阅读说明：本技术 基于变频压力维持设备的液压维持系统及自适应控制方法 (Hydraulic pressure maintaining system based on 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：基于变频压力维持设备的液压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；压力容器通过液位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,即系统压力由于消耗下降的速度与压力维持设备加压的能力大小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 system comprises a pressure container, a non-pressure container and pressure maintaining equipment; the pressure vessel is connected with the pressureless vessel through the liquid level maintaining equipment. 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 consumed load is not matched with the output power of the pressure maintaining equipment, namely the pressure of a system 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, loaded and unloaded, the abrasion consumption of equipment components is aggravated, the service life of the pressure maintaining equipment is influenced, energy loss is caused, and the energy efficiency and the economical efficiency of a system are influenced.)

1. Hydraulic pressure maintenance system based on frequency conversion pressure maintenance equipment, characterized by that this system includes: a pressure vessel (1), a non-pressure vessel (2) and a pressure maintaining device (4); the pressure container (1) is connected with the non-pressure container (2) through the liquid level maintaining equipment (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. The hydraulic maintenance system based on variable frequency pressure maintenance equipment according to claim 1, characterized in that: the pressure container (1) is a pressure oil tank.

3. The hydraulic maintenance system based on variable frequency pressure maintenance equipment according to claim 1, characterized in that: the non-pressure container (2) is a non-pressure oil tank.

4. The hydraulic maintenance system based on variable frequency pressure maintenance equipment according to claim 1, characterized in that: the pressure maintaining equipment (4) is n variable frequency oil pumps with the same model number and specification, and the serial numbers are 1#, 2# … … n #; the power frequency and the pressurization capacity of n variable frequency oil pumps 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,F_i-1＜F_i，P_i-1＜P_ipi is the pressure capacity of the oil pump corresponding to the Fi power frequency; p₁Is the minimum drainage capacity of the variable frequency drainage pump, P_mThe 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

F₁ F₂ F₃ … F_i-1 F_i … F_m-1 F_m P₁ P₂ P₃ … P_i-1 P_i … P_m-1 P_m

。

5. The hydraulic maintenance system based on variable frequency pressure maintenance equipment according to claim 1, characterized in that: 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 hydraulic maintenance system based on variable frequency pressure maintenance equipment according to claim 1, characterized in that: the controller (6) receives the rated liquid level H of the hydraulic maintenance system set by the man-machine interaction device (7)_{Forehead (forehead)}Maximum liquid level H_{Highest point of the design}Higher liquid level H_{Is higher than}Lower level H_{Is lower than}Minimum level H_{Lowest level of}The power frequency and the pressurization capacity of n variable frequency oil pumps in the pressure maintaining equipment (4) are in coordination with the parameter information of a curve parameter table, and after logical processing is carried out by adopting a self-adaptive control method according to the state signals of the hydraulic pressure maintaining system collected by the sensor (5), the frequency of power frequency converters (10) corresponding to the n variable frequency oil pumps with the same model and specification in the pressure maintaining equipment (4) is controlled, so that the operation condition of the n variable frequency oil pumps in the pressure maintaining equipment (4) is controlled, and the state information of the hydraulic pressure maintaining system is transmitted to the man-machine interaction device (7).

7. The hydraulic maintenance system based on variable frequency pressure maintenance equipment according to claim 1, characterized in that: the human-computer interaction device (7) is communicated with the controller (6) and maintains the rated liquid level H of the system through the hydraulic pressure set by the human-computer interaction device (7)_{Forehead (forehead)}Maximum liquid level H_{Highest point of the design}Higher liquid level H_{Is higher than}Lower level H_{Is lower than}Minimum level H_{Lowest level of}Pressure ofThe power frequency and the pressurization capacity of n variable frequency oil pumps in the force maintaining equipment (4) are in cooperative connection with the parameters of the curve table and transmitted to the controller (6), and meanwhile, the man-machine interaction device (7) acquires the parameter information of the hydraulic maintaining system transmitted by the controller (6) and performs graphical display.

