Measurement structure and method for rotational speed and direction of a pump turbine

Abstract

The present disclosure provides a kind of water pump water turbine rotation speed and direction measurement structure and method, comprising: main shaft;Gear disc, sleeve joint on main shaft, with coaxial rotation with main shaft;Multiple arc teeth with gradually increasing outer diameter are provided on gear disc;The radial outer side of main shaft is equipped with first displacement sensor, and first displacement sensor is used to obtain the distance between it and main shaft;The radial outer side of gear disc is equipped with second displacement sensor, and second displacement sensor is used to obtain the distance between it and the arc teeth of gear disc;First displacement sensor and second displacement sensor are connected with information processor.This scheme can accurately measure the rotation direction and rotation speed of water pump water turbine, and can eliminate the error caused by unit rotation swing, obtain accurate rotation direction and rotation speed, avoid the risk of non-synchronous closing caused by rotation direction error;And the distance obtained by subtracting two sensors offsets the error caused by unit swing, ensures the reliability and accuracy of measurement data.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of fluid machinery and engineering equipment, in particular to a water pump turbine rotating speed and rotating direction measuring structure and method. BACKGROUND

[0002] The water pump turbine has two rotating directions when it is working normally. When it is used as a generator, the water flows downward to impact the runner, and at this time the rotating direction of the main shaft is the power generation direction. When it is used as a water pump, it relies on electric energy to pump water upstream, and at this time the rotating direction of the main shaft is the water pumping direction. The power generation direction and the water pumping direction are two opposite rotating directions, so the correctness of the rotating direction of the main shaft is very important.

[0003] When it is used in the water pumping direction, the unit must be dragged to the rated rotating speed by a static frequency converter first, and at this time the correctness of the rotating direction of the unit is particularly important. If the static frequency converter drags the unit in the wrong rotating direction, a major accident of non-synchronization closing may occur, and because the actual rotating direction is different from the design, other unpredictable consequences may also occur, such as confusion in the control process.

[0004] At present, most water pump turbines do not configure a rotating direction measuring device, so the rotating direction signal does not participate in the control process, and only the rotating speed can be measured. The rotating direction and the rotating speed of the water pump turbine cannot be determined at the same time, and the error influence of unit swing on the acquisition of the rotating speed is not considered. Therefore, the present disclosure is developed and improved in view of the above problems in the prior art. SUMMARY

[0005] Therefore, the purpose of the present disclosure is to provide a water pump turbine rotating speed and rotating direction measuring structure and method, which can accurately measure the rotating direction and the rotating speed of the water pump turbine at the same time, and can eliminate the error caused by the swing of the unit to obtain accurate rotating direction and rotating speed.

[0006] To achieve the above purpose, the present disclosure provides a water pump turbine rotating speed and rotating direction measuring structure in a first aspect, which comprises: a main shaft; a gear disc sleeved on the main shaft and coaxially rotating with the main shaft; a plurality of arc-shaped teeth with gradually increasing outer diameters are arranged on the gear disc; a first displacement sensor is arranged on the radial outer side of the main shaft, and the first displacement sensor is used to acquire the distance between the first displacement sensor and the main shaft; a second displacement sensor is arranged on the radial outer side of the gear disc, and the second displacement sensor is used to acquire the distance between the second displacement sensor and the arc-shaped teeth of the gear disc; and an information processor is connected to the first displacement sensor and the second displacement sensor.

[0007] In some optional embodiments, the first displacement sensor and the second displacement sensor are fixed on a fixed component, and the first sensor and the second displacement sensor always remain stationary.

[0008] In some alternative embodiments, the distance between the first displacement sensor and the main shaft is equal to the distance between the second displacement sensor and the maximum outer diameter of the toothed disc.

[0009] In some alternative embodiments, each of the arc-shaped teeth on the main shaft is connected to each other, the bottom end of each of the arc-shaped teeth abuts against the top end of the adjacent other arc-shaped tooth, so that the arc-shaped teeth form a closed loop on the toothed disc.

[0010] In some alternative embodiments, the first displacement sensor and the second displacement sensor are arranged coaxially above and below the axis, which is parallel to the axial direction of the main shaft.

[0011] In the second aspect, a method for measuring the rotation speed and direction of a pump-turbine is also disclosed, the method comprising:

[0012] acquiring the number of teeth of the toothed disc and the height of the arc-shaped teeth;

[0013] acquiring the rotation speed information by the displacement sensor in response to the rotation of the main shaft;

[0014] generating a rotation speed waveform diagram based on the rotation speed information;

[0015] judging the rotation direction of the main shaft and the toothed disc based on the rotation speed waveform diagram;

[0016] acquiring the real-time rotation speed of the main shaft and the toothed disc based on the rotation speed waveform diagram.

[0017] In some alternative embodiments, the acquiring the number of teeth of the toothed disc and the height of the arc-shaped teeth comprises:

[0018] acquiring the number of teeth of the toothed disc and the height of each arc-shaped tooth set in advance;

[0019] wherein the number of teeth of the toothed disc and the height of the arc-shaped teeth are set based on the parameters of the pump-turbine.

