Pressure maintaining system adopting variable-frequency pressure maintaining equipment and self-adaptive control method
阅读说明：本技术 采用变频压力维持设备的压力维持系统及自适应控制方法 (Pressure maintaining system adopting variable-frequency pressure maintaining equipment and self-adaptive control method ) 是由 涂勇 于 2020-12-30 设计创作，主要内容包括：采用变频压力维持设备的压力维持系统及自适应控制方法,该系统包括压力容器,无压容器、压力维持设备；压力容器通过压力维持设备连接无压容器。压力容器设有传感器。传感器和压力维持设备均连接控制器,控制器连接人机交互装置。本发明旨在解决消耗负载与压力维持设备输出功率不匹配导致的,压力维持设备频繁启停或加卸载,设备原件磨损消耗加剧,影响压力维持设备寿命,同时导致能量损失,影响系统能效和经济性等问题。(The pressure maintaining system comprises a pressure container, a non-pressure container and pressure maintaining equipment; the pressure vessel is connected to the pressureless vessel by a pressure maintenance device. The pressure vessel is provided with a sensor. The sensor and the pressure maintaining equipment are both connected with the controller, and the controller is connected with the human-computer interaction device. The invention aims to solve the problems that the consumption load is not matched with the output power of the pressure maintaining equipment, the pressure maintaining equipment is frequently started, stopped or loaded and unloaded, the abrasion consumption of the original parts of the equipment is aggravated, the service life of the pressure maintaining equipment is influenced, the energy loss is caused, the energy efficiency and the economical efficiency of a system are influenced, and the like.)
1. A pressure maintenance system employing a variable frequency pressure maintenance device, the system comprising: a pressure vessel (1), a non-pressure vessel (2) and a pressure maintaining device (4); the pressure container (1) is connected with the pressureless container (2) through a pressure maintaining device (4); the pressure container (1) is provided with a sensor (5), the sensor (5) and the pressure maintaining equipment (4) are both connected with a controller (6), and the controller (6) is connected with a human-computer interaction device (7).
2. A pressure maintenance system using a variable frequency pressure maintenance device according to claim 1, wherein: the pressure container (1) is a pressure oil tank or a pressure gas tank.
3. A pressure maintenance system using a variable frequency pressure maintenance device according to claim 1, wherein: the non-pressure container (2) is a non-pressure oil tank or an air bag.
4. A pressure maintenance system using a variable frequency pressure maintenance device according to claim 1, wherein: the pressure maintaining equipment (4) is n frequency conversion oil pumps or air compressors with the same model number and specification, and the serial numbers are 1# and 2# … … n #; the power frequency and the pressurization capacity of n variable frequency oil pumps or air compressors in the pressure maintaining equipment (4) are shown in the following table 1, wherein m and i in the table 1 are positive integers, i is more than 1 and less than or equal to m, and Fi-1＜Fi，Pi-1＜PiPi is the pressure capacity of the oil pump or the air compressor corresponding to the Fi power frequency; p1Is the minimum drainage capacity of the variable frequency drainage pump, PmThe maximum drainage capacity of the variable-frequency drainage pump is obtained; the pressurizing capacity refers to the pressure rise per unit time, and the unit is Mpa/min;
TABLE 1 Power frequency and pressurization Capacity Joint Curve parameter Table
。
5. A pressure maintenance system using a variable frequency pressure maintenance device according to claim 1, wherein: any one pressure maintaining device (4) is provided with a power supply frequency converter (10), and the power supply frequency converter (10) is connected with the controller (6).
6. The pressure maintenance system of claim 4, wherein the variable frequency pressure maintenance device comprises: the controller (6) receives the pressure set by the man-machine interaction device (7) to maintain the rated pressure P of the systemForehead (forehead)Highest pressure PHighest point of the designHigher pressure PIs higher thanLower pressure PIs lower thanLowest pressure PLowest level ofThe power frequency and the pressurization capacity of n variable frequency oil pumps or air compressors in the pressure maintenance equipment (4) are linked together to form a curve parameter table, parameter information is obtained, logic processing is carried out by adopting a self-adaptive control method according to received pressure maintenance system state signals collected by a sensor (5), and then power supply variable parameters corresponding to the n variable frequency oil pumps or air compressors with the same model number and specification in the pressure maintenance equipment (4) are processedThe frequency controller (10) controls the frequency, thereby controlling the operation conditions of n variable frequency oil pumps or air compressors in the pressure maintaining equipment (4) and transmitting the state information of the pressure maintaining system to the man-machine interaction device (7).
