SU1227823A1 - Method of controlling power of turbine - Google Patents

Description

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The invention relates to tenloenergy and can be used to automate the control of steam turbines of power plants.

The purpose of the invention is to increase reliability in power management in emergency situations of the power system.

FIG. 1 is a diagram of a turbine power control system; in fig. 2 is a diagram of a driver for a given power; in fig. 3 is a block diagram of a long-term constraint formation unit; in fig. 4 - scheme of multimode integrator; in fig. 5 is a diagram of a multi-channel switch; in FIG. 5. 6 is a control block diagram; in fig. 7 is a diagram of a pulsed discharge forming unit. I

The turbine power control system (Fig.) Contains a shaper 1 of a given power, a limiter 2 of a given power, a minimum signal 3, one of the inputs of which is connected to the block 4 for forming a continuous power limitation level according to commands of the power supply system of automatic control, and the other inputs receive signals other maximum power limiting units (not shown). Such signals are the signals from the setter of the maximum allowable power set by the operator, from the setter of allowable power according to the state of the process equipment, from the setter of the allowable load value corresponding to the temperature and humidity of steam, from the generator of the limiting level of the rotor and The system also includes a driver of the error signal 5, a vapor pressure sensor 6 and a vapor pressure adjuster 7, a driver of the error signal 8, a sensor 9 Rotor rotation speeds and rotor speed setting device 10, power i atch i 1, first sum (aor 12, multimode integrator 13, control unit 14, input) connected to the sensor, 6 pressures, rotor rotation frequency sensor 9, power II sensor as well as to the generator switch and to the reactor (not shown), a multichannel 55 ommutator 15, a second adder 16, a dimming amplifier 17, a servo motor position sensor 18 19, a sensor

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The 20 positions of the reference spool 21, the electro-hydraulic converter 22, which controls, through the reference spool 21 and the servomotor 19, the operation of the turbine regulators (not shown). The system includes a maximum signal unit 23, an additional switch 24, a turbine pulsed discharge unit 25, a third adder 26, a zero-body 27, a logic switch 28, a signal difference limiter 29, an additional switch 30, an analog signal conditioner 31.

The shaper 1 of a given power (Fig. 2). Contains a setpoint adjuster 32, a quartz oscillator 33, analog-. beef comparator 34, the first input of which is connected to the output of the setpoint adjuster 32, analogue comparator 35, the first input of which is connected to the output of the power sensor 11. The outputs of both comparators 34 and 35, and also the outputs of the crystal oscillator 33 are connected to the inputs of the switch 36 signals. The shaper 1 of the specified power also contains a reversible counter 37, the inputs of which are connected to the outputs of the signal switch 36, and the output is connected to the input of the code-voltage converter 38, an adder-switch 39, intended for summing in the steam pressure control (RD) setting modes power corrected for pressure (OAP received from the driver 5 of the error signal, as well as the summation in the frequency maintenance (RF) and reversal (PP) modes, the power assignment corrected by the frequency Od "coming from the Mismatch Alternator 8. The output is transformed, the driver 38 is connected to the first input of the adder-switch 39, as well as to the second inputs of the analog comparators 34 and 35. In the mode of planned loading (unloading), maintaining power (PM), maintaining frequency (RF ), emergency control automation (PAIMP) switch 36 connects the inputs of the reversible counter 37 summation (sc,) or vyagitany (s) signals from the comparator 34 according to the results of the setpoint setpoint signal 32 with the output voltage code and FCV signal, from the crystal oscillator 33.

The rate of the planned loading (unloading) of the turbine to the level set by the operator in the unit 32, the charter is determined by the frequency F (quartz oscillator 33.

On commands from the control unit 14 in the pressure maintenance and reversal mode, the switch 36 is set to pass to the inputs of the reversible summation signal counter (T or subtraction (ip) from the output of the comparator 35 of the F signal from the crystal oscillator 33. The reversible counter is switched to the tracking mode the current value of the power coming from the sensor 11 power.