[0020] In some alternative embodiments, the acquiring the rotation speed information by the displacement sensor in response to the rotation of the main shaft comprises:

[0021] acquiring the first distance information between the first displacement sensor and the main shaft in the rotation of the main shaft;

[0022] acquiring the second distance information between the second displacement sensor and the arc-shaped teeth of the toothed disc in the rotation of the main shaft;

[0023] subtracting the first distance information and the second distance information to generate the rotation speed information;

[0024] wherein the distance information and the rotation speed information are real-time changes.

[0025] In some optional embodiments, the generating a rotation speed waveform based on the rotation speed information comprises:

[0026] generating a rotation speed waveform based on the rotation speed information, the rotation speed waveform having time as an X-axis and a distance difference between the first sensor and the second sensor as a Y-axis, and a slope as a rotation speed;

[0027] wherein the rotation speed waveform has time as an X-axis, a distance difference between the first sensor and the second sensor as a Y-axis, and a slope as a rotation speed;

[0028] one period of the rotation speed waveform corresponds to one of the arc-shaped teeth.

[0029] In some optional embodiments, the determining a rotation direction of the main shaft and the gear disc based on the rotation speed waveform comprises:

[0030] determining a slope of a curve of the rotation speed waveform;

[0031] when the slope is positive, determining that the rotation direction of the main shaft and the gear disc is positive;

[0032] when the slope is negative, determining that the rotation direction of the main shaft and the gear disc is negative.

[0033] In some optional embodiments, the obtaining a real-time rotation speed of the main shaft and the gear disc based on the rotation speed waveform comprises:

[0034] obtaining a slope of a curve at each moment based on the rotation speed waveform;

[0035] In some optional embodiments, the method further comprises:

[0036] determining a height deviation of each of the arc-shaped teeth based on the rotation speed waveform;

[0037] when the height deviation exceeds a predetermined range, issuing an alarm signal.

[0038] As can be seen from the above, the rotation speed and rotation direction measurement structure and method of the water pump water turbine provided by the present disclosure can determine the rotation direction and rotation speed of the water pump water turbine accurately while eliminating the error caused by the swing of the unit, and can obtain accurate rotation direction and rotation speed, thereby avoiding the risk of non-synchronous closing caused by incorrect rotation direction, and can ensure the reliability and accuracy of the measurement data. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the present disclosure or the related art, the drawings needed to be used in the embodiments or the related art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without any creative effort based on these drawings.

[0040] Figure 1 Structure diagram of prior art;

[0041] Figure 2 SFC dragging process toothed disc and PT speed measurement curve of prior art;

[0042] Figure 3 Front view of rotational speed and direction measurement structure of water pump water turbine according to embodiments of the present disclosure;

[0043] Figure 4 Plan view of rotational speed and direction measurement structure according to embodiments of the present disclosure;

[0044] Figure 5 Main shaft swing degree axis trajectory diagram according to embodiments of the present disclosure;

[0045] Figure 6 Flow chart of rotational speed and direction measurement method according to embodiments of the present disclosure;

[0046] Figure 7 Rotational speed waveform diagram of rotational speed and direction measurement method according to embodiments of the present disclosure;

[0047] Figure 8 Working principle diagram of rotational speed and direction measurement method according to embodiments of the present disclosure. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below with reference to specific embodiments and drawings.

[0049] It should be noted that, unless otherwise defined, technical terms or scientific terms used in the embodiments of the present disclosure shall have the common meaning understood by one of ordinary skill in the art to which the present disclosure belongs. The terms "first", "second" and similar terms used in the embodiments of the present disclosure do not denote any order, quantity or importance, but are used to distinguish different components. The terms "include", "contain" and similar terms mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms "connect" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right" and the like are only used to represent relative positional relationships, and when the absolute positions of the described objects change, the relative positional relationships may also change accordingly.

[0050] Before specifically describing the rotation speed and rotation direction measurement structure and method of the water pump water turbine provided by the present application, the application scenario and inventive concept of the present application are first described.

[0051] When the water pump water turbine is normally working, the rotation direction has two kinds. When the water turbine is working as a generator, the water flows downward to impact the runner, and the rotation direction of the main shaft is the power generation direction. When the water turbine is working as a water pump, the water is pumped upstream by electric energy, and at this time the rotation direction of the main shaft is the water pumping direction. The power generation direction and the water pumping direction are two opposite rotation directions, and therefore the correctness of the rotation direction of the main shaft is very important.

[0052] When the water pump water turbine is working in the water pumping direction, the unit must be dragged to the rated speed by a static frequency converter first, and at this time the correctness of the rotation direction of the unit is particularly important. If the rotation direction of the unit dragged by the static frequency converter is incorrect, a major accident of non-synchronization closing may occur, and because the actual rotation direction is different from the design, other unpredictable consequences may also occur, such as confusion in the control process.

