Equipment and methods for efficient energy harvesting

Abstract

This disclosure relates to a power management device including a voltage converter, a power point tracker for determining an optimal operating voltage for power extraction, and a controller. The device is characterized by including a sensing device configured to: i) monitor an energy harvesting signal indicating the presence of harvestable power from an energy source; ii) compare the energy harvesting signal to a first threshold; and iii) generate a trigger signal if the energy harvesting signal has increased from a value below the first threshold to a value above the first threshold. The controller is configured to perform a first energy harvest as long as the sensing device has not yet generated a trigger signal, including: cyclically running the power point tracker to determine a first target voltage and running and adjusting the voltage converter to the first target voltage; and is configured to perform a second energy harvest if the sensing device is generating a first trigger signal, including: in response to the sensing device generating a first trigger signal, running the power point tracker and determining a second target voltage, and running and adjusting the voltage converter to the second target voltage if the power point tracker has completed determining the second target voltage. Additionally, the sensing device includes a signal output terminal for outputting the first trigger signal, and the signal output terminal of the sensing device is electrically connected to the signal input terminal of the power point tracker, wherein the power point tracker is configured to begin determining the second target voltage for the first time upon receiving the first trigger signal.

Description

Invention Field

[0001] The present invention relates to a power management device for managing energy received from an energy source, and more specifically, to a power management device comprising a voltage converter and a power point tracker configured to determine an optimal operating voltage for extracting power from the energy source. Background Technology

[0002] Extracting energy from an energy source using power management devices including voltage converters is well known in the art (see, for example, EP-A1-3474407). The extracted energy can be used to charge rechargeable energy storage devices and / or power application loads. These application loads can be any type of application, such as portable devices, sensors, external circuitry, wireless transmitters, etc.

[0003] Power management devices used for managing energy are typically implemented as integrated circuits, also known as power management integrated circuits (PMICs). Reference number AEM10941 is known as an example of a PMIC obtained from the applicant of the current patent application.

[0004] Various energy sources can be used to harvest energy, such as photovoltaic cells (PV), thermoelectric generators (TEG), piezoelectric energy generators, and electromagnetic energy sources.

[0005] Typically, to efficiently extract power from an energy source, the input voltage of a voltage converter needs to be regulated. Either the input voltage is regulated to a predefined reference voltage value, or alternatively, the PMIC includes a power point tracker (PPT) to determine the optimal operating voltage based on, for example, sensed open-circuit voltage. This optimal operating voltage is typically defined for extracting maximum power from the energy source, hence the PPT is often also called a maximum power point tracker (MPPT).

[0006] When the voltage converter operates and extracts energy from the energy source, it adjusts its input voltage to be equal to the optimal operating voltage determined by a predefined reference value or by a PPT.

[0007] The disadvantage of using a predefined reference value as the optimal operating voltage is that this predefined reference value is fixed and therefore may not correspond to the actual energy source configuration. Furthermore, this optimal operating voltage, for example, used to extract maximum power from the energy source, may vary over time.

[0008] The advantage of using a PMIC with a power point tracker is that the optimal voltage can be determined periodically (e.g., every tens of milliseconds to several seconds). In embodiments, the PMIC typically includes a clock generator configured to cyclically trigger PPT operation during discrete time intervals to cyclically determine the optimal operating voltage.

[0009] Typically, the voltage converter does not operate during PPT operation. In other words, the voltage converter and the power point tracker operate in a mutually exclusive manner, meaning either the voltage converter or the PPT is running, but they do not operate simultaneously.

[0010] The example of the method used in PPT to determine the optimal operating voltage is based on the measurement of the open-circuit voltage of the energy source, and the ratio of the measured open-circuit voltage is defined as the optimal operating voltage.

[0011] However, one of the problems with existing PMICs is that they are not well-suited for situations where the PMIC receives energy from intermittent energy sources, such as those that behave as on-off sources. These types of intermittent energy sources provide large amounts of energy (e.g., from tens of milliwatts to several watts) over short periods of time (e.g., from hundreds of milliseconds to several seconds).

[0012] Examples of sources that behave as on-off sources include the radio frequency (RF) transmitter or optical transmitter of a card reader used to read access cards. Since the access card only receives energy from the reader when it is placed above it, the access card perceives this energy source as an on-off source. Another example is a piezoelectric element embedded in a tire, which only provides energy when it rotates close to the ground as the wheel spins.

[0013] Since PowerPoint is only triggered cyclically, energy is wasted as long as PowerPoint has not been triggered.

[0014] Another drawback of using intermittent power sources and existing PMICs is the delay before the PMIC can start operating efficiently, which is a serious problem for situations where energy is available for very short periods and / or for applications that require rapid response (such as those using access cards).

[0015] Therefore, there is room for improvement in power management devices used for energy harvesting. Summary of the Invention

[0016] The purpose of this invention is to provide a power management device for efficiently managing energy received from an energy source, which overcomes the shortcomings of existing power management devices, as discussed above, that are not suitable for intermittent energy sources.

[0017] The invention is defined in the appended independent claims. The dependent claims define advantageous embodiments.

[0018] According to a first aspect of the present invention, a power management device for managing energy from an energy source is provided.

[0019] The power management device includes a voltage converter configured to regulate its input voltage to a target voltage, a power point tracker configured to determine the target voltage as the optimal operating voltage for extracting power from the energy source, and a controller for controlling the operation of the voltage converter and the power point tracker. The power management device further includes a sensing device configured to: i) monitor an energy harvesting signal, wherein the energy harvesting signal indicates harvestable power from the energy source; ii) compare the energy harvesting signal to a first threshold; and iii) generate a first trigger signal if the energy harvesting signal has increased from a value below the first threshold to a value above the first threshold.

[0020] The controller of the power management device according to this disclosure is configured to perform a first energy harvest as long as the sensing device has not generated a first trigger signal, and wherein performing the first energy harvest includes: a) cyclically running the power point tracker to determine a first target voltage; and b) running and adjusting the voltage converter to the first target voltage.

[0021] The controller is further configured to switch from performing a first energy harvesting to performing a second energy harvesting if the sensing device is generating a first trigger signal, wherein performing the second energy harvesting includes: a) running the power point tracker and determining a second target voltage in response to the sensing device generating the first trigger signal; and b) running and adjusting the voltage converter to the second target voltage if the power point tracker has completed determining the second target voltage.

[0022] Additionally, the sensing device includes a signal output terminal for outputting the first trigger signal, and the signal output terminal of the sensing device is electrically connected to the signal input terminal of the power point tracker, which is configured to begin determining the second target voltage for the first time upon receiving the first trigger signal.

[0023] Advantageously, by using a sensing device that senses the energy harvesting signal and triggers the power point tracker to start operating, and determines the target voltage when, for example, power from an intermittent energy source rises above a threshold, the voltage converter will immediately begin operating at the optimal input voltage to efficiently extract power from the energy source. Therefore, there are no periods where energy is extracted inefficiently, as is the case with prior art power management devices.

[0024] Advantageously, if the power rises above a threshold, the power point tracking cycle is synchronized with the energy supply cycle of, for example, an intermittent energy source by using a sensing device to trigger the power point tracker.

[0025] In one embodiment, the controller is configured to receive a trigger signal from the sensing device and subsequently generate a first start signal for the power point tracker, wherein the power point tracker is configured to receive the first start signal and to begin determining the target voltage for the first time upon receiving the first start signal.

[0026] In one embodiment, performing the second energy harvesting further includes: after determining the second target voltage for the first time in response to the sensing device generating a first trigger signal, cyclically running the power point tracker to cyclically repeat the determination of the second target voltage.

[0027] In one embodiment, the controller is configured to operate the power management device in an energy harvesting mode and a low-power sleep mode, wherein, when in energy harvesting mode, a first energy harvest and a second energy harvest are performed. The controller is further configured to generate a sleep signal that switches the power management device from energy harvesting mode to low-power sleep mode if the energy harvesting signal has decreased from a value above a third threshold to a value below a third threshold, wherein the third threshold is lower than the first threshold.

