A voltage abnormality protection circuit

Abstract

The present application discloses a voltage anomaly protection circuit, which includes a rectifier module, a tripping circuit module, a signal detection delay module and a voltage detection module; the input end of the rectifier module is connected to an external power supply, and the output end of the rectifier module is connected to the tripping circuit, and the external power supply is rectified to supply power to the tripping circuit module; the voltage detection module is connected between the live wire of the external power supply and the signal detection delay module, and is used to detect the voltage of the live wire of the external power supply and output a signal to the signal detection delay module; the signal detection delay module includes a voltage detector U1, and when the signal output by the voltage detection module reaches the threshold value of the voltage detector U1, the voltage detector U1 outputs a trigger signal to the tripping circuit module after a delay, so that the tripping circuit module performs a tripping action; the present application has the characteristic of relatively accurate voltage detection.

Description

Technical Field

[0001] The present application relates to the field of low-voltage electrical equipment and to a voltage anomaly protection circuit. Background Art

[0002] During the power transmission process, overvoltage or undervoltage may often occur due to voltage instability or some other reasons. At this time, an overvoltage or undervoltage protection circuit is needed. When overvoltage or undervoltage occurs, the tripping device can be driven to trip, thereby protecting the load in the line.

[0003] For example, the over-voltage and under-voltage protection circuit disclosed in CN114301030A, this circuit structure simply uses a comparator to determine whether there is overvoltage or undervoltage. When it occurs, the drive module will be turned on and tripped immediately, which may lead to erroneous operation.

[0004] Therefore, how to design a voltage anomaly protection circuit that can detect relatively accurately is a direction worthy of research. Summary of the invention

[0005] In view of this, the purpose of this application is to overcome the deficiencies in the prior art and to provide a voltage anomaly protection circuit that has the characteristic of relatively accurate voltage detection.

[0006] The present application provides: a voltage anomaly protection circuit, which includes a rectifier module, a tripping circuit module, a signal detection delay module and a voltage detection module; the input end of the rectifier module is connected to an external power supply, and the output end of the rectifier module is connected to the tripping circuit, and the external power supply is rectified to supply power to the tripping circuit module; the voltage detection module is connected between the live wire of the external power supply and the signal detection delay module, and is used to detect the voltage of the live wire of the external power supply and output a signal to the signal detection delay module; the signal detection delay module includes a voltage detector U1, and when the signal output by the voltage detection module reaches the threshold value of the voltage detector U1, the voltage detector U1 outputs a trigger signal to the tripping circuit module after a delay, so that the tripping circuit module performs a tripping action.

[0007] With this structure, the voltage detection module can be used to detect each live phase line and output a signal to the signal detection delay module. The signal detection delay circuit is implemented by the voltage detector U1. When the signal output by the voltage detection module reaches the voltage detected by the voltage detector U1, the voltage detector U1 performs a delay process and then outputs a trigger signal to the tripping circuit module, and the tripping circuit module performs a tripping action. At the same time, the use of the voltage detector U1 can make the judgment of over-voltage and under-voltage more accurate.

[0008] In some embodiments of the present application, the signal detection delay module further includes a resistor R1 and a capacitor C2, wherein the capacitor C2 is connected to the input end of the voltage detector U1; and the resistor R1 is connected in series between the output end of the voltage detector U1 and the tripping circuit module.

[0009] With this structure, a signal detection delay module is formed by using the resistor R1, the capacitor C2, and the voltage detector U1, which has the characteristic of simple circuit structure.

[0010] In some embodiments of the present application, the voltage detection module includes an overvoltage detection circuit, which includes a diode D11, a voltage-dividing resistor R11, a voltage-dividing resistor R13 and a diode D12; the input end of the diode D11 is connected to the live wire to achieve half-wave rectification; the output end of the diode D11 is connected to one end of the voltage-dividing resistor R11, one end of the voltage-dividing resistor R13 and the input end of the diode D12 are connected to the other end of the voltage-dividing resistor R11; the output end of the diode D12 is connected to the input end of the voltage detector U1.

[0011] With this structure, overvoltage detection can be achieved. The current of the live wire is half-wave rectified by diode D11, then divided by resistors R11 and R13, and output through diode D12 to complete the overvoltage detection function. The circuit structure is relatively simple.