8. An adaptive control method for a hydraulic maintenance system, comprising the steps of:

step 1, initializing a controller (6), and acquiring a rated liquid level H of a hydraulic maintenance system set by a user through a man-machine interaction device (7)_{Forehead (forehead)}Maximum liquid level H_{Highest point of the design}Higher liquid level H_{Is higher than}Lower level H_{Is lower than}Minimum level H_{Lowest level of}The power supply frequency and the pressurization capacity of n variable frequency oil pumps 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 to operate and load at rated frequency, the hydraulic pressure maintaining system is pressurized to rated pressure, and then all the variable frequency oil pumps are stopped to operate;

step 3, the controller (6) collects the pressure P1 of the hydraulic maintenance system and starts timing at the same time;

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, collecting the pressure P2 of the hydraulic maintenance system by the controller (6);

step 6, the controller (6) calculates the consumption load P of the hydraulic pressure maintaining system as (P1-P2)/t;

step 7, calculating the number x of the variable frequency operating oil pumps and the operation initial power frequency F0 of the variable frequency oil pump 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 n variable frequency oil pumps in the pressure maintenance equipment (4), and outputting a frequency control signal F to a power frequency converter (10) corresponding to the variable frequency oil pump with the highest priority, wherein F is F0, so that the variable frequency oil pumps in the x pressure maintenance equipment (4) are started to serve as the variable frequency operating oil pumps, and the power frequency of the variable frequency operating oil pumps with the highest priority is controlled; is an upwardly rounded mathematical symbol; f0 calculation method: if P_i-1≤p-(x-1)P_m≤P_iIf F0 is equal to F_i-1+(F_i-F_i-1)[p-(x-1)P_m-P_i-1]/(P_i-P_i-1) (ii) a And initializes last-time frequency control signal F_{On the upper part}F; the power frequency of the rest variable frequency working oil pumps is F_m；

Step 8, the controller (6) collects the liquid level h of the hydraulic maintenance system in real time;

step 9, the controller (6) maintains the rated liquid level H of the system according to the liquid level H of the hydraulic pressure maintaining system and the rated liquid level H of the hydraulic pressure maintaining system_{Forehead (forehead)}Calculating the power frequency F ═ F of the variable frequency working oil pump with the highest priority_{On the upper part}+k(H_{Forehead (forehead)}-h), k is a proportional coefficient of pressure deviation and frequency amplification, and a frequency control signal F is output to a power frequency converter (10) corresponding to the variable-frequency working oil pump with the highest priority, so that the power frequency of the variable-frequency working oil pump with the highest priority in the pressure maintaining equipment (4) is controlled; and refreshes the last frequency control signal F_{On the upper part}＝F；

Step 10, if the liquid level H of the hydraulic maintenance system is less than the lower liquid level H_{Is lower than}Starting and loading a standby variable frequency oil pump with the highest priority, and controlling the power frequency of a standby variable frequency drainage pump to be F_m(ii) a Entering a step 11;

step 11, if the liquid level H of the hydraulic maintenance system is less than the lowest liquid level H_{Lowest level of}Starting and loading all standby variable frequency drainage pumps, and controlling the power frequency of a standby variable frequency oil pump to be F_m(ii) a Entering step 12;

step 12, if the liquid level H of the hydraulic maintenance system is not less than the higher liquid level H_{Is higher than}Unloading and stopping a standby variable frequency oil pump with the lowest priority; entering step 13;

step 13, if the liquid level H of the hydraulic maintenance system is not less than the highest liquid level H_{Highest point of the design}Unloading and stopping all the standby variable frequency oil pumps, and returning to the step 3; otherwise, return to stepAnd 8. step.

Technical Field

The invention belongs to the field of industrial control, and particularly relates to a hydraulic pressure maintaining system based on variable-frequency pressure maintaining equipment and a self-adaptive control method.

Background

In industrial control, there are many applications that require a hydraulic pressure maintenance system, such as a hydro-generator governor that adjusts the opening of the guide vanes, the power and frequency of the unit, and a governor hydraulic system, which is a typical hydraulic pressure maintenance system. The hydraulic pressure maintaining system is usually designed with a plurality of quantitative oil pumps with the same model and specification as pressure maintaining equipment, but because the load of the hydraulic pressure maintaining system has steady-state fixed consumption load and random consumption load, if the consumption load 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 consumption reduction speed, the pressure maintaining equipment is frequently started, stopped or unloaded, the abrasion consumption of equipment components is aggravated, the service life of the pressure maintaining equipment is influenced, and meanwhile, the energy loss is caused, and the energy efficiency and the economical efficiency of the system are influenced.

