CN1242117A - A termination circuit - Google Patents

Abstract

A termination circuit for N power distribution lines has resistances r<ij> connected between points P<i> on N-l of the lines and between the points P<i> and a ground which is connected to the remaining one of the lines. A circuit for transferring communication signals on a power distribution system for distributing power signals, the communication has a high frequency relative to a frequency of the power signals. The circuit includes a convertor which has windings for lines of power distribution system, and has no residual fluxes for power signals but has residual fluxes for the communication signals.

Description

Terminating circuit

The present invention relates to a kind of terminating circuit that is used for distribution wire, and a kind of method that is used for the component value of definite circuit.The invention still further relates to a kind of isolation or regulating circuit.

Distribution system provides a kind of existing fabric, and it can be advantageously used in the transmission signal of communication.With utilize distribution system to set up a relevant difficulty of communication system to provide a kind of effective terminating circuit that is used for the distribution system circuit.Another difficulty also is to provide enough isolation between the electric power signal of conventional allocation on the line and the signal of communication.May be not only in the user house but also the tie point place on system line require to isolate.

The layout of multi-thread distribution system is according to local factor, for example adjusting, developing stage and physical characteristic and marked change.In Australia, distribution wire is used for to user's dispensing high pressure low frequency power signal, this electric power signal typically has 50 hertz frequency, and on each bar of the N of system line, may be 415 volts of relative phases (LV), the distribution voltage of 6.5 kilovolts, 11 kilovolts, 22 kilovolts or 66 kilovolts of relative phases (HV).Line is counted N usually in 2 to 5 scope, but in LV and two kinds of systems of HV when contiguous together, may more can be high.Typically for 415 volts of AC electric power systems of three-phase, N=4, a line is represented neutrality.The electric wire of circuit is maked somebody a mere figurehead installing in their nakeds, and by under the air separation situation, can be for opening wide.Electric wire also can bunchy, for example in built on stilts wire harness or underground cable, in this case, their insulated separation and covering.

When circuit reaches the end points that they no longer need to continue, for example at the end in street, their not electricity stop.Also have other open circuit point, wherein comprise the physics point of tension in the line, or the power that transmits from relative direction runs into open circuit point.On the other hand, step-down transformer performance impedance discontinuity, it may be to the low frequency signal short circuit, and high-frequency signal is had high relatively impedance.These open circuits and short circuit characteristic have stoped effective transmission of low pressure radio frequency (RF) signal of communication.By comprising the terminating circuit that is used for signal of communication, make its impedance in open circuit and short dot and circuit coupling, so that eliminate the undesirable reflection of signal of communication, may deal with problems.Yet verified, provide with correct and arrange that the terminating circuit of an impedance matching is difficult especially.These difficulties main because, any RF pulse that transmits on the line all produces coupling between circuit, therefore especially when needs are fit to wide carrier frequency band, becoming is difficult to carry out effective impedance measurement, to determine the component value of terminating circuit.

The impedance discontinuity that difference occurs in distribution system, especially the impedance discontinuity that occurs at the tie point place that the great majority of overhead system support the electric pole place to form has also stoped distribution wire to transmit the capacity of high-frequency communication signal.Communication service to the user house will be sent to the house usually on supply lines, and will typically use terminal box to be connected with the remainder of distribution system at the electric pole place.Because the shunting effect introduced by impedance discontinuity at the connecting box place causes, can make a large amount of signal of communication power draw supply lines down, and stay the remainder that small-power further descends distribution system very much, to other tie points.If do not note, like this at it when the circuit of system propagates into other users downwards, can cause high-speed traffic signal attenuation.

According to the present invention, provide a kind of terminating circuit of the N of being used for bar distribution wire, its some P on the N-1 of described line bar _iBetween and described some P _iBe connected resistance r between the ground _Ij, ground is connected with one of the residue of described line.

