Electromagnetic energy collection circuit and device based on ripple threshold and constant conduction duration

Abstract

The invention discloses an electromagnetic energy collection circuit and device based on a ripple threshold and a constant conduction duration, and the circuit comprises an AC-DC conversion unit which is used for converting an AC signal outputted by an electromagnetic generator into a DC signal; the ripple detection circuit is used for detecting a ripple signal in the output voltage of the electromagnetic generator and extracting a peak value of the ripple signal; the current sampling circuit is used for sampling the output current of the electromagnetic generator and extracting the valley value of the output current; the control unit is used for generating a control signal, and the control unit is also used for controlling and driving the switching operation of the alternating current-direct current conversion unit through a constant conduction duration, so that the dynamic adjustment of the output power of the electromagnetic generator is realized; and the load is used for receiving the direct current signal converted by the alternating current-direct current conversion unit, and the energy conversion efficiency of the electromagnetic energy collection circuit can be improved, the loss can be reduced and efficient energy transmission can be realized through combination of a dynamic control strategy based on a ripple threshold value and constant conduction duration adjustment.

Description

Technical Field

[0001] The present application relates to the technical field of electric energy collection, and in particular to an electromagnetic energy collection circuit and electronic equipment based on a ripple threshold and a constant conduction time. Background Art

[0002] With the rapid development of the Internet of Things, wearable devices and portable electronic products, the demand for low-power self-powered technology is increasing. Electromagnetic energy harvesting technology uses mechanical vibration, rotation or swing in the environment to convert mechanical energy into electrical energy through the principle of electromagnetic induction. It has attracted widespread attention due to its simple structure, low cost and no radiation. However, due to the uncertainty of mechanical excitation conditions in practical applications, the AC signal output by the electromagnetic generator often has large amplitude fluctuations and ripples, which makes the subsequent energy rectification and conversion face great challenges.

[0003] At present, traditional electromagnetic energy harvesting systems usually use cascade rectifiers and DC-DC converters or single-stage AC-DC converters to convert the AC signal output by the electromagnetic generator into a stable DC signal for use by the load. Most of these systems rely on fixed duty cycle or on-time control strategies, which can achieve basic energy harvesting when the environmental excitation conditions are relatively stable. However, in actual applications, due to the significant changes in the frequency, amplitude and phase of the mechanical energy input, traditional control methods are difficult to achieve efficient matching of the output power of the electromagnetic generator, resulting in a decrease in energy conversion efficiency and increased switching losses and harmonic interference. Summary of the invention

[0004] The purpose of the present application is to provide an electromagnetic energy harvesting circuit and electronic device based on a ripple threshold and a constant conduction time, aiming to solve at least one of the above problems.

[0005] In a first aspect, an embodiment of the present application provides an electromagnetic energy harvesting circuit based on a ripple threshold and a constant conduction time, which is used to harvest electromagnetic energy from an electromagnetic generator, including:

[0006] an AC-DC conversion unit, used for converting the AC signal output by the electromagnetic generator into a DC signal;

[0007] A ripple detection circuit, used for detecting a ripple signal in the output voltage of the electromagnetic generator and extracting a peak value of the ripple signal;

[0008] A current sampling circuit, used for sampling the output current of the electromagnetic generator and extracting the valley value of the output current;

[0009] A control unit, the control unit is used to receive feedback signals from the ripple detection circuit and the current sampling circuit, and generate a control signal according to a comparison result between the peak value of the ripple signal and the valley value of the current signal, and the control unit is also used to drive the switching operation of the AC-DC conversion unit through constant conduction time control, thereby realizing dynamic adjustment of the output power of the electromagnetic generator;

[0010] A load is used to receive the DC signal converted by the AC-DC conversion unit.

[0011] In one embodiment of the present application, the control unit includes a comparator, a single pulse generator, a constant on-time pulse generating circuit and a driving circuit;

[0012] The comparator is used to compare the peak value output by the ripple detection circuit with the valley value output by the current sampling circuit, and output the comparison result to the single pulse generator;

[0013] The single pulse generator is used to generate a trigger signal when receiving the output result;

[0014] After receiving the trigger signal, the constant on-time pulse generating circuit outputs a control pulse with a fixed pulse width to drive the switching operation of the AC-DC conversion unit.

[0015] In one embodiment of the present application, the control unit controls the switching operation of the AC-DC conversion unit through a constant on-time. The control unit maintains a fixed on-time within each switching cycle of the AC-DC conversion unit, and dynamically adjusts the off-time of the AC-DC conversion unit according to the feedback signal of the ripple detection circuit and the current sampling circuit to achieve dynamic adjustment of the output power of the electromagnetic generator.

[0016] In an embodiment of the present application, the control unit controls the switching operation of the AC-DC conversion unit by adjusting the current envelope threshold, and the control formula of the current envelope threshold is:

[0017]

[0018] Among them, I th is the current envelope threshold, V EH is the output voltage of the electromagnetic generator, G iv is the conversion coefficient between current and voltage, and R is the parasitic resistance.

[0019] In one embodiment of the present application, the control unit has a built-in microcontroller or digital signal processor, which digitally processes the signals fed back by the ripple detection circuit and the current sampling circuit through a preset adaptive control algorithm, and adjusts the switching frequency of the AC-DC conversion unit in real time to match the output characteristics of the electromagnetic generator.

