MX2007010149A - Independent automatic shedding branch circuit breaker - Google Patents

Abstract

An independent automatic shedding system that automatically allows any combination of loads to powered under limited power availability (such as a standby power source) without overloading the generator or rewiring, while contributing to the stability of the power grid. A motorized disconnection actuation mechanism under control of a controller disconnects or recloses the contacts of a branch circuit breaker. A sensor detects the presence or absence of a power source and the type of power source, which is classified according to its type. A power source classification program is executed by the controller that interprets the sensor data and causes disconnection or reclosing of the disconnection actuation mechanism depending on a desired status (ON or OFF) of the branch circuit breaker when standby power is available. Conventional circuit protection is provided an optional advanced circuit protection such as ground or arc fault circuit interruption.

Description

CIRCUIT CIRCUIT CIRCUIT OF INDEPENDENT AUTOMATIC DETACHMENT Field of the Invention This invention is directed generally to power management control systems, and more particularly, to an independent automatic branch branch circuit breaker system. BACKGROUND OF THE INVENTION Circuit breakers have been used for a long time in industrial and residential applications to prevent damage to the loads connected to them and to the structures of buildings in which the loads are located. Normally, when an electrical fault or a current overload condition is detected in a particular circuit, the circuit breaker protecting the circuit "trips" and creates a physical disconnection in the circuit, thereby preventing the flow of electricity. To restore electrical flow to the circuit, the operator must physically reconnect to the circuit breaker, typically by pulling a mechanical switch back to the closed position. These detection systems work automatically, triggering circuits only when certain conditions are met. In some electrical systems, a backup power source such as a generator or standby power source is present. This configuration typically includes a main panel, a transfer switch, and a sub-panel for loads that will receive backup power. The loads that are to be backed up are determined at the time of installation, and must be wired to the sub-panel. Thus, the cables must physically move to change the loads that are energized by the backup or standby power source. Loads that are not to be backed up are "detached" or removed from the power circuit when a backup or standby power source comes online. Care must be taken not to overload the backup or standby power source, so that any rewiring to reconfigure the system must take into account the demands on the backup or standby power source. This manual process has a number of disadvantages - it can be dangerous, it is susceptible to error, and it is labor intensive. Ineffective or sub-optimal management of loads can also disadvantageously result in instability of the power grid. What is needed, therefore, is an independent automatic branch branch circuit breaker that overcomes these and other disadvantages. The present invention addresses these and other needs, as described more fully below. SUMMARY OF THE INVENTION Briefly, in accordance with an embodiment of the present invention, a branch circuit breaker for automatically disconnecting a load coupled to a power source includes disconnecting means for disconnecting the load from the power source, a sensor to detect the presence or absence of the power source, and a controller. The controller is programmed to execute a classification program that determines through the sensor whether the power source is connected and the classification of the power source (eg, public service, standby, alternative). The controller is also programmed to cause activation of the disconnection means in response to the classification program. The disconnection means may include a motor, additional motorized contacts, or a relay. The sensor may include a voltage sensing circuit such as a resistance divider or a potential transformer. In another embodiment of the present invention, the branch circuit breaker further includes selection means for selecting an energy state (e.g., ON or OFF) for the branch circuit breaker when the energy is going to supply by a standby power source. To classify a source of energy, various parameters can be used, including voltage, voltage variations, voltage frequency, voltage frequency variations, voltage harmonics, variations in voltage harmonics, and groove harmonics from a power source in wait just like a generator. In another embodiment of the present invention, multiple branch circuit breakers are used and selected ones are closed in a pseudo-sequential or random manner to help prevent starting currents in certain loads such as motors from overloading the source of energy and help to reduce the step change in charge for the energy source. According to a method for automatically detaching loads coupled to a power source, the method includes automatically disconnecting a branch circuit breaker from the power source in response to a disconnect command from a controller, detect the presence or absence of the energy source, determine if the energy source is present or absent, automatically detect the classification (eg, public service, standby, alternative) of the energy source, and execute a classification program that determines when to cause automatic disconnection based on the determination and automatic detection. In other embodiments, the method may also include automatically reclosing the load with the power source in response to a re-connection command from the controller, randomly delaying the automatic re-closing in response to detection, select a power state (eg, ON or OFF) for the branch circuit breaker when the power is being supplied by a standby power source, automatically close the circuit breaker again Branch when a standby power source is detected and when the branch circuit breaker is selected to be ON when a standby power source is detected. The above and further aspects of the present invention will be apparent to those skilled in the art in view of the detailed description of various embodiments, which is made with reference to the drawings, a brief description of which is provided below. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other advantages of the invention will become apparent upon reading the following detailed description and with reference to the drawings. Fig. 1 is a functional diagram of an independent automatic detachment system connected between a line and a load for use in a branch circuit breaker according to the present invention. Figure 2 is a functional diagram of an independent automatic release system similar to that shown in Figure 1, except that the disconnect operation mechanism is in the form of additional contacts. Figure 3 is a status chart diagram 300 of the operation of the branch circuit breaker according to an embodiment of the present invention. Figure 4 is a flow diagram illustrating an automatic release procedure 400 for carrying out a specific embodiment of the present invention. Although the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed. Instead, the invention should cover all modifications, equivalents, and alternatives that fall within the spirit and scope of the invention as defined by the appended claims. Detailed Description of the Embodied Embodiments With reference now to the drawings, and initially to Figure 1, there is illustrated a functional diagram of an independent automatic release system 100 connected between a line and a load by a line contact 102 and a load contact 104, respectively, for use in a circuit breaker of branching according to the present invention. The automatic release system 100 generally includes a disconnect operation mechanism 106, a power source sensor 108, a controller 110 that executes a power source classification program according to the present invention, a state selector 114, and a conventional circuit protection mechanism (not shown). The disconnect operation mechanism 106 is the mechanism by which the controller 110 can physically and automatically disconnect and re-close (or re-lock) the charge of the power source. In one embodiment, the disconnection operation mechanism 106 includes a motor that causes the contacts of the branch circuit breaker to separate or come together. A suitable commercial example of such an engine can be found in the circuit breakers QO-PL Powerlink of Square D as described in US Pat. No. 4,623,859. In other embodiments, the disconnect operation mechanism 106 includes additional motorized contacts (as shown in FIG. 2) or a relay. The controller 110 is operable to cause operation of the disconnect operation mechanism 106 such that it disconnects (or opens) and closes (or re-connects) the branch circuit breaker with the connected power source. In one embodiment, the controller 110 sends a disconnect command with the disconnect operation mechanism 106 to cause it to open its contacts. To re-close the contacts, the controller 110 sends a reconnect command to the disconnect operation mechanism 106 to cause it to close its contacts again.

