Dual-power-supply low-voltage power distribution system

Abstract

The utility model provides a dual-power low-voltage power distribution system. The dual-power-supply low-voltage power distribution system comprises a main power supply and a standby power supply, and the standby power supply comprises a controller, a battery, a DC-DC circuit, a DC-AC circuit and a main power supply voltage detection module. The main power supply voltage detection module comprises a main power supply voltage acquisition circuit, a first rectifier bridge, a first subtraction circuit, a first absolute value detection circuit, a first comparator and a second comparator which are connected in sequence, and the main power supply voltage acquisition circuit is used for acquiring main power supply voltage in real time; the first input end of the first subtraction circuit is connected with the output end of the first rectifier bridge, the second end of the first subtraction circuit is connected with the first reference voltage, and the output end of the first subtraction circuit is connected to the input end of the first absolute value detection circuit. The problem of long switching time between the main power supply and the standby power supply in the existing dual-power-supply low-voltage power distribution system can be solved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of power distribution automation, and in particular to a dual-power supply low-voltage power distribution system. Background Art

[0002] A dual-source low-voltage power distribution system primarily consists of two independent power sources (primary and backup), a dual-source automatic transfer system (ATS), a load balancer, control logic, and an alarm and monitoring system. This system automatically and quickly switches the load to the backup source in the event of a primary power failure, ensuring continuous and reliable power supply.

[0003] Rapid switching between primary and backup power sources can minimize power outages and prevent load equipment from shutting down or being damaged during power switching. Therefore, to further ensure power supply reliability, further improvements are needed to the dual-power low-voltage distribution system to reduce the switching time between primary and backup power sources. Utility Model Content

[0004] The embodiments of the present disclosure provide a dual-power low-voltage power distribution system to solve the problem of long switching time between a main power supply and a backup power supply in existing dual-power low-voltage power distribution systems.

[0005] The present disclosure provides a dual-power low-voltage power distribution system, including a main power supply and a backup power supply, wherein the backup power supply includes a controller, a battery, a DC-DC circuit, a DC-AC circuit, and a main power voltage detection module.

[0006] The main power supply voltage detection module includes a main power supply voltage acquisition circuit, a first rectifier bridge, a first subtraction circuit, a first absolute value detection circuit, a first comparator and a second comparator connected in sequence.

[0007] The main power supply voltage acquisition circuit is used to acquire the main power supply voltage in real time. The first input end of the first subtraction circuit is connected to the output end of the first rectifier bridge, the second end of the first subtraction circuit is connected to the first reference voltage, and the output end of the first subtraction circuit is connected to the input end of the first absolute value detection circuit.

[0008] The first input terminal of the first comparator is connected to the output terminal of the first absolute value detection circuit, the second input terminal of the first comparator is connected to the second reference voltage, and the output terminal of the first comparator is the first output terminal of the main power supply voltage detection module.

[0009] The first input terminal of the second comparator is connected to the output terminal of the first absolute value detection circuit, the second input terminal of the second comparator is connected to the third reference voltage, and the output terminal of the second comparator is the second output terminal of the main power supply voltage detection module.

[0010] The controller is configured to start the DC-DC circuit when the first output terminal of the main power voltage detection module is at a first level, and start the DC-AC circuit when the second output terminal of the main power voltage detection module is at a first level.

[0011] In an exemplary embodiment of the present disclosure, the dual-power low-voltage power distribution system further includes a main power current detection module, which includes a main power current acquisition circuit, a second rectifier bridge, a second subtraction circuit, a second absolute value detection circuit, a third comparator, and a fourth comparator connected in sequence.

[0012] The main power supply current acquisition circuit is used to acquire the main power supply current in real time. The first input end of the second subtraction circuit is connected to the output end of the second rectifier bridge, the second end of the second subtraction circuit is connected to the fourth reference voltage, and the output end of the second subtraction circuit is connected to the input end of the second absolute value detection circuit.

[0013] The first input terminal of the third comparator is connected to the output terminal of the second absolute value detection circuit, the second input terminal of the third comparator is connected to the fifth reference voltage, and the output terminal of the third comparator is the first output terminal of the main power supply current detection module.

[0014] The first input terminal of the fourth comparator is connected to the output terminal of the second absolute value detection circuit, the second input terminal of the fourth comparator is connected to the sixth reference voltage, and the output terminal of the fourth comparator is the second output terminal of the main power current detection module.

