Voltage detection circuit and circuit breaker protection system

Abstract

The utility model discloses a voltage detection circuit and a breaker protection system. The voltage detection circuit comprises a sampling module, a voltage reduction module and a comparison module. The sampling module is used for sampling live wire voltage of a wire outlet end of the circuit breaker and forming first output voltage according to the live wire voltage; the voltage reduction module is used for converting the first output voltage into second output voltage; the second output voltage is smaller than the first output voltage; the second input end of the comparison module is connected with reference voltage. The comparison module is used for outputting first voltage through the comparison output end when the second output voltage is larger than the reference voltage. When the second output voltage is smaller than the reference voltage, a second voltage is output through the comparison output end, and the first voltage is larger than the second voltage; the control module is used for determining whether voltage is input to the wire outlet end of the circuit breaker according to the voltage state output by the comparison module. According to the utility model, whether voltage input exists at the wire outlet end of the circuit breaker can be detected.

Description

Technical Field

[0001] This utility model relates to the field of low-voltage power distribution technology, and in particular to a voltage detection circuit and a circuit breaker protection system. Background Technology

[0002] With population growth and economic development, global demand for energy supply continues to increase. Compared to traditional energy sources, new energy sources such as solar and wind power are inexhaustible, so they have developed rapidly in recent years. At the same time, energy storage technology has also developed rapidly. Energy storage technology runs through all aspects of new energy development and utilization, playing a role in conversion, buffering, peak shaving, and efficiency improvement.

[0003] Traditionally, residual current circuit breakers (RCCBs) are used only between the power grid and the load, with voltage input occurring only at the incoming switch terminal. However, circuit breakers used in photovoltaic (PV) and energy storage applications connect to the power grid at the incoming terminal and the power generation equipment at the outgoing terminal, meaning voltage input exists at both ends. For grid connection management and safety warnings regarding energized outgoing terminals, it is necessary to know whether there is voltage input at the outgoing terminal.

[0004] Residual current protection circuit breakers need to meet impulse withstand voltage requirements, with a maximum test voltage of 18.5kV, including phase-to-phase tests. This necessitates that the voltage detection circuit at the outgoing terminals take precautions against voltage damage. Utility Model Content

[0005] This invention provides a voltage detection circuit and a circuit breaker protection system that can detect whether there is voltage input at the output terminal of the circuit breaker.

[0006] In a first aspect, this utility model provides a voltage detection circuit for detecting whether there is voltage input at the output terminal of a circuit breaker. The voltage detection circuit includes: a sampling module, a step-down module, a comparison module, and a control module. The input terminal of the sampling module is connected to the output terminal of the circuit breaker, the output terminal of the sampling module is connected to the input terminal of the step-down module, and the output terminal of the step-down module is connected to the first input terminal of the comparison module. The sampling module is used to sample the live wire voltage at the output terminal of the circuit breaker and form a first output voltage based on the live wire voltage. The step-down module is used to convert the first output voltage into a second output voltage. The second output voltage is less than the first output voltage. The second input terminal of the comparison module is connected to a reference voltage. The comparison module is used to output a first voltage through the comparison output terminal when the second output voltage is greater than the reference voltage, and to output a second voltage through the comparison output terminal when the second output voltage is less than the reference voltage, wherein the first voltage is greater than the second voltage. The control module is used to determine whether there is voltage input at the output terminal of the circuit breaker based on the voltage state output by the comparison module.

[0007] Optionally, the step-down module includes P series-connected voltage divider resistors; P is an integer greater than or equal to 2; the first terminal of the first voltage divider resistor serves as the input terminal of the step-down module, and the second terminal of the last voltage divider resistor serves as the output terminal of the step-down module.

[0008] Optionally, the comparison module includes a comparator, a first diode, a first resistor, a second resistor, and a first capacitor; the cathode of the first diode is connected to the first end of the first resistor and serves as the first input terminal of the comparison module; the second end of the first resistor is connected to the first end of the second resistor and the first end of the first capacitor; the second end of the first diode is connected to the second end of the second resistor and the second end of the first capacitor and is grounded; the non-inverting input terminal of the comparator is connected to the first end of the first capacitor; the inverting input terminal of the comparator serves as the second input terminal of the comparison module; and the output terminal of the comparator serves as the comparison output terminal.

