Electromagnetic plate frequency tracking system

Abstract

The utility model belongs to the technical field of electromagnetic plate frequency tracking, and relates to an electromagnetic plate frequency tracking system, which comprises a dynamic frequency tracking module used for adjusting high-frequency PWM signal frequency in real time and keeping the high-frequency PWM signal frequency consistent with the resonant frequency of an electromagnetic plate; the power closed-loop control module is used for dynamically adjusting the PWM duty ratio and stabilizing the output power through current / voltage sampling and ADC conversion; the optimized gate driving module is used for reducing the parasitic conduction risk of the MOSFET and improving the energy efficiency; the data processing interface module is used for accessing a cloud big data platform optimization model; the dynamic frequency tracking module is electrically connected with the power closed-loop control module, the optimized gate driving module and the data processing interface module respectively; according to the utility model, the frequency of the driving signal is dynamically adjusted by analyzing the operation states of load change, temperature fluctuation and the like during the operation of the electromagnetic plate in real time, so that the electromagnetic plate always works within the optimal frequency range, and therefore, the energy transmission efficiency is higher, the induction heating is faster, and the energy consumption is lower.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of electromagnetic plate frequency tracking, and relates to an electromagnetic plate frequency tracking system. BACKGROUND

[0002] As a core component for realizing efficient conversion of electric energy and mechanical energy in industrial equipment, the electromagnetic plate is widely used in the fields of electromagnetic heating, fluid delivery, industrial pump valve control, etc. Its core function is to generate a magnetic field through electromagnetic induction to generate heat energy and realize specific physical effects (such as salt brine crystallization inhibition). With the increasing demand for industrial automation and intelligence, the efficient power regulation capability of the electromagnetic plate has become a key direction for technological development. In the industrial scenarios involving salt brine treatment such as salt lake lithium extraction and seawater desalination, the electromagnetic plate is often used to inhibit salt brine crystallization and optimize fluid delivery efficiency.

[0003] However, the existing electromagnetic plates mostly adopt open-loop control schemes with fixed frequency or preset parameters, relying on manual debugging or simple PID algorithms to realize power regulation. Such open-loop control or fixed frequency regulation mode schemes cannot dynamically adjust the output according to real-time working conditions (such as fluid resistance changes and crystalline accumulation), resulting in energy waste or insufficient inhibition effect.

[0004] In addition, some electromagnetic plates also use closed-loop control systems to improve accuracy through feedback regulation, but such closed-loop control systems require external sensors (such as current transformers and temperature probes) and complex control circuits, resulting in large equipment size and high cost. For example, the traditional electromagnetic oven power regulation device needs to be externally connected to a constant voltage source and a constant current source for static detection, and relies on a stepper motor to adjust the gain, which is structurally redundant and has obvious response delay.

[0005] Therefore, there is a need for a device or method that does not require additional sensors and can adjust the working frequency of the electromagnetic plate in real time to ensure accurate matching of power output and working condition requirements. UTILITY MODEL CONTENTS

[0006] The utility model is based on the electromagnetic plate closed-loop power regulation scheme of variable frequency phase-locked control, which realizes higher electromagnetic plate energy transmission efficiency, faster induction heating, and lower energy consumption through dynamic frequency tracking, power closed-loop control, optimized gate drive circuit, and cloud model cooperation.

[0007] The technical solution adopted by the utility model to solve the technical problems is: an electromagnetic plate frequency tracking system, comprising:

[0008] Dynamic frequency tracking module: used for real-time adjustment of high-frequency PWM signal frequency to keep consistent with the resonance frequency of the electromagnetic plate.

[0009] Power closed-loop control module: used for dynamic adjustment of PWM duty cycle through current / voltage sampling and ADC conversion to stabilize output power.

[0010] Optimized gate drive module: used for reducing the risk of MOSFET parasitic conduction and improving energy efficiency.

[0011] Data processing interface module: used for accessing cloud big data platform optimization model.

[0012] The dynamic frequency tracking module is electrically connected to the power closed-loop control module, the optimized gate drive module, and the data processing interface module, respectively.

