Circuit breaker

Abstract

The embodiment of the utility model provides a circuit breaker. The circuit breaker comprises a mechanical contact, an electromagnetic coil, a driving circuit and a controller. The mechanical contact is suitable for switching between a switching-on position and a switching-off position. The electromagnetic coil is coupled to the mechanical contact. The driving circuit comprises an input end, an output end and a control end. The output end is electrically connected with the electromagnetic coil. The controller is electrically connected with the input end of the driving circuit so as to obtain the input voltage of the driving circuit. The controller is further electrically connected with the control end of the driving circuit so as to send a pulse width modulation signal to the control end of the driving circuit based on the input voltage, and the duty ratio of the pulse width modulation signal is between the minimum duty ratio and the maximum duty ratio corresponding to the input voltage. By means of the arrangement, the duty ratio of the pulse width modulation signal can be flexibly adjusted between the minimum duty ratio and the maximum duty ratio, sufficient power can be provided to enable the mechanical contact to be attracted in place, and the situation that the mechanical contact is excessively abraded due to the fact that electromagnetic force is too large can be avoided.

Description

Technical Field

[0001] The embodiments disclosed herein relate generally to the field of electrical equipment, and more particularly to a circuit breaker. Background Technology

[0002] The mechanical switch in a circuit breaker ensures the safe connection or disconnection of the main circuit. In one type of circuit breaker, the mechanical switch includes mechanical contacts, an electromagnetic coil, and a return spring. By applying an appropriate voltage to the electromagnetic coil, an electromagnetic force is generated to drive the mechanical contacts, triggering a mechanical latching mechanism to open and close the switch. However, due to manufacturing tolerances and assembly errors, the driving force required for the mechanical switch may vary in each circuit breaker. If the control voltage is too low, it will be insufficient to generate the necessary electromagnetic force, potentially leading to incomplete contact engagement. If the control voltage is too high, excessive electromagnetic force may cause excessive wear on the mechanical contacts, and could even burn out the electromagnetic coil. Utility Model Content

[0003] The purpose of embodiments of this disclosure is to provide a circuit breaker that at least partially solves the above-described problems and other potential problems.

[0004] This disclosure provides a circuit breaker. The circuit breaker includes: a mechanical contact adapted to switch between a closed position and an open position; an electromagnetic coil coupled to the mechanical contact to drive the mechanical contact to switch between the closed and open positions; a drive circuit including an input terminal, an output terminal, and a control terminal, the output terminal being electrically connected to the electromagnetic coil; and a controller electrically connected to the input terminal of the drive circuit to obtain the input voltage of the drive circuit, and the controller is also electrically connected to the control terminal of the drive circuit to send a pulse width modulation signal to the control terminal of the drive circuit based on the input voltage, the duty cycle of the pulse width modulation signal being between a minimum duty cycle and a maximum duty cycle corresponding to the input voltage.

[0005] In some embodiments, the circuit breaker further includes a position detection unit disposed adjacent to the mechanical contacts to detect the position of the mechanical contacts and generate a position signal when the mechanical contacts reach the closed position; the controller is electrically connected to the position detection unit to stop sending the pulse width modulation signal to the drive circuit upon receiving the position signal.

[0006] In some embodiments, the circuit breaker further includes a timing unit for recording the duration of the pulse width modulation signal sent by the controller to the drive circuit; the controller is electrically connected to the timing unit to stop sending the pulse width modulation signal to the drive circuit when the duration reaches a predetermined duration.

[0007] In some embodiments, the circuit breaker further includes a prompting unit, and the controller is electrically connected to the prompting unit to send a prompting signal to the prompting unit to issue a prompting message when the duration reaches a predetermined duration.

[0008] In some embodiments, the position detection unit includes a micro switch.

[0009] In some embodiments, the circuit breaker further includes a current sampling circuit electrically connected to the electromagnetic coil to detect the current value of the electromagnetic coil; the controller is electrically connected to the current sampling circuit to send a pulse width modulation signal to the drive circuit based on the input voltage and current value so that the current value in the electromagnetic coil reaches a predetermined current value.

[0010] In some embodiments, the circuit breaker further includes a power supply circuit electrically connected to the input terminal of the drive circuit.

[0011] In some embodiments, the power supply circuit includes: a rectifier circuit; a filter circuit electrically connected to the rectifier circuit; and a capacitor electrically connected between the input terminals of the filter circuit and the drive circuit.

