WO2024027834A1

WO2024027834A1 - Power source management system and management method for self-powered water meter

Info

Publication number: WO2024027834A1
Application number: PCT/CN2023/111300
Authority: WO
Inventors: 林东; 朱福巍; 姜芳
Original assignee: 杭州广迪科技有限公司
Priority date: 2022-08-04
Filing date: 2023-08-04
Publication date: 2024-02-08
Also published as: CN115333189A

Abstract

Provided in the present invention are a power source management system and management method for a self-powered water meter. The power source management system for a self-powered water meter comprises a lithium-ion capacitor or a sodium-ion capacitor, a charging circuit and a button battery or a dry battery. When the voltage value of the lithium-ion capacitor or the sodium-ion capacitor is less than the lower limit of a charging voltage threshold value, the charging circuit charges the lithium-ion capacitor or the sodium-ion capacitor. When the voltage of the lithium-ion capacitor or the sodium-ion capacitor is lower than a specific protection voltage, the button battery or the dry battery charges the lithium-ion capacitor or the sodium-ion capacitor to prevent the lithium-ion capacitor or the sodium-ion capacitor from being over-discharged.

Description

Self-generated water meter power management system and management method

Technical field

The present invention relates to the field of smart water meters, and in particular to a self-generated smart water meter power management system and management method.

Background technique

Smart water meters have the advantage of being able to electronically display counts and make readings easy. Smart water meters realize intelligent remote meter reading by reading the flow measured by traditional mechanical water meters and then remotely transmitting the corresponding readings to the terminal. Traditional smart water meters are powered by built-in batteries. Since the battery has limited power, it needs to be replaced regularly.

Usually the service life of the battery is 5 years. In practical applications, in order to ensure the accuracy of meter reading, it is not necessary to wait for the battery to run out. Instead, it is estimated that there is not much power left in the battery, and the battery is manually replaced regularly. Therefore, existing ordinary smart water meters need batteries that need to be replaced every five years. Every time the battery is replaced, special personnel need to be arranged to do the replacement, which increases the dual cost of battery and manpower. Moreover, during the period when the smart water meter is powered off and then restarted, the data is prone to errors. In particular, the replaced battery is a great pollutant to the environment.

In this regard, self-generating water meters came into being. The self-generating water meter uses the kinetic energy of the water flow in the water pipe to generate electricity. The charging and discharging energy storage device stores the electricity and provides electric energy to the water meter reading signal transmitting device to maintain the normal use of the water meter reading signal transmitting device. However, self-generated water meters have not been successfully commercialized due to the following problems.

If lithium batteries are used as charging and discharging energy storage devices, the service life of lithium batteries is too short. After experiments, the number of charge and discharge times of lithium batteries is only about 1,000 times. If put into practical application, under special circumstances where users use frequent, intermittent, and large amounts of water, the life of the water meter may even be less than one year. Moreover, the problem of overcharging or over-discharging lithium batteries cannot be solved. It is unavoidable in any area that some houses are vacant and no one uses water, so the generator will not be able to charge the lithium battery. If the lithium battery is not charged for a long time, the lithium battery will age and be damaged in less than two years. A damaged lithium battery cannot be charged or discharged again. Overcharging and over-discharging will cause irreversible damage to the performance and life of lithium batteries. Therefore, if a self-generated water meter using lithium batteries as an energy storage device is not used for a long time, its service life will be only two years at most, which is far lower than the service life of existing ordinary smart water meters. Therefore, self-generated water meters using lithium batteries as energy storage devices have always been in the theoretical stage and have not yet been successfully commercialized and applied.

In order to avoid the problem of over-discharge causing damage to the energy storage device, some self-generating water meters consider using supercapacitors to store electrical energy. Supercapacitors have the characteristics of fast charging speed, high power utilization rate, long cycle life, High safety factor and other advantages. The most important thing is that compared with lithium batteries, overcharging and over-discharging will not have a negative impact on the life of supercapacitors. However, the cost of supercapacitors will be much higher than the cost of lithium batteries. Moreover, compared with traditional ordinary smart water meters, the cost of self-generating water meters using supercapacitors is much higher after adding structures such as generators and supercapacitors to the original ones. In terms of commercial promotion, cost is a very important consideration, which has become a major constraint for the commercial promotion and application of self-generated water meters using supercapacitors. In particular, many people ignore that supercapacitors also have self-discharge problems. Although over-discharge will not affect the life of supercapacitors, the self-discharge rate of supercapacitors is faster than that of lithium batteries. In actual use, if the homeowner saves water and uses a small flow of water every time, the charging capacity will not be enough for the self-discharge capacity of the supercapacitor, and the smart water meter will not be able to send data.

Contents of the invention

In order to overcome at least one shortcoming in the prior art, the present invention provides a self-generated water meter power management system and management method.

In order to achieve an object of the present invention, in the first aspect, the present invention provides a self-generated water meter power management system, including a lithium ion capacitor or a sodium ion capacitor, a charging circuit and a button battery or dry battery. When the lithium ion capacitor or sodium ion capacitor When the voltage value is lower than the lower limit of the charging voltage threshold, the charging circuit charges the lithium ion capacitor or sodium ion capacitor. When the voltage of the lithium ion capacitor or sodium ion capacitor is lower than a specific protection voltage, the button battery or dry cell battery charges the lithium ion capacitor or sodium ion capacitor to prevent the lithium ion capacitor or sodium ion capacitor from over-discharging.

