CN213879671U

CN213879671U - Piezoelectric energy collection circuit based on maximum power point tracking

Info

Publication number: CN213879671U
Application number: CN202022715395.7U
Authority: CN
Inventors: 夏银水; 王修登
Original assignee: Ningbo University
Current assignee: Ningbo University
Priority date: 2020-11-20
Filing date: 2020-11-20
Publication date: 2021-08-03
Anticipated expiration: 2030-11-20

Abstract

The utility model discloses a piezoelectric energy collection circuit based on maximum power point tracking, the characteristics are including piezoelectric transducer, synchronous rectifier module, maximum power point tracking module, DC-DC chip, first energy storage electric capacity, second energy storage electric capacity, first inductance and load, synchronous rectifier module includes first PNP pipe, second PNP pipe, first NPN pipe, second NPN pipe, first electric capacity and second inductance, maximum power point tracking module includes diode, second electric capacity, PMOS pipe, first resistance, second resistance and third resistance; the piezoelectric vibration energy collection device has the advantages that the peak voltage of the piezoelectric transducer can be extracted through simple passive components, the passive PMOS tube is used as a comparator, the tracking control of the maximum power point is realized, the circuit is simplified, the power consumption of the circuit is reduced, the vibration amplitude change of the piezoelectric transducer can be tracked in real time, the impedance matching effect of the circuit between the piezoelectric transducer and a load is optimized, and the maximum power collection of the piezoelectric vibration energy is realized.

Description

Piezoelectric energy collection circuit based on maximum power point tracking

Technical Field

The utility model relates to an energy acquisition circuit, especially a piezoelectric energy collection circuit based on maximum power point tracking.

Background

The piezoelectric vibration energy collection is a method for collecting vibration energy in the environment by utilizing the piezoelectric effect of a piezoelectric material, and because the output voltage of a piezoelectric transducer is an alternating current signal and general electronic equipment is powered by a direct current power supply, an interface circuit for collecting the piezoelectric energy is needed between the piezoelectric transducer and the electronic equipment, and the conversion from the alternating current voltage to the direct current voltage is realized through the interface circuit; however, different piezoelectric transducers, vibration conditions and interface circuits can affect the performance of the piezoelectric transducers for outputting electric energy, and for fixed piezoelectric transducers and interface circuits, the electric energy power collected by the collecting circuit is related to the impedance matching characteristic of the interface circuit under the vibration conditions, so that the impedance matching effect of the interface circuit can be optimized through the maximum power point tracking technology, and the collecting circuit can collect the piezoelectric energy with the maximum power. Although the existing piezoelectric energy collection circuit can effectively collect piezoelectric vibration energy, the output power of the interface circuit changes along with the change of load voltage, and the interface circuit can collect the piezoelectric energy with the maximum power only when the load voltage is in the optimal impedance matching range; therefore, the collection efficiency of the piezoelectric vibration energy can be effectively improved by using the maximum power point tracking technology to assist the interface circuit. The conventional maximum power point technology mainly comprises an open-circuit voltage method, a disturbance observation method and an incremental conductance method, wherein the open-circuit voltage method needs to periodically disconnect a load from a transducer and sample, so that energy loss in a sampling time period can be caused; although the disturbance observation method and the incremental conductance method do not need to periodically disconnect the load from the transducer, both methods need complex control circuits, and are difficult to implement and high in manufacturing cost.

In addition, these maximum power point tracking techniques all need active devices to be implemented, so that the power consumption of the circuit itself cannot be ignored, and the circuit can normally operate only when the output voltage of the interface circuit is higher than the starting voltage of the active devices.

Disclosure of Invention

The utility model aims to solve the technical problem that a simple structure, the lower piezoelectricity energy collection circuit based on maximum power point tracking of consumption are provided, can trail piezoelectric transducer's vibration amplitude variation in real time, have optimized the impedance matching effect of the circuit between piezoelectric transducer and the load, realize the maximum power collection of piezoelectric vibration energy.

