two symbols is sent i.e., due to the frequency spectrum of training sequenceIt is Know, utilize the output sequence that receiving terminal receivesInformation i.e. can get the initial estimate of channel。

Channel estimation and equalization is initialized and needs to be described as follows 2 points.One, due to the existence of interchannel noise, to letter Road estimated value has certain impact.In order to accurately obtain channel estimation value, channel is estimated Tong Bu to carry out with noise suppressed. Its two, in this intelligent bridge, the design of training sequence fully combine electric power data transmission communication protocol, utilize electric power The master-slave response mechanism used during data transmission, is initiated channel by main frame and estimates and equilibrium.Now, it is only necessary to main frame will train sequence Row loaded in parallel sends on each subcarrier.

(2) decision-feedback updates channel estimation value

After completing channel estimation and equalization initialization, it is possible to use feedback judgement channel estimation methods to update channel Estimated value.This intelligent bridge takes full advantage of the feedback signal adjudicated to follow the tracks of the power line channel of slow time-varying, afterwards profit Reception signal is adjudicated by the characteristic of channel estimated, owing to this process completes in frequency domain, therefore this process really frequency Territory equilibrium and frequency domain decision.The advantage of the method is the raw information that need not demodulate transmission information, has highly versatile Advantage.

OrderRepresent by using theThe channel estimation value that block signal obtains.ByCompensate the received Individual symbol, estimate transmission signalEstimated value, whereinIt is by receivedIndividual symbol Number estimation obtains.It is to say,

(6)

This intelligent bridge, by taking specific frequency domain soft technology for adjudication, suppressesIn excessive or too small strange Different frequency component, exports last transmission information estimated value.Then, the estimated value of channel is:

(7)

Owing to said process constitutes a closed loop system, therefore this intelligent bridge is collection closed loop feedback, a frequency domain The channel estimation and equalization device of soft-decision.It should be stressed owing to power line channel is frequently encountered fast-fading, as Fruit takes no action to, and the performance estimated in real time and equalize certainly will be caused to produce severe exacerbation.This intelligent bridge have employed The adaptive channel estimation weighting of effect and averaging, by adding the channel estimation value of adjacent sub-carrier or continuous multiple signal Weight average, sufficiently lower the variance distribution that Real-time Channel is estimated, effectively alleviates the decline of channel Power estimation and equalization performance.

The data of output after channel Power estimation and equilibrium, it is necessary first to carry out the middle pressure spectrum Adaptive spectra to low pressure spectrum Map.The thought that Adaptive spectra maps is to carry data volume criterion based on channel maximum, fully rejects deep fading's Frequency point.Warp Cross the data after spectrum maps and be converted into time domain transmission data by Fast Fourier Transform Inverse ISIFF algorithm again.Finally pass through again The SPI synchrodata mouth synchronous transfer of digital signal processor TMS320F2812 is to DDS Direct Digital Frequency Synthesizers AD9854, is converted to analogue signal by AD9854.S2 mouth through SW1 analog switch exports to Phototube Coupling low pressure transmit power Amplifier OP3, delivers on 220V low voltage power line communication channel after power amplification.

Low pressure channel Power estimation and Channel Equalization Algorithm are similar, only with middle pressure channel Power estimation and Channel Equalization Algorithm The signal analyzed is from low pressure channel, and the signal demand after equilibrium is sent to middle pressure channel up.Here repeat no more.

(4) overall workflow of this intelligent bridge

1. downstream transmission signals flow process

So-called downlink transfer refers to what signal of communication " by medium voltage power line channel to low voltage power line communication channel " carried out bridging Process.First press bonder OT1 to deliver to middle pressure high frequency during signal passes through and transmit/receive isolating transformer TR1, in passing through, crimp collection of letters road After impedance matching network M1, it is then sent through in Phototube Coupling the amplification pressing reception amplifier OP2 to realize signal；After OP2 amplifies Signal is input to digital signal processor through the analog-digital converter passage ADCINA0 of digital signal processor TMS320F2812 Inside, is realized channel Power estimation and equilibrium by software, and the data after equilibrium are defeated through DDS Direct Digital Frequency Synthesizers AD9854 Go out analogue signal, be then sent through analog switch SW1；Digital signal processor sends select command PWM4=1, PWM3=0, signal warp The S2 mouth output of SW1.After Phototube Coupling low pressure transmit power amplifier OP3 amplifies, deliver to low-voltage high-frequency transmit/receive isolation change Depressor TR2；Be coupled on 220V low-voltage circuit through low voltage couplers OT2, it is achieved that by 10kV medium voltage power line channel to The bridge joint of 220V low voltage power line communication channel.

