A rapid charging circuit and a charging method and a charger for an energy storage device

Abstract

The application provides a fast charging circuit of an energy storage device and a charging method and a charger thereof, wherein the charging circuit comprises a forward conversion module, the forward conversion module outputs a first stable current or a second stable current to the energy storage device through a transformer; an energy storage capacitor is electrically connected to an output power supply of the forward conversion module, and the energy storage capacitor is electrically connected to the energy storage device through a control switch; when the output of the charging circuit is switched from the first stable current to the second stable current, the control switch is closed, the energy storage capacitor charges the energy storage device, so as to accelerate the switching process from the first stable current to the second stable current; the energy storage capacitor is electrically connected to an output port of the transformer, the output port of the transformer is allowed to be switched, so as to maintain the voltage of the energy storage capacitor at a preset voltage. The application can generate continuous current and high-quality pulse current, and the charging efficiency is high.

Description

Technical Field

[0001] This invention relates to the field of energy utilization technology, and in particular to a fast charging circuit, charging method and charger for an energy storage device. Background Technology

[0002] Power storage devices are a class of devices used to store and release large amounts of energy, typically used in energy storage and power supply systems. They feature high power density, rapid charging and discharging capabilities, long lifespan, and low maintenance costs, making them widely applicable in various fields requiring high power output, such as power systems and energy storage systems. Specifically, power storage devices mainly include electrochemical capacitors, power lithium-ion batteries, and sodium-ion batteries. Furthermore, power storage devices support clean, sustainable, and efficient energy production and utilization.

[0003] In applications where fast and even ultra-fast charging circuits are being developed for power-type energy storage devices, the characteristics of these devices are not being fully utilized. Summary of the Invention

[0004] The purpose of this invention is to provide a fast charging circuit and charging method for energy storage devices, which can balance the generation of continuous current and high-quality pulse current, and has a simple structure and high charging efficiency.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0006] As described above, the present invention provides a fast charging circuit for an energy storage device, comprising:

[0007] A forward converter module, wherein the forward converter module outputs a first stable current or a second stable current to the energy storage device through a transformer;

[0008] An energy storage capacitor is electrically connected to the output power supply of the forward converter module, and the energy storage capacitor is electrically connected to the energy storage device through a control switch. When the output of the charging circuit switches from the first stable current to the second stable current, the control switch is closed, and the energy storage capacitor charges the energy storage device to accelerate the switching process from the first stable current to the second stable current. The energy storage capacitor is electrically connected to the output port of the transformer, allowing the transformer to switch the output port to maintain the voltage of the energy storage capacitor at a preset voltage.

[0009] When the output of the charging circuit switches from the second stable current to the first stable current, one end of the branch resistor is electrically connected to the energy storage device, and the other end is electrically connected to the output of the forward converter module, so as to accelerate the switching process from the second stable current to the first stable current.

[0010] In one embodiment of the present invention, the transformer has a first port, a second port, a third port and a fourth port, and at most one output port can transfer energy to the first port at the same time.

[0011] In one embodiment of the present invention, the charging circuit includes a first anti-reverse diode, the anode of the first anti-reverse diode being electrically connected to the cathode of the input power supply, the cathode of the first anti-reverse diode being electrically connected to the same-name terminal of the second port, wherein the opposite-name terminal of the second port is electrically connected to the positive terminal of the input power supply.

[0012] In one embodiment of the present invention, the charging circuit includes an output rectifier diode. The negative terminal of the output rectifier diode is electrically connected to the energy storage device through an output inductor. The positive terminal of the output rectifier diode is electrically connected to the same-name terminal of the third port. The opposite-name terminal of the third port is electrically connected to the energy storage device. When the forward converter module outputs the first stable current and the second stable current, and the voltage of the energy storage capacitor is the preset voltage, the third port is electrically connected to the first port, and the output rectifier diode is turned on.

[0013] In one embodiment of the present invention, the charging circuit further includes:

[0014] A second reverse protection diode, the positive terminal of which is electrically connected to the fourth port, and the negative terminal of which is electrically connected to the energy storage capacitor; and

[0015] The control switch has one end electrically connected to the negative terminal of the second anti-reverse diode, and the other end electrically connected to the energy storage device through the output inductor. When the forward converter module switches from outputting the first stable current to outputting the second stable current, the control switch closes.