[0012] In some embodiments of the present application, the voltage detection module includes an undervoltage detection circuit, which includes a diode D11, a voltage-dividing resistor R15, a voltage-dividing resistor R17, a resistor R19, a voltage-stabilizing tube Z12, a transistor Q11, a diode D13, and a capacitor C11; the input end of the diode D11 is connected to the live wire to realize half-wave rectification, and the output end of the diode D11 is connected to one end of the voltage-dividing resistor R15 and one end of the resistor R19; the emitter of the transistor Q11, the negative electrode of the voltage-stabilizing tube Z12, and one end of the capacitor C12 are all connected to the other end of the resistor R19. The other end of the capacitor C12 is connected to the other end of the voltage-dividing resistor R15, so that a voltage Vb is formed on the emitter of the transistor Q11; the positive electrode of the voltage-stabilizing tube Z12 is grounded, and the capacitor C11 is connected in parallel with the voltage-stabilizing tube Z12; the base of the transistor Q11 is connected to one end of the resistor R112, and the other end of the resistor R112 is connected to the voltage-dividing resistor R15 and the voltage-dividing resistor R17 to form a voltage node Va; the collector of the transistor Q11 is connected to one end of the resistor R111 and the input end of the diode D13, and the output end of the diode D13 is connected to the input end of the voltage detector U1.

[0013] This structure can realize undervoltage detection. After the current of the live wire is half-wave rectified by diode D11, the voltage Va is obtained by resistor R15 and resistor R17. After the A phase is half-wave rectified by diode D11, the voltage Vb is obtained on the voltage regulator Z12 through resistor R19. When the voltage decreases, Va decreases. When the Va voltage is lower than Vb, transistor Q11 is turned on, and the Vb voltage transistor Q11 and diode D13 are output, completing the undervoltage detection function. The circuit structure is relatively simple and can effectively detect undervoltage.

[0014] In some embodiments of the present application, the voltage detection module includes an overvoltage detection circuit and an undervoltage detection circuit; the overvoltage detection circuit includes a diode D11, a voltage-dividing resistor R11, a voltage-dividing resistor R13 and a diode D12; the input end of the diode D11 is connected to the live wire to realize half-wave rectification; the output end of the diode D11 is connected to one end of the voltage-dividing resistor R11, one end of the voltage-dividing resistor R13 and the input end of the diode D12 are connected to the other end of the voltage-dividing resistor R11; the output end of the diode D12 is connected to the input end of the voltage detector U1; the undervoltage detection circuit includes a voltage-dividing resistor R15, a voltage-dividing resistor R17, a resistor R19, a voltage-stabilizing diode Z12, a transistor Q11, a diode D13 and a capacitor C11; the input end of the diode D11 is connected to the live wire to realize half-wave rectification, and the diode The output end of the transistor D11 is connected to one end of the voltage-dividing resistor R15 and one end of the resistor R19; the emitter of the transistor Q11, the cathode of the voltage-regulating diode Z12, and one end of the capacitor C12 are all connected to the other end of the resistor R19, and the other end of the capacitor C12 is connected to the other end of the voltage-dividing resistor R15, so that a voltage Vb is formed on the emitter of the transistor Q11; the positive electrode of the voltage-regulating diode Z12 is grounded, and the capacitor C11 is connected in parallel with the voltage-regulating diode Z12; the base of the transistor Q11 is connected to one end of the resistor R112, and the other end of the resistor R112 is connected to the voltage-dividing resistor R15 and the voltage-dividing resistor R17 to form a voltage node Va; the collector of the transistor Q11 is connected to one end of the resistor R111 and the input end of the diode D13, and the output end of the diode D13 is connected to the input end of the voltage detector U1.

[0015] With this structure, undervoltage and overvoltage detection can be achieved simultaneously.

[0016] In some embodiments of the present application, the external power supply is two-phase power, and the number of the voltage detection module is one.

[0017] This circuit structure can be applied to two-phase electricity to detect overvoltage or undervoltage or over-undervoltage.

[0018] In some embodiments of the present application, the external power supply is three-phase electricity, including three live wires and one neutral wire, and the number of voltage detection modules is three; the three voltage detection modules are respectively connected between the three live wires of the power supply and the signal detection delay module, and when the signal output by any voltage detection module reaches the threshold of the voltage detector U1, the voltage detector U1 outputs a trigger signal to the tripping circuit module after a delay, so that the tripping circuit module performs a tripping action.

