阅读说明：本技术 基于电磁炉的功率及温度双闭环的恒温加热控制方法 (Constant-temperature heating control method based on power and temperature double closed loops of induction cooker ) 是由 宋力涛 吴正华 龚宇 李艳春 于 2020-04-15 设计创作，主要内容包括：本发明公开了基于电磁炉的功率及温度双闭环的恒温加热控制方法：包括如下步骤：S1：预设工作温度值；S2：读取电磁炉面板实际的温度；S3：中央处理器判断电磁炉面板实际温度是否大于预设工作温度值；S4：读取电磁炉当前输入电压,将读取到的电压值传输给中央处理器。本发明提出的基于电磁炉的功率及温度双闭环的恒温加热控制方法,实现对锅底控温,重复多个周期的加热功率调整和温度反馈,不断的对温度进行调整,使温度趋于预设的温度值,直至温度稳定在预设的温度值,实现对锅底精确恒温加热。(The invention discloses a constant-temperature heating control method based on a power and temperature double closed loop of an induction cooker, which comprises the following steps: the method comprises the following steps: s1: presetting a working temperature value; s2: reading the actual temperature of the panel of the induction cooker; s3: the central processing unit judges whether the actual temperature of the panel of the induction cooker is greater than a preset working temperature value or not; s4: and reading the current input voltage of the induction cooker, and transmitting the read voltage value to the central processing unit. The constant-temperature heating control method based on the power and temperature double closed loop of the induction cooker realizes temperature control of the pan bottom, repeats heating power adjustment and temperature feedback for a plurality of periods, and continuously adjusts the temperature to enable the temperature to tend to a preset temperature value until the temperature is stabilized at the preset temperature value, thereby realizing accurate constant-temperature heating of the pan bottom.)

1. The constant-temperature heating control method based on the power and temperature double closed loop of the induction cooker is characterized by comprising the following steps of:

s1: presetting a working temperature value;

s2: reading the actual temperature of the panel of the induction cooker, and transmitting the read temperature signal to a central processing unit;

s3: the central processing unit judges whether the actual temperature of the panel of the induction cooker is greater than a preset working temperature value or not;

s4: reading the current input voltage of the induction cooker, and transmitting the read voltage value to a central processing unit;

s5: reading the current input current of the induction cooker, and transmitting the read voltage value to a central processing unit;

s6: the algorithm built in the cpu calculates the current input power, i.e., the voltage value read in S4 multiplied by the current value read in S5, as follows: p ═ UI;

s7: the central processing unit judges whether the input power is larger than the set input power.

2. The thermostatic heating control method based on the power and temperature double closed loop of the induction cooker according to claim 1, characterized in that: the temperature of the electromagnetic oven panel is read by adopting a temperature sampling circuit, the temperature sampling circuit comprises a pin bank CN1, a resistor R23, a resistor R26, a temperature sensor resistor Rz, a capacitor C11 and a TMAIN signal output terminal, the temperature sensor resistor Rz is attached to the electromagnetic oven panel, the input end of the temperature sensor resistor Rz is connected to a pin 3 of the pin bank CN1, the output end of the temperature sensor resistor Rz is connected to a pin 4 of the pin bank CN1, a pin 1 of the pin bank CN1 is connected to the input end of the resistor R26 and connected to the output end of the resistor R23, the input end of the resistor R23 is connected with a +5V power supply end for supplying power, the output end of the resistor R26 is connected to the output of the TMAIN signal output terminal and connected to the input end of the capacitor C11, and the output end of the capacitor C11 is connected with a pin 2 of the pin bank CN1 and then grounded.