The present invention also provides a kind of method of component value of definite terminating circuit, comprising:

At least one is connected with a communication signal source in line, and residue line and when being connected is determined the matched termination value t between the described line describedly _Ij

Described resistance r _IjBe set to nominal value, and measure described some P _iBetween resistance, to obtain measurement point impedance PI _Ij

According to described t _Ij, determine maximal end point impedance FPI _IjAnd

According to described t _IjAnd PI _IjDetermine to need order to be provided with and the order point impedance SPI of measurement _Ij, with the point impedance PI in the terminating circuit _IjBe set to maximal end point impedance FPI _Ij

The present invention also provides a kind of circuit that is used for transmitting signal of communication on the distribution system of dispensing electric power signal, the frequency of the described relatively electric power signal of described signal of communication has high frequency, described circuit comprises a converter, it has the winding that is used for each phase of distribution system, and electric power signal is not had net flux, and signal of communication is had net flux.

The hereinafter with reference accompanying drawing is only narrated the preferred embodiments of the present invention as an example, wherein:

Fig. 1 is the circuit diagram of a preferred embodiment of terminating circuit;

Fig. 2 is the flow chart that program is determined in impedance;

Fig. 3 is the circuit diagram of bridge joint distribution wire;

Fig. 4 is the circuit diagram of a preferred embodiment of the buffer circuit that is connected with the user house;

Fig. 5 is the circuit diagram of a preferred embodiment of regulating circuit;

Fig. 6 is the circuit diagram of first equivalent electric circuit of Fig. 5 circuit;

Fig. 7 is the circuit diagram of second equivalent electric circuit of Fig. 5 circuit; And

Fig. 8 is the block diagram that combines the terminal box of regulating circuit.

As shown in Figure 1, a kind ofly be used for the N line 4,6,8 of distribution system and 10 terminating circuit 2 comprises three parts: 12,14 and 16.

First 12 is isolated parts, and it is used for making the high pressure low frequency power signal on the line 4 to 10 and second and the third part 14 and 16 handled low pressure radio frequency (RF) Signal Spacing of terminating circuit 2.Electric power signal typical case has a kind of in 50 hertz frequency and the various distribution voltage, is 415 volts of relative phases on each bar of for example online 4 to 10, the distribution voltage of 6.5 kilovolts, 11 kilovolts, 22 kilovolts or 66 kilovolts relative phases.Radiofrequency signal is typically less than 1 volt of effective value, frequency at 2 megahertzes in the scope of 100 megahertzes.Therefore, in online 4 to 10, arrange isolating capacitor 18, can realize effectively isolating.

The second portion 14 of terminating circuit 2 is drive point nets, and it comprises a driving transducer 22, N-1 bar 4,6 in its secondary coil 24 and the line and 8 input/output point P ₁, P ₂And P ₃Connect.As shown in Figure 1, at coil 24 and each P ₁, P ₂And P ₃Between, with secondary coil 24 driving resistor 26,28 and 30 that is connected in parallel, they have value r ₁, r ₂And r ₃The primary winding 32 of converter 22 is connected with axle head 20 with the RF I/O that is used for input and output RF signal of communication, RF signal of communication or be arranged in a P ₁, P ₂And P ₃On, or from these some receptions.Residue line 10 is connected with RF ground 34 with the opposite end of the coil 32 of converter and 24 and with the surrounding layer of axle head 20.The line 10 that is connected with ground 34 is generally the neutral line.

The third part of circuit 2 is terminal networks 16, and it can make N-1 line 4 to 8 stop, so that any RF signal of communication performance matched impedance to receiving on the line 4 to 8.Suppose line 4 to 10 expression low-losses, in order to absorb all RF signals of incident on online 4 to 8, terminal network 16 comprises N (N-1)/2 resistor that is connected with line 4 to 10, makes up to be fit to coupling between the line with all.Be included in drive point P like this ₁, P ₂And P ₃The institute might between and each drive point P ₁, P ₂And P ₃And between the RF ground 34, connect resistor with proper resistor value.As shown in Figure 1, to N=4, at a P ₁, P ₂And P ₃Each between and drive point P ₁, P ₂And P ₃Each point and RF ground 34 between, the resistance r that is provided by potentiometer 36,38,40,42,44 and 46 is provided _Ij

For by the capable ripple of free voltage on the unit length inductance of distribution wire 4 to 10 and the distribution system that the capacitance per unit length matrix is connected, consider by coming together together with its corresponding current traveling wave, can represent the validity of terminal network 16.For the matched termination is provided, terminal network 16 need be expert at ripple when arriving net 16, keeps and to present the relation that makes between voltage and the current traveling wave continuous.Ripple can be expressed as homophase, so that terminal network 16 has an admittance matrix, its expression makes the every positive resistance net that line is interconnected, and this net is got the form of above-mentioned terminal network 16.Description resistance value r _IjCorrect determine and be provided with.

