CA2105095A1 - Electricity cost monitor - Google Patents
Electricity cost monitorInfo
- Publication number
- CA2105095A1 CA2105095A1 CA 2105095 CA2105095A CA2105095A1 CA 2105095 A1 CA2105095 A1 CA 2105095A1 CA 2105095 CA2105095 CA 2105095 CA 2105095 A CA2105095 A CA 2105095A CA 2105095 A1 CA2105095 A1 CA 2105095A1
- Authority
- CA
- Canada
- Prior art keywords
- power consumption
- voltage
- samples
- current
- measuring means
- 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.)
- Abandoned
Links
- 230000005611 electricity Effects 0.000 title claims description 7
- 238000000034 method Methods 0.000 claims abstract description 25
- 238000005070 sampling Methods 0.000 claims abstract description 13
- 238000012544 monitoring process Methods 0.000 claims abstract description 10
- 238000004891 communication Methods 0.000 claims description 11
- 238000004364 calculation method Methods 0.000 claims description 7
- 238000005259 measurement Methods 0.000 claims description 5
- 230000007935 neutral effect Effects 0.000 description 6
- 238000012935 Averaging Methods 0.000 description 4
- 238000009434 installation Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 2
- 101100353161 Drosophila melanogaster prel gene Proteins 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R22/00—Arrangements for measuring time integral of electric power or current, e.g. electricity meters
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R21/00—Arrangements for measuring electric power or power factor
- G01R21/133—Arrangements for measuring electric power or power factor by using digital technique
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Remote Monitoring And Control Of Power-Distribution Networks (AREA)
Abstract
Abstract of the Disclosure A method and apparatus for real time monitoring of power consumption of various loads by an end user utilizes conventional current and voltage measuring means to determine instantaneous power consumption, and a computer displays these values to the user, as well as recent historical values over a selcted period of time.
In a preferred embodiment of the invention a relatively few number of samples are taken per cycle, the samples being distributed such that over a selected number of cycles the samples cover the entire waveform cycle equally. An average instantaneous power determination is then calculated over the sampling interval and displayed on the computer.
In a preferred embodiment of the invention a relatively few number of samples are taken per cycle, the samples being distributed such that over a selected number of cycles the samples cover the entire waveform cycle equally. An average instantaneous power determination is then calculated over the sampling interval and displayed on the computer.
Description
21~Q9~
:
Field of Invention The present invention relates to electricity -cost monitors. In particular, the present invention relates to an electricity cost monitor which monitors the power consumption of various loads and provides instantaneous cost information to the user. -Backaround of the Invention ~ -Consumers and businesses are becoming increasingly cost-conscious and conservation-oriented in many areas, lncludlng electrical power consumption ln the home or business. ~o thls end it is advantageous to provide to a consumer of electriclty lnformation concerning power usage, to enable the consumer to adopt consumption habits which are cost-efficient and ;~
conservation-oriented. Suppliers of electrical power benefit from thls as well, in terms of reduced power consumption generally and during peak usage periods.
A number of methods are available for measuring power consumption in individual loads. These include the use of various commercial or custom watt transducers, as well as the calculation oi7 power directly from waveform ~amples involving some combination of voltage, current and phase angle.
It 18 advantageou~ to provide power con~umption feedback on a real-time basis, 80 that the user can instantaneously determlne total power consumption, and proportional power consumption of various loads, at desired intervals. Calculating power directly from waveform samples provides a means for supplying real-time load monitoring feedback, however conventional techniques for doing 80 involve constant monitoring of all portions ~
of the waveform cycle and constant calculation of ~ --- ~ --5. ~ ;~
consumption data, which requires a high speed computer and considerable computing overhead.