In an embodiment of the first aspect, the self-generated water meter power management system further includes a diode, the anode of the diode is electrically connected to a button battery or a dry battery, and the cathode of the diode is electrically connected to a lithium ion capacitor or a sodium ion capacitor.

In an embodiment of the first aspect, the self-generated water meter power management system further includes a resistor connected in series with the diode.

In an embodiment of the first aspect, the self-generated water meter power management system further includes a detection circuit. The detection circuit detects the voltage value of the lithium ion capacitor or sodium ion capacitor and sends a signal to the charging circuit. When the detection circuit detects the voltage value of the lithium ion capacitor or sodium ion capacitor, When the voltage value of the sodium ion capacitor is lower than the lower limit of the charging voltage threshold, the charging circuit charges the lithium ion capacitor or sodium ion capacitor; when the detection circuit detects that the voltage value of the lithium ion capacitor or sodium ion capacitor is higher than the upper limit of the charging voltage threshold, The charging circuit cuts off charging of the lithium-ion capacitor or sodium-ion capacitor.

In an embodiment of the first aspect, the self-generated water meter power management system further includes a self-generated power supply and a rectification and filtering circuit. The power sent by the self-generating power supply is transmitted to the charging circuit after passing through the rectification and filtering circuit.

In an embodiment of the first aspect, the self-generated water meter power management system further includes a battery protection circuit. When the voltage value of the lithium ion capacitor or sodium ion capacitor is lower than the lower limit of the discharge voltage threshold, the battery protection circuit cuts off the lithium ion capacitor or sodium ion capacitor. The discharge path of the ion capacitor. When the voltage value of the lithium ion capacitor or the sodium ion capacitor is higher than the upper discharge voltage threshold, the battery protection circuit conducts the discharge path of the lithium ion capacitor or the sodium ion capacitor.

In an embodiment of the first aspect, the battery protection circuit is electrically connected between the charging circuit and the lithium ion capacitor or the sodium ion capacitor.

In an embodiment of the first aspect, the self-generated water meter power management system further includes a signal sending circuit. When the voltage value of the lithium ion capacitor or sodium ion capacitor is lower than the lower limit of the discharge voltage threshold, the battery protection circuit cuts off the lithium ion capacitor or sodium ion capacitor. The electrical connection between the ion capacitor and the signal sending circuit is to reduce the discharge of the lithium ion capacitor or sodium ion capacitor; when the voltage value of the lithium ion capacitor or sodium ion capacitor is higher than the upper limit of the discharge voltage threshold, the battery protection circuit turns on the lithium ion capacitor or sodium ion capacitor. The ionic capacitor is electrically connected to the signal sending circuit to allow the lithium ion capacitor or sodium ion capacitor to provide power to the signal sending circuit.

In an embodiment of the first aspect, the self-generated water meter power management system further includes a step-down circuit, and part of the power transmitted by the lithium-ion capacitor or sodium-ion capacitor through the battery protection circuit is supplied to the detection circuit through the step-down circuit.

In a second aspect, the present invention also provides a power management method for a self-generated water meter power management system, including the following steps: when the detection circuit detects that the voltage value of the lithium ion capacitor or the sodium ion capacitor is lower than the lower limit of the charging voltage threshold, charging The circuit charges the lithium ion capacitor or sodium ion capacitor; when the detection circuit detects that the voltage value of the lithium ion capacitor or sodium ion capacitor is higher than the upper limit of the charging voltage threshold, the charging circuit cuts off charging of the lithium ion capacitor or sodium ion capacitor; when When the voltage value of the lithium ion capacitor or sodium ion capacitor is lower than the lower limit of the discharge voltage threshold, the battery protection circuit cuts off the discharge path of the lithium ion capacitor or sodium ion capacitor. When the voltage value of the lithium ion capacitor or sodium ion capacitor is higher than the discharge voltage threshold Within a limited time, the battery protection circuit conducts the discharge path of the lithium ion capacitor or sodium ion capacitor; when the voltage of the lithium ion capacitor or sodium ion capacitor is lower than the specific protection voltage, the button battery or dry battery charges the lithium ion capacitor or sodium ion capacitor to prevent The lithium ion capacitor or sodium ion capacitor is over discharged.

In a third aspect, the present invention also provides a self-generated water meter power management system, including: an energy storage component; a backup battery. When the voltage of the energy storage component is lower than a specific protection voltage, the backup battery charges the energy storage component to prevent storage. The active component is over discharged.

In an embodiment of the third aspect, the energy storage element is a lithium ion capacitor or a sodium ion capacitor.

In an embodiment of the third aspect, the backup battery is a button battery or a dry battery.

In an embodiment of the third aspect, the self-generated water meter power management system further includes a unidirectional conduction element, and the unidirectional conduction element is conductive to enable the backup battery to provide unidirectional power supply to the energy storage element.

In an embodiment of the third aspect, the self-generated water meter power management system further includes a current limiting component to balance the current flowing from the backup battery to the energy storage component and the self-discharge current of the energy storage component to ensure that the energy storage component is above a safe voltage. , to prevent it from being damaged by over-discharge.

