A method and system for measuring power of rotating machinery

Abstract

The present invention provides a method and system for measuring the power of rotating machinery. Because the diameter of the outlet pipe of the auxiliary cooling water circulation system is smaller than the volume of the water chamber of a hydraulic dynamometer, even if all the regulating valves on the outlet pipe are open or closed, the speed of adjusting the water volume in the water chamber is limited. Conventional methods of adjusting the regulating valves on the outlet pipe alone cannot meet the requirements for rapid adjustment. The present invention provides a regulating valve on each of the inlet and outlet pipes of the auxiliary cooling water circulation system of the hydraulic dynamometer. When the power equipment being measured has high requirements for the transient operation adjustment speed of the hydraulic dynamometer, the method adopts a method of simultaneously adjusting the two regulating valves on the inlet and outlet pipes of the auxiliary cooling water circulation system. The openings of both regulating valves are controlled by PID control, thereby achieving the purpose of adjusting the water volume in the water chamber as quickly as possible. This method minimizes the hysteresis characteristic of the hydraulic dynamometer's load adjustment and improves its transient operation adjustment speed. Furthermore, a method is provided to improve the operating instability of the hydraulic dynamometer and the inability of PID parameter settings under stable conditions to meet the requirements for rapid transient operation adjustment.

Description

Technical Field

[0001] The present invention belongs to the field of dynamometer of power equipment, and relates to a water brake system for measuring the power of rotating machinery, in particular to a method and system for quickly adjusting the transient operation of a hydraulic dynamometer. Background Art

[0002] Currently, commonly used dynamometers include hydraulic dynamometers, electric dynamometers, inertial dynamometers, torque dynamometers, and magnetic powder dynamometers. Each type of dynamometer has its own unique characteristics. Hydraulic dynamometers, due to their simple structure, low cost, ease of maintenance, high power density, and wide range of applications, are still used to measure the power of various power equipment, especially heavy-duty or high-power engines.

[0003] The hydraulic dynamometer's braking system primarily consists of the dynamometer body and an auxiliary cooling water circulation system. The body comprises three main components: the main shaft, stator, and rotor attached to the main shaft. Recesses in the stator and rotor form a water chamber, and the auxiliary cooling water circulation system ensures water supply and drainage. The power output shaft of the power equipment being tested is connected to the rotor attached to the main shaft of the hydraulic dynamometer. When the power equipment being tested drives the rotor and stator of the hydraulic dynamometer to rotate relative to each other, pressurized cooling water flows through the holes in the stator into the water chamber, causing the rotor to cause the water inside the chamber to rotate violently. Due to friction and impact between the cooling water and the surface of the water chamber, mechanical energy is transferred from the rotor to the stator through the cooling water, converting it into heat energy. Simultaneously, the relative motion between the cooling water and the stator generates a braking torque, causing the hydraulic dynamometer housing to swing about its fulcrum. This braking torque is transmitted via a lever arm to a tension and pressure sensor, enabling the measurement of the torque, speed, and power of the power equipment being tested. Finally, the cooling water is discharged through the annular gap between the outer edges of the stator and rotor of the hydraulic dynamometer.

[0004] From the operating principle, the braking torque of a hydraulic dynamometer is controlled by the amount of cooling water in the water chamber. The greater the water volume in the water chamber, the thicker the water layer formed between the rotor and stator during rotation, and the greater the braking torque. The amount of water in the water chamber depends on the cooling water flow rates at the inlet and outlet. This characteristic determines two shortcomings during the operation of the hydraulic dynamometer: First, the measurement accuracy of the hydraulic dynamometer is affected by the cooling water flow rate. Even small changes in the water volume in the water chamber will cause torque changes, making it difficult to achieve a constant speed, resulting in poor stability and affecting the stability and accuracy of the measurement data. Second, the hydraulic dynamometer's braking characteristics are lagging. Due to the poor water volume regulation ability in the water chamber and the time required for water volume changes, the hydraulic dynamometer's braking torque or speed changes slowly, resulting in slow adjustment speed in transient operation, affecting the test dynamic performance. Typically, to improve the stability of a hydraulic dynamometer, the load braking torque of the power equipment being tested is controlled via a flow control valve installed at the water chamber outlet. The cooling water pressure at the inlet is maintained stable by a high-level water tank. However, due to the hysteresis of the outlet flow control valve, the hydraulic dynamometer's transient regulation performance is poor, resulting in speed overshoot or oscillation. Therefore, hydraulic dynamometers are more suitable for steady-state testing of power equipment, where steady-state speed regulation accuracy and transient regulation capabilities are less demanding. Summary of the Invention

[0005] (1) Purpose of the invention

[0006] To address the aforementioned shortcomings and deficiencies of the prior art and to maximize the transient operation adjustment speed of a hydraulic dynamometer while ensuring stable operation, the present invention provides a method and system for measuring the power of rotating machinery. Because the diameter of the outlet pipe of the auxiliary cooling water circulation system is smaller than the volume of the hydraulic dynamometer's water chamber, even if all the regulating valves on the outlet pipe are open or closed, the speed at which the water volume in the water chamber can be adjusted is limited. The present invention provides a regulating valve on each of the inlet and outlet pipes of the hydraulic dynamometer's auxiliary cooling water circulation system. When the power equipment being measured has high requirements for the transient operation adjustment speed of the hydraulic dynamometer, the two regulating valves on the inlet and outlet pipes of the auxiliary cooling water circulation system are simultaneously adjusted. The openings of both regulating valves are controlled using PID control, thereby achieving the fastest possible adjustment of the water volume in the water chamber. This minimizes the hysteresis characteristic of the hydraulic dynamometer's load adjustment and improves its transient operation adjustment speed. Furthermore, since there are no relevant standards for hydraulic dynamometer design, commissioning, and operation in the prior art, the present invention also provides a specific commissioning method.

[0007] (2) Technical solution

[0008] In order to achieve the purpose of the invention and solve the corresponding technical problems, the present invention adopts the following technical solutions:

[0009] A rapid adjustment system for transient operation of a hydraulic dynamometer comprises at least a hydraulic dynamometer and a measured power device connected to the hydraulic dynamometer by transmission, wherein the speed and / or braking torque of the hydraulic dynamometer are determined according to the output speed and / or power of the measured power device, and is characterized in that:

[0010] The hydraulic dynamometer at least comprises a hydraulic dynamometer body and an auxiliary cooling water circulation system adapted to the hydraulic dynamometer body, wherein:

[0011] The hydraulic dynamometer body comprises at least a dynamometer stator in an overall annular shape and a dynamometer rotor disposed on a main shaft. The dynamometer rotor is coaxially disposed within the dynamometer stator, and an array of pits are disposed on the inner wall surface of the dynamometer stator and the outer wall surface of the dynamometer rotor. The annular gap between the dynamometer stator and the dynamometer rotor and the pits on the surfaces of both form a dynamometer water cavity.

