Super capacitor charging circuit and charging method thereof

Abstract

The charging circuit comprises a switching power supply circuit and a super capacitor, the switching power supply circuit is connected with the super capacitor, the switching power supply circuit is a PNP type switching power supply circuit adopting a flyback topological structure, the primary side and the secondary side of a transformer of the PNP type switching power supply circuit are in common ground, and the secondary side of the transformer of the PNP type switching power supply circuit is connected with the super capacitor. The switching power supply circuit provides constant current for the super capacitor when starting to charge the super capacitor, so that the voltage of the super capacitor is linearly increased, and when the super capacitor is charged to a target voltage, the switching power supply circuit controls the voltage of the super capacitor to keep constant, so that the super capacitor is prevented from being overcharged, and meanwhile, the voltage of the super capacitor is kept constant. And the PNP type switching power supply circuit cannot be charged reversely, so that the technical problems that the charging current cannot be effectively controlled and the reverse charging cannot be avoided in the charging process of the existing super capacitor are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and in particular to a supercapacitor charging circuit and a charging method thereof. Background Art

[0002] Supercapacitors are high-performance capacitors with the advantages of fast charging and discharging, long life, and high efficiency. Existing supercapacitors cannot effectively control the charging current during the charging process, and the charging current cannot be effectively controlled within an appropriate range. Excessive current will damage the supercapacitor, and existing supercapacitors cannot avoid reverse charging, which will damage the supercapacitor. Summary of the invention

[0003] The present invention provides a supercapacitor charging circuit and a charging method thereof, which are used to solve the technical problems that the existing supercapacitor cannot effectively control the charging current and cannot avoid reverse charging during the charging process.

[0004] In view of this, a first aspect of the present invention provides a supercapacitor charging circuit, comprising a switching power supply circuit and a supercapacitor;

[0005] The switching power supply circuit is a PNP type switching power supply circuit adopting a flyback topology structure, and the primary side and the secondary side of the transformer of the PNP type switching power supply circuit share a common ground;

[0006] The switching power supply circuit is connected to the supercapacitor;

[0007] The switching power supply circuit is used to provide a constant current to the supercapacitor when the supercapacitor starts to charge, so that the voltage of the supercapacitor increases linearly, and after the supercapacitor is charged to a target voltage, control the voltage of the supercapacitor to remain constant, and stop charging the supercapacitor after the supercapacitor is fully charged.

[0008] Optionally, the supercapacitor includes a plurality of energy storage capacitors connected in series and a plurality of hybrid energy storage devices, and each of the energy storage capacitors is connected in parallel with one of the hybrid energy storage devices.

[0009] Optionally, the thickness of the hybrid energy storage device is 2 mm.

[0010] Optionally, the energy density of the hybrid energy storage device is 15 Ws / g.

[0011] Optionally, the hybrid energy storage device has 1 to 8 capacitor cells.

[0012] Optionally, the capacitance of the capacitor monomer is 5~100F.

[0013] Optionally, the turns ratio of the primary coil to the secondary coil of the transformer is adjustable.

[0014] Optionally, the PNP type switching power supply circuit includes a switching tube, a bypass capacitor, the transformer, a rectifier diode and an output filter capacitor;

[0015] One end of the bypass capacitor is connected to the primary side of the transformer, and the other end of the bypass capacitor is grounded;

[0016] The drain of the switch tube is connected to the primary side of the transformer, the source of the switch tube is grounded, and the gate of the switch tube is suspended;

[0017] The anode of the rectifier diode is connected to the secondary side of the transformer, the cathode of the rectifier diode is connected to one end of the output filter capacitor, and the other end of the output filter capacitor is grounded to the secondary side of the transformer.

[0018] Optionally, it further includes a first grounding resistor and a second grounding resistor;

[0019] One end of the first grounding resistor is connected to the positive electrode connection end of the supercapacitor, the other end of the first grounding resistor is connected to one end of the second resistor, and the other end of the second resistor is grounded;

[0020] One end of the second resistor is connected to the ground end of the switch tube.

[0021] The second aspect of the present invention provides a charging method for the supercapacitor charging circuit according to any one of the first aspects, comprising:

[0022] The switch power supply circuit detects in real time whether there is an input voltage input;

[0023] The switch power supply circuit is turned on when an input voltage is detected to charge the super capacitor;

[0024] The switching power supply circuit provides a constant current to the supercapacitor when charging of the supercapacitor starts, so that the voltage of the supercapacitor increases linearly;

[0025] The switching power supply circuit controls the voltage of the supercapacitor to remain constant after the supercapacitor is charged to a target voltage;

[0026] The switching power supply circuit stops charging the super capacitor after the super capacitor is fully charged.

