DESC:TECHNICAL FIELD

The present invention relates generally to a circuit breaker and, particularly, to setting thresholds of circuit breakers dynamically in a power distribution system, by communicating change in state of loads to other neighboring breaker.

BACKGROUND

Circuit breakers include a set of separable main contacts, one of which is usually fixed and one of which is movable for automatically opening upon the occurrence of a fault in electrical current in the network which the circuit breaker is provided to protect. Depending on the current that is flowing circuit breaker is classified as ACB, MCCB, MCB, and relay. Based on their arrangement they form upstream or downstream breaker. Now a days each of them come with trip units (microcontroller based), which are often removable and fixed again in the circuit breaker case. A trip unit includes a microcontroller and is adapted to automatically open the circuit breaker contacts under certain electrical fault conditions.

Furthermore, the latest range of electronic (micro controller based) circuit breaker has a communication module along with them to communicate with other circuit breakers or to system responsible. Each of the circuit breaker has a threshold setting. In current art these settings are usually constant. But the load may keep on changing i.e. (not all the loads connected are going to be ON the entire time).

In prior art the threshold settings are set once for each of the CB. They are set considering that all the loads are functional all the time. However, it may be possible that a particular load if turned OFF during some time while others are ON. During such times it is necessary to change the threshold settings. The threshold settings of an upstream CB need to be decreased or increased, respectively, when the load in a downstream CB is turned OFF or ON. Based on number of loads switched ON or OFF the thresholds can be increased or decreased. This change in downstream load is to be communicated to upstream breaker and the threshold settings of upstream breaker can be changed accordingly.

Thus in view of above mentioned problems and drawbacks of the existing systems, there exists a need to provide an efficient and economical system that can dynamically change the threshold based on the load and change in status of circuit breakers in the system, thereby achieving higher sensitivity and accuracy.

SUMMARY

This summary is provided to introduce concepts related to a system and method for dynamic threshold setting in circuit breakers. This summary is not intended to identify essential features of the subject matter nor is it intended for use in determining or limiting the scope of the subject matter.

In one implementation, the system and method is disclosed that provides an efficient and economical system and method that can dynamically change the threshold based on the load and change in status of circuit breakers in the system, thereby achieving higher sensitivity and accuracy.

In one implementation, the present invention relates to setting thresholds of circuit breakers dynamically in a power distribution system, by communicating change in state of loads to other neighboring breaker.

In one implementation, an electrical power distribution system with dynamic threshold settings is disclosed.

Accordingly, in one implementation, a method for dynamically setting a threshold of at least one circuit breaker, in a system CHARACTERIZED BY having a plurality of circuit breakers each with a trip unit and a communication module and arranged to form an upstream or a downstream breaker arrangement is disclosed.

The method comprises the steps of checking at least one immediate downstream breaker; verifying rated current that possibly flow through said at least one immediate downstream breaker; communicating said verified rated current to at least one upstream breaker; analyzing, by said at least one upstream breaker, current that will be flowing through, based on said verified rated current communicated, and thereby dynamically setting said threshold based on analyzed current that will be flowing through said at least one upstream breaker.

In one impledmentnantion, a method for dynamically setting a threshold of at least one circuit breaker, in a system CHARACTERIZED BY having a plurality of circuit breakers each with a trip unit and a communication module and arranged to form an upstream or a downstream breaker arrangement is disclosed. The method may include:
· checking (302), by means of one or more current sensors, at least one immediate downstream breaker;
· verifying (304), by means of said current sensors, rated current that possibly flow through said at least one immediate downstream breaker, wherein said current sensors provides an output to an electronic trip unit which is configured to calculate the flow of rated current;
· communicating (306), by means of a communicating module, said verified rated current to at least one upstream breaker, thereby
· analyzing (308), by said at least one upstream breaker, said verified rated current communicated, wherein said verified rated current communicated is a value; and
· dynamically setting (310) said threshold based on said value analyzed.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.

Figure 1 illustrates a various circuit breakers (CB) based on their ratings is shown, in accordance with an embodiment of the present subject matter.

Figure 2 illustrates a main circuit breaker which feeds CB1, CB8 and CB9is shown, in accordance with an embodiment of the present subject matter.

Figure 3 illustrates a method for dynamically setting a threshold of at least one circuit breaker is shown, in accordance with an embodiment of the present subject matter.

