Impact transient current soft start device for UPS (Uninterrupted Power Supply)

Abstract

The utility model belongs to the technical field of UPS (Uninterrupted Power Supply) soft starters, and particularly discloses an impact transient current soft start device for a UPS, which comprises a mains supply soft start module, a battery soft start module and a current limiting circuit used for limiting the impact current and preventing transient overload. The commercial power soft start module comprises a commercial power soft starter used for introducing commercial power into the current limiting circuit, a bus voltage detection circuit used for detecting bus voltage, and an input control circuit used for controlling starting and stopping of the commercial power soft starter according to a bus voltage detection result. According to the utility model, through the combination of the commercial power soft start module, the battery soft start module and the current limiting circuit, the soft start function in a commercial power mode and a battery mode is realized, the impact current during starting is effectively reduced, the stability of the UPS is improved, and the service life of the UPS is prolonged; through the cooperation of the switching circuit, the driving pulse generation circuit and the monitoring circuit, the monitoring circuit is used for monitoring the current and voltage of the circuit, and the accuracy and reliability of the current limiting circuit are ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of UPS soft starters, in particular to an impact transient current soft starter device for UPS. Background Art

[0002] UPS soft start refers to the process of gradually accelerating or decelerating the equipment to its normal operating state by controlling the changes in current or voltage when the UPS power supply is started, so as to reduce the current shock and voltage peak in the circuit, protect the circuit components and reduce mechanical damage to the equipment.

[0003] At present, UPS usually adopts SCR-R circuit method for soft start, that is, when the power is instantaneously connected, the input voltage charges the capacitor through the rectifier bridge and the current limiting resistor. When the capacitor is charged to a certain proportion of the rated voltage, the inverter generates a trigger signal to turn on the thyristor, short-circuit the current limiting resistor, and make the switching power supply operate normally.

[0004] However, when the power is cut off instantly, the voltage on the capacitor cannot change suddenly, and the charging voltage before the power outage is still on it. In this case, the inverter may still be in working state, keeping the thyristor on. If the input power is immediately reconnected at this time, it will also fail to prevent the inrush current, causing the grid voltage to fluctuate and affecting the service life of the UPS. Therefore, we need to propose an inrush transient current soft starting device for UPS to solve the above problems, so that it can reduce the impact of the starting current on the grid, reduce the grid voltage fluctuation, and improve the stability of the grid. Utility Model Content

[0005] The purpose of the utility model is to provide an impact transient current soft starting device for UPS. By combining a mains soft starting module, a battery soft starting module and a current limiting circuit, the utility model realizes the soft starting function in mains mode and battery mode, effectively reduces the impact current during startup, and improves the stability and service life of the UPS, so as to solve the problems raised in the background technology.

[0006] To achieve the above objectives, the present invention provides the following technical solutions: a surge transient current soft start device for a UPS, comprising a mains soft start module, a battery soft start module, and a current limiting circuit for limiting surge current to prevent instantaneous overload, wherein the current limiting circuit is electrically connected to the mains soft start module and the battery soft start module, respectively;

[0007] The mains soft start module includes a mains soft starter for introducing the mains into the current limiting circuit, a bus voltage detection circuit for detecting the bus voltage, and an input control circuit for controlling the start and stop of the mains soft starter according to the bus voltage detection result, wherein the mains soft starter is electrically connected to the bus voltage detection circuit;

[0008] The battery soft start module includes a switch circuit for controlling battery charging on and off, a drive pulse generating circuit for converting battery energy into driving the switch circuit on and off, and a monitoring circuit for monitoring battery status.

[0009] Preferably, the bus voltage detection circuit includes a coupling chip U1 respectively connected to the U terminal, V terminal and W terminal of the three-phase electricity, the three coupling chips U1 are connected in parallel, one pin of the coupling chip U1 is connected to a resistor R6 with a resistance value, a diode M7 is connected between the 2nd pin of the coupling chip U1 and the resistor R6, the 4th pin of the coupling chip U1 is connected to the resistor R7, and the three resistors R7 are connected in parallel.

