The present invention generally relates to voltage conservation and more particularly, to a system and method for monitoring and adjusting a voltage supplied to a power grid to thereby reduce power consumption.
The economic and environmental cost of generating and distributing power to power customers is enormous. Even a small percentage reduction in power consumption translates to an enormous financial savings and reduced emissions.
A distribution transformer 60 may function to distribute one, two, three, or more phases of power to the customer premises 40, depending upon the demands of the user. In the United States, for example, these local distribution transformers 60 typically feed anywhere from one to ten homes, depending upon the concentration of the customer premises 40 in a particular area. Distribution transformers 60 may be pole-top transformers located on a utility pole, pad-mounted transformers located on the ground, or transformers located under ground level.
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A voltage drop is typically estimated for the customer premises 40 that are the farthest distances from the substation 14, which are assumed to experience the greatest voltage drop. However, a margin of error must be added to the estimated voltage drop (or to the voltage estimated to be received by the power customers) due to the uncertainty of the losses of various components of the power grid 1110 such as, for example, transformer losses and distribution in losses. Thus, a voltage provided by a substation 14 is set based on an educated “guess” of the voltage drop plus an added voltage to provide a margin of error. Setting a voltage based on an educated “guess” and a margin of error often results in the utility providing a voltage that is higher than required by regulatory requirements, which in some instances causes a greater than necessary delivery of power. Currently, there is no cost efficient means for an electric utility to accurately determine the voltage to be supplied by a substation 14 to provide a desired voltage at a customer premises. These and other advantages are provided by various embodiments of the present invention.
The present invention provides a system, method and device for controlling the voltage supplied to a customer premises that is supplied power from a substation via a power distribution network and wherein a resident of the customer premises obtains internet access service via an internet access network. In one embodiment, the method includes measuring a voltage at an electrical outlet of the customer premises to provide voltage data with the device, determining whether the measured voltage is beyond a threshold voltage with the device or a remote computer, transmitting the voltage data over the internet access network of the customer premises to the remote computer from the device, and adjusting a voltage supplied to the power distribution network by the substation if the voltage is beyond a threshold voltage. The method may also include processing at least some of the received voltage data at the remote computer to determine whether to increase a voltage supplied by the substation or decrease a voltage supplied by the substation and further to determine an amount of the increase or decrease (if any).
The invention is further described in the detailed description that follows, by reference to the noted drawings by way of non-limiting illustrative embodiments of the invention, in which like reference numerals represent similar parts throughout the drawings. As should be understood, however, the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
a is a diagram of a power distribution system incorporating a Voltage Control Manager (VCM), in accordance with an example embodiment of the present invention.
b shows a detailed view of a customer premises that includes a Customer Premises Voltage Monitor (CPVM) 400, in accordance with an example embodiment of the present invention.
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular networks, communication systems, computers, terminals, devices, components, techniques, data and network protocols, software products and systems, operating systems, development interfaces, hardware, etc. in order to provide a thorough understanding of the present invention.
However, it will be apparent to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. Detailed descriptions of well-known networks, communication systems, computers, terminals, devices, components, techniques, data and network protocols, software products and systems, operating systems, development interfaces, and hardware are omitted so as not to obscure the description.
Various embodiments of the present invention provide a system and method of monitoring the voltage delivered to a customer premises 40 and for using real time voltage measurement data to adjust the voltage supplied to the portion of the power grid that provides power to that customer premises. Referring to
In accordance with the principles disclosed herein, the CPVM 400 allows a utility to accurately determine the voltage at one or more customer premises 40. Through the monitoring of the voltage at one or more customer premises 40, typically at locations experiencing the greatest voltage drops across the power grid, a utility may accurately adjust the voltage supplied to a medium voltage power line 10 in real-time to satisfy a regulatory minimum and maximum voltages. Calculating the voltage to be supplied by the substation 14 eliminates the likelihood that the utility will provide a voltage to the customer premises 40 that is too high (or too low). This in turn may reduce the power requirements of the power generation source. Even a small reduction in power across a power grid can aggregate to enormous cost and environmental savings.
a is a diagram of a power distribution system 100 incorporating a Voltage Control Manager (VCM) 150, in accordance with an example embodiment of the present invention.