[0053] At present, most water pump water turbines are not equipped with rotation direction measurement devices, and therefore the rotation direction signal is not involved in the control process. If the rotation direction of the unit can be accurately measured, the signal can be added to the control process to improve the reliability of the unit grid connection.

[0054] The rotation direction of the water pump water turbine usually does not change suddenly, and in general the unit will experience a period of static state before starting to rotate in the other direction, and therefore the accuracy of the rotation direction determination is more important, and the real-time requirement is not high.

[0055] The rotation speed measurement of the water pump water turbine usually has two kinds of PT and toothed disc speed measurement, but the above two methods cannot determine whether the unit is completely static. Usually, after the rotation speed is measured to be less than 1% of the rated speed, the unit is determined to be static by delaying for 10s-20s, but this method cannot guarantee that the unit is absolutely static. For example, when the mechanical brake is not put into operation, the unit will still rotate slowly after the rotation speed is 1% and the delay is 20s.

[0056] After determining that the unit is stationary, the mechanical brake will be exited and the high-pressure oil jacking device will be stopped. If the unit is actually still rotating at this time, it may cause thrust pad wear, so accurate determination of the unit's stationary state is important.

[0057] The goals and current difficulties of precise measurement of the speed of a pump-turbine are as follows:

[0058] (1) The absolute value of the rotational speed of the pump-turbine should be precisely measured, with small errors and high real-time performance.

[0059] (2) The rotational direction of the pump-turbine should be accurately determined, and the cooperation between the main shaft rotation direction and the phase-change disconnecting switch (PRD) in the electrical main wiring should be verified.

[0060] (3) The complete stop of the main shaft rotation should be accurately determined, serving as the basis for exiting the mechanical brake and the high-pressure oil jacking device.

[0061] (4) Since the pump-turbine operation will cause vibration and main shaft oscillation, the influence of unit vibration and main shaft oscillation on the measurement accuracy of the rotational speed signal should be minimized.

[0062] The current speed measurement system of the pump-turbine only measures the absolute value of the rotational speed and does not measure the rotational direction of the unit. The determination of the absolute stationary state of the unit uses a strategy of rotational speed <1% plus a fixed delay, which is time-consuming and cannot ensure accuracy.

[0063] The inventor first describes the problems existing in the current pump-turbine technology, and based on the inventor's long-term work and learning in this field, it is known that there is currently no way to simultaneously collect the rotational speed and rotational direction of the pump-turbine;

[0064] The current collection of the rotational direction of the pump-turbine has the following two ways:

[0065] 1. Artificial observation. High-speed units can only be observed by the human eye when the unit speed is slow, the observation time window is small, and the accuracy depends on the technical level of the observer.

[0066] 2. Inference from unit operation parameters. This method is based on the PRD position signal of the unit to infer the rotational direction of the unit, but the corresponding relationship between these two signals can only be ensured to be accurate when the unit is not faulty. The main purpose of determining the rotational direction of the unit is to ensure the correct correspondence between the actual rotational direction of the unit and the PRD position, thereby reducing the risk of rotational direction error during unit dragging.

[0067] The current collection of the rotational speed of the pump-turbine has the following two ways:

[0068] 1. Gear disc speed measurement: such as Figure 1As shown, the toothed disc speed measurement refers to installing a ring-shaped toothed device (toothed disc) on the end of the rotating shaft of the unit, and the toothed disc speed measurement device is composed of a toothed disc speed measurement sensor and a corresponding rotating speed signal processor.

[0069] When the main shaft rotates, a pulse signal (i.e., a series of square waves) reflecting the rotating speed of the unit is generated by a proximity or photoelectric displacement sensor and is then sent to the rotating speed signal processor. The rotating speed signal processor is composed of a single-chip microcomputer (or an intelligent instrument) and is responsible for calculating the rotating speed of the unit by measuring the pulse width.

[0070] 2. PT speed measurement: the rotating speed of the unit is calculated according to the voltage waveform of the generator, which is usually more accurate after the unit is started and excited. Therefore, this method is usually used after the unit is connected to the grid, and is less used when the rotating speed of the unit is low.

[0071] In addition, by Figure 2 As shown, when the rotating speed of the unit is low, the PT speed measurement is obviously inaccurate due to the low terminal voltage of the unit. Therefore, in the speed measurement system of the pump-turbine, the toothed disc is usually used as the rotating speed criterion at low rotating speed, and the PT speed measurement is switched to after the unit is connected to the grid.

[0072] Therefore, the problems in the prior art include the following:

[0073] (1) The rotating speed and direction of the pump-turbine cannot be measured simultaneously.

[0074] (2) There is no accurate way to measure the direction, and the artificial observation has low reliability and large workload.

[0075] (3) When the rotating speed is measured, the vibration of the pump-turbine and the swing of the main shaft interfere with signal acquisition.