[0020] In one embodiment of the present application, the ripple detection circuit applies a capacitor-resistance filter network to filter the output voltage of the electromagnetic generator to remove the DC component in the output voltage and extract the peak value of the ripple signal.

[0021] In one embodiment of the present application, the current sampling circuit includes a low-resistance sampling resistor and an amplifier, which is used to convert the current output by the electromagnetic generator into a corresponding voltage signal and extract the valley value of the voltage signal therefrom.

[0022] In one embodiment of the present application, the AC-DC conversion unit includes:

[0023] A first N-type metal oxide semiconductor transistor and a second N-type metal oxide semiconductor transistor and a rectifying unit;

[0024] The first N-type metal oxide semiconductor transistor and the second N-type metal oxide semiconductor transistor are connected in series; the rectifying unit includes a complementary diode and a filter capacitor.

[0025] In one embodiment of the present application, the current sampling circuit includes a sampling resistor and an operational amplifier to collect the current output by the electromagnetic generator and generate a corresponding current signal.

[0026] In a second aspect, an embodiment of the present application provides an electronic device, including an electromagnetic generator and an electromagnetic energy harvesting circuit based on a ripple threshold and a constant conduction time as described in the first aspect.

[0027] The beneficial effects of the embodiments of the present application are: by combining a dynamic control strategy based on ripple threshold with constant on-time adjustment, the energy conversion efficiency of the electromagnetic energy collection circuit is improved, losses are reduced, and efficient energy transmission is achieved. At the same time, the circuit can adaptively adjust the on-time so that it can still maintain stable power output when the input voltage fluctuates violently, thereby enhancing the adaptability of the system under complex working conditions. In addition, by optimizing the current tracking performance, it is ensured that the output current signal can quickly respond to changes in the input voltage, making the inductive energy transfer of the electromagnetic generator smoother, thereby improving the stability and dynamic response capability of the overall system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1It is a schematic diagram of an electromagnetic energy collection circuit module based on a ripple threshold and a constant conduction time provided in an embodiment of the present application.

[0029] Figure 2 It is a schematic diagram of the principle circuit of the electromagnetic energy collection circuit provided in the embodiment of the present application.

[0030] Figure 3 It is a module schematic diagram of the control unit provided in an embodiment of the present application.

[0031] Figure 4 It is a schematic diagram of a local circuit module provided in an embodiment of the present application.

[0032] Figure 5 It is a circuit connection diagram of an electromagnetic energy harvesting circuit based on ripple threshold and constant conduction time provided in an embodiment of the present application.

[0033] Figure 6 It is a schematic diagram of key waveforms of a circuit under sinusoidal excitation provided in an embodiment of the present application.

[0034] Figure 7 It is an enlarged schematic diagram of the key waveform provided in the embodiment of the present application.

[0035] Figure 8 It is a module schematic diagram of the electronic device provided in an embodiment of the present application.

[0036] Main component symbols

[0037] Electromagnetic 100 based on ripple threshold and constant on-time

[0038] Energy harvesting circuit

[0039] Ripple detection circuit 110

[0040] Current sampling circuit 120

[0041] AC-DC conversion unit 130

[0042] Control unit 140

[0043] Comparator 141

[0044] Single pulse generating circuit 142

[0045] Constant on-time generating circuit 143

[0046] Driving circuit 144

[0047] Load 150

[0048] Electromagnetic generator 200

[0049] Electronic equipment 300 DETAILED DESCRIPTION

[0050] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0051] With the rapid development of the Internet of Things, wearable devices and portable electronic products, the demand for low-power self-powered technology is increasing. Electromagnetic energy harvesting technology uses mechanical vibration, rotation or swing in the environment to convert mechanical energy into electrical energy through the principle of electromagnetic induction. It has attracted widespread attention due to its simple structure, low cost and no radiation. However, due to the uncertainty of mechanical excitation conditions in practical applications, the AC signal output by the electromagnetic generator often has large amplitude fluctuations and ripples, which makes the subsequent energy rectification and conversion face great challenges.

[0052] At present, traditional electromagnetic energy harvesting systems usually use cascade rectifiers and DC-DC converters or single-stage AC-DC converters to convert the AC signal output by the electromagnetic generator into a stable DC signal for use by the load. Most of these systems rely on fixed duty cycle or on-time control strategies, which can achieve basic energy harvesting when the environmental excitation conditions are relatively stable. However, in actual applications, due to the significant changes in the frequency, amplitude and phase of the mechanical energy input, traditional control methods are difficult to achieve efficient matching of the output power of the electromagnetic generator, resulting in a decrease in energy conversion efficiency and increased switching losses and harmonic interference.

[0053] In addition, the internal parameters of the electromagnetic generator (such as internal resistance and internal inductance) will change under different working conditions, and the traditional control strategy cannot be adjusted in real time to match the generator characteristics, which limits the response speed and stability of the system under dynamic conditions. Therefore, it is urgent to develop a new energy harvesting circuit that can dynamically adjust the switching operation of the AC-DC converter by real-time detection of the ripple signal in the output voltage and combined with constant on-time control technology to achieve optimal power transmission and energy conversion efficiency under different working conditions.

