FAULT INDICATOR WITH MULTI-COLOUR LED AND AUTO BACK UP WITH CAPACITOR
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A) FIELD OF TECHNOLOGY
1. The present invention relates generally to electric powered trip units, such as circuit breakers and more particularly to UN-RS3 trip unit faults monitoring using multi colored LED's for faults such as long time fault, short time fault, instantaneous and earth fault indication. The present invention also has provisions to keep the fault history using SuperCap capacitor, which holds for longer time. '
B) DESCRIPTION OF PRIOR ART:
2. This invention relates to a method and apparatus for monitoring the trip unit faults such as long time fault, short time fault, instantaneous and earth faults by using the LED's for the display. This invention also has the capability to store the fault information in SuperCap capacitor to keep the data for longer time. Since the circuit breakers are self-powered, this invention employs SuperCap capacitor to store and keep information for longer time even after power fails in the breaker.
3. Electric circuit breakers are commonly and are generally used in pairs or groups with a handle. The position of the handle typically indicates the status or condition of the breaker. The handle usually has three different positions one at each extreme throw of the handle and an intermediate position between the two extremes. One extreme indicates the breaker is switched on, the other extreme indicates the breaker is switched off and the intermediate position shows when the breaker is "blown". "Blown" is a condition where a short circuit, or near short circuit, occurred and the current flowing through the breaker exceeded the rating of the breaker causing the breaker is open, and so disconnect the power source from the load.
4. Patents disclosed in this field have a multi-function solid-state trip unit for automatic electric circuit breaker incorporation indicator functions. These indicator functions signal when a short circuit, overload or ground fault occurred. This patent is a complex arrangement where sensitive detection circuits are used to detect the load conditions of the breaker. When a short, overload or ground fault occurs the detection circuits respond and through programmable timing circuits drive SCR's, which trip the breaker. These SCR's also are connected to indicators which signal which condition occurred. Some of the patents disclosed also has a bypass circuit which insures that tripping of the breaker is not jeopardized by failure of the indicators.
5. A limitation of the some of the patents is its reliance on complex detection and driving circuits requiring a separate power supply. This extra, complex circuitry adds cost and other reliability considerations. Also the circuitry is magnetically coupled to the breakers, it is not physically connected to the breaker circuitry so that the actual condition of the lines connected to the breaker may not be shown by the indicators.
6. Some inventions use microprocessor coupled with RAM and EPROM to store the status information about circuit breakers. This invention uses SuperCap capacitor to store the information that facilitates the cost effective way of storing information for long time period.
7. Many earlier inventions did not give a way to monitor individual phase faults like on which phase the fault occurred. There is a need for a simple, low cost, easy to maintain and manufacture circuit breaker, which indicates the state of the breaker.
This invention is to provide a means to indicate the state of a circuit breaker without a cosdy and complex mechanical design. The state of the breaker includes on, switched off and blown or tripped, various fault conditions indication such as long time faults short time faults, instantaneous faults and earth faults, thereby increasing the precise method of finding the fault condition in a cheaper manner. Our invention provides a method of indication to identify the particular phase that incurs faults.
C) OBJECT OF THE INVENTION:
8. It is the primary object of the invention to invent a method of indication that utilizes multi color LED to indicate the various faults such as long time fault, short time fault, instantaneous fault and earth faults.
9. Its another primary object of the invention that facilitates the use of SuperCap capacitor to be used for storing the state and fault information for longer time period even after the power failure.
10. It is another object of the invention that incorporates different LED's to visualize the different conditions such as on, test, query and clear.
11. It is another object of the invention that provides the precise method of showing the phase that incurs faults.
12. It is another object of the invention to identify diverse faults that are sensed in UN-RS3 series circuit breakers and store the status and faults information for longer time period.
13. It is another object of the invention to invent a circuit design with facilitates the use of SuperCap capacitor with latches.
14. It is another object of the invention that consumes very low power by utilizing the latch and LED driving circuitry.
D) PROPOSED SOLUTION:
15. We propose a novel design in the field of circuit breaker fault identification, visualizing these faults by providing LED's and storing the information for later viewing.
16. Air circuit breakers (ACB) are used in the power distribution system to protect the system against various faults. UN-RS3 is the intelligence trip unit (Release) of the ACB. It senses diverse faults and takes a smart decision to trip the breaker. The fundamental faults are long time fault, Instantaneous and earth fault. There fore these are indicated on the release using LED's.
17. These faults may not occur in all these phases simultaneously. But from the LED indication it is not possible to differentiate on which phase exactly the fault has occurred. This invention enables the user to view phase in which the fault has
' occurred through the multi color LED's. on pressing the query button, the corresponding fault LED flows either in RED, YELLOW or BLUE color referring to each phase.
18. Normally these releases will be self-powered. Therefore power will not be available after the breaker has tripped. This invention enables the user to view the trip cause on pressing a button, even when the release is in off condition.
19. The novelty of this invention is it doesn't use a battery, which may exhaust after a certain period of time. This makes use of large capacitor called the SuperCap to store the trip information. This ideally lasts forever.
