阅读说明：本技术 基于锅炉主蒸汽压力调节偏差实时修正的微分计算方法 (Differential calculation method based on real-time correction of boiler main steam pressure regulation deviation ) 是由 邹包产 刘永红 李云 赵宇 陈鹏原 郭楚珊 于 2020-04-03 设计创作，主要内容包括：本发明公开的基于锅炉主蒸汽压力调节偏差实时修正的微分计算方法,包括获取锅炉主蒸汽压力调节偏差的理论微分计算量；根据锅炉主蒸汽压力调节偏差大小与其变化方向,对理论微分计算量的微分调节幅值进行修正,得到限幅微分调节量；根据限幅微分调节量的正负值与锅炉主蒸汽压力调节偏差大小,对限幅微分调节量的微分调节衰减速率进行修正,得到限速微分调节量；之后对其增加高限和低限限幅功能,最终得到实际微分输出量。本发明的基于锅炉主蒸汽压力调节偏差实时修正的微分计算方法,根据系统调节偏差大小、变化方向和变化速率综合判断实时自动校正微分调节作用量,提高微分调节作用适应性,真正达到超前控制,最终改善系统动态调节性能。(The invention discloses a differential calculation method based on real-time correction of boiler main steam pressure regulating deviation, which comprises the steps of obtaining theoretical differential calculated quantity of the boiler main steam pressure regulating deviation; according to the main steam pressure regulating deviation and the change direction thereof, the differential regulating amplitude of the theoretical differential calculated quantity is corrected to obtain amplitude limiting differential regulating quantity; according to the positive and negative values of the amplitude limiting differential regulating variable and the regulating deviation of the main steam pressure of the boiler, the differential regulating attenuation rate of the amplitude limiting differential regulating variable is corrected to obtain a speed limiting differential regulating variable; then, the high limit and low limit limiting functions are added to the differential output value, and finally the actual differential output value is obtained. The differential calculation method based on the boiler main steam pressure regulation deviation real-time correction comprehensively judges the real-time automatic correction differential regulation action quantity according to the system regulation deviation size, the change direction and the change rate, improves the adaptability of the differential regulation action, really achieves advanced control, and finally improves the dynamic regulation performance of the system.)

1. The differential calculation method for real-time correction of the adjustment deviation based on the main steam pressure of the boiler is characterized by comprising the following steps of:

step 1: obtaining theoretical differential calculated quantity D of boiler main steam pressure regulating deviation delta₀；

Step 2: according to the main steam pressure of boiler regulating deviation delta and its change direction, the theoretical differential calculated quantity D₀The amplitude of the differential adjustment is corrected to obtain amplitude limiting differential adjustment quantity D₁；

And step 3: adjusting quantity D according to amplitude limiting differential₁The positive value and the negative value of the amplitude limiting differential regulation quantity D and the main steam pressure regulation deviation delta of the boiler₁The differential adjustment attenuation rate is corrected to obtain a speed-limiting differential adjustment quantity D₂；

And 4, step 4: differential adjustment of speed limit D₂And increasing the high limit and low limit limiting functions to finally obtain the actual differential output quantity D.

2. The differential calculation method for real-time correction of main steam pressure regulation deviation based on boiler as claimed in claim 1, wherein the theoretical differential calculated quantity obtained in step 1Wherein: Δ is the set value SP minus the actual value PV, k is the differential adjustment gain, T is the differential adjustment time, and s is the laplacian operator.

3. The differential calculation method for real-time correction of boiler main steam pressure regulation deviation according to claim 2, wherein the step 2 specifically comprises:

when the main steam pressure regulating deviation delta of the boiler is smaller than the set regulating deviation negative alarm value delta L and the main steam pressure regulating deviation delta of the boiler shows a gradually increasing trend, the theoretical differential calculated quantity D is calculated₀Multiplying by a modified differential regulation amplitude function f₁(Δ), function f₁(Delta) is determined according to the main steam pressure regulating deviation Delta of the boiler, and the smaller the main steam pressure regulating deviation Delta of the boiler is, the function f is output₁The smaller (Δ);

when the main steam pressure regulating deviation delta of the boiler is greater than the set regulating deviation forward alarm value delta H and the main steam pressure regulating deviation delta of the boiler shows a gradually decreasing trend, the theoretical differential calculated quantity D is calculated at the moment₀Multiplying by a modified differential regulation amplitude function f₂(Δ), function f₂(Delta) is determined according to the main steam pressure regulating deviation Delta of the boiler, and the larger the main steam pressure regulating deviation Delta of the boiler is, the larger the output function f₂The smaller (Δ);

when the main steam pressure regulating deviation delta of the boiler is between the negative regulating deviation alarm value delta L and the positive regulating deviation alarm value delta H, no system correction is carried out, and normal regulation is maintained.