[0054] Therefore, the present application provides an electromagnetic energy collection circuit and electronic device based on ripple threshold and constant conduction time. By combining a dynamic control strategy based on ripple threshold with constant conduction time adjustment, the energy conversion efficiency of the electromagnetic energy collection circuit is improved, losses are reduced, and efficient energy transmission is achieved. At the same time, the circuit can adaptively adjust the conduction time so that it can still maintain stable power output when the input voltage fluctuates violently, thereby enhancing the system's adaptability under complex working conditions. In addition, by optimizing the current tracking performance, it is ensured that the output current signal can quickly respond to changes in the input voltage, making the inductive energy transfer of the electromagnetic generator smoother, thereby improving the stability and dynamic response capability of the overall system.

[0055] Figure 1 Schematic diagram of an electromagnetic energy collection circuit module based on ripple threshold and constant conduction time provided in an embodiment of the present application. Figure 1 As shown, the electromagnetic energy harvesting circuit 100 based on ripple threshold and constant conduction time includes a ripple detection circuit 110, a current sampling circuit 120, an AC-DC conversion unit 130, a control unit 140 and a load 150, wherein the ripple detection circuit 110 and the current sampling circuit 120 are respectively connected to the electromagnetic generator 200.

[0056] In the embodiment of the present application, the ripple detection circuit 110 is connected to the electromagnetic generator 200, the AC-DC conversion unit 130 and the control unit 140. The ripple detection circuit 110 is used to detect the ripple signal in the output voltage of the electromagnetic generator 200 and extract the peak value of the ripple signal.

[0057] Specifically, the ripple detection circuit 110 can use a high-pass filter or a peak detection circuit to extract the high-frequency component in the output voltage of the electromagnetic generator 200 to obtain a ripple signal, and further extract the peak value of the ripple signal through a rectification and holding circuit, thereby providing a basis for subsequent signal processing by the control unit 140.

[0058] It is understandable that the function of the ripple detection circuit 110 is to identify the changing trend of the output voltage of the electromagnetic generator 200, especially when the load and input conditions fluctuate, and to provide real-time ripple signal information to assist the control unit 140 in making appropriate switch control decisions.

[0059] In the embodiment of the present application, the current sampling circuit 120 is connected to the electromagnetic generator 200 and the control unit 140, and is used to sample the output current of the electromagnetic generator 200 and extract the valley value of the output current.

[0060] Specifically, the current sampling circuit 120 can use a sampling resistor or a current sensor to obtain the output current signal of the electromagnetic generator 200, and smooth the signal through a low-pass filter to extract the valley value of the output current. The valley value can characterize the instantaneous load state of the electromagnetic generator 200 and provide the control unit 140 with necessary feedback information to optimize the switch control strategy.

[0061] It is understandable that the design of the current sampling circuit 120 can ensure that the electromagnetic energy harvesting circuit 100 maintains a stable energy conversion efficiency under different working conditions, avoids energy loss due to severe current fluctuations, and improves the reliability of the overall system.

[0062] In the embodiment of the present application, the AC-DC conversion unit 130 is connected to the ripple detection circuit 110 and the load 150 , and is used to convert the AC signal output by the electromagnetic generator 200 into a DC signal.

[0063] Specifically, the AC-DC conversion unit 130 can be composed of a full-bridge rectifier circuit or a back-to-back switch rectifier circuit to convert the AC signal output by the electromagnetic generator 200 into a DC signal, and further smooth the output voltage through a filter capacitor to ensure that the load 150 can obtain stable DC power.

[0064] It is understandable that the efficient rectification characteristics of the AC-DC conversion unit 130 are crucial for electromagnetic energy collection. Reasonable circuit design can reduce energy loss, improve the overall energy conversion efficiency of the system, and support different types of load applications.

[0065] In the embodiment of the present application, the control unit 140 is connected to the ripple detection circuit 110, the current sampling circuit 120 and the AC-DC conversion unit 130. The control unit 140 is used to receive feedback signals from the ripple detection circuit 110 and the current sampling circuit 120, and generate a control signal according to the comparison result between the peak value of the ripple signal and the valley value of the current signal. The control unit 140 is also used to control the switching operation of the AC-DC conversion unit 130 through constant conduction time control, thereby realizing dynamic adjustment of the output power of the electromagnetic generator 200.

[0066] Specifically, the control unit 140 determines the working state of the electromagnetic generator 200 by comparing the peak value of the ripple signal with the valley value of the current signal, and generates a control signal to adjust the switching operation of the AC-DC conversion unit 130. The control unit 140 adopts a constant on-time strategy to ensure the stability of the switching operation, and can adaptively adjust the on-time according to changes in input conditions to optimize the energy collection efficiency.

[0067] It is understandable that the core function of the control unit 140 is to adjust the working state of the electromagnetic energy harvesting circuit 100 in real time, so that it can maintain efficient energy transmission under different input and load conditions and improve the system's adaptability in complex environments.

[0068] In the embodiment of the present application, the load 150 is connected to the AC-DC conversion unit 130 , and the load 150 is used to receive the DC signal converted by the AC-DC conversion unit 130 .

[0069] Specifically, the load 150 can be an energy storage device (such as a supercapacitor or a battery) or a direct power supply device (such as a wireless sensor node), which is used to receive the DC signal converted by the AC-DC conversion unit 130 and use the energy to perform corresponding functions.

[0070] It is understandable that the selection of load 150 can be adjusted according to application requirements. For example, in an energy self-supply system, a supercapacitor can be used for short-term storage, while in low-power electronic devices, it can be powered directly, thereby making the electromagnetic energy harvesting circuit 100 more applicable.