The power source sensor 108 is used by the controller 110, by the classification program described herein, to detect the presence or absence of a power source. The power source sensor 108 is also used to classify the source or determine which of a group of sources (such as public service, backup / standby, alternative) is present. In one embodiment, the power source sensor 108 is a voltage sensing circuit such as a resistor divider or a potential transformer. The insulation to protect the rest of the circuit can also be optionally included. The power source classification program executed by the controller 110 determines whether a power source is currently connected via the power source sensor 108, and if so, the classification of the connected power source (such as a public utility, backup / standby, alternative). The presence of the power source is determined by identifying the presence of a sine-wave voltage in an expected range on the line side. Several parameters can be used to classify an energy source, that is, to determine if the source is public service, standby generation, or another source. These parameters include the voltage of the power source, variations in the voltage, the frequency of the sine-wave voltage of the power source, variations in the frequency of the sine-wave voltage, the harmonic content of the voltage, variations in the harmonic content of the voltage, and slot harmonics from a standby power source such as voltage harmonics created by the output stator of a generator. A standby power source is expected to exhibit greater variations in frequency, voltage, and voltage harmonics than a utility power source. These variations are quantified within the energy source classification program. The state selector 114 is used to select the power state (ON or OFF) of the branch circuit breaker when the power source is a standby generation power source. The state selector 114 may be a switch, a plug, or a programmable configuration by the controller 110, a remote computer, or by the factory. By changing (either manually or programmably) to state selector 114 to an ON position, the operator is indicating that the branch circuit breaker is to be connected to the standby power source, otherwise the circuit breaker Branch circuit is disconnected in a OFF position. When multiple branch circuit breakers are used in accordance with the present invention, the state selector 114 of each branch circuit breaker allows the operator to control which loads will be connected to the standby power source in the case of that the public service energy source is not available. The branch circuit breakers can be configured at the time of manufacture or in the field as a field configuration for easy selection of the desired state for that particular branch circuit breaker. The conventional circuit protection (not shown) can be any suitable circuit protection mechanism, such as that found in the Square D QO circuit breaker. The circuit protection must comply with applicable design requirements to protect a branch circuit. in a residence. Additional advanced circuit protection features can also be incorporated such as ground fault circuit interruption and arc fault circuit interruption. The controller 110 executes the power source rating program, interprets the status selector 114, and causes disconnection or re-connection of the disconnect operation mechanism 106 under control of the energy source rating program. Figure 3 illustrates a status chart diagram 300 of the operation of the branch circuit breaker according to an embodiment of the present invention. Initially, the state is unknown. When no power source is available, the branch circuit breaker is passed from an ON state (306) to a OFF state (304) by the disconnect operation mechanism 106. In the OFF state (304), a source of energy may become available. If a utility power source is detected by the power source sensor 108, the branch circuit breaker is switched from the OFF state (304) to the ON state (306). If the power source is a standby power source, the controller 110 checks the status selector 114 to determine the selected state of the branch circuit breaker. If the selected state is ON, then the branch circuit breaker is switched to the ON state (306) by reconnecting the disconnect operation mechanism 106. Otherwise, the branch circuit breaker remains in the OFF state ( 304). A typical panel will have numerous branch circuit breakers, and in such an embodiment, a random or pseudo-random delay is implemented by the controller 100 to cause a pseudo-sequential closure of each branch circuit breaker such that it prevents multiple branch circuit breakers turn on simultaneously. The pseudo-sequential closing process helps to prevent undesirable starting currents in certain loads such as motors overloading the power source. It also decreases the step change in the load for the power source. Figure 2 illustrates a functional diagram of an independent automatic release system 200 connected between line contact 102 and load contact 104, respectively, for use in a central load panel housing multiple branch circuit breakers according to the present invention, wherein the disconnect operation mechanism 106 is in the form of additional motorized contacts. As mentioned above, a typical residence will have a panel containing numerous branch circuit breakers, all of which operate independently from one another to automatically release their loads based on a dynamically reconfigurable energy source classification program, in accordance with the present invention. Multiple sources of energy may be available to the residence, and an independent transfer switch switches between the available energy sources. Instead of pre-selecting and pre-wiring a set of waiting loads to be active when a standby power source is activated such that it reduces the load on the standby power source, the energy source classification algorithm of the present invention advantageously reduces the load on the standby device automatically without a host or system level controller. Each branch circuit breaker has its own independent operation controller that can be programmed or pre-configured to detach its load (s).