[0027] It can be seen from the above technical solutions that the supercapacitor charging circuit provided by the present invention has the following advantages:

[0028] The supercapacitor charging circuit provided by the present invention comprises a switching power supply circuit and a supercapacitor. The switching power supply circuit is connected to the supercapacitor. The switching power supply circuit is a PNP-type switching power supply circuit adopting a flyback topology structure. The primary side and the secondary side of the transformer of the PNP-type switching power supply circuit are grounded in common. When the switching power supply circuit starts to charge the supercapacitor, the supercapacitor is provided with a constant current so that the voltage of the supercapacitor increases linearly. When the supercapacitor is charged to a target voltage, the switching power supply circuit controls the voltage of the supercapacitor to remain constant so as to avoid overcharging of the supercapacitor. Meanwhile, the PNP-type switching power supply circuit cannot be reversely charged, thereby solving the technical problems that the existing supercapacitor cannot effectively control the charging current and cannot avoid reverse charging during the charging process.

[0029] At the same time, the supercapacitor charging circuit provided by the present invention has an adjustable primary and secondary coil turns ratio of the switching power supply circuit transformer, and the charging voltage and charging current are changed by changing the primary and secondary coil turns ratio of the transformer, thereby solving the problem that the existing supercapacitor charging method cannot select a suitable charging current according to the rated voltage and capacitance value of the supercapacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A circuit schematic diagram of a supercapacitor charging circuit provided in the present invention;

[0032] Figure 2 A charging voltage and current control diagram of a supercapacitor charging circuit provided in the present invention;

[0033] Figure 3 It is a charging experiment waveform diagram of the switching power supply circuit provided in the present invention;

[0034] Figure 4 A schematic diagram of a switching voltage waveform of a switching power supply circuit during the charging process of a supercapacitor provided in the present invention;

[0035] Figure 5 A schematic diagram of the primary current waveform of the switching power supply circuit after the supercapacitor provided by the present invention is fully charged;

[0036] Figure 6 A circuit schematic diagram of a PNP type switching power supply circuit provided in the present invention;

[0037] Figure 7 A schematic diagram of the circuit structure of the supercapacitor provided in the present invention;

[0038] Figure 8 A schematic flow chart of a charging method for a supercapacitor charging circuit provided in the present invention. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] For easier understanding, see Figure 1 and Figure 2 , the present invention provides an embodiment of a supercapacitor charging circuit, comprising a switching power supply circuit and a supercapacitor;

[0041] The switching power supply circuit is a PNP type switching power supply circuit adopting a flyback topology structure, and the primary side and the secondary side of the transformer of the PNP type switching power supply circuit share a common ground;

[0042] The switching power supply circuit is connected to the supercapacitor;

[0043] The switching power supply circuit is used to provide a constant current to the supercapacitor at the beginning of supercapacitor charging, so that the voltage of the supercapacitor increases linearly. After the supercapacitor is charged to the target voltage, the voltage of the supercapacitor is controlled to remain constant. After the supercapacitor is fully charged, charging of the supercapacitor is stopped.

[0044] It should be noted that at the beginning of the charging cycle, the charging circuit operates in a constant current mode, providing a constant current to the supercapacitor, so that the voltage applied to the supercapacitor increases linearly. After the supercapacitor is charged to the target voltage, the constant voltage is activated, and the switching power supply circuit controls the voltage of the supercapacitor to remain constant to avoid overcharging the supercapacitor. When the charging voltage of the supercapacitor approaches the target voltage, the difference between the charging voltage and the energy storage voltage is close, and the current decreases rapidly until the voltage is equal, the current is 0, and the charging is completed. The switching power supply circuit is a PNP type switching power supply circuit using a flyback topology structure. The primary and secondary sides of the transformer of the PNP type switching power supply circuit are grounded. When charging the supercapacitor, the PNP type switching power supply circuit always works in a current limiting state. When the supercapacitor is fully charged, the PNP type switching power supply circuit works in a buck mode. In this way, the output voltage of the PNP type switching power supply circuit is stabilized at the set value to ensure that the supercapacitor will not be overcharged. The PNP type switching power supply circuit supports a wide range of voltage inputs and can effectively control the maximum current during startup and normal operation to less than 3 amperes. After the supercapacitor is fully charged, constant voltage control can be achieved. By turning off the switch element of the PNP type switching power supply circuit, the input side and the output side of the PNP type switching power supply circuit can be completely disconnected. The NP type switching power supply circuit has the advantages of low cost and small size. Figure 3 As can be seen from the startup waveform shown, regardless of the load capacitance What is the input current? They are all smaller than the peak current limit value of the switching element of the PNP switching power supply circuit. Figure 4 As can be seen from the output When the voltage is lower than the set value, the PNP switching power supply circuit will always work in the current limiting state. When the voltage rises to several volts, the primary peak current is always limited. Figure 5 This is the working waveform of the PNP switching power supply circuit after the output capacitor is fully charged. Since the duty cycle is very small, the primary current is very small and the output voltage Keep it at the set value.