The continuous limiting level shaping unit 4 (Fig. 3) contains an additional shaper 40 of analog signals, the output signals of which in the form of analog levels are simultaneously and continuously transmitted to the information inputs of the switch 41, to the control inputs of which receive signals from the power supply system of emergency control. These signals also arrive at circuit 42 OR. Only one of the levels can pass to the output of the switch 41 when the corresponding command is received from the power system emergency control automation. In the case of the absence of commands from the power system emergency control automatics, a zero level signal is generated at the output of the switch 41. The output signal of the circuit 42 controls the operation of the switch 43 and the power storage unit 44, the output of which receives signals from power sensor 1. The output signal of the power storage unit 44 is fed to the first information input of the switch 43, the second information input of which receives the signal of the maximum turbine power from the driver 40. The output signals of the switches 41 and 43 are fed to the inputs of the subtractor 45, the output of which is connected to the input of the reader 3 minimum signal. When a command is received for continuous unloading of a turbine by a certain amount, for example, 20% of the rated power, by

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the output of the switch 41 from the imaging unit 40 passes a signal proportional to the amount of unloading. At the same time, the output of the RSHI circuit 42 generates a signal that controls the operation of the switch 43 and the power storage unit 44. According to the signal of the circuit 42, the power storage unit 44, which monitors in normal

operating mode, the output signal of power sensor 1 records the value of the actual power of the turbine reached at the time of the signal received by the power supply system of the emergency automation, and the switch 43 ensures that the output signal of the power storage unit 44 passes to the input of the subtractor 45. At the second entrance of the subtractor 45 comes

signal proportional to the desired amount of discharge. At the output of the subtractor 45, a limit level is formed, equal to the difference between the current power value and the value by which the power needs to be reduced according to the task of the power system emergency control automation. In the absence of commands ot power system emergency automation on the output of the switch 43 and the output of the subtractor 45 passes the signal from the driver 40, proportional to the maximum power of the turbine.

Multimode integrator 13

(Fig. 4) contains the integrating direction generator 46 in the tracking mode, the integrating speed generator 47 in the tracking mode, the working integrated direction direction generator 48, the working integrator 49 of the speed-integration, made in the form of an input voltage-to-frequency converter 50 and a controlled divider 51 frequencies,

a switch 52, a reversible counter 53, and an output code to voltage converter 54. In the absence of a signal from the output of the block 25, the switch 52 is set to pass to the inputs of the reversible counter 53 of the summing signals (cii or subtraction (cp) ° T of the working driver 48 of the integration direction and signals from

Shaper 49 integration speed. Let the input signal from the adder 12, defined as the difference between the set and measured

the parameter value is positive. In this case, the working formator 48 of the integration direction, made, for example, in the form of a null organ, generates an SDC signal at its output, and the output voltage-to-frequency converter 50 generates a frequency proportional to the value of its input signal. The magnitude of this frequency is greater than that required for any of the modes for adjusting the selected parameter. However, the controlled divider

51 frequency reduces this frequency to the desired value. The division ratio of the controlled frequency divider 51 is set by the signal of the control unit 14 depending on the constant time of the automatically selected control mode. Thus, the working driver 49 provides for the integration of the error signal with the necessary speed for any selected mode.

For automatic tracking of the integrator for the position of the servomotor 19 on command from the block 25 switch

52 connects to the inputs of the reversible counter 53 output signals from the integrator 47 of the integration speed in tracking mode, for example, made in the form of a high-frequency generator, and from the integrator 48 of the integration direction, made in the form of a null organ. In accordance with the sign of the signal from adder 26, shaper 46 of the direction of integration generates a summation or subtraction signal. The reversible counter 53 at high speed changes its state in the direction of summation or subtraction until the signal from the output of the adder 26 is packaged.

will not become zero.

Multichannel switch 15 (Fig. 5) contains amplifiers 55-61 and switch 62. The amplification factor of amplifier 55 corresponds. coefficient proportional component of the control algorithm in turn mode (load shedding) The gain factor will increase (w 56 corresponds to the coefficient proportional component of the control algorithm in emergency control automatics (PAimp). Coefficients of amplifiers 57-61 are set accordingly proportional components of the control algorithms in the modes of maintaining the frequency (RF) with often 5 F networks: Y, + dG (where F. is the nominal frequency, LG is the frequency deviation), power (PM), pressure maintenance (RD-1), pressure-maintaining mode-saving (RD-2), frequency maintenance (RF) mode at the network frequency FP f NOL1 When the control unit I4 arrives at the control input of the switch 62, the signal about

5, turning on the turn mode, the output of the multi-channel switch I5 is passed through a signal passed through the amplifier 55 and corresponding to the proportional component of the control algorithm in the turn mode.

A signal from the logic switch 28 on switching on the PAimp mode, which is fed to the control input of the switch 62, passes the signal to the output of the switch 15, passing the amplifier 56 and corresponding to the proportional component of the control algorithm in the GGAimp mode.

