CN117489859A - Soft measurement system and method for valve position of power failure movable door in thermal power generating unit - Google Patents

Abstract

The invention discloses a soft measurement system and a soft measurement method for a valve position of a power failure movable door in a thermal power generating unit, wherein the system comprises a system initialization module, a system calculation module and a system output module which are connected in sequence; the method comprises the following steps: and obtaining an internal signal through a system initialization module: soft measurement is carried out to calculate a valve position reference value POsref; and calculating to obtain a system internal signal through a system calculation module: an ODL being operated, a CDL signal being operated by a valve being closed, a valve position increasing signal OID of a periodic door opening valve and a valve position decreasing signal CCD of a periodic door closing valve; the system output module receives an internal signal POSEF output by the system initialization module and receives an internal signal generated by the system calculation module: the valve is in an open operation ODL, the valve is in a close operation CDL signal, a periodic door opening valve position increasing signal OID and a periodic door closing valve position subtracting signal CCD, and the soft measurement calculation valve position POS output is obtained. According to the invention, the valve position of the electric door is automatically calculated according to the related signals of the electric door, so that operators can conveniently monitor the valve position feedback of the electric door in a centralized control room.

Description

Soft measurement system and method for valve position of power failure movable door in thermal power generating unit

Technical Field

The invention belongs to the field of automatic control of thermal power plants, and particularly relates to a soft measurement system and method for a power failure movable door position in a thermal power unit.

Background

The remote control electric door of the DCS control system of the thermal power plant unit can be opened and closed remotely in the centralized control room by an operator. The part of electric door is designed with a stop function, and an operator performs remote opening, closing and stop operations in a centralized control room. If the inlet electric door of the steam pipeline is needed, the inlet electric door of the steam pipeline needs to be opened by a small opening degree before steam enters the pipeline, and the electric door is opened again after the pipeline is preheated sufficiently. If the electric door needs to be subjected to the stop-in operation and the electric door is not provided with the DCS stop-in function, an operator needs to perform the on-site operation on the electric door through a hand crank on site to realize the stop-in function.

For the electric door which needs to stop operation without designing a DCS stop function, the wiring of an electric head of the electric door can be modified, and the DCS stop function can be realized. After the wiring of the electric head is modified, the electric door can execute the opening operation when the DCS sends the opening operation instruction, the electric door executes the opening operation when the DCS sends the closing operation instruction, and the electric door keeps the current position after the opening operation instruction and the closing operation instruction are all disappeared. However, for a valve of a thermal power generating unit part which is stopped in a DCS remote switch, if a valve position feedback measuring point is not designed for the valve, an operator cannot monitor the specific opening position of the valve switch when the DCS remote operation is performed. After the DCS middle stop function is realized by the electric door, in order to facilitate operators to check the current valve position of the electric door, local valve position signals are paved through cables to be connected into a standby channel of a DCS main control system clamping piece of the thermal power unit. Otherwise, the operator can monitor the state of the electric door in the centralized control room only when the valve is fully opened or fully closed, and the operator cannot know the current opening of the valve in the centralized control room when the valve is at a certain middle position.

Disclosure of Invention

The invention aims to provide a soft measurement system and a soft measurement method for the valve position of a power failure movable door in a thermal power generating unit, which can automatically calculate the valve position of the movable door according to related signals of the movable door, are convenient for operators to monitor valve position feedback of the movable door in a centralized control room, and save the workload and related cost of a valve position feedback signal cable laying and a new signal occupying a standby channel of a DCS clamping piece.

