Ladder-type cascaded high-power electric field induction energy harvester and control circuit thereof

Abstract

The application discloses a ladder type cascade high-power electric field induction energy collector and a control circuit thereof, and belongs to the technical field of on-line monitoring equipment of power transmission lines.The circuit comprises a power supply module, a threshold control module and a switch control module.The power supply module provides energy for a high-frequency control circuit, and generates a voltage for power supply of a subsequent module.The threshold control module is used for monitoring the size of an input voltage, judging whether the input voltage reaches a charge-discharge threshold of an energy extraction capacitor, and giving a corresponding action instruction.The switch control module timely cuts off or inputs the subsequent module according to the action instruction, reduces the loss of the high-frequency control circuit, and guarantees the correctness of the control logic.The high-frequency drive output module outputs a PWM drive switch tube action with a controllable duty cycle, and specifically, the controllable duty cycle is realized by a voltage control current source.The application can greatly improve the output efficiency of the high-power electric field induction energy extraction device.

Description

Technical Field

[0001] This invention belongs to the technical field of online monitoring equipment for power transmission lines, specifically relating to a ladder-type cascaded high-power electric field induction energy harvester and its control circuit. Background Technology

[0002] Insulators are installed on high-voltage transmission lines, and the quality of the insulators is directly related to the safe and stable operation of the power grid. Insulators that have been in operation for a long time have been exposed to wind and sun, rain and snow erosion, and stress concentration, resulting in cracks and other defects. This can cause the insulation function of the insulators to fail, leading to brittle or breakdown accidents and causing serious economic losses.

[0003] The performance of an insulator can be judged by the magnitude of the leakage current flowing through it. When an insulator has overall or local defects, its leakage current will be abnormal. Therefore, the operating condition of the insulator can be obtained by monitoring the leakage current of the insulator.

[0004] An existing cascaded ladder topology electric field induction power supply circuit is used to solve the self-powering problem of insulator leakage current monitoring equipment. It can enable the insulator leakage current monitoring equipment to operate autonomously for a long time without the need for additional power supply.

[0005] The electric field induction power supply circuit with the above-mentioned cascaded ladder topology generates a microampere-level displacement current under the action of a high-voltage alternating electric field. The energy of the microampere-level displacement current is converted into the electric field energy of the electrolytic capacitor, and then the electric field energy of the electrolytic capacitor is converted into the electric field energy of the supercapacitor through a DC-DC circuit.

[0006] In the aforementioned trapezoidal cascaded topology electric field-induced power supply circuit (DC-DC circuit), the charging speed is improved by keeping the circuit switching devices on a fixed duty cycle. However, adding a DC-DC circuit stage increases the amount of additional control circuitry, increases internal circuit losses, and reduces the overall efficiency and power of the device.

[0007] In order to support the rapid construction and development of the power Internet of Things, it is imperative to improve equipment efficiency and power. Therefore, there is an urgent need for a control circuit of a ladder-type cascaded high-power electric field induction power supply circuit to replace the DC-DC circuit in the ladder-type cascaded high-power electric field induction power supply circuit. Summary of the Invention

[0008] This invention provides a ladder-type cascaded high-power electric field induction energy harvester and its control circuit, which can improve the output efficiency and power of self-energy harvesting from leakage current of insulators in high-voltage transmission lines.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] The control circuit for a ladder-type cascaded high-power electric field induction energy harvester includes:

[0011] The power supply module is used to generate a stable voltage to provide energy for subsequent circuits.

[0012] The threshold control module is used to monitor the input voltage, determine whether it has reached the charging and discharging threshold of the energy harvesting capacitor, and issue corresponding action commands.

[0013] The switch control module is used to disconnect or activate the high-frequency drive output module according to the action command.

[0014] The high-frequency drive output module is used to output a high-frequency controllable duty cycle PWM to drive the switching devices of external circuits.

[0015] Furthermore, the power supply module includes a first branch, a second branch, and a voltage regulator LDO; the first branch and the second branch are connected in parallel; the first branch includes a resistor R connected in series. f1 and resistance R f2 and resistance R f3 One end of the first branch is connected to the input voltage U1, and the other end is connected to the reference potential GND1, so the resistor R f1 and resistance R f2 The connection point with the N-MOS transistor Q f1 The gate of the N-MOS transistor is connected to the gate of the transistor, which is used to control the Q-MOS transistor. f1 The gate voltage; the input voltage U1 at resistor R f2 and resistance R f3 The voltage at the connection point is connected to the input of the threshold control module; the second branch includes an electrolytic capacitor C connected in series. f1 and an N-MOS transistor, wherein the N-MOS transistor Q f1 The drain of the N-MOS transistor Q is connected to the input voltage U1. f1 Source and electrolytic capacitor C f1 The positive terminal of the electrolytic capacitor C is connected. f1 The negative terminal of the voltage regulator LDO is connected to the reference potential GND1; the input terminal of the voltage regulator LDO is connected to the electrolytic capacitor C. f1 The positive terminal is connected, and the output terminal is connected to the input terminal of the threshold control module.