The utility model provides a technical scheme that above-mentioned technical problem adopted does: a piezoelectric energy collecting circuit based on maximum power point tracking comprises a piezoelectric transducer, a synchronous rectification module, a maximum power point tracking module, a DC-DC chip, a first energy storage capacitor, a second energy storage capacitor, a first inductor and a load, wherein the synchronous rectification module comprises a first PNP tube, a second PNP tube, a first NPN tube, a second NPN tube, a first capacitor and a second inductor, the maximum power point tracking module comprises a diode, a second capacitor, a PMOS tube, a first resistor, a second resistor and a third resistor, one end of the piezoelectric transducer, a base electrode of the second NPN tube, a collector electrode of the second PNP tube, a collector electrode of the first NPN tube, a base electrode of the second NPN tube and an anode of the diode are connected, the other end of the piezoelectric transducer, one end of the first capacitor and one end of the second inductor are connected, the emitter of the first PNP tube, the emitter of the second NPN tube and the other end of the first capacitor are connected, the collector of the first PNP tube is connected with the base of the first NPN tube, the collector of the second NPN tube is connected with the base of the second PNP tube, the emitter of the first NPN tube, one end of the first energy storage capacitor, the source of the PMOS tube and the pin of the DC-DC chip are connected, the emitter of the second PNP tube, the other end of the second inductor and the other end of the first energy storage capacitor are connected in parallel with the ground, the cathode of the diode, one end of the second capacitor and one end of the first resistor are connected, the other end of the first resistor, one end of the second resistor and the gate of the PMOS tube are connected, the drain of the PMOS tube, the collector of the first PNP tube, the collector of the first NPN tube, the collector of the second NPN tube and the base of the second PNP tube are connected with the base of the PMOS tube, the emitter of the second PNP tube, the emitter of the second NPN tube and the collector of the second NPN tube are connected with the base of the PMOS tube, the second capacitor, the collector of the PMOS tube, the second PNP tube and the collector of the PMOS tube are connected with the emitter of the second PNP tube, the collector of the second PNP tube, the PMOS tube, the emitter of the second PNP tube and the PMOS tube are connected with the collector of the second capacitor, the emitter of the PMOS tube, the second capacitor, the emitter of the second PNP tube, the second capacitor, the PMOS tube and the PMOS tube, the emitter of the second capacitor is connected with the second capacitor, the emitter of the second capacitor, the emitter of the second capacitor, the emitter of the second capacitor is connected with the emitter of the second capacitor, the emitter of the second capacitor, the second of the emitter of the second capacitor, the emitter of the second capacitor, the emitter of the second capacitor, the emitter of the second capacitor, the emitter of, One end of the third resistor is connected with the EN pin of the DC-DC chip, the other end of the second capacitor, the other end of the second resistor and the other end of the third resistor are connected with the ground in parallel, the SW pin of the DC-DC chip is connected with one end of the first inductor, the VOUT pin of the DC-DC chip, the other end of the first inductor, one end of the second energy storage capacitor and one end of the load are connected, and the other end of the second energy storage capacitor is connected with the other end of the load in parallel.

Compared with the prior art, the utility model has the advantages of including piezoelectric transducer, synchronous rectifier module, maximum power point tracking module, DC-DC chip, first energy storage electric capacity, the second energy storage electric capacity, first inductance and load, wherein, synchronous rectifier module can convert the alternating current that piezoelectric transducer produced into direct current electric energy and store in first energy storage electric capacity, according to the characteristic of piezoelectric transducer, only when the voltage of first energy storage electric capacity and the maximum value ratio of piezoelectric transducer open circuit voltage are optimal, the electric power that piezoelectric transducer produced is the biggest, diode and the second electric capacity in the maximum power point tracking module can extract the maximum value of piezoelectric transducer open circuit voltage, rethread first resistance and second resistance partial pressure come control PMOS pipe's grid, when the voltage of first energy storage electric capacity is higher than optimal voltage, the partial pressure of first resistance and second resistance is one PMOS pipe's threshold voltage than the voltage of first energy storage electric capacity, at the moment, the PMOS tube is conducted, and an enable end EN pin of the DC-DC chip becomes a high level, so that the DC-DC chip starts to work and transfers the energy on the first energy storage capacitor to a load, and the energy on the first energy storage capacitor is reduced along with the energy; when the voltage on the first energy storage capacitor is lower than the optimal value, the PMOS tube is turned off due to the reduction of the source voltage, then the first energy storage capacitor is charged by the synchronous rectification module, the voltage slowly rises again until the voltage is higher than the optimal voltage, and the DC-DC chip is triggered again to work in a reciprocating cycle; in the whole circuit, the peak voltage of the piezoelectric transducer can be extracted through a simple passive component, and the passive PMOS tube is used as a comparator to realize the tracking control of the maximum power point, thereby not only simplifying the circuit and greatly reducing the power consumption of the circuit, but also realizing the self-starting of the whole piezoelectric energy collecting circuit,