3. The thermostatic heating control method based on the power and temperature double closed loop of the induction cooker according to claim 1, characterized in that: the voltage sampling circuit is used for sampling the output voltage of the induction cooker before the input voltage of the induction cooker is read, the voltage sampling circuit comprises a resistor R35, a resistor R36, a resistor R38, a resistor R48, a resistor R43, a capacitor C19 and a capacitor C20, the input end of the resistor R35 is connected to a bus of the power input end of the induction cooker in parallel, the output end of the resistor R35 is electrically connected with the input end of a resistor R36, the output end of the resistor R36 is electrically connected with the input end of a resistor R38, the output end of the resistor R38 is connected to the input end of a resistor R48 and is connected to the input end of the resistor R43 and the input end of the capacitor C20, the output end of the resistor R48 and the output end of the capacitor C20 are grounded, the output end of the resistor R43 is connected to the output end of an AD Vin-power signal terminal and is connected to the input end of a capacitor C19, and the output end of the capacitor C19 is grounded.

4. The thermostatic heating control method based on the power and temperature double closed loop of the induction cooker according to claim 1, characterized in that: the method comprises the steps that before the input current of the induction cooker is read, the output current of the induction cooker is sampled, a current sampling circuit is adopted for current sampling, the current sampling circuit comprises an operational amplifier IC6, a resistor R42, a resistor R48, a capacitor C40, a resistor R49, a resistor R45 and a capacitor C16, the positive electrode of the operational amplifier IC6 is connected to the output end of the resistor R42 and connected to the input end of a capacitor C29, the input end of the resistor R42 is connected to a bus of the power supply input end of the induction cooker in series, the negative electrode of the operational amplifier IC6 is connected to the output end of the capacitor C29 and connected to the input end of a resistor R48, and the output end of the resistor R48 is grounded; the negative electrode of the operational amplifier IC6 is connected to the input end of the capacitor C40 and the input end of the resistor R49, the output end of the capacitor C40 is connected to the output end of the operational amplifier IC6 after being connected with the output end of the resistor R49, the output end of the operational amplifier IC6 is connected to the input end of the resistor R45, the output end of the resistor R45 is connected to the output of the Curreng-V signal end and the input end of the capacitor C16, and the output end of the capacitor C16 is grounded.

5. The thermostatic heating control method based on the power and temperature double closed loop of the induction cooker according to claim 1, characterized in that: the central processing unit is internally provided with a main control circuit, the main control circuit comprises a chip U1, the model of the chip U1 is PIC16F, a comparator is arranged in the chip U1 and is externally connected with a PID (proportion integration differentiation) algorithm device, the PID algorithm device is an algorithm device based on FPGS (field programmable gate array), a pin 1 of the chip U1 is connected to a TMAIN (transmitter area network) signal output terminal, a pin 44 of the chip U1 is connected to an AD-Vin power supply signal terminal, and a pin 42 of the chip U1 is connected to a Curreng-V signal terminal.

6. The thermostatic heating control method based on the power and temperature double closed loop of the induction cooker according to claim 1, characterized in that: the output end of the induction cooker is connected with an IGBT driving circuit, the source electrode of the IGBT end of the IGBT driving circuit is connected to a pin 10 of a chip U1, the grid electrode of the IGBT end is connected with a power supply input, the drain electrode of the IGBT end is connected to the input end of a diode D8, and the output end of a diode D8 is connected with the source electrode of the IGBT end and then connected to a power supply output terminal to supply power to the working end of the induction cooker.

Technical Field

The invention relates to the technical field of temperature control of induction cookers, in particular to a constant-temperature heating control method based on a double closed loop of power and temperature of an induction cooker.

Background

The pan of cooking can lead to the temperature variation to be different because of the heating source, and the heating temperature of the bottom of a boiler is invariable, and is very important to the taste and the quality of the food of cooking. However, most of the induction cookers on the market at present lack the function of accurate heating and temperature control. In order to achieve the purpose of accurately heating and keeping constant temperature, a constant-temperature heating control method based on a double closed loop of power and temperature of an induction cooker is provided.