[0076] (4) The precision of the rotating speed measurement toothed disc is limited: if the toothed discs are arranged more, the vibration of the unit will have a greater impact on the signal, especially at low rotating speed, which is easy to cause the signal to jitter at the critical point of the toothed disc, thereby affecting the rotating speed determination. If the toothed discs are arranged less, the overall measurement precision is reduced.

[0077] (5) The PT speed measurement is suitable for high rotating speed and after the excitation system is built up. In the case where the excitation system is not built up, the residual voltage is unstable, so the PT speed measurement cannot be used at low rotating speed, especially when the unit is stationary.

[0078] (7) The toothed disc speed measurement is limited to the acquisition of square waves of the toothed disc to calculate the rotating speed. At low rotating speed, it takes a long time to pass through the teeth of the toothed disc, that is, a long time to collect square wave data. Therefore, only the method of calculating that the rotating speed of the unit is less than 1% and delaying for 10-20 seconds can be used to determine that the unit is stationary, which is not reliable enough.

[0079] (8) The failure diagnosis logic strategy of the toothed disc speed measurement system is to arrange several sets of sensors, such as three sets of toothed disc speed measurement sensors, calculate three rotation speed values according to the collected signals, and then determine the final rotation speed according to, for example, a 3-to-2 mode. If the toothed disc itself has a problem, this method cannot find the fault.

[0080] Therefore, based on the above as the invention concept, the inventors solve the problem that the water pump water turbine cannot simultaneously measure the rotation speed and the rotation direction as the initial intention of the invention, and make improvements to propose the present solution.

[0081] It should be noted that the field to which the present application applies and the terms included in the present solution include the following:

[0082] Water pump water turbine: a hydraulic device that can operate as a water turbine and as a water pump, with the main shaft rotating in two opposite directions.

[0083] Power generation direction: the pumped storage unit operates as a generator, discharges water from the upper reservoir to the lower reservoir, impacts the runner to rotate, and converts the potential energy of water into electrical energy. At this time, the rotation direction of the main shaft is the power generation direction.

[0084] Water pumping direction: the pumped storage unit operates as a water pump, pumping water from the lower reservoir to the upper reservoir, converting electrical energy into potential energy of water. At this time, the rotation direction of the main shaft is the water pumping direction.

[0085] Runout: due to the misalignment of the geometric center line and the rotation center line of the generator motor main shaft, the geometric center line swings around the rotation center line when the main shaft rotates. This phenomenon is called runout.

[0086] Displacement sensor: also known as a linear sensor, it is a linear device that responds to metal. The function of the sensor is to convert various measured physical quantities into electrical quantities. In the production process, the measurement of displacement is generally divided into two types: measuring the size of the physical object and measuring mechanical displacement.

[0087] Mechanical brake: a mechanical device that reduces the speed of the unit to zero by physical friction.

[0088] Static frequency converter SFC: a device that uses thyristors to convert input power frequency AC into continuously adjustable frequency AC output. It is mainly used in pumped storage power stations to start the unit according to the pump working condition.

[0089] Non-synchronous closing: closing when the pressure difference, angle difference or frequency difference between the unit side and the grid side is large, causing strong stress due to uneven three-phase load, and causing serious impact on the generator, transformer and system.

[0090] Dial plate speed measurement: install a ring-shaped toothed device (dial plate) on the main shaft of the unit, and the dial plate speed measurement device is composed of a dial plate speed measurement sensor and a corresponding rotational speed signal processor. When the unit rotates, the proximity or photoelectric sensor generates a pulse signal (i.e. a series of square waves) reflecting the rotational speed of the unit. The pulse width is measured by a single-chip microcomputer (or intelligent instrument), and the rotational speed of the unit is calculated.

[0091] PT speed measurement: calculate the rotational speed of the unit according to the voltage waveform of the generator. Generally, it is more accurate after the unit is started and excited. Therefore, this method is usually used after the unit is connected to the grid, and is less used when the unit is at low speed.

[0092] Phase-changing disconnecting switch (PRD): can change the phase sequence of the power supply, and provide a mechanical switch with a specified insulation distance at the open position. Its position is different in the direction of power generation and pumping.

[0093] Example one

[0094] In the first aspect, a rotational speed and direction measurement structure of a pump-turbine is disclosed, in some optional embodiments, in combination with Figure 3 and Figure 4 as shown, comprising:

[0095] a main shaft 1;

[0096] a dial plate 2 sleeved on the main shaft 1 and rotating coaxially with the main shaft 1;

[0097] a plurality of arc-shaped teeth 21 with gradually increasing outer diameters are arranged on the dial plate 2;

[0098] a first displacement sensor 31 is arranged on the radial outer side of the main shaft 1, and is used to obtain the distance between the first displacement sensor 31 and the main shaft 1;

[0099] a second displacement sensor 32 is arranged on the radial outer side of the dial plate 2, and is used to obtain the distance between the second displacement sensor 32 and the arc-shaped teeth 21 of the dial plate;

[0100] the first displacement sensor 31 and the second displacement sensor 32 are connected with an information processor 4.