The present invention overcomes this disadvantage by providing a method and apparatus for -~
displaying power consumption costs to the consumer in real time. The invention utilizes a variation of direct waveform sampling which involves a small number of voltage and current samples per cycle, providing corresponding instantaneous power determinations which are averaged over a large prime number of cycles to arrive at present average power usage. The samples are spaced in such a way that over the total averaging interval the samples collectively cover all parts of one waveform cycle equally. Using the present invention the determination of power remains accurate even in the presence of harmonic distortion, provided that the distortion remains constant over the averaging interval, which 18 normally the case at least approximately. The method is generally as accurate as conventional high speed direct sampling methods, but requires only a small fraction of the computing overhead. ~;
Su arY of the Invention The present invention thus provldes a method o~
monitoring electrical power consumption by a consumer of electricity, comprising the steps of periodically sampling the load current using current measuring means in communication with an electrical power supply circuit supplying a load, periodically sampling the load voltage using voltage measuring means in communication with the electrical supply circuit, calculating electrical power consumption from current and voltage values produced by the analog-to-digital converter for a desired number of -loads, and periodically displaying the calculated values of average instantaneous power consumption.
. . .:
, ,.. .
:. , 2 ~
The present invention further provides a method of calculating instantaneous power consumption of an electrical load comprising the steps of sampling values of current and voltage at selected portion~ of successive cycles such that over a predetermined number of samples the measurements collectively cover all parts of the .
waveform cycle equally, calculating a value of average instantaneous power consumption over the predetermined :.
number of samples, and displaying the value of average :
instantaneous power consumption.
The present invention further provides an apparatus for monitoring electrical power consumption by a consumer of electricity, comprising means for measuring current in communication with an electrical power supply circuit, means for measuring voltage in communication wlth the electrical power supply circuit, and means for ~;
calculating and displaying instantaneous electrical power consumption from current and voltage values.
Brlef DescrlDtlon of the Drawlnqs In drawings which illustrate by way of example only a preferred embodlment of the present invention, Flgure 1 lllustrates a 8amplin~ taken over a slngle cycle u8ing the method of the present invention, Figure 2 illustrates a composite sampling taken over 199 cycles, Flgure 3 illustrates an lnterface panel for the apparatus of the present invention, Figure 4 illustrates a typical real-time display da showing a cost of present electrical usage for 8 household loads, and - , . " . , ",.. - . rr 210~
Figure 5 illustrates a typical recent historical display mode showing a cost of electrical usage over a period of hours.
Detailed Descri~tion of the Invention The method and apparatus of the present invention provide a means for measuring and displaying in real time information concerning instantaneous power consumption by an end user. Mounted on the electrical circuits supplying the various loads being monitored are conventlonal current measuring means 10 and conventional voltage measuring means 12, both in communication with an analog-to-digital interface within a computer via -suitable termination panels 18,20 shown in Figure 3.
For residential and small commercial/industrial installations, 120/240 single phase service i8 standard, and the current is normally 200 amps or less. In a preferred Pmhodiment of the invention current is measured using a current transformer 10 mounted on each circuit 2 to be monltored, and the lndlvldual current transformer outputs are routed through a multiconductor cable 11 to the termlnation panel 18, and on through another multiconductor cable 13 to the termination resistor panel 20, whsre the current 18 fed through a 8mall 8hunt resistor 23 to produce a voltage that can be read by the 25 analog-to-digital converter inside the computer 22. ~;
~igure 3 shows an 8-load configuration of the invention.
Loads that operate solely on 240 V, such as an electric water heater, have the same current on each side of the line. They can therefore use a single current transformer for the current signal so long as the reading is multiplied by the difference of the two line-to~
neutral voltages when calculating power consumption. ~
Since the voltages are out of phase, the voltage ~ ~ -,.. ' 21~9~
_5_ difference is approximately equal to twice the individual voltage of either line.
If a 240 V device has internal parts that operate on 120 v, for example an electric furnace utilizing a 120 V fan motor, the current through the two sides of the supply 2 may be different and should be monitored separately. Each current should be multiplied by its own line side voltage to calculate power consumption. The total power for the load would be the sum of the power for the two sides. This method is accurate for all cases and should be used in cas~ of any doubt as to whether a 240 V appliance has any 120 V
components.
