Energy storage system and method, power supply system and method

Abstract

This invention belongs to the technical field of energy storage systems, providing an energy storage system and method, and a power supply system and method. The energy storage system includes: an input energy storage element: one end grounded, the other end connected to a current source; an energy storage circuit: including a control circuit and an energy storage element, one end of the control circuit connected to the other end of the input energy storage element, the other end connected to one end of the energy storage element, and the other end of the energy storage element grounded; the control circuit of the first-stage energy storage circuit is triggered to conduct through the output energy storage element, and the control circuits of other stages of energy storage circuits are triggered to conduct through the previous stage control circuit; one end of the output energy storage element is connected to the other end of the input energy storage element, and the other end is grounded; wherein, the triggering condition of the control circuit of the first-stage energy storage circuit is that the output energy storage element stores energy to a first threshold; the triggering condition of the control circuit of other stages of energy storage circuits is that the energy storage element of the previous stage energy storage circuit stores energy to a second threshold. This invention provides graded energy storage, enabling rapid attainment of the operating voltage.

Description

Technical Field

[0001] This invention relates to energy storage system technology, and particularly to energy storage systems and methods, and power supply systems and methods. Background Technology

[0002] Photovoltaic tags, mini calculators, and watches are gradually gaining popularity. Currently, the main requirements for these low-power photovoltaic devices are as follows: First: It can absorb photovoltaic power and start working in a very short time after being exposed to light; Second: After prolonged exposure to light, it can store enough electricity to work for a longer period of time; Third: The static power consumption must be low enough. The photovoltaic modules of general photovoltaic tags or small calculators, watches and other tools only have a power generation capacity of 20-80uA. Therefore, the overall power consumption needs to be low enough, such as less than 1uA. Fourth: Make the most of the voltage of the photovoltaic module, because the maximum output voltage of the photovoltaic module will vary between 4-8V depending on the brightness of the light.

[0003] Therefore, meeting the energy storage requirements of the aforementioned low-power photovoltaic equipment is an important issue that the industry urgently needs to address. Summary of the Invention

[0004] In view of this, the present invention provides an energy storage system and energy storage method, and a power supply system and power supply method, so as to achieve the technical objective of starting charging in a very short time and quickly reaching the working voltage.

[0005] According to a first aspect of the invention, an energy storage system is provided, comprising an input energy storage element, an output energy storage element, and a multi-stage energy storage circuit: One end of the input energy storage element is grounded, and the other end is connected to a current source; The energy storage circuit includes a control circuit and an energy storage element. One end of the control circuit is connected to the other end of the input energy storage element, and the other end of the control circuit is connected to one end of the energy storage element. The other end of the energy storage element is grounded. The control circuit of the first-stage energy storage circuit is triggered to conduct through the output energy storage element. The control circuits of other stages of energy storage circuits are triggered to conduct through the previous stage control circuit. When the control circuit is turned on, the energy storage element is charged. One end of the output energy storage element is connected to the other end of the input energy storage element, and the other end of the output energy storage element is grounded; The triggering condition for the output energy storage element to activate the control circuit of the first-stage energy storage circuit is that the output energy storage element stores energy to a first threshold. The triggering condition for the control circuit of other stages of energy storage circuit to activate through the previous stage control circuit is that the energy storage element of the previous stage energy storage circuit stores energy to a second threshold. The input energy storage element and the multi-stage energy storage circuit sequentially store energy to a third threshold, where the third threshold is greater than the second threshold, and the second threshold is greater than the first threshold.

[0006] In one possible implementation, the input energy storage element is an input capacitor; or / and, the energy storage element of the multi-stage energy storage circuit is a capacitor; or / and the output energy storage element is an output capacitor.

[0007] In one possible implementation, the capacitance values ​​of the capacitors in the multi-stage energy storage circuit decrease sequentially.

[0008] In one possible implementation, the control circuit of the first-stage energy storage circuit includes a first comparator, a first switch, and a first resistor: One input terminal of the first comparator is connected to one end of the output energy storage element, the voltage of the other input terminal of the first comparator is a first threshold, and the output terminal of the first comparator is connected to the enable terminal of the first switch. The input terminal of the first resistor is connected to the other end of the input energy storage element, and the output terminal of the first resistor is connected to the input terminal of the first switch. The output terminal of the first switch is connected to one end of the energy storage element.

[0009] In one possible implementation, the control circuit of the intermediate-stage energy storage circuit includes a second comparator, a first DC source, a second switch, a second resistor, and a first switching transistor. One input terminal of the second comparator is connected to the output terminal of the resistor in the previous stage energy storage circuit through a first DC source, the other input terminal is connected to the input terminal of the resistor, and the output terminal is connected to the enable terminal of the second switch. The first switching transistor is connected between the other end of the input energy storage element and the input end of the second resistor to control whether current flows into or out of the input end of the second resistor; The output terminal of the second resistor is connected to the input terminal of the second switch; The output terminal of the second switch is connected to one end of the energy storage element.

