UPS input voltage protection device

Abstract

The utility model provides a UPS input voltage protection device. The UPS input voltage protection device comprises a power supply circuit, a comparison circuit, a voltage division circuit and a switching circuit, the voltage division circuit is electrically connected between the power supply circuit and the switching circuit; the comparison circuit comprises a high-voltage comparison circuit and a low-voltage comparison circuit; the high-voltage comparison circuit comprises a first voltage division circuit, a first diode and a first comparator; when the commercial power voltage is higher than a preset threshold range, the voltage division circuit outputs a low level, the switching circuit is switched off, and the UPS works in a battery mode; the low-voltage comparison circuit comprises a second voltage division circuit, a second diode and a second comparator; when the commercial power voltage is lower than a preset threshold range, the voltage division circuit outputs a low level, the switching circuit is switched off, and the UPS works in a battery mode.

Description

Technical Field

[0001] The present application relates to the field of UPS, and in particular to a UPS input voltage protection device. Background Art

[0002] In the mains mode, the mains goes through the input EMI filter and then goes to the rectifier module. The rectified DC voltage is boosted to a stable bus voltage, which is converted into a pure sine wave output by the inverter module and finally supplies power to the load after the output EMI filter. At the same time, the mains goes to the charging module to charge the battery.

[0003] In the prior art, general UPS is usually unable to withstand frequent high-voltage or low-voltage shocks. If the mains high voltage exceeding 300V continues to enter the UPS, it is easy to cause damage and failure of the internal power semiconductors, electrolytic capacitors and other parts of the UPS. Utility Model Content

[0004] The present application provides a UPS input voltage protection device to solve the problem that the internal parts of the UPS are damaged due to frequent high voltage or low voltage shocks.

[0005] In a first aspect, the present application provides a UPS input voltage protection device, the UPS input voltage protection device comprising: a power supply circuit, a comparison circuit, a voltage dividing circuit, and a switch circuit;

[0006] The voltage divider circuit is electrically connected between the power supply circuit and the switch circuit. When the mains voltage is within a preset threshold range, the voltage divider circuit outputs a high level to close the switch circuit, and the UPS operates in the mains mode.

[0007] The comparison circuit includes: a high voltage comparison circuit and a low voltage comparison circuit; wherein,

[0008] The high-voltage comparison circuit includes: a first voltage-dividing circuit, a first diode, and a first comparator; the first voltage-dividing circuit is electrically connected to the power supply circuit, the first comparator is electrically connected between the first voltage-dividing circuit and the first diode, and the first diode is electrically connected to the voltage-dividing circuit; when the mains voltage is higher than a preset threshold range, the first comparator outputs a low level through the first voltage-dividing circuit, the first diode is turned on and outputs a low level, the voltage-dividing circuit outputs a low level, the switch circuit is disconnected, and the UPS works in battery mode;

[0009] The low-voltage comparison circuit includes: a second voltage-dividing circuit, a second diode, and a second comparator; the second voltage-dividing circuit is electrically connected to the power supply circuit, the second comparator is electrically connected between the second voltage-dividing circuit and the second diode, and the second diode is electrically connected to the voltage-dividing circuit; when the mains voltage is lower than a preset threshold range, the second comparator outputs a low level through the second voltage-dividing circuit, the second diode is turned on and outputs a low level, the voltage-dividing circuit outputs a low level, the switch circuit is disconnected, and the UPS operates in battery mode.

[0010] Furthermore, the voltage divider circuit is electrically connected to the switch circuit, and the voltage divider circuit includes: an input end and an output end, the input end is electrically connected to the power supply circuit, and the output end is electrically connected to the switch circuit; when the AC power voltage is within a preset threshold range, the AC power voltage outputs a high level through the voltage divider circuit, the switch circuit is closed, and the UPS operates in the AC power mode.

