Electronic circuit breaker and self-adaptive overcurrent protection method thereof
By integrating the current sampling circuit and microprocessor in the electronic circuit breaker, real-time detection and adaptive protection of current values are achieved, and the problem of lack of adaptability of the existing circuit breaker overcurrent protection design is solved, and the accuracy and flexibility of protection are improved.
Patent Information
- Application Number
- CN202411948432.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-04-18
Smart Images
Figure CN119852934A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of circuit breaker equipment, and in particular to an electronic circuit breaker and an adaptive overcurrent protection method thereof. Background Art
[0002] When designing overcurrent protection (including overload protection, short-circuit short-delay protection, and short-circuit instantaneous protection) for traditional circuit breakers and existing electronic circuit breakers, the design institute generally designs them based on load estimates. After the complete set factory actually designs the cabinet, the main circuit breaker in the distribution cabinet distributes power to and protects each branch circuit breaker, and each branch circuit breaker protects the corresponding load equipment.
[0003] The low-voltage electrical appliance industry at home and abroad has not used an accurate method to perfectly solve the matching of upper and lower circuit breakers (main circuit breakers and branch circuit breakers) and the overcurrent protection design problems between outgoing circuit breakers and equipment. Because in the design stage, the on-site load conditions can only be estimated, and in actual application, the equipment used will have great changes or only part of the equipment will be started. When designing, the design institute generally considers reserving circuit breakers for backup equipment according to traditional design experience, which will give the upper circuit breaker a large protection margin. The equipment protected by the branch circuit breaker will also cause the rated working current to fluctuate due to changes in use or load changes. This will cause the circuit breaker to fail to properly protect against overcurrent. Although the knob-adjustable electronic molded case circuit breaker has a certain adjustable range, it still cannot be adjusted when the user adds or subtracts equipment. The digital or LCD type does not have a design adaptive function and cannot complete overcurrent adaptive protection.
[0004] It is precisely because the rated working current of the existing circuit breaker is not adaptive that it seriously affects the design difficulty of the design institute and the actual application of the circuit breaker brings various inaccurate protection situations, and the accurate overcurrent protection of the power distribution facilities cannot be reflected. The present invention aims to solve the problem that the circuit breaker can detect and automatically adjust the overcurrent protection value according to the situation of each outgoing circuit breaker or the real-time change of the equipment load in real time, so as to realize accurate overcurrent protection of the equipment, reduce the tedious work of the design institute to pre-judge the setting of the equipment protection adjustment value, and reduce the situation of numerous circuit breaker current setting values.
[0005] The above shows that the circuit breaker overcurrent protection currently used in the electrical industry is a fixed setting value, and the distribution cabinet manufactured according to the design plan is far from the actual application overcurrent protection requirements. Summary of the invention
[0006] In view of this, the purpose of the present invention is to propose an electronic circuit breaker and an adaptive overcurrent protection method thereof to solve the problem that the overcurrent protection of circuit breakers currently used in the electrical industry is a fixed setting value, which is far from the actual application overcurrent protection requirements.
[0007] Based on the above purpose, the present invention provides an electronic circuit breaker, comprising a power supply circuit, a current sampling circuit, a microprocessor, a digital display circuit, a drive circuit, an electronic release and an operation button integrated on a circuit board; the power supply circuit provides power for the microprocessor, the drive circuit and the electronic release; the current sampling circuit is electrically connected to the microprocessor, and the microprocessor is also electrically connected to the digital display circuit, the drive circuit and the operation button respectively; the operation button inputs information to the microprocessor, the digital display circuit displays the information, the drive circuit is also electrically connected to the electronic release, and the microprocessor controls the electronic release through the drive circuit to open the electronic circuit breaker.
[0008] As a further improvement of the present application, the current sampling circuit collects the three-phase current of the electronic circuit breaker through a current transformer and transmits the data to the microprocessor.
[0009] As a further improvement of the present application, the adaptive overcurrent protection method of the electronic circuit breaker is as follows: the microprocessor determines whether the current value is constant. If the current value is constant, the microprocessor calculates the current and no overcurrent protection action is required, and the electronic release does not act; if the current value is not constant, the microprocessor calculates the current and an overcurrent protection action is required, and the electronic release performs a tripping action on the electronic circuit breaker.
