CN112015205A - Temperature control method of radio frequency heating module and radio frequency heating device - Google Patents

Abstract

The invention discloses a temperature control method of a radio frequency heating module and a radio frequency heating device, comprising the following steps: controlling the radio frequency heating module to be powered on and operated according to preset power; detecting the temperature t of the radio frequency heating module; comprehensively determining the temperature Tm of the solid semiconductor source according to the temperature T of the radio frequency heating module, the input voltage v, the time T of the normal operation and the impedance m of the solid semiconductor source packaged in the radio frequency heating module; and when Tm exceeds a set upper limit value, the preset power is adjusted downwards, the radio frequency heating module is controlled to reduce the output power of the radio frequency heating module, and the output power of the radio frequency heating module is recovered to the preset power when Tm is reduced to be below the set lower limit value. According to the invention, the temperature rise condition of the solid semiconductor source can be indirectly determined by detecting the temperature of the radio frequency heating module, and further, the temperature control and the overheating protection of the solid semiconductor source are realized by adopting a mode of adjusting the output power of the radio frequency heating module according to the temperature of the solid semiconductor source.

Description

A temperature control method for a radio frequency heating module and a radio frequency heating device

technical field

The invention belongs to the technical field of heating devices, and relates to a radio frequency heating technology, in particular to a technology for temperature monitoring and control of a radio frequency heating module in a radio frequency heating device.

Background technique

At present, heating devices such as electric ovens and microwave ovens mostly use microwave heating technology with magnetrons as emission sources. For this type of heating device, when designing a temperature protection circuit, a temperature regulator is often installed on the magnetron, and the temperature regulator is used to sense the temperature rise of the magnetron, so as to realize the overheat protection of the magnetron. The specific method is: according to the temperature range allowed by the safe operation of the magnetron, the working parameters of the temperature regulator are set in advance, for example, the working parameters of the temperature regulator are set to 160°C/60°C. When the temperature regulator detects that the temperature of the magnetron reaches above 160°C, it controls the magnetron to stop running and enter the overheat protection state. After the magnetron stops running, its temperature gradually decreases. When the temperature of the magnetron drops below 60°C, the control magnetron is put into operation again, and the heating device continues to work, thus realizing the temperature control of the magnetron and the Overheating protection.

With the rapid development and maturity of radio frequency technology, radio frequency heating devices have emerged and attracted increasing attention. Radio frequency heating technology is a technology that uses electromagnetic waves emitted by a solid-state semiconductor source (different from a magnetron) to heat food. This solid-state semiconductor source can adjust and control the power, frequency, and phase of the electromagnetic waves emitted by the solid-state semiconductor source, which is more conducive to improving the heating quality of the device.

In the current radio frequency heating device, the solid-state semiconductor source is packaged in the radio frequency heating module, and the radio frequency heating module is controlled to be powered on and run by providing DC power to the radio frequency heating module. During the power-on operation of the RF heating module, the temperature of the solid-state semiconductor source inside the module will rise sharply. It is necessary to cooperate with a cooling device to cool the solid-state semiconductor source to control the temperature of the solid-state semiconductor source to keep below a safe temperature. However, in the process of using the RF heating device, it is inevitable that the cooling device will fail or the RF heating device will operate abnormally. The consequences may cause the solid-state semiconductor source inside the module to be damaged due to excessive temperature rise. The device has failed. Therefore, temperature monitoring of the solid-state semiconductor source inside the RF heating module is very necessary. However, the temperature regulator in the traditional technology is not suitable for the radio frequency heating module, and the current radio frequency heating technology also lacks an effective means to accurately sense the temperature rise of the solid-state semiconductor source. Therefore, the radio frequency heating device has potential safety hazards.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a temperature control technology for a radio frequency heating module, which can realize overheat protection for the solid-state semiconductor source in the radio frequency heating module.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions to be realized:

In one aspect, the present invention provides a temperature control method for a radio frequency heating module, comprising: supplying power to the radio frequency heating module, and controlling the radio frequency heating module to be powered on and running according to a predetermined power; detecting the temperature t of the radio frequency heating module; The temperature t of the module, the input voltage v, the time T of this normal operation, and the impedance m of the solid-state semiconductor source packaged in the RF heating module, comprehensively determine the temperature Tm of the solid-state semiconductor source; when Tm exceeds the set upper limit When the value is set, the radio frequency heating module is controlled to reduce its output power, and when Tm falls below the set lower limit value, the output power of the radio frequency heating module is restored to the predetermined power.

Preferably, the temperature Tm of the solid-state semiconductor source is preferably obtained by calculating the formula Tm=mtT/(v-a); wherein a is a coefficient.

Further, when there are two radio frequency heating modules, the predetermined power is half of the set power selected by the user; the temperature control method further includes: adjusting the two radio frequency heating modules to emit electromagnetic waves at different frequencies; When the temperature of the solid-state semiconductor source in one of the radio frequency heating modules exceeds the upper limit value, the predetermined power of the radio frequency heating module is decreased, and the predetermined power of the other radio frequency heating module is increased by an equal amplitude, so as to reduce the predetermined power of one of the radio frequency heating modules. and increase the output power of the other radio frequency heating module at the same time, so that the sum of the output power of the two radio frequency heating modules remains at the set power to ensure the heating quality; when one of the radio frequency heating modules When the temperature of the solid-state semiconductor source in the device drops below the lower limit value, the output powers of both radio frequency heating modules can be restored to the initial predetermined power, that is, to the normal operation state.

When the solid-state semiconductor source in the radio frequency heating module works within its safe temperature range, in order to stabilize the output power of the radio frequency heating module at a predetermined power and realize the power control of the radio frequency heating module, the present invention further proposes the following output power Adjustment plan:

When there is one radio frequency heating module, the predetermined power is the set power selected by the user; the temperature control method further includes: determining the maximum and minimum input current of the radio frequency heating module according to the set power; During the normal operation of the radio frequency heating module, the input current of the radio frequency heating module is detected; when the input current of the radio frequency heating module is greater than the maximum value of the input current, the amplitude of the electromagnetic wave emitted by the radio frequency heating module is reduced, and the output power is reduced; When the input current of the radio frequency heating module is less than the minimum value of the input current, the amplitude of the electromagnetic wave emitted by the radio frequency heating module is increased, and the output power is increased.

When there are two radio frequency heating modules, the predetermined power is half of the set power selected by the user; the temperature control method further includes: respectively determining the input current of the two radio frequency heating modules according to the half of the set power Maximum value and minimum value; during the normal operation of both RF heating modules, detect the input current of the two RF heating modules; when the input current of one RF heating module is greater than its maximum input current, reduce the RF heating module The amplitude of the electromagnetic wave emitted to reduce the output power of the radio frequency heating module; when the input current of one of the radio frequency heating modules is less than the minimum value of its input current, increase the amplitude of the electromagnetic wave emitted by the radio frequency heating module to increase the radio frequency The output power of the heating module.