[0009] Optionally, the comparison module further includes a second capacitor, a third capacitor, and a third resistor; the first power supply terminal of the comparator is connected to the first terminal of the second capacitor and is connected to a third voltage, the second terminal of the second capacitor is grounded, and the second power supply terminal of the comparator is grounded; the first terminal of the third resistor is connected to a fourth voltage, the second terminal of the third resistor is connected to the first terminal of the third capacitor and the output terminal of the comparator, and the second terminal of the third capacitor is grounded.

[0010] Optionally, the voltage detection circuit further includes a reference voltage generation module. The input terminal of the reference voltage generation module is connected to a third voltage, and the output terminal of the reference voltage generation module is connected to the second input terminal of the comparison module, for generating a reference voltage based on the third voltage.

[0011] Optionally, the reference voltage generation module includes a fourth resistor, a fourth capacitor, and a Zener diode; the first end of the fourth resistor is connected to the third voltage, the second end of the fourth resistor is connected to the first end of the Zener diode, the second end of the Zener diode, and the first end of the fourth capacitor, and serves as the output terminal of the reference voltage generation module, while the third end of the Zener diode and the second end of the fourth capacitor are grounded.

[0012] Optionally, the sampling module includes three rectifier units; the input terminal of each rectifier unit is connected to the three-phase output terminals of the circuit breaker, and the output terminals of each rectifier unit are connected to a single point, which serves as the output terminal of the sampling module.

[0013] Optionally, each rectifier unit includes N series-connected current-limiting resistors and M series-connected rectifier diodes; N and M are both integers greater than or equal to 2; the first end of the first current-limiting resistor serves as the input terminal of the rectifier unit, the second end of the last current-limiting resistor is connected to the first rectifier diode, and the second end of the last rectifier diode serves as the output terminal of the rectifier unit.

[0014] Optionally, the voltage detection circuit also includes an alarm module, the input terminal of which is connected to the output terminal of the control module. The control module is also used to output a control signal to the alarm module when the comparison module outputs a first voltage; the alarm module is used to issue an alarm prompt when it receives the control signal.

[0015] Secondly, this utility model provides a circuit breaker protection system, including the voltage detection circuit provided in any embodiment of this utility model.

[0016] The voltage detection circuit provided in this embodiment of the invention samples the live wire voltage at the output terminal of the circuit breaker using a sampling module, generates a first output voltage based on the live wire voltage, converts the first output voltage to a second output voltage using a step-down module, determines the magnitude relationship between the second output voltage and a reference voltage using a comparison module, and outputs the first voltage through the comparison output terminal when the second output voltage is greater than the reference voltage; and outputs the second voltage through the comparison output terminal when the second output voltage is less than the reference voltage. The control module determines whether there is voltage input at the output terminal of the circuit breaker based on the voltage status output by the comparison module. In other words, the voltage detection circuit provided in this embodiment of the invention, through the coordinated operation of the sampling module, step-down module, comparison module, and control module, can detect the voltage status of the circuit breaker output terminal. In photovoltaic and energy storage scenarios, it can clearly determine whether the power generation equipment connected to the output terminal of the circuit breaker is supplying power normally, providing crucial information for system operation and management.

[0017] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a voltage detection circuit provided in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of another voltage detection circuit provided in this embodiment of the utility model;

[0021] Figure 3 This is a schematic diagram of another voltage detection circuit provided in this embodiment of the utility model;

[0022] Figure 4This is a schematic diagram of another voltage detection circuit provided in this embodiment of the utility model;

[0023] Figure 5 This is a schematic diagram of another voltage detection circuit provided in this embodiment of the utility model;

[0024] Figure 6 This is a schematic diagram of another voltage detection circuit provided in this embodiment of the utility model;

[0025] Figure 7 This is a schematic diagram of another voltage detection circuit provided in this embodiment of the utility model;

[0026] Figure 8 This is a schematic diagram of another voltage detection circuit provided in this embodiment of the present invention. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0028] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0029] Figure 1 This is a schematic diagram of a voltage detection circuit provided in an embodiment of the present invention. The voltage detection circuit provided in this embodiment is used to detect whether there is voltage input at the output terminal of the circuit breaker.