In an embodiment of the third aspect, the unidirectional conducting element is a diode, and the current limiting element is a resistor.

In an embodiment of the third aspect, the anode of the diode is electrically connected to the backup battery, and the cathode of the diode is electrically connected to the energy storage element.

In an embodiment of the third aspect, the self-generated water meter power management system further includes a detection circuit and a charging circuit. The detection circuit detects the voltage value of the energy storage element and sends a signal to the charging circuit. When the detection circuit detects the voltage of the energy storage element, When the value is lower than the lower limit of the charging voltage threshold, the charging circuit charges the energy storage element; when the detection circuit detects that the voltage value of the energy storage element is higher than the upper limit of the charging voltage threshold, the charging circuit cuts off charging of the energy storage element.

In an embodiment of the third aspect, the self-generated water meter power management system further includes a self-generated power supply and a rectifier and filter circuit. The power sent from the self-generated power source is transmitted to the charging circuit after passing through the rectifier and filter circuit.

In an embodiment of the third aspect, the self-generated water meter power management system further includes a battery protection circuit. When the voltage value of the energy storage element is lower than the lower limit of the discharge voltage threshold, the battery protection circuit cuts off the discharge path of the energy storage element. When the voltage value of the energy storage element is higher than the upper limit of the discharge voltage threshold, the battery protection circuit conducts the discharge path of the energy storage element.

In an embodiment of the third aspect, the battery protection circuit is electrically connected between the charging circuit and the energy storage element.

In an embodiment of the third aspect, the self-generated water meter power management system further includes a signal sending circuit. When the voltage value of the energy storage element is lower than the lower limit of the discharge voltage threshold, the battery protection circuit cuts off the power supply between the energy storage element and the signal sending circuit. electrical connection to reduce the discharge of the energy storage element; when the voltage value of the energy storage element is higher than the upper limit of the discharge voltage threshold, the battery protection circuit conducts the electrical connection between the energy storage element and the signal sending circuit to allow the energy storage element to provide the signal sending circuit with electricity.

In an embodiment of the third aspect, the self-generated water meter power management system further includes a step-down circuit, and part of the power transmitted by the energy storage element through the battery protection circuit is supplied to the detection circuit through the step-down circuit.

In a fourth aspect, the present invention also provides a power management method for a self-generated water meter power management system, including the following steps: when the detection circuit detects that the voltage value of the energy storage element is lower than the lower limit of the charging voltage threshold, the charging circuit The component is charged; when the detection circuit detects that the voltage value of the energy storage component is higher than the charging When the upper limit of the voltage threshold is reached, the charging circuit cuts off the charging of the energy storage element; when the voltage value of the energy storage element is lower than the lower limit of the discharge voltage threshold, the battery protection circuit cuts off the discharge path of the energy storage element. When the voltage value of the energy storage element is higher than When the discharge voltage threshold reaches the upper limit, the battery protection circuit conducts the discharge path of the energy storage element; when the voltage of the energy storage element is lower than the specific protection voltage, the backup battery charges the energy storage element to prevent the energy storage element from over-discharging.

In summary, the self-generated smart water meter power management system provided by the present invention uses lithium ion capacitors or sodium ion capacitors as energy storage devices. Compared with lithium batteries, lithium-ion capacitors or sodium-ion capacitors can be charged and discharged more than 500,000 times and have a long service life. Compared with supercapacitors, lithium-ion capacitors or sodium-ion capacitors have the advantages of high energy density, higher output voltage, and low self-discharge rate. Moreover, the cost of lithium-ion capacitors or sodium-ion capacitors is much lower than the cost of supercapacitors. When the lithium ion capacitor or sodium ion capacitor is discharged below a specific value, the button battery or dry cell battery will charge the lithium ion capacitor or sodium ion capacitor to prevent the lithium ion capacitor or sodium ion capacitor from over-discharging, thus greatly extending the lithium ion capacitor or sodium ion capacitor. The service life of sodium ion capacitors, thereby promoting the commercial application and promotion of self-generated water meters.

In order to make the above and other objects, features and advantages of the present invention more clearly understood, preferred embodiments are described in detail below along with the accompanying drawings.

Description of drawings

Figure 1 shows a block diagram of a self-generated smart water meter power management system according to the first embodiment of the present invention.

Figure 2 shows a block diagram of a self-generated smart water meter power management system according to a second embodiment of the present invention.

Detailed ways

Figure 1 shows a block diagram of a self-generated smart water meter power management system according to the first embodiment of the present invention. As shown in Figure 1, the self-generated smart water meter power management system provided by the first embodiment of the present invention includes a self-generated power supply 1, a rectifier and filter circuit 2, a charging circuit 3, a battery protection circuit 4, a lithium ion capacitor or a sodium ion capacitor 5, Button battery or dry cell battery 6, detection circuit 7, voltage reducing circuit 8 and signal sending circuit 9.

In this embodiment, the self-generating power source 1 is a micro-hydro-generator, which uses the water flowing through the water pipe or the water meter to drive the turbine of the generator to rotate, converting kinetic energy into electrical energy to generate electricity. After generating electricity from the power source 1, the power is transmitted to the rectifier and filter circuit 2. The rectifier and filter circuit 2 filters out the high-frequency harmonics in the alternating current, converts the filtered alternating current into direct current and transmits it to the charging circuit 3.