[0013] Preferably, the dynamic frequency tracking module comprises a dynamic frequency tracking circuit, which comprises a microcontroller MCU, a buffer element C1, drive elements U121 and U124, resistors R411, R412, R24, and R27. The connection mode of the dynamic frequency tracking circuit is as follows: the PB1B pin of the microcontroller MCU is connected to the input pin 2A of the buffer element C1 in series through the resistor R411, and the PB1A pin of the microcontroller MCU is connected to the input pin 1A of the buffer element C1 in series through the resistor R412; the output pin 2Y of the buffer element C1 is connected to the positive input terminal of the drive element U121 and the negative input terminal of the drive element U124 in series through optical coupling isolation and the resistor R24, and the output pin 1Y of the buffer element C1 is connected to the positive input terminal of the drive element U124 and the negative input terminal of the drive element U121 in series through optical coupling isolation and the resistor R27; the output terminals of the drive elements U124 and U121 output drive signals, respectively.

[0014] More preferably, the microcontroller MCU is of the type TMS320F28027FPTTR, the buffer element C1 is of the type 74LVC2G125DP, and the drive elements U121 and U124 are of the type UCC5350MCDWVR.

[0015] More preferably, the electromagnetic plate frequency tracking system further comprises a control circuit power module and a drive power circuit module, the control circuit power module is used to provide 3.3V power supply for the control circuit, and the drive power circuit module is used to provide 5V power supply for the drive circuit.

[0016] More preferably, the control circuit in the control circuit power module comprises a voltage stabilizer U98 and capacitors C425 and C426, and the connection mode of the control circuit is as follows: the input 5V is electrically connected to the input terminal of the voltage stabilizer U98, the output terminal of the voltage stabilizer U98 is connected to the TP4 input pin of the microcontroller MCU, the negative electrode of the capacitor C425 is grounded, the positive electrode of the capacitor C425 is connected to the output terminal of the voltage stabilizer U98, one end of the capacitor C426 is grounded, and the other end of the capacitor C426 is connected to the output terminal of the voltage stabilizer U98.

[0017] More preferably, the power closed loop control module comprises a power closed loop control circuit, which comprises: a microcontroller MCU, an operational amplifier U202, resistors R898, R899 and R900, capacitors C511, C504 and C505, diodes D79 and D80; the connection mode of the power closed loop control circuit is that: the output end of the current transformer is connected to the forward input end of the operational amplifier U202 in series through the resistor R898, the reverse input end of the operational amplifier U202 is connected to the output end of the operational amplifier U202, the output end of the operational amplifier U202 is connected to the ADC7 input pin of the microcontroller MCU in series through the resistor R900; one end of the capacitor C511 is grounded and the other end is connected to the output end of the current transformer, the capacitor C504 is connected in parallel with the resistor R899, one end of the capacitor C504 is grounded and the other end is connected to the forward input end of the operational amplifier U202, one end of the capacitor C505 is grounded and the other end is connected to the ADC7 input pin of the microcontroller MCU, the anode of the diode D79 is connected to the ADC7 input pin of the microcontroller MCU and the cathode is connected to the power supply 3V, and the anode of the diode D80 is connected to the ground and the cathode is connected to the ADC7 input pin of the microcontroller MCU.

[0018] The utility model has the advantages of:

[0019] 1. The utility model discloses a real-time analysis of the running state of the electromagnetic plate (such as load change, temperature fluctuation), dynamic adjustment of the frequency of the driving signal, and ensures that the electromagnetic plate always works in the optimal frequency range; compared with the traditional fixed frequency scheme, the utility model can improve the energy transmission efficiency by 10%-15%, the induction heating is faster, and the energy consumption is lower.

[0020] 2. The utility model combines current, voltage, phase and other multi-dimensional data, predicts load changes (such as sudden increase of power by the user), responds within milliseconds and adjusts the frequency; even if the load is suddenly changed, the system can still run stably and quickly without manual intervention.

[0021] 3. The utility model discloses a heat-proof design that can predict the temperature trend of the power device in advance, automatically reduce the frequency or stop the machine, and avoid overheating and damage of the equipment; through the overcurrent protection, the current anomaly is monitored in real time, the emergency adjustment or power-off is triggered, and the coil or switch device is prevented from burning out; through the cooperation of the gate drive module (miller clamp design) and the current sensor with hardware redundancy, the system can still run safely under extreme working conditions.

