An automatic control system and method for the governor oil pressure device based on PLC

Abstract

The present invention discloses an automatic control system and method for the governor oil pressure device based on PLC. The system includes multiple oil pumps, an air replenishing device, a power supply, a PLC control circuit, and a control power supply. The multiple oil pumps are used to supply oil to the governor oil pressure device. The multiple oil pumps include a main pump and a standby pump group, the first standby pump and the second standby pump. The air replenishing device is used to supply air to the governor oil pressure device to adjust the oil-gas ratio of the governor oil pressure device. The power supply is used to supply power to the multiple oil pumps. The PLC control circuit is used to control the automatic oil supply of the multiple oil pumps and the automatic air supply of the air replenishing device. The control power supply is used to supply power to the PLC control circuit. The present invention realizes the automatic start and stop of the oil pump and the air replenishing device of the governor oil pressure device.

Description

Technical Field

[0001] The present invention relates to the technical field of control of hydroelectric turbine generator sets, and particularly to an automatic control system and method for a governor oil pressure device based on a PLC. Background Art

[0002] The governor oil pressure device is an important auxiliary equipment for the control of hydroelectric turbine generator sets. It stores and supplies pressurized oil for the governor and is the energy source for operations such as starting, stopping, increasing, and decreasing the load of the hydroelectric turbine generator sets. The pressurized oil provided by the oil pressure device must have sufficient energy, and at the same time, the reliability of the oil pressure system operation must be ensured. According to requirements, the oil-gas ratio in the pressure oil tank must be appropriate, with compressed air accounting for 2 / 3 of the volume of the pressure oil tank and turbine oil accounting for 1 / 3 of the volume of the pressure oil tank. If this ratio cannot be reliably ensured, strong vibrations and damage to pressure-bearing components may occur due to excessive air, or there may be insufficient energy during the emergency shutdown of the unit due to excessive oil, resulting in the runaway of the unit. The relationship between the compressed air and turbine oil in the pressure oil tank is as follows: Since air is compressible, compressed air is the main body of the control energy, and its source is supplied through an air compressor and an air storage tank. Turbine oil is relatively incompressible and is the transmission medium for the control energy. It is supplied by pumping oil with an oil pump. During the operation of the hydroelectric turbine generator set, the ratio of compressed air to turbine oil in the pressure oil tank changes every moment. In order to maintain a certain operating energy even when the oil volume in the pressure oil tank decreases, reliably maintaining a certain oil-gas ratio is the basic guarantee for the reliable and stable operation of the unit.

[0003] At present, the following problems mainly exist in the automatic control system of the governor oil pressure device in hydroelectric power stations. The start-stop signal of the oil pump generally uses an electric contact pressure gauge, but the contact capacity of the electric contact pressure gauge is very small. The sparks generated by the frequent action of the contacts are likely to burn out the contacts, resulting in carbonization of the contacts and poor contact, and the action is unreliable; the conditions for participating in the start-stop control of the oil pump are not set sufficiently. For example, when the oil level in the oil collecting tank is lower than the submerged line of the oil inlet pipe of the oil pump, the oil pump starts to run idly and cannot build up pressure; only a pair of electric contact pressure signals are connected to the stop pump signal. Once the stop pump electric contact pressure gauge fails, the pump cannot be stopped, resulting in overpressure; relatively speaking, it is easier to maintain the oil ratio by pumping oil with the oil pump, while it is very difficult to truly achieve automatic air replenishment to maintain the gas ratio. At present, most hydroelectric power stations still use manual air replenishment for air replenishment. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above technical deficiencies and provide an automatic control system and method for a governor oil pressure device based on a PLC, which realizes the automatic start-stop of the oil pump and the automatic start-stop of the automatic air replenishment device.

[0005] To achieve the above technical objectives, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides an automatic control system for the governor oil pressure device based on PLC, which includes a plurality of oil pumps for supplying oil to the governor oil pressure device. The plurality of oil pumps include a main pump and a standby pump group, the first standby pump and the second standby pump; an air supplement device for supplying air to the governor oil pressure device to adjust the oil-gas ratio of the governor oil pressure device; a power supply for supplying power to the plurality of oil pumps; a PLC control circuit for controlling the automatic oil supply of the plurality of oil pumps and the automatic air supply of the air supplement device; and a control power supply for supplying power to the PLC control circuit.

