CN101182827A

CN101182827A - Double pumps displacement water turbine speed regulating means

Info

Publication number: CN101182827A
Application number: CNA2006101183255A
Authority: CN
Inventors: 夏嘉琪
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-11-14
Filing date: 2006-11-14
Publication date: 2008-05-21
Anticipated expiration: 2026-11-14
Also published as: CN100588835C

Abstract

The present invention discloses a dual-pump volumetric hydrogovernor. Completely different from the traditional speed governor structure, the present invention is manufactured on the basis of the principle that the oil pump directly controls the volume of the main servomotor. Without the guide valve with complex processing and high manufacturing accuracy and a main control valve as well as the consequent reduction of throttling loss and power loss, the present invention has obvious energy-saving effect and greatly reduces the large-volume oil pressure units and oil collecting containers, thus having the characteristics of simple structure, convenient production, small size, light weight and low cost. Simultaneously, the present invention adopts two oil pumps of different volumes respectively as a main control system and a deputy control system. The main control system composed of the small-volume oil pump is responsible for successive precision control of short offset signals while the deputy control system composed of the large-volume oil pump is responsible for make-and-break speedy control of large offset signals. The two systems are mutually matched and bring out the best in each other, thus improving and enhancing the dynamic and static performance of the whole speed governor. The governor is applicable to medium and small-sized power stations.

Description

Double pumps displacement water turbine speed regulating means

Technical field:

Patent of the present invention relates to a kind ofly directly controls the double pumps displacement water turbine speed regulating means of water turbine main servomotor by oil pump, is applied among the medium waterpower generator station hydrogovernor.

Background technique:

The aperture of the main servomotor of water turbine is to be controlled by the speed regulator that devices such as pilot valve and main control valve constitute, and it is classical control mode, also is unique control mode in the present water turbine industry.This control system is called the valve-controlled cylinder throttle control system.It has two macrostructure characteristics: 1. adopting the guiding valve auxiliary structure, is to realize with guiding valve chromaffin body stream limit aperture size to the control of main servomotor.2. adopt the forced oil device of forming by screw pump to the speed regulator fuel feeding.Recent decades, the speed regulator technology obtains tremendous development, and structure is updated, and performance is gradually improved, but this two great traditions structural type does not have variation all the time, does not occur the speed regulator of other patterns up to now as yet.But the speed regulator of this conventional version exists following deficiency:

1. owing to adopt guiding valve auxiliary structure pattern, the performance quality of speed regulator depends on the machining accuracy and the assembly quality of guiding valve pair to a great extent.The axial amount of lap size in guiding valve chromaffin body stream limit is the dead band and the stability of a system that has determined speed regulator, the radial clearance size of guiding valve pair determined system in let out, static drift, dexterity of action and functional reliability.Just for this reason, pilot valve in the speed regulator and main control valve become speed regulator manufacture process two big critical components, complex structure, accuracy of manufacturing height, cost height.

2. the performance index of speed regulator have static and dynamic two big classes.Some measures for the performance that improves existing speed regulator is taked often to the raising of static and dynamic performance, have the effect of conditioning each other, and this design and debugging to speed regulator brings certain degree of difficulty.

3. the speed regulator of the secondary type of guiding valve is to realize control by means of guiding valve chromaffin body stream limit aperture size, has bigger restriction loss, and the energy utilization has only about 2/3.For avoiding the governor oil temperature rise too fast, the oil supply system capacity of speed regulator must strengthen, so cause forced oil device and oil sump tank bulky.

4. the existing dynamic removal of load of speed regulator is difficult to realize quick non-overshoot process, regulates often, and settling time is long, and this bad performance more can cause the speed regulator oil consumption to increase, and the forced oil device capacity strengthens.

In hydraulic control control field, also there is another kind of speed-regulating controling mode, directly controls the control mode of oil cylinder exactly by oil pump, be called pump control cylinder volume control system.It compares the most tangible advantage with the former be the restriction loss that there is not the guiding valve auxiliary structure in it, has remarkable energy saving effect.