[0022] 4. The utility model can be connected to a cloud big data platform optimization model to adapt to different scene requirements (such as larger power electromagnetic plates or various load types).

[0023] 5. The utility model is simple to operate and easy to maintain, and the user does not need to manually set the frequency, and the system can automatically complete the matching. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a voltage stabilizing circuit diagram of the electromagnetic plate frequency tracking system of the utility model;

[0025] Figure 2 is a voltage reducing circuit diagram of the utility model;

[0026] Figure 3 is the MCU schematic diagram of the utility model;

[0027] Figure 4 is the MCU clock signal circuit diagram of the utility model;

[0028] Figure 5 is the debugging interface circuit diagram of the utility model;

[0029] Figure 6 is the buffer element, indicating element circuit diagram of the utility model;

[0030] Figure 7 is the power module, filter element circuit diagram of the utility model;

[0031] Figure 8 is the Miller clamp drive, current limiting, filter circuit diagram of the utility model;

[0032] Figure 9 is the phase detection comparison circuit diagram of the utility model;

[0033] Figure 10 is the signal conditioning circuit diagram of the utility model;

[0034] Figure 11 is the MCU connection circuit schematic diagram of the utility model. DETAILED DESCRIPTION

[0035] The related technologies in the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor fall within the protection scope of the utility model.

[0036] As shown in Figures 1-11 the electromagnetic plate frequency tracking system of the present embodiment, Figure 1 the voltage reducing or current limiting element A1: stabilizer, provides 3.3V power supply for the low-power consumption control circuit.

[0037] The 5V input power supply is reduced to 3.3V to power the low-power consumption control circuit.

[0038] Working principle:

[0039] The input 5V voltage enters through the voltage regulator Vin pin of the step-down or current-limiting element A1, and after passing through the internal voltage regulation circuit, the Vo pin outputs a stable 3.3V voltage. The output is connected to a 10μF electrolytic capacitor and a 0.1μF ceramic capacitor to filter out high-frequency noise and ensure the stability of the 3.3V power supply

[0040] Figure 2 Step-down or current-limiting element A2: step-down module, converts 12-24V input voltage to 5V to power the gate drive module.

[0041] Working principle:

[0042] The input 12-24V voltage is connected through the step-down module VIN pin of the step-down or current-limiting element A2, and the internal DC-DC converter of the step-down module adjusts the output voltage to 5V through switching. The step-down module uses a TPS5450DDAR 5A type switching regulator.

[0043] The output is connected to a 100μF electrolytic capacitor and a 10μF ceramic capacitor to smooth the output voltage and reduce ripple.

[0044] Figure 3 Core control element B1: MCU, responsible for generating PWM signals and running frequency tracking.

[0045] Core control element B1 runs PWM generation, frequency tracking, and data processing.

[0046] Working principle:

[0047] PWM signal generation: MCU uses a 32-bit microcontroller with model number TMS320F28027FPTTR for real-time control and digital signal processing.

[0048] The PB1 / PB0 pins of the MCU controller labeled B1 output complementary PWM signals (frequency 20kHz, duty cycle 50%), which are driven through an optocoupler to the gate driver. The gate driver uses a model number UCC5350MCDWVR isolated gate driver.

[0049] Frequency tracking:

[0050] The ADC module collects current sensor and voltage divider signals, calculates real-time power, and dynamically adjusts the PWM duty cycle.

[0051] Data processing:

[0052] Communicate with the Wi-Fi module through the UART interface (TXD / RXD), upload sensor data to the cloud, and receive optimization parameters.

[0053] Figure 4 Middle clock element B2, 12MHz crystal oscillator, provides clock signal for MCU.

[0054] Provides reference clock signal for core control element B1, ensures PWM precision (±1%).

[0055] Working principle: Crystal oscillator X1 is connected to the OSC_IN / OSC_OUT pin of core control element B1, and generates 72MHz system clock through internal PLL frequency multiplication.