[0010] In one possible implementation, the control circuit of the last-stage energy storage circuit includes a third comparator, a second DC source, a second switching transistor, a third switch, and a fourth switch. One input terminal of the third comparator is connected to the other end of the input energy storage element, and the other input terminal of the third comparator is connected to the output terminal of the second resistor of the previous stage energy storage circuit through the second DC source. The output terminal of the third comparator is connected to the enable terminal of the third switch. The second switch is connected between the other end of the input energy storage element and the input terminal of the third switch, and is used to control whether current flows into or out of the input terminal of the third switch; The output terminal of the third switch is connected to the input terminal of the fourth switch; The enable terminal of the fourth switch is connected to the output terminal of the second comparator of the intermediate stage energy storage circuit, and the output terminal of the fourth switch is connected to one end of the energy storage element.

[0011] In one possible implementation, the first and second switching transistors are PMOS transistors.

[0012] In one possible implementation, the energy storage circuit further includes an operational amplifier, one input terminal of which is connected to the other end of the input energy storage element, the other input terminal of which is connected to one end of the energy storage element of the first-stage energy storage circuit, and the output terminal of which is connected to the control terminals of the first and second switching transistors.

[0013] In one possible implementation, the energy storage circuit further includes a leakage protection circuit, which clamps the highest voltage of the input energy storage element and leaks excess current after the input energy storage element and the multi-stage energy storage circuit have stored energy to a third threshold.

[0014] In one possible implementation, the leakage protection circuit includes one or more protection devices, one end of which is connected to the other end of the input energy storage element, and the other end of which is connected to...

[0015] In one possible implementation, the protection device is a Zener diode.

[0016] In one possible implementation, the energy storage circuit further includes a discharge path for supplying electrical energy from the multi-stage energy storage circuit, the input energy storage element, and the output energy storage element to the load device.

[0017] In one possible implementation, the discharge path includes one or more diodes: One end of the diode is connected to the other end of the input energy storage element, and the other end of the diode is connected to one end of the energy storage element of the energy storage circuit.

[0018] In one possible implementation, the discharge path further includes a voltage regulator, one end of which is connected to the other end of the input energy storage element, and the other end of which is connected to one end of the output energy storage element.

[0019] In one possible implementation, the regulator is an LDO.

[0020] According to a second aspect of the present invention, a power supply system is provided, comprising a current source and the aforementioned energy storage system.

[0021] In one possible implementation, the power supply system is a photovoltaic power supply system, and the current source is a photovoltaic power generation element.

[0022] According to a third aspect of the present invention, an energy storage method is provided, which utilizes the above-described energy storage system for energy storage, comprising: The input and output energy storage elements store energy to a first threshold. The control circuit that triggers the first-stage energy storage circuit is turned on, and the corresponding energy storage element begins to store energy. The energy stored in the energy storage element of the first-stage energy storage circuit reaches the second threshold. The control circuit that triggers the next stage of energy storage circuit is turned on, and the corresponding energy storage element begins to store energy. The energy storage element in the last stage of the energy storage circuit stores energy up to the third threshold, which is greater than the second threshold, and the second threshold is greater than the first threshold.

[0023] According to a fourth aspect of the present invention, a power supply method is provided, which uses the above-described power supply system to supply power to a load device, comprising: The input and output energy storage elements are powered to store energy up to the first threshold by a current source. The control circuit that triggers the first-stage energy storage circuit is turned on, and the corresponding energy storage element begins to store energy. The energy stored in the energy storage element of the first-stage energy storage circuit reaches the second threshold. The control circuit that triggers the next stage of energy storage circuit is turned on, and the corresponding energy storage element begins to store energy. Until the energy storage element of the last stage energy storage circuit stores energy to the third threshold; When the load device starts working, the input energy storage element, multi-stage energy storage circuit and output energy storage element supply power to the load device until the energy stored in the output energy storage element drops to the fourth threshold.

[0024] The energy storage system and solution of this invention provide hierarchical energy storage that can absorb photovoltaic energy after exposure to sunlight, quickly reach the operating voltage of the equipment, and start working. It can also store energy for a long time under the action of photovoltaics. At the same time, the static operating current of the chip reaches the sub-microamp level. In addition, this invention can also adapt to the output voltage of the photovoltaic module and charge all energy storage capacitors to near the voltage Vin that the photovoltaic module can provide, thereby meeting people's main requirements for low-power photovoltaic equipment.

[0025] The power supply system and method of the present invention utilize the cascaded charging and discharging of multiple energy storage elements controlled by the energy storage system, which can achieve ultra-low power consumption and reduce costs. Attached Figure Description

[0026] Figure 1 This is a circuit diagram of an embodiment of the power supply system described in this invention; Figure 2 This is a schematic diagram of the charging sequence of the energy storage system described in this specification after its first exposure to light; The components are as follows: 100. Power supply system; 10. Energy storage system; 1. Input energy storage element; 2. Energy storage circuit; 21. Control circuit; 201. First comparator; 202. First switch; 203. First resistor; 204. Second comparator; 205. First DC source; 206. Second switch; 207. Second resistor; 208. First switching transistor; 209. Third comparator; 210. Second DC source; 211. Second switching transistor; 212. Third switch; 213. Fourth switch; 22. Energy storage element; 221. First capacitor; 222. Second capacitor; 223. Third capacitor; 23. Operational amplifier; 24. Leakage protection circuit; 25. Discharge path; 251. First diode; 252. Second diode; 253. Third diode; 254. Voltage regulator; 26. Reference source; 3. Output energy storage element; 20. Current source; 30. Load device. Detailed Implementation

[0027] Many specific details are set forth in the following description to provide a full understanding of this specification. However, this specification can be implemented in many other ways than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this specification. Therefore, this specification is not limited to the specific implementations disclosed below.