[0015] The controller is further configured to start the DC-DC circuit when the first output terminal of the main power current detection module is at a first level, and start the DC-AC circuit when the second output terminal of the main power current detection module is at a first level.

[0016] In an exemplary embodiment of the present disclosure, the dual-power low-voltage power distribution system further includes a main power frequency detection module, wherein the main power frequency detection module includes a phase-locked loop circuit, an F / V conversion circuit, a third subtraction circuit, a third absolute value detection circuit, a fifth comparator, and a sixth comparator connected in sequence.

[0017] The phase-locked loop circuit is used to collect the main power frequency, the first input end of the third subtraction circuit is connected to the output end of the F / V conversion circuit, the second end of the second subtraction circuit is connected to the seventh reference voltage, and the output end of the second subtraction circuit is connected to the input end of the third absolute value detection circuit.

[0018] The first input terminal of the fifth comparator is connected to the output terminal of the third absolute value detection circuit, the second input terminal of the fifth comparator is connected to the eighth reference voltage, and the output terminal of the fifth comparator is the first output terminal of the main power frequency detection module.

[0019] The first input terminal of the sixth comparator is connected to the output terminal of the third absolute value detection circuit, the second input terminal of the sixth comparator is connected to the ninth reference voltage, and the output terminal of the sixth comparator is the second output terminal of the main power frequency detection module.

[0020] The controller is further configured to start the DC-DC circuit when the first output terminal of the main power frequency detection module is at a first level, and to start the DC-AC circuit when the second output terminal of the main power frequency detection module is at a first level.

[0021] In an exemplary embodiment of the present disclosure, the dual-power low-voltage power distribution system further includes a first OR gate,

[0022] Multiple input terminals of the first OR gate are respectively connected to the first output terminals of the main power voltage detection module, the main power current detection module and the main power frequency detection module, and the output terminal of the first OR gate is connected to the controller.

[0023] In an exemplary embodiment of the present disclosure, the dual-power low-voltage power distribution system further includes a timer, which is used to regularly start a battery charging circuit and a battery discharging circuit of the backup power supply.

[0024] In an exemplary embodiment of the present disclosure, the dual-power low-voltage power distribution system further includes an overcharge detection circuit, which includes a fourth subtraction circuit, a bidirectional trigger diode, a first switch tube, and a second switch tube.

[0025] The first input end of the fourth subtraction circuit is connected to the positive electrode of the single cell battery, the second input end of the fourth subtraction circuit is connected to the negative electrode of the single cell battery, the output end of the fourth subtraction circuit is connected to the first end of the bidirectional trigger diode, the second end of the bidirectional trigger diode is connected to the control end of the first switching tube, the second end of the first switching tube is grounded, the first end of the first switching tube is connected to the control end of the second switching tube, the first end of the second switching tube is connected to the negative electrode of the single cell battery, and the second end of the second switching tube is connected to the positive electrode of the single cell battery through the resistor R16.

[0026] In an exemplary embodiment of the present disclosure, the dual-power low-voltage distribution system further includes a filter circuit, which includes a resistor R13 and a capacitor C1.

[0027] A first end of the resistor R13 is connected to the output end of the fourth subtraction circuit, a second end of the resistor R13 is grounded via the capacitor C1, and the second end of the resistor R13 is the output end of the filter circuit.

[0028] The present disclosure provides a dual-power low-voltage power distribution system, the working principle and beneficial effects of which are as follows:

[0029] In an embodiment of the present disclosure, the backup power supply includes a controller, a DC-DC circuit, and a DC-AC circuit, wherein the DC-DC circuit is used to boost the DC power output by the battery, and the DC-AC circuit is used to convert the DC voltage (i.e., the bus voltage) output by the DC-DC circuit into an AC voltage to power the load.

[0030] The real-time value of the main power supply voltage collected by the main power supply voltage acquisition circuit passes through the first rectifier bridge to obtain the effective value of the main power supply voltage. The effective value of the main power supply voltage is input to the first input of the first subtraction circuit. The first subtraction circuit calculates a first difference between the effective value of the main power supply voltage and a first reference voltage. The magnitude of the first reference voltage can be calculated based on the effective value of the rated voltage of the main power supply. The output of the first subtraction circuit is connected to the input of the first absolute value detection circuit, which outputs the absolute value of the first difference. The output of the first absolute value detection circuit is respectively connected to the first input of the second comparator of the first comparator. When the absolute value of the first difference is greater than the second reference voltage, the first comparator outputs a high-level signal to the controller. At this time, the controller determines that the main power supply voltage is about to enter a fault state. The controller activates the DC-DC circuit and increases the bus voltage to a set value in advance. When the absolute value of the first difference continues to increase and exceeds the third reference voltage, it is necessary to switch the main power supply to the backup power supply. In this way, the bus voltage is increased to the set value in advance, which saves the time of starting the DC-DC circuit, which helps to reduce the switching time and avoid excessive switching time that affects the normal operation of the load. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0032] Figure 1 is a circuit schematic diagram of a main power supply voltage detection module provided in an embodiment of the present disclosure;