4. The differential calculation method for real-time correction of regulation deviation based on boiler main steam pressure as claimed in claim 3, wherein said step 3 specifically comprises:

when limiting the differential adjustment quantity D₁Less than-0.1, and the obtained speed-limiting differential regulating quantity D₂Not more than-0.01, and amplitude limiting differential adjustment quantity D₁Switching the rate of rise at decay to a modified differential regulation decay rate function f₃(Δ), function f₃(Delta) is determined from the main steam pressure regulation deviation Delta of the boiler, the function f being the larger the main steam pressure regulation deviation Delta of the boiler is₃(Δ) the slower the output corresponds to the ramp rate;

when limiting the differential adjustment quantity D₁Greater than 0.1, and the obtained speed-limiting differential regulating quantity D₂Not less than 0.01, amplitude limiting differential modulationSaving D₁Switching the rate of decay to a modified differential regulation decay rate function f₄(Δ), function f₄(Delta) is determined according to the main steam pressure regulating deviation Delta of the boiler, and the smaller the main steam pressure regulating deviation Delta of the boiler is, the function f₄(Δ) the slower the output corresponds to the rate of decrease;

when limiting the differential adjustment quantity D₁Between-0.1 and 0.1, both the ramp-up rate and the ramp-down rate are switched to 1, i.e. no decay rate limitation is performed.

5. Differential calculation method for the real-time correction of the regulation deviation based on the main steam pressure of a boiler according to claim 4, characterized in that said function f₁(Δ)、f₂(Δ)、f₃(Delta) and f₄The value range of (delta) is 0 to 1.

Technical Field

The invention belongs to the technical field of automatic control of thermal power generation, and particularly relates to a differential calculation method for real-time correction of adjustment deviation based on main steam pressure of a boiler.

Background

In the actual thermal power automatic control technology engineering, the most widely applied regulator control rules are proportion P, integral I and differential D, which are called PID control for short. The differential regulation reflects the change rate of the system deviation signal, and the trend of deviation change can be predicted, so that an advanced control action can be generated, the dynamic performance of the system can be improved, and the differential regulation action of the system with large delay and large inertia in the power generation system is necessary. However, in practical application, the differential regulation is only calculated according to the variation rate of the deviation, the action amplitude and the attenuation time of the differential regulation do not consider the current regulation deviation at all, so that the practical application effect is poor, and even the differential regulation action of a part of regions influences the system safety.

Disclosure of Invention

The invention aims to provide a differential calculation method for correcting the adjustment deviation of the main steam pressure of a boiler in real time, which improves the adaptability of differential adjustment and the dynamic adjustment performance of a system.

The technical scheme adopted by the invention is as follows: the differential calculation method based on the real-time correction of the main steam pressure regulation deviation of the boiler comprises the following steps:

step 1: obtaining theoretical differential calculated quantity D of boiler main steam pressure regulating deviation delta₀；

Step 2: according to the main steam pressure of boiler regulating deviation delta and its change direction, the theoretical differential calculated quantity D₀The amplitude of the differential adjustment is corrected to obtain amplitude limiting differential adjustment quantity D₁；

And step 3: adjusting quantity D according to amplitude limiting differential₁The positive value and the negative value of the amplitude limiting differential regulation quantity D and the main steam pressure regulation deviation delta of the boiler₁The differential adjustment attenuation rate is corrected to obtain a speed-limiting differential adjustment quantity D₂；

And 4, step 4: differential adjustment of speed limit D₂And increasing the high limit and low limit limiting functions to finally obtain the actual differential output quantity D.

The present invention is also characterized in that,

theoretical differential calculated quantity obtained in step 1Wherein: Δ is the set value SP minus the actual value PV, k is the differential adjustment gain, T is the differential adjustment time, and s is the laplacian operator.

The step 2 specifically comprises the following steps:

when the main steam pressure regulating deviation delta of the boiler is smaller than the set regulating deviation negative alarm value delta L and the main steam pressure regulating deviation delta of the boiler shows a gradually increasing trend, the theoretical differential calculated quantity D is calculated₀Multiplying by a modified differential regulation amplitude function f₁(Δ), function f₁(Delta) is determined according to the main steam pressure regulating deviation Delta of the boiler, and the smaller the main steam pressure regulating deviation Delta of the boiler is, the function f is output₁The smaller (Δ);

when the main steam pressure regulating deviation delta of the boiler is greater than the set regulating deviation forward alarm value delta H and the main steam pressure regulating deviation delta of the boiler shows a gradually decreasing trend, the theoretical differential calculated quantity D is calculated at the moment₀Multiplying by a modified differential regulation amplitude function f₂(Δ), function f₂(Delta) is determined according to the main steam pressure regulating deviation Delta of the boiler, and the larger the main steam pressure regulating deviation Delta of the boiler is, the larger the output function f₂The smaller (Δ);

when the main steam pressure regulating deviation delta of the boiler is between the negative regulating deviation alarm value delta L and the positive regulating deviation alarm value delta H, no system correction is carried out, and normal regulation is maintained.