[0016] In one embodiment of the present invention, the charging circuit includes a freewheeling diode, the negative terminal of which is electrically connected to the energy storage device through the output inductor, and the positive terminal of which is electrically connected to the fourth port and the energy storage capacitor.

[0017] In one embodiment of the present invention, the charging circuit includes a magnetizing inductor, a first terminal of which is electrically connected to the same-name terminal of the first port, and a second terminal of which is electrically connected to the opposite-name terminal of the first port. When the voltage of the energy storage capacitor is less than the preset voltage, the magnetizing inductor charges the energy storage capacitor through the transformer.

[0018] In one embodiment of the present invention, the charging circuit includes a branch switch, one end of which is electrically connected to the energy storage device, and the other end of which is electrically connected to the output terminal of the forward converter module. When the forward converter module outputs the first stable current and the second stable current, and when the output of the charging circuit switches from the first stable current to the second stable current, the branch switch is turned on.

[0019] This invention provides a charging method for a fast charging circuit of an energy storage device. Based on the fast charging circuit of the energy storage device described above, the charging method includes the following steps:

[0020] A first output mode and a second output mode are set. In the first output mode, a first stable current is output to the energy storage device through the forward converter module.

[0021] When switching from the first output mode to the second output mode, the control switch is closed, and the energy storage device is output current through the energy storage capacitor until the output current reaches the second stable current.

[0022] In the second output mode, the forward converter module outputs the second stable current to the energy storage device;

[0023] When switching from the second output mode to the first output mode, the branch switch is disconnected, and the branch resistor is connected to the output terminal of the forward converter module to accelerate the switching process from the second stable current to the first stable current; and

[0024] Monitor and adjust the voltage of the energy storage capacitor. When the voltage of the energy storage capacitor exceeds or falls below a preset voltage, switch the output port of the transformer in the forward converter module until the voltage of the energy storage capacitor recovers to the preset voltage.

[0025] The present invention provides a charger that includes a fast charging circuit for an energy storage device as described above.

[0026] As described above, this invention provides a fast charging circuit and method for energy storage devices, as well as a charger. It can output a first stable current to a power-type energy storage device through a first output mode and a second stable current through a second output mode, thereby completing the charging process quickly, stably, and with high power. Furthermore, according to the charging circuit and method provided by this invention, the switching speed between the two modes is fast, the peak current maintenance time of the second output mode is long, and the pulse output current achievable by this invention is higher. This invention can self-adjust the voltage required to maintain the rising edge of the pulse, improving the charging stability and response rate of the charging circuit. The charging circuit of this invention can balance continuous current and high-quality pulse current, and has a high charging rate and good charging stability.

[0027] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the circuit structure of the charging circuit in one embodiment of the present invention.

[0030] Figure 2 This is a schematic diagram of the forward converter module in one embodiment of the present invention.

[0031] Figure 3 This is an equivalent circuit diagram for charging an energy storage capacitor in one embodiment of the present invention.

[0032] Figure 4 This is an equivalent circuit diagram of the charging circuit when the main power switch is off in one embodiment of the present invention.

[0033] Figure 5 This is an equivalent circuit diagram of the charging circuit switching from a first output mode to a second output mode in one embodiment of the present invention.

[0034] Figure 6 This is an equivalent circuit diagram of the charging circuit transitioning from the second output mode to the first output mode of the inductor in one embodiment of the present invention.

[0035] Figure 7 This is a flowchart of a charging method for a charging circuit according to an embodiment of the present invention.

[0036] In the diagram: V in Input voltage; L mS1 is the magnetizing inductor; S2 is the main power switch; n1 is the first number of turns; n2 is the second number of turns; n3 is the third number of turns; n4 is the fourth number of turns; D1 is the first anti-reverse diode; C is the first anti-reverse diode. s 1. Energy storage capacitor; D2. Second anti-reverse diode; D3. Output rectifier diode; D4. Freewheeling diode; L O S1, Output inductor; S2, Control switch; S3, Branch switch; R f Branch resistance; SC, energy storage device. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] like Figure 1 As shown, the energy storage device SC provided by this invention is a power-type energy storage device, mainly including electrochemical capacitors, power-type lithium-ion batteries, and sodium-ion batteries. Power-type energy storage devices can support clean, sustainable, and efficient energy production and utilization, and can be applied in multiple fields. For example, electrochemical capacitors have the characteristics of high power density, long lifespan, fast charging and discharging, and good reliability, and are widely used in power systems, aerospace, automobiles, and other fields. Power-type lithium-ion batteries have the characteristics of high energy density, high cycle life, and low self-discharge rate, and are widely used in electric vehicles, smartphones, laptops, and other devices. Sodium-ion batteries can be used in energy storage systems, solar cells, wind power batteries, and other applications. Among these, power-type energy storage devices can accept large pulse current inputs in a short time, therefore, they are suitable for charging circuits and even ultra-fast charging circuits. The charging circuit and charging method provided by this invention are used to charge the energy storage device SC.