The invention is realized by adopting the following technical scheme:

a soft measurement system of a power failure dynamic valve position in a thermal power generating unit comprises a system initialization module, a system calculation module and a system output module which are connected in sequence; the input signals of the system include: the system comprises a medium power failure dynamic door full-open signal OP, a medium power failure dynamic door full-close signal CP, a DCS, a medium power failure dynamic door open command OD, a close command CD, a stop command SD, a manual correction request signal RD and a manual correction valve position signal RPOS; the system setting parameters include: the method comprises the steps of opening an initial stroke time parameter OT0, closing an initial stroke time CT0, a system calculation period CCT and whether a valve switch instruction is a long signal DSL or not; system output signal: soft measurement calculates a valve position POS;

the system initialization module is used for judging whether the system is initialized or not and obtaining a soft measurement calculation valve position reference value POSEF;

a system calculation module for generating an internal signal: the valve is opening and operating ODL, the valve is closing and operating CDL signals, a periodic door opening valve position increasing signal OID and a periodic door closing valve position decreasing signal CCD, judging whether the current valve is opening or closing, and generating internal parameters of a system: a periodic door opening valve position increasing signal OID and a periodic door closing valve position subtracting signal CCD;

the system output module is used for receiving the internal signal POSEF output by the system initialization module and receiving the internal signal generated by the system calculation module: the valve is in an open operation ODL, the valve is in a close operation CDL signal, a periodic door opening valve position increasing signal OID and a periodic door closing valve position subtracting signal CCD, and the soft measurement calculation valve position POS output is obtained.

The invention is further improved in that the system initialization module marks the state of whether the system is initialized according to whether the system is first powered on and executed for the first time; the system initialization module is used for marking that the system is initialized when being executed for the first time, otherwise, the system is marked as initialized; when the system is not initialized and the power failure movable door full-open signal OP is true, soft measurement is carried out to calculate a valve position reference value POsref to be 100%; when the system is not initialized and the power-off movable door full-open signal OP is not sent; soft measurement calculates the valve position reference value POsref to be 100%; and when the system is initialized, the soft measurement calculation valve position reference value POSEF is converted into a soft measurement calculation valve position POS (n-1) generated by a periodic system output module on the system.

The invention is further improved in that the periodic door opening valve position increase signal OID refers to a valve position signal which needs to be increased in a system calculation period when the valve is in the process of opening.

The invention is further improved in that the periodic door opening valve position increase signal OID is calculated according to the following three conditions:

if the system is not initialized, the periodic door opening valve position increasing signal OID is the quotient of the system calculation period CCT and the door opening initial travel time parameter OT 0;

if the system is initialized, a full open signal OP of the middle power failure dynamic door is sent out, and a soft measurement calculation valve position POS (n-1) generated by a system output module of the last period of the system is not 0, the condition O1 is judged, and at the moment, the system calculation module automatically corrects a period open valve position increment signal OID according to the soft measurement dynamic door valve position output by the last period of the system to achieve the effect of reducing subsequent calculation errors; the periodic door opening valve position increment signal OID is obtained by a periodic door opening valve position increment signal OID (n-1) generated by a periodic system calculation module on the system and a soft measurement calculation valve position POS (n-1) generated by a periodic system output module on the system;

if the system is initialized, the condition O2 is judged when the power-off full-open signal OP is not sent out or the soft measurement calculation valve position POS (n-1) generated by the periodic system output module on the system is 0, the periodic door opening valve position increment signal OID is not corrected, and the periodic door opening valve position increment signal OID is reserved as the periodic door opening valve position increment signal OID (n-1) generated by the periodic system calculation module on the system.

A further improvement of the invention is that the periodic door closing valve position decrease signal CCD refers to a valve position signal which needs to be decreased in a system calculation period when the valve is in the closing process.

The invention is further improved in that the periodic door closing valve position subtracting signal CCD is calculated according to the following three conditions:

if the system is not initialized, the periodic door closing valve position subtracting signal CCD is the quotient of the system calculation period CCT and the door closing initial stroke time parameter CT 0;

if the system is initialized, a soft measurement calculation valve position POS (n-1) generated by a system output module of the last period of the system is not 100, and is judged to be a condition C1, and at the moment, the system calculation module automatically corrects a period closing valve position subtracting signal CCD according to the soft measurement valve position of the last period of the system to achieve the effect of reducing the subsequent calculation error; the periodic door closing valve position subtracting signal CCD is obtained by a periodic door closing valve position subtracting signal CCD (n-1) generated by a periodic system computing module on the system and a soft measurement computing valve position POS (n-1) generated by a periodic system output module on the system;

if the system is initialized, the condition C2 is judged when the power-off moving door complete-closing signal CP is not sent or the soft measurement calculation valve position POS (n-1) generated by a periodic system output module on the system is 100, the periodic door closing valve position subtracting signal CCD is not corrected, and the periodic door closing valve position subtracting signal CCD is reserved as the periodic door closing valve position subtracting signal CCD (n-1) generated by the periodic system calculation module on the system.