[0012] The auxiliary cooling water circulation system includes at least a high-level water tank, a hot water pool, a cooling tower, and a cold water pool, wherein the high-level water tank is arranged at a height higher than the hydraulic dynamometer, and the high-level water tank is connected to the inlet of the dynamometer water cavity through a water inlet pipe, the hot water pool is connected to the outlet of the dynamometer water cavity through a water outlet pipe, the hot water pool is connected to the cold water pool through a cooling tower, and a first water circulation pump is provided on the connecting pipe between the hot water pool and the cooling tower, and the cold water pool is connected to the high-level water tank through a connecting pipe provided with a second water circulation pump,

[0013] At least one water inlet regulating valve is provided on the water inlet pipeline, and at least one water outlet regulating valve is provided on the water outlet pipeline, and the water inlet regulating valve and the water outlet regulating valve are respectively provided with a PID controller. The openings of the water inlet regulating valve and the water outlet regulating valve are simultaneously adjusted by the two PID controllers to quickly adjust the water volume in the dynamometer water chamber, and the response speed of the water inlet regulating valve and the water outlet regulating valve is changed by adjusting the PID parameter settings of the two PID controllers to match the transient characteristics of the hydraulic dynamometer operation.

[0014] Preferably, the main shaft of the hydraulic dynamometer is connected to the power output shaft of the power equipment to be measured through a gear box.

[0015] Preferably, under the condition that the rotational speed of the power equipment under test remains unchanged, in order to improve the adjustment speed of the transient operation of the hydraulic dynamometer, if the load of the power equipment under test increases, the opening of the water inlet regulating valve is increased, and the opening of the water outlet regulating valve is reduced, so that the amount of water in the water chamber of the dynamometer increases rapidly, thereby quickly increasing the braking torque of the hydraulic dynamometer; if the load of the power equipment under test decreases, the opening of the water inlet regulating valve is reduced, and the opening of the water outlet regulating valve is increased, so that the amount of water in the water chamber of the dynamometer decreases rapidly, thereby quickly reducing the braking torque of the hydraulic dynamometer.

[0016] Preferably, under the condition that the braking torque of the hydraulic dynamometer remains unchanged, in order to improve the adjustment speed of the transient operation of the hydraulic dynamometer, if the load of the power equipment under test increases, the opening of the water inlet regulating valve is increased, and the opening of the water outlet regulating valve is reduced, so that the amount of water in the water cavity of the dynamometer increases rapidly, thereby quickly reducing the speed of the hydraulic dynamometer; if the load of the power equipment under test decreases, the opening of the water inlet regulating valve is reduced, and the opening of the water outlet regulating valve is increased, so that the amount of water in the water cavity of the dynamometer decreases rapidly, thereby quickly increasing the speed of the hydraulic dynamometer.

[0017] Preferably, when the output speed and / or torque of the power equipment under test is below the set value, the control strategy of the water inlet regulating valve is open-loop control. First, the initial opening of the water inlet regulating valve is set to the minimum opening to ensure that there is always a certain amount of cooling water in the water chamber of the dynamometer. As the output speed and / or torque of the power equipment under test gradually increases, the opening of the water inlet regulating valve is gradually increased to increase the cooling water flow entering the water chamber of the dynamometer; the control strategy of the water outlet regulating valve is closed-loop control, and its opening is adjusted according to the speed and / or braking torque of the hydraulic dynamometer to control the discharge amount of cooling water.

[0018] Furthermore, the water inlet pipeline is provided with at least one flow meter and one pressure gauge, and the flow meter is used to monitor the actual flow of cooling water in the water inlet pipeline. If the flow is too low, the opening of the water inlet regulating valve is increased to increase the flow of cooling water.

[0019] Furthermore, the water inlet pipeline is provided with at least one pressure gauge, and the pressure gauge is used to monitor the water pressure of the cooling water in the water inlet pipeline to ensure that the cooling water is sufficient to meet the requirements of the hydraulic dynamometer.

[0020] Furthermore, the outlet pipe is provided with at least one pressure gauge and one temperature gauge, which are used to monitor the pressure and temperature of the discharged cooling water respectively to ensure the accuracy of the control and ensure that the outlet water temperature does not exceed the allowable range.

[0021] Furthermore, when the output speed and / or torque of the tested power equipment is below a set value, the water inlet regulating valve and the water outlet regulating valve are adjusted according to the following steps:

[0022] SS1. First, set the initial opening of the water inlet regulating valve to the minimum opening and ensure that the water flow and pressure of the water inlet pipe are within the preset range;

[0023] SS2. Gradually increase the opening of the water inlet regulating valve as the output speed and / or torque of the tested power equipment increases to increase the cooling water flow rate entering the dynamometer water chamber. The opening of the water inlet regulating valve is adjusted as appropriate based on feedback from the flowmeter and pressure gauge installed in the water inlet pipeline.

[0024] SS3. Based on the output speed and / or torque of the tested power equipment, the opening of the water outlet regulating valve is controlled according to the speed and / or braking torque of the hydraulic dynamometer to accurately control the discharge of cooling water;

[0025] SS4. Monitor the pressure and temperature of the discharged cooling water based on the feedback information from the pressure gauge and temperature gauge on the outlet pipe to ensure that the discharged water volume does not affect the cooling effect.

[0026] The working principle of the rapid adjustment system for transient operation of the hydraulic dynamometer of the present invention is as follows:

[0027] The present invention increases the speed of regulating the water volume in the water chamber by adding a regulating valve to the inlet pipe of the auxiliary cooling water circulation system. If, under given rotational speed conditions, a faster regulating speed is required for transient operation of the hydraulic dynamometer, when the load of the tested power equipment is increased, the opening of the regulating valve on the inlet pipe of the auxiliary cooling water circulation system is simultaneously increased, and the opening of the regulating valve on the outlet pipe of the auxiliary cooling water circulation system is simultaneously decreased, so that the water volume in the water chamber increases rapidly, thereby achieving a rapid increase in braking torque. When the load of the tested power equipment is reduced, the opening of the regulating valve on the inlet pipe of the auxiliary cooling water circulation system is simultaneously decreased, and the opening of the regulating valve on the outlet pipe of the auxiliary cooling water circulation system is increased, so that the water volume in the water chamber decreases rapidly, thereby achieving a rapid decrease in braking torque. If under given braking torque conditions, the transient operation adjustment speed of the hydraulic dynamometer is required to be faster, when the power equipment under test increases the load, the opening of the regulating valve on the water inlet of the auxiliary cooling water circulation system is increased and the opening of the regulating valve on the water outlet of the auxiliary cooling water circulation system is reduced, so that the water volume in the water cavity increases rapidly, thereby achieving a rapid reduction in speed; when the power equipment under test reduces the load, the opening of the regulating valve on the water inlet of the auxiliary cooling water circulation system is reduced and the opening of the regulating valve on the water outlet of the auxiliary cooling water circulation system is increased, so that the water volume in the water cavity decreases rapidly, thereby achieving a rapid increase in speed.