[0071] Please also read Figure 2 , Figure 2 Schematic diagram of the principle circuit of the electromagnetic energy collection circuit provided in the embodiment of the present application. Figure 2 As shown, the circuit includes an electromagnetic generator, a voltage source, an inductor, an internal resistor, a switching element and a rectifier.

[0072] In the embodiment of the present application, the electromagnetic generator can be equivalently modeled as a voltage source Veh, in which an internal resistor Reh and an inductor Leh are connected in series. To achieve efficient energy collection, this embodiment adopts a simplified interface circuit, which is mainly composed of a switch SW1 and a rectifier.

[0073] During operation, the control state of switch SW1 directly affects the energy collection process. When mechanical energy is applied from the outside to make the electromagnetic generator work, switch SW1 is periodically turned on and off:

[0074] Switch SW1 conduction stage: After switch SW1 is turned on, it is equivalent to a short-circuited electromagnetic generator. At this time, the output voltage Veh of the generator drops to zero, and the external kinetic energy is converted into electromagnetic energy and stored in the inductor Leh. Since there is no energy transmission to the load at this stage, the control of the conduction time is crucial to optimize energy storage.

[0075] Switch SW1 cut-off stage: When switch SW1 is turned off, the electromagnetic energy stored in the inductor Leh is released through the rectifier and converted into DC power to provide power to the load. The rectifier can ensure that the AC output of the electromagnetic generator is stably converted into DC power, thereby improving power supply stability and reducing losses.

[0076] The key to this embodiment is that only one switch SW1 is used for control. Compared with the traditional energy harvesting circuit that requires multiple switches, this solution reduces the number of switches on the power path while effectively reducing the energy loss during switch conduction and switching, thereby improving the energy conversion efficiency of the entire system. In addition, due to the reduction of additional control circuits and power devices, this solution is simpler in hardware implementation and is suitable for energy-constrained low-power systems, such as self-powered sensor nodes or low-power wireless devices.

[0077] Please also read Figure 3 , Figure 3 Schematic diagram of the modules of the control unit 140 provided in the embodiment of the present application. Figure 3 The control unit 140 shown includes a comparator 141 , a single pulse generator 142 , a constant on-time pulse generating circuit 143 , and a driving circuit 144 .

[0078] In the embodiment of the present application, the control unit 140 includes a comparator 141, a single pulse generator 142, a constant on-time pulse generating circuit 143 and a driving circuit 144. Each module works in coordination to achieve dynamic regulation of the output power of the electromagnetic generator.

[0079] In the embodiment of the present application, the comparator 141 is used to compare the peak value output by the ripple detection circuit 110 with the valley value output by the current sampling circuit 120 , and output the comparison result to the single pulse generator 142 .

[0080] Specifically, the comparator 141 is used to receive the peak signal output by the ripple detection circuit 110 and the valley signal output by the current sampling circuit 120, and compare the two to generate a comparison result signal. When the change of the peak voltage and the valley current reaches a set threshold, the comparator 141 outputs a high level signal to indicate entering the conduction stage.

[0081] It can be understood that the function of the comparator 141 is to realize real-time monitoring of the output signal of the electromagnetic generator, and ensure that the system can adjust the working state according to the dynamic changes of voltage and current to adapt to different energy input conditions.

[0082] In the embodiment of the present application, the single pulse generator 142 is used to generate a trigger signal when receiving an output result.

[0083] Specifically, after receiving the output signal of the comparator 141, the single pulse generator 142 generates a short trigger pulse for activating the subsequent pulse generating circuit. The time length of the trigger pulse is preset by the system to ensure that the constant on-time pulse generating circuit 143 is started at an appropriate time.

[0084] It is understandable that the function of the single pulse generator 142 is to provide a precise control signal so that the system can respond quickly when a suitable ripple signal change is detected and enter the energy conversion process, thereby improving the dynamic adaptability of the system.

[0085] In the embodiment of the present application, after receiving the trigger signal, the constant on-time pulse generating circuit 143 outputs a control pulse with a fixed pulse width to control the switching operation of the AC-DC conversion unit 130 .

[0086] Specifically, after receiving the trigger signal from the single pulse generator 142, the constant on-time pulse generating circuit 143 outputs a control pulse with a fixed pulse width, which is used to drive the switching operation of the AC-DC conversion unit 130. By ensuring that the on-time is constant, the energy collection process can be stabilized and the overall efficiency of the system can be optimized.

[0087] It can be understood that the design of the constant on-time pulse generating circuit 143 can effectively reduce the system's sensitivity to the input signal, make the energy collection process more robust, avoid frequent adjustments caused by fluctuations in the input signal, and improve system stability.

[0088] Specifically, the driving circuit 144 is used to receive the control signal of the constant on-time pulse generating circuit 143, and accordingly control the switching state of the AC-DC conversion unit 130. The driving circuit 144 adopts the power MOSFET driving technology, which can provide sufficient driving capability in a short time to ensure that the switching device is reliably turned on and off.

[0089] It is understandable that the design of the driving circuit 144 directly affects the switching loss and conversion efficiency of the system. Therefore, adopting an efficient driving solution can reduce energy loss and improve energy collection efficiency while ensuring the system response speed.

[0090] In an embodiment of the present application, the control unit 140 controls the switching operation of the AC-DC conversion unit 130 through a constant on-time. The control unit 140 maintains a fixed on-time within each switching cycle of the AC-DC conversion unit 130, and dynamically adjusts the off-time of the AC-DC conversion unit according to the feedback signal of the ripple detection circuit 110 and the current sampling circuit 120, so as to realize dynamic adjustment of the output power of the electromagnetic generator.