 Similarly, when the control unit 4 turns on according to the accepted hierarchy of other modes, the output of the switch 15 passes a signal proportional to the component of the corresponding mode control algorithm.

The control unit 14 (Fig. 6) contains a setpoint adjuster 63 for setting the automatic switching on the frequency maintenance mode (RF), comparators 64 and 65, a setting dial 66 for the automatic switching on the power maintenance mode (PM), a setting dial 67 for the automatic switching on stere5.

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pressure boosting mode (RD-2), comparator 68, setpoint adjuster 69, comparator 70, hierarchical switch 71 consisting of inB and logic circuits

I-NOT, matching unit 72. The control unit operation algorithm determines the dependence of the operating modes of the turbine control system on the signals and commands of the power system, the reactor, the equipment status, and the parameters of the turbogenerator.

At the simultaneous receipt of signals for switching on modes, the priority is given to the signal at a higher level of the hierarchy. Below are the signals in order of decreasing priority.

The signal that the generator breaker is turned off, by which the load shedding mode (turn) is activated.

The signal from the power supply emergency control automation to activate the PAimp mode.

The signal that the network frequency increases above a predetermined value, generated by the comparator 64 by comparing the signals of the frequency sensor 9 and the setpoint adjuster 63. This signal should automatically switch to the RF mode and maintain the frequency of the static characteristic.

A signal for automatic activation of the power maintenance mode (PM mode). formed by the comparator 65 with the turbine power of the turbine unit is lower than the setpoint of the setpoint 66.

The signal for the automatic activation of the steaming pressure maintenance mode (RD-2 mode) generated by the comparator 68 when the vapor pressure drops below the setpoint value of the setpoint 67.

The signal from the reactor to turn on the pressure maintenance mode (

RD-1).

The signal that the network frequency has dropped below a predetermined value, generated by the comparator 70 by comparing the signals from the frequency sensor 9 and the setpoint adjuster 69. This signal should automatically switch to RF mode.

The hierarchical dependence of the inclusion of control modes in accordance with a given priority is realized by the hierarchical switch 71 The signals for switching on the modes are connected to the inputs of the hierarchical switch in order of decreasing priority.

When a signal is received for switching on a mode that is at a higher level of the hierarchy, a ban is drawn on the AND-NOT circuits of the signal passing on the switching on regimes located at the lower levels of the hierarchy. So, when the generator switch-off signal is received, the mode is activated (load shedding) regardless of the mode in which the regulator system operated before.

turbine lyration. PAimp mode can be enabled only when there is no signal} and the switch is turned off.

RF mode at F. K .. „+ dR can

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5 be turned on only in the absence of a switch-off signal and a paimp.

The inclusion of the modes RD-2, RD-1, RF with FJ P "one, - uf occurs like 10

in the same way in the absence of sig5

The numbers of the higher-priority ones correspond to jBeTCTBeHHO.

The signals for the activation of the regulation modes from the output of the hierarchical switch 71 through the matching unit 72 arrive at the inputs of the driver 1 of a given power, the multi-mode integrator 13, the multi-channel switch 15 and other nodes.

The pulse unloading unit 25 (FIG. 7) contains drivers 73, 74 and 75, triggers 76, 77 and 78, logic circuit 79 HJlIi-HE, inverter 80, logic circuit 81 PI-HE, inverter 82, logic circuit 83 AND- NOT, threshold elements 84-87, logical circuits 88, 89, 90 AND-NOT, logic 91 OR-NOT, logic 92 AND-NOT, second additional driver 93 analog signals, second additional switch 94, fourth adder 95 , analog integrator 96.

When a command is received from the energy-system emergency control automation for the pulse unloading of a turbine by a certain amount, for example, 30% of the rated power,

0, the trigger signal 73 is energized by trigger 76 and a signal appears at the output of circuit 79 and inverter 80, which determines the onset and subsequent control of the turbine in a PAimp mode.

5 According to this signal, switch 94 through the adder 95 passes the signal from shaper 93 to the input of analog integrator 96. In the integration process, the output signal of integrator 96 reaches the setpoint level of threshold element 84. At the output of logic circuit 88, IS-NOT is generated by trigger signals 76 and threshold element 84, a signal is generated with a duration dT (from the moment of raising the trigger 76 to the moment when the output signal of the integrator 96 reaches the threshold of the threshold element

84), which is fed through logic 91 and logic circuit 92 to the second output of the block. The specified duration of the signal d T, which determines the depth of discharge, is proportional to the magnitude of the setpoint for the carrier 93, arriving at the threshold element 84.

