CN103197641B - Power Plant stage load and voltage integration automatic control system - Google Patents

Abstract

The invention discloses a kind of Power Plant stage load and voltage integration automatic control system that belong to cogeneration plant's generating automatic control technology field.This integrated automatic control system is made up of data acquisition, supervision, control and communication network four part.This system can be optimized distribution to level of factory load simultaneously and voltage controls automatically.This system can the former scattered control system of seamless embedding thermal power plant and magnetic force regulating system, dispatch command and the information uploading to dispatching center, through remote terminal, input/output module, data acquisition and optimization distribute control program and are realized by a set of programmable logic controller (PLC) and some I/O modules.The power supply of this system, communication and controller are two redundant configuration.Combine together LDC and AVC networked control systems, saved place, investment, and Installation and Debugging time and operation and maintenance expenses are used.This control strategy is easily understood, and on-line calculation is little, maintains the good economy of total length, can meet the requirement of various working.<!--1-->

Description

Power Plant stage load and voltage integration automatic control system

Technical field

The invention belongs to cogeneration plant's generating automatic control technology field.In particular to a kind of Power Plant stage load and voltage integration automatic control system.

Background technology

At present, LDC) and level of factory Voltage Automatic Control System (abbreviation: AVC) be the system of two cover independent operatings, every cover system all has independently data acquisition system (DAS), communication system, industrial control computer and control result Power Plant stage load distribution system (is called for short:.Although LDC with AVC function is different, but the data gathered have very most of overlap, the analog quantity numerical value such as set generator end active power as each in thermal power plant, reactive power, busbar voltage, the and for example switching value such as set state, control system switching, this two cover system all needs to accept dispatching of power netwoks instruction simultaneously.Obviously, two cover independent operating LDC and AVC cause the repeated configuration of equipment, waste resource, add investment; Two overlap independently system simultaneously, too increase the cost of operation maintenance in the future, and therefore the present invention designs a kind of Power Plant stage load and voltage integration automatic control system (abbreviation: AGVC).

Summary of the invention

The object of the invention is the deficiency existed for existing LDC and AVC hardware repeated configuration and load optimal distribution algorithm, a kind of Power Plant stage load and voltage integration automatic control system are proposed, it is characterized in that, this integrated automatic control system is made up of data acquisition, supervision, control and communication network four part; System architecture is:

First opc server 1, second opc server 2, first unit OPC client-N unit OPC client connects with the first switch 1, second switch 2 respectively by the first netting twine 1, second netting twine 2; First controller 1 second controller 2 is connected with the first switch 1, second switch 2 respectively by the first netting twine 1, second netting twine 2, first controller 1, second controller 2 are connected with the first CAN 1, second CAN 2 respectively, are interconnected between the first controller 1 and second controller 2 by communication cable 3; First input/output module 7, second input/output module 8, the 3rd input/output module 9 and Three-Part protocol module 10 are simultaneously and connect in the first CAN 1, second CAN 2; First input/output module 7 is connected with remote terminal 6 respectively by data line with the second input/output module 8, and remote terminal 6 is connected by communication cable 4 grid dispatching center.

Described control section is made up of the first controller 1 of mutual redundancy, second controller 2, is PLC programmable logic controller (PLC), realizes computing, logic control and communication function; Being responsible for performing and optimizing allocation algorithm, is the control module of core.

Described data acquisition system (DAS) is made up of the first input/output module 7, second input/output module 8, the 3rd input/output module 9 and Three-Part protocol module 10, all comprise A/D(mould/number) change and D/A(D/A) conversion, the analog quantity of inputting modular unit collection is converted to digital quantity, and output module exports digital quantity; Above-mentioned input/output module all has light-coupled isolation to protect, and each module connects the first CAN 1, second CAN 2 of mutual redundancy respectively, is communicated with controller by CAN.

Described communication network is made up of two switches and netting twine, optical fiber, and communications protocol is ICP/IP protocol, and wherein switch is light mouth, the mixing of electric mouth; When distance is less than 75 meters, make electricity consumption mouth and netting twine; Be greater than 75 meters, then use optical fiber and Guang Kou.

Described monitoring section is made up of remote terminal, grid dispatching center, industrial computer and the control result be installed on industrial computer, monitoring software comprises Man Machine Interface, operator monitors field working conditions by Man Machine Interface and sends steering order, configuration software allows the personnel with certain authority to check the state of variable in controller, fill Logical Configuration under amendment, steering logic is debugged.