[0028] In this embodiment, the power point tracker is configured to begin determining the target voltage within less than 250 milliseconds, preferably less than 10 milliseconds, and more preferably less than 1 millisecond after the sensing device generates a trigger signal. In other words, given this rapid response time of the power point tracker to the trigger signal in the millisecond range, the response of the power point tracker to the trigger signal can be considered essentially instantaneous.

[0029] In one embodiment, the controller of the power management device is configured to delay the determination of the second target voltage by a delay period in response to the generation of a first trigger signal.

[0030] In an embodiment, the power management device according to this disclosure is further configured to receive an external trigger signal, and wherein the controller is further configured to initiate a second energy harvesting operation if the external trigger signal has been received.

[0031] This disclosure also relates to a system comprising a power management device as described in claim 1, an energy source coupled to a power input terminal of the power management device, and a rechargeable storage device or load coupled to a power output terminal of the power management device. The energy source may be, for example, an intermittent energy source.

[0032] According to a second aspect of the invention, a method is provided for managing energy from an energy source using a power management device, the power management device comprising: i) a voltage converter configured to regulate an input voltage to a target voltage; and ii) a power point tracker configured to determine the target voltage as the optimal operating voltage for extracting power from the energy source.

[0033] The method according to this disclosure includes: monitoring an energy harvesting signal indicating harvestable electricity from an energy source; comparing the energy harvesting signal with a first threshold; and generating a first trigger signal if the energy harvesting signal has increased from a value below the first threshold to a value above the first threshold. The method further includes: performing a first energy harvest as long as the first trigger signal is not generated, wherein the first energy harvest includes: a) cyclically running the power point tracker to determine a first target voltage; and b) running and adjusting the voltage converter to the first target voltage, and if the first trigger signal is generated, switching from performing the first energy harvest to performing a second energy harvest, wherein the second energy harvest includes: a) starting the power point tracker in response to the generation of the first trigger signal and using the power point tracker to determine a second target voltage; and b) if the power point tracker has completed determining the second target voltage, starting the voltage converter to adjust to the second target voltage. If the second trigger signal has been generated, the switching from the second energy harvest to the first energy harvest is performed only at the moment when the power point tracker is running to determine the target voltage.

[0034] In one embodiment, the power management device is configured to operate the power point tracker and the voltage converter in a mutually exclusive manner. Attached Figure Description

[0035] These and further aspects of the invention will be explained in more detail by way of example and with reference to the accompanying drawings, in which:

[0036] Figure 1 A block diagram illustrating a first embodiment of the power management device according to this disclosure is provided.

[0037] Figure 2 A block diagram illustrating a second embodiment of the power management device according to this disclosure is provided.

[0038] Figure 3a This illustration shows an example of timing diagrams illustrating the ON and OFF cycles of a power point tracker and a voltage converter.

[0039] Figures 3b to 3fFurther examples of timing diagrams illustrating the first EH-1 energy harvesting cycle and the second EH-2 energy harvesting cycle are schematically shown.

[0040] Figure 4 Further examples of timing diagrams illustrating the ON and OFF cycles of a power point tracker and a voltage converter are shown schematically.

[0041] Figure 5 A block diagram illustrating a third embodiment of the power management device according to this disclosure is provided.

[0042] Figure 6 Another embodiment of the power management device according to this disclosure is shown.

[0043] Figure 7 An embodiment of a power point tracker is illustrated schematically.

[0044] Figure 8 Examples of energy harvesting systems based on this disclosure are shown.

[0045] Figure 9 An example of an energy harvesting system is shown, in which the energy source is a radio frequency (RF) energy source.

[0046] Figure 10 A block diagram illustrating a fourth embodiment of the power management device according to this disclosure is provided.

[0047] Figure 11 An example of an embodiment of a voltage converter is illustrated schematically.

[0048] The accompanying drawings are neither drawn to scale nor to scale. Typically, in the accompanying drawings, the same parts are represented by the same reference numerals. Detailed Implementation

[0049] This disclosure will be described with reference to specific embodiments, which are illustrative and should not be construed as limiting. Those skilled in the art will understand that this disclosure is not limited to what has been specifically shown and / or described, and that alternative or modified embodiments can be developed based on the overall teachings of this disclosure. The described drawings are merely illustrative and not limiting.

[0050] The use of the verb "includes" and its corresponding variations does not exclude the existence of elements other than those stated. The use of the articles "a," "an," or "the" before an element does not exclude the existence of multiple such elements.

[0051] Furthermore, the terms "first," "second," etc., used in the specification and claims are used to distinguish similar elements and are not necessarily used to describe an order in time, space, hierarchy, or any other way. It should be understood that the terms thus used are interchangeable where appropriate, and the embodiments of this disclosure described herein can operate in any order other than that described or shown herein.

[0052] Throughout this specification, references to "an embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in one or more embodiments of this disclosure. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing throughout this specification do not necessarily refer to the same embodiment, but may refer to the same embodiment. Furthermore, in one or more embodiments, particular features, structures, or characteristics may be combined in any suitable manner as will be apparent to those skilled in the art based on this disclosure.

[0053] The term “controller” must be interpreted in its broadest sense as electronic digital circuits that typically include combinational logic.

[0054] Power Management Devices, Overview

[0055] Figure 1 , Figure 2 , Figure 5 , Figure 6 and Figure 10 An example of an embodiment of a power management device according to this disclosure is illustrated schematically.

[0056] Power management device 1 for managing energy from an energy source includes components configured to input voltage V in Converted to output voltage V OUT The voltage converter 10. During energy harvesting, the voltage converter 10 regulates the input voltage to the target voltage V. T。 The target voltage VT is the optimal voltage used to extract, for example, maximum power from an energy source.

[0057] The input voltage V is converted by this voltage converter in Adjusting to this target voltage must be interpreted as continuously adjusting the input voltage V in With target voltage V T The input voltage is compared and reduced when it is higher than the target voltage, and increased when it is lower than the target voltage.

[0058] In this embodiment, the voltage converter 10 is a DC-DC voltage converter. The voltage converter includes, for example, methods for increasing the input voltage V. inThe boost converter circuit is used to reduce the input voltage V. in A buck converter circuit or a buck-boost converter circuit for reducing and increasing the input voltage. These DC-DC voltage conversion circuits are known in the art.

[0059] The power management device further includes components configured to convert the target voltage V T The power point tracker PPT 20 is determined to be the optimal operating voltage for extracting electricity from an energy source. Examples of embodiments of this power point tracker are further discussed below.

[0060] Typically, the power management device is configured to operate the voltage converter and the power point tracker in a mutually exclusive manner; that is, when the power point tracker is operating to determine the target voltage, the voltage converter does not operate, and vice versa. Therefore, in these embodiments, energy cannot be harvested during the operation of the power point tracker. This is, for example... Figure 3a and Figure 4 The diagram illustrates this, with the top two rows representing examples of timing diagrams. These diagrams represent some on-time periods (PPT-ON) of the power point tracker and some on-time periods (VC-ON) of the voltage converter. The on-time periods of the power point tracker are also called sampling periods, and the on-time periods of the voltage converter are also called regulation periods or energy harvesting periods.

[0061] The controller 40 is configured to control the operation of the voltage converter 10 and the power point tracker 20.

[0062] The power management device according to this disclosure includes a sensing device 30 configured to: i) monitor an energy harvesting signal; ii) compare the energy harvesting signal with a first threshold; and iii) generate a first trigger signal T if the energy harvesting signal has increased from a value below the first threshold to a value above the first threshold. PPT The energy harvesting signal is an indication that there is harvestable electricity from an energy source.

[0063] Harvestable electricity can be obtained from different types of energy sources, and the harvestable energy can vary over time. For example, an ON / OFF source can switch to ON, thereby increasing the harvestable electricity. Another example is an energy source that emits electricity in a given direction, and the harvestable electricity of the power management device increases when it is directed towards the power management device.

[0064] The power management device according to this disclosure is characterized in that the power point tracker 20 is configured to begin determining the target voltage V in response to the sensing device generating a first trigger signal. TIn other words, if the detected power exceeds a first threshold, the sensing device 30 triggers the operation of the power point tracker 20. This contrasts with power management devices in the prior art that do not include a sensing device 30 to trigger the power point tracker to start operating. Instead, power management devices in the prior art typically use a clock generator configured to cyclically trigger the PPT 20 to operate during discrete time intervals in order to cyclically determine the optimal operating voltage.

