3KVA online UPS power supply main power circuit

Abstract

The utility model provides a 3KVA on-line UPS power supply main power circuit. The 3KVA on-line UPS power supply main power circuit comprises an AC filtering and bypass access circuit, a DC-DC conversion circuit, an AC bypass access rectification circuit, an inversion circuit, an AC bypass and output conversion circuit and an output filtering circuit. The AC filtering and bypass access circuit is electrically connected with the AC bypass access rectification circuit and the AC bypass and output conversion circuit, the DC-DC conversion circuit is electrically connected with the AC bypass access rectification circuit and the inverter circuit, and the inverter circuit is electrically connected with the AC bypass and output conversion circuit. And the alternating current bypass is electrically connected with the output conversion circuit and the output filter circuit. By means of alternating current filtering, DC-DC conversion and inversion technologies, switching between external alternating current and an inversion power supply and battery backup are achieved, and continuous power supply and automatic switching are ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply, in particular to a 3KVA online UPS power supply main power circuit. Background Art

[0002] With the rapid development of switching power supply technology, modern UPS presents new features of online and independent modularization. Uninterruptible power supply (UPS) has important applications in the fields of computers, banks, securities, communications, medical care, etc. UPS is divided into two types: online and backup. The difference is that the inverter circuit of online UPS is always active, and the AC bypass is only involved when the inverter circuit fails; the inverter circuit of backup UPS is usually in a non-working state, and the AC bypass is responsible for working. The inverter circuit is only started when the input AC power is cut off or fails. 3KVA UPS power supply is usually selected for computer rooms to provide power support for important equipment such as computers. Since the equipment in the computer room has strict requirements for high-quality AC power supply, zero switching time and long-term continuous power supply, and the equipment is widely distributed, it is necessary to use multiple small and medium-power online UPS for decentralized power supply to ensure that they are not affected by each other. Traditional backup UPS circuits cannot meet the needs of online, independent modularization and decentralized power supply.

[0003] The Chinese patent with publication number CN208046312U discloses an online UPS power supply system based on supercapacitors, which guarantees system output and prolongs battery life through supercapacitors. However, the system cannot meet the requirements of decentralized power supply, and the circuit power consumption is high and the working efficiency is low. Utility Model Content

[0004] In view of this, the utility model proposes a 3KVA online UPS power supply main power circuit, which utilizes AC filtering, DC-DC conversion, and inverter technology to achieve external AC and inverter power switching, battery backup and control, ensure continuous power supply and automatic switching, solve the output problem when the inverter power supply fails, and meet the high-quality, zero-switching power needs.

[0005] The technical solution of the utility model is implemented as follows: a 3KVA online UPS power supply main power circuit, including an AC filter and bypass access circuit, a DC-DC conversion circuit, an AC bypass access rectification circuit, an inverter circuit, an AC bypass and output conversion circuit and an output filter circuit;

[0006] The AC filtering and bypass access circuit is electrically connected to the AC bypass access rectification circuit and the AC bypass and output conversion circuit;

[0007] The DC-DC conversion circuit is electrically connected to the AC bypass access rectification circuit and the inverter circuit;

[0008] The AC bypass is connected to the rectifier circuit and is electrically connected to the inverter circuit;

[0009] The inverter circuit is electrically connected to the AC bypass and output conversion circuit;

[0010] The AC bypass and output conversion circuit are electrically connected to the output filter circuit;

[0011] The output filter circuit is electrically connected to the AC bypass and output conversion circuit.

[0012] Preferably, the AC filtering and bypass access circuit includes capacitors C1, C2, C3, C4, C5, varistors MOV1, MOV2, MOV3, MOV4, inductor L1, thermistor NTC1, and relay RY1;

[0013] Pin 1 of inductor L1 is electrically connected to one end of capacitor C1, one end of varistor MOV2, and one end of varistor MOV1. Pin 3 of inductor L1 is electrically connected to the other end of capacitor C1, the other end of varistor MOV1, and one end of varistor MOV3. Pin 2 of inductor L1 is electrically connected to one end of varistor MOV4, one end of capacitor C2, one end of capacitor C4, and one end of thermistor NTC1. Pin 4 of inductor L1 is electrically connected to the other end of MOV4, the other end of capacitor C2, one end of capacitor C3, one end of capacitor C5, and pin 1 of relay RY1. The varistor MOV3, the varistor MOV2, the other end of capacitor C3, and the other end of capacitor C4 are connected to the ground. The other end of the thermistor NTC1 is electrically connected to the other end of capacitor C5 and pin 3 of relay RY1. Pin 6 of relay RY1 is connected to a +12V power supply.

[0014] Preferably, the DC-DC conversion circuit includes resistors R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, capacitors C15, C16, C17, C18, C19, C20, insurances F2, F3, diodes D2, D3, D4, D5, D6, D7, MOSFET tubes Q2, Q3, Q4, Q5, inductors L3, L4, and transformer T1;

[0015] Pins 1 and 2 of transformer T1 are electrically connected to one end of resistor R11, the drain of MOSFET tube Q3, and the drain of MOSFET tube Q2. The other end of resistor R11 is electrically connected to one end of capacitor C17. The other end of capacitor C17 is electrically connected to the source of MOSFET tube Q3, one end of resistor R10, the source of MOSFET tube Q2, one end of resistor R8, the negative electrode of capacitor C16, the negative electrode of capacitor C15, one end of resistor R13, the source of MOSFET tube Q4, one end of resistor R15, the source of MOSFET tube Q5, and one end of capacitor C18. The gate of MOSFET tube Q3 is electrically connected to the other end of resistor R10 and one end of resistor R9. The other end of resistor R9 is electrically connected to one end of resistor R7. The other end of the resistor R7 is electrically connected to the gate of the MOSFET tube Q2 and the other end of the resistor R8, the pins 4-7 of the transformer T1 are electrically connected to the positive electrode of the capacitor C16, the positive electrode of the capacitor C15, one end of the insurance F3, and one end of the insurance F2, the pins 9 and 10 of the transformer T1 are electrically connected to one end of the resistor R16, the drain of the MOSFET tube Q5, and the drain of the MOSFET tube Q4, the other end of the resistor R16 is electrically connected to the other end of the capacitor C18, the gate of the MOSFET tube Q5 is electrically connected to one end of the resistor R14 and the other end of the resistor R15, the other end of the resistor R14 is electrically connected to one end of the resistor R12, and the other end of the resistor R12 is electrically connected to the gate of the MOSFET tube Q4 and the other end of the resistor R13;

