CN103166676A - Method capable of achieving multichannel transmission of power frequency communication uplink signals simultaneously - Google Patents

Abstract

The invention provides a method capable of achieving multichannel transmission of power frequency communication uplink signals simultaneously. Each terminal adopts the same pseudorandom sequence, and modulation of uplink data is carried out through encoding formed by displacement; and when multichannel uplink power frequency communication signals are transmitted simultaneously, master station equipment samples currents of a 10 KV line through a sensor, weighting output of signals in each channel is obtained on the basis of a time domain difference and pseudorandom sequence weighting operation and is operated through mutual correlation, and thus simultaneous demodulation of the multichannel uplink signals is achieved. According to the method, the power frequency communication rate can be improved, and advantageous conditions are created for application of an oil field power distribution network in fields of oil well remote monitoring, power distribution network load monitoring and the like for power frequency communication technology; and an information transmission channel can be provided for electric quantity statistics on the same moment on a power supply line, technical support is provided for dynamic optimization operation of a power distribution network and achieving of energy conservation and consumption reduction, a new mode is explored for management of a rod pumped well, and significant academic significances and engineering application value are provided.

Description

Realize frequency communication upward signal multiplex method simultaneously

Technical field

The present invention relates to a kind of frequency communication upward signal multiplex method simultaneously that realizes, relate to the technical fields such as field production management, power system network structure, motor, communication, signal processing

Background technology

The management of oil field pumping well is at present repeatedly patrolled well by the oil recovery work and is realized, cause the operating efficiency of field produces pipe well lower, due to the electric parameter that there is no synchronization in supply line, be difficult to realize the optimization operation of oil field distribution network, thereby cause the operation energy consumption of pumpingh well equipment higher simultaneously.

The power-frequency communication of electric technology can realize the long Distance Transmission across transformer platform area under lower cost, based on this technical transmission remote monitoring information, have investment little, need not lay communication line, there is no service fee, the advantage such as flexibility is strong, be well suited for the information transfer channel as the oil well remote monitoring; But there is the low defective of speed in power-frequency communication of electric, and the transmission capacity of monitoring information is restricted, and particularly when many mouthfuls of oil wells break down, can't realize the real-time transmission of fault message.

If up frequency communication under the prerequisite of guaranteed performance, is realized multidiameter delay transmission, just can make the demand of the more suitable oil well monitor of performance of frequency communication, thereby provide a kind of cheapness, feasible communication means for the construction in digitlization oil field.

Summary of the invention

The invention provides a kind of frequency communication upward signal multiplex method simultaneously that realizes, can high traffic rate, when making frequency communication technology be applied to the oil well remote monitoring, can transmit more monitoring information on the one hand, and, when many mouthfuls of oil wells by same 10KV branch line power supply break down, can realize simultaneously initiative alarming.Apply at oilfield electric net for frequency communication technology like this and create favorable conditions, for the enforcement in digitlization oil field provides a kind of cheapness, feasible communication means, solve the oil recovery work and repeatedly patrol well, the lower problem of operating efficiency that causes the field produces pipe well also provides the foundation for saving energy and reduce the cost by network optimization simultaneously.

The objective of the invention is to be achieved through the following technical solutions:

When sending upward signal, the different coding that adopts same pseudo random sequence to realize by displacement is controlled the modulation of distortion current when each terminal installation.

when upward signal receives, main website equipment is by the current signal of sensor sample 10KV circuit, obtain the output of each road signal by time-domain difference and pseudo random sequence ranking operation, when utilizing the correlation properties of random sequence to guarantee the weighting output of every road, when accessing greatly, the modulating-coding terminal signaling consistent with weighted coding strengthen, and the current distortion signal of all the other each terminals is suppressed, and then carry out data demodulates by each road weighting output signal and the computing cross-correlation result of distortion reference signal, so just can realize the parallel transmission of multichannel frequency communication upward signal.

The present invention passes through multi-channel data transmission, can improve frequency communication speed, advantage has been created in applying that use in the fields such as oil well remote monitoring, power distribution network load monitoring that are applied in oil field distribution network for frequency communication technology like this, for the fields such as oil well remote monitoring, power distribution network load monitoring provide feasible data transmission channel; Frequency communication technology in conjunction with basis of the present invention on, the oil well remote supervision system of structure can adapt to the demand of field production management, patrols the well number of times thereby can reduce the oil recovery work, improves the operating efficiency of field produces pipe well; Simultaneously, based on this, can also obtain the electric parameter of each node synchronization of power distribution network, dynamic optimization operation for oil field distribution network, the energy-saving and cost-reducing technical support that provides is provided, explores a kind of new model for the rod-pumped well management, have important academic significance and engineering using value.

Description of drawings

Power frequency communication system structure and multiplexing principle schematic that Fig. 1 provides for the specific embodiment of the present invention;

The telecommunication terminal structural representation that Fig. 2 provides for the specific embodiment of the present invention;

The upstream data modulation schematic diagram that Fig. 3 provides for the specific embodiment of the present invention;

The uplink demodulation apparatus structure schematic diagram that Fig. 4 provides for the specific embodiment of the present invention.