[0028] The above-mentioned rapid adjustment system for transient operation of a hydraulic dynamometer of the present invention realizes rapid adjustment of the transient operation of the hydraulic dynamometer, but has the following two problems: First, since the openings of the regulating valves on the inlet and outlet pipes of the auxiliary cooling water circulation system are adjusted simultaneously, this will lead to poor operating stability of the hydraulic dynamometer and severe speed overshoot or oscillation. This is mainly because the pressure in the water chamber is unstable and even slight changes in the water volume will cause changes in torque, making it difficult to obtain a constant speed. Second, since the speed of change of the water volume in the water chamber mainly depends on the response speed of the regulating valves on the inlet and outlet pipes of the auxiliary cooling water circulation system controlled by the PID, the PID parameter setting under stable conditions may not meet the requirements for rapid adjustment of the water volume in the water chamber during the transient operation of the hydraulic dynamometer.

[0029] Preferably, the water volume in the water chamber of the dynamometer is adjusted by the water inlet regulating valve using PID closed-loop or open-loop control, and when the measured parameters, braking torque or speed, do not reach the set value, the adjustment of the water inlet regulating valve is stopped, or the opening of the water inlet regulating valve is directly increased to the maximum or minimum allowable value to improve the working instability of the hydraulic dynamometer.

[0030] Furthermore, when the output torque of the tested power equipment exceeds the set value but its output speed does not exceed the set value, the braking torque of the hydraulic dynamometer cannot meet the requirement, and it is necessary to enter the trans-critical speed mode for adjustment. At this time, the water inlet regulating valve adopts a PID closed-loop adjustment method, and the water volume in the dynamometer water chamber is jointly controlled by the regulating valves on the water inlet pipe and the water outlet pipe, so that the speed of the hydraulic dynamometer reaches the critical speed. After that, the opening of the water inlet regulating valve is kept unchanged, and only the water outlet of the dynamometer water chamber is adjusted by the water outlet regulating valve to control the speed, thereby accelerating the speed change across the critical speed area until the set speed is reached and the adjustment is ended.

[0031] Preferably, according to the operating parameters of the power equipment under test, the PID parameter settings of the two PID controllers are adjusted to change the response speed of the opening of the water inlet regulating valve and the water outlet regulating valve, so that their dynamic characteristics are best matched with the transient characteristics of the hydraulic dynamometer.

[0032] Furthermore, the parameter settings of the PID controllers of the water inlet regulating valve and the water outlet regulating valve are adjusted according to the following methods and steps:

[0033] SS1 set target value: according to the operating parameters of the measured power equipment to set the corresponding target value of the hydraulic dynamometer;

[0034] SS2 record actual value: record the auxiliary cooling water circulation system, the water inlet regulating valve, the actual opening value of the water outlet regulating valve, the actual water value of the dynamometer water chamber;

[0035] SS3. Compare the target value with the actual value: Compare the set target value with the actual value, analyze the error between the two, and determine whether it is necessary to adjust the parameter settings of the two PID controllers;

[0036] SS4. Adjust PID parameters: Based on the error analysis results, gradually adjust the parameter settings of the two PID controllers, including at least the proportional coefficient, integral time, and differential time, so that the error between the target value and the actual value is as small as possible;

[0037] SS5. Repeat until satisfied: Repeat the above steps until the error between the target value and the actual value is less than the set threshold.

[0038] In addition, as the second invention object of the present invention, the present invention further proposes a method for improving the working instability of a hydraulic dynamometer and meeting the requirements of transient rapid adjustment. The rapid adjustment system for transient operation of the hydraulic dynamometer of the present invention is characterized in that:

[0039] Under the condition that the output speed of the power equipment under test remains unchanged, in order to improve the adjustment speed of the transient operation of the hydraulic dynamometer, if the output load of the power equipment under test increases, the opening of the water inlet regulating valve is increased, and the opening of the water outlet regulating valve is reduced, so that the amount of water in the water chamber of the dynamometer increases rapidly, thereby quickly increasing the braking torque of the hydraulic dynamometer; if the output load of the power equipment under test decreases, the opening of the water inlet regulating valve is reduced, and the opening of the water outlet regulating valve is increased, so that the amount of water in the water chamber of the dynamometer decreases rapidly, thereby quickly reducing the braking torque of the hydraulic dynamometer;

[0040] Under the condition that the braking torque of the hydraulic dynamometer remains unchanged, in order to improve the adjustment speed of the transient operation of the hydraulic dynamometer, if the output load of the power equipment under test increases, the opening of the water inlet regulating valve is increased, and the opening of the water outlet regulating valve is reduced, so that the water volume in the water cavity of the dynamometer increases rapidly, thereby quickly reducing the rotational speed of the hydraulic dynamometer; if the output load of the power equipment under test decreases, the opening of the water inlet regulating valve is reduced, and the opening of the water outlet regulating valve is increased, so that the water volume in the water cavity of the dynamometer decreases rapidly, thereby quickly increasing the rotational speed of the hydraulic dynamometer.

[0041] Preferably, when the output speed and / or torque of the power equipment under test is below the set value, the control strategy of the water inlet regulating valve is open-loop control. First, the initial opening of the water inlet regulating valve is set to the minimum opening to ensure that there is always a certain amount of cooling water in the water chamber of the dynamometer. As the output speed and / or torque of the power equipment under test gradually increases, the opening of the water inlet regulating valve is gradually increased to increase the cooling water flow entering the water chamber of the dynamometer; the control strategy of the water outlet regulating valve is closed-loop control, and its opening is adjusted according to the speed and / or braking torque of the hydraulic dynamometer to control the discharge amount of cooling water.

[0042] Preferably, when the output speed and / or torque of the tested power equipment is below a set value, the water inlet regulating valve and the water outlet regulating valve are adjusted according to the following steps:

[0043] SS1. First, set the initial opening of the water inlet regulating valve to the minimum opening and ensure that the water flow and pressure of the water inlet pipe are within the preset range;

[0044] SS2. Gradually increase the opening of the water inlet regulating valve as the output speed and / or torque of the tested power equipment increases to increase the cooling water flow rate entering the dynamometer water chamber. The opening of the water inlet regulating valve is adjusted as appropriate based on feedback from the flowmeter and pressure gauge installed in the water inlet pipeline.

[0045] SS3. Based on the output speed and / or torque of the power equipment under test, the opening of the water outlet regulating valve is controlled according to the speed and / or braking torque of the hydraulic dynamometer to accurately control the discharge amount of cooling water.

[0046] Preferably, the water volume in the water chamber of the dynamometer is adjusted by the water inlet regulating valve using PID closed-loop or open-loop control, and when the measured parameters, braking torque or speed, do not reach the set value, the adjustment of the water inlet regulating valve is stopped, or the opening of the water inlet regulating valve is directly increased to the maximum or minimum allowable value to improve the working instability of the hydraulic dynamometer.

[0047] Furthermore, when the output torque of the tested power equipment exceeds the set value but its output speed does not exceed the set value, the braking torque of the hydraulic dynamometer cannot meet the requirement, and it is necessary to enter the trans-critical speed mode for adjustment. At this time, the water inlet regulating valve adopts a PID closed-loop adjustment method, and the water volume in the dynamometer water chamber is jointly controlled by the regulating valves on the water inlet pipe and the water outlet pipe, so that the speed of the hydraulic dynamometer reaches the critical speed. After that, the opening of the water inlet regulating valve is kept unchanged, and only the water outlet of the dynamometer water chamber is adjusted by the water outlet regulating valve to control the speed, thereby accelerating the speed change across the critical speed area until the set speed is reached and the adjustment is ended.