[0016] Pins 11 and 12 of the transformer T1 are electrically connected to the anode of the diode D2 and the cathode of the diode D4. The cathode of the diode D2 is electrically connected to the cathode of the diode D3, the anode of the diode D6, and one end of the inductor L3. The cathode of the diode D6 is electrically connected to one end of the resistor R17 and one end of the capacitor C19. The other end of the resistor R17 is electrically connected to one end of the resistor R18. The other end of the resistor R18 is electrically connected to the other end of the capacitor C19 and the other end of the inductor L3. Pins 19 and 20 of the transformer T1 are electrically connected to the cathode of the diode D5 and the anode of the diode D3. The anode of the diode D4 is electrically connected to the anode of the diode D5, the anode of the diode D7, and one end of the inductor L4. The cathode of the diode D7 is electrically connected to one end of the resistor R19 and one end of the capacitor C20. The other end of the resistor R19 is electrically connected to one end of the resistor R20. The other end of the resistor R20 is electrically connected to the other end of the capacitor C20 and the other end of the inductor L4.

[0017] Preferably, the AC bypass access rectifier circuit includes resistors R4, R5, R6, R35, R36, R37, capacitors C11, C12, C13, C14, C25, C26, insurance F1, transformer CT1, inductor L2, diodes D1, D8, D9, IGBT tube Q1, rectifier bridge REC1;

[0018] One end of the fuse F1 is electrically connected to the pin 1 of the transformer CT1, the pin 6 of the transformer CT1 is electrically connected to one end of the resistor R36 and one end of the resistor R35, the pin 5 of the transformer CT1 is electrically connected to the other end of the resistor R36 and the other end of the resistor R35, the pin 4 of the transformer CT1 is electrically connected to one end of the inductor L2, the other end of the inductor L2 is electrically connected to one end of the capacitor C11, the positive electrode of the diode D8, one end of the capacitor C25, the negative electrode of the diode D9, one end of the capacitor C26, one end of the capacitor C13, and the AC positive input terminal of the rectifier bridge REC1, the other end of the capacitor C11 is electrically connected to one end of the capacitor C12 and the AC negative input terminal of the rectifier bridge REC1, the negative electrode of the diode D8 is electrically connected to the other end of the capacitor C25, and the negative electrode of the diode D9 is electrically connected to the capacitor C26. One end is electrically connected, the positive electrode of diode D9 is electrically connected to the other end of capacitor C26, the other end of capacitor C12 is electrically connected to the other end of capacitor C13, one end of capacitor C14, the collector of IGBT tube Q1, and the DC positive output end of rectifier bridge REC1, the emitter of IGBT tube Q1 is electrically connected to one end of resistor R37, and the DC negative output end of rectifier bridge REC1 is electrically connected to the working ground, the gate of IGBT tube Q1 is electrically connected to the positive electrode of diode D1, one end of resistor R6, and one end of resistor R5, the other end of capacitor C14 is electrically connected to the other end of resistor R37, the negative electrode of diode D1 is electrically connected to one end of resistor R4, the other end of resistor R4 is electrically connected to the other end of resistor R5, and the other end of resistor R6 is connected to the working ground.

[0019] Preferably, the inverter circuit includes resistors R21, R22, R23, R24, R25, R26, R27, R28, R29, R30, R31, R32, R33, R34, R38, R39, capacitors C6, C21, C22, C23, C24, C27, C28, inductors L5, L6, diodes D10, D11, D12, D13, D14, D15, IGBT tubes Q6, Q7, Q8, Q9, and transformer CT3;

[0020] Pin 4 of the transformer CT3 is electrically connected to one end of the capacitor C6, pin 5 of the transformer CT3 is electrically connected to one end of the resistor R38 and one end of the resistor R39, pin 6 of the transformer CT3 is electrically connected to the other end of the resistor R38 and the other end of the resistor R39, pin 1 of the transformer CT3 is electrically connected to one end of the inductor L6, the other end of the capacitor C6 is electrically connected to the negative electrode of the capacitor C22, the negative electrode of the capacitor C21, the positive electrode of the capacitor C23, and the positive electrode of the capacitor C24, the other end of the inductor L6 is electrically connected to one end of the inductor L5, the collector of the IGBT tube Q6 is electrically connected to the positive electrode of the capacitor C21, the positive electrode of the capacitor C22, The collector of IGBT tube Q7, one end of resistor R27, and the positive electrode of diode D12 are electrically connected. The gate of IGBT tube Q6 is electrically connected to one end of resistor R21, one end of resistor R22, and one end of resistor R23. The other end of resistor R21 is electrically connected to the positive electrode of diode D10. The cathode of diode D10 is electrically connected to the other end of resistor R22, the cathode of diode D11, and one end of resistor R25. The emitter of IGBT tube Q6 is electrically connected to the other end of resistor R23, one end of resistor R26, the emitter of IGBT tube Q7, one end of capacitor C27, the other end of inductor L5, and IGBT tube Q8. The collector of the IGBT tube Q9 is electrically connected to one end of the capacitor C28, the cathode of the diode D12 is electrically connected to the other end of the resistor R27 and the other end of the capacitor C27, the gate of the IGBT tube Q7 is electrically connected to one end of the resistor R24, the other end of the resistor R25, and the other end of the resistor R26, the anode of the diode D11 is electrically connected to the other end of the resistor R24, the gate of the IGBT tube Q8 is electrically connected to one end of the resistor R28, one end of the resistor R29, and one end of the resistor R30, the other end of the resistor R28 is electrically connected to the anode of the diode D13, the cathode of the diode D13 is electrically connected to the cathode of the resistor R29 The other end, the cathode of diode D14, and one end of resistor R32 are electrically connected, the emitter of IGBT tube Q8 is electrically connected to the other end of resistor R30, the cathode of capacitor C23, the cathode of capacitor C24, one end of resistor R33, the emitter of IGBT tube Q9, one end of resistor R34, and the cathode of diode D15, the gate of IGBT tube Q9 is electrically connected to one end of resistor R31, the other end of resistor R32, and the other end of resistor R33, the anode of diode D14 is electrically connected to the other end of resistor R31, and the other end of capacitor C28 is electrically connected to the other end of resistor R34 and the anode of diode D15.