As a preferred method for determining the maximum value and minimum value of the input current: first, ensure the normal operation of the radio frequency heating module; secondly, adjust the output power of the radio frequency heating module step by step, and detect that the radio frequency heating module works at each level of output During the power period, the normal fluctuation range of its input current; then, according to the normal fluctuation range of the input current corresponding to the output power of each stage, determine the maximum peak value Ic and the minimum trough value It of the input current, and then determine that the radio frequency heating module works at The maximum input current Imax and the minimum input current Imin under the output power of each stage, namely: Imax=Ic+△I1; Imin=It-△I2; among them, △I1 and △I2 are the current margin, and both are positive value.

In order to improve the accuracy of power control, the process of adjusting the amplitude of the electromagnetic wave emitted by the radio frequency heating module according to the input current includes: increasing or decreasing the amplitude of the electromagnetic wave step by step; after each amplitude adjustment, detecting the input of the radio frequency heating module Current I; when Imin≤I≤Imax, stop the adjustment process of the electromagnetic wave amplitude.

In another aspect, the present invention also provides a radio frequency heating device, comprising a heating cavity, a radio frequency heating module, a temperature sensor, a voltage detection module and a control module; wherein a radiator is arranged on the inner wall of the heating cavity; The radio frequency heating module emits electromagnetic waves into the heating cavity through the radiator, and a solid-state semiconductor source is packaged in the radio frequency heating module; the temperature sensor is installed on the casing of the radio frequency heating module or arranged on a circuit board And the position next to the radio frequency heating module is used to detect the temperature t of the radio frequency heating module; the voltage detection module is used to detect the input voltage v of the radio frequency heating module; the control module controls the radio frequency heating module according to The predetermined power is powered on to run, and according to the temperature t of the radio frequency heating module, the input voltage v, the time T of this normal operation, and the impedance m of the solid-state semiconductor source packaged in the radio-frequency heating module, comprehensively determine the solid-state semiconductor source. temperature Tm; when Tm exceeds the set upper limit value, control the radio frequency heating module to reduce its output power, until Tm falls below the set lower limit value, control the output power of the radio frequency heating module to restore to the set value the predetermined power.

When there are two radio frequency heating modules, the predetermined power of each radio frequency heating module is half of the set power selected by the user; the control module controls the two radio frequency heating modules to emit electromagnetic waves at different frequencies; the When the temperature of the solid-state semiconductor source in one of the radio frequency heating modules exceeds the upper limit value, the control module reduces the predetermined power of the radio frequency heating module, and increases the predetermined power of the other radio frequency heating module by an equal amplitude, so as to control one of the radio frequency heating modules. The heating module reduces its output power, and controls another RF heating module to increase its output power, so that the total output power of the two RF heating modules is still maintained at the set power selected by the user, so as to ensure the heating quality of the food; When the temperature of the solid-state semiconductor source in one of the radio frequency heating modules drops below the lower limit value, the control module restores the output power of both radio frequency heating modules to the original predetermined power.

In order to stabilize the output power of the radio frequency heating module at a predetermined power, the present invention further provides a current detection module in the radio frequency heating device for detecting the input current of the radio frequency heating module. The solid-state semiconductor in the radio frequency heating module When the source works within a safe temperature range, the control module is preferably designed to adjust the output power of the radio frequency heating module, specifically:

When there is one RF heating module, the predetermined power is the set power selected by the user; the control module determines the maximum and minimum input current of the RF heating module according to the set power; when the RF heating module is normal During operation, when the input current of the radio frequency heating module is greater than the maximum value of the input current, the control module controls the radio frequency heating module to reduce the amplitude of the electromagnetic wave emitted by the radio frequency heating module to reduce the output power; when the input current of the radio frequency heating module is When it is less than the minimum value of the input current, the radio frequency heating module is controlled to increase the amplitude of the electromagnetic wave emitted by it, so as to increase the output power;

When there are two RF heating modules, the control module respectively determines the maximum and minimum input currents of the two RF heating modules according to half of the set power; the input current of one RF heating module is greater than its input When the current is the maximum value, reduce the amplitude of the electromagnetic wave emitted by the RF heating module to reduce the output power of the RF heating module; when the input current of one of the RF heating modules is less than the minimum value of its input current, increase the RF heating module. The amplitude of the emitted electromagnetic wave increases the output power of the radio frequency heating module. Thus, the stable control of the output power of the radio frequency heating module is realized.

Compared with the prior art, the advantages and positive effects of the present invention are: the temperature control method of the present invention can indirectly determine the temperature rise of the solid-state semiconductor source packaged inside the radio frequency heating module by detecting the temperature of the radio frequency heating module, When the temperature of the solid-state semiconductor source is abnormal, the method of reducing the output power of the radio frequency heating module is adopted to achieve the purpose of controlling the cooling of the solid-state semiconductor source, thereby realizing the overheating protection of the solid-state semiconductor source and ensuring the reliability of the application of the radio frequency heating module. , solves the potential safety hazard caused by the temperature rise of the solid-state semiconductor source during the use of the radio frequency heating device, improves the safety of the use of the radio frequency heating device, reduces the probability of failure of the radio frequency heating device, and improves the user experience. .

Other features and advantages of the present invention will become more apparent upon reading the detailed description of the embodiments of the present invention in conjunction with the accompanying drawings.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the embodiments. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

1 is a structural diagram of an embodiment of a radio frequency heating device proposed by the present invention;

2 is a control flow diagram of an embodiment of a temperature control method for a radio frequency heating module proposed by the present invention;

3 is a structural diagram of another embodiment of the radio frequency heating device proposed by the present invention;

FIG. 4 is a control flow chart of another embodiment of the temperature control method for a radio frequency heating module proposed by the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

It should be noted that, in the description of the present invention, the terms "first" and "second" are only used for description purposes, and cannot be understood as indicating or implying relative importance.

Embodiment 1, this embodiment takes a radio frequency heating device as an example to describe the temperature control technology of the radio frequency heating module.

As shown in FIG. 1 , the radio frequency heating device of this embodiment mainly includes a heating cavity, a radiator AT installed on the inner wall of the heating cavity, and a main control board that controls the radiator AT to emit electromagnetic waves. Main components such as an AC-DC conversion module, a radio frequency heating module, a temperature sensor, a voltage detection module, and a control module are arranged on the main control board. Among them, the AC-DC conversion module is used to connect an external AC power supply, such as AC mains, and convert the AC power supply into a DC power supply to provide DC power supply for electrical loads such as radio frequency heating modules, temperature sensors, voltage detection modules, and control modules. In this embodiment, only one radio frequency heating module is provided, and electronic components such as a solid-state semiconductor source and a radio frequency power amplifier are encapsulated therein. Among them, the solid-state semiconductor source can generate electromagnetic wave signals of different frequencies and different phases, which are sent to the radio frequency power amplifier to amplify the power of the electromagnetic wave signal, and then transmit the electromagnetic wave through the radiator AT and feed it into the heating cavity. The electromagnetic wave vibrates in the heating cavity, so that the moisture in the food also vibrates, and the self-heating is used to achieve the cooking effect.

