CN114704822A - Control method and device of electric heating steam boiler system - Google Patents

Abstract

The invention provides a control method and device for an electric heating steam boiler system, comprising the following steps: determining two mutually coupled to-be-controlled quantities in the electric-heated steam boiler system, wherein the coupling between the two mutually coupled to-be-controlled quantities The relationship constitutes a coupled system; the two outputs and two inputs of the coupled system are determined according to the two mutually coupled quantities to be controlled; the transfer function of the coupled system is determined according to the output and input of the coupled system, and the transfer function of the coupled system is determined according to the The function obtains the transfer function of the first decoupler and the transfer function of the second decoupler; the two mutually coupled to-be-controlled quantities are decoupled and controlled by the first decoupler and the second decoupler. Therefore, considering that there are coupled quantities to be controlled in the electric heating steam boiler system, and decoupling control of the mutually coupled quantities to be controlled, it is possible to achieve relatively independent control of the mutually coupled quantities to be controlled, which is more conducive to The system runs stably.

Description

Control method and device for electric heating steam boiler system

technical field

The invention relates to the technical field of reactors, in particular to a control method of an electrically heated steam boiler system and a control device of an electrically heated steam boiler system.

Background technique

Electric steam heat storage technology solves the problem that after industrial enterprises ban coal-fired steam boilers, they can no longer turn on electric steam boilers with high operating costs during the day, but they can obtain economical steam costs and meet the needs of normal production. It also solves the problem of high operating cost of natural gas. The overall system operates safely and stably, with sufficient steam output, advanced technology and good economy.

As the most critical facility in electric steam heat storage technology: electric heating steam boilers have the advantages of fast start and stop speed, high steam quality, simple maintenance, small installation space, green environmental protection, etc., and are more and more widely used in industry and power market fields. . Therefore, the control of electric heating steam boilers is extremely important.

SUMMARY OF THE INVENTION

At present, conventional PID (Proportion Integral Differential, Proportion Integral Differential) controllers are used for electric heating steam boilers to ensure the dynamic performance of the system. The PID adjustment method has the characteristics of simple structure, stability and reliability. However, there is coupling between some variables in the system, so while controlling the conventional variables, it is also necessary to take into account the effective decoupling control of the coupling parameters.

In order to solve the problem that decoupling control cannot be taken into account in the related art, the present invention proposes the following technical solutions.

The embodiment of the first aspect of the present invention provides a control method for an electrically heated steam boiler system, including the following steps: determining two mutually coupled to-be-controlled quantities in the electrically heated steam boiler system, wherein the two mutually coupled The coupling relationship between the quantities to be controlled constitutes a coupling system; the two output quantities and the two input quantities of the coupling system are determined according to the two mutually coupled quantities to be controlled; the output quantities and the input quantities of the coupling system are determined according to the determine the transfer function of the coupling system, and obtain the transfer function of the first decoupler and the transfer function of the second decoupler according to the transfer function of the coupling system; The second decoupler performs decoupling control on the two mutually coupled to-be-controlled quantities.

In addition, the control method of the electric heating steam boiler system according to the above-mentioned embodiment of the present invention may also have the following additional technical features.

According to an embodiment of the present invention, the two mutually coupled quantities to be controlled are boiler power and steam temperature, and the two input quantities of the coupling system are the opening of the make-up water valve and the opening of the steam outlet valve, and the two output quantities are the actual boiler temperature and the actual steam temperature.

According to an embodiment of the present invention, the coupling system has a first transfer function, a second transfer function, a third transfer function and a fourth transfer function, and the coupling system is determined according to the output and input of the coupling system. The transfer function includes the following steps: according to the input quantity and output quantity corresponding to each transfer function of the coupling system, wherein the first transfer function is used to characterize the input quantity as the opening of the make-up valve, and the output quantity as the actual boiler power the relationship between the input amount and the output amount when the input amount is the opening of the make-up valve and the output amount is the actual steam temperature, and the second transfer function is used to represent the relationship between the input amount and the output amount , the third transfer function is used to characterize the relationship between the input quantity and the output quantity when the input quantity is the opening of the steam outlet valve and the output quantity is the actual boiler power, and the fourth transfer function is used to characterize the input quantity is the relationship between the input quantity and the output quantity when the opening of the steam outlet valve and the output quantity are the actual steam temperature, and the first transfer function to the fourth transfer function all satisfy the following second-order time delay model:

Among them, G(s) is the transfer function of the coupling system, a, b and c are the coefficients of each order of the transfer function, and L is the lag constant of the transfer function; corresponding to each group of the input quantity and the Obtaining multiple sets of different input and output measurement values for the output quantity; using multiple sets of the input and output measurement values to perform parameter identification on the corresponding transfer function to obtain various order coefficients and lag constants of the transfer function.

