CN209767213U - Supercapacitor energy storage system and power management system based on supercapacitor energy storage system - Google Patents

Abstract

The utility model relates to the field of power supplies, in particular to a supercapacitor energy storage system and a power management system based on the supercapacitor energy storage system. circuit; a number of input voltage equalization circuits connected to each supercapacitor unit, the input end of the input voltage equalization circuit is connected to the output end of the constant current and voltage limiting charging circuit; and one end is connected to the output end of each supercapacitor unit, and the other end Dynamic flexible output circuit connected to the load. The utility model adds a constant current and voltage limiting charging circuit, an input voltage equalization circuit, a dynamic flexible output circuit and an overvoltage protection circuit on the basis of the original series-connected supercapacitor unit, so as to realize constant current and constant voltage charging for each supercapacitor unit, each supercapacitor The voltage at both ends of the capacitor unit achieves balance, dynamic flexible voltage equalization output and overvoltage protection.

Description

Supercapacitor energy storage system and power management system based on supercapacitor energy storage system

technical field

The utility model relates to the field of power supplies, in particular to a super capacitor energy storage system and a power management system based on the super capacitor energy storage system.

Background technique

Supercapacitors (ultracapacitor), also known as Electrochemical Capacitors (Electrochemical Capacitors), Electric Double Layer Capacitors (Electrical Doule-Layer Capacitor), Gold Capacitors, Farad Capacitors, are developed from the 1970s and 1980s through the pole An electrochemical element that uses electrolytes to store energy. It is different from traditional chemical power sources. It is a power source with special properties between traditional capacitors and batteries. It mainly relies on electric double layers and redox pseudocapacitive charges to store electrical energy. However, no chemical reaction occurs in the process of its energy storage. This energy storage process is reversible, and it is precisely because this supercapacitor can be repeatedly charged and discharged hundreds of thousands of times. Its basic principle is the same as that of other types of electric double layer capacitors. It uses the electric double layer structure composed of activated carbon porous electrodes and electrolytes to obtain super large capacity. When a supercapacitor is used, multiple supercapacitor cells are usually used in series, but during the charging process of multiple supercapacitor cells, the voltages at both ends of the supercapacitor cannot be balanced. In addition, the output of the super capacitor is not stable enough.

The switching station is a power facility that supplies high-voltage power to several surrounding power units, and is located at the next level of the substation in the power system. The DC operating power supply of the switching station is usually a battery. Due to its own characteristics, in the daily operation and maintenance work, engineers need to regularly perform activity detection and equalize charge and discharge, and maintain and replace unqualified batteries. These operation and maintenance tasks take up a lot of manpower and material resources, and the working condition of the battery is easily affected by the ambient temperature, and the reliability is insufficient.

Utility model content

In order to solve the above problems, the utility model proposes a supercapacitor energy storage system and a power management system based on the supercapacitor energy storage system.

A supercapacitor energy storage system, including several supercapacitor units connected in series, the system also includes:

A constant current and voltage limiting charging circuit connected to the output of the power supply;

Several input voltage equalization circuits connected to each supercapacitor unit respectively, the input end of the input voltage equalization circuit is connected to the output end of the constant current and voltage limiting charging circuit;

And a dynamic flexible output circuit with one end connected to the output ends of each supercapacitor unit and the other end connected to the load.

Preferably, the constant current and voltage limiting charging circuit includes: a dual-transistor forward converter, a drive circuit, a current detection circuit, a voltage detection circuit and a control circuit,

The input end of the dual-tube forward converter is connected to the output end of the power supply, and the output end is connected to each supercapacitor unit;

The drive circuit is connected with the double-tube forward converter for driving the double-tube forward converter;

The current detection circuit is connected with the dual-tube forward converter for detecting the output current of the dual-tube forward converter;

The voltage detection circuit is connected to the dual-tube forward converter for detecting the output voltage of the dual-tube forward converter;

The control circuit is connected with the current detection circuit, the voltage detection circuit and the driving circuit, and is used to control the output current and output voltage of the dual-transistor forward converter according to the detection current and detection voltage and through the driving circuit.

Preferably, the constant current and voltage limiting charging circuit further includes: the input terminal is connected to the output terminal of the power supply, and the output terminal is connected to a rectifier circuit of a dual-transistor forward converter.

