Emergency switching power supply based on intelligent charging and discharging

Abstract

The utility model aims to provide the emergency switching power supply based on intelligent charging and discharging, which is small in size, light in weight, high in conversion efficiency, strong in anti-interference performance, wide in voltage input range, modularized, low in standby power consumption, and more energy-saving and power-saving. The device comprises a pulse width modulation control unit, a transformer, a charging and discharging micro-control unit, an H-bridge loop, a lithium battery protection unit and a battery end, an external alternating current and the pulse width modulation control unit are both connected to a primary coil and a secondary coil of the transformer, a secondary coil of the transformer is divided into two paths, one path is connected to an external direct current through a connector, and the other path is connected to an H-bridge loop. And the other path is sequentially connected to the charging and discharging micro-control unit, the H-bridge loop, the lithium battery protection unit and the battery end. The utility model is applied to the technical field of switching power supplies.

Description

Technical Field

[0001] The utility model is applied to the technical field of switching power supplies, and particularly relates to an emergency switching power supply based on intelligent charging and discharging. Background Art

[0002] Flyback switching power supplies, also known as flyback converters, come in two different forms, namely non-isolated flyback converters and isolated flyback converters. For a non-isolated flyback converter, during part of a cycle when the switch is on, the voltage is applied to the inductor, the current rises at a certain slope, and the energy is stored in the inductor. When the switch is off, the inductor current flows through the diode to the output capacitor and the load. An isolated flyback converter is similar. When the switch is on, the energy is stored in the inductor of the primary side of the transformer. When the switch is off, the drain voltage is higher than the input voltage, and the transformer secondary voltage is higher than ground, causing the diode to conduct and provide power to the output capacitor and the load. A non-isolated flyback converter has only one output voltage. The output voltage is not isolated from the input voltage, and the output voltage cannot be lower than the input voltage. Even if the switch is completely turned off, the output voltage can only be equal to the input voltage. On the other hand, if a power supply with only one output and no isolation is required, then a non-isolated flyback converter only needs to deal with an inductor with only one winding. The isolated flyback converter can have multiple windings on the secondary side of the transformer, which can conveniently output multiple groups of voltages. Each output voltage is isolated from the primary side, and each group of output voltages can be of any size, which can be achieved simply by adjusting the transformer ratio. Compared with the non-isolated flyback converter, the magnetic core component at this time is already a transformer with multiple windings.

[0003] Lithium battery charging is to provide power to the battery in order to maintain its mandatory charge and leave time, and ensure that the battery life and performance are optimized to the greatest extent. Charging is achieved through charge and discharge cycles, and the current is converted into voltage. When the battery needs to be charged, the charger connects the DC power supply to the positive and negative poles of the battery, and controls the output voltage and current within a certain range to charge the battery. The charger based on H-bridge architecture and software control can obtain a stable output when the input voltage changes within a certain range. Compared with other types of charging, it has the following characteristics:

[0004] 1. Higher safety: The built-in chip and intelligent algorithm are used to determine the status, voltage value, temperature and other information of the charging device, so as to more accurately control parameters such as output current and voltage, thereby ensuring the safety of charging and avoiding risks such as battery overheating and short circuit.

[0005] 2. Longer battery life: Dynamically adjust the output current and voltage according to the needs of different devices to achieve the best charging effect, which not only improves the charging efficiency but also extends the battery life.

[0006] 3. Faster charging speed: The charging speed may not be as fast as fast chargers, but they have more precise charging control and higher safety, making charging smoother and more efficient.

[0007] 4. More power saving: Through intelligent algorithms to dynamically adjust the output current and voltage and other parameters, overcharging or undercharging is avoided, making charging more power-saving, while also reducing the charging loss caused by differences in battery quality, making it more energy-saving and environmentally friendly. In summary, it has fast charging, time saving, prevention of overcharging and over-discharging, short circuit, over-current, over-temperature, over-voltage and other protection mechanisms, and has high safety characteristics.

[0008] However, since the power frequency transformer needs to transmit and convert voltage in the power system, its size is relatively large, which requires a certain amount of space in terms of design and layout. In the power system, due to the long transmission distance or large load changes, the efficiency of the power frequency transformer becomes lower, resulting in energy waste. In addition, the manufacturing cost of the power frequency transformer is high because a large amount of core material and insulation material is required. In addition, for large power systems, the power frequency transformer needs to be transported over long distances, so the transportation cost is also high. Utility Model Content

[0009] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide an emergency switching power supply based on intelligent charging and discharging which has small size, light product weight, high conversion efficiency, strong anti-interference, wide voltage input range, modularization, low standby power consumption, and is more energy-saving and power-saving.

