CN111600521B - A kind of excitation controller control method and system - Google Patents

Abstract

The invention relates to an excitation controller control method and system, and relates to the technical field of power system stability control. The method includes: using PID control and excitation control system mathematical models to determine the parameters of the control strategy; using the kth sampling error value of the excitation control system, the kth sampling error value and the first error of the k-1th sampling error value of the excitation control system The difference value and the second error difference between the k-1th sampling error value and the k-2th sampling error value determine the preset control conditions corresponding to the current state of the excitation controller; adopt the corresponding preset control conditions corresponding to the current state. The control strategy controls the output of the excitation controller. The excitation controller control method and system of the present invention can automatically determine different preset control conditions according to the working state and error conditions of the excitation control system, so that the control strategy is more flexible; the parameters of the excitation controller are automatically adjusted, and the performance of the excitation controller is improved. Adaptability, so that the control effect of the excitation control system is better.

Description

A kind of excitation controller control method and system

technical field

The invention relates to the technical field of power system stability control, in particular to an excitation controller control method and system.

Background technique

The stability of the power system has an important impact on the security and reliability of the power grid. To enhance the stability of the power system through various measures is of great significance for the healthy development of the social economy and the improvement of people's quality of life. The excitation controller is the core of the synchronous generator control system, which can effectively control the generator excitation system and is an important measure for the stable operation of the power system. Although the application of conventional PID control (proportional-integral-derivative control, proportional-integral-derivative control) in the excitation controller is very mature, the parameters of the excitation controller using this control method are fixed and the control law is single, which cannot be based on the excitation of the generator. The working state and error situation of the system can automatically change the excitation control law and adjust the parameters of the excitation controller, resulting in a poor ability of the excitation controller to adapt to the characteristics of the object. Therefore, the existing excitation controller has the problem of poor adaptability.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an excitation controller control method and system, which solves the problem of poor adaptability of the existing excitation controller.

For achieving the above object, the present invention provides the following scheme:

An excitation controller control method, comprising:

Obtain the mathematical model of the excitation control system;

Use PID control and the mathematical model of the excitation control system to determine the parameters of the control strategy of the excitation controller; the parameters include: proportional coefficient, integral coefficient and differential coefficient;

Determine the difference between the error value at the k-th sampling of the excitation control system and the first error value at the k-1-th sampling as the first error difference, and compare the first error value with the k-2-th sampling The difference between the second error values during sampling is determined as the second error difference; wherein k represents the number of sampling times;

A preset control condition corresponding to the current state of the excitation controller is determined by using the error value at the k-th sampling, the first error difference value and the second error difference value; the preset control conditions include : the first preset control condition, the second preset control condition, the third preset control condition, the fourth preset control condition and the fifth preset control condition;

A control strategy corresponding to a preset control condition corresponding to the current state is used to control the output of the excitation controller.

Optionally, the preset control condition corresponding to the current state of the excitation controller is determined by using the error value at the kth sampling, the first error difference value, and the second error difference value, specifically: include:

judging whether the absolute value of the error value during the k-th sampling is greater than a first preset error threshold, to obtain a first judgment result;

If the first judgment result is yes, the preset control condition corresponding to the current state is the first preset control condition;

If the first judgment result is no, then judge whether the product of the error value at the kth sampling time and the first error difference value is greater than zero or whether the first error difference value is equal to zero, and obtain a second judgment result;

If the second judgment result is yes, the preset control condition corresponding to the current state is the second preset control condition;

If the second judgment result is no, judge whether the product of the error value at the kth sampling time and the first error difference value is less than zero and the first error difference value and the second error difference Whether the product of the values is greater than zero, or whether the error value during the kth sampling is equal to zero, a third judgment result is obtained;

If the third judgment result is yes, the preset control condition corresponding to the current state is the third preset control condition;

If the third judgment result is no, then judge whether the product of the error value at the kth sampling time and the first error difference value is less than zero and the first error difference value and the second error difference Whether the product of the values is less than zero, the fourth judgment result is obtained;

If the fourth judgment result is yes, the preset control condition corresponding to the current state is the fourth preset control condition;

If the fourth judgment result is no, then judge whether the absolute value of the error value at the k-th sampling is less than the preset accuracy of the excitation control system error, and obtain a fifth judgment result;

If the fifth determination result is yes, the preset control condition corresponding to the current state is the fifth preset control condition.

Optionally, when the preset control condition corresponding to the current state is the first preset control condition, the control strategy corresponding to the preset control condition corresponding to the current state is used to control the output of the excitation controller, specifically including: :

The output of the excitation controller is determined as a preset value, and the excitation control system is open-loop controlled.

Optionally, when the preset control condition corresponding to the current state is the second preset control condition, the control strategy corresponding to the preset control condition corresponding to the current state is used to control the output of the excitation controller, specifically including: :

Judging whether the absolute value of the error value during the k-th sampling is greater than or equal to the second preset error threshold, and obtains a sixth judgment result;

If the sixth judgment result is yes, the output of the excitation controller is determined according to the formula u(k)=u(k-1)+K ₁ K _p e(k); The output of the excitation controller, u(k-1) represents the output of the excitation controller at the k-1th sampling, K ₁ represents the amplification factor of the excitation control system, K _p represents the proportional coefficient, e (k) represents the error value during the k-th sampling;

If the sixth judgment result is no, the output of the excitation controller is determined according to the formula u(k)=u(k-1)+K ₂ K _p e(k); wherein, K ₂ represents the excitation The suppression coefficient of the control system.

Optionally, when the preset control condition corresponding to the current state is the third preset control condition, the control strategy corresponding to the preset control condition corresponding to the current state is used to control the output of the excitation controller, specifically including: :

Hold the output of the excitation controller.

Optionally, when the preset control condition corresponding to the current state is the fourth preset control condition, the control strategy corresponding to the preset control condition corresponding to the current state is used to control the output of the excitation controller, specifically including: :

judging whether the absolute value of the error value during the k-th sampling is greater than or equal to the second preset error threshold, to obtain a seventh judgment result;

If the seventh judgment result is yes, the output of the excitation controller is determined according to the formula u(k)=u(k-1)+K ₁ K _p e(k-1); wherein u(k) represents the output of the excitation controller, u(k-1) represents the output of the excitation controller at the k-1th sampling, K ₁ represents the amplification factor of the excitation control system, and K _p represents the proportional coefficient , e(k-1) represents the first error value;

If the seventh judgment result is no, the output of the excitation controller is determined according to the formula u(k)=u(k-1)+K ₂ K _p e(k-1); wherein, K ₂ represents the The suppression coefficient of the excitation control system is described.

Optionally, when the preset control condition corresponding to the current state is the fifth preset control condition, the control strategy corresponding to the preset control condition corresponding to the current state is used to control the output of the excitation controller, specifically including: :

确定所述励磁控制器的输出；其中，u(k)表示所述励磁控制器的输出，K_p表示所述比例系数，e(k)表示所述第k次采样时的误差值，K_i表示所述积分系数，j表示采样次数，e(j)表示第j次采样时的误差值，K_d表示所述微分系数，Δe(k)表示第一误差差值。According to the formula

Determine the output of the excitation controller; wherein, u(k) represents the output of the excitation controller, K _p represents the proportional coefficient, e(k) represents the error value at the kth sampling, K _i represents the integral coefficient, j represents the number of sampling times, e(j) represents the error value at the jth sampling, K _d represents the differential coefficient, and Δe(k) represents the first error difference.