Additionally, the circuit branches that are active during branching energy can be reconfigured without the need to remove the inner cover of the central load panel. Status selector 114 can be easily changed by the operator, either manually or by a programmable configuration using controller 110. The independent automatic release system of the present invention results in a smoother operation where all branching loads are disconnected during a lack of energy, and selected branching loads are re-closed pseudo-sequentially for standby generation. All branching loads return to normal operation when utility power is restored. The system advantageously extends the life of the branching loads, contributes to the stability of the network, and minimizes manual intervention by the operator. Turning now to Figure 4, there is shown a flow diagram illustrating an automatic release procedure 400 for carrying out a specific embodiment of the present invention. The power source sensor 108 is read (402) and if a power loss is detected (404), the disconnect operation mechanism 106 is operated (406) to disconnect the branch circuit from the supply line. If a standby power source is detected (408) by the power source sensor 108, the status selector 114 is checked (414) to determine the desired state of the branch circuit breaker in the event of a supply failure. of public service energy. If the desired state is ON for that particular branch circuit breaker, the disconnect operation mechanism 106 is closed again (416) allowing backup energy to flow to the connected load (s) that branch circuit breaker. If the desired state is turned OFF, the disconnect operation mechanism 106 is not closed again and the controller 110 determines whether a public service energy source is detected (410) by the power source sensor 108. The source sensor of energy 108 is read (407), and the standby power source is detected (408). If the utility power source is detected, the disconnect operation mechanism 106 is closed again (412) and the system returns to normal operation. Otherwise, the power source sensor 108 is monitored until a change is detected. Note that the state selector status (414) does not have to be reviewed repetitively. Once is enough, and then it can be exceeded until the next energy loss is detected. Although particular embodiments and applications of the present invention have been illustrated and described, it should be understood that the invention is not limited to the precise construction and compositions disclosed herein and that various modifications, changes, and variations may be apparent from the above descriptions without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (30)