[0028] The terminology used in one or more embodiments of this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the one or more embodiments of this specification. The singular forms “a” and “the” as used in one or more embodiments of this specification and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in one or more embodiments of this specification refers to and includes any or all possible combinations of one or more associated listed items.

[0029] It should be understood that although the terms first, second, etc., may be used to describe various information in one or more embodiments of this specification, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first may also be referred to as second without departing from the scope of one or more embodiments of this specification, and similarly, second may also be referred to as first. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to a determination." Figure 1 This is a circuit diagram of one embodiment of the power supply system described in this invention, as shown below. Figure 1 As shown, the power supply system 100 includes a current source 20 and an energy storage system 10, wherein the energy storage system 10 stores the electrical energy supplied by the current source 20.

[0030] In a preferred embodiment, the power supply system 100 is a photovoltaic power supply system, and the current source 20 is a photovoltaic power generation element.

[0031] In one embodiment, such as Figure 1 As shown, the energy storage system 10 includes an input energy storage element 1, an output energy storage element 3, and a multi-stage energy storage circuit 2. One end of the input energy storage element 1 is grounded, and the other end is connected to the current source 20; The energy storage circuit 2 includes a control circuit 21 and an energy storage element 22. One end of the control circuit 21 is connected to the other end of the input energy storage element 1, and the other end of the control circuit 21 is connected to one end of the energy storage element 22. The other end of the energy storage element 22 is grounded. The control circuit 21 of the first-stage energy storage circuit is triggered to conduct through the output energy storage element 3. The control circuits 21 of other stages of the energy storage circuit 2 are triggered to conduct through the previous stage control circuit 21. When the control circuit 21 is turned on, the energy storage element 22 is charged. One end of the output energy storage element 3 is connected to the other end of the input energy storage element 1, and the other end of the output energy storage element 3 is grounded; The triggering condition for the output energy storage element 3 to trigger the control circuit 21 of the first-stage energy storage circuit to conduct is that the output energy storage element 3 stores energy to a first threshold. The triggering condition for the control circuit 21 of the other-stage energy storage circuits to conduct through the previous-stage control circuit 21 is that the energy storage element 22 of the previous-stage energy storage circuit 2 stores energy to a second threshold. The input energy storage element 1 and the multi-stage energy storage circuit 2 store energy to a third threshold in sequence. The third threshold is greater than the second threshold, and the second threshold is greater than the first threshold.

[0032] The energy storage method of the aforementioned energy storage system 10 includes: The input energy storage element 1 and the output energy storage element 3 store energy to the first threshold. The control circuit 21 that triggers the first-stage energy storage circuit is turned on, and the corresponding energy storage element 22 begins to store energy. The energy stored in the energy storage element 22 of the first-stage energy storage circuit reaches the second threshold. The control circuit 21 that triggers the next stage of energy storage circuit is turned on, and the corresponding energy storage element 22 begins to store energy. The energy storage element 22 of the last stage energy storage circuit stores energy to the third threshold, which is greater than the second threshold, and the second threshold is greater than the first threshold.

[0033] After the input energy storage element 1 and the multi-stage energy storage circuit 2 store energy to the third threshold, the energy storage is complete. The energy storage can be disconnected by a switch-like power-off device, or the excess energy can be discharged by a leakage circuit. In one feasible embodiment, the energy storage circuit 2 also includes a leakage protection circuit 24. The leakage protection is used to clamp the highest voltage of the input energy storage element 1 and to discharge the excess current after the input energy storage element 1 and the multi-stage energy storage circuit 2 have stored energy to the third threshold.

[0034] This invention can control the energy storage capacitor to be charged to near the highest voltage output of the photovoltaic power generation element (second threshold). For example, if the photovoltaic power generation element outputs 5 volts, then the energy storage capacitor should be charged to near 5V. In order to protect the chip, this invention has a maximum clamping voltage (third threshold).

[0035] Preferably, the leakage protection circuit 24 includes one or more protection devices, one end of which is connected to the other end of the input energy storage element 1, and the other end of which is connected to...

[0036] More preferably, the protection device is a Zener diode.

[0037] The energy storage system 10 can supply power to the load device 30. In one feasible embodiment, the energy storage circuit 2 further includes a discharge path 25 for supplying electrical energy from the multi-stage energy storage circuit 2, the input energy storage element 1, and the output energy storage element 3 to the load device 30.

[0038] Preferably, the discharge path 25 includes one or more diodes: One end of the diode is connected to the other end of the input energy storage element 1, and the other end of the diode is connected to one end of the energy storage element 22 of the energy storage circuit 2.

[0039] More preferably, the diode is a Schottky diode.

[0040] In a preferred embodiment, such as Figure 1 As shown, the discharge path 25 also includes a voltage regulator 254, one end of which is connected to the other end of the input energy storage element 1, and the other end of which is connected to one end of the output energy storage element 3.

[0041] Preferably, the voltage regulator 254 is an LDO.

