CN117434333A - Micro-grid line voltage abnormality detection circuit, energy management system and electric equipment - Google Patents

Abstract

The invention discloses a micro-grid line voltage abnormality detection circuit, an energy management system and electric equipment, wherein the abnormality detection circuit comprises an overvoltage detection circuit and an undervoltage detection circuit, and the overvoltage detection circuit comprises: the first high-voltage input circuit is connected with the micro-grid and used for converting the high-voltage line voltage of the micro-grid into low-voltage line voltage; and the overvoltage comparison circuit is connected with the first high-voltage input circuit, and is used for comparing the voltage of the low voltage line with an overvoltage threshold value and outputting a first overvoltage comparison signal. The circuit realizes overvoltage and undervoltage detection of the line voltage through the overvoltage detection circuit and the undervoltage detection circuit, can provide a larger line voltage fluctuation detection range, meets the line voltage detection requirement of the micro-grid, and improves the electricity safety under the micro-grid environment.

Description

Micro-grid line voltage abnormality detection circuit, energy management system and electric equipment

Technical Field

The invention relates to the technical field of electric equipment, in particular to a micro-grid line voltage abnormality detection circuit, a micro-grid energy management system and electric equipment.

Background

With the popularization of new energy power generation, the duty ratio of the new energy power generation in the micro-grid power supply is larger and larger. The instability of new energy power generation such as wind, light and the like causes the voltage fluctuation of the micro-grid to be increased, and the safety risk of micro-grid power utilization is aggravated.

In the related art, the line voltage detection circuit performs power-off protection on a power supply and a load through an undervoltage detection method, however, in a micro-grid environment, line voltage fluctuation is large, and the line voltage detection circuit cannot meet the protection requirement of the micro-grid.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems in the related art to some extent. Therefore, a first object of the present invention is to provide a micro-grid line voltage abnormality detection circuit, which can provide a larger line voltage fluctuation detection range, meet the line voltage detection requirement of the micro-grid, and improve the electricity safety in the micro-grid environment by realizing the overvoltage and undervoltage detection of the line voltage through the overvoltage detection circuit and the undervoltage detection circuit.

A second object of the present invention is to propose a micro grid energy management system.

A third object of the present invention is to propose a powered device.

To achieve the above object, an embodiment of a first aspect of the present invention provides a micro-grid line voltage abnormality detection circuit, the abnormality detection circuit including an overvoltage detection circuit and an undervoltage detection circuit, the overvoltage detection circuit including: the first high-voltage input circuit is connected with the micro-grid and used for converting the high-voltage line voltage of the micro-grid into low-voltage line voltage; and the overvoltage comparison circuit is connected with the first high-voltage input circuit, and is used for comparing the voltage of the low voltage line with an overvoltage threshold value and outputting a first overvoltage comparison signal.

According to the micro-grid line voltage abnormality detection circuit, the abnormality detection circuit comprises an overvoltage detection circuit and an undervoltage detection circuit, the overvoltage detection circuit comprises a first high-voltage input circuit and an overvoltage comparison circuit, the first high-voltage input circuit is connected with a micro-grid, the overvoltage comparison circuit is connected with the first high-voltage input circuit, the high-voltage line voltage of the micro-grid is converted into a low-voltage line voltage through the first high-voltage input circuit, the overvoltage comparison circuit compares the low-voltage line voltage with an overvoltage threshold value, and a first overvoltage comparison signal is output. Therefore, the circuit realizes overvoltage and undervoltage detection of the line voltage through the overvoltage detection circuit and the undervoltage detection circuit, can provide a larger line voltage fluctuation detection range, meets the line voltage detection requirement of the micro-grid, and improves the electricity safety in the micro-grid environment.

In addition, the micro-grid line voltage abnormality detection circuit according to the above embodiment of the present invention may further have the following additional technical features:

according to one embodiment of the present invention, a first high voltage input circuit includes: the input end of the voltage stabilizing control circuit is connected with the micro-grid and is used for generating a voltage stabilizing control signal based on the high-voltage line voltage; the control end of the first high-voltage conversion circuit is connected with the output end of the voltage stabilizing control circuit, the input end of the first high-voltage conversion circuit is connected with the micro-grid, and the output end of the first high-voltage conversion circuit is connected with the input end of the overvoltage comparison circuit and used for converting high-voltage line voltage into low-voltage line voltage based on the voltage stabilizing control signal.

According to one embodiment of the present invention, a voltage stabilizing control circuit includes: the micro-grid power supply comprises a first resistor, a first high-voltage switch tube and at least one first diode, wherein one end of the first resistor is connected with a micro-grid, and the other end of the first resistor is connected with a control end of a first high-voltage conversion circuit; the first end and the second end of the first high-voltage switch tube are respectively connected with the other end of the first resistor; at least one first diode is connected in series in the same direction, and the anode after the series connection is connected with the third end of the first high-voltage switch tube, and the cathode after the series connection is grounded.

According to one embodiment of the present invention, a first high voltage conversion circuit includes: the first end of the second high-voltage switch tube is connected with the output end of the voltage stabilizing control circuit, the second end of the second high-voltage switch tube is connected with the input end of the overvoltage comparison circuit, and the third end of the second high-voltage switch tube is connected with the micro-grid.

According to one embodiment of the present invention, an overvoltage comparing circuit includes: an overvoltage threshold providing circuit for providing an overvoltage threshold; the threshold input end of the overvoltage comparison sub-circuit is connected with the overvoltage threshold providing circuit, and the input end of the overvoltage comparison sub-circuit is connected with the output end of the first high-voltage conversion circuit and is used for comparing the voltage of the low voltage line with the overvoltage threshold and outputting a second overvoltage comparison signal; and the input end of the overvoltage output circuit is connected with the output end of the overvoltage comparison sub-circuit and is used for converting the second overvoltage comparison signal into the first overvoltage comparison signal and outputting the first overvoltage comparison signal.

According to one embodiment of the invention, the overvoltage comparison subcircuit includes: the device comprises at least one second diode, a voltage stabilizing tube, a first switching tube, a second resistor, a first inverter and a second inverter, wherein the at least one second diode is connected in series in the same direction, the anode after being connected in series is connected with the output end of a first high-voltage conversion circuit, and the cathode after being connected in series is connected with the cathode of the voltage stabilizing tube; the first end of the first switching tube is connected with the anode of the voltage stabilizing tube and the overvoltage threshold value providing circuit respectively, the second end of the first switching tube is connected with one end of the second resistor, and the third end of the first switching tube is grounded; the other end of the second resistor is connected with a first power supply; the input end of the first inverter is connected with the second end of the first switching tube; the input end of the second inverter is connected with the output end of the first inverter, and the output end of the second inverter is connected with the input end of the overvoltage output circuit.

According to one embodiment of the present invention, an overvoltage threshold value providing circuit includes: the first resistor is connected with the first end of the first switch tube and the second resistor, and the second resistor is connected with the second switch tube; the first end of the second switching tube is connected with the second end of the first switching tube, the second end of the second switching tube is connected with the other end of the third resistor, and the third end of the second switching tube is grounded; one end of the fourth resistor is connected with the other end of the third resistor; one end of the fifth resistor is connected with the other end of the fourth resistor, and the other end of the fifth resistor is grounded; the first end of the third switching tube is connected with the output end of the second inverter, the second end of the third switching tube is connected with the other end of the fourth resistor, and the third end of the third switching tube is grounded.

According to one embodiment of the present invention, an overvoltage output circuit includes: the input end of the level conversion circuit is connected with the output end of the overvoltage comparison sub-circuit and is used for converting the second overvoltage comparison signal into a corresponding logic level; and the input end of the first trigger is connected with the output end of the level conversion circuit and is used for generating and outputting a first overvoltage comparison signal based on the logic level.

According to one embodiment of the invention, the overvoltage detection circuit further comprises: and the first power supply circuit is respectively connected with the output end of the voltage stabilizing control circuit and the micro-grid and is used for providing a first power supply.