[0010] As a further improvement of the present application, the constant current value means that the fluctuation range of the current value is within a set range value, and the set range value is input through the operation key.
[0011] Specifically, the set range value is 3%.
[0012] As a further improvement of the present application, the specific process of the adaptive overcurrent protection method is as follows:
[0013] When the electronic circuit breaker is closed, the current sampling circuit of the circuit board inside the electronic circuit breaker samples the current value through the current transformer, and the digital display circuit displays the current value. The microprocessor determines whether the current is constant according to the current value. When the current value tends to be stable after a certain period of time after closing, the rated working current of the electronic circuit breaker is the displayed current value. The microprocessor will adapt to the current according to this current value, and automatically calculate and set new long delay protection, short delay protection and short circuit instantaneous protection;
[0014] When the current value is still unstable after a certain period of time after closing the circuit, and the fluctuation range is greater than the set range value, the circuit breaker is triggered to operate, and the long delay protection, short circuit short delay protection or short circuit instantaneous protection is generated, and the protection action command is executed. The driving circuit drives the electronic release to open the electronic circuit breaker. The electronic circuit breaker can be closed only after the fault is eliminated. After closing, the adaptive overcurrent protection method starts from the beginning.
[0015] Specifically, the certain time after a certain time after closing the circuit breaker is 90 seconds.
[0016] The beneficial effects of the present invention are as follows: by measuring the accurate current value, taking the measured value as a reference, automatically calculating and adjusting the overcurrent protection value, the overcurrent protection accuracy is improved, and the user is guaranteed safety. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0018] Figure 1 This is a schematic diagram of the structure of an electronic circuit breaker according to an embodiment of the present invention;
[0019] Figure 2 The present invention is a flowchart of an adaptive overcurrent protection method for an electronic circuit breaker according to an embodiment of the present invention.
[0020] The markings in the figure are:
[0021] 1. Power supply circuit, 2. Current sampling circuit, 3. Microprocessor, 4. Digital display circuit, 5. Drive circuit, 6. Electronic release, 7. Operation buttons. DETAILED DESCRIPTION
[0022] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.
[0023] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0024] like Figure 1 and Figure 2 As shown, an electronic circuit breaker includes a power supply circuit 1, a current sampling circuit 2, a microprocessor 3, a digital display circuit 4, a drive circuit 5, an electronic release 6 and an operation button 7 integrated on a circuit board; the power supply circuit 1 provides power for the microprocessor 3, the drive circuit 5 and the electronic release 6; the current sampling circuit 2 is electrically connected to the microprocessor 3, and the current sampling circuit 2 collects the three-phase current of the electronic circuit breaker through a current transformer and transmits the data to the microprocessor 3. The microprocessor 3 is also electrically connected to the digital display circuit 4, the drive circuit 5 and the operation button 7 respectively; the operation button 7 inputs information to the microprocessor 3, the digital display circuit 4 displays the information, the drive circuit 5 is also electrically connected to the electronic release 6, and the microprocessor 3 controls the electronic release 6 through the drive circuit 5 to open the electronic circuit breaker.
[0025] like Figure 2 As shown, the adaptive overcurrent protection method of the electronic circuit breaker is as follows: the microprocessor 3 determines whether the current value is constant. If the current value is constant, the microprocessor 3 calculates the current and does not need to perform overcurrent protection action, and the electronic release 6 does not act; if the current value is not constant, the microprocessor 3 calculates the current and needs to perform overcurrent protection action, and the electronic release 6 opens the electronic circuit breaker.
[0026] The constant current value means that the fluctuation range of the current value is within the set range value, and the set range value is input through the operation key 7. In order to strike a balance between avoiding malfunction and enhancing protection, the set range value is 3%.
