CN115051598A - Voltage overturning and charge extracting circuit for piezoelectric energy collection - Google Patents
Voltage overturning and charge extracting circuit for piezoelectric energy collection Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
- H02N2/00—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction
- H02N2/18—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing electrical output from mechanical input, e.g. generators
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/06—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using resistors or capacitors, e.g. potential divider
- H02M3/07—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using resistors or capacitors, e.g. potential divider using capacitors charged and discharged alternately by semiconductor devices with control electrode, e.g. charge pumps
- H02M3/071—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using resistors or capacitors, e.g. potential divider using capacitors charged and discharged alternately by semiconductor devices with control electrode, e.g. charge pumps adapted to generate a negative voltage output from a positive voltage source
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Abstract
The invention discloses a voltage overturning and charge extracting circuit for piezoelectric energy collection, which comprises a piezoelectric element, a voltage overturning and charge extracting circuit, an inductance follow current circuit and an energy storage circuit, wherein the output end of the piezoelectric element, the voltage overturning and charge extracting circuit and the inductance follow current circuit is connected with the energy storage circuit after being sequentially connected. The voltage overturning and charge extracting circuit comprises a first synchronous switch and an inductor which are connected in series, the inductor follow current circuit comprises a second synchronous switch, an inductor and a follow current diode which are connected in sequence, and the energy storage circuit comprises a filter capacitor and a load which are connected in parallel. The invention introduces the electronic circuit breaker with low power consumption to realize the self-powered voltage turnover and charge extraction circuit, avoids the use of the traditional rectifier bridge, and reduces the power consumption of the circuit, and the electronic circuit breaker comprises the peak value detector, the comparator and the electronic switch which are sequentially connected. In addition, the invention has the advantages of enhanced power collection capability and no load dependence, and realizes self power supply.
Description
Technical Field
The invention belongs to the field of piezoelectric energy collection, and particularly relates to a voltage overturning and charge extracting circuit for piezoelectric energy collection.
Background
The continuous power supply of Wireless Sensor Network (WSN) nodes is a key problem of internet of things (IoT) technology, and the conventional chemical battery has many disadvantages in practical use, such as large volume, need to be replaced regularly, and easy environmental pollution, which limits the development of wireless sensor networks. Collecting vibration energy in the environment in a piezoelectric energy collection mode is a promising solution, and has the advantages of high energy density, easiness in miniaturization, cleanness, environmental friendliness and the like. The design of the interface circuit is the key to the piezoelectric energy harvesting technology, and the performance of the interface circuit directly determines how much energy can be provided by the piezoelectric energy harvesting device to the load. The Standard Energy Harvesting (SEH) circuit is a simple and stable interface circuit, but has the problem of impedance matching, the phase difference between the output voltage and the current exists, and the power consumption of the conventional bridge rectifier is too large, so that the efficiency of the SEH circuit is extremely low, the output power of the SEH circuit is highly dependent on the load impedance, and the working bandwidth is very small. A parallel synchronous switch inductor (P-SSHI) circuit is optimized for an SEH circuit, and the phase relation between output current and output voltage of a piezoelectric energy collecting device can be adjusted by introducing a nonlinear technology, so that the output power is improved, but the output power of the P-SSHI still highly depends on a load. The synchronous charge extraction (SECE) circuit consists of a rectifier bridge and a Buck-Boost circuit, can periodically extract all charges accumulated on the piezoelectric element and transfer corresponding electric energy to a circuit load through an inductor, and the inductor plays a role in load isolation, eliminates the requirement of impedance matching and simultaneously improves the output power. In fact, in order to realize the functions of the P-SSHI and SECE circuits, a large number of auxiliary devices such as flyback transformers, displacement sensors, DSP controllers, etc. are needed, and the power consumption of these auxiliary devices is even higher than the collectable power, so that the circuits cannot realize self-power, which goes against the original purpose of the piezoelectric energy collecting device to supply power to the wireless sensor network node.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, and provides a voltage overturning and charge extracting circuit for piezoelectric energy collection aiming at the problems of overlarge power consumption, excessive auxiliary equipment of a P-SSHI circuit and a SECE circuit, incapability of realizing self power supply and the like of a traditional bridge rectifier (SEH) circuit.