According to one embodiment of the present invention, a first power supply circuit includes: the first end of the third high-voltage switching tube is connected with the output end of the voltage stabilizing control circuit, and the third end of the third high-voltage switching tube is connected with the other end of the second resistor to provide a first power supply; the first end of the fourth high-voltage switching tube is connected with the second end of the fourth high-voltage switching tube and the second end of the third high-voltage switching tube respectively, and the third end of the fourth high-voltage switching tube is connected with the micro-grid; the control end of the first high-voltage conversion circuit is connected with the second end of the third high-voltage switching tube.

According to one embodiment of the invention, the overvoltage detection circuit further comprises: the second power supply circuit is respectively connected with the output end of the voltage stabilizing control circuit, the micro-grid and the positive power supply end of the first inverter and is used for supplying power to the first inverter; and the third power supply circuit is respectively connected with the output end of the voltage stabilizing control circuit, the micro power grid and the positive power supply end of the second inverter and is used for supplying power to the second inverter.

According to one embodiment of the present invention, the second power supply circuit includes: the first end of the fifth high-voltage switching tube is connected with the second end of the fourth high-voltage switching tube, and the third end of the fifth high-voltage switching tube is connected with the micro-grid; the first end of the sixth high-voltage switching tube is connected with the output end of the voltage stabilizing control circuit, the second end of the sixth high-voltage switching tube is connected with the second end of the fifth high-voltage switching tube, and the third end of the sixth high-voltage switching tube is connected with the positive power supply end of the first inverter.

According to an embodiment of the present invention, the third power supply circuit includes: the system comprises a sixth resistor, a seventh high-voltage switch tube and a seventh resistor, wherein one end of the sixth resistor is connected with a micro-grid; the first end of the seventh high-voltage switching tube is connected with the output end of the voltage stabilizing control circuit, and the second end of the seventh high-voltage switching tube is connected with the other end of the sixth resistor; one end of the seventh resistor is connected with the third end of the seventh high-voltage switching tube, and the other end of the seventh resistor is connected with the positive power supply end of the second inverter.

According to one embodiment of the present invention, an under-voltage detection circuit includes: an under-voltage threshold providing circuit for providing an under-voltage threshold; the input end of the undervoltage comparison circuit is connected with the micro-grid and is used for comparing the voltage of the high-voltage line with the undervoltage threshold value and outputting a first undervoltage comparison signal; and the input end of the undervoltage output circuit is connected with the output end of the undervoltage comparison circuit and is used for generating and outputting a second undervoltage comparison signal based on the first undervoltage comparison signal.

According to one embodiment of the present invention, an under-voltage threshold providing circuit includes: the system comprises a first transmission gate and a second transmission gate, wherein the forward control end of the first transmission gate is used for inputting a first control signal, the reverse control end of the first transmission gate is used for inputting a second control signal opposite to the first control signal, the input end of the first transmission gate is used for inputting a first undervoltage threshold value, and the output end of the first transmission gate is connected with the threshold value input end of the undervoltage comparison circuit; the forward control end of the second transmission gate is used for inputting a second control signal, the reverse control end of the second transmission gate is used for inputting a first control signal, the input end of the second transmission gate is used for inputting a second undervoltage threshold value, and the output end of the second transmission gate is connected with the threshold value input end of the undervoltage comparison circuit.

According to one embodiment of the present invention, an under-voltage comparison circuit includes: the switching device comprises a first current source, an eighth high-voltage switching tube, a ninth high-voltage switching tube, a fourth switching tube, a fifth switching tube, a sixth switching tube, a seventh switching tube and a third inverter, wherein the first end of the eighth high-voltage switching tube is connected with a micro-grid, the first end of the ninth high-voltage switching tube is connected with an undervoltage threshold providing circuit, the third end of the eighth high-voltage switching tube and the third end of the ninth high-voltage switching tube are respectively connected with one end of the first current source, and the other end of the first current source is connected with a second power supply; the first end of the fourth switching tube, the first end of the fifth switching tube, the second end of the fifth switching tube and the second end of the ninth high-voltage switching tube are connected, the second end of the fourth switching tube is connected with the second end of the eighth high-voltage switching tube, and the third end of the fourth switching tube and the third end of the fifth switching tube are grounded; the first end of the sixth switching tube is connected with the second end of the fourth switching tube, the second end of the sixth switching tube, the first end of the seventh switching tube, the second end of the seventh switching tube and the input end of the third inverter are connected, the third end of the sixth switching tube is grounded, and the third end of the seventh switching tube is connected with the second power supply; the output end of the third inverter is connected with the under-voltage output circuit.

According to one embodiment of the present invention, the brown-out detection circuit further includes: the first diode is connected with the first power supply, and the second diode is connected with the second power supply; the anode of the third diode is connected with the other end of the second current source, and the cathode of the third diode is connected with the first end of the eighth high-voltage switching tube; the eighth resistor is connected between the first end of the eighth high-voltage switch tube and the ground.

According to one embodiment of the present invention, an under-voltage output circuit includes: the input end of the second trigger is connected with the output end of the undervoltage comparison circuit and is used for generating a third undervoltage comparison signal based on the first undervoltage comparison signal; the enabling end of the frequency divider is connected with the output end of the second trigger, the clock signal end of the frequency divider is used for inputting a clock signal, dividing the clock signal based on the third undervoltage comparison signal, and outputting the second undervoltage comparison signal based on the frequency division result.

In order to achieve the above object, a second aspect of the present invention provides a micro-grid energy management system, which includes the micro-grid line voltage abnormality detection circuit.

According to the micro-grid energy management system provided by the embodiment of the invention, based on the micro-grid line voltage abnormality detection circuit, overvoltage and undervoltage detection of line voltage can be realized, and the micro-grid energy management system has the characteristics of strong anti-interference performance and wide voltage detection range, and avoids the influence of great fluctuation of the line voltage of the micro-grid on an electric load and a power converter.

In order to achieve the above objective, an embodiment of a third aspect of the present invention provides an electric device, which includes the micro-grid line voltage abnormality detection circuit.

According to the electric equipment provided by the embodiment of the invention, based on the micro-grid line voltage abnormality detection circuit, overvoltage and undervoltage detection of line voltage can be realized, and the electric equipment is prevented from being influenced by large fluctuation of the line voltage of the micro-grid.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

Fig. 1 is a block schematic diagram of a micro-grid line voltage anomaly detection circuit according to an embodiment of the present invention;

FIG. 2 is a block schematic diagram of a micro-grid line voltage anomaly detection circuit according to one embodiment of the present invention;

FIG. 3 is a circuit diagram of an overvoltage detection circuit according to one embodiment of the invention;

FIG. 4 is a block schematic diagram of a micro-grid line voltage anomaly detection circuit according to one embodiment of the present invention;

FIG. 5 is a circuit diagram of an under-voltage detection circuit according to one embodiment of the present invention;

FIG. 6 is a block schematic diagram of a microgrid energy management system according to an embodiment of the present invention;

Fig. 7 is a block schematic diagram of a powered device according to an embodiment of the present invention.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

The micro-grid line voltage abnormality detection circuit, the micro-grid energy management system and the electric equipment provided by the embodiment of the invention are described below with reference to the accompanying drawings.

In the related art, a line voltage detection circuit is integrated in a power converter, and when the power converter works, the line voltage detection circuit detects a line voltage signal, and when an undervoltage occurs in a power grid, namely, the line voltage is smaller than a preset voltage threshold value, the power converter stops working, so that an electric load is protected. The line voltage detection circuit performs power-off protection on the power supply and the load by an undervoltage detection method. Because the voltage stability of the power grid is higher, the line voltage detection circuit based on undervoltage detection can meet the electricity safety requirement, but the line voltage fluctuation is larger in the new energy micro-grid environment, for example, in a low-voltage micro-grid, the line voltage fluctuation range is generally between 43VAC and 350VAC, and the line voltage fluctuation range is far beyond that of a common power grid, so that the line voltage detection circuit in the related art is not suitable for the micro-grid.

In order to solve the technical problems, the invention provides a micro-grid line voltage abnormality detection circuit of a micro-grid, which is based on the fluctuation of line voltage under the micro-grid environment, not only realizes the undervoltage detection function of the line voltage through an undervoltage detection circuit, but also performs overvoltage detection on the line voltage through an overvoltage detection circuit, integrates the overvoltage and undervoltage detection functions, provides a sufficient line voltage detection range, and improves the electricity safety of the micro-grid.