[0048] Preferably, according to the operating parameters of the power equipment under test, the PID parameter settings of the two PID controllers are adjusted to change the response speed of the opening of the water inlet regulating valve and the water outlet regulating valve, so that their dynamic characteristics are best matched with the transient characteristics of the hydraulic dynamometer.

[0049] Furthermore, the parameter settings of the PID controllers of the water inlet regulating valve and the water outlet regulating valve are adjusted according to the following methods and steps:

[0050] SS1 set target value: according to the operating parameters of the measured power equipment to set the corresponding target value of the hydraulic dynamometer;

[0051] SS2 record actual value: record the auxiliary cooling water circulation system, the water inlet regulating valve, the actual opening value of the water outlet regulating valve, the actual water value of the dynamometer water chamber;

[0052] SS3. Compare the target value with the actual value: Compare the set target value with the actual value, analyze the error between the two, and determine whether it is necessary to adjust the parameter settings of the two PID controllers;

[0053] SS4. Adjust PID parameters: Based on the error analysis results, gradually adjust the parameter settings of the two PID controllers, including at least the proportional coefficient, integral time, and differential time, so that the error between the target value and the actual value is as small as possible;

[0054] SS5. Repeat until satisfied: Repeat the above steps until the error between the target value and the actual value is less than the set threshold.

[0055] The present invention provides a method for improving the operational instability of a hydraulic dynamometer and ensuring rapid transient regulation. The method operates as follows: To address the operational instability of the hydraulic dynamometer and the inability of PID parameter settings under stable conditions to meet rapid transient regulation, the present invention utilizes PID closed-loop or open-loop control on the regulating valves in the auxiliary cooling water circulation system's inlet pipe. When the controlled parameters, braking torque or speed, do not reach a set value, the regulating valves in the auxiliary cooling water circulation system's inlet pipe are stopped from being adjusted, or the opening of the regulating valves in the auxiliary cooling water circulation system's inlet pipe is directly increased to the maximum or minimum allowable value. The water volume in the water chamber is then regulated solely by adjusting the regulating valves in the auxiliary cooling water circulation system's outlet pipe, thereby improving the operational instability of the hydraulic dynamometer. Based on the operating parameters of the power equipment being tested, the PID parameter settings are adjusted to change the response speed of the regulating valves in the auxiliary cooling water circulation system's inlet and outlet pipes, ensuring that the dynamic characteristics of the regulating valves in the auxiliary cooling water circulation system's inlet and outlet pipes optimally match the transient characteristics of the hydraulic dynamometer under certain operating parameters.

[0056] (3) Technical effects

[0057] Compared with the prior art, the method and system for rapid adjustment of transient operation of a hydraulic dynamometer of the present invention have the following beneficial and significant technical effects:

[0058] (1) The present invention adds a regulating valve to the water inlet pipe of the auxiliary cooling water circulation system, and jointly regulates the water volume in the water chamber through the regulating valves on the water inlet and outlet pipes of the auxiliary cooling water circulation system, so as to quickly and effectively regulate the load and speed of the hydraulic dynamometer, thereby improving the regulation speed and working efficiency of the transient operation of the hydraulic dynamometer and effectively reducing the oscillation or overshoot of the system.

[0059] (2) The present invention uses PID closed-loop or open-loop control through the regulating valve on the water inlet pipe of the auxiliary cooling water circulation system: for closed-loop control, when the adjusted parameter braking torque or speed does not reach the set value, the adjustment is stopped, and then the water volume in the water chamber is adjusted only by adjusting the regulating valve on the water outlet pipe of the auxiliary cooling water circulation system; for open-loop control, the opening of the regulating valve on the water inlet pipe of the auxiliary cooling water circulation system can be directly increased to the maximum or minimum allowable value, thereby improving the working stability of the hydraulic dynamometer.

[0060] (3) The present invention aims at the operating parameters of the working condition of the power equipment to be tested, and changes the response speed of the regulating valve on the inlet and outlet pipes of the auxiliary cooling water circulation system by adjusting the PID parameters, so that the dynamic characteristics of the regulating valve on the inlet and outlet pipes of the auxiliary cooling water circulation system are optimally matched with the transient characteristics of the hydraulic dynamometer operation, thereby improving the problem of poor regulating performance of the regulating valve restricting the regulating speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 The figure is a schematic diagram of a rapid adjustment system for transient operation of a hydraulic dynamometer;

[0062] Figure 2 is the characteristic curve of a hydraulic dynamometer;

[0063] Figure 3 Schematic diagram of the transcritical speed mode control method.

[0064] Description of reference numerals:

[0065] 1- high-speed power turbine, 2- gearbox, 3- hydraulic dynamometer, 4- high-level water tank, 5- water inlet regulating valve, 6- water inlet pipeline, 7- flow meter, 8- pressure gauge, 9- hot water tank, 10- water outlet pipeline, 11- water outlet regulating valve, 12- pressure gauge, 13- temperature gauge, 14- first water circulation pump, 15- cooling tower, 16- cold water tank, 17- second water circulation pump. DETAILED DESCRIPTION

[0066] In order to better understand the present invention, the contents of the present invention are further explained in conjunction with the embodiments below. In the accompanying drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be understood as limiting the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The structure and technical solution of the present invention are further described in detail below in conjunction with the accompanying drawings, and an embodiment of the present invention is given.

[0067] like Figure 1 As shown, the rapid adjustment system for transient operation of a hydraulic dynamometer of the present invention includes at least a hydraulic dynamometer 3 and a power device under test that is transmission-connected to the hydraulic dynamometer 3 (in this embodiment, the power device under test is a high-speed power turbine 1 provided in a megawatt-class supercritical carbon dioxide power generation system, and the main shaft of the hydraulic dynamometer 3 is transmission-connected to the power output shaft of the power device under test via a gearbox 2). The rotational speed and / or braking torque of the hydraulic dynamometer 3 are determined based on the output rotational speed and / or power of the power device under test).

[0068] The hydraulic dynamometer 3 includes at least a hydraulic dynamometer body and an auxiliary cooling water circulation system adapted to the hydraulic dynamometer body. The hydraulic dynamometer body includes at least an overall annular dynamometer stator and a dynamometer rotor arranged on a main shaft. The dynamometer rotor is coaxially arranged in the dynamometer stator, and an array of pits are arranged on the inner wall surface of the dynamometer stator and the outer wall surface of the dynamometer rotor. The annular gap between the dynamometer stator and the dynamometer rotor and the pits on the surfaces of both form a dynamometer water cavity. The auxiliary cooling water circulation system includes at least a high-level water tank 4, a hot water pool 9, a cooling tower 15, and a cold water pool 16. The high-level water tank 4 is set higher than the hydraulic dynamometer, and the high-level water tank 4 is connected to the inlet of the dynamometer water cavity through a water inlet pipe 6. The hot water pool 9 is connected to the outlet of the dynamometer water cavity through a water outlet pipe 10. The hot water pool 9 is connected to the cold water pool 16 through a cooling tower 15. The connecting pipe between the hot water pool 9 and the cooling tower 15 is provided with a first water circulation pump 14. The cold water pool 16 is connected to the cold water pool 16 through a connecting pipe provided with a second water circulation pump 17. The through pipeline is connected to the high-level water tank 4. At least one water inlet regulating valve 5 is provided on the water inlet pipeline 6, and at least one water outlet regulating valve 11 is provided on the water outlet pipeline 10. The water inlet regulating valve 5 and the water outlet regulating valve 11 are respectively provided with a PID controller. The openings of the water inlet regulating valve 5 and the water outlet regulating valve 11 are simultaneously adjusted by the two PID controllers to quickly adjust the water volume in the dynamometer water chamber. The response speed of the water inlet regulating valve 5 and the water outlet regulating valve 11 is changed by adjusting the PID parameter settings of the two PID controllers to match the transient characteristics of the hydraulic dynamometer operation.