Hydrogovernor is controlled in such a way, and then the aperture of main servomotor is directly controlled by the integral value of oil pump output discharge capacity.For the displacement pump of fixed displacement, for reaching this purpose, pump speed must be variable.Along with the development and progress of motor speed-regulating control technique, realize that pump speed is variable, the output displacement controlled has had may.Current frequency control motor and AC servo motor all are to realize the selectable motor pattern of two classes of speed governing, although the frequency control motor power controlling can be done very greatly, be enough to cover the scope of the required power controlling of speed regulator, but because the frequency response characteristic of system is not good, be difficult to the requirement of competent speed regulator, be not suitable for doing the control motor of speed regulator.The frequency response height of AC servo motor is suitable for the control motor of speed regulator very much, but because power controlling is less than normal, powerful slightly actuating motor cost is higher simultaneously, and the user is difficult to accept, so its using scope also is subjected to certain limitation.

Observe the speed regulator practical operation situation as can be known, in most times that speed regulator puts into operation, it all implements control to little deviation signal, mains frequency is followed the tracks of and the power fine setting to reach the hydraulic generator unit, only in the unit start and stop and significantly during increasing and decreasing load, the adjusting of this large deviation signal just can appear in speed regulator, and number of times is few, and the time is of short duration.Now two kinds of running statees that deviation signal is differed in size are born by two control system respectively, master control system is born long-term, the continuous and accurately control of little deviation signal, and secondary control system is born interrupted, the quick control of large deviation signal, and this design proposal might realize fully.Two control system are equipped with different devices, and performance advantage is separately finished different adjusting tasks, accomplishes to make the best use of everything, and reaches the highest cost performance.The main cause of research and development double pumps displacement speed governing that Here it is.

Summary of the invention:

Patent of the present invention is exactly comprehensive state-of-the-art at present and a kind of speed regulator of proposing, it is that volume control principle with oil pump control main servomotor constitutes, the volumetric oil pump that adopts two capacity not wait is formed the major and minor control system of speed regulator, oil pump is the control means of system, is again the assembly that power is provided to system.Master control system is by AC servo motor, the displacement pump of bidirectional reversible rotary gear pump or other types, compositions such as two-way Pilot operated check valve, make-up valve and relief valve.Its adjusting speed accuracy height, but speed governing power is limited.Therefore master control system is only born long-term, the continuous little deviation signal of speed regulator and is accurately controlled.Secondary control system is by common three phase alternating current motor, the displacement pump of unidirectional rotary gear pump or other types, compositions such as 3-position 4-way cartridge valve assembly, relief valve, one-way valve and accumulator.This system's power controlling is big, but control accuracy is not high, so it is born, and speed regulator large deviation signal is interrupted, quick control, to satisfy the control of speed regulator moment large deviation signal.

When the input deviation signal hour, only master control system is devoted oneself to work.Because of master control system by AC Servo Motor Control, its control accuracy height, control response are fast, the speed regulator control dead area is little, static performance index is comparatively desirable.Simultaneously required power controlling is little when little deviation signal control, and just the output power with AC servo motor is complementary, and makes the best use of everything, and makes that the advantage of AC servo motor is given full play to.

Arrive to a certain degree when the input deviation signal is big, this moment, major and minor control system was devoted oneself to work simultaneously, because the secondary control system power controlling is big, oil pump output discharge capacity is big, and main servomotor is mobile rapidly, and the input deviation signal is sharply reduced, the realization quick adjustment.This moment, system got back to the little deviation signal control stage again, secondary control system quits work, and finally by master control system main servomotor is controlled on the due exact position, and making deviation signal is O, realized fast and accurate control the advantage of Here it is double pumps displacement speed regulator.

The deviation signal threshold values size that secondary control system is devoted oneself to work is variable.For dissimilar and water wheels unit specification, its value all is different, can decide according to field adjustable.Because the major-minor control system cooperatively interacts, bring out the best in each other, static state, the dynamic performance of whole speed regulator are improved and improve, can realize similar intelligentized control.Owing to adopt oil pump directly to control the volume control principle of main servomotor, have remarkable energy saving effect, make the power consumption of speed regulator significantly reduce.Thereby reduce the volume of speed regulator forced oil device and oil sump tank significantly, the volume and weight of speed regulator can be descended at double.Speed regulator with 18000Nm speed governing merit is an example, and its gross weight is no more than 350Kg.