[0042] The power supply method of the power supply system 100, including the aforementioned energy storage system 10, includes: The current source 20 enables the input energy storage element 1 and the output energy storage element 3 to store energy up to the first threshold. The control circuit 21 that triggers the first-stage energy storage circuit is turned on, and the corresponding energy storage element 22 begins to store energy. The energy stored in the energy storage element 22 of the first-stage energy storage circuit reaches the second threshold. The control circuit 21 that triggers the next stage of energy storage circuit is turned on, and the corresponding energy storage element 22 begins to store energy. Until the energy storage element 22 of the last stage energy storage circuit stores energy to the third threshold; When the load device 30 starts working, the input energy storage element 1, the multi-stage energy storage circuit 2 and the output energy storage element 3 supply energy to the load device 30 until the energy stored in the output energy storage element 3 drops to the fourth threshold.

[0043] In a preferred embodiment, such as Figure 1 As shown, the energy storage system 10 includes an input energy storage element 1, an output energy storage element 3, and a three-stage energy storage circuit 2. The input energy storage element 1 is an input capacitor, and the output energy storage element 3 is an output capacitor. The first-stage energy storage circuit includes a first comparator 201, a first switch 202, a first resistor 203, and a first capacitor 221; The second-stage energy storage circuit 2 includes a second comparator 204, a first DC source 205, a second switch 206, a second resistor 207, a first switching transistor 208, and a second capacitor 222; The third-stage energy storage circuit 2 includes a third comparator 209, a second DC source 210, a second switching transistor 211, a third switch 212, a fourth switch 213, and a third capacitor 223; Wherein: one input terminal of the first comparator 201 is connected to one end of the output capacitor, the voltage of the other input terminal of the first comparator 201 is the first threshold, and the output terminal of the first comparator 201 is connected to the enable terminal of the first switch 202; The input terminal of the first resistor 203 is connected to the other end of the input capacitor, and the output terminal of the first resistor 203 is connected to the input terminal of the first switch 202. The output terminal of the first switch 202 is connected to one end of the first capacitor 221; The other end of the first capacitor 221 is grounded; One input terminal of the second comparator 204 is connected to the output terminal of the first resistor 203 through the first DC source 205, the other input terminal is connected to the input terminal of the first resistor 203, and the output terminal is connected to the enable terminal of the second switch 206. The first switching transistor 208 is connected between the other end of the input capacitor and the input terminal of the second resistor 207, and is used to control whether current flows into or out of the input terminal of the second resistor 207. The output terminal of the second resistor 207 is connected to the input terminal of the second switch 206; The output terminal of the second switch 206 is connected to one end of the second capacitor 222; The other end of the second capacitor 222 is grounded; One input terminal of the third comparator 209 is connected to the other end of the input capacitor, and the other input terminal is connected to the output terminal of the second resistor 207 of the previous stage energy storage circuit 2 through the second DC source 210. The output terminal of the third comparator 209 is connected to the enable terminal of the third switch 212. The second switch 211 is connected between the other end of the input capacitor and the input terminal of the third switch 212, and is used to control whether current flows into or out of the input terminal of the third switch 212; The output terminal of the third switch 212 is connected to the input terminal of the fourth switch 213; The enable terminal of the fourth switch 213 is connected to the output terminal of the second comparator 204 of the intermediate stage energy storage circuit 2, and the output terminal of the fourth switch 213 is connected to one end of the third capacitor 223. The other end of the third capacitor 223 is grounded.

[0044] The energy storage method of the aforementioned energy storage system 10 includes: Once the input and output capacitors are charged to the first threshold, the input capacitor continues to charge. The energy storage voltage of the output capacitor triggers the first comparator 201 to control the first switch 202 to close, and the first capacitor 221 is charged; The first capacitor 221 is charged to the second threshold. The energy storage voltage of the first capacitor 221 triggers the second comparator 204 to control the second switch 206 and the fourth switch 213 to close, and the second capacitor 222 begins to charge. The second capacitor 222 is charged to the second threshold. The energy storage voltage of the second capacitor 222 triggers the third comparator 209 to control the third switch 212 to close, and the third capacitor 223 begins to charge. Energy storage is complete when the third capacitor 223 is charged to the third threshold. Specifically, the input capacitor charges to the third threshold earlier than the first capacitor 221 charges to the third threshold earlier than the second capacitor 222 charges to the third threshold earlier than the third capacitor 223 ...1 charges to the third threshold earlier than the third capacitor 222 charges to the third threshold earlier than the third capacitor 222 charges to the third threshold earlier than the third capacitor 222 charges to the third threshold earlier than the third capacitor 223 charges to the third threshold earlier than the third capacitor 221 charges to the third threshold earlier than the third capacitor 221 charges to the third threshold earlier than the third capacitor 2

[0045] In one feasible embodiment, the energy storage circuit 2 further includes an operational amplifier 23. One input terminal of the operational amplifier 23 is connected to the other end of an input capacitor, and the other input terminal is connected to one end of a first capacitor 221. The output terminal of the operational amplifier 23 is connected to the control terminal of a first switch 208 and a second switch 211. The input capacitor reaches the third threshold earlier than the first capacitor 221, causing the operational amplifier 23 to amplify the voltage difference between the two input terminals, thus turning on the first switch 208 and the second switch 211. The output of the operational amplifier 23 is a continuous analog level used to control the conduction level of the first switch 208 and the second switch 211. Different conduction levels correspond to different currents. By controlling the current (ensuring that the current of the first switch 208 or the second switch 211 is always less than or close to the current that the photovoltaic power generation element can provide), the Vin voltage is maintained higher than the voltage of the first capacitor 221. If a comparator is used, the output will be slightly high or low, the first switch 202 will be off, and the second switch 211 will be in a switching state, sometimes on and sometimes off, the current will be uncontrolled, and it cannot be continuously conducted.