The purpose of the invention is realized by the following technical scheme.
The invention discloses a voltage overturning and charge extracting circuit for piezoelectric energy collection, which comprises a piezoelectric element equivalent circuit, a voltage overturning and charge extracting circuit, an inductance follow current circuit and an energy storage circuit. The piezoelectric element equivalent circuit, the voltage overturning and charge extracting circuit and the inductance follow current circuit are sequentially connected, and the output end of the piezoelectric element equivalent circuit is connected with the energy storage circuit.
The equivalent circuit of the piezoelectric element comprises an internal capacitor Cp of the piezoelectric element and a current source ip connected with the internal capacitor in parallel, wherein the current source ip provides alternating current proportional to the vibration magnitude of the piezoelectric element.
The voltage flipping and charge extraction circuit includes a first synchronous switch S1 and an inductor L connected in series. The positive output voltage Vp end of the piezoelectric element equivalent circuit is connected with the input end of an inductor L, the output end of the inductor L is connected with the input end of a first synchronous switch S1, and the output end of the first synchronous switch S1 is connected with the negative output voltage Vn end of the piezoelectric element equivalent circuit.
The inductance freewheeling circuit comprises a second synchronous switch S2, an inductance L, a freewheeling diode D and a filter capacitor Cr which are connected in sequence. The input end of the inductor L is simultaneously connected with the positive output voltage Vp end of the piezoelectric element equivalent circuit and the output end of the fly-wheel diode D, and the output end of the inductor L is simultaneously connected with the input ends of the first synchronous switch S1 and the second synchronous switch S2. The input end of the fly-wheel diode D is connected with the positive rectification voltage Vr end of the filter capacitor Cr, and the negative rectification voltage end of the filter capacitor Cr is connected with the output end of the second synchronous switch S2.
The energy storage circuit comprises a filter capacitor Cr and a load resistor RL which are connected in parallel.
The voltage overturning and charge extracting circuit utilizes the parallel resonance of the internal capacitance Cp and the inductance L of the piezoelectric element, and the output voltage of the equivalent circuit of the piezoelectric element is overturned from positive voltage to negative voltage by controlling the conduction time of the first synchronous switch S1 to be 1/2LC resonance period; by controlling the on-time of the first synchronous switch S1 to 1/4LC resonance period, the charge stored on the internal capacitance Cp of the piezoelectric element is transferred to the inductance L and stored as magnetic energy (current).
The inductive freewheeling circuit can transfer the current in the inductor L to the filter capacitor Cr via the freewheeling diode D for storage in the form of a charge (voltage).
The working principle of the voltage reversing and charge extracting circuit for piezoelectric energy collection is as follows:
natural charging phase of positive half cycle: the first synchronous switch S1 and the second synchronous switch S2 are both in an off state, and along with the vibration of the piezoelectric element, the internal capacitance Cp of the piezoelectric element continuously accumulates charges, so that the positive output voltage Vp of the equivalent circuit of the piezoelectric element continuously increases until Vp reaches a moment before a positive peak value, and the stage is ended;
voltage reversal phase of positive half cycle: when the positive output voltage Vp of the piezoelectric equivalent circuit reaches a positive peak, the first synchronous switch S1 is closed, the second synchronous switch S2 is opened, and the inductor L and the internal capacitance Cp of the piezoelectric element form a first LC resonant tank. The first synchronous switch S1 is turned on for a time 1/2LC resonance period, which is much shorter than the mechanical vibration period of the piezoelectric element, so that the charges accumulated in the internal capacitance Cp of the piezoelectric element are transferred to the other end of the piezoelectric element through the inductor L, and at the same time, the output voltage of the equivalent circuit of the piezoelectric element is inverted from a positive voltage to a negative voltage. The stage is finished;
natural charging phase of negative half cycle: the first synchronous switch S1 and the second synchronous switch S2 are both in an off state, and along with the vibration of the piezoelectric element, charges are continuously accumulated on the internal capacitance Cp of the piezoelectric element, so that the negative output voltage Vn of the equivalent circuit of the piezoelectric element is continuously increased until a moment before the Vn reaches a negative peak value, and the stage is ended;
charge extraction phase of negative half cycle: when the negative output voltage Vn of the piezoelectric element equivalent circuit reaches a negative peak, the first synchronous switch S1 is closed, the second synchronous switch S2 is opened, the inductor L and the piezoelectric element internal capacitance Cp form a second LC resonant circuit, the time for which the first synchronous switch S1 is closed is 1/4LC resonant cycles, and the charge accumulated on the piezoelectric element internal capacitance Cp is transferred to the inductor L through the second resonant circuit and stored in the form of magnetic energy (current). This phase ends until the charge on the internal capacitance Cp of the piezoelectric element is completely transferred to the inductance L, i.e. when the current on the inductance L is at a maximum;
inductive freewheeling phase of negative half cycle: when the charge in the internal capacitance Cp of the piezoelectric element is completely transferred to the inductor L, the first sync switch S1 is opened, and at the same time, the second sync switch S2 is closed, and the charge stored in the inductor L is transferred to the filter capacitor Cr through the freewheeling diode D. This phase ends when the current on the inductor L is 0.