[0007] In some embodiments, the system further includes a display device connected to the PLC control circuit for displaying the operating states of the plurality of oil pumps and the operating state of the air supplement device.

[0008] In a second aspect, the present invention further provides an automatic control method for the governor oil pressure device based on PLC, which adopts the automatic control system for the governor oil pressure device based on PLC as described above, and includes:

[0009] Receiving an oil pump start instruction, starting the operation of the plurality of oil pumps according to the oil pump start instruction, and supplying oil to the governor oil pressure device;

[0010] Receiving an oil pump stop instruction, stopping the oil supply of the plurality of oil pumps to the governor oil pressure device according to the oil pump stop instruction;

[0011] Receiving an air supplement instruction, starting the operation of the air supplement device according to the air supplement instruction, and supplying air to the governor oil pressure device;

[0012] Receiving a stop air supplement instruction, stopping the air supply of the air supplement device to the governor oil pressure device according to the stop air supplement instruction;

[0013] Receiving an air supplement timeout instruction, and displaying an air supplement timeout warning through the display device according to the air supplement timeout instruction;

[0014] Receiving a main pump operation timeout instruction, and displaying a main pump operation timeout warning through the display device according to the main pump operation timeout instruction;

[0015] Receiving a main pump start-stop interval time statistic instruction, and displaying the main pump start-stop interval time through the display device according to the main pump start-stop interval time statistic instruction.

[0016] In some embodiments, the receiving the oil pump start instruction includes receiving a main pump start instruction, receiving a first standby pump start instruction, and receiving a second standby pump start instruction; wherein:

[0017] The main pump start command includes a decrease in the oil pressure of the oil pressure device, normal automatic start of the main pump, the oil level in the oil sump being greater than the minimum oil level threshold, and the temperature of the main pump being less than the maximum threshold temperature;

[0018] The first standby pump start command includes the oil pressure being lower than the first oil pressure threshold, normal automatic start of the first standby pump, the oil level in the oil sump being greater than the minimum oil level threshold, and the temperature of the main pump being less than the maximum threshold temperature;

[0019] The second standby pump start command includes the oil pressure being lower than the second oil pressure threshold, normal automatic start of the second standby pump, the oil level in the oil sump being greater than the minimum oil level threshold, and the temperature of the main pump being less than the maximum threshold temperature.

[0020] In some embodiments, receiving the oil pump stop command includes receiving the main pump stop command, receiving the first standby pump stop command, and receiving the second standby pump stop command; wherein:

[0021] The main pump stop command includes the oil pressure of the oil pressure device being normal and / or the oil pressure of the oil pressure device being higher than the third oil pressure threshold;

[0022] The first standby pump stop command includes the oil pressure of the oil pressure device being normal and / or the oil pressure of the oil pressure device being higher than the first oil pressure threshold and / or the oil pressure of the oil pressure device being higher than the third oil pressure threshold;

[0023] The second standby pump stop command includes the oil pressure of the oil pressure device being normal, and / or the oil pressure of the oil pressure device being higher than the first oil pressure threshold, and / or the oil pressure of the oil pressure device being higher than the second oil pressure threshold, and / or the oil pressure of the oil pressure device being higher than the third oil pressure threshold.

[0024] In some embodiments, stopping the supply of oil to the governor oil pressure device by the plurality of oil pumps according to the oil pump stop command includes:

[0025] According to the oil pump stop command, control the supply of oil to the governor oil pressure device by the oil pump through the parallel pressure switch and digital display pressure switch in the PLC program.

[0026] In some embodiments, the air replenishment command includes an increase in the oil pressure of the oil pressure device, normal air source pressure of the oil pressure device, normal automatic start of the air replenishment device, the inlet valve of the oil pressure device being fully closed, the exhaust valve of the oil pressure device being fully open, and the oil pressure being higher than the first oil pressure threshold; according to the air replenishment command, use the PLC program to sequentially close the exhaust valve of the oil pressure device and open the inlet valve of the oil pressure device to supply air to the governor oil pressure device.

[0027] In some embodiments, the stop air replenishment command includes the oil pressure of the oil pressure device being normal and the air source pressure being lower than the first air source pressure threshold. According to the above stop air replenishment command, use the PLC program to sequentially close the inlet valve of the oil pressure device and open the exhaust valve of the oil pressure device to stop supplying air to the governor oil pressure device.

