Fast charging circuit applicable to electrochemical capacitor, charging method thereof and charger

Abstract

The present invention provides a fast charging circuit suitable for an electrochemical capacitor, a charging method and a charger thereof, wherein the fast charging circuit comprises: a forward conversion module, the forward conversion module comprises a transformer, the primary side of the transformer is electrically connected to a power supply through a main power switch, the secondary side of the transformer is electrically connected to an electrochemical capacitor, and the forward conversion module outputs a first stable current or a second stable current to the electrochemical capacitor; an energy storage capacitor is connected in parallel with the primary side of the transformer, and both ends of the energy storage capacitor are electrically connected to both ends of the electrochemical capacitor through a control switch, when the output of the fast charging circuit is switched from the first stable current to the second stable current, the control switch is closed, and the energy storage capacitor charges the electrochemical capacitor to speed up the switching process from the first stable current to the second stable current. The fast charging circuit provided by the present invention can take into account both the generation of continuous current and high-quality pulse current, and has a high charging rate and good charging stability.

Description

Technical Field

[0001] The present invention relates to the technical field of energy utilization, and particularly to a fast charging circuit applicable to an electrochemical capacitor, a charging method thereof, and a charger. Background Art

[0002] As an energy storage method, an electrochemical capacitor has characteristics such as high power density and long cycle life. Therefore, an energy storage system based on an electrochemical capacitor has been widely applied in fields such as an electrified transportation system, a renewable energy system, and a national defense system.

[0003] An electrochemical capacitor has a high power density characteristic, and the electrochemical capacitor can charge and discharge with a relatively large pulsed current within a limited time. Although various electrochemical capacitor charging circuit topologies have been proposed currently, the characteristics of the electrochemical capacitor have not been fully utilized in the application fields of developing fast and even ultrafast charging circuits. Summary of the Invention

[0004] The purpose of the present invention is to provide a fast charging circuit applicable to an electrochemical capacitor, a charging method thereof, and a charger, which can take into account the occurrence of continuous current and high-quality pulsed current, and has a high charging rate and good charging stability.

[0005] To solve the above technical problems, the present invention is realized through the following technical solutions:

[0006] The present invention provides a fast charging circuit applicable to an electrochemical capacitor, including:

[0007] A forward conversion module, the forward conversion module includes a transformer, the primary side of the transformer is electrically connected to a power supply through a main power switch, the secondary side of the transformer is electrically connected to an electrochemical capacitor, and the forward conversion module outputs a first stable current or a second stable current to the electrochemical capacitor;

[0008] A storage capacitor, which is connected in parallel with the primary side of the transformer, and both ends of the storage capacitor are electrically connected to both ends of the electrochemical capacitor through a control switch. When the output of the fast charging circuit switches from the first stable current to the second stable current, the control switch closes, and the storage capacitor charges the electrochemical capacitor to accelerate the switching process from the first stable current to the second stable current; and

[0009] A branch resistor, when the output of the fast charging circuit switches from the second stable current to the first stable current, one end of the branch resistor is electrically connected to the electrochemical capacitor, and the other end is electrically connected to the secondary side of the transformer to accelerate the switching process from the second stable current to the first stable current.

[0010] In an embodiment of the present invention, the fast charging circuit includes a branch switch, and the branch switch is connected in parallel to the branch resistor. When the output of the fast charging circuit switches from the second stable current to the first stable current, the branch switch disconnects to connect the branch resistor into the loop of the fast charging circuit.

[0011] In an embodiment of the present invention, the forward conversion module includes an output inductor. The first end of the output inductor is electrically connected to the secondary side of the transformer, and the second end of the output inductor is electrically connected to the branch resistor.

[0012] In an embodiment of the present invention, the control switch includes a first switch. One end of the first switch is electrically connected to the first end of the energy storage capacitor, and the other end of the first switch is electrically connected to the electrochemical capacitor through the branch resistor.

[0013] In an embodiment of the present invention, the control switch includes a second switch. One end of the second switch is electrically connected to the second end of the energy storage capacitor, and the other end of the second switch is electrically connected to the electrochemical capacitor.

[0014] In an embodiment of the present invention, the fast charging circuit includes an energy storage capacitor voltage stabilization module, and the energy storage capacitor voltage stabilization module includes:

[0015] A discharge resistor, the first end of the discharge resistor is electrically connected to the first end of the energy storage capacitor; and

[0016] A discharge switch, one end of the discharge switch is electrically connected to the second end of the discharge resistor, and the other end of the discharge switch is electrically connected to the second end of the energy storage capacitor;

[0017] An exciting inductor, the first end of the exciting inductor is electrically connected to the first end of the energy storage capacitor; and

[0018] A reverse protection diode, the positive electrode of the reverse protection diode is electrically connected to the second end of the exciting inductor, and the negative electrode of the reverse protection diode is electrically connected to the second end of the energy storage capacitor.