[0011] Further, the anode of the first diode is electrically connected to the output end, and the cathode of the first diode is electrically connected to the output end of the first comparator; the anode of the second diode is electrically connected to the output end, and the cathode of the second diode is electrically connected to the output end of the second comparator; when the output end of the first comparator outputs a low level, the first diode is turned on; when the output end of the second comparator outputs a low level, the second diode is turned on; when the first diode or the second diode is turned on, the output end outputs a low level.

[0012] Furthermore, the negative input terminal of the first comparator is electrically connected to the first voltage divider circuit, and the positive input terminal of the first comparator is electrically connected to the power supply circuit and the negative electrode of the first diode, respectively; when the DC voltage is higher than a preset threshold range, the voltage of the negative input terminal of the first comparator is higher than the voltage of the positive input terminal of the first comparator, and the output terminal of the first comparator outputs a low level.

[0013] Furthermore, the positive input terminal of the second comparator is electrically connected to the second voltage divider circuit and the cathode of the second diode, respectively, and the negative input terminal of the second comparator is electrically connected to the power supply circuit; when the DC voltage is lower than a preset threshold range, the voltage at the negative input terminal of the second comparison circuit is higher than the voltage at the positive input terminal of the second comparator, and the second comparator outputs a low level.

[0014] Furthermore, the first voltage-dividing circuit includes: a plurality of parallel resistors and a first filter capacitor; the second voltage-dividing circuit includes: a plurality of parallel resistors, a second filter capacitor, and a Zener diode; the parallel resistor is connected in parallel with the first filter capacitor and is electrically connected to the negative input terminal of the first comparator; the parallel resistor, the second filter capacitor, and the Zener diode are connected in parallel and are electrically connected to the positive input terminal of the second comparator.

[0015] Furthermore, the switch circuit includes: a MOS tube and a relay, the MOS tube is electrically connected between the relay and the output end; when the output end outputs a low level, the MOS tube is disconnected, the relay is powered off to enable the UPS to operate in battery mode; when the output end outputs a high level, the high level turns on the MOS tube, the relay is powered on to enable the UPS to operate in mains mode.

[0016] Furthermore, the power supply circuit includes: a rectifier bridge, a flyback transformer, and a switch tube, wherein the flyback transformer is electrically connected between the rectifier bridge and the switch tube; when the switch tube is disconnected, the flyback transformer converts the DC voltage into a working power supply; when the switch tube is closed, the flyback transformer converts the DC voltage into a reference voltage.

[0017] Furthermore, the flyback transformer is electrically connected to the relay, and the working power supply provides power for the relay.

[0018] Furthermore, the flyback transformer is electrically connected to the comparator, and the reference voltage provides voltage for the comparator.

[0019] The above-mentioned UPS input voltage protection device controls the working mode of the UPS by electrically connecting the comparison circuit and the voltage divider circuit with the switch circuit, thereby effectively suppressing the risk of damage to the UPS caused by the high or low voltage of the power grid, and has a good protective effect on the UPS power supply operating in areas with harsh power grid environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without creative work.

[0021] Figure 1 A circuit schematic diagram of a UPS input voltage protection device provided in an embodiment of the present application.

[0022] Figure 2 A circuit schematic diagram of a power supply circuit provided in an embodiment of the present application.

[0023] Figure 3 A circuit schematic diagram of a switch circuit provided in an embodiment of the present application.

[0024] Figure 4 A circuit schematic diagram of a voltage divider circuit and a comparison circuit provided in an embodiment of the present application.

[0025] Figure 5 A circuit schematic diagram of a high voltage comparison circuit provided in an embodiment of the present application.

[0026] Figure 6 A circuit schematic diagram of a low voltage comparison circuit provided in an embodiment of the present application.

[0027] The implementation, functional features and advantages of the present application will be further described in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0028] In the description of the present application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0030] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0031] In order to make the content of this application more clear and more accurate, it will now be described in detail with reference to the accompanying drawings. The accompanying drawings in the specification illustrate examples of embodiments of the present application, wherein the same reference numerals represent the same elements. It is understood that the scales shown in the accompanying drawings in the specification are not the scales actually implemented in this application, and are only for the purpose of illustration and are not drawn according to the original size.

