CN110185604B - Variable frequency control method and system for circulating water pump motor of thermal power plant - Google Patents
Variable frequency control method and system for circulating water pump motor of thermal power plant Download PDFInfo
- Publication number
- CN110185604B CN110185604B CN201910410902.5A CN201910410902A CN110185604B CN 110185604 B CN110185604 B CN 110185604B CN 201910410902 A CN201910410902 A CN 201910410902A CN 110185604 B CN110185604 B CN 110185604B
- Authority
- CN
- China
- Prior art keywords
- water pump
- circulating water
- unit
- value
- agc
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/06—Control using electricity
- F04B49/065—Control using electricity and making use of computers
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
- H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
Landscapes
- Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Non-Positive-Displacement Pumps (AREA)
- Control Of Positive-Displacement Pumps (AREA)
Abstract
The invention discloses a method and a system for controlling the frequency conversion of a circulating water pump motor of a thermal power plant, wherein the method comprises the following steps: continuously monitoring the operation mode of a circulating water pump motor, and acquiring the vacuum value of the condenser when the operation mode is a variable frequency operation mode; if the vacuum value is not the optimal vacuum value, acquiring the working state of the unit, and further judging whether to put into an AGC mode and operate in an R mode: and if the unit is put into the AGC mode and operates in the R mode, and the power frequency of the circulating water pump motor is adjusted to enable the vacuum value of the condenser to change towards the optimal vacuum value, the AGC performance index of the unit is not adversely affected, or the unit is not put into the AGC mode and operates in the R mode, the power frequency of the circulating water pump motor is adjusted to enable the vacuum of the condenser to change towards the optimal vacuum. The invention comprehensively considers the advantages and disadvantages of the prior art, and considers energy saving, consumption reduction and improvement of the AGC performance index of the unit.
Description
Technical Field
The invention belongs to the technical field of motor frequency conversion control, and particularly relates to a method and a system for controlling the frequency conversion of a circulating water pump motor of a thermal power plant.
Background
The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.
The first prior art is as follows: the energy conservation and consumption reduction of the turboset are realized by the frequency conversion regulation of the circulating water pump motor.
A circulating cooling water system composed of a circulating water pump, a cooling tower and the like is widely adopted in modern thermal power plants to absorb heat of exhaust steam of a low-pressure cylinder of a steam turbine so as to maintain the vacuum degree of a condenser. When other conditions are set, the size of the cooling water quantity determines the vacuum value of the condenser, and the heat efficiency of the steam turbine set is influenced by the vacuum value. For the steam turbine set, the higher the vacuum value of the condenser is, the higher the thermal efficiency of the steam turbine set is; however, in order to maintain a high vacuum in the condenser, a large amount of circulating water is required, and in the case of a circulating water pump motor capable of frequency conversion adjustment, a high rotating speed of the circulating water pump motor is required. The higher the rotating speed of the circulating water pump motor is, the higher the power consumption of the circulating water pump motor is, therefore, a balance point exists between the improvement of the condenser vacuum value to pursue the highest efficiency of the steam turbine unit and the avoidance of the increase of the power consumption caused by the overhigh rotating speed of the circulating water pump motor, namely, when the difference between the increased generating power of the unit and the increased power consumption caused by the increase of the rotating speed of the circulating water pump motor is the largest by improving the vacuum value, the ideal is achieved, and the corresponding condenser vacuum value is the optimal vacuum value at the moment. At present, partial thermal power generating units control the vacuum of a condenser at an optimal vacuum value by adjusting the rotating speed of a circulating water pump in real time, so that energy conservation and consumption reduction of the units are realized.
The second prior art is: and the AGC performance index of the thermal power generating unit is improved through the frequency conversion regulation of a circulating water pump motor.
AGC (Automatic Generation Control) is a Control technology for automatically controlling the power Generation power of a thermal power generating unit by a power grid dispatching center to adapt to the power demand of a power grid. The AGC performance indicators generally include an adjustment rate, an adjustment time, and an adjustment accuracy, which respectively reflect a change rate when the active power sent by the unit tracks the change of the AGC command, an adjustment time required for a complete variable load adjustment process, and a magnitude of a static error. Under the AGC control mode, the thermal power generating unit at least comprises the following two modes: unconditionally assuming an electric quantity adjusting mode, which is generally referred to as an R mode for short; and the power regulation mode is not borne, and is generally called O mode for short. In the R mode, the unit generates power according to a power grid dispatching instruction, namely an AGC instruction, the AGC instruction changes quickly and frequently, and the output of a coal mill, a fan and the like of the thermal power unit needs to be adjusted in a full force manner so as to adapt to the change requirement of quick increase and decrease of the load; under the working condition, important parameters such as main steam pressure and the like sometimes reach limit values, so that the variable load capacity or variable load rate (unit is megawatt/minute) of a unit tracking AGC instruction in an R mode AGC mode has a limit value for each unit, and operators of a thermal power plant can ensure that the main parameters are not over-limited to endanger the safe operation of equipment when the load of the unit is adjusted by manually setting the limit value. The O mode is sometimes called as a curve-dependent mode, the thermal power generating unit generates power according to a power grid dispatching command curve, and compared with the R mode, the load change speed of the thermal power generating unit in the O mode is low, the output adjustment of a coal mill, a fan and the like is relatively easy, and the fluctuation of important parameters such as main steam pressure and the like is small.