[0033] Figure 2 is a circuit schematic diagram of a main power current detection module provided by an embodiment of the present disclosure;

[0034] Figure 3 is a circuit schematic diagram of a main power frequency detection module provided by an embodiment of the present disclosure;

[0035] Figure 4 is a circuit schematic diagram of a first OR gate and a second OR gate provided by an embodiment of the present disclosure;

[0036] Figure 5 1 is a circuit schematic diagram of a battery charging circuit provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0037] To help those skilled in the art better understand this solution, the following will clearly describe the technical solutions in the embodiments of this solution in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of this solution, not all of it. Based on the embodiments of this solution, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of this solution.

[0038] Throughout the specification, claims, and accompanying figures of this solution, the term "including" and any variations thereof mean "including, but not limited to," and are intended to cover non-exclusive inclusions and are not limited to the examples listed herein. Furthermore, the terms "first" and "second," etc., are used to distinguish between different objects, not to describe a specific order.

[0039] The following describes the implementation of the present disclosure in detail with reference to the accompanying drawings:

[0040] The dual-power low-voltage power distribution system includes a main power supply and a backup power supply, wherein the backup power supply includes a controller, a battery, a DC-DC circuit, a DC-AC circuit and a main power supply voltage detection module. Figure 1 The main power supply voltage detection module includes a main power supply voltage acquisition circuit, a first rectifier bridge, a first subtraction circuit, a first absolute value detection circuit, a first comparator and a second comparator connected in sequence.

[0041] The main power supply voltage acquisition circuit is used to acquire the main power supply voltage in real time. The first input end of the first subtraction circuit is connected to the output end of the first rectifier bridge, the second end of the first subtraction circuit is connected to the first reference voltage, and the output end of the first subtraction circuit is connected to the input end of the first absolute value detection circuit.

[0042] The first input terminal of the first comparator is connected to the output terminal of the first absolute value detection circuit, the second input terminal of the first comparator is connected to the second reference voltage, and the output terminal of the first comparator is the first output terminal of the main power supply voltage detection module.

[0043] The first input terminal of the second comparator is connected to the output terminal of the first absolute value detection circuit, the second input terminal of the second comparator is connected to the third reference voltage, and the output terminal of the second comparator is the second output terminal of the main power supply voltage detection module.

[0044] The controller is configured to start the DC-DC circuit when the first output terminal of the main power voltage detection module is at a first level, and to start the DC-AC circuit when the second output terminal of the main power voltage detection module is at a first level.

[0045] In this embodiment, the backup power supply includes a controller, a DC-DC circuit, and a DC-AC circuit. The DC-DC circuit is used to boost the DC power output by the battery, and the DC-AC circuit is used to convert the DC voltage (i.e., the bus voltage) output by the DC-DC circuit into an AC voltage to power the load.

[0046] The main power supply voltage acquisition circuit includes a voltage sensor and a first amplifier circuit connected in sequence. The voltage sensor senses the main power supply voltage, and the first amplifier circuit amplifies the voltage signal output by the voltage sensor for processing by subsequent circuits. Resistors R1, R2, and R3, along with op amp U1A, form a first subtraction circuit.