Fig. 1 is a block schematic diagram of a micro-grid line voltage abnormality detection circuit according to an embodiment of the present invention.

As shown in fig. 1, the micro-grid line voltage abnormality detection circuit of the embodiment of the present invention includes an overvoltage detection circuit 10 and an undervoltage detection circuit 20, the overvoltage detection circuit 10 includes: the micro-grid overvoltage protection circuit comprises a first high-voltage input circuit 11 and an overvoltage comparison circuit 12, wherein the first high-voltage input circuit 11 is connected with a micro-grid, the overvoltage comparison circuit 12 is connected with the first high-voltage input circuit 11, the first high-voltage input circuit 11 is used for converting the high-voltage line voltage of the micro-grid into a low-voltage line voltage, and the overvoltage comparison circuit 12 is used for comparing the low-voltage line voltage with an overvoltage threshold Vref1 and outputting a first overvoltage comparison signal.

Specifically, the overvoltage detection circuit 10 and the undervoltage detection circuit 20 are respectively connected to the micro-grid, the overvoltage detection of the line voltage of the micro-grid is realized through the overvoltage detection circuit 10, and the undervoltage detection of the voltage of the micro-grid is realized through the undervoltage detection circuit 20. In addition, the line voltage of the micro-grid can be sampled by rectifying, filtering and voltage dividing peripheral circuits, and the sampled voltage is output to the overvoltage detection circuit 10 and the undervoltage detection circuit 20, and the overvoltage detection circuit 10 and the undervoltage detection circuit 20 perform overvoltage and undervoltage detection based on the sampled voltage.

In the overvoltage detection circuit 10, the high-voltage line voltage of the micro grid is first converted into a low-voltage line voltage by the first high-voltage input circuit 11, and the high-voltage line voltage can be step-down operated by a step-down circuit, for example. The overvoltage comparing circuit 12 compares the low-voltage line voltage with an overvoltage threshold Vref1 to output a first overvoltage comparing signal, for example, when the low-voltage line voltage is greater than the overvoltage threshold, the overvoltage comparing circuit 12 outputs the first overvoltage comparing signal of a high level; when the low voltage line voltage is equal to or lower than the overvoltage threshold value, the overvoltage comparing circuit 12 outputs a first overvoltage comparing signal of a low level. Thus, it is possible to determine whether an overvoltage has occurred in the micro grid based on the first overvoltage comparison signal, and perform an overvoltage protection action when the micro grid has occurred in the overvoltage.

The undervoltage detection circuit 20 may also detect an undervoltage state of the micro-grid based on an undervoltage threshold, for example, the high voltage line voltage of the micro-grid is directly compared with the undervoltage threshold to output a corresponding undervoltage comparison signal, for example, when the high voltage line voltage of the micro-grid is less than the undervoltage threshold, the undervoltage detection circuit 20 outputs a low level signal; when the high voltage line voltage of the micro-grid is greater than or equal to the undervoltage threshold, the undervoltage detection circuit 20 outputs a high level signal, so that whether the micro-grid is undervoltage is determined based on the undervoltage detection circuit 20.

The circuit is integrated with an overvoltage detection function and an undervoltage detection function, can meet the detection requirement of the line voltage with larger fluctuation in the micro-grid, and improves the electricity safety of the micro-grid.

As shown in connection with fig. 2, in one embodiment of the present invention, the first high voltage input circuit 11 includes: the input end of the voltage stabilizing control circuit 111 is connected with the micro-grid and is used for generating a voltage stabilizing control signal based on the high-voltage line voltage; the control end of the first high-voltage conversion circuit 112 is connected with the output end of the voltage stabilizing control circuit 111, the input end of the first high-voltage conversion circuit 112 is connected with the micro-grid, and the output end of the first high-voltage conversion circuit 112 is connected with the input end of the overvoltage comparison circuit 12 and is used for converting high-voltage line voltage into low-voltage line voltage based on the voltage stabilizing control signal.

That is, the voltage stabilizing control circuit 111 generates a voltage stabilizing control signal based on the high-voltage line voltage of the micro grid, controls the first high-voltage converting circuit 112 to start up by the voltage stabilizing control signal, and converts the high-voltage line voltage into the low-voltage line voltage by the first high-voltage converting circuit 112.

As shown in conjunction with fig. 3, in one embodiment of the present invention, the voltage stabilizing control circuit 111 includes: the high-voltage switching circuit comprises a first resistor R1, a first high-voltage switching tube HM1 and at least one first diode D1, wherein one end of the first resistor R1 is connected with a micro-grid, and the other end of the first resistor R1 is connected with a control end of a first high-voltage switching circuit 112; the first end and the second end of the first high-voltage switch tube HM1 are respectively connected with the other end of the first resistor R1; at least one first diode D1 is connected in series in the same direction, and the anode after being connected in series is connected with the third end of the first high-voltage switch tube HM1, and the cathode after being connected in series is grounded.

Specifically, d1_ … … d1_n-1 and d1_n are used to represent a plurality of first diodes D1, the plurality of first diodes D1 are sequentially connected in series, the first high-voltage switching tube HM1 adopts an NMOS (N-Metal-Oxide-Semiconductor) tube, wherein a first end of the first high-voltage switching tube HM1 is a gate of the NMOS tube, a second end of the first high-voltage switching tube HM1 is a drain of the NMOS tube, and a third end of the first high-voltage switching tube HM1 is a source of the NMOS tube.

In the detection process, the high-voltage line voltage is input into the voltage stabilizing control circuit 111, the first high-voltage switch tube HM1 is turned on, the first resistor R1, the first high-voltage switch tube HM1 and at least one branch of the first diode D1 are turned on, and the voltage stabilizing control signal is output through the other end of the first resistor R1 based on the conduction voltage drop of the first diode D1 and the stability of the conduction voltage of the first high-voltage switch tube HM 1.

In one embodiment of the present invention, the first high voltage conversion circuit 112 includes: the first end of the second high-voltage switching tube HM2 is connected with the output end of the voltage stabilizing control circuit 111, the second end of the second high-voltage switching tube HM2 is connected with the input end of the overvoltage comparing circuit 12, and the third end of the second high-voltage switching tube HM2 is connected with the micro-grid.

Specifically, taking a PMOS (P-Metal-Oxide-Semiconductor) tube as an example of the second high-voltage switching tube HM2, a first end of the second high-voltage switching tube HM2 is a gate of the PMOS tube, a second end of the second high-voltage switching tube HM2 is a drain of the PMOS tube, and a third end of the second high-voltage switching tube HM2 is a source of the PMOS tube.

When the voltage stabilizing control circuit 111 outputs a voltage stabilizing control signal to the gate of the second high voltage switching tube HM2, the second high voltage switching tube HM2 triggers to conduct, the high voltage line voltage provided by the micro-grid is converted into a low voltage line voltage through the conducted second high voltage switching tube HM2, and the low voltage line voltage is output to the overvoltage comparing circuit 12 for overvoltage detection.

In one embodiment of the present invention, the overvoltage comparing circuit 12 includes: an overvoltage threshold value providing circuit 121 for providing an overvoltage threshold value Vref1; the threshold input end of the overvoltage comparing sub-circuit 122 is connected with the overvoltage threshold providing circuit 121, and the input end of the overvoltage comparing sub-circuit 122 is connected with the output end of the first high voltage converting circuit 112 and is used for comparing the low voltage line voltage with the overvoltage threshold Vref1 and outputting a second overvoltage comparing signal; the input end of the overvoltage output circuit 123 is connected with the output end of the overvoltage comparison sub-circuit 122, and is used for converting the second overvoltage comparison signal into the first overvoltage comparison signal and outputting the first overvoltage comparison signal.

Specifically, the low voltage line voltage is compared with the overvoltage threshold Vref1 by the overvoltage comparing sub-circuit 122 to output a corresponding second overvoltage comparing signal, and the overvoltage output circuit 123 performs data conversion on the second overvoltage comparing signal to output the first overvoltage comparing signal.