Household and small industrial installation voltages are low enough to be easily measured by a conventional resistor divider network 12 located in the termination panel 18. For installations involving a single electrical panel voltages can be referenced to ground, since the neutral is tled to ground at the panel and the current required for the voltage measurement clrcuitry can be designed to be very low (less than 5mA).
For installations with more than one electrical panel it may be prel'erable to connect the voltage divider between line and neutral and u~e a dil'i'erential lnput signal for mea~uring the voltages i'rom the remote panel. This will eliminate problems which can occur if there is a signiflcant ground current between the electrical panels, which can result in significant voltage between the neutral of the remote panel and the ground of the local panel that could cause errors in the voltage readings.
Many small businesses have equipment that requires three phase power. To provide power to standard 120 V single phase loads as well as three phase loads, a 120/208 V three phase supply is frequently used. In 21~5~
these cases the 120 V line-to-neutral voltage is used and measured in the manner described above for single phase service. The 208 v phase to phase loads can be measured using a single current and single voltage if the appropriate phase to phase voltage is being measured.
Since neither end of this voltage signal is referenced to neutral (or ground), the voltage measurement requires a - --differential input to the analog-to-digital converter.
Care must be taken to ensure that the maximum voltage limits for the converter are not exceeded under all normal operating conditions. The power in this case can also be measured as the current through the load multiplied by the vector difference between the two phase to neutral voltages. Alternatively, in some cases it may be more economical to use a conventional voltage transformer, which might simplify some of the avove procedures.
A computer 22 is programmed to periodically sample the current and voltage values produced in the input interface 20 through ribbon cable 24, and to calculate instantaneous power consumption from the sampled values. A preferred embodiment of the invention utilizes a "distributed sampling" variation of conventional dirQct calculation methods of monitoring power consumption. A8 8hown ln Figure 1, the computer 22 calculatQs power consumptlon from a relatlvely small numbQr of voltage and current samples per cycle, and averages these values over a relatively large prlme number of cycles to calculate present average power consumption. The samples are distributed in such a way that over the averaging period, the samples collectively cover all portions of one waveform cycle equally, as shawn in Figure 2. This obviates the effects of harmonic distortion, providing that the distortion remains constant over the averaging interval, which is generally approximately the ca~e. Non-constant harmonic distortion , 2 ~ 9 ~ - :
present during transient conditions such as load start-up or shut-down can cause significant errors, but this has a negligible effect because the power consumption is changing rapidly at such times anyway.
In a 60 Hz power supply the preferred sampling rate involves approximately 4.9 samples per cycle and an integrating period of 199 samples over an interval of 41 cycles (0.68 seconds). This provides a close approximation to conventional direct calculation methods sampling one cycle at the rate o~ about 12,000 samples per second, while the invention actually operates at about 300 samples per second. It can thus be seen that significantly less computing power is required using the "distrlbuted sampllng" method descrlbed herein, while the accuracy of the calculated power consumption remains within acceptable limits. Additionally, the cost of the apparatus in an 8-load monitoring system is considerably less than that of conventional monitoring methods.
In a preferred embodlment, the apparatus of the present inventlon will display both graphically and nuMerically the cost of present power consumption on a per load basis, and a total present cost, as shown in Plgure 4. The in~tantaneous power consumptlon i8 computed approximately every 3 milliseconds, averaged, and u~ed to update the present-usage dlsplays about every 0.6 seconds. Optionally the apparatus may be directed to record the computed values and display historlcal costs for each load over a period from the recent past up to the present ~by day, week, month, year), to provlde the user with useful information that can encourage maxlmizlng efficlency in the use of the various loads.
:
Field of Invention The present invention relates to electricity -cost monitors. In particular, the present invention relates to an electricity cost monitor which monitors the power consumption of various loads and provides instantaneous cost information to the user. -Backaround of the Invention ~ -Consumers and businesses are becoming increasingly cost-conscious and conservation-oriented in many areas, lncludlng electrical power consumption ln the home or business. ~o thls end it is advantageous to provide to a consumer of electriclty lnformation concerning power usage, to enable the consumer to adopt consumption habits which are cost-efficient and ;~
conservation-oriented. Suppliers of electrical power benefit from thls as well, in terms of reduced power consumption generally and during peak usage periods.