[0091] Specifically, the control unit 140 controls the switching operation of the AC-DC conversion unit 130 by a constant on-time, that is, maintains a fixed on-time in each switching cycle, and dynamically adjusts the off-time according to the feedback signals of the ripple detection circuit 110 and the current sampling circuit 120, thereby realizing dynamic adjustment of the output power of the electromagnetic generator.

[0092] It can be understood that by adopting a constant on-time strategy, the system can maintain a stable energy conversion effect under different working environments, and at the same time, combined with the dynamic adjustment mechanism of the feedback signal, it can achieve intelligent optimization of the energy harvesting process.

[0093] In the embodiment of the present application, the control unit 140 controls the switching operation of the AC-DC conversion unit 130 by adjusting the current envelope threshold. The control formula of the current envelope threshold is:

[0094]

[0095] Among them, I th is the current envelope threshold, V EH is the output voltage of the electromagnetic generator, G iv is the conversion coefficient between current and voltage, and R is the parasitic resistance.

[0096] It can be understood that this formula reflects the output characteristics of the electromagnetic generator and provides a dynamic adjustment method based on voltage, current and parasitic parameters, which enables the system to optimize the energy harvesting efficiency under different load conditions.

[0097] In the embodiment of the present application, the control unit 140 has a built-in microcontroller or digital signal processor, which digitally processes the signals fed back by the ripple detection circuit 110 and the current sampling circuit 120 through a preset adaptive control algorithm, and adjusts the switching frequency of the AC-DC conversion unit in real time to match the output characteristics of the electromagnetic generator.

[0098] Specifically, the control unit 140 has a built-in microcontroller or digital signal processor, which digitally processes the signals fed back by the ripple detection circuit 110 and the current sampling circuit 120 through a preset adaptive control algorithm, and adjusts the switching frequency of the AC-DC conversion unit 130 in real time to match the output characteristics of the electromagnetic generator.

[0099] It is understandable that by introducing a microcontroller or a digital signal processor, the system can achieve intelligent regulation, improve its adaptability to complex working conditions, and make the energy harvesting process more efficient and stable.

[0100] Please also read Figure 4 , Figure 4 It is a schematic diagram of a local circuit module provided in an embodiment of the present application.

[0101] The present application embodiment provides a schematic diagram including a ripple detection circuit 110 and a current sampling circuit 120, as shown in FIG. Figure 4 As shown, the ripple detection circuit 110 and the current sampling circuit 120 can effectively realize the accurate sampling and monitoring of the output signal of the electromagnetic generator 200. Specifically, the ripple detection circuit 110 and the current sampling circuit 120 filter the output voltage of the electromagnetic generator 200 by connecting an RC circuit in parallel at the output end of the electromagnetic generator 200, thereby extracting the ripple signal therein, and sending the ripple signal to the control unit 140 as a reference signal. This signal will be used to compare with the output of the current sampling circuit 120 to achieve accurate control of the current. At the same time, the current sampling circuit 120 provides the necessary current sampling signal by real-time monitoring the output loop current of the electromagnetic generator 200, which is used to further optimize the performance and response speed of the system.

[0102] Through this design, the output current state of the electromagnetic generator 200 can be accurately fed back to the control system to ensure that the system always maintains the best working state under different loads and working conditions. The filtering effect of the RC circuit smoothes the fluctuations of the input chopping voltage, thereby reducing the system instability caused by high-frequency noise or voltage fluctuations, and improving the reliability and energy efficiency of the system. In addition, as needed, those skilled in the art can also choose to use other types of filtering circuits to meet the performance requirements in different application scenarios, and this application does not limit this. The design of this module can effectively improve the efficiency of electromagnetic energy collection and conversion in practical applications, and has strong adaptability and practical value.

[0103] Please also read Figure 5 , Figure 5 It is a circuit connection diagram of an electromagnetic energy harvesting circuit based on ripple threshold and constant conduction time provided in an embodiment of the present application.

[0104] In the embodiment of the present application, the ripple detection circuit 110 uses a capacitor-resistor filter network (ie Figure 4 The RC circuit in the filter (in the embodiment) performs filtering processing on the output voltage of the electromagnetic generator 200 to remove the DC component in the output voltage and extract the peak value of the ripple signal.

[0105] In the embodiment of the present application, the current sampling circuit 120 includes a low-resistance sampling resistor and an amplifier, which is used to convert the current output by the electromagnetic generator 200 into a corresponding voltage signal and extract the valley value of the voltage signal therefrom.

[0106] In the embodiment of the present application, the AC-DC conversion unit 130 includes: a first N-type metal oxide semiconductor transistor M1, a second N-type metal oxide semiconductor transistor M2 and a rectifier unit. The first N-type metal oxide semiconductor transistor M1 and the second N-type metal oxide semiconductor transistor M2 are connected in series; the rectifier unit includes a complementary diode and a filter capacitor.

[0107] In the embodiment of the present application, the current sampling circuit includes a sampling resistor and an operational amplifier to collect the current output by the electromagnetic generator and generate a corresponding current signal.

