CN219639162U - All-digital hydraulic servo system of speed regulator - Google Patents

Abstract

The utility model belongs to the field of speed regulators, and particularly relates to a full-digital hydraulic follow-up system of a speed regulator, which is provided with a hydraulic control valve box, wherein the hydraulic control valve box is hollow, the front surface of the hydraulic control valve box is provided with an oil return interface and an oil supply interface, both sides of the hydraulic control valve box are provided with a small fluctuation combined control valve block and a large fluctuation logic cartridge valve block, the top of the hydraulic control valve box is provided with a large fluctuation hydraulic control valve block and a large fluctuation logic cartridge valve block, and one side of the hydraulic control valve box is provided with a hydraulic locking control piece above the small fluctuation combined control valve block; the small fluctuation combined control valve block, the large fluctuation logic cartridge valve block, the large fluctuation hydraulic control valve block and the hydraulic locking control piece are connected with the hydraulic control valve box by adopting integrated valve blocks. Based on the quick switch valve and the logic cartridge valve assembly, the electrohydraulic conversion link adopts a digital ball valve, and the hydraulic system adopts a standard hydraulic element, so that the structure is simplified, and the interchangeability and maintainability are improved.

Description

All-digital hydraulic servo system of speed regulator

Technical Field

The utility model belongs to the technical field of regulators, and particularly relates to an all-digital hydraulic follow-up system of a speed regulator.

Background

At present, a hydraulic turbine governor has been applied to a certain degree in an oil pump combination valve, a sectional closing valve, a deflector hydraulic control system, and a blade and water guide mechanism position follow-up system. The basic functions of the hydraulic control part of the oil pressure device and the speed regulator are summarized as pressure regulation, flow regulation, direction and position control.

The hydraulic control system of the hydraulic turbine governor is mainly characterized in that: the instantaneous oil consumption is large, so that the pressure regulating valve (oil pump combined valve), the flow/direction valve (main distributing valve), namely the basic combination of the traditional hydraulic control system technology: the four-way slide valve (main distribution valve) +the two-way controllable oil cylinder (servomotor) is a symmetrical structure of a multiple-step cylindrical slide valve core and a multiple-undercut groove valve body, and is a nonstandard large-pass valve (a special form of large-flow mechanical hydraulic operation proportional/servo valve).

Because of the adoption of gap sealing and the large axial structure size, the anti-pollution capability and the reversing reliability of the motor are limited; in addition, the reversing time has a plurality of defects in aspects of oil leakage, reversing impact, dynamic response and the like. And because the hydraulic full bridge is formed by a rigid four-arm hydraulic resistor, single-arm control cannot be performed, and the controllability is limited, so that the integration is difficult to realize.

Disclosure of Invention

In order to solve the technical problems, the utility model provides a hydraulic follow-up system of an all-digital speed regulator, which is based on a quick switch valve and a logic cartridge valve assembly, wherein a digital ball valve is adopted in an electrohydraulic conversion link, a standard hydraulic element is adopted in a hydraulic system, so that the structure is simplified, the interchangeability and maintainability are improved, the digital valve has strong pollution resistance, high pressure resistance, no leakage and reliable action, and zero point adjustment is not required; the digital speed regulator has the characteristics of obvious energy saving, consumption reduction, life prolonging and the like, and provides technical assurance measures, integration and standardization for the labor reduction and synergy of the hydropower station.

The utility model provides an all-digital hydraulic servo system of a speed regulator, which solves the technical problems, and comprises an electric regulating mechanism, a hydraulic servo mechanism and a high-pressure oil pressure mechanism, and is characterized in that: the digital hydraulic control valve bank is provided with a hydraulic control valve box, the hydraulic control valve box is hollow, an oil return interface and an oil supply interface are arranged on the front surface of the hydraulic control valve box, small fluctuation combined control valve blocks and large fluctuation logic cartridge valve blocks are arranged on two sides of the hydraulic control valve box, large fluctuation hydraulic control valve blocks and large fluctuation logic cartridge valve blocks are arranged on the top of the hydraulic control valve box, and a hydraulic locking control piece is arranged above the small fluctuation combined control valve blocks on one side of the hydraulic control valve box; the small fluctuation combined control valve block, the large fluctuation logic cartridge valve block, the large fluctuation hydraulic control valve block and the hydraulic locking control piece are connected with the hydraulic control valve box by adopting integrated valve blocks, and all the structures are connected through pipelines.

In the optimization scheme, the integrated valve blocks in the digital hydraulic control valve group, namely the size fluctuation integrated valve blocks are provided with manual emergency operation ports, and emergency operation can be performed when a control system is in fault.

Each integrated block electromagnetic valve in the digital hydraulic control valve group, namely the size fluctuation hydraulic control valve group and the logic cartridge valve are respectively provided with a square plug with a lamp, so that the running state of the electromagnetic valve is visible in real time.