Disclosure of Invention

In order to solve the technical problems, the invention provides a hydraulic pressure maintaining system based on variable frequency pressure maintaining equipment and a self-adaptive control method, and aims to solve the problems that the consumed load is not matched with the output power of the pressure maintaining equipment, namely the system pressure is frequently started, stopped, loaded and unloaded due to the fact that the consumption reduction speed is not matched with the pressurizing capacity of the pressure maintaining equipment, the abrasion consumption of equipment components is aggravated, the service life of the pressure maintaining equipment is influenced, meanwhile, the energy loss is caused, and the energy efficiency and the economical efficiency of the system are influenced.

The technical scheme adopted by the invention is as follows:

hydraulic pressure maintenance system based on frequency conversion pressure maintenance equipment, this system includes: a pressure vessel, a pressureless vessel, a pressure maintenance device; the pressure vessel is connected with the non-pressure vessel through the liquid level maintaining equipment,

the pressure container is provided with a sensor for acquiring physical quantity parameters of the pressure container, such as the pressure and the liquid level of a hydraulic 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. The non-pressure container is a non-pressure oil tank.

The pressure maintaining equipment is n variable frequency oil pumps with the same model number and specification, and the serial numbers are 1#, 2# … … n #. The power frequency and pressurizing capacity tandem curve of n variable frequency oil pumps in the pressure maintaining equipment 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, F_i-1＜F_i，P_i-1＜P_iPi is the pressure capacity of the oil pump corresponding to the Fi power frequency; p₁Is the minimum drainage capacity of the variable frequency drainage pump, P_mThe 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 with the same model and specification in the pressure maintenance equipment are correspondingly provided with n power frequency converters.

The controller receives the rated liquid level H of the hydraulic maintenance system set by the human-computer interaction device_{Forehead (forehead)}Maximum liquid level H_{Highest point of the design}Higher liquid level H_{Is higher than}Lower level H_{Is lower than}Minimum level H_{Lowest level of}The power frequency and the pressurization capacity of n variable frequency oil pumps in the pressure maintenance equipment are cooperated with the parameter information of a curve parameter table, and after logical processing is carried out by adopting a self-adaptive control method according to the state signals of the hydraulic pressure maintenance system collected by a sensor, the frequency of power frequency converters corresponding to the n variable frequency oil pumps with the same model and specification in the pressure maintenance equipment is controlled, so that the operation condition of the n variable frequency oil pumps in the pressure maintenance equipment is controlled, and the state information of the hydraulic pressure maintenance system is transmitted to a man-machine interaction device.

The man-machine interaction device is communicated with the controller, and maintains the rated liquid level H of the system through the hydraulic pressure set by the man-machine interaction device_{Forehead (forehead)}Maximum liquid level H_{Highest point of the design}Higher liquid level H_{Is higher than}Lower level H_{Is lower than}Minimum level H_{Lowest level of}The power supply frequency and the pressurization capacity of the n variable frequency oil pumps in the pressure maintenance equipment are connected in a coordinated mode to form curve table parameters and are transmitted to the controller, and meanwhile, the man-machine interaction device collects parameter information of the hydraulic maintenance system sent by the controller and conducts graphical display.

An adaptive control method of a hydraulic maintenance system comprises the following steps:

step 1, initializing a controller, and acquiring a rated liquid level H of a hydraulic maintenance system set by a user through a man-machine interaction device_{Forehead (forehead)}Maximum liquid level H_{Highest point of the design}Higher liquid level H_{Is higher than}Lower level H_{Is lower than}Minimum level H_{Lowest level of}And the power supply frequency and the pressurization capacity of the n variable frequency oil pumps in the pressure maintaining equipment 4 are in coordination with the parameter information of the curve table.

And 2, controlling and starting the n variable frequency oil pumps by the controller to operate and load at rated frequency, building the pressure of the hydraulic maintenance system to the rated pressure, and then stopping all the variable frequency oil pumps from operating.