A number of methods are available for measuring power consumption in individual loads. These include the use of various commercial or custom watt transducers, as well as the calculation oi7 power directly from waveform ~amples involving some combination of voltage, current and phase angle.
It 18 advantageou~ to provide power con~umption feedback on a real-time basis, 80 that the user can instantaneously determlne total power consumption, and proportional power consumption of various loads, at desired intervals. Calculating power directly from waveform samples provides a means for supplying real-time load monitoring feedback, however conventional techniques for doing 80 involve constant monitoring of all portions ~
of the waveform cycle and constant calculation of ~ --- ~ --5. ~ ;~
consumption data, which requires a high speed computer and considerable computing overhead.
The present invention overcomes this disadvantage by providing a method and apparatus for -~
displaying power consumption costs to the consumer in real time. The invention utilizes a variation of direct waveform sampling which involves a small number of voltage and current samples per cycle, providing corresponding instantaneous power determinations which are averaged over a large prime number of cycles to arrive at present average power usage. The samples are spaced in such a way that over the total averaging interval the samples collectively cover all parts of one waveform cycle equally. Using the present invention the determination of power remains accurate even in the presence of harmonic distortion, provided that the distortion remains constant over the averaging interval, which 18 normally the case at least approximately. The method is generally as accurate as conventional high speed direct sampling methods, but requires only a small fraction of the computing overhead. ~;
Su arY of the Invention The present invention thus provldes a method o~
monitoring electrical power consumption by a consumer of electricity, comprising the steps of periodically sampling the load current using current measuring means in communication with an electrical power supply circuit supplying a load, periodically sampling the load voltage using voltage measuring means in communication with the electrical supply circuit, calculating electrical power consumption from current and voltage values produced by the analog-to-digital converter for a desired number of -loads, and periodically displaying the calculated values of average instantaneous power consumption.
. . .:
, ,.. .
:. , 2 ~
The present invention further provides a method of calculating instantaneous power consumption of an electrical load comprising the steps of sampling values of current and voltage at selected portion~ of successive cycles such that over a predetermined number of samples the measurements collectively cover all parts of the .
waveform cycle equally, calculating a value of average instantaneous power consumption over the predetermined :.
number of samples, and displaying the value of average :
instantaneous power consumption.
The present invention further provides an apparatus for monitoring electrical power consumption by a consumer of electricity, comprising means for measuring current in communication with an electrical power supply circuit, means for measuring voltage in communication wlth the electrical power supply circuit, and means for ~;
calculating and displaying instantaneous electrical power consumption from current and voltage values.
Brlef DescrlDtlon of the Drawlnqs In drawings which illustrate by way of example only a preferred embodlment of the present invention, Flgure 1 lllustrates a 8amplin~ taken over a slngle cycle u8ing the method of the present invention, Figure 2 illustrates a composite sampling taken over 199 cycles, Flgure 3 illustrates an lnterface panel for the apparatus of the present invention, Figure 4 illustrates a typical real-time display da showing a cost of present electrical usage for 8 household loads, and - , . " . , ",.. - . rr 210~
Figure 5 illustrates a typical recent historical display mode showing a cost of electrical usage over a period of hours.
Detailed Descri~tion of the Invention The method and apparatus of the present invention provide a means for measuring and displaying in real time information concerning instantaneous power consumption by an end user. Mounted on the electrical circuits supplying the various loads being monitored are conventlonal current measuring means 10 and conventional voltage measuring means 12, both in communication with an analog-to-digital interface within a computer via -suitable termination panels 18,20 shown in Figure 3.