[0010] Preferably, the input control circuit includes a driver chip U23, a resistor R11 and a diode D2 are connected in parallel between the two input ends of the driver chip U23, a diode D1 is connected to the connecting end of the resistor R11 and the diode D2, one end of the diode D1 is connected to a transistor Q3, a transistor Q4 and a transistor Q5 respectively, the base of the transistor Q3 is connected to one of the resistors R7 through a resistor R8, the base of the transistor Q4 is connected to another of the resistors R7 through a resistor R9, the base of the transistor Q5 is connected to another resistor R7 through a resistor R10, the emitter of the transistor Q3 is connected to a ground resistor R43, the emitter of the transistor Q4 is connected to a ground resistor R44, and the emitter of the transistor Q5 is connected to a ground resistor R45, a diode D4 and a resistor R12 are connected in parallel between the two output ends of the driver chip U23, and a diode D3 is connected between the diode D4 and one of the output ends of the driver chip U23.

[0011] Preferably, the switching circuit includes a MOS transistor Q1, a capacitor C1 is connected between the gate and drain of the MOS transistor Q1, a resistor R2 is connected to the connecting end of the capacitor C1 and the gate of the MOS transistor Q1, one end of the resistor R2 is connected to the resistor R1, one end of the resistor R1 is connected to the connecting end of the capacitor C1 and the drain of the MOS transistor Q1, a transistor Q2 is connected to the connecting end of the resistor R2 and the resistor R1, a resistor R3 for receiving a control signal is connected to the base of the transistor Q2, and one end of the resistor R3 is connected to a ground resistor R4.

[0012] Preferably, the drive pulse generating circuit includes an amplifier U5 and an amplifier U6, the output end of the amplifier U5 is connected to the positive end of the amplifier U6 through a resistor R22, the connection end of the positive end of the amplifier U6 and the resistor R22 is connected to an adjustable resistor R23, one end of the adjustable resistor R23 is connected to the output end of the amplifier U6, the adjustable end of the adjustable resistor R23 is connected to the negative end of the amplifier U5 through a resistor R24, a capacitor C14 is connected between the negative end and the output end of the amplifier U5, the positive end of the amplifier U5 is connected to the monitoring circuit, and the positive end of the amplifier U5 is connected to the negative end of the amplifier U6.

[0013] Preferably, the monitoring circuit includes a sampling resistor R21, one end of which is connected to the positive terminal of the amplifier U5, and a resistor R19, a ground resistor R20 and a ground capacitor C13 are connected in parallel to the connection end between the resistor R21 and the positive terminal of the amplifier U5.

[0014] Preferably, the current limiting circuit includes an amplifier U2, the positive terminal of the amplifier U2 is connected to an adjustable resistor R16, one end of the adjustable resistor R16 is connected to a resistor R17, one end of the resistor R17 is connected in parallel with a diode D5 and a ground resistor R18, a capacitor C10 is connected between the positive terminal of the amplifier U2 and the other end of the adjustable resistor R16, the output terminal of the amplifier U2 is connected to a transistor Q6, the drain of the transistor Q6 is connected to a resistor R14, and one end of the resistor R14 is connected to the output terminal of the amplifier U2 through a resistor R15.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. The utility model realizes the soft start function in mains mode and battery mode through the combination of mains soft start module, battery soft start module and current limiting circuit, effectively reduces the inrush current at startup and improves the stability and service life of UPS.

[0017] 2. The utility model cooperates with the input control circuit, the bus voltage detection circuit and the mains soft starter, uses the bus voltage detection circuit to detect the mains voltage status in real time, and controls the start and stop of the mains soft starter according to the feedback information of the bus voltage detection circuit, which can ensure that the mains soft starter operates at an appropriate voltage and improve the service life of the mains soft starter.