For the various specific arrangements that N line 4 to 10 is stopped, need set up one group of unique resistance value r _Ij(ij=0 to N-1).The existing layout of distribution wire 4 to 10 is not only counted N with line and is changed, and with the conductor size and the interval variation of line 4 to 10.As mentioned above, line 4 to 10 also may be with the close bundle of insulating material clad and the metallic cable that kinks.

By N line 4 to 10 being carried out a series of N (N-2)/2 experiments, determine one group of matched termination value t at first _Ij, this N line 4 to 10 can be the substantial portion of employed line, also can be simulation, it constitutes scale model.If use scale model, the just dimension scale in the cross section of the line 4 to 10 of needs preservation distribution system.Each experiment comprises arranges the given bridge on line 4 to 10 each end, determines matched termination value t _IjHere, " bridge joint " means at source and load two ends, connects the RF short circuit between online certain combination.The combination of each bridge joint provide a RF " " line, or combination multi-thread and a RF " activity " line, or multi-thread combination.Each bridge joint combination is also irrelevant with other combinations, and identical with load side at the source end a particular experiment kind.For these experiments,, then a suitable pulse generator is connected with RF active wire or line group with the RF ground wire by an impedance transformer if do not match in the impedance of source end proof.The source end monitors with an oscilloscope.Between RF ground and RF active wire or line group, connect single adjustable terminal resistor at load end.Each experiment is then by being provided with variable terminating resistor, the reflected signal of surveillance source end simultaneously so that the areflexia signal see from load end return form.Measure the value of this resistance, and it comprises matched termination value t to this experiment _IjOther experiments are repeated this process.Table 1 shows an example of bridge joint condition and symbol, the matched termination that their ecbatics obtain.

Table 1: bridge joint condition＜RF activity〉＜RF ground connection〉example of [matched termination symbol]

????N	????2	????3	????4	????5
					Experiment number	????1	????3	????6	????10
Experiment numbers
					????1A	????<1><0> ????[t 1a]	????<1><0-2> ????[t 1a]	????<1><0-2-3> ????[t 1a]	????<1><0-2-3-4> ????[t 1a]
????1B	?????*	????<2><0-1> ????[t 1b]	????<2><0-1-3> ????[t 1b]	????<2><0-1-3-4> ????[t 1b]
					????1C	?????*	????*	????<3><0-1-2> ????[t 1c]	????<3><0-1-2-4> ????[t 1c]
????1D	?????*	????*	????*	????<4><0-1-2-3> ????[t 1d]
					Or the like
????2A	?????*	????<1-2><0> ????[t 2a]	????<2-3><0-1> ????[t 2a]	????<2-3-4><0-1> ????[t 2a]
					????2B	?????*	????*	????<1-3><0-2> ????[t 2b]	????<1-3-4><0-2> ????[t 2b]
????2C	?????*	????*	????<1-2><0-3> ????[t 2c]	????<1-2-4><0-3> ????[t 2c]
					????2D	?????*	????*	????*	????<1-2-3><0-4> ????[t 2d]
Or the like
					????3A	?????*	????*	????*	????<1-2><0-3-4> ????[t 3a]
????3B	?????*	????*	????*	????<3-4><0-1-2> ????[t 3b]
					Or the like

^*Experiment is not suitable for the N value

Reference table 1 for example for N=4, at first three experiments 1A, 1B and 1C, comprises corresponding drive point P ₁, P ₂And P ₃Line 4,6 and 8 in one be connected with RF is active respectively, and comprise that the residue line of the neutral line 10 is connected with RF ground 34.In each experiment, between RF ground and the line that is chosen as the RF activity, be connected variable resistor.In three residue experiments 2A, 2B and 2C, in the neutral line 10 and other lines 4,6 or 8 one is connected with RF ground, remains two lines and is used as the RF activity.Remain two lines and interconnect, and be connected, and between RF active wire and RF ground wire, be connected variable resistance again with RF is active.To the electric wire open type power line group of N=4, resulting one group of matched termination value is shown in table 2.