[0065] In this embodiment, the target voltage V is initially determined using a power point tracker 20. T The first trigger signal T is generated by the sensing device 30. PPT Then it is executed within less than 250ms, preferably less than 10ms, and more preferably less than 1ms.

[0066] The generation of the first trigger signal and the operation of the power point tracker and voltage converter are in Figure 3a Some timing diagrams are used to illustrate this schematically. The bottom area schematically shows an example of the energy harvesting signal E of an energy source of the ON / OFF type. Figure 3a The two lower regions illustrate this: when the sensing device detects that the energy harvesting signal E has fallen below the first threshold E... T When the value increases to a value higher than the first threshold, a first trigger signal T is generated. PPT As a response to the generation of the first trigger signal T PPT In response, the power point tracker is triggered, set to ON, and begins determining the target voltage for operating the voltage converter. For example... Figure 3a As shown, once the target voltage is determined, the power point tracker is set to OFF, and the voltage converter is set to ON to harvest energy while adjusting the input voltage to the target voltage determined by the power point tracker.

[0067] The power management device disclosed herein, even if the first trigger signal T PPT Energy can be collected even when it has not been triggered. In fact, the first trigger signal is generated only when the available collectable power is above the first threshold, which does not mean that there is no available collectable power when it is below the first threshold.

[0068] The controller is configured to operate the power management device to perform a first energy harvesting EH-1 and a second energy harvesting EH-2. The second energy harvesting EH-2 is defined as energy harvesting performed if the energy harvesting signal has risen above a first threshold, while the first energy harvesting EH-1 is defined as energy harvesting performed if the energy harvesting signal has fallen below the first threshold.

[0069] For example, Figure 3b Schematically shows the execution of the first energy harvesting EH-1 and the second energy harvesting EH-2. The bottom region shows an example of the energy harvesting signal E over time. As discussed above, if the energy harvesting signal E increases from a value below the first threshold E T1 to a value above the first threshold, the sensing device triggers the first trigger signal T PPT , T1. As Figure 3b shown, as long as the sensing device has not generated the first trigger signal T1, the controller performs the first energy harvesting EH-1, which includes cyclically operating the power point tracker 20 to determine the first target voltage V T1 and operating and adjusting the voltage converter 10 to the first target voltage V T1 . In this example, the cyclical operation of the power point tracker for determining the first target voltage is performed once every first period P1 C . On the other hand, if the sensing device is generating the first trigger signal T1, the controller switches from performing the first energy harvesting EH-1 to performing the second energy harvesting EH-2, where the second energy harvesting includes: starting to operate the power point tracker 20 and determining the second target voltage V T2 in response to the sensing device 30 generating the first trigger signal T1, and if the power point tracker has completed determining the second target voltage V T2 , starting to operate and adjusting the voltage converter to the second target voltage V T2 .

[0070] In an embodiment, as Figure 3b schematically shown, performing the second energy harvesting EH-2 further includes: cyclically operating the power point tracker 20 to cyclically repeat determining the second target voltage V T2 after first determining the second target voltage V T2 in response to the sensing device 30 generating the first trigger signal T1. In this example, as Figure 3b schematically shown, the cyclical repetition of determining the second target voltage is performed once every second period P2 C .

[0071] In an embodiment, the cyclical operation of the power point tracker 20 for determining the first target voltage V T1 repeats at a first frequency, and the cyclical operation of the power point tracker 20 for determining the second target voltage V T2 repeats at a second frequency, where: F1 > F2, or F1 < F2 or F1 = F2, and F1 and F2 represent the first frequency and the second frequency respectively. The cycle frequency is the reciprocal of the cycle period as Figure 3b shown, so F1 = 1 / P1 C and F2 = 1 / P2C P1 C and P2 C These represent the first time period and the second time period, respectively, used to cyclically and repeatedly determine the first target voltage and the second target voltage.

[0072] like Figure 3b To further illustrate, the first target voltage V T1 Determination of the second target voltage V T2 The determination is performed within the first tracking period TP1 and the second tracking period TP2, respectively. In one embodiment, the first tracking period TP1 is different from the second tracking period TP2. In other embodiments, the first tracking period TP1 is equal to the second tracking period TP2.

[0073] There are various options for switching back from the second energy harvester EH-2 to the first energy harvester EH-1, as will be discussed below.

[0074] In an embodiment, such as Figure 3b and Figure 3d As further demonstrated, the sensing device 30 is configured to detect if the energy harvesting signal E has increased from above a first threshold E. T1 The value decreased to below the second threshold E T2 If the value of the first threshold is equal to or lower than the first threshold, a second trigger signal T2 is generated. The controller 40 is further configured to switch from performing a second energy harvesting to performing a first energy harvesting if the sensing device has generated the second trigger signal T2. Figure 3b In the embodiment shown, the second threshold is equal to the first threshold, while for Figure 3d In the embodiment shown, the second threshold E T2 Below the first threshold E T1 .

[0075] In an embodiment, such as Figure 3b As shown, when the second trigger signal T2 has been generated, the controller immediately stops operating the voltage converter in response to the second trigger signal and switches from performing the second energy harvesting to performing the first energy harvesting by, for example, starting to operate the power point tracker to perform a new determination of the target voltage.

[0076] In other embodiments, the switch from performing the first energy harvesting to performing the second energy harvesting is performed only when the power point tracker is running to determine the target voltage (e.g., when a new cycle of the target voltage is determined to have started or is in progress). Therefore, in these embodiments, if the second trigger signal T2 has already been generated, the controller is configured to perform the switch from the second energy harvesting to the first energy harvesting only when the power point tracker is running to determine the target voltage. In other words, in these embodiments, the switch from the second energy harvesting to the first energy harvesting has two conditions: the power point tracker is running and the second trigger signal has been generated.

[0077] In another embodiment, performing the second energy harvesting EH-2 further includes applying each determined second target voltage V to the target voltage V. T2 The voltage is compared to a target threshold. In these embodiments, the controller 40 is further configured to switch from performing second energy harvesting EH-2 to performing energy harvesting EH-1 if the second target voltage determined during the operation of the power point tracker is lower than the target threshold. Therefore, in these embodiments, the switch from the second energy harvesting to the first energy harvesting is performed only at the moment the power point tracker is operating to determine the target voltage. The target threshold may be a predefined value specifying the voltage condition for switching back from the second energy harvesting to the first energy harvesting.

[0078] In an embodiment where the switching from the second energy harvest to the first energy harvest is performed at the moment the power point tracker is running to determine the target voltage, the determination of the target voltage performed by the power point tracker between running the voltage converter during the second energy harvest and running the voltage converter again during the first energy harvest is performed only once.

[0079] In other embodiments, when performing the second energy harvesting EH-2, such as Figure 3c and Figure 3e As illustrated schematically, controller 40 is configured to if a predefined time period T elapses after the first generation of the first trigger signal T1. lap If the first trigger signal T1 is not generated a second time, the process switches from executing the second energy harvesting EH-2 to executing the first energy harvesting EH-1.

[0080] In some embodiments, the switching from the second energy harvester EH-2 to the first energy harvester EH-1 is based on whether a predefined time period T has elapsed. lap ,like Figure 3c and Figure 3e As shown, whenever the energy harvesting signal E drops below the first threshold E T1 When the value increases to a value higher than the first threshold, the second target value V is determined again using the power point tracker. T2 .exist Figure 3c and Figure 3e In the example, the first trigger signal T1 is shown as having been triggered three times.

[0081] In such Figure 1 In the schematically shown embodiment, the sensing device 30 includes a trigger signal T. PPT The signal output terminal of the sensing device 30 is electrically connected to the signal input terminal of the power point tracker 20. Therefore, in this embodiment, the PPT directly receives the trigger signal from the sensing device.

[0082] In other embodiments, a trigger signal from the sensing device is first sent to a controller 40, which then triggers the power point tracker 20. For example, in Figure 2 In the illustrated embodiment, the controller 40 is configured to receive a trigger signal T generated by the sensing device 30. PPT .