[0016] Furthermore, the N-MOS transistor Q f1 A resistor R is connected between the drain and the input voltage U1. f4 .

[0017] Furthermore, the resistance R f1 Resistance R f2 Resistance R f3 Resistance R f4 All of them use high-value resistors.

[0018] Furthermore, the N-MOS transistor Q f1 Source and electrolytic capacitor C f1 A diode D is connected between the positive and negative terminals. f1 .

[0019] Furthermore, the threshold control module includes a hysteresis comparator (CMP). 1,1 The hysteresis comparator CMP 1,1 The power supply terminal is connected to the output terminal of the voltage regulator LDO, and the hysteresis comparator CMP 1,1 The reference point terminal is connected to the circuit's reference potential GND1; the resistor R f2 and resistance R f3 The connection point with the hysteresis comparator CMP 1,1 The input terminal is connected; the hysteresis comparator CMP 1,1 The output terminal is connected to the P-MOS transistor Q in the switch control module. f2 and N-MOS transistor Q f3 The gate connection controls the P-MOS transistor Q. f2 and N-MOS transistor Q f3 The conduction and shutdown.

[0020] Furthermore, the switching control module includes a P-MOS transistor Q. f2 and N-MOS transistor Q f3 The P-MOS transistor Q f2 The gate of the P-MOS transistor Q is connected to the output of the threshold control module, the drain is connected to the output of the LDO regulator, and the source is connected to the high-frequency drive output module. When the input voltage U1 reaches the threshold of the threshold control module, the P-MOS transistor Q is turned off. f2 The high-frequency drive output module is stopped from receiving voltage; when the input voltage U1 is lower than the threshold of the threshold control module, voltage is supplied to the high-frequency drive output module; the N-MOS transistor Q... f3 The gate is connected to the output of the threshold control module, and the drain is connected to the capacitor C of the high-frequency drive output module. f2 One end is connected to the source and the capacitor C of the high-frequency drive output module. f2 The other end is connected and together with the circuit's reference potential GND1, and the N-MOS transistor Q is controlled by the signal from the threshold control module. f3 The conduction state occurs when the input voltage U1 reaches the hysteresis comparator CMP. 1,1 When the threshold is reached, the N-MOS transistor Q f3 Turn on when the input voltage U1 is lower than the hysteresis comparator CMP. 1,1 When the threshold is reached, the N-MOS transistor Q f3 Turn off.

[0021] Furthermore, the high-frequency drive output module includes: resistor R f5 Resistance R f6 Capacitor C f2 Hysteresis comparator CMP 1,2 Drive, voltage-controlled current source VCCS and N-MOS transistor Q f4 The resistor R f5 One end is connected to the power supply terminal of the threshold control module and to the P-MOS transistor Q in the switch control module. f2 One end is connected to the source terminal; the other end is connected to the input terminal of the threshold control module and resistor R. f6 Capacitor C f2 The voltage-controlled current source (VCCS) is connected; the hysteresis comparator (CMP) is connected. 1,2 The output terminal is connected to the driver Drive and to the N-MOS transistor Q. f4 The gate connection; the hysteresis comparator CMP 1,2 The voltage reference terminal is connected to the circuit's reference potential GND1; the resistor R f6 It is connected in parallel with the voltage-controlled current source VCCS and with the N-MOS transistor Q. f4 The drain connection is through the N-MOS transistor Q. f4 Connected to circuit reference point GND1, forming the third branch; the power supply terminal of the drive is connected to voltage V. cc1 The reference terminal is connected to the circuit reference potential GND1.

[0022] Furthermore, the voltage-controlled current source VCCS is composed of an electrolytic capacitor C. f1 Voltage V on cc1 control.

[0023] A ladder-type cascaded high-power electric field induction energy harvester includes the control circuit described above.

[0024] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0025] This invention provides a low-leakage, high-frequency control circuit for a ladder-type cascaded high-power electric field induction energy harvester. By improving existing high-voltage electric field induction energy harvesting circuits, power devices are replaced with low-loss switching devices, and the use of magnetic components is reduced, thus lowering circuit losses. Through voltage division using the input resistor, the circuit only needs to process small voltage signals to output control signals; high-voltage devices are no longer used, eliminating the need to handle high bus voltages; device size is reduced, circuit loops are shortened, parasitic parameters are reduced, and high-speed operation of MOSFETs is eliminated, resulting in smoother MOSFET drive signals. This significantly increases the output efficiency, power density, and circuit reliability of the original circuit, achieving high-efficiency, high-power output from the high-voltage electric field induction energy harvester. It boasts advantages of low loss and high reliability, greatly reducing energy loss in the high-power electric field induction energy harvester, increasing operating time, and improving charging speed.