[0021] Preferably, the AC bypass and output conversion circuit includes a resistor R1 and a relay RY2;

[0022] Pin 1 of relay RY2 is electrically connected to one end of resistor R1, and the other end of resistor R1 is connected to a +12V power supply.

[0023] Preferably, the output filter circuit includes resistors R2, R3, capacitors C7, C8, C9, C10, inductor L7, transformer CT2, and fuse F4;

[0024] Pin 6 of the transformer CT2 is electrically connected to one end of the resistor R3 and one end of the resistor R2, pin 5 of the transformer CT2 is electrically connected to the other end of the resistor R2 and the other end of the resistor R3, pin 4 of the transformer CT2 is electrically connected to one end of the capacitor C7 and pin 1 of the inductor L7, pin 3 of the inductor L7 is electrically connected to the other end of the capacitor C7, pin 2 of the inductor L7 is electrically connected to one end of the capacitor C8, one end of the capacitor C10, and one end of the fuse F4, pin 4 of the inductor L7 is electrically connected to the other end of the capacitor C8 and one end of the capacitor C9, and the other end of the capacitor C9 and the other end of the capacitor C10 are connected to the ground.

[0025] Preferably, pin 4 of relay RY1 is electrically connected to the other end of fuse F1 and pins 2 and 7 of relay RY2, pin 2 of relay RY1 is electrically connected to the other end of capacitor C6, pins 4 and 5 of relay RY2 are electrically connected to one end of capacitor C6, and pins 3 and 6 of relay RY2 are electrically connected to pin 1 of transformer CT2.

[0026] Preferably, the pins 15 and 16 of the transformer T1 are electrically connected to the negative electrode of the capacitor C21, the other end of the inductor L3 is electrically connected to the positive electrode of the capacitor C21, and the other end of the inductor L4 is electrically connected to the negative electrode of the capacitor C23;

[0027] The cathode of the diode D8 is electrically connected to the other end of the inductor L3, the anode of the diode D9 is electrically connected to the other end of the inductor L4, and the AC cathode input of the rectifier bridge REC1 is electrically connected to the other end of the capacitor C6.

[0028] Preferably, the pin 3 of the inductor L7 is electrically connected to the other end of the capacitor C6.

[0029] The utility model provides a 3KVA online UPS power supply main power circuit, which has the following beneficial effects compared with the prior art:

[0030] (1) Through AC filtering, DC-DC conversion, and inverter technology, external AC power and inverter power switching, battery backup, and control are realized to ensure continuous power supply and automatic switching, solve the output problem when the inverter power fails, and meet the power demand of high quality and zero switching;

[0031] (2) The DC-DC conversion circuit converts the 72V battery voltage signal into 300V high-voltage pulsating DC power through primary full-wave rectification and secondary full-bridge rectification and boosting. The entire circuit topology is simple in design and the performance is balanced.

[0032] (3) Through AC bypass access to the rectifier circuit, zero switching time is achieved, realizing long-term continuous power supply 24 hours a day, the inverter DC high voltage reaches 300V, the output power can reach up to 3KVA; the service life reaches 100,000h;

[0033] (4) The half-bridge inverter circuit converts 300V high-voltage pulsating DC into high-quality AC through inverter high-frequency chopping, meeting the power supply requirements of important equipment, reducing circuit power consumption and improving work efficiency;

[0034] (5) The output filter circuit uses an LC filter circuit to effectively suppress the high-frequency noise generated inside the power supply and the EMI noise conducted externally, delivering cleaner AC power to the back-end user equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 This is a structural diagram of the main power circuit of a 3KVA online UPS power supply of the utility model;

[0037] Figure 2 This is the overall circuit wiring diagram of the main power circuit of a 3KVA online UPS power supply of the utility model;

[0038] Figure 3 This is a wiring diagram of the AC filter and bypass access circuit of the main power circuit of a 3KVA online UPS power supply of the utility model;

[0039] Figure 4 This is a wiring diagram of a DC-DC conversion circuit of a 3KVA online UPS power supply main power circuit of the utility model;

[0040] Figure 5 This is a wiring diagram of the AC bypass of the main power circuit of a 3KVA online UPS power supply connected to the rectifier circuit of the utility model;

[0041] Figure 6 This is a wiring diagram of the inverter circuit of the main power circuit of a 3KVA online UPS power supply of the utility model;

[0042] Figure 7 This is a wiring diagram of the AC bypass and output conversion circuit of the main power circuit of a 3KVA online UPS power supply of the utility model;

[0043] Figure 8 The utility model discloses a wiring diagram of an output filter circuit of a main power circuit of a 3KVA online UPS power supply. DETAILED DESCRIPTION

[0044] The following will be combined with the implementation of the utility model to clearly and completely describe the technical solutions in the implementation of the utility model. Obviously, the described implementation is only a part of the implementation of the utility model, not all of the implementations. Based on the implementation of the utility model, all other implementations obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0045] This embodiment provides a 3KVA online UPS power supply main power circuit, such as Figure 1 As shown, it includes an AC filter and bypass access circuit 1, a DC-DC conversion circuit 2, an AC bypass access rectification circuit 3, an inverter circuit 4, an AC bypass and output conversion circuit 5 and an output filter circuit 6; Figure 2 , which is an overall circuit wiring diagram of a 3KVA online UPS power supply main power circuit of this embodiment.

[0046] The AC filter and bypass access circuit 1 is electrically connected to the AC bypass access rectifier circuit 3 and the AC bypass and output conversion circuit 5, and is used for switching the AC bypass on and off;

[0047] The DC-DC conversion circuit 2 is electrically connected to the AC bypass access rectification circuit 3 and the inverter circuit 4 to provide high voltage direct current;

[0048] The AC bypass access rectifier circuit 3 is electrically connected to the inverter circuit 4 to achieve zero switching time of UPS power output and improve the circuit power factor;

[0049] The inverter circuit 4 is electrically connected to the AC bypass and output conversion circuit 5, and is used for inverting high-frequency chopping, filtering high-frequency clutter, and absorbing working peak noise;

[0050] The AC bypass and output conversion circuit 5 is electrically connected to the output filter circuit 6 and is used to convert the bypass power supply when the inverter circuit 4 fails;

[0051] The output filter circuit 6 is electrically connected to the AC bypass and output conversion circuit 5 to suppress high-frequency noise interference.