[0030] like Figure 1As shown, the voltage detection circuit 10 includes a sampling module 11, a step-down module 12, a comparison module 13, and a control module 14. The input terminal of the sampling module 11 is connected to the output terminal of the circuit breaker, and the output terminal of the sampling module 11 is connected to the input terminal of the step-down module 12. The output terminal of the step-down module 12 is connected to the first input terminal of the comparison module 13. The sampling module 11 samples the live wire voltage at the output terminal of the circuit breaker and forms a first output voltage Vin1 based on the live wire voltage. The step-down module 12 converts the first output voltage Vin1 into a second output voltage Vin2; the second output voltage Vin2 is less than the first output voltage Vin1. The second input terminal of the comparison module 13 is connected to a reference voltage Vref. The comparison module 13 outputs a first voltage through the comparison output terminal BKV when the second output voltage Vin2 is greater than the reference voltage Vref; and outputs a second voltage through the comparison output terminal BKV when the second output voltage Vin2 is less than the reference voltage Vref, wherein the first voltage is greater than the second voltage. The control module 14 is used to determine whether there is voltage input at the output terminal of the circuit breaker 20 based on the voltage status output by the comparison module 13.

[0031] Specifically, circuit breaker 20 can be a residual current circuit breaker.

[0032] The sampling module 11 can be any module or circuit structure with voltage acquisition function. The first output voltage Vin1 is positively correlated with the live wire voltage, meaning that the higher the live wire voltage, the larger the value of the first output voltage Vin1; conversely, the lower the live wire voltage, the smaller the value of the first output voltage Vin1. By sampling the live wire voltage, the high-voltage three-phase electrical signal can be converted into a relatively small voltage signal that can be processed by subsequent circuits, facilitating operation and analysis by the subsequent circuits.

[0033] The step-down module 12 can be any module or circuit structure with a step-down function. The purpose of stepping down may be to reduce a high voltage signal to a range that the comparator module can handle. For example, if the first output voltage Vin1 is a high amplitude voltage that may exceed the input range of the comparator module 13, the step-down module 12 can adjust it to the input range of the comparator module 13, ensuring that subsequent circuits can work properly and avoiding damage to the comparator module 13.

[0034] Comparison module 13 can be any module or circuit structure with voltage comparison functionality. Comparison module 13 compares the second output voltage Vin2 with the reference voltage Vref. When the second output voltage Vin2 is greater than the reference voltage Vref, comparison module 13 outputs a first voltage through the comparison output terminal BKV. Conversely, when the second output voltage Vin2 is less than the reference voltage Vref, the comparison module outputs a second voltage through the comparison output terminal BKV.

[0035] The live wire voltage is also called the line voltage. The live wire voltage can include at least one of the A-phase live wire voltage LA1, the B-phase live wire voltage LB1, and the C-phase live wire voltage LC1. That is, the voltage detection circuit provided by this invention can detect whether there is voltage input at the output terminals of a single-phase circuit breaker, a two-phase circuit breaker, or a three-phase circuit breaker. This embodiment and the following embodiments illustrate the use of the voltage detection circuit to detect whether there is voltage input at the output terminals of a three-phase circuit breaker.

[0036] The control module 14 receives the output signal from the comparison module 13. When the comparison module 13 outputs a first voltage (indicating that the voltage at the circuit breaker's output terminal is higher than the set voltage), the control module 14 determines that there is voltage input at the output terminal of the circuit breaker 20. When the comparison module 13 outputs a second voltage (indicating that the voltage at the circuit breaker's output terminal is lower than the set voltage), the control module 14 determines that there is no voltage input at the output terminal of the circuit breaker 20. In practical applications, the control module 14 can be a microcontroller or a logic circuit. For example, the control module 14 can include a microcontroller, a digital signal processor (DSP), or a field-programmable gate array (FPGA).