The digital hydraulic control valve group is also provided with an emergency shutdown valve which is a two-position three-way electromagnetic reversing valve and simultaneously controls the large-fluctuation hydraulic control valve block and the hydraulic control shuttle valve.

The bottom end of the digital hydraulic control valve bank is provided with a support, and the digital hydraulic control valve bank is connected with the oil return tank into a whole through the support.

The on-off valve of the small fluctuation on-off valve and the large fluctuation control valve is a quick on-off valve, and the quick on-off digital valve acts for 3 ms-35 ms.

The speed regulator electrohydraulic follow-up system directly drives the control ring to operate the oil cylinder by the digital ball valve, and no mechanical transmission lever is arranged in the middle, so that full digital control is truly realized, and the control precision and reliability are greatly improved. The utility model adopts a logic cartridge valve in large fluctuation and combines a limiter, so that an optimal operation curve can be adjusted, the requirement of quick response is met, hydraulic impact and fluctuation can be controlled within a certain range, and the high responsiveness and stability of the system are greatly enhanced. The small fluctuation control adopts a high-speed digital ball valve, and the control has the characteristic of minimum hysteresis through PWM modulation of a control signal, so that the requirements of quickly and accurately controlling the position of the servomotor can be met, and the full closed loop control is formed on the servomotor through a high-precision displacement sensor, so that the double requirements of precision and response speed are considered.

The hydraulic element adopts the digital logic on-off oil way, and can realize various special working conditions through the on-off of different components, so that the application range of the device is greatly expanded, and the valve group logic can be changed through electric control under the condition that hardware is not changed, thereby being applicable to different working conditions and different tasks and avoiding repeated investment and waste of investment.

The utility model has the advantages of miniaturization, integration and standardization of the machine type, low requirements on oil quality, wide application range on oil quality viscosity, greatly reduced occurrence probability of blocking, and suitability for adjustment and control of medium and small water turbine generator sets.

Drawings

FIG. 1 is a schematic diagram of an electro-hydraulic follow-up system according to the present utility model

FIG. 2 is a schematic diagram of the operation of the governor system of the present utility model

FIGS. 3 and 4 are partial views of FIG. 2 of the present utility model

FIG. 5 is a block diagram of a large wave logic cartridge valve according to the present utility model

FIG. 6 is a schematic view of a square plug with a lamp according to the present utility model

FIG. 7 is a schematic diagram of various switch valve structures in the present utility model

Fig. 8-12 are schematic views of the internal structure of the digital hydraulic control valve set according to the present utility model

FIG. 13 is a schematic view of a speed governor embodying the present utility model

The specific identification in the figure is as follows:

1. the hydraulic control system comprises an energy storage gas group 2.PLC controller 3.electrohydraulic servo system 4.oil return tank 5.oil pump motor group 6.pressure hydraulic control valve group 7.large fluctuation hydraulic control valve block 8.hydraulic locking control valve block 9.small fluctuation combination control valve block 10.large fluctuation logical cartridge valve block 11.oil return port 12.oil supply port 13.bracket 14.small fluctuation closing 15.small fluctuation opening 16.small fluctuation opening time adjustment 17.small fluctuation closing time adjustment 18.section closing valve 19.large fluctuation closing 20.large fluctuation opening 21.emergency closing auxiliary valve 22.large fluctuation closing time adjustment 23.large fluctuation opening time adjustment 24.emergency closing valve 25.oil pipeline 26.pressure oil pipe 27.hydraulic control valve box 28.oil filter 29.motor 30.overflow valve 31.pressure gauge 32.closing valve 33.valve core 34.hydraulic control shuttle valve 35 valve 35.valve sleeve A.working A, B working oil chamber B, K controls the direction of opening and closing direction of the working oil chamber B

Detailed Description

The utility model is further illustrated by the following description of specific embodiments:

example 1

The utility model provides a hydraulic servo system of full digital speed regulator, includes electric adjustment mechanism, hydraulic servo mechanism and high-pressure oil pressure mechanism, its characterized in that: the digital hydraulic control valve bank is provided with a hydraulic control valve box, the hydraulic control valve box is hollow, an oil return interface and an oil supply interface are arranged on the front surface of the hydraulic control valve box, small fluctuation combined control valve blocks and large fluctuation logic cartridge valve blocks are arranged on two sides of the hydraulic control valve box, large fluctuation hydraulic control valve blocks and large fluctuation logic cartridge valve blocks are arranged on the top of the hydraulic control valve box, and a hydraulic locking control piece is arranged above the small fluctuation combined control valve blocks on one side of the hydraulic control valve box; the small fluctuation combined control valve block, the large fluctuation logic cartridge valve block, the large fluctuation hydraulic control valve block and the hydraulic locking control piece are connected with the hydraulic control valve box by adopting integrated valve blocks, and all the structures are connected through pipelines. The structure of the hydraulic control valve box body is conventionally arranged, and all structures in the hydraulic control valve box are connected through an integrated type or pipeline in a conventional connection mode.