Substation voltage controller 50 provides control of the voltage supplied to the medium voltage power line 10 by substation 14. Substation voltage controller 50 may receive instructions to provide a particular voltage to the medium voltage power line 10 from the VCM 150.
In one embodiment, the VCM 150 may communicate with both a substation voltage controller 50 and one or more CPVMs 400 via a communication network 80 (such as the Internet). As discussed, the VCM 150 may send instructions to the substation voltage controller 50 to adjust the voltage supplied to the medium voltage power line 10 by substation 14. The VCM 150 may store various types of parameters, such as location data (e.g., address(es)) of CPVM(s) 400 that are associated with a particular substation 14, historical data for voltage adjustments, etc.). Although the VCM 150 is shown as being a separate component from substation voltage controller 50, the VCM 150 may be integrated with the substation voltage controller 50. In addition, while the VCM 150 is illustrated as communication with only one substation controller 50, the VCM 150 may be communicatively coupled to a plurality of substation voltage controllers 50 to thereby adjust the voltages supplied by a plurality of different substations 14.
Each CPVM 400 may have an associated unique identification (ID) number. This unique ID number (which may comprise a Media Access Control (MAC) address associated with its communication module) may be associated in memory of the VCM 150 with the location of that CPVM 500. In addition, the VCM 150 may store data of a plurality of substations 14 and the locations (e.g., CP 40 addresses) to which they supply power in memory. Thus, the MAC address associated with the CPVM 400 may allow the VCM 150 to determine a particular customer premises (e.g., CP 40g) from a plurality of customer premises 40 communicating a voltage data or a voltage alert (e.g., either a too high voltage or too low voltage), which may be a real-time voltage data and/or voltage alert. The location (e.g., customer premises 40) of a CPVM(s) 400 may be recorded in the VCM 150 through a variety of methods that includes, for example, a web page interface (where the data is supplied by a consumer), a database entry system, a telephone prompt entry system, etc. In this manner, the ID number of the CPVM 400 (e.g., MAC address) that communicates voltage data may be used to determine the associated substation 14 that controls the voltage at that location. Once the substation 14 associated with the particular location is identified, that substation 14 may be provided a voltage adjustment instruction which is used to by the substation voltage controller 50 to supply a new voltage to the medium voltage power line 10. In some embodiments, the substation 14 associated with each CPVM unique ID is stored in memory in advance of receiving communications from the CPVMs 400.
The VCM 150 communicates with the CPVMs 400 via a communication network 80, which may comprise the Internet, a WiMAX network, a mobile telephone network, and/or another suitable network. The CPVM 40 may connect to the network 80 via any suitable communication medium, such as, for example, one or more of a power line (forming part of a power line communication network (PLCS)), a power line of in-home (e.g., HomePlug) network, a twisted pair conductor (e.g., forming part of a DSL network), a wireless connection, a coaxial cable (forming part of a cable network) and/or any other suitable medium.
Many customer premises 40 subscribe to an Internet Access Service and thus already have access to the Internet. In some embodiments, the CPVM 400 may use the Internet Access Service, used by the residents to access the internet, to communicate with the VCM 150 as illustrated in
One or more customer premises 40 may be selected by a utility as desired points within the power distribution system 100 that will have their voltage monitored. For example, referring to
Although only a single customer premises 40g is shown to include a CPVM 400 in
b shows a detailed view of a CP 40 that includes a CPVM 400, in accordance with an example embodiment of the present invention. As illustrated, many power customers already subscribe with an Internet Service Provider (ISP) for Internet service. One or more personal computers 70 may connect to a router/modem 710 that allows users within the CP 40 to communicate with the Internet as illustrated in
Communication module 320 allows the VCM 150 to communicate with one or more CPVM(s) 400. Communication module 320 may be any of a variety of communications modules suitable for a particular communication medium. Communication module 320 may be a telephone line modem, an Ethernet adapter, a fiber optic adapter, a wireless network adapter, a mobile telephone transceiver, a cellular network adapter, etc. Communication module 320 may include an appropriate transmit buffer and receive buffer, as is known within the art. Thus, communication module 320 may be any type of data interface that allows the VCM 150 to communicate with a CPVM 400.