[0056] Figure 5 Middle debug interface element B3: JTAG / SWD interface, used for program download and debugging. Interface element B3: supports program burning and online debugging.

[0057] Working principle: SWCLK / SWDIO pin is connected to the debugger, and firmware update and troubleshooting are realized through the debug interface of ARM Cor tex-M3 core.

[0058] Figure 6 Buffer element C1: receives enable signal and PWM1B / PWM1A input signal, and outputs IN_HS / IN_LS drive signal; indicating element C2: LED20 indicating lamp, indicating enable state (EN low level lighting).

[0059] Buffer element C1: uses signal 74LVC2G125DP dual-channel non-inverting tri-state buffer / line driver, which has two independent channels (i.e. "dual-channel"), and each channel has the same function, which can be configured separately or used simultaneously.

[0060] Receives enable signal and PWM1B / PWM1A input signal, and outputs IN_HS / IN_LS drive signal to drive element E1.

[0061] Working principle:

[0062] When the enable signal (EN) is low, the buffer element C1 outputs the IN_HS / IN_LS drive signal; when EN is high, it outputs a high impedance state, which closes the drive signal.

[0063] The input signal is connected to the input end of buffer element C1 through a 1kΩ current limiting resistor, and the output end is connected to drive element E1 through a 10Ω resistor.

[0064] Indicating element C2:

[0065] When the enable signal (EN) is low, it lights up, indicating that the system is in working condition.

[0066] Working principle:

[0067] EN signal is connected to the cathode of the indicator element C2 through a 1kΩ resistor, and the anode is grounded. When EN is low, the LED is turned on and emits light.

[0068] Figure 7 Power module D1: QA243C-1504R3 power module, provides high-power power supply for the main loop of electromagnetic induction; filter element D2: filter capacitor, reduces power ripple, ensures stability.

[0069] Power module D1: provides high-power power supply (24V / 15A) for the main loop of electromagnetic induction.

[0070] Working principle:

[0071] Input 12-24V DC voltage is connected to power module D1 through VIN pin, and the internal DC-DC converter outputs 24V / 15A power supply for the inverter circuit.

[0072] The output end is connected to a 1000μF electrolytic capacitor and a 10μF ceramic capacitor to smooth the power supply and reduce high-frequency noise.

[0073] Filter element D2: reduces power ripple, ensures stability of the drive circuit.

[0074] Working principle:

[0075] 1000μF electrolytic capacitor filters out low-frequency ripple, and 10μF ceramic capacitor filters out high-frequency noise, together smoothing the 24V power supply.

[0076] Figure 8 Drive element E1: driver, Miller clamp design, ensures switch stability; current limiting element E2: R24 / R27 current limiting resistor, limits input signal current; R441 / R42 pull-down resistor; filter element E3: C477 / C461 bypass capacitor; C475 / C476 filter capacitor. Drive MOSFET / IGBT switch, prevent parasitic conduction.

[0077] Working principle:

[0078] IN_HS / IN_LS pin receives the drive signal of buffer element C1, and prevents gate voltage overshoot through the Miller clamp circuit.

[0079] Output end drives MOSFET (Q1-Q4), connected to MOSFET gate through a 10Ω resistor, limits switch speed, reduces EMI.

[0080] Current limiting element E2:

[0081] Limits input signal current; ensures signal default low level.

[0082] Working principle:

[0083] R24 / R27 (1kΩ) connected to the input of the driving element E1, limiting the current to 5mA; R441 / R42 (10kΩ) connected to the ground, ensuring that the signal is low when not driven.

[0084] Filter element E3:

[0085] Filter high-frequency noise; smooth the driving power supply.

[0086] Working principle:

[0087] 0.1μF ceramic capacitor (C477 / C461 / C480 / C466) connected in parallel to the power pin of the driving element E1, filtering high-frequency noise; 10μF electrolytic capacitor (C475 / C476 / C478 / C479) smoothing the power ripple.

[0088] Figure 9 Mid-comparator element F1: comparator, comparing the phase difference between input and output, generating an error signal.

[0089] Comparator element F1: compare the phase difference between input and output, generate an error signal for frequency tracking.