When the detection circuit 7 detects that the voltage value of the lithium ion capacitor or sodium ion capacitor 5 is lower than the lower limit of the charging voltage threshold, the charging circuit 3 charges the lithium ion capacitor or sodium ion capacitor 5; when the detection circuit 7 detects that the lithium ion capacitor or sodium ion capacitor 5 When the voltage value of the sodium ion capacitor 5 is higher than the upper limit of the charging voltage threshold, the charging circuit 3 cuts off charging of the lithium ion capacitor or the sodium ion capacitor 5 . When the detection circuit 7 detects that the voltage value of the lithium ion capacitor or the sodium ion capacitor 5 is higher than or equal to the lower limit of the charging voltage threshold and lower than or equal to the upper limit of the charging voltage threshold, the charging circuit 3 The conduction or disconnection does not change, that is, if the charging state between the charging circuit 3 and the lithium ion capacitor or the sodium ion capacitor 5 is conductive, the conduction will continue. If the charging circuit 3 is not connected to the lithium ion capacitor or the sodium ion capacitor 5 The sodium ion capacitor 5 charged will remain uncharged.

Specifically, when the detection circuit 7 detects that the voltage value of the lithium ion capacitor or the sodium ion capacitor 5 is lower than the lower limit of the charging voltage threshold, the charging circuit 3 conducts the electrical connection with the lithium ion capacitor or the sodium ion capacitor 5, At this time, the charging circuit 3 charges the lithium ion capacitor or sodium ion capacitor 5. If the charging capacity of the lithium ion capacitor or sodium ion capacitor 5 is greater than the discharge capacity, the voltage of the lithium ion capacitor or sodium ion capacitor 5 will change from low to high. Make the climb. When the voltage rises to higher than or equal to the lower limit of the charging voltage threshold, charging circuit 3 does not operate, that is, charging circuit 3 and lithium ion capacitor or sodium ion capacitor 5 are still in the conductive state, and charging circuit 3 continues to charge the lithium ion capacitor or sodium ion capacitor. The ion capacitor 5 is charged, and the voltage of the lithium ion capacitor or the sodium ion capacitor 5 continues to rise. Until the voltage value of the lithium ion capacitor or sodium ion capacitor 5 is higher than the upper limit of the charging voltage threshold, the charging circuit 3 disconnects the electrical connection with the lithium ion capacitor or sodium ion capacitor 5 and cuts off the connection to the lithium ion capacitor or sodium ion capacitor. 5 charge. When the discharge capacity of the lithium ion capacitor or sodium ion capacitor 5 is greater than the charging capacity, the voltage of the lithium ion capacitor or sodium ion capacitor 5 decreases from high to low. Since the charging circuit 3 and the lithium ion capacitor or the sodium ion capacitor 5 are disconnected at the beginning, when the voltage of the lithium ion capacitor or the sodium ion capacitor 5 drops below or equal to the upper limit of the charging voltage threshold, the charging circuit 3 still does not respond to the lithium ion capacitor. The capacitor or sodium ion capacitor 5 is charged, and the charging circuit 3 will not charge the lithium ion capacitor or sodium ion capacitor 5 until the voltage of the lithium ion capacitor or sodium ion capacitor 5 drops below the lower limit of the charging voltage threshold.

In this embodiment, the upper limit of the charging voltage threshold is 4.0V, and the lower limit of the charging voltage threshold is 3.2V. However, the present invention does not place any limit on the specific value of the charging voltage threshold. Through this arrangement, overcharging of the lithium ion capacitor or sodium ion capacitor 5 is prevented, effectively protecting the lithium ion capacitor or sodium ion capacitor, and extending the service life of the lithium ion capacitor or sodium ion capacitor.

When the voltage value of the lithium ion capacitor or the sodium ion capacitor 5 is lower than the lower limit of the discharge voltage threshold, the battery protection circuit 4 cuts off the discharge path of the lithium ion capacitor or the sodium ion capacitor 5 . When lithium ion capacitor When the voltage value of the lithium ion capacitor or the sodium ion capacitor 5 is higher than the upper limit of the discharge voltage threshold, the battery protection circuit 4 conducts the discharge path of the lithium ion capacitor or the sodium ion capacitor 5 . When the voltage value of the lithium ion capacitor or sodium ion capacitor 5 is higher than or equal to the lower limit of the discharge voltage threshold and lower than or equal to the upper limit of the discharge voltage threshold, the battery protection circuit 4 conducts the discharge path of the lithium ion capacitor or sodium ion capacitor 5 Or the disconnection does not change, that is, if the discharge path of the lithium ion capacitor or sodium ion capacitor 5 is conductive, the lithium ion capacitor or sodium ion capacitor 5 will continue to discharge to the outside. If the discharge path of the lithium ion capacitor or sodium ion capacitor 5 is cut off and will continue to be discharged.