1. REIVI DICATIONS 1. A branch circuit breaker for automatically disconnecting a load coupled thereto from a power source, comprising: disconnecting means for reclosable disconnecting said load from said power source; sensor means for detecting the presence or absence of said energy source; and a controller programmed to execute a sorting program which determines by means of said sensor means if said power source is connected and its classification, and cause activation of said disconnection means in response to said sorting program.
2. 2. The branch circuit breaker of claim 1, further comprising selecting means for selecting an energy state for said branch circuit breaker when the energy is to be supplied by a different energy source than a power source of the branch circuit. public service .
3. 3. The branch circuit breaker of claim 2, wherein said controller is further programmed-to determine the selected energy state of said selection means.
4. The branch circuit breaker of claim 2, wherein said selection means includes a switch, a plug, or a programmable configuration.
5. 5. The branch circuit breaker of claim 1, further comprising a fault circuit interruption unit.
6. The branch circuit breaker of claim 1, wherein said disconnecting means includes a motor, contacts, or a relay.
7. The branch circuit breaker of claim 1, wherein said sensor means includes a voltage sensing circuit, a resistance divider, or a potential transformer.
8. The branch circuit breaker of claim 1, wherein said classification of said energy source is carried out by detecting a classification parameter of said energy source.
9. The branch circuit breaker of claim 8, wherein said classification parameter includes voltage, voltage variations, voltage frequency, voltage frequency variations, voltage harmonics, or variations in voltage harmonics.
10. The branch circuit breaker of claim 8, wherein said classification parameter includes slot harmonics.
11. 11. The branch circuit breaker of claim 1, wherein said classification includes an indication of a public utility power source and a standby power source.
12. The branch circuit breaker of claim 1, wherein said controller is further programmed to cause reclosing of said disconnection means in response to said classification program.
13. The branch circuit breaker of claim 12, wherein said resetting said disconnecting means responsive to said classification program is randomly delayed relative to the re-closing of other branch circuit breakers coupled to said source of energy.
14. The branch circuit breaker of claim 1, in combination with other branch circuit breakers, wherein said branch circuit breaker and said other branch circuit breakers operate independently from each other.
15. 15. A method for automatically releasing a load coupled to a power source, comprising: automatically disconnecting a branch circuit breaker from said power source in response to a disconnect command from a controller; detect the presence or absence of said energy source; determine using said controller, whether said energy source is present or absent; automatically detect the classification of said energy source from among a plurality of classifications; and executing in said controller a classification program that determines when to cause said automatic disconnection based on said determining and said automatically detecting.
16. The method of claim 15, further comprising automatically re-connecting said load to said power source in response to a re-connection command from said controller.
17. The method of claim 16, further comprising randomly delaying said automatically re-connecting in response to said re-connection command.
18. The method of claim 15, further comprising selecting an energy state for said branch circuit breaker when energy is to be supplied by a power source other than a public service energy source.
19. 19. The method of claim 18, wherein said selecting is carried out without a switch.
20. The method of claim 18, wherein said selecting is carried out without a programmable configuration using said controller.
21. The method of claim 15, further comprising automatically re-closing said branch circuit breaker in response to automatically detecting said classification as being indicative of a different energy source than a public service energy source and further in response to select an ON state of said branch circuit breaker.
22. 22. The method of claim 15, wherein said automatically detecting includes detecting voltage, voltage variations, voltage frequency, voltage frequency variations, voltage harmonics, or variations in voltage harmonics.
23. The method of claim 15, further comprising automatically reclosing said branch circuit breaker in response to said automatically detecting the classification detects said classification as being indicative of a public service energy source.
24. The method of claim 15, further comprising automatically disconnecting said branch circuit breaker in response to detecting an absence of said power source.
25. 25. A branch circuit breaker that is programmed to release its load automatically from a power source, comprising: a sensor coupled to a line contact in said branch circuit breaker; disconnection means for reclosable disconnecting said charge from said power source; selection means for selecting from a plurality of power states of said branch circuit breaker when a utility power source is not available; and a controller coupled to said sensor, said disconnecting means, and said selecting means, said controller being programmed to cause said disconnecting means to disconnect said load from said power source when said sensor detects an absence of said power source, determining a classification of an energy source available to said branch circuit breaker based on at least one classification parameter, detecting which one of said plurality of energy states was selected by said selection means, and causing said means of disconnection re-close when said sensor detects a source of energy different from a public service energy source and said one of said plurality of energy states is a state ON.
26. 26. The branch circuit breaker of claim 25, wherein said controller is further programmed-to randomly delay the reclosing of said disconnecting means when other branch circuit breakers are coupled in said line contact.
27. 27. The branch circuit breaker of claim 25, wherein said rating parameter is voltage, voltage variations, voltage frequency, voltage frequency variations, voltage harmonics, or variations in voltage harmonics.
28. 28. The branch circuit breaker of claim 25, wherein said plurality of energy states includes a STOP state and an ON state.
29. 29. The branch circuit breaker of claim 25, wherein said source of energy other than a public utility power source is a source of backup power.
30. 30. The branch circuit breaker of claim 25, wherein the source of energy other than a public service energy source is an alternative energy source.