A remote plasma magnetic core heat dissipation temperature regulation method and regulation system

Abstract

The present invention discloses a remote plasma core heat dissipation temperature regulation method and regulation system in the field of plasma technology. The regulation method comprises the following steps: detecting the real-time temperature value Ts of the core by a temperature sensor and comparing it with a first reference temperature value Tref1; if Ts>Tref1, then executing: increasing the cooling water flow rate of the cavity water tray and increasing the speed of the heat dissipation fan, and the interval setting time t a After that, the real-time temperature value Ts is continuously compared with the second reference temperature value Tref2; if Ts>Tref2, the following is executed: the output frequency fs of the resonant converter is reduced, and the interval setting time t b After that, the output frequency fs is controlled at the resonant frequency fsn of the resonant converter to further reduce the temperature so that the system quickly reaches thermal equilibrium. The magnetic core heat dissipation temperature regulation control method can easily and efficiently achieve temperature reduction through a three-stage temperature control strategy, realize intelligent monitoring feedback, and improve the stability of the remote plasma source system.

Description

Technical Field

[0001] The invention relates to the technical field of plasma generators, and in particular to a method and a system for regulating the heat dissipation temperature of a magnetic core of a remote plasma. Background Art

[0002] Plasma generator is a device that obtains plasma by artificial means, and is often used in chemical industry, metallurgy and other fields. Remote plasma generator uses plasma source to synthesize plasma outside the reaction zone, and introduces plasma into the reaction zone under the action of airflow, electric field, magnetic field, etc. If the temperature of ferrite core is too high, the core material will lose its magnetism instantly, which is easy to burn power devices. Therefore, the control effect of core heat dissipation directly affects the safety of equipment operation.

[0003] In the prior art, publication number CN113280935A discloses a ferrite phase shifter core temperature detection device and detection method, which does not require the embedding of a temperature sensor and adopts a ferrite single coil excitation method, with a simplified product structure, a simple excitation circuit, a microsecond response speed, and a nanosecond delay time, and can more accurately realize the temperature acquisition of the ferrite core; publication number CN117631720A discloses a temperature control method and system for a remote plasma generator, the method comprising: according to the unit positive and negative ion benchmark absorption heat, the unit negative ion benchmark absorption heat, combined with the positive and negative ion generation, the predicted heat of the electric shock generating cavity is attenuated to generate the theoretical increase heat of the generating cavity, the interactive thermocouple monitors the temperature sequence of the generating cavity, and the abnormal temperature is analyzed based on the theoretical temperature of the generating cavity to obtain the temperature anomaly coefficient. When it does not meet the preset temperature control conditions, a temperature warning information is generated and sent to the remote plasma generator management terminal.

[0004] However, in the prior art, overheating monitoring of remote plasma generators can mostly only pre-set threshold values, and an early warning is issued only when triggered, resulting in inefficient temperature management of the plasma core. In addition, the heat dissipation regulation of the plasma core adopts a fixed operating parameter setting method, the heat dissipation regulation method has low intelligence, high energy consumption, and a long time for the core to reach a thermal equilibrium point. Summary of the invention

[0005] The present application solves the technical problem of low heat dissipation regulation efficiency of plasma ferrite cores in the prior art by providing a remote plasma core heat dissipation temperature regulation method and regulation system, thereby improving the heat dissipation efficiency of the ferrite cores.

[0006] The present application provides a method for regulating the temperature of a magnetic core heat dissipation of a remote plasma, comprising the following steps:

[0007] S1: Detect the real-time temperature value Ts of the magnetic core through a temperature sensor and compare it with the first reference temperature value Tref1. If Ts>Tref1, execute step S2;

[0008] S2: Increase the cooling water flow rate of the cavity water pan and increase the speed of the cooling fan, and set the interval time t a Then, the real-time temperature value Ts is continuously compared with the second reference temperature value Tref2, and if Ts>Tref2, step S3 is executed;

[0009] S3: Reduce the output frequency fs of the resonant converter to reduce the core temperature, and set the interval time t b Then, execute step S4;

[0010] S4: Control the output frequency fs to the resonant frequency fsn of the resonant converter to further reduce the temperature so that the system quickly reaches thermal equilibrium; input the frequency signal fsn to the PWM phase-shift frequency modulation controller to obtain a driving signal for the switch tube.