Disclosure of Invention

The invention aims to provide a constant-temperature heating control method based on a power and temperature double closed loop of an induction cooker, which can adjust the heating temperature of a pan bottom to be in a constant state, realize accurate constant-temperature heating of the pan bottom and solve the problem that the constant-temperature heating of the pan bottom cannot be realized in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: the constant temperature heating control method based on the double closed loop of power and temperature of the induction cooker comprises the following steps:

s1: presetting a working temperature value;

s2: reading the actual temperature of the panel of the induction cooker, and transmitting the read temperature signal to a central processing unit;

s3: the central processing unit judges whether the actual temperature of the panel of the induction cooker is greater than a preset working temperature value or not;

s4: reading the current input voltage of the induction cooker, and transmitting the read voltage value to a central processing unit;

s5: reading the current input current of the induction cooker, and transmitting the read voltage value to a central processing unit;

s6: the algorithm built in the cpu calculates the current input power, i.e., the voltage value read in S4 multiplied by the current value read in S5, as follows: p ═ UI;

s7: the central processing unit judges whether the input power is larger than the set input power:

preferably, the temperature of the panel of the induction cooker is read by adopting a temperature sampling circuit, the temperature sampling circuit comprises a pin bank CN1, a resistor R23, a resistor R26, a temperature sensor resistor Rz, a capacitor C11 and a TMAIN signal output terminal, the temperature sensor resistor Rz is attached to the panel of the induction cooker, the input end of the temperature sensor resistor Rz is connected to a pin 3 of the pin bank CN1, the output end of the temperature sensor resistor Rz is connected to a pin 4 of the pin bank CN1, a pin 1 of the pin bank CN1 is connected to the input end of the resistor R26, and is connected to the output end of the resistor R23, the input end of the resistor R23 is connected with the +5V power supply end for supplying power, the output end of the resistor R26 is connected with the output end of the TMAIN signal output terminal, and the output end of the capacitor C11 is connected with the pin 2 of the pin CN1 and then grounded, and an AD sampling module with 12 bits is adopted to obtain an AD value formula of Tad 4096 × Rz/(Rz + 2). According to the above formula, the current temperature value can be accurately obtained by comparing the resistance value with the temperature relation table in the Rz specification.

Preferably, the output voltage of the induction cooker is sampled before the input voltage of the induction cooker is read, a voltage sampling circuit is adopted for voltage sampling, the voltage sampling circuit comprises a resistor R35, a resistor R36, a resistor R38, a resistor R48, a resistor R43, a capacitor C19 and a capacitor C20, the input end of the resistor R35 is connected to a bus of the power input end of the induction cooker in parallel, the output end of the resistor R35 is electrically connected with the input end of a resistor R36, the output end of the resistor R36 is electrically connected with the input end of a resistor R38, the output end of the resistor R38 is connected to the input end of a resistor R48 and is connected to the input end of a resistor R43 and the input end of a capacitor C20, the output end of the resistor R48 and the output end of the capacitor C20 are both grounded, the output end of the resistor R43 is connected to the output of an AD-Vin power signal terminal and is connected to the input end of a capacitor C19, and the output end of a capacitor C19 is grounded.

Preferably, the output current of the induction cooker is sampled before the input current of the induction cooker is read, a current sampling circuit is adopted for current sampling, the current sampling circuit comprises an operational amplifier IC6, a resistor R42, a resistor R48, a capacitor C40, a resistor R49, a resistor R45 and a capacitor C16, the anode of the operational amplifier IC6 is connected to the output end of the resistor R42 and is connected to the input end of the capacitor C29, the input end of the resistor R42 is connected to a bus of the power supply input end of the induction cooker in series, the cathode of the operational amplifier IC6 is connected to the output end of the capacitor C29 and is connected to the input end of the resistor R48, and the output end of the resistor R48 is grounded; the negative electrode of the operational amplifier IC6 is connected to the input end of the capacitor C40 and the input end of the resistor R49, the output end of the capacitor C40 is connected to the output end of the operational amplifier IC6 after being connected with the output end of the resistor R49, the output end of the operational amplifier IC6 is connected to the input end of the resistor R45, the output end of the resistor R45 is connected to the output of the Curreng-V signal end and the input end of the capacitor C16, and the output end of the capacitor C16 is grounded.