[0052] It should be noted that:

[0053] With the rapid development of switching power supply technology, the uninterruptible power supply UPS now has the new features of online and independent modularization. Uninterruptible power supply UPS is divided into two types: online and backup. The difference is that the back-end inverter circuit of the online UPS power supply is always working, and the AC bypass is only put into operation when the inverter circuit fails; the inverter circuit of the backup UPS power supply does not work at ordinary times, and the AC bypass is put into operation. The back-end inverter circuit only works when the input AC power is cut off or fails. 3KVA uninterruptible power supply UPS is generally used in the computer room to power important equipment such as computers. Because important equipment such as computer rooms require high-quality AC power supply, zero switching time, and long continuous power supply time, and there are many important equipment such as computer rooms. Distributed power supply requires the use of multiple small and medium-power online UPS power supplies without affecting each other. Since the uninterruptible power supply UPS has the needs of online, independent modularization, and distributed power supply, the ordinary backup UPS power supply circuit cannot solve the above problems, which can be solved by designing a 3KVA online UPS power supply main power circuit. The circuit technical indicators of a 3KVA online UPS power supply main power circuit of this embodiment meet the technical requirements of such online UPS power supply main power circuits stipulated by the state, and can be widely used in the actual circuits of uninterruptible power supply UPS modules.

[0054] like Figure 3 As shown, the AC filtering and bypass access circuit 1 includes capacitors C1, C2, C3, C4, C5, varistors MOV1, MOV2, MOV3, MOV4, inductor L1, thermistor NTC1, and relay RY1;

[0055] Pin 1 of inductor L1 is electrically connected to one end of capacitor C1, one end of varistor MOV2, and one end of varistor MOV1. Pin 3 of inductor L1 is electrically connected to the other end of capacitor C1, the other end of varistor MOV1, and one end of varistor MOV3. Pin 2 of inductor L1 is electrically connected to one end of varistor MOV4, one end of capacitor C2, one end of capacitor C4, and one end of thermistor NTC1. Pin 4 of inductor L1 is electrically connected to the other end of MOV4, the other end of capacitor C2, one end of capacitor C3, one end of capacitor C5, and pin 1 of relay RY1. The varistor MOV3, the varistor MOV2, the other end of capacitor C3, and the other end of capacitor C4 are connected to the ground. The other end of the thermistor NTC1 is electrically connected to the other end of capacitor C5 and pin 3 of relay RY1. Pin 6 of relay RY1 is connected to a +12V power supply.

[0056] It should be noted that:

[0057] The thermistor NTC1 plays the role of overcurrent protection. The varistors MOV1, MOV2, MOV3, and MOV4 form three lightning protection circuits: live wire to neutral wire, live wire to ground, and neutral wire to ground, which effectively protect the UPS power supply from the high voltage impact of lightning strikes from the external power grid. The common mode filter inductor L1, capacitors C1, C2, C3, and C4 form an LC filter circuit, which can effectively suppress the interference of external power grid EMI and high-frequency noise generated inside the power supply. The working principle is that when the inverter circuit 4 fails, the relay RY1 is connected and the AC bypass is put into working output; when the inverter circuit is normal and the external AC power is incoming, the relay RY1 is connected, and the AC bypass is connected to the working output of the rectifier circuit 3. After the DC-DC conversion circuit 2 is put into operation, the relay RY1 is turned off; when the UPS power supply is working normally, the relay RY1 is turned off.

[0058] like Figure 4 As shown, the DC-DC conversion circuit 2 includes resistors R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, capacitors C15, C16, C17, C18, C19, C20, insurance F2, F3, diodes D2, D3, D4, D5, D6, D7, MOSFET tubes Q2, Q3, Q4, Q5, inductors L3, L4, and transformer T1;

[0059] Pins 1 and 2 of transformer T1 are electrically connected to one end of resistor R11, the drain of MOSFET tube Q3, and the drain of MOSFET tube Q2. The other end of resistor R11 is electrically connected to one end of capacitor C17. The other end of capacitor C17 is electrically connected to the source of MOSFET tube Q3, one end of resistor R10, the source of MOSFET tube Q2, one end of resistor R8, the negative electrode of capacitor C16, the negative electrode of capacitor C15, one end of resistor R13, the source of MOSFET tube Q4, one end of resistor R15, the source of MOSFET tube Q5, and one end of capacitor C18. The gate of MOSFET tube Q3 is electrically connected to the other end of resistor R10 and one end of resistor R9. The other end of resistor R9 is electrically connected to one end of resistor R7. The other end of the resistor R7 is electrically connected to the gate of the MOSFET tube Q2 and the other end of the resistor R8, the pins 4-7 of the transformer T1 are electrically connected to the positive electrode of the capacitor C16, the positive electrode of the capacitor C15, one end of the insurance F3, and one end of the insurance F2, the pins 9 and 10 of the transformer T1 are electrically connected to one end of the resistor R16, the drain of the MOSFET tube Q5, and the drain of the MOSFET tube Q4, the other end of the resistor R16 is electrically connected to the other end of the capacitor C18, the gate of the MOSFET tube Q5 is electrically connected to one end of the resistor R14 and the other end of the resistor R15, the other end of the resistor R14 is electrically connected to one end of the resistor R12, and the other end of the resistor R12 is electrically connected to the gate of the MOSFET tube Q4 and the other end of the resistor R13;

[0060] Pins 11 and 12 of the transformer T1 are electrically connected to the anode of the diode D2 and the cathode of the diode D4. The cathode of the diode D2 is electrically connected to the cathode of the diode D3, the anode of the diode D6, and one end of the inductor L3. The cathode of the diode D6 is electrically connected to one end of the resistor R17 and one end of the capacitor C19. The other end of the resistor R17 is electrically connected to one end of the resistor R18. The other end of the resistor R18 is electrically connected to the other end of the capacitor C19 and the other end of the inductor L3. Pins 19 and 20 of the transformer T1 are electrically connected to the cathode of the diode D5 and the anode of the diode D3. The anode of the diode D4 is electrically connected to the anode of the diode D5, the anode of the diode D7, and one end of the inductor L4. The cathode of the diode D7 is electrically connected to one end of the resistor R19 and one end of the capacitor C20. The other end of the resistor R19 is electrically connected to one end of the resistor R20. The other end of the resistor R20 is electrically connected to the other end of the capacitor C20 and the other end of the inductor L4.

[0061] It should be noted that:

[0062] Inductors L3, L4, diodes D2, D3, D4, D5, MOSFET tubes Q2, Q3, Q4, Q5, and transformer T1 form a DC-DC conversion circuit, which converts the 72V battery voltage signal into 300V high-voltage pulsating DC. Among them, MOSFET tubes Q2, Q3, Q4, Q5, and the primary winding of transformer T1 form a primary full-wave rectifier circuit, and inductors L3, L4, diodes D2, D3, D4, D5, and the secondary winding of transformer T1 form a secondary full-bridge rectifier boost circuit. Resistors R11, R16, R17, R18, R19, R20, capacitors C17, C18, C19, C20, and diodes D6 and D7 form a spike noise absorption circuit.

[0063] like Figure 5 As shown, the AC bypass access rectifier circuit 3 includes resistors R4, R5, R6, R35, R36, R37, capacitors C11, C12, C13, C14, C25, C26, insurance F1, transformer CT1, inductor L2, diodes D1, D8, D9, IGBT tube Q1, rectifier bridge REC1;

[0064] One end of the fuse F1 is electrically connected to the pin 1 of the transformer CT1, the pin 6 of the transformer CT1 is electrically connected to one end of the resistor R36 and one end of the resistor R35, the pin 5 of the transformer CT1 is electrically connected to the other end of the resistor R36 and the other end of the resistor R35, the pin 4 of the transformer CT1 is electrically connected to one end of the inductor L2, the other end of the inductor L2 is electrically connected to one end of the capacitor C11, the positive electrode of the diode D8, one end of the capacitor C25, the negative electrode of the diode D9, one end of the capacitor C26, one end of the capacitor C13, and the AC positive input terminal of the rectifier bridge REC1, the other end of the capacitor C11 is electrically connected to one end of the capacitor C12 and the AC negative input terminal of the rectifier bridge REC1, the negative electrode of the diode D8 is electrically connected to the other end of the capacitor C25, and the negative electrode of the diode D9 is electrically connected to the capacitor C26. One end is electrically connected, the positive electrode of diode D9 is electrically connected to the other end of capacitor C26, the other end of capacitor C12 is electrically connected to the other end of capacitor C13, one end of capacitor C14, the collector of IGBT tube Q1, and the DC positive output end of rectifier bridge REC1, the emitter of IGBT tube Q1 is electrically connected to one end of resistor R37, and the DC negative output end of rectifier bridge REC1 is electrically connected to the working ground, the gate of IGBT tube Q1 is electrically connected to the positive electrode of diode D1, one end of resistor R6, and one end of resistor R5, the other end of capacitor C14 is electrically connected to the other end of resistor R37, the negative electrode of diode D1 is electrically connected to one end of resistor R4, the other end of resistor R4 is electrically connected to the other end of resistor R5, and the other end of resistor R6 is connected to the working ground.

[0065] It should be noted that:

[0066] The working principle of the AC bypass access rectifier circuit 3 is: when the external AC power is incoming, the DC-DC conversion circuit 2 does not work normally, the AC bypass access rectifier circuit 3 is put into working output, and the DC-DC conversion circuit 2 is shut down after working normally, so as to achieve the effect of zero switching time of UPS power output. Inductor L2, diodes D8 and D9 form a half-wave rectifier boost circuit to convert the input AC power into 300V high-voltage pulsating DC power. The PFC correction circuit composed of IGBT tube Q1 and rectifier bridge REC1 improves and corrects the consistency of the input voltage and current waveform of the half-wave rectifier boost circuit, thereby improving the power factor of the circuit. Transformer CT1 plays the role of input current detection.

[0067] like Figure 6 As shown, the inverter circuit 4 includes resistors R21, R22, R23, R24, R25, R26, R27, R28, R29, R30, R31, R32, R33, R34, R38, R39, capacitors C6, C21, C22, C23, C24, C27, C28, inductors L5, L6, diodes D10, D11, D12, D13, D14, D15, IGBT tubes Q6, Q7, Q8, Q9, and a transformer CT3;

[0068] Pin 4 of the transformer CT3 is electrically connected to one end of the capacitor C6, pin 5 of the transformer CT3 is electrically connected to one end of the resistor R38 and one end of the resistor R39, pin 6 of the transformer CT3 is electrically connected to the other end of the resistor R38 and the other end of the resistor R39, pin 1 of the transformer CT3 is electrically connected to one end of the inductor L6, the other end of the capacitor C6 is electrically connected to the negative electrode of the capacitor C22, the negative electrode of the capacitor C21, the positive electrode of the capacitor C23, and the positive electrode of the capacitor C24, the other end of the inductor L6 is electrically connected to one end of the inductor L5, the collector of the IGBT tube Q6 is electrically connected to the positive electrode of the capacitor C21, the positive electrode of the capacitor C22, The collector of IGBT tube Q7, one end of resistor R27, and the positive electrode of diode D12 are electrically connected. The gate of IGBT tube Q6 is electrically connected to one end of resistor R21, one end of resistor R22, and one end of resistor R23. The other end of resistor R21 is electrically connected to the positive electrode of diode D10. The cathode of diode D10 is electrically connected to the other end of resistor R22, the cathode of diode D11, and one end of resistor R25. The emitter of IGBT tube Q6 is electrically connected to the other end of resistor R23, one end of resistor R26, the emitter of IGBT tube Q7, one end of capacitor C27, the other end of inductor L5, and IGBT tube Q8. The collector of the IGBT tube Q9 is electrically connected to one end of the capacitor C28, the cathode of the diode D12 is electrically connected to the other end of the resistor R27 and the other end of the capacitor C27, the gate of the IGBT tube Q7 is electrically connected to one end of the resistor R24, the other end of the resistor R25, and the other end of the resistor R26, the anode of the diode D11 is electrically connected to the other end of the resistor R24, the gate of the IGBT tube Q8 is electrically connected to one end of the resistor R28, one end of the resistor R29, and one end of the resistor R30, the other end of the resistor R28 is electrically connected to the anode of the diode D13, the cathode of the diode D13 is electrically connected to the cathode of the resistor R29 The other end, the cathode of diode D14, and one end of resistor R32 are electrically connected, the emitter of IGBT tube Q8 is electrically connected to the other end of resistor R30, the cathode of capacitor C23, the cathode of capacitor C24, one end of resistor R33, the emitter of IGBT tube Q9, one end of resistor R34, and the cathode of diode D15, the gate of IGBT tube Q9 is electrically connected to one end of resistor R31, the other end of resistor R32, and the other end of resistor R33, the anode of diode D14 is electrically connected to the other end of resistor R31, and the other end of capacitor C28 is electrically connected to the other end of resistor R34 and the anode of diode D15.

[0069] It should be noted that:

[0070] Capacitors C21, C22, C23, C24, IGBT tubes Q6, Q7, Q8, Q9 form a half-bridge inverter circuit, which converts the 300V high-voltage pulsating DC output by DC-DC conversion circuit 2 into high-quality AC after inverter high-frequency chopping. Capacitor C6, inductors L5, L6 form an LC filter circuit, which has the function of filtering the output high-frequency noise. Resistors R27, R34, capacitors C27, C28, diodes D12, D15 form a circuit, which plays a role in absorbing the working peak noise of IGBT tubes Q6, Q7, Q8, Q9. Transformer CT3 plays the role of inverter output current detection.

[0071] like Figure 7 As shown, the AC bypass and output conversion circuit 5 includes a resistor R1 and a relay RY2;

[0072] Pin 1 of relay RY2 is electrically connected to one end of resistor R1, and the other end of resistor R1 is connected to a +12V power supply.

[0073] It should be noted that:

[0074] The working principle of the AC bypass and output conversion circuit 5 is: when the inverter circuit 4 works normally, the relay RY2 is connected to the inverter circuit 4 and outputs to the user load; when the inverter circuit 4 fails, the relay RY2 is connected to the AC bypass output to the user load to achieve long-term continuous power supply.

[0075] like Figure 8 As shown, the output filter circuit 6 includes resistors R2, R3, capacitors C7, C8, C9, C10, inductor L7, transformer CT2, and fuse F4;

[0076] Pin 6 of the transformer CT2 is electrically connected to one end of the resistor R3 and one end of the resistor R2, pin 5 of the transformer CT2 is electrically connected to the other end of the resistor R2 and the other end of the resistor R3, pin 4 of the transformer CT2 is electrically connected to one end of the capacitor C7 and pin 1 of the inductor L7, pin 3 of the inductor L7 is electrically connected to the other end of the capacitor C7, pin 2 of the inductor L7 is electrically connected to one end of the capacitor C8, one end of the capacitor C10, and one end of the fuse F4, pin 4 of the inductor L7 is electrically connected to the other end of the capacitor C8 and one end of the capacitor C9, and the other end of the capacitor C9 and the other end of the capacitor C10 are connected to the ground.

[0077] Pin 4 of relay RY1 is electrically connected to the other end of fuse F1 and pins 2 and 7 of relay RY2, pin 2 of relay RY1 is electrically connected to the other end of capacitor C6, pins 4 and 5 of relay RY2 are electrically connected to one end of capacitor C6, and pins 3 and 6 of relay RY2 are electrically connected to pin 1 of transformer CT2.

[0078] Pins 15 and 16 of the transformer T1 are electrically connected to the negative electrode of the capacitor C21, the other end of the inductor L3 is electrically connected to the positive electrode of the capacitor C21, and the other end of the inductor L4 is electrically connected to the negative electrode of the capacitor C23;

[0079] The cathode of the diode D8 is electrically connected to the other end of the inductor L3, the anode of the diode D9 is electrically connected to the other end of the inductor L4, and the AC cathode input of the rectifier bridge REC1 is electrically connected to the other end of the capacitor C6.

[0080] Pin 3 of the inductor L7 is electrically connected to the other end of the capacitor C6.

[0081] It should be noted that:

[0082] Fuse F4 plays the role of output overcurrent protection. Common mode filter inductor L7, capacitors C7, C8, C9, C10 form an LC filter circuit, which can effectively suppress the interference of external power grid EMI and high-frequency noise generated inside the power supply, and deliver cleaner AC power to the back-end user equipment. Transformer CT2 plays the role of output current detection.

[0083] It should be noted that:

[0084] The working process of the main power circuit of a 3KVA online UPS power supply of this embodiment is: when the external 220V AC power is normal, the DC charging power supply works to charge the battery and outputs it to the DC-DC conversion circuit 2 for DC conversion, and then the inverter circuit 4 inverts the high-frequency chopping, and then the AC bypass and output conversion circuit 5 selects the output mode, and finally the output filter circuit 6 performs LC filtering to output the 220V AC power required by the user equipment. When the external 220V AC power is cut off, the battery is put into operation to run the above working process, and the 220V AC power required by the user equipment is output. When the external 220V AC power is on, the DC-DC conversion circuit 2 does not work normally, and the AC bypass is opened through the AC filtering and bypass access circuit 1, and then the AC bypass is connected to the rectifier circuit 3 for rectification and boosting, and finally the inverter circuit 4 is inverted and output to the user equipment; after the DC-DC conversion circuit 2 is put into operation, the AC bypass is turned off, and the DC charging power supply works to output and run the working process; when the inverter circuit 4 fails, the AC bypass is put into output to the user equipment.

[0085] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A 3KVA online UPS power supply main power circuit, characterized in that: It comprises an AC filtering and bypass access circuit (1), a DC-DC conversion circuit (2), an AC bypass access rectification circuit (3), an inverter circuit (4), an AC bypass and output conversion circuit (5) and an output filtering circuit (6); The AC filtering and bypass access circuit (1) is electrically connected to the AC bypass access rectification circuit (3) and the AC bypass and output conversion circuit (5); The DC-DC conversion circuit (2) is electrically connected to the AC bypass rectifier circuit (3) and the inverter circuit (4); The AC bypass access rectifier circuit (3) is electrically connected to the inverter circuit (4); The inverter circuit (4) is electrically connected to the AC bypass and output conversion circuit (5); The AC bypass and output conversion circuit (5) is electrically connected to the output filter circuit (6); The output filter circuit (6) is electrically connected to the AC bypass and output conversion circuit (5).

2. A 3KVA online UPS power supply main power circuit as claimed in claim 1, characterized in that: The AC filtering and bypass access circuit (1) comprises capacitors C1, C2, C3, C4, C5, varistors MOV1, MOV2, MOV3, MOV4, inductor L1, thermistor NTC1, and relay RY1; Pin 1 of inductor L1 is electrically connected to one end of capacitor C1, one end of varistor MOV2, and one end of varistor MOV1. Pin 3 of inductor L1 is electrically connected to the other end of capacitor C1, the other end of varistor MOV1, and one end of varistor MOV3. Pin 2 of inductor L1 is electrically connected to one end of varistor MOV4, one end of capacitor C2, one end of capacitor C4, and one end of thermistor NTC1. Pin 4 of inductor L1 is electrically connected to the other end of MOV4, the other end of capacitor C2, one end of capacitor C3, one end of capacitor C5, and pin 1 of relay RY1. The varistor MOV3, the varistor MOV2, the other end of capacitor C3, and the other end of capacitor C4 are connected to the ground. The other end of the thermistor NTC1 is electrically connected to the other end of capacitor C5 and pin 3 of relay RY1. Pin 6 of relay RY1 is connected to a +12V power supply.

3. A 3KVA online UPS power supply main power circuit as claimed in claim 2, characterized in that: The DC-DC conversion circuit (2) comprises resistors R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, capacitors C15, C16, C17, C18, C19, C20, fuses F2, F3, diodes D2, D3, D4, D5, D6, D7, MOSFET tubes Q2, Q3, Q4, Q5, inductors L3, L4, and a transformer T1; Pins 1 and 2 of transformer T1 are electrically connected to one end of resistor R11, the drain of MOSFET tube Q3, and the drain of MOSFET tube Q2. The other end of resistor R11 is electrically connected to one end of capacitor C17. The other end of capacitor C17 is electrically connected to the source of MOSFET tube Q3, one end of resistor R10, the source of MOSFET tube Q2, one end of resistor R8, the negative electrode of capacitor C16, the negative electrode of capacitor C15, one end of resistor R13, the source of MOSFET tube Q4, one end of resistor R15, the source of MOSFET tube Q5, and one end of capacitor C18. The gate of MOSFET tube Q3 is electrically connected to the other end of resistor R10 and one end of resistor R9. The other end of resistor R9 is electrically connected to one end of resistor R7. The other end of the resistor R7 is electrically connected to the gate of the MOSFET tube Q2 and the other end of the resistor R8, the pins 4-7 of the transformer T1 are electrically connected to the positive electrode of the capacitor C16, the positive electrode of the capacitor C15, one end of the insurance F3, and one end of the insurance F2, the pins 9 and 10 of the transformer T1 are electrically connected to one end of the resistor R16, the drain of the MOSFET tube Q5, and the drain of the MOSFET tube Q4, the other end of the resistor R16 is electrically connected to the other end of the capacitor C18, the gate of the MOSFET tube Q5 is electrically connected to one end of the resistor R14 and the other end of the resistor R15, the other end of the resistor R14 is electrically connected to one end of the resistor R12, and the other end of the resistor R12 is electrically connected to the gate of the MOSFET tube Q4 and the other end of the resistor R13; Pins 11 and 12 of the transformer T1 are electrically connected to the anode of the diode D2 and the cathode of the diode D4. The cathode of the diode D2 is electrically connected to the cathode of the diode D3, the anode of the diode D6, and one end of the inductor L3. The cathode of the diode D6 is electrically connected to one end of the resistor R17 and one end of the capacitor C19. The other end of the resistor R17 is electrically connected to one end of the resistor R18. The other end of the resistor R18 is electrically connected to the other end of the capacitor C19 and the other end of the inductor L3. Pins 19 and 20 of the transformer T1 are electrically connected to the cathode of the diode D5 and the anode of the diode D3. The anode of the diode D4 is electrically connected to the anode of the diode D5, the anode of the diode D7, and one end of the inductor L4. The cathode of the diode D7 is electrically connected to one end of the resistor R19 and one end of the capacitor C20. The other end of the resistor R19 is electrically connected to one end of the resistor R20. The other end of the resistor R20 is electrically connected to the other end of the capacitor C20 and the other end of the inductor L4.

4. A 3KVA online UPS power supply main power circuit as claimed in claim 3, characterized in that: The AC bypass rectifier circuit (3) comprises resistors R4, R5, R6, R35, R36, R37, capacitors C11, C12, C13, C14, C25, C26, a fuse F1, a transformer CT1, an inductor L2, diodes D1, D8, D9, an IGBT tube Q1, and a rectifier bridge REC1; One end of the fuse F1 is electrically connected to the pin 1 of the transformer CT1, the pin 6 of the transformer CT1 is electrically connected to one end of the resistor R36 and one end of the resistor R35, the pin 5 of the transformer CT1 is electrically connected to the other end of the resistor R36 and the other end of the resistor R35, the pin 4 of the transformer CT1 is electrically connected to one end of the inductor L2, the other end of the inductor L2 is electrically connected to one end of the capacitor C11, the positive electrode of the diode D8, one end of the capacitor C25, the negative electrode of the diode D9, one end of the capacitor C26, one end of the capacitor C13, and the AC positive input terminal of the rectifier bridge REC1, the other end of the capacitor C11 is electrically connected to one end of the capacitor C12 and the AC negative input terminal of the rectifier bridge REC1, the negative electrode of the diode D8 is electrically connected to the other end of the capacitor C25, and the negative electrode of the diode D9 is electrically connected to the capacitor C26. One end is electrically connected, the positive electrode of diode D9 is electrically connected to the other end of capacitor C26, the other end of capacitor C12 is electrically connected to the other end of capacitor C13, one end of capacitor C14, the collector of IGBT tube Q1, and the DC positive output end of rectifier bridge REC1, the emitter of IGBT tube Q1 is electrically connected to one end of resistor R37, and the DC negative output end of rectifier bridge REC1 is electrically connected to the working ground, the gate of IGBT tube Q1 is electrically connected to the positive electrode of diode D1, one end of resistor R6, and one end of resistor R5, the other end of capacitor C14 is electrically connected to the other end of resistor R37, the negative electrode of diode D1 is electrically connected to one end of resistor R4, the other end of resistor R4 is electrically connected to the other end of resistor R5, and the other end of resistor R6 is connected to the working ground.

5. A 3KVA online UPS power supply main power circuit as claimed in claim 4, characterized in that: The inverter circuit (4) comprises resistors R21, R22, R23, R24, R25, R26, R27, R28, R29, R30, R31, R32, R33, R34, R38, R39, capacitors C6, C21, C22, C23, C24, C27, C28, inductors L5, L6, diodes D10, D11, D12, D13, D14, D15, IGBT tubes Q6, Q7, Q8, Q9, and a transformer CT3; Pin 4 of the transformer CT3 is electrically connected to one end of the capacitor C6, pin 5 of the transformer CT3 is electrically connected to one end of the resistor R38 and one end of the resistor R39, pin 6 of the transformer CT3 is electrically connected to the other end of the resistor R38 and the other end of the resistor R39, pin 1 of the transformer CT3 is electrically connected to one end of the inductor L6, the other end of the capacitor C6 is electrically connected to the negative electrode of the capacitor C22, the negative electrode of the capacitor C21, the positive electrode of the capacitor C23, and the positive electrode of the capacitor C24, the other end of the inductor L6 is electrically connected to one end of the inductor L5, the collector of the IGBT tube Q6 is electrically connected to the positive electrode of the capacitor C21, the positive electrode of the capacitor C22, The collector of IGBT tube Q7, one end of resistor R27, and the positive electrode of diode D12 are electrically connected. The gate of IGBT tube Q6 is electrically connected to one end of resistor R21, one end of resistor R22, and one end of resistor R23. The other end of resistor R21 is electrically connected to the positive electrode of diode D10. The cathode of diode D10 is electrically connected to the other end of resistor R22, the cathode of diode D11, and one end of resistor R25. The emitter of IGBT tube Q6 is electrically connected to the other end of resistor R23, one end of resistor R26, the emitter of IGBT tube Q7, one end of capacitor C27, the other end of inductor L5, and IGBT tube Q8. The collector of the IGBT tube Q9 is electrically connected to one end of the capacitor C28, the cathode of the diode D12 is electrically connected to the other end of the resistor R27 and the other end of the capacitor C27, the gate of the IGBT tube Q7 is electrically connected to one end of the resistor R24, the other end of the resistor R25, and the other end of the resistor R26, the anode of the diode D11 is electrically connected to the other end of the resistor R24, the gate of the IGBT tube Q8 is electrically connected to one end of the resistor R28, one end of the resistor R29, and one end of the resistor R30, the other end of the resistor R28 is electrically connected to the anode of the diode D13, the cathode of the diode D13 is electrically connected to the cathode of the resistor R29 The other end, the cathode of diode D14, and one end of resistor R32 are electrically connected, the emitter of IGBT tube Q8 is electrically connected to the other end of resistor R30, the cathode of capacitor C23, the cathode of capacitor C24, one end of resistor R33, the emitter of IGBT tube Q9, one end of resistor R34, and the cathode of diode D15, the gate of IGBT tube Q9 is electrically connected to one end of resistor R31, the other end of resistor R32, and the other end of resistor R33, the anode of diode D14 is electrically connected to the other end of resistor R31, and the other end of capacitor C28 is electrically connected to the other end of resistor R34 and the anode of diode D15.

6. A 3KVA online UPS power supply main power circuit as claimed in claim 5, characterized in that: The AC bypass and output conversion circuit (5) comprises a resistor R1 and a relay RY2; Pin 1 of relay RY2 is electrically connected to one end of resistor R1, and the other end of resistor R1 is connected to a +12V power supply.

7. A 3KVA online UPS power supply main power circuit as claimed in claim 6, characterized in that: The output filter circuit (6) comprises resistors R2, R3, capacitors C7, C8, C9, C10, inductor L7, transformer CT2, and fuse F4; Pin 6 of the transformer CT2 is electrically connected to one end of the resistor R3 and one end of the resistor R2, pin 5 of the transformer CT2 is electrically connected to the other end of the resistor R2 and the other end of the resistor R3, pin 4 of the transformer CT2 is electrically connected to one end of the capacitor C7 and pin 1 of the inductor L7, pin 3 of the inductor L7 is electrically connected to the other end of the capacitor C7, pin 2 of the inductor L7 is electrically connected to one end of the capacitor C8, one end of the capacitor C10, and one end of the fuse F4, pin 4 of the inductor L7 is electrically connected to the other end of the capacitor C8 and one end of the capacitor C9, and the other end of the capacitor C9 and the other end of the capacitor C10 are connected to the ground.

8. A 3KVA online UPS power supply main power circuit as claimed in claim 7, characterized in that: Pin 4 of relay RY1 is electrically connected to the other end of fuse F1 and pins 2 and 7 of relay RY2, pin 2 of relay RY1 is electrically connected to the other end of capacitor C6, pins 4 and 5 of relay RY2 are electrically connected to one end of capacitor C6, and pins 3 and 6 of relay RY2 are electrically connected to pin 1 of transformer CT2.

9. A 3KVA online UPS power supply main power circuit as claimed in claim 8, characterized in that: Pins 15 and 16 of the transformer T1 are electrically connected to the negative electrode of the capacitor C21, the other end of the inductor L3 is electrically connected to the positive electrode of the capacitor C21, and the other end of the inductor L4 is electrically connected to the negative electrode of the capacitor C23; The cathode of the diode D8 is electrically connected to the other end of the inductor L3, the anode of the diode D9 is electrically connected to the other end of the inductor L4, and the AC cathode input of the rectifier bridge REC1 is electrically connected to the other end of the capacitor C6.

10. A 3KVA online UPS power supply main power circuit as claimed in claim 9, characterized in that: Pin 3 of the inductor L7 is electrically connected to the other end of the capacitor C6.

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