METHOD FOR PARALLEL METER-READING BETWEEN CONCENTRATOR AND ELECTRICITY METERS

A parallel meter-reading method between a concentrator and electricity meters includes determining a phase of electric power supplied from a concentrator to the electricity meters, generating a reference signal synchronized with electric power determined for each phase, generating a request signal synchronized with the 3 phases electric power determined and transmitting the generated request signal to an electricity meter modem, receiving the request signal, determining a phase of electric power supplied to the electricity meter according to the request signal, generating a response signal synchronized with the determined phase and transmitting the generated response signal to the concentrator modem, and receiving the response signal of the electricity meter modem with respect to the request signal, and determining whether or not the response signal is synchronized with the reference signal to determine the phase of electric power supplied to the electricity meter.

DETAILED DESCRIPTION OF THE INVENTION

Description will now be given in detail of the exemplary embodiments, with reference to the accompanying drawings. The accompanying drawings are used to help easily understood the technical idea of the present invention and it should be understood that the idea of the present invention is not limited by the accompanying drawings. The idea of the present invention should be construed to extend to any alterations, equivalents and substitutes besides the accompanying drawings.

Furthermore, the terms including an ordinal number such as first, second, etc. can be used to describe various elements, but the elements should not be limited by those terms. The terms are used merely for the purpose to distinguish an element from the other element.

It should be noted that technological terms used herein are merely used to describe a specific embodiment, but not to limit the present disclosure. Incidentally, unless clearly used otherwise, expressions in the singular number include a plural meaning. In this application, the terms “comprising” and “including” should not be construed to necessarily include all of the elements or steps disclosed herein, and should be construed not to include some of the elements or steps thereof, or should be construed to further include additional elements or steps.

FIG. 4is an exemplary embodiment illustrating a parallel meter-reading method between a concentrator and electricity meters to avoid a hidden node in accordance with the present disclosure.

The sorted electricity meters may be classified (in other words divided) into one meter-reading group according to each phase. That is, the sorted electricity meters may be classified into a first meter-reading group37-1, a second meter-reading group37-2, and a third meter-reading group37-3for each phase.

The parallel meter-reading method according to the present disclosure illustrates that the electricity meters are classified into one meter-reading group for each phase. However, the present disclosure may not be limited to this. The electricity meters may also be classified into a plurality of meter-reading groups for each phase.

Electricity meters receiving electric power of the same phase may be allowed for executing power line communication therebetween. Therefore, by the classification into the meter-reading groups37-1,37-2and37-3for each phase, a hidden node which may be caused due to different phases of electric power supplied may be avoided, and collision between signals received by the concentrator30may also be avoided.

Hereinafter, description will be given in detail of a method for determining a phase of electric power supplied to each electricity meter to classify (in other words sort or divide) the meter-reading group for each phase.

FIG. 5is a flowchart illustrating a parallel meter-reading method between a concentrator and electricity meters to avoid a hidden node in accordance with the present disclosure.

The concentrator modem31may sort (classify) a phase (for example R-phase, S-phase, and T-phase) of three phases electric power supplied to electricity meters (S1), and generate a reference signal for classifying a meter-reading group for each phase (S2). The reference signal may be generated for each phase.

The concentrator modem31may generate a request signal synchronized with each phase-based electric power, and transmit the generated request signal to each electricity meter modem (S3). The request signal may be a signal for requesting information related to a phase of electric power supplied to the electricity meter. The concentrator modem31may transmit the request signal to a random electricity meter modem.

Each electricity meter modem may determine the phase of electric power supplied to the electricity meter, and generate a response signal synchronized with the determined electric power to transmit to the concentrator modem31(S4). The response signal may include information related to the phase of electric power supplied to the electricity meter.

The concentrator30may determine whether or not the response signal transmitted by the electricity meter modem is synchronized with the reference signal (S5). That is, the concentrator30may determine whether or not the response signal is synchronized with the reference signal generated for each phase, to determine the phase of electric power supplied to the electricity meter.