Description of drawings:

Accompanying drawing 1 is a systematic schematic diagram

Embodiment:

With reference to accompanying drawing.

Master control system: AC servo motor (2) is controlled by driver (1), and it is by means of coupling (3) and coaxial connection of bidirectional reversible rotary gear pump (4).The A of oil pump (4) both sides, B hydraulic fluid port are according to the sense of rotation of oil pump oil inlet and outlet each other.Between hydraulic fluid port A and hydraulic fluid port B, connect pattern with superimposed valve and connect Fill valve (5) and two-way Pilot operated check valve (6) respectively.The A mouth of bidirectional hydraulic one-way valve (6) uses oil pipe line (31) to be connected with main servomotor (7) with (32) respectively with the B mouth.Oil pipe line (31) is connected with relief valve (9) with pressure gauge (8), and oil pipe line (32) is connected with relief valve (11) with pressure gauge (10).

Secondary control system: three phase alternating current motor (18) is connected with unidirectional rotary gear pump (20) by means of coupling (19), and the outlet of oil pump (20) links to each other with pressure gauge (16), relief valve (21) and one-way valve (13).The outlet of one-way valve (13) is connected with accumulator (12), and accumulator (12) links to each other with three position four-way electrohy-draulic valve again simultaneously.Hydraulic operated valve that this valve is made of 4 cartridge valve plug-in units (14) and three position four-way electromagnetic valve (15) are formed.The P mouth of hydraulic operated valve (14) and three position four-way electromagnetic valve (15) and the outlet of accumulator are connected with oil pipe line (35).The A mouth of hydraulic operated valve (14) uses oil pipe line (33) to be connected with main servomotor with (34) respectively with the B mouth.

Main servomotor (7) is two shaft balanced type oil cylinders, and its output terminal connects displacement transducer (22), and the output signal of displacement transducer is sent into micro-processor controlled electrical control cabinet (24) with lead (45).Its another output terminal links to each other with the command control case of being made up of position limit switch (23), and is connected with electrical control cabinet (24) with lead (46).The electric signal line that links to each other with electrical control cabinet (24) also has two groups of electromagnet coil guide lines (42) and (43) of three position four-way electromagnetic valve (15), the guide line (40) of AC servo machinery driving device (1), pressure relay (17) guide line (41) and three phase alternating current motor (18) guide line (44).

Working principle:

When the frequency of hydraulic generator unit was identical with mains frequency, the deviation signal of speed regulator input was O, and the main servomotor aperture is constant, and power and load that water turbine sends reach balance.In case destroying, balance just can produce deviation signal.When deviation signal greater than the pairing threshold values of governor dead time, under the control of speed regulator, main servomotor action changes the aperture of water turbine, regulates the power output of water turbine, in the hope of balancing each other with extraneous load.

When deviation signal more after a little while (promptly greater than governor dead time, and when moving pairing threshold values) less than secondary control system, master control system puts into operation, the driver of AC servo motor (1) is constantly accepted the control command signal of electrical control cabinet (24), drive AC servo motor (2) rotation, its sense of rotation is corresponding with increase and decrease hydraulic generator unit output power, and the size of its rotation rotating speed is relevant with the deviation signal size, and implements control by certain adjusting rule.Drive bidirectional reversible rotary gear pump (4) rotation by AC servo motor (2), and output flow, main servomotor (7) promoted by two-way Pilot operated check valve (6).The effect of two-way Pilot operated check valve is the correct working position of guaranteeing main servomotor, prevents that main servomotor from drifting about under extraneous load effect.In addition, because the positive revesal of main servomotor exists certain difference in volume and load to leak, carry out flow-compensated so in system, be provided with Fill valve (5).For preventing the main servomotor engine knock, cause the too high and overload of oil pump (2) delivery pressure, the damage system all is provided with relief valve (9) and (11) in the both sides of main servomotor (7), plays the overflow protective action, pressure gauge (8) and (10) is set plays demonstration and supervisory function bit.Main servomotor (7) is two shaft balanced type oil cylinders, and its end is connected with displacement transducer (22), by the displacement of displacement transducer (22) detection main servomotor (7), presents to electrical control cabinet (24) with electrical signal form, realizes position feedback.Its other end is connected with position limit switch assembly (23), and it is to determine according to requirements such as monitoring of water wheels unit and protections that position limit switch is provided with the position.