[0026] Furthermore, the N-MOS transistor Q f1 A resistor R is connected between the drain and the input voltage U1. f4 The input voltage U1 is connected to a resistor R. f4 Limiting electrolytic capacitor C f1 The charging current is adjusted to prevent damage to circuit components.

[0027] Furthermore, the N-MOS transistor Q f1 Source and electrolytic capacitor C f1 A diode D is connected between the positive and negative terminals. f1 Electrolytic capacitor C f1 The positive terminal of the diode D f1 The cathode connection prevents electrolytic capacitor C f1 The voltage on the input voltage U1 flows back into the input voltage U1. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below; obviously, the drawings described below are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram showing the relationship between the power main circuit provided in the embodiment of the present invention and the present invention itself;

[0030] Figure 2 This is a schematic diagram of a specific circuit structure provided in an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the waveform change in the circuit that varies with the output voltage in an embodiment of the present invention.

[0032] Figure 3 From top to bottom, the middle section consists of: Figure 1 The voltage U1 of capacitor C1, Figure 2 Medium capacitor C f1 voltage V cc1 CMP 1,1 Output voltage U CM1 Drive output voltage U G1 , Figure 1 Inductor L1 current I L and C S Voltage U S t1 is the moment when capacitor C1 begins to charge after the circuit has stabilized. Detailed Implementation

[0033] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0034] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0035] The present invention will now be described in further detail with reference to the accompanying drawings:

[0036] Example 1

[0037] Please see Figure 1 In this embodiment of the invention, a high-voltage electric field induction energy harvesting main circuit is proposed. Figure 1 The high-frequency control circuit (HFCC) in the device not only solves the problem in traditional high-voltage electric field induction energy harvesting circuits, but also addresses the issue of electrolytic capacitor U... s The voltage on it keeps rising, approaching the level of capacitors C.n When the input voltage is applied, it causes the electrolytic capacitor C to... S The issue of slow charging has been addressed, and improvements have been made to address the energy loss caused by using a buck chopper circuit to create a voltage difference. Figure 1 The main circuit and the high-voltage electric field induction energy harvesting main circuit and control circuit are similar in topology and control method. They all adopt multi-stage energy harvesting and series charging and parallel discharging, with energy harvesting capacitors C1, C2...C n The charging process generates a voltage U1, which serves as the input voltage for the HFCC. The source of the N-MOS transistor Q1 in the circuit is used as the voltage reference point GND1 for the HFCC. The output signal of the HFCC is connected to the gate of the N-MOS transistor Q1 to drive the N-MOS transistor Q1. The high-voltage electric field induction energy harvesting main circuit and control circuit can specifically adopt the cascaded ladder topology electric field induction energy harvesting power supply circuit disclosed in Chinese invention patent application No. 2020104205650.

[0038] Please see Figure 1 and 2 The low-leakage high-frequency control circuit for the ladder-type cascaded high-power electric field-induced energy harvester provided in this embodiment of the invention includes:

[0039] The power supply module provides energy to the high-frequency control circuit by dividing the input voltage and powering the electrolytic capacitor C. f1 The charging and discharging of the circuit and the voltage regulation by the LDO generate a stable voltage to provide energy for the subsequent circuits.

[0040] The threshold control module monitors the input voltage U1 and determines whether it reaches the threshold values ​​of the energy harvesting capacitors C1, C2...C1. n The charging and discharging thresholds are determined and corresponding action commands are given.

[0041] The switch control module, based on action commands, promptly cuts off or engages the subsequent high-frequency drive output module, and during the charging process of the energy harvesting capacitor, it uses Q... f2 Disconnect the power supply to the high-frequency drive output module to reduce HFCC losses while ensuring the correctness of the control logic;

[0042] The high-frequency drive output module outputs a high-frequency, controllable duty cycle PWM to drive the switching devices in the external circuit. Specifically, the controllable duty cycle is achieved by a voltage-controlled current source (VCCS). The use of a high-frequency, controllable duty cycle PWM discharge method accelerates the discharge process of the energy-harvesting capacitor, thereby reducing the operating time of the high-frequency drive output module and further reducing the losses of the HFCC.