[0045] The supercapacitor charging circuit provided by the present invention comprises a switching power supply circuit and a supercapacitor. The switching power supply circuit is connected to the supercapacitor. The switching power supply circuit is a PNP-type switching power supply circuit adopting a flyback topology structure. The primary side and the secondary side of the transformer of the PNP-type switching power supply circuit are grounded in common. When the switching power supply circuit starts to charge the supercapacitor, the supercapacitor is provided with a constant current so that the voltage of the supercapacitor increases linearly. When the supercapacitor is charged to a target voltage, the switching power supply circuit controls the voltage of the supercapacitor to remain constant so as to avoid overcharging of the supercapacitor. Meanwhile, the PNP-type switching power supply circuit cannot be reversely charged, thereby solving the technical problems that the existing supercapacitor cannot effectively control the charging current and cannot avoid reverse charging during the charging process.

[0046] In one embodiment, the turns ratio of the primary and secondary coils of the transformer of the PNP type switching power supply circuit is adjustable. The charging voltage and charging current are changed by changing the turns ratio of the primary and secondary coils of the transformer. This solves the problem that the existing supercapacitor charging method cannot select a suitable charging current according to the rated voltage and capacitance value of the supercapacitor.

[0047] In one embodiment, Figure 6 As shown, the PNP type switching power supply circuit includes a switch tube Q, a bypass capacitor C1, a transformer T1, a rectifier diode D1 and an output filter capacitor C2, one end of the bypass capacitor C1 is connected to the primary side of the transformer T1, the other end of the bypass capacitor C1 is grounded, the drain of the switch tube Q is connected to the primary side of the transformer T1, the source of the switch tube Q is grounded, the gate of the switch tube Q is suspended, the anode of the rectifier diode D1 is connected to the secondary side of the transformer T1, the cathode of the rectifier diode D1 is connected to one end of the output filter capacitor C2, and the other end of the output filter capacitor C2 is grounded with the secondary side of the transformer T1. One end of the supercapacitor SuperCAP is connected to the cathode of the rectifier diode D1, and the other end of the supercapacitor Super CAP is grounded with the output filter capacitor C2. The cathode of the rectifier diode D1 is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is grounded, and one end of the second resistor R2 is connected to the grounding end of the switch tube Q, so that the primary and secondary sides of the transformer of the PNP type switching power supply circuit are grounded. The bypass capacitor C1 is used to filter out ripples, strays and high-frequency pulses in the input, and protect the circuit. The output filter capacitor C2 is used to prevent high-frequency and high-energy signals from breaking down the supercapacitor.

[0048] In one embodiment, Figure 7As shown, the supercapacitor includes several energy storage capacitors connected in series and several hybrid energy storage devices Balance CKT, and a hybrid energy storage device Balance CKT is connected in parallel to each energy storage capacitor. The hybrid energy storage device Balance CKT has a large capacity for electricity storage. The thickness of the hybrid energy storage device Balance CKT is only 2mm, and the energy density reaches 15Ws / g. It has outstanding flexibility and better charging and discharging performance, and can be used in energy collection and power line backup products. The hybrid energy storage device Balance CKT has a maximum of 8 capacitor cells, each of which has a capacitance of 5 to 100F, with stacked through-holes, surface mount flat packages, and flat structures with pins, pull rings and connectors. The voltage level of the capacitor cell ranges from 1V to 10V, the soft charging current is less than 0.5A, and the leakage current is 0.05 to 0.184mA after 48 hours, with the best energy / volume ratio and excellent performance indicators.