[0032] Please see Figure 1 , Figure 1 A circuit schematic diagram of a UPS input voltage protection device provided in an embodiment of the present application.

[0033] The UPS input voltage protection device 1 comprises a power circuit 10, a switch circuit 20, a resistor voltage divider circuit 30, and a comparison circuit 40. The power circuit 10 is electrically connected to the voltage divider circuit 30 and the comparison circuit 40, respectively, and the voltage divider circuit 30 is electrically connected between the comparison circuit 40 and the switch circuit 20.

[0034] When the mains voltage is within the preset range, the voltage divider circuit 30 outputs a high level to close the switch circuit 20, and the UPS works in the mains mode. When the mains voltage is not within the preset threshold range, the comparison circuit 40 pulls down the output level of the voltage divider circuit 30, the switch circuit 20 is disconnected, and the UPS works in the battery mode.

[0035] like Figure 2 As shown, the power supply circuit 10 includes a rectifier bridge BR1, a flyback transformer TX1, and a switch tube Q1, and the flyback transformer TX1 is electrically connected between the rectifier bridge BR1 and the switch tube Q1. Specifically, pin 3 of the rectifier bridge BR1 is electrically connected to the live wire of the mains, pin 4 is grounded, pin 2 is electrically connected to the neutral wire, and pin 1 is electrically connected to pin 3 of the flyback transformer. Pin 4 of the flyback transformer TX1 is electrically connected to pin 2 of the switch tube Q1. The rectifier bridge BR1 converts the AC power of the mains into DC power. The flyback transformer TX1 converts the DC voltage into a working power supply and a reference voltage. When the switch tube Q1 is disconnected, the flyback transformer TX1 converts the DC voltage into a working power supply; when the switch tube Q1 is closed, the flyback transformer TX1 converts the DC voltage into a reference voltage.

[0036] like Figure 4 As shown, the comparison circuit 40 is electrically connected to the voltage divider circuit 30 , and the comparison circuit 40 includes a high voltage comparison circuit 41 and a low voltage comparison circuit 42 .

[0037] like Figure 5 As shown, the high voltage comparison circuit 41 includes a first voltage divider circuit 411, a first diode D4, and a first comparator U2: B. The first comparator U2: B is electrically connected between the first voltage divider circuit 411 and the first diode D4.

[0038] The first voltage divider circuit 41 includes a plurality of parallel resistors and a first filter capacitor C2. Specifically, R7-R11 are connected in series and then in parallel with R20 to form a resistor parallel circuit, the first filter capacitor C2 is connected in parallel with R20, and the resistor parallel circuit is connected in series with R19 and then electrically connected to the negative input terminal 6 of the first comparator U2:B. The resistor parallel circuit is used to divide the DC voltage to obtain a low-voltage DC. The low-voltage DC is filtered by the first filter capacitor C2 and then passes through R19 to the negative input terminal 6 of the first comparator U2:B.

[0039] An anode of the first diode D4 is electrically connected to the output terminal OVCD_RLY, and a cathode of the first diode D4 is electrically connected to the output terminal 7 of the first comparator U2:B.

[0040] The first comparator U2:B includes a negative input terminal 6, a positive input terminal 5, and an output terminal 7. The negative input terminal 6 is electrically connected to the first voltage divider circuit 411, and the positive input terminal 5 of the first comparator U2:B is electrically connected to the power supply circuit 10 and the negative electrode of the first diode D4, respectively. Specifically, the positive input terminal 5 is electrically connected to the flyback transformer TX1 through a voltage divider resistor in parallel, and the positive input terminal 5 is electrically connected to the negative electrode of the first diode D3 through a resistor and a diode. The reference voltage provides a voltage for the first comparator U2:B. When the mains voltage is higher than the preset threshold range, the voltage of the negative input terminal 6 of the first comparator U2:B is higher than the voltage of the positive input terminal 5 of the first comparator U2:B, and the output terminal 7 of the first comparator U2:B outputs a low level.