[0011] The beneficial effects of the above embodiments are: the core heat dissipation temperature regulation control method can easily and efficiently achieve cooling through a three-stage temperature control strategy, so that the system can quickly enter a thermal equilibrium state, realize intelligent monitoring feedback, and improve the stability of the remote plasma source system.

[0012] Based on the above embodiments, the present application can be further improved as follows:

[0013] In one of the embodiments of the present application, the output frequency fs of the resonant converter is reduced by closed-loop regulating the output current value Ipri and the output voltage Vloop of the resonant converter.

[0014] The embodiment of the present application also provides a regulation system using the magnetic core heat dissipation temperature regulation method of the remote plasma source coupled transformer, including a control unit, a PWM drive unit, an LCL resonant converter, a sampling unit, a temperature control unit, and a heat dissipation unit;

[0015] The control unit is used to control the PWM drive unit to output a pulse signal; the LCL resonant converter is used to convert the pulse signal output by the PWM drive unit into an AC source and provide an input AC source for the ignition circuit; the sampling unit is used to collect the output voltage and current of the LCL resonant converter and feed them back to the control unit; the temperature control unit is used to collect the real-time temperature of the magnetic core and generate a corresponding trigger signal to the control unit when the real-time temperature exceeds a set value, and the control unit adjusts the heat dissipation power of the heat dissipation unit according to the trigger signal, and adjusts the output current, output voltage and / or output frequency of the LCL resonant converter.

[0016] In one embodiment of the present application, the temperature control unit includes a temperature sensor and a first op amp comparator and a second op amp comparator arranged on the magnetic core. The first op amp comparator is used to trigger a first trigger signal Flag1 to the control unit when the real-time temperature of the magnetic core exceeds the first reference temperature value Tref1 set by the first op amp comparator. The second op amp comparator compares the real-time temperature of the magnetic core with the second reference temperature value Tref2 set by the second op amp comparator after the first trigger signal Flag1 is triggered. If the real-time temperature of the magnetic core is greater than the second reference temperature value Tref2, the second trigger signal Flag2 is triggered to the control unit. The multi-stage temperature control strategy makes it easy to efficiently achieve cooling and realize intelligent monitoring feedback.

[0017] In one embodiment of the present application, the heat dissipation unit includes a heat conductive sheet, a heat pipe and the cavity water tray. The heat conductive sheet is arranged between the magnetic core and the heat pipe, and between the heat pipe and the cavity water tray. The cavity water tray is connected with cooling water, and a heat dissipation fan is arranged outside the cavity water tray. The heat of the magnetic core is transferred to the heat pipe through the heat conductive sheet, and the heat pipe then transfers the heat to the cavity water tray through the heat conductive sheet. The cavity water tray is connected to cooling water to dissipate the heat and dissipate the heat. Rapid cooling can be achieved by cooling water circulation combined with air cooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0019] Figure 1 This is a structural schematic diagram of a magnetic core heat dissipation adjustment system of a remote plasma source coupled transformer in an embodiment of the present application;

[0020] Figure 2 This is a structural block diagram of a heat dissipation unit in an embodiment of the present application;

[0021] Figure 3 This is a flow chart of the steps of a method for regulating the temperature of a magnetic core heat dissipation of a remote plasma in an embodiment of the present application;

[0022] Figure 4 Schematic diagram of the temperature change of the magnetic core using the magnetic core heat dissipation temperature adjustment method in the embodiment of the present application. DETAILED DESCRIPTION

[0023] The present invention is further explained below in conjunction with specific implementation methods. It should be understood that these implementation methods are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0024] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0025] In the description of the present invention, it should be noted that the terms "first", "second", "third", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance. Unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, and it can be the internal connection of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In the description of the present invention, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in the present invention and the features of different embodiments or examples without contradiction.

[0027] The embodiments of the present application provide a remote plasma core heat dissipation temperature regulation method and regulation system, thereby solving the technical problem of low heat dissipation regulation efficiency of plasma ferrite cores in the prior art and improving the heat dissipation efficiency of ferrite cores.