[0049] For easier understanding, see Figure 8 The present invention provides a charging method applied to the supercapacitor charging circuit provided in the present invention, comprising:

[0050] Step S1, the switching power supply circuit detects in real time whether there is an input voltage input;

[0051] Step S2, the switch power circuit is turned on when an input voltage is detected to charge the supercapacitor;

[0052] Step S3: When the supercapacitor starts to charge, the switching power supply circuit provides a constant current to the supercapacitor, so that the voltage of the supercapacitor increases linearly;

[0053] Step S4, after the supercapacitor is charged to the target voltage, the switching power supply circuit controls the voltage of the supercapacitor to remain constant;

[0054] Step S5: After the supercapacitor is fully charged, the switching power supply circuit stops charging the supercapacitor.

[0055] In one embodiment, before step S2, the method further includes:

[0056] Step S0: determining the charging current of the supercapacitor according to the rated voltage and capacitance value of the supercapacitor, and adjusting the primary-to-secondary coil turns ratio of the transformer of the PNP type switching power supply circuit according to the charging current of the supercapacitor.

[0057] The charging method of the supercapacitor charging circuit provided in the present invention is applied to the supercapacitor charging circuit provided in the present invention. Its principle and technical effects are the same as those of the supercapacitor charging circuit provided in the present invention, and will not be repeated here.

[0058] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A supercapacitor charging circuit, characterized in that: Including a switching power supply circuit and a super capacitor; The switching power supply circuit is a PNP type switching power supply circuit adopting a flyback topology structure, and the primary side and the secondary side of the transformer of the PNP type switching power supply circuit share a common ground; The switching power supply circuit is connected to the supercapacitor; The switching power supply circuit is used to provide a constant current to the supercapacitor when the supercapacitor starts to charge, so that the voltage of the supercapacitor increases linearly, and after the supercapacitor is charged to a target voltage, control the voltage of the supercapacitor to remain constant, and stop charging the supercapacitor after the supercapacitor is fully charged.

2. The supercapacitor charging circuit according to claim 1, characterized in that: The supercapacitor comprises a plurality of energy storage capacitors connected in series and a plurality of hybrid energy storage devices, and each of the energy storage capacitors is connected in parallel with one of the hybrid energy storage devices.

3. The supercapacitor charging circuit according to claim 2, characterized in that: The thickness of the hybrid energy storage device is 2 mm.

4. The supercapacitor charging circuit according to claim 2, characterized in that: The energy density of the hybrid energy storage device is 15 Ws / g.

5. The supercapacitor charging circuit according to claim 2, characterized in that: The hybrid energy storage device has 1 to 8 capacitor cells.

6. The supercapacitor charging circuit according to claim 5, characterized in that: The capacitance of the capacitor monomer is 5~100F.

7. The supercapacitor charging circuit according to claim 1, characterized in that: The turns ratio of the primary and secondary coils of the transformer is adjustable.

8. The supercapacitor charging circuit according to claim 1, characterized in that: The PNP type switching power supply circuit includes a switching tube, a bypass capacitor, the transformer, a rectifier diode and an output filter capacitor; One end of the bypass capacitor is connected to the primary side of the transformer, and the other end of the bypass capacitor is grounded; The drain of the switch tube is connected to the primary side of the transformer, the source of the switch tube is grounded, and the gate of the switch tube is suspended; The anode of the rectifier diode is connected to the secondary side of the transformer, the cathode of the rectifier diode is connected to one end of the output filter capacitor, and the other end of the output filter capacitor is grounded to the secondary side of the transformer.

9. The supercapacitor charging circuit according to claim 8, characterized in that: Also includes a first grounding resistor and a second grounding resistor; One end of the first grounding resistor is connected to the positive electrode connection end of the supercapacitor, the other end of the first grounding resistor is connected to one end of the second resistor, and the other end of the second resistor is grounded; One end of the second resistor is connected to the ground end of the switch tube.

10. A charging method for a supercapacitor charging circuit according to any one of claims 1 to 9, characterized in that: include: The switch power supply circuit detects in real time whether there is an input voltage input; The switch power supply circuit is turned on when an input voltage is detected to charge the super capacitor; The switching power supply circuit provides a constant current to the supercapacitor when charging of the supercapacitor starts, so that the voltage of the supercapacitor increases linearly; The switching power supply circuit controls the voltage of the supercapacitor to remain constant after the supercapacitor is charged to a target voltage; The switching power supply circuit stops charging the super capacitor after the super capacitor is fully charged.

Images