Preferably, the central processing unit is internally provided with a main control circuit, the main control circuit comprises a chip U1, the model of the chip U1 is PIC16F, the chip U1 is internally provided with a comparator and externally connected with a PID (proportion integration differentiation) algorithm, the PID algorithm is an algorithm based on FPGS (fast food gateway), a pin 1 of the chip U1 is connected to a TMAIN (TMAIN) signal output terminal, a pin 44 of the chip U1 is connected to an AD-Vin power supply signal terminal, and a pin 42 of the chip U1 is connected to a Curreng-V signal terminal.

Preferably, the output end of the induction cooker is connected with an IGBT driving circuit, the source of the IGBT end of the IGBT driving circuit is connected to the pin 10 of the chip U1, the gate of the IGBT end is connected to the power input, the drain of the IGBT end is connected to the input end of the diode D8, and the output end of the diode D8 is connected to the source of the IGBT end and then connected to the power output terminal to supply power to the working end of the induction cooker.

Compared with the prior art, the invention has the beneficial effects that: the invention provides a power and temperature double-closed-loop constant-temperature heating control method based on an induction cooker, which comprises the steps of presetting a temperature value, acquiring real-time temperature of a panel of the induction cooker by a temperature sampling circuit, transmitting a temperature signal to a central processing unit, comparing the received temperature value with the preset temperature value by the central processing unit to obtain a difference value, substituting the difference value into a PID (proportion integration differentiation) algorithm device arranged in the central processing unit for calculation, taking the obtained data as an actual power set value, multiplying a current value detected by a current detection circuit and a voltage value sampled by a voltage sampling circuit to obtain a power value, marking the power value as an actual power value, subtracting the actual power value from the set power value to obtain an error value Err1, and substituting Err1 into a formula: the Output1 is Kp1 Err1 plus Sigma Ki1 Err1, the Output1 value is calculated, the calculated Output1 value is used as a heating power Output parameter, the heating power of the IGBT is reduced by the heating power Output parameter according to a proportion, the temperature of the pot bottom can be reduced, the temperature control of the pot bottom is realized, the heating power adjustment and the temperature feedback of a plurality of cycles are repeated, the temperature is continuously adjusted, and the temperature tends to a preset temperature value until the temperature is stabilized at the preset temperature value; the whole can adjust the heating temperature of the pan bottom to a constant state, and the pan bottom can be heated accurately at a constant temperature.

Drawings

FIG. 1 is a constant temperature control flow diagram of the present invention;

FIG. 2 is a block diagram of the working principle of the present invention;

FIG. 3 is a temperature sampling circuit diagram of the present invention;

FIG. 4 is a circuit diagram of the voltage sampling of the present invention;

FIG. 5 is a current sampling circuit diagram of the present invention;

FIG. 6 is a circuit diagram of an IGBT drive circuit of the present invention;

FIG. 7 is a control circuit diagram of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-2, a constant temperature heating control method based on a double closed loop of power and temperature of an induction cooker includes the following steps:

the first step is as follows: presetting a working temperature value;

the second step is that: reading the actual temperature of the panel of the induction cooker, and transmitting the read temperature signal to a central processing unit;

the third step: the central processing unit judges whether the actual temperature of the panel of the induction cooker is greater than a preset working temperature value or not: the set output power is subtracted by the PID algorithm.

Less than the preset working temperature value: the PID algorithm is used for increasing the set output power, and the temperature of the panel of the induction cooker is determined by the power.

The fourth step: reading the current input voltage of the induction cooker, and transmitting the read voltage value to a central processing unit;

the fifth step: reading the current input current of the induction cooker, and transmitting the read voltage value to a central processing unit;

and a sixth step: the algorithm built in the cpu calculates the current input power, i.e., the voltage value read in S4 multiplied by the current value read in S5, as follows: p ═ UI;

the seventh step: the CPU judges whether the input power is larger than the set input power

Greater than the input power: and the working opening of the induction cooker is reduced by a PID algorithm.

Less than the input power: the working opening of the electromagnetic oven is increased by a PID algorithm, and the size of the opening determines the size of the current input power.