[0083] In one embodiment, the controller 40 is configured to generate a first start signal S1 for the power point tracker if a first trigger signal T1 is generated. The power point tracker includes an input for receiving the first start signal S1, and the power point tracker 20 is further configured to begin determining the target voltage for the first time upon receiving the first start signal S1.

[0084] The controller 40 used to control the power point tracker and voltage converter discussed above can be a dedicated controller, or it can be part of the power management device or the main controller 60. In an embodiment, a sub-controller 40a, as part of the controller 40, is configured to receive a trigger signal from the sensing device 30 and to generate a start signal S1 for the power point tracker, such as... Figure 10 It is shown schematically.

[0085] The trigger signal T generated by the sensing device PPT Yes, for example, a voltage signal or a current-based signal, and the first start signal S1 is, for example, a binary signal used to represent a high voltage level or a low voltage level.

[0086] In this embodiment, the controller 40 is configured to delay the first start signal S1 by a delay period ΔT relative to the first trigger signal T1 generated by the sensing device 30. This avoids errors caused by transient effects, i.e., the delay allows the energy source to reach a steady state, thus preventing the operating point determined by PPT from being incorrect.

[0087] exist Figure 4 In the example of the embodiment shown, relative to the trigger signal T generated by the sensing device PPTThe start signal S1 is delayed by a delay period ΔT.

[0088] In one embodiment, the controller 40 is configured to generate a second start signal S2 after the generation of the first start signal S1, wherein the second start signal S2 is generated after a first time period T1 has elapsed since the generation of the first start signal S1. In response to the second start signal S2, the power point tracker is triggered a second time and repeatedly determines the target voltage. Generating the first start signal S1 and the subsequent second start signal S2 is an alternative solution to transient problems.

[0089] In embodiments, as discussed above, the controller is configured to switch from performing second energy harvesting EH-2 to performing first energy harvesting EH-1 if the energy harvesting signal has decreased below a second threshold. In these embodiments, the controller 40 is configured to generate a third start signal S3 if a second trigger signal T2 is generated, and the power point tracker 20 is configured to begin determining a first target voltage V upon receiving the third start signal S3. T1 .

[0090] In an embodiment, as discussed above, the controller is configured to switch from performing the second energy harvesting EH-2 to performing the first energy harvesting EH-1 after a predefined time period Tlap has elapsed without a second generation of the first trigger signal T1. The controller 40 is configured to switch if the predefined time period Tlap has elapsed... lap A fourth start signal S4 is then generated, wherein the power point tracker is configured to begin determining the target voltage upon receiving the fourth start signal S4. This allows the voltage converter to efficiently extract energy, for example, in the presence of continuously available low-power ambient energy, which may originate from an energy source other than the main ON / OFF energy source. This other energy source may, for example, be an ambient radio frequency (RF) energy source.

[0091] In this embodiment, the power management device for managing energy from an energy source is implemented as an integrated circuit, i.e., a microchip comprising electronic circuitry and multiple input / output pins (also referred to as terminals, connectors, or leads). Typically, the integrated circuit can have 12 to 48 terminals.

[0092] In an embodiment, such as Figure 1 and Figure 2 The illustrated power management device 1, implemented as an integrated circuit, includes at least one function for controlling the input voltage V. in The power input terminal 11 receives power from the energy source and is used to output voltage V. out Power output terminal 12 for outputting power.

[0093] In an embodiment, the power management device is further configured to receive an external trigger signal, and the controller 40 is further configured to initiate a second energy harvesting EH-2 in response to receiving the external trigger signal. For example, if the power management device receives an external trigger signal while performing a first energy harvesting, the power management device switches from performing the first energy harvesting EH-1 to performing the second energy harvesting EH-2. Similarly, if the power management device receives an external trigger signal while in sleep mode, the power management device switches from sleep mode to performing the second energy harvesting EH-2.

[0094] In one embodiment, the power management device includes a signal detector for detecting the external trigger signal.

[0095] In other embodiments, the power management device includes a trigger input for receiving the external trigger signal.

[0096] In some embodiments, the external trigger signal is a wireless external trigger signal. In these embodiments, the signal detector includes, for example, an antenna.

[0097] In one embodiment, the controller 40 is configured to generate another start signal S-EXT for the power point tracker 20 if the external trigger signal has been received, and wherein the power point tracker 20 is configured to receive the other start signal S-EXT and to begin determining the second target voltage V upon receiving the other start signal S-EXT. T2 .

[0098] In this embodiment, similar to the generation of a first trigger signal by a sensing device, if an external trigger signal is received, the controller 40 is configured to delay the start of operation of the power point tracker by a delay period ΔT relative to that external trigger signal. Therefore, in Figure 4 In the middle, if the trigger signal T PPT The four upper regions, i.e., trigger T, are external trigger signals received by the power management device. PPT The same applies to the start signal, PPT-ON, and VC-ON.

[0099] Sensing devices

[0100] In one embodiment, the sensing device 30 includes a signal input terminal for receiving an energy harvesting signal. In an embodiment where the energy harvesting signal is an input voltage, the signal input terminal of the sensing device is electrically connected to the power input terminal 11 of the power management device to sense the input voltage V at the power input terminal 11. in ,like Figure 1 and Figure 2 It is shown schematically.

[0101] If, for example, the input voltage rises above a predefined threshold voltage, indicating that the energy supplied by the energy source has suddenly increased to exceed the energy that the voltage converter 10 (e.g., a DC-DC voltage converter) can deliver, then the input voltage is adjusted to a target voltage level corresponding to the low energy harvesting EH1.

[0102] In one embodiment, the sensing device 30 includes a signal comparator for comparing an energy harvesting signal with a first threshold.

[0103] The signal comparator can be an analog signal comparator or a digital signal comparator, as is known in the art. The comparator can be based on an operational amplifier. In embodiments using a digital signal comparator, the typical analog energy harvesting signal acquired by the sensing device is first digitized using an analog-to-digital converter (ADC).

[0104] The first threshold can be generated, for example, by a bandgap reference voltage generator, or it can be generated by flowing a reference current through a resistor. Alternatively, the threshold can be obtained via a communication bus.

[0105] The sensing device 30 disclosed herein is not limited to a sensor that monitors an input voltage and compares the input voltage to a threshold. Other embodiments of a sensor device for monitoring energy harvesting signals that indicate the availability of harvestable electricity can be considered.

[0106] In embodiments, sensing device 30 is, for example, configured to monitor the energy transferred by voltage converter 10 (e.g., DC-DC voltage converter) over a fixed time reference (e.g., from 1 to 250 milliseconds). This can be achieved, for example, by counting the number of pulses transmitted within a reference time window. If the number of pulses increases above a predefined pulse threshold, it means that the power generated by the energy harvester has suddenly increased. Therefore, in these embodiments, the energy harvesting signal E corresponds to the number of pulses counted over the fixed time reference.

[0107] In some embodiments, the threshold compared to the energy harvesting signal can be a dynamically adjustable threshold. For example, when the energy harvesting signal E corresponds to the number of pulses counted on a fixed-time reference, the pulse threshold can be a function of the input and output voltages, for example, by using a lookup table.

[0108] In embodiments where the energy harvesting signal E corresponds to the number of pulses counted on a fixed-time reference, the number of pulses is evaluated to determine if it has increased significantly, for example, by a factor greater than 5 to 1000 compared to previous counts. Therefore, in these embodiments, this threshold corresponds to the previous count and is thus dynamically adjusted.

[0109] Power point tracker

[0110] In one embodiment, the power point tracker 20 includes a voltage tracking input, and the power point tracker is configured to sample a voltage sensed at the voltage tracking input. Typically, the power point tracker further stores the sampled voltage or a percentage of the sampled voltage as a target voltage V for adjusting the voltage converter. T Sampling the input voltage must be interpreted as capturing or measuring the input voltage.

[0111] In this embodiment, the voltage tracked at the voltage tracking input is the open-circuit voltage, therefore the target voltage V T It is defined as a percentage of the open-circuit voltage.