Since the radio frequency heating module has the characteristics of adjustable electromagnetic wave output power, frequency and phase, when the heating device is put into operation, the control module can use the set power input by the user as the predetermined power, and generate a control signal according to the predetermined power, send to the radio frequency heating module to control the radio frequency heating module to emit electromagnetic waves according to a predetermined power when it is powered on and put into operation. The set power may be directly input by the user through the man-machine interface, or may be automatically generated by the control module according to the selected cooking mode after the user selects the cooking mode through the man-machine interface.

Since the temperature of the solid-state semiconductor source inside the RF heating module will rise rapidly after the RF heating module is powered on and run, if it exceeds the safe temperature for normal operation, the solid-state semiconductor source will be overheated and damaged, thereby causing the RF heating device to fail. . In order to control the temperature of the solid-state semiconductor source, in this embodiment, a temperature sensor is set to detect the temperature t of the radio-frequency heating module, combined with the input voltage v of the radio-frequency heating module, the normal operation time T and the impedance m of the solid-state semiconductor source , and comprehensively determine the temperature Tm of the solid-state semiconductor source, so as to effectively monitor the temperature rise state of the solid-state semiconductor source.

Specifically, the temperature sensor can be installed on the casing of the radio frequency heating module, or arranged on the main control board and at a position close to the radio frequency heating module, for example, beside the radio frequency heating module and be connected with the radio frequency heating module Stick to each other or leave only a gap to accurately sense the temperature t of the RF heating module. At the same time, a voltage detection module is added to collect the input voltage v of the radio frequency heating module, and then the temperature Tm of the solid-state semiconductor source is calculated by the following formula, namely:

Tm=mtT/(v-a);

Among them, a is the coefficient, a is the empirical value, and the value range is between 1 and 100.

In order to achieve overheating protection for the solid-state semiconductor source, the upper limit Tmax and lower limit Tmin of the temperature can be set in advance according to the safe temperature range allowed for the normal operation of the solid-state semiconductor source. For example, Tmax=75℃; Tmin= 70°C. Then, compare the calculated temperature Tm of the solid-state semiconductor source with the set upper limit Tmax and lower limit Tmin; if Tm>Tmax, it is considered that the temperature of the solid-state semiconductor source is too high, and overheat protection needs to be implemented. , the predetermined power (less than the set power) input to the radio frequency heating module can be reduced by the control module, and the output power of the radio frequency heating module can be controlled to reduce its output power, thereby reducing the temperature of the solid-state semiconductor source until Tm<Tmin, it is considered that the solid-state semiconductor source has The temperature has returned to normal and can continue to be put into use. At this time, the predetermined power input to the radio frequency heating module can be restored to the set power through the control module, and then the radio frequency heating module can be controlled to increase its output power and resume normal operation. After the radio frequency heating module resumes normal operation, the time T of this normal operation is cleared and the time is re-timed.

In this embodiment, the temperature of the solid-state semiconductor source is reduced by reducing the output power of the radio frequency heating module, which may specifically include the following two means:

One is to step down the predetermined power input to the RF heating module according to the set power variable ΔP, so as to control the RF heating module to reduce its output power step by step, and then gradually reduce the temperature of the solid-state semiconductor source;

The second is to reduce the predetermined power input to the radio frequency heating module to 0, that is, control the radio frequency heating module to stop running and reduce its output power to 0, so that the temperature of the solid-state semiconductor source drops rapidly.

By implementing the above temperature control strategy on the radio frequency heating module, it can be ensured that the solid-state semiconductor source in the radio frequency heating module will not be damaged due to excessive temperature, thereby improving the operation safety of the radio frequency heating device.

Since the control module controls the operation of the radio frequency heating module, it is unknown whether the radio frequency heating module operates normally according to the predetermined power. In order to effectively sense the output power of the radio frequency heating module, in this embodiment, a current detection module is added to the main control board of the radio frequency heating device, as shown in FIG. The fluctuation of the current I indirectly reflects the change of the output power of the radio frequency heating module, and when the input current I is abnormal, the amplitude of the electromagnetic wave output by the radio frequency heating module is increased or decreased to adjust the output power of the radio frequency heating module. Output Power. In the process of adjusting the output power of the radio frequency heating module, the change of the input current I is also used as the judgment criterion. When the input current I returns to the normal fluctuation range, the adjustment process of the electromagnetic wave amplitude can be ended. At this time, the output power of the radio frequency heating module will be adjusted to be close to the predetermined power, thereby realizing stable control of the output power of the radio frequency heating module.

In this embodiment, the above-mentioned power adjustment process is designed to be performed when the temperature of the solid-state semiconductor source inside the radio frequency heating module is in a normal state, that is, during the period of overheating protection for the solid-state semiconductor source, the above-mentioned power adjustment process is not performed.

The current detection module is connected to the control module, and the control module obtains the input current I of the radio frequency heating module through the current detection module. The control module can pre-determine the normal fluctuation range of the input current of the radio frequency heating module under the set power according to the set power, that is, the maximum value Imax and the minimum value Imin of the input current can be determined, and then the radio frequency heating module can be used. During the normal operation of the module, by comparing the actual input current I of the RF heating module with the maximum value Imax and minimum value Imin, it can be accurately judged whether the RF heating module is stably working near the set power. in particular,

If the control module detects that the input current I of the radio frequency heating module is between Imax and Imin, it can be determined that the output power of the radio frequency heating module is normal, and the current working parameters of the radio frequency heating module are maintained to continue to run;

If the control module detects that the input current I>Imax of the radio frequency heating module, it is considered that the output power of the radio frequency heating module has become larger and far exceeds the set power. At this time, the control module generates an amplitude adjustment signal and sends it to the radio frequency heating module, and controls the radio frequency heating module to reduce the amplitude of the electromagnetic wave when transmitting the electromagnetic wave signal, so as to reduce the output power of the radio frequency heating module and make it return to the setting near power;

If the control module detects the input current I<Imin of the radio frequency heating module, it is considered that the output power of the radio frequency heating module becomes smaller and far lower than the set power. At this time, the control module should generate an amplitude adjustment signal and send it to the radio frequency heating module, and control the radio frequency heating module to increase the amplitude of the electromagnetic wave when transmitting the electromagnetic wave signal, so as to improve the output power of the radio frequency heating module and make it run stably in the setting near constant power.

The temperature control method of the radio frequency heating module of the present embodiment is described in detail below in conjunction with the above-mentioned power adjustment strategy, as shown in FIG. 2 , which specifically includes the following processes:

1. Test phase

S201 , confirming that the radio frequency heating module is fault-free, and controlling the radio frequency heating module to operate normally.