[0028] In some embodiments, according to the air replenishment timeout instruction, displaying an air replenishment timeout warning through the display device includes:

[0029] When the air inlet valve of the oil pressure device is fully open, use the PLC program to start counting with a second pulse to obtain the air replenishment count;

[0030] According to a preset data processing method, statistically process the air replenishment count to obtain the air replenishment time;

[0031] When the air replenishment time exceeds a preset air replenishment time threshold, issue an air replenishment timeout warning through the display device.

[0032] In some embodiments, according to the oil pump operation timeout instruction, displaying an oil pump operation timeout warning through the display device includes:

[0033] When the main pump starts running, based on the number of energizations of the rising edge of the pulse relay in the PLC program, use a preset register to start timing in seconds and obtain the main pump running time in real time;

[0034] Display the main pump running time in real time through the real-time display device.

[0035] Compared with the prior art, the automatic control system and method for the governor oil pressure device based on PLC provided by the present invention supply power to the oil pump and the air replenishment device by setting a power supply, and control the oil pump and the air replenishment device to automatically supply oil or gas to the governor oil pressure device through a PLC control circuit, so that the oil-gas ratio of the governor oil pressure device always maintains a set ratio. The present invention realizes the automatic start and stop of the oil pump and the automatic start and stop of the automatic air replenishment device. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic structural diagram of an embodiment of the PLC main control loop in the automatic control method for the governor oil pressure device based on PLC provided by the present invention;

[0037] Figure 2 )]is a schematic structural diagram of an embodiment of the automatic control system for the governor oil pressure device based on PLC provided by the present invention;

[0038] Figure 3 is a schematic structural diagram of an embodiment of the power supply in the automatic control system for the governor oil pressure device based on PLC provided by the present invention;

[0039] Figure 4 is a schematic structural diagram of an embodiment of the control power supply in the automatic control system for the governor oil pressure device based on PLC provided by the present invention;

[0040] Figure 5It is a schematic structural diagram of an embodiment of the automatic control method for the governor oil pressure device based on PLC provided by the present invention;

[0041] Figure 6 It is a schematic structural diagram of an embodiment of the start-stop control circuit of the oil pump in the automatic control method for the governor oil pressure device based on PLC provided by the present invention;

[0042] Figure 7 It is a schematic structural diagram of another embodiment of the start-stop control circuit of the oil pump in the automatic control method for the governor oil pressure device based on PLC provided by the present invention;

[0043] Figure 8 It is a schematic structural diagram of an embodiment of the input signal of the PLC control circuit in the automatic control method for the governor oil pressure device based on PLC provided by the present invention;

[0044] Figure 9 It is a schematic structural diagram of an embodiment of the statistical control circuit of the oil pump operation time in the automatic control method for the governor oil pressure device based on PLC provided by the present invention. Detailed implementation manners

[0045] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0046] The automatic control system and method for the governor oil pressure device based on PLC involved in the present invention realizes automation by controlling the start and stop of the oil pump and the air supplement device through the PLC program. In order to prevent the change of the oil-gas ratio of the oil pressure device when the PLC fails, the system involved in the present invention also includes a full manual control operation, which can be completed by on-site manual operation when the PLC fails. In a specific embodiment, please refer to Figure 1 , SA1, SA2, SA3, and SA6 are respectively the manual-automatic changeover switches of the main pump, the first standby pump, the second standby pump, and the air supplement device; in the automatic control mode, SA1, SA2, SA3, and SA6 are placed in the automatic position, and with the PLC as the control core, logical operations are performed on the pressure signals, oil level signals, etc. connected to the PLC to implement full-automatic control.

[0047] It should be noted that in order to overcome the limitation of the small contact capacity of the electric contact pressure gauge, the system involved in the present invention uses a digital display pressure transmitter controller and a pressure switch as control components. Specifically, the auxiliary contact capacity of the digital display pressure transmitter controller is large and the service life is long. The pressure action value of the digital display pressure transmitter controller only needs to be set on the pressure gauge, and there is no need to use a pressure gauge calibration bench, and the operation is simple and convenient. The digital display pressure transmitter controller can output up to 5 pairs of contacts and is flexible to use. The contact capacity of the pressure switch is large.