[0112] The percentage value depends on the type of energy source. For example, if the energy source is a photovoltaic cell, the percentage value is typically between 70% and 85% of the open-circuit voltage of the energy source. If the collected energy comes from a radio frequency (RF) energy source, the percentage is typically set to 50% of the open-circuit voltage.

[0113] In some embodiments, the power point tracker 20 is configured to use a predefined voltage or a percentage of a predetermined voltage as the target voltage VT.

[0114] In an embodiment, such as Figure 6 The power management device 1 shown includes a buffer capacitor terminal 13 for connecting a buffer capacitor 85. The buffer capacitor terminal 13 is electrically connected to the input terminal 11. The buffer capacitor charges during operation of the voltage converter as energy is transferred from an energy source to a storage device or to a load connected to the power output terminal 12. The buffer capacitor 85 prevents input node failure while the inductor of the voltage converter is generating current.

[0115] In an embodiment, such as Figure 6 As further illustrated, the power management device includes a switch SW configured to electrically decouple the buffer capacitor terminal 13 from the input terminal 11 when the power point tracker 20 is operational, and to electrically connect the buffer capacitor terminal 13 to the input terminal 11 when the voltage converter 10 is operational. In other words, the switch SW is open during power point tracker 30 operation and closed during voltage converter 10 operation. This reduces transient effects when the power point tracker starts operating. The switch SW is typically controlled by the main controller of the power management device.

[0116] Power point trackers are known in the art, and exemplary embodiments are shown in Figure 7 The diagram schematically illustrates that the power point tracker 20 is implemented as, for example, an analog-to-digital converter (ADC) based on a successive approximation register (SAR) architecture. Figure 7 and Figure 10 As schematically shown, a power point tracker 20 typically includes a PPT electronic circuit 20a and a PPT controller 20b that controls the PPT electronic circuit. In this example, the PPT electronic circuit 20a includes a resistor ladder 22, a series of switches 25 for selecting the output of the resistor ladder, a capacitor ladder 23, switches SC_1 and SC_2 for resetting the capacitor ladder, and a voltage comparator 21. By closing... Figure 7 The switches SC_1 and SC-2 shown can discharge the capacitor ladder 23. The PPT controller 20b can be a dedicated controller or a controller that is part of the main controller 60, such as... Figure 10 It is shown schematically.

[0117] When the power point tracker is triggered by the trigger signal T from the sensing device 30 PPT During subsequent operation, several consecutive steps occur. In the first step, the voltage converter 20 is disabled and the input voltage at the power input terminal is stabilized at the open-circuit voltage.

[0118] In the second step, a preset ratio of the voltage at the power point tracker input is used at the positive input of voltage comparator 21. This ratio can be 100% or a lower value. For example, for open-circuit voltage evaluation, this ratio can be set to, for example, 80% or, for example, 50%. This ratio is determined using capacitive voltage divider 23. If the ratio is 100%, capacitive voltage divider 23 is an optional component.

[0119] In the third step, a ratio of a known voltage is used at the negative input terminal of comparator 21. Different ratios of this known voltage can be selected by individual switches 25 located at different positions on the resistor ladder.

[0120] In the fourth step, the PPT controller 20b uses a successive approximation method to determine the proportion of a known voltage that best matches the voltage at the output of the capacitor divider. Finally, when the optimal match is found, the matched voltage on the resistor divider becomes the new optimal operating voltage, used as the target value V for adjusting the input voltage of the voltage converter. T In this way, the optimal operating voltage is stored through the matching settings of the resistor divider. Alternatively, the PPT controller can digitize and store the matching voltage as the optimal operating voltage by acquiring continuous comparator output values.

[0121] In one embodiment, the power point tracker is configured to define two or more values ​​representing a percentage of the sampled voltage. In another embodiment, the power management device includes, for example, a configuration terminal coupled to the power point tracker 20 to provide a configuration signal to the power point tracker, which allows defining what percentage or proportion of the voltage V sensed at the power input terminal. inThe optimal operating voltage is required. This configuration signal can, for example, have three defined levels indicating whether the power point tracker needs to utilize 50%, 80%, or 100% of the open-circuit voltage, respectively. The configuration signal can consist of multiple signals, such as bus signals that transmit configuration information.

[0122] In an alternative embodiment, the PPT does not include a capacitor divider, and the open-circuit voltage is measured in step 2. In step 4, the PPT controller uses the ratio of the matched voltage as the target voltage.

[0123] In one embodiment, the percentage of open-circuit voltage to be acquired is hard-coded, while in other embodiments, a configuration signal is transmitted to the power point tracker that allows defining what percentage of the open-circuit voltage is required as the optimal operating voltage. This configuration signal may, for example, have four defined levels indicating whether the power point tracker needs to utilize, for example, 50%, 70%, 80%, or 100% of the open-circuit voltage. The configuration signal may consist of multiple signals, such as a bus signal transmitting configuration information. In some embodiments, the PMIC includes more than one configuration terminal to provide the configuration signal or the bus signal.

[0124] Sleep mode and reset mode

[0125] In this embodiment, the controller 40 is configured to switch the power management device between energy harvesting mode EH-M and low-power sleep mode SLP-M. First energy harvesting EH-1 and second energy harvesting EH-2 operate in energy harvesting mode. Energy harvesting mode can also be referred to as active mode.

[0126] In an embodiment, such as Figures 3d to 3f As illustrated schematically, sensing device 30 is configured to detect if the energy harvesting signal E has increased from above a third threshold E. T3 If the value decreases to below the third threshold, a third trigger signal T3 is generated, wherein the third threshold is lower than the first threshold E. T1 In these embodiments, the controller 40 is configured to generate a sleep signal SLP, which is used to switch the power management device 1 from energy harvesting mode EH-M to low-power sleep mode SLP-M if a third trigger signal T3 is generated.

[0127] Thus, by switching from energy harvesting mode (EH-M) to sleep mode (SLP-M), power consumption can be reduced when the power management device is not activated to harvest energy. In this embodiment, during sleep mode, the clock frequency is reduced, and typically a portion of the voltage converter is turned off to reduce PMIC quiescent current.

[0128] In an embodiment, such as Figures 3d to 3fAs further demonstrated, the sensing device 30 is configured to detect if the energy harvesting signal E has fallen below a third threshold E. T3 If the value increases to a value higher than the third threshold, a fourth trigger signal T4 is generated. In these embodiments, the controller 40 is configured to switch from sleep mode SLP-M to energy harvesting mode EH-M if the fourth trigger signal T4 is generated. Figure 3d and Figure 3e In the illustrated embodiment, there is a switching from sleep mode SLP-M to the first energy harvesting mode EH-1.

[0129] For specific situations, such as Figure 3f This is illustrated schematically, where, during sleep mode SLP-M, the energy harvesting signal E increases rapidly, and when it increases above the third threshold E... T3 First, a fourth trigger signal T4 is generated, and then when it further increases to above the first threshold E... T1 A first trigger signal T1 is generated. Subsequently, the voltage converter operates and begins energy harvesting, regulating the input voltage to the second target voltage V. T2 Therefore, in this example, there is a direct switch from sleep mode SLP-M to performing the second energy harvesting EH-2. Even in response to the fourth trigger signal. T4 The power point tracker has begun to determine the first target voltage V. T1 The determination of the first target voltage is interrupted by the first trigger signal T1, and the determination of the target voltage begins again, as follows. Figure 3f It is shown schematically.

[0130] In another embodiment, the controller 40 is configured to if a reset period ΔT has elapsed. R If no trigger signal is received from the sensing device, the power management device 1 is reset. This reset mode is the mode in which the power management device is turned off and does not consume power.

[0131] Figure 5 An embodiment of a power management device is shown, wherein if the time interval is longer than a predefined reset period ΔT R The sensing device 30 did not generate a trigger signal T for a longer period of time. PPT Then the controller 40 outputs a reset signal R to the voltage converter 10 and the power point tracker 20.

[0132] In one embodiment, the power management device includes a cold start circuit 50 for activating the circuit after a reset.