The invention further improves that the specific implementation method of the system output module is as follows:

when the full-open signal OP of the stop electric door is true, outputting a soft measurement calculation valve position POS as 100%; when the stop electric door full-closing signal CP is true, outputting a soft measurement calculation valve position POS to be 0%; when the valve is in an open operation ODL, outputting a soft measurement calculation valve position POS which is the sum of a valve position reference value POSEF and a door opening valve position increment signal OID of a soft measurement calculation valve position output by a system initialization module; when the valve is in closing operation CDL is true, the soft measurement calculation valve position POS is outputted as the difference between the valve position reference value POSEF and the closing valve position subtraction signal CDD of the soft measurement calculation valve position POS outputted by the system initialization module.

A further improvement of the present invention is that the system further includes a manual correction function for calculating the valve position by which the calculated valve position is consistent with the in-situ displayed valve position when there is an operator in-situ opening and closing the operator operated electric door.

A soft measurement method for a power failure movable door valve position in a thermal power generating unit comprises the following steps:

and obtaining an internal signal through a system initialization module: soft measurement is carried out to calculate a valve position reference value POsref;

and calculating to obtain a system internal signal through a system calculation module: an ODL being operated, a CDL signal being operated by a valve being closed, a valve position increasing signal OID of a periodic door opening valve and a valve position decreasing signal CCD of a periodic door closing valve;

the system output module receives an internal signal POSEF output by the system initialization module and receives an internal signal generated by the system calculation module: the valve is in an open operation ODL, the valve is in a close operation CDL signal, a periodic door opening valve position increasing signal OID and a periodic door closing valve position subtracting signal CCD, and the soft measurement calculation valve position POS output is obtained.

The invention has at least the following beneficial technical effects:

the invention provides a soft measurement system and a soft measurement method for a power failure movable valve position in a thermal power unit, which are used for automatically calculating the power failure movable valve position according to received power door opening feedback, closing feedback, opening instructions and closing instructions, and automatically calculating to obtain power failure movable valve position output for soft measurement of the power failure movable valve, and are convenient for operators to monitor the power door position feedback in a centralized control room, so that the workload and related cost of laying valve position feedback signal cables and occupying standby channels of DCS clamping pieces can be saved. The invention can automatically adjust the calculation error when the valve reaches the full open or full close position each time. When the valve is fully opened or fully closed, the system automatically corrects the internal signal based on the soft measurement electric door valve position output in the last period, thereby achieving the effect of reducing the subsequent calculation error.

Drawings

Fig. 1 is a control flow chart of the present invention.

Fig. 2 is a logic diagram of the system calculation module of the present invention generating an on-operation ODL and a valve off-operation CDL signal, wherein fig. 2 (a) is a logic diagram of the on-operation ODL and the valve off-operation CDL signal when the system parameter valve switch command is a long signal DSL of 0, and fig. 2 (b) is a logic diagram of the on-operation ODL and the valve off-operation CDL signal when the system parameter valve switch command is a long signal DSL of 1.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other. The invention will be described in detail below with reference to the drawings in connection with embodiments.

After the electric head wiring of the thermal power unit is modified to realize the DCS middle stop function, in order to facilitate operators to check the current valve position of the electric door, local valve position signals are paved into a standby channel of a DCS main control system clamping piece of the thermal power unit through cables. The invention provides a valve position soft measuring point method for a middle power failure movable door, which can calculate the valve position of the movable door according to related signals (opening instruction, closing instruction, opening feedback and closing feedback) of the movable door, is convenient for operators to monitor the valve position feedback of the movable door in a centralized control room, and saves the workload and related cost of laying valve position feedback signal cables and occupying a standby channel of a DCS clamping piece.