Referring to fig. 3, a temperature sampling circuit is used for reading the temperature of the panel of the induction cooker, the temperature sampling circuit includes a pin bank CN1, a resistor R23, a resistor R26, a temperature sensor resistor Rz, a capacitor C11 and a TMAIN signal output terminal, the temperature sensor resistor Rz is attached to the panel of the induction cooker, an input end of the temperature sensor resistor Rz is connected to a pin 3 of a pin bank CN1, an output end of the temperature sensor resistor Rz is connected to a pin 4 of a pin bank CN1, a pin 1 of the pin bank CN1 is connected to an input end of the resistor R26 and connected to an output end of the resistor R23, an input end of the resistor R23 is connected to a +5V power supply terminal, an output end of the resistor R26 is connected to an output of the TMAIN signal output terminal and to an input end of the capacitor C11, and an output end of the capacitor C11 is connected to a pin 2 of the pin bank CN1 and then grounded.

Referring to fig. 4, before the input voltage of the induction cooker is read, the output voltage of the induction cooker is sampled, a voltage sampling circuit is used for voltage sampling, the voltage sampling circuit includes a resistor R35, a resistor R36, a resistor R38, a resistor R48, a resistor R43, a capacitor C19 and a capacitor C20, an input end of the resistor R35 is connected to a bus of a power input end of the induction cooker in parallel, an output end of the resistor R35 is electrically connected to an input end of the resistor R36, an output end of the resistor R36 is electrically connected to an input end of the resistor R38, an output end of the resistor R38 is connected to an input end of the resistor R48 and to an input end of the resistor R43 and an input end of the capacitor C20, an output end of the resistor R48 and an output end of the capacitor C20 are both grounded, an output end circuit of the resistor R43 is connected to an AD-Vin power signal terminal and to an input end of the capacitor C19, and an output end of the capacitor C19 is grounded.

Referring to fig. 5, before reading the input current of the induction cooker, the output current of the induction cooker is sampled, the current sampling employs a current sampling circuit, the current sampling circuit includes an operational amplifier IC6, a resistor R42, a resistor R48, a capacitor C40, a resistor R49, a resistor R45, and a capacitor C16, an anode of the operational amplifier IC6 is connected to an output terminal of the resistor R42 and to an input terminal of the capacitor C29, an input terminal of the resistor R42 is connected in series to a bus of a power input terminal of the induction cooker, a cathode of the operational amplifier IC6 is connected to an output terminal of the capacitor C29 and to an input terminal of the resistor R48, and an output terminal of the resistor R48 is grounded; the negative electrode of the operational amplifier IC6 is connected to the input end of the capacitor C40 and the input end of the resistor R49, the output end of the capacitor C40 is connected to the output end of the operational amplifier IC6 after being connected with the output end of the resistor R49, the output end of the operational amplifier IC6 is connected to the input end of the resistor R45, the output end of the resistor R45 is connected to the output of the Curreng-V signal end and the input end of the capacitor C16, and the output end of the capacitor C16 is grounded.

Referring to fig. 7, the cpu has a main control circuit built therein, the main control circuit includes a chip U1, the chip U1 has a model of PIC16F, the chip U1 has a built-in comparator and is externally connected to a PID algorithm, the PID algorithm is an FPGS-based algorithm, a pin 1 of the chip U1 is connected to a TMAIN signal output terminal, a pin 44 of the chip U1 is connected to an AD-Vin power supply signal terminal, and a pin 42 of the chip U1 is connected to a Curreng-V signal terminal.

Referring to fig. 6, the output end of the induction cooker is connected to an IGBT driving circuit, the source of the IGBT end of the IGBT driving circuit is connected to the pin 10 of the chip U1, the gate of the IGBT end is connected to the power input, the drain of the IGBT end is connected to the input end of the diode D8, and the output end of the diode D8 is connected to the source of the IGBT end and then connected to the power output terminal to supply power to the working end of the induction cooker.

