KR101982634B1 - Triboelectric energy harvesting device with high voltage dual input dc-dc converter - Google Patents

Abstract

The present invention relates to a frictional energy harvesting device using a dual input DC-DC converter for a high voltage. According to the present invention, a frictional energy harvesting device includes: a frictional electricity power source transmitting frictional electricity; an AC-DC conversion unit converting two AC voltages received from the frictional electricity power into two DC voltages; a DC-DC conversion unit converting the magnitude of the two DC voltages converted by the AC-DC conversion unit at a setting ratio; a control circuit unit controlling at least one voltage among positive DC voltages and negative DC voltages of the two DC voltages to be delivered to an output terminal based on the magnitude of the output voltage of the DC-DC conversion unit and the two DC voltages converted by the AC-DC conversion unit. According to the present invention, it is possible to provide stable electric power with high efficiency by converting AC voltages which have different positive and negative voltage peaks of a frictional electricity power source into DC voltages to respectively save the same, and supplying the two DC voltages to a dual input DC-DC converter for a high voltage by detecting the maximum output point.

Description

TECHNICAL FIELD [0001] The present invention relates to a triboelectric energy harvesting device using a high-voltage double-input DC-DC converter,

The present invention relates to a triboelectric energy harvesting apparatus using a high voltage double input DC-DC converter.

Friction electric energy harvesting is a power source that can harvest electric power from the friction generated in the body, and is a technique of harvesting electric power by using triboelectricity having a maximum value of a positive voltage and a negative voltage as a power source. Conventional triboelectric energy harvesting circuits use a general-purpose DC-DC converter that drives a circuit based on the instantaneous power that is not equipped with the maximum power point tracking technology, or use a DC-DC converter with a maximum value of positive and negative voltages Only low power harvesting was possible using an AC-to-DC converter that does not account for the output characteristics of the electric power source.

Furthermore, the conventional direct-current high voltage - direct current converter is a single input came to be designed only for the conventional direct current for a single input high voltage - when applying the dual input to DC converters, withstand the transistor (LDMOS) for high-voltage high V _DS Only V _GS can withstand a voltage of 5 volts or less, which is a typical CMOS rated voltage, resulting in the transistor being destroyed by a high voltage of 10 volts or more. Conventional dual-input dc-to-dc converters can not withstand high voltages due to the nature of the process itself, since they are designed within the typical CMOS rated voltage.

Therefore, it is necessary to study the high - voltage dual - input DC - DC converter capable of energy harvesting while tracking the maximum output point of the triboelectric power source and using it as a dual input.

The present invention relates to a high voltage double input DC-DC converter having a high voltage protection circuit for protecting a transistor by harvesting a double input of a triboelectric current using a DC-DC converter, maximizing transmission efficiency using maximum output point analysis, And to provide a triboelectric energy harvesting apparatus using a DC converter.

In order to achieve the above object, a triboelectric energy harvesting apparatus according to an embodiment of the present invention includes a triboelectric power source for transferring triboelectric energy, two alternating-current voltages transferred from the triboelectric power source to two direct- A DC-DC converter for converting the magnitude of the two DC voltages converted by the AC-DC converter into a predetermined ratio, and a DC-DC converter for converting the output voltage of the DC- And a control circuit for controlling at least one of a positive DC voltage and a negative DC voltage of the two DC voltages to be transmitted to the output terminal based on the two DC voltage magnitudes converted from the two DC voltages.

In addition, the triboelectric energy harvesting apparatus may further include a high voltage protection unit including a plurality of P-type LDMOSs and a level shifter.

The high voltage protection unit switches each P type LDMOS from the ON state to the OFF state when the rated voltage is satisfied according to the two DC voltages, downs the magnitude of the negative DC voltage to a voltage as low as the rated voltage, Output terminal.

The control circuit part stores the two DC voltages converted by the AC-DC converter in different capacitors, tracks the maximum output point of the two DC voltages, and outputs two DC voltages corresponding to the maximum output point, DC-DC converter.

The control circuit may determine the maximum output point and transmit the two DC voltages to the DC-DC converter when the two DC voltages correspond to a set percentage voltage of the open circuit voltage of the AC-DC converter.

The control circuit portion may deliver the positive voltage to the output terminal until the output voltage becomes greater than the negative voltage and may deliver the negative voltage to the output terminal if the output voltage is greater than the negative voltage.