Specifically, when the voltage value of the lithium ion capacitor or sodium ion capacitor 5 is higher than the upper discharge voltage threshold, the battery protection circuit 4 conducts the discharge path of the lithium ion capacitor or sodium ion capacitor 5. If the lithium ion capacitor or sodium ion capacitor 5 is The discharge amount of the ion capacitor 5 is greater than the charging amount, and the voltage of the lithium ion capacitor or sodium ion capacitor 5 will drop. When the voltage value of the lithium ion capacitor or sodium ion capacitor 5 drops below or equal to the upper limit of the discharge voltage threshold, the battery protection circuit 4 does not operate, the lithium ion capacitor or the sodium ion capacitor 5 continues to discharge to the outside, until the voltage value of the lithium ion capacitor or the sodium ion capacitor 5 is lower than the lower limit of the discharge voltage threshold, the battery protection circuit 4 will cut off the lithium ion capacitor or the sodium ion capacitor. The discharge path of the ion capacitor 5. If the discharge capacity of the lithium ion capacitor or sodium ion capacitor 5 is less than the charging capacity at this time, the voltage of the lithium ion capacitor or sodium ion capacitor 5 will continue to rise. When the voltage value of the lithium ion capacitor or sodium ion capacitor 5 rises to a value higher than or When it is equal to the lower limit of the discharge voltage threshold, since the discharge path of the lithium ion capacitor or sodium ion capacitor 5 was previously disconnected, the battery protection circuit 4 does not operate at this time, and the lithium ion capacitor or sodium ion capacitor 5 will not discharge to the outside. The voltage of the ion capacitor or sodium ion capacitor 5 will continue to rise until the voltage value of the lithium ion capacitor or sodium ion capacitor 5 is higher than the upper limit of the discharge voltage threshold, then the battery protection circuit 4 will turn on the lithium ion capacitor or sodium ion capacitor. 5 discharge path.

Through this arrangement, over-discharge of the lithium ion capacitor or sodium ion capacitor 5 is prevented, effectively protecting the lithium ion capacitor or sodium ion capacitor, and extending the service life of the lithium ion capacitor or sodium ion capacitor. In this embodiment, the upper limit of the discharge voltage threshold is 4.0V, and the lower limit of the discharge voltage threshold is 3.0V. However, the present invention does not impose any limit on the specific value of the discharge voltage threshold.

In this embodiment, the battery protection circuit 4 is an integrated circuit, which itself includes a controller and a sensor for detecting the voltage of the lithium ion capacitor or the sodium ion capacitor 5 . However, the present invention does not impose any limitation on this. In other embodiments, the detection circuit 7 may transmit the signal of the detected voltage value of the lithium ion capacitor or the sodium ion capacitor 5 to the battery protection circuit 4 .

In this embodiment, the battery protection circuit 4 is electrically connected between the charging circuit 3 and the lithium ion capacitor or the sodium ion capacitor 5 . The charging circuit 3 of the present invention is not directly connected to the lithium ion capacitor or the sodium ion capacitor. The sub-capacitor 5 is connected to the lithium-ion capacitor or the sodium-ion capacitor 5 through the battery protection circuit 4. With this arrangement, when the voltage of the lithium ion capacitor or sodium ion capacitor 5 is lower than the lower limit of the discharge voltage threshold, the battery protection circuit 4 cuts off all external connections of the lithium ion capacitor or sodium ion capacitor 5 (except those with button batteries or dry batteries). connection), ensure that only the self-discharge caused by the loss of the lithium-ion capacitor or sodium-ion capacitor 5 is left, and no other circuit will continue to obtain power from the lithium-ion capacitor or sodium-ion capacitor, thereby reducing the lithium-ion capacitor or sodium-ion capacitor. The self-discharge amount of the ionic capacitor extends the self-discharge time of the lithium-ion capacitor or sodium-ion capacitor.

In this embodiment, when the voltage value of the lithium ion capacitor or sodium ion capacitor 5 is lower than the lower limit of the discharge voltage threshold, the battery protection circuit 4 cuts off the electrical connection between the lithium ion capacitor or sodium ion capacitor 5 and the signal transmitting circuit 9 to reduce Discharge of the lithium ion capacitor or the sodium ion capacitor 5; when the voltage value of the lithium ion capacitor or the sodium ion capacitor 5 is higher than the upper limit of the discharge voltage threshold, the battery protection circuit 4 conducts the lithium ion capacitor or the sodium ion capacitor 5 and the signal sending circuit 9 The electrical connection allows the lithium ion capacitor or the sodium ion capacitor to provide power to the signal sending circuit 9 . The signal sending circuit 9 transmits the water meter data remotely, thereby realizing remote meter reading.

In this embodiment, part of the power transmitted by the lithium ion capacitor or sodium ion capacitor 5 through the battery protection circuit 4 is supplied to the detection circuit 7 through the voltage reducing circuit 8 . When the battery protection circuit 4 cuts off the external power supply of the lithium-ion capacitor or the sodium-ion capacitor 5, the detection circuit 7 and the voltage-reducing circuit will also stop working due to the lack of power source, thus minimizing the self-consumption of the entire power management system.

In this embodiment, the button battery or dry battery 6 of the present invention is only connected in series with the lithium ion capacitor or the sodium ion capacitor 5, and does not have any direct electrical connection with other circuits of the self-generated water meter power management system. There is no parallel or series relationship between loads outside the system. With this arrangement, the button battery or dry cell battery 6 only needs to maintain the self-discharge power requirement of the lithium ion capacitor or sodium ion capacitor, and does not need excess power to power other circuits or external loads, extending the service life of the button cell battery or dry cell battery 6 . It is precisely through this setting that there is no need to use a large-power battery, but a button battery or a dry battery 6, which greatly reduces the manufacturing cost of the self-generated water meter power management system. In particular, because the button battery or dry cell battery 6 is only connected in series with the lithium ion capacitor or sodium ion capacitor 5 and has no series or parallel connection with other circuits or external loads, the self-generated water meter power management system does not need to set up additional switching circuits, simplifying the circuit structure. reduce manufacturing cost.