The overvoltage threshold value providing circuit 121 may be a voltage dividing circuit connected to a preset power supply, where the voltage dividing circuit 121 divides a preset voltage provided by the preset power supply and outputs a corresponding divided voltage, and the divided voltage is used as the overvoltage threshold value Vref1. The over-voltage comparison subcircuit 122 may be set based on the comparator to complete the comparison action. The overvoltage output circuit 123 may perform operations such as filtering and voltage reduction on the second overvoltage signal to obtain the first overvoltage comparison signal, or may perform operations such as filtering and voltage reduction on the second overvoltage signal to obtain the corresponding first overvoltage comparison signal, which is not limited herein.

In one embodiment of the present invention, the overvoltage comparison subcircuit 122 includes: the device comprises at least one second diode D2, a voltage stabilizing tube Z0, a first switching tube M1, a second resistor R2, a first inverter INV1 and a second inverter INV1, wherein the at least one second diode D2 is connected in series in the same direction, the anode after being connected in series is connected with the output end of a first high-voltage conversion circuit 112, and the cathode after being connected in series is connected with the cathode of the voltage stabilizing tube Z0; the first end of the first switching tube M1 is respectively connected with the anode of the voltage stabilizing tube Z0 and the overvoltage threshold value providing circuit 121, the second end of the first switching tube M1 is connected with one end of the second resistor R2, and the third end of the first switching tube M1 is grounded; the other end of the second resistor R2 is connected with a first power supply VCC 1; the input end of the first inverter INV1 is connected with the second end of the first switching tube M1; an input terminal of the second inverter INV2 is connected to an output terminal of the first inverter INV1, and an output terminal of the second inverter INV2 is connected to an input terminal of the overvoltage output circuit 123.

Specifically, a plurality of second diodes D2 are respectively denoted by d2_ … … d2_m1 and d2_m, and a plurality of d2_ … … d2_m1 and d2_m are sequentially connected in series, wherein an anode of the diode d2_1 is connected to an output terminal of the first high voltage conversion circuit 112 to receive a low voltage line voltage, a cathode of the diode d2_m is connected to a cathode of the voltage regulator tube Z0, and an anode of the voltage regulator tube Z0 is connected to the overvoltage threshold value providing circuit 121 to receive an overvoltage threshold value Vref1.

Taking the first switching tube M1 as an NMOS tube as an example, the first end of the first switching tube M1 is a grid electrode of the NMOS tube, the second end of the first switching tube M1 is a drain electrode of the NMOS tube, and the third end of the first switching tube M1 is a source electrode of the NMOS tube.

When the low voltage line voltage does not reach the overvoltage threshold Vref1, the branches of d2_ … … d2_m1, d2_m and the voltage stabilizing tube Z0 are in an off state, the first switching tube M1 is turned off, the input end of the first inverter INV1 is connected with the first power supply VCC1 through the second resistor R2, that is, the input end of the first inverter INV1 is at a high level, the first inverter INV1 outputs a low level to the second inverter INV2, and the second inverter INV2 outputs a high level second overvoltage comparison signal.

When the low voltage line voltage reaches the overvoltage threshold Vref1, the branches of the D2_ … … D2_m1, D2_m and the voltage stabilizing tube Z0 start to be conducted, the voltage at the first end of the first switching tube M1 reaches the conducting threshold of the first switching tube M1, the first switching tube M1 is conducted, the input end of the first inverter INV1 is grounded through the conducted first switching tube M1, the input end of the first inverter INV1 is in a low level, the first inverter INV1 outputs a high level to the second inverter INV2, and the second inverter INV2 outputs a low level second overvoltage comparison signal.

In one embodiment of the present invention, the overvoltage threshold value providing circuit 121 includes: the third resistor R3, the second switching tube M2, the fourth resistor R4, the fifth resistor R5 and the third switching tube M3. One end of the third resistor R3 is respectively connected with the anode of the voltage stabilizing tube Z0 and the first end of the first switching tube M1; the first end of the second switching tube M2 is connected with the second end of the first switching tube M1, the second end of the second switching tube M2 is connected with the other end of the third resistor R3, and the third end of the second switching tube M2 is grounded; one end of the fourth resistor R4 is connected with the other end of the third resistor R3; one end of the fifth resistor R5 is connected with the other end of the fourth resistor R4, and the other end of the fifth resistor R5 is grounded; the first end of the third switching tube M3 is connected with the output end of the second inverter INV2, the second end of the third switching tube M3 is connected with the other end of the fourth resistor R4, and the third end of the third switching tube M3 is grounded.

Specifically, taking the second switching tube M2 and the third switching tube M3 as NMOS tubes as examples, wherein the first ends of the second switching tube M2 and the third switching tube M3 are gates of the NMOS tubes, the second ends of the second switching tube M2 and the third switching tube M3 are drains of the NMOS tubes, and the third ends of the second switching tube M2 and the third switching tube M3 are sources of the NMOS tubes.

When the low voltage line voltage is smaller and the overvoltage threshold Vref1 is not reached, the first switching tube M1 is in an off state, the second inverter INV2 outputs a high level, the first end of the second switching tube M2 is pulled up to a high level based on the second resistor R2, the second switching tube M2 is turned on, the first end of the second switching tube M3 is in a conductive state based on the output of the second inverter, and at this time, only the third resistor R3, d2_ … … d2_m-1, d2_m, and the voltage stabilizing tube Z0 are connected in series to form a voltage dividing circuit. As the high-voltage line voltage increases gradually, the low-voltage line voltage converted and output by the first high-voltage converting circuit 112 increases gradually, when the low-voltage line voltage reaches the low-voltage threshold Vref1, the d2_ … … d2_m-1, d2_m, and the regulator Z0 branch are turned on, when the upper voltage of the third resistor R3 reaches the on threshold of the first switch tube M1, the first switch tube M1 is turned on, and the overvoltage comparing sub-circuit 122 outputs the second overvoltage comparing signal with a low level.

When the first switching tube M1 is turned on and the overvoltage comparing sub-circuit 122 outputs the second overvoltage comparing signal with the low level, the first ends of the second switching tube M2 and the third switching tube M3 are at the low level, the second switching tube M2 and the third switching tube M3 are in the off state, at this time, the fourth resistor R4, the fifth resistor R5, the third resistor R3, the d2_ … … d2_m-1, the d2_m, and the voltage stabilizing tube Z0 are connected in series to form a voltage dividing circuit, and the voltage at the first end of the first switching tube M1 is the divided voltage of the fourth resistor R4, the fifth resistor R5, and the third resistor R3, so as to raise the voltage at the first end of the first switching tube M1, so that the voltage at the first end of the first switching tube M1 is greater than the on threshold of the first switching tube M1.

When the low voltage line voltage is lower than the overvoltage threshold Vref1, the second comparison signal output from the second inverter INV2 is not switched to the high level because the voltage of the first terminal of the first switching transistor M1 is raised. Along with the continuous decrease of the low voltage line voltage, the voltage at the first end of the first switching tube M1 is finally lower than the turn-on threshold of the first switching tube M1, and at this time, the first switching tube M1 is turned off to exit the overvoltage mode.

Therefore, the circuit realizes the entering and exiting double threshold values of overvoltage detection, and is beneficial to the stable operation of the overvoltage detection circuit.

In one embodiment of the present invention, the overvoltage output circuit 123 includes: the input end of the level conversion circuit 1231 is connected to the output end of the overvoltage comparing sub-circuit 122, and is used for converting the second overvoltage comparing signal into a corresponding logic level; the first flip-flop ST1, an input terminal of the first flip-flop ST1 is connected to an output terminal of the level conversion circuit 1231, and generates and outputs a first overvoltage comparison signal based on the logic level.

Specifically, the second overvoltage comparison signal output from the overvoltage comparison sub-circuit 122 is converted into a logic level of the low voltage domain by the level conversion circuit 1231. The generated logic level is shaped by the first flip-flop ST1 and then outputs a first overvoltage signal. The first flip-flop ST1 may be a schmitt trigger.

In one embodiment of the present invention, the overvoltage detection circuit 10 further includes: the first power supply circuit 13, the first power supply circuit 13 is connected to the output end of the voltage stabilizing control circuit 111 and the micro-grid respectively, for providing the first power supply VCC1.

That is, the first power supply circuit 13 performs voltage conversion on the high-voltage line voltage output from the micro grid according to the voltage stabilizing control signal to convert and output a corresponding voltage signal as the first power supply VCC1.