An excitation controller control system, comprising:

The mathematical model acquisition module is used to acquire the mathematical model of the excitation control system;

a parameter determination module, used for using PID control and the mathematical model of the excitation control system to determine the parameters of the control strategy of the excitation controller; the parameters include: proportional coefficient, integral coefficient and differential coefficient;

A difference determination module, configured to determine the difference between the error value at the k-th sampling of the excitation control system and the first error value at the k-1-th sampling as the first error difference, and the first error The difference between the value and the second error value in the k-2th sampling is determined as the second error difference; wherein k represents the number of sampling times;

A preset control condition determination module, configured to determine the preset control corresponding to the current state of the excitation controller by using the error value at the kth sampling, the first error difference value and the second error difference value conditions; the preset control conditions include: a first preset control condition, a second preset control condition, a third preset control condition, a fourth preset control condition, and a fifth preset control condition;

The control excitation controller output module is used for controlling the output of the excitation controller by adopting the control strategy corresponding to the preset control conditions corresponding to the current state.

Optionally, the preset control condition determination module specifically includes:

a first judgment unit, configured to judge whether the absolute value of the error value during the k-th sampling is greater than a first preset error threshold, and obtain a first judgment result;

a first preset control condition determination unit, configured to, when the first judgment result is yes, the preset control condition corresponding to the current state is the first preset control condition;

a second judging unit, configured to judge whether the product of the error value at the k-th sampling time and the first error difference value is greater than zero or the first error difference value when the first judgment result is no Whether it is equal to zero, the second judgment result is obtained;

a second preset control condition determining unit, configured to, when the second judgment result is yes, the preset control condition corresponding to the current state is the second preset control condition;

a third judging unit, configured to judge whether the product of the error value at the k-th sampling time and the first error difference value is less than zero and the first error difference value when the second judgment result is no Whether the product of the second error difference value is greater than zero, or whether the error value during the kth sampling is equal to zero, to obtain a third judgment result;

a third preset control condition determining unit, configured to, when the third judgment result is yes, the preset control condition corresponding to the current state is the third preset control condition;

a fourth judging unit, configured to judge whether the product of the error value at the k-th sampling time and the first error difference value is less than zero and the first error difference value when the third judgment result is no Whether the product of the second error difference is less than zero, a fourth judgment result is obtained;

a fourth preset control condition determining unit, configured to, when the fourth judgment result is yes, the preset control condition corresponding to the current state is the fourth preset control condition;

a fifth judgment unit, configured to judge whether the absolute value of the error value at the k-th sampling is less than the preset accuracy of the excitation control system error when the fourth judgment result is no, and obtain a fifth judgment result;

A fifth preset control condition determination unit, configured to, when the fifth determination result is yes, the preset control condition corresponding to the current state is the fifth preset control condition.

Optionally, the control excitation controller output module specifically includes:

The open-loop control unit is configured to determine the output of the excitation controller as a preset value when the preset control condition corresponding to the current state is the first preset control condition, and perform a control operation on the excitation control system. Open loop control.

According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

The invention provides an excitation controller control method and system. The method includes: acquiring a mathematical model of an excitation control system; using the PID control and the mathematical model of the excitation control system to determine parameters of a control strategy of the excitation controller; the parameters include: proportional coefficient, integral coefficient and differential coefficient; The difference between the error value at the time of the second sampling and the first error value at the k-1th sampling time is determined as the first error difference value, and the difference between the first error value and the second error value at the k-2th sampling time is determined as the first error value. The value is determined as the second error difference value; wherein k represents the number of sampling times; the preset control condition corresponding to the current state of the excitation controller is determined by using the error value, the first error difference value and the second error difference value during the kth sampling; The preset control conditions include: first preset control conditions, second preset control conditions, third preset control conditions, fourth preset control conditions, and fifth preset control conditions; using preset control conditions corresponding to the current state The corresponding control strategy controls the output of the excitation controller. The excitation controller control method and system of the present invention can automatically determine different excitation control laws according to the working state and error conditions of the excitation control system, that is, preset control conditions, so that the control strategy is more flexible; the parameters of the excitation controller are automatically adjusted to improve the The adaptability of the excitation controller is improved, the adaptability of the excitation controller is stronger, the characteristics of intelligent control are reflected, and the control effect of the excitation control system is better.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative labor.

FIG. 1 is a flowchart of an excitation controller control method provided by an embodiment of the present invention;

2 is a structural diagram of a synchronous generator excitation control system provided by an embodiment of the present invention;

3 is a structural diagram of an excitation controller control system provided by an embodiment of the present invention;

4 is an output response curve diagram of an excitation system provided by an embodiment of the present invention;

Fig. 5 is the error change curve diagram of the excitation system provided by the embodiment of the present invention;

FIG. 6 is a graph showing the variation of the control amount of the excitation system provided by the embodiment of the present invention.

Symbol description: 1. Excitation controller; 2. Power amplification unit; 3. Synchronous generator; 4. Voltage measurement unit.

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.

The purpose of the present invention is to provide an excitation controller control method and system, which solves the problem of poor adaptability of the existing excitation controller.

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

This embodiment provides an excitation controller control method. FIG. 1 is a flowchart of the excitation controller control method provided by the embodiment of the present invention. Referring to FIG. 1 , the excitation controller control method includes:

Step 101, acquiring a mathematical model of the excitation control system. The excitation control system of this embodiment is a synchronous generator excitation control system. Before determining the control method of the excitation controller, it is necessary to analyze the composition of each link of the synchronous generator excitation control system to obtain the transfer function of the synchronous generator excitation control system. Thereby, the mathematical model of the excitation control system of the synchronous generator is obtained.

FIG. 2 is a structural diagram of a synchronous generator excitation control system provided by an embodiment of the present invention. Referring to FIG. 2 , the excitation control system includes: an excitation controller 1 , a power amplification unit 2 , a synchronous generator 3 and a voltage measurement unit 4 . The output end of the excitation controller 1 is connected to the input end of the power amplifying unit 2, the output end of the power amplifying unit 2 is connected to the input end of the synchronous generator 3, and the input end of the voltage measuring unit 4 is connected to the output end of the synchronous generator 3 , the output end of the voltage measuring unit 4 is connected with the input end of the excitation controller 1 .

Power amplification mainly refers to the power conversion between the small control signal output by the excitation controller and the output of the excitation power device. The power amplification unit can be considered as a first-order inertial link, and its transfer function is:

In formula (1), G ₁ (s) represents the transfer function of the power amplifying unit, s represents a variable in the complex domain, K _A is the voltage ratio of the amplifying link, and T _A is the time constant of the amplifying link.

When only the excitation control system is studied, and the saturation characteristics of the generator magnetic circuit are not considered, the transfer function of the synchronous generator can be simplified to the following first-order inertia link:

In formula (2), G ₂ (s) represents the transfer function of the synchronous generator, K _G is the generator amplification factor, and T _G is the generator time constant.

The voltage measurement unit completes the conversion of the output voltage of the synchronous generator to the input signal of the excitation controller, which can be described by the first-order inertial link. The transfer function of the voltage measurement unit can be expressed by the following formula:

In formula (3), G ₃ (s) represents the transfer function of the voltage measurement unit, K ₃ is the voltage proportional coefficient, and T ₃ is the time constant of the measurement loop.