Preferably, the input voltage equalization circuit includes: a voltage sensor L1, a comparator A1, a switch tube Q1, a discharge resistor R1 and a reference voltage source S,

The voltage sensor L1 is connected to both ends of the supercapacitor unit for voltage detection at both ends of the supercapacitor unit;

The non-inverting input terminal of the comparator A1 is connected to the output terminal of the voltage sensor L1, and the inverting input terminal is connected to the common terminal through the reference voltage source S;

The gate of the switching tube Q1 is connected to the output terminal of the comparator A1, the drain is connected to one end of the supercapacitor unit, and the source is connected to one end of the discharge resistor R1;

The other end of the discharge resistor R1 is connected to the other end of the supercapacitor unit.

Preferably, the dynamic flexible output circuit includes: resistors R2, R3, R4, R5, R6, comparator A2, transistor Q2 and Zener diode D1,

One end of the resistor R2 is connected to one end of the resistor R3 and the non-inverting input end of the comparator A2, the other end of the resistor R3 is connected to the anode of the Zener diode D1, and the cathode of the Zener diode D1 is connected to the inverting phase of the comparator A2 The input terminal and one terminal of the resistor R4, the output terminal of the comparator A2 is connected to one terminal of the resistor R5, the other terminal of the resistor R5 is connected to the base of the transistor Q2, and the emitter of the transistor Q2 is connected to the anode of the Zener diode D1 And one end of the resistor R3, the collector of the transistor Q2 is connected to one end of the resistor R6 and the load, and the other end of the resistor R6 is connected to the resistor R2, the other end of the resistor R4 and the output end of the supercapacitor unit.

Preferably, the system also includes:

An overvoltage protection circuit connected with the constant current and voltage limiting charging circuit.

Preferably, the overvoltage protection circuit includes: a control chip U1, an optocoupler U2, resistors R7, R8, R9, R10, capacitors Ca, Cb, a controllable voltage regulator D2, and a voltage regulator diode D3,

The negative pole of the Zener diode D3 is connected to the voltage output terminal, the positive pole of the Zener diode D3 is connected to one end of the resistor R7 and one end of the resistor R9, the other end of the resistor R7 is connected to the first end of the optocoupler U2, and the resistor R9 The other end of the capacitor Ca is connected to the second end of the optocoupler U2, one end of the capacitor Ca, one end of the resistor R10, and the K pole of the controllable voltage regulator D2, and the other end of the capacitor Ca is connected to one end of the resistor R8 and one end of the capacitor Cb. The other end of the resistor R10 is connected to the other end of the capacitor Cb, the other end of the resistor R8 is connected to the voltage output end, the third end of the optocoupler U2 is connected to the input end of the control chip U1, and the fourth end of the optocoupler U2 Connect to common.

The utility model adds a constant current and voltage limiting charging circuit, an input voltage equalization circuit, a dynamic flexible output circuit and an overvoltage protection circuit on the basis of the original series-connected supercapacitor unit, so as to realize constant current and constant voltage charging for each supercapacitor unit, each supercapacitor The voltage at both ends of the capacitor unit achieves balance, dynamic flexible voltage equalization output and overvoltage protection.

Based on the supercapacitor energy storage system power management system, including: the supercapacitor energy storage system, the input end of the supercapacitor energy storage system is connected to the output terminal of the power supply and

The input end is connected to the output end of the power supply, and the output end is connected to the first switching switch K1 of the load;

The input end is connected to the output end of the supercapacitor energy storage system, and the output end is connected to the second switching switch K2 of the load;

The input end is connected to the output end of the power supply, and the output end is connected to the switch control unit of the supercapacitor energy storage system. When the power supply is cut off, the switch control unit controls the first switch K1 to turn off, and controls the second switch K2 to turn on , the supercapacitor energy storage system supplies power to the load; when the power comes in, the switching control unit controls the first switching switch K1 to turn on, controls the second switching switch K2 to turn off, and the power supply supplies power to the load.