the maximum power point tracking technology adopted in the circuit extracts an envelope signal of the interface circuit through a capacitance-resistance network and controls the DC-DC converter through PMOS tube hysteresis, thereby realizing the target according to the maximum power point; and the vibration amplitude change of the piezoelectric transducer can be tracked in real time, the impedance matching effect of a circuit between the piezoelectric transducer and a load is optimized, and the maximum power collection of piezoelectric vibration energy is realized.

Drawings

FIG. 1 is a schematic diagram of the overall circuit of the present invention;

fig. 2 is a circuit diagram of the synchronous rectification module of the present invention;

fig. 3 is a circuit diagram of the medium maximum power point tracking module of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments.

A piezoelectric energy collecting circuit based on maximum power point tracking comprises a piezoelectric transducer U1, a synchronous rectification module U2, a maximum power point tracking module U3, a DC-DC chip U4, a first energy storage capacitor C1, a second energy storage capacitor C2, a first inductor L1 and a Load, wherein the synchronous rectification module U2 comprises a first PNP tube Q1, a second PNP tube Q4, a first NPN tube Q4, a second NPN tube Q4, a first capacitor C4 and a second inductor L4, the maximum power point tracking module U4 comprises a diode D4, a second capacitor C4, a PMOS tube MP 4, a first resistor R4, a second resistor R4 and a third resistor R4, one end of the piezoelectric transducer U4, the base of the second NPN tube Q4, the collector of the second PNP tube Q4, the collector of the first NPN tube Q4, the base of the second NPN tube Q4, the positive electrode of the NPN tube Q4 and the other end of the NPN tube Q4 are connected with the first inductor C4 and the other end of the NPN tube P4, an emitter of a first PNP transistor Q1, an emitter of a second NPN transistor Q3, and the other end of a first capacitor C3 are connected, a collector of a first PNP transistor Q1 is connected to a base of a first NPN transistor Q2, a collector of a second NPN transistor Q3 is connected to a base of a second PNP transistor Q4, an emitter of a first NPN transistor Q2, one end of a first energy storage capacitor C1, a source of a PMOS transistor MP1, and a VIN pin of a DC-DC chip U4 are connected, an emitter of a second PNP transistor Q4, the other end of a second inductor L2, and the other end of a first energy storage capacitor C1 are connected in parallel to ground, a cathode of a diode D1, one end of a second capacitor C4, and one end of a first resistor R1 are connected, the other end of the first resistor R1, one end of a second resistor R2, and a gate of a PMOS transistor MP1 are connected, a drain of a third PMOS transistor MP1, one end of a third resistor R3, one end of a DC-DC chip U3, and the other end of the second resistor R3, and the other end of the second resistor R3 are connected in parallel to the second resistor 3, the SW pin of the DC-DC chip U4 is connected with one end of a first inductor L1, the VOUT pin of the DC-DC chip U4, the other end of the first inductor L1, one end of a second energy storage capacitor C2 and one end of a Load are connected, and the other end of the second energy storage capacitor C2 is connected with the other end of the Load in parallel.