The mathematical model of the controlled object in the available excitation control system is:

Among them, _G (s) represents the transfer function of the mathematical model of the controlled object in the excitation control system, KA is the voltage ratio of the amplification link, _TA is the time constant of the amplification link, s represents the variable in the complex domain, and _KG is the synchronous power generation is the amplification factor of the generator, and T _G is the time constant of the synchronous generator.

The controlled objects in this embodiment are the power amplifying unit and the synchronous generator. The purpose of step 101 is to give the specific form of the controlled objects, that is, to give the controlled objects in the form of transfer functions. The excitation controller controls the controlled object, and the control method of the excitation controller is based on the mathematical model of the controlled object. The specific parameters of the excitation controller can only be determined by knowing the mathematical model of the controlled object. On the basis of the mathematical model of the controlled object, the parameters include: proportional coefficient, integral coefficient, differential coefficient, integral time constant, differential time constant, sampling time, upper limit value S ₁ of control quantity, lower limit value S ₂ of control quantity, A preset error threshold L ₁ and a second preset error threshold L ₂ .

Step 102, using the PID control and the excitation control system mathematical model to determine the parameters of the control strategy of the excitation controller; the parameters include: proportional coefficient, integral coefficient, differential coefficient, integral time constant, differential time constant, sampling time, the upper limit of the control amount. The limit value S ₁ , the lower limit value S ₂ of the control amount, the first preset error threshold value L ₁ and the second preset error threshold value L ₂ . In practical application, the parameters of the control strategy of the excitation controller are obtained through the simulation experiment of conventional PID control on the mathematical model of the controlled object.

After the excitation control system is added to the PID controller, a step signal is applied to the input of the excitation control system. After the response of the excitation control system, the output response curve of the excitation control system, the change curve of the control amount and the error of the excitation control system can be observed through the oscilloscope. change curve, etc. The upper limit value S ₁ and the lower limit value S ₂ of the control variable are determined according to the change curve of the control variable, so as to realize the saturation processing of the control variable; the first preset error threshold value L ₁ and the second preset error threshold value L 1 are determined according to the change curve of the error Error threshold L ₂ . The error is the error e(k) of the excitation control system, the deviation between the input r(k) of the excitation control system and the output y(k) of the excitation control system, that is, e(k)=r(k)-y(k ). The maximum value of the error of the excitation control system can be obtained through the change curve of the error. In this embodiment, the maximum value of the error is 1, L ₁ is taken as 80% of the maximum value of the error, that is, 0.8; L ₂ is taken as the maximum value of the error 5%, that is, 0.05; L ₁ is a large error threshold, that is, when the error is greater than L ₁ , the error is considered to be very large; L ₂ is a larger error threshold, that is, when the error is greater than L ₂ , it is considered that the error is relatively large. big.

The excitation control system is controlled by PID control method, the output of the excitation controller is determined, and then the parameters of the excitation controller are obtained.

in,

In the above formula, u'(k) represents the output of the excitation controller when the PID control method is used; K _p is the proportional coefficient; e(k) represents the error value of the kth sampling; K _i is the integral coefficient; j and k Both represent the sampling times, j represents the jth sampling, k represents the kth sampling, and 0≤j≤k; e(j) represents the error value of the excitation control system at the jth sampling; K _d is the differential coefficient; Δe (k) represents the error difference between the error value at the k-th sampling of the excitation control system and the error value at the k-1-th sampling; T is the sampling time; T _i is the integral time constant; T _d is the differential time constant.

Step 103: Determine the difference between the error value at the k-th sampling of the excitation control system and the first error value at the k-1-th sampling as the first error difference, and determine the difference between the first error value and the k-2-th sampling. The difference between the second error values at the time of sub-sampling is determined as the second error difference value; wherein k represents the number of sampling times.

Step 103 specifically includes: acquiring the error value of the excitation control system at the k-th sampling, the first error value at the k-1-th sampling, and the second error value at the k-2-th sampling.

The difference between the error value at the kth sampling and the first error value is determined as the first error difference, that is, Δe(k)=e(k)-e(k-1), and Δe(k) represents the first error value. An error difference, e(k) represents the error value at the k-th sampling, and e(k-1) represents the first error value.

The difference between the first error value and the second error value is determined as the second error difference, that is, Δe(k-1)=e(k-1)-e(k-2), Δe(k-1) represents the second error difference value, and e(k-2) represents the second error value.

Step 104: Determine a preset control condition corresponding to the current state of the excitation controller by using the error value, the first error difference value and the second error difference value at the kth sampling; the preset control conditions include: a first preset control condition , a second preset control condition, a third preset control condition, a fourth preset control condition, and a fifth preset control condition.

Step 104 specifically includes:

It is judged whether the absolute value of the error value at the k-th sampling is greater than the first preset error threshold, and a first judgment result is obtained.

If the first determination result is yes, the preset control condition corresponding to the current state is the first preset control condition.

If the first judgment result is no, then judge whether the product of the error value at the kth sampling and the first error difference value is greater than zero or whether the first error difference value is equal to zero, and obtain a second judgment result.

或(2)

或(3)e(k)-e(k-1)＝0。对于(1)，表示第k次采样时的误差值为正，且在增大，第k次采样时的误差值的绝对值在增大；对于(2)，表示第k次采样时的误差值为负，且继续减小，第k次采样时的误差值的绝对值在增大；对于(3)表示误差未发生变化。If the second judgment result is yes, the preset control condition corresponding to the current state is the second preset control condition. The second judgment result is that e(k)Δe(k)>0 or Δe(k)=0, that is, (1)

or (2)

or (3) e(k)-e(k-1)=0. For (1), it means that the error value at the kth sampling is positive and increasing, and the absolute value of the error value at the kth sampling is increasing; for (2), it means the error at the kth sampling The value is negative and continues to decrease, and the absolute value of the error value at the kth sampling is increasing; for (3), it means that the error has not changed.

If the second judgment result is no, then judge whether the product of the error value at the kth sampling time and the first error difference value is less than zero and whether the product of the first error difference value and the second error difference value is greater than zero, or whether the product of the kth sampling error value and the first error difference value is greater than zero. Whether the error value at the time of sub-sampling is equal to zero, the third judgment result is obtained.

If the third determination result is yes, the preset control condition corresponding to the current state is the third preset control condition. The third judgment result is that e(k)△e(k)<0 and △e(k)△e(k-1)>0, or e(k)=0, that is (1)e(k- 2)<e(k-1)<e(k)<0 or (2)0<e(k)<e(k-1)<e(k-2) or (3)r(k)-y (k)=0, where (1) and (2) mean that the absolute value of the error is changing in a decreasing direction, and (3) means that the error has reached an equilibrium state.

If the third judgment result is no, then judge whether the product of the error value in the kth sampling and the first error difference value is less than zero and whether the product of the first error difference value and the second error difference value is less than zero, and obtain the fourth critical result.

(1)和(2)均意味着误差处于极值状态。If the fourth determination result is yes, the preset control condition corresponding to the current state is the fourth preset control condition. The fourth judgment result is that e(k)△e(k)<0 and △e(k)△e(k-1)<0, that is (1)0<e(k)<e(k-1 )>e(k-2) or (2)

Both (1) and (2) imply that the error is in an extreme state.

If the fourth judgment result is no, it is judged whether the absolute value of the error value at the kth sampling is less than the preset accuracy of the excitation control system error, and the fifth judgment result is obtained.