The above is all the movements of the piezoelectric element in one complete cycle, and the above operation process is repeated thereafter.
Compared with the traditional bridge rectifier circuit, the technical scheme of the invention has the following beneficial effects:
the circuit topology structure is simple, the power consumption is low, the functions of voltage turnover, charge extraction, inductance follow current and the like are realized under the condition of not using a traditional rectifier bridge, the advantages of enhanced power collection capability, no load dependence and the like are realized, and the key self-power supply problem is solved.
Drawings
FIG. 1 is a block diagram of a voltage inversion and charge extraction circuit according to the present invention;
FIG. 2 is a schematic diagram of a voltage inversion and charge extraction circuit according to the present invention;
FIG. 3 is a schematic diagram of a self-powered voltage flipping and charge extraction circuit implemented based on an electronic circuit breaker according to the present invention;
FIG. 4 is a schematic diagram of voltage and current waveforms corresponding to a self-powered voltage flipping and charge extraction circuit according to the present invention;
FIG. 5 is a schematic diagram of an experimental test of the voltage inversion and charge extraction circuit of the present invention;
FIG. 6 is a comparison plot of collected power for the voltage inversion and charge extraction circuit of the present invention versus the SEH, P-SSHI, and SECE circuits;
reference numerals: the piezoelectric constant current source circuit comprises an ip piezoelectric element equivalent current source, an internal capacitor of a Cp piezoelectric element, an L inductor, an S1 first synchronous switch, an S2 second synchronous switch, a freewheeling diode D, a filter capacitor Cr, a load RL, a C1 first capacitor, a C2 second capacitor, a Q1 first PNP tube, a Q2 first NPN tube, a Q3 second NPN tube and a Q4 second PNP tube.
Detailed Description
The present invention will be described in further detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Examples
As shown in fig. 3, the self-powered voltage flipping and charge extracting circuit implemented based on the electronic circuit breaker includes a piezoelectric element equivalent circuit, a piezoelectric voltage positive half-cycle electronic circuit breaker, a piezoelectric voltage negative half-cycle electronic circuit breaker, and an inductive freewheeling circuit.
The piezoelectric element equivalent circuit comprises a piezoelectric element internal capacitance Cp and a current source ip connected with the piezoelectric element internal capacitance in parallel.
The piezoelectric voltage positive half-cycle electronic circuit breaker comprises a first capacitor C1 of a piezoelectric voltage positive half-cycle peak value detector, a first PNP tube Q1 of a piezoelectric voltage positive half-cycle comparator and a second NPN tube Q3 of a piezoelectric voltage positive half-cycle electronic switch. The input end of the positive half-cycle peak detector C1 is simultaneously connected with the positive output voltage Vp end of the piezoelectric element equivalent circuit, the base of the positive half-cycle comparator Q1 and the collector of the positive half-cycle electronic switch Q3, and the output end of the positive half-cycle peak detector C1 is simultaneously connected with the emitter of the positive half-cycle comparator Q1, the input end of the negative half-cycle peak detector C2 and the emitter of the negative half-cycle comparator Q2. The collector of the positive half-cycle comparator Q1 is connected to the base of a positive half-cycle electronic switch Q3. The emitter of the positive half-cycle electronic switch Q3 is connected to the emitter of the negative half-cycle electronic switch Q4 and the input of the inductor L.
