CN105676692B - Generating unit excitation intelligence control system - Google Patents

Abstract

The present invention relates to an intelligent control system for generator set excitation. The system includes a voltage detection unit, a data processing unit, a PID calculation unit, a power amplification unit, and an intelligent command table. The intelligent command table is used to determine the PID parameters of the PID calculation unit. There are multiple groups of instructions stored in the smart instruction table, and each group of instructions is composed of a preset voltage deviation, a preset voltage deviation change rate and its corresponding PID parameters; an intelligent control unit is used to receive the voltage deviation e and the voltage deviation change rate ec information, and judge whether the difference rate between the voltage deviation amount e and the voltage deviation change rate ec and the preset voltage deviation amount and the preset voltage deviation change rate in the intelligent instruction table are lower than the preset difference rate, if so, Then input the PID parameter in the command into the PID calculation unit, if not, select the command with the lowest sum of the above two difference rates, and input the PID parameter in the command into the PID calculation unit. The system has a better excitation control effect.

Description

Generator set excitation intelligent control system

technical field

The invention relates to an excitation intelligent control system of a generator set, in particular to an excitation intelligent control system of a diesel generator set, a gasoline generator set, etc.

Background technique

The construction of a strong and smart grid is inseparable from "strong" and "smart", which are two basic development requirements of a modern power grid. "Strength" is the foundation, and "intelligence" is the tool. A strong smart grid is to achieve efficient and intelligent power supply on the basis of safe and stable operation. Automation is an intuitive reflection of the development level of the smart grid. Relying on efficient information, collection and transmission, and integrated system control applications, the level of automatic operation control and management of the grid can be improved.

With the rapid development of the electric power industry and the continuous expansion of the scale of the power system, the requirements for the reliability, safety and economy of the power generation system are getting higher and higher. The excitation control system is an important control component in the power generation system, and plays a vital role in the normal operation or accident of the power system. The control task of the excitation system of a synchronous generator extends from maintaining a constant terminal voltage and distributing the reactive output of the unit to improving the dynamic and static stability of the power system. The excitation control system with excellent performance can not only ensure the reliable and stable operation of the generator, but also effectively Improve the technical indicators of the system and deliver high-quality electric energy to the grid. Among many measures to improve the stable operation of synchronous generators, using modern intelligent control theory to improve the control performance of the excitation system is recognized as one of the economical and effective means. Therefore, its performance directly affects the synchronous generating set and even the whole power system.

In order to improve the control quality of synchronous generator sets, many scholars at home and abroad have proposed the optimal control of excitation, variable structure control and so on.

Control, nonlinear control using differential geometric control theory. The above-mentioned control methods are all based on the traditional mathematical control theory, and their control effects have a great relationship with the accuracy of the controlled object mathematical model. The power system is essentially a large nonlinear system, and it is difficult to obtain an accurate mathematical model.

Contents of the invention

In order to solve the above-mentioned technical problems, the present invention provides an intelligent excitation control system for a generator set on the one hand, the intelligent excitation control system is used to control the current of the excitation coil of the generator, and the system includes:

A voltage detection unit for real-time detection of generator stator terminal voltage;

The data processing unit is used to process the stator terminal voltage of the generator, and calculate the voltage deviation e and the voltage deviation change rate ec according to the preset voltage;

A PID calculation unit, the PID calculation unit adopts an incremental PID control algorithm, and outputs a control signal according to the voltage deviation and the PID parameters input by the intelligent control unit;

A power amplifying unit, the power amplifying unit is used to amplify the control signal so as to control the current of the excitation coil of the generator;

An intelligent instruction table, the intelligent instruction table is used to determine the PID parameters of the PID calculation unit, and there are many sets of instructions stored in the intelligent instruction table, each set of instructions consists of a preset voltage deviation, a preset voltage deviation change rate and its corresponding Composition of PID parameters;

The intelligent control unit is used to receive the information of the voltage deviation e and the voltage deviation change rate ec, and determine the relationship between the voltage deviation e, the voltage deviation change rate ec and the preset voltage deviation and the preset voltage deviation change rate in the intelligent command table Whether the difference rate is lower than the preset difference rate, if so, input the PID parameter in the command into the PID calculation unit, if not, select the command with the lowest sum of the above two difference rates, and input the PID parameter in the command Enter the PID calculation unit.

The preset difference rate is 1%-30%.

The multiple sets of PID parameters are obtained through different tuning methods, and the tuning methods are ZN empirical method, ZN critical proportionality method, ISTE optimal tuning method, characteristic area method, relay self-tuning method, cohen-coon method , GPM method, SPMA method, least square method model identification method, weighted error square integral index method, maximum tangent method, approximate calculation method.