[0047] The real-time value of the main power supply voltage collected by the main power supply voltage acquisition circuit passes through the first rectifier bridge to obtain the effective value of the main power supply voltage. The effective value of the main power supply voltage is input to the first input of the first subtraction circuit. The first subtraction circuit calculates a first difference between the effective value of the main power supply voltage and a first reference voltage. The magnitude of the first reference voltage can be calculated based on the effective value of the rated voltage of the main power supply. The output of the first subtraction circuit is connected to the input of the first absolute value detection circuit, which outputs the absolute value of the first difference. The output of the first absolute value detection circuit is respectively connected to the first input of the first comparator U2A and the second comparator U2B. When the absolute value of the first difference is greater than the second reference voltage, the first comparator U2A outputs a high-level signal to the controller. At this time, the controller determines that the main power supply voltage is about to enter a fault state. The controller activates the DC-DC circuit and increases the bus voltage to a set value in advance. When the absolute value of the first difference continues to increase and exceeds the third reference voltage, it is necessary to switch the main power supply to the backup power supply. In this way, the bus voltage is increased to the set value in advance, which saves the time of starting the DC-DC circuit, which helps to reduce the switching time and avoid excessive switching time that affects the normal operation of the load.

[0048] Among them, the operational amplifier U1B, the operational amplifier U1C, the resistor R21, the resistor R4 and the diode D1 constitute a first absolute value detection circuit, and its working principle is: when the output voltage of the first subtraction circuit (that is, the first difference) is greater than zero, the output terminal of the operational amplifier U1B is low, the diode D1 is cut off, and the output voltage of the first subtraction circuit is connected to the non-inverting input terminal of the operational amplifier U1C through the resistor R21 and the resistor R4. The operational amplifier U1C constitutes a voltage follower, and the output voltage of the operational amplifier U1C is equal to the output voltage of the first subtraction circuit. When the output voltage of the first subtraction circuit (i.e., the first difference) is less than zero, the output terminal of op amp U1B is high, diode D1 is conductive, and resistors R21, R4, and op amp U1B form an inverting proportional amplifier circuit. The resistance values of resistors R21 and R4 can be set equal, and the amplification factor of the inverting proportional amplifier circuit is -1. Op amp U1B outputs a voltage signal opposite to the first difference, and op amp U1C forms a voltage follower, outputting a voltage signal opposite to the first difference. In other words, the above process calculates the absolute value of the first difference.

[0049] Reference Figure 2 In an exemplary embodiment of the present disclosure, a dual-power low-voltage power distribution system further includes a main power current detection module, which includes a main power current acquisition circuit, a second rectifier bridge, a second subtraction circuit, a second absolute value detection circuit, a third comparator, and a fourth comparator connected in sequence.

[0050] The main power supply current acquisition circuit is used to acquire the main power supply current in real time. The first input end of the second subtraction circuit is connected to the output end of the second rectifier bridge, the second end of the second subtraction circuit is connected to the fourth reference voltage, and the output end of the second subtraction circuit is connected to the input end of the second absolute value detection circuit.

[0051] The first input terminal of the third comparator is connected to the output terminal of the second absolute value detection circuit, the second input terminal of the third comparator is connected to the fifth reference voltage, and the output terminal of the third comparator is the first output terminal of the main power supply current detection module.

[0052] The first input terminal of the fourth comparator is connected to the output terminal of the second absolute value detection circuit, the second input terminal of the fourth comparator is connected to the sixth reference voltage, and the output terminal of the fourth comparator is the second output terminal of the main power supply current detection module.

[0053] The controller is further configured to start the DC-DC circuit when the first output terminal of the main power current detection module is at a first level, and to start the DC-AC circuit when the second output terminal of the main power current detection module is at a first level.

[0054] The main power supply current acquisition circuit includes a current sensor and a second amplifier circuit connected in sequence. The current sensor senses the main power supply's output current, and the second amplifier circuit amplifies the voltage signal output by the current sensor for processing by subsequent circuits. Resistors R7, R8, and R6, along with op amp U3A, form the second subtraction circuit.

[0055] The real-time value of the main power supply current collected by the main power supply current acquisition circuit passes through the second rectifier bridge to obtain the effective value of the main power supply current. The effective value of the main power supply current is input to the first input of the second subtraction circuit. The second subtraction circuit calculates the second difference between the effective value of the main power supply current and the fourth reference voltage. The magnitude of the fourth reference voltage can be calculated based on the effective value of the rated current of the main power supply. The output of the second subtraction circuit is connected to the input of the second absolute value detection circuit, which outputs the absolute value of the second difference. The output of the second absolute value detection circuit is respectively connected to the first input of the third comparator U4A and the fourth comparator U4B. When the absolute value of the second difference is greater than the fifth reference voltage, the third comparator U4A outputs a high-level signal to the controller. At this time, the controller determines that the main power supply current is about to enter a fault state. The controller starts the DC-DC circuit and increases the bus voltage to a set value in advance. When the absolute value of the second difference continues to increase and exceeds the sixth reference voltage, it is necessary to switch the main power supply to the backup power supply. Raising the bus voltage to the set value in advance can save the time of starting the DC-DC circuit, which is conducive to reducing the switching time and avoiding excessive switching time that affects the normal operation of the load.

