Abstract:
The present invention relates generally to a load center. More particularly, the invention encompasses a self contained kilowatt-hour meter which is integral to a standard load center. The present invention is also directed to a novel printed circuit board and housing for the self contained kilowatt-hour meter. The self contained kilowatt-hour meter of this invention measures the energy usage of a facility, such as, residential unit, a house, an apartment, a condominium, and then it communicates the energy usage in a timely manner or as desired to a local requester, such as, the owner, occupant or any other entity, as well as, to another requester, such as, a remote requester, for example, an energy provider.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The instant patent application claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 61/093,883, filed on Sep. 3, 2008, titled “Self Contained Kilowatt-Hour Meter Integral to Standard Load Center,” the entire disclosure of which provisional application is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to a load center. More particularly, the invention encompasses a self contained kilowatt-hour meter which is integral to a standard load center. The present invention is also directed to a novel printed circuit board and housing for the self contained kilowatt-hour meter. The self contained kilowatt-hour meter of this invention measures the energy usage of a facility, such as, residential unit, a house, an apartment, a condominium, and then it communicates the energy usage in a timely manner or as desired to a local requester, such as, the owner, occupant or any other entity, as well as, to another requester, such as, a remote requester, for example, an energy provider. 
     BACKGROUND INFORMATION 
     Every residence requires an energy meter to measure electrical energy that is used by that household. Presently, this is accomplished by a wide variety of devices: both electromechanical and electronic. Many of the newest meters also provide a means of communicating energy usage readings to a remote collection point so that power companies do not require anyone to actually visit each meter for a monthly reading. Yet this new technology still lacks the ability to get this information directly to the customer. What all of these devices share in common is that they plug into a standard socket at the residential service entrance. However, none of these energy reading meters provide a local display of energy usage or communicate this information to the local user of the energy. 
     Therefore there is a need for improvement in a load center and in particular a load center that has a self contained kilowatt-hour meter. 
     This invention improves on the deficiencies of the prior art and provides an inventive load center that has a self contained kilowatt-hour meter. 
     PURPOSES AND SUMMARY OF THE INVENTION 
     The invention is a novel self contained kilowatt-hour meter. 
     Therefore, one purpose of this invention is to provide a self contained kilowatt-hour meter. 
     Another purpose of this invention is to provide a self contained kilowatt-hour meter that can be integrated into a standard load center. 
     Still another purpose of this invention is to provide an economic solution to a standard load center by integrated it with at least one self contained kilowatt-hour meter. 
     Yet another purpose of this invention is to provide a robust self contained kilowatt-hour meter which is integrated with a standard load center. 
     Therefore, in one aspect this invention comprises a self contained kilowatt-hour meter, comprising: 
     (a) a meter housing having at least two openings for the passage of at least one electrical connection; 
     (b) a middle assembly comprising at least one printed circuit board, at least two toroidal transformers, and at least two openings for the passage of at least one electrical connection, such that each of said toroidal transformer is adjacent each opening for the passage of at least one electrical connection;
 
(c) a meter cover having at least two openings for the passage of at least one electrical connection; and
 
(d) at least one securing means to secure said meter cover to said meter housing such that said middle assembly is contained inside said meter cover and said meter housing, and wherein each of said at least two openings for the passage of at least one electrical connection are substantially aligned each with other, and thereby forming said self contained kilowatt-hour meter.