The integrated valve blocks in the digital hydraulic control valve group, namely the size fluctuation integrated valve blocks are provided with manual emergency operation ports, and emergency operation can be performed when a control system fails. Each integrated block electromagnetic valve in the digital hydraulic control valve group, namely the size fluctuation hydraulic control valve group and the logic cartridge valve are respectively provided with a square plug with a lamp, and the operation state of the electromagnetic valve is visible in real time.

The large-fluctuation logic cartridge valve block is provided with a control cover plate, a valve sleeve, a valve core, a sealing piece and the like, the cartridge block and the pilot element are conventionally arranged on the control cover plate, and the control cover plate is fixedly connected with the hydraulic control valve box through a bolt structure. The plug-in unit composed of valve sleeve, valve core and sealing element mainly has the function of controlling on and off in the loop. The control cover plate seals the plug-in unit in the plug-in block body and communicates the pilot valve and the plug-in unit. The on-off of the main oil way can be controlled by the opening and closing of the valve core. The pilot element comprises, for example, a switching valve or the like, which are of conventional construction and are connected to one another in a conventional manner.

The small fluctuation combined control valve block, the large fluctuation logic cartridge valve block, the large fluctuation hydraulic control valve block and the hydraulic locking control piece are connected with the hydraulic control valve box in an integrated valve block mode. The small fluctuation combined control valve block is used for small disturbance control of a unit, the large fluctuation logic cartridge valve block is used for emergency starting and normal switching of the unit, the large fluctuation hydraulic control valve block is used for load shedding and other adjustment, and the hydraulic locking control piece is used for preventing misoperation. The oil return interface is connected with the T port and communicated with the oil return tank; the oil supply interface is connected with the P port and is connected with the working A/B cavity through the control valve group.

The small fluctuation combined control valve block is a high-speed digital valve group, and the model of the product is 3SEW6/10-UK/CK. The model of the large fluctuation logic cartridge valve block and the large fluctuation hydraulic control valve block and the hydraulic locking control piece are HYFK-40/50.

The logic cartridge valve is adopted for large fluctuation, and the limiter is combined, so that an optimal operation curve can be adjusted, the requirement of quick response is met, hydraulic impact and fluctuation can be controlled within a certain range, and the high responsiveness and stability of the system are greatly enhanced. The small fluctuation control adopts a high-speed digital ball valve, the control signal PWM is modulated, namely, the opening degree (controlled quantity) of a guide vane is converted by V/F and then is fed into the counting, 0-10V corresponds to 0-100 KHzd frequency, the counting time is 10ms, the digital control quantity with the precision of +/-0.2, such as the modulation of pulse frequency and pulse width, can be obtained, the control has the characteristic of extremely small hysteresis, the requirement of rapidly and accurately controlling the position of a servomotor can be met, the high-precision displacement sensor is adopted, namely, a resistance ruler KTC series pull rod type displacement sensor is adopted to achieve the feedback of high-precision displacement and the precision grade of 0.01%, the servomotor forms the full-closed loop control, and the double requirements of precision and response speed are considered.

The oil supply interface and the oil return interface are fixedly connected with the hydraulic control valve box through oil pipes, and other parts of the large fluctuation hydraulic control valve block, the hydraulic locking control piece, the small fluctuation combined control valve block and the large fluctuation logic cartridge valve block are fixedly connected with the hydraulic control valve box through screws.

The large-fluctuation logic cartridge valve block is suitable for high pressure and large flow; the working medium has wide application range and can realize leakage-free control; the system has the characteristics of large flow and low liquid resistance, is high in system efficiency, has the characteristics of quick opening and closing, and can control the switching characteristic; the flow control characteristic is good, the pollution resistance is strong, the performance is reliable, and the service life is long.

The speed regulator valve block of the utility model replaces the traditional electrohydraulic servo valve, the proportional valve or the stepping motor, the traditional main distributing valve and the like with the standard hydraulic elements such as the digital electromagnetic valve, the logic cartridge valve and the like respectively, and is matched with a computer monitoring system to bear the control tasks of the opening degree of the guide vane of the unit, the frequency of the unit, the power of the unit and the like. The digital intelligent speed regulator is stable and has no discrete property, the standard control capability of the programmable logic controller is provided in the application process, the reliability is high, the expansion is easy, the operation capability is strong, the timeliness is good, the programming is convenient, the switching value and the analog value are conveniently processed, and the loop regulation is well carried out.

The above structures or components, and the specific connection modes not mentioned, are conventional structures and conventional connection modes, such as connection through lines, integrated blocks, oil pipes, and the like.