The step 3 specifically comprises the following steps:

when limiting the differential adjustment quantity D₁Less than-0.1, and the obtained speed-limiting differential regulating quantity D₂Not more than-0.01, and amplitude limiting differential adjustment quantity D₁Switching the rate of rise at decay to a modified differential regulation decay rate function f₃(Δ), function f₃(delta) is determined according to the main steam pressure regulation deviation delta of the boiler, and the main steam pressure regulation deviation of the boilerThe larger the difference Δ, the function f₃(Δ) the slower the output corresponds to the ramp rate;

when limiting the differential adjustment quantity D₁Greater than 0.1, and the obtained speed-limiting differential regulating quantity D₂Not less than 0.01, amplitude limiting differential adjustment quantity D₁Switching the rate of decay to a modified differential regulation decay rate function f₄(Δ), function f₄(Delta) is determined according to the main steam pressure regulating deviation Delta of the boiler, and the smaller the main steam pressure regulating deviation Delta of the boiler is, the function f₄(Δ) the slower the output corresponds to the rate of decrease;

when limiting the differential adjustment quantity D₁Between-0.1 and 0.1, both the ramp-up rate and the ramp-down rate are switched to 1, i.e. no decay rate limitation is performed.

Function f₁(Δ)、f₂(Δ)、f₃(Delta) and f₄The value range of (delta) is 0 to 1.

The invention has the beneficial effects that: the differential calculation method based on the boiler main steam pressure regulation deviation real-time correction comprehensively judges the real-time automatic correction differential regulation action quantity according to the system regulation deviation size, the change direction and the change rate, improves the adaptability of the differential regulation action, really achieves advanced control, and finally improves the dynamic regulation performance of the system.

Drawings

FIG. 1 is a logic block diagram of a differential calculation method of the present invention based on real-time correction of boiler main steam pressure regulation deviation.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

The invention provides a differential calculation method based on real-time correction of boiler main steam pressure regulation deviation, as shown in figure 1, comprising the following steps:

1. theoretical differential calculation loop

Differential calculation is carried out according to the deviation delta between the set value and the actual value of the main steam pressure of the boiler of the thermal generator set, and the calculation formula is as follows:wherein: d₀Calculating an output for the theoretical differential; delta is the system regulation deviation, generally the set value SP minus the actual value PV; k is a differential adjustment gain; t is differential adjustment time; s is the laplace operator.

2. Differential regulation amplitude correction loop

The amplitude limiting differential regulation quantity D is obtained by comprehensively judging the size of the deviation delta of the main steam pressure of the boiler and the change direction of the deviation delta and correcting the differential regulation amplitude according to the deviation delta₁. Mainly comprises the following loops:

1) when the main steam pressure regulating deviation delta of the boiler is smaller than the deviation regulating negative alarm value delta L manually set by the regulating system and the deviation delta shows a gradually increasing trend, the theoretical differential calculating loop is multiplied by a correction function f₁(Δ) thereby automatically correcting the theoretical differential calculation amount. Function f₁(Delta) is determined from the input deviation Delta, the smaller the deviation Delta, the larger the deviation of the actual value from the set value, and the smaller the deviation Delta, the smaller the output coefficient, and is determined by the function f₁The (delta) correction attenuates its differential counter-regulation effect. Example f₁(Δ) the following table:

f₁(Δ)＝k₁Δ+b₁wherein: f. of₁(Delta) is the deviation △ corresponding to the modified differential modulation amplitude function₁Is the slope; b₁Is an offset; k is a radical of₁、b₁Obtained according to the regulation characteristics of different systems and the real-time deviation delta in a comprehensive way, and finally satisfies f₁The (Δ) correction factor is between 0 and 1.