[0101] In this example, the accurate distances of the two sensors from the dial plate and the main shaft are measured respectively, and the two displacement signals are transmitted to the rotational speed accurate measurement signal processor. The signal acquisition error caused by the vibration and swing of the unit can be filtered out by subtracting the two distances.

[0102] Furthermore, in some optional embodiments, the first displacement sensor 31 and the second displacement sensor 32 are fixed to a fixing component (not shown in the figure, only used to fix the sensors), and the first sensor 31 and the second displacement sensor 32 always remain stationary. This ensures that the sensors always measure the distance between the spindle and the gear plate, and transmits the two displacement signals to the speed precision measurement signal processor.

[0103] In some alternative embodiments, the distance between the first displacement sensor 31 and the main shaft 1 is equal to the distance between the second displacement sensor 32 and the maximum outer diameter of the arc-shaped tooth 21 of the gear disk 2.

[0104] In some optional embodiments, each arc-shaped tooth 21 on the spindle 1 is interconnected, with the bottom edge of each arc-shaped tooth 21 abutting against the top edge of another adjacent arc-shaped tooth 21, forming a closed loop on the gear disk 2. This ensures no gaps during distance measurement and improves the real-time performance of the measurement.

[0105] In some optional embodiments, the first displacement sensor 31 and the second displacement sensor 32 are arranged vertically on the same axis, which is parallel to the axial direction of the main shaft 2. This facilitates sensor installation.

[0106] Further integration Figure 4 As shown, the scheme for accurately measuring the rotational speed of this water pump turbine mainly consists of an arc-shaped toothed disc with a radius that increases uniformly with the angle, two displacement sensors arranged vertically, and a rotational speed accurate measurement signal processor 3.

[0107] Combination Figure 3 As shown, when viewing the unit from top to bottom, the clockwise rotation of the pump turbine main shaft can be set as the power generation direction, and the direction definition can be adjusted according to the specific application scenario.

[0108] According to such Figure 3 As shown, when viewed from top to bottom, an arc-shaped gear disk with a radius that increases uniformly with the angle is installed on the upper end of the unit's main shaft. This part is the scale for determining whether the unit is rotating (the number of teeth on the gear disk in the figure is only for illustration and can be adjusted as needed).

[0109] Two displacement sensors are arranged vertically. The lower first distance sensor 31 obtains the distance from it to the main shaft 1 of the water pump turbine, and the upper second distance sensor 32 obtains the distance from it to the arc-shaped gear disk 2. The two displacement signals are transmitted to the speed precision measurement signal processor 4.

[0110] During the rotation of the main shaft of the water pump turbine, the main shaft is a rotating component, and therefore subject to fluctuations in power source and electromagnetic tension, resulting in a certain degree of oscillation. The sensor, however, is positioned stably on a fixed component. The trajectory of the main shaft's oscillation axis during rated load operation of a 300MW unit is as follows: Figure 5 As shown. To determine the unit speed based on distance, the influence of spindle oscillation on the measurement data needs to be filtered out.

[0111] In this example, when the main shaft drives the toothed disc with arc-shaped teeth to rotate, displacement sensors for measuring distance are respectively installed on the sides of the main shaft and the toothed disc to collect distance information during the rotation process, thereby obtaining the rotational speed and direction of rotation. This solution can accurately measure the direction of rotation and rotational speed of the water pump turbine simultaneously, and can eliminate the error caused by the unit's rotational sway, obtaining accurate direction of rotation and rotational speed, thus avoiding risks such as asynchronous closing caused by incorrect rotation; and the distance obtained by subtracting the two sensors cancels out the error caused by the unit's sway, ensuring the reliability and accuracy of the measurement data.

[0112] Example 2

[0113] Firstly, in some optional embodiments, a method for measuring the rotational speed and direction of a water pump turbine is disclosed, combined with... Figure 6 As shown, the method includes the following steps:

[0114] S1: Obtain the number of teeth on the toothed disc and the height of the curved teeth;

[0115] Step S1 also includes,

[0116] S101: Obtain the pre-set number of teeth on the toothed disc and the height of each arc tooth;

[0117] The number of teeth on the gear disc and the height of the arc-shaped teeth are based on the parameter settings of the water pump turbine.

[0118] S2: In response to the rotation of the spindle, the rotation speed information is obtained through the displacement sensor;

[0119] Step S2 also includes,

[0120] S201: Obtain the first distance information between the first displacement sensor and the main shaft when the main shaft rotates;

[0121] S202: Obtain the second distance information between the second displacement sensor and the arc-shaped teeth of the gear disk when the spindle rotates;

[0122] S203: Calculate the difference between the first distance information and the second distance information to generate rotation speed information;

[0123] The distance and rotation speed information are real-time changing quantities.