[0012] In some embodiments, the circuit breaker further includes: a body; a slidable core slidably coupled to an electromagnetic coil and the body, and the slidable core being coupled to a mechanical contact to drive the mechanical contact to switch between a closed position and an open position.

[0013] In some embodiments, the circuit breaker further includes: an elastic element coupled to the mechanical contacts and the body, and adapted to apply a force to the mechanical contacts to move the mechanical contacts to the open position.

[0014] In embodiments of this disclosure, the circuit breaker includes mechanical contacts, an electromagnetic coil, a drive circuit, and a controller. The mechanical contacts are adapted to switch between a closed position and an open position. The electromagnetic coil is coupled to the mechanical contacts to drive the mechanical contacts to switch between the closed and open positions. The drive circuit includes an input terminal, an output terminal, and a control terminal. The output terminal is electrically connected to the electromagnetic coil. The controller is electrically connected to the input terminal of the drive circuit to obtain the input voltage of the drive circuit. The controller is also electrically connected to the control terminal of the drive circuit to send a pulse width modulation (PWM) signal to the control terminal of the drive circuit based on the input voltage. The duty cycle of the PWM signal is between a minimum duty cycle and a maximum duty cycle corresponding to the input voltage. With this arrangement, the duty cycle of the PWM signal sent by the controller to the drive circuit can be flexibly adjusted between the minimum and maximum duty cycles. This not only provides sufficient power to make the mechanical contacts close properly but also avoids excessive wear of the mechanical contacts due to excessive electromagnetic force, thus avoiding the risk of the electromagnetic coil burning out.

[0015] It should be understood that the content described in this section is not intended to limit the key or essential features of the embodiments of this disclosure, nor is it intended to restrict the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0016] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein:

[0017] Figure 1 A circuit block diagram of a circuit breaker according to an embodiment of the present disclosure is shown;

[0018] Figure 2 A graph showing the output of the pulse width modulation signal of a circuit breaker according to an embodiment of the present disclosure is illustrated.

[0019] Figure 3 The output curves of the minimum pulse width modulation signal and the maximum pulse width modulation signal of the circuit breaker according to an embodiment of the present disclosure are shown.

[0020] Figure 4 A flowchart illustrating the control of a circuit breaker based on the mechanical contact position according to an embodiment of the present disclosure is shown;

[0021] Figure 5 A timing diagram of a pulse width modulation signal for a circuit breaker according to an embodiment of the present disclosure is shown, wherein the mechanical contacts are closed before the duty cycle of the pulse width modulation signal reaches the maximum duty cycle;

[0022] Figure 6 A timing diagram of a pulse width modulation signal for a circuit breaker according to an embodiment of the present disclosure is shown, wherein the mechanical contacts close when the duty cycle of the pulse width modulation signal reaches the maximum duty cycle;

[0023] Figure 7 A timing diagram of the pulse width modulation signal of a circuit breaker according to an embodiment of the present disclosure is shown, wherein the mechanical contacts have not closed after the operating time has expired;

[0024] Figure 8 A flowchart illustrating the control of a circuit breaker based on the current value of an electromagnetic coil according to an embodiment of the present disclosure is shown;

[0025] Figure 9 The current variation of an electromagnetic coil according to an embodiment of the present disclosure is shown, wherein the output duration of the pulse width modulation signal reaches a fixed duration;

[0026] Figure 10 A flowchart illustrating the control of a circuit breaker based on the current value of the electromagnetic coil and the position of the mechanical contacts according to an embodiment of the present disclosure is shown.

[0027] Figure 11 The current variation of the electromagnetic coil of a circuit breaker according to an embodiment of this disclosure is shown; and

[0028] Figure 12 The current variation of the electromagnetic coil of a circuit breaker according to another embodiment of this disclosure is shown.

[0029] Explanation of reference numerals in the attached figures:

[0030] 10. Body; 11. Sliding core; 12. Elastic element;

[0031] 1. Mechanical contact;

[0032] 2. Electromagnetic coil;

[0033] 3. Drive circuit;

[0034] 4. Controller; 41. Timing unit;

[0035] 5. Position detection unit;

[0036] 6. Prompt Unit;

[0037] 7. Current sampling circuit;

[0038] 8. Power supply circuit; 81. Rectifier circuit; 82. Filter circuit; 83. Capacitor. Detailed Implementation

[0039] Preferred embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0040] The term "comprising" and its variations as used herein signify open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "one example embodiment" and "one embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc., may refer to different or the same objects.