[0133] The cold start circuit 50 is a startup circuit used to obtain energy from an energy source and to power the power management device 1. Typically, the voltage converter 10 cannot operate when there is insufficient power available to power the PMIC controller. In fact, for example, the voltage converter controller only supplies the voltage V at the power input terminal of the controller. sup It can only operate when the supply voltage is equal to or higher than the minimum required supply voltage. When there is sufficient supply voltage available to operate the controller, cold start energy harvesting stops, and then the power management device sequentially operates the power point tracker and the voltage converter based on trigger signals received from the sensing device, as discussed above.

[0134] voltage converter

[0135] The power management device 1 according to this disclosure includes at least one voltage converter 10. Typically, the voltage converter 10 includes voltage converter electronic circuitry 10a and a voltage converter controller 10b for controlling the voltage converter electronic circuitry.

[0136] As discussed above, in embodiments, the voltage converter may be, for example, used to increase the input voltage V. in The boost converter circuit is used to reduce the input voltage V. in A buck converter circuit or a buck-boost converter circuit used to reduce and increase the input voltage.

[0137] An example of a boost converter circuit is in Figure 11 The diagram is shown schematically. Typically, the voltage converter electronics 10a includes an inductor 15 and a first switch SVC_1 and a second switch SVC_2 controlled by a voltage converter controller 10b. In an embodiment, the voltage converter controller 10b may be part of the main controller 60 of the power management device, such as... Figure 10 It is shown illustratively. For example... Figure 11 As shown, when using a boost converter, inductor 15 is connected in series with power input terminal 11. As is known in the art, by cyclically controlling the first switch SVC_1 and the second switch SVC_2, the magnetic energy stored in inductor 15 is cyclically transferred to, for example, a load or battery connected to the output terminal 12 of the voltage converter, at which the output voltage V... out Higher than the voltage V at the converter input terminal in .

[0138] In this embodiment, a switched-capacitor converter is used instead of an inductive voltage converter as discussed above. Switched-capacitor converters are known in the art, and these converters deliver power by charging and discharging a capacitor.

[0139] When drawing power from an energy source, the voltage converter uses the last value defined and stored by the power point tracker as the optimal operating voltage to convert the input voltage V. in Adjust to target voltage V T .

[0140] In one embodiment, the last stored target voltage may be the target voltage determined by the power point tracker after the sensing device generates a trigger signal. However, in some embodiments, the last stored target voltage is not necessarily the target voltage determined after the sensing device generates a trigger signal. This falls under the category of cases where the power point tracker is additionally triggered by a signal other than the trigger signal from the sensing device. For example, as discussed above, in one embodiment, the controller 40 generates a second trigger signal S2 after the first trigger signal S1 is generated, and in response to the second trigger signal S2, the power point tracker is triggered a second time and the target voltage is determined again, and the determined second value becomes the last defined and stored value. In other embodiments, after the PPT is first triggered by a trigger signal from the sensing device, the PPT may be further repeatedly triggered by, for example, an internal clock generator.

[0141] In one embodiment, the voltage converter controller 10b includes features for sensing the input voltage V of the voltage converter. in The sensor and the method for comparing the input voltage with the target voltage V determined by the power point tracker T A comparator or amplifier is used for comparison. When the voltage at the converter input is lower than the target value, the voltage converter is disabled to prevent the voltage at the converter input from dropping further. On the other hand, when the voltage at the voltage converter input is higher than the target value, power transfer from the converter input to the converter output is enabled. In this way, the input voltage is regulated to approach the target voltage.

[0142] In some embodiments where the power management device is implemented as an IC, the inductor 15 is located outside the IC and provides additional terminals to couple the inductor to the IC.

[0143] The voltage converter is disabled by disconnecting its first switch SVC_1 and second switch SVC_2. This prevents the voltage converter from drawing power. The voltage converter is disabled, for example, during the operation of the power point tracker.

[0144] In an embodiment, such as Figure 4 As shown, the voltage converter operates within a fixed, predefined time period ΔT VC-ON On (ON). For example, if the energy source is a repetitive on / off (ON / OFF) energy source, a predefined time period ΔT can be selected. VC-ONThis corresponds to the time period during which the ON / OFF energy source is expected to be turned on.

[0145] In other embodiments, such as Figure 3a As shown, the voltage converter is turned on (ON) until the energy harvesting signal drops below another threshold, which can be the threshold used to trigger the trigger signal T. PPT First threshold E T The same or different thresholds. In one embodiment, the other threshold is lower than the first threshold. In other embodiments, such as... Figure 3a As shown, the first threshold is equal to the other threshold. In an embodiment, the other threshold is higher than the first threshold.

[0146] Energy harvesting system

[0147] Figure 8 An example of an energy harvesting system 100 including a power management device 1 according to this disclosure is schematically shown.

[0148] exist Figure 8 In the illustrated embodiment, energy source 70 is coupled to power input terminal 11 of the power management device, and rechargeable storage device 80 is coupled to power output terminal 12. In other embodiments, a load is coupled to power output terminal 12. The energy source is, for example, an intermittent energy source.

[0149] refer to Figure 9 This illustration schematically shows another embodiment of an energy harvesting system 100 including a power management device 1 according to this disclosure. In this example, the energy source is a radio frequency (RF) energy source 70. In this embodiment, the system 100 includes an antenna 75 for harvesting radio frequency (RF) energy from the RF energy source 70, and further includes a rectifier 90, wherein the output of the rectifier is coupled to a power input terminal 11 of the power management device 1.

[0150] Figure 8 and Figure 9 The controller 40 used to control the operation of the power point tracker and voltage converter is not shown. As discussed above, controller 40 may correspond to the main controller 60 of the power management device, or controller 40 may be a sub-controller of the main controller 60 of the power management device. A method for managing energy from an energy source.

[0151] This disclosure also relates to a method for managing energy from an energy source using a power management device, the power management device comprising: i) a voltage converter 10 configured to regulate an input voltage to a target voltage V. T ; and ii) a power point tracker 20, which is configured to track the target voltage V TThe optimal operating voltage for extracting electricity from this energy source was determined.

[0152] The method for managing energy from an energy source includes the following steps:

[0153] • Monitor energy harvester E, which indicates the presence of energy from an energy source;

[0154] • Compare the energy harvesting signal E with the first threshold E T1 Compare;

[0155] • If the energy harvesting signal has already fallen below the first threshold E T1 If the value increases to a value higher than the first threshold, a first trigger signal T is generated. PPT ,T1;

[0156] • As long as the first trigger signal T is not generated PPT T1, then execute the first energy harvest EH-1, wherein the first energy harvest includes:

[0157] a) Cyclicly run the power point tracker 20 to determine the first target voltage V. T1 ,as well as

[0158] b) Run and adjust the voltage converter 10 to the first target voltage V. T1 ;

[0159] • If the first trigger signal T is generated PPT If T1 is selected, the system switches from performing the first energy harvest EH-1 to performing the second energy harvest EH-2, wherein the second energy harvest includes:

[0160] a) In response to the generation of the first trigger signal T PPT The power point tracker 20 is then started and used to determine the second target voltage V. T2 ,as well as

[0161] b) If the power point tracker has already determined the second target voltage V T2 Then it starts running and adjusts the voltage converter 10 to the second target voltage V. T2 .

[0162] In an embodiment, the method further includes:

[0163] • If the energy harvesting signal E has already increased from above the first threshold E T1 The value decreased to below the second threshold E T2 If the value of E is specified, a second trigger signal T2 is generated, wherein the second threshold E is specified. T2 Equal to or below the first threshold E T1 ,

[0164] If a second trigger signal T2 is generated, the process switches from performing the second energy harvest to performing the first energy harvest.

[0165] In an embodiment, the method includes:

[0166] • The second target voltage V is determined for the first time in response to the generation of the first trigger signal T1. T2 Then, the power point tracker 20 is run cyclically to repeatedly determine the second target voltage V. T2 .

[0167] In this embodiment, if a second trigger signal T2 has already been generated, the switching from the second energy harvester EH-2 to the first energy harvester EH-1 is performed only when the power point tracker is running to determine the target voltage. In other words, the switching from the first energy harvester to the second energy harvester is not performed while the voltage converter is running, but only when the power point tracker's cyclic operation has started or is in progress.