20. When and over load fault occurs in one phase the O/L LED glows with the corresponding color. The model of the such over load fault indicator is given in Figure 1.0 Instantaneous fault detected in the air circuit breaker is indicated through the model provided in Figure 2.0.
21. Many of the advance circuit breaker trip units have the feature of logging the fault details during tripping. These details include magnitude of the fault current or voltage or whatever, date and time, which phase the fault has occurred, oscillography etc.
22. Our trip unit, the release, has right now all these features implemented and it has many LED's n the front panel indication different trip causes or faults. When the release trips the breaker on a fault die corresponding LED is made ON. This information is available even after the power fail, which happens for all self-powered releases. And this new invention makes use of multi-color LED's to indicate the phase information also along with the faults.
23. For example when the unit is tripped sensing overload in B phase, O/L LED on the front panel glows in blue color, implying breaker has tripped for overload in B.
E) BLOCK DIAGRAM OF THE CIRCUIT DEISGN:
I
The Block diagram of the circuit design is shown in Figure no. 3.
1. Charging circuit for the SUPERCAP.
This circuitry enables a smooth charging of the SUPERCAP to the-supply voltage.
2. Latch
This octal latch stores the trip information from the micro controller. In the absence of power this latch will be powered from the SUPERCAP.
3. LED Driving circuit
This circuit drives the multi-colored LED's in the particular colour. Corresponding to the fault type and the phase in which fault has occurred.
4. LED array
This is the multi-colored LED arrangement for the fault display. This can be an array of 3 LED groups also.
5. Query Key
It is the key on the front panel. Upon pressing this key, the fault will be indicated on the corresponding LED in the particular color.
6. Circuits that are powered from SUPERCAP
These are very low-power devises. This section consists of Latch and other LED driving circuitry.
F) OPERATION AND WORKING OF CIRCUITS:
24. In the above circuit the SuperCap is charged to 5V through the charging logic. The diodes prevent it from getting discharged when the supply falls.
25. The query circuit comprises of one latch, the LED's an Analog switch and the query button. These devises are powered from two sources, one being the normal supply and another from the SuperCap. SuperCap voltage tuned to be lesser than the nominal supply such that it is always regular supply used. When the release senses some fault and before tripping it, writes the data into the latch for glowing the LED corresponding to the fault.
26. When power fails after trip, the query circuit is still active from the QueryVcc
)
(Super-CAP voltage). These devices are micro power devices such that the QueryVcc is available for the required duration. When the Query button is pressed, the analog switch is powered through the diode, which makes the witch turn ON. Once the switch is turned ON the circuit for the LED is complete and the corresponding LED glows. Query is available up to 48 hours after the trip and it glows for 2 minutes continuously.
G) The best method of performing the invention:
27. To summarize, the scheme presented here is implemented by designing a novel solution that provides the way to monitor circuit breaker for faults and visualize the faults through multi color LED indicators. This method has the precise method for identifying the particular phase that incurs fault. The SuperCap capacitor is used to store these information and later viewing of those materials that are stored.
28. When the release senses some fault and before tripping it, writes the data into the latch for glowing the LED corresponding to the fault. When power fails after trip, the query circuit is still active from the QueryVcc (Super-CAP voltage). When the Query button is pressed, the analog switch is powered through the diode, which makes the witch turn ON. Once the switch is turned ON the circuit for the LED is complete and the corresponding LED glows.
29. Query is available up to 48 hours after the trip and it glows for 2 minutes continuously. The main advantage of this circuit is that it doesn't require a battery for its operation. Thus many problems like looking for battery charge, recharging the battery, replacement of battery, etc are eliminated. And capacitor does not contain any hazardous materials as in the battery.
WE CLAIM:
Accordingly, one embodiment of the present invention comprises the fault monitoring mechanism that houses the multicolored LED's, which provides the visualization of different fault in the particular phase. The circuit breaker auto back up mechanism that works when the release senses some fault and before tripping it, writes the data into the latch for glowing the LED corresponding to the fault. As per the inventors
What is HaimPtf jc-
1. A circuit breaker fault identification unit with following functionality
a multicolor LED that facilitates the visualization of different fault conditions; auto backup mechanism that stores the information;
a circuit design that provides the backup mechanism with SuperCap capacitor;
2. The method of claim 1, wherein said the method of identifying the different fault conditions such as the long time fault, short time fault, instantaneous fault and earth faults is claimed here.
3. The method of claim 1, wherein said the method of employing multicolored LED's that is used for visualizing the above faults is claimed here.
4. The method of claim 1, wherein said the provision of different LED's that shows the status of the breaker such as on, trip, alarm, test, clear and query condition is claimed here.
5. The method of claim 1, wherein said the employment of SuperCap capacitors that are used to store the fault information for the breaker to the maximum of 48 hours is claimed here.
6. The method of claim 1, where in the usage of SuperCap capacitors provides the cost effective way of storing information is claimed here.
7. The method of claim 1, where in the design of cost effective and easy implementation of the circuit design is claimed here.
8. The method of claim 1, wherein the identification of fault condition on each phase is done individually for precise identification of particular phase is claimed here.