Tripping drive circuit for circuit breaker and inverter

Abstract

The utility model provides a circuit breaker's tripping drive circuit and inverter. Tripping drive circuit includes: control unit, pulse width comparison unit and drive unit, pulse width comparison unit is connected with control unit and drive unit respectively, and drive unit is connected with circuit breaker still, control unit is used for to the output drive signal of pulse width comparison unit, pulse width comparison unit is used for receiving drive signal, and determines whether the pulse width of drive signal satisfies the preset requirement, and when the pulse width of drive signal satisfies the preset requirement, to drive unit output target signal, and target signal is used for indicating drive unit drive circuit breaker to execute tripping function. The utility model provides technical scheme can improve the reliability of drive circuit breaker to execute tripping function.

Description

Technical Field

[0001] This utility model relates to the field of power electronics technology, and in particular to a tripping drive circuit for a circuit breaker and an inverter. Background Technology

[0002] In photovoltaic inverter equipment, DC circuit breakers or tripped disconnect switches are usually installed on the DC side to disconnect the DC photovoltaic panels during regular inspections of the photovoltaic inverter equipment, or to actively trip and disconnect the DC circuit breaker to prevent the fault from escalating when the photovoltaic inverter equipment malfunctions.

[0003] Currently, the tripping function of the DC circuit breaker is usually achieved by sending a drive signal from the controller inside the photovoltaic inverter equipment to drive the tripping actuator.

[0004] However, the above control process is prone to circuit breaker malfunction, which can affect the reliable operation of photovoltaic inverter equipment. Utility Model Content

[0005] This invention provides a tripping drive circuit for a circuit breaker and an inverter to solve the problem of unreliable operation of a photovoltaic inverter caused by circuit breaker malfunction.

[0006] In a first aspect, this utility model provides a tripping drive circuit for a circuit breaker, comprising: a control unit, a pulse width comparison unit, and a drive unit; the pulse width comparison unit is connected to the control unit and the drive unit respectively, and the drive unit is also connected to the circuit breaker; the control unit is configured to output a drive signal to the pulse width comparison unit; the pulse width comparison unit is configured to receive the drive signal, determine whether the pulse width of the drive signal meets a preset requirement, and output a target signal to the drive unit when the pulse width of the drive signal meets the preset requirement, the target signal being used to instruct the drive unit to drive the circuit breaker to perform a tripping function.

[0007] In conjunction with the first aspect, in one possible implementation, the control unit is also connected to the drive unit; the control unit is further configured to output a control signal to the drive unit; the drive unit is configured to receive the target signal and the control signal, and drive the circuit breaker to perform a tripping function when the levels of the target signal and the control signal are both at the target level.

[0008] In conjunction with the first aspect, in one possible implementation, the tripping drive circuit further includes: a standard pulse width generation unit; the standard pulse width generation unit is connected to the control unit and the pulse width comparison unit respectively; the control unit is further configured to output the drive signal to the standard pulse width generation unit, the drive signal being used to trigger the standard pulse width generation unit to output a standard pulse width signal; the pulse width comparison unit is configured to receive the drive signal and the standard pulse width signal, and determine whether the pulse width of the drive signal meets the preset requirement based on the pulse width error between the drive signal and the standard pulse width signal.

[0009] In conjunction with the first aspect, in one possible implementation, the active state of the driving signal, the target signal, and the standard pulse width signal is high, and the active state of the control signal is low.

[0010] In conjunction with the first aspect, in one possible implementation, the pulse width comparison unit includes: an XOR logic circuit, a filter integration circuit, a voltage comparison circuit, and an AND logic circuit; the XOR logic circuit is connected to the control unit, the standard pulse width generation unit, the filter integration circuit, and the AND logic circuit respectively; the filter integration circuit is connected to the AND logic circuit through the voltage comparison circuit; and the AND logic circuit is also connected to the driving unit; the XOR logic circuit is used to receive the driving signal and the standard pulse width signal, and to output a first signal after performing XOR logic processing on the driving signal and the standard pulse width signal, the first signal being used to indicate the pulse width error between the driving signal and the standard pulse width signal; The filtering and integrating circuit is used to filter and integrate the first signal and output a second signal, the voltage of the second signal being proportional to the pulse width error; the voltage comparison circuit is used to input a reference signal based on a first input terminal, input the second signal based on a second input terminal, and output a third signal based on the voltage comparison result between the reference signal and the second signal; the AND logic circuit is used to input the driving signal through a first input terminal, input the third signal through a second input terminal, and output the target signal to the driving unit through an output terminal when both the third signal and the driving signal are at high levels, and the level of the third signal is high when the voltage of the reference signal is greater than the voltage of the second signal.

[0011] In conjunction with the first aspect, in one possible implementation, the XOR logic circuit includes: a first NAND gate, a second NAND gate, a third NAND gate, and a fourth NAND gate; the first input terminal of the first NAND gate is connected to the control unit, the first input terminal of the second NAND gate, and the first input terminal of the AND logic circuit, respectively; the second input terminal of the first NAND gate is connected to the standard pulse width generation unit and the first input terminal of the third NAND gate, respectively; the output terminal of the first NAND gate is connected to the second input terminal of the second NAND gate and the second input terminal of the third NAND gate, respectively; the output terminal of the second NAND gate is connected to the first input terminal of the fourth NAND gate; the output terminal of the third NAND gate is connected to the second input terminal of the fourth NAND gate; and the output terminal of the fourth NAND gate is connected to the filter integration circuit.

[0012] In conjunction with the first aspect, in one possible implementation, the filter integration circuit includes: a second resistor and a second capacitor; one end of the second resistor is connected to the output terminal of the fourth NAND gate, the other end of the second resistor is connected to one end of the second capacitor and the second input terminal of the voltage comparison circuit, and the other end of the second capacitor is grounded; the second resistor is used to limit the charging current of the second capacitor; the second capacitor is used to filter and integrate the first signal to obtain a second signal, the second signal being the voltage signal on the second capacitor.

[0013] In conjunction with the first aspect, in one possible implementation, the driving unit includes: a first switch, a second switch, a third switch, a third resistor, and a fourth resistor; a first terminal of the first switch is connected to the output terminal of the pulse width comparison unit through the third resistor, a second terminal of the first switch is connected to the control unit, the third terminals of both the first and second switches are grounded, the first terminal of the second switch is connected to the second terminal of the third switch, the second terminal of the second switch is connected to the first terminal of the first switch, the first terminal of the third switch is connected to the circuit breaker, the second terminal of the third switch is also connected to its third terminal through the fourth resistor, and the third terminal of the third switch is also connected to an external power supply; the first switch is turned on when the voltage difference between the signal input through the second terminal and the signal input through the third terminal is greater than a first preset value; the second switch is turned on when the voltage difference between the signal input through the second terminal and the signal input through the third terminal is greater than the first preset value; the third switch is turned on when the voltage difference between the signal input through the second terminal and the signal input through the third terminal is less than a second preset value.

[0014] In conjunction with the first aspect, in one possible implementation, the driving unit further includes: a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a ninth resistor; the second terminal of the first switch is connected to the control unit through the fifth resistor, the second terminal of the first switch is also connected to the third terminal of the first switch through the sixth resistor, the second terminal of the second switch is connected to the first terminal of the first switch through the seventh resistor, the second terminal of the second switch is also connected to the third terminal of the second switch through the eighth resistor, and the first terminal of the second switch is connected to the second terminal of the third switch through the ninth resistor.

[0015] Secondly, this utility model provides an inverter that may include a trip drive circuit as described in the first aspect or any possible implementation thereof. The inverter may be a photovoltaic inverter.

[0016] This invention provides a tripping drive circuit for a circuit breaker and an inverter. The technical solution provided by this invention verifies the pulse width of the drive signal by adding a pulse width comparison unit. Only when the pulse width of the drive signal meets preset requirements will the drive unit be instructed to drive the circuit breaker to perform the tripping function. This prevents interference pulses from mistakenly triggering the drive unit and causing the circuit breaker to malfunction, thereby improving the reliability of the tripping drive circuit. Furthermore, the control unit outputs drive and control signals. The drive unit will only drive the circuit breaker to perform the tripping function when the drive signal is high and the control signal is low. This prevents the control unit from mistakenly sending signals during power-on and power-off, reducing risk and improving drive reliability. Attached Figure Description

[0017] Figure 1 This is a schematic structural diagram of a circuit breaker tripping drive circuit; Figure 2 A schematic structural diagram of a circuit breaker tripping drive circuit provided by this utility model; Figure 3 A schematic structural diagram of the tripping drive circuit of another circuit breaker provided by this utility model; Figure 4 This invention provides a timing diagram of the signals in a tripping drive circuit. Detailed Implementation

[0018] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0019] In photovoltaic inverter equipment, DC circuit breakers or tripped disconnect switches are usually installed on the DC side to disconnect the DC photovoltaic panels during regular inspections of the photovoltaic inverter equipment, or to actively trip and disconnect the DC circuit breaker to prevent the fault from escalating when the photovoltaic inverter equipment malfunctions.

[0020] Currently, the tripping function of the DC circuit breaker is usually achieved by sending a drive signal from the controller inside the photovoltaic inverter equipment to drive the tripping actuator.

[0021] Figure 1 A schematic structural diagram of a circuit breaker tripping drive circuit is shown. Figure 1 As shown, the drive circuit includes a control unit and a drive unit. The drive unit is connected to the circuit breaker, such as to the circuit breaker's tripping actuator. The control unit can be an internal controller in a photovoltaic inverter device.

[0022] The control unit can send a drive signal to the drive unit. The valid state of this drive signal can be either high or low.

[0023] The drive unit can drive the circuit breaker to perform the tripping function after receiving a drive signal. This drive signal can be an input / output (IO) signal.

[0024] It can be seen that the existing circuit breaker's tripping drive circuit has a simple structure and occupies few resources. However, this circuit uses only one drive signal to drive the circuit breaker's tripping function, which can easily lead to malfunctions and affect the reliable operation of the photovoltaic inverter equipment. For example, in harsh electromagnetic environments, or during the power-on and power-off processes of the control unit, interference signals or erroneous drive signals from the control unit may occur, causing the circuit breaker to malfunction and preventing the photovoltaic inverter equipment from operating reliably. This, in turn, increases the maintenance cost and difficulty of the photovoltaic inverter.

[0025] In view of this, the present invention provides a tripping drive circuit for a circuit breaker and an inverter. In the technical solution provided by this invention, a pulse width comparison unit is added to verify the pulse width of the drive signal. Only when the pulse width of the drive signal meets the preset requirements will the drive unit be instructed to drive the circuit breaker to perform the tripping function. This prevents interference pulses from mistakenly triggering the drive unit and causing the circuit breaker to malfunction, thereby improving the reliability of the tripping drive circuit. Furthermore, the control unit outputs drive and control signals. The drive unit will only drive the circuit breaker to perform the tripping function when the drive signal is high and the control signal is low. This prevents the control unit from mistakenly sending signals during power-on and power-off, reducing risk and improving drive reliability.

[0026] The following is combined Figures 2 to 4The technical solution provided by this utility model will be described in detail below.

[0027] Figure 2 A schematic structural diagram of a circuit breaker tripping drive circuit provided by this utility model. Figure 2 The tripping drive circuit 200 shown includes: a control unit 210, a pulse width comparison unit 220, and a drive unit 230.

[0028] like Figure 2 As shown, the pulse width comparison unit 220 is connected to the control unit 210 and the drive unit 230 respectively, and the drive unit 230 is also connected to the circuit breaker.

[0029] The control unit 210 is used to output a drive signal to the pulse width comparison unit 220. This drive signal can be an I / O signal.

[0030] The pulse width comparison unit 220 receives the drive signal, determines whether the pulse width of the drive signal meets the preset requirements, and outputs a target signal to the drive unit 230 when the pulse width of the drive signal meets the preset requirements. The target signal is used to instruct the drive unit 230 to drive the circuit breaker to perform the tripping function. It should be noted that the preset requirements can be set according to actual needs, and no specific restrictions are imposed here.

[0031] The drive unit 230 is used to drive the circuit breaker to perform the tripping function after receiving the target signal.

[0032] In the technical solution provided by this utility model, a pulse width comparison unit is added to verify the pulse width of the drive signal. Only when the pulse width of the drive signal meets the preset requirements will the drive unit be instructed to drive the circuit breaker to perform the tripping function. This can prevent interference pulses from accidentally triggering the drive unit and causing the circuit breaker to malfunction, thereby improving the reliability of the tripping drive circuit.

[0033] In one possible implementation, the trip drive circuit 200 may further include: a standard pulse width generation unit 240, which may be connected to the control unit 210 and the pulse width comparison unit 220 respectively, such as... Figure 2 As shown.

[0034] The control unit 210 is also used to output a drive signal to the standard pulse width generation unit 240. The drive signal is used to trigger the standard pulse width generation unit 240 to output a standard pulse width signal.

[0035] The pulse width comparison unit 220 is used to receive the drive signal output by the control unit 210 and the standard pulse width signal output by the standard pulse width generation unit 240, determine the pulse width error between the drive signal and the standard pulse width signal, and determine whether the pulse width of the drive signal meets the preset requirements based on the pulse width error. For example, if the pulse width error is less than or equal to a preset threshold, the pulse width of the drive signal can be considered to meet the preset requirements; if the pulse width error is greater than the preset threshold, the pulse width of the drive signal can be considered not to meet the preset requirements.

[0036] This implementation adds a standard pulse width generator to output a standard pulse width signal, allowing the pulse width comparison unit to determine whether the pulse width of the driving signal meets the preset requirements based on the standard pulse width signal. This implementation quantifies the preset requirements using the standard pulse width signal, thereby improving the accuracy and reliability of the judgment.

[0037] In one possible implementation, the control unit 210 can also be connected to the drive unit 230, such as... Figure 2 As shown.

[0038] The control unit 210 is also used to output a control signal to the drive unit 230. This control signal can be an I / O signal.

[0039] The drive unit 230 is used to receive the target signal output by the pulse width comparison unit 220 and the control signal output by the control unit 210, and to drive the circuit breaker to perform the tripping function when the levels of the target signal and the control signal are both at the target level.

[0040] In this implementation, the drive unit can also receive the control signal output by the control unit and verify the levels of the control signal and the target signal. Only when the levels of the control signal and the target signal are both at the target level will the circuit breaker be driven to perform the tripping function. This can prevent the problem of the control unit sending signals erroneously during power-on and power-off, reduce the risk, and improve the reliability of the drive.

[0041] Figure 3 This is a schematic structural diagram of another circuit breaker tripping drive circuit provided by this utility model. It should be noted that... Figure 3 Yes Figure 2 The exemplary description of the tripping drive circuit is not intended to limit the specific implementation of the tripping drive circuit.

[0042] like Figure 3 As shown, the standard pulse width generation unit 240 may include: a pulse generator, a first resistor, and a first capacitor. The pulse generator is connected to both the first resistor and the first capacitor, and the first resistor is also connected to both the first capacitor and an external power supply. The pulse generator is as follows: Figure 3 In U1, the first resistor is as follows Figure 3R1 in the first capacitor is as follows: Figure 3 C1 in the diagram is connected to an external power supply, VCC, as shown in the figure. This invention does not limit the specific implementation of the pulse generator; it can be a hardware and / or software module, or a chip.

[0043] The pulse generator, upon receiving a drive signal, outputs a standard pulse width signal based on the resistance value of the first resistor and the capacitance value of the first capacitor. For example, the standard pulse width can be expressed as (R1*C1) / 2, where R1 is the resistance value of the first resistor and C1 is the capacitance value of the first capacitor.

[0044] In this invention, the effective state of the driving signal, the target signal, and the standard pulse width signal can be high level.

[0045] like Figure 3 As shown, the pulse width comparison unit 220 may include: an XOR logic circuit, a filter integration circuit, a voltage comparison circuit, and an AND logic circuit.

[0046] The XOR logic circuit can be connected to the control unit 210, the standard pulse width generation unit 240, the filter integration circuit, and the AND logic circuit, respectively. The filter integration circuit is connected to the AND logic circuit through the voltage comparison circuit, and the AND logic circuit is also connected to the drive unit 230.

[0047] The XOR logic circuit receives the drive signal output by the control unit 210 and the standard pulse width signal output by the standard pulse width generation unit 240, and outputs a first signal after performing XOR logic processing on the drive signal and the standard pulse width signal. The first signal can be used to indicate the pulse width error between the drive signal and the standard pulse width signal. The standard pulse width signal is as follows: Figure 3 The signal at point A in the diagram, the first signal is as follows: Figure 3 The signal at point B in the diagram.

[0048] Optionally, the XOR logic circuit can be implemented using four NAND gates. For example... Figure 3 As shown, the XOR logic circuit includes: a first NAND gate, a second NAND gate, a third NAND gate, and a fourth NAND gate. The first NAND gate is shown below. Figure 3 In U2, the second NAND gate is as follows Figure 3 U3, the third NAND gate, such as Figure 3 U4, the fourth NAND gate, such as Figure 3 U5 in the middle.

[0049] like Figure 3As shown, the first input terminal of the first NAND gate is connected to the control unit 210, the first input terminal of the second NAND gate, and the first input terminal of the logic circuit, respectively. The second input terminal of the first NAND gate is connected to the standard pulse width generation unit and the first input terminal of the third NAND gate, respectively. The output terminal of the first NAND gate is connected to the second input terminal of the second NAND gate and the second input terminal of the third NAND gate, respectively. The output terminal of the second NAND gate is connected to the first input terminal of the fourth NAND gate. The output terminal of the third NAND gate is connected to the second input terminal of the fourth NAND gate. The output terminal of the fourth NAND gate is connected to the filter integration circuit.

[0050] Figure 4 This invention provides a timing diagram of the signals in a tripping drive circuit. The pulse width of the drive signal is shown below. Figure 4 In the t1, the standard pulse width signal is as follows: Figure 4 In t2, the pulse width error is as follows Figure 4 The pulse width t3 of the first signal.

[0051] In this invention, a filtering and integrating circuit is used to filter and integrate the first signal before outputting a second signal. The voltage of the second signal is proportional to the pulse width error. The second signal is as follows: Figure 3 The signal at point C in the diagram.

[0052] In one possible implementation, the filter integrator circuit includes: a second resistor and a second capacitor, such as... Figure 3 As shown in the diagram. One end of the second resistor is connected to the output of the fourth NAND gate, and the other end of the second resistor is connected to one end of the second capacitor and the second input of the voltage comparator circuit. The other end of the second capacitor is grounded. The second resistor is as follows... Figure 3 R2 in the middle, the second capacitor is as follows Figure 3 C2 in the middle.

[0053] The second resistor is used to limit the charging current of the second capacitor in order to protect the second capacitor.

[0054] The second capacitor is used to filter and integrate the first signal to obtain the second signal. The second signal is the voltage signal across the second capacitor, or in other words, the voltage across the second capacitor is the integrated signal of the pulse width error. The smaller the pulse width error, the smaller the voltage across the second capacitor; the larger the pulse width error, the larger the voltage across the second capacitor.

[0055] In this implementation, the preset threshold can be determined based on the resistance value of the second resistor and the capacitance value of the second capacitor. For example, the preset threshold can be expressed as: R2*C2*ln(VCC / (VCC-V REF R2 is the resistance of the second resistor, C2 is the capacitance of the second capacitor, VCC is the external power supply for the tripping drive circuit, and V REF The voltage is the reference signal voltage.

[0056] A voltage comparator circuit is used to input a reference signal based on a first input terminal, input a second signal based on a second input terminal, and input a second signal based on the reference signal (such as...). Figure 3 V in REF The voltage comparison result between the first signal and the second signal outputs a third signal. The third signal is as follows: Figure 3 The signal at point D in the diagram. The voltage comparison circuit is as follows: Figure 3 The voltage comparator U6 in the middle.

[0057] like Figure 4 As shown, when the voltage of the reference signal is greater than the voltage of the second signal, the level of the third signal is high; when the voltage of the reference signal is less than the voltage of the second signal, the level of the third signal is low.

[0058] The logic circuit is used to input a drive signal through a first input terminal, input a third signal through a second input terminal, and output a target signal to the drive unit 230 through an output terminal when both the third signal and the drive signal are at a high level, so as to instruct the drive unit to drive the circuit breaker to perform a tripping function. The target signal is as follows: Figure 3 The signal at point E in the circuit. And the logic circuit, as shown... Figure 3 The AND gate U7 in the middle.

[0059] It should be noted that when the third signal is low, and the logic circuit outputs a low-level signal, the drive unit will no longer drive the circuit breaker to perform the tripping function.

[0060] In this invention, the pulse width error between the drive signal and the standard pulse width signal is determined by an XOR logic unit. A filtering and integrating circuit converts the pulse width error into a voltage signal. The comparison between the converted voltage signal and a reference signal reflects whether the pulse width of the drive signal meets the preset requirements. For example, the larger the pulse width error between the drive signal and the standard pulse width signal, the larger the voltage of the second signal. If the voltage of the second signal is greater than the voltage of the reference signal, it indicates that the pulse width of the drive signal does not meet the preset requirements; if the voltage of the second signal is less than the voltage of the reference signal, it indicates that the pulse width of the drive signal meets the preset requirements, and the level of the third signal is high. The XOR logic circuit can determine whether the pulse width of the drive signal meets the preset requirements and / or whether the drive signal is in a valid state by comparing the levels of the third signal and the drive signal, thereby further improving the reliability of the circuit breaker in performing its tripping function.

[0061] In this invention, the effective state of the control signal can be low level.

[0062] like Figure 3 As shown, the drive unit 230 may include: a first switching transistor, a second switching transistor, a third switching transistor, a third resistor, and a fourth resistor. The first switching transistor is as follows: Figure 3 Q1 in the middle, the second switching transistor is as follows Figure 3 Q2, the third switching transistor, is as follows Figure 3 Q3 in the middle, the third resistor is as follows Figure 3 R3, the fourth resistor, is as follows Figure 3 R4 in the middle.

[0063] The first terminal of the first switching transistor is connected to the output terminal of the pulse width comparison unit 220 through the third resistor. The second terminal of the first switching transistor is connected to the control unit 210. The third terminals of the first and second switching transistors are both grounded. The first terminal of the second switching transistor is connected to the second terminal of the third switching transistor. The second terminal of the second switching transistor is connected to the first terminal of the first switching transistor. The first terminal of the third switching transistor is connected to the circuit breaker. The second terminal of the third switching transistor is also connected to the third terminal of the third switching transistor through the fourth resistor. The third terminal of the third switching transistor is also connected to an external power supply.

[0064] The first switching transistor is used to turn on when the voltage difference between the signal input through the second terminal and the signal input through the third terminal is greater than a first preset value.

[0065] The second switch is used to turn on when the voltage difference between the signal input through the second terminal and the signal input through the third terminal is greater than a first preset value.

[0066] The third switch is used to turn on when the voltage difference between the signal input through the second terminal and the signal input through the third terminal is less than a second preset value.

[0067] The third resistor is used to provide current-limiting protection for the first switching transistor.

[0068] The fourth resistor is the pull-up resistor for the third switching transistor.

[0069] In one possible implementation, the first and second switching transistors can be NPN transistors, and the third switching transistor can be a PNP transistor. In this implementation, the first terminal of the first, second, and third switching transistors can be understood as the collector, the second terminal as the base, and the third terminal as the emitter.

[0070] In some implementations, the driving unit may further include: a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a ninth resistor. The fifth resistor is as follows: Figure 3 R5, the sixth resistor, is as follows Figure 3 R6, the seventh resistor, is as follows Figure 3 R7, the eighth resistor, is as follows Figure 3 R8, the ninth resistor, is as follows Figure 3 R9 in the middle.

[0071] The second terminal of the first switch is connected to the control unit 210 through the fifth resistor. The second terminal of the first switch is also connected to the third terminal of the first switch through the sixth resistor. The second terminal of the second switch is connected to the first terminal of the first switch through the seventh resistor. The second terminal of the second switch is also connected to the third terminal of the second switch through the eighth resistor. The first terminal of the second switch is connected to the second terminal of the third switch through the ninth resistor.

[0072] The fifth resistor is used for current limiting protection of the first switching transistor; the sixth resistor is a pull-down resistor for the first switching transistor. By adjusting the ratio of the fifth and sixth resistors, the preset conduction value of the first switching transistor can be adjusted.

[0073] The seventh resistor is used for current limiting protection of the second switching transistor; the eighth resistor is a pull-down resistor for the second switching transistor. By adjusting the ratio of the seventh and eighth resistors, the preset conduction value of the second switching transistor can be adjusted.

[0074] The ninth resistor is used for current limiting protection of the third switching transistor.

[0075] Combination Figure 3 and Figure 4 It can be seen that when the target signal is high and the control signal is low, the first switch in the drive unit 230 is turned off, while the second and third switches are turned on. The drive unit 230 then outputs a high-level signal to the circuit breaker, such as... Figure 3 The signal at point F in the circuit breaker is used to drive the circuit breaker to perform the tripping function.

[0076] In some implementations, the circuit breaker may include a trip coil. The drive unit drives the circuit breaker to perform the tripping function, which can be understood as the drive unit driving the trip coil to perform the tripping function.

[0077] This application also provides an inverter, including the trip drive circuit described in the foregoing embodiments. Optionally, the inverter can be a photovoltaic inverter.

[0078] The term "multiple" in this document refers to two or more. The character " / " generally indicates an "or" relationship between related objects; in formulas, " / " indicates a "division" relationship between related objects. Furthermore, it should be understood that in the description of this application, terms such as "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or order.

[0079] It is understood that, in the embodiments of this application, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0080] It should be emphasized that the above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A tripping drive circuit for a circuit breaker, characterized in that, include: Control unit, pulse width comparison unit, and drive unit; The pulse width comparison unit is connected to the control unit and the drive unit respectively, and the drive unit is also connected to the circuit breaker; The control unit is used to output a drive signal to the pulse width comparison unit; The pulse width comparison unit is used to receive the drive signal, determine whether the pulse width of the drive signal meets the preset requirements, and output a target signal to the drive unit when the pulse width of the drive signal meets the preset requirements. The target signal is used to instruct the drive unit to drive the circuit breaker to perform the tripping function.

2. The tripping drive circuit according to claim 1, characterized in that, The control unit is also connected to the drive unit; The control unit is also used to output control signals to the drive unit; The drive unit is configured to receive the target signal and the control signal, and drive the circuit breaker to perform a tripping function when the levels of the target signal and the control signal are both at the target level.

3. The tripping drive circuit according to claim 2, characterized in that, Also includes: Standard pulse width generation unit; The standard pulse width generation unit is connected to the control unit and the pulse width comparison unit, respectively. The control unit is further configured to output the driving signal to the standard pulse width generation unit, the driving signal being used to trigger the standard pulse width generation unit to output a standard pulse width signal; The pulse width comparison unit is used to receive the drive signal and the standard pulse width signal, and to determine whether the pulse width of the drive signal meets the preset requirement based on the pulse width error between the drive signal and the standard pulse width signal.

4. The tripping drive circuit according to claim 3, characterized in that, The driving signal, the target signal, and the standard pulse width signal are all active at a high level, while the control signal is active at a low level.

5. The tripping drive circuit according to claim 4, characterized in that, The pulse width comparison unit includes: an XOR logic circuit, a filter integration circuit, a voltage comparison circuit, and an AND logic circuit; The XOR logic circuit is connected to the control unit, the standard pulse width generation unit, the filter integration circuit, and the AND logic circuit, respectively. The filter integration circuit is connected to the AND logic circuit through the voltage comparison circuit. The AND logic circuit is also connected to the driving unit. The XOR logic circuit is used to receive the driving signal and the standard pulse width signal, and to output a first signal after performing XOR logic processing on the driving signal and the standard pulse width signal. The first signal is used to indicate the pulse width error between the driving signal and the standard pulse width signal. The filtering and integrating circuit is used to filter and integrate the first signal and output a second signal, wherein the voltage of the second signal is proportional to the pulse width error. The voltage comparison circuit is used to input a reference signal based on a first input terminal, input the second signal based on a second input terminal, and output a third signal based on the voltage comparison result between the reference signal and the second signal; The AND logic circuit is configured to input the driving signal through a first input terminal, input the third signal through a second input terminal, and output the target signal to the driving unit through an output terminal when both the third signal and the driving signal are at high levels, wherein the third signal is at a high level when the voltage of the reference signal is greater than the voltage of the second signal.

6. The tripping drive circuit according to claim 5, characterized in that, The XOR logic circuit includes: a first NAND gate, a second NAND gate, a third NAND gate, and a fourth NAND gate; The first input terminal of the first NAND gate is connected to the control unit, the first input terminal of the second NAND gate, and the first input terminal of the AND logic circuit, respectively. The second input terminal of the first NAND gate is connected to the standard pulse width generation unit and the first input terminal of the third NAND gate, respectively. The output terminal of the first NAND gate is connected to the second input terminal of the second NAND gate and the second input terminal of the third NAND gate, respectively. The output terminal of the second NAND gate is connected to the first input terminal of the fourth NAND gate. The output terminal of the third NAND gate is connected to the second input terminal of the fourth NAND gate. The output terminal of the fourth NAND gate is connected to the filter integration circuit.

7. The tripping drive circuit according to claim 6, characterized in that, The filter integration circuit includes: a second resistor and a second capacitor; One end of the second resistor is connected to the output terminal of the fourth NAND gate, and the other end of the second resistor is connected to one end of the second capacitor and the second input terminal of the voltage comparator circuit, respectively. The other end of the second capacitor is grounded. The second resistor is used to limit the charging current of the second capacitor; The second capacitor is used to filter and integrate the first signal to obtain a second signal, which is the voltage signal across the second capacitor.

8. The tripping drive circuit according to claim 4, characterized in that, The driving unit includes: a first switching transistor, a second switching transistor, a third switching transistor, a third resistor, and a fourth resistor; The first terminal of the first switching transistor is connected to the output terminal of the pulse width comparison unit through the third resistor. The second terminal of the first switching transistor is connected to the control unit. The third terminals of both the first and second switching transistors are grounded. The first terminal of the second switching transistor is connected to the second terminal of the third switching transistor. The second terminal of the second switching transistor is connected to the first terminal of the first switching transistor. The first terminal of the third switching transistor is connected to the circuit breaker. The second terminal of the third switching transistor is also connected to the third terminal of the third switching transistor through the fourth resistor. The third terminal of the third switching transistor is also connected to an external power supply. The first switch is configured to turn on when the voltage difference between the signal input through the second terminal and the signal input through the third terminal is greater than a first preset value; The second switch is used to turn on when the voltage difference between the signal input through the second terminal and the signal input through the third terminal is greater than the first preset value; The third switch is used to turn on when the voltage difference between the signal input through the second terminal and the signal input through the third terminal is less than a second preset value.

9. The tripping drive circuit according to claim 8, characterized in that, The driving unit further includes: a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a ninth resistor; The second terminal of the first switch is connected to the control unit through the fifth resistor. The second terminal of the first switch is also connected to the third terminal of the first switch through the sixth resistor. The second terminal of the second switch is connected to the first terminal of the first switch through the seventh resistor. The second terminal of the second switch is also connected to the third terminal of the second switch through the eighth resistor. The first terminal of the second switch is connected to the second terminal of the third switch through the ninth resistor.

10. An inverter, characterized in that, Includes the tripping drive circuit as described in any one of claims 1 to 9.

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