[0041] like Figure 6 As shown, the low voltage comparison circuit 42 includes a second voltage divider circuit 422, a second diode D3, and a second comparator U2:A. The second comparator U2:A is electrically connected between the second voltage divider circuit 422 and the second diode D3.

[0042] The second voltage divider circuit 42 includes a plurality of parallel resistors, a second filter capacitor C1, and a voltage stabilizing diode ZD1. Specifically, R1-R6 are connected in series and then in parallel with R16 to form a resistor parallel circuit, the second filter capacitor C1 is connected in parallel with R16, and R17 and the voltage stabilizing diode ZD1 are connected in parallel with the resistor parallel circuit and then electrically connected to the positive input terminal 3 of the second comparator U2:A. The resistor parallel circuit is used to divide the DC voltage to obtain a low-voltage DC. The low-voltage DC is filtered by the second filter capacitor C1 and then passes through R17 to the positive input terminal 3 of the second comparator U2:A. In some feasible embodiments, when the voltage of the positive input terminal 3 of the second comparator U2:A is too high, the voltage stabilizing diode ZD1 clamps the positive input terminal 3 within a certain range, which can protect the second comparator U2:A from damage.

[0043] An anode of the second diode D3 is electrically connected to the output terminal OVCD_RLY, and a cathode of the second diode D3 is electrically connected to the output terminal 1 of the second comparator U2:A.

[0044] The second comparator U2:A includes a negative input terminal 2, a positive input terminal 3, and an output terminal 1. The positive input terminal 3 is electrically connected to the second voltage divider circuit 422 and the negative electrode of the second diode D3, respectively, and the negative input terminal 2 of the second comparator U2:A is electrically connected to the power supply circuit 10. Specifically, the negative input terminal 2 is electrically connected to the flyback transformer TX1 through the parallel voltage divider resistors R23 and R26, and the reference voltage provides voltage for the second comparator U2:A. The positive input terminal 3 is electrically connected to the negative electrode of the second diode D4 through the resistor R25 and the diode. When the DC voltage is lower than the preset threshold range, the voltage of the negative input terminal 2 of the second comparison circuit U2:A is higher than the voltage of the positive input terminal 3 of the second comparator U2:A, and the output terminal 1 of the second comparator U2:A outputs a low level.

[0045] When the output terminal 7 of the first comparator U2:B outputs a low level, the first diode D4 is turned on. When the output terminal 1 of the second comparator U2:A outputs a low level, the second diode D3 is turned on. When the first diode D4 or the second diode D3 is turned on, the output terminal OVCD_RLY outputs a low level.

[0046] In some feasible embodiments, the DC voltage is 370V, which is higher than the preset range of 60V to 360V. The DC voltage passes through the first voltage divider circuit, the voltage at pin 6 of the first comparator is greater than the voltage at pin 5, and the level of the output pin 7 of the first comparator is flipped, outputting a low level. The low level pulls down the level of the output terminal OVCD_RLY through the first diode. The low level disconnects the MOS tube Q2, and the relay RY2 is powered off to disconnect the AC power from the UPS input terminal, and the UPS works in battery mode.

[0047] In some feasible embodiments, the DC voltage is 50V, which is lower than the preset range of 60V to 360V. The DC voltage passes through the second voltage divider circuit R2, and the voltage of the 3rd pin of the second comparator U2:B is greater than the voltage of the 2nd pin. The output level of the 1st pin of the second comparator U2:B is flipped, and a low level is output. The low level pulls down the output terminal OVCD_RLY level through the second diode R2. The low level disconnects the MOS tube Q2, and the relay RY2 is powered off to disconnect the mains power from the UPS input terminal, and the UPS works in battery mode.