7. The pressure maintenance system of claim 4, wherein the variable frequency pressure maintenance device comprises: the human-computer interaction device (7) is communicated with the controller (6) and maintains the pressure set by the user through the human-computer interaction device (7) to be the rated pressure P of the systemForehead (forehead)Highest pressure PHighest point of the designHigher pressure PIs higher thanLower pressure PIs lower thanLowest pressure PLowest level ofThe power supply frequency and the pressurization capacity of n variable frequency oil pumps or air compressors in the pressure maintenance equipment (4) are in cooperative connection with the parameters of the curve table and transmitted to the controller (6), and meanwhile, the human-computer interaction device (7) acquires the parameter information of the pressure maintenance system sent by the controller (6) and carries out graphical display.
8. An adaptive control method for a pressure maintenance system, comprising the steps of:
step 1, initializing a controller (6), and acquiring a pressure maintenance system rated pressure P set by a user through a man-machine interaction device (7)Forehead (forehead)Highest pressure PHighest point of the designHigher pressure PIs higher thanLower pressure PIs lower thanLowest pressure PLowest level ofThe power supply frequency and the pressurization capacity of n variable frequency oil pumps or air compressors in the pressure maintenance equipment (4) are linked together to form parameter information of a curve table;
step 2, the controller (6) controls and starts n variable frequency oil pumps or air compressors to operate and load at rated frequency, and the pressure maintenance system is pressurized to rated pressure PForehead (forehead)Then stopping all the variable frequency oil pumps or air compressors from operating;
step 3, the controller (6) collects pressure to maintain the system pressure P1, and starts timing;
step 4, the controller (6) detects whether the timing is over t minutes, if yes, the step 5 is carried out, and if not, the detection is continued;
step 5, the controller (6) collects pressure to maintain the system pressure P2;
step 6, the controller (6) calculates the consumption load P of the pressure maintaining system as (P1-P2)/t;
step 7, calculating the number x of the variable-frequency working oil pumps or air compressors and the operation initial power frequency F0 of the variable-frequency oil pump or air compressor with the highest priority by the controller (6) according to a consumption load p and a power frequency and pressurization capacity linkage curve table of n variable-frequency oil pumps or air compressors in the pressure maintenance equipment (4), outputting a frequency control signal F to a power frequency converter (10) corresponding to the variable-frequency oil pump or air compressor with the highest priority, wherein F is F0, so that the variable-frequency oil pumps or air compressors in the x pressure maintenance equipment (4) are started to serve as the variable-frequency working oil pumps or air compressors, and the control of the power frequency of the variable-frequency oil pumps or air compressors with the highest priority is realized; is an upwardly rounded mathematical symbol; f0 calculation method: if Pi-1≤p-(x-1)Pm≤PiIf F0 is equal to Fi-1+(Fi-Fi-1)[p-(x-1)Pm-Pi-1]/(Pi-Pi-1) (ii) a And initializes last-time frequency control signal FOn the upper partF; the power frequency of the rest of variable-frequency working oil pumps or air compressors is Fm；
Step 8, the controller (6) collects the pressure P of the pressure maintenance system in real time;
step 9, the controller (6) maintains the system pressure P according to the pressure and maintains the rated pressure P of the systemForehead (forehead)Calculating the power frequency F ═ F of the frequency conversion working oil pump or air compressor with the highest priorityOn the upper part+k(PForehead (forehead)-P), k is a proportional coefficient of pressure deviation and frequency amplification, and a frequency control signal F is output to a power supply frequency converter (10) corresponding to the variable-frequency working oil pump or air compressor with the highest priority, so that the power supply frequency of the variable-frequency working oil pump or air compressor with the highest priority in the pressure maintaining equipment (4) is controlled; and refreshes the last frequency control signal FOn the upper part＝F；
Step 10, if the pressure is maintained to be lower than the lower pressure PIs lower thanStarting and loading a standby variable frequency oil pump or air compressor with the highest priority, and controlling the power supply frequency of a standby variable frequency drainage pump to be Fm(ii) a Entering a step 11;
step 11, if the pressure P of the pressure maintaining system is less than the lowest pressure PLowest level ofStarting and loading all standby variable-frequency drainage pumps, and controlling the power frequency of a standby variable-frequency oil pump or air compressor to be Fm(ii) a Entering step 12;
step 12, if the pressure is maintained to be not less than the higher pressure PIs higher thanUnloading and stopping a standby variable frequency oil pump or air compressor with the lowest priority; entering step 13;
step 13, if the pressure P of the system is maintained to be not less than the highest pressure PHighest point of the designUnloading and stopping all the standby variable frequency oil pumps or air compressors and returning to the step 3; otherwise, return to step 8.
Technical Field
The invention belongs to the field of industrial control, and particularly relates to a pressure maintaining system adopting variable-frequency pressure maintaining equipment and a self-adaptive control method.
Background
In industrial control, there are many applications that require a pressure maintenance system, such as a hydro-generator set governor that regulates vane opening, set power and frequency, requiring a governor hydraulic system; the middle-low pressure gas system is needed in occasions such as a large shaft gas supplementing system of the hydroelectric generating set, a bus micro-positive pressure system, a speed regulator pressure oil tank gas supplementing system, an air brake mechanical braking system and the like. Governor hydraulic systems and medium and low pressure air systems are typical pressure maintenance systems.