[0019] In an embodiment of the present invention, the capacitance of the electrochemical capacitor is 0.1F to 50000F.

[0020] The present invention provides a charging method applicable to an electrochemical capacitor. Based on the fast charging circuit applicable to an electrochemical capacitor as described above, the charging method includes the following steps:

[0021] Set a stable output mode and a pulse output mode. In the stable output mode, a first stable current is output to the electrochemical capacitor through the forward conversion module;

[0022] When switching from the stable output mode to the pulse output mode, close the control switch and output current to the electrochemical capacitor through the energy storage capacitor until the output current reaches the second stable current;

[0023] In the pulse output mode, the forward conversion module outputs the second stable current to the electrochemical capacitor; and

[0024] The fast charging circuit includes a branch switch. When switching from the pulse output mode to the stable output mode, open the branch switch, and the branch resistor is electrically connected to the forward conversion module until the output current to the electrochemical capacitor reaches the first stable current.

[0025] In an embodiment of the present invention, the fast charging circuit includes an exciting inductor and a discharge switch. The charging method includes monitoring and adjusting the voltage of the energy storage capacitor, and the step of monitoring and adjusting the voltage of the energy storage capacitor includes:

[0026] Charging the energy storage capacitor by the exciting inductor; and

[0027] When the voltage of the energy storage capacitor is greater than the preset voltage, close the discharge switch and perform a discharging operation on the energy storage capacitor.

[0028] The present invention provides a charger applicable to an electrochemical capacitor, including the fast charging circuit applicable to an electrochemical capacitor described in any one of the above.

[0029] As described above, the present invention provides a fast charging circuit applicable to an electrochemical capacitor, its charging method, and a charger, which can output a first stable current to the electrochemical capacitor through the stable output mode and output a second stable current to the electrochemical capacitor through the pulse output mode, thereby realizing fast and stable charging of the electrochemical capacitor. Moreover, according to the fast charging circuit and its charging method provided by the present invention, the switching speed between the two modes is fast, the peak current maintenance time in the pulse output mode is long, and the pulse output current that the present invention can achieve is higher. The fast charging circuit of the present invention can take into account continuous current and high-quality pulse current, and has a high charging rate and good charging stability.

[0030] Of course, it is not necessary for any product implementing the present invention to achieve all the above advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 It is a schematic diagram of the functional structure of the fast charging circuit in an embodiment of the present invention.

[0033] Figure 2 It is a schematic diagram of the circuit structure of the fast charging circuit in an embodiment of the present invention.

[0034] Figure 3 It is a schematic diagram of the structure of the forward conversion module in an embodiment of the present invention.

[0035] Figure 4 It is an equivalent circuit diagram when S1 is closed in the stable current output mode of the fast charging circuit in an embodiment of the present invention.

[0036] Figure 5 It is an equivalent circuit diagram for charging the energy storage capacitor in an embodiment of the present invention.

[0037] Figure 6 It is an equivalent circuit diagram for discharging the energy storage capacitor in an embodiment of the present invention.

[0038] Figure 7 It is an equivalent circuit diagram for discharging the energy storage capacitor in an embodiment of the present invention.

[0039] Figure 8 It is an equivalent circuit diagram for discharging the energy storage capacitor in an embodiment of the present invention.

[0040] Figure 9 It is an equivalent circuit diagram of the rising edge of the pulse current output mode of the fast charging circuit in an embodiment of the present invention.

[0041] Figure 10 It is an equivalent circuit diagram of the falling edge of the pulse current output mode of the fast charging circuit in an embodiment of the present invention.

[0042] Figure 11 It is a flowchart of the working method of the fast charging circuit in an embodiment of the present invention.