[0028] The technical solution in the embodiment of the present application is to solve the above problems, and the overall idea is as follows:

[0029] Embodiment 1:

[0030] like Figure 1 As shown, a magnetic core heat dissipation adjustment system of a remote plasma source coupled transformer includes a control unit, a PWM drive unit, a full-bridge inverter circuit, an LCL resonant converter, a transformer, a sampling unit, a temperature control unit, and a heat dissipation unit (cavity structure, Figure 1 not shown);

[0031] The full-bridge inverter circuit is composed of switch tubes T1-T4; U inis the input DC voltage source; inductor L r , L k and capacitor C r The LCL resonant network is formed; the transformer T is a high-frequency transformer with a turn ratio of n:1; R p For load.

[0032] The temperature control unit includes a temperature sensor (not shown in the figure) arranged on the magnetic core and a first operational amplifier comparator C1 and a second operational amplifier comparator C2. The first operational amplifier comparator C1 is used to trigger a first trigger signal Flag1 to the control unit when the real-time temperature Ts of the magnetic core exceeds a first reference temperature value Tref1 set by the first operational amplifier comparator C1. The second operational amplifier comparator C2 compares the real-time temperature Ts of the magnetic core with a second reference temperature value Tref2 set by the second operational amplifier comparator C2 after the first trigger signal Flag1 is triggered. If the real-time temperature Ts of the magnetic core is greater than the second reference temperature value Tref2, the second trigger signal Flag2 is triggered to the control unit.

[0033] The control unit is used to control the PWM drive unit to output a pulse signal; the LCL resonant converter is used to convert the pulse signal output by the PWM drive unit into an AC source and provide an input AC source for the ignition circuit; the sampling unit is used to collect the output voltage and current of the LCL resonant converter and feed it back to the control unit;

[0034] The temperature control unit is used to collect the real-time temperature of the magnetic core and send a corresponding trigger signal to the control unit when the real-time temperature exceeds the set value. The control unit adjusts the power of the heat dissipation unit to cool the magnetic core according to the trigger signal, and adjusts the output current, output voltage and / or output frequency of the LCL resonant converter.

[0035] Among them, the first end of the operational amplifier comparator C1 is connected to the output end of the temperature acquisition signal modulation circuit, and the second input end of the operational amplifier comparator C1 is the reference signal end Vref; the first end of the resistor R1 is connected to the second input end of the operational amplifier comparator C1, and the second end of the resistor R1 is connected to the output end of the operational amplifier comparator C1; the first end of the resistor R2 is connected to the external power supply, and the second end of the resistor R2 is connected to the output end of the operational amplifier comparator C1; the structure of the operational amplifier comparator C2 is consistent with that of the operational amplifier comparator C1.

[0036] like Figure 2 As shown, the heat dissipation unit includes a heat conductive sheet, a heat pipe, and a cavity water pan. The heat conductive sheet is arranged between the magnetic core and the heat pipe, and between the heat pipe and the cavity water pan. The cavity water pan is connected to cooling water, and a heat dissipation fan is arranged outside the cavity water pan. The heat of the magnetic core is transferred to the heat pipe through the heat conductive sheet, and the heat pipe then transfers the heat to the cavity water pan through the heat conductive sheet. The cavity water pan is connected to cooling water to dissipate the heat, and rapid cooling can be achieved by cooling the cooling water in a circulating way combined with air cooling.

[0037] Embodiment 2:

[0038] like Figure 3 As shown, a method for regulating the heat dissipation temperature of a remote plasma core is provided, which records parameters affecting the temperature of the plasma core in real time, including the cavity, the core temperature, the output current value Ipri of the resonant converter, and the output voltage Vloop, and stores them in an internal controller; then the temperature and voltage and current are sampled, and a threshold is determined from the historical values ​​and known good values ​​of the parameters, and the real-time core temperature of the system is compared with the determined threshold, and the temperature of the remote plasma source cavity is judged in real time, and the corresponding heat dissipation temperature control is carried out in a targeted manner, which specifically includes the following steps:

[0039] S1: Detect the real-time temperature value Ts of the magnetic core through a temperature sensor and compare it with the first reference temperature value Tref1. If Ts>Tref1, execute step S2;

