CN117811410A - Micro-energy collection system - Google Patents

Abstract

The invention relates to a micro-energy collecting system, which comprises a current sampling module, a charge overturning module, a voltage doubling rectifying module, a voltage stabilizing module and a voltage sampling module which are arranged between an energy collector and a load applied by a terminal and are sequentially connected; the energy collection system also comprises a control module, wherein the control module collects the output current value of the current sampling module and transmits a switch control signal to the charge overturning module, and the control module collects the output voltage and current of the voltage sampling module and transmits a PWM signal to the voltage stabilizing module. Compared with the prior art, the invention can realize the charge extraction of the internal capacitor, low-voltage amplification, self-adaptive high-precision current overturn tracking and PID control voltage stabilization output, and can collect micro energy and amplify and make up the defect of unstable output voltage by using feedback control.

Description

Micro-energy collection system

Technical Field

The invention belongs to the technical field of energy collection, and particularly relates to a micro energy collection system.

Background

With the continued development of the energy harvesting field, more and more collector circuits are being produced, which are widely used in the field of large generator devices, but less for the micro energy harvesting field. The sensor industry in today's society is evolving towards miniaturization, portability, and their power consumption is also reduced to the range of tens to hundreds of microwatts. How to collect this portion of the energy generated by the micro-energy harvester and apply it to electrical energy storage and power sensors is a popular topic today.

The micro-energy harvesting circuits currently known are mainly bridge rectifier output circuits (FBR), synchronous charge extraction circuits (SECE), conventional switch flip circuits (SSHI), and capacitor flip circuits (SSHC), but all have certain limitations. FBR rectification is limited by low charge extraction efficiency, low output voltage and inability to provide stable voltage output, pulsed direct current is difficult to stably power sensors and batteries; the SECE circuit needs to pass through circuits such as a front-end rectifier diode and the like, and the back-end charge extraction rate is high and the consumption is high; SSHC and general SSHI circuits require complex logic gate control circuits, which require a large number of switching transistors and cold starts, consume large amounts, output voltage instability, and have low tracking accuracy. In addition, most research models are limited to inorganic materials with better piezoelectric performance, and the energy collection aspect of the skin-friendly organic flexible material is more blank. The organic flexible material energy collector has good skin-friendly performance, but the characteristics of poor piezoelectric property and unstable output frequency limit the practical application of the organic flexible material energy collector in the field of medical instruments. If progress is made in this respect, great breakthroughs will be made in the field of medical devices such as artificial hearts, cardiac pacemakers, etc. for supplying power.

Accordingly, there is a need to develop energy harvesting systems that can be applied to organic flexible materials.

Disclosure of Invention

The invention aims to provide a micro-energy collecting system aiming at the defects that the existing organic flexible material energy collector is poor in piezoelectric property, cannot effectively collect micro-energy and is unstable in output frequency.

The aim of the invention can be achieved by the following technical scheme:

the micro-energy collecting system comprises a current sampling module, a charge overturning module, a voltage doubling rectifying module, a voltage stabilizing module and a voltage sampling module which are sequentially arranged between an energy collector and a load applied by a terminal;

the energy collection system also comprises a control module, wherein the control module collects the output current value of the current sampling module and transmits a switch control signal to the charge overturning module, and the control module collects the output voltage and current of the voltage sampling module and transmits a PWM signal to the voltage stabilizing module.

Further, the control module collects current commutation information through the current sampling module and outputs control signals to the charge overturning module, the charge overturning module outputs overturned voltage to enter the voltage doubling rectifying module, the voltage doubling rectifying module outputs amplified and rectified voltage to enter the voltage stabilizing module, the voltage stabilizing module adjusts output voltage to work voltages required by different loads, and two ends of the voltage stabilizing module are connected with the positive electrode and the negative electrode of the load.

Further, the energy collector is an organic flexible energy collector, preferably an energy collector made of PVDF organic material.

Further, the charge flipping module includes an SSHI (parallel switched inductor circuit) loop for flipping the internal charge of the energy collector, the SSHI loop being connected to and feedback-regulated by a control module that performs switching control on the front-end SSHI, the SSHI loop and the control module forming an automatic parallel switched charge flipping module (a-SSHI).

Further, the voltage doubling rectifying module comprises four energy storage capacitors and four diodes for controlling the energy storage direction, and the output voltage is 4 times of the input voltage.

Further, the capacitance of the energy storage capacitor is 100 mu F.