2. upstream signals flow process

So-called uplink refers to what signal of communication " by low voltage power line communication channel to medium voltage power line channel " carried out bridging Process.First signal is delivered to low-voltage high-frequency through low voltage couplers OT2 and is transmitted/received isolating transformer TR2, receives channel through low pressure After impedance matching network M2, it is then sent through in Phototube Coupling the amplification pressing reception amplifier OP4 to realize signal；After OP4 amplifies Signal is input to digital signal processor through the analog-digital converter passage ADCINB0 of digital signal processor TMS320F2812 Inside, is realized channel Power estimation and equilibrium by software, and the data after equilibrium are defeated through DDS Direct Digital Frequency Synthesizers AD9854 Go out analogue signal, deliver to analog switch SW1；Digital signal processor sends select command PWM3=1, PWM4=0, and signal is through SW1 S1 mouth output.Send power amplifier OP1 to deliver to middle pressure high frequency after amplifying through Hair Fixer in Phototube Coupling and transmit/receive isolating transformer TR1；Bonder OT1 is pressed to be coupled on 10kV medium-voltage line in Jing Guo, it is achieved that by 220V low voltage power line communication channel in 10kV The bridge joint of piezoelectricity line of force channel.

Four, application practice and detailed description of the invention

It is that the 10kV/220V adapted electric network information applying intelligent bridge composition proposed by the invention passes as shown in Figure 6 Communication system composition frame chart.Pressure and 220V it is arranged in the 10kV of distribution transformer by the intelligent bridge that the present invention relates to Low-pressure side, achieves the network interconnection by medium voltage power line channel and low voltage power line communication channel.Within the system, middle pressure PLC master station Low voltage terminal equipment that equipment is responsible on low-voltage circuit circuit send order and collect that each low voltage terminal equipment collects each Class power information etc..Owing to which need not set up specially communication channel, have investment little, the construction period is short, motility is strong Etc. advantage, it is that vast rural power grids adapted electric line realizes one of intelligentized preferred communication means.

Claims (5)

1. an intelligent bridge, is characterized in that, it include medium voltage side signal isolation with transmission circuit, low-side signal isolation with Transmission circuit and signal processing and transmission control circuit (CTRL), the signal of communication of medium voltage power line is isolated through medium voltage side signal With the input that transmission circuit delivers to signal processing and transmission control circuit (CTRL), by signal processing and transmission control circuit (CTRL) it is coupled to low-voltage power line through low-side signal isolation with transmission circuit after processing；The signal of communication warp of low-voltage power line Low-side signal isolation delivers to the input of signal processing and transmission control circuit (CTRL) with transmission circuit, by signal processing and Transmission control circuit (CTRL) is coupled to medium voltage power line through the isolation of medium voltage side signal with transmission circuit after processing；

With transmission circuit, the signal isolation of medium pressure side includes that middle pressure bonder (OT1), middle pressure high frequency transmit/receive isolating transformer (TR1) reception amplifier (OP2) and middle crimping is pressed to collect mail during, Hair Fixer send power amplifier (OP1), Phototube Coupling in Phototube Coupling Road impedance matching network (M1), medium pressure high frequency transmits/receives isolating transformer (TR1) and arranges 3 groups of coils, wherein, transmit-receive sharing Coil one end ground connection, presses bonder (OT1) to connect medium voltage power line in the warp of one end, and its receiving coil one terminates DC power cathode, One end presses reception amplifier (OP2) to connect the input of signal processing and transmission control circuit (CTRL) in Phototube Coupling, described In Phototube Coupling, Hair Fixer send the input termination signal processing of power amplifier (OP1) and the output of transmission control circuit (CTRL) End, the transmission coil pressing high frequency to transmit/receive isolating transformer (TR1) in outfan warp connects DC power cathode；Described low-pressure side is believed Number isolation with transmission circuit include that low voltage couplers (OT2), low-voltage high-frequency transmit/receive isolating transformer (TR2), Phototube Coupling low pressure Transmit power amplifier (OP3), Phototube Coupling low pressure reception amplifier (OP4) and low pressure receive channel impedance matching network (M2), described low-voltage high-frequency transmits/receives isolating transformer (TR2) and arranges 3 groups of coils, wherein, transmit-receive sharing coil one end ground connection, and one End connects low-voltage power line through low voltage couplers (OT2), and its receiving coil one terminates DC power cathode, and one end is low through Phototube Coupling Pressure reception amplifier (OP4) connects the input of signal processing and transmission control circuit (CTRL), and described Phototube Coupling low pressure sends The input termination signal processing of power amplifier (OP3) and the outfan of transmission control circuit (CTRL), outfan is high through low pressure Frequency transmits/receives the transmission coil of isolating transformer (TR2) and connects DC power cathode；