 
     In another aspect this invention comprises an electrical load center comprising: 
     (a) at least one main circuit breaker connected to AC power lines for transferring electrical energy for use by a local user or resident; and 
     (b) a load center meter proximal to the at least one main circuit breaker comprising: 
     an enclosure containing at least two openings through which at least one AC power line is conveyed through each opening to connect to the at least one main circuit breaker; and 
     a load center meter connected for monitoring the electrical energy used by the local user or resident, said load center comprising: 
     at least one current sense device for sensing a current transferred through the at least one power line and generating a current signal representing the current on the AC power line, 
     at least one voltage sense device for sensing a voltage present on the at least one AC power line and generating a signal representing the voltage present on the at least one AC power line, 
     a measurement circuit in communication with the at least one current sense device and the at least one voltage sense device for determining an active, reactive, and apparent energy level, RMS (root mean square) and instantaneous values for current and voltage, and line frequency information of the electrical energy used by the local user or resident, 
     a data analyzer analyzes the active, reactive, and apparent energy, RMS and instantaneous values for current and voltage, and line frequency information to create the energy usage data, and 
     a data storage device in communication with the data analyzer to receive and retain the active, reactive, and apparent energy, RMS and the instantaneous values for current and voltage, the line frequency information, and the energy usage data. 
     In yet another aspect this invention comprises a load center meter proximal to at least one main circuit breaker within a load center comprising: 
     (a) an enclosure containing at least two openings through which at least one AC power line is conveyed through each opening to connect to the at least one main circuit breaker; and 
     (b) a load center meter place within the enclosure connected for monitoring the electrical energy used by the local user or resident, said load center comprising: 
     at least one current sense device for sensing a current transferred through the at least one power line and generating a current signal representing the current on the AC power line, 
     at least one voltage sense device for sensing a voltage present on the at least one AC power line and generating a signal representing the voltage present on the at least one AC power line, 
     a measurement circuit in communication with the at least one current sense device and the at least one voltage sense device for determining an active, reactive, and apparent energy level, RMS (root mean square) and instantaneous values for current and voltage, and line frequency information of the electrical energy used by the local user or resident, 
     a data analyzer analyzes the active, reactive, and apparent energy, RMS and instantaneous values for current and voltage, and line frequency information to create the energy usage data, and 
     a data storage device in communication with the data analyzer to receive and retain the active, reactive, and apparent energy, RMS and the instantaneous values for current and voltage, the line frequency information, and the energy usage data. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Although the scope of the present invention is much broader than any particular embodiment, a detailed description of the preferred embodiment follows together with drawings. These drawings are for illustration purposes only and are not drawn to scale. Like numbers represent like features and components in the drawings. The invention may best be understood by reference to the ensuing detailed description in conjunction with the drawings in which: 
         FIG. 1  illustrates a first embodiment of an inventive self contained kilowatt-hour meter of this invention. 
         FIG. 2  is an exploded view of the inventive self contained kilowatt-hour meter of this invention. 
         FIG. 3  is a front view showing a meter mounting assembly secured to a main breaker. 
         FIG. 4  is a rear view showing a meter mounting assembly secured to a main breaker. 
         FIG. 5  is a front view of the inventive self contained kilowatt-hour meter of this invention secured to a meter mounting assembly and a main breaker. 
         FIG. 6  is a detailed top view of an embodiment of a middle assembly of the inventive self contained kilowatt-hour meter of this invention. 
         FIG. 7  is a detailed bottom view of an embodiment of a middle assembly of the inventive self contained kilowatt-hour meter of this invention. 
         FIG. 8  is a detailed first circuit schematic of an embodiment of the inventive self contained kilowatt-hour meter of this invention. 
         FIG. 9  is a detailed second circuit schematic of an embodiment of the inventive self contained kilowatt-hour meter of this invention. 
         FIG. 10  is a yet another embodiment of the inventive self contained kilowatt-hour meter of this invention utilizing a wireless network. 
         FIG. 11  is a generalized functional block diagram of an inventive load center meter of this invention. 
     
    
    
     DETAILED DESCRIPTION 
     This invention secures the inventive kilowatt-hour meter within the standard load center. This reduces installation costs by eliminating the meter socket. Additionally this inventive metering device allows not only the power companies to get energy measurements, but also the local user or resident, who can now get the same information that the energy provider is getting in a timely manner, such as, hourly, daily, weekly, monthly, or any other desired schedule. This invention also allows a local user or resident to get instant and up-to-date cost of energy information utilizing an energy display unit that communicates with the load center meter. 