And 3, collecting the pressure P1 of the hydraulic maintenance system by the controller, and starting timing.

And 4, detecting whether the timing is finished for t minutes by the controller, if so, entering the step 5, and otherwise, continuously detecting.

And 5, collecting the pressure P2 of the hydraulic maintenance system by the controller.

And 6, calculating the consumption load P of the hydraulic pressure maintaining system as (P1-P2)/t by the controller.

And 7, the controller calculates the number x of the variable-frequency working oil pumps and the operation initial power frequency F0 of the variable-frequency oil pump with the highest priority according to the consumption load p and a power frequency and pressurization capacity collaborative curve table of the n variable-frequency oil pumps in the pressure maintenance equipment, and outputs a frequency control signal F to the power frequency converter corresponding to the variable-frequency oil pump with the highest priority, wherein F is F0, so that the variable-frequency oil pumps in the x pressure maintenance equipment 4 are started to serve as the variable-frequency working oil pumps, and the control of the power frequency of the variable-frequency working oil pumps with the highest priority is realized. To round up the mathematical sign. f0 calculation method: if P_i-1≤p-(x-1) P_m≤P_iIf F0 is equal to F_i-1+(F_i-F_i-1)[p-(x-1)P_m-P_i-1]/(P_i-P_i-1). And initializes the last frequency control signal F on F. The power frequency of the rest variable frequency working oil pumps is F_m. Working pump and backup pump alternation method referring to fig. 3, an intelligent queuing alternation working method of a plurality of working pumps and a plurality of backup pumps is shown.

And 8, acquiring the liquid level h of the hydraulic maintenance system in real time by the controller.

Step 9, the controller 6 maintains the system liquid level H and the rated liquid level H according to the hydraulic pressure_{Forehead (forehead)}Calculating the power frequency F ═ F of the variable frequency working oil pump with the highest priority_{On the upper part}+k(H_{Forehead (forehead)}-h) outputting a frequency control signal F to the power frequency converter 10 corresponding to the variable frequency operating oil pump with the highest priority, thereby giving priority to the pressure maintenance device 4And controlling the power frequency of the variable-frequency working oil pump with the highest level. And refreshes the last frequency control signal F_{On 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 liquid level H of the hydraulic maintenance system is less than the lower liquid level H_{Is lower than}Starting and loading a standby variable frequency oil pump with the highest priority, and controlling the power frequency of a standby variable frequency drainage pump to be F_m. Step 11 is entered.

Step 11, if the liquid level H of the hydraulic maintenance system is less than the lowest liquid level H_{Lowest level of}Starting and loading all standby variable frequency drainage pumps, and controlling the power frequency of a standby variable frequency oil pump to be F_m. Step 12 is entered.

Step 12, if the liquid level H of the hydraulic maintenance system is not less than the higher liquid level H_{Is higher than}And unloading and stopping a standby variable frequency oil pump with the lowest priority. Step 13 is entered.

Step 13, if the liquid level H of the hydraulic maintenance system is not less than the highest liquid level H_{Highest point of the design}And unloading and stopping all the standby variable frequency oil pumps, and returning to the step 3. Otherwise, return to step 8.

The hydraulic 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 hydraulic 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 components 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 hydraulic pressure maintaining system adopting the variable-frequency pressure maintaining equipment replaces the constant-frequency pressure maintaining equipment, can solve the problem that the consumed load of the hydraulic 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 liquid level of the system stable, and fully reduces the speed of system liquid level reduction due to consumption. Meanwhile, the problem of mismatching is solved, unnecessary hydraulic pressure maintaining equipment starting and stopping and loading and unloading can be avoided, the abrasion consumption of original equipment is reduced, the service life of the hydraulic pressure maintaining 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 hydraulic maintaining equipment, the power frequency output by the power frequency converter corresponding to the variable-frequency hydraulic maintaining equipment is accurately controlled by adopting a closed-loop control algorithm, the problem that the consumed load of a hydraulic maintaining system is not matched with the output power of the hydraulic maintaining equipment, namely the speed of system pressure reduction due to consumption is not matched with the pressure capacity of the hydraulic maintaining equipment can be solved, the matching accuracy and precision are automatically and dynamically improved, the liquid level of the system can be more effectively stabilized, and the speed of system liquid level reduction due to consumption is fully reduced. Meanwhile, the problem of mismatching is solved, unnecessary hydraulic pressure maintaining equipment starting and stopping and loading and unloading can be avoided, the abrasion consumption of original equipment is reduced, the service life of the hydraulic pressure maintaining equipment is prolonged, the energy consumption of a system is reduced, and the economical efficiency is improved.