The piezoelectric voltage negative half-cycle electronic circuit breaker comprises a piezoelectric voltage negative half-cycle peak value detector second capacitor C2, a piezoelectric voltage negative half-cycle comparator first NPN tube Q2 and a piezoelectric voltage negative half-cycle electronic switch second PNP tube Q4. The output end of the negative half-cycle peak value detector C2 is simultaneously connected with the negative output voltage Vn end of the piezoelectric element equivalent circuit and the output end of the inductor L, the base of the negative half-cycle comparator Q2 is simultaneously connected with the collector of the negative half-cycle electronic switch Q4 and the positive output voltage Vp end of the piezoelectric element equivalent circuit, the base of the negative half-cycle electronic switch Q4 is connected with the collector of the negative half-cycle comparator Q2, and the collector of the negative half-cycle electronic switch Q4 is connected with the positive output voltage Vp end of the piezoelectric element equivalent circuit.
The inductance follow current circuit comprises an inductance L, a follow current diode D and a filter capacitor Cr, wherein the input end of the follow current diode D is simultaneously connected with the input end of the inductance L, the emitter electrodes of a positive electronic switch Q3 and a negative electronic switch Q4, the output end of the diode D needing follow current is connected with the positive rectification voltage Vr end of the filter capacitor Cr, and the negative rectification voltage end of the filter capacitor Cr and the output end of the inductance L are simultaneously grounded.
As shown in fig. 4, a voltage-current waveform diagram of the voltage inverting and charge extracting circuit is shown, and the operation principle of the embodiment is as follows:
a positive natural charging stage: before the piezoelectric element equivalent current source ip crosses zero from positive to negative, all transistors are turned off, and positive and negative peak detection capacitors C1 and C2 are connected in parallel with the piezoelectric element internal capacitance Cp. Along with the vibration of the piezoelectric element, the alternating current ip positively charges the internal capacitance Cp of the piezoelectric element, the positive output voltage Vp of the piezoelectric element is increased until the Vp reaches the moment before the peak value, and the stage is finished;
and (3) voltage turning stage: when the equivalent current source ip of the piezoelectric element crosses the zero point from positive to negative, the positive output voltage Vp begins to decrease because the deformation of the piezoelectric element changes direction, but because the first PNP transistor Q1 of the positive half-cycle comparator of the piezoelectric voltage has a turn-on threshold voltage, the charge on the first capacitor C1 of the positive peak detector cannot be immediately released, the equivalent circuit output voltage Vp of the piezoelectric element is temporarily unchanged, and when the positive output voltage Vp of the equivalent circuit of the piezoelectric element decreases to be lower than the threshold voltage V of the PNP transistor by one voltage lower than the positive peak detector C1 by the threshold voltage V of the PNP transistor BE When the voltage is applied, the first PNP tube Q1 of the positive comparator is conducted, and the second NPN tube Q3 of the electronic switch in the positive half period of the piezoelectric voltage is also conducted, at this time, the voltage is appliedThe voltage of the electric element is VP-2V BE . At this time, the piezoelectric element internal capacitance Cp, the positive and negative peak detection capacitances C1 and C2, and the inductance L form a first LC resonance circuit: cp → C1 → C2 → L → Cp. After 1/2LC resonance period, the charge stored in the internal capacitor Cp of the piezoelectric element is firstly converted into magnetic energy (current) of the inductor L through the first resonance loop and then converted into voltage with opposite direction to be stored in the internal capacitor Cp, the output voltage of the equivalent circuit of the piezoelectric element is overturned from positive voltage to negative voltage, the reverse initial voltage of the equivalent circuit of the piezoelectric element is raised, and the voltage overturning stage is finished;
and (3) reverse natural charging stage: when the voltage overturning phase is finished, the initial voltage value of the equivalent circuit of the piezoelectric element is a negative value. At this time, the current in the inductor L is 0, and the positive half-cycle electronic switch Q3 is turned off, causing the positive half-cycle comparator Q1 to be turned off, all transistors to be turned off, and the first resonant tank to be open. The piezoelectric element equivalent current source ip reversely charges the internal capacitance Cp of the piezoelectric element, the negative output voltage Vn of the piezoelectric element equivalent circuit is increased until the moment before the Vn reaches the negative peak value, and the stage is ended;