[0019] This circuit structure can be applied to three-phase electricity to detect overvoltage or undervoltage or over-undervoltage.

[0020] In some embodiments of the present application, the rectifier module is a full-wave rectifier or a half-wave rectifier.

[0021] The rectifier circuit can use either full-wave rectification or half-wave rectification.

[0022] In some embodiments of the present application, the tripping circuit module includes a tripping coil L, a thyristor VT1 and a capacitor C1; one end of the tripping coil L is connected to the output end of the rectifier module; the A pole of the thyristor VT1 is connected to the other end of the tripping coil L, and the G pole of the thyristor VT1 is connected to one end of the resistor R1 and one end of the capacitor C1; the other end of the capacitor C1, the K pole of the thyristor VT1 and the input end of the diode D4 are grounded together. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 A principle block diagram showing the application of the voltage anomaly protection circuit in a three-phase power system according to an embodiment of the present application is shown;

[0025] Figure 2 Shows Figure 1 The circuit schematic diagram of the rectifier module, the tripping circuit module and the signal detection delay module;

[0026] Figure 3 A circuit schematic diagram of a first implementation of a voltage detection module in an embodiment of the present application is shown;

[0027] Figure 4 A circuit schematic diagram of a second implementation of a voltage detection module in an embodiment of the present application is shown;

[0028] Figure 5A circuit schematic diagram of a third implementation of a voltage detection module in an embodiment of the present application is shown;

[0029] Figure 6 The schematic diagram of the voltage anomaly protection circuit according to the embodiment of the present application is shown in the schematic diagram of the single-phase power supply;

[0030] Figure 7 Shows Figure 6 Circuit schematic diagram of the rectifier module, tripping circuit module and signal detection delay module. DETAILED DESCRIPTION

[0031] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0032] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0034] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0035] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature. Example

[0036] like Figure 1-Figure 7 As shown, an embodiment of the present application is a voltage anomaly protection circuit, which can be applied to switching electrical appliances that only include overvoltage protection, switching electrical appliances that only include undervoltage protection, and switching electrical appliances that include both overvoltage and undervoltage protection.

[0037] The voltage anomaly protection circuit comprises a rectifier module, a trip circuit module, a signal detection delay module and a voltage detection module.

[0038] Here, the number of voltage detection modules set varies according to the phase lines of the applied switchgear. Taking three-phase electricity as an example, the voltage anomaly protection circuit is connected to the three-phase four-wire circuit input from the power grid. The three-phase four-wire here includes three live wires (A, B, C phases) and one neutral wire (N phase).

[0039] like Figure 2 As shown, the rectifier module is a half-wave rectifier, comprising diodes D1, D2, D3 and D4, wherein the input end of diode D1 is connected to the C phase live wire, the input end of diode D2 is connected to the B phase live wire, and the input end of diode D3 is connected to the A phase live wire. The input end of diode D4 is connected to the K pole of thyristor VT1, and the output end of diode D4 is connected to the N phase wire.

[0040] like Figure 2 As shown, the tripping circuit module includes a tripping coil L, a thyristor VT1 and a capacitor C1. One end of the tripping coil L is connected to the output ends of the diodes D1, D2 and D3. The A pole of the thyristor VT1 is connected to the other end of the tripping coil L, and the G pole of the thyristor VT1 is connected to one end of the resistor R1 and one end of the capacitor C1. The other end of the capacitor C1, the K pole of the thyristor VT1 and the input end of the diode D4 are grounded in common. When the G pole of the thyristor VT1 receives a trigger signal from the voltage detector U1, the thyristor VT1 is turned on, and the grid current is rectified by three-phase half-wave, and then forms a loop after passing through the tripping coil L and the thyristor VT1. After the tripping coil L is energized, it drives the tripping mechanism to operate.