[0048] The automatic control system of the governor oil pressure device based on PLC provided by the embodiments of the present invention, as Figures 2 - 4 shown, includes a plurality of oil pumps 201 for supplying oil to the governor oil pressure device. The plurality of oil pumps 201 includes a main pump and a standby pump group, the first standby pump and the second standby pump; an air supplement device 202 for supplying air to the governor oil pressure device to adjust the oil-gas ratio of the governor oil pressure device; a power supply 203 for supplying power to the plurality of oil pumps 201; a PLC control circuit 204 for controlling the automatic oil supply of the plurality of oil pumps 201 and the automatic air supply of the air supplement device 202; and a control power supply 205 for supplying power to the PLC control circuit 204.

[0049] In the embodiments of the present invention, by setting the power supply to supply power to the oil pump and the air supplement device, and controlling the oil pump and the air supplement device to automatically supply oil or air to the governor oil pressure device through the PLC control circuit, so that the oil-gas ratio of the governor oil pressure device always maintains a set ratio, the automatic start and stop of the oil pump and the automatic start and stop of the automatic air supplement device are realized.

[0050] Further, please refer to Figure 3 , the power supply is powered by three-way power. AC 1 and AC 2 are respectively connected to the 400V first section busbar and the 400V second section busbar of the plant power supply, and AC 3 is connected to the in-plant standby diesel generator. The automatic switching is respectively carried out by the double-power automatic switching switches QF1 and QF2, thereby improving the power supply reliability of the power supply and ensuring the reliable operation of the oil pump motor.

[0051] It should be noted that, please refer to Figure 4 , to ensure the reliability of the control power supply, the control power supply adopts AC-DC dual-power supply. In a specific embodiment, a 220V AC power supply is connected from the plant system, and is connected to the AC-DC automatic switching device through an isolation transformer. A 220V DC power supply is connected from the DC system. The AC-DC automatic switching device can realize non-disturbing automatic switching, and the disappearance of any one power supply does not affect the output, ensuring the reliability of the control power supply.

[0052] In some embodiments, the system further includes a display device connected to the PLC control circuit for displaying the operating states of the plurality of oil pumps and the operating state of the air supplement device.

[0053] In this embodiment, the display device is specifically a touch screen. The touch screen edits a total of 5 screens, namely: main operation display, digital input monitoring, fault signal, cumulative operation time, and parameter setting. The 5 screens can be switched through the screen index. The main operation display mainly shows important information, such as the operation status of the oil pump, the operation status of automatic air replenishment, and the pop-up window of alarm information. When the oil pump starts, the corresponding oil pump operation note will automatically pop up on the main display screen, and the operation time will be displayed. When the operation timeout alarm occurs, the timeout alarm will pop up, and the time will be fixed on the screen so that the inspection personnel can view the alarm information and the specific timeout time. Press the fault reset button to make the fault information disappear. The digital input monitoring screen is divided into two parts: PLC digital inputs and PLC digital outputs. Through the digital input monitoring screen, the position signals of PLC digital inputs and outputs can be very intuitively seen. The fault signal screen shows all fault signals. The fault signals are hold signals. After the fault is processed, the fault reset operation is required. The fault reset operation requires logging in with operator permissions. The cumulative operation time screen shows the cumulative operation time of the main pump, the cumulative operation time of the first standby pump, the cumulative operation time of the second standby pump, the start interval time of the main pump, the start interval time of the first standby pump, the start interval time of the second standby pump, and the automatic air replenishment interval time. Switching to the parameter setting screen allows setting the timeout time for the oil pump and air replenishment operation, and clearing the cumulative operation time of the oil pump. Parameter setting requires logging in with administrator permissions to operate.

[0054] Based on the above PLC-based automatic control system for the governor oil pressure device, the present invention also provides a PLC-based automatic control method for the governor oil pressure device. Please refer to Figure 5 , including:

[0055] S501. Receive the oil pump start instruction, start the operation of the multiple oil pumps according to the oil pump start instruction, and supply oil to the governor oil pressure device;

[0056] S502. Receive the oil pump stop instruction, stop the supply of oil to the governor oil pressure device by the multiple oil pumps according to the oil pump stop instruction;

[0057] S503. Receive the air replenishment instruction, start the operation of the air replenishment device according to the air replenishment instruction, and supply air to the governor oil pressure device;

[0058] S504. Receive the stop air replenishment instruction, stop the supply of air to the governor oil pressure device by the air replenishment device according to the stop air replenishment instruction;

[0059] S505. Receive the air replenishment timeout instruction, and display the air replenishment timeout alarm through the display device according to the air replenishment timeout instruction;

[0060] S506. Receive the main pump operation timeout instruction, and display the main pump operation timeout alarm through the display device according to the main pump operation timeout instruction;

[0061] S507. Receive the main pump start-stop interval time statistical instruction. According to the main pump start-stop interval time statistical instruction, display the main pump start-stop interval time through the display device.