and (3) reverse charge extraction stage: when the reverse natural charging phase is finished, the voltage Vn output by the equivalent circuit of the piezoelectric element reaches a negative peak value, at this time, because the deformation of the piezoelectric element changes the direction, the negative output voltage Vn of the equivalent circuit of the piezoelectric element begins to decrease, but because the first NPN tube Q2 of the piezoelectric voltage negative half-cycle comparator has a conduction threshold voltage, the charge on the negative peak detector C2 cannot be immediately released, the output voltage Vn of the equivalent circuit of the piezoelectric element is kept unchanged temporarily, and when the negative output voltage Vn of the equivalent circuit of the piezoelectric element decreases to be lower than the threshold voltage V of the NPN tube by one voltage on the negative peak detector C2 BE When the voltage of the equivalent circuit of the piezoelectric element is Vn-2V, the first NPN tube Q2 of the negative comparator is conducted, and the second PNP tube Q4 of the negative electronic switch is simultaneously promoted to be conducted BE . At this time, the piezoelectric element internal capacitance Cp, the positive and negative peak detection capacitances C1 and C2, and the inductance L form a second LC resonance circuit Cp → L → C2 → C1 → Cp, and the charge stored in the piezoelectric element internal capacitance Cp is entirely transferred through the second resonance circuit by 1/4LC resonance periodMagnetic energy (current) of the inductor L is formed, and when the current on the inductor L reaches the maximum, the charge extraction stage is finished;
reverse inductance freewheeling stage: when the reverse charge extraction phase is over, the voltage drop across the piezoelectric equivalent circuit is 0, the negative comparator first NPN transistor Q2 turns off, causing the negative electronic switch second PNP transistor Q4 to turn off, all transistors are in the off state, and the second resonant tank is open. Because the freewheeling diode D has threshold voltage, the current on the inductor L cannot flow to the filter capacitor Cr immediately until the voltage at the two ends of the freewheeling diode D exceeds the conduction threshold of the freewheeling diode D, the freewheeling diode D is conducted, and the inductor L, the freewheeling diode D and the filter capacitor Cr form a third loop: l → D → Cr. The current in the inductor L flows to the filter capacitor Cr through the third loop, and at this time, the current in the inductor L continuously decreases until the inductor current is insufficient to turn on the freewheeling diode D, the freewheeling diode D is turned off, and the inductor freewheeling stage is ended.
All the above is the operation of the piezoelectric element in one complete cycle, and the operation process is repeated thereafter.
Comparative example 1
The SEH circuit for standard energy extraction comprises a full-bridge rectifier and a filter capacitor, in order to ensure the comparison effect, the piezoelectric element uses the same type, the applied excitation is unchanged, and the used load is also unchanged, only the topological structure of the circuit is changed into full-bridge rectification consisting of diodes, specifically, positive and negative output voltage ends (Vp and Vn) of an equivalent circuit of the piezoelectric element are respectively connected with two alternating current ends of a rectifier bridge, and the rear end of the rectifier bridge is connected with the same filter capacitor and load as those in the embodiment.
Comparative example 2
A parallel synchronous switch (P-SSHI) inductance circuit is characterized in that an inductance and a synchronous switch which are connected in series are added between a piezoelectric element and a rectifier bridge of a comparative example 1(SEH) circuit, and auxiliary elements such as a displacement sensor, a DSP controller and the like are required for realizing the function of the synchronous switch. The filter capacitance and the load after the rectifier bridge are the same as in the embodiment.
Comparative example 3
A buck-boost circuit is connected and added between a rectifier bridge and a load of a comparative example 1, the buck-boost circuit comprises a synchronous switch, a freewheeling diode and an inductor, and the synchronous switch function needs to be realized by adopting a turn ratio of 1: the flyback transformer, filter capacitor and load of fig. 2 are the same as those of the embodiment.
Test example
As shown in fig. 5, the experimental apparatus of the test example includes: piezoelectric element, excitation platform, voltage upset and charge extraction circuit, function signal generator, power amplifier, oscilloscope, universal meter etc.. The piezoelectric element is fixed on the excitation platform through a clamp.