Therefore, compared with a hydraulic maintaining system and a control method adopting fixed-frequency hydraulic maintaining equipment, the method provided by the invention has better control performance, adaptability and economy.

The self-adaptive control method adopting the variable-frequency hydraulic maintenance equipment can convert the hydraulic control into the liquid level control, is suitable for the conditions that the hydraulic sensor is inconvenient to install and measure or the sensor precision cannot meet the control requirement, and realizes the stable control of the hydraulic pressure through the stable control of the liquid level.

Drawings

FIG. 1 is a schematic diagram of the hydraulic maintenance system of 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 hydraulic pressure maintenance system comprises a plurality of variable frequency oil pumps with the same model and specification as a pressure maintenance device 4, and only one pump needs to be started to operate under normal conditions; the system also comprises a pressure container 1, a non-pressure container 2, a pipeline 3, a sensor 5, a controller 6, a human-computer interaction device 7, an electric loop 8 and a communication loop 9.

The pressure container 1 is connected with the pressureless container 2 through a pressure maintaining device 4;

the pressure vessel 1 is provided with a sensor 5.

The sensor 5 and the pressure maintaining device 4 are both connected with a controller 6, and the controller 6 is connected with a human-computer interaction device 7.

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.

The non-pressure container 2 is a non-pressure oil tank.

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 variable frequency oil pumps with the same model number and specification, and the serial numbers are 1#, 2# … … n #.

The sensor 5 collects physical quantity parameters of the pressure vessel 1 in the hydraulic pressure maintaining system, such as the pressure and the liquid level of the hydraulic pressure maintaining system.

The controller 6 receives the rated liquid level H of the hydraulic maintenance system set by the man-machine interaction device 7 through the communication loop 9_{Forehead (forehead)}Maximum liquid level H_{Highest point of the design}Higher liquid level H_{Is higher than}Lower level H_{Is lower than}Minimum level H_{Lowest level of}The power frequency and the pressurization capacity of n variable frequency oil pumps in the pressure maintaining equipment 4 are cooperated with parameter information such as a curve parameter table, and after logical processing is carried out by adopting a self-adaptive control method of the variable frequency pressure maintaining equipment according to a hydraulic pressure maintaining system state signal acquired by a sensor 5 received by an electric circuit 8, frequency control is carried out on power frequency converters 10 corresponding to the n variable frequency oil pumps with the same model and specification in the pressure maintaining equipment 4 through the electric circuit 8, thereby carrying out operation condition control on the n variable frequency oil pumps in the pressure maintaining equipment 4, and simultaneously carrying out the state information of the hydraulic pressure maintaining systemAnd is transmitted to the man-machine interaction device 7 through the communication loop 9.

The power frequency and pressurizing capacity tandem curve of n variable frequency oil pumps 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, F_i-1＜F_i，P_i-1＜P_iPi is the pressure capacity of the oil pump corresponding to the Fi power frequency; p₁Is the minimum drainage capacity of the variable frequency drainage pump, P_mThe 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. The rated liquid level H of the hydraulic maintenance system set by a user through the man-machine interaction device 7_{Forehead (forehead)}Maximum liquid level H_{Highest point of the design}Higher liquid level H_{Is higher than}Lower level H_{Is lower than}Minimum level H_{Lowest level of}Parameters such as power supply frequency and pressurization capacity of n variable frequency oil pumps 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 acquires parameter information of the hydraulic maintenance system sent by the controller 6 for 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 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 with the same model and specification in the pressure maintaining 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 electric loop 8, and outputs a power signal with a corresponding frequency to the n variable frequency oil pumps in the pressure maintenance equipment 4, thereby controlling the power switch and the power frequency of the n variable frequency oil pumps in the pressure maintenance equipment 4.