[0062] It should be noted that in this embodiment, by receiving the corresponding PLC instruction, the automatic operation of starting or stopping the oil pump and the air replenishing device is performed.

[0063] Furthermore, this embodiment further includes an automatic air replenishing start-stop interval time instruction. Through the main pump running time statistical instruction, running overtime instruction, air replenishing overtime instruction, automatic air replenishing start-stop interval time instruction, and main pump start-stop interval time statistical instruction, the PLC program is controlled to obtain the corresponding status quantities, and the obtained status quantities are displayed through the display device. Thus, the equipment status can be analyzed based on the main pump running time status, main pump start-stop interval time status, main pump running overtime statistical status, air replenishing overtime status, and automatic air replenishing start-stop interval time status, providing basic data for equipment status maintenance. Specifically, by checking the cumulative running time of the main pump, a decision can be made on whether the oil pump needs maintenance; by checking the main pump start-stop interval time and the running time of each start of the main pump, it can be judged and analyzed whether there is oil leakage, pressure relief in the governor oil circuit, whether the servo cylinder seal is intact, and whether the mechanical part of the governor is working properly. It can also be compared and analyzed with the same model units in the station; by checking the automatic air replenishing time and automatic air replenishing interval time, it can be judged and analyzed whether there is air leakage in the oil storage tank, etc.

[0064] In some embodiments, please refer to Figure 6 , the receiving of the oil pump start instruction includes receiving the main pump start instruction, receiving the first standby pump start instruction, and receiving the second standby pump start instruction; where:

[0065] The main pump start instruction includes that the oil pressure of the oil pressure device drops, the main pump automatically starts normally, the oil level in the oil sump is greater than the lowest oil level threshold, and the main pump temperature is less than the highest threshold temperature;

[0066] The first standby pump start instruction includes that the oil pressure is lower than the first oil pressure threshold, the first standby pump automatically starts normally, the oil level in the oil sump is greater than the lowest oil level threshold, and the main pump temperature is less than the highest threshold temperature;

[0067] The second standby pump start instruction includes that the oil pressure is lower than the second oil pressure threshold, the second standby pump automatically starts normally, the oil level in the oil sump is greater than the lowest oil level threshold, and the main pump temperature is less than the highest threshold temperature.

[0068] In this embodiment, for the main pump start control logic, please refer to Figure 6 and Figure 7, when the oil pressure drop signal connected to the PLC is 1 (3.75 Mpa), the main pump automatic start normal signal is 1, the oil tank oil level is greater than the minimum oil level threshold signal is 1, and the main pump temperature is less than the maximum threshold temperature signal is 1, start the main pump.

[0069] Furthermore, when the oil pressure connected to the PLC is lower than the first oil pressure threshold signal is 1 (3.7 Mpa), the standby pump automatic start normal signal is 1, the oil tank oil level is greater than the minimum oil level threshold signal is 1, and the main pump temperature is less than the maximum threshold temperature signal is 1, start 1 standby pump; among them, in this embodiment, the first standby pump and the second standby pump are alternately rotated in sequence. When the oil pressure is lower than the first oil pressure threshold, start the standby pump, and the standby #1 pump and #2 pump are automatically rotated in sequence; when the oil pressure connected to the PLC is lower than the second oil pressure threshold, start two standby pumps at the same time. When the oil pressure normal signal connected to the PLC is 1 (4.0 Mpa) or the oil pressure is too high signal is 1 (4.2 Mpa), the standby pump stops.