[0048] The voltage divider circuit 30 is electrically connected to the switch circuit 20, and the voltage divider circuit 30 includes an input terminal IN and an output terminal OVCD_RLY. The input terminal IN is electrically connected to the power supply circuit 10, and the output terminal OVCD_RLY is electrically connected to the switch circuit 20. When the mains voltage is within the preset threshold range, the mains voltage outputs a high level through the voltage divider circuit 20, the switch circuit 20 is closed, and the UPS operates in the mains mode. In this embodiment, the input terminal IN is electrically connected to the flyback transformer TX1, and the operating voltage passes through the parallel circuit of R27 and R28, and outputs a high level from the output terminal OVCD_RLY.

[0049] In some feasible embodiments, the DC voltage 340V is within the preset range of 60V to 360V, and the DC voltage enters the resistor voltage divider circuit 30 through the input terminal VCC. After voltage division, the output terminal OVCD_RLY outputs a high level. The high level turns on the MOS tube Q2, and the relay RY2 is energized to connect the mains power to the UPS input terminal, and the UPS works in the mains power mode.

[0050] like Figure 3 As shown, the switch circuit 20 includes a MOS tube Q2 and a relay RY2, and the MOS tube Q2 is electrically connected between the relay RY2 and the output terminal OVCD_RLY. The relay RY2 is electrically connected to the flyback transformer TX1, and the reference voltage provides voltage for the relay RY2. When the output terminal OVCD_RLY outputs a low level, the MOS tube Q2 is disconnected, and the relay RY2 is powered off to make the UPS work in the battery mode. When the output terminal OVCD_RLY outputs a high level, the MOS tube Q2 is turned on, and the relay RY2 is powered on to make the UPS work in the mains mode. By selectively opening or closing the switch circuit 20 according to the conditions, the risk of damage to the UPS caused by the high or low voltage of the power grid can be effectively suppressed.

[0051] In this embodiment, the output terminal OVCD_RLY passes through the parallel circuit of resistors R40 and R41 to the gate G of the MOS tube Q2. The drain D of the MOS tube Q2 is electrically connected to the relay RY2. In some feasible embodiments, the output terminal OVCD_RLY outputs a high level, the MOS tube Q2 is turned on, the relay RY2 is energized, the mains live wire 4 is connected to the UPS input live wire 5, and the UPS works in the mains mode. In some other feasible embodiments, the output terminal OVCD_RLY outputs a low level, the MOS tube Q2 is disconnected, the relay RY2 is powered off, the mains live wire 4 is connected to the input terminal 3 of the relay RY2, and the UPS works in the battery mode.

[0052] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0053] The above examples are only preferred embodiments of the present invention, and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A UPS input voltage protection device, characterized in that: The UPS input voltage protection device comprises: a power supply circuit, a comparison circuit, a voltage dividing circuit, and a switch circuit; The voltage divider circuit is electrically connected between the power supply circuit and the switch circuit. When the mains voltage is within a preset threshold range, the voltage divider circuit outputs a high level to close the switch circuit, and the UPS operates in the mains mode. The comparison circuit includes: a high voltage comparison circuit and a low voltage comparison circuit; wherein, The high-voltage comparison circuit includes: a first voltage-dividing circuit, a first diode, and a first comparator; the first voltage-dividing circuit is electrically connected to the power supply circuit, the first comparator is electrically connected between the first voltage-dividing circuit and the first diode, and the first diode is electrically connected to the voltage-dividing circuit; when the mains voltage is higher than a preset threshold range, the first comparator outputs a low level through the first voltage-dividing circuit, the first diode is turned on and outputs a low level, the voltage-dividing circuit outputs a low level, the switch circuit is disconnected, and the UPS works in battery mode; The low-voltage comparison circuit includes: a second voltage-dividing circuit, a second diode, and a second comparator; the second voltage-dividing circuit is electrically connected to the power supply circuit, the second comparator is electrically connected between the second voltage-dividing circuit and the second diode, and the second diode is electrically connected to the voltage-dividing circuit; when the mains voltage is lower than a preset threshold range, the second comparator outputs a low level through the second voltage-dividing circuit, the second diode is turned on and outputs a low level, the voltage-dividing circuit outputs a low level, the switch circuit is disconnected, and the UPS operates in battery mode.