DETAILED DESCRIPTION OF THE PRESENT INVNENTION

Preferred embodiments of the present disclosure will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail.

The terms and words used in the following description are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention.

It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

By the term “substantially” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

In one implementation, the proposed invention relates to setting thresholds of circuit breakers dynamically in a power distribution system, by communicating change in state of loads to other neighboring breaker.

In one implementation, a method for dynamically setting a threshold of at least one circuit breaker, in a system CHARACTERIZED BY having a plurality of circuit breakers, and arranged to form an upstream or a downstream breaker arrangement is disclosed.

The method comprises the steps of checking at least one immediate downstream breaker; verifying rated current that possibly flow through said at least one immediate downstream breaker; communicating said verified rated current to at least one upstream breaker; analyzing, by said at least one upstream breaker, current that will be flowing through, based on said verified rated current communicated, and thereby dynamically setting said threshold based on analyzed current that will be flowing through said at least one upstream breaker.

In one implementation, the method steps are repeated for plurality of circuit breakers arranged to form said upstream or said downstream breaker arrangement.

In one implementation, the said threshold dynamically set based on loads connected.

In one implementation, said load connected is due to plurality of circuit breakers arranged to form said upstream or said downstream breaker arrangement.

In one implementation, the method further comprises notifying, to at least one upstream breaker, if a load connected in said upstream or said downstream breaker arrangement is turned OFF, and thereby dynamically setting said threshold of said at least one upstream breaker.

In one implementation, dynamically setting said threshold is based on a change of status of at least one circuit breaker from said plurality of circuit breakers arranged to form said upstream or said downstream breaker arrangement.

In one implementation, the power distribution system as shown in figure 1 includes various circuit breakers (CB) based on their ratings. The main circuit breaker branches out to feeders which further branch out into sub feeders. This branching continues further up to the load. There can be multiple feeders and hence multiple circuit breakers at each level, but in this embodiment the number of feeders is restricted to as shown in the figure for better understanding. Each circuit breaker has a microcontroller based electronic trip unit each of it having a communication module attached to it which makes communication possible between the CBs.

As shown in the figure 2 the main circuit breaker which feeds CB1, CB8 and CB9. CB1 Further feeds CB2 and CB7 while CB2 further feeds CB3, CB4, CB5 and CB6.

At the start all the breaker will check their immediate downstream breakers and checks the rated current that can flow through them. This will be communicated to the upstream breaker. Based on this the Upstream breaker will find out the current that will be flowing through it and then set the thresholds accordingly. This thing will be repeated for all pairs of upstream and downstream breaker. In one impledmentnantion, the upstream breaker may not have current more than the sum of currents of all the downstream breakers. Now suppose a load is turned OFF in Downstream CB it shall notify it to its upstream breaker and the upstream breaker will change its thresholds accordingly thus achieving dynamic threshold setting. Let us consider an example and suppose that CB2 is 400A CB while CB3, CB4, CB5 and CB6 are 100A CBs each and the thresholds settings are done according to loads (considering Normal current and rated current are same). Suppose all the loads are ON this is communicated to CB2 (upstream CB) by CB3, CB4, CB5 and CB6 (downstream CBs). The CB2 will communicate this to CB1 which will consider this while setting its thresholds.

Similarly the CB1 will communicate this to Main CB which will again set its thresholds based on this data. Now suppose that the load on CB6 is turned OFF, there will be no current flowing through it. Naturally the current flowing through the upstream breakers will be reduced. Since all four downstream breakers CB1, CB2, CB3and CB4 had 100A currents flowing through them the upstream breaker CB2 had a threshold setting of 400A. Now that CB6 has been shut and this has been communicated to CB2 the threshold settings are reduced by 100A i.e. from400A earlier to 300A. This change of status of CB6 is communicated to the upstream breakers which will change the threshold settings accordingly. Thus dynamic threshold setting system is proposed in the present invention.

Referring now to figure 3, a method for dynamically setting a threshold of at least one circuit breaker is shown, in accordance with an embodiment of the present subject matter. The method may be described in the general context of computer executable instructions. Generally, computer executable instructions can include routines, programs, objects, components, data structures, procedures, modules, functions, etc., that perform particular functions or implement particular abstract data types. The method may also be practiced in a distributed computing environment where functions are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, computer executable instructions may be located in both local and remote computer storage media, including memory storage devices.