S202, adjusting the output power of the radio frequency heating module step by step;

In this embodiment, the output power range (0 to maximum power) corresponding to the normal operation of the radio frequency heating module can be divided into intervals, for example: roughly divided into three large intervals of low power, medium power and high power; or Finely divided into five, ten or more distinct intervals. The finer the interval division, the more stable the power control.

The control signal is generated by the control module to adjust the output power of the RF power amplifier in the RF heating module to control the RF heating module to work under different output powers, that is, to adjust the output power of the RF heating module step by step to make it work in different power ranges.

S203. Detect the normal fluctuation range of the input current of the radio frequency heating module during each stage of output power;

When the radio frequency heating module works in a certain power range, the control module can control the output power of the radio frequency heating module to change continuously within this range, and during the power adjustment process, the input current I of the radio frequency heating module is detected in real time, and the input current I is recorded. The normal fluctuation range, and then determine the maximum wave peak value Ic and the minimum wave valley value It of the input current corresponding to the output power of each stage (each interval).

S204, determine the input current maximum value Imax and the input current minimum value Imin of the radio frequency heating module working under each level of output power;

In this embodiment, the maximum value Imax of the input current and the minimum value of the input current Imin of the radio frequency heating module working under the output power of each stage are determined according to the maximum peak value Ic and the minimum value It of the input current corresponding to the output power of each stage, which is,

Imax=Ic+△I1;

Imin=It-△I2;

Among them, △I1 and △I2 are the current margins, and both are positive values, and △I1 and △I2 can be equal or unequal. As a result, a normal fluctuation range [Imin, Imax] of the input current I of the RF heating module is determined for each stage of output power, and recorded to the control module for later use in the actual application process.

In this embodiment, in order to facilitate finding the maximum value Imax and the minimum value Imin of the input current corresponding to the output power of each stage of the radio frequency heating module, in this embodiment, it is preferable to set the input current corresponding to the output power of each stage in the control module. The maximum value Imax and the minimum value Imin are established and the corresponding relationship between the output power and the input current is established and saved.

The corresponding relationship can be to generate a comparison table between the output power and the input current, and use a look-up table method to determine the maximum value Imax and the minimum value Imin of the input current corresponding to different set powers; or, form a storage address mapping relationship, according to Different output powers access different storage addresses, and retrieve the maximum value Imax and minimum value Imin of the input current stored therein. Of course, this embodiment is not limited to the above examples.

S205, determine the input current limit value Iext of the radio frequency heating module;

In order to avoid overheating damage to the radio frequency heating module, in this embodiment, it is preferable to determine the maximum input current that the radio frequency heating module can withstand according to the maximum calorific value that the internal components of the radio frequency heating module can withstand, to form the input current limit value Iext, and save it to the control module to be called in the actual application process in the future.

Second, the practical application stage

S206, receive set power, and determine the predetermined power, input current maximum value Imax and minimum value Imin of the radio frequency heating module according to the set power;

In the actual application process of the radio frequency heating device, the control module receives the set power or the selected cooking mode input by the user through the man-machine interface. If the user inputs a cooking mode, the control module automatically determines the corresponding set power according to the cooking mode selected by the user and according to a predetermined cooking program.

The control module determines the predetermined power input to the radio frequency heating module according to the set power, and determines the power range where the set power is located, and then quickly searches for the corresponding relationship between the output power and the input current stored in the control module in advance. The maximum value Imax and the minimum value Imin of the input current corresponding to the power interval are obtained.

S207, controlling the radio frequency heating module to be put into operation according to the predetermined power;

The control module generates a control signal according to the predetermined power, and controls the radio frequency heating module to start running. After receiving the control signal, the radio frequency heating module receives the DC power supply output by the AC-DC conversion module, outputs electromagnetic wave signals, and transmits electromagnetic waves to the heating cavity through the radiator AT to heat the food.

S208. Detect the input voltage v of the radio frequency heating module and the temperature t of the radio frequency heating module, and comprehensively determine the the temperature Tm of the solid-state semiconductor source;

In this embodiment, the control module obtains the input voltage v of the radio frequency heating module through the voltage detection module, obtains the temperature t of the radio frequency heating module through the temperature sensor, and then uses the formula:

Tm=mtT/(v-a)

Calculate the temperature Tm of the solid state semiconductor source in the RF heating module.

S209. If Tm is less than or equal to the set upper limit value Tmax, execute the subsequent process; if Tm is higher than the set upper limit value Tmax, reduce the predetermined power and reduce the output power of the radio frequency heating module, so as to reduce the power of the solid-state semiconductor source. Temperature Tm, until Tm is lower than the set lower limit value Tmin, the predetermined power is restored to the set power, and the radio frequency heating module is controlled to operate normally. At this time, clear T to zero, re-time, record the time of this normal operation, and then execute the subsequent process.

S210, detect the input current I of the radio frequency heating module, if I>Iext, cut off the DC power supply of the radio frequency heating module, and enter the protection state; otherwise, execute the subsequent process;

During the operation of the radio frequency heating module, the current detection module detects the input current I of the radio frequency heating module in real time, and sends it to the control module. The control module retrieves its pre-stored input current limit value Iext, and if the input current I>Iext, cuts off the DC power supply of the RF heating module, controls the RF heating module to stop running, and enters a protection state to avoid overheating damage to the RF heating module. If the input current I≤Iext, the subsequent output power stabilization control process is performed.

S211, according to the input current I of the radio frequency heating module, adjust the amplitude of the electromagnetic wave emitted by the radio frequency heating module;

In this embodiment, if the current detection module detects that the input current I of the radio frequency heating module fluctuates in the interval [Imin, Imax], the control module determines that the output power of the radio frequency heating module is stable, and the output power is basically equal to the predetermined power (ie , set the power). During this period, the control module can control the radio frequency heating module to keep the current working state and continue to run, emit electromagnetic waves according to a predetermined power, and cook the food in the heating cavity.

If the current detection module detects that the input current of the radio frequency heating module is I>Imax, it means that the output power of the radio frequency heating module has increased. At this time, the control module can generate an amplitude adjustment signal and send it to the radio frequency heating module, so as to control the radio frequency heating module to reduce the amplitude of the electromagnetic wave emitted by the radio frequency heating module, so as to achieve the purpose of reducing the output power.

If the current detection module detects the input current I<Imin of the radio frequency heating module, it means that the output power of the radio frequency heating module becomes smaller. At this time, the control module can generate an amplitude adjustment signal and send it to the radio frequency heating module to control the radio frequency heating module to increase the amplitude of the electromagnetic wave emitted by the radio frequency heating module to achieve the purpose of increasing the output power.