According to an embodiment of the present invention, using multiple sets of the input and output measurement values to perform parameter identification on the corresponding transfer function includes the following steps: selecting the phase angles and amplitudes of P different frequency points to match the transfer function to obtain The following matched model:

Among them, ω _n is the frequency of the nth frequency point, n=1,2,...,P, P≥10;

According to the matched model, the following formula 1 is obtained:

a ² ω ⁴ |G(jω)| ² +(2ac-b ² )ω ² |G(jω)| ² +c ² |G(jω)| ² =1

After converting the formula 1 into a matrix, each order coefficient and lag constant of the transfer function are determined by the least square method.

According to an embodiment of the present invention, obtaining the transfer function of the first decoupler and the transfer function of the second decoupler according to the transfer function of the coupling system includes: according to the first transfer function and the second transfer function function determines the transfer function of the first decoupler, and determines the transfer function of the second decoupler according to the third transfer function and the fourth transfer function, wherein the first decoupler The transfer function and the second decoupler transfer function are:

Wherein, D ₁₂ (s) is the transfer function of the first decoupler, D ₂₁ (s) is the transfer function of the second decoupler, G ₁ (s) is the first transfer function, G ₂ (s) is the second transfer function, G ₃ (s) is the third transfer function, and G ₄ (s) is the fourth transfer function.

According to an embodiment of the present invention, performing decoupling control on the two mutually coupled to-be-controlled quantities through the first decoupler and the second decoupler includes the following steps: obtaining the electrically heated steam The actual boiler power and actual steam temperature output by the boiler system, and obtain the set boiler power and set steam temperature; calculate the error power between the set boiler power and the actual boiler, and send the error power to the first a controller to obtain the opening degree of the make-up water valve, and calculate the error temperature between the set steam temperature and the actual steam temperature, and send the error temperature to the second controller to obtain the opening degree of the steam outlet valve; The opening of the replenishment valve is sent to the first decoupler to obtain a second decoupling signal, and the opening of the replenishment valve is accumulated with the first decoupling signal output by the second decoupler to obtain a second decoupling signal. Obtain the decoupling valve opening degree; send the steam outlet valve opening degree to the second decoupler to obtain the first decoupling signal, and compare the steam outlet valve opening degree with the first decoupling signal. The second decoupling signal output by a decoupler is accumulated to obtain the decoupled steam outlet valve opening; the decoupling water replenishment valve opening and the decoupling steam outlet valve opening are Enter the coupling system to obtain the actual boiler power and the actual steam temperature, and return to the steps of calculating the error power and calculating the error temperature, so as to carry out closed-loop control of the boiler power and steam temperature respectively, until the actual boiler power is equal to the set The boiler power and the actual steam temperature are equal to the set steam temperature.

According to an embodiment of the present invention, the control method for an electric heating steam boiler system further includes: determining an independent quantity to be controlled in the electric heating steam boiler system; independently controlling the independent quantity to be controlled by a third controller control.

According to an embodiment of the present invention, the independent quantity to be controlled includes steam flow, and the independent control of the independent quantity to be controlled by the third controller specifically includes the following steps: acquiring the actual data of the electric heating steam boiler system steam flow, and obtain the set steam flow; calculate the error flow between the set steam flow and the actual steam flow; input the error flow into the third controller to obtain the voltage control amount, and use the The voltage control amount controls the electric heating steam boiler system so that the electric heating steam boiler system outputs the actual steam flow; returns to the step of calculating the error flow to perform closed-loop control on the steam flow until the actual steam flow is equal to the Set the steam flow as described above.

According to an embodiment of the present invention, the first controller, the second controller and the third controller are PID controllers.

The embodiment of the second aspect of the present invention provides a control device for an electric heating steam boiler system, including: a first determination module for determining two mutually coupled to-be-controlled quantities in the electric heating steam boiler system, wherein the The coupling relationship between the two mutually coupled to-be-controlled quantities constitutes a coupling system; the second determination module is used to determine the two output quantities and the two inputs of the coupling system according to the two mutually coupled to-be-controlled quantities The third determining module is used to determine the transfer function of the coupling system according to the output and input of the coupling system, and obtain the transfer function of the first decoupler and the second decoupler according to the transfer function of the coupling system. The transfer function of the decoupler; a decoupling control module, configured to perform decoupling control on the two mutually coupled to-be-controlled quantities through the first decoupler and the second decoupler.