2. The UPS input voltage protection device according to claim 1, characterized in that: The voltage divider circuit is electrically connected to the switch circuit, and the voltage divider circuit includes: an input end and an output end, the input end is electrically connected to the power supply circuit, and the output end is electrically connected to the switch circuit; when the AC power voltage is within a preset threshold range, the AC power voltage outputs a high level through the voltage divider circuit, the switch circuit is closed, and the UPS operates in the AC power mode.

3. The UPS input voltage protection device according to claim 2, characterized in that: The anode of the first diode is electrically connected to the output end, and the cathode of the first diode is electrically connected to the output end of the first comparator; the anode of the second diode is electrically connected to the output end, and the cathode of the second diode is electrically connected to the output end of the second comparator; when the output end of the first comparator outputs a low level, the first diode is turned on; when the output end of the second comparator outputs a low level, the second diode is turned on; when the first diode or the second diode is turned on, the output end outputs a low level.

4. The UPS input voltage protection device according to claim 3, characterized in that: The negative input terminal of the first comparator is electrically connected to the first voltage divider circuit, and the positive input terminal of the first comparator is electrically connected to the power supply circuit and the negative electrode of the first diode respectively; when the mains voltage is higher than a preset threshold range, the voltage of the negative input terminal of the first comparator is higher than the voltage of the positive input terminal of the first comparator, and the output terminal of the first comparator outputs a low level.

5. The UPS input voltage protection device according to claim 3, characterized in that: The positive input terminal of the second comparator is electrically connected to the second voltage divider circuit and the cathode of the second diode, respectively, and the negative input terminal of the second comparator is electrically connected to the power supply circuit; when the DC voltage is lower than a preset threshold range, the voltage at the negative input terminal of the second comparator is higher than the voltage at the positive input terminal of the second comparator, and the second comparator outputs a low level.

6. The UPS input voltage protection device according to claim 1, characterized in that: The first voltage-dividing circuit includes: a plurality of parallel resistors and a first filter capacitor; the second voltage-dividing circuit includes: a plurality of parallel resistors, a second filter capacitor, and a voltage-stabilizing diode; the parallel resistor is connected in parallel with the first filter capacitor and is electrically connected to the negative input terminal of the first comparator; the parallel resistor, the second filter capacitor, and the voltage-stabilizing diode are connected in parallel and are electrically connected to the positive input terminal of the second comparator.

7. The UPS input voltage protection device according to claim 2, characterized in that: The switch circuit includes: a MOS tube and a relay, wherein the MOS tube is electrically connected between the relay and the output end; when the output end outputs a low level, the MOS tube is disconnected, the relay is powered off, and the UPS works in battery mode; when the output end outputs a high level, the high level turns on the MOS tube, the relay is powered on, and the UPS works in mains mode.

8. The UPS input voltage protection device according to claim 7, characterized in that: The power supply circuit includes: a rectifier bridge, a flyback transformer, and a switch tube, wherein the flyback transformer is electrically connected between the rectifier bridge and the switch tube; when the switch tube is disconnected, the flyback transformer converts the DC voltage into a working power supply; when the switch tube is closed, the flyback transformer converts the DC voltage into a reference voltage.

9. The UPS input voltage protection device according to claim 8, characterized in that: The flyback transformer is electrically connected to the relay, and the working power supply provides power for the relay.

10. The UPS input voltage protection device according to claim 8, characterized in that: The flyback transformer is electrically connected to the comparator, and the reference voltage provides voltage for the comparator.

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