[0018] 3. The utility model ensures the accuracy and reliability of the current limiting circuit by cooperating with the switching circuit, the driving pulse generating circuit and the monitoring circuit and utilizing the monitoring circuit to monitor the current and voltage of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1This is a system block diagram of the utility model;

[0020] Figure 2 This is a circuit diagram of the bus voltage detection circuit of the utility model;

[0021] Figure 3 This is a circuit diagram of the input control circuit of the utility model;

[0022] Figure 4 This is a circuit diagram of the switch circuit of the utility model;

[0023] Figure 5 This is a circuit diagram of a drive pulse generating circuit of the utility model;

[0024] Figure 6 This is a circuit diagram of the current limiting circuit of the utility model. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] See also Figure 1-6 The utility model provides a technical solution: an impact transient current soft starting device for UPS, comprising a mains soft starting module, a battery soft starting module and a current limiting circuit for limiting the impact current to prevent instantaneous overload, wherein the current limiting circuit is electrically connected to the mains soft starting module and the battery soft starting module respectively;

[0027] The mains soft start module includes a mains soft starter for introducing the mains into the current limiting circuit, a bus voltage detection circuit for detecting the bus voltage, and an input control circuit for controlling the start and stop of the mains soft starter according to the bus voltage detection result. The mains soft starter is electrically connected to the bus voltage detection circuit, and the bus voltage detection circuit is used to detect the mains voltage state in real time. The mains soft starter is controlled to start and stop according to the feedback information of the bus voltage detection circuit, which can ensure that the mains soft starter is operated at an appropriate voltage and improve the service life of the mains soft starter.

[0028] The bus voltage detection circuit includes a coupling chip U1 connected to the U terminal, V terminal and W terminal of the three-phase power respectively. The three coupling chips U1 are connected in parallel. One pin of the coupling chip U1 is connected to a resistor R6. A diode M7 is connected between the 2nd pin of the coupling chip U1 and the resistor R6. The 4th pin of the coupling chip U1 is connected to the resistor R7. The three resistors R7 are connected in parallel. The three coupling chips U1 are used to monitor the voltage status of the three-phase power. The diode M7 plays a unidirectional conductive role to prevent reverse current flow and protect the circuit.

[0029] The input control circuit includes a driver chip U23. A resistor R11 and a diode D2 are connected in parallel between the two input ends of the driver chip U23. A diode D1 is connected to the connecting end of the resistor R11 and the diode D2. One end of the diode D1 is connected to a transistor Q3, a transistor Q4, and a transistor Q5, respectively. The base of the transistor Q3 is connected to one of the resistors R7 through a resistor R8. The base of the transistor Q4 is connected to another of the resistors R7 through a resistor R9. The base of the transistor Q5 is connected to the other resistor R7 through a resistor R10. The emitter of the transistor Q3 is connected to a ground resistor R43. The emitter of the transistor Q4 is connected to a ground resistor R44. The emitter of the transistor Q5 is connected to a ground resistor R45. A diode D4 and a resistor R12 are connected in parallel between the two output terminals of the driver chip U23. A diode D3 is connected between the diode D4 and one of the output terminals of the driver chip U23. The driver chip U23 is responsible for receiving and processing input signals and converting these signals into control commands suitable for recognition by external devices. The resistor R11 and the diode D2 are connected in parallel between the two input terminals of the driver chip U23 to form a voltage divider network for stabilizing the input voltage and protecting the driver chip from overvoltage damage. The transistors Q3, Q4, and Q5 are turned on or off according to changes in the input signal, thereby controlling the working state of the subsequent circuit.

[0030] The battery soft-start module includes a switching circuit that controls the on / off charging of the battery, a driving pulse generating circuit for converting battery energy into a driving pulse for switching the switching circuit on and off, and a monitoring circuit for monitoring the battery status. The monitoring circuit monitors the current and voltage of the circuit to ensure the accuracy and reliability of the current limiting circuit.