[0037] by Figure 1 Taking the circuit structure shown as an example, the specific working principle of the voltage detection circuit 10 provided in this embodiment is as follows:

[0038] When any one of the phase voltages at the circuit breaker's outgoing terminals—phase A (LA1), phase B (LB1), and phase C (LC1)—is lower than a set voltage (e.g., 20V), the second output voltage Vin from the step-down module 12 will be less than a reference voltage (e.g., 1.25V). The comparator module 13 will then output a second voltage (e.g., 0V) through its comparator output terminal BKV. When the comparator module 13 outputs the second voltage (indicating that the circuit breaker's outgoing terminal voltage is lower than the set voltage), the control module 14 determines that there is no voltage input at the circuit breaker 20's outgoing terminals.

[0039] When any one of the phase voltages at the circuit breaker's outgoing terminals—phase A (LA1), phase B (LB1), and phase C (LC1)—is higher than a set voltage (e.g., 20V), the second output voltage Vin from the step-down module 12 will be greater than a reference voltage (e.g., 1.25V). The comparator module 13 will then output a first voltage (e.g., 3.3V) through its comparator output terminal BKV. When the comparator module 13 outputs the first voltage (indicating that the circuit breaker's outgoing terminal voltage is higher than the set voltage), the control module 14 determines that there is voltage input at the circuit breaker 20's outgoing terminals to alert the operator that the circuit breaker's outgoing terminals are energized, thus preventing the risk of electric shock.

[0040] The voltage detection circuit provided in this embodiment of the invention samples the live wire voltage at the output terminal of the circuit breaker using a sampling module, generates a first output voltage based on the live wire voltage, converts the first output voltage to a second output voltage using a step-down module, determines the magnitude relationship between the second output voltage and a reference voltage using a comparison module, and outputs the first voltage through the comparison output terminal when the second output voltage is greater than the reference voltage; and outputs the second voltage through the comparison output terminal when the second output voltage is less than the reference voltage. The control module determines whether there is voltage input at the output terminal of the circuit breaker based on the voltage status output by the comparison module. In other words, the voltage detection circuit provided in this embodiment of the invention, through the coordinated operation of the sampling module, step-down module, comparison module, and control module, can detect the voltage status of the circuit breaker output terminal. In photovoltaic and energy storage scenarios, it can clearly determine whether the power generation equipment connected to the output terminal of the circuit breaker is supplying power normally, providing crucial information for system operation and management.

[0041] Figure 2 This is a schematic diagram of another voltage detection circuit provided in an embodiment of this utility model. (See diagram below.) Figure 2 As shown, optionally, the step-down module 12 includes P series-connected voltage divider resistors; P is an integer greater than or equal to 2.

[0042] The first end of the first voltage divider resistor VDR1 serves as the input terminal of the buck module, and the second end of the last voltage divider resistor serves as the output terminal of the buck module 12. Figure 2 The case where P=3 is illustrated. The step-down module 12 uses multiple (P, P≥2) voltage-dividing resistors connected in series, a structure based on the principle of resistor voltage division. In a series circuit, the total voltage is distributed across each resistor according to their resistance values. By appropriately selecting the resistance values ​​of the voltage-dividing resistors, the higher first output voltage from the sampling module can be accurately reduced to a range suitable for the comparator module to process.

[0043] Optionally, the first voltage divider resistor VDR1, the second voltage divider resistor VDR2, and the third voltage divider resistor VDR3 can be surface-mount resistors with megaohms. The buck module 12 outputs the voltage at the output terminal (i.e., the first output voltage Vin1) after half-wave rectification to the first input terminal of the comparator module 13.