[0040] S2: Increase the cooling water flow rate of the cavity water pan and increase the speed of the cooling fan, and set the interval time t a Then, the real-time temperature value Ts is continuously compared with the second reference temperature value Tref2, and if Ts>Tref2, step S3 is executed;

[0041] S3: Reduce the output frequency fs of the resonant converter by adjusting the output current value Ipri and output voltage Vloop of the resonant converter in a closed loop, thereby reducing the core temperature, and the interval setting time t b Then, execute step S4;

[0042] S4: Control the output frequency fs at the resonant frequency fsn of the resonant converter to further reduce the temperature so that the system quickly reaches thermal equilibrium; input the frequency signal fsn to the PWM phase-shift frequency modulation controller to obtain a driving signal for the switch tube.

[0043] The core temperature rise detection is continuously performed, and a correction control matching result is generated based on the monitoring result. The feedback result is compensated based on the correction control matching result, and the heat dissipation system adjustment operation is performed.

[0044] Figure 4 FIG. 2 shows a schematic diagram of the temperature change of the magnetic core using the above magnetic core heat dissipation temperature adjustment method. Figure 4As shown, from 0 to t1, the ferrite core temperature Ts increases with the increase of gas load and power. Since the LCL resonant converter adopts a frequency phase-shift hybrid control strategy, the increase in load will cause a sharp increase in the frequency fs, and the duty cycle D will decrease accordingly; at this time, the cooling measures are only water cooling and air cooling, and the slope curve of the core temperature rise is faster; when the core temperature Ts exceeds the first reference pre-alarm value, measures are taken to increase the cooling water flow rate and the fan speed to cool the core temperature. In order to meet the needs of different working conditions, air cooling and water cooling cannot meet user needs in actual application scenarios. Therefore, an adaptive cooling control method is adopted. At time t2, when the temperature drop of the ferrite core temperature Ts is still greater than the second reference pre-alarm value, the system increases the output current value Ipri of the resonant converter and reduces the output voltage Vloop to reduce the output frequency fs and continuously reduce the core temperature. At this time, in order to balance the output stability of the LCL resonant converter, the duty cycle will also increase accordingly; finally, at time t3, the output frequency fs is maintained near the resonant frequency fsn, and the ferrite core temperature Ts fluctuates near the temperature reference value Tref3.

[0045] The basic principle of this magnetic core heat dissipation temperature regulation method is as follows:

[0046] The core loss is closely related to the properties of the magnetic material and the operating frequency. During the AC magnetization process, the core loss P is mainly composed of hysteresis loss Pv and eddy current loss Pw; it can be expressed as follows:

[0047] P=P v +P w (1);

[0048] Hysteresis damage Pv is the loss caused by repeated friction of magnetic domains when the ferrite material is repeatedly magnetized during the magnetization process of the core material. It is proportional to the area surrounded by the hysteresis loop of the material and the number of repeated magnetizations per second, and is a type of frequency loss in magnetic recording. The energy loss generated by this part is eventually consumed in the form of heating of the core. Generally speaking, the smaller the area of ​​the hysteresis curve, the smaller the hysteresis loss; the larger the frequency fs, the greater the loss and the greater the heat generated; the eddy current loss Pw is the loss caused by the eddy current induced in the normal conductive matrix or structural material of the superconductor in a changing external magnetic field or self-field. Because the resistivity of the core material is not infinite and has a certain resistance value, at high frequencies, eddy currents will still be generated in the core due to the excitation magnetic field, causing losses.

[0049] For soft ferrites, the empirical formula for engineering calculation of core loss is:

[0050] P=C m f s α B β (2);

[0051] This formula shows that the loss per unit volume Pv is an exponential function of the operating frequency fs and the magnetic flux density B. m =2π, α and β are empirical parameters, both exponents may not be integers, generally 1<α<3 and 2<β<3.