The pressure maintenance system is usually designed with a plurality of quantitative oil pumps or air compressors with the same model and specification as pressure maintenance equipment, but because the load of the pressure maintenance system has a steady-state fixed consumption load and a random consumption load, if the consumption load is not matched with the output power of the pressure maintenance equipment, namely the speed of system pressure reduction due to consumption is not matched with the pressure capacity of the pressure maintenance equipment, the pressure maintenance equipment is frequently started, stopped or unloaded, the abrasion consumption of equipment elements is aggravated, the service life of the pressure maintenance equipment is influenced, and meanwhile, the energy loss is caused, and the energy efficiency and the economy of the system are influenced.
Disclosure of Invention
In order to solve the above technical problems, the present invention provides a pressure maintenance system and an adaptive control method using a variable frequency pressure maintenance device, which aims to solve the problem that the output power of the consumption load is not matched with the output power of the pressure maintenance device, that is, the speed of the system pressure due to consumption reduction is not matched with the capacity of the pressure maintenance device for pressurization: the pressure maintenance equipment is frequently started and stopped or loaded and unloaded, the abrasion consumption of equipment components is aggravated, the service life of the pressure maintenance equipment is influenced, energy loss is caused, and the energy efficiency and the economical efficiency of a system are influenced.
The technical scheme adopted by the invention is as follows:
a pressure maintenance system employing a variable frequency pressure maintenance device, the system comprising:
a pressure vessel, a pressureless vessel, a pressure maintenance device; the pressure container is connected with the non-pressure container through pressure maintaining equipment;
the pressure container is provided with a sensor for acquiring physical quantity parameters of the pressure container, such as pressure of a pressure maintenance system;
the sensor and the pressure maintaining equipment are both connected with the controller, and the controller is connected with the human-computer interaction device.
The pressure container is a pressure oil tank or a gas tank.
The non-pressure container is a non-pressure oil tank or an air bag.
The pressure maintaining equipment is n frequency conversion oil pumps or air compressors with the same model number and specification, and the serial numbers are 1# and 2# … … n #. The power frequency and the pressurization capacity of n variable frequency oil pumps or air compressors in the pressure maintenance equipment are shown in the following table 1, wherein m and i in the table 1 are positive integers, i is more than 1 and less than or equal to m, and Fi-1＜Fi，Pi-1＜PiPi is oil pump or air pressure corresponding to Fi power frequencyThe pressurization capacity of the machine; p1Is the minimum drainage capacity of the variable frequency drainage pump, PmThe maximum drainage capacity of the variable-frequency drainage pump. The pressurizing capacity refers to the pressure rise per unit time, and the unit is Mpa/min;
TABLE 1 Power frequency and pressurization Capacity Joint Curve parameter Table
F1
F2
F3
…
Fi-1
Fi
…
Fm-1
Fm
P1
P2
P3
…
Pi-1
Pi
…
Pm-1
Pm
Any pressure maintaining equipment is provided with a power supply frequency converter, and the power supply frequency converter is connected with the controller. N frequency conversion oil pumps or air compressors with the same model and specification in the pressure maintenance equipment are correspondingly provided with n power frequency converters.
The controller receives the rated pressure P of the pressure maintenance system set by the human-computer interaction deviceForehead (forehead)Highest pressure PHighest point of the designHigher pressure PIs higher thanLower pressure PIs lower thanLowest pressure PLowest level ofThe power frequency and the pressurization capacity of n variable frequency oil pumps or air compressors in the pressure maintenance equipment are in coordination with the parameter table parameter information of the curve, and the frequency of the power frequency corresponding to the n variable frequency oil pumps or air compressors with the same model and specification in the pressure maintenance equipment is controlled according to the received state signals of the system, such as pressure, acquired by a sensor after logical processing is carried out by adopting a self-adaptive control method, so that the operating condition of the n variable frequency oil pumps or air compressors in the pressure maintenance equipment is controlled, and the state information of the pressure maintenance system is transmitted to a man-machine interaction device. The man-machine interaction device is communicated with the controller and maintains the pressure set by the user through the man-machine interaction device to be the rated pressure P of the systemForehead (forehead)Highest pressure PHighest point of the designHigher pressure PIs higher thanLower pressure PIs lower thanLowest pressure PLowest level ofThe power supply frequency and the pressurization capacity of n variable frequency oil pumps or air compressors in the pressure maintenance equipment are linked to form parameters and transmitted to the controller, and meanwhile, the man-machine interaction device acquires the parameter information of the pressure maintenance system transmitted by the controller and conducts graphical display.