In the technical solution of the embodiment of the present invention, considering that there are coupled quantities to be controlled in the electric heating steam boiler system, and decoupling control the mutually coupled quantities to be controlled, it is possible to implement relatively independent control of the mutually coupled quantities to be controlled. control, which is more conducive to the stable operation of the system.

Description of drawings

FIG. 1 is a schematic structural diagram of an electric heating steam boiler system according to an embodiment of the present invention.

FIG. 2 is a flowchart of a control method of an electrically heated steam boiler system according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of the principle of decoupling control of boiler power and steam temperature according to an example of the present invention.

FIG. 4 is a flow chart of independent control of steam flow according to an example of the present invention.

5 is a schematic block diagram of a control device of an electrically heated steam boiler system according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

FIG. 1 is a schematic structural diagram of an electric heating steam boiler system according to an embodiment of the present invention.

As shown in FIG. 1 , the electric heating steam boiler system includes an electric heating steam boiler, a softened water tank, various valve openings (including steam outlet valve openings and make-up water valve openings) and the like. The softened water tank mainly provides the steam boiler with water that meets the steam production standards, such as pH value, soluble metal ion concentration, etc. The system built-in temperature sensor, valve opening sensor, etc. are responsible for collecting signals for the controller.

FIG. 2 is a flowchart of a control method of an electrically heated steam boiler system according to an embodiment of the present invention.

As shown in FIG. 2 , the control method of the electric heating steam boiler system includes the following steps S1 to S4.

S1, determine two mutually coupled to-be-controlled quantities in the electric heating steam boiler system, wherein the coupling relationship between the two mutually coupled to-be-controlled quantities constitutes a coupling system.

Among them, the quantity to be controlled refers to the variables that need to be controlled in the electric heating steam boiler system, such as steam temperature and steam flow.

It should be noted that the quantities to be controlled in the electric heating steam boiler system may be coupled (that is, the quantities to be controlled that are coupled with each other), or there may not be coupling (that is, independent quantities to be controlled), and there may be coupling between the quantities to be controlled. The coupling relationship constitutes a coupled system.

S2, two output quantities and two input quantities of the coupling system are determined according to the two mutually coupled quantities to be controlled.

Specifically, after the two mutually coupled to-be-controlled quantities are determined, the two mutually-coupled to-be-controlled quantities can be used as the output quantities of the coupling system, and the corresponding control quantities of the two mutually-coupled to-be-controlled quantities can be obtained, for example , the control quantity corresponding to the steam temperature is the opening of the steam outlet valve, and then two control quantities are obtained, so the two control quantities are used as the input quantities of the coupling system, that is, the coupling system is a two-input two-output system.

S3: Determine the transfer function of the coupling system according to the output quantity and the input quantity of the coupling system, and obtain the transfer function of the first decoupler and the transfer function of the second decoupler according to the transfer function of the coupling system.

It can be understood that the transfer function is used to characterize the relationship between the output and input of the system.

Specifically, since the coupled system is a two-input two-output system, four transfer functions are required to describe the coupled system according to the coupling relationship. After the transfer function of the coupling system is obtained according to the output and input, the transfer functions of the two decouplers are calculated according to the origin function of the coupling function.

S4, performing decoupling control on the two mutually coupled to-be-controlled quantities through the first decoupler and the second decoupler.

Specifically, in order to realize the decoupling control of the two mutually coupled variables to be controlled, after the transfer functions of the first decoupler and the second decoupler are determined, the first decoupler and the second decoupler are used to pair the Two mutually coupled to-be-controlled quantities are decoupled and controlled to achieve decoupling control of the coupled system. Through decoupling, relatively independent control of the mutually coupled to-be-controlled quantities can be achieved.

Therefore, the control method of the electric heating steam boiler system according to the embodiment of the present invention takes into account the existence of coupled quantities to be controlled in the electric heating steam boiler system, and performs decoupling control on the mutually coupled quantities to be controlled, so as to realize the control of each other. The coupled variables to be controlled are controlled relatively independently, which is more conducive to the stable operation of the system.

It should be noted that the two to-be-controlled quantities or variables that are coupled to each other in the electric heating steam boiler system may be boiler power and steam flow. The opening of the steam valve and the opening of the make-up water valve can both affect the boiler power and outlet steam temperature.