[0124] S3: Generate a speed waveform based on the speed information;

[0125] Step S3 also includes,

[0126] S301: Based on the rotational speed information, generate a rotational speed waveform diagram showing the time versus the distance acquired by the sensor;

[0127] The rotational speed waveform uses time as the X-axis, the distance difference between the first and second sensors as the Y-axis, and the slope as the rotational speed.

[0128] Meanwhile, one periodic curve of the rotational speed waveform corresponds to one of the arc-shaped teeth.

[0129] S4: Determine the direction of rotation of the spindle and the gear plate based on the aforementioned speed waveform diagram;

[0130] Step S4 also includes,

[0131] S401: Determine the slope of the speed waveform curve;

[0132] S402: When the slope is positive, the rotation direction of the main shaft and the gear plate is determined to be positive;

[0133] S403: When the slope is negative, it is determined that the rotation direction of the spindle and the gear plate is opposite.

[0134] S5: Obtain the real-time rotational speeds of the spindle and gear plate based on the aforementioned rotational speed waveform.

[0135] Step S5 also includes,

[0136] S501: Obtain the slope of the curve at each moment based on the speed waveform;

[0137] S502: Obtain the real-time rotational speed based on the slope of the curve at each moment.

[0138] In some optional embodiments, the method may further include:

[0139] S601: Determine the height deviation of each of the arc-shaped teeth by means of the rotational speed waveform.

[0140] S602: When the height deviation is determined to exceed the predetermined range, an alarm signal is issued.

[0141] Specifically: The speed precision measurement signal processor collects signals from two sensors in real time. Because these two sensors are arranged at two points on the same axis, the influence of unit sway on the analyzed data can be filtered out by subtracting the data from the two distance measuring sensors. The speed precision measurement signal processor obtains the speed by subtracting the displacement signals acquired by these two sensors.

[0142] like Figure 7 The waveform diagram of rotational speed shown is as follows. When the rotational speed is constant, its shape is a right triangle. When the rotational speed changes, its hypotenuse will become a curve of different shapes depending on the rotational speed, which is called a curvilinear triangle.

[0143] The spindle direction is determined by the increase or decrease of the hypotenuse height, and the real-time rotation speed can be accurately calculated by the rate of change of the hypotenuse height.

[0144] Further integration Figure 8 As shown, the working principle of this method for measuring the speed and direction of rotation of the water pump turbine is as follows:

[0145] After obtaining signals from two displacement sensors through a speed precision measurement signal processor, the two signals are subtracted to obtain the accurate waveform of the unit during rotation. The waveform has a consistent height.

[0146] Based on the number of teeth on the gear disc, the waveform data of one revolution of the unit must first be collected. This is done by rotating the unit more than one revolution in a clockwise direction (generating power) from top to bottom. If there are n gear discs on the unit, then collecting n consecutive complete triangles is sufficient.

[0147] The generator unit's rotation direction is determined by incrementing or decrementing the hypotenuse of n triangular signals. For example, the signal collected at this time is as follows: Figure 7 The data shown shows that the hypotenuse increases and the right-angled side decreases. If the hypotenuse increases in the future, it can be determined that the unit is rotating in the power generation direction.

[0148] The cumulative increase in the height of the hypotenuse in n consecutive complete triangular waveforms is defined as SUM. SUM is the exact figure for the total increase in the height of the hypotenuse of n triangles when the unit rotates 360° (one revolution).

[0149] Theoretically, SUM = n × I (l = the height of each designed tooth). However, due to potential errors in processing and construction, the program needs to correct the value of SUM in real time to ensure that it is always the accurate figure of the total increment of the hypotenuses of n right triangles when the unit rotates 360° (one revolution). An alarm should be triggered if the numerical deviation exceeds 3%, or if the height deviation among the n teeth exceeds 5% (the deviation between any measured l and the initial average I exceeds 5%), and it should be recommended to check the precision speed measurement system, including checking the tooth arrangement and troubleshooting the sensors.

[0150] The total increment of the hypotenuse measured in the most recent second is defined as I. 测速 Therefore, the unit rotated I within the last second. 测速 / SUM circle, through the formula 60×I 测速 / SUM can calculate the number of revolutions per minute of the unit. Then, based on the percentage of the rated speed the current unit is at, it can participate in control.

[0151] Because this method uses the method of accumulating inclined sides, it can accurately measure the unit even if it only rotates within one tooth of the gear disk, thus achieving higher measurement accuracy, especially for determining when the unit is stationary.

[0152] The method for measuring the speed and direction of the pump-turbine provided in this example can accurately measure the direction of rotation of the pump-turbine, avoiding risks such as asynchronous closing caused by incorrect rotation. For speed measurement, the data is calculated from analog signals, allowing for accurate measurement of low speeds and ensuring the accuracy of the unit's absolute stationary signal. This provides precise timing for engaging / disengaging the creepage device and stopping auxiliary equipment. The base waveform is obtained by subtracting the upper and lower distance probes, offsetting errors caused by unit sway and ensuring data reliability. Furthermore, a self-checking function for the speed measuring device is provided, automatically triggering an alarm when the data from a single gear or the total data per revolution deviates from the design value.