[0044] Figure 3 This is a schematic diagram of another voltage detection circuit provided in an embodiment of this utility model. (See diagram below.) Figure 3 As shown, optionally, the comparison module 13 includes a comparator U1, a first diode D1, a first resistor R1, a second resistor R2, and a first capacitor C1.

[0045] The cathode of the first diode D1 is connected to the first terminal of the first resistor R1 and serves as the first input terminal of the comparator module 13. The second terminal of the first resistor R1 is connected to the first terminal of the second resistor R2 and the first terminal of the first capacitor C1. The second terminal of the first diode D1 is connected to the second terminal of the second resistor R2 and the second terminal of the first capacitor C1, and is grounded. The non-inverting input terminal of the comparator U1 is connected to the first terminal of the first capacitor C1. The inverting input terminal of the comparator U1 serves as the second input terminal of the comparator module 13. The output terminal of the comparator U1 serves as the comparator output terminal BKV.

[0046] Specifically, the first diode D1 serves both protection and signal processing functions. When the second output voltage Vin2 experiences an abnormality or a negative voltage, the first diode D1 is cut off to prevent the abnormal voltage from damaging subsequent circuits. Under normal conditions, it allows positive signals to pass through, transmitting the signal to the first resistor R1.

[0047] The first resistor R1 and the second resistor R2 form a voltage divider circuit. They divide the input signal (i.e., the second output voltage Vin2) to adjust its amplitude, making it suitable for the input range of comparator U1. By appropriately selecting the values ​​of the first resistor R1 and the second resistor R2, the voltage input to the non-inverting input of comparator U1 can be changed, thereby affecting the comparison result and output state of comparator U1.

[0048] The first capacitor C1 serves to filter and stabilize the voltage. It can filter out high-frequency noise and spurious signals in the input signal, making the signal input to the non-inverting input of comparator U1 more stable and smooth, improving the comparison accuracy and anti-interference capability of comparator U1, and avoiding misjudgments in the comparison result due to signal fluctuations.

[0049] Comparator U1 compares the voltage at its non-inverting input with the reference voltage Vref connected to its inverting input. When the voltage at the non-inverting input is greater than the reference voltage Vref, comparator U1 outputs a high level, i.e., outputs the first voltage through the comparison output terminal BKV; when the voltage at the non-inverting input is less than the reference voltage Vref, comparator U1 outputs a low level, i.e., outputs the second voltage through the comparison output terminal BKV. This achieves the function of outputting different voltage signals based on the relationship between the input voltage and the reference voltage Vref, providing a basis for judgment in subsequent circuits.

[0050] Continue to refer to Figure 3Optionally, the comparator module 13 further includes a second capacitor C2, a third capacitor C3, and a third resistor R3. The first power supply terminal of the comparator U1 is connected to the first terminal of the second capacitor C2 and is connected to a third voltage V3. The second terminal of the second capacitor C2 is grounded, and the second power supply terminal of the comparator U1 is grounded. The first terminal of the third resistor R3 is connected to a fourth voltage V4. The second terminal of the third resistor R3 is connected to the first terminal of the third capacitor C3 and the output terminal of the comparator U1. The second terminal of the third capacitor C3 is grounded.

[0051] Specifically, the second capacitor C2 is connected between the first power supply terminal of comparator U1 and ground. In the power supply circuit of comparator U1, it acts as a filter. The third voltage V3 (e.g., 12V) may contain some ripple or noise; the second capacitor C2 can effectively bypass these high-frequency interference signals, making the power supply to comparator U1 more stable. A stable power supply is fundamental to the accurate operation of the comparator, preventing unstable output or misjudgments due to power fluctuations. For example, when the third voltage V3 experiences a momentary small fluctuation, the second capacitor C2 can quickly absorb or release charge, maintaining the relative stability of the power supply voltage of comparator U1.