[0027] like Figure 2As shown, the specific process of the adaptive overcurrent protection method is as follows
[0028] When the electronic circuit breaker is closed, the current sampling circuit 2 of the circuit board inside the electronic circuit breaker samples the current value through the current transformer, and the digital display circuit 4 displays the current value. The microprocessor 3 determines whether the current is constant according to the current value. Since the current is still abnormal after 90 seconds of the motor starting time, it is basically an abnormal situation. Therefore, when the current value tends to be stable after 90 seconds after closing, the rated working current of the electronic circuit breaker is the displayed current value. The microprocessor 3 will adapt to the current according to this current value, and automatically calculate and set new long-delay protection, short-delay protection and short-circuit instantaneous protection; when the current value is still unstable after 90 seconds after closing, and the fluctuation range is greater than the set range value, the circuit breaker is triggered to act, and the long-delay protection, short-circuit short-delay protection or short-circuit instantaneous protection generated is executed. The protection action command is executed, and the drive circuit 5 drives the electronic release 6 to open the electronic circuit breaker. The electronic circuit breaker can be closed only after the fault is eliminated. After closing, the adaptive overcurrent protection method is restarted.
[0029] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.
[0030] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. An electronic circuit breaker, characterized in that: It comprises a power supply circuit (1), a current sampling circuit (2), a microprocessor (3), a digital display circuit (4), a drive circuit (5), an electronic release (6) and an operating button (7) which are integrated on a circuit board; The power supply circuit (1) provides power to the microprocessor (3), the drive circuit (5) and the electronic release (6); The current sampling circuit (2) is electrically connected to the microprocessor (3), and the microprocessor (3) is also electrically connected to the digital display circuit (4), the drive circuit (5) and the operation button (7) respectively; the operation button (7) inputs information to the microprocessor (3), the digital display circuit (4) displays the information, and the drive circuit (5) is also electrically connected to the electronic release (6). The microprocessor (3) controls the electronic release (6) through the drive circuit (5) to determine whether to open the electronic circuit breaker.
2. The electronic circuit breaker according to claim 1, characterized in that: The current sampling circuit (2) collects the three-phase current of the electronic circuit breaker through a current transformer, and transmits the data to the microprocessor (3).
3. The adaptive overcurrent protection method for an electronic circuit breaker according to any one of claims 1 or 2, characterized in that: The adaptive overcurrent protection method for an electronic circuit breaker is as follows: the microprocessor (3) determines whether the current value is constant; if the current value is constant, the microprocessor (3) calculates that the current does not need to perform an overcurrent protection action, and the electronic release (6) does not act; if the current value is not constant, the microprocessor (3) calculates that the current needs to perform an overcurrent protection action, and the electronic release (6) performs a tripping action on the electronic circuit breaker.
4. The electronic circuit breaker and the adaptive overcurrent protection method thereof according to claim 3, characterized in that: The constant current value means that the fluctuation range of the current value is within a set range value, and the set range value is input through the operation button (7).
5. The electronic circuit breaker and the adaptive overcurrent protection method thereof according to claim 4, characterized in that: The set range value is 3%.
6. The electronic circuit breaker and the adaptive overcurrent protection method thereof according to claim 1, characterized in that: The specific process of the adaptive overcurrent protection method is as follows When the electronic circuit breaker is closed, the current sampling circuit (2) of the circuit board inside the electronic circuit breaker samples the current value through the current transformer, and the digital display circuit (4) displays the current value. The microprocessor (3) determines whether the current is constant based on the current value. When the current value tends to be stable after a certain period of time after closing, the rated working current of the electronic circuit breaker is the displayed current value. The microprocessor (3) will adapt to the current based on this current value and automatically calculate and set new long-delay protection, short-delay protection and short-circuit instantaneous protection. When the current value is still unstable after a certain period of time after closing the circuit breaker, and the fluctuation range is greater than the set range value, the circuit breaker is triggered to operate, and the long delay protection, short circuit short delay protection or short circuit instantaneous protection is generated, and the protection action command is executed, and the driving circuit (5) drives the electronic release (6) to open the electronic circuit breaker. The electronic circuit breaker can be closed only after the fault is eliminated, and the adaptive overcurrent protection method is restarted after closing.
7. The electronic circuit breaker and the adaptive overcurrent protection method thereof according to claim 6, characterized in that: The certain time after the certain time after the closing of the circuit breaker is 90 seconds.