[0052] From the conversion relationship between power and energy, it can be seen that there is a positive proportional relationship between power and energy, that is, the greater the power, the more energy is generated, and the greater the output heat is. From formula (2), it can be seen that the frequency fs has a greater impact on the generation of energy, so the heat dissipation efficiency of the remote plasma ferrite core can be improved by reducing the output frequency fs;

[0053] Considering the constant current characteristic of the LCL resonant converter, when the circuit operates at the resonant frequency point fsn, the current on the inductor Lr is the smallest. The larger the Q value, the smaller the current of the resonant inductor, and the temperature generated by the ferrite core will also decrease accordingly.

[0054] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0055] 1. The core heat dissipation temperature regulation method adopts a three-stage core heat dissipation regulation control. The system samples the ferrite core temperature in real time through the temperature sensor, and compares it with the set first reference pre-alarm reference value. After exceeding the threshold, the cooling water flow and the fan speed are increased; and it is judged again whether the core temperature is greater than the second reference pre-alarm value. After exceeding, the output frequency fs is reduced by increasing Ipri and reducing Vloop, thereby reducing the core temperature; finally, the frequency fs is limited to the resonant converter fsn to further reduce the temperature, so that the system quickly reaches the thermal equilibrium point.

[0056] 2. Adopt the closed-loop control method, monitor the core temperature rise, compare the actual temperature detected with different temperature thresholds, take different measures to cool down, and finally make the temperature and frequency reach the preset values, and generate a corrected control matching result for the monitoring result.

[0057] 3. The control system is relatively simple and easy to implement in engineering.

[0058] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for regulating the temperature of a magnetic core heat dissipation of a remote plasma, comprising the following steps: S1: Detect the real-time temperature value Ts of the magnetic core through a temperature sensor and compare it with the first reference temperature value Tref1. If Ts>Tref1, execute step S2; S2: Increase the cooling water flow rate of the cavity water pan and increase the speed of the cooling fan, and set the interval time t a Then, the real-time temperature value Ts is continuously compared with the second reference temperature value Tref2, and if Ts>Tref2, step S3 is executed; S3: Reduce the output frequency fs of the resonant converter, and set the interval time t b Then, execute step S4; S4: Control the output frequency fs to the resonant frequency fsn of the resonant converter.

2. The magnetic core heat dissipation temperature adjustment method according to claim 1, characterized in that: The output frequency fs of the resonant converter is reduced by closed-loop regulating the output current value Ipri and the output voltage Vloop of the resonant converter.

3. A regulating system using the core heat dissipation temperature regulating method of the remote plasma source coupled transformer according to any one of claims 1-2, comprising a control unit, a PWM drive unit, an LCL resonant converter, a sampling unit, a temperature control unit, and a heat dissipation unit; The control unit is used to control the PWM drive unit to output a pulse signal; the LCL resonant converter is used to convert the pulse signal output by the PWM drive unit into an AC source and provide an input AC source for the ignition circuit; the sampling unit is used to collect the output voltage and current of the LCL resonant converter and feed them back to the control unit; the temperature control unit is used to collect the real-time temperature of the magnetic core and generate a corresponding trigger signal to the control unit when the real-time temperature exceeds a set value, and the control unit adjusts the heat dissipation power of the heat dissipation unit according to the trigger signal, and adjusts the output current, output voltage and / or output frequency of the LCL resonant converter; the heat dissipation unit includes a heat conductive sheet, a heat pipe and the cavity water tray, the heat conductive sheet is arranged between the magnetic core and the heat pipe, the heat pipe and the cavity water tray, the cavity water tray is connected with cooling water, and a heat dissipation fan is arranged outside the cavity water tray; the heat of the magnetic core is transferred to the heat pipe through the heat conductive sheet, and the heat pipe then transfers the heat to the cavity water tray through the heat conductive sheet.

4. The adjustment system according to claim 3, characterized in that: The temperature control unit includes the temperature sensor and the first op amp comparator and the second op amp comparator arranged on the magnetic core. The first op amp comparator is used to trigger the first trigger signal Flag1 to the control unit when the real-time temperature of the magnetic core exceeds the first reference temperature value Tref1 set by the first op amp comparator. The second op amp comparator compares the real-time temperature of the magnetic core with the second reference temperature value Tref2 set by the second op amp comparator after the first trigger signal Flag1 is triggered. If the real-time temperature of the magnetic core is greater than the second reference temperature value Tref2, the second trigger signal Flag2 is triggered to the control unit.

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