Further, the voltage stabilizing module comprises a low-pass filter and a control switch, and the control switch is controlled by a PWM signal.

Further, the voltage sampling module comprises a voltage transformer and a proportional resistor, and is used for converting the output voltage of the voltage stabilizing module into a voltage acceptable by the control module, and the voltage is preferably not more than 3V.

Further, the current sampling module comprises a current transformer circuit with an amplifying function.

Further, the control module is preferably a low-power-consumption singlechip, and PID control algorithm processing is performed at the output end of the control module.

Further, the load of the terminal application comprises one or more of a singlechip, a timer or a sensor.

The invention also provides application of the micro energy collection system in the field of energy collection of organic flexible materials.

Further, the micro energy collection system is capable of collecting micro energy of the organic flexible material and powering the sensor for the medical device.

Compared with the prior art, the invention has the following beneficial effects:

(1) The invention uses a charge overturning module for overturning the internal charge of the organic flexible material collector, the rear end of the charge overturning module is connected with a voltage doubling rectifying module for piezoelectric performance amplification, then the voltage stabilizing module is connected with the voltage stabilizing module for converting the pulsating direct current into stable direct current, the voltage and the current of the output end are collected for data processing, and the voltage and the current are led into a control module and controlled and regulated by a PID algorithm to output PWM wave duty ratio so as to achieve the purpose of feedback regulation of the output voltage. The invention can realize the charge extraction of the internal capacitor, low-voltage amplification, self-adaptive high-precision current overturn tracking and PID control voltage stabilizing output, and can collect micro energy and amplify, and simultaneously make up the defect of unstable output voltage by using feedback control, thereby finally realizing the purposes of collecting micro energy and amplifying and simultaneously controlling stable output voltage.

(2) The charge overturning module has the characteristics of high charge extraction rate, good voltage overturning efficiency and small charge loss, and can keep high-precision and stable tracking of current commutation points in an environment with changeable frequency amplitude.

(3) According to the invention, the rectification voltage-stabilizing module and the PID feedback regulation algorithm are introduced, so that the voltage can be amplified according to the characteristic of poor piezoelectric performance of the organic material, and the application terminals such as sensors with different specifications can be stably powered, so that the method has good practicability.

Drawings

Fig. 1 is a block flow diagram of the system of the present invention.

Fig. 2 is a control flow diagram of the control module of the present invention.

Fig. 3 is a simplified schematic circuit diagram of the present invention.

FIG. 4 is a schematic diagram of a circuit protein of the present invention.

FIG. 5 is a graph of the result of a protease simulation of the charge flipping module of the present invention.

Fig. 6 is a diagram of inversion waveform parameters (a) and simulation results versus (b) of the charge inversion module of the present invention.

FIG. 7 is a graph showing the comparison of the simulation results of the output voltages of the voltage stabilizing module according to the present invention.

Fig. 8 is a schematic diagram of the output voltage simulation of the voltage regulator module of the present invention.

Detailed Description

The invention will now be described in detail with reference to the drawings and specific examples. The present embodiment is implemented on the premise of the technical scheme of the present invention, and a detailed implementation manner and a specific operation process are given, but the protection scope of the present invention is not limited to the following examples.

The hardware circuit of the following embodiment is built in a protein platform and simulated, the result is displayed by oscillograph waveforms, and the software is programmed and developed by Keil 5.

Example 1:

a micro-energy collection system, as shown in figure 1, comprises a current sampling module, a charge overturning module, a voltage doubling rectifying module, a voltage stabilizing module and a voltage sampling module which are arranged between an energy collector and a load applied by a terminal and are sequentially connected. The energy collection system also comprises a control module, wherein the control module collects the output current value of the current sampling module and transmits a switch control signal to the charge overturning module, and the control module collects the output voltage and current of the voltage sampling module and transmits a PWM signal to the voltage stabilizing module.

The energy collector in this embodiment is an organic flexible energy collector, i.e. an energy collector based on an organic flexible material. The charge overturning module comprises an SSHI loop for overturning the internal charge of the energy collector, the SSHI loop is connected with the control module and is subjected to feedback regulation by the control module, the control module carries out switch control on the front-end SSHI, and the SSHI loop and the control module form an automatic parallel switch charge overturning module. The voltage doubling rectifying module comprises four energy storage capacitors and four diodes for controlling the energy storage direction, and the output voltage is 4 times of the input voltage. The voltage stabilizing module comprises a low-pass filter and a control switch, and the control switch is controlled by a PWM signal. The voltage sampling module comprises a voltage transformer and a proportional resistor and is used for converting the output voltage of the voltage stabilizing module into voltage acceptable by the control module. The current sampling module is a current transformer circuit with an amplifying function. The control module is a singlechip with low power consumption, and PID control algorithm processing is performed at the output end of the control module. The load of the terminal application comprises one or more of a singlechip, a timer or a sensor.