Similarly, at the second output of the block (output of the logic circuit 92), signals for other unloading values are generated when commands are received for forming 74 and 75.

The output of logic circuit 83 (third block output) signals from the output of logic circuit 79 and threshold 87 generates a signal with duration T, (from the moment of triggering any of the triggers 76; 77 78 until the output signal of the integrator 96 reaches the setpoint of threshold element 87 ).

The duration of the signal Tj exceeds the maximum duration of the signal dT at the second output of the block (the output of logic circuit 92) by an amount corresponding to the time of the end of transient processes of power change associated with the opening of shut-off valves (gates) after the end of the signal at the output of circuit 92 and the return of cut-off spools cutoff position. The triggers 76, 77 to 78 are reset to the initial state by a signal from the null organ 27, fed through logic 81 to the second inputs of the triggers, when there is no signal at the output of the threshold element 87. The signal at the output of the circuit 81 determines the end of the turbine control in the PAimp mode. After the adjustment is completed, the turbish, in the PAimp, the switch 94 passes the integrator output signal to its input through the adder 95, as a result of which the integrator returns to

initial zero state. I

The system in the power maintenance mode operates as follows.

If the signal from the output of the imager 1 of the specified power does not exceed any of the levels of the limitation coming from the extractor 3 of the minimum signal, then through the limiter 2 it enters the input of the first adder 12 as the specified power value.

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If the driver signal exceeds the output signal of Display 3, then the last, minimum of limit 5 levels is transmitted to adder 12 as a power reference.

In adder 12, the difference between the setpoint and the current power is calculated, which is proportional to the output signal of the power sensor 11. The difference signal from the expander of the adder 12 is fed to the first information input of the multi-mode integrator 13 and if there is no signal at the first output of the block 25 through the limiter 29 without restriction (the second input of the limiter 29 in this case receives from the imager 31 a signal that exceeds the maximum difference value) on the information input of the multichannel ko-mutator 15,

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The help unit 14 establishes in the integrator 13 a time constant corresponding to the power maintenance (PM) mode 5, and in the multi-channel switch 15 connects to the output an accelerator signal corresponding to the proportional component for this cutting.

The output signals of the integrator 13 and com UE / tator 15 through the second adder 16 is fed to the total amplifier i 7.

The control signal formed from the output of the amplifier 17, formed according to the algorithms: r-sy, goes to the electro-hydraulic converter 22, through the shut-off valve 2 and the servomotor 19, acting on the turbine bellows.

The control process in the frequency support (RF) mode differs from that described in that in shaper 1, as commanded by the control unit 14

When switching on the power supply, Lenin set by the operator j is summed with the frequency correction from the error generator 8, and in the integrator 13 and the switch 15, the integration time constant is established and a proportional control algorithm is formed to maintain the frequency

In the pressure maintenance mode in the imaging unit 1, at the command of the control unit 14, the reversible counter 37 is switched to the mode from one day to one.

The lower power value received from sensor 11. In addition, in this mode, in the driver 1, the power reference equal to the current value of the power is summed with the correction for the pressure from the driver 5 of the dissipation signal.

If the output signal of the imaging unit 1 does not exceed any of the levels of limitation, then it will go through the limiter 2 to the input of the adder 12, the second input of which is connected to the power sensor 11. As a result, the control action generated according to the control algorithm in the pressure maintenance mode does not depend on the value of the current power, and is actually determined only by the output signals of the error signal generator 5. The process of forming a control action in the reversal mode is the same as in the pressure maintenance mode. The only difference is that according to the commands of the control unit 14 in the integrator 13 and the switch 15, the time constant and the proportional component coefficient are set corresponding to the rotation mode. If, in the pressure maintenance mode, the signal from the output of the imaging unit 1 exceeds the output signal of the display 3 of the minimum signal, the smallest of the levels of limitation is fed to the adder 12 as a power task.

The control action in this case ensures the maintenance of power at the level reached at the time of the occurrence of the limitation, which prevents emergencies and increases the reliability of the turbine unit. After removing the restriction, the control system again proceeds to maintain the vapor pressure.