Table 2: for N=4, from the example of the matched termination value that the experiment that table 1 limited obtains

The matched termination	Value (ohm)
		????[t 1a]	????363
????[t 1b]	????333
		????[t 1c]	????370
????[t 2a]	????281
		????[t 2b]	????242
????[t 2c]	????224

In case determined terminal value t _Ij, they just can be used for as shown in Figure 2 by 50 processes that can carry out of computer program, so that determine need be at a P _iBetween, but also at a P _iAnd the maximal end point impedance FPI that is seen between the RF ground 34 _Ij, so that terminal network 16 becomes effectively.In the step 52 of program 50, input matched termination value t _Ij, and, use linear transformation LT1 that they are transformed into the terminal network admittance element g that is used for net 16 in the step 54 _IjIn the step 55, use the second linear transformation LT2 to be worth t then from the matched termination _IjObtain admittance matrix [Y _TN].Secondly,, use the 3rd conversion LT3, to use admittance matrix [Y in the step 56 _TN] obtain maximal end point impedance FPI _IjMaximal end point impedance FPI _IjBe the some P of terminal network 16 _iThe measured resistance value of the last hope between (i=0 to N-1).Under the end condition that sets gradually as described in Table 1, given one group of terminal value t that represents with admittance _IjCan determine maximal end point impedance FPI _IjValue.For example, for N=4, in experiment 1A, second line 6 and the three-way 8 with RF ground 34 bridge joints, the neutral line 10 is at the source end, and remains first line 4 as the RF activity, with reception RF stimulus.At relative load end, stimulus will leave the same form arrival of source end with it, and therefore bridging load will not influence reflected wave.Therefore, t _1aCan be according to resistance r _IjOr corresponding admittance g _IjRepresent that they are not bridged short circuit to this experiment, as shown in Figure 3.Therefore, satisfy t _1a=1/r ₀₁+ 1/r ₁₂+ 1/r ₁₃=g ₀₁+ g ₁₂+ g ₁₃Other expression formulas are similar.According to t _IjFind the solution g _IjThen define conversion LT1.For example for N=4, linear transformation LT1 is defined as by equation:

g ₀₁＝1/2(t _2b+t _2c-t _1b-t _1c)

g ₀₂＝1/2(t _2c+t _2a-t _1c-t _1a)

g ₀₃＝1/2(t _2a+t _2b-t _1a-t _1b)

g ₁₂＝1/2(t _1a+t _1b-t _2c)

g ₂₃＝1/2(t _1b+t _1c-t _2a)

g ₃₁＝1/2(t _1c+t _1a-t _2b)

As mentioned below, they are to be used to go on foot 66 g _IjValue.Application standard circuit analysis technology can obtain to be used to go on foot 55 conversion LT2.For N=4, linear transformation LT2 is by following terminal network admittance matrix element Y _TNijWith t _IjRelevant equation limits:

Y _TN11＝t _1a

Y _TN22＝t _1b

Y _TN33＝t _1c

Y _TN12＝Y _TN21＝1/2(t _2c-t _1a-t _1b)

Y _TN23＝Y _TN32＝1/2(t _2a-t _1b-t _1c)

Y _TN31＝Y _TN13＝1/2(t _2b-t _1c-t _1a)