[0052] The third resistor, R3, acts as a pull-up resistor. One end is connected to the fourth voltage V4 (e.g., 3.3V), and the other end is connected to the output of comparator U1 and the first terminal of the third capacitor C3. When comparator U1 outputs a high level, the pull-up resistor R3 ensures that the output voltage is close to the fourth voltage V4, enhancing the driving capability of the output signal. The third capacitor C3, connected in series with the third resistor R3 and grounded, serves to filter and delay changes in the output signal. When the output state of comparator U1 changes abruptly, the third capacitor C3 smooths the rising and falling edges of the output signal, reducing signal glitches and oscillations. In circuits with high signal quality requirements, this smoothing process can prevent interference to subsequent circuits caused by signal abrupt changes.

[0053] Figure 4 This is a schematic diagram of another voltage detection circuit provided in an embodiment of this utility model. (See diagram below.) Figure 4 As shown, optionally, the voltage detection circuit 10 further includes a reference voltage generation module 15. The input terminal of the reference voltage generation module 15 is connected to a third voltage V3, and the output terminal of the reference voltage generation module 15 is connected to the second input terminal of the comparison module 13, for generating a reference voltage Vref based on the third voltage V3.

[0054] As a preferred embodiment of this utility model, Figure 5 This is a schematic diagram of another voltage detection circuit provided in an embodiment of this utility model. (See diagram below.) Figure 5As shown, optionally, the reference voltage generation module 15 includes a fourth resistor R4, a fourth capacitor C4, and a Zener diode ZD2. The first terminal of the fourth resistor R4 is connected to the third voltage V3, the second terminal of the fourth resistor R4 is connected to the first terminal of the Zener diode ZD2, the second terminal of the Zener diode ZD2, and the first terminal of the fourth capacitor C4, and serves as the output terminal of the reference voltage generation module 15. The third terminal of the Zener diode ZD2 and the second terminal of the fourth capacitor C4 are grounded.

[0055] Specifically, the Zener diode ZD2 is the core component for generating a stable reference voltage. It utilizes its reverse breakdown characteristic to stabilize the voltage. When the third voltage V3 is connected to the circuit, within a certain range, even if the third voltage V3 fluctuates, as long as the reverse breakdown current is within the allowable operating range of the Zener diode ZD2, the voltage across the Zener diode ZD2 will remain relatively stable. This stable voltage value is the reference voltage Vref. For example, if the Zener diode ZD2 has a Zener voltage of 5V, then during normal operation, the voltage across it will be maintained at approximately 5V, providing a stable reference voltage Vref for the comparator module 13.

[0056] The fourth resistor, R4, primarily functions as a current limiter. It restricts the current flowing through the Zener diode ZD2, preventing damage due to excessive current. When the third voltage V3 is applied, the fourth resistor R4 is connected in series with the Zener diode ZD2. According to Ohm's law, the resistance of the fourth resistor R4 determines the magnitude of the current in the circuit. Without the fourth resistor R4, excessive current could cause the Zener diode ZD2 to overheat and burn out, affecting the stable output of the reference voltage. Simultaneously, the fourth resistor R4 also helps adjust the circuit's operating state, ensuring that the Zener diode ZD2 operates at an appropriate current to achieve optimal voltage regulation.

[0057] The fourth capacitor, C4, acts as a filter. It further eliminates noise and ripple in the voltage, making the output reference voltage Vref smoother and more stable. In actual circuits, even though the Zener diode ZD2 has already regulated the voltage, some minor fluctuations may still exist. The fourth capacitor, C4, through its charging and discharging characteristics, can absorb these fluctuations, making the voltage curve of the reference voltage Vref smoother. For example, when there are high-frequency interference signals in the circuit, the fourth capacitor, C4, can bypass these high-frequency signals to ground, avoiding their influence on the reference voltage, thereby improving the accuracy of the comparison module 13's judgment.

[0058] Figure 6 This is a schematic diagram of another voltage detection circuit provided in an embodiment of this utility model. (See diagram below.) Figure 6 As shown, optionally, the sampling module 11 includes three rectifier units 110.

[0059] The input terminal of each rectifier unit 110 is connected to the three-phase output terminal of the circuit breaker 20, and the output terminals of each rectifier unit 110 are connected to a single point, which serves as the output terminal of the sampling module 11.