An adaptive control method for a pressure maintenance system, comprising the steps of:
step 1, initializing a controller, and acquiring a rated pressure P of a pressure maintenance system set by a user through a man-machine interaction deviceForehead (forehead)Highest pressure PHighest point of the designHigher pressure PIs higher thanLower pressure PIs lower thanLowest pressure PLowest level ofAnd the power supply frequency and the pressurization capacity of n variable frequency oil pumps or air compressors in the pressure maintenance equipment are in coordination with the parameter information of the curve table.
And 2, the controller 6 controls and starts n main oil pumps or air compressors to operate and load at the rated frequency of 50Hz, builds the pressure of the pressure maintenance system to the rated pressure, and then stops all the variable frequency oil pumps or air compressors from operating.
And 3, collecting the pressure maintaining system pressure P1 by the controller 6, and starting timing.
And 4, detecting whether the timing is finished for t minutes by the controller 6, if so, entering the step 5, and otherwise, continuously detecting.
Step 5, the controller 6 collects the pressure maintenance system pressure P2.
In step 6, the controller 6 calculates the pressure maintenance system consumption load P ═ P1-P2)/t.
And 7, calculating the number x of the variable-frequency working oil pumps or air compressors and the operation initial power frequency F0 of the variable-frequency oil pump or air compressor with the highest priority by the controller 6 according to the consumption load p and a power frequency and pressurization capacity co-relation curve table of the n variable-frequency oil pumps or air compressors in the pressure maintenance equipment 4, outputting a frequency control signal F to the power frequency converter 10 corresponding to the variable-frequency oil pump or air compressor with the highest priority, wherein F is F0, so that the variable-frequency oil pumps or air compressors in the x pressure maintenance equipment 4 are started to serve as the variable-frequency working oil pumps or air compressors, and the control of the power frequency of the variable-frequency working oil pumps or air compressors with the highest priority is realized. To round up the mathematical sign. f0 calculation method: if Pi-1≤p-(x-1)Pm≤PiIf F0 is equal to Fi-1+ (Fi-Fi-1)[p-(x-1)Pm-Pi-1]/(Pi-Pi-1). And initializes last-time frequency control signal FOn the upper partF. The power frequency of the rest of variable-frequency working oil pumps or air compressors is Fm. Worker's toolThe working pump or air compressor and the standby pump or air compressor are alternated, and the intelligent queuing alternation working method of a plurality of working pumps and a plurality of standby pumps is shown in figure 3.
And 8, acquiring the pressure P of the pressure maintenance system in real time by the controller 6.
Step 9, the controller 6 maintains the system pressure P according to the pressure and maintains the rated system pressure PForehead (forehead)Calculating the power frequency F ═ F of the frequency conversion working oil pump or air compressor with the highest priorityOn the upper part+k(PForehead (forehead)P), k is a pressure deviation and frequency amplification proportionality coefficient, and is a constant, and is usually set according to the regulation performance requirement. And outputting a frequency control signal F to a power frequency converter 10 corresponding to the variable-frequency working oil pump or air compressor with the highest priority, so as to control the power frequency of the variable-frequency working oil pump or air compressor with the highest priority in the pressure maintenance equipment 4. And refreshes the last frequency control signal FOn the upper part＝F。
Step 10, if the pressure is maintained to be lower than the lower pressure PIs lower thanStarting and loading a standby variable frequency oil pump or air compressor with the highest priority, and controlling the power supply frequency of a standby variable frequency drainage pump to be Fm. Step 11 is entered.
Step 11, if the pressure P of the pressure maintaining system is less than the lowest pressure PLowest level ofStarting and loading all standby variable-frequency drainage pumps, and controlling the power frequency of a standby variable-frequency oil pump or air compressor to be Fm. Step 12 is entered.
Step 12, if the pressure is maintained to be not less than the higher pressure PIs higher thanAnd unloading and stopping a standby variable frequency oil pump or air compressor with the lowest priority. Step 13 is entered.
Step 13, if the pressure P of the system is maintained to be not less than the highest pressure PHighest point of the designAnd unloading and stopping all the standby variable frequency oil pumps or air compressors, and returning to the step 3. Otherwise, return to step 8.
The invention discloses a pressure maintaining system adopting variable-frequency pressure maintaining equipment and a self-adaptive control method, which have the following technical effects:
the pressure maintaining system adopting the variable-frequency pressure maintaining equipment and the self-adaptive control method can solve the problems that the consumed load of the pressure maintaining system is not matched with the output power of the pressure maintaining equipment, namely the system pressure is not matched with the pressurizing capacity of the pressure maintaining equipment due to the fact that the consumption reduction speed is not matched with the pressure maintaining equipment, the pressure maintaining equipment is frequently started, stopped or unloaded, the abrasion consumption of equipment elements is intensified, the service life of the pressure maintaining equipment is influenced, meanwhile, energy loss is caused, the energy efficiency and the economical efficiency of the system are influenced, and the like.