[0069] When the rapid adjustment system for transient operation of the hydraulic dynamometer of the present invention is in operation, under the condition that the rotational speed of the power equipment being measured remains unchanged, in order to improve the adjustment speed of transient operation of the hydraulic dynamometer 3, if the load of the power equipment being measured increases, the opening of the water inlet regulating valve 5 is increased, and the opening of the water outlet regulating valve 11 is reduced, so that the amount of water in the water cavity of the dynamometer is rapidly increased, thereby rapidly increasing the braking torque of the hydraulic dynamometer 3; if the load of the power equipment being measured decreases, the opening of the water inlet regulating valve 5 is reduced, and the opening of the water outlet regulating valve 11 is increased, so that the amount of water in the water cavity of the dynamometer is rapidly reduced, thereby rapidly reducing the braking torque of the hydraulic dynamometer 3. In addition, under the condition that the braking torque of the hydraulic dynamometer 3 remains unchanged, in order to improve the adjustment speed of the transient operation of the hydraulic dynamometer 3, if the load of the power equipment under test increases, the opening of the water inlet regulating valve 5 is increased, and the opening of the water outlet regulating valve 11 is reduced, so that the water volume in the dynamometer water chamber increases rapidly, thereby quickly reducing the rotational speed of the hydraulic dynamometer 3; if the load of the power equipment under test decreases, the opening of the water inlet regulating valve 5 is reduced, and the opening of the water outlet regulating valve 11 is increased, so that the water volume in the dynamometer water chamber decreases rapidly, thereby quickly increasing the rotational speed of the hydraulic dynamometer 3.

[0070] In a preferred embodiment of the present invention, when the output speed and / or torque of the power equipment under test is below the set value, the control strategy of the water inlet regulating valve 5 is open-loop control. First, the initial opening of the water inlet regulating valve 5 is set to the minimum opening to ensure that there is always a certain amount of cooling water in the dynamometer water chamber. As the output speed and / or torque of the power equipment under test gradually increases, the opening of the water inlet regulating valve 5 is gradually increased to increase the cooling water flow rate entering the dynamometer water chamber; the control strategy of the water outlet regulating valve 11 is closed-loop control, and its opening is adjusted according to the speed and / or braking torque of the hydraulic dynamometer 3 to control the discharge amount of cooling water.

[0071] In a further embodiment of the present invention, the water inlet pipe 6 is further provided with at least one flow meter 7 and one pressure gauge 8. Flow meter 7 is used to monitor the actual flow rate of cooling water in the water inlet pipe. If the flow rate is too low, the opening of the water inlet regulating valve 5 is increased to increase the cooling water flow rate. Pressure gauge 8 is used to monitor the water pressure of the cooling water in the water inlet pipe to ensure that the cooling water is sufficient to meet the requirements of the hydraulic dynamometer 3. The water outlet pipe 10 is further provided with at least one pressure gauge 12 and one temperature gauge 13. Pressure gauge 12 and temperature gauge 13 are respectively used to monitor the pressure and temperature of the discharged cooling water to ensure control accuracy and ensure that the outlet water temperature does not exceed the allowable range.

[0072] In a further embodiment of the present invention, when the output speed and / or torque of the power equipment under test is below the set value, the water inlet regulating valve 5 and the water outlet regulating valve 11 are adjusted according to the following steps:

[0073] SS1. First, set the initial opening of the water inlet regulating valve 5 to the minimum opening and ensure that the water flow and pressure of the water inlet pipe are within the preset range;

[0074] SS2. As the output speed and / or torque of the tested power equipment increases, gradually increase the opening of the water inlet regulating valve 5 to increase the cooling water flow into the dynamometer water chamber. The opening of the water inlet regulating valve 5 is adjusted appropriately based on feedback from the flowmeter 7 and pressure gauge 8 installed on the water inlet line 6.

[0075] SS3. Based on the output speed and / or torque of the power equipment being tested, the opening of the water regulating valve 11 is controlled according to the speed and / or braking torque of the hydraulic dynamometer 3 to precisely control the discharge of cooling water;

[0076] SS4. Monitor the pressure and temperature of the discharged cooling water according to the feedback information from the pressure gauge and temperature gauge 13 on the outlet pipe 10 to ensure that the discharged water volume does not affect the cooling effect.

[0077] In a preferred embodiment of the present invention, the water amount in the water chamber of the dynamometer is adjusted by using a PID closed-loop or open-loop control method through the water inlet regulating valve 5, and when the measured parameters, braking torque or speed, do not reach the set value, the adjustment of the water inlet regulating valve 5 is stopped, or the opening of the water inlet regulating valve 5 is directly increased to the maximum or minimum allowable value to improve the working instability of the hydraulic dynamometer.

[0078] In a further example of the present invention, when the output torque of the power equipment under test exceeds the set value but its output speed does not exceed the set value, the braking torque of the hydraulic dynamometer cannot meet the requirements, and it is necessary to enter the trans-critical speed mode for adjustment. At this time, the water inlet regulating valve 5 adopts a PID closed-loop adjustment method, and the water volume in the dynamometer water chamber is jointly controlled by the regulating valves on the water inlet pipe and the water outlet pipe, so that the speed of the hydraulic dynamometer reaches the critical speed. After that, the opening of the water inlet regulating valve 5 is kept unchanged, and only the water outlet of the dynamometer water chamber is adjusted by the water outlet regulating valve 11 to control the speed, thereby accelerating the speed change across the critical speed area until the set speed is reached and the adjustment is ended.

[0079] More specifically, Figures 1 to 3 As shown, during the testing of a megawatt-class supercritical CO2 power generation system, a hydraulic dynamometer 3 was used to measure the output power of a high-speed power turbine 1. If the main shaft of high-speed power turbine 1 utilizes a non-rigid shaft, the rotor speed must quickly cross the critical speed to ensure operational stability. Given a given braking torque, the hydraulic dynamometer requires a sufficiently fast adjustment speed during transient operation to quickly cross the critical speed range. Otherwise, prolonged operation at the critical speed will cause strong rotor resonance, leading to serious consequences.