A soft measurement system of a power failure movable door valve position in a thermal power generating unit provides a system calculation module of the power failure movable door, and the power failure movable door valve position is automatically calculated according to received power failure movable door opening feedback, closing feedback, opening instructions and closing instructions.

An input signal of a soft measurement system of a power failure dynamic valve position in a thermal power generating unit comprises: the system comprises a medium power failure dynamic door full-open signal OP, a medium power failure dynamic door full-close signal CP, a DCS, a medium power failure dynamic door open command OD, a close command CD, a stop command SD, a manual correction request signal RD and a manual correction valve position signal RPOS; the system settable parameters include an opening initial travel time parameter OT0 (e.g. 100 s), a closing initial travel time CT0 (e.g. 100 s), a system calculation period CCT (e.g. 0.5 s), whether a valve opening and closing instruction is long signal DSL (the opening and closing quantity is 1, the valve opening and closing instruction is long signal, and 0, the valve opening and closing instruction is pulse short signal). System output signal: the soft measurement calculates the valve position POS.

A soft measurement system for a power failure dynamic valve position in a thermal power generating unit comprises a system initialization module, a system calculation module and a system output module.

The system initialization module is used for judging whether the system is initialized or not and obtaining an internal signal: soft measurements calculate the valve position reference value POSref.

The main function of the system computing module is to generate internal signals: the valve is opening ODL, the valve is closing CDL signal, the valve increasing signal OID of the periodic door opening valve, and the valve decreasing signal CCD of the periodic door closing valve. The system calculation module automatically corrects internal signals (a periodic door opening valve position increasing signal OID and a periodic door closing valve position subtracting signal CCD) according to the calculated soft measurement electric door valve position output when the valve is fully opened or fully closed, so that the effect of reducing subsequent calculation errors is achieved.

The system output module is used for receiving an internal signal POSEF output by the system initialization module and receiving an internal signal generated by the system calculation module: the valve is in an open operation ODL, the valve is in a close operation CDL signal, a periodic door opening valve position increasing signal OID and a periodic door closing valve position subtracting signal CCD, and the soft measurement calculation valve position POS output is obtained. When the valve is opening operation ODL is true, the output soft measurement calculation valve position POS is equal to the sum of the soft measurement calculation valve position reference value POSEF and the periodic door opening valve position increment signal OID output by the system initialization module. When the valve is in closing operation CDL, the output soft measurement calculation valve position POS is equal to the difference between the soft measurement calculation valve position reference value POSEF output by the system initialization module and the periodic closing valve position subtracting signal CCD. When the valve is at the full open position, the soft measurement calculated valve position output calculated by the system output module is 100%; when the valve is at the fully closed position, the actual switching travel time calculated by the system output module automatically calibrates the travel time of the valve, and the soft measurement calculated valve position output calculated by the system output module is 0%. Meanwhile, the system output module provides a manual correction function for calculating the valve position, and when an operator opens and closes the electric door in situ, the calculated valve position can be kept consistent with the in-situ display valve position through the manual correction function.

A soft measurement method of a power failure movable door valve position in a thermal power generating unit is shown in figure 1, and comprises the following steps: s01, obtaining a soft measurement calculation valve position reference value POSEF through a system initialization module; s02, obtaining a system internal signal through a system calculation module: a periodic door opening valve position increasing signal OID and a periodic door closing valve position subtracting signal CCD; s03, generating soft measurement calculation valve position POS output POS of the current calculation period through a system output module, and finishing the execution of the current calculation period. And then, the system in the next system calculation period sequentially executes the system calculation module and the system output module again to generate soft measurement calculation valve position POS output in the next calculation period, so that continuous calculation output of the soft measurement calculation valve position POS is realized.