The multiple groups of PID parameter acquisition steps include:

Tuning to obtain the array PID parameters;

Select m groups of closest PID parameters K _P , K _I , K _D;

Take n K _{P values at equal intervals between the maximum value and the minimum value among the m K P values} ;

Take n K _{I values at equal intervals between the maximum value and the minimum value among the m K I values} ;

Take n K _{D values at equal intervals between the maximum value and the minimum value among the m K D values} ;

Recombine the above n values of KP, KI, and KD to obtain n sets of PID parameters.

The multiple groups of PID parameter acquisition steps include:

Tuning to obtain the array PID parameters;

Select m groups of closest PID parameters K _P , K _I , K _D ;

Take n K _{P values at equal intervals between the maximum value and the minimum value among the m K P values} ;

Use m coordinates (K _P , KI ) to fit a polynomial function of degree m- ₁ , and use this polynomial function and n K _P values to obtain n K _I ;

Use m coordinates (K _P , K _D ) to get m-1 degree polynomial function, and use this polynomial function and n K _P values to get n K _D ;

Recombine the above n values of KP, KI, and KD to obtain n sets of PID parameters.

The excitation intelligent control system also includes an intelligent instruction table generation unit, the intelligent instruction table generation unit includes a recording module and an analysis storage module, and the recording module is used to receive the voltage deviation e and the voltage deviation change rate ec of the data processing unit The PID parameter corresponding to the output of the intelligent control unit, the analysis storage module is used to analyze the control effect value of the PID parameter corresponding to the output of the intelligent control unit within a preset period, if the control effect value reaches the preset value, then the The array PID parameters and the corresponding voltage deviation e and voltage deviation change rate ec in the preset period are stored in the intelligent command table, and the array tuning PID parameters are regarded as a PID control group. If the control effect value does not reach the preset value , there is no storage action.

The preset value is represented by one or more of delay time T _D , rise time T _r , adjustment time T _s , and overshoot σ.

The excitation intelligent control method also includes an intelligent instruction table finishing module:

Described intelligent command list finishing module, is used for judging whether the PID control parameter that does not form a group and the PID parameter of the PID control group in the intelligent command list are identical, if so, then deletes the PID control parameter that does not form a group in the intelligent command list, If not, keep the ungrouped PID control parameters in the smart instruction table.

Generator set excitation intelligent control method, the excitation intelligent control method is used to control the current of the generator excitation coil, the method includes the following steps:

a. Real-time detection of generator stator terminal voltage;

b. Process the stator terminal voltage of the generator, and calculate the voltage deviation e and the voltage deviation change rate ec according to the preset voltage;

c. Receive the information of the voltage deviation e and the voltage deviation change rate ec, and judge whether the difference rate between the voltage deviation e, the voltage deviation change rate ec and the preset voltage deviation amount and the preset voltage deviation change rate in the intelligent command table are lower than the preset difference rate, if yes, the PID parameter in the command is the set PID parameter, if not, choose the command with the lowest sum of the above two difference rates, then the PID parameter in the command is the set PID parameter Parameters, the intelligent instruction table is used to determine the PID parameters of the PID calculation unit, there are multiple sets of instructions stored in the intelligent instruction table, each set of instructions consists of a preset voltage deviation and a preset voltage deviation change rate and its corresponding PID parameter composition;

d. Adopt incremental PID control algorithm, output control signal according to voltage deviation e and setting PID parameters;

e. The control signal is amplified to control the current of the excitation coil of the generator.

The multiple groups of PID parameter acquisition steps include:

Tuning to obtain the array PID parameters;

Select m groups of closest PID parameters K _P , K _I , K _D;

Take n K _{P values at equal intervals between the maximum value and the minimum value among the m K P values} ;

Take n K _{I values at equal intervals between the maximum value and the minimum value among the m K I values} ;

Take n K _{D values at equal intervals between the maximum value and the minimum value among the m K D values} ;

Recombine the above n values of KP, KI, and KD to obtain n sets of PID parameters.

The multiple groups of PID parameter acquisition steps include:

Tuning to obtain the array PID parameters;

Select m groups of closest PID parameters K _P , K _I , K _D ;

Take n K _{P values at equal intervals between the maximum value and the minimum value among the m K P values} ;

Use m coordinates (K _P , KI ) to fit a polynomial function of degree m- ₁ , and use this polynomial function and n K _P values to obtain n K _I ;

Use m coordinates (K _P , K _D ) to get m-1 degree polynomial function, and use this polynomial function and n K _P values to get n K _D ;

Recombine the above n values of KP, KI, and KD to obtain n sets of PID parameters.