The domestic power grid examines indexes such as electric quantity, speed and precision of the thermal power generating unit for bearing power regulation in an AGC mode, such as: in the R mode, the higher the variable load rate of the thermal power generating unit is, the more electric quantity participating in regulation is, the higher the AGC performance index corresponding to the thermal power generating unit is, the higher the electric quantity compensation of the power grid is, and the higher the income obtained by the power plant is; and if the AGC performance index is unqualified, the AGC performance index is subjected to corresponding punitive examination. In the O mode, the actual power of the unit is not subjected to punitive examination as long as the actual power does not exceed the error range of the command curve. Therefore, in order to seek maximum benefit, part of thermal power plants adopt a mode of changing the rotating speed of the circulating water pump to improve the variable load capacity and AGC performance indexes of the unit, namely: the rotating speed of the circulating water pump is changed, so that the circulating water quantity is changed, the vacuum change of the condenser is changed, the power of the unit is further changed, the speed of the unit for tracking the load instruction of the dispatching center is increased, the AGC performance index is improved, and the electric quantity involved in regulation is increased, so that the unit obtains more economic benefits.
The two prior art techniques, while each producing beneficial results, also produce adverse results. In the prior art, although the condenser vacuum can be controlled to be the best vacuum by changing the rotating speed of the circulating water pump, the economic benefit is maximized, when the unit is put into an AGC (automatic gain control) and undertakes a power regulation operation mode, namely an R mode, if the change direction of the generating power of the unit is opposite to the change direction of an AGC (automatic gain control) instruction when the rotating speed of the circulating water pump is changed, the variable load rate of the unit is reduced, and the AGC performance index of the unit is reduced; in the second prior art, although the AGC performance index of the unit can be indirectly improved by changing the rotating speed of the circulating water pump, the situation that the power consumption of the motor is greatly increased due to the increase of the rotating speed of the circulating water pump sometimes is not considered, so that the comprehensive economic benefit of the unit is reduced.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a variable frequency control method and a variable frequency control system for a circulating water pump motor of a thermal power plant, which comprehensively consider the advantages and disadvantages of the prior art, save energy, reduce consumption and improve the AGC performance index of a unit.
In order to achieve the above object, one or more embodiments of the present invention provide the following technical solutions:
a frequency conversion control method for a circulating water pump motor of a thermal power plant comprises the following steps:
continuously monitoring the operation mode of a circulating water pump motor, and acquiring the vacuum value of the condenser when the operation mode is a variable frequency operation mode;
if the vacuum value is not the optimal vacuum value, acquiring the working state of the unit, and further judging whether to put into an AGC mode and operate in an R mode:
and if the unit is put into the AGC mode and operates in the R mode, and the power frequency of the circulating water pump motor is adjusted to enable the vacuum value of the condenser to change towards the optimal vacuum value, the AGC performance index of the unit is not adversely affected, or the unit is not put into the AGC mode and operates in the R mode, the power frequency of the circulating water pump motor is adjusted to enable the vacuum value of the condenser to change towards the optimal vacuum value.
One or more embodiments provide a variable frequency control system for a circulating water pump motor of a thermal power plant, comprising:
the unit parameter acquisition module is used for acquiring the operation parameters of the unit and the circulating water pump;
the motor power frequency/frequency conversion judging module is used for continuously monitoring the operation mode of the circulating water pump motor, and when the operation mode is the frequency conversion operation mode, the motor power frequency/frequency conversion judging module enters the condenser optimal vacuum judging module;
the condenser optimal vacuum judging module is used for judging whether the current vacuum value of the condenser is the optimal vacuum value or not, and if not, the working state judging module of the unit is started;
the unit working state judging module is used for judging whether to put into an AGC mode and operate in an R mode: if yes, entering a module for judging the influence of frequency conversion regulation on AGC performance indexes; if not, entering a frequency conversion adjusting module
The AGC performance index influence judging module is used for judging whether the AGC performance index of the unit is adversely influenced or not when the power supply frequency of the circulating water pump motor is adjusted to enable the vacuum value of the condenser to change towards the optimal vacuum value; if no adverse effect is generated, entering a variable frequency adjusting module;
and the variable-frequency adjusting module is used for adjusting the power supply frequency of the circulating water pump motor to enable the vacuum value of the condenser to change towards the optimal vacuum value.
One or more embodiments provide an electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor implements the method for variable frequency control of a circulating water pump motor of a thermal power plant when executing the program.
One or more embodiments provide a computer-readable storage medium having a computer program stored thereon, the program, when executed by a processor, implementing the method for variable frequency control of a circulating water pump motor of a thermal power plant.
The above one or more technical solutions have the following beneficial effects:
when the unit is not put into the R mode AGC operation mode, the frequency conversion regulation is controlled according to the optimal vacuum of the unit; when the unit is put into the R mode AGC operation mode, the variable frequency regulation only plays a role under the condition of being beneficial to the AGC performance index of the unit, so that the energy conservation and the consumption reduction are realized, the regulation electric quantity is increased, the AGC performance index is not reduced, the speed of the unit participating in the AGC regulation is increased, and more economic benefits are created for a power plant.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.