In one embodiment of the present invention, the first power supply circuit 13 includes: a third high voltage switching tube HM3 and a fourth high voltage switching tube HM4, wherein a first end of the third high voltage switching tube HM3 is connected with the output end of the voltage stabilizing control circuit 111, and a third end of the third high voltage switching tube HM3 is connected with the other end of the second resistor R2 to provide a first power supply VCC1; the first end of the fourth high-voltage switch tube HM4 is respectively connected with the second end of the fourth high-voltage switch tube HM4 and the second end of the third high-voltage switch tube HM3, and the third end of the fourth high-voltage switch tube HM4 is connected with the micro-grid; wherein, the control end of the first high voltage converting circuit 112 is connected to the second end of the third high voltage switching tube HM 3.

Specifically, taking the third high-voltage switch tube HM3 as an NMOS tube, the fourth high-voltage switch tube HM4 as a PMOS tube as an example, the first end of the third high-voltage switch tube HM3 is the gate of the NMOS tube, the second end of the third high-voltage switch tube HM3 is the drain of the NMOS tube, and the third end of the third high-voltage switch tube HM3 is the source of the NMOS tube; the first end of the fourth high-voltage switch tube HM4 is a grid electrode of the PMOS tube, the second end of the fourth high-voltage switch tube HM4 is a drain electrode of the PMOS tube, and the third end of the fourth high-voltage switch tube HM4 is a source electrode of the PMOS tube.

The voltage stabilizing control circuit 111 outputs a voltage stabilizing control signal to control the third high-voltage switching tube HM3 to be turned on, provides corresponding voltage signals based on the turned-on third high-voltage switching tube HM3, namely a fourth high-voltage switching tube HM4 and a second high-voltage switching tube HM2, so as to trigger the fourth high-voltage switching tube HM4 and the second high-voltage switching tube HM2 to be turned on, and the high-voltage line voltage output by the micro-grid is output in a step-down mode through the turned-on fourth high-voltage switching tube HM4 and the turned-on third high-voltage switching tube HM3, so that the first power supply VCC1 is provided.

In one embodiment of the present invention, the overvoltage detection circuit 10 further includes: the second power supply circuit 14, the second power supply circuit 14 is respectively connected with the output end of the voltage stabilizing control circuit 111, the micro-grid and the positive power supply end of the first inverter INV1, and is used for supplying power to the first inverter INV 1; and the third power supply circuit 15, wherein the third power supply circuit 15 is respectively connected with the output end of the voltage stabilizing control circuit 111, the micro-grid and the positive power supply end of the second inverter INV2, and is used for supplying power to the second inverter INV 2.

That is, the second power supply circuit 14 down-converts the high-voltage line voltage output from the micro-grid based on the voltage stabilizing control signal output from the voltage stabilizing control circuit 111 to output a corresponding voltage signal to power the first inverter INV 1. The third power supply circuit 15 performs buck conversion on the high-voltage line voltage output from the micro-grid based on the voltage stabilizing control signal output from the voltage stabilizing control circuit 111, so as to output a corresponding voltage signal to supply power to the second inverter INV 2.

In one embodiment of the present invention, the second power supply circuit 14 includes: a fifth high voltage switching tube HM5 and a sixth high voltage switching tube HM6, wherein a first end of the fifth high voltage switching tube HM5 is connected with a second end of the fourth high voltage switching tube HM4, and a third end of the fifth high voltage switching tube HM5 is connected with the micro-grid; the first end of the sixth high voltage switching tube HM6 is connected to the output end of the voltage stabilizing control circuit 111, the second end of the sixth high voltage switching tube HM6 is connected to the second end of the fifth high voltage switching tube HM5, and the third end of the sixth high voltage switching tube HM6 is connected to the positive power supply end of the first inverter INV 1.

Specifically, taking the fifth high-voltage switching tube HM5 as a PMOS tube, the sixth high-voltage switching tube HM6 as an NMOS tube as an example, the first end of the fifth high-voltage switching tube HM5 is a gate of the PMOS tube, the second end of the fifth high-voltage switching tube HM5 is a drain of the PMOS tube, the second end of the fifth high-voltage switching tube HM5 is a source of the PMOS tube, the first end of the sixth high-voltage switching tube HM6 is a gate of the NMOS tube, the second end of the sixth high-voltage switching tube HM6 is a drain of the NMOS tube, and the third end of the sixth high-voltage switching tube HM6 is a source of the NMOS tube.

The voltage stabilizing control circuit 111 outputs a voltage stabilizing control signal to control the sixth high-voltage switching tube HM6 and the third high-voltage switching tube HM3 to be conducted, the fifth high-voltage switching tube HM5 is conducted based on the conducted third high-voltage switching tube M3, and the high-voltage line voltage output by the micro-grid is subjected to voltage reduction output through the fifth high-voltage switching tube HM5 and the sixth high-voltage switching tube HM6 so as to supply power to the positive power supply end of the first inverter INV 1.

In one embodiment of the present invention, the third power supply circuit 15 includes: a sixth resistor R6, a seventh high-voltage switching tube HM7 and a seventh resistor R7, wherein one end of the sixth resistor R6 is connected with the micro-grid; the first end of the seventh high-voltage switching tube HM7 is connected with the output end of the voltage stabilizing control circuit 111, and the second end of the seventh high-voltage switching tube HM7 is connected with the other end of the sixth resistor R6; one end of the seventh resistor R7 is connected to the third end of the seventh high voltage switching transistor HM7, and the other end of the seventh resistor R7 is connected to the positive power supply end of the second inverter INV 2.

Specifically, taking the seventh high-voltage switching tube HM7 as an NMOS tube, the first end of the seventh high-voltage switching tube HM7 is the gate of the NMOS tube, the second end of the seventh high-voltage switching tube HM7 is the drain of the NMOS tube, and the third end of the seventh high-voltage switching tube HM7 is the source of the NMOS tube.

The voltage stabilizing control signal output by the voltage stabilizing control circuit 111 controls the conduction of the seventh high-voltage switching tube HM7, and the high-voltage line voltage output by the micro-grid is reduced in voltage and output through a branch circuit formed by the sixth resistor R6, the conducted seventh high-voltage switching tube HM7 and the seventh resistor R7, so as to supply power for the positive power end of the second inverter INV 2.

Thus, the overvoltage detection circuit 10 of this embodiment is connected to the micro grid through the first high voltage switching transistor HM1, the second high voltage switching transistor HM2, the third high voltage switching transistor HM3, the fourth high voltage switching transistor HM4, the fifth high voltage switching transistor HM5, the sixth high voltage switching transistor HM6 and the seventh high voltage switching transistor HM7 in order to withstand higher line voltages.

As shown in connection with fig. 4, in one embodiment of the present invention, the brown-out detection circuit 20 includes: an under-voltage threshold providing circuit 21 for providing an under-voltage threshold Vref2; the undervoltage comparison circuit 22, the threshold input end of the undervoltage comparison circuit 22 is connected with the undervoltage threshold providing circuit 21, the input end of the undervoltage comparison circuit 22 is connected with the micro-grid, and is used for comparing the voltage of the high voltage line with the undervoltage threshold Vref2 and outputting a first undervoltage comparison signal; the under-voltage output circuit 23, the input end of the under-voltage output circuit 23 is connected with the output end of the under-voltage comparison circuit 22, and is used for generating and outputting a second under-voltage comparison signal based on the first under-voltage comparison signal.

Specifically, the high voltage line voltage is compared with the undervoltage threshold Vref2 by the undervoltage comparison circuit 22 to output a corresponding first undervoltage comparison signal, and the undervoltage output circuit 23 performs data processing on the first undervoltage comparison signal to output a corresponding second undervoltage comparison signal for undervoltage protection.

The under-voltage threshold value providing circuit 21 may be a voltage dividing circuit connected to a preset power supply, where the under-voltage threshold value providing circuit 21 divides a preset voltage provided by the preset power supply and outputs a corresponding divided voltage, and the divided voltage is used as the under-voltage threshold value Vref2. The brown-out compare circuit 22 may be set based on the comparator to complete the comparison action. The under-voltage output circuit 23 may perform filtering, level shifting, etc. on the first under-voltage comparison signal to obtain a corresponding second under-voltage comparison signal, which is not limited herein.