[0041] like Figure 2 As shown, the signal detection delay module includes a voltage detector U1, a resistor R1 and a capacitor C2. The voltage detector U1 has a delay function. When the voltage monitored by the voltage detector U1 reaches the detection voltage (at the threshold), the voltage detector U1 does not output the detection signal immediately, but outputs the detection signal after a certain period of time. In this embodiment, the capacitor C2 is connected to the input end of the voltage detector U1 (that is, between the Vin pin and the Vss pin), and the resistor R1 is connected between the output end of the voltage detector U1 (that is, the Vout pin) and the G pole of the thyristor VT1 (also called the tripping circuit module). In this way, the input end of the voltage detector U1 receives the output signal of the three-phase voltage detection module. When the output signal reaches the detection voltage of the voltage detector U1 (at the threshold), the voltage detector U1 will start the delay function, and after the delay time, the trigger signal is output to the thyristor VT1 through the output end.

[0042] Since the voltage detection module includes three implementation methods, the following examples are respectively for those with only overvoltage protection function, those with only undervoltage protection function, and those with both overvoltage protection function. Take the voltage detection module of phase A as an example (the other two phases refer to phase A):

[0043] like Figure 4 As shown, the voltage detection module only includes an overvoltage detection circuit, which includes a diode D11, a voltage-dividing resistor R11, a voltage-dividing resistor R13 and a diode D12. The input end of the diode D11 is connected to the A-phase live wire to achieve half-wave rectification, and the output end of the diode D11 is connected to one end of the voltage-dividing resistor R11. The other end of the voltage-dividing resistor R11 is connected to one end of the voltage-dividing resistor R13, and the other end of the voltage-dividing resistor R13 is grounded. The other end of the voltage-dividing resistor R11 is also connected to the input end of the diode D12, and the output end of the diode D12 is connected to the Vin pin of the voltage detector U1 (that is, the input end of the voltage detector U1). In this way, the A phase is half-wave rectified by the diode D11, and then divided by the resistors R11 and R13, and output to the signal detection delay module through the diode D12 to complete the overvoltage detection function.

[0044] like Figure 5As shown, the voltage detection module only includes an undervoltage detection circuit, which includes a diode D11, a voltage-dividing resistor R15, a voltage-dividing resistor R17, a resistor R19, a voltage-stabilizing tube Z12, a transistor Q11, a diode D13, and a capacitor C11. The input end of the diode D11 is connected to the A-phase live wire to realize half-wave rectification, and the output end of the diode D11 is connected to one end of the voltage-dividing resistor R15 and one end of the resistor R19. The emitter of the transistor Q11, the negative electrode of the voltage-stabilizing tube Z12, one end of the capacitor C12 and the other end of the resistor R19 are connected, and the other end of the capacitor C12 is connected to the other end of the voltage-dividing resistor R15, so that a voltage Vb is formed on the emitter of the transistor Q11. The positive electrode of the voltage-stabilizing tube Z12 is grounded, and the capacitor C11 is connected in parallel with the voltage-stabilizing tube Z12. The base of transistor Q11 is connected to one end of resistor R112, and the other end of resistor R112 is connected to voltage-dividing resistor R15 and voltage-dividing resistor R17 to form voltage node Va. The collector of transistor Q11 is connected to one end of resistor R111 and the input end of diode D13, and the output end of diode D13 is connected to the Vin pin of voltage detector U1 (that is, the input end of voltage detector U1). This structure can be used to achieve that the voltage of phase A live wire is half-wave rectified by diode D11, and then divided by resistor R15 and resistor R17 to obtain voltage Va. Phase A is half-wave rectified by diode D11, and voltage Vb is obtained on voltage regulator Z12 through resistor R19. When the voltage decreases, Va decreases. When the Va voltage is lower than Vb, transistor Q11 is turned on and output to the signal detection delay module through diode D13 to complete the undervoltage detection function.

[0045] like Figure 3As shown, the voltage detection module includes both an overvoltage detection circuit and an undervoltage detection circuit. The overvoltage detection circuit here includes a diode D11, a voltage-dividing resistor R11, a voltage-dividing resistor R13 and a diode D12. The input end of the diode D11 is connected to the A-phase live wire to achieve half-wave rectification, and the output end of the diode D11 is connected to one end of the voltage-dividing resistor R11. The other end of the voltage-dividing resistor R11 is connected to one end of the voltage-dividing resistor R13, and the other end of the voltage-dividing resistor R13 is grounded. The other end of the voltage-dividing resistor R11 is also connected to the input end of the diode D12, and the output end of the diode D12 is connected to the Vin pin of the voltage detector U1 (that is, the input end of the voltage detector U1). In this way, the A phase is half-wave rectified by the diode D11, and then divided by the resistors R11 and R13, and output to the signal detection delay module through the diode D12 to complete the overvoltage detection function. The undervoltage detection circuit here includes a voltage-dividing resistor R15, a voltage-dividing resistor R17, a resistor R19, a voltage-stabilizing tube Z12, a transistor Q11, a diode D13 and a capacitor C11. The input end of the diode D11 is connected to the A-phase live wire to realize half-wave rectification, and the output end of the diode D11 is connected to one end of the voltage-dividing resistor R15 and one end of the resistor R19. The emitter of the transistor Q11, the negative electrode of the voltage-stabilizing tube Z12, one end of the capacitor C12 and the other end of the resistor R19 are connected, and the other end of the capacitor C12 is connected to the other end of the voltage-dividing resistor R15, so that a voltage Vb is formed on the emitter of the transistor Q11. The positive electrode of the voltage-stabilizing tube Z12 is grounded, and the capacitor C11 is connected in parallel with the voltage-stabilizing tube Z12. The base of the transistor Q11 is connected to one end of the resistor R112, and the other end of the resistor R112 is connected to the voltage-dividing resistor R15 and the voltage-dividing resistor R17 to form a voltage node Va. The collector of transistor Q11 is connected to one end of resistor R111 and the input end of diode D13, and the output end of diode D13 is connected to the Vin pin of voltage detector U1 (that is, the input end of voltage detector U1). This structure can be used to achieve that the voltage of phase A live wire is half-wave rectified by diode D11, and then divided by resistors R15 and R17 to obtain voltage Va. Phase A is half-wave rectified by diode D11, and then voltage Vb is obtained on voltage regulator Z12 through resistor R19. When the voltage decreases, Va decreases. When the Va voltage is lower than Vb, transistor Q11 is turned on and output to the signal detection delay module through diode D13 to complete the undervoltage detection function.

[0046] The above is a voltage anomaly protection circuit for three-phase power. This circuit principle can also be applied to single-phase power. When applied to single-phase power, the internal voltage detection module, signal detection delay module, trip circuit module and other circuit structure principles are basically the same, except for the rectifier module, the number of external power live wires, and the number of voltage detection modules. Figure 6-7As shown, the specific circuits such as the voltage detection module, the signal detection delay module, the tripping circuit module, etc. will not be described in detail, and reference will be made to the relevant structure of the three-phase electricity.

[0047] In this embodiment, the rectifier module adopts half-wave rectification, of course, full-wave rectification can also be adopted.

[0048] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without contradiction.

[0049] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A voltage abnormality protection circuit, characterized in that: It includes a rectifier module, a trip circuit module, a signal detection delay module and a voltage detection module; the input end of the rectifier module is connected to an external power supply, and the output end of the rectifier module is connected to the trip circuit, and the external power supply is rectified to supply power to the trip circuit module; the voltage detection module is connected between the live wire of the external power supply and the signal detection delay module, and is used to detect the voltage of the live wire of the external power supply and output a signal to the signal detection delay module; the signal detection delay module includes a voltage detector U1, and when the signal output by the voltage detection module reaches the threshold value of the voltage detector U1, the voltage detector U1 outputs a trigger signal to the trip circuit module after a delay, so that the trip circuit module performs a tripping action.

2. The voltage abnormality protection circuit according to claim 1, characterized in that: The signal detection delay module further includes a resistor R1 and a capacitor C2. The capacitor C2 is connected to the input end of the voltage detector U1. The resistor R1 is connected in series between the output end of the voltage detector U1 and the tripping circuit module.

3. The voltage abnormality protection circuit according to claim 1, characterized in that: The voltage detection module includes an overvoltage detection circuit, which includes a diode D11, a voltage-dividing resistor R11, a voltage-dividing resistor R13 and a diode D12; the input end of the diode D11 is connected to the live wire to achieve half-wave rectification; the output end of the diode D11 is connected to one end of the voltage-dividing resistor R11, one end of the voltage-dividing resistor R13 and the input end of the diode D12 are connected to the other end of the voltage-dividing resistor R11; the output end of the diode D12 is connected to the input end of the voltage detector U1.