[0043] In this embodiment of the invention, the power supply module mainly includes: a resistor R f1 R f2 R f3 and R f4, N-MOS tube Q f1 Diode D f1 Electrolytic capacitor C f1 And a voltage regulator LDO. The power supply module mainly consists of two parallel branches and an LDO; the first branch is composed of resistor R. f1 and resistance R f2 Resistance R f3 These resistors are connected in series, with one end connected to the input voltage U1 and the other end connected to the reference potential GND1. A voltage divider is formed through the series resistors, with resistor R... f1 and resistance R f2 A voltage signal is taken out from the connection point as the Q of the N-MOS transistor. f1 The gate drive signal, when the value of the input voltage U1 after voltage division is greater than that of the N-MOS transistor Q. f1 When the on-voltage of the N-MOS transistor Q is reached, f1 When the input voltage U1 is turned on, the value after voltage division is less than that of the N-MOS transistor Q. f1 When the on-voltage of the N-MOS transistor Q is reached, f1 Off; input voltage U1 passes through resistor R f1 Resistance R f2 and resistance R f3 Voltage division is performed in resistor R. f2 and resistance R f3 The voltage at the connection point is connected to the input of the threshold control module, which provides a signal to the threshold control module. By judging the change in the input voltage U1, the threshold control module outputs a hysteresis signal; the other branch is the resistor R. f4 , N-MOS tube Q f1 Diode D f1 Electrolytic capacitor C f1 Series connection; resistor R f4 One end is connected to the input voltage U1, and the other end is connected to the N-MOS transistor Q. f1 Drain connection, N-MOS transistor Q f1 Source and diode D f1 Anode connection, diode cathode D f1 With electrolytic capacitor C f1 The positive terminal is connected to the electrolytic capacitor C. f1 The negative terminal is connected to the reference potential GND1; the input voltage U1 is connected through resistor R. f4 Diode D f1 and N-MOS transistor Q f1 Forming a source follower for the electrolytic capacitor C f1 Charging. Electrolytic capacitor C f1 The positive terminal of the diode D f1 The cathode connection prevents electrolytic capacitor C f1 The voltage across the capacitor flows back into the input voltage U1. Electrolytic capacitor Cf1 The energy stored in the upper part not only provides a stable drive voltage V for the drive circuit of the subsequent high-frequency drive output module. cc1 And it serves as the energy input source for the LDO.

[0044] In U1 via R f1 and R f2 R f3 Voltage division yields the N-MOS transistor Q in HFCC. f1 Gate voltage U G U G With V cc1 Comparison to determine the Q of the N-MOS transistor. f1 The conducting state of capacitor C makes capacitor C f1 Charge and discharge the LDO near its required input voltage to provide a stable voltage for subsequent modules.

[0045] When the input voltage U1 rises above the set value, the N-MOS transistor Q... f1 When the circuit is turned on, the input voltage U1 flows through resistor R. f4 To electrolytic capacitor C f1 The voltage V generated during charging cc1 When the input voltage U1 drops below the set value, the N-MOS transistor Q... f1 Turn off and stop supplying power to electrolytic capacitor C. f1 Charging; using resistor R f4 Limiting electrolytic capacitor C f1 The charging current is controlled to prevent damage to circuit components; diode D f1 Used to prevent the electrolytic capacitor C from... f1 Voltage V cc1 When the voltage exceeds the input voltage U1, a backflow of electrical energy occurs; the electrolytic capacitor C f1 Voltage V cc1 It will fluctuate with the input voltage U1; electrolytic capacitor C f1 Voltage V cc1 A stable voltage V is generated by an LDO. cc2 Voltage V cc1 Power is supplied to the driver in the high-frequency drive output module, voltage V cc2 It supplies power to the devices in the threshold control module, switch control module and high-frequency drive output module.

[0046] In this embodiment of the invention, the threshold control module mainly includes: a hysteresis comparator (CMP). 1,1 ; via hysteresis comparator CMP 1,1 Monitor the input voltage U1 to determine the P-MOS transistor Q. f2 and N-MOS transistor Q f3 The driving situation.

[0047] Hysteresis comparator CMP 1,1 The power supply terminal is connected to the output terminal of the LDO, and the stable voltage V cc2 As a hysteresis comparator CMP 1,1 The supply voltage, hysteresis comparator CMP 1,1 The reference point terminal is connected to the circuit's reference potential GND1; the input voltage U1 is connected through resistor R. f1 R f2 and R f3 Voltage division is performed in resistor R f2 and R f3 The connection point with the hysteresis comparator CMP 1,1 Input connection; Hysteresis comparator CMP 1,1 The output terminal is simultaneously connected to the P-MOS transistor Q in the next stage switching control module. f2 and N-MOS transistor Q f3 The gate connection generates a control signal to control the P-MOS transistor Q. f2 and N-MOS transistor Q f3 The hysteresis comparator CMP is turned on and off; when the input voltage U1 is low, the hysteresis comparator CMP... 1,1 Upon receiving a low-voltage signal from the power supply module, the hysteresis comparator CMP... 1,1 Output high voltage signal; when input voltage U1 is high, hysteresis comparator CMP 1,1 Upon receiving a high-voltage signal from the power supply module, the hysteresis comparator CMP... 1,1 Output a low voltage signal.

[0048] In this embodiment of the invention, the switch control module mainly includes: a P-MOS transistor Q. f2 and N-MOS transistor Q f3 .