[0090] Working principle:

[0091] The positive input is connected to the feedback signal of label G1, and the negative input is connected to the reference voltage (1.25V).

[0092] When the input phase difference causes the feedback signal to be higher than the reference voltage, the output end outputs high level, informing the core control element B1 to adjust the PWM frequency.

[0093] Figure 10 Mid operational amplifier element F2: MCP6022-E / SN, used for signal conditioning.

[0094] Operational amplifier element F2: conditioning sensor feedback signal (such as current, temperature).

[0095] Working principle:

[0096] Differential amplifier circuit configuration: the input is connected to the secondary winding of the current transformer, and the output is divided by 10kΩ resistor and 100kΩ resistor, amplifying the signal to the range of 0-5V.

[0097] The amplifier element uses MCP6022-E / SN operational amplifier to amplify the feedback signal; the sampling element uses ADC module to convert the analog signal to digital signal.

[0098] Cloud collaborative control process:

[0099] Local data acquisition:

[0100] Collect current, temperature, voltage data through the ADC module of the core control element B, and upload to the cloud.

[0101] Cloud model analysis:

[0102] The cloud model calculates the optimal PWM duty cycle, resonance frequency, and other control parameters based on historical data and real-time parameters.

[0103] Parameter issuance and execution:

[0104] The cloud issues optimized parameters to the core control element B1 through the API, adjusts the PWM signal, and drives the drive element E1 to change the high-frequency current output.

[0105] Closed-loop feedback:

[0106] The adjusted power state is collected by the sensor and uploaded to the cloud again, forming a closed-loop optimization cycle.

[0107] Embodiment

[0108] This embodiment is to use a salt brine pump to extract high-concentration brine (mainly composed of sodium chloride NaCl) from a salt field in a certain salt production plant, and transport these brines to an evaporation crystallizer for further processing to produce industrial salt. The plant is located in an area with large temperature changes, and the day-night temperature difference sometimes exceeds 20 degrees Celsius. As the seasons change and the temperature drops at night, the salt brine pump frequently experiences crystallization. This embodiment uses both the current market ordinary electromagnetic plate and the electromagnetic plate with the electromagnetic plate frequency tracking system of the present application to extract water from the salt field at the same time.

[0109] The market ordinary electromagnetic plate uses a fixed frequency inverter, adopts an IGBT or MOSFET half-bridge structure, outputs a fixed frequency, and is a fixed power gear based on preset value adjustment power. The market ordinary electromagnetic plate has no signal feedback and no closed-loop control system, and can only rely on temperature probes for passive protection.

[0110] The electromagnetic plate with the electromagnetic plate frequency tracking system of the present application uses dynamic control frequency, adjusts frequency and power in real time through algorithm, and controls power fluctuation within ±2%. It dynamically matches the inductance value of the load. Moreover, the electromagnetic plate with the electromagnetic plate frequency tracking system of the present application uses real-time signal feedback, combines current, voltage, and temperature sensors into a PID algorithm, and protects the plate operation in real time. After a period of salt brine pump operation, the test results are shown in Table 1:

[0111] Table 1

[0112] Dimension Traditional electromagnetic plate Electromagnetic plate of the present embodiment Core advantage Thermal efficiency 85％-90％ 93％-95％ Energy saving 15%-20%, reduce long-term operation cost. Compatibility Iron carbon steel Iron / carbon steel / stainless steel, etc. Expand application scenarios, reduce equipment modification cost. Maintenance cost Quarterly shutdown inspection Online real-time protection Save 75% maintenance cost, reduce production interruption risk. Life 3-5 years (estimated) 5-8 years (estimated) Dynamic adjustment technology reduces coil loss and prolongs equipment life.

[0113] It can be seen by comparison that the electromagnetic plate frequency tracking system in the embodiment can make the electromagnetic plate have higher thermal efficiency, better compatibility, lower maintenance cost and longer service life when suppressing salt brine crystallization.

[0114] In summary, the utility model discloses through real -time analysis electromagnetic plate running load change, temperature fluctuation etc.