The invention provides a soft measurement method for a valve position of a power failure movable door in a thermal power generating unit, which comprises the following detailed implementation processes:

the first step: s01, obtaining an internal signal through a system initialization module: soft measurements calculate the valve position reference value POSref.

A soft measurement system for a power failure dynamic valve position in a thermal power generating unit comprises a system initialization module. The system initialization module is used for judging whether the system is initialized or not and obtaining a soft measurement calculation valve position reference value POsref. The system is suitable for primary power-on input when the middle power failure movable door is fully opened or fully closed.

And the system initialization module marks the state of whether the system is initialized or not according to whether the system is first executed when the system is powered on for the first time. The first time the system initialization module is executed, the marking system is not initialized, otherwise, the marking system is initialized. When the system is not initialized and the power failure movable door full-open signal OP is true, soft measurement is carried out to calculate a valve position reference value POsref to be 100%; when the system is not initialized and the power-off movable door full-open signal OP is not sent; soft measurement calculates the valve position reference value POsref to be 0%; the system is initialized, and the soft measurement calculation valve position reference value POSEF is the soft measurement calculation valve position POS (n-1) generated by a periodic system output module on the system. The related calculation formula of the numerical value POref (n) of the current system calculation period POref is as follows:

and a second step of: s02, calculating to obtain a system internal signal through a system calculation module: an ODL is being operated, a CDL signal is being operated by the valve being closed, a valve position increase signal OID is being opened periodically, and a valve position decrease signal CCD is being closed periodically.

A soft measurement system for a valve position of a power failure movable door in a thermal power generating unit comprises a system calculation module. The main function of the system computing module is to judge whether the current valve is on or off and generate internal parameters of the system: the valve position increment signal OID of the periodic door opening and the valve position decrement signal OID of the periodic door closing. The valve position increasing signal OID of the periodic door opening refers to a valve position signal which specifically indicates that a system calculates the period to be increased when the valve is in the process of opening; the periodic door closing valve position subtracting signal CCD specifically refers to a valve position signal which needs to be reduced in a system computing period when the valve is in the closing process.

In the system operation process, the internal signal periodic door opening valve position increasing signal OID and the periodic door closing valve position decreasing signal CCD are changed in real time. When the valve is fully opened or fully closed, the system calculation module automatically corrects the internal signals (the periodic door opening valve position increasing signal OID and the periodic door closing valve position subtracting signal CCD) according to the soft measurement electric door valve position output by the system in the last period, so that the effect of reducing the subsequent calculation error is achieved.

The method comprises the following specific steps:

2.1 generating an internal signal: the ODL is being operated on and the CDL signal is being operated off.

If the system judges that the current valve is in positive operation, the ODL signal is 1 in the opening operation, otherwise, the ODL signal is 0. If the system judges that the current valve is in the closing operation, the CDL signal is 1 in the closing operation, otherwise, the CDL signal is 0.

The system designs whether the internal parameter valve switch instruction is long signal DSL (the switch quantity, 1, 0, the valve switch instruction is pulse short signal).

Specifically, if the system parameter DCS switch command is 0 if the long signal DSL indicates that (i.e., the DCS has a stop command to the stop electric gate and the DCS has pulses to the stop, switch, and switch commands to the stop electric gate), the valve on operation ODL and the valve off operation CDL signals are generated in fig. 2 (a). If the system parameter valve switch command is 1 (i.e. the DCS is long for the on and off commands of the centering electric gate, the on command OD remains output during the DCS on operation, and the off command CD remains output during the DCS off operation), then the valve on operation ODL and the valve off operation CDL signals are generated through fig. 2 (b).

2.2 generating an internal signal: the valve position of the periodically opened door increases the signal OID.

The calculation of the valve opening and closing command period door opening valve position increase signal OID is divided into the following three cases:

1. if the system is not initialized, the periodic door opening valve position increasing signal OID is the quotient of the system calculation period CCT and the door opening initial travel time parameter OT 0.