[0080] like Figure 1As shown, a high-speed power turbine 1 is connected to a hydraulic dynamometer 3 via a shaft with a gearbox 2. When the turbine is generating power, it drives the main shaft of the hydraulic dynamometer 3 to rotate, and cooling water enters the water chamber of the hydraulic dynamometer 3 from a high-level water tank 4. The opening of the water inlet regulating valve 5, located on the water inlet line 6, gradually increases as the throttle is increased. At this time, the opening of the water inlet regulating valve 5 on the water inlet line 6 is regulated in an open-loop manner. The opening of the water inlet regulating valve 5 is set to a minimum to ensure that a certain amount of cooling water is always present in the water chamber. A flow meter 7 and a pressure gauge 8 are provided on the water inlet line 6 to measure the flow rate and pressure of the cooling water, respectively. The cooling water inside the water chamber of the hydraulic dynamometer 3 rotates vigorously due to the agitation of the rotor. During this process, mechanical energy is transferred from the rotor to the stator through the cooling water and converted into heat energy. Simultaneously, the rotating water layer, with a certain thickness, drives the housing of the hydraulic dynamometer 3 to oscillate, transmitting torque and rotational speed to the tension and pressure sensors and rotational speed sensor, respectively. These signals are converted into voltage signals and sent to the detection and control instrumentation for reading, ultimately measuring the turbine's output power, torque, and rotational speed. Cooling water, now at a certain temperature, then drains into the hot water reservoir 9. The amount of water discharged is controlled by a regulating valve 11 on the outlet pipe 10. This valve 11 utilizes a closed-loop regulation system, with the amount of water discharged depending on the throttle position and the rotational speed or braking torque of the hydraulic dynamometer 3. A pressure gauge 12 and a thermometer 13 are installed on the outlet pipe 10 to measure the pressure and temperature of the discharged cooling water, respectively. The outlet cooling water temperature must not exceed the permitted value. The discharged cooling water is cooled to a certain temperature in the cooling tower 15 by a first water circulation pump 14 before entering the cold water reservoir 16. It then passes through a second water circulation pump 17 and returns to the overhead water tank 4, completing a complete cycle.

[0081] When the output of high-speed power turbine 1 reaches a certain value, if it falls below the critical speed, the braking torque of hydraulic dynamometer 3 cannot meet the required value. At this point, the speed of high-speed power turbine 1 must cross the critical speed, and hydraulic dynamometer 3 transiently enters transcritical speed mode. Transcritical speed mode is characterized by the PID closed-loop control of the opening of control valve 5 on the water inlet pipe 6. The water volume in the water chamber is controlled by both control valve 5 on the water inlet pipe 6 and control valve 11 on the water outlet pipe 10.

[0082] Taking a domestic hydraulic dynamometer as an example, the characteristic curve of the hydraulic dynamometer is shown in Figure 2The critical speed of high-speed power turbine 1 is between 1750 and 2250 rpm. When turbine 1 outputs 1500 kW, the hydraulic dynamometer 3 is required to rapidly cross from 1750 rpm to 2250 rpm at maximum torque. Here, the speed setting value is set to be slightly greater than the upper limit of the critical speed range, 2300 rpm. By jointly controlling the regulating valve 5 on the water inlet pipe 6 and the regulating valve 11 on the water outlet pipe 10, when the speed of the hydraulic dynamometer reaches 2250 rpm, the opening of the regulating valve 5 on the water inlet pipe 6 remains unchanged. Only the regulating valve 11 on the water outlet pipe 10 is used to adjust the water flow in the water chamber to control the speed. When the speed reaches 2300 rpm, the transcritical speed mode adjustment ends.

[0083] In transcritical speed mode, the rate of change in the water volume within the water chamber of hydraulic dynamometer 3 is primarily determined by the PID control of the opening response speed of water inlet regulating valve 5 on the inlet pipe 6 and water outlet regulating valve 11 on the outlet pipe 10 of the auxiliary cooling water circulation system. However, the PID parameter settings under stable conditions may not meet the requirements for rapid water volume regulation within the water chamber during transient operation of hydraulic dynamometer 3. Therefore, it is necessary to improve the regulation performance of regulating valve 5 on the inlet pipe 6 and regulating valve 11 on the outlet pipe 10 of the cooling water circulation system during transient operation by adjusting the PID parameter settings.

[0084] Transcritical speed mode control method see Figure 3 Before entering transcritical speed mode, repeatedly adjust the PID parameter settings of the control valve 5 on the cooling water circulation system's inlet pipe 6 and the control valve 11 on the outlet pipe 10 until a satisfactory control speed is achieved. Then, enter transcritical speed mode. Specifically, repeatedly adjust the parameter settings of the PID controllers for the inlet control valve 5 and the outlet control valve 11 according to the following method and steps:

[0085] SS1. Set target value: Set the corresponding target value of the hydraulic dynamometer according to the operating parameters of the power equipment being tested;

[0086] SS2. Record actual values: Record the actual opening values ​​of the auxiliary cooling water circulation system's inlet regulating valve 5 and outlet regulating valve 11, and the actual water volume in the dynamometer's water chamber;

[0087] SS3. Compare target value with actual value: Compare the set target value with the actual value, analyze the error between the two, and determine whether the parameter settings of the two PID controllers need to be adjusted;

[0088] SS4. Adjust PID parameters: Based on the error analysis results of step SS7, gradually adjust the parameter settings of the two PID controllers, including at least the proportional coefficient, integral time, and differential time, so that the error between the target value and the actual value is as small as possible;

[0089] SS5. Repeat until satisfied: Repeat the above steps until the error between the target value and the actual value is less than the set threshold to achieve satisfactory control speed.

[0090] By repeatedly adjusting the parameter settings of the PID controller as described above, the regulation performance can be improved and a satisfactory control speed can be obtained, thereby achieving a dual improvement in the stable operation and transient operation regulation capabilities of the hydraulic dynamometer.

[0091] The above embodiments fully and effectively achieve the objectives of the present invention. Those skilled in the art will appreciate that the present invention includes, but is not limited to, the contents described in the accompanying drawings and the above specific embodiments. Although the present invention has been described with reference to the embodiments currently considered to be the most practical and preferred, it should be understood that the present invention is not limited to the disclosed embodiments, and any modifications that do not deviate from the functional and structural principles of the present invention are intended to be included within the scope of the claims.