The pressure maintaining system adopting the variable-frequency pressure maintaining equipment replaces the constant-frequency pressure maintaining equipment by the variable-frequency pressure maintaining equipment, can solve the problem that the consumed load of the pressure maintaining system is not matched with the output power of the pressure maintaining equipment, namely the speed of system pressure reduction due to consumption is not matched with the pressure capacity of the pressure maintaining equipment, can improve the matching accuracy and accuracy compared with the constant-frequency pressure maintaining equipment, can effectively keep the system pressure stable, and fully reduces the speed of system pressure reduction due to consumption. Meanwhile, the problem of mismatching is solved, unnecessary pressure maintenance equipment can be prevented from being started and stopped and loaded and unloaded, the abrasion consumption of original parts of the equipment is reduced, the service life of the pressure maintenance equipment is prolonged, the energy consumption of a system is reduced, and the economical efficiency is improved.
By adopting the self-adaptive control method adopting the variable-frequency pressure maintaining equipment, the power frequency output by the power frequency converter corresponding to the variable-frequency pressure maintaining equipment is accurately controlled by adopting a closed-loop control algorithm, the problem that the consumed load of a pressure maintaining system is not matched with the output power of the pressure maintaining equipment, namely the speed of system pressure reduction due to consumption is not matched with the pressure capacity of the pressure maintaining equipment can be solved, the matching accuracy and precision are automatically and dynamically improved, the system pressure can be more effectively stabilized, and the speed of system pressure reduction due to consumption is fully reduced. Meanwhile, the problem of mismatching is solved, unnecessary pressure maintenance equipment can be prevented from being started and stopped and loaded and unloaded, the abrasion consumption of original parts of the equipment is reduced, the service life of the pressure maintenance equipment is prolonged, the energy consumption of a system is reduced, and the economical efficiency is improved.
Therefore, compared with a pressure maintaining system and a control method adopting fixed-frequency pressure maintaining equipment, the method provided by the invention has better control performance, adaptability and economy.
Drawings
FIG. 1 is a schematic diagram of a pressure maintenance system according to the present invention.
Fig. 2 is a flow chart of the adaptive control method of the present invention.
Fig. 3 is a flow chart of an intelligent queuing alternate working method of a plurality of working pumps and a plurality of standby pumps.
Detailed Description
As shown in fig. 1, a pressure maintenance system includes a plurality of variable frequency oil pumps or air compressors with the same model and specification as pressure maintenance equipment 4, and further includes a pressure vessel 1, a non-pressure vessel 2, a pipeline 3, a sensor 5, a controller 6, a human-computer interaction device 7, an electrical circuit 8, and a communication circuit 9.
Any pressure maintenance equipment 4 is provided with a power frequency converter 10, and the power frequency converter 10 is connected with the controller 6.
The pressure container 1 is a pressure oil tank or a pressure gas tank.
The non-pressure container 2 is a non-pressure oil tank or an air bag.
The pressure vessel 1 is connected to a pressure maintenance device 4 by a pipe, and the pressure maintenance device 4 is connected to the pressureless vessel 2 by a pipe 3.
The pressure maintaining equipment 4 is n frequency conversion oil pumps or air compressors with the same model number and specification, and the serial numbers are 1# and 2# … … n #.
The sensor 5 collects physical quantity parameters of the pressure vessel 1 in the pressure maintenance system, such as pressure of the pressure maintenance system.
The controller 6 receives the pressure set by the man-machine interaction device 7 through the communication circuit 9 to maintain the rated pressure P of the systemForehead (forehead)Highest pressure PHighest point of the designHigher pressure PIs higher thanLower pressure PIs lower thanLowest pressure PLowest level ofThe power frequency and the pressurization capacity of n frequency conversion oil pumps or air compressors in the pressure maintaining equipment 4 are cooperated with the parameter information of a curve parameter table and the like, and the self-adaptive control method of the frequency conversion pressure maintaining equipment is adopted to carry out logic processing according to the pressure maintaining system state signal acquired by the sensor 5 received by the electric loop 8, and then the pressure is maintained by the electric loop 8The frequency of the power frequency converters 10 corresponding to the n frequency conversion oil pumps or air compressors with the same model and specification in the equipment 4 is controlled, so that the operation condition of the n frequency conversion oil pumps or air compressors in the pressure maintenance equipment 4 is controlled, and meanwhile, the state information of the pressure maintenance system is transmitted to the man-machine interaction device 7 through the communication loop 9. The power frequency and pressurizing capacity co-joined curve of n variable frequency oil pumps or air compressors in the pressure maintaining equipment 4 is shown in the following table 1, wherein m and i in the table 1 are positive integers, i is more than 1 and less than or equal to m, and Fi-1＜Fi，Pi-1＜PiPi is the pressure capacity of the oil pump or the air compressor corresponding to the Fi power frequency; p1Is the minimum drainage capacity of the variable frequency drainage pump, PmThe maximum drainage capacity of the variable-frequency drainage pump. The pressurizing capacity refers to the pressure rise per unit time, and the unit is Mpa/min;
TABLE 1 Power frequency and pressurization Capacity Joint Curve parameter Table
F1
F2
F3
…
Fi-1
Fi
…
Fm-1
Fm
P1
P2
P3
…
Pi-1
Pi
…
Pm-1
Pm
The human-computer interaction device 7 communicates with the controller 6. Maintaining the pressure set by the user through the human-computer interaction device 7 at the nominal pressure P of the systemForehead (forehead)Highest pressure PHighest point of the designHigher pressure PIs higher thanLower pressure PIs lower thanLowest pressure PLowest level ofParameters such as power supply frequency and pressurization capacity of n variable frequency oil pumps or air compressors in the pressure maintenance equipment 4 are transmitted to the controller 6 in a cooperative curve table mode, and meanwhile, the human-computer interaction device 7 collects parameter information of the pressure maintenance system sent by the controller 6 to conduct graphical display.
