Fully autonomous ultra-low startup current energy harvesting intermittent power supply and its circuit topology and control method

Abstract

The present invention belongs to the power management circuit in the field of electronic technology, and particularly relates to a fully autonomous ultra-low starting current energy collection intermittent power supply and its circuit topology and control method. It includes: a transducer: used to convert different forms of energy into alternating current; a rectifier component: used to convert the alternating current output by the transducer into direct current; an energy storage component: used to store the direct current output by the energy rectifier component, and to supply power to the protection control component and the load; a protection control component: performs detection and controls the output power of the energy storage component to the load according to the set strategy. Therefore, the present invention has the following advantages: 1. The present invention has high sensitivity and can significantly expand the application range of "battery-free" sensors; 2. The present invention has a simple structure, a compact size, strong adaptability, and high reliability; 3. The present invention requires few components and greatly reduces costs.

Description

Technical Field

[0001] The invention belongs to the field of electronic technology and belongs to a power management circuit, and in particular to a fully autonomous energy-collecting intermittent power supply with an ultra-low starting current. Background Art

[0002] Power management technology has been a key area of ​​research in recent years, especially in the field of energy collection, which has been widely used. At the moment when sensor technology is being promoted and applied, various ultra-low power consumption and high-performance components are constantly emerging. The sensor system formed by this can operate in ultra-low system power consumption and ultra-wide power supply range, laying a material foundation for the wider promotion and application of sensors. However, how to collect and utilize environmental energy to promote the operation of sensors is still seriously lagging behind. As we all know, when traditional sensors work, they mainly rely on wired power or batteries and other energy sources to promote their work. At the moment when sensors are "ubiquitous", it is extremely arduous to maintain and replace batteries in time; and the recycling and management of a large number of waste batteries is extremely difficult, which may also cause great pressure on the environment. Wired power supply requires a lot of wiring, which not only consumes a lot of resources, but also has a large installation and maintenance workload. In some special application sites, such as high-voltage equipment, it is impossible to carry out wiring power supply. Therefore, it is becoming more and more important and urgent to use the collected environmental energy to promote the operation of sensors. It has become a bottleneck restricting the large-scale application of sensors.

[0003] In terms of environmental energy collection, it mainly involves key links such as converting different forms of environmental energy and effectively managing power. Among them, power management is crucial and has become a "short board". At present, a large amount of research and promotion and application have been carried out at home and abroad in terms of power management, forming two major achievements: theoretical research results and the launch of commercial devices. In the theoretical research of power management, a large number of studies at home and abroad have introduced rich results, and various local functional circuits and system-type interface circuits have been introduced, providing methods and means for application research. However, some theoretical research results also have obvious shortcomings: first, the structure is complex and there are too many components, which hinders the advancement to practical application; second, additional power supplies or other auxiliary means are required, which further increases the difficulty of application; third, no in-depth analysis and research for application has been carried out. For example, a large amount of research work is limited to "normal temperature" conditions, and no further analysis of the thermal stability of local circuits or integrated management circuit systems has been carried out. These shortcomings have formed obstacles to the advancement from theory to practical application.

[0004] In terms of applied research, a large number of achievements have been made at home and abroad, including in-depth theoretical analysis and in-depth research on a large number of functional links. Various technical solutions formed on this basis have been continuously introduced, promoting the application of sensor systems supported by the collected environmental energy. However, some technical solutions still have room for improvement and enhancement. For example, the technical solution proposed in the patent document 201310535117.5 uses three transducers and corresponding module circuits, making the system too complicated and difficult to apply on site. For example, the technical solution proposed in the patent document 201611152002.8 has a very simple circuit system, but its own energy consumption is too large. Without considering the possible consumption of its full-bridge rectifier part, bias circuit and other parts within the full temperature range, only two analog switches may consume 20uA working current, which seriously restricts its application.