The excitation intelligent control method also includes an intelligent instruction table generation step:

Receive the voltage deviation e and the voltage deviation change rate ec of the data processing unit and set the PID parameters,

Analyze the control effect value of several tuning PID parameters within a preset period, if the control effect value reaches the preset value, set the PID parameters of the array within the preset period and the corresponding voltage deviation e and voltage deviation change The rate ec is stored in the intelligent command table, and the PID parameters set by the array are regarded as a PID control group. If the control effect value does not reach the preset value, there will be no storage action.

The excitation intelligent control method also includes the step of organizing the intelligent instruction table:

Determine whether the ungrouped PID control parameters are exactly the same as the PID parameters of the PID control group in the smart command table, if so, delete the ungrouped PID control parameters in the smart command table, if not, keep them in the smart command table The ungrouped PID control parameters.

The preset value is represented by one or more of delay time T _D , rise time T _r , adjustment time T _s , and overshoot σ.

The present invention can realize the setting of PID parameters faster through the preset intelligent instruction table. The PID parameters of the environment enable the set PID parameters to more effectively realize the excitation control, and achieve higher efficiency while realizing intelligence.

These and other features, aspects and advantages of the present application will be better understood with reference to the following detailed description.

Description of drawings

Figure 1 shows a typical excitation system.

Fig. 2 is a schematic structural block diagram of the excitation intelligent control system of the present invention.

Fig. 3 is a schematic block diagram of the intelligent update structure of the intelligent instruction table of the present invention.

Fig. 4 is a schematic diagram of a calculation method for delay time T _D , rise time T _r , adjustment time T _s , and overshoot σ.

Voltage detection unit 1

PID calculation unit 2

Power amplifier unit 3

Smart Command Table 4

Intelligent instruction table generation unit 5

Recording Module 51

Analysis storage module 52

Smart instruction list sorting module 6

Data Processing Unit 7

Intelligent control unit8.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the following will clearly and completely describe the technical solutions of the embodiments of the present invention in conjunction with the drawings of the embodiments of the present invention. Apparently, the described embodiments are some, not all, embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative effort fall within the protection scope of the present invention.

Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by those skilled in the art to which the present invention belongs. "First", "second" and similar words used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Likewise, words like "a" or "one" do not denote a limitation in quantity, but indicate that there is at least one.

One of the typical excitation systems of the present invention mainly includes a voltage detection unit for real-time detection of the generator stator terminal voltage; a data processing unit for processing the generator stator terminal voltage, and calculates the voltage deviation e and Voltage deviation change rate ec; PID calculation unit, the PID calculation unit adopts incremental PID control algorithm, output control signal according to the PID parameters input by voltage deviation and intelligent control unit; power amplification unit, the power amplification unit is used to The control signal is amplified to control the current of the excitation coil of the generator, thereby forming a control loop.

In addition, one of the main components of a typical excitation system of the present invention includes: an exciter, a voltage regulator, and a power unit. A typical excitation system structure is shown in Figure 1:

The generator terminal voltage U _t can be compared with the given reference voltage U _ref after the measurement link, and its deviation e. After entering the voltage regulator for amplification, the output voltage _UR is used as the excitation voltage of the exciter to control the output voltage Ef of the exciter. In order to stabilize the operation of the excitation system and improve its dynamic quality, a negative feedback link of the excitation system and an excitation system stabilizer are introduced. , generally a soft feedback link, also known as speed feedback. U _s is the excitation additional control signal, here is the output control signal of the power system stabilizer PSS.

The measurement link is expressed as an inertial link with a time constant of T _R , and the value of T _R is usually very small, so it is often ignored. A voltage regulator can usually be represented by a lead-lag link connected in series with an inertial amplifier link. The lead-lag link reflects the phase characteristics of the regulator, and the values of T _B and T _C are very small, which can be ignored when simplifying the system. The magnification factor of the inertial amplification link is K _A , and the time constant is T _A . In the silicon controlled rectifier excitation regulator, the standard value of K _A can reach hundreds, and the time constant T _A is about tens of milliseconds. The transfer function of the exciter is the inertial link taking into account the saturation effect, and K _L = l for the separately excited AC excitation. For the static excitation system, there is no exciter link.