[0056] Among them, the resistor R22, the resistor R5, the diode D2, the operational amplifier U3B and the operational amplifier U3C constitute the second absolute value detection circuit, and its working principle is the same as that of the first absolute value detection circuit, which will not be described here.

[0057] Reference Figure 3 In an exemplary embodiment of the present disclosure, a dual-power low-voltage power distribution system further includes a main power frequency detection module, which includes a phase-locked loop circuit, an F / V conversion circuit, a third subtraction circuit, a third absolute value detection circuit, a fifth comparator, and a sixth comparator connected in sequence.

[0058] The phase-locked loop circuit is used to collect the main power frequency. The first input end of the third subtraction circuit is connected to the output end of the F / V conversion circuit. The second end of the second subtraction circuit is connected to the seventh reference voltage. The output end of the second subtraction circuit is connected to the input end of the third absolute value detection circuit.

[0059] The first input terminal of the fifth comparator is connected to the output terminal of the third absolute value detection circuit, the second input terminal of the fifth comparator is connected to the eighth reference voltage, and the output terminal of the fifth comparator is the first output terminal of the main power frequency detection module.

[0060] The first input terminal of the sixth comparator is connected to the output terminal of the third absolute value detection circuit, the second input terminal of the sixth comparator is connected to the ninth reference voltage, and the output terminal of the sixth comparator is the second output terminal of the main power frequency detection module.

[0061] The controller is further configured to start the DC-DC circuit when the first output terminal of the main power frequency detection module is at a first level, and to start the DC-AC circuit when the second output terminal of the main power frequency detection module is at a first level.

[0062] In this embodiment, a phase-locked loop circuit is used to acquire the frequency of the main power supply. The frequency signal output by the phase-locked loop circuit is converted into a voltage signal by an F / V conversion circuit, where the F / V conversion circuit can be implemented using an existing LM331, AD7740, or the like. The voltage signal output by the F / V conversion circuit is connected to the first input of a third subtraction circuit. The third subtraction circuit calculates a third difference between a voltage corresponding to the main power supply frequency and a seventh reference voltage. The magnitude of the seventh reference voltage can be calculated based on the rated frequency of the main power supply. The output of the third subtraction circuit is connected to the input of a third absolute value detection circuit, which outputs the absolute value of the third difference. The output ends of the third absolute value detection circuit are respectively connected to the first input ends of the sixth comparator U5B of the fifth comparator U5A. When the absolute value of the third difference is greater than the eighth reference voltage, the fifth comparator U5A outputs a high-level signal to the controller. At this time, the controller determines that the main power current is about to enter a fault state, and the controller starts the DC-DC circuit to increase the bus voltage to a set value in advance. When the absolute value of the third difference continues to increase and is greater than the ninth reference voltage, it is necessary to switch the main power supply to the backup power supply. Raising the bus voltage to the set value in advance can save the time for starting the DC-DC circuit, which is beneficial to reducing the switching time and avoiding excessive switching time that affects the normal operation of the load.

[0063] Among them, resistor R23, resistor R20, diode D4, operational amplifier U9B and operational amplifier U9C constitute a third absolute value detection circuit, and its working principle is the same as that of the first absolute value detection circuit, which will not be repeated here.

[0064] Reference Figure 4 In an exemplary embodiment of the present disclosure, a dual-power low-voltage power distribution system further includes a first OR gate.

[0065] Multiple input terminals of the first OR gate are respectively connected to the first output terminals of the main power voltage detection module, the main power current detection module and the main power frequency detection module, and the output terminal of the first OR gate is connected to the controller.

[0066] In this embodiment, the first output terminals of the main power supply voltage detection module, the main power supply current detection module, and the main power supply frequency detection module are respectively connected to the three input terminals of the first OR gate U7. A high-level signal output by any of the main power supply voltage detection module, the main power supply current detection module, and the main power supply frequency detection module causes the first OR gate U7 to output a high-level signal, triggering the controller to activate the DC-DC circuit. Therefore, the provision of the first OR gate U7 facilitates timely activation of the DC-DC circuit.