If the fifth determination result is yes, the preset control condition corresponding to the current state is the fifth preset control condition. The fifth judgment result is that |e(k)|<ε, ε is the preset accuracy of the excitation control system error, indicating that the error is already small, and an integral link can be added to the excitation controller to reduce the steady-state error.

Step 105: Control the output of the excitation controller by using a control strategy corresponding to the preset control condition corresponding to the current state.

Step 105 specifically includes:

When the preset control condition corresponding to the current state is the first preset control condition, the control strategy corresponding to the preset control condition corresponding to the current state is used to control the output of the excitation controller, which specifically includes: determining the output of the excitation controller as the preset control condition. set value, and open-loop control of the excitation control system. The control quantity output by the excitation controller is adjusted to the preset value, and the open-loop control of the excitation control system is carried out.

When the error value at the k-th sampling exceeds 80% of the maximum value of the error of the excitation control system, that is, exceeds L ₁ , the control quantity is given as the upper limit value S ₁ of the control quantity. This embodiment refines the value of L1 to 80%, 60%, 40%, 20% or ₁ % of the maximum error value. The upper limit value S ₁ of the control variable corresponds to L ₁ , that is, when the error value at the kth sampling is greater than 80%, 60%, 40%, 20% or 1% of the maximum value of the error of the excitation control system ( When L ₁ takes 80%, 60%, 40%, 20% or 1% of the maximum error value respectively), the upper limit value of the control quantity S ₁ corresponds to 100, 80, 40, 10 or 0.1 respectively, that is, the control quantity output The preset values of , respectively, are: 100, 80, 40, 10 or 0.1. When the error value of the kth sampling is greater than 80% of the maximum error value, S ₁ =100; when the error value of the kth sampling is greater than 60% of the maximum error value, S ₁ =80; the error value of the kth sampling When the error value is greater than 40% of the maximum error value, S ₁ =40; when the error value of the kth sampling is greater than 20% of the maximum error value, S ₁ =10; when the error value of the kth sampling is greater than 1% of the maximum error value S ₁ =0.1. This embodiment only refines the value of L ₁ to five values of 80%, 60%, 40%, 20% or 1% of the maximum error value, but the value of L ₁ is not limited to these five values , the value of L ₁ is adjusted according to actual needs, and the value of L ₁ can be refined into more than 5 values or less than 5 values.

When the preset control condition corresponding to the current state is the second preset control condition, the control strategy corresponding to the preset control condition corresponding to the current state is used to control the output of the excitation controller, specifically including:

It is judged whether the absolute value of the error value at the kth sampling is greater than or equal to the second preset error threshold, and a sixth judgment result is obtained.

If the sixth judgment result is yes, the output of the excitation controller is determined according to the formula u(k)=u(k-1)+K ₁ K _p e(k); wherein, u(k) represents the output of the excitation controller , u(k-1) represents the output of the excitation controller at the k-1th sampling, K ₁ represents the amplification factor of the excitation control system, K ₁ >1, K _p represents the proportional coefficient, e(k) represents the kth time Error value when sampling. The sixth judgment result is yes, indicating that the error is changing in the direction of increasing the absolute value of the error and the error is large, and the excitation controller needs to produce a strong control action to rapidly reduce the absolute value of the error.

If the sixth judgment result is no, the output of the excitation controller is determined according to the formula u(k)=u(k-1)+K ₂ K _p e(k); wherein, K ₂ represents the suppression coefficient of the excitation control system, K ₂ <1. The sixth judgment result is No, indicating that although the error changes in the direction of increasing the absolute value of the error, the error is not very large.

When the preset control condition corresponding to the current state is the third preset control condition, the control strategy corresponding to the preset control condition corresponding to the current state is used to control the output of the excitation controller, specifically including: maintaining the output of the excitation controller. The output of the excitation controller can remain unchanged, ie u(k)=u(k).

When the preset control condition corresponding to the current state is the fourth preset control condition, the control strategy corresponding to the preset control condition corresponding to the current state is used to control the output of the excitation controller, specifically including:

It is judged whether the absolute value of the error value at the kth sampling is greater than or equal to the second preset error threshold, and a seventh judgment result is obtained.

The seventh judgment result is yes, then the output of the excitation controller is determined according to the formula u(k)=u(k-1)+K ₁ K _p e(k-1); wherein, e(k-1) represents the first difference. The seventh judgment result is yes, indicating that the absolute value of the error is large at this time, and the excitation controller can implement a strong control action.

If the seventh judgment result is no, the output of the excitation controller is determined according to the formula u(k)=u(k-1)+K _{2 Kpe} (k-1). The seventh judgment result is No, indicating that the absolute value of the error is small, and the excitation controller can implement a weaker control action.

When the preset control condition corresponding to the current state is the fifth preset control condition, the control strategy corresponding to the preset control condition corresponding to the current state is used to control the output of the excitation controller, specifically including:

确定励磁控制器的输出；其中，K_i表示积分系数，j表示采样次数，e(j)表示第j次采样时的误差值，K_d表示微分系数，Δe(k)表示第一误差差值。According to the formula

Determine the output of the excitation controller; where, K _i represents the integral coefficient, j represents the sampling times, e(j) represents the error value at the jth sampling, K _d represents the differential coefficient, and Δe(k) represents the first error difference .

The excitation controller control method and system of the present invention can automatically determine different excitation control laws according to the working state and error conditions of the excitation control system, that is, preset control conditions, so that the control strategy is more flexible; and the parameters of the excitation controller are automatically adjusted so that the The adaptability of the excitation controller is stronger, which reflects the characteristics of intelligent control and makes the control effect of the excitation control system better.

This embodiment also provides an excitation controller control system, and FIG. 3 is a structural diagram of the excitation controller control system provided by the embodiment of the present invention. Referring to Figure 3, the excitation controller control system includes:

The mathematical model acquisition module 201 is used to acquire the mathematical model of the excitation control system. The mathematical model of the controlled object in the excitation control system is:

Among them, _G (s) represents the transfer function of the mathematical model of the controlled object in the excitation control system, KA is the voltage ratio of the amplification link, _TA is the time constant of the amplification link, s represents the variable in the complex domain, and _KG is the synchronous power generation is the amplification factor of the generator, and T _G is the time constant of the synchronous generator.

The parameter determination module 202 is used to determine the parameters of the control strategy of the excitation controller by using the PID control and the excitation control system mathematical model; the parameters include: proportional coefficient, integral coefficient, differential coefficient, integral time constant, differential time constant, sampling time, The upper limit value S ₁ of the control amount, the lower limit value S ₂ of the control amount, the first preset error threshold value L ₁ and the second preset error threshold value L ₂ .

The difference value determination module 203 is used to determine the difference between the error value at the k-th sampling of the excitation control system and the first error value at the k-1-th sampling as the first error difference, and the first error value The difference from the second error value at the k-2th sampling is determined as the second error difference; wherein k represents the number of sampling times.

The difference determination module 203 specifically includes:

The error value obtaining unit is used for obtaining the error value of the excitation control system at the kth sampling, the first error value at the k-1th sampling, and the second error value at the k-2th sampling.

The first error difference value determination unit is used to determine the difference between the error value at the k-th sampling and the first error value as the first error difference value, that is, Δe(k)=e(k)-e(k -1), Δe(k) represents the first error difference, e(k) represents the error value at the k-th sampling, and e(k-1) represents the first error value.