In the process of adjusting the amplitude of the electromagnetic wave emitted by the radio frequency heating module according to the input current I of the radio frequency heating module, the control module can control the radio frequency heating module to gradually increase or decrease the amplitude of the electromagnetic wave according to the set amplitude adjustment amount ΔA, and The input current I detected by the current detection module is received after each amplitude adjustment. When the input current I of the radio frequency heating module returns to the interval [Imin, Imax], it means that the output power of the radio frequency heating module returns to the vicinity of the predetermined power. At this time, the control module can stop the adjustment process of the electromagnetic wave amplitude, so that the output power of the radio frequency heating module can be stabilized near the predetermined power.

As a result, the power control of the radio frequency heating module is realized, so that the radio frequency heating module can always run stably with a predetermined power, and the heating quality of the radio frequency heating device is improved.

Embodiment 2, this embodiment takes a radio frequency heating device as an example to describe the temperature control technology of the radio frequency heating module.

Due to the different characteristics of electromagnetic waves in different frequency bands, the lower the frequency of electromagnetic waves, the longer the wavelength and the stronger the penetrating ability to food, but the corresponding cooking efficiency and heating uniformity will decrease to a certain extent; and the higher the frequency of electromagnetic waves , the shorter the wavelength, the weaker the penetration of the food, but the cooking efficiency and heating uniformity of the food are improved to a certain extent. In order to further improve the heating quality of the food by the radio frequency heating device, in this embodiment, two radiators AT1 and AT2 are preferably built in the heating cavity of the radio frequency heating device. As shown in FIG. 3 , the two radiators AT1 and AT2 are preferably arranged On the opposite sides of the inner wall of the heating chamber, electromagnetic waves are emitted together to heat the food in the heating chamber. In addition, two radio frequency heating modules RM1 and RM2 can be arranged on the main control board of the radio frequency heating device, which are respectively connected with the two radiators AT1 and AT2 in a one-to-one correspondence. The AC-DC conversion module outputs two DC power supplies, respectively providing independent DC power supply for the two radio frequency heating modules RM1 and RM2, and sets two voltage detection modules V1 and V2 to detect the two radio frequency heating modules RM1 and RM2 respectively. The input voltage v, v' is sent to the control module. A temperature sensor W1, W2 is installed on the housing of each RF heating module RM1, RM2, or on the main control board and adjacent to the two RF heating modules RM1, RM2, respectively, for detecting the two RF The temperatures t, t' of the heating modules RM1, RM2 are sent to the control module for determining the temperatures Tm, Tm' of the solid semiconductor sources in the two RF heating modules RM1, RM2. in particular,

The temperature Tm of the solid semiconductor source in the first radio frequency heating module RM1 can be calculated and obtained by using the following formula:

Tm=mtT/(v-a) (1);

Wherein, m is the impedance of the solid semiconductor source in the first radio frequency heating module RM1; t is the temperature of the first radio frequency heating module RM1; T is the normal operation time of the first radio frequency heating module RM1; v is the first radio frequency heating module Input voltage of module RM1; a is the coefficient.

The temperature Tm' of the solid semiconductor source in the second radio frequency heating module RM2 can be calculated and obtained by using the following formula:

Tm'=m't'T'/(v'-a) (2);

Wherein, m' is the impedance of the solid semiconductor source in the second radio frequency heating module RM2; t' is the temperature of the second radio frequency heating module RM2; T' is the normal operation time of the second radio frequency heating module RM2; v' is the The input voltage of the second radio frequency heating module RM2.

In order to realize overheating protection for the solid-state semiconductor sources in the two RF heating modules RM1 and RM2, the upper and lower temperature limits Tmax and Tmin can be set in advance according to the safe temperature range allowed for the normal operation of the solid-state semiconductor sources. Then, compare the calculated temperature Tm, Tm' of the solid-state semiconductor source with the set upper limit Tmax and lower limit Tmin; if Tm>Tmax, it is considered that the solid-state semiconductor source in the first radio frequency heating module RM1 has a If the temperature is too high, overheat protection needs to be performed on the first radio frequency heating module RM1. If Tm'>Tmax, it is considered that the temperature of the solid-state semiconductor source in the second radio frequency heating module RM2 is too high, and overheat protection needs to be performed on the second radio frequency heating module RM2. In this embodiment, the radio frequency heating module RM1 or RM2 can be controlled to reduce its output power by reducing the predetermined power input to the radio frequency heating module RM1 or RM2 by the control module, thereby reducing the temperature of its solid-state semiconductor source. For the first radio frequency heating module RM1, until Tm<Tmin, it is considered that the temperature of the solid-state semiconductor source in the first radio frequency heating module RM1 has returned to normal, and it can continue to be put into use. For the second radio frequency heating module RM2, until Tm'<Tmin, it is considered that the temperature of the solid-state semiconductor source in the second radio frequency heating module RM2 returns to normal, and it can continue to be put into use. At this time, the predetermined power input to the radio frequency heating module RM1 or RM2 can be restored to the original predetermined power through the control module, and then the radio frequency heating module RM1 or RM2 can be controlled to increase its output power to resume normal operation. After the radio frequency heating module RM1 or RM2 resumes normal operation, the time T or T' of this normal operation is cleared and the time is re-timed.

In this embodiment, two methods of reducing the predetermined power input to the radio frequency heating module step by step or controlling the radio frequency heating module to stop running can also be used to achieve the purpose of reducing the output power of the radio frequency heating module, thereby making the solid state semiconductor source The temperature is reduced to realize overheating protection.

During the normal operation of the radio frequency heating modules RM1 and RM2, in order to control the output power of the two radio frequency heating modules RM1 and RM2 to be stable at a predetermined power, two currents are also set on the main control board of the radio frequency heating device in this embodiment. The detection modules A1 and A2, as shown in FIG. 3 , are respectively used to detect the input currents I and I′ of the two radio frequency heating modules RM1 and RM2, and send them to the control module for monitoring the two radio frequency heating modules RM1. , The output power of RM2 is automatically adjusted, so that the sum of the output power of the two radio frequency heating modules RM1 and RM2 can be stabilized near the set power.

The temperature control method of the radio frequency heating module of the present embodiment is described in detail below in conjunction with the above-mentioned power adjustment strategy, as shown in FIG. 4 , which specifically includes the following processes:

(1) Test phase

Before the radio frequency heating device leaves the factory, each radio frequency heating module RM1 and RM2 in the radio frequency heating device can be tested respectively according to the procedures S201-S205 in the first embodiment, and it is determined that each radio frequency heating module RM1 and RM2 work at different outputs During the power period, the maximum value Imax/Imax' and the minimum value Imin/Imin' corresponding to the normal fluctuation of the input current, and the corresponding relationship between the output power and the input current are respectively generated and stored in the control module.

In addition, according to the maximum calorific value that the internal devices of each RF heating module RM1 and RM2 can withstand, the maximum input current that each RF heating module RM1 and RM2 can accept is determined to form the maximum input current of each RF heating module RM1 and RM2. The current limit values Iext and Iext' are entered and stored in the control module.