[0010] The technical solution adopted by the utility model is: the utility model includes a pulse width modulation control unit, a transformer, a charge and discharge micro control unit, an H-bridge circuit, a lithium battery protection unit and a battery terminal, the external alternating current and the pulse width modulation control unit are both connected to the primary and secondary coils of the transformer, the secondary coil of the transformer is divided into two paths, one path is connected to the external direct current through the connector, and the other path is connected to the charge and discharge micro control unit, the H-bridge circuit, the lithium battery protection unit and the battery terminal in sequence.

[0011] It can be seen from the above scheme that the emergency switching power supply based on intelligent charging and discharging has small size, light product weight, high conversion efficiency, strong anti-interference ability, wide voltage input range, modularization, low standby power consumption, and is more energy-saving and power-saving.

[0012] A preferred solution is that the emergency switching power supply based on intelligent charging and discharging further includes a rectifier diode, the positive electrode of the rectifier diode is connected to the secondary coil of the transformer, and the negative electrode of the rectifier diode is connected to the connector.

[0013] A preferred solution is that the H-bridge loop includes an inductor, a first MOS tube, a second MOS tube, the third MOS tube and a fourth MOS tube, one end of the inductor is connected to the node of the first MOS tube and the third MOS tube, and the other end of the inductor is connected to the node of the second MOS tube and the fourth MOS tube.

[0014] A preferred solution is that the emergency switching power supply based on intelligent charging and discharging also includes a fifth MOS tube and a sixth MOS tube, the drain of the fifth MOS tube is connected to the VM pin of the lithium battery protection unit, the gate of the fifth MOS tube is connected to the CO pin of the lithium battery protection unit, the source of the fifth MOS tube is connected to the source of the sixth MOS tube, the gate of the sixth MOS tube is connected to the DO pin of the lithium battery protection unit, and the drain of the sixth MOS tube is connected to the VI pin of the lithium battery protection unit.

[0015] A preferred solution is that the emergency switching power supply based on intelligent charging and discharging further includes a lightning protection unit, and the lightning protection unit is connected to the output end of the external alternating current.

[0016] A preferred solution is that the emergency switching power supply based on intelligent charging and discharging further includes an electromagnetic interference unit, and the electromagnetic interference unit is connected to the output end of the lightning protection unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural block diagram of the utility model;

[0018] Figure 2 It is a circuit schematic diagram of the utility model. DETAILED DESCRIPTION

[0019] like Figure 1 and Figure 2 As shown, in this embodiment, the utility model includes a pulse width modulation control unit 1, a transformer T1, a charge and discharge micro control unit 2, an H-bridge circuit, a lithium battery protection unit 3 and a battery terminal BAT. The external AC power 4 and the pulse width modulation control unit 1 are both connected to the primary and secondary coils of the transformer T1. The secondary coil of the transformer T1 is divided into two paths, one of which is connected to the external DC power through the connector CN1, and the other is connected to the charge and discharge micro control unit 2, the H-bridge circuit, the lithium battery protection unit 3, and the battery terminal BAT in sequence. The model of the charge and discharge micro control unit 2 is IP5386, and the model of the lithium battery protection unit is IP3232.

[0020] like Figure 1 and Figure 2As shown, in this embodiment, the emergency switching power supply based on intelligent charging and discharging also includes a rectifier diode D3, the positive pole of the rectifier diode D3 is connected to the secondary coil of the transformer T1, and the negative pole of the rectifier diode D3 is connected to the connector CN1. When the switch tube is turned on, the current flows through the primary coil N1 of the transformer T1, and the transformer stores the energy in the form of a magnetic field. Since the primary and secondary coils are in different phases, when the current flows through the primary coil, no current flows through the secondary coil N2. When the switch tube is turned off, the disappearing magnetic field reverses the polarity of the voltage in the primary coil, and the rectifier diode D3 is turned on. The current flows to the load through the rectifier diode D3, and the energy of the transformer T1 is released to provide load voltage and current.