In this embodiment, the self-generated water meter power management system also includes a diode, which is electrically connected between the button battery or dry cell battery 6 and the lithium ion capacitor or sodium ion capacitor 5 . Due to the one-way conduction characteristic, the diode functions as a switch to conduct or cut off the electrical connection between the button battery or dry cell battery 6 and the lithium ion capacitor or sodium ion capacitor 5 . The anode of the diode is electrically connected to the button battery or dry The cathode of battery 6 is electrically connected to the lithium ion capacitor or sodium ion capacitor 5, so that current can only flow from the button battery or dry cell battery to the lithium ion capacitor or sodium ion capacitor. In this embodiment, the self-generated water meter power management system further includes a resistor and a diode connected in series. The resistor plays a current limiting role, protecting the diode and extending the service life of the button battery. According to the daily fixed current demand of the lithium-ion capacitor or sodium-ion capacitor (that is, the daily self-discharge, such as about 2uA), select a resistor with a corresponding resistance to ensure that the button battery charges the lithium-ion capacitor or sodium-ion capacitor every day equal to Self-discharge capacity of lithium-ion capacitors or sodium-ion capacitors. This setting method prevents the button battery from charging "excess" power to the lithium-ion battery, thereby greatly extending the service life of the button battery.

In practical applications, if no one uses water for a long time, lithium-ion capacitors or sodium-ion capacitors will not have any charging source and will only self-discharge. Due to the setting of button batteries or dry batteries, the voltage of the lithium-ion capacitor or sodium-ion capacitor is always maintained at a certain value (such as 2.0V). In practical applications, when residents use tap water, the self-generated power source 1 generates electricity and continuously charges the lithium ion capacitor or sodium ion capacitor. At this time, since the voltage of the lithium ion capacitor or sodium ion capacitor is lower than the lower limit of the charging voltage threshold (such as 3.2V), the charging circuit charges the lithium ion capacitor or sodium ion capacitor normally. And because the upper limit of the discharge voltage threshold has not been reached (such as 4.0V), the lithium ion capacitor or sodium ion capacitor will not be discharged externally under the protection of the charging protection circuit, and the electric energy will be continuously stored. The real-time voltage on the lithium ion capacitor or sodium ion capacitor will The voltage value keeps increasing.

When the voltage value of the lithium ion capacitor or sodium ion capacitor rises to greater than the upper limit of the charging voltage threshold (4.0V), the charging circuit stops charging the lithium ion capacitor or sodium ion capacitor. At the same time, due to the voltage of the lithium ion capacitor or sodium ion capacitor, When the value is greater than the upper limit of the discharge voltage threshold (4.0V), the lithium ion capacitor or sodium ion capacitor provides power to the signal sending circuit, and the signal sending circuit sends the water meter numerical signal. Since the lithium ion capacitor or sodium ion capacitor only discharges without charging source at this time, the real-time voltage value begins to decrease. When the lithium ion capacitor or sodium ion capacitor drops below the lower charging voltage threshold (3.2V), the charging circuit resumes charging the lithium ion capacitor or sodium ion capacitor. At this time, the lithium ion capacitor or sodium ion capacitor is charged and discharged simultaneously. If the user consumes a large amount of water at this time, the charging capacity of the lithium ion capacitor or sodium ion capacitor will be greater than the discharge capacity. At this time, the real-time voltage value of the lithium ion capacitor or sodium ion capacitor will rise, and the status of the lithium ion capacitor or sodium ion capacitor will Repeat the above mentioned state (discharge while charging -> voltage rise -> discharge while stopping charging -> voltage drop -> discharge while starting charging -> voltage rise -> cycle).

If the user does not consume much water at this time, the discharge capacity of the lithium ion capacitor or sodium ion capacitor will be greater than the charging capacity, and the real-time voltage value of the lithium ion capacitor or sodium ion capacitor will continue to decrease. When the lithium-ion capacitor or sodium-ion capacitor drops below the lower discharge voltage threshold (3.0V), the lithium-ion capacitor Or the sodium ion capacitor does not discharge to the outside under the protection of the battery protection circuit, and stores the electric energy provided by the self-generated power supply. At this time, the detection circuit 7 and the voltage-reducing circuit do not work because there is no power supply source.