Described second opc server 2 exports and is connected with printer 11.

Described first opc server 1, second opc server 2 is redundancy mutually.

Described first netting twine 1, second netting twine 2 is redundancy mutually.

Described first switch 1, second switch 2 is redundancy mutually.

Described Three-Part protocol module is communications protocol modular converter, comprises A/D analog/digital conversion and D/A D/A switch, the analog quantity of inputting modular unit collection is converted to digital quantity, and output module exports digital quantity; Common Fieldbus agreement (as MODBUS, PROFIBUS etc.) is converted to CAN agreement in rack, to improve the compatibility of AGVC system.

The invention has the beneficial effects as follows that this integral control system can complete the function that level of factory load Automatic Optimal is distributed and level of factory voltage controls automatically, achieve level of factory load/voltage overall-in-one control schema; Particularly level of factory load secondary adjusting and optimizing allocation strategy is while raising full factory load responding speed, achieves load shifting rate, ensures the good economy of full factory., saved investment and maintenance cost.

Accompanying drawing explanation

Fig. 1 is level of factory load/voltage integration automatic control system structured flowchart.

Fig. 2 is switch board structural representation.

Embodiment

The present invention proposes a kind of Power Plant stage load and voltage integration automatic control system.Below in conjunction with drawings and Examples, the present invention will be further described.

This integrated automatic control system is made up of data acquisition, supervision, control and communication network four part.Its system architecture is shown in Fig. 1, Fig. 2.

First opc server 1 of mutual redundancy is connected (N is full brand-name computer group sum) with the first switch 1, second switch 2 respectively by the first netting twine 1, second netting twine 2 to N unit OPC client with the second opc server 2, first unit OPC client, and the second opc server 2 exports and is connected with printer 11.In switch board 13, first controller 1 second controller 2 is connected with the first switch 1, second switch 2 respectively by the first netting twine 1, second netting twine 2, first controller 1, second controller 2 are connected with the first CAN 1, second CAN 2 respectively, are interconnected between the first controller 1 and second controller 2 by communication cable 3; First input/output module 7, second input/output module 8, the 3rd input/output module 9 and Three-Part protocol module 10 are simultaneously and connect in the first CAN 1, second CAN 2, in switch board 13 bottom, air switch group is installed, power module is installed respectively in air switch group both sides, and voltage table, reometer, LED light and switch, be connected to AC power 1 and AC power 2(respectively as shown in Figure 2), the voltage that power module exports is connected to corresponding parts by air switch group.First input/output module 7 is connected with remote terminal 6 respectively by data line with the second input/output module 8, and remote terminal 6 is connected by communication cable 4 grid dispatching center.Remote terminal 6 transmits unit information (104 stipulations) by communication cable 4 to grid dispatching center 12, also accepts dispatch command simultaneously.In order to ensure the reliability of dispatch command and teletransmission information, remote terminal 6 carries out data interaction by data line 5 and AGVC.

Described control section is made up of the first controller 1 of mutual redundancy, second controller 2, is PLC programmable logic controller (PLC), realizes computing, logic control and communication function; Being responsible for performing and optimizing allocation algorithm, is the control module of core.

Described data acquisition system (DAS) is made up of the first input/output module 7, second input/output module 8, the 3rd input/output module 9 and Three-Part protocol module 10, all comprise A/D analog/digital conversion and D/A D/A switch, the analog quantity of inputting modular unit collection is converted to digital quantity, and output module exports digital quantity; Above-mentioned input/output module all has light-coupled isolation to protect, and each module connects the first CAN 1, second CAN 2 of mutual redundancy respectively, is communicated with controller by CAN.

Described communication network is made up of the netting twine of the switch of two mutual redundancies and mutual redundancy, optical fiber, and communications protocol is ICP/IP protocol, and wherein switch is light mouth, the mixing of electric mouth; When distance is less than 75 meters, make electricity consumption mouth and netting twine; Be greater than 75 meters, then use optical fiber and Guang Kou.

Described monitoring section is made up of remote terminal, grid dispatching center, industrial computer and the control result be installed on industrial computer, monitoring software comprises Man Machine Interface, operator monitors field working conditions by Man Machine Interface and sends steering order, configuration software allows the personnel with certain authority to check the state of variable in controller, fill Logical Configuration under amendment, steering logic is debugged.