[0049] P-MOS transistor Q of the switching control module f2 Gate connection threshold control module hysteresis comparator CMP 1,1 The output terminal is used to control the P-MOS transistor Q. f2 The conduction state of the P-MOS transistor Q. f2 The drain of the LDO is connected to the output and the terminal stable voltage V. cc2 Connection, P-MOS transistor Q f2 The source of the transistor is connected to the high-frequency drive output module; the N-MOS transistor Q of the switch control module... f3 Gate-connected hysteresis comparator CMP 1,1 The output terminal is used to control the N-MOS transistor Q. f3 The conduction state of the N-MOS transistor Q. f3 The drain of the high-frequency drive output module and the capacitor C f2 One end is connected to the N-MOS transistor Q.f3 The source and capacitor C of the high-frequency drive output module f2 The other end is connected and together with the circuit's reference potential GND1; as the input voltage U1 decreases to reach the hysteresis comparator CMP... 1,1 When the threshold is reached, the P-MOS transistor Q f2 Shut down and stop supplying voltage to the high-frequency drive output module to prevent damage to components and reduce circuit losses; when the input voltage U1 rises to the level of the hysteresis comparator CMP... 1,1 When the threshold is reached, the P-MOS transistor Q f2 Turn off via P-MOS transistor Q f2 Provides power to the high-frequency drive output module; and works with the P-MOS transistor Q. f2 Unlike other methods, the threshold control module uses a hysteresis comparator (CMP). 1,1 The signal is used to control the N-MOS transistor Q. f3 Whether it is turned on depends on the input voltage U1 decreasing to reach the hysteresis comparator CMP. 1,1 When the threshold is reached, the N-MOS transistor Q f3 When the input voltage U1 rises to the level of the hysteresis comparator CMP, it is turned on. 1,1 When the threshold is reached, the N-MOS transistor Q f3 Shutdown; via hysteresis comparator CMP 1,1 Control of P-MOS transistor Q at the same time f2 and N-MOS transistor Q f3 Only one MOSFET is turned on; when the P-MOSFET Q... f2 When the N-MOS transistor Q is turned on f3 Turn off, stabilize voltage V cc2 Through P-MOS transistor Q f2 Power is supplied to the high-frequency drive output module; when the P-MOS transistor Q... f2 When the N-MOS transistor Q is turned off f3 On, stable voltage V cc2 Unable to supply power to the high-frequency drive output module, and capacitor C in the high-frequency drive output module... f2 Through the conducted N-MOS transistor Q f3 Discharge.

[0050] In this embodiment of the invention, the high-frequency drive output module mainly includes: resistor R f5 R f6 Capacitor C f2 , N-MOS tube Q f4 Voltage-controlled current source (VCCS), hysteresis comparator (CMP) 1,2 The high-frequency drive output module mainly consists of a resistor R. f5 R f6 Capacitor C f2 , N-MOS tube Qf4 A hysteresis comparator CMP composed of a voltage-controlled current source (VCCS) 1,2 Control signal triggering section, hysteresis comparator CMP 1,2 and drive; the voltage-controlled current source VCCS is composed of an electrolytic capacitor C f1 Voltage V on cc1 Control, V cc1 The larger the value of VCCS, the larger the current. cc1 The smaller the value, the smaller the VCCS current.

[0051] resistor R f5 One end is connected to the hysteresis comparator CMP 1,2 Connect to the power supply terminal and to the P-MOS transistor Q in the switching control module. f2 Source connection; resistor R f5 The other end is connected to the hysteresis comparator CMP. 1,2 The input terminal is simultaneously connected to resistor R. f6 Capacitor C f2 The voltage-controlled current source (VCCS) is connected in phase; the hysteresis comparator (CMP) is connected in phase. 1,2 The output terminal is connected to the driver Drive and to the N-MOS transistor Q. f4 The gate connection provides a drive signal for the drive driver, and for the N-MOS transistor Q. f4 Provides control signals; hysteresis comparator CMP 1,2 The voltage reference terminal is connected to the circuit's reference terminal GND1; resistor R f6 It is connected in parallel with the voltage-controlled current source VCCS and with the N-MOS transistor Q. f4 The drain connection is through the N-MOS transistor Q. f4 Connected to circuit reference point GND1, and N-MOS transistor Q f4 The source of capacitor C is connected to the circuit reference point GND1; f2 Connected in parallel with the circuit described above, capacitor C f2 One end is connected to a resistor R f6 One end is connected to the voltage-controlled voltage terminal VCCS, and the other end is connected to the circuit reference point GND1; when capacitor C f2 Voltage drop over hysteresis comparator CMP 1,2 When the threshold is reached, the hysteresis comparator CMP 1,2 The threshold output is low; when capacitor C f2 Voltage rises over hysteresis comparator CMP 1,2 When the threshold is reached, the hysteresis comparator CMP 1,2 The threshold output is high; the power supply terminal of the driver is connected to a stable voltage V. cc1The reference terminal of the driver is connected to the circuit reference point GND1; when the driver receives a high-frequency signal, the output voltage of the driver is the supply voltage V. cc1 The high-voltage drive signal; when the Drive receives a low-frequency signal, the Drive receives a low-voltage drive signal; resistor R f5 With capacitor C f2 Perform RC charge / discharge with hysteresis comparator CMP 1,2 To generate a drive signal for the drive; resistor R f6 In N-MOS transistor Q f4 When turned off, it provides a current loop for the voltage-controlled current source VCCS.