Claims

1. A rapid adjustment system for transient operation of a hydraulic dynamometer, comprising at least a hydraulic dynamometer and a measured power device connected to the hydraulic dynamometer by a transmission mechanism, wherein the speed and / or braking torque of the hydraulic dynamometer is determined based on the output speed and / or power of the measured power device, and wherein: The hydraulic dynamometer at least comprises a hydraulic dynamometer body and an auxiliary cooling water circulation system adapted to the hydraulic dynamometer body, wherein: The hydraulic dynamometer body comprises at least a dynamometer stator in an overall annular shape and a dynamometer rotor disposed on a main shaft. The dynamometer rotor is coaxially disposed within the dynamometer stator, and an array of pits are disposed on the inner wall surface of the dynamometer stator and the outer wall surface of the dynamometer rotor. The annular gap between the dynamometer stator and the dynamometer rotor and the pits on the surfaces of both form a dynamometer water cavity. The auxiliary cooling water circulation system includes at least a high-level water tank, a hot water pool, a cooling tower, and a cold water pool, wherein the high-level water tank is arranged at a height higher than the hydraulic dynamometer, and the high-level water tank is connected to the inlet of the dynamometer water cavity through a water inlet pipe, the hot water pool is connected to the outlet of the dynamometer water cavity through a water outlet pipe, the hot water pool is connected to the cold water pool through a cooling tower, and a first water circulation pump is provided on the connecting pipe between the hot water pool and the cooling tower, and the cold water pool is connected to the high-level water tank through a connecting pipe provided with a second water circulation pump, At least one water inlet regulating valve is provided on the water inlet pipeline, and at least one water outlet regulating valve is provided on the water outlet pipeline, and the water inlet regulating valve and the water outlet regulating valve are respectively provided with a PID controller, and the openings of the water inlet regulating valve and the water outlet regulating valve are simultaneously adjusted by the two PID controllers to quickly adjust the water volume in the water chamber of the dynamometer, and the response speed of the water inlet regulating valve and the water outlet regulating valve is changed by adjusting the PID parameter settings of the two PID controllers to match the transient characteristics of the operation of the hydraulic dynamometer; The water volume in the water chamber of the dynamometer is adjusted by the water inlet regulating valve using a PID closed-loop or open-loop control method, and when the measured parameters, braking torque or speed, do not reach a set value, the adjustment of the water inlet regulating valve is stopped, or the opening of the water inlet regulating valve is directly increased to a maximum or minimum allowable value, so as to improve the working instability of the hydraulic dynamometer; When the output torque of the tested power equipment exceeds the set value but its output speed does not exceed the set value, the braking torque of the hydraulic dynamometer cannot meet the requirement, and it is necessary to enter the trans-critical speed mode for adjustment. At this time, the water inlet regulating valve adopts a PID closed-loop adjustment method, and the water volume in the dynamometer water cavity is jointly controlled by the regulating valves on the water inlet pipe and the water outlet pipe, so that the speed of the hydraulic dynamometer reaches the critical speed. After that, the opening of the water inlet regulating valve is kept unchanged, and only the water outlet of the dynamometer water cavity is adjusted by the water outlet regulating valve to control the speed, thereby accelerating the speed change across the critical speed area until the set speed is reached and the adjustment is ended.

2. The rapid adjustment system for transient operation of a hydraulic dynamometer according to claim 1, characterized in that: The main shaft of the hydraulic dynamometer is connected to the power output shaft of the tested power equipment through a gear box.

3. The rapid adjustment system for transient operation of a hydraulic dynamometer according to claim 1, characterized in that: Under the condition that the rotational speed of the power equipment under test remains unchanged, in order to improve the adjustment speed of the transient operation of the hydraulic dynamometer, if the load of the power equipment under test increases, the opening of the water inlet regulating valve is increased, and the opening of the water outlet regulating valve is reduced, so that the amount of water in the water cavity of the dynamometer increases rapidly, thereby quickly increasing the braking torque of the hydraulic dynamometer; if the load of the power equipment under test decreases, the opening of the water inlet regulating valve is reduced, and the opening of the water outlet regulating valve is increased, so that the amount of water in the water cavity of the dynamometer decreases rapidly, thereby quickly reducing the braking torque of the hydraulic dynamometer.

4. The rapid adjustment system for transient operation of a hydraulic dynamometer according to claim 1, characterized in that: Under the condition that the braking torque of the hydraulic dynamometer remains unchanged, in order to improve the adjustment speed of the transient operation of the hydraulic dynamometer, if the load of the power equipment being measured increases, the opening of the water inlet regulating valve is increased, and the opening of the water outlet regulating valve is reduced, so that the water volume in the water cavity of the dynamometer increases rapidly, thereby quickly reducing the rotational speed of the hydraulic dynamometer; if the load of the power equipment being measured decreases, the opening of the water inlet regulating valve is reduced, and the opening of the water outlet regulating valve is increased, so that the water volume in the water cavity of the dynamometer decreases rapidly, thereby quickly increasing the rotational speed of the hydraulic dynamometer.

5. The rapid adjustment system for transient operation of a hydraulic dynamometer according to claim 1, characterized in that: When the output speed and / or torque of the power equipment under test is below the set value, the control strategy of the water inlet regulating valve is open-loop control. First, the initial opening of the water inlet regulating valve is set to the minimum opening to ensure that there is always a certain amount of cooling water in the water chamber of the dynamometer. As the output speed and / or torque of the power equipment under test gradually increases, the opening of the water inlet regulating valve is gradually increased to increase the flow of cooling water entering the water chamber of the dynamometer; the control strategy of the water outlet regulating valve is closed-loop control, and its opening is adjusted according to the speed and / or braking torque of the hydraulic dynamometer to control the discharge amount of cooling water.

6. The rapid adjustment system for transient operation of a hydraulic dynamometer according to claim 1, characterized in that: The water inlet pipeline is also provided with at least one flow meter and one pressure gauge. The flow meter is used to monitor the actual flow of cooling water in the water inlet pipeline. If the flow is too low, the opening of the water inlet regulating valve is increased to increase the flow of cooling water.

7. The rapid adjustment system for transient operation of a hydraulic dynamometer according to claim 1, characterized in that: The water inlet pipeline is also provided with at least one pressure gauge, which is used to monitor the water pressure of the cooling water in the water inlet pipeline to ensure that the cooling water is sufficient to meet the requirements of the hydraulic dynamometer.

8. The rapid adjustment system for transient operation of a hydraulic dynamometer according to claim 1, characterized in that: The outlet water pipeline is also provided with at least one pressure gauge and one temperature gauge, which are used to monitor the pressure and temperature of the discharged cooling water respectively to ensure the accuracy of control and ensure that the outlet water temperature does not exceed the allowable range.

9. The rapid adjustment system for transient operation of a hydraulic dynamometer according to claim 5, characterized in that: When the output speed and / or torque of the tested power equipment is below the set value, the water inlet regulating valve and the water outlet regulating valve are adjusted according to the following steps: SS1. First, set the initial opening of the water inlet regulating valve to the minimum opening and ensure that the water flow and pressure of the water inlet pipe are within the preset range; SS2. Gradually increase the opening of the water inlet regulating valve as the output speed and / or torque of the tested power equipment increases to increase the flow of cooling water into the dynamometer water chamber. The opening of the water inlet regulating valve is adjusted appropriately based on feedback from a flow meter and pressure gauge installed in the water inlet pipeline. SS3. Based on the output speed and / or torque of the tested power equipment, the opening of the water outlet regulating valve is controlled according to the speed and / or braking torque of the hydraulic dynamometer to accurately control the discharge of cooling water; SS4. Monitor the pressure and temperature of the discharged cooling water based on the feedback information from the pressure gauge and temperature gauge on the outlet pipe to ensure that the discharged water volume does not affect the cooling effect.

10. The rapid adjustment system for transient operation of a hydraulic dynamometer according to claim 1, characterized in that: According to the operating parameters of the power equipment under test, the PID parameter settings of the two PID controllers are adjusted to change the response speed of the opening of the water inlet regulating valve and the water outlet regulating valve, so that their dynamic characteristics are best matched with the transient characteristics of the hydraulic dynamometer.