As shown in connection with fig. 5, in one embodiment of the present invention, the brown-out threshold providing circuit 21 includes: the first transmission gate TG1 and the second transmission gate TG2, wherein the forward control end of the first transmission gate TG1 is used for inputting a first control signal control1, the reverse control end of the first transmission gate TG1 is used for inputting a second control signal control2 opposite to the first control signal control1, the input end of the first transmission gate TG1 is used for inputting a first under-voltage threshold value vbias_1, and the output end of the first transmission gate TG1 is connected with the threshold value input end of the under-voltage comparison circuit 22; the forward control end of the second transmission gate TG2 is used for inputting a second control signal control2, the reverse control end of the second transmission gate TG2 is used for inputting a first control signal control1, the input end of the second transmission gate TG2 is used for inputting a second under-voltage threshold value vbias_2, and the output end of the second transmission gate TG2 is connected with the threshold value input end of the under-voltage comparison circuit 22.

That is, the first and second transmission gates TG1 and TG2 are controlled to be turned on and off based on the first and second control signals control1 and control 2. For example, when the first control signal control1 is at a high level and the second control signal control2 is at a low level, the first transmission gate TG1 is in an on state, the second transmission gate TG2 is in an off state, and the under-voltage threshold providing circuit 21 outputs the first under-voltage threshold vbias_1 to the threshold input terminal of the under-voltage comparing circuit 22; when the first control signal control1 is at a low level and the second control signal control2 is at a high level, the first transmission gate TG1 is in an off state, the second transmission gate TG2 is in an on state, and the under-voltage threshold providing circuit 21 outputs the second under-voltage threshold vbias_2 to the threshold input terminal of the under-voltage comparing circuit 22.

The undervoltage threshold providing circuit 21 provides a first undervoltage threshold vbias_1 and a second undervoltage threshold vbias_2, and controls the first transmission gate TG1 and the second transmission gate TG2 to input the corresponding undervoltage threshold into the undervoltage comparing circuit 22, so that double-threshold undervoltage control can be performed according to actual situations.

In one embodiment of the present invention, the brown-out comparison circuit 22 includes: the switching device comprises a first current source A1, an eighth high-voltage switching tube HM8, a ninth high-voltage switching tube HM9, a fourth switching tube M4, a fifth switching tube M5, a sixth switching tube M6, a seventh switching tube M7 and a third inverter INV3, wherein the first end of the eighth high-voltage switching tube HM8 is connected with a micro-grid, the first end of the ninth high-voltage switching tube HM9 is connected with an undervoltage threshold providing circuit 21, the third end of the eighth high-voltage switching tube HM8 and the third end of the ninth high-voltage switching tube HM9 are respectively connected with one end of a first current source A1, and the other end of the first current source A1 is connected with a second power source VCC 2; the first end of the fourth switching tube M4, the first end of the fifth switching tube M5, the second end of the fifth switching tube M5 and the second end of the ninth high-voltage switching tube HM9 are connected, the second end of the fourth switching tube M4 is connected with the second end of the eighth high-voltage switching tube HM8, and the third end of the fourth switching tube M4 and the third end of the fifth switching tube M5 are grounded; the first end of the sixth switching tube M6 is connected with the second end of the fourth switching tube M4, the second end of the sixth switching tube M6, the first end of the seventh switching tube M7, the second end of the seventh switching tube M7 and the input end of the third inverter INV3 are connected, the third end of the sixth switching tube M6 is grounded, and the third end of the seventh switching tube M7 is connected with the second power supply VCC 2; an output end of the third inverter INV3 is connected to the under-voltage output circuit 23.

Specifically, taking the eighth high-voltage switching tube HM8, the ninth high-voltage switching tube HM9 and the seventh switching tube M7 as PMOS tubes, the fourth switching tube M4, the fifth switching tube M5 and the sixth switching tube M6 as NMOS tubes as examples, the first ends of the eighth high-voltage switching tube HM8, the ninth high-voltage switching tube HM9 and the seventh switching tube M7 as gates of the PMOS tubes, the second ends of the eighth high-voltage switching tube HM8, the ninth high-voltage switching tube HM9 and the seventh switching tube M7 as drains of the PMOS tubes, and the third ends of the eighth high-voltage switching tube HM8, the ninth high-voltage switching tube HM9 and the seventh switching tube M7 as sources of the PMOS tubes; the first ends of the fourth switching tube M4, the fifth switching tube M5 and the sixth switching tube M6 are grids of NMOS tubes, the second ends of the fourth switching tube M4, the fifth switching tube M5 and the sixth switching tube M6 are drains of the NMOS tubes, and the third ends of the fourth switching tube M4, the fifth switching tube M5 and the sixth switching tube M6 are sources of the NMOS tubes.

The eighth high-voltage switching tube HM8, the ninth high-voltage switching tube HM9, the fourth switching tube M4 and the fifth switching tube M5 form a comparator to compare the high-voltage line voltage provided by the micro-grid with the low-voltage threshold Vref 2. When the high voltage line voltage is smaller than the low voltage threshold Vrf2, the comparator outputs a high level, the sixth switching tube M6 is turned on, the input end of the third inverter INV3 is low, and the under-voltage comparing circuit 22 outputs a first under-voltage comparing signal of high level. When the high voltage line voltage is equal to or higher than the low voltage threshold Vrf2, the comparator outputs a low level, the sixth switching tube M6 is kept in an off state, and under the action of the seventh switching tube M7 and the second power source VCC2, the input end of the third inverter INV3 is at a high level, and the under-voltage comparing circuit 22 outputs a first under-voltage comparing signal at a low level.

In this embodiment, the eighth high-voltage switching transistor HM8 and the ninth high-voltage switching transistor HM9 are used as the input stage of the under-voltage comparing circuit 22, so as to withstand the overvoltage condition of the line voltage.

In one embodiment of the present invention, the brown-out detection circuit 20 further includes: a second current source A2, a third diode D3 and an eighth resistor R8, wherein one end of the second current source A2 is connected to a second power source VCC 2; the anode of the third diode D3 is connected with the other end of the second current source A2, and the cathode of the third diode D3 is connected with the first end of the eighth high-voltage switch tube HM 8; the eighth resistor R8 is connected between the first end of the eighth high-voltage switching transistor HM8 and ground.

Specifically, a pull-up network is formed by the second current source A2, the third diode D3 and the eighth resistor R8, and when the input end of the undervoltage detection circuit 20 is open, the voltage of the first end of the eighth high-voltage switching tube HM8 is pulled up to a high voltage, so as to ensure that the undervoltage is not misreported when the input end is open.

In one embodiment of the present invention, the under-voltage output circuit 23 includes: a second trigger ST2 and a frequency divider 231, wherein an input end of the second trigger ST2 is connected to an output end of the under-voltage comparing circuit 22, and is used for generating a third under-voltage comparing signal based on the first under-voltage comparing signal; the enable terminal EN of the frequency divider 231 is connected to the output terminal of the second flip-flop ST2, and the clock signal terminal of the frequency divider 231 is used for inputting the clock signal CLK, dividing the clock signal CLK based on the third under-voltage comparison signal, and outputting the second under-voltage comparison signal based on the division result.

Specifically, taking a signal at the input end of the third inverter INV3 as the first control signal control1, and a signal at the output end of the third inverter INV3 as the second control signal control2 as an example. When the first control signal control1 is at a low level and the second control signal control2 is at a high level, the first transmission gate TG1 is turned on, and the second transmission gate TG2 is turned off; when the first control signal control1 is at a high level and the second control signal control2 is at a low level, the first transmission gate TG1 is turned off, the second transmission gate TG2 is turned on, and the first under-voltage threshold vbias_1 is greater than the second under-voltage threshold vbias_2.

When the high voltage line voltage is large, the comparator composed of the eighth high voltage switching transistor HM8, the ninth high voltage switching transistor HM9, the fourth switching transistor M4, and the fifth switching transistor M5 outputs a low level, the sixth switching transistor M6 is in an off state, the first control signal control1, which is a signal of the input end of the third inverter INV3, is at a high level, the second control signal control2, which is a signal of the output end of the third inverter INV3, is at a low level, the first transmission gate TG1 is in an off state, the second transmission gate TG2 is in an on state, and the under-voltage threshold providing circuit 21 outputs the second under-voltage threshold vbias_2 to the under-voltage comparing circuit 22. The current under-voltage threshold Vref2 is the second under-voltage threshold Vbias_2.