[0070] It should be noted that the oil tank is an external container for holding oil, providing an oil source for the oil pump. Specifically, the signal of the too low oil level in the oil tank is connected to the oil pump control circuit as one of the additional conditions for starting the oil pump. When the oil level in the oil tank is too low, the oil pump cannot be started, which can effectively prevent the oil pump from idling when the oil level in the oil tank is too low; the specific parameter of the oil pressure drop of the oil pressure device is that when the oil pressure drops to 3.75 Pa, the detection signal output is the oil pressure drop; specifically, the oil pressure corresponding to the first oil pressure threshold is 3.7 Pa, and the oil pressure corresponding to the second oil pressure threshold is 3.65 Pa.

[0071] In some embodiments, receiving the oil pump stop instruction includes receiving the main pump stop instruction, receiving the first standby pump stop instruction, and receiving the second standby pump stop instruction; among them:

[0072] The main pump stop instruction includes that the oil pressure of the oil pressure device is normal and / or the oil pressure of the oil pressure device is higher than the third oil pressure threshold;

[0073] The first standby pump stop instruction includes that the oil pressure of the oil pressure device is normal and / or the oil pressure of the oil pressure device is higher than the first oil pressure threshold and / or the oil pressure of the oil pressure device is higher than the third oil pressure threshold;

[0074] The second standby pump stop instruction includes that the oil pressure of the oil pressure device is normal, and / or the oil pressure of the oil pressure device is higher than the first oil pressure threshold, and / or the oil pressure of the oil pressure device is higher than the second oil pressure threshold, and / or the oil pressure of the oil pressure device is higher than the third oil pressure threshold.

[0075] In this embodiment, when the oil pressure of the oil pressure device reaches normal, the main pump, the first standby pump and the second standby pump can be closed simultaneously. Among them, when the oil pressure is higher than the second oil pressure threshold, the second standby pump is preferentially closed. When the oil pressure is higher than the first oil pressure threshold, both standby pumps are closed. When the oil pressure reaches normal or is higher than the third oil pressure threshold, the main pump is closed; specifically, the third oil pressure threshold is 4.2 Pa; the oil pressure value when the oil pressure is normal is 4 Pa.

[0076] In some embodiments, please refer to Figure 8 , and stopping the supply of oil to the governor oil pressure device by the plurality of oil pumps according to the oil pump stop instruction includes:

[0077] According to the oil pump stop instruction, the supply of oil to the governor oil pressure device by the oil pump is controlled through the parallel pressure switch and the digital display pressure switch in the PLC program.

[0078] In this embodiment, in order to increase the reliability of pump shutdown, a redundant protection device for the pump shutdown pressure signal is set. Specifically, the normal oil pressure signals of the pressure switch P1 and the digital display pressure controller PT1 are connected in parallel to the PLC as the protection pump shutdown signal to prevent the inability to stop the pump due to the lack of output of the normal oil pressure caused by the failure of PT1; specifically, the normal oil pressure (pump shutdown signal) and the oil pressure reduction (start the main pump) are connected to the digital display pressure controller. When the oil pressure reduction signal is turned on, the main pump is started, and when the normal oil pressure signal is turned on, the pump is stopped.

[0079] Further, P2 is an oil pressure too low pressure switch. When the oil pressure too low signal is turned on, 1 standby pump is started, and the two standby pumps are alternately rotated under the control of the PLC program; P3 is an oil pressure ultra-low signal. When the oil pressure ultra-low signal is turned on, the two standby pumps are started simultaneously. Therefore, no matter which pressure control instrument fails, there is always 1 or 2 oil pumps running, ensuring the reliability of the oil pump operation and providing a reliable pressure oil source for the governor.

[0080] In some embodiments, the air replenishment instruction includes that the oil pressure of the oil pressure device increases, the air source pressure of the oil pressure device is normal, the air replenishment device starts automatically normally, the intake valve of the oil pressure device is fully closed, the exhaust valve of the oil pressure device is fully open, and the oil pressure is higher than the first oil pressure threshold; according to the air replenishment instruction, the PLC program is used to sequentially close the exhaust valve of the oil pressure device and open the intake valve of the oil pressure device to supply air to the governor oil pressure device.

[0081] In this embodiment, the automatic adjustment of the oil-gas ratio of the oil pressure device can be realized by receiving the air replenishment instruction; further, two necessary conditions, namely, the increase of the oil pressure of the oil pressure device and the normal air source pressure, are added to the air replenishment instruction. When the air source pressure is lower than the starting pressure value of the standby oil pump, the automatic air replenishment cannot be started or the air replenishment cannot be stopped, which can effectively prevent the reverse drop of the storage tank pressure caused by the start of the automatic air replenishment when the air source pressure is too low..