This 9 number forms admittance matrix [Y _TN], it makes a P _iPlace (i=1 to 3) is RF ground P relatively ₀Three voltages of 34 with flow into the current related of these points.Invert and then provide impedance matrix elements Z _TNij, this matrix of the value of his-and-hers watches 2 is as follows: $\left[Z_{\mathrm{TN}}\right]={\left[Y_{\mathrm{TN}}\right]}^{-1}=\left[\begin{array}{ccc}440.3& 155.5& 169.7\\ 155.5& 443.0& 214.1\\ 169.7& 214.1& 496.1\end{array}\right]$ Maximal end point impedance FPI _IjWith ZTN _IjRelevant, as go on foot 56 determine as follows: FPI ₀₁=Z _TN11FPI ₀₂=Z _TN22FPI ₀₃=Z _TN33FPI ₁₂=Z _TN11+ Z _TN22-2Z _TN12FPI ₂₃=Z _TN22+ Z _TN33-2Z _TN23

FPI ₃₁＝Z _TN33+Z _TN11-2Z _TN31

It provides the end value in the following table 3.Make Y _TNijWith FPI _IjThe last two groups of relations that link to each other limit conversion LT3.

If what all require is terminated line 4 to 10, can not comprise drive point net 14.Yet if there is drive point net 14, it will influence from 4 to the 8 being seen impedances of N-1 line.Arrange for N=4 shown in Figure 1, as from a P ₁, P ₂And P ₃Finding, drive point net 14 show as the equivalent terminal network in parallel with physical end net 16.Drive point net 14 can be with an admittance matrix [Y _DPN] expression, and therefore effectively terminal network has and equals [Y _TN]+[Y _DPN] [Y _TNeff] given admittance matrix.Use or without drive point net 14 maximal end point impedance FPI _IjAll will keep identical, yet the set point of potentiometer 36 to 46 is with difference.Under the DC measuring condition,, has resistance value r so be arranged in parallel one with converter 22 because coil 24 shows short circuit under the DC measuring condition ₀Resistor 49, the input impedance that is showed by the secondary coil 24 of the converter 22 in using with expression.Therefore converter 22 will be wound in the impedance transformer with RF source impedance, typically be 50 ohm on primary winding 32.Impedance conversion is one and is similar to, so that r ₀Actual value be chosen as under interested RF frequency, promptly under the carrier frequency of signal of communication, from secondary coil 24 sees into measuring resistance.For actuality, promptly in order to produce the positive electricity resistance, for N=4, to each ij=1...3, because Y _DPNij+ Y _TNij=Y _TNefijSo, the plain Y of latter two entry of a matrix _TNefijAnd Y _DPNijTherefore must satisfy Y _DPNij＜Y _TNefijLike this with the value of helping determine driving resistor device 26,28 and 30.Select the value of driving resistor 26 to 30,, make the power maximum that is sent to line 4 to 8 with to given RF input.To the similar signal level on wired 4 to 8, driving resistor 26 to 30 can be given as same resistance value, and because the star-delta transformation of driving resistor 26 to 30 makes r ₁+ r ₂+ r ₃Be changed to and each line resistance r _IjParallel connection, thus for actuality, the driving resistor value and r ₁+ r ₂+ r ₃Select than maximum resistance r _IjGreatly.As mentioned above, r is set _Ij, so that a matched termination net 16 to be provided, and if driving resistor too high, then insert loss with excessive, therefore will repeat this selection course, up to r with less driving resistor _IjJust can just be embodied as according to program 50.