[0043] In the figure: 100, fast charging circuit; 200, forward conversion module; 300, energy storage module; 400, energy storage capacitor voltage stabilization module; 500, branch resistance module; V in , input voltage; R r , discharge resistance; C s , energy storage capacitor; D1, output rectifier diode; D2, anti - reverse diode; D3, free - wheeling diode; L m , exciting inductor; S1, main power switch; S2, discharge switch; S3, first switch; S4, second switch; S5, branch switch; SC, electrochemical capacitor; T, transformer; R f , branch resistance; Lo, output inductor. Specific embodiments

[0044] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0045] Electrochemical capacitors have the characteristics of short charging time, long service life, good temperature characteristics, energy conservation and environmental friendliness. Therefore, energy storage systems based on electrochemical capacitors have been widely used in fields such as electrified transportation systems, renewable energy systems and defense systems. Electrochemical capacitors have the characteristic of high power density, and electrochemical capacitors can be charged and discharged with a relatively large pulsed current within a limited time. For example, an Eaton 100F / 2.7V electrochemical capacitor cell with part number HV1860-2R7107-R can carry a continuous current of, for example, 11A and a pulsed current of, for example, 61A. Another example is that a Maxwell Technologies 100F / 2.7V electrochemical capacitor cell with part number BCAP0100T01 can carry a continuous current of, for example, 10A and a pulsed current of, for example, 36A. In order to utilize this characteristic of electrochemical capacitors to achieve rapid charging of them, the present invention proposes a charging mode of alternating continuous current and pulsed current. Among them, when the continuous current and the pulsed current are converted into each other, the output current needs to increase or decrease by several times, resulting in a slow switching process. The present invention provides a fast charging circuit that can provide pulsed current and continuous current, and has a relatively fast conversion speed between the two. In this embodiment, the capacitance of the electrochemical capacitor is 0.1F to 50000F.

[0046] Please refer to Figure 1As shown in the figure, the present invention provides a fast charging circuit 100. The fast charging circuit 100 includes a forward conversion module 200, an energy storage module 300, an energy storage capacitor voltage regulation module 400, and a branch resistor module 500. The fast charging circuit 100 includes a stable output mode and a pulse output mode. The stable output mode can output a first stable current, and the pulse output mode can output a second stable current. Among them, the pulse output mode alternates with the stable output mode. During the alternation between the stable output mode and the pulse output mode, the current output by the fast charging circuit 100 is a variable current. In this embodiment, the output terminal of the forward conversion module 200 is electrically connected to the electrochemical capacitor SC, and outputs a first stable current or a second stable current to the electrochemical capacitor SC. In this embodiment, the first stable current is, for example, 11A or 10A, and the second stable current is, for example, 61A or 36A. In practical applications, an error range can be set for the first stable current and the second stable current, and the present invention does not limit the specific error range values. In this embodiment, during the switching process between the first stable current and the second stable current, specifically, when the fast charging circuit 100 is switched from outputting the first stable current to outputting the second stable current, the output terminal of the energy storage module 300 is electrically connected to the electrochemical capacitor SC, and the energy storage module 300 provides energy for the electrochemical capacitor SC during the transition process from the first stable current to the second stable current. In this embodiment, during the switching process between the first stable current and the second stable current, specifically, when the fast charging circuit 100 is switched from outputting the second stable current to outputting the first stable current, the branch resistor module 500 is electrically connected to the electrochemical capacitor SC. By accessing the branch resistor, the current in the loop is quickly reduced, thereby quickly switching the output mode of the fast charging circuit 100.

[0047] Please refer to Figures 1 to 3 As shown in the figure, in an embodiment of the present invention, the forward conversion module 200 includes an input power supply V in , a main power switch S1, a transformer T, an output inductor Lo, an output rectifier diode D1, and a freewheeling diode D3. Among them, the transformer T includes a primary side and a secondary side, and the primary side of the transformer T is electrically connected to the input power supply V in , and the secondary side of the transformer T is electrically connected to the electrochemical capacitor SC. In this embodiment, the main power switch S1 is arranged between the primary side of the transformer T and the negative pole of the input power supply V in . When the main power switch S1 is turned on, the input power supply V in supplies power to the transformer T. When the main power switch S1 is turned off, the transformer T and the input power supply V inIn a state of ceasing to work. In this embodiment, the secondary side of the transformer T is electrically connected to the positive electrode of the output rectifying diode D1. The negative electrode of the output rectifying diode D1 is electrically connected to the first end of the output inductor Lo. The second end of the output inductor Lo is electrically connected to the first end of the electrochemical capacitor SC, and the second end of the electrochemical capacitor SC is electrically connected to the secondary side of the transformer T. In this embodiment, the turns ratio of the transformer T is N:1, and the present invention does not limit the value of the voltage transformation ratio of the transformer T. The input power supply V in After being processed by the transformer T, the output voltage of the transformer T changes to V in / N. The voltage V in / N output by the transformer T will be divided by the output rectifying diode D1, the electrochemical capacitor SC, and the output inductor Lo. As Figure 3 shown, when S1 is closed, in the forward conversion module 200, the input power supply V in charges the electrochemical capacitor SC through the transformer T.