4. The voltage abnormality protection circuit according to claim 1, characterized in that: The voltage detection module includes an undervoltage detection circuit, which includes a diode D11, a voltage-dividing resistor R15, a voltage-dividing resistor R17, a resistor R19, a voltage-stabilizing tube Z12, a transistor Q11, a diode D13 and a capacitor C11; the input end of the diode D11 is connected to the live wire of the external power supply to realize half-wave rectification, and the output end of the diode D11 is connected to one end of the voltage-dividing resistor R15 and one end of the resistor R19; the emitter of the transistor Q11, the negative electrode of the voltage-stabilizing tube Z12, and one end of the capacitor C12 are all connected to the other end of the resistor R19, and the transistor Q11 is connected to the live wire of the external power supply to realize half-wave rectification. The other end of capacitor C12 is connected to the other end of voltage-dividing resistor R15, so that voltage Vb is formed on the emitter of transistor Q11; the positive electrode of voltage-stabilizing tube Z12 is grounded, and capacitor C11 is connected in parallel with voltage-stabilizing tube Z12; the base of transistor Q11 is connected to one end of resistor R112, and the other end of resistor R112 is connected to voltage-dividing resistor R15 and voltage-dividing resistor R17 to form voltage node Va; the collector of transistor Q11 is connected to one end of resistor R111 and the input end of diode D13, and the output end of diode D13 is connected to the input end of voltage detector U1.

5. The voltage abnormality protection circuit according to claim 1, characterized in that: The voltage detection module includes an overvoltage detection circuit and an undervoltage detection circuit; the overvoltage detection circuit includes a diode D11, a voltage-dividing resistor R11, a voltage-dividing resistor R13 and a diode D12; the input end of the diode D11 is connected to the live wire of the external power supply to realize half-wave rectification; the output end of the diode D11 is connected to one end of the voltage-dividing resistor R11, one end of the voltage-dividing resistor R13 and the input end of the diode D12 are connected to the other end of the voltage-dividing resistor R11; the output end of the diode D12 is connected to the input end of the voltage detector U1; the undervoltage detection circuit includes a voltage-dividing resistor R15, a voltage-dividing resistor R17, a resistor R19, a voltage-stabilizing diode Z12, a transistor Q11, a diode D13 and a capacitor C11; the output end of the diode D11 is connected to the voltage-dividing resistor R1 5 and one end of the resistor R19; the emitter of the transistor Q11, the cathode of the voltage-regulating tube Z12, and one end of the capacitor C12 are all connected to the other end of the resistor R19, and the other end of the capacitor C12 is connected to the other end of the voltage-dividing resistor R15, so that a voltage Vb is formed on the emitter of the transistor Q11; the positive electrode of the voltage-regulating tube Z12 is grounded, and the capacitor C11 is connected in parallel with the voltage-regulating tube Z12; the base of the transistor Q11 is connected to one end of the resistor R112, and the other end of the resistor R112 is connected to the voltage-dividing resistor R15 and the voltage-dividing resistor R17 to form a voltage node Va; the collector of the transistor Q11 is connected to one end of the resistor R111 and the input end of the diode D13, and the output end of the diode D13 is connected to the input end of the voltage detector U1.

6. The voltage abnormality protection circuit according to claim 1, characterized in that: The external power supply is single-phase electricity, and the number of the voltage detection module is one.

7. The voltage abnormality protection circuit according to claim 1, characterized in that: The external power supply is three-phase electricity, including three live wires and one neutral wire, and the number of voltage detection modules is three; the three voltage detection modules are respectively connected between the three live wires of the power supply and the signal detection delay module. When the signal output by any voltage detection module reaches the threshold of the voltage detector U1, the voltage detector U1 outputs a trigger signal to the tripping circuit module after a delay, so that the tripping circuit module performs a tripping action.

8. The voltage abnormality protection circuit according to claim 1, characterized in that: The rectification module is a full-wave rectification module or a half-wave rectification module.

9. The voltage abnormality protection circuit according to claim 1, characterized in that: The tripping circuit module includes a tripping coil L, a thyristor VT1 and a capacitor C1; one end of the tripping coil L is connected to the output end of the rectifier module; the A pole of the thyristor VT1 is connected to the other end of the tripping coil L, and the G pole of the thyristor VT1 is connected to one end of the resistor R1 and one end of the capacitor C1; the other end of the capacitor C1, the K pole of the thyristor VT1 and the input end of the diode D4 are grounded together.

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