[0041] As described above, in a circuit breaker, the mechanical switch includes mechanical contacts, an electromagnetic coil, and a return spring. By applying an appropriate voltage to the electromagnetic coil, an electromagnetic force can be generated to drive the mechanical contacts to move, and the opening and closing operations of the mechanical switch are realized by triggering a mechanical latching mechanism. However, due to part tolerances and assembly errors during the manufacturing process, the driving force required for the mechanical switch in each circuit breaker may vary. If the control voltage is too low, it will be insufficient to generate the necessary electromagnetic force in the electromagnetic coil, which may result in incomplete engagement of the mechanical contacts. If the control voltage is too high, excessive electromagnetic force may cause excessive wear of the mechanical contacts, and there is even a risk of burning out the electromagnetic coil.

[0042] Embodiments of this disclosure provide a circuit breaker. The circuit breaker includes mechanical contacts, an electromagnetic coil, a drive circuit, and a controller. The mechanical contacts are adapted to switch between a closed position and an open position. The electromagnetic coil is coupled to the mechanical contacts to drive the mechanical contacts to switch between the closed and open positions. The drive circuit includes an input terminal, an output terminal, and a control terminal. The output terminal is electrically connected to the electromagnetic coil. The controller is electrically connected to the input terminal of the drive circuit to obtain the input voltage of the drive circuit. The controller is also electrically connected to the control terminal of the drive circuit to send a pulse width modulation (PWM) signal to the control terminal of the drive circuit based on the input voltage. The duty cycle of the PWM signal is between a minimum duty cycle and a maximum duty cycle corresponding to the input voltage. Using this arrangement, the duty cycle of the PWM signal sent by the controller to the drive circuit can be flexibly adjusted between the minimum and maximum duty cycles. This not only provides sufficient power to the mechanical contacts to engage properly but also avoids excessive wear of the mechanical contacts due to excessive electromagnetic force, thus avoiding the risk of electromagnetic coil burnout. The following will describe the process in conjunction with… Figures 1 to 12 The principles of this disclosure will be described in detail below.

[0043] like Figure 1 As shown, the circuit breaker includes a mechanical contact 1, an electromagnetic coil 2, a drive circuit 3, and a controller 4. The mechanical contact 1 can switch between the closed and open positions and can control the current flow in the main circuit. When the mechanical contact 1 is in the closed position, it is in contact with the stationary contact on the circuit breaker, allowing current to flow. When the mechanical contact 1 is in the open position, it separates from the stationary contact on the circuit breaker, cutting off the current path.

[0044] The electromagnetic coil 2 is coupled to the mechanical contact 1. After receiving electrical energy, it can generate a magnetic field, which in turn uses magnetic force to push or pull the mechanical contact 1, thereby moving the mechanical contact 1 between the closed position and the open position.

[0045] The drive circuit 3 is electrically connected to the controller 4 and the electromagnetic coil 2, forming a control loop. The drive circuit 3 includes an input terminal, an output terminal, and a control terminal. The input terminal of the drive circuit 3 is connected to an external power supply or an internal power supply circuit to receive electrical energy. The output terminal of the drive circuit 3 is electrically connected to the electromagnetic coil 2, allowing it to supply electrical energy to the electromagnetic coil 2. The control terminal of the drive circuit 3 is electrically connected to the controller 4 to receive pulse width modulation (PWM) signals from the controller 4.

[0046] The PWM signal consists of periodic high and low levels. For example, when the controller 4 sends a high-level signal to the drive circuit 3, the drive circuit 3 is activated and supplies power to the electromagnetic coil 2, causing the electromagnetic coil to generate a driving force. When the controller 4 sends a low-level signal, the drive circuit 3 is deactivated, and the electromagnetic coil 2 no longer generates a driving force. By adjusting the duty cycle of the PWM signal (i.e., the ratio of the high-level duration to the entire cycle time), the drive circuit 3 can provide an equivalent voltage to the electromagnetic coil 2, thereby precisely controlling the electromagnetic force generated by the electromagnetic coil 2. In this way, the electromagnetic force generated by the electromagnetic coil 2 can drive the mechanical contact 1 to move, and the mechanical switch can complete the opening and closing of the circuit.

[0047] The controller 4 is electrically connected to the input terminal of the drive circuit 3, and can obtain the input voltage of the drive circuit 3 from the input terminal, and send a PWM signal to the control terminal according to the input voltage. In addition, the controller 4 dynamically adjusts the duty cycle of the PWM signal according to different input voltages, so that the duty cycle is kept within a preset range, thereby precisely controlling the magnitude of the electromagnetic force generated by the electromagnetic coil 2.