[0039] Please see Figure 1 As shown, the charging circuit provided by this invention includes a first output mode and a second output mode. In the first output mode, the charging circuit can provide a first stable current as the charging current. The first stable current is a stable, continuous, and long-term output current. In the second output mode, the charging circuit can provide a second stable current as the charging current. The second stable current is a pulse current. In this embodiment, the first stable current is less than the second stable current. By switching between the first and second output modes, high-efficiency output of the charging current is achieved, thereby realizing fast or even ultra-fast charging. The energy storage device SC completes energy storage through the charging current.

[0040] Please see Figure 1 As shown, in one embodiment of the present invention, in the second output mode, the charging current has a rising edge and a falling edge. At the rising edge of the pulse, the charging current of the charging circuit switches from a first stable current to a second stable current. At the falling edge of the pulse, the charging current of the charging circuit switches from the second stable current back to the first stable current. At the rising and falling edges of the pulse, the charging current is an unstable continuous current, wherein the unstable continuous current is greater than the first stable current and less than the second stable current. The completion time of the rising and falling edges of the pulse is limited by the specific charging circuit. The charging circuit provided by the present invention can shorten the completion time of the rising and falling edges of the pulse as much as possible, thereby achieving efficient switching between the two output modes, improving charging efficiency, and realizing fast charging or even ultra-fast charging. In this embodiment, the first stable current is, for example, 11 A or 10 A, and the second stable current is, for example, 61 A or 36 A. In practical applications, an error range can be set for the first and second stable currents; the present invention does not limit the specific error range value. It should be noted that during the alternation between the second output mode and the first output mode, and during the alternation between the first output mode and the second output mode, the charging current of the charging circuit is a continuous and variable current.

[0041] Please see Figure 1 As shown, in one embodiment of the present invention, the energy storage device SC can be an electrochemical capacitor, and the capacitance of the electrochemical capacitor is 0.1 F to 50000 F. For example, an Eaton 100 F / 2.7 V electrochemical capacitor cell with part number HV1860-2R7107-R can carry, for example, a first stable current of 11 A and a second stable current of 61 A. As another example, a Maxwell Technologies 100 F / 2.7 V electrochemical capacitor cell with part number BCAP0100T01 can carry, for example, a first stable current of 10 A and a second stable current of 36 A.

[0042] Please see Figure 1 and Figure 2 As shown, in one embodiment of the present invention, the charging circuit includes a forward converter module 100 and an energy storage capacitor C. s and branch resistance R f The output of the forward converter module 100 is electrically connected to the energy storage device SC, and outputs a first stable current or a second stable current to the energy storage device SC. Specifically, during the switching process between the first and second stable currents, when the charging circuit switches from outputting the first stable current to outputting the second stable current, the energy storage capacitor C... s The output terminal is electrically connected to the energy storage device SC, and is connected to the energy storage capacitor C. sThe energy storage device SC is provided with energy for the transition from the first stable current to the second stable current. Specifically, during the switching process between the first and second stable currents, when the charging circuit switches from outputting the second stable current to outputting the first stable current, the branch resistance R... f Electrically connected to the energy storage device SC. Through branch resistor R f The connection and energy consumption are reduced quickly, thereby rapidly reducing the current in the circuit and quickly switching the output mode of the charging circuit.

[0043] Please see Figure 1 As shown, in one embodiment of the present invention, the energy storage capacitor C s With preset voltage V z When the energy storage capacitor C s The voltage exceeds the preset voltage V z Or below the preset voltage V z At that time, adjust the energy storage capacitor C s The charging status is monitored to maintain the voltage of the energy storage module 300 at a preset voltage V. z It should be noted that the present invention does not limit the preset voltage V. z The specific value.