The pressure maintaining equipment 4 is connected with a power supply frequency converter 10; the sensor 5 is connected with the controller 6; the controller 6 is connected with a power supply frequency converter 10 through an electric loop 8; and the transmission of the state signal and the control signal is realized. N frequency conversion oil pumps or air compressors with the same model number and specification in the pressure maintenance equipment 4 are correspondingly provided with n power frequency converters in the power frequency converter 10.
The controller 6 is connected with the man-machine interaction device 7 through the communication loop 9, and transmission of pressurization capacity information and state information is achieved.
The power frequency converter 10 receives the frequency control signal output by the controller 6 through the electrical loop 8, and outputs a power signal with a corresponding frequency to n variable frequency oil pumps or air compressors in the pressure maintenance equipment 4, so as to control the power switches and the power frequency of the n variable frequency oil pumps or air compressors in the pressure maintenance equipment 4.
The sensor 5 is a pressure transmitter with a brand of KELLER and a model number of PA.23SY/100 bar/81594.55.
The controller 6 is a PLC controller with the model number of 140CPU67160 and the brand number of Schneider.
The man-machine interaction device 7 adopts a touch screen with the brand name of Schneider and the model number of XBTGT 7340.
The electric loop 8 adopts a universal national standard cable.
The communication loop 9 adopts a universal Ethernet network cable.
The power frequency converter 10 adopts a three-in three-out frequency conversion power supply with the brand of Euro-Yang Wass and the model of 983150.
The variable frequency oil pump motor adopts a three-phase asynchronous motor with the brand ABB and the model QABP series.
The variable frequency air compressor adopts a Deshal brand, a DAV250-250(W) model and a double-stage compression permanent magnet variable frequency air compressor.
As shown in fig. 2, a pressure maintenance system adaptive control method using a variable frequency pressure maintenance device includes the following detailed steps:
step 1, initializing a controller 6, and acquiring a pressure maintenance system rated pressure P set by a user through a man-machine interaction device 7Forehead (forehead)Highest pressure PHighest point of the designHigher pressure PIs higher thanLower pressure PIs lower thanLowest pressure PLowest level ofAnd the power supply frequency and the pressurization capacity of the n variable frequency oil pumps or air compressors in the pressure maintaining equipment 4 are in coordination with the parameter information of the curve table.
And 2, the controller 6 controls and starts n variable frequency oil pumps or air compressors to operate and load at the rated frequency of 50Hz, builds the pressure of the pressure maintenance system to the rated pressure, and then stops all the oil pumps or air compressors from operating.
And 3, collecting the pressure maintaining system pressure P1 by the controller 6, and starting timing.
And 4, detecting whether the timing is finished for t minutes by the controller 6, if so, entering the step 5, and otherwise, continuously detecting.
Step 5, the controller 6 collects the pressure maintenance system pressure P2.
In step 6, the controller 6 calculates the pressure maintenance system consumption load P ═ P1-P2)/t.
And 7, calculating the number x of the variable-frequency working oil pumps or air compressors and the operation initial power frequency F0 of the variable-frequency oil pump or air compressor with the highest priority by the controller 6 according to the consumption load p and a power frequency and pressurization capacity co-relation curve table of the n variable-frequency oil pumps or air compressors in the pressure maintenance equipment 4, outputting a frequency control signal F to the power frequency converter 10 corresponding to the variable-frequency oil pump or air compressor with the highest priority, wherein F is F0, so that the variable-frequency oil pumps or air compressors in the x pressure maintenance equipment 4 are started to serve as the variable-frequency working oil pumps or air compressors, and the control of the power frequency of the variable-frequency working oil pumps or air compressors with the highest priority is realized. To round up the mathematical sign. f0 calculation method: if Pi-1≤p-(x-1)Pm≤PiIf F0 is equal to Fi-1+ (Fi-Fi-1)[p-(x-1)Pm-Pi-1]/(Pi-Pi-1). And initializes last-time frequency control signal FOn the upper partF. The power frequency of the rest of variable-frequency working oil pumps or air compressors is Fm. The main-standby alternate starting method refers to an intelligent queuing alternate working method of a plurality of working pumps and a plurality of standby pumps shown in fig. 3.