Substation interface 310 is used to communicate with the substation 14 and may include a transceiver for communicating with the substation controller 50. The processor 324 may formulate and send one or more voltage adjustment instructions to substation 14 via the substation interface 310. As discussed in more detail with relation to
The electrical outlet 410 being used to measure voltage at the CP 40 may be any electrical outlet 410 includes 110-120 volt outlet or a 220-240 volt outlet, commonly used to power a clothes dryer. One benefit of using a 220-240 volt outlet is that both energized low voltage power line conductors are present there so that the CPVM 400 can measure the voltage to ground on each low voltage energized conductor.
The communication module 430 allows the CPVM 400 to communicate with a VCM 150. Communication module 430 may be any of a variety of communications modules that are suitable for a particular communication medium. Communication module 430 may be a telephone line modem, an Ethernet adapter, a fiber optic adapter, a wireless network adapter, a mobile telephone network transceiver, a cellular network adapter, etc. Communication module 430 may include an appropriate transmit buffer and receive buffer, as is known within the art. Thus, communication module 430 may be any type of data interface that allows the CPVM 400 to communicate with a VCM 150.
The voltage monitor 420 receives the AC voltage from an electrical outlet 410 and measures the RMS voltage received. Thus, the voltage monitor 420 may include an analog to digital converter or a digital signal processor. The measurement data is provided to processor 424. Processor 424 may provide voltage data and/or an alert to be transmitted by communication module 430, as described in more detail in
Memory 422 may store voltage data as measured by the voltage monitor 420. Memory 422 may also store a unique serial number for the CPVM 400 that allows a VCM 150 to uniquely identify the CPVM 400 on a power grid 100. In some embodiments, memory 422 may store program code to be executed by processor 424 as well as parameters such as thresholds (minimum and maximum voltages) that are used as a basis to transmit an alert to the VCM 150, if the CPVM 400 is so configured. More specifically, the processor 424 may compare the measurement data from the voltage monitor 420 with the minimum and maximum threshold data retrieved from memory and, if a threshold is exceeded (too high or low) the processor 424 transmits an alert to the VCM 150 via the communication module 430 in real-time (or near real-time). Thus, the VCM 150 may receive the alert or voltage data within five minutes, more preferably within two minutes, even more preferably within one minute, and yet more preferably within fifteen seconds of the measurement. In addition or alternately, VCM 150 may request data from the CPVM 400 and the processor 424 retrieves the time stamped data from memory 422 and transmits the time stamped data to the VCM 150.
The VCM 150 (or other computer system) may transmit program code, gateway IP address(es), and/or threshold values for storage in memory 422 of the CPVM 400 to be used by the processor 424 to perform various processing.
The CPVM 400 may be a dedicated box or “brick” (mechanical form fit sized like a deck of playing cards) that plugs directly into an electrical outlet 410 (e.g., wall socket), similar to a wall socket plug-in transformer. Communication module 430 also may plug into the communication medium (for connection to the Internet) through a hardwired connection (e.g., Ethernet connection) or connect via a wireless connection (e.g., WiFi). As illustrated in
At step 520, processor 424 may determine if a measured RMS voltage is beyond a threshold voltage (either greater than a high threshold or less than a low threshold). For example, processor 424 may compare the measured voltage with each of a high and low threshold to determine if the measured voltage is above a high threshold or below a low threshold. As a more specific example, the processor 224 (or alternately the DSP (Digital Signal Processor) forming part voltage monitor 420) may determine if the measured voltage is within six percent of a nominal voltage (e.g., 120 volts) that is, determine if the measured voltage is below 112.8 volts RMS or above 127.2 volts RMS.
If at step 520 the process 500 determines that the measured voltage is not beyond a threshold voltage, the process branches to step 510 to take additional measurements. In this manner the process 500 may continuously monitor for a voltage that is either too high or too low, and may provide real-time voltage data to the VCM 150. If at step 520 the process determines that the measured voltage is beyond a threshold voltage, the process branches to step 530.