Optional group scattered control system (DCS) historic data server of selecting a good opportunity of each unit OPC client in Fig. 1, because OPC is the decentralised control communication modes based on Windows operating system.For non-Windows operating system by Three-Part protocol module, use RS485 bus, realize according to communications protocol.

Its control flow is: by input/output module collection in worksite signal (each set state), and the CAN through two redundancies each other enters the first controller 1, second controller 2; Dispatch command accesses remote terminal by communication cable, enters input/output module by some data lines; By load optimal distribution algorithm and voltage automatic control algorithm, calculate meritorious, the reactive power that each unit distributes, by output class I/O module (AO, DO) enter each unit scattered control system (DCS) system and excitation control system (AVR), finally completed the adjustment of load, voltage by the topworks of each unit.

About load distribution in power plants algorithm:

Variable declarations: P _refdispatching of power netwoks load instruction, P _ibe the active power that i-th unit exports, Δ P _mAX-i, Δ P _mIN-ibe respectively the bound of i-th unit load increment, N is the total operating unit number of this factory, f _i(P _i) be i-th unit coal consumption curve.

1. according to coal consumption active power historical data matching unit coal consumption curve: (F _i, P _i) _mbe i-th unit M group coal consumption power historical data, C _ifor fitting coefficient to be asked.By least square curve fit, then quadratic fit normal equation system is:

$\left\{\begin{array}{c}{C}_{i1}M+C_{i2}\underset{j=1}{\overset{M}{\mathrm{\&Sigma;}}}{P}_i^{\left(j\right)}+C_{i3}\underset{j=1}{\overset{M}{\mathrm{\&Sigma;}}}{\left(P_i^{\left(j\right)}\right)}^2=\underset{j=1}{\overset{M}{\mathrm{\&Sigma;}}}{F}_i^{\left(j\right)}\\ C_{i1}\underset{j=1}{\overset{M}{\mathrm{\&Sigma;}}}{P}_i^{\left(j\right)}+C_{i2}\underset{j=1}{\overset{M}{\mathrm{\&Sigma;}}}{\left(P_i^{\left(j\right)}\right)}^2+C_{i3}\underset{j=1}{\overset{M}{\mathrm{\&Sigma;}}}{\left(P_i^{\left(j\right)}\right)}^3=\underset{j=1}{\overset{M}{\mathrm{\&Sigma;}}}{P}_i^{\left(j\right)}{F}_i^{\left(j\right)}\\ C_{i1}\underset{j=1}{\overset{M}{\mathrm{\&Sigma;}}}{\left(P_i^{\left(j\right)}\right)}^2+C_{i2}\underset{j=1}{\overset{M}{\mathrm{\&Sigma;}}}{\left(P_i^{\left(j\right)}\right)}^3+C_{i3}\underset{j=1}{\overset{M}{\mathrm{\&Sigma;}}}{\left(P_i^{\left(j\right)}\right)}^4=\underset{j=1}{\overset{M}{\mathrm{\&Sigma;}}}{\left(P_i^{\left(j\right)}\right)}^2{F}_i^{\left(j\right)}\end{array}\right.---\left(2.1\right)$

Separate above-mentioned equation, obtain i-th unit coal consumption curve:

2. economic optimum distributes:

Economic target function: $H=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{f}_i\left(P_i\right)---\left(2.3\right)$

Constraint condition is: P _mIN-i≤ P _i≤ P _mAX-i,

By the variational method, dynamic programming or particle cluster algorithm optimize economic index, obtain each unit load increment size Δ P _i.This method adopts dynamic programming algorithm, and its algorithm is:

Variable declarations: X _ii platform unit total load before representative; More than other variable symbols are same.

State transition equation: X _i+1=X _i+ P _i+1; Boundary condition: X ₀=0 optimal value function:

Decision-making set: G _i(P _i)={ P _i| P _min-i≤ P _i≤ P _max-i, P _i+ X _i-1=X _i}

Recurrence equation: $M_i\left(X_i\right)=\underset{p}{\min }\{M_{i-1}\left(X_{i-1}\right)+f_i\left(P_i\right)\}$

Dynamic programming solution procedure:

1. order is made a list:

The first step: $\left\{\begin{array}{c}{M}_1\left(X_1\right)=f_i\left(P_i\right)\\ X1=P_1\\ P_{\min -1}\&le;P_1\&le;P_{\max -1}\end{array}\right.$