For residential and small commercial/industrial installations, 120/240 single phase service i8 standard, and the current is normally 200 amps or less. In a preferred Pmhodiment of the invention current is measured using a current transformer 10 mounted on each circuit 2 to be monltored, and the lndlvldual current transformer outputs are routed through a multiconductor cable 11 to the termlnation panel 18, and on through another multiconductor cable 13 to the termination resistor panel 20, whsre the current 18 fed through a 8mall 8hunt resistor 23 to produce a voltage that can be read by the 25 analog-to-digital converter inside the computer 22. ~;
~igure 3 shows an 8-load configuration of the invention.
Loads that operate solely on 240 V, such as an electric water heater, have the same current on each side of the line. They can therefore use a single current transformer for the current signal so long as the reading is multiplied by the difference of the two line-to~
neutral voltages when calculating power consumption. ~
Since the voltages are out of phase, the voltage ~ ~ -,.. ' 21~9~
_5_ difference is approximately equal to twice the individual voltage of either line.
If a 240 V device has internal parts that operate on 120 v, for example an electric furnace utilizing a 120 V fan motor, the current through the two sides of the supply 2 may be different and should be monitored separately. Each current should be multiplied by its own line side voltage to calculate power consumption. The total power for the load would be the sum of the power for the two sides. This method is accurate for all cases and should be used in cas~ of any doubt as to whether a 240 V appliance has any 120 V
components.
Household and small industrial installation voltages are low enough to be easily measured by a conventional resistor divider network 12 located in the termination panel 18. For installations involving a single electrical panel voltages can be referenced to ground, since the neutral is tled to ground at the panel and the current required for the voltage measurement clrcuitry can be designed to be very low (less than 5mA).
For installations with more than one electrical panel it may be prel'erable to connect the voltage divider between line and neutral and u~e a dil'i'erential lnput signal for mea~uring the voltages i'rom the remote panel. This will eliminate problems which can occur if there is a signiflcant ground current between the electrical panels, which can result in significant voltage between the neutral of the remote panel and the ground of the local panel that could cause errors in the voltage readings.
Many small businesses have equipment that requires three phase power. To provide power to standard 120 V single phase loads as well as three phase loads, a 120/208 V three phase supply is frequently used. In 21~5~
these cases the 120 V line-to-neutral voltage is used and measured in the manner described above for single phase service. The 208 v phase to phase loads can be measured using a single current and single voltage if the appropriate phase to phase voltage is being measured.
Since neither end of this voltage signal is referenced to neutral (or ground), the voltage measurement requires a - --differential input to the analog-to-digital converter.
Care must be taken to ensure that the maximum voltage limits for the converter are not exceeded under all normal operating conditions. The power in this case can also be measured as the current through the load multiplied by the vector difference between the two phase to neutral voltages. Alternatively, in some cases it may be more economical to use a conventional voltage transformer, which might simplify some of the avove procedures.
A computer 22 is programmed to periodically sample the current and voltage values produced in the input interface 20 through ribbon cable 24, and to calculate instantaneous power consumption from the sampled values. A preferred embodiment of the invention utilizes a "distributed sampling" variation of conventional dirQct calculation methods of monitoring power consumption. A8 8hown ln Figure 1, the computer 22 calculatQs power consumptlon from a relatlvely small numbQr of voltage and current samples per cycle, and averages these values over a relatively large prlme number of cycles to calculate present average power consumption. The samples are distributed in such a way that over the averaging period, the samples collectively cover all portions of one waveform cycle equally, as shawn in Figure 2. This obviates the effects of harmonic distortion, providing that the distortion remains constant over the averaging interval, which is generally approximately the ca~e. Non-constant harmonic distortion , 2 ~ 9 ~ - :
present during transient conditions such as load start-up or shut-down can cause significant errors, but this has a negligible effect because the power consumption is changing rapidly at such times anyway.