Example 2:

the embodiment provides a micro-energy collection system, which comprises an A-SSHI charge overturning module, a QVR rectifier module, a boost voltage stabilizing module, a voltage sampling module, a current sampling module and a control module.

The A-SSHI (AUTO-SSHI) module consists of a first inductor L1, a first capacitor C1, a first resistor R1, an inner capacitor C2, an NPN tube Q1, a PNP tube Q2, a first diode D1, a second diode D2 and a second inductor L2, wherein the first inductor L1, the first capacitor C1 and the first resistor R1 are connected end to form an organic collector analog circuit; the C2 is an internal capacitor connected in parallel with two ends of the transformer TR1, the Q1 and Q2 are connected in parallel, the emitter of the Q1 is connected with the negative end of the D1, the positive end of the D2 is connected with the collector of the Q2 and is commonly connected with the L2, the phase-change inductance is L2, the Q1 and Q2 are 2N2222BJT tubes, and the A-SSHI is conducted; the singlechip O1 and O2 are used as control signals and connected with two pins Q1 and Q2, when an alternating current signal generator generates 30Hz and 10Vpp signals of an organic energy collector, L1, C1 and R1 form an analog acquisition material to generate corresponding output waveforms and transmit the corresponding output waveforms to an A-SSHI circuit, the output waveforms are acquired at the front end through a current sampling circuit, when current Ip is output by a negative-change timing singlechip, a pulse signal SN with the pulse width of 99.9% enters the PNP tube high level of Q2 for continuous period to perform charge inversion of an inner capacitor C2, the charge generated by a collector does not need to be consumed again after current commutation, reverse neutralization is performed on the inner capacitor, when the current Ip is changed from positive to negative, other steps of the pulse width of 0.1% control signal output by the singlechip are the same, finally, the self-adaption high-precision tracking of the time-varying collector zero-crossing current signal is realized, and the high-efficiency extraction of the charge of the inner capacitor is realized.

The working principle of the A-SSHI module is as follows: when the alternating current signal generator generates 30Hz and 10Vpp signals of an organic energy collector, L1, C1 and R1 form an analog acquisition material to generate corresponding output waveforms, the corresponding output waveforms are transmitted to an A-SSHI circuit, output wave information is acquired at the front end through a current sampling circuit, when current Ip is output from negative change timing to pulse width 99.9% pulse signal SN, the high level of a PNP tube of Q2 enters for one period to carry out charge inversion of an inner capacitor C2, after current commutation, the charge is not required to be consumed again in the inner capacitor for carrying out reverse compensation, when current Ip is changed from positive to negative, otherwise, the rest steps of a single chip microcomputer output pulse width 0.1% control signal are the same, finally self-adaptive high-precision tracking time-varying and unstable collector zero-crossing current signals are realized, and the inner capacitor charge is extracted efficiently.

The A-SSHI module is controlled by the singlechip to flow as shown in figure 2, and the current at the two ends of the energy collector is collected by the current sampling module at the front end and then transmitted to the singlechip for tracking calculation of positive and negative crossing points.

The configuration position of the A-SSHI module in the circuit system is shown in a simplified schematic diagram of fig. 3, the front-end organic collector generates approximate alternating current through vibration and then inputs the approximate alternating current into the two ends of the A-SSHI module, the charge generated by the collector charges an inner capacitor firstly in a first period and then charges a later-stage capacitor, when the generated alternating current crosses zero, a switch Q is closed, the inner capacitor and an inductor form an LC oscillating circuit, the charge of the inner capacitor is extracted into the inductor and then is converted, and the charge overturning collector of the inner capacitor does not need to charge the inner capacitor any more after the next period starts, so that the utilization rate of the charge is greatly improved; secondly, the SSHI switching technology used by the current research institute is limited to a logic gate control circuit, a large amount of complex logic control and cold start are often needed, the tracking effect is poor, the problem is also applicable to a passive self-adaptive switching circuit, and therefore, the use of a low-power-consumption singlechip as detection and control logic ensures that the circuit can accurately track the current zero crossing time under complex frequency, and can provide feedback regulation for a later-stage voltage stabilizing circuit, so that the circuit is applicable to sensors with different power supply voltages.