[0005] In terms of the production and supply of commercial devices, relevant semiconductor component manufacturers have invested resources in research and development, launched corresponding PMIC devices, and promoted engineering applications in the field of energy harvesting. For example, the MB39C811 and LTC3588 series are PMIC devices for engineering applications. Such devices have developed relatively successful application cases in specific fields. However, the static operating current of these two types of PMIC devices is still high, and they have limitations in application sites with low environmental energy density or limited space. The static operating current of the LTC3588 series at 25 degrees Celsius is 700nA. Considering the impact of temperature rise and the consumption of the internal full-bridge circuit and protection circuit, when the operating temperature reaches the industrial requirement range of 85 degrees Celsius, its static current will rise sharply, reducing its sensitivity and efficiency, and limiting its application. The static operating current of MB39C811 reaches 775nA at 25 degrees Celsius. Combined with the leakage current of the two internal full-bridge circuits, when the operating temperature reaches the industrial requirement of 85 degrees Celsius, its static operating current will also rise sharply, restricting its application in the actual engineering field. This model was announced as not recommended for new designs in 2018. In many actual engineering applications, operating temperatures far exceeding 25 degrees Celsius, or even close to 85 degrees Celsius, are often encountered, such as the internal environment of the high-voltage switchgear in the distribution room.

[0006] In the collection and conversion of some different forms of environmental energy, the output power is very small, the output current is extremely weak, but the output voltage is relatively high. For example, in the environmental vibration energy collection based on piezoelectric conversion and the alternating electric field energy collection based on electric field induction, the technology is very mature, the output voltage of the conversion is very high, but the output current is very weak. Although environmental vibration energy and environmental alternating electric field energy are ubiquitous, it is difficult to collect them and realize large-scale applications in engineering sense. It is both important and urgent to collect the extremely weak conversion output current very sensitively and efficiently to achieve the requirements of "battery-free" engineering applications such as sensors. Summary of the invention

[0007] The above technical problems of the present invention are mainly solved by the following technical solutions:

[0008] A fully autonomous ultra-low starting current energy harvesting intermittent power supply, characterized by comprising:

[0009] Transducer: used to convert different forms of energy into alternating current;

[0010] Rectification component: used to convert the AC power output by the transducer into DC power;

[0011] Energy storage component: used to store the DC power output by the energy rectifier component and to supply power to the protection control component and the load;

[0012] Protection and control components: perform detection and control the output power of the energy storage components to the load according to the set strategy.

[0013] In the above-mentioned fully autonomous ultra-low starting current energy harvesting intermittent power supply, the setting strategy includes the interval time, the output duration and the amount of each output energy.

[0014] In the above-mentioned fully autonomous ultra-low starting current energy collection intermittent power supply, the energy storage component includes two energy storage protection units connected in series, and both ends of the two energy storage protection units are connected to the output of the rectifier component after being connected in series.

[0015] In the above-mentioned fully autonomous ultra-low starting current energy harvesting intermittent power supply, the protection control component includes a control unit connected in parallel to one of the energy storage protection units, and a control conduction module. The control unit monitors the other energy storage protection unit used for load power supply by starting or shutting down the control conduction module.

[0016] In the above-mentioned fully autonomous ultra-low starting current energy harvesting intermittent power supply, the protection control component also includes a measurement and control unit connected in parallel to another energy storage protection unit, and a measurement and control conduction module. The measurement and control unit controls another energy storage protection unit to supply power to the load by starting or shutting down the measurement and control conduction module.

[0017] A circuit topology for realizing a fully autonomous ultra-low starting current energy collection intermittent power supply, characterized in that it includes a conductor arranged in an alternating electric field for inducing current, the output end of the conductor is linked to the input end of a rectifier unit, an energy storage capacitor C1 and an energy storage capacitor C2 are connected in series and then connected to the output end of the rectifier unit; a measurement and control unit connected to the output end of the energy storage capacitor C1 controls the energy storage capacitor C1 to provide a given electric energy to a load through a transistor TS2; and a control unit connected in parallel to the output end of the energy storage capacitor C2 controls the measurement and control unit through the transistor TS2 to perform timed detection on the energy storage capacitor C1.

[0018] In the above circuit topology, it is characterized in that the output end of the energy storage capacitor C2 is also connected to a protection diode D2.

[0019] A circuit topology for realizing a fully autonomous ultra-low starting current energy harvesting intermittent power supply, characterized in that it includes a conductor arranged in an alternating electric field for inducing current, the output end of the conductor is linked to the input end of a rectifier unit, energy storage capacitors C3 and C4 are connected in series and then connected to the output end of the rectifier unit; a control unit connected to the output end of the energy storage capacitor C4 controls the energy storage capacitor C3 through a transistor TS to provide a given electric energy to a load.