[0067] Similarly, the second output ends of the main power supply voltage detection module, the main power supply current detection module and the main power supply frequency detection module are respectively connected to the three input ends of the second OR gate U8. The high-level signal output by any module among the main power supply voltage detection module, the main power supply current detection module and the main power supply frequency detection module will cause the second OR gate U8 to output a high-level signal, triggering the controller to start the DC-AC circuit.

[0068] In an exemplary embodiment of the present disclosure, a dual-power low-voltage power distribution system further includes a timer, which is used to regularly start a battery charging circuit and a battery discharging circuit of the backup power supply.

[0069] In this embodiment, the backup power battery can be charged and discharged regularly by setting a timer, thereby preventing the battery from not working for a long time and causing the battery performance to deteriorate.

[0070] Reference Figure 5 In an exemplary embodiment of the present disclosure, a dual-power low-voltage power distribution system further includes an overcharge detection circuit, which includes a fourth subtraction circuit, a bidirectional trigger diode, a first switch tube, and a second switch tube.

[0071] A first input end of the fourth subtraction circuit is connected to the positive electrode of the single cell battery, a second input end of the fourth subtraction circuit is connected to the negative electrode of the single cell battery, an output end of the fourth subtraction circuit is connected to the first end of the bidirectional trigger diode, a second end of the bidirectional trigger diode is connected to the control end of the first switch tube, a second end of the first switch tube is grounded, a first end of the first switch tube is connected to the control end of the second switch tube, a first end of the second switch tube is connected to the negative electrode of the single cell battery, and a second end of the second switch tube is connected to the positive electrode of the single cell battery via a resistor R16.

[0072] In this embodiment, using overcharge detection of battery cell BAT2 as an example, resistors R10, R12, and R11, along with op amp U6A, form a fourth subtraction circuit. The output terminal of op amp U6A outputs the voltage across battery cell BAT2. When battery cell BAT2 is overcharged, the output voltage of op amp U6A exceeds the forward voltage of diac D3, causing diac D3 to conduct. This turns on the first switch Q1, pulling the control terminal of the second switch Q2 low. This turns on the second switch Q2, allowing battery cell BAT2 to discharge through resistor R11. When battery cell BAT2 discharges to its normal charging voltage, the output voltage of op amp U6A falls below the forward voltage of diac D3, causing diac D3 to turn off. This turns on the first switch Q1 and the second switch Q2, halting discharge of battery cell BAT2.

[0073] It can be concluded from the above that the arrangement of the fourth subtraction circuit, the bidirectional trigger diode, the first switch tube and the second switch tube in this embodiment avoids overcharging of the single battery cell, which is conducive to extending the service life of the battery.

[0074] In an exemplary embodiment of the present disclosure, a dual-power low-voltage power distribution system further includes a filter circuit, which includes a resistor R13 and a capacitor C1.

[0075] A first end of the resistor R13 is connected to the output end of the fourth subtraction circuit, a second end of the resistor R13 is grounded via the capacitor C1 , and the second end of the resistor R13 is the output end of the filter circuit.

[0076] In this embodiment, the resistor R13 and the capacitor C1 form a low-pass filter circuit, which can filter out high-frequency interference signals at the output of the operational amplifier U6A and prevent the interference signals from causing the bidirectional trigger diode D3 to be mis-conducted.

[0077] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present disclosure.

Claims

1. A dual-power low-voltage power distribution system, characterized in that: It includes a main power supply and a backup power supply, wherein the backup power supply includes a controller, a battery, a DC-DC circuit, a DC-AC circuit and a main power supply voltage detection module. The main power supply voltage detection module includes a main power supply voltage acquisition circuit, a first rectifier bridge, a first subtraction circuit, a first absolute value detection circuit, a first comparator and a second comparator connected in sequence. The main power supply voltage acquisition circuit is used to acquire the main power supply voltage in real time. The first input end of the first subtraction circuit is connected to the output end of the first rectifier bridge, the second end of the first subtraction circuit is connected to the first reference voltage, and the output end of the first subtraction circuit is connected to the input end of the first absolute value detection circuit. The first input terminal of the first comparator is connected to the output terminal of the first absolute value detection circuit, the second input terminal of the first comparator is connected to the second reference voltage, and the output terminal of the first comparator is the first output terminal of the main power supply voltage detection module. The first input terminal of the second comparator is connected to the output terminal of the first absolute value detection circuit, the second input terminal of the second comparator is connected to the third reference voltage, and the output terminal of the second comparator is the second output terminal of the main power supply voltage detection module. The controller is configured to start the DC-DC circuit when the first output terminal of the main power voltage detection module is at a first level, and start the DC-AC circuit when the second output terminal of the main power voltage detection module is at a first level.