If the user completely stops using water at this time, the lithium-ion capacitor or sodium-ion capacitor will start to self-discharge from 3.0V. Lithium-ion capacitors or sodium-ion capacitors self-discharge very slowly. When there is no charging source for a long time, the voltage of the lithium-ion capacitor or sodium-ion capacitor drops below a specific protection voltage (the specific protection voltage value is the voltage value of a button cell or dry cell battery minus The value obtained by subtracting the voltage drop of the resistor from the conduction voltage of the diode). In this embodiment, the voltage of the button battery or dry cell battery is 3V. The turn-on voltage of the diode remains basically unchanged (0.7v for silicon tubes and 0.3v for germanium tubes). There is a very tiny voltage drop across the resistor (since the current is so small, the voltage drop across the resistor is almost negligible). In this embodiment, when the voltage value of the lithium ion capacitor or sodium ion capacitor 5 is lower than 2.3V, the voltage difference between the button battery or dry cell 6 and the lithium ion capacitor or sodium ion capacitor 5 will cause the diode to conduct in the forward direction, and the button battery or The dry battery 6 will supply power to the lithium ion capacitor or the sodium ion capacitor 5, thereby preventing the lithium ion capacitor or the sodium ion capacitor 5 from over-discharge problems, effectively protecting the lithium ion capacitor or the sodium ion capacitor 5, and thereby greatly extending the life of the lithium ion capacitor. capacitor or sodium ion capacitor 5 life.

Due to the setting of button batteries or dry batteries, the voltage of the lithium-ion capacitor or sodium-ion capacitor is always maintained at a certain value (such as 2.3V). If someone uses water at this time, the lithium-ion capacitor or sodium-ion capacitor will repeat the above-mentioned state.

Generally, the service life of button batteries or dry batteries is at least 5 years, and the service life of lithium-ion capacitors or sodium-ion capacitors without external charging is 2 years. In extreme cases, the service life of a self-generated water meter using the power management system provided by the present invention is at least 7 years, which is higher than the service life of ordinary smart water meters using traditional batteries. At the same time, button batteries or dry batteries and lithium-ion capacitors or sodium-ion capacitors are used, both of which are low-cost electronic components. In summary, the above reasons enable the self-generated water meter provided by the present invention to be truly commercially promoted and used.

In other embodiments, the self-generating water meter power management system may only have lithium-ion capacitors or sodium-ion capacitors and button batteries or dry batteries. The self-generated power source can be an external generator. There is no need to install diodes and resistors between the lithium ion capacitor or sodium ion capacitor and the button battery or dry cell battery. Instead, a triode or switch can be used to control cutting off and conduction.

In summary, the self-generated smart water meter power management system provided by the present invention uses lithium ion capacitors or sodium ion capacitors as energy storage devices. Compared with lithium batteries, lithium-ion capacitors or sodium-ion capacitors can be charged and discharged more than 500,000 times and have a long service life. Compared with supercapacitors, lithium-ion capacitors or sodium-ion capacitors have the advantages of high energy density, higher output voltage, and low self-discharge rate. Moreover, the cost of lithium-ion capacitors or sodium-ion capacitors is much lower than the cost of supercapacitors. When lithium ion capacitors or sodium ion capacitors After the capacitor is discharged below a specific value, the button battery or dry cell battery will charge the lithium ion capacitor or sodium ion capacitor to prevent the lithium ion capacitor or sodium ion capacitor from over-discharging, thereby greatly extending the life of the lithium ion capacitor or sodium ion capacitor, and thus Promote the commercial application and promotion of self-generated water meters.

In the present invention, the present invention also provides a power management method for a self-generated water meter power management system, which includes the following steps: when the detection circuit detects that the voltage value of the lithium ion capacitor or the sodium ion capacitor is lower than the lower limit of the charging voltage threshold, charging The circuit charges the lithium ion capacitor or sodium ion capacitor; when the detection circuit detects that the voltage value of the lithium ion capacitor or sodium ion capacitor is higher than the upper limit of the charging voltage threshold, the charging circuit cuts off charging of the lithium ion capacitor or sodium ion capacitor; when When the voltage value of the lithium ion capacitor or sodium ion capacitor is lower than the lower limit of the discharge voltage threshold, the battery protection circuit cuts off the discharge path of the lithium ion capacitor or sodium ion capacitor. When the voltage value of the lithium ion capacitor or sodium ion capacitor is higher than the discharge voltage threshold Within a limited time, the battery protection circuit conducts the discharge path of the lithium ion capacitor or sodium ion capacitor; when the voltage of the lithium ion capacitor or sodium ion capacitor is lower than the specific protection voltage, the button battery or dry battery charges the lithium ion capacitor or sodium ion capacitor to prevent The lithium ion capacitor or sodium ion capacitor is over discharged. The above three steps are not sequential and can be performed at the same time.

As shown in Figure 2, in the second embodiment, the self-generated water meter power management system includes a self-generated power supply 1, a rectifier and filter circuit 2, a charging circuit 3, a battery protection circuit 4, an energy storage element 5', a backup battery 6', One-way conducting element 91, current limiting element 92, detection circuit 7, voltage reducing circuit 8 and signal transmitting circuit 9.

In the second embodiment, self-generated power supply 1, rectifier and filter circuit 2, charging circuit 3, battery protection circuit 4, energy storage element 5', backup battery 6', one-way conduction element 91, current limiting element 92, detection circuit 7, The voltage reducing circuit 8 and the signal transmitting circuit 9 may have the same or similar structures as the corresponding elements in the first embodiment. The energy storage element 5' in the second embodiment can be a lithium ion capacitor, a sodium ion capacitor, or other types of capacitors, and the backup battery 6' can be a button cell battery, a dry cell battery, or other storage battery. The one-way conduction component 91 in the second embodiment may be a diode or other component/circuit capable of realizing one-way conduction. The current limiting element 92 can be a resistor or other component/circuit that can balance the current flowing from the backup battery to the energy storage element and the self-discharge current of the energy storage element to ensure that the energy storage element is above a safe voltage and prevent it from being damaged by over-discharge.