The output effect of the A-SSHI module is shown in fig. 5 and 6, and the voltage output results of two ends of the capacitor Cp in the collector are shown in fig. 5, so that the circuit output is converted into an approximate square wave signal from an original alternating current sinusoidal signal under the action of the A-SSHI module, the efficiency of charge extraction is greatly improved, compared with the sinusoidal signal, the charge loss is only at the position of deflection in a small range at the front end, as the interval shown by the broken line in fig. 6 is a charge loss interval, and compared with the FBR, SSHC, SECE circuit, the charge loss of the A-SSHI circuit is minimum. Comparing the flip effect of the a-SSHI module with that shown in fig. 6 (a) and (b), it is obvious that the flip effect of the a-SSHI circuit is better than that of SSHC, the charge loss interval of the a-SSHI circuit is 16.7% less than 27.8% of SSHC, 50% of the FBR circuit is closer to 15.7% of the SECE circuit, but compared with the amplitude of the a-SSHI circuit of 12.8V, the amplitude of the SECE circuit needs to pass through more rectifying components in the LC circuit, so that the amplitude is partially affected by only 10.7V, which is slightly lower than that of the a-SSHI circuit, and the a-SSHI has more advantages in charge extraction efficiency.

The QVR rectifier is composed of a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a third diode D3, a fourth diode D4, a fifth diode D5 and a sixth diode D6, wherein the energy storage capacitance values of the four capacitors are 100 mu F, the C3 is connected with the A-SSHI and then connected with the negative electrode of the D3, and the negative end of the D3 is connected with the positive end of the D4 and the positive end of the C4; c4 is connected with C3, connects the D5 positive end afterwards, and the D5 negative end connects the D6 positive end, and the D5 positive end connects the D6 negative end, and the D6 positive end connects the C6 negative end, and the C6 positive end links to each other with C4 negative end, and when weak low frequency low voltage signal was through charge upset entering QVR circuit, four electric capacities would collect two-way electric charge, and final C4, C6 both ends output voltage is close 4 times former input voltage.

The QVR rectifier works in the following principle: as shown in the simplified circuit diagram of fig. 2, when the weak low-frequency low-voltage signal passes through charge inversion and enters the QVR circuit, the four capacitors collect bidirectional charges, when the loop current is forward, the voltages are stored in the C3 and C5 capacitors, when the loop current is backward, the voltages are stored in the C4 and C6 capacitors, and the output voltages at the two ends of the final C4 and C6 capacitors are overlapped to be 4 times the original input voltage. As shown in fig. 7 and 8, the output effect of the QVR rectifier is that the output voltage without voltage stabilization is a pulsating direct current signal, more clutters cannot supply power to a singlechip, a timer and other sensors, most collector schemes are terminated by simple FBR or SSHC pulsation output, micro voltage is not amplified, and sensors with different starting voltages cannot be supplied with power, so that the conventional collection scheme has poor practicability in the field of weak electric energy collectors, and after the weak voltage is amplified, a QVR module is adopted, a boost voltage stabilizing circuit is introduced into a later stage through a feedback control algorithm, so that the stability of circuit output is further improved.

The boost voltage stabilizing circuit module consists of a seventh capacitor C7, a third inductor L3, a third switch Q3 (model 2N 7008), a seventh diode D7 and an eighth capacitor C8, RV2 is an analog load, the C7 is connected with two ends of QVR rectification in parallel, the positive electrode of the C7 is connected with the negative electrode of the L3 and is connected with the positive electrode of the D7 and the collector of the Q3, the base of the Q3 is connected with the singlechip O3, the emitter of the Q3 is connected with the negative electrode of the C7 and is connected with the negative electrode of the C7 in parallel, and the C8 is connected with two ends of the negative electrode of the D7 and the negative electrode of the C7 in parallel, when QVR outputs pulsating direct current, the singlechip firstly operates O3 according to the minimum duty ratio to output PWM waves, and after passing through the boost voltage stabilizing module, the characteristic values are output to the Q3 through the adjustment of the duty ratio by sampling and PID feedback control algorithm according to preset voltage values of different sensors, so that the purpose of feedback control is achieved, and the pulsating direct current is converted into direct current usable by the sensors. In addition, the cold start of the singlechip is output through the front end QVR and is connected with the AMS1117 for starting, when the singlechip enters an operating state, an output control signal enters a relay to start a boost main loop, the singlechip is ensured to be started before the voltage stabilizing circuit module is started, and redundant charges in the cold start period are stored in the C7 to improve the charge utilization rate.

