阅读说明：本技术 一种变频微波炉的快速启动方法与可读存储介质 (Quick starting method of variable frequency microwave oven and readable storage medium ) 是由 陈志杰 李云欢 于 2021-08-16 设计创作，主要内容包括：本发明提供了一种变频微波炉的快速启动方法,包括以下步骤：S1、控制磁控管灯丝电流,让灯丝迅速发热起来便于迅速发出微波,并通过灯丝功率的截止反馈调节量作为对谐振腔参数和磁控管状态参数的补偿量；S2、控制磁控管的阳极电压,在离线标定参数基础上加上步骤S1获取的补偿量作为启机频率,然后在逐渐升频,以达到微波炉的快速启动。本发明还提供了一种可读存储介质。本发明的有益效果是：稳定了启动时间,降低了功率超调,无需进行来料把控,可以较好的实现变频微波炉的快速精准启动。(The invention provides a quick starting method of a variable frequency microwave oven, which comprises the following steps: s1, controlling the current of the magnetron filament to make the filament quickly heat and conveniently quickly emit microwaves, and using the cut-off feedback adjustment quantity of the filament power as the compensation quantity of the resonant cavity parameter and the magnetron state parameter; s2, controlling the anode voltage of the magnetron, adding the compensation quantity obtained in the step S1 on the basis of off-line calibration parameters as the starting frequency, and then gradually increasing the frequency to achieve the quick start of the microwave oven. The invention also provides a readable storage medium. The invention has the beneficial effects that: the starting time is stabilized, the power overshoot is reduced, the incoming material handle control is not needed, and the quick and accurate starting of the variable frequency microwave oven can be better realized.)

1. A quick starting method of a variable frequency microwave oven is characterized by comprising the following steps:

s1, controlling the current of the magnetron filament to make the filament quickly heat and conveniently quickly emit microwaves, and using the cut-off feedback adjustment quantity of the filament power as the compensation quantity of the resonant cavity parameter and the magnetron state parameter;

s2, controlling the anode voltage of the magnetron, adding the compensation quantity obtained in the step S1 on the basis of off-line calibration parameters as the starting frequency, and then gradually increasing the frequency to achieve the quick start of the microwave oven.

2. The method for rapidly starting a variable frequency microwave oven according to claim 1, wherein: in step S1, on the one hand, a large filament current is maintained as much as possible without exceeding the maximum filament current and the maximum anode voltage, and on the other hand, the state parameter of the system is identified by the off-negative feedback of the filament power as the compensation amount in step S2.

3. The method for rapidly starting a variable frequency microwave oven according to claim 2, wherein: the calculation process of step S1 is as follows:

(101) collecting input voltage u, calculating expected wave frequency f according to expected filament current_s1，

f_s1＝a₁u+a₀

Desired wave frequency f at a fixed filament current_s1Approximately linear with the input voltage u, where a₁And a₀For linear coefficients, take f_s1A% as an initial value of the start-up frequency,

f_r1(0)＝A％f_s1

(102) calculating the output frequency f of the nth period_r1(n) generating wave, collecting input voltage u (n) and input current i (n), calculating power p (n) of system,

f_r1(n)＝f_r1(n-1)+f_1step

p(n)＝u(n)i(n)

wherein f is_1stepThe frequency step size of step S1;

when the power p (n) of the system is greater than the filament power threshold p_dRecord the output frequency f at that time_r1(n) and calculating a frequency compensation amount f_c1，

f_c1＝f_r1(n)-f_r1(0)

When the power p (n) of the system is greater than the maximum power p set in the step S1_1maxStep S1 is completed.

4. A method for rapid start-up of a variable frequency microwave oven according to claim 3, characterized in that: a% is between 50% and 100%.

5. A method for rapid start-up of a variable frequency microwave oven according to claim 3, characterized in that: a% is 70%, i.e. f_r1(0)＝0.7f_s1。

6. A method for rapid start-up of a variable frequency microwave oven according to claim 3, characterized in that: in step S2, the anode voltage of the magnetron is quickly brought to the desired anode voltage, the desired output power is reached, and overshoot is suppressed as much as possible.