The sensor 5 adopts a liquid level sensor with the brand of KSR KEUBLER and the model of MG-AU-VK10-TS-L2350/M2200 (K).

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 hydraulic maintenance system usually has two control modes, one is system pressure control in the pressure vessel 1, and the other is liquid level control in the pressure vessel 1.

As shown in fig. 2, the adaptive control method for a hydraulic pressure maintaining system using a variable frequency pressure maintaining device according to the present invention includes the following detailed steps:

step 1, initializing a controller 6, and acquiring a rated liquid level H of a hydraulic maintenance system set by a user through a man-machine interaction device 7_{Forehead (forehead)}Maximum liquid level H_{Highest point of the design}Higher liquid level H_{Is higher than}Lower level H_{Is lower than}Minimum level H_{Lowest level of}And the power supply frequency and the pressurization capacity of the n variable frequency oil pumps 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 the n variable frequency oil pumps to operate and load at rated frequency, builds the pressure of the hydraulic maintenance system to the rated pressure, and then stops all the variable frequency oil pumps from operating.

And 3, acquiring the hydraulic 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.

And step 5, the controller 6 collects the hydraulic pressure maintaining system pressure P2.

In step 6, the controller 6 calculates the hydraulic pressure maintaining system consumption load P ═ P1-P2)/t.

Step 7, the controller 6 maintains the power frequency and the pressurization capacity of the n variable frequency oil pumps in the equipment 4 according to the consumption load p and the power frequency and pressurization capacity joint curve tableAnd calculating the number x of the variable-frequency working oil pumps and the operation initial power frequency F0 of the variable-frequency oil pump with the highest priority, outputting a frequency control signal F to the power frequency converter 10 corresponding to the variable-frequency oil pump with the highest priority, wherein F is F0, so that the variable-frequency oil pumps in the x pressure maintenance devices 4 are started to serve as the variable-frequency working oil pumps, and the control of the power frequency of the variable-frequency working oil pumps with the highest priority is realized. To round up the mathematical sign. f0 calculation method: if P_i-1≤p-(x-1)P_m≤P_iIf F0 is equal to F_i-1+(F_i-F_i-1)[p-(x-1)P_m-P_i-1]/(P_i-P_i-1). And initializes last-time frequency control signal F_{On the upper part}F. The power frequency of the rest variable frequency working oil pumps is F_m. Working pump and backup pump alternation method referring to fig. 3, an intelligent queuing alternation working method of a plurality of working pumps and a plurality of backup pumps is shown.

And 8, acquiring the liquid level h of the hydraulic maintenance system in real time by the controller 6.

Step 9, the controller 6 maintains the system liquid level H and the rated liquid level H according to the hydraulic pressure_{Forehead (forehead)}Calculating the power frequency F ═ F of the variable frequency working oil pump with the highest priority_{On the upper part}+k(H_{Forehead (forehead)}H), outputting a frequency control signal F to the power frequency converter 10 corresponding to the variable frequency operating oil pump with the highest priority, thereby controlling the power frequency of the variable frequency operating oil pump with the highest priority in the pressure maintaining equipment 4. And refreshes the last frequency control signal F_{On 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 liquid level H of the hydraulic maintenance system is less than the lower liquid level H_{Is lower than}Starting and loading a standby variable frequency oil pump with the highest priority, and controlling the power frequency of a standby variable frequency drainage pump to be F_m. Step 11 is entered.

Step 11, if the liquid level H of the hydraulic maintenance system is less than the lowest liquid level H_{Lowest level of}Starting and loading all standby variable frequency drainage pumps, and controlling the power frequency of a standby variable frequency oil pump to be F_m. Step 12 is entered.

Step 12, if the liquid level H of the hydraulic maintenance system is not less than the higher liquid level H_{Is higher than}And unloading and stopping a standby variable frequency oil pump with the lowest priority. Step 13 is entered.

Step 13, if the liquid level H of the hydraulic maintenance system is not less than the highest liquid level H_{Highest point of the design}And unloading and stopping all the standby variable frequency oil pumps, and returning to the step 3. Otherwise, return to step 8.