[0031] The switch circuit includes a MOS transistor Q1, a capacitor C1 is connected between the gate and drain of the MOS transistor Q1, a resistor R2 is connected to the connection end of the capacitor C1 and the gate of the MOS transistor Q1, one end of the resistor R2 is connected to the resistor R1, one end of the resistor R1 is connected to the connection end of the capacitor C1 and the drain of the MOS transistor Q1, a transistor Q2 is connected to the connection end of the resistor R2 and the resistor R1, a resistor R3 for receiving a control signal is connected to the base of the transistor Q2, one end of the resistor R3 is connected to a ground resistor R4, and the capacitor C1, MOS tube Q1 and resistor R2 form an RC filter network for smoothing the gate voltage and reducing noise interference. At the same time, resistor R2 also plays a current limiting role to prevent excessive current from flowing into the gate. When its base receives the control signal from resistor R3 (the signal is usually a high level or a low level), transistor Q2 will be turned on or off. When transistor Q2 is turned on, it will lower the gate voltage of MOS tube Q1, turning on MOS tube Q1; when transistor Q2 is turned off, it will release the gate voltage, turning off MOS tube Q1.

[0032] The drive pulse generating circuit includes an amplifier U5 and an amplifier U6. The output end of the amplifier U5 is connected to the positive end of the amplifier U6 through a resistor R22. The connection end of the positive end of the amplifier U6 and the resistor R22 is connected to an adjustable resistor R23. One end of the adjustable resistor R23 is connected to the output end of the amplifier U6. The adjustable end of the adjustable resistor R23 is connected to the negative end of the amplifier U5 through a resistor R24. A capacitor C14 is connected between the negative end and the output end of the amplifier U5. The positive end of the amplifier U5 is connected to a monitoring circuit, and the positive end of the amplifier U5 is connected to the negative end of the amplifier U6. Through the cascade amplification, feedback control, signal shaping and filtering, and output control of the amplifiers U5 and U6, accurate processing of the input signal and output control are achieved.

[0033] The monitoring circuit includes a sampling resistor R21, one end of which is connected to the positive terminal of the amplifier U5. A resistor R19, a ground resistor R20 and a ground capacitor C13 are connected in parallel to the connection end between the resistor R21 and the positive terminal of the amplifier U5.

[0034] The current limiting circuit includes an amplifier U2, the positive terminal of the amplifier U2 is connected to an adjustable resistor R16, one end of the adjustable resistor R16 is connected to a resistor R17, one end of the resistor R17 is connected in parallel with a diode D5 and a ground resistor R18, a capacitor C10 is connected between the positive terminal of the amplifier U2 and the other end of the adjustable resistor R16, the output end of the amplifier U2 is connected to a transistor Q6, the drain of the transistor Q6 is connected to a resistor R14, one end of the resistor R14 is connected to the output end of the amplifier U2 via a resistor R15, and the transistor Q6 is used as a switch. When the current is too large, the transistor is turned on, diverting part of the current to the ground, thereby reducing the current in the main circuit.

[0035] When the mains power is available, the mains soft start module works first, and by controlling the mains soft starter and input control circuit, the mains power is smoothly introduced into the UPS system. At the same time, the current limiting circuit starts working to limit the current at startup to prevent instantaneous overload.

[0036] When the mains power is unavailable or the battery is used for power supply, the battery soft start module takes over the work. It smoothly converts the battery energy into the input of the UPS system through the switching circuit and the drive pulse generating circuit. Similarly, the current limiting circuit will also limit the current size at startup.

[0037] When the mains power is restored, the mains soft start module will detect the presence of mains power and gradually reduce the proportion of battery power until it is completely switched to mains power. During this process, the current limiting circuit will continue to work to ensure a smooth switching process, realizing the soft start function in mains mode and battery mode, effectively reducing the inrush current at startup and improving the stability and service life of the UPS.

[0038] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A transient current soft start device for UPS, characterized by: It includes a mains soft start module, a battery soft start module and a current limiting circuit for limiting the magnitude of the inrush current to prevent instantaneous overload, wherein the current limiting circuit is electrically connected to the mains soft start module and the battery soft start module respectively; The mains soft start module includes a mains soft starter for introducing the mains into the current limiting circuit, a bus voltage detection circuit for detecting the bus voltage, and an input control circuit for controlling the start and stop of the mains soft starter according to the bus voltage detection result, wherein the mains soft starter is electrically connected to the bus voltage detection circuit; The battery soft start module includes a switch circuit for controlling battery charging on and off, a drive pulse generating circuit for converting battery energy into driving the switch circuit on and off, and a monitoring circuit for monitoring battery status.