7. A method for rapid start-up of a variable frequency microwave oven according to claim 3, characterized in that: the calculation process of step S2 is as follows:

(201) collecting input voltage u, calculating expected wave frequency f according to expected anode voltage_s2，

f_s2＝b₁u+b₀

Desired wave-generating frequency f at a fixed anode voltage_s2Approximately linear relationship to the input voltage u, where b₁And b₀For linear coefficients, take f_s2And adding the compensation amount f calculated in step S1 to B%_c1To obtain the initial value of the actual output frequency,

f_r2(0)＝B％f_s2+f_c1

(202) calculating the output frequency f of the nth period_r2(n) generating wave, collecting input voltage u (n) and input current i (n), calculating power p (n) of system

f_r2(n)＝f_r2(n-1)+f_2step

p(n)＝u(n)i(n)

Wherein f is_2stepThe frequency step size of step S2;

when the power p (n) of the system is greater than the maximum power p set in the step S2_2maxStep S2 is complete and exits, entering the constant power control phase.

8. The method for rapidly starting a variable frequency microwave oven according to claim 7, wherein: b% is between 50% and 100%.

9. The method for rapidly starting a variable frequency microwave oven according to claim 7, wherein: b% is 70%, i.e. f_r2(0)＝0.7f_s2+f_c1。

10. A readable storage medium, characterized by: the readable storage medium stores executable instructions which, when executed by a processor, are adapted to implement the method of any one of claims 1 to 9.

Technical Field

The invention relates to a variable frequency microwave oven, in particular to a quick starting method and a readable storage medium of the variable frequency microwave oven.

Background

The variable frequency microwave oven adjusts the output microwave power by adjusting the output frequency, and is characterized by high heating speed, for example, fresh milk and the like only need to be heated for about 10 seconds, the entrance is right, and more than two or three seconds can be possibly scalded, so the heating time of the microwave oven is very accurate. The start-up of the frequency conversion microwave oven usually needs about 5 seconds, firstly, the start-up time is fixed each time, and secondly, the set power is quickly reached and the overshoot is small.

According to a system model of a resonant cavity, off-line calibration of starting parameters is one of the good methods for solving the starting problem. However, in practical applications, the variation of the input voltage (165V-265V), the difference and dispersion of resonant cavity parameters of the variable frequency drive (deviation of resonant capacitance of 5%, deviation of resonant inductance of 20%, etc.), and the state parameters of the magnetron (cold, hot, new, old, etc.) all affect the starting speed (deviation of starting time greater than 3 seconds), and therefore, the fast and accurate starting of the variable frequency microwave oven is one of the problems to be solved by the variable frequency microwave oven.

At present, the existing variable frequency microwave oven is started by keeping a certain power through a method of fixing resonant current, can realize quick start by increasing the starting power, and controls the deviation of starting time by controlling the incoming materials such as the deviation of resonant inductance and resonant capacitance in actual application, and the method has the following defects:

1. when the deviation of the resonance parameters is large, the matching of the filament current and the anode voltage is disordered, and the starting time becomes slow or the starting speed is greatly overshot;

2. when the magnetron is cold, the starting is slow, and when the magnetron is hot, the starting is fast, and the starting time is not fixed;

3. the procedure is increased by the incoming material control, and the cost is increased.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a quick starting method and a readable storage medium for a variable frequency microwave oven.

The invention provides a quick starting method of a variable frequency microwave oven, which comprises the following steps:

s1, controlling the current of the magnetron filament to make the filament quickly heat and conveniently quickly emit microwaves, and using the cut-off feedback adjustment quantity of the filament power as the compensation quantity of the resonant cavity parameter and the magnetron state parameter;

s2, controlling the anode voltage of the magnetron, adding the compensation quantity obtained in the step S1 on the basis of off-line calibration parameters as the starting frequency, and then gradually increasing the frequency to achieve the quick start of the microwave oven.

As a further improvement of the present invention, in step S1, on one hand, a large filament current is maintained as much as possible without exceeding the maximum filament current and the maximum anode voltage, and on the other hand, the state parameter of the system is identified by the off negative feedback of the filament power as the compensation amount in step S2.