FIG. 1 is a schematic diagram of a method for controlling a variable frequency of a circulating water pump motor of a thermal power plant according to one or more embodiments of the invention;
fig. 2 is a schematic diagram of a variable frequency control system of a circulating water pump motor of a thermal power plant according to one or more embodiments of the invention.
Detailed Description
It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
The embodiments and features of the embodiments of the present invention may be combined with each other without conflict.
Example one
The purpose of this embodiment is to comprehensively consider the advantages and disadvantages of the prior art, consider energy saving and consumption reduction, and improve the unit AGC performance index, and in order to achieve the above purpose, this embodiment discloses a method for controlling the frequency conversion of a circulating water pump motor of a thermal power plant, as shown in fig. 1, including the following steps:
step 1, judging whether a circulating water pump motor is in a variable frequency operation mode, if so, executing step 2; otherwise, the step is continuously executed.
The step is the premise of variable frequency control of the circulating water pump motor, namely, the following steps are necessary only when the circulating water pump motor is in a variable frequency operation mode.
The prior art and documents have many references to the optimal vacuum value of the condenser, namely: when the steam inlet quantity of the steam turbine set and the conditions such as parameters and the like are not changed, the vacuum value of the condenser is increased to enable the difference between the generating power of the set and the power consumption power increased by increasing the circulating water quantity needed for increasing the vacuum value, namely increasing the rotating speed of the circulating water pump motor to be the maximum, and the corresponding vacuum value of the condenser is the optimal vacuum value. That is, when the amount of steam entering the turbine unit, its parameters, and other conditions are fixed, if the vacuum value of the condenser does not reach the limit vacuum, the vacuum value of the condenser is increased, which can improve the efficiency of the turbine unit and increase the electric power generated by the generator, but increasing the vacuum value requires increasing the amount of circulating water, increasing the rotational speed of the circulating water pump motor and increasing the power consumption, and if the increased power consumption of the circulating water pump is higher than the electric power generated by the generator more than the electric power generated by the generator, such adjustment is not compensated, and the vacuum value is not the optimum vacuum value. Similarly, if the rotation speed of the circulating water pump is reduced, the power consumption of the motor can be reduced, but the vacuum of the condenser is reduced, the electric power generated by the generator set is reduced, and when the electric power generated by the small generator is larger than the electric power reduced by the motor of the circulating water pump, the small generator is not compensated, and the vacuum value is not the optimal vacuum. The optimal vacuum value is obtained by calculation according to the performance curves of the condenser and the turbine unit, the performance curve of the circulating water pump and other data, and the specific calculation method is introduced in the prior art and published documents.
The embodiment provides a computing method suitable for computer processing:
calculating which of the unit power increase value and the circulating water pump power consumption increase value is larger after the current vacuum value is increased by a smaller value by taking the current vacuum value as a reference, and if the unit power increase value is larger than the circulating water pump power consumption increase value, continuously increasing the vacuum value until the unit power increase value is equal to the circulating water pump power consumption increase value, wherein the vacuum value is the optimal vacuum value; if the corresponding unit power increase value is smaller than the circulating water pump power consumption increase value after the vacuum is increased by a smaller value, the vacuum value is reduced by a smaller value for calculation, if the unit power reduction value is smaller than the circulating water pump power consumption reduction value, the vacuum value is continuously reduced by a smaller value for calculation and comparison until the unit power reduction value is equal to the circulating water pump power consumption reduction value, and the vacuum value is the optimal vacuum value; if the current vacuum value is taken as a reference, calculating that the corresponding unit power increase value is lower than the circulating water pump power consumption increase value after the current vacuum value is increased by a smaller value, and the corresponding unit power decrease value is more than the circulating water pump power consumption decrease value after the current vacuum value is decreased by a smaller value, the current vacuum value is the optimal vacuum value; the smaller value ranges from 0.1kPa to 0.5 kPa.
It should be noted that, in the calculation process of the optimal vacuum value, the value range of the optimal vacuum value is not equal to the lowest vacuum allowed, and the lowest vacuum is the lower limit value for ensuring the safety of the equipment specified by the operation regulations and the equipment specifications.
Because the calculation is complex and the operation condition of the unit changes frequently, the manual calculation is hard to be qualified, and the real-time calculation is carried out by a computer in the actual operation.
Description of the drawings: the method comprises the steps that an AGC mode for adjusting electric quantity is unconditionally undertaken, the AGC mode is also called as an R mode AGC, in the mode, a unit generates power according to a power grid dispatching instruction, namely an AGC instruction, the AGC instruction changes quickly and frequently, and the output of a coal mill, a fan and the like of a thermal power unit needs to be adjusted fully to adapt to the change requirement of quick increase and decrease of load; under the working condition, important parameters such as main steam pressure and the like sometimes reach limit values. The unit tracks the variable load capacity of the AGC instruction or is called variable load rate (unit is megawatt/minute) in the R mode AGC mode, each unit has a limit value, and the thermal power plant operator can ensure that the safe operation of the equipment is not endangered due to the fact that main parameters are out of limit when the unit load is adjusted by manually setting the limit value.