The working principle of the above embodiment is as follows:

the synchronous rectification module U2 can convert the alternating current generated by the piezoelectric transducer U1 into direct current electric energy to be stored in the first energy storage capacitor C1, according to the characteristics of the piezoelectric transducer U1, the electric power generated by the piezoelectric transducer U1 is maximum only when the ratio of the maximum value of the voltage of the first energy storage capacitor C1 to the maximum value of the open-circuit voltage of the piezoelectric transducer U1 is optimal, the diode D1 and the second capacitor C4 in the maximum power point tracking module U3 can extract the maximum value of the open-circuit voltage of the piezoelectric transducer U1, then the voltage division is carried out by the first resistor R1 and the second resistor R2 to control the grid of the PMOS tube MP1, when the voltage of the first energy storage capacitor C1 is higher than the optimal voltage, the voltage division of the first resistor R1 and the second resistor R2 is lower than the threshold voltage of the first energy storage capacitor C1 by one PMOS tube, at the time the PMOS tube MP1 is conducted, the enable terminal of the DC-DC chip U4 becomes high level, so that the EN-DC chip U4 starts to work, the energy in the first energy-storing capacitor C1 is transferred to the Load, so the energy in the first energy-storing capacitor C1 decreases; when the voltage of the first energy-storage capacitor C1 is lower than the optimal value, the PMOS transistor MP1 is turned off due to the source voltage drop, and then the first energy-storage capacitor C1 is charged by the synchronous rectification module U2, the voltage slowly rises again until it is higher than the optimal voltage, and the DC-DC chip U4 is triggered again, so as to work in a reciprocating cycle.

Claims

1. A piezoelectric energy collection circuit based on maximum power point tracking is characterized by comprising a piezoelectric transducer, a synchronous rectification module, a maximum power point tracking module, a DC-DC chip, a first energy storage capacitor, a second energy storage capacitor, a first inductor and a load, wherein the synchronous rectification module comprises a first PNP tube, a second PNP tube, a first NPN tube, a second NPN tube, a first capacitor and a second inductor, the maximum power point tracking module comprises a diode, a second capacitor, a PMOS tube, a first resistor, a second resistor and a third resistor, one end of the piezoelectric transducer, a base electrode of the second NPN tube, a collector electrode of the second PNP tube, a collector electrode of the first NPN tube, a base electrode of the second NPN tube and an anode of the diode are connected, the other end of the piezoelectric transducer, one end of the first capacitor and one end of the second inductor are connected, the emitter of the first PNP tube, the emitter of the second NPN tube and the other end of the first capacitor are connected, the collector of the first PNP tube is connected with the base of the first NPN tube, the collector of the second NPN tube is connected with the base of the second PNP tube, the emitter of the first NPN tube, one end of the first energy storage capacitor, the source of the PMOS tube and the pin of the DC-DC chip are connected, the emitter of the second PNP tube, the other end of the second inductor and the other end of the first energy storage capacitor are connected in parallel with the ground, the cathode of the diode, one end of the second capacitor and one end of the first resistor are connected, the other end of the first resistor, one end of the second resistor and the gate of the PMOS tube are connected, the drain of the PMOS tube, the collector of the first PNP tube, the collector of the first NPN tube, the collector of the second NPN tube and the base of the second PNP tube are connected with the base of the PMOS tube, the emitter of the second PNP tube, the emitter of the second NPN tube and the collector of the second NPN tube are connected with the base of the PMOS tube, the second capacitor, the collector of the PMOS tube, the second PNP tube and the collector of the PMOS tube are connected with the emitter of the second PNP tube, the collector of the second PNP tube, the PMOS tube, the emitter of the second PNP tube and the PMOS tube are connected with the collector of the second capacitor, the emitter of the PMOS tube, the second capacitor, the emitter of the second PNP tube, the second capacitor, the PMOS tube and the PMOS tube, the emitter of the second capacitor is connected with the second capacitor, the emitter of the second capacitor, the emitter of the second capacitor, the emitter of the second capacitor is connected with the emitter of the second capacitor, the emitter of the second capacitor, the second of the emitter of the second capacitor, the emitter of the second capacitor, the emitter of the second capacitor, the emitter of the second capacitor, the emitter of, One end of the third resistor is connected with the EN pin of the DC-DC chip, the other end of the second capacitor, the other end of the second resistor and the other end of the third resistor are connected with the ground in parallel, the SW pin of the DC-DC chip is connected with one end of the first inductor, the VOUT pin of the DC-DC chip, the other end of the first inductor, one end of the second energy storage capacitor and one end of the load are connected, and the other end of the second energy storage capacitor is connected with the other end of the load in parallel.