[0168] In an embodiment, the method includes:

[0169] • The second target voltage (V) is determined for the first time in response to the generation of the first trigger signal (T1). T2 After that, the power point tracker (20) is run cyclically to repeatedly determine the second target voltage (V). T2 ),

[0170] • Determine each second target voltage (V) T2 Compare with the target threshold, and

[0171] • During the operation of the power tracker, if the determined second target voltage is lower than the target threshold, the system switches from performing the second energy harvest (EH-2) to performing the first energy harvest (EH-1).

[0172] In other embodiments, the method includes:

[0173] • If a predefined time period T elapses after the first trigger signal T1 is generated for the first time lap If the first trigger signal T1 is not generated a second time, the process switches from executing the second energy harvest to executing the first energy harvest.

[0174] In an embodiment, the method includes:

[0175] • If the energy harvesting signal E has already risen above the third threshold E T3 If the value decreases below the third threshold, the system switches to a low-power sleep mode, where the third threshold E... T3 Below the first threshold E T1 .

[0176] In an embodiment, the method includes:

[0177] • Receive an external trigger signal, and if an external trigger signal is received, begin executing the second energy harvesting EH-2.

[0178] In an embodiment, in response to the generation of a first trigger signal T1,T using the power point tracker 20 PPT Using this power point tracker, the first target voltage V is determined. T The steps are performed in less than 250ms, preferably in less than 10ms, and more preferably in less than 1ms.

[0179] In one embodiment, the power point tracker is disabled before the voltage converter is started; in other words, the power management device is configured to operate the power point tracker 20 and the voltage converter 10 in a mutually exclusive manner.

Claims

1. A power management device (1) for managing energy from an energy source, comprising: • A voltage converter (10) configured to adjust the input voltage of the voltage converter to a target voltage (V). T ), • Power point tracker (20), which is configured to transfer the target voltage (V) T The optimal operating voltage for extracting electricity from the energy source was determined. · A controller (40) for controlling the operation of the voltage converter (10) and the power point tracker (20), The power management device (1) comprises: · A sensing device (30) configured to: i) Monitor an energy harvesting signal (E), and wherein the energy harvesting signal indicates the collectable electric power from the energy source, and ii) The energy harvesting signal (E) is compared with a first threshold (E). T, E T1 ) for comparison, iii) If the energy harvesting signal has been below the first threshold (E) T E T1 If the value of ) increases to a value higher than the first threshold, then a first trigger signal (T) is generated. PPT, T1), The controller (40) is configured to: i) As long as the sensing device (30) has not yet generated the first trigger signal (T) PPT T1), then perform the first energy harvest (EH-1), wherein performing the first energy harvest includes: a) Run the power point tracker (20) cyclically to determine the first target voltage (V). T1 ),as well as b) Run and adjust the voltage converter (10) to the first target voltage (V T1 ),as well as ii) If the sensing device is generating the first trigger signal (T1), switch from performing the first energy harvesting (EH-1) to performing the second energy harvesting (EH-2), and wherein performing the second energy harvesting comprises: a) In response to the sensing device (30) generating the first trigger signal (T) PPT ,T1), run the power point tracker (20) and determine the second target voltage (V T2 ),as well as b) If the power point tracker has already determined the second target voltage (V) T2 If the voltage converter is activated, it will operate and adjust the voltage converter to the second target voltage (V). T2 ), The sensing device (30) includes a function for outputting the first trigger signal (T). PPT The signal output terminal of the sensing device (30) is electrically connected to the signal input terminal of the power point tracker (20), and the power point tracker (20) is configured to respond to the first trigger signal (T1) upon receiving the first trigger signal (T1). PPT The first determination of the second target voltage (V) begins at time T1. T2 ).

2. The power management device according to claim 1, wherein, The sensing device (30) includes a function for outputting the first trigger signal (T). PPT The signal output terminal of ).

3. The power management according to claim 1 or claim 2, wherein, The controller 40 is configured to generate a first start signal (S1) for the power point tracker (20) if the first trigger signal (T1) is generated, and wherein the power point tracker 20 is configured to receive the first start signal (S1) and to begin determining the second target voltage (V) for the first time upon receiving the first start signal (S1). T2 ).

4. The power management device according to claim 3, wherein, The controller (40) is configured to respond to the first trigger signal (T) generated by the sensing device (30). PPT, T1) Delay the first start signal (S1) by a delay period (ΔT).

5. The power management device according to claim 3 or claim 4, wherein, The controller (40) is configured to generate a second start signal (S2) after a first period (T1) from the generation of the first start signal (S1), and wherein the power point tracker (20) is configured to start a second determination of the second target voltage (VT2) upon receiving the second start signal (S2).

6. The power management device according to any one of the preceding claims, in, The sensing device (30) is configured to detect if the energy harvesting signal (E) has been above the first threshold (E). T1 The value of ) decreases to below the second threshold (E) T2 If the value of ) is true, then a second trigger signal (T2) is generated, wherein the second threshold is equal to or lower than the first threshold. And wherein the controller (40) is further configured to: iii) If the sensing device (30) has generated the second trigger signal (T2), switch from performing the second energy harvesting (EH-2) to performing the first energy harvesting (EH-1).

7. The power management device according to claim 6, wherein, The controller (40) is configured to generate a third start signal (S3) if the second trigger signal (T2) is generated, and wherein the power point tracker (20) is configured to begin determining the first target voltage (V) upon receiving the third start signal (S3). T1 ).

8. The power management device according to claim 6, wherein, If the sensing device (30) has generated the second trigger signal (T2), the switching from performing the second energy harvesting (EH-2) to performing the first energy harvesting (EH-1) is performed only at the moment when the power point tracker is operating to determine the target voltage.

9. The power management device according to any one of claims 1 to 5, wherein, The controller (40) is further configured to: iii) If a predefined time period (T) elapses after the first generation of the first trigger signal (T1) lap If the first trigger signal (T1) is not generated a second time, the process switches from performing the second energy harvest (EH-2) to performing the first energy harvest (EH-1).

10. The power management device according to claim 9, wherein, The controller (40) is configured to if the predefined time period (T) has elapsed. lap If the power point tracker (20) receives the fourth activation signal (S4), a fourth activation signal (S4) is generated, wherein the power point tracker (20) is configured to begin determining the first target voltage (V) upon receiving the fourth activation signal (S4). T1 ).

11. The power management device according to any one of the preceding claims, wherein, The performing of the second energy harvesting (EH-2) further comprises: c) The second target voltage (V) is determined for the first time in response to the generation of the first trigger signal (T1) by the sensing device (30). T2 After that, the power point tracker (20) is run cyclically to repeatedly determine the second target voltage (V). T2 ).

12. The power management device according to any one of claims 1 to 5, wherein, in, The performing of the second energy harvesting (EH-2) further comprises: c) The second target voltage (V) is determined for the first time in response to the generation of the first trigger signal (T1) by the sensing device (30). T2 After that, the power point tracker (20) is run cyclically to repeatedly determine the second target voltage (V). T2 ), d) Determine each second target voltage (V) T2 Compare with the target threshold. And wherein the controller (40) is further configured to: iii) During the operation of the power tracker, if the determined second target voltage is lower than the target threshold, switch from performing the second energy harvesting (EH-2) to performing the first energy harvesting (EH-1).

13. The power management device according to claim 11 or claim 12, wherein, The power point tracker (20) is run cyclically to determine the first target voltage (V). T1 The process repeats at a first frequency, wherein the power point tracker (20) is cyclically run to determine the second target voltage (V). T2 Repeated at a second frequency, and wherein: F1 > F2, or F1 < F2 or F1 = F2, where F1 and F2 respectively represent the first frequency and the second frequency.

14. The power management device according to any one of claims 11 to 13, wherein, The determination of the first target voltage (V) T1 ) and the determination of the second target voltage (V T2 The tracking time period (TP1) and the tracking time period (TP2) are executed respectively, wherein the first tracking time period (TP1) is different from the second tracking time period (TP2), or wherein the first tracking time period (TP1) is equal to the second tracking time period (TP2).