Example 2

The digital hydraulic control valve bank is provided with a hydraulic control valve box, a large fluctuation hydraulic control valve block, a hydraulic locking control valve, a small fluctuation combined control valve block and a large fluctuation logic cartridge valve block in parallel, an oil return interface and an oil supply interface are arranged on the positive side face of the digital hydraulic control valve bank main body, the large fluctuation logic cartridge valve block is arranged on the left side face, the right side face and the upper surface of the hydraulic control valve box, the large fluctuation hydraulic control valve block is arranged on the upper surface of the hydraulic control valve box, the hydraulic locking control valve block and the small fluctuation combined control valve block are arranged on the same side face of the hydraulic control valve box, the hydraulic locking control valve block is arranged above the small fluctuation combined control valve block, and the PLC control cabinet is connected with the oil return interface through a pipeline. The bottom end of the digital hydraulic control valve group is provided with a support, and the digital hydraulic control valve group is connected with the oil tank into a whole through the support. The small fluctuation combined control valve block is a high-speed digital ball valve, and the operation time is less than 25ms. As shown in fig. 1, 8-12.

The small fluctuation combined control valve block and the large fluctuation logic cartridge valve have certain sealing specific pressure, the sealing specific pressure is a linear seal of 31-33 Mpa, the sealing performance is good, the pressure drop rate of the oil pressure device is small, the starting times of the oil pump are obviously reduced, the pressure maintaining time is 4-6 hours in the working range of the speed regulator under 13.5-16.5 Mpa, and the pressure maintaining time is more than 25 times of that of the traditional speed regulator with the main valve structure, and the pressure maintaining device has obvious energy saving effect.

The bottom end of the digital hydraulic control valve group is provided with a support, and the digital hydraulic control valve group is connected with other devices, such as an oil return box, into a whole through the support. The digital ball valve and the digital logic cartridge valve can be used for being connected with a hydraulic control system in parallel, so that the anti-interference performance and the oil pollution resistance are greatly improved. The logic cartridge valve block enables the traditional hydraulic control basic combination to be further divided into two controllable hydraulic half-bridges and one controlled cavity combination, and various hydraulic control systems and circuits all comprise a plurality of the combinations. The system is regulated by a combination of on-off digital logic, replaces the middle position regulation of a main distribution valve, has stable operation and high regulation quality, reduces the workload of system regulation and is convenient to regulate.

Manual emergency operation ports are arranged on the integrated valve blocks in the digital hydraulic control valve block, and emergency operation can be performed when a control system fails. Each integrated block electromagnetic valve in the digital hydraulic control valve group, namely the size fluctuation hydraulic control valve group and the logic cartridge valve are respectively provided with a square plug with a lamp, and the specific structure is as shown in fig. 6, so that the running state of the electromagnetic valve is visible in real time.

The automatic regulating part in the hydraulic operation adopts a large fluctuation and small fluctuation parallel regulating mode, the large fluctuation valve adopts a large fluctuation hydraulic control valve block as a pilot valve, and the logic cartridge valve is controlled to carry out large flow control. And a manual button is additionally arranged on the small fluctuation combined control valve block and is also used as a manual operation valve.

The emergency shutdown valve also arranged on the digital hydraulic control valve group is a two-position three-way electromagnetic reversing valve, and simultaneously controls the large-fluctuation hydraulic control valve block and the hydraulic control shuttle valve, as shown in figure 4. The emergency shutdown valve prevents the turbine from operating at a rapid rotational speed for a long period of time. When the unit normally operates, the emergency shutdown valve is only used as a pressure oil channel, so that the speed regulator is communicated with the pipeline of the servomotor. When the unit gets rid of load and encounters a fault of the speed regulating system, the emergency shutdown valve acts to cut off the connection between the main distributing valve and the servomotor, and the pressure oil is directly connected into the servomotor from the high-pressure oil pressure mechanism, so that the servomotor is quickly closed, the emergency stop surface of the unit is realized, the over-speed time of the unit is shortened, and the water turbine is protected.

The digital hydraulic control valve group is provided with an on-off valve, a small fluctuation on-off valve and an on-off valve of a large movement control valve, wherein the on-off valve is a quick on-off valve, the quick on-off digital valve acts for 3ms to 35ms, see figure 7, and the model is 3SEW6/10-UK/CK. The quick switch valve is used as a pilot valve for adjustment, has strong pollution resistance, good repeatability and high stability, and can be directly connected with a computer. A digital speed regulator based on a quick switch valve and a logic cartridge valve component is characterized in that the logic cartridge valve is used as a single control liquid resistor, so that the traditional hydraulic control basic combination can be further divided into two controllable liquid resistors and a hydraulic half-bridge with a controlled cavity combination, and the problems of the existing water turbine speed regulator are solved: refusing movement, sending card, leaking oil, large oil consumption, poor static performance and dynamic quality. The method has the characteristics of obvious energy saving, consumption reduction, life prolonging and the like, and provides technical guarantee measures for people reduction and synergy of the hydropower station.

The system principle in the utility model is shown in fig. 2 and 3, and the operation flow of the system principle is as follows:

the speed regulator valve block controls the oil quantity by controlling the water guide vane servomotor (or blade servomotor for short) so as to promote the opening degree of the water guide vane (blade) to control the water flow of the water turbine and regulate the rotating speed of the water turbine, namely the speed regulating function of the water turbine speed regulator.