[0044] Please see Figures 1 to 3 As shown, in one embodiment of the present invention, the forward converter module 100 includes an input power supply V. in The system includes a main power switch S1 and a transformer T. The output of the forward converter module 100 is electrically connected to the energy storage device SC, providing a first stable current or a second stable current to the energy storage device SC. In this embodiment, the transformer T includes multiple ports. Specifically, the transformer T includes a first port n1, a second port n2, a third port n3, and a fourth port n4. In this embodiment, n1:n2:n3:n4 is, for example, 10:1:2:10. It should be noted that the turns ratio of the transformer T provided by this invention is only an example, based on a preset voltage V. z Different values ​​can be used to adjust the turns ratio of transformer T, but this invention is not limited to this. The first port n1 of transformer T is connected to the input power supply V. in Electrical connection: The main power switch S1 is located at the first port of transformer T and the input power supply V. in Between the negative and positive terminals. When the main power switch S1 is turned on, the input power V... in Power is supplied to transformer T. When the main power switch S1 is open, transformer T is in a non-operating state or the energy storage capacitor C is powered. s Charging or self-magnetic reset.

[0045] Please see Figures 1 to 4As shown, in one embodiment of the present invention, only one port transfers energy to the first port n1 at a time. For example, when there is energy transfer between the first port n1 and the second port n2, the input power supply V... in After being processed by transformer T, the output voltage of transformer T changes to V. in / (n1:n2).

[0046] Please see Figure 1 and Figure 4 As shown, in one embodiment of the present invention, when the main power switch S1 is turned off, if the energy storage capacitor C s The voltage is the preset voltage V z At this time, energy is transferred between the first port n1 and the second port n2. The charging circuit includes a first anti-reverse diode D1 and a magnetizing inductor L. m In this embodiment, the magnetizing inductor L m It is a parasitic element of transformer T. Magnetizing inductance L m The first terminal is electrically connected to the input power supply V. in The positive terminal, the magnetizing inductor L m The second terminal is electrically connected to the main power switch S1, and is connected to the input power supply V through the main power switch S1. in The negative terminal is electrically connected. In this embodiment, the positive terminal of the first anti-reverse diode D1 is connected to the input power supply V. in The negative terminal of the first reverse protection diode D1 is electrically connected to the negative terminal of the second terminal n2. Specifically, the same-name terminal of the second terminal n2 is electrically connected to the negative terminal of the first reverse protection diode D1, and the opposite-name terminal of the second terminal n2 is connected to the input power supply V. in The positive electrode is electrically connected.

[0047] Please see Figure 1 and Figure 2 As shown, in one embodiment of the present invention, when the forward converter module 100 provides a first stable current or a second stable current to the energy storage device SC, the main power switch S1 is closed, and the first port n1 and the third port n3 are electrically connected. In this embodiment, the forward converter module 100 includes an output rectifier diode D3 and an output inductor L. O The same-name terminal of the third port n3 is electrically connected to the positive terminal of the output rectifier diode D3, and the opposite-name terminal of the third port n3 is electrically connected to the second terminal of the energy storage device SC. The negative terminal of the output rectifier diode D3 is electrically connected to the output inductor L. O The first terminal. Output inductor L O The second terminal is electrically connected to the first terminal of the energy storage device SC. The voltage V output by transformer T... in / (n1:n3) will be the output rectifier diode D3, the energy storage device SC and the output inductor L O Pressure divider. For example... Figure 2 As shown, when the main power switch S1 is closed, the input power V in the forward converter module 100 is... in The energy storage device SC is charged through the third port n3 of transformer T. Specifically, when the second port n3 is electrically connected to the first port n1, the input power supply V... in While charging the energy storage device SC through transformer T, the excitation inductance L is also increased. m Energy storage.

[0048] Please see Figure 1 and Figure 3 As shown, in one embodiment of the present invention, when the main power switch S1 is off, and the energy storage capacitor C... s The voltage is lower than the preset voltage V z At that time, through the excitation inductor L m For energy storage capacitor C s During recharging, the first port n1 and the fourth port n4 are electrically connected. In this embodiment, the charging circuit includes a second anti-reverse diode D2. The cathode of the second anti-reverse diode D2 is connected to the energy storage capacitor C. s Electrically connected, the positive terminal of the second reverse protection diode D2 is electrically connected to the fourth port n4. Specifically, the corresponding terminal of the fourth port n4 is connected to the energy storage capacitor C. s The first terminal is electrically connected, and the opposite terminal of the fourth port n4 is electrically connected to the negative terminal of the second anti-reverse diode D2. When the main power switch S1 is off, the energy storage capacitor C... s The voltage is lower than the preset voltage V z At that time, the first port n1 and the fourth port n4 are electrically connected, and the magnetizing inductance L m The energy storage capacitor C is connected through the fourth port n4 of transformer T. s Charging is performed, and simultaneously the excitation inductor L is energized. m Demagnetization.