The PID calculator realizes the control of the controlled object according to the deviation value e(t) formed by the target value r(t) and the actual output value y(t) of the system. Its control law can be expressed as:

In the formula, _Kp is the proportional coefficient, T _I is the integral time constant, and T _D is the differential time constant. The influence of the three on the control performance of the system:

Proportionality factor K _p :

Proportional control is the most important part of PID control, it can reflect the deviation e(t) linearly. Increasing _Kp can reduce the steady-state error, improve the control precision of the system, and make the system more sensitive and respond faster. Once _Kp is too large, there will be a large overshoot and oscillation , reducing the dynamic performance of the system.

Integral time constant T _I :

Integral control is generally used to eliminate or reduce the steady-state error of the system, and its strength depends on _TI . It can be seen from the formula that the _larger TI is, the weaker the effect of the integral term is. Therefore, increasing _TI can reduce the overshoot and oscillation of the system and make the system more stable, but this is not conducive to eliminating the steady-state error of the system. Decreasing _TI will strengthen the integral effect, which is beneficial to eliminate the steady-state error, but once _TI is too small, the dynamic performance of the system will deteriorate.

Differential time constant T _D

Differential control can predict the variation trend of the deviation. If T _D is increased, the system response will become faster, and the overshoot will be reduced accordingly, but this will reduce the anti-interference ability of the system.

Digital PID controller emerges at the historic moment with the development of computer technology, it is developed on the basis of the original analog system, the realization of PID control on the computer must discretize the mathematical model of the original continuous system. which is:

Where T is the sampling period, k is the sampling sequence, k=0,1,2,3,.... For the convenience of writing, e(kT) is simplified as e(k). Calculate the discrete PID expression:

which is:

Derived incremental PID control algorithm:

.

As shown in Figure 2, the generator set excitation intelligent control system, the excitation intelligent control system is used to control the current of the generator excitation coil, the system includes:

A voltage detection unit for real-time detection of generator stator terminal voltage;

The data processing unit is used to process the stator terminal voltage of the generator, and calculate the voltage deviation e and the voltage deviation change rate ec according to the preset voltage;

A PID calculation unit, the PID calculation unit adopts an incremental PID control algorithm, and outputs a control signal according to the voltage deviation and the PID parameters input by the intelligent control unit;

A power amplifying unit, the power amplifying unit is used to amplify the control signal so as to control the current of the excitation coil of the generator;

An intelligent instruction table, the intelligent instruction table is used to determine the PID parameters of the PID calculation unit, and there are many sets of instructions stored in the intelligent instruction table, each set of instructions consists of a preset voltage deviation, a preset voltage deviation change rate and its corresponding Composition of PID parameters;

The intelligent control unit is used to receive the information of the voltage deviation e and the voltage deviation change rate ec, and determine the relationship between the voltage deviation e, the voltage deviation change rate ec and the preset voltage deviation and the preset voltage deviation change rate in the intelligent command table Whether the difference rate is lower than the preset difference rate, if so, input the PID parameter in the command into the PID calculation unit, if not, select the command with the lowest sum of the above two difference rates, and input the PID parameter in the command Enter the PID calculation unit.

The preset difference rate=|(voltage deviation-preset voltage deviation)/preset voltage deviation*100%| in the present invention; or the preset difference rate=|(voltage deviation change rate-preset Voltage deviation change rate)/preset voltage deviation change rate*100%|. The default difference rates are all positive numbers.

The preset difference rate is 1%-30%. By adjusting the preset difference rate, the number of instructions in the intelligent command table can be effectively reduced, and as the speed of the computer increases, the preset difference rate can be reduced.

By setting a certain preset difference rate and using e and ec to adjust the PID parameters, the PID parameters can be self-tuned during the PID calculation process. At the same time, the PID parameter self-tuning method of the present invention is simple, easy to realize, and has no complicated logic operation. At the same time, this method is easier to realize the intelligent learning of PID parameters, and realizes the intelligent control of the excitation system.

The multiple sets of PID parameters are obtained through different tuning methods, and the tuning methods are ZN empirical method, ZN critical proportionality method, ISTE optimal tuning method, characteristic area method, relay self-tuning method, cohen-coon method , GPM method, SPMA method, least square method model identification method, weighted error square integral index method, maximum tangent method, approximate calculation method.

The above methods are common methods in this field, and these tuning methods all have good tuning effects, but in different fields and environments, some tuning methods may be closer to the ideal value. It is for this reason that the present invention adopts multiple tuning parameters for use in the PID calculation unit of the generator.