[0052] The resistor R f1 Resistance R f2 Resistance R f3 Resistance R f4 Resistance R f6 Using high-value resistors simplifies the circuit structure, reduces the number of components, lowers costs, and reduces the power supply startup current.

[0053] When the input voltage U1 is relatively low, the generated voltage V cc1 If the current is smaller, the current generated by the voltage-controlled current source VCCS will be smaller, and the capacitance C will be smaller. f2 The discharge time becomes longer, and the hysteresis comparator CMP... 1,2 The input drive signal time becomes longer, and the hysteresis comparator CMP... 1,2 The higher output time increases, the longer the high output time of the driver, the larger the duty cycle of the PWM wave, and the longer the power extraction capacitors C1, C2...C n To capacitor C s The charging time becomes longer; when the input voltage U1 is large, the generated voltage V cc1 If the capacitance is large, the current generated through the voltage-controlled current source VCCS will be large, and the capacitance C will be large. f2 The discharge time is shortened, and the hysteresis comparator CMP 1,2 The input drive signal time becomes shorter, and the hysteresis comparator CMP... 1,2 The output high-level time becomes shorter, the drive output high-level time becomes shorter, the PWM wave duty cycle becomes smaller, and the energy harvesting capacitors C1, C2...C n To capacitor C s The charging time is reduced; the capacitor C is controlled by the threshold control module. f2 The voltage on the P-MOS transistor Q is such that when the input voltage U1 is large, the voltage across the P-MOS transistor Q is high. f2 Turn on, N-MOS transistor Q f3 When turned off, the stable voltage V generated by the LDO cc2 Continuing for capacitor C f2Charging; when the input voltage U1 is small, the P-MOS transistor Q... f2 Turn off, N-MOS transistor Q f3 When the capacitor C is turned on, it releases the circuit. f2 When the energy is depleted, the HFCC stops working to prevent energy backflow, and waits for the input voltage U1 to recharge to the discharge threshold before starting the next energy cycle.

[0054] Example 2

[0055] A ladder-type cascaded high-power electric field induction energy harvester includes a main circuit for energy harvesting based on a high-voltage electric field induction and a control circuit as described in Example 1.

[0056] The power supply module provides energy to the HFCC, generating V cc1 and V cc2 The threshold control module monitors the value of U1, determines whether it has reached the charging / discharging threshold of the energy-harvesting capacitor, and issues corresponding action commands. The switch control module promptly cuts off or engages subsequent modules based on the action commands, reducing HFCC losses while ensuring the correctness of the control logic. The high-frequency drive output module outputs a high-frequency, controllable duty cycle PWM to drive Q1. Specifically, the controllable duty cycle is implemented by the VCCS (voltage-controlled current source). The VCCS is controlled by V... cc1 Control, as the energy harvesting capacitor discharges, V cc1 Decrease, controlled current I c Decrease, capacitance C f2 The rate of voltage drop across the terminals decreases, CMP 1,2 The high-level output duration becomes longer, and the duty cycle becomes larger.

[0057] Please see Figure 1 and Figure 3 The diagram shows the waveform changes with the output voltage in the first stage of the power circuit.

[0058] During the initial charging phase: t1~t2: displacement current I DC When capacitor C1 is charged, the rate of rise of the voltage U1 across capacitor C1 is I. DC / C1 (ignoring the voltage divider current I1 in HFCC), N-MOS transistor Q in HFCC f1 Gate voltage U G From U1 via R f1 and R f2 and R f3 U is obtained by voltage division. G <V cc1 Q f1 When switched off, the energy required by the HFCC is supplied by capacitor C. f1 Provided, V cc1 Decrease, the rate of decrease is I s1 / C f1 Is1 This is the sum of the current losses of the LDO, threshold control module, and switch control module of the HFCC.

[0059] t2~t3: At time t2, U1 and V cc1 satisfy

[0060]

[0061] Q f1 On, V cc1 As U1 increases, the above equation is always satisfied. Displacement current I DC A portion of the current I DC1 For capacitor C f1 As the battery is charged and provides energy to the HFCC, the rate of rise of U1 decreases, becoming (I DC -I DC1 ) / C1,V cc1 The rate of increase is (I DC1 -I s1 ) / C f1 The V Df1 For diode D f1 The pipe pressure drop, U th(Qf1) For Q f1 The conduction threshold;

[0062] t3~t5: At time t3, U1 reaches the discharge threshold U of the threshold control module. 1max CMP 1,1 Output low level, P-MOS transistor Q f2 Turn on, N-MOS transistor Q f3 When the circuit is off, the high-frequency drive output module operates, outputting a high-frequency, controllable duty cycle PWM. Energy is converted from capacitor C1 to C. S In the middle, the output voltage U S The voltage rises. Simultaneously, U1 rapidly decreases, causing the N-MOS transistor Q to... f1 Turn off, electrolytic capacitor C f1 Powering HFCC, V cc1 Decrease, at a rate of I s2 / C f1 I s2 This is the sum of the current losses of the LDO, threshold control module, switch control module, and high-frequency drive output module of the HFCC.