[0046] Preferably, the first switch 208 and the second switch 211 are field-effect transistors (FETs). The sources of the first FET and the second FET are connected to the output terminal of the operational amplifier 23. The gates of the first FET and the second FET are connected to the other end of the input capacitor. The drain of the first FET is connected to the input terminal of the second resistor 207, and the drain of the second FET is connected to the input terminal of the third switch 212.

[0047] More preferably, the first switch 208 and the second switch 211 are PMOS transistors, because NMOS requires a voltage difference to reach the turn-on threshold Vth, and the energy storage element 22 can only be charged up to Vin-Vth, not up to Vin. PMOS can solve this technical problem.

[0048] In a preferred embodiment of the present invention, the power supply system 100 includes a current source 20, an input capacitor, protection devices, a first diode 251, an operational amplifier 23, a first comparator 201, a first resistor 203, a first switch 202, a first capacitor 221, a first DC power supply 206, a second comparator 204, a second diode 252, a first switching transistor 208, a second resistor 207, a second switch 206, a second capacitor 222, a second DC power supply 210, a third comparator 209, a second switching transistor 211, a third switch 212, a fourth switch 213, a third capacitor 223, a third diode 253, a voltage regulator 254, and an output capacitor, wherein: The current source 20 provides electrical energy to the input capacitor, the first capacitor 221, the second capacitor 222, the third capacitor 223, and the output capacitor; One end of the input capacitor is grounded, and the other end is electrically connected to the output terminal of the current source 20; One end of the protection device is electrically connected to the other end of the input capacitor, and the other end of the protection device is grounded. One end of the first diode 251 is connected to the other end of the input capacitor and one input terminal of the operational amplifier 23, and the other end of the first diode 251 is connected to one end of the first capacitor 221 and the other input terminal of the operational amplifier 23. The output terminal of operational amplifier 23 is connected to the control terminals of the first switching transistor 208 and the second switching transistor 211, respectively. One input terminal of the first comparator 201 is connected to one end of the first capacitor 221, and the voltage of the other input terminal is the first threshold voltage. The output terminal is connected to the enable terminal of the first switch 202. The input terminal of the first resistor 203 is connected to the other end of the input capacitor, and the output terminal is connected to the input terminal of the first switch 202. The output terminal of the first switch 202 is connected to one end of the first capacitor 221; The other end of the first capacitor 221 is grounded; One input terminal of the second comparator 204 is connected to the output terminal of the first resistor 203 through the first DC source 205, the other input terminal is connected to the input terminal of the first resistor 203, and the output terminal is connected to the enable terminal of the second switch 206 and the fourth switch 213. One end of the second diode 252 is connected to the other end of the input capacitor, and the other end of the second diode 252 is connected to one end of the second capacitor 222. The current input terminal of the first switching transistor 208 is connected to the other end of the input capacitor, and the current output terminal is connected to the input terminal of the second resistor 207. The output terminal of the second resistor 207 is connected to the input terminal of the second switch 206; The output terminal of the second switch 206 is connected to one end of the second capacitor 222; The other end of the second capacitor 222 is grounded; One input terminal of the third comparator 209 is connected to the other end of the input capacitor, and the other input terminal is connected to the output terminal of the second resistor 207 through the second DC source 210. The output terminal of the third comparator 209 is connected to the enable terminal of the third switch 212. The current input terminal of the second switch 211 is connected to the other end of the input capacitor, and the current output terminal is connected to the input terminal of the third switch 212. The output terminal of the third switch 212 is connected to the input terminal of the fourth switch 213; The output terminal of the fourth switch 213 is connected to one end of the third capacitor 223; The other end of the third capacitor 223 is grounded; One end of the third diode 253 is connected to the other end of the input capacitor, and the other end of the third diode 253 is connected to the input terminal of the third capacitor 223; One end of the voltage regulator 254 is connected to the other end of the input capacitor, and the other end of the voltage regulator 254 is connected to one end of the output capacitor; The other end of the output capacitor is grounded.

[0049] When powering the load device 30, one end of the output capacitor is connected to the load device 30.

[0050] In one feasible embodiment, the energy storage circuit 2 further includes a reference source 26 that provides a reference voltage for the first comparator 201 and the regulator 254, for example, generating a reference voltage of 3.25V for the first comparator 201 and generating a reference voltage of 3.3V for the regulator 254.

[0051] In one specific embodiment of the present invention, the power supply system 100 is a photovoltaic power supply system; the current source 20 is a photovoltaic power generation element; the energy storage system 10 is a chip; the voltage regulator 254 is an LDO, the rated voltage of the voltage regulator 254 is 3.3V; the first threshold is 3.25V, the third threshold is 6.5V; the protection device is a Zener diode, the breakdown voltage is 6.5V.