       FIG. 1  illustrates a first embodiment of an inventive self contained kilowatt-hour meter  23 , of this invention. The meter  23 , comprises of a meter cover  10 , which is secured to a meter housing  20 . Holes or openings  28 , allow the meter  23 , to be secured to a meter mounting bracket or assembly  30 , shown in  FIG. 3 . The self contained kilowatt-hour meter  23 , is powered via two spring pins  55 , located in such a way so as to make electrical contact with the corresponding lugs or lock nut  35 , as shown in  FIG. 3 . An optional display  25 , can also be provided with the meter  23 . 
       FIG. 2  is an exploded view of the inventive self contained kilowatt-hour meter  23 , of this invention. The inventive self contained kilowatt-hour meter  23 , basically comprises of the meter cover  10 , a meter housing  20 , a middle assembly  15 , and an optional display  25 . The meter cover  10 , has at least two holes or openings  11 , for an electrical connection, such as, a wire, not shown. The meter cover  10 , is preferably provided with a plurality of assembly holes or openings  13  that are used to secure the meter cover  10 , to the meter housing  20 . The meter cover  10 , could also have an optional lip or extension  12 , to support and secure a lip or ridge  19 , of a display  25 . The middle assembly  15 , basically comprises of at least one printed circuit board (PCB)  14 , and at least two toroidal transformers  17 . The toroidal transformers  17 , have at least one opening or hole  18 , for the passage of an electrical connection, such as, a wire. The middle assembly  15 , also has a plurality of cut-outs or notches or openings  16 , to allow for the passage of a securing device (not shown). The meter housing  20 , preferably has a plurality of stand-offs  21 , to support and secure the middle assembly  15 , inside the meter housing  20 . The meter housing  20 , also has holes or openings  22 , for the passage of an electrical connection, such as, a wire (not shown). Preferably, a plurality of stand-offs  27 , are also provided in the meter housing  20 . The stand-offs  27 , are in-line with the openings  13 , and  16 , such that a securing device (not shown) can be inserted into the stand offs  27 , via the openings  13 , and  16 , to secure the meter cover  10 , to the meter housing  20 . The meter housing  20 , is also provided with at least one opening or hole  28 , such that a securing device  58 , (shown in  FIG. 5 ) can be inserted into the opening  28 , and secured to feature  38 , shown in  FIG. 4 . The meter housing  20 , preferably has a lip or ledge or wall  26 , around the opening  22 , to accommodate the toroidal transformers  17 , and prevent any sliding movement of the middle assembly  15 . The cut-out or opening or notch  16 , slides along the outer surface of the standoffs  27 , and this prevents the sliding or any lateral movement of the middle assembly  15 . The meter housing  20 , can also be provided with an optional well  24 , having channels  29 , to accommodate the display  25 . Basically, the lip or ledge  19 , of the display  25 , slides into the channel  29 , and upon assembly the display  25 , is held in place by the channel  29 , and the lip  12 . 
       FIG. 3  is a front view showing a meter mounting assembly or bracket  30 , secured to a main breaker  40 . The meter mounting assembly  30 , has at least two lock nuts  35 , having holes or openings  32 , to accommodate an electrical connection, such as, a wire. The meter mounting assembly  30 , has a bracket  34 , having at least two openings  38 , to accommodate securing means  58 , shown in  FIG. 5 , that passes through openings  28 , in the self contained kilowatt-hour meter  23 . The main breaker  40 , preferably has at least one OFF/ON switch  45 , and a plurality of brackets  44 , having securing means  42 . The securing means  42 , secure the main breaker  40 , to a standard load center  50 , shown in  FIG. 5 . 
       FIG. 4  is a rear view showing a meter mounting assembly  30 , secured to a main breaker  40 . As one can see that the main breaker  40 , has openings  46 , in the bracket  44 , for the passage of the securing means  42 . 
       FIG. 5  is a front view of the inventive self contained kilowatt-hour meter  23 , of this invention secured to a meter mounting assembly  30 , and a main breaker  40 . As one can see that the self contained kilowatt-hour meter  23 , is secured via securing means  58 , to the meter mounting assembly  30 , while the main breaker  40 , is secured to a load center  50 , via securing means  42 . 