In case the high voltage line voltage is smaller than the brown-out threshold Vref2, i.e. the second brown-out threshold vbias_2, the brown-out detection circuit 20 enters a brown-out mode. Specifically, the eighth high-voltage switching transistor HM8, the ninth high-voltage switching transistor HM9, the fourth switching transistor M4, and the fifth switching transistor M5 form a comparator to output a high level, the sixth switching transistor M6 is turned on, the signal at the input end of the third inverter INV3, that is, the first control signal control1, is at a low level, the signal at the output end of the third inverter INV3, that is, the second control signal control2, is at a high level, the first transmission gate TG1 is switched to an on state, the second transmission gate TG2 is turned to an off state, and the under-voltage threshold providing circuit 21 outputs a larger first under-voltage threshold vbias_1 to the under-voltage comparing circuit 22. The current under-voltage threshold Vref2 is the first under-voltage threshold Vbias_1.

Meanwhile, the high-level signal output by the third inverter INV3 is processed by the second trigger ST2 to generate a third under-voltage comparison signal, and the third under-voltage comparison signal is input to the enable end EN of the frequency divider 231 to start to perform frequency division timing on the clock signal CLK, if the high-voltage line voltage is always smaller than the first under-voltage threshold vbias_1 at the end of the frequency divider 231 timing, it is determined that the micro-grid is always in an under-voltage state, and the frequency divider 231 outputs the second under-voltage comparison signal of the high level at the end of timing. When the high voltage line voltage gradually rises and exceeds the first brown-out threshold value vbias_1, the brown-out detection circuit 20 exits the brown-out mode.

Therefore, the technical scheme improves the stability of undervoltage detection based on double undervoltage threshold detection and frequency division timing, and prevents undervoltage protection from false triggering.

The micro-grid line voltage abnormality detection circuit disclosed by the invention integrates line voltage overvoltage and undervoltage detection functions, has strong anti-interference performance, is compatible with a BCD (Bipolar-CMOS-DMOS, bipolar-complementary-Bipolar-metal oxide half field effect transistor technology) integrated circuit technology, and can be integrated in a power converter chip. Meanwhile, the line voltage detection range is enlarged based on the application of the high-voltage switching tube, and the detection circuit can be suitable for an application scene of a micro-grid through the parameter configuration of the high-voltage switching tube, for example, a line voltage fluctuation range of 43VAC-350VAC can be covered by using a high-voltage MOS tube of 20V. Therefore, the micro-grid line voltage detection circuit provided by the invention can realize overvoltage and undervoltage detection of line voltage, has strong anti-interference performance and wide voltage detection range, and can avoid the damage of electric loads and power converters caused by the large fluctuation of micro-grid voltage.

In summary, according to the micro-grid line voltage abnormality detection circuit provided by the embodiment of the invention, the abnormality detection circuit comprises an overvoltage detection circuit and an undervoltage detection circuit, the overvoltage detection circuit comprises a first high-voltage input circuit and an overvoltage comparison circuit, wherein the first high-voltage input circuit is connected with the micro-grid, the overvoltage comparison circuit is connected with the first high-voltage input circuit, the high-voltage line voltage of the micro-grid is converted into a low-voltage line voltage through the first high-voltage input circuit, the overvoltage comparison circuit compares the low-voltage line voltage with an overvoltage threshold value, and a first overvoltage comparison signal is output. Therefore, the circuit realizes overvoltage and undervoltage detection of the line voltage through the overvoltage detection circuit and the undervoltage detection circuit, can provide a larger line voltage fluctuation detection range, meets the line voltage detection requirement of the micro-grid, and improves the electricity safety in the micro-grid environment.

Corresponding to the embodiment, the invention further provides a micro-grid energy management system.

As shown in fig. 6, the micro grid energy management system 100 according to the embodiment of the present invention includes the micro grid line voltage abnormality detection circuit 110 described above.

According to the micro-grid energy management system provided by the embodiment of the invention, based on the micro-grid line voltage abnormality detection circuit, overvoltage and undervoltage detection of line voltage can be realized, a larger line voltage fluctuation detection range can be provided, the line voltage detection requirement of the micro-grid is met, and the electricity safety in the micro-grid environment is improved.

Corresponding to the embodiment, the invention also provides electric equipment.

As shown in fig. 7, the electric device 200 according to the embodiment of the present invention includes the micro-grid line voltage abnormality detection circuit 110 described above.

According to the electric equipment provided by the embodiment of the invention, based on the micro-grid line voltage abnormality detection circuit, overvoltage and undervoltage detection of line voltage can be realized, the electric equipment is prevented from being influenced by large fluctuation of the line voltage of the micro-grid, and the electricity safety is improved.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.

Claims (20)

1. A micro-grid line voltage abnormality detection circuit, characterized in that the abnormality detection circuit includes an overvoltage detection circuit and an undervoltage detection circuit, the overvoltage detection circuit includes:

the first high-voltage input circuit is connected with the micro-grid and used for converting the high-voltage line voltage of the micro-grid into low-voltage line voltage;

and the overvoltage comparison circuit is connected with the first high-voltage input circuit, and is used for comparing the low-voltage line voltage with an overvoltage threshold value and outputting a first overvoltage comparison signal.

2. The micro grid line voltage abnormality detection circuit according to claim 1, wherein the first high voltage input circuit includes:

the input end of the voltage stabilizing control circuit is connected with the micro-grid and used for generating a voltage stabilizing control signal based on the high-voltage line voltage;

the control end of the first high-voltage conversion circuit is connected with the output end of the voltage stabilizing control circuit, the input end of the first high-voltage conversion circuit is connected with the micro-grid, and the output end of the first high-voltage conversion circuit is connected with the input end of the overvoltage comparison circuit and used for converting the high-voltage line voltage into the low-voltage line voltage based on the voltage stabilizing control signal.

3. The micro-grid line voltage abnormality detection circuit according to claim 2, wherein the voltage stabilization control circuit includes: a first resistor, a first high voltage switch tube and at least one first diode, wherein,

one end of the first resistor is connected with the micro-grid, and the other end of the first resistor is connected with the control end of the first high-voltage conversion circuit;

the first end and the second end of the first high-voltage switch tube are respectively connected with the other end of the first resistor;

at least one first diode is connected in series in the same direction, and an anode after being connected in series is connected with a third end of the first high-voltage switch tube, and a cathode after being connected in series is grounded.

4. A micro grid line voltage abnormality detection circuit according to claim 2 or 3, characterized in that the first high voltage conversion circuit includes: the first end of the second high-voltage switch tube is connected with the output end of the voltage stabilizing control circuit, the second end of the second high-voltage switch tube is connected with the input end of the overvoltage comparison circuit, and the third end of the second high-voltage switch tube is connected with the micro-grid.

5. The micro grid line voltage abnormality detection circuit according to claim 2, wherein the overvoltage comparison circuit includes:

An overvoltage threshold value providing circuit for providing the overvoltage threshold value;

the threshold input end of the overvoltage comparison sub-circuit is connected with the overvoltage threshold providing circuit, and the input end of the overvoltage comparison sub-circuit is connected with the output end of the first high-voltage conversion circuit and is used for comparing the low-voltage line voltage with the overvoltage threshold and outputting a second overvoltage comparison signal;

and the input end of the overvoltage output circuit is connected with the output end of the overvoltage comparison sub-circuit and is used for converting the second overvoltage comparison signal into the first overvoltage comparison signal and outputting the first overvoltage comparison signal.