[0052] The power supply methods of the above-mentioned photovoltaic power supply system include: The photovoltaic power generation element 101 generates current by absorbing photons, which can be equivalent to a current source 20. Depending on the intensity of the ambient light, the current source 20 has a current capability of approximately 20-80uA and a maximum voltage of 4-8V. The chip controls the distribution of current generated by the photovoltaic module, including: Zener diodes clamp the chip's Vin (the energy storage voltage of the input capacitor) to a maximum of 6.5V, preventing damage to the chip from excessively high voltage in the photovoltaic module. When the photovoltaic power supply system is exposed to sunlight, the photovoltaic power generation element, equivalent to current source 20, begins to charge the input capacitor. When it is charged to about 1V, reaching the chip's turn-on voltage Vth (Vth for a 5V device is between 0.7-0.9V; it can work normally when the voltage reaches 1V), the chip begins to work normally. The internal 3.3V ultra-low power LDO of the chip starts to work, charging the output capacitor. That is, from this moment on, the input capacitor and the output capacitor are charged simultaneously. Because the current provided by the photovoltaic power generation element is only 20-80uA, the current is very small, and the voltage drop of the LDO is almost negligible. That is, at this time, Vin=Vout (the energy storage voltage of the output capacitor). When the output capacitor is charged to 3.25V, the output of the first comparator 201 flips, controlling the first switch 202 to conduct. The current source 20 of the photovoltaic power generation element charges the first capacitor 221 through the first resistor 203 and the first switch 202. The first resistor 203 is used to detect the charging current of the first capacitor 221. At the beginning, the charging current is large, and the first voltage generated by the first resistor 203 is greater than the voltage Vos1 of the first DC source 205. The second comparator 204 outputs a low level, controlling the second switch 206 and the fourth switch 213 to be in the off state. Therefore, the charging path of the second capacitor 222 and the third capacitor 223 is disconnected, and the chip controls all the current generated by the photovoltaic power generation element to charge the first capacitor 221 first.

[0053] As the energy storage voltage Vo1 of the first capacitor 221 gradually rises to near Vin, the charging current gradually decreases. When the current decreases to a level where the first voltage is less than Vos1, the output of the second comparator 204 flips to a high level, controlling the second switch 206 and the fourth switch 213 to conduct. Simultaneously, the operational amplifier 23 controls the Vin voltage, keeping it near its highest point (Vin > Vo1). The output voltage V1 of the operational amplifier 23 remains at a lower level, causing the first switch 208 and the second switch 211 it controls to conduct. This prevents the Vin voltage from being pulled down when the second capacitor 222 and the third capacitor 223 are charging, ensuring that Vin is always maintained at a voltage higher than Vo1. In other words, the conduction of the first switch 208 and the second switch 211 is equivalent to the two LDO power transistors operating in the saturation region, rather than acting as switches. The first switch 208 and the second switch 211 are powered by the photovoltaic element at the input terminal. The electrical current is finite, 20-80uA. If used directly as a switch, the on-resistance is very small, and the current is large and uncontrollable. As soon as it is turned on, the current exceeds the current that the photovoltaic module can provide, which will pull Vin down. By controlling the on-resistance of the first switch 208 or the second switch 211 through the operational amplifier 23, the current is ultimately controlled so that it is close to the current that the photovoltaic power generation element can provide. In this way, Vin will not be pulled down. For example, if the current of the first switch 208 and the second switch 211 is slightly greater than the current that the photovoltaic power generation element can provide, then Vin will drop slightly. Since the non-inverting input Vo1 of the operational amplifier 23 is constant, the drop in Vin will cause the voltage V1 to rise. This will make the absolute value of Vgs of the first switch 208 or the second switch 211 smaller and the on-resistance larger, which will cause the current of the first switch 208 or the second switch 211 to drop and eventually stabilize near the current value provided by the photovoltaic power generation element. Then, since the second capacitor 222 has just started to be charged, the energy storage voltage Vo2 of the second capacitor 222 has a large voltage difference with Vin, that is: Vin>Vo2+Vos2 (the voltage of the second DC source 210). The third comparator 209 outputs a low level, controlling the third switch 212 to be in the open state. Therefore, the charging path of the third capacitor 223 is cut off, and the current generated by the photovoltaic power generation element controlled by the chip is preferentially used to charge the second capacitor 222.

[0054] When the second capacitor 222 is fully charged, its energy storage voltage Vo2 gradually approaches Vin. When Vo2 + Vos2 > Vin, the third comparator 209 outputs a high level, controlling the third switch 212 to turn on. In addition, the fourth switch 213 and the second switch 211 have already been turned on. The chip controls the current generated by the photovoltaic power generation element to start charging the third capacitor 223 until it is fully charged to a voltage close to Vin.

[0055] Figure 2This is a timeline diagram illustrating the charging process of the entire energy storage system (10 energy storage units) after the photovoltaic power generation modules are first exposed to sunlight. Figure 2 As shown, the energy generated by the photovoltaic power generation element, in the form of current source 20, first charges the input capacitor. When its energy storage capacitor reaches approximately 1V, the chip begins to operate, and the 3.3V LDO starts working. The current source 20 of the photovoltaic power generation element simultaneously charges both the input and output capacitors. When the output capacitor is charged to a level greater than 3.25V and close to 3.3V, that is... Figure 2 At point T1, the current source 20 of the photovoltaic power generation element begins charging the first capacitor 221 of the first-stage energy storage circuit. Initially, the energy storage capacitor Vin of the input capacitor is maintained at 3.3V, and the energy storage voltage Vo1 of the first capacitor 221 starts to rise from 0V. When Vo1 approaches 3.3V, Vin and Vo1 rise with a fixed voltage difference and the same slope. At point T2, Vo1 approaches Vin, and the voltage difference between Vin and Vo1 is less than the first set voltage Vos1. The chip considers the first capacitor 221 to be fully charged and begins charging the second capacitor 222 of the second-stage energy storage circuit 2. Under the control of the operational amplifier 23, Vin is maintained at a maximum voltage slightly higher than Vo1, while the energy storage voltage Vo2 of the second capacitor 222 slowly rises from 0V. At point T3, Vo2 approaches Vin, and the voltage difference between Vin and Vo2 is less than the second set voltage Vos2. The chip assumes that the second capacitor 222 is fully charged and begins to charge the third capacitor 223 of the third-stage energy storage circuit 2. Vin remains at its highest voltage, and the energy storage voltage Vo3 of the third capacitor 223 slowly rises from 0V until point T4. Finally, the energy storage voltages of the first capacitor 221, the second capacitor 222, and the third capacitor 223 are all charged to the Vin voltage. After that, all the energy generated by the photovoltaic power generation element is discharged through the Zener diode, and the energy storage voltage on the capacitor of the third-stage energy storage circuit 2 remains unchanged.