Because the driving power of master control system is limited, the capacity of the gear pump (4) of the bidirectional reversible rotation that it drove is less, and centering capacity is less, and it can only implement control to little deviation signal.When uprushing load shedding, depend merely on it and will seem that adjustment process is too slow, can not reach due adjusting function index, the reason of introducing secondary control system just is this.

Secondary control system is the gear pump (20) that adopts unidirectional rotation, promotes for realizing the main servomotor positive and negative direction, adopts the three position four-way electrohy-draulic valve of being made up of the hydraulic operated valve (14) of three position four-way electromagnetic valve (15) and four cartridge valve plug-in unit formations in secondary control system.Positive and negative promotion main servomotor (7) is whether to control by two electromagnet coil powers of three position four-way electromagnetic valve (15).When threshold values that deviation signal puts into operation greater than secondary control system, secondary control system just puts into operation.This threshold values is to decide by field adjustable.Threshold value setting gets suitable, can make speed control system realize quick non-overshoot control, and it is short not only to regulate transient time, and the control accuracy height has been realized similar intelligent control.

Native system has adopted the volume control mode, has implemented quick non-overshoot control; Adopt the less cartridge valve element of flow resistance again, make the consumption of energy of control procedure significantly reduce, have obvious energy-saving effect, thereby the oil gear of whole speed regulator and oil sump tank volume and weight can be reduced at double exponentially, this also is one of major advantage of patent of the present invention.

Claims

Patent disclosure of the present invention a kind of double pumps displacement water turbine speed regulating means, it is characterized in that: it is to constitute with the volume control principle that oil pump is directly controlled main servomotor, water turbine for the little control capacity of spy, can constitute speed regulator control system (being following master control system) by the separate unit oil pump, general gear pump that does not wait by two capacity or the other types volumetric oil pump major-minor control system of forming speed regulator respectively, its structural feature is as follows:

1) actuating motor (2) that controlled by driver (1) is connected with the volumetric oil pump (4) of gear pump with two-way spinfunction or other types by coupling (3), and make-up valve (5) is connected with oil pump (4) with the Sandwich plate valve installation form with two-way Pilot operated check valve (6);

2) three-phase alternating-current motor (18) is connected with the gear pump of unidirectional rotation or the volumetric oil pump of other types (20) by coupling (19) in the secondary control system, be connected with the end of relief valve (21) pressure gauge (16) at oil pump (20) outlet end with one-way valve (13), the other end of one-way valve (13) links to each other with the P mouth of accumulator (12), three position four-way electromagnetic valve (15) and the P mouth of 3-position 4-way cartridge valve assembly (14), and oil sump tank is inserted directly from the oil sump tank oil suction in the suction side of oil pump (20);

3) major and minor control system all is subjected to be controlled by the electrical control cabinet that microcomputer constitutes, and the displacement transducer (22) of the pressure relay (17) in the motor servo driver in the master control system (1), the secondary control system, two electromagnet coils of three position four-way electromagnetic valve (15), the three-phase alternating-current motor (18) that drives unidirectional backing pump (20), main servomotor (7), the position limit switch assembly (23) of main servomotor (7) use lead (40), (41), (42), (43), (44), (45) to be connected with electric control box (1) with (46) respectively.
2. as the described speed regulator of claim 1., it is characterized in that: the A mouth and the B mouth of the two-way Pilot operated check valve (6) in the master control system, input and output mouth for master control system, because the oil pump (2) of master control system has two-way spinfunction, therefore their changes along with oil pump sense of rotation difference, and be connected with pass side mouth with the side of opening of main servomotor (7) with (32) with pipeline (31).
3. as the described speed regulator of claim 1., it is characterized in that: the input and output mouth that the A mouth of the 3-position 4-way cartridge valve assembly (14) of secondary control system and B mouth are secondary control system is connected with pass side mouth with the side of opening of main servomotor (7) with (34) with pipeline (33).
4. as the described speed regulator of claim 1., it is characterized in that: the main servomotor that it drove (7) is two shaft balanced type oil cylinders, and its one stretches out axle head installation position displacement sensor (21), and another stretches out axle head installation position limit switch assembly (23).