Preferably, it also includes: a first AC-DC conversion unit, a second AC-DC conversion unit, a first DC-DC conversion unit,

The input end of the first AC-DC conversion unit is connected to the output end of the first switch K1, and the output end of the first AC-DC conversion unit is connected to the load;

The input end of the second AC-DC conversion unit is connected to the output end of the power supply, and the output end of the first AC-DC conversion unit is connected to the input end of the super capacitor energy storage system;

The input end of the first DC-DC conversion unit is connected to the output end of the supercapacitor energy storage system, and the output end of the first DC-DC conversion unit is connected to the load.

Preferably, it also includes: a third switch K3 and a third AC-DC conversion unit,

One end of the third switch K3 is connected to the supercapacitor energy storage system, and the other end is connected to the output end of the third AC-DC conversion unit,

The input end of the AC-DC conversion unit is connected to the switch control unit.

Because the utility model does not have a storage battery, it does not need regular checking and charging and discharging experiments, so it truly realizes maintenance-free and greatly reduces the work intensity of operation and maintenance personnel. Supercapacitors use physical technology to store energy, have no pollution to the environment, have a long cycle life, and save costs.

Description of drawings

Below in conjunction with accompanying drawing and specific embodiment, the utility model is described in further detail.

Fig. 1 is the overall structure schematic diagram of the utility model embodiment one;

Fig. 2 is a schematic structural diagram of a constant current and voltage limiting charging circuit in Embodiment 1 of the present utility model;

Fig. 3 is a circuit schematic diagram of the input voltage equalization circuit in Embodiment 1 of the utility model;

Fig. 4 is a circuit schematic diagram of a dynamic flexible output circuit in Embodiment 1 of the present utility model;

Fig. 5 is a schematic structural diagram of the overvoltage protection circuit in Embodiment 1 of the present utility model;

Fig. 6 is a schematic circuit diagram of the overvoltage protection circuit in Embodiment 1 of the present utility model;

Fig. 7 is a schematic diagram of the first structure of Embodiment 2 of the utility model;

Fig. 8 is a second structural schematic diagram of the second embodiment of the utility model;

Fig. 9 is a third structural schematic diagram of the second embodiment of the utility model;

Fig. 10 is a fourth structural schematic diagram of the second embodiment of the utility model.

Detailed ways

The technical solution of the utility model will be further described below in conjunction with the accompanying drawings, but the utility model is not limited to these embodiments.

Embodiment one

The embodiment of the utility model provides a supercapacitor energy storage system, as shown in Figure 1, comprising several supercapacitor units C1-Cn connected in series; a constant current and voltage limiting charging circuit connected to the output end of the power supply; The input voltage equalization circuit connected to the supercapacitor unit, the input end of the input voltage equalization circuit is connected to the output end of the constant current and voltage limiting charging circuit; and a dynamic flexible output with one end connected to the output end of each supercapacitor unit and the other end connected to the load circuit.

As shown in Figure 2, the constant current and voltage limiting charging circuit includes: a dual-tube forward converter, a drive circuit, a current detection circuit, a voltage detection circuit and a control circuit. The input terminal of the dual-tube forward converter is connected to the output terminal of the power supply, and the output terminal is connected to each supercapacitor unit; the drive circuit is connected to the dual-tube forward converter for driving the dual-tube forward converter; the current detection The circuit is connected with the dual-tube forward converter for output current detection of the dual-tube forward converter; the voltage detection circuit is connected with the dual-tube forward converter for output voltage detection of the dual-tube forward converter; The control circuit is connected with the current detection circuit, the voltage detection circuit and the driving circuit, and is used for controlling the output current and the output voltage of the dual-tube forward converter according to the detection current and detection voltage through the driving circuit.

In one embodiment, the constant-current-limited-voltage charging circuit further includes: an input end connected to an output end of a power supply, and an output end connected to a rectification circuit of a dual-transistor forward converter.

First, the AC output of the power supply is rectified and filtered to obtain DC power, and then the double-tube forward converter is used to realize step-down, and the isolation of input and output is realized electrically. The output current and voltage of the dual-tube forward converter are detected respectively through the current detection circuit and the voltage detection circuit, and according to the detected current and voltage, the output current and voltage of the dual-tube forward converter are controlled through the drive circuit, thereby Realize the constant current limiting voltage charging of the supercapacitor unit.