[0063] The increase in current flowing through inductor L1, ΔI, during each PWM cycle L(on) for:

[0064]

[0065] Decrease ΔI L(off) for:

[0066]

[0067] Where D is the duty cycle, T is the switching period, and U... D1,2 For diode D 1,2 Pipe pressure drop;

[0068] From the two formulas above, we can see that U1 is relatively large within the range of t3 to t4, and U S Smaller, therefore ΔI L(on) >ΔI L(off) The current generally shows an upward trend; as time goes on, U1 decreases, U S Increase, ΔI L(on) Decrease, ΔI L(off) It increases, at t4, ΔI L(off) =ΔI L(on) Within the range of t4 to t5, ΔI L(off) >ΔI L(on) Current I L The overall trend is downward;

[0069] t5~t6: At time t5, U1 drops to the charging threshold U of the threshold control module. 1min CMP 1,1 Output high level, P-MOS transistor Q f2 When switched off, the high-frequency drive output module stops working, and U1 begins to rise, thus ending one charge-discharge cycle of C1. L It drops to 0 at time t6 and remains continuous from t3 to t6;

[0070] During the later stages of charging:

[0071] The later stages of charging are generally similar to the earlier stages, but there are some unique aspects, including the following:

[0072] t7~t9: The working process is similar to t1~t3, but V at t7 is different. cc1 The initial value is lower than that at t1, and Q is satisfied faster under the same charging efficiency. f1 The conduction condition and Q at time t8. f1 When the circuit is turned on, the inflection point of the U1 rise rate is brought forward, and the charging time of C1 becomes longer.

[0073] t8: Q f1 Conducting I DC A portion of the current I DC1 For capacitor C f1 As the battery is charged and provides energy to the HFCC, the rate of rise of U1 decreases, becoming (I DC -I DC1 ) / C1,V cc1 The rate of increase is (I DC1-I s1 ) / C f1 ;

[0074] t9~t 10 Due to U S Larger, ΔI L(on) Always less than ΔI L(off) I L Intermittent, as time progresses, the PWM duty cycle gradually increases, ΔI L(on) The increase in current accelerates the decrease in U1, shortening the original discharge time of C1. Therefore, in the early stage of charging, the inductor current I... L The charging process is continuous, with a large peak current, a short discharge time for the energy harvester capacitor, and minimal change in the PWM duty cycle. However, in the later stages of charging, the charging time for the energy harvester capacitor becomes longer, and the inductor current I... L Intermittent operation leads to a smaller peak current and a gradually increasing PWM duty cycle, which shortens the discharge time of the original energy-harvesting capacitor.

[0075] This invention, in summary, discloses a low-leakage, high-frequency control circuit for a ladder-type cascaded high-power electric field induction energy harvester. By improving existing high-voltage electric field induction energy harvesting circuits, this invention replaces the voltage-dropping chopper section of the original circuit with the aforementioned control circuit. This reduces the use of power semiconductors and magnetic components, significantly increasing the output efficiency and power density of the original circuit. This has significant practical implications for the better and more stable operation of related devices, leading to substantial economic and social benefits. In conclusion, the circuit device provided by this invention can greatly improve the high-efficiency, high-power output efficiency of high-voltage electric field energy harvesting circuits, reduce circuit losses, and has the advantages of low loss and high reliability. It significantly reduces energy loss in related equipment, increases operating time, and improves charging speed, thus possessing significant practical implications and bringing substantial economic and social benefits.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention without departing from the spirit and scope of the present invention.

Claims

1. A control circuit for a ladder-type cascaded high-power electric field induction energy harvester, characterized in that, include: The power supply module is used to generate a stable voltage to provide energy for subsequent circuits. The threshold control module is used to monitor the input voltage, determine whether it has reached the charging and discharging threshold of the energy harvesting capacitor, and issue corresponding action commands. The switch control module is used to disconnect or activate the high-frequency drive output module according to the action command. The high-frequency drive output module is used to output a high-frequency controllable duty cycle PWM signal to drive the switching devices of external circuits.

2. The control circuit of the ladder-type cascaded high-power electric field induction energy harvester according to claim 1, characterized in that, The power supply module includes a first branch, a second branch, and a voltage regulator LDO; the first branch and the second branch are connected in parallel; The first branch includes a series resistor R f1 and resistance R f2 and resistance R f3 One end of the first branch is connected to the input voltage U1, and the other end is connected to the reference potential GND1, so the resistor R f1 and resistance R f2 The connection point with the N-MOS transistor Q f1 The gate of the N-MOS transistor is connected to the gate of the transistor, which is used to control the Q-MOS transistor. f1 The gate voltage; The input voltage U1 is at the resistance R f2 and resistance R f3 The voltage at the connection point is connected to the input of the threshold control module; The second branch includes an electrolytic capacitor C connected in series. f1 and an N-MOS transistor, wherein the N-MOS transistor Q f1 The drain of the N-MOS transistor Q is connected to the input voltage U1. f1 Source and electrolytic capacitor C f1 The positive terminal of the electrolytic capacitor C is connected. f1 The negative terminal is connected to the reference potential GND1; The input terminal of the voltage regulator LDO is connected to the electrolytic capacitor C. f1 The positive terminal is connected, and the output terminal is connected to the input terminal of the threshold control module.