[0108] Specifically, this circuit uses NMOS tubes M1 and M2 to form back-to-back switches to control the bidirectional flow of current, and cooperates with diodes D1 / D2 and capacitors C1 / C2 to form an AC-DC rectifier unit. In each switching cycle, when switch SW1 is turned on, the energy of the electromagnetic generator 200 is stored in the internal inductor Leh; when switch SW1 is turned off, the stored energy is transmitted to the load RL (load 150) through the rectifier to achieve efficient energy transmission. Among them, D1 and C1 are turned on in the positive half cycle of Veh, while D2 and C2 are turned on in the negative half cycle, thereby effectively completing the stable conversion of AC to DC.

[0109] In the embodiment of the present application, the current sampling circuit 120 is composed of an operational amplifier U1 and resistors R1 and R2 to form an inverting proportional amplifier, which is used to collect the output current of the electromagnetic generator 200 and convert it into a current signal Vsi. The ripple detection circuit 110 extracts the ripple signal Vsv of the input voltage Vin through a first-order filter to reflect the dynamic output characteristics of the electromagnetic generator 200. The comparator U2 compares the Vsv and Vsi signals and outputs a signal reflecting the falling edge of the positive half-cycle and the rising edge of the negative half-cycle of the output voltage of the electromagnetic generator 200. These edge signals are input into the XOR gate after delay processing to generate a narrow pulse signal.

[0110] During the constant on-time control process, the narrow pulse signal triggers the capacitor Cr to discharge, causing its charge to be released to zero instantly. At this time, the comparator U4 outputs a high-level signal. After the pulse ends, the constant current source Ir starts to charge the capacitor Cr. When the capacitor voltage rises to the set value Vset, the comparator U4 outputs a low level. Since Ir charges Cr with a constant current, the time required for the voltage to rise from zero to Vset is fixed, which is Therefore, U4 can output a pulse signal with a constant conduction time.

[0111] The driving circuit 144 is composed of a capacitor Cb, a diode Db and a resistor Rb, and the driving voltage is increased by a charge pump to ensure the stable conduction and cutoff of the NMOS tubes M1 and M2. Through the synergistic effect of the above modules, the circuit realizes efficient electromagnetic energy collection control based on ripple threshold and constant conduction time, effectively improving the energy conversion efficiency.

[0112] It can be understood that the key to this circuit is to maintain the dynamic balance of the Vsv and Vsi signals, that is, the load impedance adaptation of the generator. The advantage of this design is that the constant conduction time T on It is not absolutely fixed under harsh conditions, but can be adaptively adjusted as the environment changes. For example, when the input voltage Veh fluctuates violently, the change amplitude of the Vsv signal increases, and the Vsi signal may not be able to quickly follow the Vsv signal within one switching cycle. If the on-time is still kept constant at this time, the tracking speed of Vsi for the Vsv signal will be reduced. To address this problem, the design of this circuit enables the drive signal to always maintain the on-state of switch SW1, so that the inductance Leh of the electromagnetic generator continues to store energy, speeds up the rise speed of the Vsi signal, and enhances its ability to track the Vsv signal. Therefore, this solution not only improves the dynamic response capability of the circuit, but also demonstrates its adaptability advantages under complex working conditions.

[0113] Please also read Figure 6 , Figure 6 It is a schematic diagram of key waveforms of a circuit under sinusoidal excitation provided in an embodiment of the present application.

[0114] like Figure 6 As shown, the schematic diagram is used to demonstrate the working principle of the circuit and intuitively show the dynamic changes of current valley control, ripple signal and inductor current.

[0115] In this embodiment, the key waveforms of the circuit include three main curves. First, the thick dotted line represents the valley envelope threshold line of the current, which serves as the valley control reference line of the current ripple to ensure the stability of the current sampling circuit. The current-to-voltage conversion coefficient is defined as It is used to characterize the gain relationship of converting the current signal into the voltage signal. Secondly, the thin dotted line represents the ripple signal, which is extracted by the first-order RC filter circuit and reflects the AC component in the output voltage of the electromagnetic generator 200. Finally, the solid line represents the current waveform of the internal inductor of the electromagnetic generator 200, showing the change of the current during the switching cycle.

[0116] Compared with the conventional discontinuous current mode (DCM) and critical conduction mode (CRM), the AC-DC conversion unit 130 provided in this embodiment can effectively reduce the current ripple, thereby reducing the switching loss and improving the overall efficiency of the system. Its core advantage is that the switch on time T onThe current remains constant within each switching cycle, while the total duration of the switching cycle can be varied.

[0117] When approaching the zero-crossing point, due to the rapid change of the input signal, the switching frequency will increase accordingly to ensure that the current signal quickly tracks the input signal. In the area far from the zero-crossing point, the input signal changes tend to be stable, and the switching frequency decreases accordingly to reduce unnecessary switching losses. This adaptive adjustment mechanism based on dynamic changes in the signal not only improves the dynamic response capability of the circuit, but also further optimizes the energy collection efficiency, enabling it to more stably adapt to the electromagnetic energy conversion requirements in different working environments.

[0118] Please also read Figure 7 , Figure 7 is an enlarged schematic diagram of a key waveform provided in an embodiment of the present application. Figure 4 It can be clearly seen that the circuit has three switching modes during operation.