[0060] Continue to refer to Figure 6 Optionally, each rectifier unit 110 includes N series-connected current-limiting resistors and M series-connected rectifier diodes; N and M are both integers greater than or equal to 2.

[0061] The first end of the first current-limiting resistor CLR1 serves as the input terminal of the rectifier unit 110, the second end of the last current-limiting resistor is connected to the first rectifier diode RD1, and the second end of the last rectifier diode serves as the output terminal of the rectifier unit 110. Figure 6 The diagram illustrates the case where both N and M are equal to 3. The first current-limiting resistor CLR1, the second current-limiting resistor CLR2, and the third current-limiting resistor CLR3 are used to buffer instantaneous surge voltages. The first rectifier diode RD1, the second rectifier diode RD2, and the third rectifier diode RD3 constitute a three-phase half-wave rectifier to trigger the subsequent DC voltage divider comparison module 13.

[0062] Figure 7 This is a schematic diagram of another voltage detection circuit provided in an embodiment of this utility model. (See diagram below.) Figure 7 As shown, optionally, the voltage detection circuit 10 also includes an alarm module 16. The input terminal of the alarm module 16 is connected to the output terminal of the control module 14. The control module 14 is also used to output a control signal to the alarm module 16 when the comparison module 13 outputs a first voltage. The alarm module 16 is used to issue an alarm prompt when it receives the control signal.

[0063] Specifically, after receiving the control signal from the control module 14, the alarm module 16 quickly issues an alarm notification. The alarm method can be varied, such as an audible and visual alarm, which alerts operators by illuminating indicator lights and emitting a buzzer; it can also send alarm information to a remote monitoring terminal via a communication interface, allowing staff to promptly grasp the system status. This alarm notification function is crucial for ensuring the safe operation of the power system, enabling staff to be immediately aware of any abnormal energization at the circuit breaker's outgoing terminals and take timely measures to prevent electric shock accidents or equipment damage caused by misoperation.

[0064] In some complex power systems, the control module 14 can control the operating status of other related equipment based on the energized status signal of the outgoing line. When energization is detected at the outgoing line, real-time status information is sent to the monitoring center via the communication module so that remote monitoring personnel can understand the system operation status in a timely manner; or it can be linked with other protection devices to ensure the stable operation of the entire power system.

[0065] Figure 8 This is a schematic diagram of another voltage detection circuit provided in an embodiment of this utility model. (See diagram below.) Figure 8 As shown, the voltage detection circuit 10 includes: a sampling module 11, a step-down module 12, a comparison module 13, and a control module 14.

[0066] Optionally, the step-down module 12 includes P series-connected voltage divider resistors; P is an integer greater than or equal to 2. Figure 8 The schematic diagram illustrates the buck module 12 including a first voltage divider resistor VDR1, a second voltage divider resistor VDR2, and a third voltage divider resistor VDR3.

[0067] Optionally, the comparison module 13 includes a comparator U1, a first diode D1, a first resistor R1, a second resistor R2, and a first capacitor C1. Optionally, the comparison module 13 also includes a second capacitor C2, a third capacitor C3, and a third resistor R3.

[0068] Optionally, the voltage detection circuit 10 further includes a reference voltage generation module 15. Optionally, the sampling module 11 includes three rectifier units 110. Optionally, each rectifier unit 110 includes N series-connected current-limiting resistors and M series-connected rectifier diodes; N and M are both integers greater than or equal to 2. Optionally, the voltage detection circuit 10 further includes an alarm module 16.

[0069] Based on the same inventive concept, this utility model also provides a circuit breaker protection system, including the voltage detection circuit provided in any embodiment of this utility model, which has the corresponding functional modules and beneficial effects of the voltage detection circuit, and will not be described in detail here.