Whether the unit is in an R mode AGC mode or not is judged by observing the fluctuation range of an AGC command, and when the fluctuation range of the AGC command is large, the unit is in an R mode; when the AGC command fluctuation range is small and the command curve is a slowly-changing curve, the unit is in an O mode, and an operator can easily distinguish the R mode from the O mode by checking the curve. In addition, the automatic judgment can be carried out according to the information such as the input state of the AGC and the fluctuation range of the AGC command by the control program of the distributed control system.
It should be noted that, when the unit is in the O mode AGC or not put into the AGC, and the power frequency of the circulating water pump motor is changed, the vacuum value of the condenser is affected and then the actual power of the unit is affected, and the actual power of the unit also deviates from the AGC instruction or the predetermined target power, but because the automatic control system of the unit can adjust the deviation in real time, and when the unit is in the O mode AGC or not put into the AGC, the evaluation scale of the scheduling center on the actual power deviating from the target power is much wider than that of the R mode AGC, as follows: and the Shandong power grid is not checked when the specified actual power does not exceed +/-2% of the command curve. Therefore, under the working conditions, only the variable-frequency energy conservation of the circulating water pump motor can be considered without considering the influence on the actual power deviating from the target load. However, for the R-mode AGC condition, even if the unit power automatic adjustment system can affect the frequency conversion adjustment of the circulating water pump to adjust the actual power of the unit to deviate from the target power, the adjustment time index in the AGC performance index is affected by the extension of the adjustment time, and the AGC comprehensive performance index is affected.
Step 4, judging whether the power frequency of the circulating water pump motor is changed when the vacuum value of the condenser is changed to the optimal vacuum value, and if so, returning to the step 1; otherwise, step 5 is executed.
It can be understood that the first purpose of the frequency conversion regulation of the circulating water pump is energy saving, but if the regulation affects the AGC performance index of the unit, the frequency conversion regulation of the circulating water pump motor leads the vacuum value of the condenser to change, which further leads the change direction of the unit power, and is opposite to the change direction of the unit power required by the AGC instruction, in this case, the power supply frequency of the circulating water pump cannot be changed; on the contrary, the power supply frequency of the circulating water pump motor is allowed to be changed, so that the energy-saving purpose can be realized, and the direction change of the unit power to the AGC instruction requirement can be accelerated, thereby improving the AGC performance index and increasing the electric quantity of the unit participating in AGC load adjustment.
The method for judging whether the power supply frequency change of the circulating water pump motor can generate adverse effect on the AGC performance index of the unit comprises the following steps:
firstly, calculating the difference value between an AGC load instruction and the actual power of a unit:
if the actual power of the unit is obviously higher than the AGC load instruction, and the power supply frequency of the circulating water pump motor needs to be increased to enable the vacuum to tend to the optimal vacuum value, the change of the power supply frequency of the circulating water pump motor is considered to generate adverse effect on the AGC performance index of the unit;
similarly, if the actual power of the unit is obviously lower than the AGC load instruction, and the power supply frequency of the circulating water pump motor needs to be reduced to enable the vacuum to approach the optimal vacuum value, the power supply frequency change of the circulating water pump motor is considered to generate adverse effect on the AGC performance index of the unit;
if the actual power of the unit is equal to the AGC load instruction or the difference value of the AGC load instruction and the actual power is within the error range required by the AGC performance index, no matter the power supply frequency of the circulating water pump motor rises or falls, deviation is generated between the AGC load instruction and the actual power, the adjustment precision in the AGC performance index is influenced, and the situation that the AGC performance index is not facilitated belongs to the situation that the AGC performance index is not facilitated.
And 5, changing the power supply frequency of the circulating water pump motor to change the vacuum value of the condenser to the optimal vacuum value.
The specific method is that if the current vacuum value is lower than the optimal vacuum value, the frequency of the motor is increased; conversely, the frequency of the motor is reduced.
It should be noted that, because the limit of the lower limit of the rotation speed is provided during the frequency conversion control of the circulating water pump motor, and the safety control range of each parameter of the thermal system of the steam turbine unit also needs to be considered, when the power frequency of the circulating water pump motor is changed, the adjustment range of the frequency needs to be necessarily limited according to the requirements of the device specification, the operation regulation and the like.
And after the steps are executed, returning to the step 1 to continue the operation.
It is noted that the above steps are similar to an automatic control program of an industrial computer, i.e., the respective steps are periodically executed from the beginning of the steps.
Example two
The purpose of this embodiment is to provide a circulating water pump motor frequency conversion control system of thermal power plant, as shown in fig. 2, the control system includes 6 modules, is respectively: 21. a unit parameter acquisition module; 22. a motor power frequency/frequency conversion judgment module; 23. a condenser optimal vacuum calculation module; 24. a unit R mode AGC mode judging module; 25. a module for judging the influence of the frequency conversion regulation on AGC performance indexes; 26. and a frequency conversion adjusting module.