When the emergency shutdown valve is filled with pressure oil (left position), the following five working conditions exist:

(1) Small fluctuation shutdown condition: when the servomotor is slightly regulated, the output signal controls the small fluctuation shutdown ball valve to act, so that the small fluctuation shutdown ball valve is positioned at the left position, pressure oil flows to the servomotor from the small fluctuation shutdown ball valve, and the servomotor acts after the throttle valve is regulated;

(2) Small fluctuation starting-up working condition: when the servomotor is slightly regulated, the output signal controls the small-fluctuation starting ball to enable the valve servomotor to act;

(3) Large fluctuation shutdown condition: when the servomotor needs to act for a large stroke, the output signal controls the large-fluctuation shutdown ball valve, controls the control oil of the cartridge valve, and realizes the shutdown action of the servomotor;

(4) Large fluctuation starting-up working condition: when the servomotor needs to act for a larger stroke, the output signal controls the large-fluctuation starting ball valve to act and the servomotor to start;

(5) Stabilizing the balance working condition: under the condition that the electromagnet is in a power failure, the servomotor is in a stable balance state, and each electromagnetic valve is in a self-locking state (oil way is closed), namely, when an electric part fails, the servomotor maintains the original opening degree unchanged. At this time, manual operation can be performed by a manual button.

When the emergency shutdown valve is in the right position through automatic or manual signal action under the condition of accident shutdown, the control oil source of the large fluctuation shutdown ball valve is discharged from the oil return tank, the action working condition of the system is the same as that of the large fluctuation shutdown, no matter the control signal of the emergency shutdown valve is disconnected, the guide vane servomotor is continuously closed back, and the servomotor stops action only when a reset signal is given.

When the mechanical hydraulic lock is in place: when the electromagnet on the hydraulic locking electromagnetic valve obtains a control signal, locking input; when the electromagnet below the hydraulic locking electromagnetic valve obtains a control signal, locking and pulling out; when the device is started again, a signal for locking and pulling out is given.

In the hydraulic control mechanism of the hydraulic turbine speed regulator, which consists of a large-fluctuation logic cartridge valve and a small-fluctuation digital ball valve, the working characteristics and the connecting structure of a main valve unit are as shown in fig. 5: A. two working chambers B) and the control chamber K, the valve core is controlled to be opened (resultant force is less than 0), closed (resultant force is more than 0) and no position is left (resultant force=0), and the on-off control of the large fluctuation logic valve is realized through the pressure change of the control chambers. Different pilot valves are used to form pressure control, direction control or flow control, and may form a compound control. A plurality of two-way cartridge valves with different control functions are assembled in one or a plurality of cartridge blocks to form a hydraulic circuit.

Selection principle of pilot control oil: in order to ensure the stability and reliability of the speed regulator, the opening and closing actions of the large fluctuation logic valve are required to be highly reliable and rapid, so that the control oil pressure is stable and reliable, and the pressure fluctuation is small.

Compared with a four-way slide valve, the utility model adopts micro-structure pilot valve control to control the main stage of the large-fluctuation pilot valve block pilot control and the two-way logic cartridge valve seat, and can accept the control of various types of switches, analog quantity and digital signals without limitation. And the feedback and comparison of mechanical and hydraulic parameters are carried out, the pressure, flow and direction required by the actuating mechanism are precisely controlled, and the hydraulic control valve is compatible with a switch valve, a servo valve, a proportional valve and a digital valve. If the pilot signal is continuously or proportionally regulated, the valve seat main stage of the plug-in element can realize the servo/proportional control function and has excellent controllability and flexibility. The valve seat structure overcomes the defects of new poor technology, radial clearance leakage and the like of the slide valve. The main stage of the logic cartridge valve seat is wire sealing, zero covering, short axial dimension and small valve core quality, so that the dynamic quality of a control system is improved, and the multifunctional, flexible and changeable integrated combination is realized. The main stage of the cartridge valve seat is wire seal, zero cover, short axial dimension and small valve core mass. The dynamic quality of the control system is improved, and the multifunctional, flexible and changeable integrated combination is realized.

According to the technical requirements of GB/T9652-2019 speed governor: the unit automatically operates under no-load working condition, and when the effective frequency difference of the frequency step change is not less than 4% of the rated frequency fr, the dynamic regulation performance of the no-load disturbance response process of the regulating system is: the adjustment time Tfr from the start of the step disturbance until the adjustment stabilizes does not exceed 35s. The regulating system adopting the power regulating mode is characterized in that the unit stably operates under the wabby load working condition, and the dynamic regulating performance of the power response process is realized by taking the power regulating instruction received by the speed regulator as a starting point: the adjustment time ts satisfies: when the target value variation of the active power is not less than 25% of the fixed active power Pr of the unit , ts is not more than 45S, when the target value variation of the active power is 5% -25% of the fixed active power Pr of the unit , ts is preferably 30-45S, and when the target value variation of the active power is less than 5% of the fixed active power Pr of the unit and is more than the artificial power dead zone EP, ts is preferably not more than an electrohydraulic servo valve for a 30S hydraulic turbine governor, and the response frequency is generally 5-10 Hz.