The multiple groups of PID parameter acquisition steps include:

Tuning to obtain the array PID parameters;

Select m groups of closest PID parameters K _P , K _I , K _D;

Take n K _{P values at equal intervals between the maximum value and the minimum value among the m K P values} ;

Take n K _{I values at equal intervals between the maximum value and the minimum value among the m K I values} ;

Take n K _{D values at equal intervals between the maximum value and the minimum value among the m K D values} ;

Recombine the above n values of KP, KI, and KD to obtain n sets of PID parameters.

For example, the parameters of the generator excitation system of the present invention are adjusted respectively by the maximum tangent method, the characteristic area method and the approximate calculation method to obtain three groups of PID parameters:

10, 20, 50;

14, 24, 40;

12, 25, 45;

According to the interval of 0.8, get 6 values 10, 10.8, 11.6, 12.4, 13.2, 14;

According to the interval of 1, get 6 values 20, 21, 22, 23, 24, 25;

According to the interval of 2, get 6 values 40, 42, 44, 46, 48, 50;

Recombine to get 6 sets of PID parameters:

10, 20, 40;

10.8, 21, 42;

11.6, 22, 44;

12.4, 23, 46;

13.2, 24, 48;

14, 25, 50.

Of course, the above data can also be randomly combined.

List the possible values of e and ec, for example, e takes -3, 0, 3, ec takes -6, 0, 6.

Then list all the combinations of e and ec, and randomly pair them with the aforementioned 9 groups of PID parameters.

In addition, in order to obtain a better setting effect, for example, 1024 groups or even more combinations of e and ec can be randomly selected and combined with PID parameters to form an intelligent instruction table.

The multiple groups of PID parameter acquisition steps include:

Tuning to obtain the array PID parameters;

Select m groups of closest PID parameters K _P , K _I , K _D ;

Take n K _{P values at equal intervals between the maximum value and the minimum value among the m K P values} ;

Use m coordinates (K _P , KI ) to fit a polynomial function of degree m- ₁ , and use this polynomial function and n K _P values to obtain n K _I ;

Use m coordinates (K _P , K _D ) to get m-1 degree polynomial function, and use this polynomial function and n K _P values to get n K _D ;

Recombine the above n values of KP, KI, and KD to obtain n sets of PID parameters.

In the present invention, a function of the form f(x)=a _n x ⁿ +a _n-1 x ^n-1 +...+a ₁ x+a ₀ is called a polynomial function. Using polynomial functions, more PID parameters K _P , _KI , K _D can be obtained effectively.

As shown in Figure 3, the excitation intelligent control system also includes an intelligent instruction table generation unit, the intelligent instruction table generation unit includes a recording module and an analysis storage module, and the recording module is used to receive the voltage deviation e of the data processing unit and the PID parameter output corresponding to the voltage deviation change rate ec and the intelligent control unit, the analysis storage module is used to analyze the control effect value of the PID parameter corresponding to the output of the intelligent control unit within a preset period, if the control effect value reaches the preset value If the value is set, the array PID parameters and the corresponding voltage deviation e and voltage deviation change rate ec in the preset period are stored in the intelligent command table, and the array setting PID parameters are regarded as a PID control group. If the control effect If the value does not reach the preset value, there will be no storage action.

The preset value is represented by one or more of delay time T _D , rise time T _r , adjustment time T _s , and overshoot σ.

The delay time T _D , rise time T _r , adjustment time T _s , and overshoot σ of the present invention are calculated as shown in Fig. 4, where the abscissa is time and the ordinate is voltage or current.

Delay time T _D is the time from when the excitation system inputs a step signal to when the system begins to respond.

Rise time T _r The time required for the response value to rise from 10% to 90% of the steady state value.

Time to Peak T _p The time required for the response value to exceed the steady state value to reach the first peak.

Adjustment time T _s The time required for the response value to reach the steady-state value ± 5% error range.

Overshoot σ% In the response process, the system overshoot is defined as the difference between the system peak response output (h(T _p ) and the steady-state value (h(∞)) corresponding to the peak time T _p , expressed as follows :

.

The characterization method can use one or more of the delay time T _D , rise time T _r , adjustment time T _s , and overshoot σ to give a certain weight, and sum to get a value, for example, delay time T _D , rise time The time T _r , adjustment time T _s , and overshoot σ can be used as characterizations alone, or the delay time T _D , rise time T _r , and adjustment time T _s can be given the same or different weights, and a time value can be calculated. Analyze the control effect value of the control parameters within a period of time, calculate the control effect value, and compare it with the preset value. If the control effect value reaches the preset value, that is, it is lower than or equal to the preset value, then several Command combination storage. The control effect can also be characterized by the adjustment time T _s and the overshoot σ, set a time standard T _s and the standard overshoot σ _m , calculate the sum of T _s /T _s and σ/σ _m , and obtain the control effect value, Compared with the preset value, if the control effect value reaches the preset value, that is, is lower than or equal to the preset value, several instructions within the period are combined and stored. It is also possible to set different weights for T _s /T _s and σ/σ _m respectively, for example, the weight of T _s /T _s is 30%, and the weight of σ/σ _m is 70%, and the control effect value is calculated. Generally speaking, the aforementioned period of time is shown in FIG. 2 , and time 0-16 can be used.