When commands are received from the power system emergency control automation for pulsed unloading, unit 25 at its output (output of logic circuit 92) generates a signal duration iT (depending on the required amount of unloading), allowing the additional switch 24 to pass through the input of electro-hydraulic signal converter 22 from unit 23. The result is

27823 .12

unloading turbine with maximum speed. At the same time, the signal from the output of block 25 (output of logic circuit 80) of control unit 14, when there is no signal that the generator air switch is turned off, switches the control system to the PAimp mode, which is characterized as follows.

to the integrator 13 during the time T according to the signal from the output of block 25 (output of logic circuit 83) switches to the tracking mode of the servomotor 19. At the same time, the second information input of the integrator 13 from the third adder 26 receives the signal of the difference between the signals of the sensor 18 and the second adder 16. Logic switch 28; sochi

20 from the inverter and the NAND logic, and the time Tj prohibits the connection of the proportional component for the PAimp mode in the switch 15, and therefore, for the time T, the signal from the output of the cz mamator 16 is equal to the signal from the output of the integrator 13. After the time T (the integrator 13 proceeds to the formation of a signal coming to the information

3Q input, integral component for the PAimp mode with a given constant time. According to the signal from the output of the block 25, the switch 30 passes from the imaging unit 31 to the second input of the limiter 29 a signal of a predetermined level of the output signal output from the output of the adder 12 through the limiter 29 to the information input of the switch 15.

Q The need to form and limit the proportional component in the PAimp mode is associated with the nonlinearity of the initial portion of the flow characteristic. In most cases, the commands for the long-term and the impulse from the power system emergency control automation arrive simultaneously.

In this case, after the completion of 50 pulsed unloading, the current turbine power returns not to the specified, but to the level of long-term power limitation. If, before or during the impulse unloading, other power limitations were observed, then after the end of the PAimp mode the current power will return to the level corresponding to the output signal 35

13

Restrictor 2 time. The moment of completion of the PAimp mode is determined by the zero-body 27 in the absence of a signal at the output of block 25 (output of the logic element 87 and logic circuit 83). the output of the adder 12 may be equal to zero (in the case of

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simultaneous continuous and pulse unloading) by opening the shut-off valves (dampers) after closing the control valves in the 5th process of returning the shut-off spools to the cut-off position.

After the end of the mode, the system switches to the control mode according to the specified hierarchy 1 | Hin,

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R. Editor A. Dlinich

Compiled by A. Kalashnikov

Techred L Olaine IC. Proofreader M. Sharoshi

Order 2273/35

Circulation 500 Subscription

VNIIGSh of the USSR State Committee

Inventions and discoveries 113035, Moscow, Raushsk nab., 4/5

Production Printing Polygraph, g, Uzhgorod, st. Project, 4

Claims (1)

SYSTEM. TURBINE POWER CONTROL SYSTEM, comprising a driver of a given power connected together with a minimum signal detector to the inputs of a limiter of a given power, a unit for generating a level of long-term limit connected to a detector of a minimum signal, a power sensor connected to a specified block of formation, to a driver of a given power and to the input of the first adder, also connected by its input to the output of the limiter of a given power, and the output - with a multi-mode integrator, control unit, the odes of which are connected to the generator circuit breaker and to sensors of power, rotational speed and steam pressure, and the outputs are connected to a multi-mode integrator and a multi-channel switch, the outputs of which through the second adder are connected to the input of the summing amplifier together with the position sensors of the servomotor and its shut-off valve connected to the output electro-hydraulic Converter, connected by its input to the output of the summing amplifier, characterized in that, in order to increase reliability when controlling power in emergency in situations of the power system, the system is equipped with a maximum signal unit, an additional switch, a pulse unloading generation unit, a third adder, a zero-organ, a logical switch, a signal difference limiter, an additional switch and an analog signal shaper, and the pulse unloading formation unit is connected by an output to the inputs of the control unit, additional switch and integrator, the maximum signal unit is connected to an additional switch, the output of which is inen with the input of the electro-hydraulic converter, the inputs of the third adder are connected to the position sensor of the servo motor and to the output of the second totalizer, and the output to the integrator, the input of the zero-organ is connected to the output of the first adder, and the output is connected to the input of the pulse discharge forming unit, the inputs of the logic converter are connected to the output of the control units and the formation of pulse unloading, and the output to the multichannel switch, the signal difference limiter is connected by the inputs to the outputs of the first adder and additional reklyuchatelya connected to the analog signal generator and the pulse forming unit unloading and output - to a multichannel commutative 1227823 A1 torus. ί