The concentrator30may sort the electricity meters for each phase and classify the sorted electricity meters into a meter-reading group according to each phase (S6).

FIG. 6is a view illustrating a detection principle of a zero-cross detector in accordance with the present invention.

As illustrated inFIG. 6, three phases electric power may include R-phase electric power, S-phase electric power and T-phase electric power, and each may have a form of sine wave. The sine wave may have a moment (in other words time point) that its size becomes 0(zero) per every cycle. This is referred to as a zero-cross point. That is, a zero-cross detector may search for a point where the size of the sine wave is 0(zero).

For example, if it is assumed that a case where an initial point (origin point) is the zero-cross point is R-phase electric power, there may be two zero-cross points found, having a phase difference of 120° based on the initial point where the size of the R-phase electric power becomes 0. Electric power flowing through one of the two zero-cross points may have the S-phase, and electric power flowing through the other may have the T-phase.

Therefore, the concentrator modem31may classify a phase of three-phases electric power supplied to the electricity meters into R-phase, S-phase and T-phase using the zero-cross detector.

FIG. 7is an exemplary view illustrating a method of detecting a phase of electric power supplied to an electricity meter in accordance with the present disclosure.

Referring toFIGS. 2,4and7, the concentrator modem31may generate a request signal synchronized with each phase of three phases electric power, and transmit the request signal to each electricity meter.

The concentrator30may be allowed to transmit the request signal to a random electricity meter because of having a list of power line communication modems of all the electricity meters. The concentrator30may register (in other words record and save) the list of power line communication modems in an automatic or manual manner.

The request signal may be a signal for requesting information related to a phase of electric power supplied to an electricity meter, and preferably use a frequency of 60 Hz. This is because electric power supplied to a consumer generally uses a frequency of 60 Hz, and the request signal is able to be transmitted to the consumer by being synchronized with electric power when the frequency of the request signal is equal to the frequency of electric power supplied. Here, the frequency may not be limited to this, and it may be obvious that other frequencies can also be used.

Since a consumer receives single-phase electric power (in other words single-phase alternating current electric power), an electricity meter modem (not shown) may detect a zero-cross point of the single-phase electric power supplied by using a zero-cross detector.

The electricity meter modem may generate a response signal synchronized with the detected zero-cross point, and transmit the response signal to the concentrator modem31. The response signal may include information related to a phase of electric power supplied to the meter.

A modem processing time denotes a time spent for detecting the zero-cross point.

The concentrator modem31may detect a zero-cross point of the response signal using the zero-cross detector. The concentrator modem31may determine whether the response signal is synchronized with a reference signal of R-phase, S-phase or T-phase based on the zero-cross point of the response signal.

That is, upon being synchronized with one of the three phases, the concentrator30may determine it as the phase of the electric power supplied to the electricity meter. This may allow the concentrator30to be aware of the phase of electric power supplied to the electricity meter.

When such processes are repeated, the phases of electric power supplied to all of the electricity meters may be determined. Accordingly, the concentrator30may classify the plurality of electricity meters sorted for each phase into a plurality of meter-reading groups matching each phase.

When the electricity meter modem and the concentrator modem31exceed a maximum distance (One-hop range) allowing for communication, the concentrator modem31may be unable to receive a response signal transmitted by the electricity meter modem, and the electricity meter modem may be unable to receive a request signal transmitted by the concentrator modem31.

The electricity meter modem located within the one-hop range from the concentrator30may receive a response signal of an electricity meter modem located at a distance that the response signal is unable to be transmitted to the concentrator30, and then transmit the received response signal to the concentrator modem. Consequently, the electricity meter modem may operate as a repeater.

The repeater may receive the response signal of the electricity meter modem located away from the one-hop range from the concentrator30, and transmit a response signal synchronized with its own zero-cross point to the concentrator modem30. Therefore, the repeater may transmit its own response signal and the response signal of the electricity meter modem located outside the one-hop range to the concentrator modem31. This may allow the electricity meters to be sorted not only into one meter-reading group but also into a plurality of meter-reading groups for each phase.