2. If the system is initialized, a full open signal OP of the middle power failure dynamic door is sent out, and when a soft measurement calculation valve position POS (n-1) generated by a system output module of the last period of the system is not 0, the condition O1 is judged to be met, and at the moment, the system calculation module automatically corrects a period open valve position increment signal OID according to the soft measurement dynamic door valve position output by the last period of the system to achieve the effect of reducing subsequent calculation errors. The periodic door opening valve position increment signal OID is obtained by a periodic door opening valve position increment signal OID (n-1) generated by a periodic system calculation module on the system and a soft measurement calculation valve position POS (n-1) generated by a periodic system output module on the system;

3. if the system is initialized, the open signal OP of the power failure stop valve is not sent out or the condition O2 is judged to be met when the soft measurement calculation valve position POS (n-1) generated by the system output module of the last period system of the system is 0, the increase signal OID of the valve position of the period open valve is not corrected, and the increase signal OID of the valve position of the period open valve is reserved as the increase signal OID (n-1) of the valve position of the period open valve generated by the system calculation module of the last period system of the system.

The numerical OID (n) related calculation formula of the current system calculation period OID is as follows:

2.3 internal signals are generated: the valve position of the door is periodically closed by a signal CCD.

The calculation of the periodic door closing valve position subtracting signal CCD is divided into the following three cases:

1. if the system is not initialized, the periodic door closing valve position subtracting signal CCD is the quotient of the system calculation period CCT and the door closing initial stroke time parameter CT 0.

2. If the system is initialized, a power failure power-off gate total-closing signal CP is sent out, and a condition C1 is judged to be met when a soft measurement calculation valve position POS (n-1) generated by a system output module of a last period of the system is not 100, and at the moment, the system calculation module automatically corrects a period of a gate closing valve position subtracting signal CCD according to the soft measurement power-off gate valve position output by the last period of the system to achieve the effect of reducing subsequent calculation errors. The periodic door closing valve position subtracting signal CCD is obtained by a periodic door closing valve position subtracting signal CCD (n-1) generated by a periodic system computing module on the system and a soft measurement computing valve position POS (n-1) generated by a periodic system output module on the system;

3. if the system is initialized, the condition C2 is judged to be satisfied when the power-off moving door complete-closing signal CP is not sent or the soft measurement calculation valve position POS (n-1) generated by the periodic system output module on the system is 100, the periodic door closing valve position subtracting signal CCD is not corrected, and the periodic door closing valve position subtracting signal CCD is reserved as the periodic door closing valve position subtracting signal CCD (n-1) generated by the periodic system calculation module on the system.

The calculation formula of the numerical CCD (n) of the current system calculation period CCD is as follows:

and a third step of: s03, generating soft measurement calculation valve position POS output of the current calculation period through a system output module, and finishing the execution of the current calculation period.

A soft measurement system for a power failure dynamic valve position in a thermal power generating unit comprises a system output module. The main function is to calculate the valve position POS for soft measurement of the output signal of the calculation generating system. The calculation of the valve position POS by soft measurement of the system output signal is specifically as follows: when the stop electric door full-open signal OP is true, the output soft measurement calculation valve position POS is 100%. When the stop electric door full-close signal CP is true, the output soft measurement calculation valve position POS is 0%. When the valve is opening ODL, outputting a soft measurement calculation valve position POS which is the sum of a valve position reference value POSEF and a periodic door opening valve position increment signal OID of the soft measurement calculation valve position POS output by a system initialization module. When the CDL of the valve is true, the soft measurement calculation valve position POS is the difference between the valve position reference value POSEF and the periodic closing valve position subtracting signal CCD of the soft measurement calculation valve position POS output by the system initialization module. Because the middle power failure movable door can be operated in situ rather than through DCS operation, the DCS side does not send out an electric door opening and closing instruction and the electric door position changes during in-situ operation, and the soft measurement system of the middle power failure movable door position in the thermal power generating unit provides a manual calibration function after in-situ operation. When the system receives the manual correction request signal RD, the soft measurement calculation valve position POS is output as a manual correction valve position signal RPOS. When the stop electric door full-open signal OP, the middle power cut electric door full-close signal CP, the valve opening operation ODL, the valve closing operation ODL and the manual correction request signal RD are not sent, the soft measurement calculation valve position reference value POSEF output by the soft measurement calculation valve position POS system initialization module is kept to be the output of the last period.