       FIG. 6  is a detailed top view of an embodiment of a middle assembly  15 , of the inventive self contained kilowatt-hour meter  23 , of this invention. The printed circuit board  15 , has pins  61 , that connect to the back of the display  25 , and allows the display  25 , to display digital data. The middle assembly  15 , can have a plurality of openings or cut-outs or notches  16 , and a plurality of notches or protrusions  66 . The cut-outs  16 , and the protrusions  66 , are used to secure the middle assembly  15 , inside the meter housing  20 . 
       FIG. 7  is a detailed bottom view of an embodiment of a middle assembly  15 , of the inventive self contained kilowatt-hour meter  23 , of this invention. As shown the toroidal transformers  17 , are on the upper surface of the middle assembly  15 , however, for some applications the toroidal transformers  17 , and the associated circuitry could be on back or bottom side of the middle assembly  15 . 
       FIG. 8  is a detailed first circuit schematic  80 , of an embodiment of the inventive self contained kilowatt-hour meter  23 , of this invention. The first circuit schematic  80 , comprises basically of at least one metering ASIC (Application Specific Integrated Circuit)  81 , at least one general purpose microprocessor  82 , at least one power supply  83 , at least one voltage input circuit  84 , and at least one current input circuit  85 . 
       FIG. 9  is a detailed second circuit schematic  90 , of an embodiment of the inventive self contained kilowatt-hour meter  23 , of this invention. The second circuit schematic  90 , comprises of at least one power line carrier communications ASIC  90 . 
       FIG. 10  is a yet another embodiment of the inventive self contained kilowatt-hour meter  23 , of this invention utilizing a wireless network  100 . The wireless network  100 , can comprise of at least one data concentrator  101 , and at least one load center  103 . The wireless network  100 , can further comprise of at least one kilowatt-hour meter  104 ,  105 ,  106 , where, for example, kilowatt-hour meter  104 , communicates with the data concentrator  101 , using wireless mesh at 2.4 GHz, while kilowatt-hour meter  105 , communicates with the data concentrator  101 , using wireless 900 MHz Point-to-Point, and kilowatt-hour meter  106 , communicates with the data concentrator  101 , using wireless cellular at 1.9 GHz. The data concentrator  101 , can then transmit the desired data to the local energy display  107 , using any of the known wireless communication protocols. The data concentrator  101 , can also communicate the received data to another computer  102 , or a data concentrator  102 , having a display and a keypad. The received energy data can also be transmitted to another device or location using at least one Ethernet  108 , or at least one WiFi  109 . It should be appreciated that the data concentrator  101 , preferably has the ability to communicate with each of the devices using any of the known wireless protocols. This can be done by providing the data concentrator with card slots that are interchangeable. 
     As stated earlier, the inventive self contained kilowatt-hour meter  23 , of this invention is secured to a standard load center  50 , having a main breaker  40 . Preferably, the self contained kilowatt-hour meter  23 , is in an insulated modular package that will attach directly to the main breaker  40 . The two main conductors (not shown) feed through the openings  11 ,  18 ,  22 ,  32 , and into the lugs of the main breaker  40 . These conductors pass through the current transformers  17 , in the self contained kilowatt-hour meter  23 , providing inputs proportional to the current in the mains. In addition pins (J 1  and J 2 ) on the meter module will contact each lug providing voltage inputs. A pigtail wire (not shown) must be connected to the neutral bus to provide a reference for the self contained kilowatt-hour meter  23 . 