[0082] In some embodiments, the stop air supply command includes that the oil pressure of the oil pressure device is normal and the air source pressure is lower than the first air source pressure threshold. According to the above stop air supply command, the PLC program is used to sequentially close the air inlet valve of the oil pressure device and open the exhaust valve of the oil pressure device in logical order, and stop supplying air to the governor oil pressure device.

[0083] In this embodiment, when the PLC detects the stop air supply command, it can automatically control the closing of the air inlet valve and the opening of the exhaust valve, realizing the automation of air supply.

[0084] In some embodiments, according to the air supply timeout command, the display device is used to display an air supply timeout warning, including:

[0085] When the air inlet valve of the oil pressure device is fully open, the PLC program starts counting with a second pulse to obtain the air supply count number;

[0086] According to a preset data processing method, the air supply count number is statistically processed to obtain the air supply time;

[0087] When the air supply time exceeds the preset air supply time threshold, an air supply timeout warning is issued through the display device.

[0088] In this embodiment, the data processing method is a commonly used method for converting counting data into time data, which is the prior art in this field.

[0089] In some embodiments, please refer to Figure 9 , according to the oil pump operation timeout command, the display device is used to display an oil pump operation timeout warning, including:

[0090] When the main pump starts running, based on the number of energizations of the rising edge of the pulse relay in the PLC program, a preset register starts timing in seconds, and the running time of the main pump is obtained in real time;

[0091] The running time of the main pump is displayed in real time through the real-time display device.

[0092] In this embodiment, X017 is the main pump operation signal, connected to the normally open contact of the main pump AC contactor. The rising edge M8013 is a second pulse relay. When the main pump starts and the AC contactor closes, X017 becomes 1, M8013 is turned on once, and the data register D200 is incremented to start counting seconds. When the data register D200 equals 60 (60 seconds), the data register D201 is incremented to start counting minutes, and at the same time, the data register D200 is cleared to start counting again in this cycle; when the data register D201 equals 60 (60 minutes), the data register D202 is incremented to start counting hours, and at the same time, the data register D201 is cleared to start counting again in this cycle; when the data register D202 equals 24 (24 hours), the data register D203 is incremented to start counting days, and at the same time, the data register D202 is cleared to start counting again in this cycle; in this way, the cumulative operation time of the main pump is obtained as XXXX days XX hours XX minutes XX seconds.

[0093] Writing the cumulative operation time of the oil pump provides data for regular maintenance. For example, when the oil pump has run for a certain number of days, grease needs to be added to the bearings, or when it has run for a certain number of days, the bearings need to be replaced, or when it has run for a certain number of days, the oil pump needs to be replaced, etc.

[0094] The specific implementation manners of the present invention described above do not constitute a limitation to the protection scope of the present invention. Any other corresponding changes and deformations made according to the technical concept of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. An automatic control system for the governor oil pressure device based on PLC, characterized in that, Comprising: A plurality of oil pumps for supplying oil to the governor oil pressure device. The plurality of oil pumps include a main pump and a standby pump group, and the standby pump group includes a first standby pump and a second standby pump; An air supplement device for supplying air to the governor oil pressure device to adjust the oil-gas ratio of the governor oil pressure device; A power supply for supplying power to the plurality of oil pumps; A PLC control circuit for controlling the automatic oil supply of the plurality of oil pumps and the automatic air supply of the air supplement device; A control power supply for supplying power to the PLC control circuit; The system further includes a display device connected to the PLC control circuit for displaying the operating status of the plurality of oil pumps and the operating status of the air supplement device; The system is used for: Receiving an oil pump start instruction, starting the plurality of oil pumps according to the oil pump start instruction, and supplying oil to the governor oil pressure device; Receiving an oil pump stop instruction, stopping the supply of oil to the governor oil pressure device by the plurality of oil pumps according to the oil pump stop instruction; Receiving an air supplement instruction, starting the air supplement device according to the air supplement instruction, and supplying air to the governor oil pressure device; Receiving a stop air supplement instruction, stopping the supply of air to the governor oil pressure device by the air supplement device according to the stop air supplement instruction; Receiving an air supplement timeout instruction, and displaying an air supplement timeout alarm through the display device according to the air supplement timeout instruction; Receiving a main pump operation timeout instruction, and displaying a main pump operation timeout alarm through the display device according to the main pump operation timeout instruction; Receiving a main pump start-stop interval time statistics instruction, and displaying the main pump start-stop interval time through the display device according to the main pump start-stop interval time statistics instruction; The receiving of the oil pump start instruction includes receiving a main pump start instruction, receiving a first standby pump start instruction, and receiving a second standby pump start instruction; wherein: The main pump start instruction includes that the oil pressure of the oil pressure device drops, the main pump automatically starts normally, the oil level in the oil sump is greater than the lowest oil level threshold, and the main pump temperature is less than the highest threshold temperature; The first standby pump start instruction includes that the oil pressure is lower than the first oil pressure threshold, the first standby pump automatically starts normally, the oil level in the oil sump is greater than the lowest oil level threshold, and the main pump temperature is less than the highest threshold temperature; The second standby pump start instruction includes that the oil pressure is lower than the second oil pressure threshold, the second standby pump automatically starts normally, the oil level in the oil sump is greater than the lowest oil level threshold, and the main pump temperature is less than the highest threshold temperature.