The specific working principle and power management method of the self-generated water meter power management system in the second embodiment are as shown in the first embodiment, and will not be described again here.

Although the present invention has been disclosed above through preferred embodiments, it is not intended to limit the present invention. Anyone familiar with the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention is The scope of protection shall be determined by the scope of protection required by the claims.

Claims

A self-generated water meter power management system, which is characterized by including:

Lithium-ion capacitors or sodium-ion capacitors;

A charging circuit, when the voltage value of the lithium ion capacitor or the sodium ion capacitor is lower than the lower limit of the charging voltage threshold, the charging circuit charges the lithium ion capacitor or the sodium ion capacitor;

Button batteries or dry batteries, when the voltage of the lithium ion capacitor or sodium ion capacitor is lower than a specific protection voltage, the button battery or dry battery charges the lithium ion capacitor or sodium ion capacitor to prevent the lithium ion capacitor or sodium ion capacitor from over-discharging.
The self-generated water meter power management system according to claim 1, further comprising a diode, the anode of the diode is electrically connected to the button battery or dry battery, and the cathode of the diode is electrically connected to the lithium ion capacitor. Or sodium ion capacitor.
The self-generated water meter power management system according to claim 2, further comprising a resistor connected in series with the diode.
The self-generated water meter power management system according to claim 1, further comprising a detection circuit, the detection circuit detects the voltage value of the lithium ion capacitor or the sodium ion capacitor and sends a signal to the charging circuit. When the detection circuit detects When the voltage value of the lithium ion capacitor or sodium ion capacitor is lower than the lower limit of the charging voltage threshold, the charging circuit charges the lithium ion capacitor or sodium ion capacitor; when the detection circuit detects that the voltage value of the lithium ion capacitor or sodium ion capacitor is higher than When the charging voltage threshold reaches the upper limit, the charging circuit cuts off charging of the lithium ion capacitor or sodium ion capacitor.
The self-generated water meter power management system according to claim 4, further comprising a self-generated power supply and a rectification and filtering circuit, and the power sent by the self-generating power supply is transmitted to the charging circuit after passing through the rectification and filtering circuit.
The self-generated water meter power management system according to claim 1, further comprising a battery protection circuit, when the voltage value of the lithium ion capacitor or the sodium ion capacitor is lower than the lower limit of the discharge voltage threshold, the battery protection circuit cuts off the lithium ion capacitor. When the voltage value of the lithium ion capacitor or sodium ion capacitor is higher than the upper limit of the discharge voltage threshold, the battery protection circuit conducts the discharge path of the lithium ion capacitor or sodium ion capacitor.
The self-generating water meter power management system according to claim 6, wherein the battery protection circuit is electrically connected between the charging circuit and the lithium ion capacitor or the sodium ion capacitor.
The self-generated water meter power management system according to claim 6, further comprising a signal sending circuit. When the voltage value of the lithium ion capacitor or the sodium ion capacitor is lower than the lower limit of the discharge voltage threshold, the battery protection circuit cuts off the lithium ion capacitor. The electrical connection between the ion capacitor or the sodium ion capacitor and the signal sending circuit to reduce the discharge of the lithium ion capacitor or the sodium ion capacitor; when the lithium ion capacitor or the sodium ion capacitor When the voltage value of the capacitor is higher than the upper limit of the discharge voltage threshold, the battery protection circuit conducts the electrical connection between the lithium ion capacitor or sodium ion capacitor and the signal sending circuit to allow the lithium ion capacitor or sodium ion capacitor to provide power to the signal sending circuit.
The self-generated water meter power management system according to claim 6, further comprising a voltage-reducing circuit, and part of the power transmitted by the lithium-ion capacitor or sodium-ion capacitor through the battery protection circuit is supplied to the detection circuit through the voltage-reducing circuit.
A method for power management using a self-generated water meter power management system as claimed in claim 1, characterized in that it includes the following steps:

When the detection circuit detects that the voltage value of the lithium ion capacitor or sodium ion capacitor is lower than the lower limit of the charging voltage threshold, the charging circuit charges the lithium ion capacitor or sodium ion capacitor; when the detection circuit detects the voltage of the lithium ion capacitor or sodium ion capacitor When the value is higher than the upper limit of the charging voltage threshold, the charging circuit cuts off charging of the lithium-ion capacitor or sodium-ion capacitor;

When the voltage value of the lithium ion capacitor or sodium ion capacitor is lower than the lower limit of the discharge voltage threshold, the battery protection circuit cuts off the discharge path of the lithium ion capacitor or sodium ion capacitor. When the voltage value of the lithium ion capacitor or sodium ion capacitor is higher than the discharge voltage threshold When the upper limit is reached, the battery protection circuit conducts the discharge path of the lithium-ion capacitor or sodium-ion capacitor;

When the voltage of the lithium ion capacitor or sodium ion capacitor is lower than a specific protection voltage, the button battery or dry cell battery charges the lithium ion capacitor or sodium ion capacitor to prevent the lithium ion capacitor or sodium ion capacitor from over-discharging.