[0049] Please see Figure 1 , Figure 2 and Figure 6 As shown, in one embodiment of the present invention, the forward converter module 100 further includes a freewheeling diode D4 and an output inductor L. O In this embodiment, the positive terminal of the freewheeling diode D4 is electrically connected to the second terminal of the energy storage device SC, and the negative terminal of the freewheeling diode D4 is electrically connected to the output inductor L. O The first terminal. When transformer T is working normally, the main power switch S1 is closed, and the input power V... in The transformer T is used as the output inductor L. O Charging. When the main power switch S1 is off and the transformer T is not in operation, the output inductor L... O The energy storage device SC and the freewheeling diode D4 form a circuit, which is connected by the output inductor L.O Continue charging the energy storage device SC, such as Figure 6 As shown.

[0050] Please see Figure 1 , Figure 3 and Figure 5 As shown, in one embodiment of the present invention, the charging circuit includes a control switch S2. One end of the control switch S2 is electrically connected to the energy storage capacitor Cs, and the other end of the control switch S2 is electrically connected to the first end of the energy storage device SC through multiple components. Specifically, the other end of the control switch S2 is connected to the output inductor L. O Electrical connection, and output inductance L O Through the branch resistance R f Alternatively, branch switch S3 can be electrically connected to the energy storage device SC. In this embodiment, the energy storage capacitor C... s One end is electrically connected to the second end of the energy storage device SC, and the energy storage capacitor C s The other end is controlled by switch S2 and output inductor L. O Branch resistance R f Alternatively, branch switch S3 can be electrically connected to the first terminal of energy storage device SC. Specifically, energy storage capacitor C... s The first terminal is electrically connected to the second terminal of the energy storage device SC. Energy storage capacitor C s The second terminal is electrically connected to one end of control switch S2, and the other end of control switch S2 is electrically connected to the output inductor L. O The first terminal. Output inductor L O The second terminal is electrically connected to the first terminal of the energy storage device SC. When the charging circuit switches from outputting the first stable current to outputting the second stable current, the main power switch S1 is turned off, and the input power supply V... in Charging of the energy storage device SC is stopped. Furthermore, when the charging circuit switches from outputting the first stable current to outputting the second stable current, control switch S2 closes, and the energy storage capacitor C... s A circuit is formed with the energy storage device SC, and the energy storage capacitor C s Charging current is provided to the energy storage device SC. When the main power switch S1 is open and the control switch S2 is closed, the energy storage capacitor C... s Control switch S2, output inductor L O A circuit is formed with the energy storage device SC, and the energy storage capacitor C is used to achieve this. s The stored electrical energy provides the energy required for the energy storage device SC to transition from the first stable current to the second stable current, such as... Figure 5 As shown.

[0051] Please see Figures 2 to 6 As shown, in one embodiment of the present invention, when the magnetizing inductor L... m For energy storage capacitor C s Charging, energy storage capacitor Cs The charging speed is shown in equation (1).

[0052]

[0053] In equation (1), i Lm Represents the flow through the magnetizing inductor L m The current, C s Represents the energy storage capacitor C s The capacitance. t represents time, V Cs Represents the energy storage capacitor C s The voltage value.

[0054] Please see Figures 2 to 6 In one embodiment of the present invention, the magnetizing inductor L m The current is shown in equation (2).

[0055]

[0056] In equation (2), i Lm Represents the flow through the magnetizing inductor L m The current quantity, where t represents time. V represents the forward voltage drop of the first anti-reverse diode D1. Cs This represents the voltage value of the energy storage capacitor. Represents the excitation inductance L m The self-induction value.

[0057] Please see Figure 2 and Figure 3 As shown, in one embodiment of the present invention, when the main power switch S1 is turned off, the excitation inductor L... m For energy storage capacitor C s Charge until the circuit current drops to 0, thus energizing the energy storage capacitor C. s A high voltage is established. Furthermore, the excitation inductance L can be achieved without the need for an additional magnetic reset circuit. m Magnetic reset. This is achieved in the energy storage capacitor C. s The high voltage established on it is shown in equation (3).