3. The control circuit of the ladder-type cascaded high-power electric field induction energy harvester according to claim 2, characterized in that, The N-MOS transistor Q f1 A resistor R is connected between the drain and the input voltage U1. f4 .

4. The control circuit of the ladder-type cascaded high-power electric field induction energy harvester according to claim 3, characterized in that, The resistor R f1 Resistance R f2 Resistance R f3 Resistance R f4 All of them use high-value resistors.

5. The control circuit of the ladder-type cascaded high-power electric field induction energy harvester according to claim 2, characterized in that, The N-MOS transistor Q f1 Source and electrolytic capacitor C f1 A diode D is connected between the positive and negative terminals. f1 .

6. The control circuit of the ladder-type cascaded high-power electric field induction energy harvester according to claim 2, characterized in that, The threshold control module includes a hysteresis comparator (CMP). 1,1 The hysteresis comparator CMP 1,1 The power supply terminal is connected to the output terminal of the voltage regulator LDO, and the hysteresis comparator CMP 1,1 The reference point terminal is connected to the circuit's reference potential GND1; The resistor R f2 and resistance R f3 The connection point with the hysteresis comparator CMP 1,1 The input terminal is connected; The hysteresis comparator CMP 1,1 The output terminal is connected to the P-MOS transistor Q in the switch control module. f2 and N-MOS transistor Q f3 The gate connection controls the P-MOS transistor Q. f2 and N-MOS transistor Q f3 The conduction and shutdown.

7. The control circuit of the ladder-type cascaded high-power electric field induction energy harvester according to claim 1, characterized in that, The switching control module includes a P-MOS transistor Q. f2 and N-MOS transistor Q f3 ; The P-MOS transistor Q f2 The gate of the P-MOS transistor Q is connected to the output of the threshold control module, the drain is connected to the output of the LDO regulator, and the source is connected to the high-frequency drive output module. When the input voltage U1 reaches the threshold of the threshold control module, the P-MOS transistor Q is turned off. f2 Stop supplying voltage to the high-frequency drive output module; when the input voltage U1 is lower than the threshold of the threshold control module, supply voltage to the high-frequency drive output module. The N-MOS transistor Q f3 The gate is connected to the output of the threshold control module, and the drain is connected to the capacitor C of the high-frequency drive output module. f2 One end is connected to the source and the capacitor C of the high-frequency drive output module. f2 The other end is connected and together with the circuit's reference potential GND1, and the N-MOS transistor Q is controlled by the signal from the threshold control module. f3 The conduction state occurs when the input voltage U1 reaches the hysteresis comparator CMP. 1,1 When the threshold is reached, the N-MOS transistor Q f3 Turn on when the input voltage U1 is lower than the hysteresis comparator CMP. 1,1 When the threshold is reached, the N-MOS transistor Q f3 Turn off.

8. The control circuit of the ladder-type cascaded high-power electric field induction energy harvester according to claim 1, characterized in that, The high-frequency drive output module includes: resistor R f5 Resistance R f6 Capacitor C f2 Hysteresis comparator CMP 1,2 Drive, voltage-controlled current source VCCS and N-MOS transistor Q f4 ; The resistor R f5 One end is connected to the power supply terminal of the threshold control module and to the P-MOS transistor Q in the switch control module. f2 One end is connected to the source terminal; the other end is connected to the input terminal of the threshold control module and resistor R. f6 Capacitor C f2 1. Connect the voltage-controlled current source (VCCS); The hysteresis comparator CMP 1,2 The output terminal is connected to the driver Drive and to the N-MOS transistor Q. f4 Gate connection; The hysteresis comparator CMP 1,2 The voltage reference terminal is connected to the circuit's reference potential GND1; The resistor R f6 It is connected in parallel with the voltage-controlled current source VCCS and with the N-MOS transistor Q. f4 The drain connection is through the N-MOS transistor Q. f4 Connect it to the circuit reference point GND1 to form the third branch; The power supply terminal of the drive is connected to a voltage V. cc1 The reference terminal is connected to the circuit reference potential GND1.

9. The control circuit of the ladder-type cascaded high-power electric field induction energy harvester according to claim 8, characterized in that, The voltage-controlled current source VCCS consists of an electrolytic capacitor C f1 Voltage V on cc1 control.

10. A ladder-type cascaded high-power electric field induction energy harvester, characterized in that, Includes the control circuit as described in claim 1.

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