Wherein the control circuit part generates an enable signal for determining whether to deliver the negative DC voltage to the output terminal based on an output voltage of the DC-DC converting part and a voltage magnitude of the negative DC voltage, A first comparator for comparing the positive direct current voltage with a first reference voltage, and a second comparator for comparing the negative direct current voltage and a second reference voltage when the enable signal is received from the first comparator, And a switching unit for determining whether to deliver the positive DC voltage or the negative DC voltage to the output terminal according to an output value of the second comparator.

According to the present invention, an AC voltage having a negative voltage peak different from that of a triboelectric power source is converted into a DC voltage and stored, and the two DC voltages are detected as a maximum output point and transferred to a high voltage double input DC- It is possible to supply stable electric power with high efficiency.

Also, by harvesting and managing the output power with high efficiency, it is possible to apply to the ultra-small sensor node using the friction generated in the body motion.

1 is a block diagram of a triboelectric energy harvesting apparatus using a high voltage dual input DC-DC converter according to an embodiment of the present invention.
FIGS. 2A to 2C are circuit diagrams, operation circuits, and output waveforms of a high-voltage protection circuit included in a triboelectric energy harvesting apparatus using a high-voltage double-input DC-DC converter according to an embodiment of the present invention .
FIG. 3 is a diagram for explaining a method of tracking a maximum power point of a triboelectric power source used in a triboelectric energy harvesting apparatus using a high-voltage double-input DC-DC converter according to an embodiment of the present invention.
FIG. 4 is a waveform showing the maximum output point analysis shown in FIG. 3 as a result of measurement. Each positive and negative maximum output point corresponds to 35% of each open-circuit voltage.
FIG. 5 shows a circuit diagram and operation waveform of a synchronous pulse-skipping modulation used in a triboelectric energy harvesting apparatus using a high-voltage double-input DC-DC converter according to an embodiment of the present invention.

The present invention is capable of various modifications and various embodiments, and specific embodiments will be described in detail with reference to the drawings. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

The terms first, second, A, B, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The term " and / or " includes any combination of a plurality of related entry items or any of a plurality of related entry items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but it should be understood that other elements may be present in between something to do. On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Throughout the specification and claims, it is to be understood that when a component comprises a component, it does not exclude other components, but may include other components, unless specifically stated otherwise.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a triboelectric energy harvesting apparatus using a high voltage dual input DC-DC converter according to an embodiment of the present invention.

1, a triboelectric energy harvesting apparatus according to an embodiment of the present invention includes a triboelectric power source 100, an AC-DC converter 200, a DC-DC converter 300, (400). In addition, the triboelectric energy harvesting device may further comprise a high voltage protection part 500.

Specifically, the triboelectric power source 100 (TENG) can collect friction through the sensor node that occurs in body motion. Here, the sensor node for collecting the triboelectricity may be formed of a film-like generator.

The AC-DC converter 200 can convert the AC voltage transmitted from the triboelectric power source 100 into a positive DC voltage V _{RECT, P} and a negative DC voltage V _{RECT, M.} At this time, the positive dc voltage (V _{REC, .P} ) and the negative dc voltage (V _{RECT, M} ) of the triboelectric peak have different peaks. The converted positive DC voltage (V _{RECT, P} ) and the negative DC voltage (V _{RECT, M} ) are stored separately in the capacitors C _{IN, P} and C _{IN, M} respectively.

The DC-DC converter 300 can convert the magnitude of the two DC voltages transmitted from the AC-DC converter 200 into a predetermined ratio. Specifically, when at least one of the positive DC voltage (V _{RECT, P} ) and the negative DC voltage (V _{RECT, M} ) stored in the capacitors C _{IN, P} and C _IN, The voltage can be converted into a predetermined ratio and output.