[0056] When the load device 30 starts working, the capacitor in the three-stage energy storage circuit 2 supplies power to Vin through the first diode 251, the second diode 252, and the third diode 253, and then supplies power to the load device 30 through the LDO, until the output voltage Vout < 1.5V, at which point the load device 30 can no longer operate normally. During this process, the voltage drop across the first diode 251, the second diode 252, and the third diode 253 is approximately 0.3V, meaning that Vin and Vout eventually drop to 1.5V, and the energy storage voltage across the capacitor in the three-stage energy storage circuit 2 drops to approximately 1.8V. After this, if the load device 30 is turned off and in standby mode, the chip controls the entire energy storage system 10 to recharge according to the above charging sequence.

[0057] In a preferred embodiment, the capacitance of the first capacitor 221 is less than that of the second capacitor 222, and the capacitance of the second capacitor 222 is less than that of the third capacitor 223. For example, the capacitance values ​​are in a multiple relationship, so as to achieve both fast operation and sufficient energy storage even with long charging time. For example, the first capacitor 221 is 3mF, the second capacitor 222 is 10mF, and the third capacitor 223 is 100mF.

[0058] When powering a charging system with the aforementioned energy storage capacitors, the input and output capacitors are first charged to 3.25V, close to the rated voltage of 3.3V. Next, the smallest energy storage capacitor, the first capacitor 221, is charged until its energy storage voltage is close to Vin. Then, the second capacitor 222, with a medium capacitance, is charged until its energy storage voltage is close to Vin. Finally, the largest energy storage capacitor, the third capacitor 223, is charged, also until it reaches Vin. When the photovoltaic power generation element is exposed to sunlight, the first capacitor 221 can be quickly charged to approximately 6.5V in a short time. Subtracting the unusable 1.5V, the energy that the load device 30 on the first capacitor 221 might use is C (the capacitance value of the first capacitor 221) * (5V). 2 It is sufficient to keep the load device working for a period of time.

[0059] To reduce costs, the chip uses a standard 5V CMOS process, and the chip withstands a voltage of approximately 7V-9V to protect the chip's safety.

[0060] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0061] The preferred embodiments disclosed above are merely illustrative of this specification. The optional 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 embodiments described herein. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the embodiments, thereby enabling those skilled in the art to better understand and utilize this specification. This specification is limited only by the claims and their full scope and equivalents.

Claims

1. An energy storage system, characterized by, It includes an input energy storage element, an output energy storage element, and a multi-stage energy storage circuit, wherein the multi-stage energy storage circuit includes a first-stage energy storage circuit and at least one intermediate-stage energy storage circuit. One end of the input energy storage element is grounded, and the other end is connected to a current source; The multi-stage energy storage circuit includes a control circuit and an energy storage element. One end of the control circuit is connected to the other end of the input energy storage element, the other end of the control circuit is connected to one end of the energy storage element, and the other end of the energy storage element is grounded. The control circuit of the first-stage energy storage circuit is triggered to conduct through the output energy storage element. The control circuits of other energy storage circuits are triggered to conduct through the control circuit of the previous stage. When the control circuit is turned on, the energy storage element is charged. One end of the output energy storage element is connected to the other end of the input energy storage element, and the other end of the output energy storage element is grounded; The triggering condition for the output energy storage element to trigger the control circuit of the first-stage energy storage circuit to conduct is that the output energy storage element stores energy to a first threshold. The triggering condition for the control circuit of other stages of energy storage circuit to conduct through the previous stage control circuit is that the energy storage element of the previous stage energy storage circuit stores energy to a second threshold. The input energy storage element and the multi-stage energy storage circuit sequentially store energy to a third threshold, where the third threshold is greater than the second threshold, and the second threshold is greater than the first threshold. The control circuit of the first-stage energy storage circuit includes a first comparator, a first switch, and a first resistor; The control circuit of the intermediate-stage energy storage circuit includes a second comparator, a first DC source, a second switch, a second resistor, and a first switching transistor. One input terminal of the second comparator in the first stage of the intermediate energy storage circuit is connected to the output terminal of the first resistor in the first stage energy storage circuit through a first DC source, the other input terminal is connected to the input terminal of the first resistor in the first stage energy storage circuit, and the output terminal is connected to the enable terminal of the second switch. One input terminal of the other stage second comparator of the other intermediate stage energy storage circuit is connected to the output terminal of the second resistor of the previous stage intermediate stage energy storage circuit through its first DC source, and the other input terminal is connected to the input terminal of the second resistor of the previous stage intermediate stage energy storage circuit. The output terminal is connected to the enable terminal of the other stage second switch. The first switching transistor is connected between the other end of the input energy storage element and the input end of the second resistor to control whether current flows into or out of the input end of the second resistor; The output terminal of the second resistor is connected to the input terminal of the second switch; The output terminal of the second switch is connected to one end of the energy storage element.