     The self contained kilowatt-hour meter  23 , shown in  FIG. 1 , comprises of a multipart plastic enclosure  10 ,  20 , containing a single electronic circuit assembly  15 . The enclosures  10 ,  20 , provides several functions including insolating the circuit from wires and debris inside the load center  50 , funneling the mains conductors into the lugs, supporting spring loaded pin connections to the lugs for voltage inputs, optional front panel LCD, and attachment to the main breaker  40 , from the bottom side to resist tampering. The enclosures  10 ,  20 , preferably use, securing means, such as, screws, to attach the two halves  10 ,  20 , enclosing the electronics  15 , and capturing a spacer  25 , if no display  25 , is present. Then two securing devices  58 , such as, screws  58 , can be used to attach the self contained kilowatt-hour meter  23 , to the main breaker  40 , via the meter mounting bracket or assembly  30 . 
     As stated earlier that there are preferably two distinct parts to the electronic circuitry  14 . The first is the actual energy metering circuit  80 , shown in schematic, as  FIG. 8 , including a power supply  83 , and the second is a communications circuit  90 , as shown in  FIG. 9 . The energy meter  23 , begins with a power supply circuit  83 , that creates regulated low voltage DC power from the AC mains by rapidly switching the mains on and off via a high voltage FET (Q 4 ) with feedback to control the turn on/off timing (Q 3 ). The resulting pulsed voltage is then filtered using a large capacitor (C 32 ) and fed into linear voltage regulators (U 7  &amp; U 8 ) to provide stable low voltage power for the microprocessor (U 4 ) and ASICs (U 5  and surrounding components). Next is a circuit composed of current transformers (T 1  &amp; T 2 ) which generate a current proportional to that of the load center mains and resistive dividers which generate voltages directly proportional to the mains voltages. These signals are then further scaled (the scaling circuitry between transformers and U 5 ), filtered and sent to an integrated circuit specifically designed to measure energy (U 5 ). This component (U 5 ) measures active, reactive, and apparent energy, RMS (root mean square) and instantaneous values for current and voltage, and line frequency information. In addition to this application specific integrated circuit, there is a general purpose microprocessor (U 4 ), such as, an Atmel ATMEGA88, that analyzes and stores the energy usage data. The ATMEGA88 was chosen from many alternatives due to its built-in communications ports, variable memory configurations, processing capability, and low cost. The ASIC and microprocessor communicate with each other via a common serial peripheral interface. At this point the data can be made available for the customer, either by display on an optional LCD or by transmission to a remote receiver. 
     The second part of the electronics circuitry is another ASIC (Application Specific Integrated Circuit) (U 3 ). This one is designed to communicate digital data across a power line, such as, for example, ST Microelectronics ST7540. This portion of the circuit could easily be replaced by a circuit for wireless communication using whatever protocol the customer chooses. It is preferred to communicate over the power lines because it is most economical, and the wiring is already provided. 
     As stated earlier that the wireless communications from inside a load center  50 , would be more difficult and expensive requiring isolation of low voltage wiring, an external antenna and modification to the standard cabinet. Data from the general purpose microprocessor is transferred to the communications ASIC via an asynchronous communication interface. The ASIC then generates signals that are coupled onto the power line using a small signal transformer. These signals can then be picked up by a remote receiver and displayed by a computer or other special purpose display device or by an energy provider to be used for monitoring, billing, or other purposes. 
     Furthermore,  FIG. 10 , shows the integration of the load center meter  23 ,  50 , with a wireless system  100 . This wireless system  100 , includes data concentrators  101 , which are devices used to collect and compress data from a multitude of meters. These could be electric, gas, or water using conventional point to point wireless communications, such as, Itron Open-Way, or many other potential communications means, such as, Zigbee, cellular, Wi-fi, or even wired schemes, such as, Modbus or PLC (Power Line Carrier). The data concentrators  101 , are computer-like devices with add-in cards for the various communications methods. Each of the data concentrators  101 , would in turn be able to send their information to a local computer or data concentrator  102 , with display/keyboard which could then display, process, and transfer the data to the appropriate providers. 