In the embodiment, 1 hydraulic locking control piece is arranged, 2 small fluctuation combined control valve blocks are arranged, and two sides of the hydraulic control valve box are respectively provided with one hydraulic control valve; the hydraulic control valve box is characterized in that 4 large-fluctuation logic cartridge valve blocks are arranged, one large-fluctuation logic cartridge valve block is arranged on each of two side surfaces of the hydraulic control valve box, and 2 large-fluctuation logic cartridge valve blocks are arranged at the top of the hydraulic control valve box; the number of the oil supply interfaces is 1, the number of the oil return interfaces is 2, and the oil supply interfaces are all arranged on the same front surface of the hydraulic control valve box, so that the adjustment requirements of the unit on adjusting fluctuation setting on-direction and off-direction are met.

The high-pressure oil pressure device can be arranged at the same time, so that the problems of refusal action, hairpin, oil leakage, large oil consumption, poor static performance and dynamic quality and the like are solved, the reliable work can be more than 30 ten thousand hours, and the dead zone of the rotating speed is 0.0027% on the technical index, which is better than the national standard of 0.06%; the resolution is 0.0005Hz, which is far superior to the standard (standard < 0.003 HZ); the nonlinearity is 0.128%, which is better than the standard (standard < 0.25%). In the load shedding process, the fluctuation times deviating from the steady-state rotating speed by more than 3% are not more than 1 time, and the guide vane opening adjustment time is less than 30s.

For example, the hydraulic servo system can be connected with other mechanisms in parallel, such as an oil pressure device and an electric regulating device, the oil pressure device is controlled by a sensor, the electric regulating device and the hydraulic servo system have strong practicability and intelligence, and the state of a hydraulic element and a sensing element can be monitored and regulated in real time. In the concrete structure, the speed regulator control valve block is provided with an energy storage gas group, a PLC control cabinet, a digital hydraulic control valve group, an oil return tank, an oil pump motor group and a pressure hydraulic control valve group in parallel, wherein the energy storage gas group and the oil pump motor group are respectively arranged on two sides of the oil return tank, the PLC control cabinet and the digital hydraulic control valve group are arranged on the upper surface of the oil return tank, and the pressure hydraulic control valve group is arranged at the bottom end part of the oil pump motor group; the PLC controller is arranged in the PLC control cabinet. As shown in fig. 13.

The oil pump motor set is provided with 1 main pump and 1 standby pump, and 1 pressure hydraulic control valve group is arranged between the main pump and the standby pump. The high-pressure oil press mechanism is also provided with an air filter, an oil filter, a pressure controller, a control valve group and a meter, and the structures are positioned on a pipeline at a required position in the pressure hydraulic control valve group and are conventionally arranged. The high-pressure bag type energy accumulator is formed by connecting 3 bag type energy storage tanks in parallel. Other parts for control such as an electric contact pressure gauge, a safety valve, a gas compensating valve, a check valve and the like are also arranged at corresponding positions in the high-pressure oil pressure mechanism.

The speed regulator with electrohydraulic servo system of the present utility model measures the rotation speed signal of the water turbine generator set via the frequency measuring element, synthesizes the signals from the frequency measuring element and the signal feedback element, amplifies the synthesized signals and transmits the amplified signals to the executing element of the speed regulator, i.e. the hydraulic system, to regulate and control the motion of the water guiding mechanism of the water turbine surface, thus completing the regulation and control of the rotation speed and output power of the water turbine. The microcomputer controller is a control core component of the speed regulator and is mainly responsible for signal acquisition of water level, frequency, active power, guide vane opening and the like, data operation, operation condition and operation mode switching, analog quantity input and output, discrete quantity input and output, control value output, actuator control, networked digital communication and other additional functions. The servomotor and the high-precision displacement sensor are arranged on other units of the power plant. The rotational speed dead zone was set to 0.0027% resolution to 0.0005Hz and the nonlinearity to 0.128%.

The PLC is a programmable controller and has the functions of measuring active power, measuring water head, touch screen and operation. The PLC outputs a pulse sequence through PID operation, and the pulse sequence is amplified and is used as an input signal of the switch valve, but the switch valve is only in an open state and a close state, the output flow is intermittent, at the moment, the PWM control technology is required to control the high-speed switch valve to output continuous flow signals and enter the servomotor, so that the displacement of the servomotor is controlled, the feedback signals are obtained from the displacement of the servomotor, are converted into frequency signals through V/F and are input into the PLC again, and the frequency signals are comprehensively compared with the operation value, so that the aim of adjusting the opening of the guide vane is achieved. Due to the water flow penetration time constant, the water head change, the tail water fluctuation and the pulsation caused by the uneven flow field in the volute, the microcomputer speed regulator of the water turbine has the condition that the opening degree of the guide vane is not adjusted in place, namely the dead zone for controlling the opening degree of the guide vane. If the dead zone is too large, the substance is failure of theory and automatic control, and the method is particularly characterized in that the frequency swing of a unit is too large, the main and auxiliary pumping is severe, the oil is frequently pumped, the pipeline is vibrated, the grid connection is difficult, and the like. Of course, the smaller the dead zone is, the better, the more accurate the dead zone, the more sensitive the main pressure valve, if there is a dead zone in the system, the dead zone will "scatter" in the whole adjusting process during dynamic adjusting process, so that the vane feedback curve and the given curve are not completely consistent, and a relatively gentle adjusting transition process is formed, which is beneficial to effectively suppressing the frequency feedback lag caused by the inertia of the machine set.

When the utility model is used, an ASIC (application specific integrated circuit of VSS-3) can be used, a Automation Studio 4.0.0 software development platform is used by a controller, GV-S-D-1.0 is used, the adjustment is quick and accurate, the control logic of a traditional servo valve structure is combined, the control is converted into digital logic valve control, the speed regulator is ensured to operate the guide vane servomotor under any working condition, the quick action to a set position can be realized, meanwhile, the pressure oil for simultaneously closing two cavities of the servomotor switch can be cut off under a steady state condition, and the pressure maintaining time is improved while the position is prevented from being disturbed and drifting.

The microcomputer processing system with high reliability is adopted, the PLC is used as a core, the ASIC technology is utilized to realize the detection of machine frequency and network frequency, the displacement of the operating cylinder is transmitted into the ASIC for measurement through voltage/frequency (V/F) conversion, the reliability of the frequency measurement and detection feedback part of the speed regulator is effectively improved, meanwhile, the digital ball valve and the digital cartridge valve are adopted, the hydraulic control system is connected in parallel, and the anti-interference performance and the resistance to oil pollution are greatly improved.

According to the speed regulator electrohydraulic follow-up system, the digital ball valve directly drives the control ring to operate the oil cylinder, no mechanical transmission lever is arranged in the middle, full digital control is truly realized, and the control precision and reliability are greatly improved. The electrohydraulic conversion link adopts a digital ball valve, and the hydraulic system adopts a standard hydraulic element, so that the structure is simplified, and the interchangeability and maintainability are improved. The digital valve has strong pollution resistance, high pressure resistance, no leakage, reliable action and no need of zero point adjustment.

Test one

The test method comprises the following steps:

(1) Setting the signal of a frequency signal generator to be 50Hz, connecting the frequency signal into a unit frequency measurement input terminal, adjusting power setting to enable the servomotor to be opened to 50%, gradually increasing the frequency of a signal source to enable the opening degree of the servomotor to be close to full closing, reducing a frequency signal to enable the servomotor to start moving to a point towards the opening;

(2) And sequentially and unidirectionally increasing a 0.25Hz signal frequency source, and recording the frequency f and the servomotor stroke y after the servomotor is stable. Until the servomotor is fully opened (directly collected by a computer);

(3) And then sequentially decreasing the frequency signal by 0.25 in a unidirectional way, and recording the frequency f and the servomotor stroke y after the servomotor is stable. Until the servomotor is fully closed (directly collected by a computer);

(4) Repeat 2 times bp=4% (6%);

(5) And (3) solving (directly acquiring by calculation software) a speed dead zone of the speed regulator according to the test record, and obtaining the linear error of the servomotor.

The static characteristics of the speed regulator in the utility model: static characteristic linearity: the linear error is not more than 3 percent when the linear error is approximately a straight line;

the dead zone of the rotating speed of the static characteristic curve is less than or equal to 0.02 percent (measured to the main servomotor).

The dynamic characteristics of the speed regulator in the utility model: when the hydro-generator set can meet the standard steady operation under various automatic working conditions, the dynamic characteristics of the speed regulator can reach the state.

(1) Dynamic characteristics:

under the condition that the open-loop gain of the electrohydraulic adjusting device is not less than 60 percent of the limit open-loop gain, step frequency signals are input, and the dynamic characteristics under various adjusting parameter combinations have good PID rules without twitching and other abnormal phenomena:

the device can stably operate under various working conditions; the relative swing value of the rotating speed of the unit is not more than +/-0.15% after the automatic idle running for 3 min;

the motionless time of the servomotor is not more than 0.2s;

dynamic quality at 100% load shedding: the fluctuation times of the hyperstable rotating speed above 3% of the rated rotating speed are not more than 1.5 times;

the adjustment time does not exceed 4Tm (Tm is the time from the start of load shedding to the rise of the rotational speed of the unit to the maximum value).

Primary frequency modulation and isolated network performance meet DL/T1245-2013 specification requirements.