In the test example, the rectifying voltage range is 0-8V, the transistors Q1 and Q4 adopt PNP transistors 2N3906, the transistors Q2 and Q3 adopt NPN transistors 2N3904, the freewheeling diodes adopt schottky diodes BAT54, the same type of piezoelectric patches are selected for all the embodiments and comparative examples, the same excitation is applied to the piezoelectric patches, and a group of output power values are selected for comparative analysis. Fig. 6 is a graph of the power collected by the voltage flipping and charge extraction circuit of the present invention versus a conventional bridge rectifier (SEH) circuit, a parallel synchronous switched inductor (P-SSHI) circuit, and a synchronous charge extraction (SECE) circuit. Fig. 6 shows that the power harvesting bandwidth is greater when the voltage-reversing and charge-extracting circuits of the present invention are used than when conventional bridge rectifier (SEH) circuits and parallel synchronous switched inductor (P-SSHI) circuits are used, and the power harvesting bandwidth is greater than when conventional bridge rectifier (SEH) circuits and synchronous charge-extracting (SECE) circuits are used.
Table 1 shows the comparison of the performance of the voltage-inverting and charge-extracting circuit of the present invention with the performance of the conventional bridge rectifier circuit (SEH), parallel synchronous switching inductor (P-SSHI) circuit, and synchronous charge-extracting (see) circuit:
TABLE 1 comparison of the Performance of the examples and comparative examples 1, 2 and 3
| Serial number | Technique of | Self-powered | Control difficulty | Load independence |
| Comparative example 1 | SEH | YES | In general | NO |
| Comparative example 2 | P-SSHI | NO | Difficulty in | NO |
| Comparative example 3 | SECE | NO | It is difficult to use | YES |
| The invention | P-SSHI+SECE | YES | Simple | YES |
In a conventional bridge rectifier circuit (SEH), the power consumption of a conventional bridge rectifier diode is overlarge, and particularly when the mechanical vibration of a piezoelectric plate is weak, the power consumed by the rectifier diode even exceeds the power obtained by a load, so that the circuit efficiency is extremely low, the output power depends on the load, and the working bandwidth is small;
parallel synchronous switch inductor (P-SSHI) circuits require a large number of auxiliary devices such as displacement sensors, controllers, etc. to implement the control of the synchronous switch, which require much higher power consumption than can be collected from the piezoelectric energy harvesting devices, and therefore these auxiliary devices must be powered externally and cannot be self-powered. In addition, the performance of the P-SSHI circuit is very dependent on the LC resonance quality, and there is an impedance matching problem, and the optimal performance can be exerted only under the optimal impedance matching condition, and in practice, such a power supply is very unstable;
in order to realize the control of the circuit, a flyback transformer with a large volume is needed by a synchronous charge extraction (SECE) circuit, the flyback transformer is non-ideal in practice and has magnetic leakage, the loss of the circuit is increased to a certain extent, the flyback transformer needs to be designed according to the circuit attribute, the control difficulty is increased, and although the collected power is irrelevant to the load, the power consumption of the circuit is large, and self-power supply cannot be realized.
The voltage overturning and charge extracting circuit realizes self power supply by introducing the electronic circuit breaker, has simple circuit structure, does not need auxiliary equipment and an external power supply, has no load dependence, low conduction threshold value and low power consumption, can realize self power supply, and has more stable and reliable performance. The switch-on can be realized only by the voltage difference being larger than the switch-on threshold of the transistor, so that cold start is easy to realize, and the advantage is more obvious under the weak excitation condition.
While the present invention has been described in terms of its functions and operations with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise functions and operations described above, and that the above-described embodiments are illustrative rather than restrictive, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined by the appended claims.