As shown in Figure 3, the input voltage equalization circuit includes: a voltage sensor L1, a comparator A1, a switch tube Q1, a discharge resistor R1 and a reference voltage source S. The voltage sensor L1 is connected to both ends of the supercapacitor unit Ci for voltage detection at both ends of the supercapacitor unit Ci; the noninverting input terminal of the comparator A1 is connected to the output terminal of the voltage sensor L1, and the inverting input terminal passes through the reference voltage source S connected to the common terminal; the gate of the switching tube Q1 is connected to the output terminal of the comparator A1, the drain is connected to one end of the supercapacitor unit CI, and the source is connected to one end of the discharge resistor R1; the other end of the discharge resistor R1 is connected to the supercapacitor unit Ci the other end.

When each supercapacitor unit is being charged, the voltage at its two ends will gradually increase. The voltage sensor L1 detects the voltage at both ends of each supercapacitor unit. When the voltage at both ends of a certain supercapacitor unit reaches the reference voltage of the reference voltage source S, The trigger switch Q1 is turned on to shunt the charging current so as to maintain it at the rated voltage. The other supercapacitor units also perform the same process, and finally the voltage across each supercapacitor unit reaches equilibrium.

As shown in Figure 4, the dynamic flexible output circuit includes: resistors R2, R3, R4, R5, R6, comparator A2, transistor Q2 and Zener diode D1. One end of the resistor R2 is connected to one end of the resistor R3 and the non-inverting input end of the comparator A2, the other end of the resistor R3 is connected to the anode of the Zener diode D1, and the cathode of the Zener diode D1 is connected to the inverting phase of the comparator A2 The input terminal and one terminal of the resistor R4, the output terminal of the comparator A2 is connected to one terminal of the resistor R5, the other terminal of the resistor R5 is connected to the base of the transistor Q2, and the emitter of the transistor Q2 is connected to the anode of the Zener diode D1 And one end of the resistor R3, the collector of the transistor Q2 is connected to one end of the resistor R6 and the load, and the other end of the resistor R6 is connected to the resistor R2, the other end of the resistor R4 and the output end of the supercapacitor unit.

When the voltage output by the supercapacitor units connected in series passes through the non-inverting terminal of the voltage divider amplifier A1 of R2 and R3, and the divided voltage value is below the set voltage value, the amplifier A2 outputs a low potential, and the current expansion transistor Q2 is not turned on. The output voltage of the connected supercapacitor unit is higher than the set voltage value, the output voltage of the amplifier A2 begins to rise (its rising rate depends on the gain of the amplifier A1), and the collector current of the current expansion transistor Q2 increases with the output voltage of the power consumption amplifier A2 As it rises, it increases, so as to realize the dynamic and flexible voltage equalization output of the voltage.

As shown in FIG. 5 , in an embodiment, the supercapacitor energy storage system further includes an overvoltage protection circuit connected to the constant current and voltage limiting charging circuit on the basis of the above embodiments.

As shown in Figure 6, the overvoltage protection circuit includes: a control chip U1, an optocoupler U2, resistors R7, R8, R9, R10, capacitors Ca, Cb, a controllable voltage regulator D2 and a voltage regulator diode D3. The negative pole of the Zener diode D3 is connected to the voltage output terminal, the positive pole of the Zener diode D3 is connected to one end of the resistor R7 and one end of the resistor R9, the other end of the resistor R7 is connected to the first end of the optocoupler U2, and the resistor R9 The other end of the capacitor Ca is connected to the second end of the optocoupler U2, one end of the capacitor Ca, one end of the resistor R10, and the K pole of the controllable voltage regulator D2, and the other end of the capacitor Ca is connected to one end of the resistor R8 and one end of the capacitor Cb. The other end of the resistor R10 is connected to the other end of the capacitor Cb, the other end of the resistor R8 is connected to the voltage output end, the third end of the optocoupler U2 is connected to the input end of the control chip U1, and the fourth end of the optocoupler U2 Connect to common.

The Zener diode D3 receives the total voltage output of the supercapacitor units connected in series, and the Zener diode D3 is introduced into the K pole of the controllable voltage stabilizer D2, and the optocoupler U2 realizes electrical isolation and outputs a voltage. When the supercapacitor is close to the set threshold, the output current IC of the optocoupler U2 increases, the output voltage decreases, and the signal entering the compensation terminal of the control chip U1 decreases, and the corresponding output PWM duty also decreases; when the supercapacitor voltage exceeds the set When the threshold is set, the compensation terminal of the control chip U1 is pulled low, and the PWM is turned off, which plays the role of overvoltage protection.