[0048] By using this arrangement, the electromagnetic force generated by the electromagnetic coil 2 can be controlled by adjusting the duty cycle of the PWM signal, ensuring that the mechanical contact 1 can not only obtain sufficient power to complete the engagement action, but also avoids additional wear due to over-excitation.

[0049] In some embodiments, such as Figure 1 As shown, the circuit breaker also includes a body 10 and a sliding core 11. The sliding core 11 is slidably coupled to the electromagnetic coil 2 and the body 10, and is also coupled to the mechanical contact 1. The sliding core 11 can drive the mechanical contact 1 to switch between the closed and open positions. In this way, when the circuit needs to be closed, the electromagnetic coil 2 receives current and generates a magnetic field. The magnetic field acts on the sliding core 11, thereby driving it to move along a predetermined path. As the sliding core 11 displaces, it drives the mechanical contact 1 connected to it to move towards the closed position, thereby making contact between the two contacts and establishing a current path.

[0050] In some embodiments, such as Figure 1As shown, the circuit breaker also includes a resilient element 12. The resilient element 12 is coupled to the mechanical contact 1 and the body 10, and is adapted to apply a force to the mechanical contact 1 to move the mechanical contact 1 to the open position.

[0051] As an example, such as Figure 1 As shown, the elastic element 12 can be a spring. One end of the elastic element 12 is fixed to the body 10 of the circuit breaker, and the other end is connected to the mechanical contact 1. When the circuit breaker is closed, the electromagnetic force generated by the electromagnetic coil 2 can overcome the reset force provided by the elastic element 12, allowing the mechanical contact 1 to overcome the pressure of the spring and remain closed. When it is necessary to disconnect the circuit, the electromagnetic coil 2 drives the mechanical contact 1 to move again, so that the mechanical contact 1 is unlocked from the body 10. At this time, the elastic element 12 can quickly push the mechanical contact 1 back to the open position, cutting off the current path.

[0052] like Figure 2 As shown, after the specifications and materials of the circuit breaker components are determined, the electromagnetic force and motion resistance of the electromagnetic coil 2 can be calculated based on the component specifications, thereby calculating the theoretical PWM duty cycle. For example, the nominal number of turns of the electromagnetic coil 2 can be 100 turns, and the nominal free length of the spring is 10cm. The theoretical PWM duty cycle can then be determined based on the electromagnetic force of the electromagnetic coil 2 under the corresponding input voltage and the elastic force of the spring. The theoretical PWM duty cycle varies under different input voltages. For example, the larger the input voltage of the drive circuit 3, the smaller the theoretical duty cycle. Conversely, the smaller the input voltage of the drive circuit 3, the larger the theoretical duty cycle.

[0053] like Figure 3 As shown, in order to overcome the tolerance of parts and assembly errors in the manufacturing process, the minimum PWM output curve and the maximum PWM output curve can be obtained by multiplying the theoretical PWM output curve by a certain tolerance coefficient.

[0054] As an example, the nominal number of turns for electromagnetic coil 2 is 100 turns with a tolerance of 1%, so the actual number of turns for electromagnetic coil 2 is in the range of 99 to 101 turns. The nominal free length of the spring is 10 cm with a tolerance of 1%, so the free length of the spring is in the range of 9.9 cm to 10.1 cm. The theoretical minimum PWM value is calculated using 101 turns and 9.9 cm, and then the theoretical maximum PWM value is calculated using 99 turns and 10.1 cm. Furthermore, assuming a tolerance factor of 0.1, the theoretical minimum PWM value is multiplied by (1-0.1) to obtain the minimum PWM value, and the theoretical maximum PWM value is multiplied by (1+0.1) to obtain the maximum PWM value.

[0055] It should be understood that in other embodiments, the minimum and maximum PWM values ​​can also be obtained by combining multiple sets of experiments, and this disclosure is not intended to limit this.

[0056] In this way, based on a fixed input voltage, the duty cycle of the PWM signal sent by the controller 4 to the drive circuit 3 can be flexibly adjusted between the minimum and maximum duty cycles. This not only provides sufficient power for the mechanical contact 1 to engage properly, but also avoids excessive wear of the mechanical contact 1 due to excessive electromagnetic force, thus avoiding the risk of the electromagnetic coil 2 burning out.