That is, in an embodiment of the present invention, the two mutually coupled quantities to be controlled are boiler power and steam temperature, the two input quantities of the coupling system are the opening of the make-up water valve and the opening of the steam outlet valve, and the two output quantities are the actual quantity. Boiler temperature and actual steam temperature.

Specifically, after determining that the two coupled quantities to be controlled are boiler power and steam temperature, the control quantities of boiler power and steam temperature in the system can be determined, and the control quantities are the opening of the water supply valve and the opening of the steam outlet valve, so When the two coupled quantities to be controlled are boiler power and steam temperature, the two input quantities of the coupling system are the opening of the make-up water valve and the opening of the steam outlet valve, and the two output quantities are the actual boiler temperature and the actual steam temperature, namely Words: when the opening of the make-up valve is input to the coupling system, the actual boiler power and the actual steam temperature corresponding to the output of the coupling system; when the opening of the steam outlet valve is input to the coupling system, the actual boiler power and the actual steam temperature corresponding to the output of the coupling system ; When inputting the opening of the make-up water valve and the opening of the steam outlet valve to the coupling system, the coupling system outputs the corresponding actual boiler power and actual steam temperature.

In an embodiment of the present invention, the coupling system has a first transfer function, a second transfer function, a third transfer function, and a fourth transfer function, and in the above step S3, the coupling system is determined according to the output and input of the coupling system The transfer function may include the following steps: according to the input quantity and output quantity corresponding to each transfer function of the coupling system, wherein the first transfer function is used to represent the input quantity when the input quantity is the opening of the make-up valve and the output quantity is the actual boiler power. The relationship between the output and the second transfer function is used to characterize the relationship between the input and the output when the input is the opening of the make-up valve and the output is the actual steam temperature. The third transfer function is used to characterize the input as the steam outlet. The relationship between the input and output when the valve opening and output are the actual boiler power. The fourth transfer function is used to characterize the relationship between the input and output when the input is the valve opening of the steam outlet and the output is the actual steam temperature. relationship, the first to fourth transfer functions all satisfy the following second-order delay model:

Among them, G(s) is the transfer function of the coupled system, a, b and c are the coefficients of each order of the transfer function, and L is the lag constant of the transfer function; multiple sets of different input and output measurements are obtained corresponding to each set of input and output Use multiple sets of input and output measurement values to perform parameter identification on the corresponding transfer function to obtain the various order coefficients and lag constants of the transfer function.

Further, using multiple groups of input and output measurement values to perform parameter identification on the corresponding transfer function, including the following steps: selecting the phase angle and amplitude matching transfer functions of P different frequency points to obtain the following matched models:

Among them, ω _n is the frequency of the nth frequency point, n=1,2,...,P, P≥10; according to the matched model, the following formula 1 is obtained:

a ² ω ⁴ |G(jω)| ² +(2ac-b ² )ω ² |G(jω)| ² +c ² |G(jω)| ² =1 (3)

After the formula 1 is converted into a matrix, the coefficients and lag constants of each order of the transfer function are determined by the least square method.

Specifically, since the coupling system is a two-input and output system, the coupling system can have four transfer functions, namely the first transfer function, the second transfer function, the third transfer function and the fourth transfer function. According to the electric heating steam The operation mechanism of the boiler system can be obtained that the transfer function of the opening of the steam outlet valve or the opening of the make-up water valve corresponding to the boiler power or steam temperature satisfies the second-order delay system, and the second-order delay model is formula (1), so it can be determined that for For each transfer function, the four parameters that need to be identified are the coefficients a, b, c and the lag constant L of each order.

After that, different input and output measurement values (that is, the actual measured input and corresponding output) can be obtained corresponding to each group of input and output, and the phase angle and amplitude matching formula (1) of P different frequency points can be selected. The model of formula (2) is obtained, and formula (2) can be divided into amplitude relationship and phase angle relationship by squaring, namely, the amplitude relationship represented by formula (3) can be obtained.

Equation (3) is then converted into the following matrix form:

Φθ=Γ (4)

Each matrix in the formula is:

Substitute equations (5) and (6) into the following least squares formula:

θ=(Φ ^T Φ) ^-1 Φ ^T Γ (7)

Find the matrix θ with parameters a, b, c:

And then inversely solve the matrix of parameters a, b, and c as:

Again using the least squares method to get the lag constant L:

So far, all four parameters a, b, c and L of the transfer function have been found.