11. The rapid adjustment system for transient operation of a hydraulic dynamometer according to claim 10, characterized in that: Adjust the parameter settings of the PID controllers of the water inlet regulating valve and the water outlet regulating valve according to the following method and steps: SS1 set target value: according to the operating parameters of the measured power equipment set the corresponding target value of the hydraulic dynamometer; SS2 record actual value: record the auxiliary cooling water circulation system, the water inlet regulating valve, the actual opening value of the water outlet regulating valve, the actual water value of the dynamometer water chamber; SS3. Comparing the target value with the actual value: Comparing the set target value with the actual value, analyzing the error between the two, and determining whether the parameter settings of the two PID controllers need to be adjusted; SS4. Adjust PID parameters: Based on the error analysis results, gradually adjust the parameter settings of the two PID controllers, including at least the proportional coefficient, integral time, and differential time, so that the error between the target value and the actual value is as small as possible; SS5. Repeat until satisfied: Repeat the above steps until the error between the target value and the actual value is less than the set threshold.

12. A method for improving the working instability of a hydraulic dynamometer and meeting the requirements of rapid transient adjustment, based on the rapid adjustment system for transient operation of a hydraulic dynamometer according to any one of claims 1 to 11, characterized in that: Under the condition that the output speed of the power equipment under test remains unchanged, in order to improve the adjustment speed of the transient operation of the hydraulic dynamometer, if the output load of the power equipment under test increases, the opening of the water inlet regulating valve is increased, and the opening of the water outlet regulating valve is reduced, so that the amount of water in the water chamber of the dynamometer increases rapidly, thereby quickly increasing the braking torque of the hydraulic dynamometer; if the output load of the power equipment under test decreases, the opening of the water inlet regulating valve is reduced, and the opening of the water outlet regulating valve is increased, so that the amount of water in the water chamber of the dynamometer decreases rapidly, thereby quickly reducing the braking torque of the hydraulic dynamometer; Under the condition that the braking torque of the hydraulic dynamometer remains unchanged, in order to improve the adjustment speed of the transient operation of the hydraulic dynamometer, if the output load of the power equipment under test increases, the opening of the water inlet regulating valve is increased, and the opening of the water outlet regulating valve is reduced, so that the water volume in the water cavity of the dynamometer increases rapidly, thereby quickly reducing the rotational speed of the hydraulic dynamometer; if the output load of the power equipment under test decreases, the opening of the water inlet regulating valve is reduced, and the opening of the water outlet regulating valve is increased, so that the water volume in the water cavity of the dynamometer decreases rapidly, thereby quickly increasing the rotational speed of the hydraulic dynamometer.

13. The method for improving the working instability of a hydraulic dynamometer and meeting the requirements of transient rapid regulation according to claim 12, characterized in that: When the output speed and / or torque of the power equipment under test is below the set value, the control strategy of the water inlet regulating valve is open-loop control. First, the initial opening of the water inlet regulating valve is set to the minimum opening to ensure that there is always a certain amount of cooling water in the water chamber of the dynamometer. As the output speed and / or torque of the power equipment under test gradually increases, the opening of the water inlet regulating valve is gradually increased to increase the flow of cooling water entering the water chamber of the dynamometer; the control strategy of the water outlet regulating valve is closed-loop control, and its opening is adjusted according to the speed and / or braking torque of the hydraulic dynamometer to control the discharge amount of cooling water.

14. The method for improving the working instability of a hydraulic dynamometer and meeting the requirements of transient rapid regulation according to claim 12, characterized in that: When the output speed and / or torque of the tested power equipment is below the set value, the water inlet regulating valve and the water outlet regulating valve are adjusted according to the following steps: SS1. First, set the initial opening of the water inlet regulating valve to the minimum opening and ensure that the water flow and pressure of the water inlet pipe are within the preset range; SS2. Gradually increase the opening of the water inlet regulating valve as the output speed and / or torque of the tested power equipment increases to increase the flow of cooling water into the dynamometer water chamber. The opening of the water inlet regulating valve is adjusted appropriately based on feedback from a flow meter and pressure gauge installed in the water inlet pipeline. SS3. Based on the output speed and / or torque of the power equipment under test, control the opening of the water outlet regulating valve according to the speed and / or braking torque of the hydraulic dynamometer to accurately control the discharge volume of cooling water.

15. The method for improving the working instability of a hydraulic dynamometer and meeting the requirements of transient rapid regulation according to claim 12, characterized in that: The water volume in the water chamber of the dynamometer is adjusted by the water inlet regulating valve using PID closed-loop or open-loop control. When the measured parameters, braking torque or speed, do not reach the set value, the adjustment of the water inlet regulating valve is stopped, or the opening of the water inlet regulating valve is directly increased to the maximum or minimum allowable value to improve the working instability of the hydraulic dynamometer.

16. The method for improving the working instability of a hydraulic dynamometer and meeting the requirements of transient rapid regulation according to claim 15, characterized in that: When the output torque of the tested power equipment exceeds the set value but its output speed does not exceed the set value, the braking torque of the hydraulic dynamometer cannot meet the requirement, and it is necessary to enter the trans-critical speed mode for adjustment. At this time, the water inlet regulating valve adopts a PID closed-loop adjustment method, and the water volume in the dynamometer water cavity is jointly controlled by the regulating valves on the water inlet pipe and the water outlet pipe, so that the speed of the hydraulic dynamometer reaches the critical speed. After that, the opening of the water inlet regulating valve is kept unchanged, and only the water outlet of the dynamometer water cavity is adjusted by the water outlet regulating valve to control the speed, thereby accelerating the speed change across the critical speed area until the set speed is reached and the adjustment is ended.

17. The method for improving the working instability of a hydraulic dynamometer and meeting the requirements of transient rapid regulation according to claim 13, characterized in that: According to the operating parameters of the power equipment under test, the PID parameter settings of the two PID controllers are adjusted to change the response speed of the opening of the water inlet regulating valve and the water outlet regulating valve, so that their dynamic characteristics are best matched with the transient characteristics of the hydraulic dynamometer.

18. The method for improving the working instability of a hydraulic dynamometer and meeting the requirements of transient rapid regulation according to claim 17, characterized in that: Adjust the parameter settings of the PID controllers of the water inlet regulating valve and the water outlet regulating valve according to the following method and steps: SS1 set target value: according to the operating parameters of the measured power equipment set the corresponding target value of the hydraulic dynamometer; SS2 record actual value: record the auxiliary cooling water circulation system, the water inlet regulating valve, the actual opening value of the water outlet regulating valve, the actual water value of the dynamometer water chamber; SS3. Comparing the target value with the actual value: Comparing the set target value with the actual value, analyzing the error between the two, and determining whether the parameter settings of the two PID controllers need to be adjusted; SS4. Adjust PID parameters: Based on the error analysis results, gradually adjust the parameter settings of the two PID controllers, including at least the proportional coefficient, integral time, and differential time, so that the error between the target value and the actual value is as small as possible; SS5. Repeat until satisfied: Repeat the above steps until the error between the target value and the actual value is less than the set threshold.

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