At step 530, the voltage data measured in step 510 may be formulated into one or more data packet(s) by processor 424 to provide an alert by reporting (to the VCM 150) in real-time (or near real-time) voltages that are beyond a threshold. The transmission (or alert) may also include time stamp data for the measurement and information identifying the CPVM 400 to allow the VCM 150 to determine the location of the voltage measurement (and the substation providing the voltage to that location). The voltage data from each (or some) measurements also may be stored in memory 422. In addition to transmitting an alert, processor 424 may retrieve the most recently stored voltage data (e.g., the last hour or day), and/or more historical voltage data (e.g., the last week or month), from the memory 422 and provide the voltage data to communication module 430 for transmission to the VCM 150. The transmission of data may be performed by processor 424 in accordance with program code that causes periodic data transmission or may be performed in response to a to receiving a request for data from the VCM 150. The data packet(s) may be placed into a transmit data buffer of communication module 430. Communication module 430 may then transmit the voltage data packet(s) over the communication medium, through the internet to the VCM 150.
In some embodiments, the communication of voltage data provides an alert that a voltage is either too high or too low. In some embodiments, voltage data may be communicated with a VCM 150 on a periodic basis (either in real time or not), whether the measured voltage is considered a “normal” value or not. In such an instance, the VCM 150 may make the sole determination as whether the voltage at a CP 40 is either too high or too low.
At step 620, processor 324 may determine if a measured voltage is beyond a threshold voltage value (either greater than a high threshold value or less than a lower threshold value). For example, processor 324 may compare the measured voltage with each of a high and low threshold to determine if the measured voltage is above a high threshold or below a low threshold. If at step 620 the process 600 determines that the measured voltage is not beyond a threshold voltage, the process branches to step 610 to wait for additional data. In some embodiments, the received data may be stored in memory for later processing. If at step 620 the process determines that the measured voltage is beyond a threshold voltage, the process branches to step 625.
At step 625, processor 324 determines the particular substation 14 that is associated with the customer premises 40 has indicated a voltage that is either too high or too low. For example, the processor may query the database for a location (e.g., an address) associated with the identifying information of the CPMV 400, which is received with the voltage data. Upon determining the location, the processor determines the substation supplying power to that location by, for example, querying a database. Note that in some embodiments, this step may be omitted if, for example, each VCM 150 of multiple VCMs 150 control only a single substation.
At step 630, the voltage data received from the CPVM 400 in step 610 may be used to determine a voltage adjustment instruction by processor 324. Processor 324 may retrieve the most recently received voltage data (and, in some instances, the most recent voltage adjustment instruction) from the memory 322 and formulate an appropriate substation voltage adjustment instruction in accordance with the requirements of the particular substation 14 employed to control the voltage on the medium voltage power line 10. A historical record of the substation voltage adjustment instruction may be stored in the voltage adjusting storage 322. The voltage adjustment instruction may be either a new voltage to be supplied (e.g., 15,152 volts) or a voltage adjustment (e.g., increase by 93 volts or decrease by 70 volts). In some instances, the voltage instruction may be transmitted to the substation controller 50, in which case the data packet(s) may be placed into a transmit data buffer of voltage adjusting module 310 for transmission to substation 14. In other embodiments the VCM 150 may form part of the same computer system as controller 50, in which case transmission may not be necessary.
At step 640, the substation 14 implements the voltage adjustment instruction formulated in step 630 to appropriately adjust substation 14. Thus, substation voltage controller, upon receipt of the voltage adjustment instruction, may respond appropriately causing the substation 14 to adjust the voltage placed on the medium voltage power line 10 in accordance with the voltage adjustment instruction.
Step 520 may determine if a voltage is either too high or too low as measured at a customer premises 40. Step 620 also may determine if a voltage is too high or too low as determined by the VCM 150. However, the VCM 150 may use different threshold voltages for its determinations than those used by the CPVMs 400. For example, the CPVMs 400 may report voltages beyond thresholds and thereby provide a preliminary alert that a voltage is beyond a first threshold (and getting close to a second threshold), while the VCM 150 may, for example, make the determination that the voltage is beyond the second threshold warranting a voltage adjustment. Thus, the CPVM 400 alerts may be used to give a warning that, should loads change significantly, the voltage at a customer premises 40 is at risk of dropping below a threshold voltage (the threshold used by VCM).
In this manner, a pre-established threshold voltage that controls whether the voltage is adjusted by the substation 14 can be more easily controlled at a centralized location, such as the VCM 150. This may be helpful in the event that a pre-established threshold voltage requires adjustment.