The first transfer function G ₁ (s), the second transfer function G ₂ (s), the third transfer function G ₃ (s) and the fourth transfer function G 3 (s) of the coupled system can be obtained by repeating the equations (1) to (10) four times. The order coefficients and lag constants of the transfer function G ₄ (s) are:

Among them, a ₁ , b ₁ and c ₁ are the coefficients of each order of the first transfer function, L ₁ is the lag constant of the first transfer function, and a ₂ , b ₂ and c ₂ are the coefficients of each order of the second transfer function , L ₂ is the lag constant of the second transfer function, a ₃ , b ₃ and c ₃ are the coefficients of each order of the third transfer function, L ₃ is the lag constant of the third transfer function, a ₄ , b ₄ and c ₄ are the coefficients of each order of the fourth transfer function, and L ₄ is the lag constant of the fourth transfer function.

Further, obtaining the transfer function of the first decoupler and the transfer function of the second decoupler according to the transfer function of the coupling system in the above step S4 may include: determining the first transfer function according to the first transfer function and the second transfer function. The transfer function of the decoupler is determined, and the transfer function of the second decoupler is determined according to the third transfer function and the fourth transfer function, wherein the transfer function of the first decoupler and the transfer function of the second decoupler are:

Wherein, D ₁₂ (s) is the transfer function of the first decoupler, and D ₂₁ (s) is the transfer function of the second decoupler.

Then the decoupling control matrix D of the coupled system is obtained as:

The four transfer functions of the coupled system are decoupled through the decoupling control matrix to realize the independent control of the quantity to be controlled.

Thereby, the transfer function D ₁₂ (s) of the first decoupler and the transfer function D ₂₁ (s) of the second decoupler are obtained, and then step S4 is performed to realize decoupling control of boiler power and steam temperature.

In an example of the present invention, the above step S4 may be the following steps: obtaining the actual boiler power and actual steam temperature output by the electric heating steam boiler system, and obtaining the set boiler power and set steam temperature; calculating the set boiler power and the actual steam temperature; The error power between the boilers, and the error power is sent to the first controller to obtain the opening of the make-up valve, and the error temperature between the set steam temperature and the actual steam temperature is calculated, and the error temperature is sent to the second controller to obtain The opening degree of the steam outlet valve; the opening degree of the replenishment valve is sent to the first decoupler to obtain the second decoupling signal, and the opening degree of the replenishment valve and the first decoupling signal output by the second decoupler are accumulated to obtain The opening of the make-up water valve after decoupling; the opening of the steam outlet valve is sent to the second decoupler to obtain the first decoupling signal, and the opening of the steam outlet valve is connected with the second decoupling signal output by the first decoupler Accumulate to obtain the decoupled steam outlet valve opening; input the decoupled makeup water valve opening and the decoupled steam outlet valve opening into the coupling system to obtain the actual boiler power and actual steam temperature, and return the calculation error The steps of calculating the error temperature of power and temperature are used for closed-loop control of boiler power and steam temperature respectively, until the actual power of the boiler is equal to the set power of the boiler, and the actual steam temperature is equal to the set steam temperature.

Wherein, the first controller and the second controller may be PID (Proportion IntegralDifferential, proportional integral derivative) controllers.

Among them, the set boiler power is the preset value of the boiler power that needs to be controlled by the electric heating steam boiler system, and the set steam temperature is the preset steam temperature setting that needs to be controlled by the electric heating steam boiler system. value.

Specifically, as shown in Figure 3, first, the actual boiler power P* and actual steam temperature T* of the electric heating steam boiler system can be collected, and the set boiler power P and set steam temperature T can be obtained, and P and P * The difference is obtained to obtain the error power, and the error power is sent to the first controller, and then the first controller outputs the opening degree m ₁ of the replenishment valve, and the difference between T and T* is used to obtain the error temperature, and the error temperature is sent to the second controller. The controller, and then the second controller outputs the steam outlet valve opening m ₂ , and then sends m ₁ into the first decoupler to obtain the second decoupling signal d ₂ , and outputs m ₁ and the second decoupler The first decoupling signal d ₁ is accumulated to obtain the decoupled replenishment valve opening μ ₁ , and at the same time, m ₂ is sent to the second decoupling device to obtain the first decoupling signal d ₁ , and m ₂ is combined with the first decoupling signal d 1 . The second decoupling signal d ₂ output by a decoupler is accumulated to obtain the decoupled steam outlet valve opening μ ₂ . After that, the decoupled water replenishment valve opening μ ₁ and the decoupled steam outlet valve opening are The degree μ ₂ acts on the coupling system that determines the transfer function, and then the coupling system outputs the actual boiler power and the actual steam temperature, feeds back the actual boiler power and the actual steam temperature, and calculates the error power and error temperature, so as to determine the difference between the boiler power and the actual steam temperature, respectively. Closed-loop control of steam temperature, until the actual boiler power output by the coupling system is equal to the set boiler power and the actual steam temperature is equal to the set steam temperature, the control process ends, thereby realizing the decoupling control of boiler power and steam temperature.

When the actual boiler power is equal to the set boiler power, the make-up valve is adjusted according to the opening of the make-up valve acting on the coupling system at this time. For example, the opening of the make-up valve can be adjusted to 50%; when the actual steam temperature is equal to the set steam At the time of temperature, the steam outlet valve is adjusted according to the opening degree of the steam outlet valve acting on the coupling system at this time, for example, the opening degree of the steam outlet valve can be adjusted to 60%.

It should be noted that the above describes how to control two mutually coupled quantities to be controlled. The electric heating steam boiler system also includes independent quantities to be controlled, that is, there is no coupled quantity to be controlled. Controlled by an independent quantity to be controlled.

That is, in an embodiment of the present invention, the control method of the electric heating steam boiler system further includes: determining an independent quantity to be controlled in the electric heating steam boiler system; and independently controlling the independent quantity to be controlled through a third controller.

Wherein, the third controller may be a PID controller.

Specifically, since the independent variables to be controlled have no coupling phenomenon, conventional PID control can be performed on at least one independent variable to be controlled.

Further, the independent quantity to be controlled includes steam flow, and the independent control of the independent quantity to be controlled by the third controller specifically includes the following steps: obtaining the actual steam flow of the electric heating steam boiler system, and obtaining the set steam flow; calculating Set the error flow between the steam flow and the actual steam flow; input the error flow into the third controller to obtain the voltage control amount, and control the electric heating steam boiler system with the voltage control amount, so that the electric heating steam boiler system outputs the actual steam Flow; return to the step of calculating the error flow for closed-loop control of the steam flow until the actual steam flow is equal to the set steam flow.

Among them, the set steam flow is a preset value of the steam flow that needs to be controlled by the electric heating steam boiler system.

Specifically, as shown in Fig. 4, the error flow is obtained by taking the difference between the set steam flow F and the system actual steam flow F*, which is sent to the third controller to output the voltage control amount m ₃ , and control the voltage The amount m ₃ acts on the boiler power supply, thereby changing the boiler voltage u, and then controlling the boiler system to output the actual steam flow, and feeding back the actual steam flow to form a closed-loop control of the steam flow, until the actual steam flow is equal to the set steam flow. The control of the steam flow ends.

When the actual steam flow is equal to the set steam flow, the three-phase power supply of the boiler system is adjusted according to the voltage control amount acting on the boiler power supply at this time.

To sum up, the embodiments of the present invention perform different controls on different quantities to be controlled, and can relatively independently control the parameters coupled with each other in the electric heating steam boiler system, that is, decoupling control; PID control, so as to realize the stable operation of the whole system.

Corresponding to the control method of the electric heating steam boiler system in the above embodiment, the present invention also provides a control device for the electric heating steam boiler system.

5 is a schematic block diagram of a control device of an electrically heated steam boiler system according to an embodiment of the present invention.

As shown in FIG. 5 , the control device of the electric heating steam boiler system includes: a first determination module 10 , a second determination module 20 , a third determination module 30 and a decoupling control module 40 .

Wherein, the first determination module 10 is used to determine two mutually coupled to-be-controlled quantities in the electric heating steam boiler system, wherein the coupling relationship between the two mutually coupled to-be-controlled quantities constitutes a coupling system; the second The determination module 20 is used for determining two output quantities and two input quantities of the coupling system according to the two mutually coupled to-be-controlled quantities; the third determination module 30 is used for determining the output quantities and the input quantities of the coupling system according to the The transfer function of the coupling system is determined, and the transfer function of the first decoupler and the transfer function of the second decoupler are obtained according to the transfer function of the coupling system; the decoupling control module 40 is used to pass the first decoupling function. The coupler and the second decoupler perform decoupling control on the two mutually coupled variables to be controlled.

It should be noted that, for the specific implementation and implementation principle of the control device of the electric heating steam boiler system, reference may be made to the specific implementation of the control method for the electric heating steam boiler system. To avoid redundancy, details are not repeated here.

The control device of the electric heating steam boiler system according to the embodiment of the present invention takes into account the existence of coupled quantities to be controlled in the electric heating steam boiler system, and performs decoupling control on the mutually coupled quantities to be controlled, so as to realize the control of the mutually coupled quantities to be controlled. The control quantity is controlled relatively independently, which is more conducive to the stable operation of the system.

In the description of the present invention, the terms "first" and "second" are only used for the purpose of description, and cannot be understood as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. "Plurality" means two or more, unless expressly specifically limited otherwise.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other.

Any description of a process or method in the flowcharts or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing a specified logical function or step of the process , and the scope of the preferred embodiments of the present invention includes alternative implementations in which the functions may be performed out of the order shown or discussed, including performing the functions substantially concurrently or in the reverse order depending upon the functions involved, which should It is understood by those skilled in the art to which the embodiments of the present invention belong.

It should be understood that various parts of the present invention may be implemented in hardware, software, firmware or a combination thereof. In the above-described embodiments, various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one or a combination of the following techniques known in the art: Discrete logic circuits, application specific integrated circuits with suitable combinational logic gates, Programmable Gate Arrays (PGA), Field Programmable Gate Arrays (FPGA), etc.

Those skilled in the art can understand that all or part of the steps carried by the methods of the above embodiments can be completed by instructing the relevant hardware through a program, and the program can be stored in a computer-readable storage medium, and the program can be stored in a computer-readable storage medium. When executed, one or a combination of the steps of the method embodiment is included. In addition, each functional unit in each embodiment of the present invention may be integrated into one processing module, or each unit may exist physically alone, or two or more units may be integrated into one module. The above-mentioned integrated modules can be implemented in the form of hardware, and can also be implemented in the form of software function modules. If the integrated modules are implemented in the form of software functional modules and sold or used as independent products, they may also be stored in a computer-readable storage medium.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and should not be construed as limiting the present invention. Embodiments are subject to variations, modifications, substitutions and variations.

Claims (10)

1. a control method of an electric heating steam boiler system, is characterized in that, comprises the following steps: determining two mutually coupled to-be-controlled quantities in the electric heating steam boiler system, wherein the coupling relationship between the two mutually coupled to-be-controlled quantities constitutes a coupling system; Determine two output quantities and two input quantities of the coupling system according to the two mutually coupled to-be-controlled quantities; Determine the transfer function of the coupling system according to the output and input of the coupling system, and obtain the transfer function of the first decoupler and the transfer function of the second decoupler according to the transfer function of the coupling system; The two mutually coupled variables to be controlled are decoupled and controlled by the first decoupler and the second decoupler. 2. The control method of an electrically heated steam boiler system according to claim 1, wherein the two mutually coupled quantities to be controlled are boiler power and steam temperature, and the two input quantities of the coupled system are water make-up The valve opening and the steam outlet valve opening, and the two output quantities are the actual boiler temperature and the actual steam temperature. 3. The control method of the electric heating steam boiler system according to claim 2, wherein the coupling system has a first transfer function, a second transfer function, a third transfer function and a fourth transfer function, according to the The output and input quantities of the coupling system determine the transfer function of the coupling system, including the following steps: According to the input quantity and output quantity corresponding to each transfer function of the coupling system, the first transfer function is used to characterize the difference between the input quantity and the output quantity when the input quantity is the opening of the make-up valve and the output quantity is the actual boiler power. The second transfer function is used to represent the relationship between the input and the output when the input is the opening of the make-up valve and the output is the actual steam temperature, and the third transfer function It is used to characterize the relationship between the input quantity and the output quantity when the input quantity is the opening of the steam outlet valve and the output quantity is the actual boiler power, and the fourth transfer function is used to characterize the input quantity as the opening of the steam outlet valve, The output is the relationship between the input and the output when the actual steam temperature is present, and the first to fourth transfer functions all satisfy the following second-order delay model:

Wherein, G(s) is the transfer function of the coupling system, a, b and c are the coefficients of each order of the transfer function, and L is the lag constant of the transfer function; Obtaining multiple sets of different input and output measurement values corresponding to each group of the input quantity and the output quantity; Parameter identification is performed on the corresponding transfer function by using a plurality of sets of the input and output measurement values, so as to obtain various order coefficients and hysteresis constants of the transfer function. 4. The control method of the electric heating steam boiler system according to claim 3, characterized in that, using multiple groups of the input and output measured values to carry out parameter identification to the corresponding transfer function, comprising the following steps: The phase angles and amplitudes of P different frequency points are selected to match the transfer function to obtain the following matched model:

Among them, ω _n is the frequency of the nth frequency point, n=1,2,...,P, P≥10; According to the matched model, the following formula 1 is obtained: a ² ω ⁴ |G(jω)| ² +(2ac-b ² )ω ² |G(jω)| ² +c ² |G(jω)| ² =1 After converting the formula 1 into a matrix, each order coefficient and lag constant of the transfer function are determined by the least square method. 5. The method for controlling an electrically heated steam boiler system according to claim 3, wherein the transfer function of the first decoupler and the transfer function of the second decoupler are obtained according to the transfer function of the coupling system, comprising: : The transfer function of the first decoupler is determined according to the first transfer function and the second transfer function, and the transfer function of the second decoupler is determined according to the third transfer function and the fourth transfer function transfer function, wherein the transfer function of the first decoupler and the transfer function of the second decoupler are:

Wherein, D ₁₂ (s) is the transfer function of the first decoupler, D ₂₁ (s) is the transfer function of the second decoupler, G ₁ (s) is the first transfer function, G ₂ (s) is the second transfer function, G ₃ (s) is the third transfer function, and G ₄ (s) is the fourth transfer function. 6 . The control method for an electrically heated steam boiler system according to claim 2 , wherein the two mutually coupled to-be-controlled quantities are performed by the first decoupling device and the second decoupling device. 7 . Decoupled control, including the following steps: Obtain the actual boiler power and actual steam temperature output by the electric heating steam boiler system, and obtain the set boiler power and set steam temperature; Calculate the error power between the set boiler power and the actual boiler, and send the error power to the first controller to obtain the opening of the make-up valve, and calculate the set steam temperature and the actual steam temperature The error temperature between, and the error temperature is sent to the second controller to obtain the steam outlet valve opening; sending the opening of the water replenishment valve into the first decoupler to obtain a second decoupling signal, and accumulating the opening of the replenishing valve and the first decoupling signal output by the second decoupler, In order to obtain the opening of the replenishment valve after decoupling; The steam outlet valve opening is sent to the second decoupler to obtain the first decoupling signal, and the steam outlet valve opening is related to the second decoupling output from the first decoupler. The decoupling signals are accumulated to obtain the steam outlet valve opening degree after decoupling; Input the decoupled water make-up valve opening and the decoupled steam outlet valve opening into the coupling system to obtain the actual boiler power and actual steam temperature, and return to the steps of calculating error power and calculating error temperature, to The closed-loop control of boiler power and steam temperature is performed respectively until the actual boiler power is equal to the set boiler power and the actual steam temperature is equal to the set steam temperature. 7. The control method of the electric heating steam boiler system according to claim 1, characterized in that, further comprising: determining the independent quantity to be controlled in the electric heating steam boiler system; The independent quantity to be controlled is independently controlled by the third controller. 8 . The method for controlling an electric heating steam boiler system according to claim 7 , wherein the independent quantity to be controlled comprises steam flow, and the independent quantity to be controlled is independently controlled by a third controller. 9 . Include the following steps: Obtain the actual steam flow of the electric heating steam boiler system, and obtain the set steam flow; calculating the error flow between the set steam flow and the actual steam flow; inputting the error flow into the third controller to obtain a voltage control amount, and controlling the electric heating steam boiler system with the voltage control amount, so that the electric heating steam boiler system outputs an actual steam flow; Return to the step of calculating the error flow to close-loop control the steam flow until the actual steam flow is equal to the set steam flow. 9 . The control method for an electrically heated steam boiler system according to claim 7 , wherein the first controller, the second controller and the third controller are PID controllers. 10 . 10. A control device for an electric heating steam boiler system, characterized in that it comprises: a first determination module, configured to determine two mutually coupled to-be-controlled quantities in the electric heating steam boiler system, wherein the coupling relationship between the two mutually coupled to-be-controlled quantities constitutes a coupling system; a second determining module, configured to determine two output quantities and two input quantities of the coupling system according to the two mutually coupled to-be-controlled quantities; The third determining module is configured to determine the transfer function of the coupling system according to the output and input of the coupling system, and obtain the transfer function of the first decoupler and the second decoupling according to the transfer function of the coupling system The transfer function of the device; A decoupling control module, configured to perform decoupling control on the two mutually coupled to-be-controlled quantities through the first decoupler and the second decoupler.

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