The utility model adds a constant current and voltage limiting charging circuit, an input voltage equalization circuit, a dynamic flexible output circuit and an overvoltage protection circuit on the basis of the original series-connected supercapacitor unit, so as to realize constant current and constant voltage charging for each supercapacitor unit, each supercapacitor The voltage at both ends of the capacitor unit achieves balance, dynamic flexible voltage equalization output and overvoltage protection.

Embodiment two

In order to ensure the normal operation of the switch protection device, there must be a stable and reliable backup power supply. However, the operation and maintenance of the traditional battery backup power supply is extremely heavy and unreliable. Therefore, a stable, reliable and maintenance-free backup DC power supply energy storage device is required. As a backup power supply for relay protection devices, solving the problem of huge maintenance workload and increasing the reliability of use will greatly improve the work efficiency of the operation management unit and have huge economic and social benefits.

Supercapacitors (also known as farad capacitors, gold capacitors) are between batteries and ordinary capacitors. They have the advantages of large current and fast charge and discharge of capacitors, and also have the energy storage characteristics of batteries. Reusable and long life. Discharge is the movement of electrons between conductors, rather than relying on chemical reactions, to provide electrical energy to a device.

In this embodiment, the supercapacitor energy storage system is used as the backup power supply of the relay protection device for the line-in experiment. After the power failure of the line, the function of power failure communication and opening operation is realized. After the trial production is completed, the equivalent resistance method is adopted, and the constant impedance discharge test is adopted, that is, the discharge test is directly connected in parallel at both ends of the supercapacitor energy storage system, and the parallel resistance is 50Ω. , 100W, normal device rated current is 4A.

Calculate according to the discharge formula of the supercapacitor energy storage system |C×dv-I×C×R|=I×t, where C: capacitor rated capacity; V: capacitor operating voltage; I: capacitor discharge current; t: capacitor discharge time is s (seconds); R: capacitor parallel resistance, the calculation can be t≈1716s, and the discharge working time of a set of supercapacitor energy storage system is 1716 seconds, about 28 minutes. As the normal load may vary, the current and discharge time will vary accordingly. After the simulation test, the supercapacitor energy storage system meets the discharge time requirement and can be put into production in theory.

Simulation test: Select a load switch in the switching station to conduct the opening test of the supercapacitor energy storage system connected to the load switch of the feeder line. The test results are shown in the following table:

Capacitance trip times test table

It can be seen from the above table that the opening time is 20ms, and the voltage drop is about 0.5-1V each time. Therefore, after the AC power failure, the supercapacitor energy storage system can still be reliably opened 20 times, which has met the requirements of the backup power supply of the 10kV switching station.

Based on the above experiments, this embodiment proposes a power management system based on a supercapacitor energy storage system, as shown in Figure 7, including: the supercapacitor energy storage system in Embodiment 1, the input terminal of the supercapacitor energy storage system is connected to The output terminal of the power supply and the input terminal are connected to the output terminal of the power supply, and the output terminal is connected to the first switching switch K1 of the load; the input terminal is connected to the output terminal of the super capacitor energy storage system, and the output terminal is connected to the second switching switch K2 of the load; the input terminal is connected to the output terminal of the power supply , the output terminal is connected to the switching control unit of the supercapacitor energy storage system.

When the power supply is cut off, the switch control unit controls the first switch K1 to be turned off, controls the second switch K2 to be turned on, and the supercapacitor energy storage system supplies power to the load; The switch control unit controls the first switch K1 to be turned on, and controls the second switch K2 to be turned off. The power supply supplies power to the load and charges the supercapacitor energy storage system at the same time.

Since the supercapacitor energy storage system does not have a battery, it does not need regular checking and charging and discharging experiments, so it is truly maintenance-free and greatly reduces the work intensity of operation and maintenance personnel. Supercapacitors use physical technology to store energy, have no pollution to the environment, have a long cycle life, and save costs.