The calculation formula of the value POS (n) of the current system calculation period POS is:

after the soft measurement valve position output of the current calculation period is generated, the system of the next system calculation period sequentially executes the system calculation module again, and the system output module generates the soft measurement calculation valve position POS output of the next calculation period, so that the continuous calculation output of the soft measurement calculation valve position POS is realized.

While the invention has been described in detail in the foregoing general description and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that modifications and improvements can be made thereto. Accordingly, such modifications or improvements may be made without departing from the spirit of the invention and are intended to be within the scope of the invention as claimed.

Claims (9)

1. The soft measurement system for the valve position of the power failure movable door in the thermal power generating unit is characterized by comprising a system initialization module, a system calculation module and a system output module which are connected in sequence; the input signals of the system include: the system comprises a medium power failure dynamic door full-open signal OP, a medium power failure dynamic door full-close signal CP, a DCS, a medium power failure dynamic door open command OD, a close command CD, a stop command SD, a manual correction request signal RD and a manual correction valve position signal RPOS; the system setting parameters include: the method comprises the steps of opening an initial stroke time parameter OT0, closing an initial stroke time CT0, a system calculation period CCT and whether a valve switch instruction is a long signal DSL or not; system output signal: soft measurement calculates a valve position POS;

the system initialization module is used for judging whether the system is initialized or not and obtaining a soft measurement calculation valve position reference value POSEF;

a system calculation module for generating an internal signal: the valve is opening and operating ODL, the valve is closing and operating CDL signals, a periodic door opening valve position increasing signal OID and a periodic door closing valve position decreasing signal CCD, judging whether the current valve is opening or closing, and generating internal parameters of a system: a periodic door opening valve position increasing signal OID and a periodic door closing valve position subtracting signal CCD;

the system output module is used for receiving the internal signal POSEF output by the system initialization module and receiving the internal signal generated by the system calculation module: the valve is in an open operation ODL, the valve is in a close operation CDL signal, a periodic door opening valve position increasing signal OID and a periodic door closing valve position subtracting signal CCD, and the soft measurement calculation valve position POS output is obtained.

2. The soft measurement system of a valve position of a power failure movable door in a thermal power generating unit according to claim 1, wherein the system initialization module marks whether the system is initialized according to whether the system is first powered on and executed for the first time; the system initialization module is used for marking that the system is initialized when being executed for the first time, otherwise, the system is marked as initialized; when the system is not initialized and the power failure movable door full-open signal OP is true, soft measurement is carried out to calculate a valve position reference value POsref to be 100%; when the system is not initialized and the power-off movable door full-open signal OP is not sent; soft measurement calculates the valve position reference value POsref to be 100%; and when the system is initialized, the soft measurement calculation valve position reference value POSEF is converted into a soft measurement calculation valve position POS (n-1) generated by a periodic system output module on the system.

3. The soft measurement system of a power outage valve position in a thermal power generating unit according to claim 1, wherein the periodic door opening valve position increase signal OID is a valve position signal which needs to be increased in a system calculation period when the valve is being opened.

4. The soft measurement system of a power failure valve position in a thermal power generating unit according to claim 3, wherein the periodic door opening valve position increment signal OID is calculated according to the following three conditions:

if the system is not initialized, the periodic door opening valve position increasing signal OID is the quotient of the system calculation period CCT and the door opening initial travel time parameter OT 0;

if the system is initialized, a full open signal OP of the middle power failure dynamic door is sent out, and a soft measurement calculation valve position POS (n-1) generated by a system output module of the last period of the system is not 0, the condition O1 is judged, and at the moment, the system calculation module automatically corrects a period open valve position increment signal OID according to the soft measurement dynamic door valve position output by the last period of the system to achieve the effect of reducing subsequent calculation errors; the periodic door opening valve position increment signal OID is obtained by a periodic door opening valve position increment signal OID (n-1) generated by a periodic system calculation module on the system and a soft measurement calculation valve position POS (n-1) generated by a periodic system output module on the system;