2. The automatic control system of the governor oil pressure device based on PLC according to claim 1, characterized in that, Receiving an oil pump stop instruction includes receiving a main pump stop instruction, receiving a first standby pump stop instruction, and receiving a second standby pump stop instruction; wherein: The main pump stop instruction includes that the oil pressure of the oil pressure device is normal or the oil pressure of the oil pressure device is higher than the third oil pressure threshold; The first standby pump stop instruction includes that the oil pressure of the oil pressure device is normal, or the oil pressure of the oil pressure device is higher than the first oil pressure threshold, or the oil pressure of the oil pressure device is higher than the third oil pressure threshold; The second standby pump stop instruction includes that the oil pressure of the oil pressure device is normal, or the oil pressure of the oil pressure device is higher than the first oil pressure threshold, or the oil pressure of the oil pressure device is higher than the second oil pressure threshold, or the oil pressure of the oil pressure device is higher than the third oil pressure threshold.

3. The automatic control system of the governor oil pressure device based on PLC according to claim 2, characterized in that, Stopping the supply of oil by the multiple oil pumps to the governor oil pressure device according to the oil pump stop instruction, including: According to the oil pump stop instruction, controlling the supply of oil by the oil pump to the governor oil pressure device through the parallel pressure switch and digital display pressure switch in the PLC program.

4. The automatic control system for the governor oil pressure device based on PLC according to claim 1, wherein, The air replenishment instruction includes that the oil pressure of the oil pressure device rises, the air source pressure of the oil pressure device is normal, the air replenishment device starts automatically normally, the intake valve of the oil pressure device is fully closed, the exhaust valve of the oil pressure device is fully open, and the oil pressure is higher than the first oil pressure threshold; according to the air replenishment instruction, the PLC program is used to sequentially close the exhaust valve of the oil pressure device and open the intake valve of the oil pressure device in logical order to supply air to the governor oil pressure device.

5. The automatic control system for the governor oil pressure device based on PLC according to claim 1, wherein The stop air replenishment instruction includes that the oil pressure of the oil pressure device is normal and the air source pressure is lower than the first air source pressure threshold. According to the above stop air replenishment instruction, the PLC program is used to sequentially close the intake valve of the oil pressure device and open the exhaust valve of the oil pressure device in logical order to stop supplying air to the governor oil pressure device.

6. The automatic control system for the governor oil pressure device based on PLC according to claim 1, characterized in that According to the air replenishment timeout instruction, displaying an air replenishment timeout warning through the display device, including: When the intake valve of the oil pressure device is fully open, the PLC program is used to start counting with a second pulse to obtain the air replenishment count. According to the preset data processing method, the air replenishment count is statistically processed to obtain the air replenishment time. When the air replenishment time exceeds the preset air replenishment time threshold, an air replenishment timeout warning is issued through the display device.

7. The automatic control system of the governor oil pressure device based on PLC according to claim 1, characterized in that, According to the oil pump operation timeout instruction, displaying an oil pump operation timeout warning through the display device, including: When the main pump starts to run, based on the number of power-on times of the rising edge of the pulse relay in the PLC program, the preset register is used to start timing in seconds to obtain the real-time operation time of the main pump. The real-time operation time of the main pump is displayed through the real-time display device.

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