(2) Practical application stage

S401, receiving the set power, and determining the predetermined power of each radio frequency heating module RM1 and RM2 according to half of the set power;

In this embodiment, the set power input by the user or the set power corresponding to the selected cooking mode is the sum of the output powers of the two radio frequency heating modules RM1 and RM2. In this embodiment, the predetermined power of each radio frequency heating module RM1 and RM2 is preferably determined to be half of the set power in an equalized manner.

S402, according to half of the set power, determine the maximum value and the minimum value of the input current of each radio frequency heating module RM1 and RM2;

The control module of this embodiment can determine the maximum and minimum values of the input current of each radio frequency heating module RM1 and RM2 by using the corresponding relationship between the output power and the input current stored in the control module in advance according to half of the set power. . For example, when the first radio frequency heating module RM1 works at half of the set power, the corresponding maximum value of the input current is Imax and the minimum value is Imin; when the second radio frequency heating module RM2 works at half of the set power, the corresponding input current The maximum value of the input current is Imax' and the minimum value is Imin'.

S403, determine the operating frequency of each radio frequency heating module RM1, RM2, so that the frequencies of the electromagnetic waves emitted by the two radio frequency heating modules RM1, RM2 are different;

In this embodiment, the two radio frequency heating modules RM1 and RM2 can be adjusted to work in different frequency bands through the control module. In order to improve the heating quality, it is preferable to adjust the frequency of the electromagnetic wave emitted by the first radio frequency heating module RM1 to be in the middle frequency band, for example, the center frequency is 915 MHz;

S404, control each radio frequency heating module RM1, RM2 to be put into operation according to half of the set power;

In this embodiment, the control module generates two control signals according to half of the set power, and sends them to the two radio frequency heating modules RM1 and RM2 respectively to control the two radio frequency heating modules RM1 and RM2 to start running. After receiving the control signal, the two radio frequency heating modules RM1 and RM2 receive the DC power supply output by the AC-DC conversion module, output electromagnetic wave signals, and respectively transmit electromagnetic waves to the heating cavity through the two radiators AT1 and AT2 to jointly treat the food. to heat.

S405. Detect the input voltage v, v' of each radio frequency heating module RM1, RM2 and the temperature t, t' of each radio frequency heating module RM1, RM2, and combine the normal operation time of each radio frequency heating module RM1, RM2 this time T, T' and the impedance m, m' of the solid-state semiconductor source packaged in each radio frequency heating module RM1, RM2, comprehensively determine the temperature Tm, Tm' of the solid-state semiconductor source in each radio frequency heating module RM1, RM2;

In this embodiment, the control module obtains the input voltages v and v' of the two radio frequency heating modules RM1 and RM2 through the two voltage detection modules V1 and V2 respectively, and obtains the two radio frequency heating modules through the two temperature sensors W1 and W2 respectively. The temperatures t and t' of the heating modules RM1 and RM2, and then the temperature Tm of the solid-state semiconductor source in the first radio frequency heating module RM1 is calculated by formula (1), and the temperature Tm in the second radio frequency heating module RM2 is calculated by formula (2). The temperature Tm' of the solid-state semiconductor source.

S406, if both Tm and Tm' are less than or equal to the set upper limit value Tmax, execute the process S409;

In this embodiment, if the temperatures Tm and Tm' of the solid-state semiconductor sources inside the two radio frequency heating modules RM1 and RM2 are both below the set upper limit value Tmax, it is considered that the solid state semiconductor sources in the two radio frequency heating modules RM1 and RM2 are If the temperature of the semiconductor source is normal, jump to S409 to execute the subsequent process, so as to stably control the output power of the two radio frequency heating modules RM1 and RM2.

S407. If Tm>Tmax, reduce the predetermined power input to the first radio frequency heating module RM1, and increase the predetermined power of the second radio frequency heating module RM2 by equal amplitude, until Tm<Tmin, then connect the two radio frequency heating modules RM1, RM2 The predetermined power is restored to half of the set power, and the two radio frequency heating modules are controlled to operate normally, and then the process S409 is executed;

In this embodiment, if Tm>Tmax, it is considered that the temperature of the solid-state semiconductor source in the first radio frequency heating module RM1 is abnormal, and there is a danger of overheating and damage. At this time, the predetermined power input to the first radio frequency heating module RM1 can be reduced by the control module to control the first radio frequency heating module RM1 to reduce its output power, thereby reducing the temperature Tm of the solid-state semiconductor source in the first radio frequency heating module RM1 Effect. At the same time, the predetermined power input to the second radio frequency heating module RM2 is increased by the control module in equal amplitude, so that the sum of the predetermined power input to the two radio frequency heating modules RM1 and RM2 is still equal to the set power to ensure the heating quality. Until Tm<Tmin, the predetermined power input into the two radio frequency heating modules RM1 and RM2 is restored to half of the set power, and the two radio frequency heating modules RM1 and RM2 are controlled to operate normally. At this time, T is cleared to zero, the timer is re-timed, the time of the normal operation of the first radio frequency heating module RM1 this time is recorded, and then the subsequent process S409 is performed.

For the temperature control strategy of reducing the output power of the radio frequency heating module by controlling the radio frequency heating module to stop running, and then realizing overheating protection of the solid semiconductor source in the radio frequency heating module, when Tm>Tmax, the first radio frequency can be controlled. The heating module RM1 stops running, and the predetermined power input to the second RF heating module RM2 is increased to the set power, and the second RF heating module RM2 is used to cook food alone until the temperature of the solid semiconductor source in the first RF heating module RM1 is reached After Tm<Tmin, the predetermined power input into the two radio frequency heating modules RM1 and RM2 is restored to half of the set power, and the first radio frequency heating module RM1 is controlled to be put into operation again.

S408. If Tm'>Tmax, lower the predetermined power input to the second radio frequency heating module RM2, and increase the predetermined power of the first radio frequency heating module RM1 by the same amplitude, until Tm'<Tmin, then connect the two radio frequency heating modules RM1 . The predetermined power of RM2 is restored to half of the set power, and the two radio frequency heating modules are controlled to operate normally, and then the process S409 is executed;

In this embodiment, if Tm'>Tmax, it is considered that the temperature of the solid-state semiconductor source in the second radio frequency heating module RM2 is abnormal, and there is a risk of overheating damage. At this time, the predetermined power input to the second radio frequency heating module RM2 can be reduced by the control module to control the second radio frequency heating module RM2 to reduce its output power, thereby reducing the temperature Tm of the solid-state semiconductor source in the second radio frequency heating module RM2 'Effect. At the same time, the predetermined power input to the first radio frequency heating module RM1 is increased by the control module in equal amplitude, so that the sum of the predetermined power input to the two radio frequency heating modules RM1 and RM2 is still equal to the set power to ensure the heating quality. Until Tm'<Tmin, restore the predetermined power input to the two radio frequency heating modules RM1 and RM2 to half of the set power, and control the two radio frequency heating modules RM1 and RM2 to operate normally. At this time, T' is reset to zero, the timer is re-timed, the normal operation time of the second radio frequency heating module RM2 is recorded this time, and then the subsequent process S409 is performed.