The excitation intelligent control method also includes an intelligent instruction table finishing module:

Described intelligent command list finishing module, is used for judging whether the PID control parameter that does not form a group and the PID parameter of the PID control group in the intelligent command list are identical, if so, then deletes the PID control parameter that does not form a group in the intelligent command list, If not, keep the ungrouped PID control parameters in the smart instruction table.

Through the intelligent instruction table sorting module, redundant instructions can be deleted, thereby controlling the number of intelligent instruction tables and reducing the delay in issuing instructions.

For example, there is an intelligent instruction table containing 1024 groups of instructions. In the steady state of the excitation system, a negative 15% voltage pulse interference signal is applied. 345, 432, 589, 901, 1000, 232, 478, 641, 478 groups of intelligent instruction tables are output, the intelligent instruction table generation unit records the above instruction groups, and analyzes the control effect of the above instruction groups, and the overshoot σ does not exceed 10% is the standard, and the control effect value is 8%, then the control effect of this group of instructions meets the requirements. , 1000, 232, 478, 641, 478 are used as a control instruction group, which are stored in the intelligent instruction table in this order.

And in the intelligent command table sorting module, if 880, 132, 555 are stored as in the smart command list because the command meets the preset requirements, and e and ec do not change, then in the smart command list sorting module and just stored as smart The 880, 132, 555 data of the control instruction group in the instruction table are exactly the same, so in the intelligent instruction table sorting module, if the 880, 132, 555 data does not form an instruction group, the redundant 880, 132, 555 data will be deleted . In addition, the instructions that form the instruction group will not be deleted in the smart instruction list sorting module.

At the same time, it can also be seen that except for the 880, 132, and 555 groups of instructions, other instructions newly stored in the smart instruction table are new and different instructions. After a large amount of data learning, it can effectively eliminate the manual designation of the previous instructions. the impact.

Through the above-mentioned recombination, the time for issuing instructions can be greatly saved, and the speed of instruction feedback can be improved. At the same time, through the learning of instructions, the intelligent control system will learn a series of fixed instruction groups to deal with the interference signals encountered by the generator set.

Generator set excitation intelligent control method, the excitation intelligent control method is used to control the current of the generator excitation coil, the method includes the following steps:

a. Real-time detection of generator stator terminal voltage;

b. Process the stator terminal voltage of the generator, and calculate the voltage deviation e and the voltage deviation change rate ec according to the preset voltage;

c. Receive the information of the voltage deviation e and the voltage deviation change rate ec, and judge whether the difference rate between the voltage deviation e, the voltage deviation change rate ec and the preset voltage deviation amount and the preset voltage deviation change rate in the intelligent command table are lower than the preset difference rate, if yes, the PID parameter in the command is the set PID parameter, if not, choose the command with the lowest sum of the above two difference rates, then the PID parameter in the command is the set PID parameter Parameters, the intelligent instruction table is used to determine the PID parameters of the PID calculation unit, there are multiple sets of instructions stored in the intelligent instruction table, each set of instructions consists of a preset voltage deviation and a preset voltage deviation change rate and its corresponding PID parameter composition;

d. Adopt incremental PID control algorithm, output control signal according to voltage deviation e and setting PID parameters;

e. The control signal is amplified to control the current of the excitation coil of the generator.

The multiple groups of PID parameter acquisition steps include:

Tuning to obtain the array PID parameters;

Select m groups of closest PID parameters K _P , K _I , K _D;

Take n K _{P values at equal intervals between the maximum value and the minimum value among the m K P values} ;

Take n K _{I values at equal intervals between the maximum value and the minimum value among the m K I values} ;

Take n K _{D values at equal intervals between the maximum value and the minimum value among the m K D values} ;

Recombine the above n values of KP, KI, and KD to obtain n sets of PID parameters.