if the system is initialized, the condition O2 is judged when the power-off full-open signal OP is not sent out or the soft measurement calculation valve position POS (n-1) generated by the periodic system output module on the system is 0, the periodic door opening valve position increment signal OID is not corrected, and the periodic door opening valve position increment signal OID is reserved as the periodic door opening valve position increment signal OID (n-1) generated by the periodic system calculation module on the system.

5. A soft measurement system for a power outage valve position in a thermal power unit according to claim 1, wherein the periodic closed valve position decrease signal CCD is a valve position signal for which a system calculation period is to be decreased while the valve is being closed.

6. The soft measurement system of a power failure valve position in a thermal power generating unit according to claim 5, wherein the periodic door closing valve position subtracting signal CCD is calculated according to the following three conditions:

if the system is not initialized, the periodic door closing valve position subtracting signal CCD is the quotient of the system calculation period CCT and the door closing initial stroke time parameter CT 0;

if the system is initialized, a soft measurement calculation valve position POS (n-1) generated by a system output module of the last period of the system is not 100, and is judged to be a condition C1, and at the moment, the system calculation module automatically corrects a period closing valve position subtracting signal CCD according to the soft measurement valve position of the last period of the system to achieve the effect of reducing the subsequent calculation error; the periodic door closing valve position subtracting signal CCD is obtained by a periodic door closing valve position subtracting signal CCD (n-1) generated by a periodic system computing module on the system and a soft measurement computing valve position POS (n-1) generated by a periodic system output module on the system;

if the system is initialized, the condition C2 is judged when the power-off moving door complete-closing signal CP is not sent or the soft measurement calculation valve position POS (n-1) generated by a periodic system output module on the system is 100, the periodic door closing valve position subtracting signal CCD is not corrected, and the periodic door closing valve position subtracting signal CCD is reserved as the periodic door closing valve position subtracting signal CCD (n-1) generated by the periodic system calculation module on the system.

7. The soft measurement system of a valve position of a power failure gate in a thermal power generating unit according to claim 1, wherein the specific implementation method of the system output module is as follows:

when the full-open signal OP of the stop electric door is true, outputting a soft measurement calculation valve position POS as 100%; when the stop electric door full-closing signal CP is true, outputting a soft measurement calculation valve position POS to be 0%; when the valve is in an open operation ODL, outputting a soft measurement calculation valve position POS which is the sum of a valve position reference value POSEF and a door opening valve position increment signal OID of a soft measurement calculation valve position output by a system initialization module; when the valve is in closing operation CDL is true, the soft measurement calculation valve position POS is outputted as the difference between the valve position reference value POSEF and the closing valve position subtraction signal CDD of the soft measurement calculation valve position POS outputted by the system initialization module.

8. A soft measurement system for a power outage valve position in a thermal power plant according to claim 1, further comprising a manual correction function for calculating the valve position, wherein the manual correction function is operable to maintain the calculated valve position consistent with the in-situ displayed valve position when there is an in-situ operator opening and closing of the electrically operated valve.

9. A soft measurement method of a power failure movable door valve position in a thermal power generating unit is characterized by comprising the following steps:

and obtaining an internal signal through a system initialization module: soft measurement is carried out to calculate a valve position reference value POsref;

and calculating to obtain a system internal signal through a system calculation module: an ODL being operated, a CDL signal being operated by a valve being closed, a valve position increasing signal OID of a periodic door opening valve and a valve position decreasing signal CCD of a periodic door closing valve;

the system output module receives an internal signal POSEF output by the system initialization module and receives an internal signal generated by the system calculation module: the valve is in an open operation ODL, the valve is in a close operation CDL signal, a periodic door opening valve position increasing signal OID and a periodic door closing valve position subtracting signal CCD, and the soft measurement calculation valve position POS output is obtained.