GB2511162A - Signal demodulation - Google Patents
Signal demodulation Download PDFInfo
- Publication number
- GB2511162A GB2511162A GB1321424.2A GB201321424A GB2511162A GB 2511162 A GB2511162 A GB 2511162A GB 201321424 A GB201321424 A GB 201321424A GB 2511162 A GB2511162 A GB 2511162A
- Authority
- GB
- United Kingdom
- Prior art keywords
- zero crossing
- waveform
- power line
- voltage
- line voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/54—Systems for transmission via power distribution lines
- H04B3/542—Systems for transmission via power distribution lines the information being in digital form
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00006—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
- H02J13/00007—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using the power network as support for the transmission
- H02J13/00009—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using the power network as support for the transmission using pulsed signals
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00006—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
- H02J13/00007—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using the power network as support for the transmission
- H02J13/0001—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using the power network as support for the transmission using modification of a parameter of the network power signal
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B47/00—Circuit arrangements for operating light sources in general, i.e. where the type of light source is not relevant
- H05B47/10—Controlling the light source
- H05B47/175—Controlling the light source by remote control
- H05B47/185—Controlling the light source by remote control via power line carrier transmission
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B2203/00—Indexing scheme relating to line transmission systems
- H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
- H04B2203/5404—Methods of transmitting or receiving signals via power distribution lines
- H04B2203/542—Methods of transmitting or receiving signals via power distribution lines using zero crossing information
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
- Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
- Y04S10/52—Outage or fault management, e.g. fault detection or location
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
The present disclosure relates to the demodulation of power line communication (PLC) signals modulated using a zero crossing modulation technique. The modulation technique involves selectively perturbing (100, Fig. 1) a powerline voltage waveform (102, Fig. 1) in the vicinity of a zero crossings. In the signal demodulation method of the invention, the incoming powerline voltage waveform is integrated only around detected zero crossing points. A control signal at a multiple of the powerline waveform frequency is generated 204. The control signal is phase locked 206 with the powerline waveform. This control signal is used to control when the powerline waveform is switched 222 to an integration module 220. To determine whether a given zero-crossing has been modulated, a digital representation of the integration value associated with the zero-crossing is compared 212 with an integration value representing a zero-crossing at which no perturbation was applied.
Description
Signal Demodulation The present disclosure relates to signal demodulation, and in particular to apparatus and methods for demodulating data that is transmitted by zero crossing modulation of a power line voltage.
Electrical power is distributed at either 50 or 60 Hertz (Hz] alternating current (AC) depending on the prevailing standard at a given location in the world. Power line communication [PLC] is a technique enabling the transfer of data on a conductor that is also used simultaneously for AC electric power transmission or electric power distribution to consumers. It is also known as power line carrier, power line digital subscriber line [PDSL], mains communication, power line telecommunications, or power line networking.
More specifically, power line carrier relies upon superimposing a frequency in addition to the AC power frequency to carry digital data and control commands to remote devices. Typically the superimposed signal is a modulated carrier wave of between 20 and 200 kflz. The power and data frequencies coexist on the same wiring system without ever affecting each other.
Distance is a limitation when superimposing a separate carrier. The further a signal has to travel, the more it will degrade or dampen. If the signal degrades too much, the target device will never recognize it. Another potential problem results from filters -devices such as surge protectors that are designed to take out high frequency noise.
These filters are intended to protect equipment from damaging noise but they can inadvertently filter out the power line carrier signal.
An example application area where distance limitations are of particular concern is that of public lighting systems. Particular streetlights are connected to complex electrical networks and operate over long distances. This potentially results in loss of the control signal that controls the target light(s). In many cases lighting systems share the same wires as domestic and other loads therefore any system intended to control lighting must have high penetration of the network to reach the remote lights.
In order to achieve effective network penetration for public lighting and similar applications, it is possible to provide a pulse transmitter that generates a series of small short-circuit pulses which are impressed upon the mains voltage waveform, without interfering with its quality.
The pulses are arranged in unique sequences to form coded signals that can be used to activate relays tuned to recognise them. Because data does not depend on adding a high frequency carrier to the power waveform but actually modifies the power wave form itself, it permeates all parts of the electrical network. The transmitter sends sequences of logic states over an electrical power distribution network by purposely causing a momentary distortion of selected cycles of the supply voltage waveform in the region of zero cross-over. By this means, maximum signal is achieved with the minimum disturbance to the R.M.S. value of the supplyvoltage.