[0058] .

[0059] In equation (3), V z Energy storage capacitor C s The preset voltage, V in n is the input power supply voltage, n4 is the number of turns at the fourth port, and n2 is the number of turns at the second port.

[0060] Please see Figure 2 and Figure 4 As shown, in one embodiment of the present invention, when the energy storage capacitor C...s During the process of establishing a high voltage, when the energy storage capacitor C s The voltage reaches the preset voltage V z The first reverse protection diode D1 is turned on under high voltage, while the second reverse protection diode D2 is turned off. At this time, the magnetizing inductor L... m Stop the operation on energy storage capacitor C s Charging, and at this time the port electrically connected to the first port n1 is the second port n2.

[0061] Please see Figure 2 As shown, when the forward converter module 100 provides the second stable current for switching the energy storage device SC, the switching speed from the first output mode to the second output mode is as shown in equation (4).

[0062]

[0063] In equation (4), For output inductor L O The current, t represents time, and V represents the input power supply. in The voltage value, where N represents the turns ratio of transformer T. This represents the forward voltage drop of the output rectifier diode D3. Lo represents the voltage drop across the energy storage device SC, and Lo represents the output inductance L. O The self-inductance.

[0064] Please see Figure 2 As shown, in one embodiment of the present invention, when the charging circuit needs to switch from the first output mode to the second output mode, the output current of the energy storage device SC is switched from the first stable current to the second stable current. In this embodiment, the main power switch S1 is open, the control switch S2 is closed, and the energy storage capacitor C... s Control switch S2, output inductor L O And the energy storage device SC are in the same circuit loop, such as Figure 5 As shown, the energy storage capacitor C s The energy storage device SC is charged. The switching speed of the energy storage device SC from the first stable current to the second stable current is shown in equation (5).

[0065]

[0066] Please see Figure 2 and Figure 5 As shown in equations (4) and (5), in one embodiment of the present invention, due to V z V in / N, therefore through the energy storage capacitor C sCharging the energy storage device SC allows for a faster conversion of the first stable current to the second stable current. After conversion to the second stable current, the control switch S2 is disconnected, and the input power supply V... in The energy storage device SC is charged through transformer T to maintain the output of the second stable current. At the input power supply V... in While the energy storage device SC outputs a second stable current, the input power supply V... in Also for the excitation inductance L m Charging is performed through the magnetizing inductor L m The current is increased. In this embodiment, the input power supply V... in While outputting the second stable current to the energy storage device SC, the energy storage capacitor C continues to... s The voltage value is maintained at the preset voltage V. z .

[0067] Please see Figure 2 As shown, when the forward converter module 100 switches from the second output mode to the first output mode, that is, when the output current switches from the second stable current to the first stable current, the rate of decrease of the output current is as shown in equation (6).

[0068]

[0069] In equation (6), For output inductor L O The current quantity, t is time, L O The self-inductance of the output inductor. V is the forward voltage drop of the freewheeling diode D4. SC This represents the voltage drop across the energy storage device SC.

[0070] Please see Figures 2 to 6 As shown, in one embodiment of the present invention, the branch resistance R f The first terminal is electrically connected to the output inductor L O The second terminal, branch resistance R f The second terminal is electrically connected to the first terminal of the energy storage device SC. One terminal of the branch switch S3 is electrically connected to the branch resistor R. f The first terminal of branch switch S3 is electrically connected to the branch resistor R. f The second end. In this embodiment, at the input power supply V in When the energy storage device SC outputs a first stable current and a second stable current, branch switch S3 closes when the charging circuit switches from outputting the first stable current to outputting the second stable current. When the charging circuit switches from outputting the second stable current to outputting the first stable current, branch switch S3 opens, and the main power switch S1, control switch S2, and discharge switch S2 also open. The freewheeling diode D4 and output inductor L... OBranch resistance R f A circuit loop is formed with the energy storage device SC. When the output current of the charging circuit to the energy storage device SC switches from the second stable current to the first stable current, the rate of decrease of the output current of the charging circuit is as shown in equation (7).

[0071]

[0072] In equation (7), For output inductor L O The amount of current, The resistance value of the branch circuit. The forward voltage drop of the freewheeling diode D4 is... This represents the voltage division value of the energy storage device SC. t is time, L... O This is the self-inductance of the output inductor.