As a further improvement of the present invention, the calculation process of step S1 is as follows:

(101) collecting input voltage u, calculating expected wave frequency f according to expected filament current_s1，

f_s1＝a₁u+a₀

Desired wave frequency f at a fixed filament current_s1Approximately linear with the input voltage u, where a₁And a₀For linear coefficients, take f_s1A% as an initial value of the start-up frequency,

f_r1(0)＝A％f_s1

(102) calculating the output frequency f of the nth period_r1(n) generating wave, collecting input voltage u (n) and input current i (n), calculating power p (n) of system,

f_r1(n)＝f_r1(n-1)+f_1step

p(n)＝u(n)i(n)

wherein f is_1stepThe frequency step size of step S1;

when the power p (n) of the system is greater than the filament power threshold p_dRecord the output frequency f at that time_r1(n) and calculating a frequency compensation amount f_c1，

f_c1＝f_r1(n)-f_r1(0)

When the power p (n) of the system is greater than the maximum power p set in the step S1_1maxStep S1 is completed.

As a further improvement of the invention, A% is between 50% and 100%.

As a further development of the invention, A% is 70%, i.e.f_r1(0)＝0.7f_s1。

In step S2, the anode voltage of the magnetron is quickly brought to the desired anode voltage, the desired output power is reached, and overshoot is suppressed as much as possible.

As a further improvement of the present invention, the calculation process of step S2 is as follows:

(201) collecting input voltage u, calculating expected wave frequency f according to expected anode voltage_s2，

f_s2＝b₁u+b₀

Desired wave-generating frequency f at a fixed anode voltage_s2Approximately linear relationship to the input voltage u, where b₁And b₀For linear coefficients, take f_s2And adding the compensation amount f calculated in step S1 to B%_c1To obtain the initial value of the actual output frequency,

f_r2(0)＝B％f_s2+f_c1

(202) calculating the output frequency f of the nth period_r2(n) generating wave, collecting input voltage u (n) and input current i (n), calculating power p (n) of system

f_r2(n)＝f_r2(n-1)+f_2step

p(n)＝u(n)i(n)

Wherein f is_2stepThe frequency step size of step S2;

when the power p (n) of the system is greater than the maximum power p set in the step S2_2maxStep S2 is complete and exits, entering the constant power control phase.

As a further improvement of the invention, B% is between 50% and 100%.

As a further development of the invention, B% is 70%, i.e.f_r2(0)＝0.7f_s2+f_c1。

The invention also provides a readable storage medium having stored thereon executable instructions for implementing the method as claimed in any one of the above when executed by a processor.

The invention has the beneficial effects that: the starting time is stabilized, the power overshoot is reduced, the incoming material handle control is not needed, and the quick and accurate starting of the variable frequency microwave oven can be better realized.

Drawings

FIG. 1 is a flow chart of a method for rapidly starting a variable frequency microwave oven according to the present invention.

Detailed Description

The invention is further described with reference to the following description and embodiments in conjunction with the accompanying drawings.

As shown in figure 1, a quick start method of a frequency conversion microwave oven divides the start into two steps, step 1 is mainly to control the filament current of a magnetron, the filament is heated quickly to emit microwaves quickly, the cut-off feedback adjustment quantity of the filament power is used as the compensation quantity of the parameters of a resonant cavity and the state parameters of the magnetron, step 2 is mainly to control the anode voltage of the magnetron, the compensation quantity obtained in step 1 is added on the basis of off-line calibration parameters to be used as the starting frequency, then the frequency is gradually increased to achieve the quick start of the microwave oven, and experiments prove that the fixed start time (the time deviation is less than 500 milliseconds) can be realized under various working conditions, and the power overshoot is less than 5 percent.