2. The energy storage system of claim 1, wherein, The energy storage element of the multi-stage energy storage circuit is a capacitor; and / or the input energy storage element is an input capacitor; and / or the output energy storage element is an output capacitor.

3. The energy storage system of claim 2, wherein, The capacitance values ​​of the capacitors in the multi-stage energy storage circuit decrease sequentially.

4. The energy storage system according to claim 1, characterized in that, One input terminal of the first comparator is connected to one end of the output energy storage element, the voltage of the other input terminal of the first comparator is a first threshold, and the output terminal of the first comparator is connected to the enable terminal of the first switch. The input terminal of the first resistor is connected to the other end of the input energy storage element, and the output terminal of the first resistor is connected to the input terminal of the first switch. The output terminal of the first switch is connected to one end of the energy storage element.

5. The energy storage system of claim 4, wherein, The control circuit of the final stage energy storage circuit includes a third comparator, a second DC source, a second switching transistor, a third switch, and a fourth switch. One input terminal of the third comparator is connected to the other end of the input energy storage element, and the other input terminal of the third comparator is connected to the output terminal of the second resistor of the previous stage energy storage circuit through the second DC source. The output terminal of the third comparator is connected to the enable terminal of the third switch. The second switch is connected between the other end of the input energy storage element and the input terminal of the third switch, and is used to control whether current flows into or out of the input terminal of the third switch; The output terminal of the third switch is connected to the input terminal of the fourth switch; The enable terminal of the fourth switch is connected to the output terminal of the second comparator of the intermediate stage energy storage circuit, and the output terminal of the fourth switch is connected to one end of the energy storage element.

6. The energy storage system of claim 5, wherein, The first and second switching transistors are PMOS transistors.

7. The energy storage system of claim 5, wherein, The energy storage circuit also includes an operational amplifier. One input terminal of the operational amplifier is connected to the other end of the input energy storage element, and the other input terminal of the operational amplifier is connected to one end of the energy storage element of the first-stage energy storage circuit. The output terminal of the operational amplifier is connected to the control terminals of the first and second switching transistors.

8. The energy storage system of claim 1, wherein, The energy storage circuit also includes a leakage protection circuit, which is used to clamp the highest voltage of the input energy storage element and to discharge excess current after the input energy storage element and the multi-stage energy storage circuit have stored energy to the third threshold.

9. The energy storage system of claim 8, wherein, The leakage protection circuit includes one or more protection devices, one end of which is connected to the other end of the input energy storage element, and the other end of which is grounded.

10. The energy storage system of claim 9, wherein, The protection device is a Zener diode.

11. The energy storage system of claim 1, wherein, The energy storage circuit also includes a discharge path, which is used to supply electrical energy from the multi-stage energy storage circuit, the input energy storage element, and the output energy storage element to the load device.

12. The energy storage system of claim 11, wherein, The discharge path includes one or more diodes: One end of the diode is connected to the other end of the input energy storage element, and the other end of the diode is connected to one end of the energy storage element of the energy storage circuit.

13. The energy storage system of claim 11, wherein, The discharge path also includes a voltage regulator, one end of which is connected to the other end of the input energy storage element, and the other end of which is connected to one end of the output energy storage element.

14. The energy storage system of claim 13, wherein, The voltage regulator is an LDO.

15. A power supply system characterized by comprising: It includes a current source and an energy storage system as described in any one of claims 1-14.

16. The power supply system of claim 15, wherein, The power supply system is a photovoltaic power supply system, and the current source is a photovoltaic power generation element.

17. A method of storing energy, characterized by Energy storage using the energy storage system according to any one of claims 1-14 includes: The input and output energy storage elements store energy to a first threshold. The control circuit that triggers the first-stage energy storage circuit is turned on, and the corresponding energy storage element begins to store energy. The energy stored in the energy storage element of the first-stage energy storage circuit reaches the second threshold. The control circuit that triggers the next stage of energy storage circuit is turned on, and the corresponding energy storage element begins to store energy. The energy storage element in the last stage of the energy storage circuit stores energy up to the third threshold, which is greater than the second threshold, and the second threshold is greater than the first threshold.

18. A power supply method characterized by, Powering a load device using the power supply system of claim 15 or 16 includes: The input and output energy storage elements are powered to store energy up to the first threshold by a current source. The control circuit that triggers the first-stage energy storage circuit is turned on, and the corresponding energy storage element begins to store energy. The energy stored in the energy storage element of the first-stage energy storage circuit reaches the second threshold. The control circuit that triggers the next stage of energy storage circuit is turned on, and the corresponding energy storage element begins to store energy. Until the energy storage element of the last stage energy storage circuit stores energy to the third threshold; When the load device starts working, the input energy storage element, the multi-stage energy storage circuit and the output energy storage element supply energy to the load device until the energy stored in the output energy storage element drops to the fourth threshold.

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