The principle is explained by reference to the simplified distribution network illustrated in the Figure 1. Here, a perturbation 100 is impressed on a power line voltage waveform 102 around its zero crossing point The perturbation causes a variation, SV from the expected voltage waveform that forms the basis for encoding data. Successive zero crossing points of the power line waveform may have the perturbation present representing a first logic state, or absent, representing a second logic state. This succession of logic states can be used to encode data.
However, this technique is prone to data loss or corruption as spurious noise in the power line waveform can be confused as being the intended data carrying perturbations. Whole packets of data can be lost in this way.
Furthermore, the frequency of the power wave form is asynchronous with respect to recovery circuits used in analogue demodulation techniques for recovering the signal.
Jitter in the frequency of the power waveform with respect to the detection circuit in the receiver will appear as noise.
It is therefore desirable to provide a signal demodulation technique with improved noise performance and tolerance to frequency perturbations.
According to a first aspect of the present disclosure there is provided a method of demodulating a signal encoded with zero crossing modulation of a power line voltage, comprising: detecting a zero crossing point of an incoming power line voltage waveform; selectively integrating the voltage at or around said zero crossing point and converting said analogue integrated signal into a digital representation of the detected voltage.
Optionally) the method comprises) after detecting a zero crossing point: multip'ying the frequency of the waveform to obtain a high frequency phase locked equivalent signal; and carrying out said selective voltage integration based on a comparison of the incoming zero crossing point with the high frequency phase locked equivalent signal.
Optionally, the method comprises storing a sampled signal for at least one cycle period of the power waveform, sampling data from another power cycle, comparing the sampled digital values, and determining that a data bit has been transmitted if the difference between said sampled digital values meets or exceeds a predetermined threshold.
Optionally, the method comprises storing n+1 data bits where n is the length of a data sequence.
According to a second aspect of the disclosure there is provided demodulation apparatus comprising: an input for receiving a power line voltage waveform encoded with zero crossing modulation; a zero crossing detector arranged to detect a zero crossing point of the received power line voltage waveform; a voltage integrator; and switch means arranged to selectively couple the input power line voltage waveform with the voltage integrator; wherein the switch means is arranged to couple the input power line voltage waveform with the voltage integrator in response to a zero crossing event detected by the zero crossing detector.
Optionally, the apparatus further comprises a digital frequency multiplier and a phase calculator coupled with said zero crossing detector for multiplying the frequency of the waveform to obtain a high frequency phase locked equivalent signal; and wherein the switch means is arranged to couple the input power line voltage waveform with the voltage integrator in response to the zero crossing point of said high frequency phase locked equivalent signal.
Optionally, the apparatus comprises storage means arranged to store a sampled signal for at least one cycle period of the power waveform, and comparator means for comparing sampled digital values from successive data samples, and determining that a data bit has been transmitted if the difference between said sampled digital values meets or exceeds a predetermined threshold.
Optionally, the storage means is arranged to store n+1 data bits where n is the length of a data sequence.
The disclosure will be described below, by way of example only, with reference to the accompanying drawings, in which: Figure 1 illustrates a method of encoding data by impressing a perturbation at the zero crossing points of a power line voltage waveform; and Figure 2 illustrates a circuit for demodulating a signal encoded according to the method illustrated in Figure 1.
The present disclosure uses digital recovery techniques to significantly improve the reliability of signal detection and to improve the signal to noise ratio of the recovered signal compared to alternative methods of signal detection.
Figure 2 shows an example embodiment of components that may form part of an interface unit or receiver for receiving and demodulating signals that are transmitted by zero crossing modulation of a power line voltage.
As shown in Figure 2, a microprocessor 200 is provided that comprises a zero-crossing detector 202, a digital frequency multiplier 204, phase calculator 206, analogue to digital converter [ADC] 208, delay line 210, comparator 212, data decoder 214 and control circuit 216. The control circuit outputs a control command 218 that is transmitted to a host system or device for controlling a connected device. The receiver also comprises a sampling switch 220 and voltage integrator 224, which provides an input for the ADC 208.
The zero-crossing detector 202 detects the zero-crossing point of the incoming power line waveform 224. A detection of a zero-crossing event is used as a trigger that is precisely synchronised for the operation of switch 220 to the time from when the zero crossing event occurred in that individual cycle, which enables the voltage integrator 222. The time the integrator samples the incoming wave is such that it is only active when a valid signal should be present, thus reducing the effects of spurious signals due to other forms of voltage disturbance. The incoming power line signal is digitally processed such that the signal recovery process is both phase and frequency locked, this control is derived from a digital frequency multiplier and phase calculator 206 to derive a high frequency phase locked equivalent of the original power line waveform.
These components (204 & 206] are optional but will provide an improved performance.
Comparing the incoming zero-crossing point with the multiplied version allows precise control of the data sampling. When a data bit is transmitted over the power signal its position will always be at the same point with respect to the phase angle of the power waveform.
Using this digital technique allows the sampling gate 220 to anticipate when signal should be present and allows the receiver to synchronously detect the exact time and position of the modulated signal. The voltage integrator 22 integrates the sampled signal for a precise time and digitised by an analogue to digital converter 208. The sampled signal is stored at storage and delay line component 210 for exactly one cycle period of the power waveform, and then the process is repeated whereby the next power cycle is sampled and compared to the digital value of the last cycle.
A change in level between the first and second cycle can be due to a data transmission.
In order to distinguish between data transmission and other variations caused by noise, the difference can be checked against a predetermined digital threshold which can be expressed as a defined percentage difference between successive values. It will be appreciated that other thresholds may be defined based on absolute sampled values or other statistical metrics. A difference that meets or exceeds the threshold is then accepted as valid data.
The data decoder can keep a scrolling store of sampled data bits and can be arranged such that n+1 data bits are stored where n is the maximum length of a data sequence.
By continuously processing and comparing a valid data sequence can be recognised and any noise spikes rejected. The payload of the data can be arranged such that data redundancy will detect or correct and error in the received payload.
The control command 218 may be a command for controlling devices according to a variety of different protocols. One example is the digital addressable lighting interface (DALI) standard for controlling lighting fixtures. The disclosure provides for reliable and improved demodulation of lighting control commands sent over a power line. The power line communication data is converted by the receiver into DALI commands that can be decoded by a suitable DALI lighting controller.
A DALI network comprises a controller and one or more lighting devices (e.g., electrical ballasts and dimmers) that have DALI interfaces. The controller can monitor and control each lightby means ofabi-directional data exchange. The DALI protocol permits devices to be individually addressed and it also incorporates Group and Scene broadcast messages to simultaneously address multiple devices.
Modern lighting devices using LEDs and other technologies now include the ability to electronically reduce the light intensity. Such combined lights and controllable ballasts are applied to street and architectural lighting.
Other application areas of the disclosure include street lights and other lighting systems that are controlled by other protocols e.g. DMxS12. it will be appreciated that the disclosure is not limited to any one example, but can be used for the demodulation of signals in general.
Various modifications and improvements can be made to the above without departing
from the scope of the disclosure.
Claims (8)
- CLAIMS1. A method of demodulating a signal encoded with zero crossing modulation of a power line voltage, comprising: detecting a zero crossing point of an incoming power line voltage waveform; selectively integrating the voltage at or around said zero crossing point; and converting said analogue integrated signa' into a digital representation of the detected voltage.
- 2. The method of claim 1, comprising, after detecting a zero crossing point: multiplying the frequency of the waveform to obtain a high frequency phase locked equivalent signal; and carrying out said selective voltage integration based on a comparison of the incoming zero crossing point with the high frequency phase locked equivalent signal.
- 3. The method of claim 1 or claim 2, comprising storing a sampled signal for at least one cycle period of the power waveform, sampling data from another power cycle) comparing the sampled digital values, and determining that a data bit has been transmitted if the difference between said sampled digital values meets or exceeds a predetermined threshold.
- 4. The method of claim 3, comprising storing n+ 1 data bits where n is the length of a data sequence.
- 5. Demodulation apparatus comprising: an input for receiving a power line voltage waveform encoded with zero crossing modulation; a zero crossing detector arranged to detect a zero crossing point of the received power line voltage waveform; a voltage integrator; and switch means arranged to selectively couple the input power line voltage waveform with the voltage integrator; wherein the switch means is arranged to couple the input power line voltage waveform with the voltage integrator in response to a zero crossing event detected by the zero crossing detector.
- 6. The demodulation apparatus of claim 5, further comprising a digital frequency multiplier and a phase calculator coupled with said zero crossing detector for multiplying the frequency of the waveform to obtain a high frequency phase thcked equivalent signal; and wherein the switch means is arranged to couple the input power line voltage waveform with the voltage integrator in response to the zero crossing point of said high frequency phase locked equivalent signal.
- 7. The demodulation apparatus of claim S or claim 6, comprising storage means arranged to store a sampled signal for at least one cycle period of the power waveform, and comparator means for comparing sampled digital values from successive data samples, and determining that a data bit has been transmitted if the difference between said sampled digital values meets or exceeds a predetermined threshold.
- 8. The demodulation apparatus of claim 7, wherein the storage means is arranged to store n+1 data bits where n is the length of a data sequence.AMENDMENTS TO THE CLAIMS HAVE BEEN FILED AS FOLLOWS:CLAIMS1. A method of demodulating a signal encoded with zero crossing modulation of a power line voltage, comprising: coupling an input power line voltage waveform with a zero crossing detector; digitally frequency multiplying the waveform and performing a phase calculation to obtain a high frequency phase locked equivalent signal; and operating a switch means in response to a zero crossing point of said high frequency phase locked equivalent signal to selectively couple the power line voltage with a voltage integrator.2. The method of claim 1, further comprising converting an analogue integrated signal from the voltage integrator into a digital representation of the detected voltage.3. The method of claim 2, comprising storing said digital representation of the detected voltage for at least one cycle period of the power line voltage waveform, obtaining a C digital representation of a detected voltage from another power cycle, comparing the o values of the digital representations, and determining that a data bit has been transmitted if the difference between said values meets or exceeds a predetermined threshold.4. The method of claim 3, comprising storing n+ 1 data bits where n is the length of a data sequence.5. Demodulation apparatus comprising: an input for receiving a power line voltage waveform encoded with zero crossing modulation; a zero crossing detector arranged to detect a zero crossing point of the received power line voltage waveform; a voltage integrator; and switch means arranged to selectively couple the input power line voltage waveform with the voltage integrator; wherein the switch means is arranged to couple the input power line voltage waveform with the voltage integrator in response to a zero crossing event detected by the zero crossing detector; and further comprising a digital frequency multiplier and a phase calculator coupled with said zero crossing detector for multiplying the frequency of the waveform to obtain a high frequency phase locked equivalent signal; and wherein the switch means is arranged to couple the input power line voltage waveform with the voltage integrator in response to the zero crossing point of said high frequency phase locked equivalent signal.6. The demodulation apparatus of claim 5, comprising an analogue to digital converter for converting an analogue integrated signal from the voltage integrator into a digital representation of the detected voltage.7. The demodulation apparatus of claim 6, comprising storage means arranged to store said digital representation of the detected voltage for at least one cycle period of the C power waveform, and comparator means for comparing digital representations from c successive cycle periods of the power waveform, and determining that a data bit has been transmitted if the difference between said values of said digital representations meets or exceeds a predetermined threshold.8. The demodulation apparatus of claim 7, wherein the storage means is arranged to store n+1 data bits where n is the length of a data sequence.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB201321424A GB2511162B (en) | 2013-12-04 | 2013-12-04 | Signal demodulation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB201321424A GB2511162B (en) | 2013-12-04 | 2013-12-04 | Signal demodulation |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB201321424D0 GB201321424D0 (en) | 2014-01-15 |
| GB2511162A true GB2511162A (en) | 2014-08-27 |
| GB2511162B GB2511162B (en) | 2015-04-29 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB201321424A Expired - Fee Related GB2511162B (en) | 2013-12-04 | 2013-12-04 | Signal demodulation |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2511162B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106230482A (en) * | 2016-08-26 | 2016-12-14 | 北京艾普智城网络科技有限公司 | Power-line carrier communication method and system |
| CN106451793A (en) * | 2016-11-29 | 2017-02-22 | 国网江苏省电力公司常州供电公司 | Intelligent substation breaker phase selection control method based on digital voltage signal |
| CN108173571A (en) * | 2017-12-29 | 2018-06-15 | 国网北京市电力公司 | Transmission of phase method, apparatus, storage medium and processor |
| EP3701693A4 (en) * | 2017-10-27 | 2021-07-07 | Terawave, LLC | Receiver for high spectral efficiency data communications system using encoded sinusoidal waveforms |
| US11876659B2 (en) | 2017-10-27 | 2024-01-16 | Terawave, Llc | Communication system using shape-shifted sinusoidal waveforms |
Citations (5)
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| GB1500891A (en) * | 1974-07-18 | 1978-02-15 | Gen Electric Co Ltd | Systems for transmitting information in an alternating current electricity supply system |
| GB2065425A (en) * | 1979-10-12 | 1981-06-24 | Zellweger Uster Ag | Signal transmission over power lines |
| EP0030816A1 (en) * | 1979-12-07 | 1981-06-24 | THE GENERAL ELECTRIC COMPANY, p.l.c. | A.C. electrical supply signalling arrangements |
| US4914418A (en) * | 1989-01-03 | 1990-04-03 | Emerson Electric Co. | Outbound detector system and method |
| EP1071186A1 (en) * | 1999-07-14 | 2001-01-24 | BCN Data Systems Inc. | Detecting and mapping power line loss in a power network |
-
2013
- 2013-12-04 GB GB201321424A patent/GB2511162B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1500891A (en) * | 1974-07-18 | 1978-02-15 | Gen Electric Co Ltd | Systems for transmitting information in an alternating current electricity supply system |
| GB2065425A (en) * | 1979-10-12 | 1981-06-24 | Zellweger Uster Ag | Signal transmission over power lines |
| EP0030816A1 (en) * | 1979-12-07 | 1981-06-24 | THE GENERAL ELECTRIC COMPANY, p.l.c. | A.C. electrical supply signalling arrangements |
| US4914418A (en) * | 1989-01-03 | 1990-04-03 | Emerson Electric Co. | Outbound detector system and method |
| EP1071186A1 (en) * | 1999-07-14 | 2001-01-24 | BCN Data Systems Inc. | Detecting and mapping power line loss in a power network |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106230482A (en) * | 2016-08-26 | 2016-12-14 | 北京艾普智城网络科技有限公司 | Power-line carrier communication method and system |
| CN106230482B (en) * | 2016-08-26 | 2019-08-09 | 北京艾普智城网络科技有限公司 | Power-line carrier communication method and system |
| CN106451793A (en) * | 2016-11-29 | 2017-02-22 | 国网江苏省电力公司常州供电公司 | Intelligent substation breaker phase selection control method based on digital voltage signal |
| CN106451793B (en) * | 2016-11-29 | 2018-10-16 | 国网江苏省电力公司常州供电公司 | Circuit breaker of intelligent transformer substation phase-controlled method based on digital voltage signal |
| EP3701693A4 (en) * | 2017-10-27 | 2021-07-07 | Terawave, LLC | Receiver for high spectral efficiency data communications system using encoded sinusoidal waveforms |
| US11228474B2 (en) | 2017-10-27 | 2022-01-18 | Terawave, Llc | High spectral efficiency data communications system |
| EP4156617A1 (en) * | 2017-10-27 | 2023-03-29 | Terawave, LLC | Receiver for high spectral efficiency data communications system using encoded sinusoidal waveforms |
| US11876659B2 (en) | 2017-10-27 | 2024-01-16 | Terawave, Llc | Communication system using shape-shifted sinusoidal waveforms |
| CN108173571A (en) * | 2017-12-29 | 2018-06-15 | 国网北京市电力公司 | Transmission of phase method, apparatus, storage medium and processor |
| CN108173571B (en) * | 2017-12-29 | 2021-09-21 | 国网北京市电力公司 | Phase transmission method, phase transmission device, storage medium and processor |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2511162B (en) | 2015-04-29 |
| GB201321424D0 (en) | 2014-01-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20191204 |