The boost voltage stabilizing circuit module works according to the following principle: as shown in fig. 2, when QVR outputs pulsating direct current and enters a boost voltage stabilizing module, the singlechip firstly operates O3 according to the minimum duty ratio to output PWM waves, after passing through the boost voltage stabilizing module, the characteristic values are output to Q3 according to preset voltage values of different sensors through the adjustment of the duty ratio through sampling and PID feedback control algorithm to achieve the purpose of feedback control, the pulsating direct current is converted into the direct current which can be used by the sensors, in addition, the cold start of the singlechip is output through the front end QVR and is connected with the AMS1117 to start, when the singlechip enters an operation state, the output control signal enters a relay to start a boost main loop, the boost is ensured to be in an effective working interval, and the charge in the period of time is stored in the C7 to improve the charge utilization rate. The output effect of the boost voltage stabilizing circuit module is shown in fig. 7 and 8, and fig. 8 shows that the pulsating direct current rectified by QVR is more stable compared with the stable direct current output by voltage stabilization, and the non-pulsating component has the condition of being capable of stably supplying energy to the sensor. Fig. 8 shows that the duty ratio of the PWM wave of the singlechip is adjusted from 50% to 32% under the load condition, and the voltage of the output end is reduced from 8.7V to 5.2V, which indicates that the module can accurately control the output voltage, and meets the requirements of rated voltages of different sensors.

The voltage sampling module is composed of a voltage transformer and a proportional resistor as shown in fig. 3 and 4, and is used for converting output voltage into voltage which is less than or equal to 3V and can be accepted by the singlechip.

The current sampling module is composed of current transformer circuits with amplifying function as shown in fig. 3 and 4.

The control flow of the control module is shown in fig. 1, which can be any low-power consumption singlechip and controller, and carries out zero crossing tracking processing at the input end and PID control algorithm processing at the output end. The current is sampled through the input end, and the current is amplified by a fixed multiple and then is sampled through the singlechip, and pulse signals are output according to the control thought of FIG. 2 to control the on-off of Q1 and Q2, so that the overturning effect is achieved. The same control thought according to fig. 2 is fed back to the voltage value of the singlechip through the voltage sampling circuit, and the characteristic value output through the PID control algorithm is used as the PWM duty ratio control basis.

The previous description of the embodiments is provided to facilitate a person of ordinary skill in the art in order to make and use the present invention. It will be apparent to those skilled in the art that various modifications can be readily made to these embodiments and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above-described embodiments, and those skilled in the art, based on the present disclosure, should make improvements and modifications without departing from the scope of the present invention.

Claims (10)

1. The micro-energy collecting system is characterized by comprising a current sampling module, a charge overturning module, a voltage doubling rectifying module, a voltage stabilizing module and a voltage sampling module which are sequentially arranged between an energy collector and a load applied by a terminal;

the energy collection system further comprises a control module, wherein the control module collects an output current value of the current sampling module and transmits a switch control signal to the charge overturning module, and the control module collects an output voltage of the voltage sampling module and transmits a PWM signal to the voltage stabilizing module.

2. The micro energy harvesting system of claim 1, wherein the energy harvester is an organic flexible energy harvester.

3. The micro energy harvesting system of claim 1, wherein the charge flipping module comprises an SSHI loop for flipping the charge within the energy harvester, the SSHI loop being coupled to and feedback regulated by the control module.

4. The micro energy harvesting system of claim 1, wherein the voltage doubler rectifier module comprises four storage capacitors and four diodes controlling the direction of the stored energy, the output voltage being 4 times the input voltage.

5. The micro energy harvesting system of claim 1, wherein the voltage stabilizing module comprises a low pass filter and a control switch, the control switch being controlled by a PWM signal.

6. The micro energy harvesting system of claim 1, wherein the voltage sampling module comprises a voltage transformer and a proportional resistor for converting the output voltage of the voltage regulator module into a voltage acceptable to the control module.

7. The micro energy harvesting system of claim 1, wherein the current sampling module comprises a current transformer circuit with amplification.

8. A micro energy harvesting system according to claim 1, wherein the control module performs PID control algorithm processing at its output.

9. The micro energy harvesting system of claim 1, wherein the end-use load comprises one or more of a single-chip microcomputer, a timer, or a sensor.

10. Use of a micro energy harvesting system according to any one of claims 1-9 in the field of energy harvesting of organic flexible materials.