A utility may desire certain of its customers to use a CPVM 400. However, some customers may not want a CPVM 400 that is a wall plug “brick” that may be unsightly or that provides no other function. To entice a customer into using a CPVM 400 in their customer premises 40, a utility may offer its customers an aesthetically pleasant device (or other device) that incorporates a CPVM 400, but that also includes alternate functionality. A wireless photo frame 700 may be such a device.
Many utility customers already have a wireless network such as a WiFi network within their homes. WiFi networks are typically established within customer premises 40 to allow residence to connect to the Internet from a wireless device. The wireless photo frame 700, in accordance with the principles disclosed herein, may communicate via an existing WiFi network to gain assess to a communication medium to communicate via the Internet.
In some such embodiments, the CPVM 400 may not include a separate communication module 430 and a power supply, and instead rely on a communication module and a power supply forming part of the photo frame 700 and shared by functional components of the photo frame 700. In other embodiments, the memory and processor used to perform voltage monitoring and comparison function (i.e., CPVM 400 functions) may also perform conventional photo frame function (storing photos, sequencing through photos, etc.).
In operation, the wireless photo frame 700 communicates voltage data, as measured from electrical outlet 410, via a wireless network router/modem 710 to communication medium 80. The wireless network router/modem 710 formulates one or more appropriate packets, depending upon the particular communication medium 80 employed, to communicate measured voltage with a remote VCM 150. The VCM 150 may adjust a voltage at a substation 14 based on the received measured voltage, as discussed above in relation to
A set top box 800 is used to allow a user to control the programming provided to the television 810. The set top box 800 is also connected to a bi-directional network that provides programming to the set top box. Because the set top box includes a processor, storage (e.g., memory), and a communication module, some these (e.g., the communication module) or all of these components may be used by the CPVM 400 functionality so that fewer extra components are necessary.
In operation, the set top box 800 communicates voltage data via the internet to the VCM 150 as measured from an electrical outlet 410 to which the set top box is plugged in. The VCM 150 may adjust a voltage at a substation 14 based on the received voltage data, as discussed above in relation to
In some embodiments, the CPVM 400 may be connected to a set top box 800 through an external communication port, such as a Universal Serial Bus (USB) port, External Serial Advanced Technology Attachment (eSATA) port, etc. In this type of implementation, the CPVM 400 may connect to both an external communication port of the set top box 800 to communicate with the VCM 150 and an electrical outlet 410 to measure a voltage at a CP 40.
As discussed above, in addition to measuring the voltage over time (i.e., monitoring the voltage), the CPVM (400 (or more generally the customer premise electricity monitor) may also be configured to measure and monitor the power factor (i.e., the difference between the phase angle of the voltage and current received by the device 400), voltage harmonics, voltage noise, voltage spikes, average voltage, peak-to-peak voltage, and other such parameters. In addition, the failure of the VCM 150 to receive a response to a control message (e.g., a request for data or status) from one or more CPVMs 400 may be used by the VCM 150 (or other computer system) to determine the location(s) of a power outage. Upon power up, the CPVMs 400 may be programmed to initiate communications with the VCM 150. Thus, data and/or notifications from the one or more CPVMs 400 may be used by the VCM 150 to identify the location(s) of a power restoration (e.g., after an outage). Furthermore, wherein a CPVM 400 measures the voltage of both energized low voltage conductors (e.g., at a 240V socket often used for a clothes dryer), the CPVM 400 may detect a disparity (difference) in the two voltages that exceeds a threshold disparity, which may be a signature (or predictive) of a failing transformer. In such a scenario, the CPVM 400 may be programmed to transmit an alert, which may be processed by the VCM 150 to dispatch personnel to repair or replace the distribution transformer serving the customer premise.
It is to be understood that the foregoing illustrative embodiments have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the invention. Words used herein are words of description and illustration, rather than words of limitation. In addition, the advantages and objectives described herein may not be realized by each and every embodiment practicing the present invention. Further, although the invention has been described herein with reference to particular structure, materials and/or embodiments, the invention is not intended to be limited to the particulars disclosed herein. Rather, the invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims. Those skilled in the art, having the benefit of the teachings of this specification, may affect numerous modifications thereto and changes may be made without departing from the scope and spirit of the invention.