[0073] Please see Figures 2 to 6 As shown in equations (6) and (7), in one embodiment of the present invention, because Therefore, in this embodiment, the output current of the charging circuit decreases more rapidly. When the output current of the charging circuit reaches the first stable current, branch switch S3 closes, and the input power supply V... in The energy storage device SC is supplied with a first stable current through a transformer T. The charging circuit of this invention can efficiently charge the energy storage device SC in two modes, and the processes of outputting the first stable current, the second stable current, and switching between the first and second stable currents are all dynamically performed.

[0074] Please see Figures 1 to 7 As shown, the present invention provides a charging method for a charging circuit, the charging method including steps S10 to S50.

[0075] Step S10: Set the first output mode and the second output mode. In the first output mode, the first stable current is output to the power storage device through the forward converter module, wherein the transformer of the forward converter module outputs the first stable current through the third port.

[0076] Step S20: When switching from the first output mode to the second output mode, close the control switch and output charging current to the power energy storage device through the energy storage capacitor until the output current reaches the second stable current.

[0077] Step S30: In the second output mode, the forward converter module outputs a second stable current to the power storage device, wherein the transformer of the forward converter module outputs the second stable current through the third port.

[0078] Step S40: When switching from the second output mode to the first output mode, disconnect the branch switch until the output current to the power storage device reaches the first stable current.

[0079] Step S50: Monitor the voltage of the energy storage capacitor. When the voltage of the energy storage capacitor is lower than the preset voltage, the magnetizing inductor charges the energy storage capacitor through the fourth port of the transformer. When the voltage of the energy storage capacitor is higher than the preset voltage, adjust the output port of the transformer to the second port to reduce the voltage of the energy storage capacitor.

[0080] Please see Figures 2 to 7 As shown, in one embodiment of the present invention, in step S10, in the first output mode, branch switch S3 is closed, control switch S2 is open, and the input power supply V... in The energy storage device SC outputs a first stable current. In step S30, in the second output mode, branch switch S3 is closed, control switch S2 is open, and the input power supply V... in A second stable current is output to the energy storage device SC. It should be noted that in practical applications, step S10 can be executed before or after step S30. It should also be noted that in this embodiment, when the forward converter module 100 provides the first or second stable current to the energy storage device SC, the main power switch S1 is closed and opened with a duty cycle.

[0081] Please see Figures 2 to 7 As shown, in one embodiment of the present invention, in step S20, when the output current of the charging circuit switches from the first stable current to the second stable current, that is, when the charging circuit switches from the first output mode to the second output mode, the main power switch S1 is opened, the branch switch S3 is closed, and the control switch S2 is closed, and the energy storage capacitor C... s The energy storage device SC is charged, and the charging current for the energy storage device SC increases from a first stable current to a second stable current. Furthermore, in this embodiment, in step S40, when the charging circuit switches from outputting the second stable current to outputting the first stable current, that is, when the charging circuit switches from the second output mode to the first output mode, the main power switch S1, control switch S2, and branch switch S3 are disconnected, and the output inductor L... O To maintain the charging current of the energy storage device SC, a branch resistance R is introduced. f This accelerates the drop of the second stable current to the first stable current until the output current of the charging circuit to the energy storage device SC drops to the first stable current. In the operation of the charging circuit of this invention, the energy storage capacitor C is automatically adjusted by adjusting the conduction port of the transformer T. s The voltage, and through the magnetizing inductor L m To improve the energy storage capacitor C s The voltage simultaneously achieves control over the magnetizing inductor L mThe reset is achieved. Furthermore, in this invention, the input and output circuits are clearly distinguished, which is beneficial for improving the spatial distribution efficiency of components.

[0082] The embodiments of the present invention disclosed above are merely illustrative of the invention. The embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A fast charging circuit for an energy storage device, characterized in that, include: A forward converter module includes an input power supply, a main power switch, and a transformer. The transformer has a first port, a second port, a third port, and a fourth port. The first port of the transformer is electrically connected to the input power supply. The main power switch is located between the first port of the transformer and the negative terminal of the input power supply. The forward converter module outputs a first stable current or a second stable current to the energy storage device through the third port of the transformer. An energy storage capacitor is electrically connected to the output side of the forward converter module, and the energy storage capacitor is electrically connected to the energy storage device through a control switch. When the output of the charging circuit switches from the first stable current to the second stable current, the control switch is closed, and the energy storage capacitor charges the energy storage device to accelerate the switching process from the first stable current to the second stable current. The energy storage capacitor is electrically connected to the output port of the transformer, allowing the transformer to switch its output port to maintain the voltage of the energy storage capacitor at a preset voltage. Branch resistor: When the output of the charging circuit switches from the second stable current to the first stable current, one end of the branch resistor is electrically connected to the energy storage device, and the other end is electrically connected to the output of the forward converter module, so as to accelerate the switching process from the second stable current to the first stable current. A magnetizing inductor, wherein the first end of the magnetizing inductor is electrically connected to the same-named end of the first port, and the second end of the magnetizing inductor is electrically connected to the opposite-named end of the first port; At most one output port can transfer energy to the first port at the same time. When the voltage of the energy storage capacitor is lower than the preset voltage, the magnetizing inductor charges the energy storage capacitor through the fourth port of the transformer. When the voltage of the energy storage capacitor is higher than the preset voltage, the output port of the transformer is adjusted to the second port to reduce the voltage of the energy storage capacitor. The voltage of the energy storage capacitor is increased by using an excitation inductor, which also enables the resetting of the excitation inductor.

2. The fast charging circuit for an energy storage device according to claim 1, characterized in that, The charging circuit includes a first anti-reverse diode, the anode of which is electrically connected to the cathode of the input power supply, and the cathode of which is electrically connected to the same-name terminal of the second port, wherein the opposite-name terminal of the second port is electrically connected to the anode of the input power supply.

3. The fast charging circuit for an energy storage device according to claim 1, characterized in that, The charging circuit includes an output rectifier diode. The negative terminal of the output rectifier diode is electrically connected to the energy storage device through an output inductor. The positive terminal of the output rectifier diode is electrically connected to the same-name terminal of the third port. The opposite-name terminal of the third port is electrically connected to the energy storage device. When the forward converter module outputs the first stable current and the second stable current, and the voltage of the energy storage capacitor is the preset voltage, the third port is electrically connected to the first port, and the output rectifier diode is turned on.

4. The fast charging circuit for an energy storage device according to claim 3, characterized in that, The charging circuit also includes: A second reverse protection diode, the positive terminal of which is electrically connected to the fourth port, and the negative terminal of which is electrically connected to the energy storage capacitor; and The control switch has one end electrically connected to the negative terminal of the second anti-reverse diode, and the other end electrically connected to the energy storage device through the output inductor. When the forward converter module switches from outputting the first stable current to outputting the second stable current, the control switch closes.

5. The fast charging circuit for an energy storage device according to claim 3, characterized in that, The charging circuit includes a freewheeling diode, the negative terminal of which is electrically connected to the energy storage device through the output inductor, and the positive terminal of which is electrically connected to the fourth port and the energy storage capacitor.

6. The fast charging circuit for an energy storage device according to claim 1, characterized in that, When the voltage of the energy storage capacitor is less than the preset voltage, the magnetizing inductor charges the energy storage capacitor through the transformer.

7. The fast charging circuit for an energy storage device according to claim 1, characterized in that, The charging circuit includes a branch switch, one end of which is electrically connected to the energy storage device, and the other end of which is electrically connected to the output terminal of the forward converter module. When the forward converter module outputs the first stable current and the second stable current, and when the output of the charging circuit switches from the first stable current to the second stable current, the branch switch is turned on.

8. A fast charging method for an energy storage device, based on the fast charging circuit for an energy storage device as described in claim 1, characterized in that, The charging method includes the following steps: A first output mode and a second output mode are set. In the first output mode, a first stable current is output to the energy storage device through the forward converter module. When switching from the first output mode to the second output mode, the control switch is closed, and the energy storage device is output current through the energy storage capacitor until the output current reaches the second stable current. In the second output mode, the forward converter module outputs the second stable current to the energy storage device; When switching from the second output mode to the first output mode, the branch switch is disconnected, and the branch resistor is connected to the output terminal of the forward converter module to accelerate the switching process from the second stable current to the first stable current; and Monitor and adjust the voltage of the energy storage capacitor. When the voltage of the energy storage capacitor exceeds or falls below a preset voltage, switch the output port of the transformer in the forward converter module until the voltage of the energy storage capacitor recovers to the preset voltage.

9. A charger, characterized in that, The fast charging circuit includes an energy storage device as described in any one of claims 1 to 7.

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