As shown in FIG. 8 , in an embodiment, on the basis of the above embodiments, the power management system further includes: a first AC-DC conversion unit, a second AC-DC conversion unit, and a first DC-DC conversion unit. The input end of the first AC-DC conversion unit is connected to the output end of the first switch K1, the output end of the first AC-DC conversion unit is connected to the load; the input end of the second AC-DC conversion unit is connected to the power supply Output terminal, the output terminal of the first AC-DC conversion unit is connected to the input terminal of the supercapacitor energy storage system; the input terminal of the first DC-DC conversion unit is connected to the output terminal of the supercapacitor energy storage system, and the first DC-DC The output end of the conversion unit is connected to a load.

When the power management system is connected to the mains 220V AC output, it is necessary to convert the AC output to DC through the first AC-DC conversion unit and the second AC-DC conversion unit. And the first DC-DC conversion unit realizes boosting the output direct current of the supercapacitor energy storage system.

As shown in FIG. 9 , in an embodiment, on the basis of the above embodiments, the power management system further includes: a third switch K3 and a third AC-DC conversion unit. One end of the third switch K3 is connected to the supercapacitor energy storage system, the other end is connected to the output end of the third AC-DC conversion unit, and the input end of the AC-DC conversion unit is connected to the switch control unit.

The third switch K3 can cut off the output of the supercapacitor energy storage system, and the operation and maintenance of the equipment can partially determine whether each unit is normal, and it is also more convenient to determine the status of internal components.

As shown in Figure 10, in an embodiment, on the basis of the above embodiments, the power management system further includes: a first voltage detection unit, a second voltage detection unit, the first voltage detection unit, the second voltage detection unit They are respectively connected to the supercapacitor energy storage system through the second DC-DC conversion unit and the third DC-DC conversion unit.

The first voltage detection unit is used to detect the input voltage of the supercapacitor energy storage system, and the second voltage detection unit is used to detect the output voltage of the supercapacitor energy storage system, so as to monitor the working state of the supercapacitor energy storage system.

Those skilled in the technical field to which the utility model belongs can make various modifications or supplements to the described specific embodiments or adopt similar methods to replace them, but they will not deviate from the spirit of the utility model or go beyond the appended claims defined range.

Claims (10)

1. super capacitor energy storage system, including a plurality of series connection's super capacitor unit, its characterized in that, this system still includes:

The constant-current voltage-limiting charging circuit is connected to the output end of the power supply;

the input ends of the input voltage equalizing circuits are connected with the output ends of the constant-current voltage-limiting charging circuits;

And one end of the dynamic flexible output circuit is connected with the output end of each super capacitor unit, and the other end of the dynamic flexible output circuit is connected with the load.

2. The supercapacitor energy storage system according to claim 1, wherein the constant current voltage limiting charging circuit comprises: a two-transistor forward converter, a drive circuit, a current detection circuit, a voltage detection circuit and a control circuit,

The input end of the double-tube forward converter is connected with the output end of a power supply, and the output end of the double-tube forward converter is connected with each super capacitor unit;

The driving circuit is connected with the double-tube forward converter and used for driving the double-tube forward converter;

The current detection circuit is connected with the double-tube forward converter and is used for detecting the output current of the double-tube forward converter;

The voltage detection circuit is connected with the double-tube forward converter and is used for detecting the output voltage of the double-tube forward converter;

the control circuit is connected with the current detection circuit, the voltage detection circuit and the drive circuit and is used for controlling the output current and the output voltage of the double-tube forward converter through the drive circuit according to the detection current and the detection voltage.

3. the supercapacitor energy storage system according to claim 2, wherein the constant current voltage limiting charging circuit further comprises: the input end is connected with the output end of the power supply, and the output end is connected with the rectifying circuit of the double-tube forward converter.

4. The supercapacitor energy storage system according to claim 1, wherein the input voltage balancing circuit comprises: a voltage sensor L1, a comparator A1, a switch tube Q1, a discharge resistor R1 and a reference voltage source S,

The voltage sensor L1 is connected to two ends of the super capacitor unit and is used for detecting the voltage of the two ends of the super capacitor unit;

The non-inverting input end of the comparator A1 is connected with the output end of the voltage sensor L1, and the inverting input end of the comparator A1 is connected with the common end through a reference voltage source S;

the grid electrode of the switching tube Q1 is connected with the output end of the comparator A1, the drain electrode of the switching tube Q1 is connected with one end of the super capacitor unit, and the source electrode of the switching tube Q1 is connected with one end of the discharge resistor R1;

The other end of the discharge resistor R1 is connected with the other end of the super capacitor unit.