The constant-temperature heating control method based on the power and temperature double closed loop of the induction cooker has the following use states: for example, the temperature of the panel of the electromagnetic oven is 120 degrees, and needs to be adjusted to 60 degrees for heat preservation, and the following procedures are required:

1. the user presses the button of electromagnetism stove, sets the gear to 60 degrees.

2. The temperature sensor resistor Rz detects a temperature signal, transmits the temperature signal to the chip U1 through a TMAIN signal output terminal, and reads the current temperature of the panel of the induction cooker.

3. The chip U1 compares the read temperature value with a preset temperature value (i.e., 60 degrees of the shift setting), and determines that the detected temperature is higher than the set temperature.

4. The detected temperature is subtracted from the set temperature to obtain a negative error value Err.

5. Introduce Err into the equation: since Output is a negative number, Output calculated must be smaller than before, and the calculated value is used as the set value of the actual power.

6. The voltage sampling circuit collects input voltage signals, the current sampling circuit collects input current signals, the chip U1 reads input current values and voltage values, the obtained current values and voltage values are multiplied to obtain actual input power, and the obtained actual power is higher than set input power.

7. Subtracting the actual input power from the set input power to obtain a negative error value Err1, and substituting Err1 into the equation: output1 Kp1 Err1+ ∑ Ki1 Err1 because Err1 is a negative number, the calculated Output1 is definitely smaller than before.

8. And taking the calculated Output1 value as a heating power Output parameter, and reducing the heating power of the IGBT according to the heating power Output parameter in proportion, thereby reducing the temperature of the pot bottom and realizing the temperature control of the pot bottom.

9. And repeating the heating power adjustment and the temperature feedback of a plurality of cycles, and continuously adjusting the temperature to make the temperature tend to the preset temperature value until the temperature is stabilized at the preset temperature value.

10. When the chip U1 compares the read temperature value with a preset temperature value (i.e., 60 degrees of the shift setting), it determines that the detected temperature is lower than the set temperature, and subtracts the detected temperature from the set temperature to obtain a positive error value Err; introduce Err into the equation: the Output is Kp Err + ∑ Ki Err, because Err is a positive number, the calculated Output is definitely larger than the previous one, and the calculated value is used as the set value of the actual power; and multiplying the obtained current value and the obtained voltage value to obtain the actual input power, wherein the obtained actual power is higher than the set input power, the set input power is adopted to subtract the actual input power to obtain a negative error value Err1, and Err1 is substituted into a formula: output1 Kp1 Err1+ ∑ Ki1 Err1, because Err1 is a positive number, the calculated Output1 is definitely larger than before; and taking the calculated Output1 value as a heating power Output parameter, and increasing the heating power of the IGBT according to the heating power Output parameter in proportion, thereby realizing the reduction of the temperature of the pot bottom and the realization of the temperature control of the pot bottom.

In summary, in the power and temperature dual-closed-loop constant temperature heating control method based on the induction cooker, the temperature value is preset, the temperature sampling circuit collects the real-time temperature of the induction cooker panel, the temperature signal is transmitted to the central processing unit, the central processing unit compares the received temperature value with the preset temperature value to obtain a difference value, the difference value is brought into a PID algorithm built in the central processing unit for calculation, the obtained data is used as an actual power set value, the current value detected by the current detection circuit is multiplied by the voltage value sampled by the voltage sampling circuit to obtain a power value, the power value is recorded as an actual power value, the set power value is subtracted from the actual power value to obtain an error value Err1, and Err1 is brought into a formula: the Output1 is Kp1 Err1 plus Sigma Ki1 Err1, the Output1 value is calculated, the calculated Output1 value is used as a heating power Output parameter, the heating power of the IGBT is reduced by the heating power Output parameter according to a proportion, the temperature of the pot bottom can be reduced, the temperature control of the pot bottom is realized, the heating power adjustment and the temperature feedback of a plurality of cycles are repeated, the temperature is continuously adjusted, and the temperature tends to a preset temperature value until the temperature is stabilized at the preset temperature value; the whole can adjust the heating temperature of the pan bottom to a constant state, and the pan bottom can be heated accurately at a constant temperature.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.