The decline of program 50 comprises the series of points impedance SPI that determines energy proceeding measurement and setting _Ij, finally to reach the maximal end point impedance FPI of hope _IjOrder is very important, because regulate resistance value r _IjIn any one all will influence point impedance PI _IjIn the step 58,, potentiometer 36 to 46 comes initial setting up resistance r by being placed on the center _Ij, and measure initial point impedance PI _IjIf preamble is discussed, during measuring condition, converter 22 breaking circuits, but by having value r ₀Resistor 49 represent, it allows to obtain DC and measures, the practical impedance that simulation manifests under the operation radio frequency.In the step 60, measurement point impedance PI _IjBe transformed into element admittance g actual or that measure _IjEnter order in the step 64 then and determine circulation 62, to repeat k time.Repeat number k is that point is to P _iBetween and the some P _iAnd the impedance number between the RF ground 34.For N=4, k=6.In the first step 66 of circulation 62, with going on foot the 54 hope admittance g that determine _IjReplace actual admittance g _IjIn one.Use previously described g in the step 68 then _IjWith t _IjBetween relation and conversion LT2 and LT3, all admittance are transformed into point impedance PI _IjIn the step 70, make order be set to SPI _IjThe k point impedance have value PI _Ij, it be derived from step 68 matrix in resulting impedance corresponding, and element g that select with the step 66 _IjCorresponding.For example, if g ₁₀Be set to its desired value, so SPI in the step 66 ₁₀Be first impedance in the order, and be derived from the value of obtaining PI in step 70 of 68 in step ₁₀In the decision step 72, whether all of definite circulation 62 repeat to finish.In case circulate 62 all repeat to finish, then the step 74 by together with last FPI _IjOrder record sequence valve SPI _Ij, and program 50 is finished.Following table 3 has provided for N=4, the result that produces by program 50, wherein first row stipulated line between point impedance, neutral corresponding to RF ground wire 34, red corresponding to first line 4, in vain corresponding to second line 6, and blue corresponding to the three-way 8.The initial measurement point impedance PI of step 58 inputs _IjProvide by first row, by the 62 order point impedance SPI that determine that circulate _IjBe shown in secondary series, and maximal end point impedance FPI _IjBe shown in the 3rd row.Therefore in order to realize maximal end point impedance FPI _Ij, at first put P ₁The red line and the impedance between the ground at place need be provided with and be measured as 381 ohm.Next 6 P of white line ₂And the impedance between the ground need be provided with and be measured as 411 ohm etc., up to 8 P of blue line ₃With 4 P of red line ₁Between impedance final measure and be set to till 598 ohm.

Table 3: terminal network impedance

Point ij	Initial p I ij	Order SPI ij	Final FPI ij
				Red-neutrality	????340	????381	????440.3
In vain-neutrality	????352	????411	????443.0
				Indigo plant-neutrality	????359	????488	????496.7
Red-Bai	????445	????563	????572.3

In vain-indigo plant	???460	???496	???511.5
				Blue-red	???454	???598	???597.5

As shown in Figure 4, terminating circuit 2 can be used for the user house, with the signal of 103 reception distribution wires, 4 to 10 inputs from the source.Distribution wire 4 to 10 also provides electric power to the user house that constitutes electrical load 100 according to their common function.Isolate in order to make terminating circuit 2 and load 100, use a buffer circuit 102, it comprises the annular core 104 of and line 4 to 10 arranged in series that be connected with load 100, and the capacitor C that is connected respectively between the neutral line 10 and red line 4, white line 6 and blue line 8 ₁, C ₂And C ₃To the neutral line 10,160, also between the coil two ends of annular core 104, connect an impedance Z 0.Buffer circuit 102 is at terminating circuit 2 and look genuine isolation is provided between the noise, and under the RF frequency for load 100 provides impedance effect, and under the mains frequency of distribution system, allow the greatest requirements electric current to deliver to load 100.Annular core has different characteristics for mains frequency with the RF frequency.Under mains frequency, the coil of each phase is wrapped on the ring 104, so that magnetic flux is increased.The coil of the neutral line 10 also is wound, but to offset this sample loading mode winding of flux that other line 4 to 8 each phases are produced, so that the net flux in annular core 104 is 0 under mains frequency, guarantees that ring will can not cause saturated because of mains frequency.Guarantee under mains frequency the low-down impedance of 102 pairs of sources of buffer circuit, 104 performances like this.Under the RF frequency, the neutral line 10 is substantially by impedance Z ₀Therefore bypass with the clean RF flux of generation in ring, and introduces an inductance as the part of the RF filter of circuit 102.Impedance Z ₀Comprise a series capacitor C ₀And resistor R ₀Comprise R ₀Be for activity is prevented magnet short-cut path mutually.Capacitor C ₁, C ₂And C ₃Form the remainder of the RF filter of circuit 102.Guarantee that like this circuit 102 shows high impedances to terminating circuit 2 under the RF frequency.Capacitor C ₁, C ₂And C ₃Make any RF signal of load 100 outputs, for example the RF noise along separate routes.