       FIG. 11  illustrates the functional structure of the load center meter  23 . The AC power lines (L 1 , L 2 , and neutral N)  200  are connected to the load center meter  23  at the main breaker  40  of  FIGS. 3 ,  4 ,  5 . The AC power lines  200  are connected to the current sense circuit  205  and the voltage sense circuit  210  for providing the inputs for the sampling the power line current and voltage as being consumed by local user or resident. The current sense circuit in the embodiments as shown are the toroidal transformers  17  T 1  and T 2  of  FIG. 8 . The terminal points J 1  and J 2  for the power lines L 1  and L 2  and terminal H 1  connected to the pig tail that is connected to the neutral wire form the voltage sense circuit  210 . 
     The output of the current sense circuit  205  is the input to the current scaler  215 . The current scaler  215  is formed by a voltage divider circuit and filter placed between the toroidal transformers  17  T 1  and T 2  and the measurement ASIC U 5  of  FIG. 8 . The current scaler scales the voltage present at the outputs of the current sense circuit  205  (the toroidal transformers  17  T 1  and T 2 ) proportionally to the current present in the power lines L 1  and L 2  for transfer to the measurement circuit  220  (ASIC U 5  of  FIG. 8 ). 
     The output of the voltage sense circuit  210  is the input to the voltage scaler  220 . The voltage scaler  220  is formed of the voltage divider and filter formed between the terminal J 2  and the ASIC U 5  of  FIG. 8 . The voltage scaler  220  scales the power line voltage present at the voltage sense circuit  210  (terminal J 2 ) proportionally for transfer to the measurement circuit  220 . The measurement circuit  220  determines the active, reactive, and apparent energy, RMS and instantaneous values for current and voltage, and line frequency of the AC power lines  200 . The active, reactive, and apparent energy, RMS and instantaneous values for current and voltage, and line frequency information is transferred to the data analyzer  230 . The data analyzer  230  transfers the active, reactive, and apparent energy, RMS and instantaneous values for current and voltage, and line frequency information is placed in the data storage  235 . The data analyzer analyzes the active, reactive, and apparent energy, RMS and instantaneous values for current and voltage, and line frequency information to create the energy usage data that is transferred to the display  25  for monitoring by the local user or resident or to a communication port  250  for transfer externally to the load center meter  23 . An optional control panel  245  is shown such that input command and programming signal may entered through the control panel for programming, maintenance, or diagnostics of the load center meter  23 . Alternately, these functions may be communicated through the communications port  250 . 
     The data analyzer  230 , the data storage  235 , the interface to the display  25 , the interface to the control panel  245 , and the communications port  250  are integrated into the function of the microprocessor  82  of  FIG. 8 . The Atmel ATMEGA88 of the embodiment provides 512 bytes of EEPROM storage and 1K bytes of SRAM storage for the data storage  235 . An asynchronous communication port is present for the communications port  250 . The display  25  and control panel  245  may communicate through the asynchronous communication port or through the other data ports of the microprocessor. 
     The power line communications port  90  as described in  FIG. 9  provides an alternate communication port to external circuitry through the AC power lines. The electrical usage data is transferred to the power line communication port  90  and then transmitted from the power line communication port  90  on the AC power lines  200  to a remote power line communication port  255  that receives the electrical usage data. The remote power line communication port  255  transfers the usage data to a personal computer  260  for review by the local user or resident or to a wireless transmitter  265  or wired transmitter  270  for transfer to data concentrators  101  of  FIG. 10  for transfer to an electrical utility provider for billing, usage monitoring, and other purposes as needed. 
     The power supply  83  as explained above is connected to the AC power lines  200  to extract energy from the AC power lines  200  to generate the necessary voltage and current levels necessary for powering the measurement circuit  225 , the data analyzer  230 , the data storage  235 , the communication port  250  and the power line communication port  90 . Optionally, the power supply may supply the required voltage and current to the display  25  and the optional control panel  245 . The structure and operation of the power supply  83  is as described above in  FIG. 8 . 
     This invention can also be upgraded so that this load center meter device can communicate with other meters at the residence, e.g. water meter, gas meter, to name a few. This information can now also be sent to water and gas suppliers for billing or other purposes. 
     While the present invention has been particularly described in conjunction with a specific preferred embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present invention.