6. The micro-grid line voltage anomaly detection circuit of claim 5, wherein the overvoltage comparison sub-circuit comprises: at least one second diode, a voltage stabilizing tube, a first switching tube, a second resistor, a first inverter and a second inverter, wherein,

at least one second diode is connected in series in the same direction, the anode after being connected in series is connected with the output end of the first high-voltage conversion circuit, and the cathode after being connected in series is connected with the cathode of the voltage stabilizing tube;

the first end of the first switching tube is connected with the anode of the voltage stabilizing tube and the overvoltage threshold value providing circuit respectively, the second end of the first switching tube is connected with one end of the second resistor, and the third end of the first switching tube is grounded;

The other end of the second resistor is connected with a first power supply;

the input end of the first inverter is connected with the second end of the first switching tube;

the input end of the second inverter is connected with the output end of the first inverter, and the output end of the second inverter is connected with the input end of the overvoltage output circuit.

7. The micro-grid line voltage abnormality detection circuit according to claim 6, wherein the overvoltage threshold value providing circuit includes: a third resistor, a second switching tube, a fourth resistor, a fifth resistor and a third switching tube, wherein,

one end of the third resistor is connected with the anode of the voltage stabilizing tube and the first end of the first switching tube respectively;

the first end of the second switching tube is connected with the second end of the first switching tube, the second end of the second switching tube is connected with the other end of the third resistor, and the third end of the second switching tube is grounded;

one end of the fourth resistor is connected with the other end of the third resistor;

one end of the fifth resistor is connected with the other end of the fourth resistor, and the other end of the fifth resistor is grounded;

the first end of the third switching tube is connected with the output end of the second inverter, the second end of the third switching tube is connected with the other end of the fourth resistor, and the third end of the third switching tube is grounded.

8. The micro grid line voltage abnormality detection circuit according to claim 5, wherein the overvoltage output circuit includes:

the input end of the level conversion circuit is connected with the output end of the overvoltage comparison sub-circuit and is used for converting the second overvoltage comparison signal into a corresponding logic level;

and the input end of the first trigger is connected with the output end of the level conversion circuit and is used for generating and outputting the first overvoltage comparison signal based on the logic level.

9. The micro grid line voltage abnormality detection circuit according to claim 6, wherein the overvoltage detection circuit further comprises: and the first power supply circuit is respectively connected with the output end of the voltage stabilizing control circuit and the micro-grid and is used for providing the first power supply.

10. The micro-grid line voltage abnormality detection circuit according to claim 9, wherein the first power supply circuit includes: a third high-voltage switching tube and a fourth high-voltage switching tube, wherein,

the first end of the third high-voltage switching tube is connected with the output end of the voltage stabilizing control circuit, and the third end of the third high-voltage switching tube is connected with the other end of the second resistor to provide the first power supply;

The first end of the fourth high-voltage switch tube is connected with the second end of the fourth high-voltage switch tube and the second end of the third high-voltage switch tube respectively, and the third end of the fourth high-voltage switch tube is connected with the micro-grid; the control end of the first high-voltage conversion circuit is connected with the second end of the third high-voltage switching tube.

11. The micro grid line voltage abnormality detection circuit according to claim 10, wherein the overvoltage detection circuit further comprises:

the second power supply circuit is respectively connected with the output end of the voltage stabilizing control circuit, the micro-grid and the positive power supply end of the first inverter and is used for supplying power to the first inverter;

and the third power supply circuit is respectively connected with the output end of the voltage stabilizing control circuit, the micro power grid and the positive power supply end of the second inverter and is used for supplying power to the second inverter.

12. The micro-grid line voltage abnormality detection circuit according to claim 11, wherein the second power supply circuit includes: a fifth high-voltage switching tube and a sixth high-voltage switching tube, wherein,

the first end of the fifth high-voltage switching tube is connected with the second end of the fourth high-voltage switching tube, and the third end of the fifth high-voltage switching tube is connected with the micro-grid;

The first end of the sixth high-voltage switching tube is connected with the output end of the voltage stabilizing control circuit, the second end of the sixth high-voltage switching tube is connected with the second end of the fifth high-voltage switching tube, and the third end of the sixth high-voltage switching tube is connected with the positive power supply end of the first inverter.

13. The micro-grid line voltage abnormality detection circuit according to claim 11, wherein the third power supply circuit includes: a sixth resistor, a seventh high voltage switching tube and a seventh resistor, wherein,

one end of the sixth resistor is connected with the micro-grid;

the first end of the seventh high-voltage switching tube is connected with the output end of the voltage stabilizing control circuit, and the second end of the seventh high-voltage switching tube is connected with the other end of the sixth resistor;

one end of the seventh resistor is connected with the third end of the seventh high-voltage switching tube, and the other end of the seventh resistor is connected with the positive power supply end of the second inverter.

14. The micro-grid line voltage abnormality detection circuit according to claim 1, characterized in that the undervoltage detection circuit includes:

an under-voltage threshold providing circuit for providing an under-voltage threshold;

the input end of the undervoltage comparison circuit is connected with the micro-grid and is used for comparing the high-voltage line voltage with the undervoltage threshold and outputting a first undervoltage comparison signal;

And the input end of the undervoltage output circuit is connected with the output end of the undervoltage comparison circuit and is used for generating and outputting a second undervoltage comparison signal based on the first undervoltage comparison signal.

15. The micro-grid line voltage anomaly detection circuit of claim 14, wherein the brown-out threshold providing circuit comprises: a first transmission gate and a second transmission gate, wherein,

the forward control end of the first transmission gate is used for inputting a first control signal, the reverse control end of the first transmission gate is used for inputting a second control signal opposite to the first control signal, the input end of the first transmission gate is used for inputting a first undervoltage threshold value, and the output end of the first transmission gate is connected with the threshold value input end of the undervoltage comparison circuit;

the forward control end of the second transmission gate is used for inputting the second control signal, the reverse control end of the second transmission gate is used for inputting the first control signal, the input end of the second transmission gate is used for inputting a second undervoltage threshold value, and the output end of the second transmission gate is connected with the threshold value input end of the undervoltage comparison circuit.

16. The micro-grid line voltage anomaly detection circuit of claim 14, wherein the brown-out comparison circuit comprises: a first current source, an eighth high-voltage switching tube, a ninth high-voltage switching tube, a fourth switching tube, a fifth switching tube, a sixth switching tube, a seventh switching tube and a third inverter, wherein,

The first end of the eighth high-voltage switching tube is connected with the micro-grid, the first end of the ninth high-voltage switching tube is connected with the undervoltage threshold providing circuit, the third end of the eighth high-voltage switching tube and the third end of the ninth high-voltage switching tube are respectively connected with one end of the first current source, and the other end of the first current source is connected with the second power supply;

the first end of the fourth switching tube, the first end of the fifth switching tube, the second end of the fifth switching tube and the second end of the ninth high-voltage switching tube are connected, the second end of the fourth switching tube is connected with the second end of the eighth high-voltage switching tube, and the third end of the fourth switching tube and the third end of the fifth switching tube are grounded;

the first end of the sixth switching tube is connected with the second end of the fourth switching tube, the second end of the sixth switching tube, the first end of the seventh switching tube, the second end of the seventh switching tube and the input end of the third inverter are connected, the third end of the sixth switching tube is grounded, and the third end of the seventh switching tube is connected with the second power supply;

the output end of the third inverter is connected with the undervoltage output circuit.

17. The micro-grid line voltage anomaly detection circuit of claim 16, wherein the brown-out detection circuit further comprises: a second current source, a third diode and an eighth resistor, wherein,

one end of the second current source is connected with the second power supply;

the anode of the third diode is connected with the other end of the second current source, and the cathode of the third diode is connected with the first end of the eighth high-voltage switching tube;

the eighth resistor is connected between the first end of the eighth high-voltage switching tube and the ground.

18. The micro-grid line voltage abnormality detection circuit according to any one of claims 14 to 17, wherein the undervoltage output circuit includes: a second flip-flop, and a frequency divider, wherein,

the input end of the second trigger is connected with the output end of the undervoltage comparison circuit and is used for generating a third undervoltage comparison signal based on the first undervoltage comparison signal;

the enabling end of the frequency divider is connected with the output end of the second trigger, the clock signal end of the frequency divider is used for inputting a clock signal, dividing the frequency of the clock signal based on the third under-voltage comparison signal, and outputting the second under-voltage comparison signal based on a frequency division result.

19. A microgrid energy management system comprising a microgrid line voltage anomaly detection circuit according to any one of claims 1 to 18.

20. A powered device comprising a microgrid line voltage anomaly detection circuit according to any one of claims 1 to 18.