(2) Drift effect: the drift (nr) of the electrical device is less than 0.01 percent, and the comprehensive drift (nr) is less than 0.3 percent.

(3) Reliability: average fault interval time not less than 25000h; average overhaul interval time is more than 4 years; the availability of the automatic mode is 99.9%, and the availability of the automatic and manual modes is 100%.

Test II

In the test method I, the opening degree increasing and decreasing time is provided when the difference is adjusted: when the power increasing or decreasing button is continuously pressed, the time for changing the opening of the unit guide vane servomotor by 100% is adjustable within 2.5-120S, and the given step length of the pressing button is adjusted from 0.01% -5%.

Various switches: the stroke change of the guide vane servomotor caused by the mutual switching between the alternating current power supply and the direct current power supply is not more than 0.01% of the full stroke; when the speed regulator is switched between the automatic operation mode and the manual operation mode, the stroke change of the guide vane servomotor is not more than 1% of the full stroke.

According to the utility model, the communication interface Modbus RTU (RS 485) or Modbus TCP (RJ 45) of the speed regulator is adjustable, the full-open time of the guide vane is 6-20 seconds, and the full-close time of the guide vane is 6-20 seconds. Electromagnetic compatibility meets the relevant requirements of the electromagnetic compatibility in IEC61000-4-1, IEC61000-3-2, IEC61000-3, CISPR11 and GB standards. In the using process, the alternating current power supply is AC220V15%50Hz or 60Hz, and the direct current power supply is DC220V15%. The structure of the local components is conventionally set.

The speed regulator has good dynamic quality, and all performance indexes reach or are superior to national standards; the self-adaptive starting-up rule can rapidly (operating power 75000 N.m) and safely start up the unit to no-load for different units; the frequency of the power grid is automatically tracked in an idle load way, so that the frequency of a unit can reach the synchronous requirement rapidly (less than 30S); the intelligent variable structure PID regulation rule ensures that the unit always works in the optimal state; active power closed-loop adjustment can be automatically performed according to instructions of a monitoring system in a channeling communication mode (RS 422 and RS485 can be converted and used); the operation conditions are switched randomly without disturbance by adopting a sectional pulse width (processed by a size fluctuation hydraulic control valve).

The modulation mode adopts a pulse width modulation mode, and the speed regulator valve block is applied to a microcomputer, a pulse width modulation digital valve, a pulse width modulation amplifier, an execution device (servomotor) and an energy device (high-pressure oil pressure mechanism) in the operation of an open loop and a closed loop, and has the advantages of quick response, higher precision and good stability.

The PLC controller can feed back the opening degree of the servomotor and the state of the intelligent hydraulic servo system to the regulator in real time, and the opening degree of the servomotor can also be fed back to the unit LCU in real time for logic sequential control and monitoring recording such as surface opening and shutdown, and the state of the intelligent hydraulic servo system comprises an oil filter blocking signal, a servo driver fault, an oil-free electric conversion feedback fault, a servomotor feedback fault and the like.

The above examples/experiments are only examples for clarity of illustration and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the utility model.

Claims (5)

1. The utility model provides a full digital hydraulic servo system of speed regulator, is equipped with digital hydraulically-controlled valves, its characterized in that: the digital hydraulic control valve bank is provided with a hydraulic control valve box, the hydraulic control valve box is hollow, the front surface of the hydraulic control valve box is provided with an oil return interface and an oil supply interface, both sides of the hydraulic control valve box are provided with a small fluctuation combined control valve block and a large fluctuation logic cartridge valve block, the top of the hydraulic control valve box is provided with a large fluctuation hydraulic control valve block and a large fluctuation logic cartridge valve block, and one side of the hydraulic control valve box is provided with a hydraulic locking control piece above the small fluctuation combined control valve block; the small fluctuation combined control valve block, the large fluctuation logic cartridge valve block, the large fluctuation hydraulic control valve block and the hydraulic locking control piece are connected with the hydraulic control valve box by adopting integrated valve blocks.

2. An all-digital hydraulic follow-up system for a governor according to claim 1, wherein: the digital hydraulic control valve group is also provided with an emergency shutdown valve which is a two-position three-way electromagnetic reversing valve and simultaneously controls the large-fluctuation hydraulic control valve block and the hydraulic control shuttle valve.

3. An all-digital hydraulic follow-up system for a governor according to claim 1, wherein: the bottom end of the digital hydraulic control valve group is provided with a support, and the digital hydraulic control valve group is connected with other devices into a whole through the support.

4. An all-digital hydraulic follow-up system for a governor according to claim 1, wherein: and each integrated valve block on the speed regulator control valve block is respectively provided with a manual emergency operation port, so that emergency operation is performed when a control system fails.

5. An all-digital hydraulic follow-up system for a governor according to claim 4, wherein: each integrated block electromagnetic valve on the speed regulator control valve block is respectively provided with a square plug with a lamp, and the running state of the electromagnetic valve is visible in real time.