[0070] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A voltage detection circuit, characterized by, The application discloses a voltage detection circuit for detecting the outlet end voltage of a circuit breaker, which comprises a sampling module, a voltage reduction module, a comparison module and a control module. The input end of the sampling module is connected with the outlet end of the circuit breaker, the output end of the sampling module is connected with the input end of the voltage reduction module, the output end of the voltage reduction module is connected with the first input end of the comparison module, and the sampling module is used for sampling the live wire voltage of the outlet end of the circuit breaker and forming a first output voltage according to the live wire voltage. The voltage reduction module is used for converting the first output voltage into a second output voltage, and the second output voltage is smaller than the first output voltage. The second input end of the comparison module is connected with a reference voltage, the comparison module is used for outputting a first voltage through a comparison output end when the second output voltage is greater than the reference voltage, and outputting a second voltage through the comparison output end when the second output voltage is smaller than the reference voltage, wherein the first voltage is greater than the second voltage. The control module is used for determining whether the outlet end of the circuit breaker has voltage input according to the voltage state output by the comparison module.

2. The voltage detection circuit according to claim 1, characterized by, The voltage reduction module comprises P series-connected voltage division resistors, and P is an integer greater than or equal to 2. The first end of the first voltage division resistor is used as the input end of the voltage reduction module, and the second end of the last voltage division resistor is used as the output end of the voltage reduction module.

3. The voltage detection circuit according to claim 1, characterized by, The comparison module comprises a comparator, a first diode, a first resistor, a second resistor and a first capacitor. The cathode of the first diode is connected with the first end of the first resistor and used as the first input end of the comparison module, the second end of the first resistor is connected with the first end of the second resistor and the first end of the first capacitor, the second end of the first diode is connected with the second end of the second resistor and the second end of the first capacitor and grounded. The non-inverting input end of the comparator is connected with the first end of the first capacitor, the inverting input end of the comparator is used as the second input end of the comparison module, and the output end of the comparator is used as the comparison output end.

4. The voltage detection circuit according to claim 3, characterized by The comparison module further comprises a second capacitor, a third capacitor and a third resistor. The first supply end of the comparator is connected with the first end of the second capacitor and connected with a third voltage, the second end of the second capacitor is grounded, and the second supply end of the comparator is grounded. The first end of the third resistor is connected with a fourth voltage, the second end of the third resistor is connected with the first end of the third capacitor and the output end of the comparator, and the second end of the third capacitor is grounded.

5. The voltage detection circuit of claim 1, wherein The comparison module further comprises a reference voltage generation module, the input end of the reference voltage generation module is connected with the third voltage, the output end of the reference voltage generation module is connected with the second input end of the comparison module, and the reference voltage generation module is used for generating the reference voltage according to the third voltage.

6. The voltage detection circuit according to claim 5, characterized by The reference voltage generation module comprises a fourth resistor, a fourth capacitor and a voltage stabilizing diode. The first end of the fourth resistor is connected to the third voltage, the second end of the fourth resistor is connected to the first end of the voltage stabilizing diode, the second end of the voltage stabilizing diode and the first end of the fourth capacitor, and serves as the output end of the reference voltage generating module, the third end of the voltage stabilizing diode and the second end of the fourth capacitor are grounded.

7. The voltage detection circuit of claim 1, wherein The sampling module comprises three rectifying units. The input end of each rectifying unit is connected to the three-phase outlet end of the circuit breaker, the output end of each rectifying unit is connected to a point, and the output end of each rectifying unit serves as the output end of the sampling module.

8. The voltage detection circuit according to claim 7, characterized by Each rectifying unit comprises N current-limiting resistors connected in series and M rectifying diodes connected in series; N and M are integers greater than or equal to 2. The first end of the first current-limiting resistor serves as the input end of the rectifying unit, the second end of the last current-limiting resistor is connected to the first rectifying diode, and the second end of the last rectifying diode serves as the output end of the rectifying unit.

9. The voltage detection circuit of claim 1, wherein, The control module is further configured to output a control signal to the alarm module when the comparison module outputs the first voltage. The alarm module is configured to issue an alarm prompt when the control signal is received.

10. A circuit breaker protection system characterized by, The voltage detection circuit comprises the voltage detection circuit according to any one of claims 1-9.

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