X ₁its interval [P is traveled through with a fixed step size _min-1, P _max-1], record relevant data at data acquisition { X simultaneously ₁, P ₁, f ₁(P ₁) in.Second step: $\left\{\begin{array}{c}{M}_2{X}_2=\underset{P_2}{\min }\{M_1\left(X_1\right)+f_2\left(P_2\right)\}\\ X_2=X_1+P_2\\ \underset{i=1}{\overset{2}{\mathrm{\&Sigma;}}}{P}_{\min -1}\&le;X_2\&le;\underset{i=1}{\overset{2}{\mathrm{\&Sigma;}}}{P}_{\max -i}\\ P_{\min -2}\&le;P_2\&le;P_{\max -2}\end{array}\right.$

X ₂travel through its interval with certain step-length, the result of calculation of associating one-phase, calculates corresponding different X ₂time, different P ₂corresponding M ₂(X ₂) optimal value, simultaneously record relevant data at data acquisition { X ₂, P ₂, f ₂(P ₂).

Intermediate steps: $\left\{\begin{array}{c}{M}_j\left(X_j\right)=\underset{P_j}{\min }\{M_{j-1}\left(X_{j-1}\right)+f_j\left(P_j\right)\}\\ X_j=X_{j-1}+P_j\\ \underset{i=1}{\overset{j}{\mathrm{\&Sigma;}}}{P}_{\min -i}\&le;X_j\&le;\underset{i=1}{\overset{j}{\mathrm{\&Sigma;}}}{P}_{\max -i}\\ P_{\min -j}\&le;P_j\&le;P_{\max -j}\end{array}\right.$

Similar with the 2nd step, related data is recorded in data acquisition { X _j, P _j, f _j(P _j).

Final step: because the last stage clearly knows X _n, therefore need not calculate as above.Can walk in conjunction with N-1, directly calculate X _n=P _ref, without P _ncorresponding M during value _n(X _n) value, finally obtain optimal value, be recorded in { X simultaneously _n, P _n, f _n(P _n) in.

2. backward is tabled look-up:

Corresponding full factory total load is P _reftime, directly can find the optimization load P that N platform unit should bear from table in the N stage _n; In the N-1 stage, the total load of inquiry correspondence is X _n-1=P _ref-P _noptimization load P _n-1; According to state transition equation X _i=X _i+1-P _i+1the like, the load optimal distribution result { P in N number of stage can be determined _n, P _n-1... P ₂, P ₁, thus complete the load distribution of whole power plant.

2, level of factory voltage automatic control algorithm

Dispatching of power netwoks sends busbar voltage setting value and power plant's bus current voltage enters PLC control system through AI module, by " Voltage-Reactive Power conversion " module, is converted to the reactive power that full factory need provide to electrical network.The reactive power of each unit output is distributed according to full factory constant power factor.

The reactive power that the full factory of variable declarations: Q sends, Q _ref-ii-th unit reactive power apportioning cost, Q _ii-th unit reactive power real output value, Δ Q _ii-th unit reactive power increment size, Q _refthe reactive power that full factory need send, U _refbusbar voltage setting value, the current busbar voltage of U, U ^kkth moment bus voltage value, Q ^kthe kth moment, full factory was without work value, system X impedance identifier, full factory power factor (PF), e _ii-th unit PID controller deviation.

2.1, Voltage-Reactive Power transfer algorithm: $Q_{\mathrm{ref}}=U_{\mathrm{ref}}(\frac{U_{\mathrm{ref}}-U}{X}+\frac{Q}{U})---\left(3.1\right)$

Wherein: $X=(U^k-U^{k-i})(\frac{\underset{j=1}{\overset{k}{\mathrm{\&Sigma;}}}{Q}^j}{U^k}-\frac{\underset{j=1}{\overset{k-i}{\mathrm{\&Sigma;}}}{Q}^j}{U^{k-i}})---\left(3.2\right)$

When reality uses X computing formula, through engineering approaches process is carried out to system impedance: system impedance bound is set.When system can not identification system impedance time, getting reaches the standard grade calculates.As voltage difference U ^k-U ^k-iwhen being greater than 0.5% rated voltage, computing system impedance X.

2.2, the idle allocation algorithm of constant power factor

1. full factory power factor is calculated :

2. basis calculate the reactive power sent needed for each unit:

3. the idle increment of each unit is calculated: Δ Q _i=Q _ref-i-Q _i(3.5)

Existing excitation controller mostly is proportional controller, but generator unloading phase, field voltage and set end voltage are not proportional, so ratio excitation controller has poor when unit starting, control accuracy is low.Native system adopts PID controller, and deviation is e _i=Q _ref-Q _i, the integral element in PID controller can eliminate dynamic deviation during unit starting, and improve control accuracy, differentiation element can improve control response speed.