The order in which the method is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method or alternate methods. Additionally, individual blocks may be deleted from the method without departing from the scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof. However, for ease of explanation, in the embodiments described below, the method may be considered to be implemented in the above described system.

The method for dynamically setting a threshold of at least one circuit breaker, in a system CHARACTERIZED BY having a plurality of circuit breakers, arranged to form an upstream or a downstream breaker arrangement, said method comprising the following steps:

At step 302, at least one immediate downstream breaker in the arrangement is checked.

At step 304, rated current that possibly flow through said at least one immediate downstream breaker is verified.

At step 306, said verified rated current is communicated to at least one upstream breaker.

At step 308, the current that will be flowing throughsaid at least one upstream breaker is analyzed, based on said verified rated current communicated.

At step 310, said threshold is dynamically set based on analyzed current that will be flowing through said at least one upstream breaker.

In one impledmentnantion, a method for dynamically setting a threshold of at least one circuit breaker, in a system CHARACTERIZED BY having a plurality of circuit breakers each with a trip unit and a communication module and arranged to form an upstream or a downstream breaker arrangement is disclosed. The method may include:
· checking (302), by means of one or more current sensors, at least one immediate downstream breaker;
· verifying (304), by means of said current sensors, rated current that possibly flow through said at least one immediate downstream breaker, wherein said current sensors provides an output to an electronic trip unit which is configured to calculate the flow of rated current;
· communicating (306), by means of a communicating module, said verified rated current to at least one upstream breaker, thereby
· analyzing (308), by said at least one upstream breaker, said verified rated current communicated, wherein said verified rated current communicated is a value; and
· dynamically setting (310) said threshold based on said value analyzed

In one example, CB3, CB4 and CB5 have 100A each flowing through them while that in CB6 has changed to 0A, this will be communicated to CB2. Then CB2 which had an earlier threshold setting of 400 A will change it to 300A based on the messages from each downstream breaker. Further CB2 will communicate this to CB1 which will reduce its threshold settings by 100A. This will continue till the final Main Circuit breaker.

Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include those provided by the following features:

One features of the invention is that, in the presented invention, the electrical power distribution system with dynamic threshold settings is disclosed.

Another feature of the invention is that, a better sensitivity towards fault currents is disclosed.

Another feature of the invention is that, a better safety and robust system as it considers the changing nature of load currents is disclosed.

Another feature of the invention is that, a cost effective as it can be implemented on present releases which have communication module is disclosed.

Although a system and method for dynamic threshold setting in circuit breakers is been described in language specific to structural features and/or methods, it is to be understood that the embodiments disclosed in the above section are not necessarily limited to the specific features or methods or devices described. Rather, the specific features are disclosed as examples of implementations of a system and method for dynamic threshold setting in circuit breakers.
,CLAIMS:1. A method for dynamically setting a threshold of at least one circuit breaker, in a system CHARACTERIZED BY having a plurality of circuit breakers, arranged to form an upstream or a downstream breaker arrangement, said method comprising:
checking (302), by means of one or more current sensors, at least one immediate downstream breaker;
verifying (304), by means of said current sensors, rated current that possibly flow through said at least one immediate downstream breaker, wherein said current sensors provides an output to an electronic trip unit which is configured to calculate the flow of rated current;
communicating (306), by means of a communicating module, said verified rated current to at least one upstream breaker, thereby
analyzing (308), by said at least one upstream breaker, said verified rated current communicated, wherein said verified rated current communicated is a value; and
dynamically setting (310) said threshold based on said value analyzed.

2. The method as claimed in claim 1 is repeated for plurality of circuit breakers arranged to form said upstream or said downstream breaker arrangement.

3. The method as claimed in claims 1 and 2, wherein dynamically setting of said threshold is based on loads connected.

4. The method as claimed in claims 1-3, wherein said load connected is due to plurality of circuit breakers arranged to form said upstream or said downstream breaker arrangement.

5. The method as claimed in claims 1-4, comprises notifying, to at least one upstream breaker, if a load connected in said upstream or said downstream breaker arrangement is turned OFF, and thereby dynamically setting said threshold of said at least one upstream breaker.

6. The method as claimed in claims 1-5, wherein dynamically setting of said threshold is based on a change of status of at least one circuit breaker from said plurality of circuit breakers arranged to form said upstream or said downstream breaker arrangement.