CN106410747A - UPS input protection circuit and UPS - Google Patents

Abstract

UPS input protection circuit relates to UPS protection technical field, and it includes high-pressure detection module, low pressure detection module and is used for controlling the commercial power to the switch module of the break-make of the power supply line of UPS's main circuit power supply, and high-pressure detection module detects mains voltage and touches output high voltage trigger signal to switch module when mains voltage is higher than first preset voltage and cuts off with trigger switch module power supply line, low pressure detection module detect mains voltage and touch output low voltage trigger signal to switch module when mains voltage is less than the second preset voltage and cut off with trigger switch module power supply line. Whether high voltage detection module detects mains voltage and whether low voltage detection module detects mains voltage and crosses lowly, and when mains voltage was too high or crossed lowly, high voltage detection module or low voltage detection module will trigger the switch module and cut off the power supply line to prevent that mains voltage from being too high or crossing lowly and leading to the main circuit of UPS to break down.

Description

ups input protection circuit and ups

technical field

The invention relates to the technical field of UPS protection, in particular to a UPS input protection circuit.

Background technique

UPS (Uninterruptable Power Supply, uninterruptible power supply) is a power protection device that contains a battery energy storage device and uses an inverter as the main unit. The main circuit of the UPS is mainly composed of an inverter and a battery. When the mains power input is normal, the UPS will convert the mains power into a stable AC voltage for the load through the rectification and inverter circuit, and complete the charging of the battery at the same time; When the electricity is abnormal, the UPS converts the energy stored in the battery into constant voltage and constant frequency alternating current to supply power to the load through the DC booster and inverter circuit. When the UPS has abnormal phenomena such as overload and over temperature, the UPS will switch the output terminal of the UPS from the inverter output terminal to the bypass output terminal, and the bypass will supply power to the load, so as to ensure that the output terminal of the UPS will not be powered off. .

Many UPSs have protection circuits in their main circuits, such as overvoltage protection circuits, overcurrent protection circuits, etc., to protect the UPS from being damaged when the main circuit fails, and to ensure that the load will not be powered off. However, if the mains voltage input to the UPS is too high or too low, it may also cause the main circuit of the UPS to fail, thereby powering off the load.

Contents of the invention

Aiming at the above-mentioned technical problems existing in the prior art, the invention provides a UPS input protection circuit and UPS, which can cut off the power supply line from the mains to the main circuit of the UPS when the mains voltage is too high or too low, thereby preventing The mains circuit of the UPS fails due to the high or low mains voltage.

In order to achieve the above object, the present invention provides the following technical solutions.

The UPS input protection circuit includes a high-voltage detection module, a low-voltage detection module and a switch module for controlling the on-off of the power supply line for supplying power from the mains to the main circuit of the UPS. The high-voltage detection module detects the mains voltage and detects when the mains voltage is higher than the When a preset voltage is reached, output a high-voltage trigger signal to the switch module to trigger the switch module to cut off the power supply line; the low-voltage detection module detects the mains voltage and outputs a low-voltage trigger to the switch module when the mains voltage is lower than the second preset voltage signal to trigger the switch module to cut off the power supply line. This is technical scheme 1.

According to the UPS input protection circuit described in technical solution 1, the high-voltage detection module includes an operational amplifier U1, the non-inverting input terminal of the operational amplifier U1 is input into the mains, and the inverting input terminal is input with the first reference voltage corresponding to the first preset voltage, The output terminal outputs a high-voltage trigger signal to the switch module. The low-voltage detection module includes an operational amplifier U2. The non-inverting input terminal of the operational amplifier U2 is input with the second reference voltage corresponding to the second preset voltage, the inverting input terminal is input into the mains, and the output terminal Outputting a low-voltage trigger signal to the switch module. This is technical scheme 2.

According to the input protection circuit of UPS described in technical solution 2, the high voltage detection module includes a first voltage dividing circuit for providing a first reference voltage, the first voltage dividing circuit includes at least two voltage dividing resistors, and the at least two voltage dividing resistors After being connected in series between the power supply and the ground, at least one of the at least two voltage-dividing resistors is an adjustable resistor. The low-voltage detection module includes a second voltage-dividing circuit for providing a second reference voltage. The second voltage-dividing circuit includes At least two voltage-dividing resistors are connected in series between the power supply and the ground, and at least one of the at least two voltage-dividing resistors is an adjustable resistor. This is technical scheme 3.

According to the UPS input protection circuit described in technical solution 1, it also includes a mains power sampling module, which samples the mains power and sends it to the high-voltage detection module and the low-voltage detection module, so that the high-voltage detection module detects whether the mains voltage is higher than the first preset The voltage is used for the low-voltage detection module to detect whether the mains voltage is lower than the second preset voltage. This is technical scheme 4.

According to the UPS input protection circuit described in technical solution 4, the mains sampling module includes a voltage dividing resistor R1, a voltage dividing resistor R2 and a rectifying diode D1, one end of the voltage dividing resistor R1 is connected to the mains, and the other end is connected to the anode of the rectifying diode D1, and the One end of the resistor R2 is connected to the cathode of the rectifier diode D1, and the other end is grounded. The cathode of the rectifier diode D1 is connected to the high voltage detection module and the low voltage detection module. This is technical scheme 5.