The multiple groups of PID parameter acquisition steps include:

Tuning to obtain the array PID parameters;

Select m groups of closest PID parameters K _P , K _I , K _D ;

Take n K _{P values at equal intervals between the maximum value and the minimum value among the m K P values} ;

Use m coordinates (K _P , KI ) to fit a polynomial function of degree m- ₁ , and use this polynomial function and n K _P values to obtain n K _I ;

Use m coordinates (K _P , K _D ) to get m-1 degree polynomial function, and use this polynomial function and n K _P values to get n K _D ;

Recombine the above n values of KP, KI, and KD to obtain n sets of PID parameters.

In the present invention, a function of the form f(x)=a _n x ⁿ +a _n-1 x ^n-1 +...+a ₁ x+a ₀ is called a polynomial function. Using polynomial functions, more PID parameters K _P , _KI , K _D can be obtained effectively.

The excitation intelligent control method also includes an intelligent instruction table generation step:

Receive the voltage deviation e and the voltage deviation change rate ec of the data processing unit and set the PID parameters,

Analyze the control effect value of several tuning PID parameters within a preset period, if the control effect value reaches the preset value, set the PID parameters of the array within the preset period and the corresponding voltage deviation e and voltage deviation change The rate ec is stored in the intelligent command table, and the PID parameters set by the array are regarded as a PID control group. If the control effect value does not reach the preset value, there will be no storage action.

The excitation intelligent control method also includes the step of organizing the intelligent instruction table:

Determine whether the ungrouped PID control parameters are exactly the same as the PID parameters of the PID control group in the smart command table, if so, delete the ungrouped PID control parameters in the smart command table, if not, keep them in the smart command table The ungrouped PID control parameters.

The preset value is represented by one or more of delay time T _D , rise time T _r , adjustment time T _s , and overshoot σ.

Through the above intelligent control, the output of the excitation coil current can be effectively controlled, so that the voltage output of the generator set is stable. Compared with other intelligent control systems, the overall control effect is good and the adaptability is strong when facing different disturbances. Compared with other intelligent control systems, since the setting data is pre-imported, the rule base is simpler and more effective, and the processing is faster.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. All equivalent changes and modifications made according to the contents of the present invention are covered within the patent scope of the present invention.

Claims (10)