In the same way, for the temperature control strategy of reducing the output power of the radio frequency heating module by controlling the radio frequency heating module to stop running, and then realizing the overheating protection of the solid semiconductor source in the radio frequency heating module, when Tm'>Tmax, it can be Control the second radio frequency heating module RM2 to stop running, and increase the predetermined power input to the first radio frequency heating module RM1 to the set power, and use the first radio frequency heating module RM1 to cook food alone until the solid in the second radio frequency heating module RM2 is After the temperature of the semiconductor source is Tm'<Tmin, the predetermined power input to the two RF heating modules RM1 and RM2 is restored to half of the set power, and the second RF heating module RM2 is controlled to be put into operation again.

S409. Detect the input currents I and I' of each radio frequency heating module RM1 and RM2. If I>Iext or I'>Iext', cut off the DC power supply of the two radio frequency heating modules RM1 and RM2, and control the radio frequency heating device to enter the protection Status; otherwise, execute subsequent procedures;

During the operation of the two radio frequency heating modules RM1 and RM2, the two current detection modules A1 and A2 detect the input currents I and I' of the two radio frequency heating modules RM1 and RM2 in real time and send them to the control module. The control module retrieves the pre-stored input current limit values Iext and Iext' of each radio frequency heating module RM1 and RM2.

If the input current I of the first radio frequency heating module RM1 is greater than its limit value Iext, or the input current I' of the second radio frequency heating module RM2 is greater than its limit value Iext', the control module will immediately cut off the two radio frequency heating modules RM1, RM2. The DC power supply controls the two RF heating modules RM1 and RM2 to stop running and enter the protection state.

If the input current I of the first radio frequency heating module RM1≤Iext, and the input current I'≤Iext' of the second radio frequency heating module RM2, the subsequent output power stabilization control process is performed.

S410, adjusting the amplitudes of the electromagnetic waves emitted by the two radio frequency heating modules RM1 and RM2 according to the input currents I and I' of the two radio frequency heating modules RM1 and RM2;

In this embodiment, if the first current detection module A1 detects that the input current I of the first radio frequency heating module RM1 fluctuates in the interval [Imin, Imax], the control module determines that the output power of the first radio frequency heating module RM1 is stable, And the output power is basically equal to half of the set power. During this period, the control module can control the first radio frequency heating module RM1 to keep the current working state and continue to run, emit electromagnetic waves at half the set power, and cook the food in the heating cavity.

Similarly, if the second current detection module A2 detects that the input current I' of the second radio frequency heating module RM2 fluctuates in the interval [Imin', Imax'], the control module determines that the output power of the second radio frequency heating module RM2 is stable, And the output power is basically equal to half of the set power. During this period, the control module can control the second radio frequency heating module RM2 to keep the current working state and continue to run, emit electromagnetic waves according to half of the set power, and cook the food in the heating cavity.

If the first current detection module A1 detects that the input current I>Imax of the first radio frequency heating module RM1, it means that the output power of the first radio frequency heating module RM1 becomes larger. At this time, the control module can generate an amplitude adjustment signal and send it to the first radio frequency heating module RM1 to control the first radio frequency heating module RM1 to reduce the amplitude of the electromagnetic wave emitted by the first radio frequency heating module RM1, so as to achieve the purpose of reducing the output power of the first radio frequency heating module RM1 .

Similarly, if the second current detection module A2 detects that the input current I'>Imax' of the second radio frequency heating module RM2, it means that the output power of the second radio frequency heating module RM2 increases. At this time, the control module can generate an amplitude adjustment signal and send it to the second radio frequency heating module RM2 to control the second radio frequency heating module RM2 to reduce the amplitude of the electromagnetic wave emitted by the second radio frequency heating module RM2 to achieve the purpose of reducing the output power of the second radio frequency heating module RM2 .

If the first current detection module A1 detects that the input current I<Imin of the first radio frequency heating module RM1, it means that the output power of the first radio frequency heating module RM1 is reduced. At this time, the control module can generate an amplitude adjustment signal and send it to the first radio frequency heating module RM1 to control the first radio frequency heating module RM1 to increase the amplitude of the electromagnetic wave it emits, so as to increase the output power of the first radio frequency heating module RM1. Purpose.

Similarly, if the second current detection module A2 detects the input current I'<Imin' of the second radio frequency heating module RM2, it means that the output power of the second radio frequency heating module RM2 becomes smaller. At this time, the control module can generate an amplitude adjustment signal and send it to the second radio frequency heating module RM2 to control the second radio frequency heating module RM2 to increase the amplitude of the electromagnetic wave it emits, so as to increase the output power of the second radio frequency heating module RM2. Purpose.

In the process of adjusting the amplitudes of the electromagnetic waves emitted by the two radio frequency heating modules RM1 and RM2 according to the input currents I and I' of the two radio frequency heating modules RM1 and RM2, the control module can control the two according to the set amplitude adjustment amount ΔA. The radio frequency heating modules RM1 and RM2 gradually increase or decrease the amplitude of the electromagnetic wave, and receive the input currents I and I' detected by the two current detection modules A1 and A2 after each amplitude adjustment. When the input current I/I' of the RF heating module RM1/RM2 whose output power deviates returns to the normal range, for example, the input current I is in the [Imin, Imax] range, and the input current I' is in the [Imin', Imax' range. ] interval, it means that the output power of the RF heating module RM1/RM2 that has deviated returns to about half of the set power. At this time, the control module can stop the amplitude adjustment process of the radio frequency heating modules RM1/RM2, so that the output power of the radio frequency heating modules RM1/RM2 is stabilized at about half of the set power, so as to realize the output power of the radio frequency heating modules RM1 and RM2. stability control.

Of course, more radio frequency heating modules and radiators can also be set in the radio frequency heating device. By adjusting the frequency of the electromagnetic waves emitted by each radio frequency heating module, it can meet the high-quality heating requirements of different types of food.

In addition, a sensing protection module can be further set on the main control board of the radio frequency heating device, as shown in Figure 1 and Figure 3, for sensing the intensity of the electromagnetic waves emitted by the radiator and the electromagnetic waves that are partially absorbed by the food and then reflected back The intensity of the electromagnetic wave of the radiator, and when an abnormality is sensed, the transmission of the electromagnetic wave signal to the radiator is cut off, and the protection function is performed.