[0048] Please refer to Figure 2 、 Figure 3 and Figure 5 shown. In an embodiment of the present invention, the positive electrode of the freewheeling diode D3 is electrically connected to the second end of the electrochemical capacitor SC, and the negative electrode of the freewheeling diode D3 is electrically connected to the first end of the output inductor Lo. The first end of the output inductor Lo is electrically connected to the first end of the electrochemical capacitor SC. In this embodiment, when S1 is disconnected, the freewheeling diode D3, the electrochemical capacitor SC, and the output inductor Lo form a circuit loop, and the output inductor Lo continues to charge the electrochemical capacitor SC.

[0049] Please refer to Figure 1 、 Figure 2 and Figure 9 shown. In an embodiment of the present invention, the energy storage module 300 includes an energy storage capacitor C s and a control switch 301. When the fast charging circuit 100 switches from outputting a first stable current to outputting a second stable current, the main power switch S1 is disconnected, and the input power supply V in stops charging the electrochemical capacitor SC. And, when the fast charging circuit 100 switches from outputting a first stable current to outputting a second stable current, the control switch 301 is closed, and the energy storage capacitor C s 、the output inductor Lo, and the electrochemical capacitor SC form a loop. Among them, the first end of the energy storage capacitor C s is electrically connected to the second end of the electrochemical capacitor SC, the second end of the energy storage capacitor C s is electrically connected to the first end of the output inductor Lo, and the second end of the output inductor Lo is electrically connected to the first end of the electrochemical capacitor SC. Through the energy storage capacitor C sThe stored electrical energy provides the energy required for the electrochemical capacitor SC to transition from the first stable current to the second stable current, as Figure 9 shown.

[0050] Please refer to Figure 1 , Figure 2 and Figure 9 shown. In an embodiment of the present invention, the control switch 301 includes a first switch S3 and a second switch S4. The first switch S3 is disposed between the second end of the energy storage capacitor C s and the output inductor Lo, and the second switch S4 is disposed between the electrochemical capacitor SC and the first end of the energy storage capacitor C s . By controlling the closing and opening of the first switch S3 and the second switch S4, the charging process of the energy storage capacitor C s to the electrochemical capacitor SC can be controlled when switching from the first stable current to the second stable current. Specifically, when the first switch S3 and the second switch S4 are closed simultaneously, the energy storage capacitor C s can provide an output current to the electrochemical capacitor SC until the output current reaches the second stable current. Among them, when the output current of the energy storage capacitor C s reaches the second stable current, the input power supply V in continues to provide the second stable current to the electrochemical capacitor SC. When either the first switch S3 or the second switch S4 is opened, the input power supply V in provides the first stable current or the second stable current to the electrochemical capacitor SC. In this embodiment, when the first switch S3 and the second switch S4 are both opened or closed, the input power supply V in provides the first stable current or the second stable current to the electrochemical capacitor SC. Specifically, in the stable output mode, the first stable current is provided to the electrochemical capacitor SC. In the pulse output mode, the second stable current is provided to the electrochemical capacitor SC.

[0051] Please refer to Figures 1 to 8 shown. In an embodiment of the present invention, the energy storage capacitor voltage regulation module 400 includes an excitation inductor L m , a reverse protection diode D2, a discharge resistor R r and a discharge switch S2. Among them, the excitation inductor L m is electrically connected to the energy storage capacitor C s , and the excitation inductor L m is electrically connected to the discharge resistor R r . In this embodiment, the first end of the excitation inductor L m is electrically connected to the positive pole of the input power supply V in , and the second end of the excitation inductor L m is electrically connected to the main power switch S1. Specifically, the second end of the excitation inductor L m is connected to the input power supply V through the main power switch S1in is negatively electrically connected. When the main power switch S1 is closed, the input power supply V in charges the electrochemical capacitor SC through the transformer T, and at the same time, the input power supply V in also charges the exciting inductor L m . And in this embodiment, the first end of the exciting inductor L m is electrically connected to the first end of the energy storage capacitor C s , and the second end of the exciting inductor L m is electrically connected to the positive electrode of the anti-reverse diode D2. The negative electrode of the anti-reverse diode D2 is electrically connected to the second end of the energy storage capacitor C s . When the main power switch S1 is opened, the input power supply V in stops charging the exciting inductor L m . At this time, the exciting inductor L m charges the energy storage capacitor C s , so that the level of the energy storage capacitor C s reaches the preset voltage V P . It should be noted that the charging process of the exciting inductor L m to the energy storage capacitor C s can be carried out simultaneously with the process of outputting the first stable current and the second stable current, or can occur during the process of switching the second stable current to the first stable current. And it should be noted that in the practical application of this embodiment, the exciting inductor L m is a parasitic element of the transformer T.