2. The impulse transient current soft starting device for UPS according to claim 1, characterized in that: The bus voltage detection circuit includes a coupling chip U1 connected to the three-phase power U terminal, V terminal and W terminal respectively. The three coupling chips U1 are connected in parallel. One pin of the coupling chip U1 is connected to a resistor R6 with a resistance value. A diode M7 is connected between the 2nd pin of the coupling chip U1 and the resistor R6. The 4th pin of the coupling chip U1 is connected to a resistor R7, and the three resistors R7 are connected in parallel.

3. The impact transient current soft starting device for UPS according to claim 2, characterized in that: The input control circuit includes a driver chip U23. A resistor R11 and a diode D2 are connected in parallel between the two input ends of the driver chip U23. A diode D1 is connected to the connecting end of the resistor R11 and the diode D2. One end of the diode D1 is connected to a transistor Q3, a transistor Q4 and a transistor Q5 respectively. The base of the transistor Q3 is connected to one of the resistors R7 through a resistor R8, the base of the transistor Q4 is connected to another of the resistors R7 through a resistor R9, and the base of the transistor Q5 is connected to the other resistor R7 through a resistor R10. The emitter of the transistor Q3 is connected to a ground resistor R43, the emitter of the transistor Q4 is connected to a ground resistor R44, and the emitter of the transistor Q5 is connected to a ground resistor R45. A diode D4 and a resistor R12 are connected in parallel between the two output ends of the driver chip U23. A diode D3 is connected between the diode D4 and one of the output ends of the driver chip U23.

4. The impulse transient current soft starting device for UPS according to claim 3, characterized in that: The switching circuit includes a MOS transistor Q1. A capacitor C1 is connected between the gate and drain of the MOS transistor Q1. A resistor R2 is connected to the connecting end of the capacitor C1 and the gate of the MOS transistor Q1. One end of the resistor R2 is connected to the resistor R1. One end of the resistor R1 is connected to the connecting end of the capacitor C1 and the drain of the MOS transistor Q1. The connecting end of the resistor R2 and the resistor R1 is connected to a transistor Q2. The base of the transistor Q2 is connected to a resistor R3 for receiving a control signal. One end of the resistor R3 is connected to a ground resistor R4.

5. The impulse transient current soft starting device for UPS according to claim 4, characterized in that: The drive pulse generating circuit includes an amplifier U5 and an amplifier U6. The output end of the amplifier U5 is connected to the positive end of the amplifier U6 through a resistor R22. The connection end of the positive end of the amplifier U6 and the resistor R22 is connected to an adjustable resistor R23. One end of the adjustable resistor R23 is connected to the output end of the amplifier U6. The adjustable end of the adjustable resistor R23 is connected to the negative end of the amplifier U5 through a resistor R24. A capacitor C14 is connected between the negative end and the output end of the amplifier U5. The positive end of the amplifier U5 is connected to the monitoring circuit, and the positive end of the amplifier U5 is connected to the negative end of the amplifier U6.

6. The impulse transient current soft starting device for UPS according to claim 5, characterized in that: The monitoring circuit includes a sampling resistor R21, one end of which is connected to the positive terminal of the amplifier U5. A resistor R19, a ground resistor R20 and a ground capacitor C13 are connected in parallel to the connection end between the resistor R21 and the positive terminal of the amplifier U5.

7. The impulse transient current soft starting device for UPS according to claim 6, characterized in that: The current limiting circuit includes an amplifier U2, the positive terminal of the amplifier U2 is connected to an adjustable resistor R16, one end of the adjustable resistor R16 is connected to a resistor R17, one end of the resistor R17 is connected in parallel with a diode D5 and a ground resistor R18, a capacitor C10 is connected between the positive terminal of the amplifier U2 and the other end of the adjustable resistor R16, the output terminal of the amplifier U2 is connected to a transistor Q6, the drain of the transistor Q6 is connected to a resistor R14, and one end of the resistor R14 is connected to the output terminal of the amplifier U2 through a resistor R15.

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