The control circuit unit 400 receives the positive DC voltage V _RECT of the two DC voltages based on the output voltage of the DC-DC converting unit 300 and the two DC voltage magnitudes converted by the AC- _{, P} ) or negative DC voltage (V _{RECT, M} ) to be transmitted to the output terminal. Specifically, the accumulated positive DC voltage (V _{RECT, P} ) is first transmitted to the output terminal side, and the accumulated negative DC voltage (V _{RECT, M} ) can be used as an energy source for controlling the triboelectric energy harvesting device have. When the negative DC voltage V _{RECT, M} is continuously accumulated and becomes equal to or higher than the reference voltage (output voltage V _OUT ), not only the accumulated positive DC voltage V _{RECT, M} but also the accumulated negative DC voltage V _{RECT, M} ) can also be transmitted to the output terminal side. At this time, the positive direct current voltage V _{RECT, M} and the negative direct current voltage V _{RECT, M} may be sequentially transmitted to the output terminal side in accordance with a predetermined order. In addition, the control circuit 400 traces the maximum output point in transmitting the two DC voltages stored in the capacitors C _{IN, P} and C _{IN, M} to the output terminal side, and outputs the two DC voltages corresponding to the maximum output point to the DC- DC converter 300 according to an embodiment of the present invention. The maximum output point means a point where the open circuit voltage of the AC-DC converter 200 becomes the set percentage voltage and the voltage value within the error range, and the set percentage will be described in detail in FIG.

In addition, the control circuit unit 400 may include a V _DD mux, first and second comparators, and a switching unit. V _DD multiplexer (MUX) is a direct current-passing to the output voltage and the DC negative voltage (V _{RECT, M),} an output terminal that the DC voltage (V _{RECT, M)} of the basis of the voltage of the direct-current conversion section 300 The enable signal V _EN can be generated. The first comparator compares the positive DC voltage V _{RECT, PL} with the first reference voltage V _{REF, P} to generate a control signal when the enable signal V _EN is received from the MUX _, The comparator can generate the control signal by comparing the negative DC voltage (V _{RECT, ML} ) with the second reference voltage (V _{REF, M} ). At this time, the DC voltage of the positive input to the comparator (V _{RECT, PL)} and a negative direct current voltage (V _{RECT, ML)} of the V _{RECT, P} and V _{RECT, M} represents a value output from the voltage divider. The switching unit can switch whether the positive DC voltage V _{RECT, P} or the negative DC voltage V _{RECT, M} is transferred to the output terminal according to the output values φ _M , φ _P of the first comparator and the second comparator have. The control circuit unit 400 operates the circuit while the power-on-reset (POR) circuit detects the voltage _{VRECR, M} and outputs a control signal when the voltage becomes higher than a preset internal reference voltage. Shortly after the control signal is output, the power stored in the C _{IN, M's} are used as a power for driving the control unit to the final output terminal (V _OUT) can not be transmitted to, C _IN, power only the final output terminal (V _OUT) is stored in _P .

The high-voltage protection unit 500 may include a plurality of P-type LDMOSs and a level shifter. When the rated voltage is satisfied according to the two DC voltages, the high voltage protection unit 500 switches the respective P-type LDMOS from the ON state to the OFF state and downs the magnitude of the negative DC voltage to a voltage as low as the rated voltage Output terminal.

FIGS. 2A to 2C are circuit diagrams, operation circuits, and output waveforms of a high-voltage protection circuit included in a triboelectric energy harvesting apparatus using a high-voltage double-input DC-DC converter according to an embodiment of the present invention .

Referring to FIG. 2A, the high-voltage protection unit 500 may include a plurality of P-type LDMOSs and a level shifter.

Referring to FIG. 2B, when the high voltage protection unit 500 satisfies the rated voltage according to two DC voltages, the P-type LDMOS is switched from the ON state to the OFF state, and the magnitude of the negative DC voltage is changed to the magnitude of the rated voltage Down to the output terminal.

Specifically, when the high voltage protection unit 500 transfers the power of V _{RECT, P} (State 1), the V _{RECT, P} voltage is simultaneously applied to the inductor node V _LX and the internal node V _PRT of the high voltage protection unit 500. In this case, all switches connected from the inductor node V _LX to V _{RECT, M} are turned off, meeting the process rated voltage.

Further, in the V _RECT, or going out to the time the transmission of the power _M (State1-> State2), the level shifter (Level shifter) charge accumulated on _PRT V V V _{RECT RPT is, M} with voltages as low as V _DD . At this time _, the transistor carrying the power of V _{RECT, P} is turned off, and all three switches connecting node V _{RECT, M} and node V _LX are turned on, so that voltage V _{RECT, M} is applied to node V _LX (State 2).

Referring to FIG. 2C, as a result, the process of switching from State 1 to State 2 is repeated while the OFF and ON operations of the M _PRT switch are repeated.