The unit parameter acquisition module is used for acquiring operation parameters of related units and circulating water pumps, such as condenser vacuum, atmospheric pressure, active power of a thermal power unit, motor power of a circulating water pump and the like, and supplying the operation parameters to other modules.
And the motor power frequency/frequency conversion judging module is used for judging whether the circulating water pump motor is in a power frequency operation mode or a frequency conversion operation mode.
And the condenser optimal vacuum calculating module is used for calculating the optimal vacuum of the condenser. According to the data such as relevant parameters, condenser performance curve data and circulating water pump performance curves acquired by the unit parameter acquisition module, how the power supply frequency of the circulating water pump motor changes is calculated to enable the vacuum value of the condenser to change towards the optimal vacuum value. The method can be configured as follows: calculating which of the unit power increase value and the circulating water pump power consumption increase value is larger after the current vacuum value is increased by a smaller value by taking the current vacuum value as a reference, and if the unit power increase value is larger than the circulating water pump power consumption increase value, continuously increasing the vacuum value until the unit power increase value is equal to the circulating water pump power consumption increase value, wherein the vacuum value is the optimal vacuum value; if the corresponding unit power increase value is smaller than the circulating water pump power consumption increase value after the vacuum is increased by a smaller value, the vacuum value is reduced by a smaller value for calculation, if the unit power reduction value is smaller than the circulating water pump power consumption reduction value, the vacuum value is continuously reduced by a smaller value for calculation and comparison until the unit power reduction value is equal to the circulating water pump power consumption reduction value, and the vacuum value is the optimal vacuum value; if the current vacuum value is taken as a reference, calculating that the corresponding unit power increase value is lower than the circulating water pump power consumption increase value after the current vacuum value is increased by a smaller value, and the corresponding unit power decrease value is more than the circulating water pump power consumption decrease value after the current vacuum value is decreased by a smaller value, the current vacuum value is the optimal vacuum value; the smaller value ranges from 0.1kPa to 0.5 kPa;
it should be noted that, in the calculation process of the optimal vacuum value, the value range of the optimal vacuum value is not equal to the lowest vacuum allowed, and the lowest vacuum is the lower limit value for ensuring the safety of the equipment specified by the operation regulations and the equipment specifications.
The unit R-mode AGC mode determining module is configured to determine whether the unit operates in the R-mode AGC mode, and the specific determining method may be configured as: AGC is put into use, and within the last period of time t minutes, the deviation of an AGC command from the actual unit power is more than 2 times of the allowable deviation delta specified by the AGC performance index of the unit. Because the AGC command is not a smooth curve but is changed in a step mode in the R-mode AGC mode, when the command is changed, the difference between the command and the actual power of the unit is large and far exceeds the allowable deviation delta specified by the AGC performance index; and the AGC commands change frequently, typically once in minutes. Therefore, the value of t can be 10, that is, if the deviation between the AGC instruction and the actual power of the unit is detected to exceed 2 times of the allowable deviation delta specified by the AGC performance index of the unit at least once within 10 minutes, the unit is considered to be in the R-mode AGC mode. In addition, the allowable deviation delta specified by the AGC performance index of the unit is respectively specified by the power grid debugging center according to the type of each unit.
The module for judging the influence of the frequency conversion regulation on the AGC performance index is configured as follows: and analyzing whether the AGC performance index of the unit is adversely affected when the power supply frequency of the circulating water pump motor is changed to change the vacuum value of the condenser to the optimal vacuum value when the unit is in the R-mode AGC mode. This module embodiment may be configured to:
firstly, calculating the difference value between the AGC load instruction and the actual power of the unit,
if the actual power of the unit is obviously higher than the AGC load instruction, and the power supply frequency of the circulating water pump motor needs to be increased to enable the vacuum to tend to the optimal vacuum value, the change of the power supply frequency of the circulating water pump motor is considered to generate adverse effect on the AGC performance index of the unit;
similarly, if the actual power of the unit is obviously lower than the AGC load instruction, and the power supply frequency of the circulating water pump motor needs to be reduced to enable the vacuum to approach the optimal vacuum value, the power supply frequency change of the circulating water pump motor is considered to generate adverse effect on the AGC performance index of the unit;
if the actual power of the unit is equal to the AGC load instruction or the difference value of the AGC load instruction and the actual power is within the error range required by the AGC performance index, no matter the power supply frequency of the circulating water pump motor rises or falls, deviation is generated between the AGC load instruction and the actual power, the adjustment precision in the AGC performance index is influenced, and the situation that the AGC performance index is not facilitated belongs to the situation that the AGC performance index is not facilitated.
The frequency conversion adjustment module is configured to: when the frequency conversion adjustment of the circulating water pump motor does not generate adverse effect on AGC performance indexes of a unit operated in an R mode AGC mode or the unit is not in the R mode AGC mode, the power supply frequency of the circulating water pump motor is changed, and the vacuum value of the condenser is changed to the optimal vacuum value.