[0021] like Figure 1 and Figure 2 As shown, in this embodiment, the H-bridge loop includes an inductor L2, a first MOS tube Q1, a second MOS tube Q2, a third MOS tube Q3 and a fourth MOS tube Q4, one end of the inductor L2 is connected to the node of the first MOS tube Q1 and the third MOS tube Q3, and the other end of the inductor L2 is connected to the node of the second MOS tube Q2 and the fourth MOS tube Q4. When the chip power supply pin detects a 5V voltage, the chip starts to work. The VBUSG pin gives the input path Mosfet drive voltage to turn on the input MOSFET and establish an input voltage loop. Mosfet Q1, Q2, Q3, Q4 and inductor L2 form an H-bridge circuit. When charging, the inductor current flows from left to right, that is, Q1, Q2 is turned on, and the current flows through BAT+, Q1, L2, Q2 to the ground to charge the battery. When discharging, the inductor current flows from right to left, that is, Q3, Q4 is turned on, and the current flows through BAT+, Q4, L2, Q3 to the ground, and the battery is discharged. When the battery voltage is less than VTRKL, trickle current charging is adopted; when the battery voltage is greater than VTRKL, input constant current charging is entered; when the battery voltage is close to the set battery voltage, constant voltage charging is entered; when the battery terminal charging current is less than the stop charging current ISTOP and the battery voltage is close to the constant voltage, charging is stopped. After charging is completed, if the battery voltage is lower than (VTRGT –N*0.1)V, battery charging is restarted.

[0022] like Figure 1 and Figure 2As shown, in this embodiment, the emergency switch power supply based on intelligent charging and discharging further includes a fifth MOS tube Q5 and a sixth MOS tube Q6, the drain of the fifth MOS tube Q5 is connected to the VM pin of the lithium battery protection unit 3, the gate of the fifth MOS tube Q5 is connected to the CO pin of the lithium battery protection unit 3, the source of the fifth MOS tube Q5 is connected to the source of the sixth MOS tube Q6, the gate of the sixth MOS tube Q6 is connected to the DO pin of the lithium battery protection unit 3, and the drain of the sixth MOS tube Q6 is connected to the VI pin of the lithium battery protection unit 3. Under normal conditions, the control ICCO and DO pins in the circuit both output high levels, the fifth MOS tube Q5 and the sixth MOS tube Q6 are both turned on, the circuit can charge and discharge freely, and is in a normal working state. When overcharging, the lithium battery terminal voltage will exceed the normally set battery terminal voltage, and the CO charging control pin outputs a low level, so that the fifth MOS tube Q5 is disconnected, charging stops, and overcharging is prevented. When the discharge circuit is short-circuited, the voltage at the S terminal of the sixth MOS tube Q6 rises, and the loop current will be detected by the VI pin. If the voltage at the VI terminal is greater than the set value, the control IC determines that the load is short-circuited, and the DO pin will be converted from a high level to a zero voltage, so that the sixth MOS tube Q6 is turned on and turned off, thereby cutting off the discharge circuit and playing a role in short-circuit protection. In the normal discharge process, when the discharge current passes through the fifth MOS tube Q5 and the sixth MOS tube Q6 connected in series, due to the on-resistance of the MOSFET, a voltage will be generated at both ends of the MOSFET. The voltage value U=I*RDS*2, RDS is the on-resistance of a single mosfet, and the "V-" pin on the control IC detects the voltage value. If the load is abnormal for some reason, the loop current increases. When the loop current is greater than the voltage setting value detected by the VI pin, its DO pin will be converted from a high voltage to a zero voltage, so that the sixth MOS tube Q6 is turned from on to off, thereby cutting off the discharge circuit and making the current in the circuit zero, playing a role in overcurrent protection.

[0023] like Figure 1 and Figure 2 As shown, in this embodiment, the emergency switch power supply based on intelligent charging and discharging also includes a lightning protection unit 5, which includes a fuse F1, a fuse resistor FR1 and a varistor MOV1. The lightning protection unit 5 is connected to the output end of the external AC power 4. When there is a lightning strike and high voltage is generated and introduced into the power supply through the power grid, the circuit composed inside the lightning protection unit 5 performs protection. When the voltage applied to the two ends of the varistor MOV1 exceeds the working voltage of the device, its resistance value decreases, so that the high voltage energy is consumed on the varistor. If the current is too large, the fuse F1 will burn to protect the subsequent circuit.