As shown in Figure 5, annular core 104 can also be advantageously used for the part of a regulating circuit, the service cable 152 in user house is connected with overhead distribution line 4 to 10 being used for.For three phase supply, user's supply lines 152 of linking the user house from overhead wire 4 to 10 comprises red line 154, white line 156, blue line 158 and the neutral line 160.Red, white, blue and neutral distribution wire 4 to 10 is connected with red, white, blue and neutral user's supply lines 154 to 160 respectively by each series connection winding that is wrapped on the iron core 104.Between the winding two ends of the neutral line 10 and 160, connect an impedance Z again ₀, and between the winding two ends of residue line, connect separately adjusting impedance Z _R, Z _WAnd Z _B Twine iron core 104 again, so that for mains frequency, magnetic flux increases around the iron core of red, white and Lan Gexiang, and the winding of the neutral line is for like this, so that its offsets by remaining the flux that phase produced, thereby the net flux in mains frequency lower core 104 is 0.Also select impedance Z ₀Capacitor C ₀Value so that under the RF frequency, the neutral line 10,160 makes iron core 104 bypass substantially, thereby produces clean RF flux in iron core 104.R ₀Be used for preventing magnet short-cut path once more to active phase.Therefore can between mains frequency and RF frequency, change overhead wire 4 to 10 resistance values that showed, providing constant impedance adjustment, and also prevent the signal of communication impedance adjustment that signal is decayed fast under the RF frequency the distribution on the service cable 152.Mains frequency and be used for official post regulating circuit 150 between the RF frequency of signal of communication 4 to 10 one of performance have low-down reactance to line under 50 hertz, and under RF, have the inductance value of very high reactance.Since in iron core 104 net flux and be 0, so circuit 150 also under mains frequency by may the big caused saturated any problem that do not exist of electric current.

Consider the characteristic of regulating circuit 150 under the RF frequency, Fig. 6 shows an equivalent electric circuit 170.Under the RF frequency, the inductance L of each phase winding _R, L _WAnd L _BAll will have quite big reactance.Because converter 104 is not closely to be coupled, and uses the seldom number of turn, so leakage inductance L _LR, L _LWAnd L _LBAlso will have quite big reactance.Reducing of magnetic permeability also arranged under the RF frequency.From equivalent electric circuit 170 as seen, the impedance that each active phase showed in each input user house, i.e. R-R _C, B-B _CAnd W-W _CTo the RF frequency with height, thereby to along distribution system respectively organize service cable 152, prevented the quite big loss of signal of communication or decay fast.As seen the combinatorial input impedance of active phase be overhead distribution line 4 to 10 and supply lines 152 impedance and, these lines are all shared a neutral line 10,160 altogether, and therefore this impedance and with height.The red phase input side of iron core 104 being seen since is connected with iron core 104 in vain phase and the mutually caused impedance of indigo plant will and L _RReactance X _RHas the identical order of magnitude.

Yet may occur in the signal that arrives on each active service cable 152 of 154 to 158 mutually disequilibrium unfriendly.Shown in the RF equivalent electric circuit 172 of Fig. 7, this situation can be by comprising the adjusting impedance Z in circuit 150 _R, Z _WAnd Z _BHandle, these are regulated impedance and are included in resistor and the capacitor that connects between each phase winding two ends of iron core 104.Select Z _R, Z _WAnd Z _BCapacitor so that they show short circuit under the RF frequency, and under mains frequency, provide blocked impedance to electric power signal.Allow to regulate and select Z like this _R, Z _WAnd Z _BResistor so that make each RF that goes up mutually that submits the user house to signal-balanced.Circuit 150 also by the coupling winding of iron core 104, plays a signal equalization device inherently.Therefore circuit produces reactive isolates and regulates effect, and they can be according to the number of turn, the iron core 104 employed size and the materials of winding, and are regulating element Z _R, Z _W, Z _BAnd Z ₀Selected value is regulated as hope.

As shown in Figure 8, circuit 150 can be incorporated in the terminal box 180, and this terminal box 180 is installed on the support electric pole of overhead distribution system, so that overhead distribution line 4 to 10 is connected with user's supply lines 152 to 160.

As above with reference to the accompanying drawings as described in, do not violating under the scope of the present invention, many for a person skilled in the art changes are conspicuous.