The above-mentioned specific embodiments of the modules can be configured to be jointly completed by a distributed control system (i.e. DCS) or a programmable logic controller (i.e. PLC) and a variable frequency control cabinet. DCS or PLC accomplishes the relevant function of module 21 to module 25, and the frequency conversion control cabinet accomplishes the relevant function of module 26, namely: the DCS or the PLC is used for completing the functions of unit parameter acquisition, motor power frequency/frequency conversion judgment, condenser optimal vacuum calculation, unit R mode AGC judgment, judgment and analysis of the influence of frequency conversion regulation on AGC performance indexes and the like, and the frequency conversion control cabinet is used for completing the frequency conversion regulation on the circulating water pump motor.
EXAMPLE III
The embodiment aims at providing an electronic device.
In order to achieve the above object, this embodiment provides an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the computer program to implement the following steps, including:
step 1, judging whether a circulating water pump motor is in a variable frequency operation mode, if so, executing step 2; otherwise, the step is continuously executed.
Step 4, judging whether the power frequency of the circulating water pump motor is changed when the vacuum value of the condenser is changed to the optimal vacuum value, and if so, returning to the step 1; otherwise, step 5 is executed.
And 5, changing the power supply frequency of the circulating water pump motor to change the vacuum value of the condenser to the optimal vacuum value.
Example four
An object of the present embodiment is to provide a computer-readable storage medium.
To achieve the above object, the present embodiment provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, performs the steps of:
step 1, judging whether a circulating water pump motor is in a variable frequency operation mode, if so, executing step 2; otherwise, the step is continuously executed.
Step 4, judging whether the power frequency of the circulating water pump motor is changed when the vacuum value of the condenser is changed to the optimal vacuum value, and if so, returning to the step 1; otherwise, step 5 is executed.
And 5, changing the power supply frequency of the circulating water pump motor to change the vacuum value of the condenser to the optimal vacuum value.
The steps involved in the above second, third and fourth embodiments correspond to the first embodiment of the method, and the detailed description thereof can be found in the relevant description of the first embodiment. The term "computer-readable storage medium" should be taken to include a single medium or multiple media containing one or more sets of instructions; it should also be understood to include any medium that is capable of storing, encoding or carrying a set of instructions for execution by a processor and that cause the processor to perform any of the methods of the present invention.
One or more of the above embodiments have the following technical effects:
when the unit is not put into the R mode AGC operation mode, the frequency conversion regulation is controlled according to the optimal vacuum of the unit; when the unit is put into the R mode AGC operation mode, the variable frequency regulation only plays a role under the condition of being beneficial to the AGC performance index of the unit, so that the energy conservation and the consumption reduction are realized, the regulation electric quantity is increased, the AGC performance index is not reduced, the speed of the unit participating in the AGC regulation is increased, and more economic benefits are created for a power plant.
Those skilled in the art will appreciate that the modules or steps of the present invention described above can be implemented using general purpose computer means, or alternatively, they can be implemented using program code that is executable by computing means, such that they are stored in memory means for execution by the computing means, or they are separately fabricated into individual integrated circuit modules, or multiple modules or steps of them are fabricated into a single integrated circuit module. The present invention is not limited to any specific combination of hardware and software.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Although the embodiments of the present invention have been described with reference to the accompanying drawings, it is not intended to limit the scope of the present invention, and it should be understood by those skilled in the art that various modifications and variations can be made without inventive efforts by those skilled in the art based on the technical solution of the present invention.
Claims (10)
1. A frequency conversion control method for a circulating water pump motor of a thermal power plant is characterized by comprising the following steps:
continuously monitoring the operation mode of a circulating water pump motor, and acquiring the vacuum value of the condenser when the operation mode is a variable frequency operation mode;
if the vacuum value is not the optimal vacuum value, acquiring the working state of the unit, and further judging whether to put into an AGC mode and operate in an R mode:
AGC, automatic power generation control; unconditionally assuming an electric quantity adjusting mode, generally referred to as an R mode for short;
and if the unit is put into the AGC mode and operates in the R mode, and the power frequency of the circulating water pump motor is adjusted to enable the vacuum value of the condenser to change towards the optimal vacuum value, the AGC performance index of the unit is not adversely affected, or the unit is not put into the AGC mode and operates in the R mode, the power frequency of the circulating water pump motor is adjusted to enable the vacuum value of the condenser to change towards the optimal vacuum value.
2. The method for controlling the variable frequency of the circulating water pump motor of the thermal power plant according to claim 1, wherein if the vacuum value is an optimal vacuum value, the operation mode of the circulating water pump motor is continuously monitored.
3. The method for controlling the variable frequency of the circulating water pump motor of the thermal power plant according to claim 1, wherein the method for calculating the optimal vacuum value comprises the following steps:
taking the current vacuum value of the condenser as a reference, improving the vacuum value, obtaining a corresponding unit power increase value and a corresponding circulating water pump power consumption increase value after improvement, and judging the size relation between the two values:
if the power increase value of the unit is larger than the power consumption increase value of the circulating water pump, the vacuum value is continuously increased until the power increase value of the unit is equal to the power consumption increase value of the circulating water pump, and the vacuum value is the optimal vacuum value;
if the power increase value of the unit is smaller than the power consumption increase value of the circulating water pump, reducing the vacuum value, and judging the size relation between the reduced power decrease value of the unit and the power consumption decrease value of the circulating water pump: if the reduced value of the unit power is larger than the reduced value of the power consumption of the circulating water pump, the current vacuum value is the optimal vacuum value; and if the reduced value of the unit power is smaller than the reduced value of the power consumption of the circulating water pump, continuing to reduce the vacuum value until the reduced value of the unit power is equal to the reduced value of the power consumption of the circulating water pump, and determining the vacuum value as the optimal vacuum value.