And 8, acquiring the pressure P of the pressure maintenance system in real time by the controller 6.
Step 9, the controller 6 maintains the system pressure P according to the pressure and maintains the rated system pressure PForehead (forehead)Calculating the power frequency F ═ F of the frequency conversion working oil pump or air compressor with the highest priorityOn the upper part+k(PForehead (forehead)P), outputting a frequency control signal F to the power frequency converter 10 corresponding to the variable frequency operating oil pump or air compressor with the highest priority, thereby controlling the power frequency of the variable frequency operating oil pump or air compressor with the highest priority in the pressure maintenance equipment 4. And refreshes the last frequency control signal FOn the upper part＝F. k is a pressure deviation and frequency amplification proportional coefficient, and is a constant, and is usually set according to the regulation performance requirement.
Step 10, if the pressure is maintained to be lower than the lower pressure PIs lower thanStarting and loading a standby variable frequency oil pump or air compressor with the highest priority, and controlling the power supply frequency of a standby variable frequency drainage pump to be Fm. Step 11 is entered.
Step 11, if the pressure P of the pressure maintaining system is less than the lowest pressure PLowest level ofStarting and loading all standby variable-frequency drainage pumps, and controlling the power frequency of a standby variable-frequency oil pump or air compressor to be Fm. Step 12 is entered.
Step 12, if the pressure is maintained to be not less than the higher pressure PIs higher thanAnd unloading and stopping a standby variable frequency oil pump or air compressor with the lowest priority. Step 13 is entered.
Step 13, if the pressure P of the system is maintained to be not less than the highest pressure PHighest point of the designAnd unloading and stopping all the standby variable frequency oil pumps or air compressors, and returning to the step 3. Otherwise, return to step 8.
An intelligent queuing alternate working method of a plurality of working pumps and a plurality of standby pumps is shown in fig. 3 and comprises the following steps:
the method comprises the following steps: and initializing, and determining the number i of the working pumps of the system and the total number j of the pumps.
Step two: and collecting multiple working condition factors of all pumps and determining various working condition values of all pumps.
Step three: and (4) carrying out weight sequencing according to various working condition factors of all the pumps, and determining the weight values of various working condition factors of all the pumps.
Step IV: and calculating the priority score of each pump according to the working condition values corresponding to the various working condition factors of all the pumps and the weight values corresponding to the corresponding working condition factors.
Step five: prioritizing all pumps in the system according to the priority score of each pump;
step (c): according to the priority sequence of all pumps, the first i pumps with the priority sequence from high to low are taken as working pumps, and other j-i pumps are taken as standby pumps;
step (c): and detecting the running states of all the pumps, and if any pump stops running, returning to the step II.
In the second step, the multiple working condition factors include: the operation times of the pump, whether the pump can work normally or not, and the operation state of the pump is manually set by a handle of 'active', 'standby' or 'cut'. The steps of the invention take the three working condition factors as examples, and the working condition factors can be expanded according to the actual application condition in actual application.
The various operating conditions of all pumps are as follows:
in all the pumps, if the pumps can work normally, the working condition value X is 1; if the pump can not work normally, the working condition value X is 0. Setting the working condition value of the n number pump as Xn；
In all the pumps, if the pumps can work normally, the working condition value X is 1; if the pump can not work normally, the working condition value X is 0. Setting the working condition value of the n number pump as Xn。
In all pumps, if the operating state of the pump is manually set as 'main use', the value of the state working condition value Y is 2; if the operating state handle of the pump is manually set as 'standby', the working condition value Y of the state is 1; if the operating state handle of the pump is artificially set to be cut off, the state working condition value Y is 0. The reason for taking the value is that the operating state of the pump is manually set to be 'primary' with higher priority than manually set to be 'standby', and manually set to be 'standby' with higher priority than manually set to be 'cut'. Setting the state working condition value of the n number pump as Yn。
In all the pumps, the operation times of the pumps are sequenced, and the pump time working condition values Z corresponding to the times from high to low are sequentially 1, 2 … … 5 and 6. The number working condition value of the n number pump is set as Zn。
In the step 3, the importance of three factors considered by the pump alternation is that: whether the pump can work normally or not, the running state handle of the pump is manually set in a primary mode, a standby mode or a cutting mode, and the running times of the pump are counted;
setting the weight value a of 100 for the normal operation of the pump;
the running state of the pump is characterized in that the weight value b of the handle which is manually set as 'primary', 'standby' or 'cut-off' is 10;
the weighted value c of the number of pump operations is 1.