[0057] In some embodiments, such as Figure 1 As shown, the circuit breaker also includes a position detection unit 5. The position detection unit 5 is located adjacent to the mechanical contact 1, allowing for real-time monitoring of the position changes of the mechanical contact 1. Furthermore, the position detection unit 5 can generate a corresponding position signal when the mechanical contact 1 reaches the closed position. The controller 4 is electrically connected to the position detection unit 5, and the controller 4 can stop sending pulse width modulation signals to the drive circuit 3 upon receiving the position signal. In this way, the controller 4 can promptly obtain the position information of the mechanical contact 1, thereby achieving precise control of the circuit breaker operation process.

[0058] As an example, the position detection unit 5 can be a microswitch that can sense changes in the position of the mechanical contact 1. When the mechanical contact 1 moves from the open position to the closed position, the position detection unit 5 is triggered and generates a position signal. This position signal is transmitted to the controller 4. After confirming that the mechanical contact 1 has been successfully closed, the controller 4 will stop sending pulse width modulation signals to the drive circuit 3, thereby cutting off the excitation current of the electromagnetic coil 2 to prevent unnecessary energy waste.

[0059] Using this arrangement, the circuit breaker has the ability to determine whether it has successfully completed the opening and closing action based on the actual position of the mechanical contact 1. The real-time feedback provided by the position detection unit 5 can help technicians quickly confirm the equipment status, improving work efficiency while also reducing potential safety hazards.

[0060] It should be understood that in other embodiments, the position detection unit 5 may also use non-contact sensing technology (such as Hall effect sensors, photoelectric sensors or magnetic switches, etc.) to sense the position change of the mechanical contact 1, and this disclosure is not intended to limit it.

[0061] In some embodiments, such as Figure 1As shown, the circuit breaker also includes a timing unit 41 for recording the duration of the PWM signal sent by the controller 4 to the drive circuit 3. The controller 4 is electrically connected to the timing unit 41 and can stop sending the PWM signal to the drive circuit 3 when the duration of sending the PWM signal reaches a predetermined duration. In this way, the timing unit 41 can track the time interval of the PWM signal from start to end and feed this duration information back to the controller 4. The controller 4 determines whether the predetermined duration has been reached based on preset logic. If this critical point is indeed reached, the controller 4 will immediately interrupt the transmission of the PWM signal to prevent unnecessary energy loss or overheating risk due to prolonged excitation of the electromagnetic coil 2.

[0062] As an example, the predetermined duration includes a timeout period. If the duration for which the controller 4 sends the PWM signal to the drive circuit 3 reaches the timeout period, it indicates that the circuit breaker has a mechanical fault and needs to be repaired and maintained as soon as possible.

[0063] As another example, the predetermined duration includes a fixed duration. When the duration for which the controller 4 sends the PWM signal to the drive circuit 3 reaches the fixed duration, it indicates that the movement duration of the mechanical contact 1 meets the requirements, and the mechanical contact 1 has reached the closed position.

[0064] In some embodiments, such as Figure 1 As shown, the circuit breaker also includes a notification unit 6. The controller 4 is electrically connected to the notification unit 6. When the duration of sending the PWM signal reaches a predetermined duration, the controller 4 can send a notification signal to the notification unit 6 to cause it to issue a notification message. When the controller 4 detects that the duration of sending the PWM signal has reached a preset time limit, it activates the notification unit 6 to generate an easily identifiable notification message.

[0065] As an example, the prompts can be in the form of flashing indicator lights, ringing buzzers, or text messages. In this way, operators can immediately know the status changes of the circuit breaker, such as whether the closing or opening action has been successfully completed, or whether there are any abnormalities that need to be addressed.

[0066] In some embodiments, such as Figure 1 As shown, the circuit breaker also includes a current sampling circuit 7. The current sampling circuit 7 is electrically connected to the electromagnetic coil 2. The current sampling circuit 7 can detect the current value of the electromagnetic coil 2. The controller 4 is electrically connected to the current sampling circuit 7 and can send a PWM signal to the drive circuit 3 based on the input voltage and the sampled current value, so that the current value in the electromagnetic coil 2 reaches a predetermined current value. By controlling the current in the electromagnetic coil 2 to the predetermined current value and maintaining it for a fixed duration, the mechanical contact 1 can be driven to the closed position.

[0067] In other embodiments, the controller 4 may also control the output of the PWM signal based on both the current value in the electromagnetic coil 2 and the position signal from the position detection unit 5. For example, the controller 4 first sends a PWM signal to the drive circuit 3 based on the sampled current value to make the current value in the electromagnetic coil 2 reach a predetermined current value. When the mechanical contact 1 reaches the closed position, the controller 4 can stop outputting the PWM signal based on the position signal without needing to continue controlling the current in the electromagnetic coil 2 at the predetermined current value.

[0068] In some embodiments, such as Figure 1 As shown, the circuit breaker also includes a power supply circuit 8. The power supply circuit 8 is electrically connected to the input terminal of the drive circuit 3 and can provide power to the drive circuit 3. As an example, such as... Figure 1 As shown, the power supply circuit 8 includes a rectifier circuit 81, a filter circuit 82, and a capacitor 83. The rectifier circuit 81 converts the AC voltage provided by the power grid or main circuit into a DC voltage, initially meeting the DC power requirements of the drive circuit 3. The filter circuit 82 further smooths the rectified voltage waveform, reducing ripple components and thus improving the purity of the output voltage. The capacitor 83 is electrically connected to the filter circuit 82 and the input terminal of the drive circuit 3. In this way, the capacitor 83 can store a large amount of charge in a short time and quickly release energy when necessary, compensating for voltage drops caused by load changes and ensuring that the drive circuit 3 always receives a stable power supply.

[0069] As an example, the three-phase power is rectified by the rectifier circuit 81 to charge the capacitor 83. The voltage of the capacitor 83 is then modulated by the PWM of the drive circuit 3 and the controller 4 and output to the electromagnetic coil 2.

[0070] In other embodiments, capacitor 83 may also be powered by single-phase alternating current or direct current, and this disclosure is not intended to limit it.

[0071] Example process

[0072] Figure 4 A flowchart of an example process 400 for controlling a circuit breaker based on the position of mechanical contacts according to some embodiments of the present disclosure is shown. Process 400 can be implemented at a controller. Reference is made below. Figure 5 To describe process 400.

[0073] In box 410, the controller can measure the input voltage of the electromagnetic coil and calculate the minimum and maximum PWM that can be output under this input voltage. For example... Figure 2 As shown, before each closing action, the input voltage magnitude is first determined, and then the corresponding minimum and maximum PWM values ​​are selected according to the output curve.

[0074] In box 420, the controller first starts outputting with the minimum PWM. In this way, excessive electromagnetic force during the startup phase can be avoided, which could cause the mechanical contacts to move too fast and damage them.

[0075] In frame 430, the controller determines whether it has received a position signal indicating that the mechanical contacts have successfully closed.

[0076] In box 440, if the controller receives a position signal indicating that the mechanical contacts have successfully closed, it stops outputting PWM signals to the drive circuit.

[0077] In box 450, if the controller does not receive a position signal indicating that the mechanical contact has successfully closed, it continues to determine whether the duration of the pulse width modulation signal sent by the controller to the drive circuit has exceeded the time limit.

[0078] In box 460, if the controller determines that the timeout period for sending the pulse width modulation signal to the drive circuit has expired and the mechanical contacts have failed to close, it indicates a mechanical fault, such as a failure of the electromagnetic coil. The controller stops outputting PWM signals to the drive circuit and can send a prompt signal to the prompting unit to issue a prompt message. In this way, the prompt message reminds technicians to resolve the relevant fault as soon as possible.

[0079] In box 470, if the controller determines that the duration of sending the pulse width modulation signal to the drive circuit has not yet timed out, it further determines whether the PWM output has reached the maximum PWM output value. If the PWM output value has reached the maximum PWM output value, it directly returns to box 430 to further determine whether a position signal indicating successful mechanical contact closing has been received.

[0080] In box 480, if the PWM output does not reach the maximum output value, the PWM output is gradually increased by a certain amount, and then the process returns to box 430 to further determine whether a position signal indicating successful mechanical contact closing has been received.

[0081] like Figure 5 As shown, the controller starts outputting the minimum PWM signal and then gradually increases the duty cycle of the pulse width modulation signal output to the drive circuit. Let the start time be t0. The controller starts outputting from the minimum PWM value and increases the PWM output at a certain rate until it detects a position signal and stops outputting PWM. Here, the mechanical contacts are already closed before the PWM signal's duty cycle reaches its maximum.

[0082] like Figure 6 As shown, t0' indicates that the controller starts outputting the minimum PWM signal and gradually increases the duty cycle of the PWM signal output to the drive circuit according to a specific growth curve. When the controller receives a signal indicating successful closing of the mechanical contacts, it stops the PWM output; the stop time is t1'. Figure 6As shown, the mechanical contacts are still not closed when the duty cycle of the PWM signal reaches its maximum. However, the timeout period for the controller to send the PWM signal to the drive circuit has not yet expired, and the controller maintains the duty cycle of the output PWM signal at its maximum until the mechanical contacts successfully close.

[0083] like Figure 7 As shown, the controller starts outputting the minimum PWM signal and then gradually increases the duty cycle of the PWM signal output to the drive circuit. When the duty cycle of the PWM signal reaches the maximum duty cycle, the mechanical contacts still have not closed. At this time, the duration for which the controller sends the PWM signal to the drive circuit has not yet expired, and the controller maintains the duty cycle of the output PWM signal at the maximum duty cycle. After the timeout period, the mechanical contacts still fail to close successfully. At this point, it indicates that there is a mechanical fault in the circuit breaker. The controller stops outputting the PWM signal to the drive circuit to avoid burning out the electromagnetic coil and can send a warning signal to the warning unit.

[0084] Figure 8 A flowchart of an example process 800 for controlling a circuit breaker based on the current value of an electromagnetic coil according to some embodiments of the present disclosure is shown. Process 800 can be implemented at a controller. Reference is made below. Figure 9 To describe process 400.

[0085] In block 810, the controller can measure the input voltage of the electromagnetic coil and calculate the minimum and maximum PWM that can be output under this input voltage.

[0086] In block 820, the controller obtains the current feedback of the electromagnetic coil, calculates the PWM output value, and limits the output value to the minimum PWM and the maximum PWM.

[0087] In box 830, the controller determines whether the duration of sending the pulse width modulation signal to the drive circuit has reached a fixed duration. If the duration has not reached the fixed duration, it returns to box 820.

[0088] In block 840, if the controller determines that the duration of sending the pulse width modulation signal to the drive circuit has reached a fixed duration, it stops sending the pulse width modulation signal to the drive circuit.

[0089] like Figure 9 As shown, by obtaining the predetermined current value and fixed time T of the electromagnetic coil... 固定Once the current in the electromagnetic coil stabilizes at a predetermined current for a certain period, the mechanical contacts can be driven to close the circuit. Before the controller outputs the PWM, the minimum and maximum values ​​of the PWM output are determined based on the input voltage. Let the start time be t0 and the stop time be t1. The controller continuously monitors the current in the electromagnetic coil and calculates the PWM output based on the current feedback value, controlling the coil current within the predetermined range. The PWM output stops when the running time reaches the predetermined limit.

[0090] Figure 10 A flowchart illustrating an example process 1000 for controlling a circuit breaker based on the current value of an electromagnetic coil and the position of mechanical contacts, according to some embodiments of this disclosure, is shown. Process 1000 can be implemented at a controller. Reference is made below. Figure 11 and Figure 12 To describe process 1000.

[0091] In box 1010, the controller can measure the input voltage of the electromagnetic coil and calculate the minimum and maximum PWM that can be output under this input voltage.

[0092] In box 1020, the controller obtains the current feedback of the electromagnetic coil, calculates the PWM output value, and limits the output value to the minimum PWM and the maximum PWM.

[0093] In box 1030, the controller determines whether it has received a position signal indicating that the mechanical contacts have successfully closed.

[0094] In box 1040, if the controller receives a position signal indicating that the mechanical contact has successfully closed, the position signal takes priority, and the controller stops continuously outputting PWM signals to the drive circuit.

[0095] In box 1050, if the controller does not receive a position signal indicating successful closing of the mechanical contacts, the controller determines whether the duration of sending the PWM signal to the drive circuit has reached a fixed duration. If the duration has not reached the fixed duration, the process returns to box 1020.

[0096] In box 1060, if the controller determines that the duration of sending the PWM signal to the drive circuit has reached a fixed duration and no position signal indicating successful closing of the mechanical contacts has been received, it indicates that the circuit breaker has a mechanical fault. At this time, the controller can send a prompt signal to the prompting unit to issue a prompt message. In this way, the prompt message reminds technicians to resolve the relevant fault as soon as possible.

[0097] like Figure 11As shown, by adjusting the duty cycle of the PWM signal, the current in the electromagnetic coil can gradually approach a predetermined current value, and the controller can maintain the current value in the electromagnetic coil at the predetermined current value based on the feedback current. After the current value in the electromagnetic coil reaches the predetermined current value and is maintained for a period of time, if the controller receives a position signal indicating successful closing of the mechanical contacts, the position signal takes priority, and the controller stops continuously outputting the PWM signal to the drive circuit. In this way, the current value in the electromagnetic coil does not need to be maintained for a fixed duration after reaching the predetermined current value, thus avoiding overheating of the electromagnetic coil.

[0098] like Figure 12 As shown, by adjusting the duty cycle of the PWM signal, the current in the electromagnetic coil can gradually approach a predetermined current value, and the controller can maintain a stable current value in the electromagnetic coil based on the feedback current. After the current value in the electromagnetic coil reaches the predetermined current value and is maintained for a period of time, if the controller receives a position signal indicating successful closing of the mechanical contacts, the position signal takes priority, and the controller stops continuously outputting the PWM signal to the drive circuit. Figure 11 Compared to the circuit breaker shown, this circuit breaker experiences greater resistance during the movement of its mechanical contacts, resulting in a longer time required to reach the closed position. For example... Figure 12 As shown, the controller stops outputting PWM signals to the drive circuit later than... Figure 11 The stop time is shown.

[0099] Using the above methods, the controller can control the operation of the circuit breaker based on the current value of the electromagnetic coil and the position of the mechanical contacts, and can precisely control the opening and closing of the mechanical contacts.

[0100] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A circuit breaker, characterized in that, include: Mechanical contact (1), suitable for switching between the closed position and the open position; An electromagnetic coil (2) is coupled to the mechanical contact (1) to drive the mechanical contact (1) to switch between the closed position and the open position; The driving circuit (3) includes an input terminal, an output terminal and a control terminal, wherein the output terminal is electrically connected to the electromagnetic coil (2); as well as The controller (4) is electrically connected to the input terminal of the drive circuit (3) to obtain the input voltage of the drive circuit (3), and the controller (4) is also electrically connected to the control terminal of the drive circuit (3) to send a pulse width modulation signal to the control terminal of the drive circuit (3) based on the input voltage, the duty cycle of the pulse width modulation signal being between the minimum duty cycle and the maximum duty cycle corresponding to the input voltage.

2. The circuit breaker according to claim 1, characterized in that, It also includes a position detection unit (5), which is disposed adjacent to the mechanical contact (1) to detect the position of the mechanical contact (1) and generate a position signal when the mechanical contact (1) reaches the closed position; The controller (4) is electrically connected to the position detection unit (5) to stop sending the pulse width modulation signal to the drive circuit (3) upon receiving the position signal.

3. The circuit breaker according to claim 2, characterized in that, It also includes a timing unit for recording the duration of the pulse width modulation signal sent by the controller (4) to the drive circuit (3); The controller (4) is electrically connected to the timing unit (41) to stop sending the pulse width modulation signal to the drive circuit (3) when the duration reaches a predetermined duration.

4. The circuit breaker according to claim 3, characterized in that, It also includes a prompting unit (6), the controller (4) being electrically connected to the prompting unit (6) to send a prompting signal to the prompting unit (6) to issue a prompting message when the duration reaches the predetermined duration.

5. The circuit breaker according to claim 2, characterized in that, The position detection unit (5) includes a micro switch.

6. The circuit breaker according to claim 1 or 2, characterized in that, It also includes a current sampling circuit (7), which is electrically connected to the electromagnetic coil (2) to detect the current value of the electromagnetic coil (2); The controller (4) is electrically connected to the current sampling circuit (7) to send the pulse width modulation signal to the drive circuit (3) based on the input voltage and the current value, so that the current value in the electromagnetic coil (2) reaches a predetermined current value.

7. The circuit breaker according to claim 1, characterized in that, Also includes: The power supply circuit (8) is electrically connected to the input terminal of the drive circuit (3).

8. The circuit breaker according to claim 7, characterized in that, The power supply circuit (8) includes: Rectifier circuit (81); The filter circuit (82) is electrically connected to the rectifier circuit (81); and A capacitor (83) is electrically connected between the input terminal of the filter circuit (82) and the drive circuit (3).

9. The circuit breaker according to any one of claims 1 to 5, 7 and 8, characterized in that, Also includes: Ontology(10); A slidable core (11) is slidably coupled to the electromagnetic coil (2) and the body (10), and the slidable core (11) is coupled to the mechanical contact (1) to drive the mechanical contact (1) to switch between the closed position and the open position.

10. The circuit breaker according to claim 9, characterized in that, Also includes: An elastic element (12) is coupled to the mechanical contact (1) and the body (10) and is adapted to apply a force to the mechanical contact (1) to move the mechanical contact (1) toward the open position.

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