[0119] The key waveform analysis provided by the embodiment of the present application is as follows: Figure 6 As shown in the figure, by magnifying the waveform characteristics of two adjacent switching cycles, we can deeply understand the circuit working mechanism and parameter influence. Set t = 0 as the inductor current valley point, combined with Figure 4 The circuit structure shown in the figure shows three main switching mode characteristics when the system is working. In the switching mode 1 stage (corresponding to the time interval [t0, t1]), when the switch SW1 is turned on, a charging circuit consisting of the power supply Veh, the equivalent resistor Reh, the energy storage inductor Leh, the switch SW1 and the sampling resistor Rm is formed. At this time, the diodes D1 and D2 are in the cut-off state, and the series capacitors C1 and C2 release the stored energy through the load resistor RL. In this process, the output voltage Veh of the electromagnetic generator linearly charges the inductor Leh through the loop resistance, and its current dynamics can be expressed as The solution of the first-order differential equation is shown in Figure 1, where the total resistance R includes parasitic parameters such as Reh and Rm. It is worth noting that the RC compensation network is discharged through SW1 at this stage, and its ripple voltage follows the formula: The exponential decay law of the current can be used to effectively suppress the shunting effect on the main circuit by optimizing the Cf and Rf parameters.

[0120] When the circuit enters the switching mode 2 / 3 stage (corresponding to the [t1, t2] interval), after SW1 is turned off, the energy stored in the inductor is transferred to the capacitor C1 / C2 through D1 / D2. At this time, the formula The nonlinear attenuation characteristics of the inductor current under the action of the capacitor voltage VC1 are described. To ensure the feasibility of the analysis, the capacitance of C1 and C2 is preset to be large enough during the design so that the terminal voltage remains relatively constant during the switching cycle. At the same time, the RC network is charged and compensated by the electromagnetic generator during this stage, and its voltage change law is given by the formula Quantitative characterization. Based on the physical characteristics of low-frequency vibration input, the current valley value and ripple voltage peak value of adjacent switching cycles are expressed as I th =i L,on (0) = i L,off (T sw )(5), Formula V th =V sv,on (0) = V sv,off (T sw )(6) shows the equivalent relationship. This characteristic enables the system to achieve stable control with a fixed on-time Ton.

[0121] Key derivation present tense The linear relationship between the threshold current Ith and the equivalent admittance Giv is revealed, and this discovery provides a core theoretical basis for power regulation. By dynamically adjusting the Giv parameter, the current envelope threshold can be accurately set, thereby achieving closed-loop control of the output power of the electromagnetic generator. It is particularly important to point out that this control strategy is not only suitable for sinusoidal excitation conditions, but is also robust to complex vibration excitations with multi-frequency characteristics. This intelligent control method based on ripple injection comparison effectively solves the problem of adaptive regulation of traditional AC-DC converters in wide-band energy harvesting scenarios.

[0122] The electromagnetic energy harvesting circuit 100 based on ripple threshold and constant on-time provided in the embodiment of the present application realizes more efficient energy conversion by precisely controlling the valley value of the current ripple and the adjustment of the switching frequency. The circuit design makes the peak value and valley value of the inductor current almost equal in adjacent switching cycles, thereby reducing energy loss and switching loss. In addition, the circuit adopts the design of constant on-time and variable switching cycle, so that when approaching the zero point, the switching frequency automatically increases, improving the dynamic response capability of the circuit, and when away from the zero point, the frequency decreases, thereby realizing adaptive regulation and further optimizing the circuit performance.

[0123] Secondly, by controlling the current-to-voltage conversion coefficient, the circuit can flexibly adjust the current envelope threshold line, effectively improving the electromagnetic energy collection efficiency. Since this design is not only suitable for the output of sinusoidally excited electromagnetic generators, but can also be widely used in other low-frequency excitation scenarios, it has strong versatility and adaptability. In general, the embodiment of the electromagnetic energy collection circuit optimizes the power conversion efficiency, reduces energy loss, and has excellent dynamic response performance, which is of great significance for improving the overall performance of the electromagnetic energy collection system.

[0124] like Figure 8 As shown, Figure 8 Schematic diagram of an electronic device module provided by an embodiment of the present application. Figure 8 The electronic device 300 shown includes Figure 1 The electromagnetic energy harvesting circuit 100 and the electromagnetic generator 200 based on the ripple threshold and the constant conduction time are shown.

[0125] The electronic device 300 provided in the embodiment of the present application integrates the electromagnetic energy harvesting circuit 100 based on the ripple threshold and the constant conduction time and the electromagnetic generator 200. First, the electronic device 300 can efficiently convert mechanical vibration or other forms of energy into electrical energy, especially in a low-frequency excitation environment, and exhibits excellent energy harvesting capabilities. By precisely controlling the output current and voltage of the electromagnetic generator 200, the electromagnetic energy harvesting circuit 100 can effectively reduce switching losses and improve energy conversion efficiency, thereby significantly improving the energy utilization of the overall system.

[0126] In addition, the electronic device 300 is designed with an adaptive switching frequency mechanism, so that under different working conditions, the electromagnetic energy harvesting circuit 100 can optimize the working parameters according to environmental changes, thereby ensuring that efficient energy collection and conversion capabilities can be maintained under various working conditions. This flexible adaptability enables the electronic device 300 to be widely used in a variety of scenarios, with strong versatility and stability. In general, the design of the electronic device 300 improves the energy collection efficiency, and by optimizing the circuit performance, it has higher energy efficiency and reliability in practical applications, and has broad application prospects.

[0127] In addition, the electronic device 300 in the above embodiment can also be implemented as a collection (device group) composed of multiple devices. Each device constituting the device group can have a part or all of the functions or functional blocks of the electronic device 300 in the above embodiment. As a device group, it is sufficient to have all the functions or functional blocks of the electronic device 300.