[0115] It needs to emphasize: above is only the preferred embodiment of the utility model, and does not limit the utility model in any form, and any simple modification, equivalent change and modification of the above embodiment according to the technical essence of the utility model still belong to the range of the utility model technical scheme.

Claims

1. An electromagnetic plate frequency tracking system, characterized in that, include: Dynamic frequency tracking module: used to adjust the frequency of high-frequency PWM signal in real time to keep it consistent with the resonant frequency of electromagnetic board; Power closed-loop control module: used to dynamically adjust the PWM duty cycle and stabilize the output power through current / voltage sampling and ADC conversion; Optimized gate drive module: used to reduce the risk of MOSFET parasitic conduction and improve energy efficiency; Data processing interface module: used to connect to the cloud big data platform to optimize the model; The dynamic frequency tracking module is electrically connected to the power closed-loop control module, the optimized gate drive module, and the data processing interface module, respectively.

2. The electromagnetic plate frequency tracking system according to claim 1, characterized in that, The dynamic frequency tracking module includes a dynamic frequency tracking circuit, which comprises a microcontroller (MCU), a buffer element C1, driving elements U121 and U124, and resistors R411, R412, R24, and R27. The dynamic frequency tracking circuit is connected as follows: the PB1B pin of the MCU is connected in series with resistor R411 to the input pin 2A of the buffer element C1; the PB1A pin of the MCU is connected in series with resistor R412 to the input pin 1A of the buffer element C1; the output pin 2Y of the buffer element C1 is connected in series with optocoupler isolation and resistor R24 ​​to the positive input terminal of driving element U121 and the negative input terminal of driving element U124; the output pin 1Y of the buffer element C1 is connected in series with optocoupler isolation and resistor R27 to the positive input terminal of driving element U124 and the negative input terminal of driving element U121; the output terminals of driving elements U124 and U121 respectively output driving signals.

3. The electromagnetic plate frequency tracking system according to claim 2, characterized in that, The microcontroller MCU is model TMS320F28027FPTTR, the buffer element C1 is model 74LVC2G125DP, and the drive elements U121 and U124 are model UCC5350MCDWVR.

4. The electromagnetic plate frequency tracking system according to claim 2, characterized in that, The electromagnetic plate frequency tracking system further includes a control circuit power supply module and a drive power supply circuit module. The control circuit power supply module is used to provide 3.3V power to the control circuit, and the drive power supply circuit module is used to provide 5V power to the drive circuit.

5. The electromagnetic plate frequency tracking system according to claim 4, characterized in that, The control circuit in the power supply module includes a voltage regulator U98, capacitors C425 and C426. The control circuit is connected as follows: the input 5V is connected to the input terminal of the voltage regulator U98, the output terminal of the voltage regulator U98 is connected to the TP4 input pin of the microcontroller MCU, the negative terminal of capacitor C425 is grounded and the positive terminal is connected to the output terminal of the voltage regulator U98, and one end of capacitor C426 is grounded and the other end is connected to the output terminal of the voltage regulator U98.

6. The electromagnetic plate frequency tracking system according to claim 2, characterized in that, The power closed-loop control module includes a power closed-loop control circuit, which comprises: a microcontroller (MCU), an operational amplifier (U202), resistors R898, R899, and R900, capacitors C511, C504, and C505, and diodes D79 and D80. The power closed-loop control circuit is connected as follows: the output of the current transformer is connected in series with resistor R898 and then to the forward input of operational amplifier U202; the inverting input of operational amplifier U202 is connected to its output; and operational amplifier U202... The output of capacitor 2 is connected in series with resistor R900 and then connected to the ADC7 input pin of the microcontroller MCU; one end of capacitor C511 is grounded and the other end is connected to the output of the current transformer; capacitor C504 is connected in parallel with resistor R899, one end is grounded and the other end is connected to the forward input of operational amplifier U202; one end of capacitor C505 is grounded and the other end is connected to the ADC7 input pin of the microcontroller MCU; the positive terminal of diode D79 is connected to the ADC7 input pin of the microcontroller MCU and the negative terminal is connected to the 3V power supply; the positive terminal of diode D80 is grounded and the negative terminal is connected to the ADC7 input pin of the controller MCU.

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