Embodiment

Below the present invention is described in further detail: the present embodiment is implemented under take technical solution of the present invention as prerequisite, has provided detailed execution mode, but protection scope of the present invention is not limited to following embodiment.

A kind of frequency communication upward signal multiplex method simultaneously that realizes comprises:

When upward signal sent, the different coding that each terminal adopts same pseudo random sequence to realize by displacement was controlled the modulation of distortion current.

During uplink receiving, main website equipment obtains the output of each road signal by the current signal of sensor sample 10KV current circuit by time-domain difference and pseudo random sequence ranking operation;

Carry out data demodulates by each road weighting output signal and the computing cross-correlation result of distortion reference signal.

Concrete, existing power frequency communication system forms by the main website equipment that is positioned at electric substation with the telecommunication terminal that is positioned at the distribution transformer low-pressure side, upward signal from the distribution transformer to the electric substation is realized by current distortion, in order to realize the multiplexing of upward signal, this embodiment is carried out the modulation of upward signal based on pseudorandom sequence coding, the loopy moving of pseudo random sequence chip, each terminal can configure different modulating-codings, as shown in Figure 1.

During uplink receiving, main website equipment is by the current signal of sensor sample 10KV current circuit, and enough obtain the output of each road signal by time-domain difference and pseudo random sequence ranking operation, because the waveform of current distortion signal can know in advance, carry out data demodulates by each road weighting output signal and the computing cross-correlation result of distortion reference signal; To have an autocorrelation very strong due to the modulating-coding of each terminal, and the very low characteristics of cross correlation, during the multiple signals transmission, the impact between each road signal is very low, transmits when so just can realize the multichannel upward signal.

In power frequency communication system, be positioned at the telecommunication terminal of distribution transformer with fast processor MCU, high-precision adc A/D, the compositions such as controllable silicon and drive circuit, as shown in Figure 2.

The function of telecommunication terminal is to complete descending demodulation, then carries out the modulation of upward signal according to agreement.When needs sent upstream data, terminal, was then controlled drive circuit according to modulating-coding and is carried out the modulation of current distortion signal by the initial time of agreement specified data coding at downstream signal solution timing; Concrete grammar is front about the 30 ° triggering controlled silicon conductings of voltage over zero that rely on distribution transformer secondary phase, makes near the distortion of the generation of voltage over zero Weak current carry signal.

In this embodiment, the pseudo random sequence code that the upstream data modulating-coding adopts the communications field to be widely used is established p (k) and is the twin-stage pseudo random sequence, and length is N, has following characteristics:

(1) periodically, p (k+N)=p (k) (1)

(2) sharp-pointed autocorrelation performance, $\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}p\left(k\right)p(k+l)=\left\{\begin{array}{c}N,l=0\\ -1,l\≠0\end{array}\right.---\left(2\right)$

Every uplink information is comprised of N sequence chip, and the front and back of each chip by the distortion current place cycle in two power frequency periods represent, 1 interior distortion current v (t) of power frequency period appears at the sending-end voltage zero passage near the moment, p (k) has determined modulated current signal v (t) place power frequency period, as shown in Figure 3.

Coding is modulated if j road upstream data information adopts p (k+j), and N sequence chip wherein arranged, and each chip represents with distorted signal position in 2 cycles, x _j(t) be the modulation signal of this road targeting signal within 1 cycle, constantly modulating pulse arranged at two voltage zero-cross, in modulation signal shown in Figure 3, x _j(t) can be expressed as:

$x_j\left(t\right)=v_j\left(t\right)-v_j(t+\frac{T}{2})---\left(3\right)$

When carrying out the M circuit-switched data when transmitting simultaneously on same 6KV branch line, the leading uplink information in M road at the modulation composition in 2N power frequency period on the 10KV branch line is:

$\underset{j=0}{\overset{5}{\mathrm{\Σ}}}\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}\{\frac{1+p(k+j)}{2}{x}_j(t-2\mathrm{kT})+\frac{1-p(k+j)}{2}{x}_j(t-2\mathrm{kT}-T)\}---\left(4\right)$

Wherein, T is power frequency period, and p (k) is the twin-stage pseudo random sequence, and because current distortion signal attenuation is fast, v (t) basic configuration can be determined.

The uplink demodulation equipment of frequency communication as shown in Figure 4, the uplink demodulation device is by formations such as the voltage and current instrument transformer (PT, CT) of industrial computer, 16 A/D capture cards, 10KV (or 6KV) circuit, Signal Matching modulate circuits, voltage, the current sensing signal of PT, CT output carry out digitlization through signal conditioning circuit and A/D card, industrial computer judges that by voltage signal voltage zero-cross constantly, then carries out Digital Signal Processing at the right current sampling signal of voltage zero-cross time domain and realizes uplink demodulation.

In frequency communication main website equipment, there is the RS485 circuit to carry out information exchange between downlink drive device and uplink demodulation device, therefore, demodulating equipment can know the initial time of every upstream data in advance.