15. According to any one of the preceding claims Power management devices, among which, The sensing device (30) is configured to detect if the energy harvesting signal (E) has increased from above a third threshold (E). T3 If the value of ) decreases to below the third threshold, a third trigger signal (T3) is generated, wherein the third threshold is lower than the first threshold. Furthermore, the controller (40) is configured to switch the power management device between an energy harvesting mode (EH-M) and a low-power sleep mode (SLP-M), wherein the first energy harvesting and the second energy harvesting are performed in the energy harvesting mode, and wherein the controller (40) is configured to generate a sleep signal (SLP) for switching the power management device (1) from the energy harvesting mode (EH-M) to the low-power sleep mode (SLP-M) if the third trigger signal (T3) is generated.

16. The power management device according to claim 15, in, The sensing device (30) is configured to detect if the energy harvesting signal (E) has fallen below the third threshold (E). T3 If the value of ) increases to a value higher than the third threshold, then a fourth trigger signal (T4) is generated. Furthermore, the controller (40) is configured to switch from the sleep mode to the energy harvesting mode if the fourth trigger signal (T4) is generated.

17. The power management device according to any one of the preceding claims, wherein, The sensing device 30 includes a comparator for comparing the energy harvesting signal with the first threshold.

18. The power management device according to any one of the preceding claims, wherein, The sensing device (30) is configured to monitor the energy transmitted by the voltage converter (10) over a fixed time reference by counting the number of energy pulses transmitted over a reference time window, wherein the number of pulses counted over the fixed time reference corresponds to the energy harvesting signal (E).

19. The power management device according to claim 18, wherein, The fixed time reference is a time value between 1 and 250 milliseconds.

20. The power management device according to any one of the preceding claims, wherein, The voltage converter (10) is configured to, if the power point tracker (20) completes the adjustment of the target voltage (V) T1 V T2 Once the determination of ) is made, the process will begin.

21. The power management device according to any one of the preceding claims, wherein, During a fixed time period (ΔT) VC-ON During operation, the voltage converter (10) is regulated to the second target voltage (V). T2 ).

22. The power management device according to any one of claims 1 to 21, wherein, Perform the operation and adjust the voltage converter (10) to the second target voltage (V). T2 ), until the sensing device (30) detects that the energy harvesting signal has dropped below another threshold, and wherein the other threshold is equal to or lower than the first threshold (E). T1 ).

23. The power management device according to any one of the preceding claims, wherein, The power management device is further configured to receive an external trigger signal, and the controller (40) is further configured to start performing a second energy harvesting (EH-2) if the external trigger signal has been received.

24. The power point tracker according to claim 23, wherein, The controller (40) is configured to delay the start of operation of the power point tracker by a delay period (ΔT) relative to the external trigger signal.

25. The power management device according to any one of the preceding claims, further comprising: • Power input terminal (11), which is used to receive energy from an energy source, • Buffer capacitor terminal (13), which is used to connect the buffer capacitor, • A switch (SW) configured such that when the switch is open or closed, the buffer capacitor terminal (13) is electrically decoupled from or electrically coupled to the power input terminal (11), respectively. Furthermore, the power management device is configured to keep the switch (SW1) open when the power point tracker (20) is operable, and to keep the switch (SW1) closed when the voltage converter (10) is operable.

26. A method for managing energy from an energy source using a power management device (1), said power management device comprising: i) A voltage converter (10) configured to regulate the input voltage to a target voltage (V T ); and ii) a power point tracker (20), which is configured to transfer the target voltage (V) T The optimal operating voltage for extracting electricity from the energy source was determined. The method includes: • Monitor energy harvesting signals (E), which indicate harvestable electricity from an energy source; • The energy harvesting signal (E) is compared with a first threshold (E). T1 ) for comparison; • If the energy harvesting signal has fallen below the first threshold (E T1 If the value of ) increases to a value higher than the first threshold, then a first trigger signal (T) is generated. PPT ,T1); • As long as the first trigger signal (T) is not generated PPT ), then perform the first energy harvest (EH-1), wherein the first energy harvest includes: a) Run the power point tracker (20) cyclically to determine the first target voltage (V). T1 ),as well as b) Run and adjust the voltage converter (10) to the first target voltage (V T1 ); • If the first trigger signal (T) is generated PPT If the first energy harvesting (EH-1) is switched to the second energy harvesting (EH-2), the second energy harvesting (EH-2) includes: a) in response to generating the first trigger signal (T) PPT The power point tracker (20) is then started and used to determine the second target voltage (V). T2 ),as well as b) If the power point tracker has already determined the second target voltage (V) T2 If the voltage converter (10) is activated, it will start operating and adjust the voltage converter (10) to the second target voltage (V). T2 );as well as If a second trigger signal (T2) has already been generated, the switching from the second energy harvester (EH-2) to the first energy harvester (EH-1) is performed only at the moment when the power point tracker is running to determine the target voltage.

27. The method of claim 26, comprising: • If the energy harvesting signal (E) has been above the first threshold (E) T1 The value of ) decreases to below the second threshold (E) T2 If the value of ) is true, then a second trigger signal (T2) is generated, and wherein the second threshold (E) is true. T2 ) equal to or below the first threshold (E) T1 ),as well as If the second trigger signal (T2) has been generated, switch from performing the second energy harvest (EH-2) to performing the first energy harvest (EH-1).

28. The method of claim 27, comprising: • The second target voltage (V) is determined for the first time in response to the generation of the first trigger signal (T1). T2 After that, the power point tracker (20) is run cyclically to repeatedly determine the second target voltage (V). T2 ).

29. The method of claim 26, comprising: • The second target voltage (V) is determined for the first time in response to the generation of the first trigger signal (T1). T2 After that, the power point tracker (20) is run cyclically to repeatedly determine the second target voltage (V). T2 ),as well as • Determine each second target voltage (V) T2 Compare with the target threshold. • During the operation of the power tracker, if the determined second target voltage is lower than the target threshold, the system switches from performing the second energy harvest (EH-2) to performing the first energy harvest (EH-1).

30. The method of claim 26, comprising: • If a predefined time period (T) elapses after the first generation of the first trigger signal (T1) lap If the first trigger signal (T1) is not generated a second time, the process switches from performing the second energy harvest (EH-2) to performing the first energy harvest (EH-1).

31. The method according to any one of claims 26 to 30, comprising: Execute the above within a fixed time period (ΔT) VC-ON During operation, the voltage converter (10) is regulated to the second target voltage (V). T2 Alternatively, it can operate and adjust the voltage converter (10) to the second target voltage (V). T2 The energy harvesting signal continues until it drops below another threshold, wherein the other threshold is equal to or lower than the first threshold.

32. The method according to any one of claims 26 to 31, comprising: • If the energy harvesting signal (E) has been above the third threshold (E) T3 If the value of ) decreases to below the third threshold, then the system switches to a low-power sleep mode (SLP-M), wherein the third threshold (E) T3 ) is lower than the first threshold (E) T1 ).

33. The method of claim 32, comprising: • If the energy harvesting signal (E) has fallen below the third threshold (E) T3 If the value of ) increases to a value higher than the third threshold, then the sleep mode (SLP-M) is switched to perform the first energy harvesting (EH-1).

34. The method according to any one of claims 26 to 33, comprising: • Receive an external trigger signal, and if the external trigger signal is received, start performing the second energy harvest (EH-2).

35. The power management device according to any one of claims 1 to 25 or the method according to any one of claims 26 to 34, wherein, The power point tracker (20) includes a voltage tracking input, and wherein the power point tracker is configured to sample a voltage sensed at the voltage tracking input and to store the sampled voltage or a percentage of the sampled voltage as the target voltage.

36. The power management device according to any one of claims 1 to 25 or the method according to any one of claims 25 to 35, wherein, The power management device (1) is configured to operate the power point tracker (20) and the voltage converter (10) in a mutually exclusive manner.

37. The power management device according to any one of claims 1 to 25 or the method according to any one of claims 26 to 36, wherein, The first trigger signal (T) is generated in response to the sensing device (30). PPT The power point tracker (20) is started and the second target voltage (V) is determined. T2 The first trigger signal (T1) is executed within 250ms, preferably within 10ms, and more preferably within 1ms after the first trigger signal (T1) is generated.

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