The invention has the beneficial effects as follows, combine together LDC and AVC networked control systems, saved place, investment, and Installation and Debugging time and operation and maintenance expenses are used.Level of factory load adjustment optimization simultaneously distributes, level of factory Voltage Automatic Control System, can to total length active power, and reactive power on-line optimization distributes.This control strategy is easily understood, and on-line calculation is little, maintains the good economy of total length, can meet the requirement of various working.

Claims (10)

1. a Power Plant stage load and voltage integration automatic control system, it is characterized in that, this integrated automatic control system is made up of data acquisition, supervision, control and communication network four part, is integrated with the function that load distribution in power plants and level of factory voltage control automatically; System architecture is:

First opc server 1/ second opc server 2, first unit OPC client-N unit OPC client connects with the first switch 1, second switch 2 respectively by the first netting twine 1, second netting twine 2; First controller 1 second controller 2 is connected with the first switch 1, second switch 2 respectively by the first netting twine 1, second netting twine 2, first controller 1, second controller 2 are connected with the first CAN 1, second CAN 2 respectively, by communication cable (3) interconnection between the first controller 1 and second controller 2; First input/output module 7, second input/output module 8, the 3rd input/output module 9 and Three-Part protocol module 10 are simultaneously and connect in the first CAN 1, second CAN 2; First input/output module 7 is connected with remote terminal (6) respectively by data line (5) with the second input/output module 8, and remote terminal (6) is connected with grid dispatching center (12) by communication cable (4).

2. according to claim 1 a kind of Power Plant stage load and voltage integration automatic control system, it is characterized in that, described control section is made up of the first controller 1 of mutual redundancy, second controller 2, be PLC programmable logic controller (PLC), realize computing, logic control and communication function; Being responsible for performing and optimizing allocation algorithm, is the control module of core.

3. according to claim 1 a kind of Power Plant stage load and voltage integration automatic control system, it is characterized in that, described data acquisition is made up of the first input/output module 7, second input/output module 8, the 3rd input/output module 9 and Three-Part protocol module 10, all comprise A/D (mould/number) conversion and D/A (D/A) conversion, the analog quantity of inputting modular unit collection is converted to digital quantity, and output module exports digital quantity; Above-mentioned input/output module all has light-coupled isolation to protect, and each module connects the first CAN 1, second CAN 2 of mutual redundancy respectively, is communicated with controller by the CAN of a pair mutual redundancy.

4. according to claim 1 a kind of Power Plant stage load and voltage integration automatic control system, it is characterized in that, described communication network is made up of two switches and netting twine, optical fiber, and communications protocol is ICP/IP protocol, and wherein switch is light mouth, the mixing of electric mouth; When distance is less than 75 meters, make electricity consumption mouth and netting twine; Be greater than 75 meters, then use optical fiber and Guang Kou.

5. according to claim 1 a kind of Power Plant stage load and voltage integration automatic control system, it is characterized in that, described monitoring section is by remote terminal, industrial computer and be installed on industrial computer control resultform, monitoring configurationsoftware package is containing Man Machine Interface, operator monitors field working conditions by Man Machine Interface and sends steering order, control result allows the personnel with certain authority to check the state of variable in controller, fills Logical Configuration, debug steering logic under amendment.

6. according to claim 1 a kind of Power Plant stage load and voltage integration automatic control system, it is characterized in that, described second opc server 2 export be connected with printer (11).

7. a kind of Power Plant stage load and voltage integration automatic control system according to claim 1, is characterized in that, described first opc server 1, second opc server 2 mutually redundancy.

8. a kind of Power Plant stage load and voltage integration automatic control system according to claim 1, is characterized in that, described first netting twine 1, second netting twine 2 mutually redundancy.

9. a kind of Power Plant stage load and voltage integration automatic control system according to claim 1, is characterized in that, described first switch 1, second switch 2 mutually redundancy.

10. according to claim 1 a kind of Power Plant stage load and voltage integration automatic control system, it is characterized in that, described Three-Part protocol module is communications protocol modular converter, comprise A/D analog/digital conversion and D/A D/A switch, the analog quantity of inputting modular unit collection is converted to digital quantity, and output module exports digital quantity; Be CAN agreement in rack by Common Fieldbus protocol conversion, to improve the compatibility of AGVC system.