1. Generator set excitation intelligent control system, the excitation intelligent control system is used to control the current of the generator excitation coil, the system includes: A voltage detection unit for real-time detection of generator stator terminal voltage; The data processing unit is used to process the stator terminal voltage of the generator, and calculate the voltage deviation e and the voltage deviation change rate ec according to the preset voltage; A PID calculation unit, the PID calculation unit adopts an incremental PID control algorithm, and outputs a control signal according to the voltage deviation and the PID parameters input by the intelligent control unit; A power amplifying unit, the power amplifying unit is used to amplify the control signal so as to control the current of the excitation coil of the generator; An intelligent instruction table, the intelligent instruction table is used to determine the PID parameters of the PID calculation unit, and there are many sets of instructions stored in the intelligent instruction table, each set of instructions consists of a preset voltage deviation, a preset voltage deviation change rate and its corresponding Composition of PID parameters; The intelligent control unit is used to receive the information of the voltage deviation e and the voltage deviation change rate ec, Compare the voltage deviation e with the difference rate of the preset voltage deviation in the intelligent command table and the preset difference rate, and compare the voltage deviation change rate ec with the difference rate of the preset voltage deviation in the smart command table Compared with the preset difference rate, And judge whether the above two difference rates are lower than the preset difference rate, If yes, input the PID parameters in the command into the PID calculation unit, if not, select the command with the lowest sum of the above two difference rates, and input the PID parameters in the command into the PID calculation unit. 2. The intelligent excitation control system of the generating set according to claim 1, wherein the preset difference rate is 1%-30%. 3. The generator set excitation intelligent control system according to claim 1, characterized in that, the PID parameters are obtained through different tuning methods, and the described tuning methods are ZN empirical method, ZN critical proportionality method, ISTE most Optimal tuning method, characteristic area method, relay self-tuning method, cohen-coon method, GPM method, SPMA method, least square method model identification method, weighted error square integral index method, maximum tangent method, approximate calculation method. 4. The generator set excitation intelligent control system according to claim 1, wherein the PID parameter acquisition step comprises: Tuning to obtain the array PID parameters; Select m groups of closest PID parameters K _P , K _I , K _D; Take n K _{P values at equal intervals between the maximum value and the minimum value among the m K P values} ; Take n K _{I values at equal intervals between the maximum value and the minimum value among the m K I values} ; Take n K _{D values at equal intervals between the maximum value and the minimum value among the m K D values} ; Recombine the above n values of K _P , _KI , and K _D to obtain n sets of PID parameters, The K _P is the proportional coefficient in the incremental PID control algorithm, K _I is the integral coefficient in the incremental PID control algorithm, and K _D is the differential coefficient in the incremental PID control algorithm. 5. The generator set excitation intelligent control system according to claim 1, wherein the PID parameter acquisition step comprises: Tuning to obtain the array PID parameters; Select m groups of closest PID parameters K _P , K _I , K _D ; Take n K _{P values at equal intervals between the maximum value and the minimum value among the m K P values} ; Use m coordinates (K _P , KI ) to fit a polynomial function of degree m- ₁ , and use this polynomial function and n K _P values to obtain n K _I ; Use m coordinates (K _P , K _D ) to get m-1 degree polynomial function, and use this polynomial function and n K _P values to get n K _D ; Recombine the above n values of K _P , _KI , and K _D to obtain n sets of PID parameters, The K _P is the proportional coefficient in the incremental PID control algorithm, K _I is the integral coefficient in the incremental PID control algorithm, and K _D is the differential coefficient in the incremental PID control algorithm. 6. The generator set excitation intelligent control system according to claim 1, characterized in that, the excitation intelligent control system also includes an intelligent instruction table generation unit, and the intelligent instruction table generation unit includes a recording module and an analysis storage module, the The recording module is used to receive the voltage deviation e and the voltage deviation change rate ec of the data processing unit and the PID parameters corresponding to the output of the intelligent control unit, and the analysis and storage module is used to analyze the corresponding output of the intelligent control unit within a preset period The control effect value of the PID parameter, if the control effect value reaches the preset value, the array PID parameters in the preset cycle, the corresponding voltage deviation e and the voltage deviation change rate ec are stored in the intelligent command table, and Array setting PID parameters are regarded as a PID control group, if the control effect value does not reach the preset value, there will be no storage action. 7. The intelligent control system for generator set excitation according to claim 1, characterized in that, the preset value passes through one of delay time T _D , rise time T _r , adjustment time T _s , and overshoot σ or several characterizations. 8. The generator set excitation intelligent control system according to claim 1, characterized in that, the excitation intelligent control method further comprises an intelligent instruction table sorting module: Described intelligent command list finishing module, is used for judging whether the PID control parameter that does not form a group and the PID parameter of the PID control group in the intelligent command list are identical, if so, then deletes the PID control parameter that does not form a group in the intelligent command list, If not, keep the ungrouped PID control parameters in the smart instruction table. 9. A generator set excitation intelligent control method, the excitation intelligent control method is used to control the current of the generator excitation coil, and the method comprises the following steps: a. Real-time detection of generator stator terminal voltage; b. Process the stator terminal voltage of the generator, and calculate the voltage deviation e and the voltage deviation change rate ec according to the preset voltage; c. Receive the information of the voltage deviation e and the voltage deviation change rate ec, compare the voltage deviation e with the preset voltage deviation rate in the intelligent instruction table with the preset difference rate, and compare the voltage deviation change rate ec Compare with the difference rate of the preset voltage deviation in the intelligent command table and the preset difference rate, and judge whether the above two difference rates are lower than the preset difference rate, if so, the PID in the command Parameter is the setting PID parameter, if not, then select the instruction that the sum of the above-mentioned two difference rates is the lowest, then the PID parameter in the instruction is the setting PID parameter, and the intelligent instruction table is used to determine the PID parameter of the PID calculation unit, There are multiple groups of instructions stored in the intelligent instruction table, and each group of instructions is composed of preset voltage deviation, preset voltage deviation change rate and corresponding PID parameters; d. Adopt incremental PID control algorithm, output control signal according to voltage deviation e and setting PID parameters; e. The control signal is amplified to control the current of the excitation coil of the generator. 10. The intelligent control method for excitation of generator set according to claim 9, characterized in that, the intelligent control method for excitation further comprises the step of generating an intelligent instruction table: Receive the voltage deviation e and the voltage deviation change rate ec of the data processing unit and set the PID parameters, Analyze the control effect value of several tuning PID parameters within a preset period, if the control effect value reaches the preset value, set the PID parameters of the array within the preset period and the corresponding voltage deviation e and voltage deviation change The rate ec is stored in the intelligent command table, and the array setting PID parameters are regarded as a PID control group. If the control effect value does not reach the preset value, there will be no storage action; The excitation intelligent control method also includes the step of organizing the intelligent instruction table: Determine whether the ungrouped PID control parameters are exactly the same as the PID parameters of the PID control group in the smart command table, if so, delete the ungrouped PID control parameters in the smart command table, if not, then keep them in the smart command table The ungrouped PID control parameters.