[0020] In the above circuit topology, it is characterized in that the output end of the energy storage capacitor C3 and the output end of the energy storage capacitor C4 are connected to a protection diode DS1 and a protection diode D1 respectively.

[0021] A circuit topology control method, characterized by comprising:

[0022] Rectification and power supply steps: two conductors B1 and B2 separated in the alternating electric field space are led to the rectifier unit, which converts the current and charges the capacitors C1 and C2, and supplies power to the control unit;

[0023] Measurement and control steps: The diode D2 connected to both ends of C2 protects the connected components and makes them work within the appropriate voltage range. The control unit controls the transistor TS1 at its output end according to the pre-set settings;

[0024] Output electric energy steps: Under the control of the control unit, the measurement and control unit detects the capacitor C1. When the energy storage state on the capacitor C1 meets the set requirements, the measurement and control unit controls TS2 to open and conduct, and the capacitor C1 provides the given energy to the load via TS1 and TS2.

[0025] A circuit topology control method, characterized by comprising:

[0026] Rectification and charging step: two conductors B1 and B2 separated in the alternating electric field space are led to the rectification unit, which, after transformation, charges capacitors C3 and C4 and supplies power to the control unit;

[0027] Output electric energy step: the control unit controls TS to open and conduct, and the capacitor C3 provides a given energy to the load via TS.

[0028] Therefore, the present invention has the following advantages: 1. The present invention has high sensitivity and can significantly expand the application range of "battery-free" sensors; 2. The present invention has a simple structure, a small size, strong adaptability, and high reliability; 3. The present invention requires fewer components and greatly reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Attached Figure 1 It is a functional schematic diagram of the present invention.

[0030] Attached Figure 2 It is the overall structural diagram of the present invention.

[0031] Attached Figure 3 This is the first embodiment of the present invention (quantitative energy supply type).

[0032] Attached Figure 4 This is the second embodiment of the present invention (timed energy supply type).

[0033] Attached Figure 5 Yes Figure 3 Schematic diagram of the specific circuit model structure.

[0034] Attached Figure 6 Yes Figure 4 Schematic diagram of the specific circuit model structure. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0036] Attached Figure 1 The figure is a functional diagram. The environmental energy acts on the transducer through electromechanical coupling, causing the transducer to output the corresponding electrical quantity, converting different forms of energy into electrical energy; the rectifier unit converts the alternating form of electrical energy into direct current form of electrical energy; the "energy storage protection control" link performs detection and controls the output energy according to the set strategy, and its interval time, output duration and the amount of energy output each time are determined by the preset strategy.

[0037] Attached Figure 2 The figure is the overall structure diagram. Environmental energy acts on the "energy conversion" link through electromechanical coupling, stimulating a specific transducer to output alternating electrical quantity, charging and supplying "energy storage protection 1", "energy storage protection 2" and the control unit through the rectifier unit. The control unit controls the timing measurement to the measurement and control unit through TS1. When the set conditions are met, the measurement and control unit intermittently provides energy to the "load" through TS2. The amount of energy provided is programmed and determined in the measurement and control unit according to the load requirements.

[0038] The two conductors B1 and B2 separated in the alternating electric field space are led to the rectifier unit, which, after transformation, charges capacitors C1 and C2 and supplies power to the control unit; the diode D2 connected to both ends of C2 protects the connected components and makes them work in an appropriate voltage range. The control unit controls the transistor TS1 at its output end according to the pre-set settings; the measurement and control unit detects the capacitor C1 under the control of the control unit. When the energy storage state on the capacitor C1 meets the set requirements, the measurement and control unit controls TS2 to open and conduct, and the capacitor C1 provides the given energy to the "load" through TS1 and TS2, so that the "load" can achieve the set function and complete the specified work task.