2) When the main steam pressure regulating deviation delta of the boiler is larger than the deviation regulating positive alarm value delta H artificially set by the regulating system and the deviation delta shows a gradually decreasing trend, the main steam pressure regulating deviation delta is multiplied by a correction function f in a theoretical differential calculation loop₂(Δ) thereby automatically correcting the theoretical differential calculation amount. Function f₂(Delta) is determined from the input deviation Delta, the larger the deviation Delta the larger the deviation of the actual value from the set value, the larger the deviation Delta the smaller the output coefficient, and the function f₂(Delta) correction to reverseThe effect on regulation is reduced. Example f₂(Δ) the following table:

f₂(Δ)＝k₂Δ+b₂wherein: f. of₂(Delta) is the deviation △ corresponding to the modified differential modulation amplitude function₂Is the slope; b₂Is an offset; k is a radical of₂、b₂Obtained according to the regulation characteristics of different systems and the real-time deviation delta in a comprehensive way, and finally satisfies f₂The (Δ) correction factor is between 0 and 1.

3) When the main steam pressure regulating deviation delta of the boiler is between the negative alarm value delta L and the positive alarm value delta H, the system correction coefficient is 1.0, the system correction is not carried out, and the normal regulation is maintained.

3. Differential attenuation rate correction loop

Correcting the differential regulation attenuation rate according to the current pressure deviation delta of the main steam pressure regulation system of the thermal power generating unit boiler to obtain the speed-limiting differential regulation quantity D₂. Mainly comprises the following loops:

1) amplitude limiting differential adjustment quantity D after amplitude correction₁Less than-0.1, and the differential regulating quantity D of speed limit after speed limit₂Less than or equal to-0.01, and the raising rate of the differential speed limiting function block is switched to the corresponding function f of the main steam pressure regulation deviation delta of the boiler₃(Delta). Function f₃(Delta) is determined from the deviation Delta, the larger the deviation Delta indicates that the actual pressure value deviates from the set value, and the larger the deviation Delta is, the function f₃The slower the (delta) output rise rate, the slower its differential regulation decay rate is corrected for. Example f₃(Δ) the following table:

f₃(Δ)＝k₃Δ+b₃wherein: f. of₃(Delta) is a function of the corrected differential modulation decay rate for the deviation △₃Is the slope; b₃Is an offset; k is a radical of₃、b₃According to different systemsThe regulation characteristic and the real-time deviation delta are obtained comprehensively and finally satisfy f₃The (delta) rise rate is between 0 and 1.

2) Amplitude limiting differential adjustment quantity D after amplitude correction₁Greater than 0.1, and the differential regulating quantity D of speed limit after speed limit₂When the differential speed limiting function block reduces the speed and switches to the corresponding function f of the main steam pressure regulation deviation delta of the boiler when the differential speed limiting function block reduces the speed and is greater than or equal to 0.01₄(Delta). Function f₄(Delta) is determined from the deviation Delta, the smaller the deviation Delta, the larger the deviation of the actual value from the set value, and the smaller the deviation Delta, the function f₄The (delta) output is corrected to reduce the rate of decay of its differential regulation, the slower the corresponding rate of decay. Example f₄(Δ) the following table:

f₄(Δ)＝k₄Δ+b₄wherein: f. of₄(Delta) is a function of the corrected differential modulation decay rate for the deviation △₄Is the slope; b₄Is an offset; k is a radical of₄、b₄Obtained according to the regulation characteristics of different systems and the real-time deviation delta in a comprehensive way, and finally satisfies f₄The (Δ) rate of decrease is between 0 and 1.

3) Amplitude limiting differential adjustment quantity D after amplitude correction₁When the speed is more than or equal to-0.1 and less than or equal to 0.1, the rising rate and the falling rate are both cut to 1, namely, the speed is not limited.

4. Differential clipping

Differential adjustment of speed limit D₂And the amplitude limiting functions of the upper limit H and the lower limit L are added to finally obtain the actual differential output quantity D, so that the influence of overlarge differential action amplitude on the system safety is prevented.

Through the mode, the technical scheme of the invention has the characteristics that:

(1) in the process of automatically adjusting the main steam pressure of the thermal power generation boiler, the differential adjustment amplitude is automatically corrected according to the magnitude and the variation trend of the real-time pressure deviation delta of the adjusting system, so that the accurate control of the adjustment process in a subarea mode is achieved.

(2) In the process of automatically adjusting the main steam pressure of the thermal power generation boiler, the differential adjustment attenuation rate is automatically corrected according to the current pressure deviation delta of the adjusting system, and the adaptability of the differential adjustment action is improved.

The invention relates to a differential calculation method based on real-time correction of boiler main steam pressure regulation deviation, which corrects the amplitude and the attenuation rate of a differential regulation action in real time according to the current deviation delta of a boiler main steam pressure regulation system, improves the adaptability of the differential regulation action, really achieves advanced control and finally improves the dynamic regulation performance of the system.