According to the UPS input protection circuit described in technical solution 1, the switch module includes an AND gate circuit, a switch tube Q1, and a relay JQ1, and the AND gate circuit includes a diode D2, a diode D3, and an operational amplifier U3. The anode of the diode D2 receives a high-voltage trigger signal, and the cathode is connected to The non-inverting input terminal of the operational amplifier U3, the anode of the diode D3 receives the low-voltage trigger signal, the negative terminal is connected to the non-inverting input terminal of the operational amplifier U3, the inverting input terminal of the operational amplifier U3 is input with the third reference voltage, and the output terminal is connected to the control terminal of the switch tube Q1. The two controlled conduction ends of the switch tube Q1 are connected in series with the coil of the relay JQ1 and then connected between the power supply and the ground, and the normally closed contact of the relay JQ1 is connected in series with the power supply line. This is technical scheme 6.

According to the UPS input protection circuit described in technical solution 1, it also includes a power supply module for supplying power to other modules of the protection circuit. The power supply module includes a rectifier and a voltage stabilizer. input terminal of the device. This is technical scheme 7.

The UPS includes a main circuit, and also includes the UPS input protection circuit described in any one of technical solutions 1-7.

The beneficial effects of the present invention are: the UPS input protection circuit created by the present invention is provided with a switch module, which controls the on-off of the power supply line that supplies power to the main circuit of the UPS from the mains, and is also provided with a high-voltage detection module and a low-voltage detection module. The detection module detects whether the mains voltage is too high, and the low-voltage detection module detects whether the mains voltage is too low. When the mains voltage is too high or too low, the high-voltage detection module or the low-voltage detection module will trigger the switch module to cut off the power supply line. So as to prevent the main circuit of the UPS from malfunctioning due to the high or low mains voltage. The circuit structure is simple, easy to realize and low in cost. A UPS with the input protection circuit is capable of self-protection at the input.

Description of drawings

Fig. 1 is a schematic diagram of the UPS input protection circuit created by the present invention.

Reference signs include: mains power sampling module 1 , high voltage detection module 2 , low voltage detection module 3 , switch module 4 .

detailed description

The invention will be described in detail below in conjunction with specific embodiments.

The UPS of this embodiment includes a main circuit and a UPS input protection circuit. Figure 1 shows the UPS input protection circuit. L is the live wire of the mains power, and N is the neutral wire of the mains power. The power module includes a rectifier and a voltage stabilizer. The commercial power of the module is rectified, the voltage stabilizer is stabilizing, and the power supply module outputs stable VCC power and VDD power to supply power to other modules of the input protection circuit.

As shown in Figure 1, resistors R1, R2, R11, capacitor C1 and diode D1 form the mains sampling module 1. Capacitor C1 steps down the mains voltage and discharges it in the negative half cycle of the mains to continuously provide voltage. Resistor R11 is the capacitor The discharge resistor of C1, the resistors R1 and R2 divide the mains power, the diode D1 rectifies the mains power, and the divided mains power is sent to the high-voltage detection module 2 and the low-voltage detection module 2 from the junction between the diode D1 and the resistor R2 Detection module 3. The high-voltage detection module 2 includes an operational amplifier U1, resistors R3 and R4, and the resistors R3 and R4 are connected in series between the power supply VCC and the ground to form a first voltage divider circuit. The low-voltage detection module 3 includes an operational amplifier U2, resistors R5 and R6, The resistors R5 and R6 are connected in series between the power supply VCC and the ground to form a second voltage divider circuit. In this embodiment, the normal range of the mains voltage is set to 160V-280V, so the first preset voltage is 280V, and the second preset voltage is 160V. According to the voltage division of the mains voltage by resistors R1 and R2, set The resistance values of the resistors R3 and R4 are divided to obtain a first reference voltage corresponding to 280V, and the resistance values of the resistors R5 and R6 are set to obtain a second reference voltage corresponding to 160V. Further, the resistors R4 and R6 are adjustable resistors, so by adjusting the resistance values of the resistors R4 and R6, the first reference voltage and the second reference voltage are adjusted, thereby adjusting the first preset voltage and the second preset voltage. Diodes D2, D3, operational amplifier U3, resistors R7-R9, and capacitor C2 form an AND gate circuit, and the AND gate circuit together with transistor Q1, diode D4 and relay JQ1 form a switch module 4, and transistor Q1 is an NPN transistor.

If the mains voltage is higher than 280V, the voltage input to the non-inverting input terminal of the operational amplifier U1 after divided by resistors R1 and R2 will be higher than the first reference voltage obtained after divided by resistors R3 and R4. The level of the non-inverting input terminal of the amplifier U1 is higher than the level of the inverting input terminal, so the output terminal of the operational amplifier U1 outputs a high level, the diode D2 is turned on, and the non-inverting input terminal of the operational amplifier U3 is input with a high level, so the operational amplifier U3 The output end of the output terminal outputs a high level, the transistor Q1 is turned on, the coil of the relay JQ1 has current flowing, the normally closed contact of the relay JQ1 is disconnected, and the INPUT end supplying power to the main circuit of the UPS is therefore cut off, and the mains The power supply line feeding the main circuit of the UPS is thereby cut off.