[0039] In this embodiment, the threshold limit value refers to the set value when the measurement and control module monitors the changes of the monitored object and determines whether it has reached a predetermined state. Specifically, in this embodiment, it refers to setting two thresholds of the main energy storage capacitor C1, namely the upper energy storage threshold and the lower energy storage threshold. The measurement and control module monitors the energy storage situation on the main energy storage capacitor through the control module. When the charging reaches the upper energy storage threshold, the measurement and control module controls to turn on the power supply to the load; as the power supply continues, when the main energy storage capacitor C1 discharges to the lower energy storage threshold, the measurement and control module controls to turn off the power supply to the load, and so on.

[0040] In this embodiment, for specific practical applications, the selection and setting of "energy storage capacitor", "control unit" and "measurement and control unit" are involved: the "energy storage capacitor" can choose its capacity, which mainly depends on the energy consumption in the target application. If the energy consumption is high, a capacitor with a larger capacity needs to be selected; otherwise, a smaller capacitor is selected. The "control unit" is mainly used to control the "measurement and control unit". By setting the "open time" of the "control unit" and the "time interval" between two openings, the "measurement and control unit" is not continuously measured and controlled, so as to minimize the self-consumption of the circuit. The circuit structure involved in this implementation is a very important innovation in energy harvesting applications. Under the control of the control unit, the measurement and control unit detects the energy storage state of the main energy storage capacitor C1 and jointly with TS2 determines whether to supply power to the load.

[0041] The conductors B1 and B2 described in this example are conductors of any shape that meet the requirements. The conductors B1 and B2 can be conductors that are both suspended in the electric field; or they can be conductors that connect the original charged body in the environment to one end in the target application, and the other end is suspended. The two conductors B1 and B2 induce current in the alternating electric field through subsequent links such as "rectification" to achieve energy extraction in the electric field; the rectification unit is composed of a diode or a transistor to form a "bridge rectifier circuit"; the "bridge rectifier circuit" must meet the extremely small leakage current characteristics and maintain good overall thermal stability to meet the requirements of the application object and application site.

[0042] The capacitors used should be ultra-low leakage current capacitors and have shock, vibration and heat resistance characteristics.

[0043] The protection diodes used are low leakage current Zener diodes or voltage regulating diodes.

[0044] The control unit is composed of a dedicated IC or an ultra-low power consumption oscillation circuit; the dedicated IC is an ultra-low power consumption programmable timer; the timer or oscillation circuit can drive the transistor TS1 according to the set time interval and duration.

[0045] The transistor TS1 is an ultra-low leakage current junction field effect transistor (NJFET), which can be used alone or in combination as needed.

[0046] The measurement and control unit is a low-power voltage detection circuit. The voltage detection circuit is composed of a voltage comparator or an operational amplifier and its peripheral components. The measurement and control unit can set the "threshold" and "hysteresis" to decide whether to supply power to the "load" or cut off power when the conditions are met.

[0047] The TS2 used in this example is a low leakage current, ultra-low on-resistance transistor.

[0048] All circuit structures and components involved in this example are installed on a PCB and integrated with the application system on a PCB. The circuit core is placed in a shell with magnetic and electrical double shielding and potting treatment is performed to achieve the effects of electrical isolation, magnetic isolation, shock isolation, dust and moisture resistance to enhance device reliability. The electrical shielding shell that plays a shielding role is also one end of the conductor.

[0049] Embodiment 2:

[0050] Attached Figure 4 This is Example 2. Example 2 is another implementation of the present invention. Like Example 1, it is an inductive energy harvesting device used in an alternating electric field. Different from Example 1, in this embodiment, protection measures are provided at both ends of C3, and the measurement and control unit is omitted. A control unit supplies the energy required for the "load" to perform its task at a set time interval and a set duration.

[0051] This embodiment is used in applications with relatively lower energy consumption. This embodiment is significantly simplified compared to the first embodiment: a protection diode DS1 is connected across the capacitor C3, and the DS1 is a low leakage current voltage regulator diode, a voltage regulating diode, or a combination thereof. The second embodiment omits the measurement and control unit and the controlled transistor TS2. The rest of the second embodiment is similar to the first embodiment in terms of structure, component arrangement, and performance and process requirements.