The current signal of the demodulating unit sampling 6KV circuit in communication main station, voltage or the current sampling signal of 2N power frequency period are divided into the N group, the sampled signal in every group of two cycles, obtain like this N adjacent periods and make difference signal, then this N is done producing composite signal after difference signal is crossed modulating-coding p (k+j) weighting with this road information.

If I (t) is current sampling signal, j road composite signal can be expressed as s _j(t):

$S_j\left(t\right)=\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}[I(t-2\mathrm{kT})-I(t-2\mathrm{kT}-T)]p(k+j)---\left(5\right)$

According to the characteristic suc as formula (1), (2) pseudo random sequence, the modulation composition substitution in formula (7) is got:

$s_j\left(t\right)={\mathrm{Nx}}_j\left(t\right)-\underset{i=0}{\overset{M-1}{\mathrm{\Σ}}}{x}_i\left(t\right)+\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}{n}_m\left(t\right)p(k+j)---\left(6\right)$

Because the modulating-coding of each road upstream data has the strong and low characteristics of cross correlation of autocorrelation, the modulation composition that reflects j road information can obtain N doubly to be strengthened, the modulation composition of other M-1 road uplink information can not, in formula (6), the 3rd is the electrical network interfering components, disturb synthetic by remaining non-integer harmonics after many groups of front and back adjacent periods current signal difference, due to uncorrelated with p (k+j), electrical network disturbs the enhancing after compose operation very limited.

With the x in formula (3) _j(t) substitution gets:

$s_j\left(t\right)=N[v_j\left(t\right)-v_j(t+\frac{T}{2})]+n_x\left(t\right)---\left(7\right)$

Wherein, n _x(t) comprise the interference of electric network noise and other branch road preface informations, because modulation signal exists constantly at two voltage zero-cross, can two distorted pulses be merged by the superposition of front and back half period signal, can be expressed as:

$c_j\left(t\right)=s_j\left(t\right)[h\left(t\right)-h(t+\frac{T}{2})]=2N{v}_j\left(t\right)+n_c\left(t\right)---\left(8\right)$

H (t) is the rectangular window function of half power frequency period, so c _j(t) comprise j road distorted pulse and the interference signal n that 2N doubly strengthens _c(t) (comprise the up modulation composition in other roads and electrical network disturb), because the basic configuration of current distortion signal v (t) can be determined, just can realize demodulation to the j upward signal by the cross-correlation mode like this.

Doubly strengthen because the modulation composition of j road upward signal can obtain N, the impact that is subject to other each road upward signals modulation compositions is very low.

In the same way, can obtain the demodulation output of other each road upstream datas, transmission when so just having realized the multichannel upstream data.

The present invention has obtained application on some machine-pumped oil wells of oil recovery factory; can in time grasp the operation conditions of oil well after application; reduced because the production loss that machine halt trouble causes; realized the electric quantity metering of oil well individual well; can effectively improve the managerial skills of oil production equipment; all kinds of electrical quantitys of oil pumper that real-time precise and high efficiency obtains reach the remote monitoring that realizes machine-pumped oil well under low-cost condition, have economic benefit and social benefit widely.

The technical scheme that adopts this embodiment to provide, obtain the output of each road signal and carry out data demodulates by each road weighting output signal and the computing cross-correlation result of distortion reference signal by time-domain difference and pseudo random sequence ranking operation, realized multi-channel data transmission, for widening data transmission channel in the fields such as oil well remote monitoring, power distribution network load monitoring; Realize the oil well remote monitoring, reduced the oil recovery work and patrol the well number of times, improved the operating efficiency of field produces pipe well; The electric weight of realizing synchronization in supply line calculates, and the energy-saving and cost-reducing technical support that provides is provided the dynamic optimization operation for power distribution network, explores a kind of new model for the rod-pumped well management, has important academic significance and engineering using value.

The above; only be the better embodiment of the present invention; these embodiments all are based on the different implementations under general idea of the present invention; and protection scope of the present invention is not limited to this; anyly be familiar with those skilled in the art in the technical scope that the present invention discloses; the variation that can expect easily or replacement are within all should being encompassed in protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claims.

Claims (1)

1. realize frequency communication upward signal multiplex method simultaneously for one kind, it is characterized in that, comprising:

When upward signal sent, the different coding that each terminal adopts same pseudo random sequence to realize by displacement was controlled the modulation of distortion current.

When upward signal receives, the current signal of the equipment utilization sensor sample 10KV of main website circuit, obtain the output of each road signal by time-domain difference and pseudo random sequence ranking operation, when utilizing the correlation properties of random sequence to guarantee the weighting output of every road, when accessing greatly, the modulating-coding terminal signaling consistent with weighted coding strengthen, and the current distortion signal of all the other each terminals is suppressed, and then carry out data demodulates by each road weighting output signal and the computing cross-correlation result of distortion reference signal, realize the parallel transmission of multichannel frequency communication upward signal.

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