In the step (iv), the priority score M ═ aX + bY + cZ ═ 100X +10Y + Z is calculated for each pump; the priority score M for pump number nn＝100Xn+10Yn+Zn。
In the fifth step, according to MnThe size of the pump, the priority score M of the number n pumpnThe larger the priority, the more forward it will be in the queue, let M ben1≧Mn2≧Mn3≧Mn4≧Mn5≧Mn6Then the priority ranking is as follows: n1, n2, n3, n4, n5 and n 6.
Example (b):
the invention is applied to the start-stop control of the pressurized oil pump of a hydraulic system of a speed regulator of a certain power station. The system is designed with 4 variable-frequency pressurized oil pumps. The method of the present invention will be described in detail below with reference to the examples.
The method for controlling the pressurized oil pump of the hydraulic system of the speed regulator of a certain power station comprises the following detailed steps:
1. the controller of the speed regulator hydraulic system is initialized, and the rated pressure P of the pressure maintenance system set by a user through a man-machine interaction device is collectedForehead (forehead)Highest pressure PHighest point of the designHigher pressure PIs higher thanLower pressure PIs lower thanLowest pressure PLowest level ofAnd parameter information such as power supply frequency and pressurization capacity of 4 variable frequency oil pumps or air compressors are linked together by a curve table.
2. And the speed regulator hydraulic system controller controls and starts 4 variable frequency oil pumps or air compressors to operate and load at the rated frequency of 50Hz, builds the pressure of the pressure maintenance system to the rated pressure, and then stops all the variable frequency oil pumps or air compressors from operating.
3. The governor hydraulic system controller collects pressure to maintain the system pressure P1 and begins timing.
4. And (5) detecting whether the timing is finished for t minutes by a speed regulator hydraulic system controller, if so, entering the step 5, and otherwise, continuously detecting.
5. The governor hydraulic system controller collects pressure to maintain the system pressure P2.
6. The governor hydraulic system controller calculates the pressure maintenance system consumption load P ═ P1-P2/t.
7. The speed regulator hydraulic system controller calculates the number x of the variable frequency working oil pumps or air compressors and the operation initial power frequency F0 of the variable frequency oil pump or air compressor with the highest priority according to a consumption load p and a power frequency and pressurization capacity co-linkage curve table of n variable frequency oil pumps or air compressors, outputs a frequency control signal F to a power frequency converter corresponding to the variable frequency oil pump or air compressor with the highest priority, and F is F0, so that x variable frequency oil pumps or air compressors are started to serve as the variable frequency working oil pumps or air compressors, and the control of the power frequency of the variable frequency working oil pumps or air compressors with the highest priority is realized. To round up the mathematical sign. f0 calculation method: if Pi-1≤p-(x-1)Pm≤PiIf F0 is equal to Fi-1+(Fi-Fi-1)[p-(x-1)Pm-Pi-1]/ (Pi-Pi-1). And initializes last-time frequency control signal FOn the upper partF. The power frequency of the rest of variable-frequency working oil pumps or air compressors is Fm. The main-standby alternate starting method refers to an intelligent queuing alternate working method of a plurality of working pumps and a plurality of standby pumps shown in fig. 3.
8. The governor hydraulic system controller collects pressure in real time to maintain system pressure P.
9. The governor hydraulic system controller maintains the system pressure P according to the pressure and maintains the system nominal pressure PForehead (forehead)Calculating the power frequency F ═ F of the frequency conversion working oil pump or air compressor with the highest priorityOn the upper part+k(PForehead (forehead)-p) outputting the frequency control signal F to the highest priorityThe frequency conversion working oil pump or the air compressor 10 corresponding to the power frequency converter, thereby realizing the control of the power frequency of the frequency conversion working oil pump or the air compressor with the highest priority in the pressure maintenance equipment. And refreshes the last frequency control signal FOn the upper partF. k is a pressure deviation and frequency amplification proportional coefficient, and is a constant, and is usually set according to the regulation performance requirement.
10. If the pressure maintains the system pressure P less than the lower pressure PIs lower thanStarting and loading a standby variable frequency oil pump or air compressor with the highest priority, and controlling the power supply frequency of a standby variable frequency drainage pump to be Fm. Step 11 is entered.
11. If the pressure maintains the system pressure P less than the minimum pressure PLowest level ofStarting and loading all standby variable-frequency drainage pumps, and controlling the power frequency of a standby variable-frequency oil pump or air compressor to be Fm. Step 12 is entered.
12. If the pressure is maintained at a system pressure P not less than the higher pressure PIs higher thanAnd unloading and stopping a standby variable frequency oil pump or air compressor with the lowest priority. Step 13 is entered.
13. If the pressure maintains the system pressure P not less than the maximum pressure PHighest point of the designAnd unloading and stopping all the standby variable frequency oil pumps or air compressors, and returning to the step 3. Otherwise, return to step 8.
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