[0052] Please refer to Figures 1 to 6 As shown, in an embodiment of the present invention, when the exciting inductor L m charges the energy storage capacitor C s , the charging speed of the energy storage capacitor C s is as shown in Equation (1).

[0053]

[0054] Please refer to Figures 1 to 6 and Equation (1) as shown. In an embodiment of the present invention, in Equation (1), i Lm represents the current flowing through the exciting inductor L m , C s represents the capacitance of the energy storage capacitor C s . t represents time, and V Cs represents the voltage value of the energy storage capacitor C s . In this embodiment, the current amount of the exciting inductor L m is as shown in Equation (2).

[0055]

[0056] Please refer toFigures 1 to 6 , and as shown in Formula (1) and Formula (2), in an embodiment of the present invention, in Formula (2), i Lm represents the current flowing through the excitation inductor L m , t represents time, represents the forward conduction voltage drop of the anti - reverse diode D2, V Cs represents the voltage value of the energy - storage capacitor, L m represents the self - inductance value of the excitation inductor L m . In this embodiment, when S1 is turned off, the energy - storage capacitor C m is charged through the excitation inductor L s until its current drops to 0, thereby establishing a high voltage on the energy - storage capacitor C s . And, without setting an additional magnetic reset circuit, the magnetic reset of the excitation inductor L m can be achieved.

[0057] Please refer to Figures 1 to 6 as shown. In an embodiment of the present invention, the first end of the discharge resistor R r is electrically connected to the first end of the energy - storage capacitor C s and the first end of the excitation inductor L m , and the second end of the discharge resistor R r is electrically connected to the discharge switch S2. The discharge switch S2 is electrically connected to the second end of the energy - storage capacitor C s and the second end of the excitation inductor L m , and the negative electrode of the anti - reverse diode D2. When the voltage value of the energy - storage capacitor C s is higher than the preset voltage V P , the discharge switch S2 is closed, and the discharge resistor R r is connected in parallel to both ends of the energy - storage capacitor C s , and the energy - storage capacitor C r is discharged through the discharge resistor R s , thereby reducing the voltage value of the energy - storage capacitor C s , and maintaining the voltage value of the energy - storage capacitor C s at the preset voltage V P . In this embodiment, through the excitation inductor L m and the discharge resistor R r , the voltage value of the energy - storage capacitor C s is maintained at the preset voltage V P . Wherein the preset voltage V P is much larger than the input voltage V in .

[0058] Please refer to Figure 2 , Figures 6 to 8 as shown. In an embodiment of the present invention, when the energy - storage capacitor C sThe voltage value is higher than the preset voltage V P When this happens, the energy storage capacitor C s is discharged. Specifically, when the excitation inductor L m charges the energy storage capacitor C s and the voltage value of the energy storage capacitor C s is higher than the preset voltage V P , the discharge switch S2 is closed. As shown in Figure 6 , the current of the excitation inductor L m and the energy storage capacitor C s flows through the discharge resistor R r , thereby reducing the voltage across the energy storage capacitor C s . As the current of the excitation inductor L m continues to decrease to 0, when the voltage of the energy storage capacitor C s is still higher than the preset voltage V P , then as shown in Figure 7 , at this time, the energy storage capacitor C s provides current to the discharge resistor R r , thereby reducing the voltage of the energy storage capacitor C s . In the next cycle, after closing the main power switch S1, if the voltage of the energy storage capacitor C s is still higher than the preset voltage V P , the discharge switch S2 remains closed. As shown in Figure 8 , the energy storage capacitor C s and the discharge resistor R r form a loop, and the energy storage capacitor C s discharges the discharge resistor R r , thereby reducing the voltage of the energy storage capacitor C s . It should be noted that in actual operation, the discharge switch S2 performs repeated switching operations, so that the voltage of the energy storage capacitor C s is stabilized at the preset voltage V p .

[0059] Please refer to Figures 1 to 9 shown. In an embodiment of the present invention, when the forward conversion module 200 provides the second stable current during the switching of the electrochemical capacitor SC, the switching speed from the stable output mode to the pulse output mode is as shown in Equation (3).

[0060]

[0061] Please refer to Figures 1 to 9 and Equation (3) shown. In an embodiment of the present invention, in Equation (3), is the current of the output inductor Lo, t represents time, represents the voltage value of the input power supply V in , and N represents the turns ratio of the transformer T. Represents the forward conduction voltage drop of the output rectifier diode D1, V SC Represents the voltage division value of the electrochemical capacitor SC, and Lo represents the self-inductance of the output inductor Lo. When the fast charging circuit 100 needs to switch from the stable output mode to the pulse output mode, the output current of the electrochemical capacitor SC is converted from the first stable current to the second stable current. In this embodiment, the main power switch S1 is disconnected, the discharge switch S2 is disconnected, the control switch 301 is closed, and the energy storage capacitor C s , the control switch 301, the output inductor Lo, and the electrochemical capacitor SC are in the same circuit loop, as Figure 9 shown, and the energy storage capacitor C s charges the electrochemical capacitor SC. The switching speed of the electrochemical capacitor SC from the first stable current to the second stable current is as shown in Equation (4).

[0062]

[0063] Please refer to Figures 1 to 9 , and as shown in Equation (3) and Equation (4), in an embodiment of the present invention, in Equation (4), V P represents a preset voltage. In this embodiment, V P >>V in / N, so charging the electrochemical capacitor SC through the energy storage capacitor Cs can convert the first stable current into the second stable current faster. After converting to the second stable current, the control switch 301 is disconnected, and the input power supply V in charges the electrochemical capacitor SC through the transformer T to maintain the output of the second stable current, as Figure 4 shown. While the input power supply V in outputs the second stable current to the electrochemical capacitor SC, the input power supply V in also charges the excitation inductor L m , and the current flowing through the excitation inductor L m increases. While the input power supply V in outputs the second stable current to the electrochemical capacitor SC, the voltage of the energy storage capacitor C s is monitored, and the voltage value of the energy storage capacitor C s is maintained at the preset voltage V P .

[0064] Please refer to Figures 1 to 3 and Figure 10 shown. In an embodiment of the present invention, when the forward conversion module 200 switches from the pulse output mode to the stable output mode, that is, when the output current switches from the second stable current to the first stable current, the falling speed of the output current is as shown in Equation (5). In Equation (5), is the current of the output inductor Lo, t is the time, and Lo is the self-inductance of the output inductor. is the forward conduction voltage drop of the freewheeling diode D3, V SC is the voltage division value of the electrochemical capacitor SC.

[0065]

[0066] Please refer to Figures 1 to 3 and Figure 10 As shown in, in an embodiment of the present invention, the branch resistance module 500 includes a branch resistance R f and a branch switch S5. Among them, one end of the branch resistance R f is electrically connected to the second end of the output inductor Lo, and the second end of the branch resistance R f is electrically connected to the first end of the electrochemical capacitor SC. One end of the branch switch S5 is electrically connected to the first end of the branch resistance R f , and the other end of the branch switch S5 is electrically connected to the second end of the branch resistance R f . In this embodiment, when the input power supply V in outputs the first stable current and the second stable current to the electrochemical capacitor SC, when the fast charging circuit 100 switches from outputting the first stable current to outputting the second stable current, the branch switch S5 is closed. When the fast charging circuit 100 switches from outputting the second stable current to outputting the first stable current, the branch switch S5 is disconnected and the main power switch S1, the control switch 301, and the discharge switch S2 are disconnected, and the freewheeling diode D3, the output inductor Lo, the branch resistance R f and the electrochemical capacitor SC form a circuit loop. When the output current of the fast charging circuit 100 to the electrochemical capacitor SC switches from the second stable current to the first stable current, the falling speed of the output current of the fast charging circuit 100 is as shown in Equation (6).

[0067]

[0068] Please refer to Figures 1 to 3 and Figure 10 , as well as shown in Equation (5) and Equation (6), in an embodiment of the present invention, in Equation (6), is the current of the output inductor Lo, R f is the resistance value of the branch resistance, is the forward conduction voltage drop of the freewheeling diode D3, V SC is the voltage division value of the electrochemical capacitor SC. t is the time, and Lo is the self-inductance of the output inductor. And in this embodiment, According to Equation (6) and Equation (5), in this embodiment, the output current of the fast charging circuit 100 decreases faster. When the output current of the fast charging circuit 100 reaches the first stable current, the branch switch S5 closes, and the input power supply V in Outputs the first stable current to the electrochemical capacitor SC through the transformer T. Among them, the fast charging circuit 100 of the present invention can charge the electrochemical capacitor SC in two modes with high efficiency, and multiple processes such as the fast charging circuit 100 outputting the first stable current, the second stable current, and the switching between the first stable current and the second stable current, and the switching between the second stable current and the first stable current are carried out dynamically.

[0069] Please refer to Figures 1 to 11 As shown, the present invention provides a charging method for the fast charging circuit 100, and the charging method includes steps S10 to S50.

[0070] Step S10: Set the stable output mode and the pulse output mode. In the stable output mode, output the first stable current to the electrochemical capacitor through the forward conversion module.

[0071] Step S20: When switching from the stable output mode to the pulse output mode, close the control switch, and output the charging current to the electrochemical capacitor through the energy storage capacitor until the output current reaches the second stable current.

[0072] Step S30: In the pulse output mode, the forward conversion module outputs the second stable current to the electrochemical capacitor.

[0073] Step S40: When switching from the pulse output mode to the stable output mode, open the branch switch until the output current to the electrochemical capacitor reaches the first stable current.

[0074] Step S50: Monitor the voltage of the energy storage capacitor, charge the energy storage capacitor by the exciting inductor, and when the voltage of the energy storage capacitor is greater than the preset voltage, close the discharge switch to reduce the voltage division of the energy storage capacitor.

[0075] Please refer to Figures 1 to 11 As shown, in an embodiment of the present invention, in step S10, in the stable output mode, the branch switch S5 is closed, the control switch 301 is open, and the working mode of the discharge switch S2 is not limited. The input power supply V in Outputs the first stable current to the electrochemical capacitor SC. In step S30, in the pulse output mode, the branch switch S5 is closed, the control switch 301 is open, and the working mode of the discharge switch S2 is not limited. The input power supply V inOutput the second stable current to the electrochemical capacitor SC. It should be noted that, in practical applications, step S10 can be performed before step S30 or after step S30. It should be noted that, in this embodiment, when the forward conversion module 200 provides the first stable current or the second stable current to the electrochemical capacitor SC, the main power switch S1 is closed and opened with a duty cycle.

[0076] See also Figures 1 to 11 As shown, in one embodiment of the present invention, in step S20, when the output current of the fast charging circuit 100 is switched from the first stable current to the second stable current, that is, when the fast charging circuit 100 is switched from the stable output mode to the pulse output mode, the main power switch S1 and the discharge switch S2 are disconnected, the branch switch S5 is closed, the control switch 301 is closed, and the energy storage capacitor C s The electrochemical capacitor SC is charged, and the charging current of the electrochemical capacitor SC increases from the first stable current to the second stable current. In this embodiment, in step S40, when the fast charging circuit switches from outputting the second stable current to outputting the first stable current, that is, when the fast charging circuit 100 switches from the pulse output mode to the stable output mode, the main power switch S1, the control switch 301 and the branch switch S5 are disconnected, the working mode of the discharge switch S2 is not limited, the output inductor Lo maintains the charging current of the electrochemical capacitor SC, and the branch resistor R is introduced. f , accelerating the speed at which the second stable current drops to the first stable current, until the output current of the fast charging circuit 100 to the electrochemical capacitor SC drops to the first stable current. In step S50, the current of the electrochemical capacitor SC and the energy storage capacitor C are monitored by an external electrical component or a monitoring instrument. s The voltage of the energy storage capacitor C is monitored and controlled. In the working process of the fast charging circuit of the present invention, the discharge switch S2 is adjusted to reduce the energy storage capacitor C s The voltage through the excitation inductance L m To increase the energy storage capacitor C s voltage, and at the same time realize the excitation inductance L m The present invention does not limit conventional voltage and current monitoring.

[0077] The present invention provides a fast charging circuit applicable to an electrochemical capacitor, a charging method thereof, and a charger. The fast charging circuit includes a forward conversion module, an energy storage module, an energy storage capacitor voltage stabilizing module, and a branch resistor module. Among them, the output end of the forward conversion module is electrically connected to the electrochemical capacitor, and the forward conversion module outputs a first stable current or a second stable current. When the fast charging circuit switches from outputting the first stable current to outputting the second stable current, the output end of the energy storage module is electrically connected to the electrochemical capacitor, rapidly increasing the output current until the output current reaches the second stable current. Among them, the energy storage capacitor voltage stabilizing module is electrically connected to the energy storage module and maintains the voltage of the energy storage module at a preset voltage. When the fast charging circuit switches from outputting the second stable current to outputting the first stable current, the branch resistor in the branch resistor module is electrically connected to the electrochemical capacitor, rapidly decreasing the output current until the output current reaches the first stable current. Through the fast charging circuit and the charging method provided by the invention, the first stable current can be output to the electrochemical capacitor through a stable output mode, and the second stable current can be output to the electrochemical capacitor through a pulse output mode, thereby realizing fast and stable charging of the electrochemical capacitor. Moreover, the fast charging circuit provided by the invention has a fast mode switching speed and a long current maintaining time in the pulse output mode, and the second stable current that can be achieved is significantly higher than the current peak value that can be achieved by the existing level. According to the fast charging circuit provided by the invention, the charging efficiency is higher.

[0078] The embodiments of the present invention disclosed above are only used to help explain the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art in the relevant technical field can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A fast charging circuit applicable to an electrochemical capacitor, characterized in that, Comprising: A forward conversion module, the forward conversion module includes a transformer, the primary side of the transformer is electrically connected to a power supply through a main power switch, the secondary side of the transformer is electrically connected to an electrochemical capacitor, and the forward conversion module outputs a first stable current or a second stable current to the electrochemical capacitor; A storage capacitor, which is connected in parallel with the primary side of the transformer, and both ends of the storage capacitor are electrically connected to both ends of the electrochemical capacitor through a control switch. When the output of the fast charging circuit switches from the first stable current to the second stable current, the control switch closes, and the storage capacitor charges the electrochemical capacitor to quickly increase the output current of the fast charging circuit and accelerate the switching process from the first stable current to the second stable current, where the second stable current is greater than the first stable current; And A branch resistor, when the output of the fast charging circuit switches from the second stable current to the first stable current, one end of the branch resistor is electrically connected to the electrochemical capacitor, and the other end is electrically connected to the secondary side of the transformer to accelerate the switching process from the second stable current to the first stable current.

2. The fast charging circuit applicable to an electrochemical capacitor according to claim 1, characterized in that, The fast charging circuit includes a branch switch, the branch switch is connected in parallel with the branch resistor, and when the output of the fast charging circuit switches from the second stable current to the first stable current, the branch switch disconnects to connect the branch resistor into the loop of the fast charging circuit.

3. The fast charging circuit applicable to an electrochemical capacitor according to claim 1, characterized in that The forward conversion module includes an output inductor, the first end of the output inductor is electrically connected to the secondary side of the transformer, and the second end of the output inductor is electrically connected to the branch resistor.

4. The fast charging circuit applicable to an electrochemical capacitor according to claim 1, characterized in that, The control switch includes a first switch, one end of the first switch is electrically connected to the first end of the storage capacitor, and the other end of the first switch is electrically connected to the electrochemical capacitor through the branch resistor.

5. The fast charging circuit applicable to an electrochemical capacitor according to claim 1, characterized in that, The control switch includes a second switch, one end of the second switch is electrically connected to the second end of the storage capacitor, and the other end of the second switch is electrically connected to the electrochemical capacitor.

6. The fast charging circuit applicable to an electrochemical capacitor according to claim 1, characterized in that, The fast charging circuit includes a storage capacitor voltage stabilizing module, and the storage capacitor voltage stabilizing module includes: A discharge resistor, the first end of the discharge resistor is electrically connected to the first end of the storage capacitor; and A discharge switch, one end of the discharge switch is electrically connected to the second end of the discharge resistor, and the other end of the discharge switch is electrically connected to the second end of the storage capacitor; An exciting inductor, the first end of the exciting inductor is electrically connected to the first end of the storage capacitor; and A reverse protection diode, the positive electrode of the reverse protection diode is electrically connected to the second end of the exciting inductor, and the negative electrode of the reverse protection diode is electrically connected to the second end of the storage capacitor.

7. The fast charging circuit applicable to an electrochemical capacitor according to claim 1, characterized in that, The capacitance of the electrochemical capacitor is 0.1F to 50000F.

8. A charging method applicable to an electrochemical capacitor, based on the fast charging circuit applicable to an electrochemical capacitor as described in claim 1, characterized in that, The charging method includes the following steps: Set a stable output mode and a pulse output mode. In the stable output mode, a first stable current is output to the electrochemical capacitor through the forward conversion module; When switching from the stable output mode to the pulse output mode, close the control switch and output current to the electrochemical capacitor through the energy storage capacitor until the output current reaches the second stable current; In the pulse output mode, the forward conversion module outputs the second stable current to the electrochemical capacitor; and The fast charging circuit includes a branch switch. When switching from the pulse output mode to the stable output mode, disconnect the branch switch, and the branch resistor is electrically connected to the forward conversion module until the output current to the electrochemical capacitor reaches the first stable current.

9. The charging method of the fast charging circuit applicable to an electrochemical capacitor according to claim 8, characterized in that, The fast charging circuit includes an exciting inductor and a discharge switch. The charging method includes monitoring and adjusting the voltage of the energy storage capacitor, and the step of monitoring and adjusting the voltage of the energy storage capacitor includes: Charging the energy storage capacitor by the exciting inductor; and When the voltage of the energy storage capacitor is greater than the preset voltage, close the discharge switch to discharge the energy storage capacitor.

10. A charger applicable to an electrochemical capacitor, characterized in that, Comprising the fast charging circuit for an electrochemical capacitor according to any one of claims 1 to 8.

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