As shown in fig. 3, an intelligent queuing alternate working method of multiple working pumps and multiple standby pumps includes 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 X_n；

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 X_n。

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 Y_n。

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 Z_n。

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 n_n＝100X_n+10Y_n+Z_n。

In the fifth step, according to M_nThe size of the pump, the priority score M of the number n pump_nThe larger the priority, the more forward it will be in the queue, let M be_n1≧M_n2≧M_n3≧M_n4≧M_n5≧M_n6Then 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 liquid level H of the hydraulic maintenance system set by a user through a man-machine interaction device is collected_{Forehead (forehead)}Maximum liquid level H_{Highest point of the design}Higher liquid level H_{Is higher than}Lower level H_{Is lower than}Minimum level H_{Lowest level of}And parameter information such as power frequency and pressurization capacity collaborative curve table of 2 variable frequency oil pumps.

2. The speed regulator hydraulic system controller controls and starts 4 main oil pumps to operate and load at rated frequency, builds the pressure of the hydraulic maintaining system to the rated pressure, and then stops all the variable frequency oil pumps from operating.

3. The governor hydraulic system controller collects the hydraulic maintenance system pressure P1 and starts 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 a hydraulic maintenance system pressure P2.

6. The governor hydraulic system controller calculates the hydraulic maintenance system consumption load P ═ P1-P2/t.

7. The governor hydraulic system controller is cooperated with the pressurizing capacity according to the consumption load p and the power frequency of 4 variable frequency oil pumpsAnd (3) connecting with a curve table, calculating the number x of the variable-frequency working oil pumps, and the operation initial power frequency F0 of the variable-frequency oil pump with the highest priority, outputting a frequency control signal F to the power frequency converter corresponding to the variable-frequency oil pump with the highest priority, wherein F is F0, so that the x variable-frequency oil pumps are started to serve as the variable-frequency working oil pumps, and the control of the power frequency of the variable-frequency working oil pump with the highest priority is realized. To round up the mathematical sign. f0 calculation method: if P_i-1≤p-(x-1)P_m≤P_iIf F0 is equal to F_i-1+(F_i-F_i-1) [p-(x-1)P_m-P_i-1]/(P_i-P_i-1). And initializes last-time frequency control signal F_{On the upper part}F. The power frequency of the rest variable frequency working oil pumps is F_m. Working pump and backup pump alternation method referring to fig. 3, an intelligent queuing alternation working method of a plurality of working pumps and a plurality of backup pumps is shown.

8. The speed regulator hydraulic system controller collects the liquid level h of the hydraulic maintenance system in real time.

9. The speed regulator hydraulic system controller maintains the system liquid level H and the rated liquid level H according to the hydraulic pressure_{Forehead (forehead)}Calculating the power frequency F ═ F of the variable frequency working oil pump with the highest priority_{On the upper part}+k(H_{Forehead (forehead)}And-h), outputting a frequency control signal F to a power supply frequency converter corresponding to the variable-frequency working oil pump with the highest priority, thereby realizing the control of the power supply frequency of the variable-frequency working oil pump with the highest priority. And refreshes the last frequency control signal F_{On 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.

10. If the liquid level H of the hydraulic maintenance system is less than the lower liquid level H_{Is lower than}Starting and loading a priorityThe highest standby variable frequency oil pump controls the power frequency of a standby variable frequency drainage pump to be F_m. Step 11 is entered.

11. If the liquid level H of the hydraulic maintenance system is less than the lowest liquid level H_{Lowest level of}Starting and loading all standby variable frequency drainage pumps, and controlling the power frequency of a standby variable frequency oil pump to be F_m. Step 12 is entered.

12. If the liquid level H of the hydraulic pressure maintaining system is not less than the higher liquid level H_{Is higher than}And unloading and stopping a standby variable frequency oil pump with the lowest priority. Step 13 is entered.

13. If the liquid level H of the hydraulic maintenance system is not less than the highest liquid level H_{Highest point of the design}And unloading and stopping all the standby variable frequency oil pumps, and returning to the step 3. Otherwise, return to step 8.