[0024] like Figure 1 and Figure 2As shown, in this embodiment, the emergency switching power supply based on intelligent charging and discharging also includes an electromagnetic interference unit 7, which includes a rectifier bridge BD1 and an electrolytic capacitor CE1, and the electromagnetic interference unit 7 is connected to the output end of the lightning protection unit 5. The internal parts form a filter network to suppress the electromagnetic noise and clutter signals of the input power supply to prevent interference with the power supply, and also prevent the high-frequency clutter generated by the power supply itself from interfering with the power grid. When the power is turned on, the capacitor is charged. Due to the large instantaneous current, the thermistor can effectively prevent surge current.

[0025] like Figure 1 and Figure 2 As shown, in this embodiment, the emergency switching power supply based on intelligent charging and discharging further includes a rectifier filter unit 8, the rectifier filter unit 8 includes a low-pass filter LF1, and the electromagnetic interference unit 7 is connected to the primary and secondary coils of the transformer T1 through the rectifier filter unit 8. After rectification, the AC voltage is filtered by CE1 to obtain a relatively pure DC voltage.

Claims

1. An emergency switching power supply based on intelligent charging and discharging, characterized in that: It comprises a pulse width modulation control unit (1), a transformer (T1), a charge and discharge micro control unit (2), an H-bridge circuit, a lithium battery protection unit (3) and a battery terminal (BAT). External alternating current (4) and the pulse width modulation control unit (1) are both connected to the primary and secondary coils of the transformer (T1). The secondary coil of the transformer (T1) is divided into two paths, one path is connected to the external direct current via a connector (CN1), and the other path is connected to the charge and discharge micro control unit (2), the H-bridge circuit, the lithium battery protection unit (3) and the battery terminal (BAT) in sequence.

2. According to claim 1, an emergency switching power supply based on intelligent charging and discharging is characterized in that: The emergency switch power supply based on intelligent charging and discharging further comprises a rectifier diode (D3), the positive electrode of the rectifier diode (D3) is connected to the secondary coil of the transformer (T1), and the negative electrode of the rectifier diode (D3) is connected to the connector (CN1).

3. According to claim 1, an emergency switching power supply based on intelligent charging and discharging is characterized in that: The H-bridge loop comprises an inductor (L2), a first MOS transistor (Q1), a second MOS transistor (Q2), a third MOS transistor (Q3) and a fourth MOS transistor (Q4); one end of the inductor (L2) is connected to a node between the first MOS transistor (Q1) and the third MOS transistor (Q3), and the other end of the inductor (L2) is connected to a node between the second MOS transistor (Q2) and the fourth MOS transistor (Q4).

4. According to claim 1, an emergency switching power supply based on intelligent charging and discharging is characterized in that: The emergency switch power supply based on intelligent charging and discharging further comprises a fifth MOS tube (Q5) and a sixth MOS tube (Q6); the drain of the fifth MOS tube (Q5) is connected to the VM pin of the lithium battery protection unit (3); the gate of the fifth MOS tube (Q5) is connected to the CO pin of the lithium battery protection unit (3); the source of the fifth MOS tube (Q5) is connected to the source of the sixth MOS tube (Q6); the gate of the sixth MOS tube (Q6) is connected to the DO pin of the lithium battery protection unit (3); and the drain of the sixth MOS tube (Q6) is connected to the VI pin of the lithium battery protection unit (3).

5. The emergency switching power supply based on intelligent charging and discharging according to claim 1 is characterized in that: The emergency switch power supply based on intelligent charging and discharging further comprises a lightning protection unit (5), wherein the lightning protection unit (5) comprises a fuse (F1), a fuse resistor (FR1) and a varistor (MOV1), and the lightning protection unit (5) is connected to the output end of the external alternating current (4).

6. The emergency switching power supply based on intelligent charging and discharging according to claim 5 is characterized in that: The emergency switch power supply based on intelligent charging and discharging further comprises an electromagnetic interference unit (7), wherein the electromagnetic interference unit (7) comprises a rectifier bridge stack (BD1) and an electrolytic capacitor (CE1), and the electromagnetic interference unit (7) is connected to the output end of the lightning protection unit (5).

7. The emergency switching power supply based on intelligent charging and discharging according to claim 6 is characterized in that: The emergency switching power supply based on intelligent charging and discharging further comprises a rectifying and filtering unit (8), the rectifying and filtering unit (8) comprising a low-pass filter (LF1), and the electromagnetic interference unit (7) is connected to the primary and secondary coils of the transformer (T1) via the rectifying and filtering unit (8).

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