In a 60 Hz power supply the preferred sampling rate involves approximately 4.9 samples per cycle and an integrating period of 199 samples over an interval of 41 cycles (0.68 seconds). This provides a close approximation to conventional direct calculation methods sampling one cycle at the rate o~ about 12,000 samples per second, while the invention actually operates at about 300 samples per second. It can thus be seen that significantly less computing power is required using the "distrlbuted sampllng" method descrlbed herein, while the accuracy of the calculated power consumption remains within acceptable limits. Additionally, the cost of the apparatus in an 8-load monitoring system is considerably less than that of conventional monitoring methods.
In a preferred embodlment, the apparatus of the present inventlon will display both graphically and nuMerically the cost of present power consumption on a per load basis, and a total present cost, as shown in Plgure 4. The in~tantaneous power consumptlon i8 computed approximately every 3 milliseconds, averaged, and u~ed to update the present-usage dlsplays about every 0.6 seconds. Optionally the apparatus may be directed to record the computed values and display historlcal costs for each load over a period from the recent past up to the present ~by day, week, month, year), to provlde the user with useful information that can encourage maxlmizlng efficlency in the use of the various loads.
Claims (20)
1. A method of monitoring electrical power consumption by a consumer of electricity, comprising the steps of:
periodically sampling the load current using current measuring means in communication with an electrical power supply circuit supplying a load, periodically sampling the load voltage using voltage measuring means in communication with the electrical supply circuit, calculating electrical power consumption from current and voltage values produced by the analog-to-digital converter for a desired number of loads, and periodically displaying the calculated values of average instantaneous power consumption.
periodically sampling the load current using current measuring means in communication with an electrical power supply circuit supplying a load, periodically sampling the load voltage using voltage measuring means in communication with the electrical supply circuit, calculating electrical power consumption from current and voltage values produced by the analog-to-digital converter for a desired number of loads, and periodically displaying the calculated values of average instantaneous power consumption.
2. The method of claim 1 in which the step of displaying the calculated values includes a graphic display.
3. The method of claim 1 in which the current measuring means includes a current transformer.
4. The method of claim 1 in which the voltage measuring means includes a resistor divider network.
5. The method of claim 1 in which the voltage measuring means includes a voltage transformer.
6. The method of claim 1 in which the voltage measuring means and the current measuring means sample only select portions of successive cycles of the load signal, whereby over a plurality of samples the samples collectively cover all parts of a waveform cycle equally and an average of the calculations of power from these samples provides the measurements of current and voltage for a calculation of average instantaneous power consumption.
7. The method of claim 1 in which the average instantaneous power consumption is displayed separately for each load.
8. The method of claim 1 including the step of recording calculated values and displaying recent historical power consumption.
9. A method of calculating instantaneous power consumption of an electrical load comprising the steps of:
sampling values of current and voltage at selected portions of successive cycles such that over a predetermined number of samples the measurements collectively cover all parts of the waveform cycle equally, calculating a value of average instantaneous power consumption over the predetermined number of samples, and displaying the value of average instantaneous power consumption.
sampling values of current and voltage at selected portions of successive cycles such that over a predetermined number of samples the measurements collectively cover all parts of the waveform cycle equally, calculating a value of average instantaneous power consumption over the predetermined number of samples, and displaying the value of average instantaneous power consumption.
10. The method of claim 9 in which less than 10 samples are taken in each cycle.
11. The method of claim 10 in which approximately 4.9 samples are taken in each cycle.
12. The method of claim 11 in which the predetermined number of samples is approximately 199.
13. An apparatus for monitoring electrical power consumption by a consumer of electricity, comprising:
means for measuring current in communication with an electrical power supply circuit, means for measuring voltage in communication with the electrical power supply circuit, and means for calculating and displaying instantaneous electrical power consumption from current and voltage values.
means for measuring current in communication with an electrical power supply circuit, means for measuring voltage in communication with the electrical power supply circuit, and means for calculating and displaying instantaneous electrical power consumption from current and voltage values.
14. The apparatus of claim 13 including an analog-to-digital converter in communication with the current measuring means and the voltage measuring means and wherein the means for calculating and displaying power consumption includes a computer in communication with the converter.
15. The apparatus of claim 13 in which the current measuring means includes a current transformer.
16. The apparatus of claim 13 in which the voltage measuring means includes a resistor divider network.
17. The apparatus of claim 13 in which the current measuring means and the voltage measuring means sample only select portions of successive cycles of the load potential, whereby over a plurality of cycles the samples collectively cover all parts of a waveform cycle equally and an average of the calculation of power from the samples over a selected number of samples provides the average instantaneous power consumption.
18. The apparatus of claim 13 in which the voltage measuring means includes a voltage transformer.
19. The apparatus of claim 13 in which the average instantaneous power consumption is displayed separately for each load.
20. The apparatus of claim 13 including the step of recording calculated values and displaying recent historical power consumption.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2105095 CA2105095A1 (en) | 1993-08-30 | 1993-08-30 | Electricity cost monitor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2105095 CA2105095A1 (en) | 1993-08-30 | 1993-08-30 | Electricity cost monitor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2105095A1 true CA2105095A1 (en) | 1995-03-01 |
Family
ID=4152220
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2105095 Abandoned CA2105095A1 (en) | 1993-08-30 | 1993-08-30 | Electricity cost monitor |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2105095A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2020164998A1 (en) * | 2019-02-11 | 2020-08-20 | Beckhoff Automation Gmbh | Method for the distributed determination of electrical power |
-
1993
- 1993-08-30 CA CA 2105095 patent/CA2105095A1/en not_active Abandoned
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2020164998A1 (en) * | 2019-02-11 | 2020-08-20 | Beckhoff Automation Gmbh | Method for the distributed determination of electrical power |
| CN113383240A (en) * | 2019-02-11 | 2021-09-10 | 倍福自动化有限公司 | Method for distributed electric power determination |
| CN113383240B (en) * | 2019-02-11 | 2022-09-13 | 倍福自动化有限公司 | Method for distributed electric power determination |
| US11774471B2 (en) | 2019-02-11 | 2023-10-03 | Beckhoff Automation Gmbh | Method for distributed electrical power determination |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0777125B1 (en) | Vector electricity meters and associated vector electricity metering methods | |
| US4253151A (en) | Apparatus for monitoring and controlling consumer power consumption | |
| EP3367111B1 (en) | Energy metering system | |
| US9329659B2 (en) | Power monitoring system that determines frequency and phase relationships | |
| CN108802462B (en) | Voltage measurement | |
| US6493644B1 (en) | A-base revenue meter with power quality features | |
| US5247454A (en) | Reconfigurable circuit monitoring system | |
| US6483291B1 (en) | Apparatus for measuring electrical power consumption | |
| US20100324845A1 (en) | Intelligent electronic device with enhanced power quality monitoring and communication capabilities | |
| US20030014200A1 (en) | Revenue meter with power quality features | |
| JP2000193695A (en) | Power usage monitoring method and device | |
| JP2001103622A (en) | Home Energy Measurement System | |
| CA2203748C (en) | Device used for long term monitoring of magnetic fields | |
| JPH1082801A (en) | Display device for consumed power quantity in power consumer | |
| JP2001183399A (en) | Power monitoring system | |
| JPH02263170A (en) | Imbalance monitoring apparatus for power line | |
| CA2105095A1 (en) | Electricity cost monitor | |
| KR100880563B1 (en) | Digital power measurement inverter | |
| KR20100064186A (en) | Auto-monitoring device for cut down on electric energy | |
| US5717388A (en) | Method for long term monitoring of magnetic fields | |
| JP3325738B2 (en) | Composite indicating instrument | |
| AU2018203426A1 (en) | Electricity meter | |
| JP2005233879A (en) | Single-phase three-wire watt-hour meter with line current monitoring function and its line current management system | |
| KR101120076B1 (en) | Total electric power calculating apparatus using parallel circuit type electric power calculating apparatus without power interruption | |
| KR100316485B1 (en) | The electronic watt-hour metter for multiple house hold |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Dead |