It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be used for The technical solutions described in the foregoing embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. a temperature control method of a radio frequency heating module, is characterized in that, comprising: Supply power to the radio frequency heating module, and control the radio frequency heating module to power on and operate according to the predetermined power; Detect the temperature t of the RF heating module; According to the temperature t of the radio frequency heating module, the input voltage v, the time T of this normal operation and the impedance m of the solid state semiconductor source packaged in the radio frequency heating module, comprehensively determine the temperature Tm of the solid state semiconductor source; When Tm exceeds the set upper limit value, the RF heating module is controlled to reduce its output power, and when Tm falls below the set lower limit value, the output power of the RF heating module is restored to the predetermined power. 2. the temperature control method of the radio frequency heating module according to claim 1, is characterized in that, the temperature Tm of described solid-state semiconductor source adopts following formula to calculate and obtain: Tm=mtT/(v-a); where a is a coefficient. 3. The temperature control method for a radio frequency heating module according to claim 1, wherein when the number of the radio frequency heating modules is one, the predetermined power is a set power selected by a user; The temperature control method also includes: Determine the maximum and minimum input current of the RF heating module according to the set power; During the normal operation of the radio frequency heating module, detecting the input current of the radio frequency heating module; When the input current of the radio frequency heating module is greater than the maximum value of the input current, the amplitude of the electromagnetic wave emitted by the radio frequency heating module is reduced, and the output power is reduced; When the input current of the radio frequency heating module is less than the minimum value of the input current, the amplitude of the electromagnetic wave emitted by the radio frequency heating module is increased to increase the output power. 4. The temperature control method for a radio frequency heating module according to claim 1, wherein when there are two radio frequency heating modules, the predetermined power is half of the set power selected by the user; The temperature control method also includes: Adjust the two RF heating modules to emit electromagnetic waves at different frequencies; When the temperature of the solid-state semiconductor source in one of the radio frequency heating modules exceeds the upper limit value, the predetermined power of the radio frequency heating module is decreased, and the predetermined power of the other radio frequency heating module is increased by an equal amplitude, so as to reduce the predetermined power of one of the radio frequency heating modules. output power, and increase the output power of another RF heating module; When the temperature of the solid-state semiconductor source in one of the radio frequency heating modules drops below the lower limit value, the output powers of the two radio frequency heating modules are both restored to the original predetermined power. 5. The temperature control method of the radio frequency heating module according to claim 4, characterized in that, further comprising: Determine the maximum and minimum input currents of the two RF heating modules according to half of the set power; During the normal operation of the two RF heating modules, the input current of the two RF heating modules is detected; When the input current of one of the radio frequency heating modules is greater than the maximum value of its input current, reducing the amplitude of the electromagnetic wave emitted by the radio frequency heating module to reduce the output power of the radio frequency heating module; When the input current of one of the radio frequency heating modules is less than the minimum value of its input current, the amplitude of the electromagnetic wave emitted by the radio frequency heating module is increased to increase the output power of the radio frequency heating module. 6. The temperature control method of the radio frequency heating module according to any one of claims 3 to 5, wherein the method for determining the maximum value and the minimum value of the input current is: Ensure the normal operation of the RF heating module; Adjust the output power of the RF heating module step by step; Detect the normal fluctuation range of the input current of the RF heating module during each stage of output power; Determine the maximum peak value Ic and the minimum valley value It of the input current according to the normal fluctuation range of the input current corresponding to the output power of each stage; Determine the maximum input current Imax and the minimum input current Imin of the RF heating module working under each stage of output power: Imax=Ic+△I1; Imin=It-△I2; Among them, △I1 and △I2 are the current margins, and both are positive values. 7. The temperature control method of the radio frequency heating module according to claim 6, wherein in the process of adjusting the amplitude of the electromagnetic wave emitted by the radio frequency heating module according to the input current, comprising: Increase or decrease the amplitude of electromagnetic waves step by step; After each amplitude adjustment, detect the input current I of the RF heating module; When Imin≤I≤Imax, the adjustment process of the electromagnetic wave amplitude is stopped. 8. A radio frequency heating device, characterized in that, comprising: a heating cavity, the inner wall of which is provided with a radiator; a radio frequency heating module, which emits electromagnetic waves into the heating cavity through the radiator, and a solid-state semiconductor source is packaged in the radio frequency heating module; a temperature sensor, which is installed on the casing of the radio frequency heating module or arranged on the circuit board and is adjacent to the radio frequency heating module, and is used for detecting the temperature t of the radio frequency heating module; a voltage detection module, which is used to detect the input voltage v of the radio frequency heating module; A control module, which controls the radio frequency heating module to be powered on and run according to a predetermined power, and according to the temperature t of the radio frequency heating module, the input voltage v, the time T of this normal operation and the impedance of the solid-state semiconductor source packaged in the radio frequency heating module m, comprehensively determine the temperature Tm of the solid-state semiconductor source; when Tm exceeds the set upper limit, control the radio frequency heating module to reduce its output power, until Tm drops below the set lower limit, control The output power of the radio frequency heating module is restored to the predetermined power. 9. The radio frequency heating device according to claim 8, characterized in that, When there are two radio frequency heating modules, the predetermined power of each radio frequency heating module is half of the set power selected by the user; The control module controls the two radio frequency heating modules to emit electromagnetic waves at different frequencies; When the temperature of the solid-state semiconductor source in one of the radio frequency heating modules exceeds the upper limit value, the control module reduces the predetermined power of the radio frequency heating module, and increases the predetermined power of the other radio frequency heating module by an equal amplitude, so as to control the predetermined power of the radio frequency heating module. One RF heating module reduces its output power and controls the other RF heating module to increase its output power; when the temperature of the solid-state semiconductor source in said one of the RF heating modules drops below the lower limit value, the control The module restores the output power of both radio frequency heating modules to the original predetermined power. 10. The radio frequency heating device according to claim 9, further comprising: a current detection module for detecting the input current of the radio frequency heating module; When there is one RF heating module, the predetermined power is the set power selected by the user; the control module determines the maximum and minimum input current of the RF heating module according to the set power; when the RF heating module is normal During operation, when the input current of the radio frequency heating module is greater than the maximum value of the input current, the control module controls the radio frequency heating module to reduce the amplitude of the electromagnetic wave emitted by the radio frequency heating module to reduce the output power; when the input current of the radio frequency heating module is When it is less than the minimum value of the input current, the radio frequency heating module is controlled to increase the amplitude of the electromagnetic wave emitted by it, so as to increase the output power; When there are two RF heating modules, the control module determines the maximum and minimum input currents of the two RF heating modules respectively according to half of the set power; during the normal operation of both RF heating modules, all When the control module detects that the input current of one of the radio frequency heating modules is greater than the maximum value of its input current, it reduces the amplitude of the electromagnetic wave emitted by the radio frequency heating module to reduce the output power of the radio frequency heating module; in one of the radio frequency heating modules When the input current of the radio frequency heating module is less than the minimum value of the input current, the amplitude of the electromagnetic wave emitted by the radio frequency heating module is increased to increase the output power of the radio frequency heating module.

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