Step 1, controlling the current of the filament, namely stage 1, wherein the function of the stage is to heat the filament and rapidly heat the filament, which is the premise of microwave generation of a magnetron. The goal of this stage is to maintain the larger filament current as much as possible on the premise of not exceeding the maximum filament current and the maximum anode voltage, and on the other hand, to identify the state parameters of the system through the cut-off negative feedback of the filament power as the compensation quantity of step 2, and its calculation steps are:

(1) collecting input voltage u, calculating expected wave frequency f according to expected filament current_s1，

f_s1＝a₁u+a₀

Desired wave frequency f at a fixed filament current_s1Can be approximately considered as a linear relationship with the input voltage u, where a₁And a₀Is a linear coefficient. Take f_s1Is taken as the initial value of the start-up frequency,

f_r1(0)＝0.7f_s1

(2) calculating the output frequency f of the nth period_r1(n) generating wave, collecting input voltage u (n), input current i (n), calculating power p (n) of system,

f_r1(n)＝f_r1(n-1)+f_1step

p(n)＝u(n)i(n)

wherein f is_1stepThe frequency step size for phase 1.

When p (n) is greater than the filament power threshold p_dRecord the output frequency f at that time_r1(n) and calculating a frequency compensation amount f_c1，

f_c1＝f_r1(n)-f_r1(0)

When p (n) is larger than the maximum power p set in the step 1_1maxStep 1 is complete and exits. The specific algorithm flow is as follows:

(1) collecting input voltage u to obtain expected wave frequency f_s1And calculating the actual wave-emitting frequency initial value f_r1(0)＝0.7f_s1And (4) jumping to the step (2).

(2) Calculating the output frequency f of the nth period_r1(n) generating wave, collecting input voltage u (n), input current i (n), calculating power p (n) and f of system_r1(n)＝f_r1(n-1)+f_1step，p(n)＝u(n)i(n)

When p (n) is greater than the filament power threshold p_dAnd skipping to the step (3),

when p (n) is larger than the maximum power p set in the step 1_1maxAnd jumping to the step (4),

otherwise, jumping to the step (2).

(3) Recording the output frequency f at that time_r1(n) and calculating a frequency compensation amount f_c1，

f_c1＝f_r1(n)-f_r1(0)

And (4) jumping to the step (2).

(4) The algorithm is completed and exits.

And step 2, controlling the anode voltage stage, namely stage 2, wherein the function of the stage is to control the voltage output by the anode, and the output power and the anode voltage are approximately in a direct proportion relation. The aim of this phase is to quickly bring the anode voltage of the magnetron to the desired anode voltage, to the desired output power and to suppress overshoot as much as possible, by the calculation steps:

(1) collecting input voltage u, calculating expected wave frequency f according to expected anode voltage_s2，

f_s2＝b₁u+b₀

Desired wave-generating frequency f at a fixed anode voltage_s2Can be approximately considered as a linear relationship with the input voltage u, where b₁And b₀Is a linear coefficient. Take f_s2And adding the compensation amount f calculated in step 1_c1A starting value of the actual output frequency is obtained,

f_r2(0)＝0.7f_s2+f_c1

(2) calculating the output frequency f of the nth period_r2(n) generating wave, collecting input voltage u (n), input current i (n), calculating power p (n) of system

f_r2(n)＝f_r2(n-1)+f_2step

p(n)＝u(n)i(n)

Wherein f is_2stepThe frequency step size for phase 2.

When p (n) is larger than the maximum power p set in the step 2_2maxStep 2 is complete and exit may enter the constant power control phase. The specific algorithm flow is as follows:

(1) collecting input voltage u, calculating expected wave frequency f according to expected anode voltage_s2Take f_s2And adding the compensation amount f calculated in step 1_c1Obtaining the initial value of the actual wave frequency, f_r2(0)＝0.7f_s2+f_c1. And (5) skipping to the step (2).

(2) Calculating the output frequency f of the nth period_r1(n) generating wave, collecting input voltage u (n), input current i (n) and power p (n) and f of current calculating system_r2(n)＝f_r2(n-1)+f_2step，p(n)＝u(n)i(n)。

When p (n) is larger than the maximum power p set in the step 2_2maxAnd skipping to the step (3),

otherwise, jumping to the step (2).

(3) The algorithm is completed and exits and the constant power control stage can be entered.

Experiments prove that under various working conditions, the quick starting method of the variable frequency microwave oven provided by the invention can realize fixed starting time (the time deviation is less than 500 milliseconds) and the power overshoot is less than 5%.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.