[0128] The electromagnetic energy collection circuit 100 based on ripple threshold and constant conduction time and the electronic device 300 provided in the present application improve the energy conversion efficiency of the electromagnetic energy collection circuit, reduce losses, and achieve efficient energy transmission through a dynamic control strategy based on ripple threshold combined with constant conduction time adjustment. At the same time, the circuit can adaptively adjust the conduction time so that it can still maintain stable power output when the input voltage fluctuates violently, thereby enhancing the adaptability of the system under complex working conditions. In addition, by optimizing the current tracking performance, it is ensured that the output current signal can quickly respond to changes in the input voltage, making the inductive energy transfer of the electromagnetic generator smoother, thereby improving the stability and dynamic response capability of the overall system.

[0129] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional modules and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional modules and modules as needed, that is, the internal structure of the device can be divided into different functional modules or modules to complete all or part of the functions described above. The functional modules and modules in the embodiment can be integrated into a processing module, or each module can exist physically separately, or two or more modules can be integrated into one module, and the above-mentioned integrated modules can be implemented in the form of hardware or in the form of software functional modules. In addition, the specific names of the functional modules and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application.

[0130] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0131] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. An electromagnetic energy harvesting circuit based on ripple threshold and constant conduction time, used to harvest electromagnetic energy from an electromagnetic generator, characterized in that: include: an AC-DC conversion unit, used for converting the AC signal output by the electromagnetic generator into a DC signal; A ripple detection circuit, used for detecting a ripple signal in the output voltage of the electromagnetic generator and extracting a peak value of the ripple signal; A current sampling circuit, used for sampling the output current of the electromagnetic generator and extracting the valley value of the output current; A control unit, the control unit is used to receive feedback signals from the ripple detection circuit and the current sampling circuit, and generate a control signal according to a comparison result between the peak value of the ripple signal and the valley value of the current signal, and the control unit is also used to drive the switching operation of the AC-DC conversion unit through constant conduction time control, thereby realizing dynamic adjustment of the output power of the electromagnetic generator; A load is used to receive the DC signal converted by the AC-DC conversion unit.

2. The electromagnetic energy harvesting circuit based on ripple threshold and constant conduction time according to claim 1, characterized in that: The control unit includes a comparator, a single pulse generator, a constant on-time pulse generating circuit and a driving circuit; The comparator is used to compare the peak value output by the ripple detection circuit with the valley value output by the current sampling circuit, and output the comparison result to the single pulse generator; The single pulse generator is used to generate a trigger signal when receiving the output result; After receiving the trigger signal, the constant on-time pulse generating circuit outputs a control pulse with a fixed pulse width to drive the switching operation of the AC-DC conversion unit.

3. The electromagnetic energy harvesting circuit based on ripple threshold and constant conduction time according to claim 2, characterized in that: The control unit controls the switching operation of the AC-DC conversion unit through a constant on-time. The control unit maintains a fixed on-time in each switching cycle of the AC-DC conversion unit, and dynamically adjusts the off-time of the AC-DC conversion unit according to the feedback signal of the ripple detection circuit and the current sampling circuit, so as to realize dynamic adjustment of the output power of the electromagnetic generator.

4. The electromagnetic energy harvesting circuit based on ripple threshold and constant conduction time according to claim 3, characterized in that: The control unit controls the switching operation of the AC-DC conversion unit by adjusting the current envelope threshold. The control formula of the current envelope threshold is: Among them, I th is the current envelope threshold, V EH is the output voltage of the electromagnetic generator, G iv is the conversion coefficient between current and voltage, and R is the parasitic resistance.

5. The electromagnetic energy harvesting circuit based on ripple threshold and constant conduction time according to claim 4, characterized in that: The control unit has a built-in microcontroller or digital signal processor, which digitally processes the signals fed back by the ripple detection circuit and the current sampling circuit through a preset adaptive control algorithm, and adjusts the switching frequency of the AC-DC conversion unit in real time to match the output characteristics of the electromagnetic generator.

6. The electromagnetic energy harvesting circuit based on ripple threshold and constant conduction time according to claim 1, characterized in that: The ripple detection circuit applies a capacitor-resistance filter network to filter the output voltage of the electromagnetic generator to remove the DC component in the output voltage and extract the peak value of the ripple signal.

7. The electromagnetic energy harvesting circuit based on ripple threshold and constant conduction time according to claim 1, characterized in that: The current sampling circuit comprises a low-resistance sampling resistor and an amplifier, and is used to convert the current output by the electromagnetic generator into a corresponding voltage signal and extract the valley value of the voltage signal.

8. The electromagnetic energy harvesting circuit based on ripple threshold and constant conduction time according to claim 1, characterized in that: The AC-DC conversion unit comprises: A first N-type metal oxide semiconductor transistor and a second N-type metal oxide semiconductor transistor and a rectifying unit; The first N-type metal oxide semiconductor transistor and the second N-type metal oxide semiconductor transistor are connected in series; the rectifying unit includes a complementary diode and a filter capacitor.

9. The electromagnetic energy harvesting circuit based on ripple threshold and constant conduction time according to claim 1, characterized in that: The current sampling circuit includes a sampling resistor and an operational amplifier to collect the current output by the electromagnetic generator and generate a corresponding current signal.

10. An electronic device, characterized in that: It comprises an electromagnetic generator and an electromagnetic energy collection circuit based on ripple threshold and constant conduction time as described in any one of claims 1 to 9.

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