Claims (4)
1. A voltage overturning and charge extracting circuit for piezoelectric energy collection is characterized by comprising a piezoelectric element, a voltage overturning and charge extracting circuit, an inductance follow current circuit and an energy storage circuit, wherein after the piezoelectric element, the voltage overturning and charge extracting circuit and the inductance follow current circuit are sequentially connected, the output end of the piezoelectric element is connected with the energy storage circuit. The voltage overturning and charge extracting circuit comprises a first synchronous switch (S1) and an inductor (L) which are connected in series, the inductor continuous current circuit is formed by sequentially connecting a second synchronous switch (S2), the inductor (L) and a continuous current diode (D), and the energy storage circuit comprises a filter capacitor (Cr) and a load (RL) which are connected in parallel;
the self-powered voltage overturning and charge extracting circuit is realized by using the electronic circuit breaker, and comprises a piezoelectric equivalent circuit, a piezoelectric voltage positive half-cycle electronic circuit breaker, a piezoelectric voltage negative half-cycle electronic circuit breaker and an inductance follow current circuit which are sequentially connected.
2. The voltage flipping and charge extraction circuit for piezoelectric energy harvesting of claim 1, wherein the piezoelectric voltage positive half-cycle electronic circuit breaker comprises a piezoelectric voltage positive half-cycle peak detector first capacitance (C1), a piezoelectric voltage positive half-cycle comparator first PNP transistor (Q1), a piezoelectric voltage positive half-cycle electronic switch second NPN transistor (Q3), an input terminal of the positive half-cycle peak detector (C1) is connected to a positive output voltage (Vp) terminal of the piezoelectric equivalent circuit, a base terminal of the positive half-cycle comparator (Q1), a collector terminal of the positive half-cycle electronic switch (Q3) at the same time, an output terminal of the positive half-cycle peak detector (C1) is connected to an emitter terminal of the positive half-cycle comparator (Q1), an input terminal of the negative half-cycle peak detector (C2), and an emitter terminal of the negative half-cycle comparator (Q2) at the same time, the collector terminal of the positive half-cycle comparator (Q1) is connected to the base terminal of the positive half-cycle electronic switch (Q3), the emitter of the positive half-cycle electronic switch (Q3) is simultaneously connected with the emitter of the negative half-cycle electronic switch (Q4) and the input end of the inductor (L).
3. The voltage flipping and charge extraction circuit for piezoelectric energy harvesting of claim 1, wherein the piezoelectric voltage negative half-cycle electronic breaker comprises a piezoelectric voltage negative half-cycle peak detector second capacitor (C2), a piezoelectric voltage negative half-cycle comparator first NPN transistor (Q2), a piezoelectric voltage negative half-cycle electronic switch second PNP transistor (Q4), an output of the negative half-cycle peak detector (C2) is connected to a negative output voltage (Vn) terminal of the piezoelectric element equivalent circuit, an output of the inductor (L), a base of the negative half-cycle comparator (Q2) is connected to a collector of the negative half-cycle electronic switch (Q4), a positive output voltage (Vp) terminal of the piezoelectric element equivalent circuit, a base of the negative half-cycle electronic switch (Q4) is connected to a collector of the negative half-cycle comparator (Q2), a collector of the negative half-cycle electronic switch (Q4) is connected to a positive output voltage of the piezoelectric element equivalent circuit (Q4), (v Vp) end connection.
4. The voltage flipping and charge extraction circuit for piezoelectric energy harvesting of claim 1, wherein the inductive freewheeling circuit comprises an inductor (L), a freewheeling diode (D) and a filter capacitor (Cr), wherein the freewheeling diode (D) input is connected to the inductor (L) input, the electronic switch (Q3) and the emitter of Q4) simultaneously, the freewheeling diode (D) output is connected to the positive rectified voltage terminal (Vr) of the filter capacitor (Cr), and the negative rectified voltage terminal of the filter capacitor (Cr) is connected to ground simultaneously with the output of the inductor (L).
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| CN202210701531.8A CN115051598A (en) | 2022-06-21 | 2022-06-21 | Voltage overturning and charge extracting circuit for piezoelectric energy collection |
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| CN202210701531.8A CN115051598A (en) | 2022-06-21 | 2022-06-21 | Voltage overturning and charge extracting circuit for piezoelectric energy collection |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115864829A (en) * | 2023-02-09 | 2023-03-28 | 长安大学 | Capacitive array type energy collecting system and collecting method |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115864829A (en) * | 2023-02-09 | 2023-03-28 | 长安大学 | Capacitive array type energy collecting system and collecting method |
| CN115864829B (en) * | 2023-02-09 | 2023-05-30 | 长安大学 | Capacitor array type energy collection system and collection method |
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