2. A dual-power low-voltage power distribution system according to claim 1, characterized in that: The main power supply current detection module further includes a main power supply current detection module, which includes a main power supply current acquisition circuit, a second rectifier bridge, a second subtraction circuit, a second absolute value detection circuit, a third comparator and a fourth comparator connected in sequence. The main power supply current acquisition circuit is used to acquire the main power supply current in real time. The first input end of the second subtraction circuit is connected to the output end of the second rectifier bridge, the second end of the second subtraction circuit is connected to the fourth reference voltage, and the output end of the second subtraction circuit is connected to the input end of the second absolute value detection circuit. The first input terminal of the third comparator is connected to the output terminal of the second absolute value detection circuit, the second input terminal of the third comparator is connected to the fifth reference voltage, and the output terminal of the third comparator is the first output terminal of the main power supply current detection module. The first input terminal of the fourth comparator is connected to the output terminal of the second absolute value detection circuit, the second input terminal of the fourth comparator is connected to the sixth reference voltage, and the output terminal of the fourth comparator is the second output terminal of the main power current detection module. The controller is further configured to start the DC-DC circuit when the first output terminal of the main power current detection module is at a first level, and start the DC-AC circuit when the second output terminal of the main power current detection module is at a first level.

3. A dual-power low-voltage power distribution system according to claim 2, characterized in that: The main power frequency detection module is further included, and the main power frequency detection module includes a phase-locked loop circuit, an F / V conversion circuit, a third subtraction circuit, a third absolute value detection circuit, a fifth comparator and a sixth comparator connected in sequence. The phase-locked loop circuit is used to collect the main power frequency, the first input end of the third subtraction circuit is connected to the output end of the F / V conversion circuit, the second end of the second subtraction circuit is connected to the seventh reference voltage, and the output end of the second subtraction circuit is connected to the input end of the third absolute value detection circuit. The first input terminal of the fifth comparator is connected to the output terminal of the third absolute value detection circuit, the second input terminal of the fifth comparator is connected to the eighth reference voltage, and the output terminal of the fifth comparator is the first output terminal of the main power frequency detection module. The first input terminal of the sixth comparator is connected to the output terminal of the third absolute value detection circuit, the second input terminal of the sixth comparator is connected to the ninth reference voltage, and the output terminal of the sixth comparator is the second output terminal of the main power frequency detection module. The controller is further configured to start the DC-DC circuit when the first output terminal of the main power frequency detection module is at a first level, and to start the DC-AC circuit when the second output terminal of the main power frequency detection module is at a first level.

4. A dual-power low-voltage power distribution system according to claim 3, characterized in that: Also includes the first OR gate, Multiple input terminals of the first OR gate are respectively connected to the first output terminals of the main power voltage detection module, the main power current detection module and the main power frequency detection module, and the output terminal of the first OR gate is connected to the controller.

5. A dual-power low-voltage power distribution system according to claim 1, characterized in that: The device also includes a timer, which is used to regularly start the battery charging circuit and the battery discharging circuit of the backup power supply.

6. A dual-power low-voltage power distribution system according to claim 1, characterized in that: It also includes an overcharge detection circuit, which includes a fourth subtraction circuit, a bidirectional trigger diode, a first switch tube and a second switch tube. The first input end of the fourth subtraction circuit is connected to the positive electrode of the single cell battery, the second input end of the fourth subtraction circuit is connected to the negative electrode of the single cell battery, the output end of the fourth subtraction circuit is connected to the first end of the bidirectional trigger diode, the second end of the bidirectional trigger diode is connected to the control end of the first switching tube, the second end of the first switching tube is grounded, the first end of the first switching tube is connected to the control end of the second switching tube, the first end of the second switching tube is connected to the negative electrode of the single cell battery, and the second end of the second switching tube is connected to the positive electrode of the single cell battery through the resistor R16.

7. A dual-power low-voltage power distribution system according to claim 6, characterized in that: It also includes a filter circuit, which includes a resistor R13 and a capacitor C1. A first end of the resistor R13 is connected to the output end of the fourth subtraction circuit, a second end of the resistor R13 is grounded via the capacitor C1, and the second end of the resistor R13 is the output end of the filter circuit.

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