The second error difference value determining unit is configured to determine the difference between the first error value and the second error value as the second error difference value, that is, Δe(k-1)=e(k-1)-e(k -2), Δe(k-1) represents the second error difference value, and e(k-2) represents the second error value.

The preset control condition determination module 204 is used to determine the preset control condition corresponding to the current state of the excitation controller by using the error value, the first error difference value and the second error difference value during the kth sampling; the preset control conditions include : a first preset control condition, a second preset control condition, a third preset control condition, a fourth preset control condition, and a fifth preset control condition.

The preset control condition determination module 204 specifically includes:

The first judgment unit is used for judging whether the absolute value of the error value at the k-th sampling is greater than the first preset error threshold, and obtains a first judgment result.

The first preset control condition determination unit is configured to, when the first judgment result is yes, the preset control condition corresponding to the current state is the first preset control condition.

The second judgment unit is configured to judge whether the product of the error value at the kth sampling time and the first error difference value is greater than zero or whether the first error difference value is equal to zero when the first judgment result is no, and obtain the second judgment result .

或(2)

或(3)e(k)-e(k-1)＝0。对于(1)，表示第k次采样时的误差值为正，且在增大，第k次采样时的误差值的绝对值在增大；对于(2)，表示第k次采样时的误差值为负，且继续减小，第k次采样时的误差值的绝对值在增大；对于(3)表示误差未发生变化。The second preset control condition determination unit is configured to, when the second judgment result is yes, the preset control condition corresponding to the current state is the second preset control condition. The second judgment result is that e(k)Δe(k)>0 or Δe(k)=0, that is, (1)

or (2)

or (3) e(k)-e(k-1)=0. For (1), it means that the error value at the kth sampling is positive and increasing, and the absolute value of the error value at the kth sampling is increasing; for (2), it means the error at the kth sampling The value is negative and continues to decrease, and the absolute value of the error value at the kth sampling is increasing; for (3), it means that the error has not changed.

a third judging unit, configured to judge whether the product of the error value at the k-th sampling and the first error difference value is less than zero and the product of the first error difference value and the second error difference value when the second judgment result is no Whether it is greater than zero, or whether the error value at the kth sampling is equal to zero, a third judgment result is obtained.

The third preset control condition determination unit is configured to, when the third judgment result is yes, the preset control condition corresponding to the current state is the third preset control condition. The third judgment result is that e(k)△e(k)<0 and △e(k)△e(k-1)>0, or e(k)=0, that is (1)e(k- 2)<e(k-1)<e(k)<0 or (2)0<e(k)<e(k-1)<e(k-2) or (3)r(k)-y (k)=0, where (1) and (2) mean that the absolute value of the error is changing in a decreasing direction, and (3) means that the error has reached an equilibrium state.

The fourth judging unit is used for judging whether the product of the error value at the k-th sampling and the first error difference value is less than zero and the difference between the first error difference value and the second error difference value when the third judgment result is no Whether the product is less than zero, a fourth judgment result is obtained.

(1)和(2)均意味着误差处于极值状态。The fourth preset control condition determination unit is configured to, when the fourth determination result is yes, the preset control condition corresponding to the current state is the fourth preset control condition. The fourth judgment result is that e(k)△e(k)<0 and △e(k)△e(k-1)<0, that is (1)0<e(k)<e(k-1 )>e(k-2) or (2)

Both (1) and (2) imply that the error is in an extreme state.

The fifth judgment unit is configured to judge whether the absolute value of the error value at the k-th sampling is less than the preset accuracy of the excitation control system error when the fourth judgment result is no, and obtain the fifth judgment result.

The fifth preset control condition determination unit is configured to, when the fifth determination result is yes, the preset control condition corresponding to the current state is the fifth preset control condition. The fifth judgment result is that |e(k)|<ε, ε is the preset accuracy of the excitation control system error, indicating that the error is already small, and an integral link can be added to the excitation controller to reduce the steady-state error.

The control excitation controller output module 205 is used to control the output of the excitation controller by adopting the control strategy corresponding to the preset control condition corresponding to the current state.

The control excitation controller output module 205 specifically includes:

The open-loop control unit is configured to determine the output of the excitation controller as a preset value when the preset control condition corresponding to the current state is the first preset control condition, and perform open-loop control of the excitation control system.

The sixth judgment unit is used for judging whether the absolute value of the error value during the kth sampling is greater than or equal to the second preset error threshold when the preset control condition corresponding to the current state is the second preset control condition, and obtains the first Six judgment results.

The first output unit is used to determine the output of the excitation controller according to the formula u(k)=u(k-1)+K ₁ K _p e(k) when the sixth judgment result is yes; wherein, u(k ) represents the output of the excitation controller, u(k-1) represents the output of the excitation controller at the k-1th sampling, K ₁ represents the amplification factor of the excitation control system, K ₁ >1, K _p represents the proportional coefficient, e (k) represents the error value at the k-th sampling. The sixth judgment result is yes, indicating that the error is changing in the direction of increasing the absolute value of the error and the error is large, and the excitation controller needs to produce a strong control action to rapidly reduce the absolute value of the error.

The second output unit is configured to determine the output of the excitation controller according to the formula u(k)=u(k-1)+K ₂ K _p e(k) when the sixth judgment result is no; wherein, K ₂ represents Suppression coefficient of excitation control system, K ₂ <1. The sixth judgment result is No, indicating that although the error changes in the direction of increasing the absolute value of the error, the error is not very large.

The holding output unit is used for holding the output of the excitation controller when the preset control condition corresponding to the current state is the third preset control condition. The output of the excitation controller can remain unchanged, ie u(k)=u(k).

The seventh judgment unit is used for judging whether the absolute value of the error value during the kth sampling is greater than or equal to the second preset error threshold when the preset control condition corresponding to the current state is the fourth preset control condition, and obtains the first Seven judgment results.

The third output unit is configured to determine the output of the excitation controller according to the formula u(k)=u(k-1)+K ₁ K _p e(k-1) when the seventh judgment result is yes; wherein, e (k-1) represents the first error value. The seventh judgment result is yes, indicating that the absolute value of the error is large at this time, and the excitation controller can implement a strong control action.

The fourth output unit is configured to determine the output of the excitation controller according to the formula u(k)=u(k-1)+K _{2 Kpe} (k-1) when the seventh judgment result is negative. The seventh judgment result is No, indicating that the absolute value of the error is small, and the excitation controller can implement a weaker control action.

确定励磁控制器的输出；其中，K_i表示积分系数，j表示采样次数，e(j)表示第j次采样时的误差值，K_d表示微分系数，Δe(k)表示第一误差差值。The fifth output unit is used for, when the preset control condition corresponding to the current state is the fifth preset control condition, according to the formula

Determine the output of the excitation controller; where, K _i represents the integral coefficient, j represents the sampling times, e(j) represents the error value at the jth sampling, K _d represents the differential coefficient, and Δe(k) represents the first error difference .

The present embodiment also provides a control method for the generator excitation controller based on the expert PID, and the control method for the generator excitation controller includes:

1. Establishment of the mathematical model of the excitation control system

The excitation control system of this embodiment is a synchronous generator excitation control system. Before determining the control method of the excitation controller, it is necessary to analyze the composition of each link of the synchronous generator excitation control system to obtain the transfer function of the synchronous generator excitation control system. Thereby, the mathematical model of the excitation control system of the synchronous generator is established.