If the mains voltage is lower than 160V, the voltage input to the inverting input terminal of the op amp U2 after divided by resistors R1 and R2 will be lower than the second reference voltage obtained after divided by resistors R5 and R6, that is, at this time The level of the inverting input terminal of the operational amplifier U2 is lower than the level of the non-inverting input terminal, so the output terminal of the operational amplifier U2 outputs a high level, the diode D2 conducts, and the non-inverting input terminal of the operational amplifier U3 is input with a high level, so the operational amplifier The output terminal of U3 outputs a high level, the transistor Q1 is thus turned on, the coil of the relay JQ1 has current flowing, the normally closed contact of the relay JQ1 is disconnected, and the INPUT terminal supplying power to the main circuit of the UPS is therefore cut off, and the market The power supply line that supplies power to the main circuit of the UPS is thereby cut off.

If the mains voltage is within the range of 160V-280V, the level of the non-inverting input terminal of the operational amplifier U1 is lower than the level of the inverting input terminal, the output terminal of the operational amplifier U1 outputs a low level, the diode D2 is cut off, and the inverting input terminal of the operational amplifier U2 The level is higher than the level of the non-inverting input terminal, the output terminal of the operational amplifier U2 outputs a low level, the diode D3 is cut off, the output terminal of the operational amplifier U3 outputs a low level, the transistor Q1 is cut off, and the INPUT terminal that supplies power to the main circuit of the UPS gets The power supply line from the utility power to the main circuit of the UPS is normal.

Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention, rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art Personnel should understand that the technical solution of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solution of the present invention.

Claims (8)

1.UPS input protection circuit; it is characterized in that; switch module including high pressure detection module, low pressure detection module and the break-make being used for from the supply line controlling civil power to power to the main circuit of UPS; high pressure detection module detection line voltage simultaneously touches output high-voltage trigger signal with the described supply line of trigger switch module cut-out when line voltage is higher than the first predeterminated voltage to switch module, and low pressure detection module detection line voltage simultaneously touches output low pressure trigger with the described supply line of trigger switch module cut-out when line voltage is less than the second predeterminated voltage to switch module.

2. UPS input protection circuit according to claim 1; it is characterized in that; high pressure detection module includes amplifier U1; amplifier U1 in-phase input end is transfused to civil power; inverting input is transfused to first reference voltage corresponding with the first predeterminated voltage; outfan exports high-voltage trigger signal to switch module; low pressure detection module includes amplifier U2; amplifier U2 in-phase input end is transfused to second reference voltage corresponding with the second predeterminated voltage; inverting input is transfused to civil power, and outfan exports low pressure trigger to switch module.

3. the input protection circuit of UPS according to claim 2, it is characterized in that, high pressure detection module includes the first bleeder circuit for providing the first reference voltage, first bleeder circuit includes at least two divider resistances, it is connected between power supply and ground after the series connection of this at least two divider resistance, in this at least two divider resistance, at least one is adjustable resistance, low pressure detection module includes the second bleeder circuit for providing the second reference voltage, second bleeder circuit includes at least two divider resistances, it is connected between power supply and ground after the series connection of this at least two divider resistance, in this at least two divider resistance, at least one is adjustable resistance.

4. UPS input protection circuit according to claim 1; it is characterized in that; also include civil power sampling module; its sampling civil power is simultaneously conveyed to high pressure detection module and low pressure detection module; so that whether high pressure detection module detection line voltage is higher than the first predeterminated voltage, whether it is less than the second predeterminated voltage for low pressure detection module detection line voltage.

5. UPS input protection circuit according to claim 4; it is characterized in that; civil power sampling module includes divider resistance R1, divider resistance R2 and commutation diode D1; divider resistance R1 mono- terminates civil power; the other end connects commutation diode D1 positive pole; divider resistance R2 one end connects commutation diode D1 negative pole, and the other end is grounded, and the negative pole of commutation diode D1 connects high pressure detection module and low pressure detection module.

6. UPS input protection circuit according to claim 1, it is characterized in that, switch module includes and gate circuit, switching tube Q1 and relay JQ1, include diode D2 with gate circuit, diode D3 and amplifier U3, diode D2 positive pole receives high-voltage trigger signal, negative pole connects the in-phase input end of amplifier U3, diode D3 positive pole receives low pressure trigger, negative pole connects the in-phase input end of amplifier U3, amplifier U3 inverting input is transfused to the 3rd reference voltage, the control end of outfan connecting valve pipe Q1, two controlled conduction terminal of switching tube Q1 are connected between power supply and ground after being connected with the coil of relay JQ1, the normally-closed contact of relay JQ1 is serially connected with described supply line.

7. UPS input protection circuit according to claim 1; it is characterized in that, also include the power module for the other module for power supply to described protection circuit, power module includes commutator and manostat; rectifier input connects civil power, and outfan connects the input of manostat.

8.UPS, including main circuit, is characterized in that, also includes the UPS input protection circuit described in any one of claim 1-7.