Described signal processing and transmission control circuit (CTRL) include that digital signal processor (U1), DDS Direct Digital frequency are closed Grow up to be a useful person (U2) and analog switch (U3)；The SPISIMOA of described digital signal processor (U1), SPISOMIA, SPICLKA, SPISIEA and R/W port connects SPISO, SPISI, CLK, EN and R/W end of DDS Direct Digital Frequency Synthesizers (U2) respectively, its ADCINAO and ADCINBO port connects respectively presses reception amplifier (OP2) and Phototube Coupling low pressure reception amplifier in Phototube Coupling (OP4) outfan, PWM1～the PWM6 port of digital signal processor (U1) connects respectively presses transmit power to put in Phototube Coupling Big device (OP1) and the control end of Phototube Coupling low pressure transmit power amplifier (OP3), C2, C1 end of analog switch (U3) and Middle crimping collection of letters road impedance matching network (M1) and low pressure receive channel impedance matching network (M2) and control end, described analog switch (U3) D port connects the SOUT end of DDS Direct Digital Frequency Synthesizers (U2), and its S1, S2 end connects Hair Fixer in Phototube Coupling respectively Send power amplifier (OP1) and the input of Phototube Coupling low pressure transmit power amplifier (OP3).

A kind of intelligent bridge the most according to claim 1, is characterized in that, medium pressure bonder (OT1) includes high frequency Coupled high voltage capacitor (C1), high frequency secondary coupled high voltage capacitor (C2), power frequency lead coil (L1), critesistor (Rt), Varistor (RV) and stabilivolt (D1), high-frequency coupling high-voltage capacitor (C1) is gone here and there with high frequency secondary coupled high voltage capacitor (C2) After connection connects, one terminates medium voltage power line, presses high frequency to transmit/receive the transmit-receive sharing coil of isolating transformer (TR1) in a termination；Work Frequently lead coil (L1), critesistor (Rt), varistor (RV) and stabilivolt (D1) four are connected in parallel rear one end ground connection, and one Termination high-frequency coupling high-voltage capacitor (C1) concatenates a little with high frequency secondary coupled high voltage capacitor (C2's).

A kind of intelligent bridge the most according to claim 2, is characterized in that, described low voltage couplers (OT2) includes high pressure Resonant capacitance (C3), series resonance inductor (L2) and varactor (D2), high pressure resonant capacitance (C3), series resonance inductor (L2) being connected in series rear one terminate low-voltage power line with varactor (D2), a termination low-voltage high-frequency transmits/receives isolating transformer (TR2) transmit-receive sharing coil.

A kind of intelligent bridge the most according to claim 3, is characterized in that, medium pressure receives channel impedance matching network (M1) circuit receiving channel impedance matching network (M2) with low pressure is identical, all includes compound key decoder (DCODER), low pass Wave filter (LPF), digital potentiometer (VCR), varactor (VC), reactance transformer (LC), described compound key decoder (DCODER) D/U end receives the serial composite coding of PWM5 or the PWM6 end output of digital signal processor (U1), its B1～ The control end of B4 termination digital potentiometer (VCR), the low-pass filtered device of Carry out end (LPF) connects crimping in Phototube Coupling and receives Amplifier (OP2) or the input of Phototube Coupling low pressure reception amplifier (OP4)；One termination of described digital potentiometer (VCR) Middle pressure high frequency transmits/receives isolating transformer (TR1) or low-voltage high-frequency transmits/receives the receiving coil of isolating transformer (TR2), another termination Phototube Coupling is pressed reception amplifier (OP2) or the input of Phototube Coupling low pressure reception amplifier (OP4) and via transfiguration two (VC) and reactance transformer (LC) the line build-out reactor ground connection being connected into are managed in pole.

A kind of intelligent bridge the most according to claim 4, is characterized in that, in described Phototube Coupling, Hair Fixer send power amplification Device (OP1), Phototube Coupling are pressed reception amplifier (OP2), Phototube Coupling low pressure transmit power amplifier (OP3) and Phototube Coupling The circuit of low pressure reception amplifier (OP4) is identical, all includes linear photoconductor coupling preamplifier (O1) and tri-state integrated power Amplifier (O2), the output of described linear photoconductor coupling preamplifier (O1) terminates the defeated of tri-state integrated power amplifier (O2) Enter end.