The excitation control system includes: excitation controller, power amplification unit, synchronous generator and voltage measurement unit. The output end of the excitation controller is connected with the input end of the power amplifying unit, the output end of the power amplifying unit is connected with the input end of the synchronous generator, the input end of the voltage measuring unit is connected with the output end of the synchronous generator, and the The output terminal is connected with the input terminal of the excitation controller.

1.1 The transfer function of the power amplifier unit is:

1.2 The transfer function of the synchronous generator is:

1.3 The transfer function of the voltage measurement unit is:

The mathematical model of the controlled object in the excitation control system of the synchronous generator is:

In the above formula, G ₁ (s) represents the transfer function of the power amplifying unit, s represents a variable in the complex domain, K _A is the voltage ratio of the amplifying link, T _A is the time constant of the amplifying link, and G ₂ (s) represents the synchronous power generation. is the transfer function of the generator, K _G is the generator amplification factor, T _G is the generator time constant, G ₃ (s) represents the transfer function of the voltage measurement unit, K ₃ is the voltage proportional coefficient, T ₃ is the measurement loop time constant, G (s) represents the transfer function of the mathematical model of the controlled object in the excitation control system.

2. Control method of generator excitation controller based on expert PID

Before determining the control method of the generator excitation controller based on the expert PID, the excitation control system should be controlled by the conventional PID controller, and the relevant parameters of the conventional PID control should be obtained, so as to provide the control method for determining the expert PID controller. Relevant basis and basis.

Step 1: Obtain relevant parameters through conventional PID control, the relevant parameters include: proportional coefficient K _p , integral coefficient K _i , differential coefficient K _d , integral time constant T _i , differential time constant T _d , sampling time T , the upper limit of the control variable The limit value S ₁ , the lower limit value S ₂ of the control amount, the first preset error threshold value L ₁ and the second preset error threshold value L ₂ .

其中

u’(k)表示采用PID控制方法时励磁控制器的输出；K_p为比例系数；e(k)表示第k次采样时的误差值；K_i为积分系数；j和k均代表采样次数，j代表第j次采样，k代表第k次采样，且0≤j≤k；e(j)表示第j次采样时励磁控制系统的误差值；K_d为微分系数；Δe(k)表示励磁控制系统第k次采样时的误差值与第k-1次采样时的误差值的误差差值；T为采样时间；T_i为积分时间常数；T_d为微分时间常数。According to the PID control algorithm of the conventional PID controller, namely

in

u'(k) represents the output of the excitation controller when the PID control method is used; K _p is the proportional coefficient; e(k) represents the error value at the kth sampling time; K _i is the integral coefficient; j and k both represent the sampling times , j represents the jth sampling, k represents the kth sampling, and 0≤j≤k; e(j) represents the error value of the excitation control system at the jth sampling; K _d is the differential coefficient; Δe(k) represents The error difference between the error value at the kth sampling of the excitation control system and the error value at the k-1th sampling; T is the sampling time; T _i is the integral time constant; T _d is the differential time constant.

After the excitation control system is added to the PID controller, a step signal is applied to the input end of the excitation control system, and the change curve of the control variable is obtained through the response of the excitation control system, and then the upper limit of the control variable is determined through the change curve of the control variable. S ₁ and the lower limit S ₂ to realize the saturation treatment of the control variable; that is, the variation range and the corresponding duration of the control variable must be observed according to the change curve of the control variable, and the response curve of the system must be observed in combination with the simulation experiment. The upper limit and lower limit of the control amount, if you don't go through this process, there is no way to know the upper limit and lower limit of the control amount.

After the excitation control system is added to the PID controller, a step signal is applied to the input end of the excitation control system, and the change curve of the error is obtained through the response of the excitation control system, and then the _first preset error threshold L1 and the second preset error threshold L1 and the second preset value are determined. Error threshold L ₂ . The error is the error e(k) of the excitation control system, which is the deviation between the system input r(k) of the excitation control system and the system output y(k), that is, e(k)=r(k)-y(k ). The corresponding error range can be determined by using the change curve of the error. In this embodiment, the maximum error value is 1, L ₁ is taken as 80% of the maximum error value, that is, 0.8; L ₂ is taken as 5% of the maximum error value, That is, 0.05; L ₁ is a large error threshold, that is, when the error is greater than L ₁ , it is considered that the error is large; L ₂ is a large error threshold, that is, when the error is greater than L ₂ , it is considered that the error is large. The output response curve of the excitation control system, the change curve of the control quantity and the change curve of the error can all be observed through the oscilloscope.

Step 2: Determine the expert PID control conditions. Let e(k) represent the discretized error value at the k-th sampling, e(k-1) represent the error value (ie, the first error value) at the k-1-th sampling, and e(k-2) represent The error value (ie the second error value) at the k-2th sampling time is: △e(k)=e(k)-e(k-1), △e(k-1)=e(k -1)-e(k-2), Δe(k-1) represents the second error difference value, and e(k-2) represents the second error value.

Condition 1: If |e(k)|>L ₁ , it means that the error of the excitation control system is very large, and a larger control amount needs to be applied. Combined with the change curve of the error in step 1 and the degree of the error size, the control amount is equal to A fixed value output that implements open-loop control of the excitation control system. In this embodiment, when the error is greater than 80%, 60%, 40%, 20% or 1% of its maximum value, the control variable output is set to 100, 80, 40, 10 or 0.1, respectively. The system implements open loop control. When the error exceeds 80% of the maximum error value, the control amount is given as the upper limit value S ₁ of the control amount. L ₁ can be further subdivided into multiple points to implement open-loop control, that is, L ₁ is subdivided into multiple points. For example, in this embodiment, L ₁ is subdivided into 5 points, which are the maximum error values. 80%, 60%, 40%, 20% or 1%, that is, when the error is greater than 80%, 60%, 40%, 20% or 1% of its maximum value, the control amount corresponds to the fixed value of the output (control The upper limit value S ₁ ) of the quantity is: 100, 80, 40, 10 or 0.1, in order to achieve the effect of rapidly reducing the error of the excitation control system. According to the actual control needs, if L ₁ is refined into multiple points, the control effect of the excitation controller will be better. If the requirements for the control effect are not very high, it is not necessary to refine it into multiple points or reduce the number of refined points. .

或(2)

或(3)e(k)-e(k-1)＝0。对于(1)，表示第k次采样时的误差为正，且在增大，误差的绝对值在增大；对于(2)，表示第k次采样时的误差为负，且继续减小，误差的绝对值在增大；对于(3)表示误差未发生变化。Condition 2: If e(k)△e(k)>0 or △e(k)=0, that is (1)

or (2)

or (3) e(k)-e(k-1)=0. For (1), it means that the error at the kth sampling is positive and increasing, and the absolute value of the error is increasing; for (2), it means that the error at the kth sampling is negative and continues to decrease, The absolute value of the error is increasing; for (3) it means that the error has not changed.

Furthermore, if |e(k)|≥L ₂ , it means that the error is changing in the direction of increasing the absolute value of the error and the error is large, and the excitation controller needs to have a strong control effect to rapidly reduce the absolute value of the error, The output of the excitation controller is: u(k)=u(k-1)+K ₁ K _p e(k); K ₁ >1, which is an amplification factor.

If |e(k)|<L ₂ , it means that although the error changes in the direction of increasing the absolute value of the error, the error is not very large, and the output of the excitation controller is: u(k)=u(k-1) +K ₂ K _p e(k); K ₂ <1, is the suppression coefficient.