State 1 is controlled by the control signal V _GP , V _PRT is the positive DC voltage V _{RECT, P} , State 2 is controlled by the control signal V _GM , and V _LX is the negative DC voltage V _RECT, V _DD .

FIG. 3 is a diagram for explaining a method of tracking a maximum power point of a triboelectric power source used in a triboelectric energy harvesting apparatus using a high-voltage double-input DC-DC converter according to an embodiment of the present invention.

3, a maximum output point of a positive DC voltage (V _{RECT, P} ) and a negative DC voltage (V _{RECT, M} ) are separated and analyzed on the assumption that the voltage coming from the output of the triboelectric power source is respectively harvested do.

First, the amount of charge (Q _{HV, P} ) _usable from the positive DC voltage (V _RECT.P ) can be calculated by applying the following formula (1).

That is, the amount of charge (Q _{AV, P} ) that can be utilized from the positive DC voltage (V _RECT.P ) is _calculated from the total electric charge amount (Q _{HV, P} ) generated from the triboelectric power source and forming the positive DC voltage _P ) by _subtracting the amount of charge (Q _{LOSS, P} ) lost by the parasitic capacitor C _TENG .

In addition, the amount of power (P _AV , _P ) can be calculated based on the total amount of charge available by applying Equation (2). The maximum power point with respect to the positive voltage is expressed by Equation (3) when the voltage V _{RECT, P} in which the power point is maximized by differentiating (2) into V _{RECT, P} is found.

The voltage V _{RECT, P,} which corresponds to the maximum power point, can be expressed as an open-circuit voltage (V _{OC, P} ) through the charge quantity Q _AV and the parasitic capacitor C _TENG .

Therefore, the maximum output point tracking technology to be mounted on the triboelectric energy harvesting circuit can be realized by controlling the input voltage of the DC-DC converter to be a DC voltage of about 35% of the open-circuit voltage.

In the same way, tracking the maximum power point with respect to negative DC voltage can be obtained by controlling the negative voltage to be about 35% of the open-circuit voltage (V _{OC, N} ).

FIG. 4 is a waveform obtained by simulating the maximum output point analysis shown in FIG. 3 and comparing a theoretical value with a measured value. The theoretical values are indicated by dotted lines and the measured values are indicated by solid lines.

Referring to FIG. 4, it can be seen that the theoretical value and the measured value are so small that they can be seen as one curve according to the scale. Specifically, when the voltage of the open circuit (open circuit voltage) is 83.7 V, the maximum output point is measured at 30.6 V, and the theoretically calculated theoretical value is calculated as 29.6 V, indicating that the error rate is very small at 3.27% have.

Therefore, it was verified that the relationship between the output value of the positive and negative open circuit and the maximum output point was controlled to be 35% of the open circuit output value.

FIG. 5 shows a circuit diagram and operation waveform of a synchronous pulse-skipping modulation used in a triboelectric energy harvesting apparatus using a high-voltage double-input DC-DC converter according to an embodiment of the present invention.

Referring to FIG. 5, the control circuit 400 may include first and second comparators, and a switching unit.

The V _DD MUX outputs a negative DC voltage V _{RECT, M} based on the output voltage of the DC-DC converter 300 and the voltage magnitude of the negative DC voltage V _RECT, (V _EN ) which determines whether to transfer the signal to the output terminal.

The first comparator compares the positive DC voltage V _{RECT, PL} with the first reference voltage V _{REF, P} to generate a control signal when the enable signal V _EN is received from the MUX _, The comparator can generate the control signal by comparing the negative DC voltage (V _{RECT, ML} ) with the second reference voltage (V _{REF, M} ). At this time, the DC voltage of the positive input to the comparator (V _{RECT, PL)} and a negative direct current voltage (V _{RECT, ML)} of the V _{RECT, P} and V _{RECT, M} represents a value output from the voltage divider.

Specifically, two comparators monitor the two input voltages V _{RECT, P} and V _{RECT, M} of a high voltage dual input DC-DC converter. If V _RECT, if _P is the reference voltage V _REF, is higher than _P, φ _P is _1, V _{RECT, P} is the reference voltage V _REF, is not higher than _P, φ _P represents 0.