[0153] It should be noted that the above description describes some embodiments of this disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0154] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this disclosure (including the claims) is limited to these examples; within the framework of this disclosure, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this disclosure as described above, which are not provided in detail for the sake of brevity.

[0155] This disclosure is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A rotational speed and direction measuring structure of a pump turbine, characterized by, The utility model relates to a kind of water pump water turbine test device, including: Main shaft; Gear disc, sleeve joint on the main shaft, rotate coaxially with the main shaft; A plurality of arc teeth of gradually increasing outer diameter are provided on the gear disc; The radial outer side of the main shaft is equipped with first displacement sensor, and the first displacement sensor is used to obtain the distance between it and the main shaft; The radial outer side of the gear disc is equipped with second displacement sensor, and the second displacement sensor is used to obtain the distance between it and the arc teeth of the gear disc; The first displacement sensor and the second displacement sensor are connected with information processor.

2. The rotational speed and direction of rotation measuring arrangement according to claim 1, characterized in that The first displacement sensor and the second displacement sensor are fixed on the fixed component, and the first displacement sensor and the second displacement sensor are always stationary.

3. The rotational speed and direction of rotation measuring arrangement according to claim 1, characterized in that The distance between the first displacement sensor and the main shaft is equal to the distance between the second displacement sensor and the maximum outer diameter of the gear disc.

4. The rotational speed and direction of rotation measuring arrangement according to claim 1, characterized in that Each arc tooth on the main shaft is connected with each other, and the bottom end of each arc tooth abuts against the top end of adjacent another arc tooth, so that the arc tooth forms a closed loop on the gear disc.

5. The rotational speed and direction of rotation measuring arrangement according to claim 1, characterized in that The first displacement sensor and the second displacement sensor are arranged coaxially up and down, and the axis is parallel to the axial direction of the main shaft.

6. A method of measuring the rotational speed and direction of a pump turbine, characterized by, The utility model relates to a kind of water pump water turbine test device, including: Obtaining the number of teeth and the height of arc tooth of gear disc; When the main shaft rotates, the rotational speed information is obtained by displacement sensor; Rotational speed waveform chart is generated based on the rotational speed information; The rotation direction of the main shaft and the gear disc is determined based on the rotational speed waveform chart; The real-time rotational speed of the main shaft and the gear disc is obtained based on the rotational speed waveform chart.

7. The rotational speed and direction of rotation measuring method according to claim 6, characterized in that, The utility model relates to a kind of water pump water turbine test device, including: Obtaining the number of teeth and the height of arc tooth of gear disc; When the main shaft rotates, the rotational speed information is obtained by displacement sensor; 8. The rotational speed and direction of rotation measuring method according to claim 6, characterized in that, Rotational speed waveform chart is generated based on the rotational speed information; The rotation direction of the main shaft and the gear disc is determined based on the rotational speed waveform chart; The real-time rotational speed of the main shaft and the gear disc is obtained based on the rotational speed waveform chart. The utility model relates to a kind of water pump water turbine test device, including: Obtaining the number of teeth and the height of arc tooth of gear disc; 9. The rotational speed and direction of rotation measuring method according to claim 6, characterized in that, When the main shaft rotates, the rotational speed information is obtained by displacement sensor; Rotational speed waveform chart is generated based on the rotational speed information; The rotation direction of the main shaft and the gear disc is determined based on the rotational speed waveform chart; The real-time rotational speed of the main shaft and the gear disc is obtained based on the rotational speed waveform chart.

10. The rotational speed and direction of rotation measuring method according to claim 6, characterized in that, The utility model relates to a kind of water pump water turbine test device, including: Obtaining the number of teeth and the height of arc tooth of gear disc; When the main shaft rotates, the rotational speed information is obtained by displacement sensor; Rotational speed waveform chart is generated based on the rotational speed information; 11. The rotational speed and direction of rotation measuring method according to claim 6, characterized in that, The rotation direction of the main shaft and the gear disc is determined based on the rotational speed waveform chart; The real-time rotational speed of the main shaft and the gear disc is obtained based on the rotational speed waveform chart. The utility model relates to a kind of water pump water turbine test device, including:

12. The rotational speed and direction of rotation measuring method according to claim 6, characterized in that, Obtaining the number of teeth and the height of arc tooth of gear disc; When the main shaft rotates, the rotational speed information is obtained by displacement sensor; Rotational speed waveform chart is generated based on the rotational speed information; The rotation direction of the main shaft and the gear disc is determined based on the rotational speed waveform chart; The real-time rotational speed of the main shaft and the gear disc is obtained based on the rotational speed waveform chart. The utility model relates to a kind of water pump water turbine test device, including: Obtaining the number of teeth and the height of arc tooth of gear disc; When the main shaft rotates, the rotational speed information is obtained by displacement sensor; Rotational speed waveform chart is generated based on the rotational speed information; The rotation direction of the main shaft and the gear disc is determined based on the rotational speed waveform chart; The real-time rotational speed of the main shaft and the gear disc is obtained based on the rotational speed waveform chart. The utility model relates to a kind of water pump water turbine test device, including: Obtaining the number of teeth and the height of arc tooth of gear disc; When the main shaft rotates, the rotational speed information is obtained by displacement sensor; Rotational speed waveform chart is generated based on the rotational speed information; The rotation direction of the main shaft and the gear disc is determined based on the rotational speed waveform chart; The real-time rotational speed of the main shaft and the gear disc is obtained based on the rotational speed waveform chart. The utility model relates to a kind of water pump water turbine test device, including: Obtaining the number of teeth and the height of arc tooth of gear disc; When the main shaft rotates, the rotational speed information is obtained by displacement sensor; Rotational speed waveform chart is generated based on the rotational speed information; The rotation direction of the main shaft and the gear disc is determined based on the rotational speed waveform chart; The real-time rotational speed of the main shaft and the gear disc is obtained based on the rotational speed waveform chart. The utility model relates to a kind of water pump water turbine test device, including: Obtaining the number of teeth and the height of arc tooth of gear disc; When the main shaft rotates, the rotational speed information is obtained by displacement sensor; Rotational speed waveform chart is generated based on the rotational speed information; The rotation direction of the main shaft and the gear disc is determined based on the rotational speed waveform chart; The real-time rotational speed of the main shaft and the gear disc is obtained based on the rotational speed waveform chart. The utility model relates to a kind of water pump water turbine test device, including: Obtaining the number of teeth and the height of arc tooth of gear disc; When the main shaft rotates, the rotational speed information is obtained by displacement sensor; Rotational speed waveform chart is generated based on the rotational speed information; The rotation direction of the main shaft and the gear disc is determined based on the rotational speed waveform chart; The real-time rotational speed of the main shaft and the gear disc is obtained based on the rotational speed waveform chart. The utility model relates to a kind of water pump water turbine test device, including: Obtaining the number of teeth and the height of arc tooth of gear disc; When the main shaft rotates, the rotational speed information is obtained by displacement sensor; Rotational speed waveform chart is generated based on the rotational speed information; The rotation direction of the main shaft and the gear disc is determined based on the rotational speed waveform chart; The real-time rotational speed of the main shaft and the gear disc is obtained based on the rotational speed waveform chart. The utility model relates to a kind of water pump water turbine test device, including: Obtaining the number of teeth and the height of arc tooth of gear disc; When the main shaft rotates, the rotational speed information is obtained by displacement sensor; Rotational speed waveform chart is generated based on the rotational speed information; The rotation direction of the main shaft and the gear disc is determined based on the rotational speed waveform chart; The real-time rotational speed of the main shaft and the gear disc is obtained based on the rotational speed waveform chart. The utility model relates to a kind of water pump water turbine test device, including: Obtaining the number of teeth and the height of arc tooth of gear disc; When the main shaft rotates, the rotational speed information is obtained by displacement sensor; Rotational speed waveform chart is generated based on the rotational speed information; The rotation direction of the main shaft and the gear disc is determined based on the rotational speed waveform chart; The real-time rotational speed of the main shaft and the gear disc is obtained based on the rotational speed waveform chart. The utility model relates to a kind of water pump water turbine test device, including: Obtaining the number of teeth and the height of arc tooth of gear disc; When the main shaft rotates, the rotational speed information is obtained by displacement sensor; Rotational speed waveform chart is generated based on the rotational speed information; The rotation direction of the main shaft and the gear disc is determined based on the rotational speed waveform chart; The real-time rotational speed of the main shaft and the gear disc is obtained based on the rotational speed waveform chart. The utility model relates to a kind of water pump water turbine test device, including: Obtaining the number of teeth and the height of arc tooth of gear disc; When the main shaft rotates, the rotational speed information is obtained by displacement sensor; Rotational speed waveform chart is generated based on the rotational speed information; The rotation direction of the main shaft and the gear disc is determined based on the rotational speed waveform chart; The real-time rotational speed of the main shaft and the gear disc is obtained based on the rotational speed waveform chart. The utility model relates to a kind of water pump water turbine test device, including: Obtaining the number of teeth and the height of arc tooth of gear disc; When the main shaft rotates, the rotational speed information is obtained by displacement sensor; Rotational speed waveform chart is generated based on the rotational speed information; The rotation direction of the main shaft and the gear disc is determined based on the rotational speed waveform chart; The real-time rotational speed of the main shaft and the gear disc is obtained based on the rotational speed waveform chart. The utility model relates to a kind of water pump water turbine test device, including: Obtaining the number of teeth and the height of arc tooth of gear disc; When the main shaft rotates, the An alarm signal is issued when the height deviation is determined to exceed a predetermined range.

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