5. The supercapacitor energy storage system according to claim 1, wherein the dynamic flexible output circuit comprises: resistors R2, R3, R4, R5, R6, a comparator A2, a transistor Q2 and a zener diode D1,

One end of the resistor R2 is connected with one end of a resistor R3 and a non-inverting input end of a comparator A2, the other end of the resistor R3 is connected with an anode of a voltage stabilizing diode D1, a cathode of the voltage stabilizing diode D1 is connected with an inverting input end of a comparator A2 and one end of a resistor R4, an output end of the comparator A2 is connected with one end of a resistor R5, the other end of the resistor R5 is connected with a base of a transistor Q2, an emitter of the transistor Q2 is connected with an anode of a voltage stabilizing diode D1 and one end of a resistor R3, a collector of the transistor Q2 is connected with one end of a resistor R6 and a load, and the other end of the resistor R6 is connected with the other ends of a resistor R2, a resistor R4 and an output.

6. the supercapacitor energy storage system according to any one of claims 1 to 5, further comprising:

And the overvoltage protection circuit is connected with the constant-current voltage-limiting charging circuit.

7. The supercapacitor energy storage system according to claim 6, wherein the overvoltage protection circuit comprises: a control chip U1, an optical coupler U2, resistors R7, R8, R9, R10, capacitors Ca and Cb, a controllable voltage-stabilizing source D2 and a voltage-stabilizing diode D3,

The negative electrode of the zener diode D3 is connected with the voltage output end, the positive electrode of the zener diode D3 is connected with one end of the resistor R7 and one end of the resistor R9, the other end of the resistor R7 is connected with the first end of the optocoupler U2, the other end of the resistor R9 is connected with the second end of the optocoupler U2, one end of the capacitor Ca, one end of the resistor R10 and the K pole of the controllable voltage stabilization source D2, the other end of the capacitor Ca is connected with one end of the resistor R8 and one end of the capacitor Cb, the other end of the resistor R10 is connected with the other end of the capacitor Cb, the other end of the resistor R8 is connected with the voltage output end, the third end of the optocoupler U2 is connected with the input end of the control chip U.

8. based on super capacitor energy storage system power management system, its characterized in that includes: the super capacitor energy storage system as claimed in any one of claims 1 to 7, wherein the input terminal of the super capacitor energy storage system is connected to the output terminal of the power supply and

the input end of the first selector switch K1 is connected with the power supply output end, and the output end of the first selector switch K1 is connected with the load;

The input end of the first selector switch K2 is connected with the output end of the super capacitor energy storage system, and the output end of the first selector switch K2 is connected with the load;

the input end of the super-capacitor energy storage system is connected with the output end of a power supply, the output end of the super-capacitor energy storage system is connected with a change-over switch control unit of the super-capacitor energy storage system, when the power supply is powered off, the change-over switch control unit controls a first change-over switch K1 to be switched off and controls a second change-over switch K2 to be switched on, and the super-capacitor energy storage system supplies power to a; when the power supply is powered on, the change-over switch control unit controls the first change-over switch K1 to be switched on and controls the second change-over switch K2 to be switched off, and the power supply supplies power to the load.

9. the supercapacitor based energy storage system power management system according to claim 8, further comprising: a first AC-DC converting unit, a second AC-DC converting unit, a first DC-DC converting unit,

the input end of the first AC-DC conversion unit is connected with the output end of the first switch K1, and the output end of the first AC-DC conversion unit is connected with a load;

The input end of the second AC-DC conversion unit is connected with the output end of the power supply, and the output end of the first AC-DC conversion unit is connected with the input end of the super capacitor energy storage system;

the input end of the first DC-DC conversion unit is connected with the output end of the super capacitor energy storage system, and the output end of the first DC-DC conversion unit is connected with a load.

10. the supercapacitor based energy storage system power management system according to claim 8, further comprising: a third changeover switch K3 and a third AC-DC converting unit,

One end of the third selector switch K3 is connected with the super capacitor energy storage system, the other end is connected with the output end of the third AC-DC conversion unit,

and the input end of the AC-DC conversion unit is connected with the change-over switch control unit.