Also, if V _{RECT, M} is the reference voltage V _REF, is higher than the _M φ _M is 1, V _{RECT, M} is the reference voltage V _REF, is not higher than _M φ _M represents 0. The control signals of the power transfer switches M _P and M _M are determined according to the output signals φ _P and φ _M of the two comparators. First, when φ _P is 1 and φ _M is 0, it means that V _{RECT, P} is sufficient to supply power to the final output. Therefore, only V _GP , which is the switch control signal, is applied. At the moment V _GP becomes 0, So that the driving signal V _GN is generated.

The switching unit can switch whether the positive DC voltage V _{RECT, P} or the negative DC voltage V _{RECT, M} is transferred to the output terminal according to the output values φ _M , φ _P of the first comparator and the second comparator have. The control circuit unit 400 operates the circuit while the power-on-reset (POR) circuit detects the voltage _{VRECR, M} and outputs a control signal when the voltage becomes higher than a preset internal reference voltage. Shortly after the control signal is output, the power stored in the C _{IN, M's} are used as a power for driving the control unit to the final output terminal (V _OUT) can not be transmitted to, C _IN, power, only the last output terminal (V _OUT) is stored in _P .

Similarly, if only V _{RECT, M} is sufficient to carry power, only V _GM is applied to the switch and V _GN is applied to the NMOS accordingly. In the last case, V _{RECT, P} and V _{RECT, M} is all there is formed a sufficiently high voltage to deliver power V _GP is to operate the switch M _P, M _P is turned off and at the same time V _GM is operating a M _M . Finally, at the moment M _M turns off, V _GN finally drives the NMOS to complete the power transfer process.

According to the recognition, that is, _{(φ M, φ P) =} (1, 0), (0, 1), (1, 1) in accordance with the first comparator and the output of the second comparator (φ _M, φ _P), a switching The switching state of the part is changed, and the I _L transmitted to the output terminal can be changed.

The description above is merely illustrative of the technical idea of the present invention and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

100: Triboelectric power source 200: AC-DC converter
300: DC-DC converter 400: Control circuit
500: High Voltage Protection Unit

Claims (7)

A triboelectric power source for transferring triboelectricity;
An AC-DC converter for converting two AC voltages delivered from the triboelectric power source into two DC voltages;
A DC-DC converting unit converting the magnitude of the two DC voltages converted by the AC-DC converting unit into a predetermined ratio;
Wherein at least one of a positive DC voltage or a negative DC voltage of the two DC voltages is transmitted to an output terminal based on an output voltage of the DC-DC converter and two DC voltage magnitudes converted by the AC- A control circuit unit for controlling the control circuit unit to be controlled; And
A high voltage protection unit including a plurality of P-type LDMOSs, and a level shifter;
And a triboelectric energy harvesting device.

delete The method according to claim 1,
The high voltage protection unit switches the P-type LDMOS from the ON state to the OFF state when the rated voltage is satisfied according to the two DC voltages, and reduces the magnitude of the negative DC voltage to a voltage as low as the rated voltage To the output terminal.
The method according to claim 1,
Wherein the control circuit unit stores the two DC voltages converted by the AC-DC converter in different capacitors, tracks the maximum output point of the two DC voltages, and outputs two DC voltages corresponding to the maximum output point To the DC-DC converting unit, the triboelectric energy harvesting device.
5. The method of claim 4,
Wherein the control circuit unit determines that the two DC voltages correspond to a set percentage voltage of the open circuit voltage of the AC-DC converter, and transmits the two DC voltages to the DC- Friction electric energy harvesting device.
The method according to claim 1,
Wherein the control circuit section transfers the positive voltage to the output terminal until the output voltage becomes greater than the negative voltage and transfers the negative voltage to the output terminal when the output voltage is greater than the negative voltage , Triboelectric energy harvesting device.
The method according to claim 1,
Wherein the control circuit part generates an enable signal for determining whether to deliver the negative DC voltage to the output terminal based on a voltage magnitude of the output voltage of the DC-DC converter and the negative DC voltage;
A first comparator for comparing the positive DC voltage with a first reference voltage when an enable signal is received from the mux, a second comparator comparing the negative DC voltage and a second reference voltage; And
A switching unit for determining whether to deliver the positive DC voltage or the negative DC voltage to the output terminal according to an output value of the first comparator and the second comparator;
And a triboelectric energy harvesting device.

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