Claims (21)

1. terminating circuit that is used for N bar distribution wire, the some P on the N-1 of described line bar _iBetween, and described some P _iBe connected resistance r between the ground _Ij, ground is connected with one of the residue of described line.

2. a terminating circuit as claimed in claim 1 comprises the isolating capacitor in the described line, so that the electric power signal of dispensing has the high-frequency communication signal isolation with the frequency of relative described electric power signal on the described line.

3. a terminating circuit as claimed in claim 2 comprises a drive circuit, and to import described signal of communication at described some place, to transmit on described line, the described relatively electric power signal of described signal of communication has low-voltage.

4. terminating circuit as claimed in claim 3, wherein said drive circuit comprises a converter, its secondary coil by driving resistor respectively with described some P _iConnect described driving resistor parallel connection.

5. terminating circuit as claimed in claim 2, wherein said signal of communication is radio frequency (RF) signal, and described be RF ground.

One kind determine as above-mentioned claim in the method for value of element of any one described terminating circuit, comprising:

At least one is connected with a communication signal source in line, and residue line and when being connected describedly, determines the matched termination value t between the described line _Ij

Described resistance r _IjBe set to nominal value, and measure described some P _iBetween resistance, to obtain measurement point impedance PI _Ij

According to described t _Ij, determine maximal end point impedance FPI _IjAnd

According to described t _IjAnd PI _IjDetermine to need order to be provided with and the order point impedance SPI of measurement _Ij, with the point impedance PI in the terminating circuit _IjBe set to maximal end point impedance FPI _Ij

7. a method as claimed in claim 6 wherein according to the structure of described terminating circuit, is worth t by the described matched termination of conversion _Ij, obtain described maximal end point impedance FPI _Ij

8. a method as claimed in claim 7 wherein is worth t to the matched termination _IjBe transformed into an admittance matrix, admittance matrix is transformed into an impedance matrix, obtain maximal end point impedance FP by impedance matrix _Ij

9. a method as claimed in claim 6 is wherein passed through matched termination value t _IjBe transformed into match admittance, measurement point impedance PI _IjBe transformed into the measurement admittance, and to each resistance value r _IjRepeatedly replace one that measures in the admittance with one in the match admittance, to produce a transformation matrix, this transformation matrix is transformed into the point impedance matrix, and the order point impedance is set in the point impedance matrix and measures corresponding impedance described in the admittance, obtains described order point impedance SP _Ij

10. one kind as each described terminating circuit in the claim 2 to 5, comprises a buffer circuit, isolates to make electric power signal and signal of communication in user's premises.

11. circuit that is used on the distribution system of dispensing electric power signal, transmitting signal of communication, the frequency of the described relatively electric power signal of described signal of communication has high frequency, described circuit comprises a converter, it has the winding that is used for each line of distribution system, and electric power signal is not had net flux substantially, and signal of communication is had net flux.

12. a circuit as claimed in claim 11, wherein converter comprises a single magnetic circuit iron core of closure.

13. a circuit as claimed in claim 11 wherein is being used for connecting a capacitor between the winding two ends of a line.

14. a circuit as claimed in claim 13, wherein winding has and is connected with load supplying with first end of electric power signal, and is connected second end with the supply signal of communication with terminating circuit.

15. a circuit as claimed in claim 14 wherein is connected isolating capacitor between first end of first end of the winding that is used for a described line and the winding of other lines.

16. a circuit as claimed in claim 15 wherein makes described second end be connected with the distribution wire of distribution system.

17. a circuit as claimed in claim 14, wherein said terminating circuit is as in the claim 1 to 5 as described in any one.

18. a circuit as claimed in claim 14, wherein first end of winding is connected with the supply lines in user house, and second end of winding is connected with the distribution wire of distribution system.

19. a circuit as claimed in claim 18 wherein connects between the winding two ends of other lines and regulates impedance.

20. a circuit as claimed in claim 19 is wherein regulated impedance and is comprised a series resistance and electric capacity.

21. one kind as claim 13 or 15 described circuit, a wherein said line is the neutral line.

Images