[0052] It should be noted that in the above two embodiments, when the components and circuit structures are appropriately selected, very good results can be achieved. Under the idea of ​​"overall structure diagram", it can generally be applied to (but not limited to) the collection of environmental vibration energy based on the piezoelectric conversion principle and the collection and utilization of environmental alternating electric field energy based on the electric field induction principle. After repeated tests, in Example 1 and Example 2, when at room temperature, the minimum starting current of the present invention can be as low as 30nA. Considering that the part sensitive to the operating temperature increases with the temperature rise, the total static working current, that is, the starting current, will still increase. According to the semiconductor PN junction theory and engineering processing experience, that is, the leakage current increases by 1 times for every 10 degrees Celsius increase in temperature, when the operating temperature reaches 85 degrees Celsius, even considering that the leakage current increases with the temperature rise, the static working current is about 100nA. This will significantly reduce the volume of the "power supply", greatly expand the scope of application, and can integrate the "power supply" part and the sensor part into one, making the entire application system more compact, significantly improving the environmental adaptability of the sensor system, and thus expanding the scope of application of the sensor system.

[0053] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A circuit topology of a fully autonomous ultra-low starting current energy harvesting intermittent power supply, characterized in that: It includes a conductor set in an alternating electric field for inducing current, the output end of the conductor is connected to the input end of the rectifier unit, the energy storage capacitor C1 and the energy storage capacitor C2 are connected in series and then connected to the output end of the rectifier unit; the output end of the energy storage capacitor C1 is connected to one end of the measurement and control unit, and the measurement and control unit controls the energy storage capacitor C1 through the transistor TS2 to provide a given electric energy to the load; a control unit is connected in parallel to the output end of the energy storage capacitor C2, and the control unit controls the measurement and control unit through the transistor TS1 to perform timed detection on the energy storage capacitor C1; The control end of transistor TS1 is connected to the control unit, the first end of transistor TS1 is connected to the connection point between energy storage capacitor C1 and energy storage capacitor C2, the second end of transistor TS1 is connected to the first end of transistor TS2 and the other end of the measurement and control unit, the second end of transistor TS2 is connected to the load, and the control end of transistor TS2 is connected to the measurement and control unit; The output end of the energy storage capacitor C2 is also connected to a protection diode D2; The control method of the circuit topology includes: Rectification and power supply steps: two conductors B1 and B2 separated in the alternating electric field space are led to the rectifier unit, which converts the current and charges the capacitors C1 and C2, and supplies power to the control unit; Measurement and control steps: The diode D2 connected to both ends of C2 protects the connected components and makes them work within the appropriate voltage range. The control unit controls the transistor TS1 at its output end according to the preset settings; Output electric energy steps: Under the control of the control unit, the measurement and control unit detects the capacitor C1. When the energy storage state on the capacitor C1 meets the set requirements, the measurement and control unit controls TS2 to open and conduct, and the capacitor C1 provides the given energy to the load via TS1 and TS2.

2. A fully autonomous ultra-low starting current energy harvesting intermittent power supply, characterized in that: The circuit topology as claimed in claim 1 is implemented as follows: Transducer: used to convert different forms of energy into alternating current; Rectification component: used to convert the AC power output by the transducer into DC power; Energy storage component: used to store the DC power output by the energy rectifier component and to supply power to the protection control component and the load; Protection and control components: perform detection and control the output power of the energy storage components to the load according to the set strategy.

3. A fully autonomous ultra-low starting current energy harvesting intermittent power supply according to claim 2, characterized in that: The setting strategy includes the interval time, output duration and the amount of energy for each output.

4. A fully autonomous ultra-low starting current energy harvesting intermittent power supply according to claim 2, characterized in that: The energy storage component includes two energy storage protection units connected in series, and both ends of the two energy storage protection units are connected to the output of the rectification component after being connected in series.

5. A fully autonomous ultra-low starting current energy harvesting intermittent power supply according to claim 4, characterized in that: The protection control component includes a control unit connected in parallel to one of the energy storage protection units and a control conduction module. The control unit monitors another energy storage protection unit used for powering the load by starting or shutting down the control conduction module.

6. A fully autonomous ultra-low starting current energy harvesting intermittent power supply according to claim 5, characterized in that: The protection and control component also includes a measurement and control unit connected in parallel to another energy storage protection unit, and a measurement and control conduction module. The measurement and control unit controls another energy storage protection unit to supply power to the load by starting or shutting down the measurement and control conduction module.

Images