4. The method for controlling the variable frequency of the circulating water pump motor of the thermal power plant according to claim 3, wherein the values for increasing the vacuum value and decreasing the vacuum value range from 0.1kPa to 0.5 kPa.
5. The method for controlling the frequency conversion of the circulating water pump motor of the thermal power plant according to claim 1, wherein whether the unit is put into an AGC mode and operates in an R mode is judged according to the fluctuation amplitude of an AGC command;
AGC, automatic power generation control; the mode of adjusting the electric quantity is unconditionally undertaken, and is generally referred to as an R mode.
6. The variable frequency control method of the circulating water pump motor of the thermal power plant according to claim 1, characterized in that if the AGC performance index of the unit is adversely affected, the operation mode of the circulating water pump motor is continuously monitored; AGC, automatic generation control.
7. The method for controlling the variable frequency of the circulating water pump motor of the thermal power plant according to claim 1, wherein the situation that the AGC performance index of the unit is adversely affected comprises the following steps:
AGC, automatic power generation control;
calculating the difference value between the AGC load instruction and the actual power of the unit:
if the difference is within the set error range, the AGC performance index of the unit is considered to be adversely affected;
if the difference exceeds a set error range and the power frequency of the circulating water pump motor needs to be increased to enable the vacuum value to approach the optimal vacuum value, and the difference is further expanded due to the increase of the power frequency of the circulating water pump motor, the AGC performance index of the unit is considered to be adversely affected;
if the difference exceeds the set error range and the power frequency of the circulating water pump motor needs to be reduced to enable the vacuum value to approach the optimal vacuum value, and the difference is further expanded due to the reduction of the power frequency of the circulating water pump motor, the AGC performance index of the unit is considered to be adversely affected.
8. The utility model provides a circulating water pump motor frequency conversion control system of thermal power plant which characterized in that includes:
the unit parameter acquisition module is used for acquiring the operation parameters of the unit and the circulating water pump;
the motor power frequency/frequency conversion judging module is used for continuously monitoring the operation mode of the circulating water pump motor, and when the operation mode is the frequency conversion operation mode, the motor power frequency/frequency conversion judging module enters the condenser optimal vacuum judging module;
the condenser optimal vacuum judging module is used for judging whether the current vacuum value of the condenser is the optimal vacuum value or not, and if not, the working state judging module of the unit is started;
the unit working state judging module is used for judging whether to put into an AGC mode and operate in an R mode: if yes, entering a frequency conversion regulation module for judging the influence of AGC performance indexes, and if not, entering a frequency conversion regulation module;
AGC, automatic power generation control; unconditionally assuming an electric quantity adjusting mode, generally referred to as an R mode for short;
the AGC performance index influence judging module is used for judging whether the AGC performance index of the unit is adversely influenced or not when the power supply frequency of the circulating water pump motor is adjusted to enable the vacuum value of the condenser to change towards the optimal vacuum value; if no adverse effect is generated, entering a variable frequency adjusting module;
and the variable-frequency adjusting module is used for adjusting the power supply frequency of the circulating water pump motor to enable the vacuum value of the condenser to change towards the optimal vacuum value.
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the method of variable frequency control of a circulating water pump motor of a thermal power plant according to any one of claims 1 to 7 when executing the program.
10. A computer-readable storage medium on which a computer program is stored, which program, when executed by a processor, implements the thermal power plant circulating water pump motor frequency conversion control method according to any one of claims 1 to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910410902.5A CN110185604B (en) | 2019-05-16 | 2019-05-16 | Variable frequency control method and system for circulating water pump motor of thermal power plant |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910410902.5A CN110185604B (en) | 2019-05-16 | 2019-05-16 | Variable frequency control method and system for circulating water pump motor of thermal power plant |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110185604A CN110185604A (en) | 2019-08-30 |
| CN110185604B true CN110185604B (en) | 2020-05-08 |
Family
ID=67716629
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910410902.5A Active CN110185604B (en) | 2019-05-16 | 2019-05-16 | Variable frequency control method and system for circulating water pump motor of thermal power plant |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110185604B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103244397A (en) * | 2013-05-09 | 2013-08-14 | 国家电网公司 | Optimal operation control method for variable-frequency circulating water pump |
| CN103244433A (en) * | 2013-05-09 | 2013-08-14 | 国家电网公司 | Operation optimizing and monitoring method for variable-frequency circulating water pump of power plant |