Condition 3: If e(k)△e(k)<0 and △e(k)△e(k-1)>0, or when e(k)=0, that is (1)e(k-2 )<e(k-1)<e(k)<0 or (2)0<e(k)<e(k-1)<e(k-2) or (3)r(k)-y( k)=0, where (1) and (2) mean that the absolute value of the error is changing in a decreasing direction, and (3) means that the error has reached an equilibrium state. At this time, the output of the excitation controller can remain unchanged, that is, u(k)=u(k).

(1)和(2)均意味着误差处于极值状态。Condition 4: If e(k)△e(k)<0 and △e(k)△e(k-1)<0, that is (1)0<e(k)<e(k-1)> e(k-2) or (2)

Both (1) and (2) imply that the error is in an extreme state.

Furthermore, if |e(k)|≥L ₂ , it means that the absolute value of the error is large at this time, and the excitation controller can implement a strong control effect. The output of the excitation controller is: u(k)=u(k-1 )+K ₁ K _p e(k-1).

Furthermore, if |e(k)|<L ₂ , it means that the absolute value of the error is small, the excitation controller can implement a weaker control effect, and the output of the excitation controller is: u(k)=u(k-1)+ K ₂ K _p e(k-1).

Condition 5: When |e(k)|<ε, ε is the preset accuracy of the excitation control system error, indicating that the error is already small, and an integral link can be added to the excitation controller to reduce the steady-state error. At this time, the output of the excitation controller after adding the integral link is:

In order to easily reflect the control effect of the control method of the generator excitation controller of the present invention, three control methods, namely the simple negative feedback closed-loop control method, the conventional PID control method and the generator excitation controller control method of the present invention are respectively implemented for the excitation control system. The output response curve, error change curve and control variable change curve of the synchronous generator excitation control system corresponding to the control method are shown in Figure 4, Figure 5 and Figure 6, respectively. The horizontal axis of Figure 4, Figure 5 and Figure 6 is the excitation control The response time of the system, unit: second (s); in Figure 4, the system input represents the system input r of the excitation control system, the conventional PID control represents the system output y of the excitation control system implementing the conventional PID control method, and the expert PID control represents the implementation of this The system output y of the excitation control system of the invention generator excitation controller control method, the simple negative feedback closed-loop control represents the system output y of the excitation control system implementing the simple negative feedback closed-loop control method. It can be seen from Figure 5 and Figure 6 that the two parameters of error and control amount change under the three control methods; it can be clearly seen from Figure 4 that when the excitation control system adopts the generator excitation controller control method of the present invention The dynamic performance indicators such as overshoot and adjustment time of the excitation control system are obviously better than those of the other two control methods, and the output responses of the three control methods are compared with the system input respectively. It can be seen that the control method of the generator excitation controller of the present invention is Compared with the other two control methods, the output is closer to the system input, so the control effect of the excitation control system is better.

This embodiment also provides a specific application example of the excitation controller control method: taking a synchronous generator excitation control system as an example, the control method of the generator excitation controller is determined.

The mathematical model of the excitation control system is established: the specific parameters of the excitation control system of the synchronous generator are shown in Table 1:

Table 1 Specific parameters of synchronous generator excitation control system

The corresponding mathematical model of the controlled object can be obtained as:

Among them, G(s) represents the transfer function of the mathematical model of the controlled object in the excitation control system of the synchronous generator, and s represents the variable in the complex domain.

Control method of generator excitation controller: obtain relevant parameters through conventional PID control.

The conventional PID controller is used for the above-mentioned synchronous generator excitation control system. After the relevant parameters are adjusted, when the conventional PID control can be obtained, the corresponding K _p , K _i , K _d , T _i , T _d and T are 60, 40 respectively. , 25, 0.0015 seconds, 0.00042 seconds, and 0.001 seconds. Through the step response of the excitation control system of the synchronous generator, the change curve of the control variable is obtained, and the upper limit value S ₁ =100 and the lower limit value S ₂ =-100 of the control variable are determined. Through the response of the excitation control system of the synchronous generator, the change curve of the error is obtained, and then the first preset error threshold L ₁ and the second preset error threshold L ₂ are determined. In this application example, L ₁ is subdivided into 5 The points are 0.8, 0.6, 0.4, 0.2 and 0.01 respectively, the maximum value is 0.8, and the minimum value is 0.01, which are specifically expressed as L ₁₀ =0.8, L ₁₁ =0.6, L ₁₂ =0.4, L ₁₃ =0.2 and L ₁₄ = 0.01, L ₂ =0.05.

Condition 1: When |e(k)|>L ₁₀ =0.8, u(k)=S ₁ =100. When |e(k)|>L ₁₁ =0.6, u(k)=80. When |e(k)|>L ₁₂ =0.4, u(k)=40. When |e(k)|>L ₁₃ =0.2, u(k)=10. When |e(k)|>L ₁₄ =0.01, u(k)=0.1. In this condition 1, the control variables output by the excitation controller are output in different fixed value ways according to the specific value of L ₁ , and open-loop control is implemented for the excitation control system of the synchronous generator to reduce the error quickly.

Condition 2: When e(k)△e(k)>0 or △e(k)=0,

If |e(k)|≥0.05, the output of the controller is: u(k)=u(k-1)+1.5×60e(k), K ₁ =1.5;

If |e(k)|<0.05, the output of the controller is: u(k)=u(k-1)+0.4×60e(k), K ₂ =0.4.

Condition 3: When e(k)△e(k)<0 and △e(k)△e(k-1)>0, or when e(k)=0, the output of the excitation controller can be It remains the same, ie u(k)=u(k).

Condition 4: When e(k)△e(k)<0 and △e(k)△e(k-1)<0,

If |e(k)|≥0.05, it means that the absolute value of the error is large at this time, and the excitation controller can implement a strong control effect, u(k)=u(k-1)+1.5×60e(k-1 );

If |e(k)|<0.05, it means that the absolute value of the error is small, and the excitation controller can implement a weaker control effect, u(k)=u(k-1)+0.4×60e(k-1).

Condition 5: When |e(k)|<ε=0.001, the output of the excitation controller is:

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method.

In this paper, specific examples are used to illustrate the principles and implementations of the present invention. The descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention; meanwhile, for those skilled in the art, according to the present invention There will be changes in the specific implementation and application scope. In conclusion, the contents of this specification should not be construed as limiting the present invention.

Claims (8)

1. an excitation controller control method, is characterized in that, comprises: Obtain the mathematical model of the excitation control system; Use PID control and the mathematical model of the excitation control system to determine the parameters of the control strategy of the excitation controller; the parameters include: proportional coefficient, integral coefficient and differential coefficient; Determine the difference between the error value at the k-th sampling of the excitation control system and the first error value at the k-1-th sampling as the first error difference, and compare the first error value with the k-2-th sampling The difference between the second error values during sampling is determined as the second error difference; wherein k represents the number of sampling times; A preset control condition corresponding to the current state of the excitation controller is determined by using the error value at the k-th sampling, the first error difference value and the second error difference value; the preset control conditions include : the first preset control condition, the second preset control condition, the third preset control condition, the fourth preset control condition and the fifth preset control condition; Control the output of the excitation controller by using the control strategy corresponding to the preset control condition corresponding to the current state; The determining the preset control condition corresponding to the current state of the excitation controller by using the error value at the k-th sampling, the first error difference value and the second error difference value specifically includes: judging whether the absolute value of the error value during the k-th sampling is greater than a first preset error threshold, to obtain a first judgment result; If the first judgment result is yes, the preset control condition corresponding to the current state is the first preset control condition; If the first judgment result is no, then judge whether the product of the error value at the kth sampling time and the first error difference value is greater than zero or whether the first error difference value is equal to zero, and obtain a second judgment result; If the second judgment result is yes, the preset control condition corresponding to the current state is the second preset control condition; If the second judgment result is no, judge whether the product of the error value at the kth sampling time and the first error difference value is less than zero and the first error difference value and the second error difference Whether the product of the values is greater than zero, or whether the error value during the kth sampling is equal to zero, a third judgment result is obtained; If the third judgment result is yes, the preset control condition corresponding to the current state is the third preset control condition; If the third judgment result is no, then judge whether the product of the error value at the kth sampling time and the first error difference value is less than zero and the first error difference value and the second error difference Whether the product of the values is less than zero, the fourth judgment result is obtained; If the fourth judgment result is yes, the preset control condition corresponding to the current state is the fourth preset control condition; If the fourth judgment result is no, then judge whether the absolute value of the error value at the k-th sampling is less than the preset accuracy of the excitation control system error, and obtain a fifth judgment result; If the fifth determination result is yes, the preset control condition corresponding to the current state is the fifth preset control condition. 2 . The excitation controller control method according to claim 1 , wherein when the preset control condition corresponding to the current state is the first preset control condition, the preset control condition corresponding to the current state is used. 3 . The corresponding control strategy controls the output of the excitation controller, specifically including: The output of the excitation controller is determined as a preset value, and the excitation control system is open-loop controlled. 3 . The excitation controller control method according to claim 1 , wherein when the preset control condition corresponding to the current state is the second preset control condition, the preset control condition corresponding to the current state is used. 4 . The corresponding control strategy controls the output of the excitation controller, specifically including: Judging whether the absolute value of the error value during the k-th sampling is greater than or equal to the second preset error threshold, and obtains a sixth judgment result; If the sixth judgment result is yes, the output of the excitation controller is determined according to the formula u(k)=u(k-1)+K ₁ K _p e(k); The output of the excitation controller, u(k-1) represents the output of the excitation controller at the k-1th sampling, K ₁ represents the amplification factor of the excitation control system, K _p represents the proportional coefficient, e (k) represents the error value during the k-th sampling; If the sixth judgment result is no, the output of the excitation controller is determined according to the formula u(k)=u(k-1)+K ₂ K _p e(k); wherein, K ₂ represents the excitation The suppression coefficient of the control system. 4 . The control method of the excitation controller according to claim 1 , wherein when the preset control condition corresponding to the current state is a third preset control condition, the preset control condition corresponding to the current state is used. 5 . The corresponding control strategy controls the output of the excitation controller, which specifically includes: Hold the output of the excitation controller. 5 . The control method of the excitation controller according to claim 3 , wherein when the preset control condition corresponding to the current state is the fourth preset control condition, the preset control condition corresponding to the current state is used. 6 . The corresponding control strategy controls the output of the excitation controller, specifically including: judging whether the absolute value of the error value during the k-th sampling is greater than or equal to the second preset error threshold, to obtain a seventh judgment result; If the seventh judgment result is yes, the output of the excitation controller is determined according to the formula u(k)=u(k-1)+K ₁ K _p e(k-1); wherein u(k) represents the output of the excitation controller, u(k-1) represents the output of the excitation controller at the k-1th sampling, K ₁ represents the amplification factor of the excitation control system, and K _p represents the proportional coefficient , e(k-1) represents the first error value; If the seventh judgment result is no, the output of the excitation controller is determined according to the formula u(k)=u(k-1)+K ₂ K _p e(k-1); wherein, K ₂ represents the The suppression coefficient of the excitation control system is described. 6 . The control method of the excitation controller according to claim 1 , wherein when the preset control condition corresponding to the current state is the fifth preset control condition, the preset control condition corresponding to the current state is used. 7 . The corresponding control strategy controls the output of the excitation controller, specifically including: According to the formula

Determine the output of the excitation controller; wherein, u(k) represents the output of the excitation controller, K _p represents the proportional coefficient, e(k) represents the error value at the kth sampling, K _i represents the integral coefficient, j represents the number of sampling times, e(j) represents the error value at the jth sampling, K _d represents the differential coefficient, and Δe(k) represents the first error difference. 7. An excitation controller control system, characterized in that, comprising: The mathematical model acquisition module is used to acquire the mathematical model of the excitation control system; a parameter determination module, used for using PID control and the mathematical model of the excitation control system to determine the parameters of the control strategy of the excitation controller; the parameters include: proportional coefficient, integral coefficient and differential coefficient; A difference determination module, configured to determine the difference between the error value at the k-th sampling of the excitation control system and the first error value at the k-1-th sampling as the first error difference, and the first error The difference between the value and the second error value in the k-2th sampling is determined as the second error difference; wherein k represents the number of sampling times; A preset control condition determination module, configured to determine the preset control corresponding to the current state of the excitation controller by using the error value at the kth sampling, the first error difference value and the second error difference value conditions; the preset control conditions include: a first preset control condition, a second preset control condition, a third preset control condition, a fourth preset control condition, and a fifth preset control condition; Controlling the excitation controller output module, which is used for controlling the output of the excitation controller by adopting the control strategy corresponding to the preset control condition corresponding to the current state; The preset control condition determination module specifically includes: a first judgment unit, configured to judge whether the absolute value of the error value during the k-th sampling is greater than a first preset error threshold, and obtain a first judgment result; a first preset control condition determination unit, configured to, when the first judgment result is yes, the preset control condition corresponding to the current state is the first preset control condition; a second judging unit, configured to judge whether the product of the error value at the k-th sampling time and the first error difference value is greater than zero or the first error difference value when the first judgment result is no Whether it is equal to zero, the second judgment result is obtained; a second preset control condition determining unit, configured to, when the second judgment result is yes, the preset control condition corresponding to the current state is the second preset control condition; a third judging unit, configured to judge whether the product of the error value at the k-th sampling time and the first error difference value is less than zero and the first error difference value when the second judgment result is no Whether the product of the second error difference value is greater than zero, or whether the error value during the kth sampling is equal to zero, to obtain a third judgment result; a third preset control condition determining unit, configured to, when the third judgment result is yes, the preset control condition corresponding to the current state is the third preset control condition; a fourth judging unit, configured to judge whether the product of the error value at the k-th sampling time and the first error difference value is less than zero and the first error difference value when the third judgment result is no Whether the product of the second error difference is less than zero, a fourth judgment result is obtained; a fourth preset control condition determining unit, configured to, when the fourth judgment result is yes, the preset control condition corresponding to the current state is the fourth preset control condition; a fifth judgment unit, configured to judge whether the absolute value of the error value at the k-th sampling is less than the preset accuracy of the excitation control system error when the fourth judgment result is no, and obtain a fifth judgment result; A fifth preset control condition determination unit, configured to, when the fifth determination result is yes, the preset control condition corresponding to the current state is the fifth preset control condition. 8. The excitation controller control system according to claim 7, wherein the controlling the excitation controller output module specifically comprises: The open-loop control unit is configured to determine the output of the excitation controller as a preset value when the preset control condition corresponding to the current state is the first preset control condition, and perform a control operation on the excitation control system. Open loop control.

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