| CN204462879U (en) * | 2015-01-20 | 2015-07-08 | 大唐淮南洛河发电厂 | Fired power generating unit water circulating pump operating control device |
| CN107420142A (en) * | 2017-05-15 | 2017-12-01 | 西安热工研究院有限公司 | A kind of Turbine Cold Junction that pump is followed based on frequency conversion optimizes progress control method |
| CN207004782U (en) * | 2017-08-01 | 2018-02-13 | 上海东方威尔节能技术有限公司 | Environmental Power Plant circulating water energy-saving device |
| CN108412558A (en) * | 2018-02-11 | 2018-08-17 | 国电南京电力试验研究有限公司 | A kind of Turbo-generator Set intellect economy operating system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9725652B2 (en) * | 2015-08-24 | 2017-08-08 | Saudi Arabian Oil Company | Delayed coking plant combined heating and power generation |
-
2019
- 2019-05-16 CN CN201910410902.5A patent/CN110185604B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103244397A (en) * | 2013-05-09 | 2013-08-14 | 国家电网公司 | Optimal operation control method for variable-frequency circulating water pump |
| CN103244433A (en) * | 2013-05-09 | 2013-08-14 | 国家电网公司 | Operation optimizing and monitoring method for variable-frequency circulating water pump of power plant |
| CN204462879U (en) * | 2015-01-20 | 2015-07-08 | 大唐淮南洛河发电厂 | Fired power generating unit water circulating pump operating control device |
| CN107420142A (en) * | 2017-05-15 | 2017-12-01 | 西安热工研究院有限公司 | A kind of Turbine Cold Junction that pump is followed based on frequency conversion optimizes progress control method |
| CN207004782U (en) * | 2017-08-01 | 2018-02-13 | 上海东方威尔节能技术有限公司 | Environmental Power Plant circulating water energy-saving device |
| CN108412558A (en) * | 2018-02-11 | 2018-08-17 | 国电南京电力试验研究有限公司 | A kind of Turbo-generator Set intellect economy operating system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110185604A (en) | 2019-08-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105257471B (en) | Wind power generating set award setting method, apparatus and system | |
| CN113221373B (en) | Method and system for optimizing circulating water cold-end system configured with multiple mechanical ventilation cooling towers | |
| CH700888A2 (en) | Systems and methods for providing surge protection for a turbine component. | |
| CN108695863A (en) | A kind of power supply friendly receiving end primary frequency regulation of power network control method and system | |
| CN105391078A (en) | Primary frequency regulation closed loop control method for generator set | |
| CN110513158B (en) | Feed-forward multistage speed regulation method for steam turbine | |
| CN114844064A (en) | Self-adaptive variable parameter frequency modulation method and device for double-fed variable-speed pumped storage unit | |
| CN109779891B (en) | Method for optimizing backpressure and circulating water quantity of steam turbine generator unit | |
| CN113452092B (en) | Control method for improving AGC comprehensive frequency modulation performance index of thermal power generating unit | |
| CN109857033A (en) | Condensate throttling switching control method, device and computer equipment | |
| CN113530793A (en) | Intelligent adjusting system for air compression station | |
| CN112039091A (en) | Primary frequency modulation control method based on zero number high-order addition | |
| WO2022267209A1 (en) | Parallel valve set control method and apparatus, controller, and storage medium | |
| CN110185604B (en) | Variable frequency control method and system for circulating water pump motor of thermal power plant | |
| CN112431748B (en) | Optimal operation method and system for circulation unit circulation pump based on condenser inlet water temperature | |
| CN110107489B (en) | Control method, system and unit for condensate water pump | |
| CN116111610A (en) | Frequency dynamic characteristic analysis method and related device for wind power variable pitch control | |
| CN111752203B (en) | Variable-load air classification dynamic control system and method | |
| CN114893348A (en) | Dynamic shutdown control method, system, equipment and storage medium for wind driven generator | |
| CN109710020B (en) | Active approximation type power control method and system for new energy power station | |
| CN112502894A (en) | Method and device for controlling speed regulator of water turbine for monitoring efficiency of generator set | |
| CN111105085A (en) | Method, system and medium for optimizing water pump working condition shutdown strategy of pumped storage unit | |
| CN114576149B (en) | Optimal operation control system and method for circulating water pump of thermal power plant | |
| CN112287535B (en) | Method and system for determining minimum operation load of thermal power generating unit | |
| CN116994787B (en) | Method and system for controlling nuclear power of high-temperature gas cooled reactor nuclear power plant |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information |
Address after: 250101 Shandong Province Jinan Hi-tech Zone Shunhua Road 2000 Shuntai Square 9 North District 10 floors Applicant after: National energy (Shandong) Engineering Technology Co.,Ltd. Address before: 250101 Shandong Province Jinan Hi-tech Zone Shunhua Road 2000 Shuntai Square 9 North District 10 floors Applicant before: SHANDONG GUODIAN POWER GENERATION ENGINEERING CO.,LTD. |
|
| CB02 | Change of applicant information | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20200119 Address after: 250101 Shandong Province Jinan Hi-tech Zone Shunhua Road 2000 Shuntai Square 9 North District 10 floors Applicant after: National energy (Shandong) Engineering Technology Co.,Ltd. Applicant after: National Energy Power Generation Co.,Ltd. Address before: 250101 Shandong Province Jinan Hi-tech Zone Shunhua Road 2000 Shuntai Square 9 North District 10 floors Applicant before: National energy (Shandong) Engineering Technology Co.,Ltd. |
|
| TA01 | Transfer of patent application right | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |