Wind turbine and method and system for detecting performance of cooling systems inside and outside the wind turbine

Abstract

The application discloses a wind power generator body and a detection method and system for performance of an internal and external cooling system of the wind power generator body. The method comprises the following steps: starting a motor and a cooling system; controlling power of the motor to increase from an initial state to rated power, and recording a power curve and a corresponding motor temperature rise curve in the process; controlling test conditions in the temperature rise process to keep a ratio of a heat dissipation rate and a heat capacity of the motor constant; obtaining a steady-state temperature rise parameter and a temperature rise change parameter representing thermal characteristics of the motor based on the temperature rise curve; calculating a thermal response time constant of the motor cooling system according to the temperature rise curve, the steady-state temperature rise parameter and the temperature rise change parameter; and determining the performance of the cooling system according to the time constant. The thermal response characteristics of the temperature rise process are analyzed, the accurate and online evaluation of the performance of the cooling system is realized, and the defect that the traditional method needs to be stopped for detection is effectively overcome, thereby providing an evaluation basis for design of the wind power generator body and the internal and external cooling system thereof.

Description

Technical Field

[0001] This invention relates to the evaluation of the cooling structure of heat-generating devices such as engines, generators, electric motors, gearboxes or other transmission devices, diesel engines, gasoline engines, bearings, power batteries and their power battery assemblies, capacitors, resistors or inductors, and the evaluation of the cooling capacity or performance of the cooling systems configured for such heat-generating devices. It also relates to a method and apparatus for testing the cooling performance of the entire cooling system, including the cooling structure of the heat-generating device and the external cooling devices embedded in or connected to the device. This invention belongs to the technical field of overall performance evaluation of motors and their cooling systems, and particularly relates to a method and system for testing the performance of a wind turbine generator body and its internal and external cooling systems. Background Technology

[0002] The task of a wind turbine cooling system is to transfer the heat generated by the heat-generating components of the wind turbine towards the cold source through the three basic modes of heat transfer (conduction, convection, and radiation) according to the temperature requirements of the motor's insulation structure or magnetic components. This keeps the actual temperature of the motor's insulation structure or magnetic components within their operating range, ensuring that the insulation structure or magnetic components can function normally.

[0003] Wind turbine cooling systems typically utilize a fluid medium that enters the heat-generating stage inside the motor. As the fluid passes over the surface of heat-generating or heat-generating components, convective heat transfer occurs between the cooling medium and the heat-generating components. The heat-generating components transfer heat to the fluid medium, which gains velocity under the pressure difference created by the fluid transport drive source (e.g., ventilation equipment, pumps). This transfers heat energy from inside the motor to the outside, releasing it to a cold source. Alternatively, a closed-loop system can be formed, using a heat exchanger to release heat for reuse, or an open-loop system can release it directly into the environment. The performance characteristics of a heat exchanger are broad, encompassing heat transfer performance, resistance performance, mechanical performance, and economic efficiency.

[0004] For a long time, the thermal performance of heat exchangers has been evaluated using several single-performance indicators, such as: the temperature efficiency of the individual hot and cold fluids; a thermal performance evaluation method combining heat transfer and flow resistance losses; entropy analysis; σ analysis; longitudinal comparison method for evaluating the thermal performance of heat exchangers with enhanced heat transfer surfaces; and thermoeconomic analysis. However, these methods all have shortcomings. As is known in the field of fluid transport, the performance curves of pumps and fans (not short for wind turbines, but for ventilation fluid transport equipment) only describe the performance of the pumps and fans themselves. When pumps and fans operate in pipelines, their performance depends not only on their own performance but also on the performance of the pipeline system, i.e., the pipeline characteristic curve. The intersection of these two curves determines the operating conditions of the pumps and fans within the pipeline system. Furthermore, the exposed surfaces of heat-generating or heat-generating components inside the motor, such as the rotary air gap and ventilation channels, are part of the cooling fluid transport pipeline. This point has not received enough attention in the past because it requires a sufficient and systematic collection of interdisciplinary professional knowledge, such as heat transfer, fluid mechanics, thermodynamics, fluid distribution, process control, and even a professional background in thermal dynamic regulation processes, in order to comprehensively and accurately view the heat energy transfer and control issues in the heat generation (or heating) and cooling of motors, and avoid a one-sided view of the electromechanical energy conversion process achieved by motors, and a one-sided and fragmented evaluation of the motor's cooling system. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a method and system for testing the performance of a wind turbine generator body and its internal and external cooling systems, so as to solve at least one of the above-mentioned technical problems.

[0006] To achieve the above objectives, in one aspect, the present invention provides a method for testing the performance of a wind turbine generator body and its internal and external cooling systems, comprising:

[0007] S1: Start the wind turbine and its cooling system. The wind turbine is started and operated by a prime mover, an electric motor, or a wind turbine in electric motor operation mode.

[0008] S2: The power of the motor is controlled to increase from the initial state to the rated power by the prime mover or motor, and the power curve and the corresponding motor temperature rise curve are recorded during the process;

[0009] S3: Control the test conditions during the heating process to keep the ratio of the motor's heat dissipation rate to its heat capacity constant;

[0010] S4: Based on the temperature rise curve, obtain the steady-state temperature rise parameters and temperature rise change parameters used to characterize the thermal properties of the motor;

[0011] S5: Calculate the thermal response time constant of the motor cooling system based on the temperature rise curve, the steady-state temperature rise parameter, and the temperature rise change parameter;

[0012] S6: Determine the performance of the wind turbine body and its internal and external cooling systems based on the thermal response time constant.

[0013] Furthermore, the method of increasing the power of the wind turbine in step S2 is a continuous linear growth mode, specifically including: continuously increasing the power of the wind turbine from the initial power to the rated power at a constant power increase rate.

[0014] Further, step S2 specifically includes: gradually increasing the power of the wind turbine according to a piecewise linear growth pattern, and obtaining a power curve and a corresponding temperature rise curve of the wind turbine; wherein, the piecewise linear growth pattern in step S2 is implemented according to the following steps:

[0015] S2.1: Increase the power of the wind turbine to an initial power level and maintain the operation at the initial power level;

[0016] S2.2: Continuously operate and monitor the motor temperature rise until the wind turbine temperature rise reaches the steady-state value corresponding to the current power level;

[0017] S2.3: Upgrade the power of the wind turbine to the next higher power level;

[0018] S2.4: Repeat steps S2.2 and S2.3 until the power of the wind turbine reaches the rated power, and continue to operate until the temperature rise reaches the final steady-state temperature rise under the rated power.

[0019] During the entire step-by-step power increase process from step S2.1 to step S2.4, record the power curve and the corresponding wind turbine temperature rise curve.

[0020] Step S3 specifically includes: maintaining a constant ratio between the heat dissipation rate of the wind turbine and the heat capacity of the motor during the heating process, and maintaining a constant ratio between the heat loss power of the wind turbine and the heat capacity of the wind turbine.

[0021] Step S4 specifically includes: obtaining the initial temperature of the wind turbine at each stage of the segmented power increase or segmented temperature increase process, and the steady-state temperature rise of the motor at the corresponding power level;

[0022] Step S5 specifically includes: determining the thermal response time constant of the temperature rise process of the wind turbine generator based on the temperature rise value, initial temperature, steady-state temperature rise value and relationship in the temperature rise curve of the wind turbine generator.

[0023] Secondly, a method for testing the performance of a wind turbine generator body and its internal and external cooling systems is provided, comprising:

[0024] S1': Under natural wind conditions at the wind farm, start the prime mover of the wind turbine to make the motor in the wind turbine start running from the starting wind speed;

[0025] S2': By taking advantage of the natural change process of the wind speed in the wind farm randomly increasing to the rated wind speed, the output power of the wind turbine is increased from the initial power to the rated power, and the power curve and the corresponding temperature rise curve of the wind turbine are recorded throughout the process.

[0026] S3': During the power increase and temperature rise process, the ratio of the heat dissipation rate to the heat capacity of the wind turbine is kept constant by adjusting the externally connected cooling system other than the wind turbine body.

[0027] S4': Based on the temperature rise curve, obtain the steady-state temperature rise of the wind turbine after reaching its rated power and the temperature rise rate during the heating process;

[0028] S5': Calculate the thermal response time constant of the wind turbine body and its internal and external cooling systems based on the temperature rise curve of the wind turbine, the steady-state temperature rise and the temperature rise rate obtained in step S4';

[0029] S6': Determine the performance of the wind turbine body and its internal and external cooling systems based on the thermal response time constant.

[0030] Furthermore, the method also includes the following steps:

[0031] After the wind turbine generator reaches its rated power and continues to operate at the rated power until the wind turbine generator reaches its steady-state temperature rise, the wind turbine generator is shut down while the external cooling system other than the wind turbine generator body is not shut down, and the cooling system is kept in the same operating state as before the wind turbine generator was shut down.

[0032] During the heating process, the ratio of the wind turbine's heat dissipation rate to its heat capacity should be kept constant.

[0033] Obtain the power curve of the wind turbine and the cooling curve of the wind turbine corresponding to the power curve in time, the initial temperature and cooling rate when the wind turbine is operating at full power, and reduce it to the ambient temperature;

[0034] The thermal response time constant of the wind turbine cooling process is obtained from the cooling curve of the wind turbine.

[0035] Furthermore, the method also includes the following steps:

[0036] Once the wind turbine's output reaches the rated power and continues to operate at the rated power until the wind turbine reaches its steady-state temperature rise, the wind turbine is shut down while the external cooling system connected to the wind turbine is disconnected.

[0037] The power curve of the motor and the time-related cooling curve of the motor, the initial temperature of the motor when the motor is at full power, and the cooling rate of the motor are obtained.

[0038] Until the motor temperature drops to the ambient temperature, the thermal response time constant of the motor cooling process is obtained from the motor cooling process curve.

[0039] Furthermore, the method also includes the following steps:

[0040] The motor operating power is gradually reduced according to a linear decreasing pattern until it stops at zero power, and the power curve and the corresponding cooling curve are obtained during this process.

[0041] During the motor cooling process, the ratio of the motor's heat dissipation rate to its heat capacity is controlled and maintained constant.

[0042] The initial temperature of the motor at the start of the cooling process is obtained, and the cooling system continues to run until the motor temperature drops to the ambient temperature after the motor power drops to zero.

[0043] Based on the cooling curve of the motor cooling process, the thermal response time constant of the motor and the cooling system of the motor during the cooling process is obtained.

[0044] Furthermore, the method also includes the following steps:

[0045] The motor operating power is gradually reduced according to a piecewise linear power reduction mode. This piecewise linear reduction mode refers to: first, reducing the motor power to an initial power level and maintaining constant operation, continuously monitoring the motor temperature until it drops to the steady-state value corresponding to the current power level; then, reducing the power to the next lower power level and maintaining constant operation, again monitoring and waiting for the temperature to drop to the new steady-state value corresponding to that power level; repeating the above process of reducing power and waiting for the temperature to reach the corresponding steady-state value until the motor power drops to zero; after the motor power drops to zero, the cooling system continues to operate until the motor temperature drops to ambient temperature; during the motor cooling process, the ratio of the motor's heat dissipation rate to its heat capacity is controlled and maintained constant until the motor temperature drops to ambient temperature.

[0046] Based on the cooling curve of the motor cooling process, the thermal response time constant of the entire cooling process of the motor and its cooling system is obtained.

[0047] Furthermore, the method also includes the following steps:

[0048] When the wind turbine is in operation at the wind farm, cooling is achieved to bring its temperature down to a stable state or to match the ambient temperature through the following methods: First, the wind speed naturally decreases from the rated wind speed to below the turbine's starting wind speed, causing the wind turbine's operating power to decrease from the rated power to zero. Second, the wind turbine's pitch is adjusted to reduce its output torque, thereby reducing the mechanical energy input to the wind turbine's shaft system until the turbine's operating power reaches zero. During this cooling process, the ratio of the wind turbine's heat dissipation rate to its heat capacity is controlled and maintained constant.

[0049] Obtain the cooling curve of the wind turbine corresponding to the time of the accompanying power reduction process;

[0050] Based on the cooling curve, the initial temperature of the wind turbine, the steady-state cooling value of the wind turbine, and the temperature drop rate are obtained at the beginning of the cooling process.

[0051] Based on the cooling curve, the initial temperature, the steady-state cooling value of the wind turbine generator, and the temperature drop rate, the thermal response time constant of the motor and its cooling system during the cooling process is obtained.

[0052] Thirdly, a system for testing the performance of a wind turbine generator body and its internal and external cooling systems is provided, the system performing the method described in the first aspect, the system comprising:

[0053] The start control module is used to start the prime mover in the wind turbine, drive the wind turbine, and start the cooling system connected to the external parts of the wind turbine.

[0054] The power control module is used to control the power of the motor to increase from the initial state to the rated power, and to record the power curve and the corresponding motor temperature rise curve during the process.

[0055] The test condition control module is used to control the test conditions during the heating process so that the ratio of the heat dissipation rate to the heat capacity of the motor remains constant.

[0056] The parameter acquisition module is used to acquire steady-state temperature rise parameters and temperature rise variation parameters that characterize the thermal properties of the wind turbine based on the temperature rise curve.

[0057] The calculation module is used to calculate the thermal response time constant of the motor cooling system based on the temperature rise curve, the steady-state temperature rise parameter, and the temperature rise change parameter.

[0058] A cooling performance determination module is used to determine the performance of the cooling system based on the thermal response time constant.

[0059] Fourthly, a testing system for the performance of a wind turbine generator body and its internal and external cooling systems, comprising:

[0060] The prime mover start control module is used to start the prime mover of the wind turbine under natural wind conditions in the wind farm, so that the wind turbine can start running from the starting wind speed.

[0061] The operation status recording module is used to record the power curve and corresponding temperature rise curve of the wind turbine during the entire process of the motor's output power increasing from the initial power to the rated power, taking advantage of the natural change process of the wind speed in the wind farm randomly increasing to the rated wind speed.

[0062] The cooling system control module is communicatively connected to an external cooling system outside the wind turbine generator body. It is used to control the external cooling system during the power increase and temperature rise process to keep the ratio of the wind turbine generator's heat dissipation rate to its heat capacity constant.

[0063] The temperature rise parameter extraction module is used to obtain the steady-state temperature rise of the wind turbine after it reaches its rated power and the temperature rise rate during the heating process based on the temperature rise curve recorded by the operating status recording module.

[0064] The thermal response time constant calculation module is used to calculate the thermal response time constant of the wind turbine body and its internal and external cooling systems based on the temperature rise curve, the steady-state temperature rise and temperature rise rate obtained by the temperature rise parameter extraction module;

[0065] The cooling performance evaluation module is used to determine the performance of the wind turbine body and its internal and external cooling systems based on the thermal response time constant obtained by the thermal response time constant calculation module.

[0066] Furthermore, the wind turbine is replaced by an engine, electric motor, gearbox or other transmission device (gearbox, gearbox), diesel engine, gasoline engine, bearing, power battery and its power battery assembly, capacitor, resistor or inductor.

[0067] Fifthly, a testing system for the performance of a heat-generating equipment body and its internal and external cooling systems is provided, the system comprising:

[0068] The start control module is used to start the prime mover corresponding to the heat-generating equipment, drive the heat-generating equipment, and start the cooling system externally connected to the heat-generating equipment.

[0069] The power control module is used to control the power of the heat-generating equipment to increase from the initial state to the rated power, and to record the power curve and the corresponding temperature rise curve of the heat-generating equipment during this process.

[0070] The test condition control module is used to control the test conditions during the heating process so that the ratio of the heat dissipation rate to the heat capacity of the heat-generating equipment remains constant.

[0071] The parameter acquisition module is used to acquire steady-state temperature rise parameters and temperature rise change parameters that characterize the thermal properties of the heat-generating equipment based on the temperature rise curve.

[0072] The calculation module is used to calculate the thermal response time constant of the cooling system of the heat-generating equipment based on the temperature rise curve, the steady-state temperature rise parameter, and the temperature rise change parameter.

[0073] A cooling performance determination module is used to determine the performance of the cooling system based on the thermal response time constant.

[0074] Sixthly, a testing system for the performance of a heat-generating equipment body and its internal and external cooling systems is provided, comprising:

[0075] The prime mover start control module is used to start the prime mover used to drive the heat-generating equipment in a natural environment, and to start the external cooling equipment matched with the heat-generating equipment. The flow rate of the cooling medium used in the external cooling equipment increases from zero. For example, when testing the power battery pack and its cooling system of an electric vehicle, the starting speed of the vehicle is controlled to gradually increase from zero to the maximum speed and run continuously at the maximum speed to test whether the temperature rise of the power battery pack reaches a stable temperature rise.

[0076] The operation status recording module is used to record the power curve and the corresponding temperature rise curve of the heat-generating equipment during the entire process of the output power of the heat-generating equipment increasing from the initial power to the rated power by taking advantage of the natural change process of wind speed in the natural environment. Among them, the higher the vehicle speed, the higher the relative natural wind speed. Controlling the vehicle speed is equivalent to controlling the flow speed of the external cooling medium, which is also applicable to the cooling of fuel engines.

[0077] The cooling system control module is communicatively connected to an external cooling system other than the heat-generating equipment body. It is used to control the external cooling system during the power increase and temperature rise process so that the ratio of the heat dissipation rate to the heat capacity of the heat-generating equipment remains constant.

[0078] The temperature rise parameter extraction module is used to obtain the steady-state temperature rise of the heat-generating equipment after it reaches its rated power and the temperature rise rate during the heating process, based on the temperature rise curve recorded by the operating status recording module.

[0079] The thermal response time constant calculation module is used to calculate the thermal response time constant of the heat-generating equipment body and its internal and external cooling systems based on the temperature rise curve, the steady-state temperature rise and temperature rise rate obtained by the temperature rise parameter extraction module;

[0080] The cooling performance evaluation module is used to determine the performance of the heat-generating equipment body and its internal and external cooling systems, as well as whether the temperature rise process has self-balancing capability, based on the thermal response time constant obtained by the thermal response time constant calculation module.

[0081] The above technical solution has the following beneficial effects: This testing method first starts the wind turbine and cooling system, then records the power and temperature rise curves simultaneously with the power rise, while keeping the ratio of heat dissipation rate to heat capacity constant to eliminate interference factors. Combining steady-state temperature rise parameters and temperature rise change parameters, it accurately calculates the thermal response time constant and uses this to determine the performance of the cooling system. This not only avoids testing errors caused by fluctuations in test conditions and ensures the accuracy and reliability of test results, but also comprehensively captures the changing patterns of the motor's thermal characteristics, achieving a quantitative evaluation of the cooling system's performance. Moreover, the process is highly practical and can quickly and efficiently complete the testing of the cooling system's performance in wind farm scenarios. This provides a scientific basis for the design optimization and upgrading, fault prediction, and stable operation of the wind turbine itself and its internal and external cooling systems, thereby improving the operational safety and service life of the wind turbine. This invention achieves accurate, online evaluation of the performance of the wind turbine generator body and its internal and external cooling systems by analyzing the thermal response characteristics of the temperature rise process. It not only evaluates the cooling capacity of the wind turbine generator body structure and its self-balancing ability to suppress temperature rise (a standard professional term in the field of automatic control systems for thermal processes), but also simultaneously evaluates the ability of all external cooling systems designed in conjunction with the wind turbine generator body to suppress and control the temperature rise of the wind turbine generator body. This effectively overcomes the drawback of traditional methods that require shutdown for testing, providing an evaluation basis for the design of wind turbine generator bodies and their internal and external cooling systems, and providing an important guarantee for safe and efficient operation. Attached Figure Description

[0082] Figure 1A This is a schematic diagram of a test apparatus for identifying (verifying) the relationship between wind turbine power and temperature rise and cooling system performance, according to an embodiment of the present invention.

[0083] Figure 1B This is a flowchart of a method for testing the performance of a wind turbine cooling system according to an embodiment of the present invention;

[0084] Figure 1C This is a flowchart of another method for testing the performance of a wind turbine cooling system according to an embodiment of the present invention (operating in a real natural environment of a wind farm).

[0085] Figure 2This is a schematic diagram of the temperature rise curve obtained by controlling the power of the wind turbine generator according to a linear growth mode in an embodiment of the present invention;

[0086] Figure 3 This is a schematic diagram of the temperature rise curve obtained by controlling the power of the wind turbine generator according to a piecewise linear growth mode in an embodiment of the present invention;

[0087] Figure 4 This is a schematic diagram of the temperature rise curve obtained by the wind turbine in the wind farm wind turbine operation mode according to an embodiment of the present invention (that is, the wind turbine power increases randomly with the wind speed to the rated wind speed and maintains the rated power operation until the wind turbine temperature rise reaches a stable temperature rise state).

[0088] Figure 5 This is a schematic diagram of the temperature change curve of the wind turbine generator being instantly shut down from its rated power state without disconnecting the cooling system, according to an embodiment of the present invention.

[0089] Figure 6 This is a schematic diagram of the temperature change curve of the wind turbine generator being instantly shut down from its rated power state and the cooling system being cut off, according to an embodiment of the present invention.

[0090] Figure 7 This is a schematic diagram of the temperature change curve of a wind turbine generator in an embodiment of the present invention, which controls the wind turbine generator to linearly reduce its power from the rated power state to zero power while the cooling system always maintains a constant cooling power.

[0091] Figure 8 This is a schematic diagram of the motor temperature change curve in the mode of maintaining constant cooling power in the wind turbine power cooling system that reduces the power of the wind turbine in a piecewise linear manner from the rated power state according to an embodiment of the present invention.

[0092] Figure 9 This is a schematic diagram of the motor temperature change curve obtained when the generator is in the wind turbine generator operation mode of the wind farm according to an embodiment of the present invention (the motor temperature change curve is a schematic diagram of the mode in which the wind turbine generator power decreases randomly with the wind speed and stops when it is below the wind speed at which the wind turbine is started, or the wind turbine output power is reduced to zero power by controlling the blade angle of attack with the pitch system, and the cooling system maintains a constant cooling power during the process).

[0093] Figure 10 This is a schematic diagram of the temperature rise curve and time constant of the wind turbine under different external cooling systems or different cooling conditions according to an embodiment of the present invention;

[0094] Figure 11 This is a schematic diagram illustrating the temperature rise decay process and time constant determination of a wind turbine under different cooling capacity conditions according to an embodiment of the present invention.

[0095] Figure 12This is a schematic diagram of the dimensionless temperature rise decay curve and the determination of time constants for different cooling systems according to an embodiment of the present invention;

[0096] Figure 13 This is a functional block diagram of a computer device according to an embodiment of the present invention. Detailed Implementation

[0097] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0098] This invention provides a test method and apparatus for evaluating the cooling structure of the heat-generating device body and the cooling system configured with the heat-generating device, verifying the cooling performance of the entire cooling system, including the cooling structure of the heat-generating device body and the embedded or connected cooling devices. Additionally, this invention provides a control program for wind turbine insulation temperature protection during wind turbine operation or a monitoring program for the full life-cycle health status of wind turbine insulation temperature.

[0099] In view of this, and in response to the aforementioned problems in the prior art, the embodiments of the present invention differ from traditional methods. They take the heat generated during the operation of the wind turbine as the heat source, and establish a holistic thermodynamic system based on the organic connection between the heat source and cold source during the operation of the wind turbine and its cooling system. Furthermore, a dynamic system approach is used to obtain the dynamic characteristics of the thermodynamic system during the transition process of the wind turbine being cooled as a heat source. A process controller algorithm is used to develop an experimental method and apparatus for obtaining the thermodynamic dynamic transfer relationship between the power of the wind turbine and its temperature rise, as well as the performance of its cooling system. This also serves as the control basis for the temperature protection of the insulation structure during wind turbine operation, including the temperature rise rate and the temperature rise value.

[0100] This invention utilizes the temperature rise curve of a wind turbine during power output to determine and evaluate the performance of the cooling system of the wind turbine itself and its internal and external cooling systems. It also assesses the quality of the cooling channels constructed during the wind turbine's structural design, specifically the rate and magnitude of temperature rise suppression, to differentiate and compare the performance of different cooling systems. The internal cooling system refers to the cooling system comprised of the wind turbine's internal channels, internal structural components, outer surface, and its surrounding environment. The external cooling system refers to the external system that provides cooling medium to the generator's internal cooling channels, including external heat exchange equipment, external cooling medium driving equipment, valves, and their controllers. Driving equipment refers to fluid transport equipment such as pumps or fans, as well as various sensors for measuring the temperature and flow rate of the cooling medium.

[0101] The cooling system includes: a fan or pump and its drive motor and speed controller, a fluid transmission channel, an internal cooling fluid transmission channel for the wind turbine, and a process controller for monitoring the operation of the wind turbine.

[0102] The process controller is used to collect real-time data from temperature sensors inside the wind turbine and data from the wind turbine power measurement module. It controls the drivers (or drive motors) of pumps, fans, or induced draft fans in the cooling system. The process controller also uses the wind turbine's controller to control the turbine's pitch angle to adjust the turbine's output, adapting to the power input requirements of the wind turbine and meeting the requirements of maintaining a constant or changing the wind turbine's power output.

[0103] The test methods and apparatus for cooling system performance rely on the wind turbine power curve and its corresponding temperature rise curve obtained from wind turbine operation or ground tests, the temperature change curve of the wind turbine after the cooling system is disconnected at the same time as the wind turbine is shut down, and the temperature curve of the wind turbine without disconnecting the cooling system after the wind turbine is shut down. The process controller gives a cooling system performance evaluation based on these temperature curves.

[0104] like Figure 1A As shown, the wind turbine (body) is the core heat-generating component of the system. For example... Figure 1A As shown on the left, its rotating shaft receives mechanical energy converted from the wind turbine, driving the internal components of the wind turbine to output electrical energy. During this process, the main internal heat sources include: the armature winding (heat generated by the current effect), the magnetic poles (heat generated by eddy current losses due to the alternating magnetic field in permanent magnets or excitation windings), and the bearings (heat generated by friction). These heat sources are collectively referred to as the internal heat sources of the motor. If the heat generated is not dissipated in time, it will cause the wind turbine to overheat, affecting insulation life and operating efficiency. ω represents the rotational speed of the wind turbine, used to indicate the rotational state of the wind turbine. The angular velocity Ω represents the drive shaft or prime mover output shaft. The left side of these shafts represents various forms of prime movers, which are omitted from the diagram. Prime movers include diesel engines, gasoline engines, wind turbines, and water turbines; any device that can generate and output mechanical energy is called a prime mover.

[0105] To dissipate the aforementioned heat, internal heat exchange channels are pre-installed inside the wind turbine. These channels are directly embedded in or arranged around the heat-generating components, forming the path for the cooling medium to flow. When the cooling medium flows through these channels, it directly and efficiently absorbs and carries away heat through convection heat transfer with the surface of the heat-generating components, thereby achieving directional cooling of key internal components of the turbine and suppressing their temperature rise.

[0106] The indirect heat exchanger is the core of the entire cooling system, located outside the wind turbine (right side of the diagram). As a typical surface heat exchanger, its characteristic is that the primary (hot side) and secondary (cold side) fluids involved in heat exchange are separated by a solid partition, preventing them from mixing. Its primary side flow channel is connected to the internal heat exchange channel of the wind turbine, receiving the high-temperature cooling medium exiting the turbine; its secondary side flow channel is open to the external environment, receiving the cold air driven by the induced draft fan. Its function is to transfer the heat carried by the primary cooling medium to the cold air on the secondary side through the heat conduction of the partition, thereby cooling the high-temperature cooling medium and preparing it for re-entry into the wind turbine's cooling cycle. The induced draft fan is connected to the secondary side flow channel of the indirect heat exchanger.

[0107] Regarding the fluid transport drive units (pumps / fans), the system is equipped with two sets of transport drive units, driving the internal and external circulation respectively. The primary side drive unit (a pump for liquid cooling and a fan for gas cooling) provides power to continuously flow the cooling medium in a closed loop (i.e., the internal circulation) consisting of the "heat exchange channel inside the wind turbine → primary side of the partition wall heat exchanger". The secondary side drive unit (i.e., the induced draft fan) draws in cool air from the environment, directs it through the secondary side channel of the partition wall heat exchanger, removes heat, and then discharges it into the environment, forming the external circulation.

[0108] Figure 1A The fluid cooling pipeline shown is a rectangular frame structure forming a closed loop, containing channels for heat exchange. This pipeline serves as the carrier of the cooling system, providing a closed path for the circulating flow of the cooling fluid and ensuring that the fluid can flow through the equipment requiring cooling (such as a wind turbine) and heat exchange units. The inlet and outlet of the fluid cooling pipeline are connected by a drive, forming a complete circulation loop. The design of its internal channels maximizes heat exchange efficiency and ensures smooth fluid flow.

[0109] The process controller is located at Figure 1A As shown in the upper left corner, it is connected to the wind turbine, wind generator, and other actuators (such as the drive unit) of the system via control lines. Its function is to act as the brain of the entire cooling system, automatically monitoring and regulating the operating status of the wind turbine and wind generator, as well as the operating intensity of the cooling system (such as the speed of the drive unit), based on preset logic or sensor feedback (such as temperature signals), thereby ensuring that the wind turbine operates efficiently and safely within the optimal temperature range. Figure 1AThe two arrows point to the process controller, which means that the process controller relies on temperature sensors, power sensors, etc. in its forward channel to collect relevant status parameters of the wind turbine (wind turbine temperature, operating power) and the system and transmit them to the controller. This enables comprehensive monitoring of the operating status of the entire wind turbine and cooling system. Based on this feedback information, the system can accurately control the operating status of components such as the wind turbine and drive to ensure stable and efficient operation of the system.

[0110] The actuator is specifically connected between the inlet and outlet of the fluid cooling pipeline. Its function is to act as the power source for the cooling system, providing the necessary pressure or differential pressure for the circulation of the cooling fluid within the closed fluid cooling pipeline. Depending on the cooling medium (liquid or gas), the actuator may function as a water pump or a fan. It receives instructions from the process controller and adjusts the flow rate of the cooling medium by changing its own rotational speed, thereby precisely controlling the system's cooling capacity. The actuator shown in Figure 1A is directly connected to the primary side flow channel of the indirect heat exchanger via physical piping. Its function is to provide the flow power for the primary side cooling medium flowing through this channel. Simultaneously, the actuator is connected to the process controller via control lines to receive control commands to adjust its operating state (e.g., rotational speed), thereby precisely controlling the flow rate of the primary side cooling medium. The inlet refers to the entrance point of the cooling fluid pipeline, i.e., the point where the cooling medium enters the pipeline from an external or upstream component. The outlet refers to the exit point of the cooling fluid pipeline, i.e., the point where the cooling medium flows out of the pipeline to the downstream component.

[0111] The entire cooling system is based on the principle of forced convection heat transfer, with two interconnected loops working in tandem. The inner loop works as follows: the primary-side drive unit (pump / fan) propels the cooling medium into the heat exchange channel inside the wind turbine, where it absorbs heat and heats up to become a high-temperature medium. This high-temperature medium flows into the primary side of the partition heat exchanger, releases heat to the metal partition, and cools down, returning to a low-temperature medium. The low-temperature medium is then returned to the wind turbine by the drive unit, completing a closed loop. Simultaneously, the outer loop works as follows: the induced draft fan blows or draws ambient cool air into or into the secondary side of the partition heat exchanger. As the cool air flows through the partition, it absorbs heat conducted from the primary side, heats up, and is then discharged back into the atmosphere as hot air. Through the coupling of these two loops at the partition heat exchanger, the heat generated inside the wind turbine is continuously and effectively transferred to the external environment, ensuring the safe, stable, and efficient operation of the wind turbine.

[0112] like Figure 1BAs shown, this embodiment provides a test method for identifying or verifying the relationship between wind turbine power and temperature rise and the performance of the wind turbine cooling system. The method utilizes the power curve of the wind turbine and its corresponding temperature rise curve obtained from wind turbine operation or testing. The test method employs a test process device where a process controller (i.e., a controller) controls various actuators. This method can be applied in real wind farms or in ground environments, including production workshops or laboratories. The method includes the following steps:

[0113] S1: Start the wind turbine and its cooling system. The wind turbine is started and operated by a prime mover, an electric motor, or a wind turbine in electric motor operation mode. The prime mover includes diesel engines, gasoline engines, wind turbines, and water turbines. Any device that can generate mechanical energy is called a prime mover.

[0114] S2: The power of the motor is controlled to increase from the initial state to the rated power by the prime mover or motor, and the power curve and the corresponding motor temperature rise curve are recorded during the process;

[0115] In one specific example, the controller increases the power of the wind turbine generator. During this process, the controller relies on the power measurement unit and the temperature sensor inside the wind turbine generator to obtain the power curve of the wind turbine generator and the temperature rise curve of the wind turbine generator corresponding to the power curve in time. In another specific example, the controller gradually increases the power of the wind turbine generator according to a linear growth law until the rated power is reached, and obtains the power curve and the temperature rise curve of the wind turbine generator corresponding to the power curve.

[0116] S3: Control the test conditions during the heating process to maintain the ratio of the cooling rate to the heat capacity of the wind turbine. The Reynolds number is essentially constant, meaning the Reynolds number of the cooling medium flow is essentially constant.

[0117] S4: Based on the temperature rise curve, obtain the steady-state temperature rise parameters and temperature rise variation parameters used to characterize the thermal properties of the wind turbine generator;

[0118] Specifically, the controller obtains the initial temperature of the wind turbine based on the temperature sensor of the wind turbine, and controls the wind turbine to continue operating at the rated power after the operating power of the wind turbine reaches the rated power based on the power measurement unit, and obtains the steady-state temperature rise and temperature rise rate of the wind turbine based on the temperature sensor of the wind turbine.

[0119] S5: Calculate the thermal response time constant of the wind turbine cooling system based on the temperature rise curve, the steady-state temperature rise parameter, and the temperature rise change parameter;

[0120] Specifically, this step establishes the heat transfer differential equation for the unstable transient process based on Newton's law of cooling and Fourier's law of heat conduction, obtaining the thermal response time constant of the wind turbine and its cooling system during the temperature rise process. The process controller is used for monitoring the operation of the wind turbine. This embodiment also includes a forward measurement channel power measurement unit and a temperature sensor for measuring the temperature rise.

[0121] S6: Determine the performance of the cooling system based on the thermal response time constant.

[0122] The wind turbine can be replaced by an engine, electric motor, gearbox or other transmission device, diesel engine, gasoline engine, bearing, power battery and its assembly, capacitor, resistor or inductor. Figure 2 As shown, starting from power 0 in the lower left corner, the power of the wind turbine increases linearly to the rated power Pe. At time t1, the power reaches the rated power Pe, and from time t1 to infinity, the power remains constant. At time t1, the heat accumulated inside the wind turbine is not yet sufficient. The external cooling system initially has a strong cooling capacity, and the temperature rise inside the wind turbine at time t1 is only a fraction of the initial value. The temperature of the wind turbine kept rising while its power output remained constant. At that point, which is several hours later, the internal temperature of the wind turbine, specifically the temperature of the heating components in the armature winding, stopped rising. Because the insulation material of the wind turbine deteriorates at high temperatures, it is expected that the temperature will decrease from t1 to... The smaller the time difference, the better. This reflects that the internal flow channels and cooling system of the wind turbine are optimally combined, with excellent matching between the two. This indicates that the cooling flow channels inside the wind turbine maximize the load effect of surface heat transfer, while the cooling power of the main cooling system on the right side of Figure 1 is maximized. This experiment can identify the quality of the design of the external cooling system and the internal flow structure (cooling flow channels) of the wind turbine. Figure 2 In the middle, the temperature rise curve of the wind turbine from 0 to t1 and from t1 to The temperature rise curve of the wind turbine is an exponential curve, with two different exponents. This experiment can determine the matching degree between the external cooling system and the internal cooling channels, and whether the cooling capacity of the main cooling system is being maximized.

[0123] In some embodiments, the method of increasing the power of the wind turbine in step S2 is a continuous linear growth mode, specifically including: continuously increasing the power of the wind turbine from the initial power to the rated power at a constant power increase rate.

[0124] In some embodiments, step S2 specifically includes: gradually increasing the power of the wind turbine according to a piecewise linear growth pattern, and obtaining a power curve and a temperature rise curve of the wind turbine corresponding to the power curve; wherein, the piecewise linear growth pattern in step S2 is implemented according to the following steps:

[0125] S2.1: Increase the power of the wind turbine to an initial power level and maintain the operation at the initial power level;

[0126] S2.2: Continuously operate and monitor the temperature rise of the wind turbine until the temperature rise of the wind turbine reaches the steady-state value corresponding to the current power level;

[0127] S2.3: Upgrade the power of the wind turbine to the next higher power level;

[0128] S2.4: Repeat steps S2.2 and S2.3 until the power of the wind turbine reaches the rated power, and continue to operate until the temperature rise reaches the final steady-state temperature rise under the rated power.

[0129] During the entire step-by-step power increase process from step S2.1 to step S2.4, record the power curve and the corresponding wind turbine temperature rise curve.

[0130] Step S3 specifically includes: maintaining the ratio of the wind turbine's heat dissipation rate to its heat capacity during the heating process. The ratio of the heat loss power of the wind turbine to its heat capacity should be kept constant. Constant;

[0131] Step S4 specifically includes: obtaining the initial temperature of the wind turbine at each stage of the segmented power increase or segmented temperature increase process, and the steady-state temperature rise of the wind turbine at the corresponding power level;

[0132] Step S5 specifically includes: based on the temperature rise value in the temperature rise curve of the wind turbine generator. Initial temperature The value of steady-state temperature rise and relation Determine the thermal response time constant of the temperature rise process of a wind turbine generator. .

[0133] like Figure 3 As shown, the power of the wind turbine increases in a piecewise linear manner. By time t5, the power of the wind turbine has reached the rated power Pe, and the temperature rise has increased to [value missing]. The segmented increase in power output of a wind turbine is beneficial for protecting its insulation structure. From time 0 to t1, the wind turbine's power increases to P1, and its temperature rises to... From time t1 to time t2, the power remains constant, but the temperature rises exponentially. Growth to Therefore, the time difference can be calculated as t2-t1, and the temperature difference is: minus . and The difference between them is not necessarily equal to and The difference between them. Through Figure 3 The curves shown can identify the quality of the combination between the external cooling system and the internal cooling channel structure. When it is necessary to determine which external cooling system to use, two external cooling systems can be connected and tested in the workshop under the same experimental conditions, and the curves corresponding to the two external cooling systems can be plotted. Figure 3 The curves shown are compared, and the curve with an overall downward trend and a shorter temperature rise time is identified as the better external cooling system. From time t2 to t3, the wind turbine power increases linearly from P1 to P2, during which the temperature rise increases exponentially from Δτ2 to Δτ3; from time t3 to t4, the power remains stable at P2, and the temperature rise continues to rise exponentially to Δτ4; from time t4 to t5, the power increases linearly from P2 to the rated power P. e The temperature rise rapidly increases from Δτ4 to Δτ5; after time t5, the wind turbine power output remains at the rated power P. e The temperature rise gradually approaches the steady-state temperature rise Δτ ∞ During this process, the rate of temperature rise gradually slows down, eventually reaching a state of thermal equilibrium. By observing the exponential growth rate of the temperature rise curves at each stage and the magnitude of the steady-state temperature rise, the matching degree between the thermal response characteristics of the wind turbine and the cooling system can be further analyzed: if the exponential growth slope of the temperature rise curve is large at a certain stage, it indicates that the wind turbine accumulates heat quickly at this power level, and it is necessary to determine whether there is room for thermal management optimization in conjunction with the heat dissipation capacity of the cooling system; while the steady-state temperature rise Δτ ∞ This directly reflects the final thermal state of the wind turbine at its rated power, and its value can be used as one of the key indicators for evaluating whether the heat dissipation performance of the cooling system meets the long-term stable operation requirements of the wind turbine.

[0134] In some alternative embodiments, the method specifically includes:

[0135] The controller gradually increases the power of the wind turbine generator according to a piecewise linear growth mode. That is, after each piece of linear growth mode, it continues to operate at a constant power until the temperature rise reaches a steady state value. Then, it continues to increase the power of the wind turbine generator according to the linear growth law and continues to operate at the increased power state until the temperature rise reaches a new steady state, until the rated power is reached and then it continues to operate at the rated power to generate a steady state temperature rise.

[0136] The controller acquires the wind turbine's power output in stages, the initial temperature of each stage of the staged heating process, the wind turbine's steady-state temperature rise, and the temperature rise rate.

[0137] The controller obtains the thermal response time constant of the wind turbine and its cooling system throughout the temperature rise process.

[0138] like Figure 1C As shown, this embodiment of the invention also provides a method for testing the performance of a wind turbine generator body and its internal and external cooling systems, which operates in a wind farm. The method includes:

[0139] S1': Under natural wind conditions at the wind farm, start the prime mover (wind turbine or wind turbine) of the wind turbine generator, so that the motor in the wind turbine generator starts running from the starting wind speed;

[0140] S2': By taking advantage of the natural change process of the wind speed in the wind farm randomly increasing to the rated wind speed, the output power of the wind turbine is increased from the initial power to the rated power, and the power curve and the corresponding temperature rise curve of the wind turbine are recorded throughout the process.

[0141] S3': During the power increase and temperature rise process, the ratio of the heat dissipation rate to the heat capacity of the wind turbine is kept constant by adjusting the externally connected cooling system other than the wind turbine body.

[0142] S4': Based on the temperature rise curve, obtain the steady-state temperature rise of the wind turbine after reaching its rated power and the temperature rise rate during the heating process;

[0143] S5': Calculate the thermal response time constant of the wind turbine body and its internal and external cooling systems based on the temperature rise curve of the wind turbine, the steady-state temperature rise and the temperature rise rate obtained in step S4';

[0144] S6': Determine the performance of the wind turbine body and its internal and external cooling systems based on the thermal response time constant.

[0145] The wind turbine can be replaced by an engine, electric motor, gearbox or other transmission device, diesel engine, gasoline engine, bearing, power battery and its assembly in new energy vehicles, capacitor, resistor or inductor. The wind farm is replaced by a natural environment for testing.

[0146] like Figure 4 As shown, Figure 4In the operating mode of a medium-sized wind turbine at a wind farm site, the power output of the wind turbine increases randomly with the wind speed, fluctuating like a sawtooth pattern, with periods of increase and decrease, but the overall trend is upward. From 0 to t1, the temperature generally rises, and the power output also gradually increases. During the t1 to t2 stage, the wind turbine power increases in a sawtooth pattern. Although the temperature rise fluctuates slightly with the power fluctuations, it generally shows an upward trend, and the growth rate of the temperature rise curve adjusts with the sawtooth changes in power. From t2 to t3, the power continues to climb in a sawtooth pattern, and the temperature rise continues to rise, with a small period of stabilization within this range, reflecting a brief dynamic balance between heat accumulation and heat dissipation in the wind turbine during this stage. From t3 to t4, both power and temperature rise show a downward trend. From t4 to t5, the power rapidly increases in a sawtooth pattern to the rated power Pe, while the temperature rise quickly rebounds from the downward trend of t3 to t4 and accelerates its growth rate. After t5, the wind turbine power stabilizes at the rated power Pe, and the temperature rise gradually stabilizes, eventually slowly approaching the steady-state temperature rise Δτ. ∞ By analyzing the correlation between sawtooth power fluctuations and temperature rise curves, we can delve into the thermal response patterns of wind turbines under scenarios of random wind speed variations at wind farms. Each sawtooth rise or fall in power causes a corresponding fluctuation in temperature rise, while the overall trend of the temperature rise curve still clearly reflects the heat accumulation process of the wind turbine. This characteristic can be used to evaluate the adaptability of the wind turbine cooling system to random power fluctuations under on-site conditions: if the temperature rise fluctuates little during power fluctuations and can quickly recover and stabilize, it indicates excellent dynamic heat dissipation performance of the cooling system; if the temperature rise fluctuates greatly and recovers slowly, the response efficiency or heat dissipation capacity of the cooling system needs to be improved. Alternatively, Figure 4 The power curve in the calculation is not smooth. When using it, the average value filtering method can be used to obtain a continuously smoothed approximate power curve, and the calculation can be performed with the help of the smoothed approximate power curve.

[0147] In some alternative embodiments, the method specifically includes:

[0148] When a wind turbine is in the wind farm, it is in the wind turbine operation mode. The motor starts running from the wind speed of the wind turbine. During the process of the wind speed in the wind farm changing randomly, the wind speed increases over a period of time until it reaches the rated wind speed. The wind turbine output reaches the rated power and continues to maintain the power, so that the wind turbine temperature rises to a new stable temperature rise state.

[0149] The controller acquires the accompanying power curve increase process and its corresponding wind turbine temperature rise curve;

[0150] The controller acquires the initial temperature of the wind turbine, the steady-state temperature rise of the wind turbine, and the rate of temperature rise.

[0151] Based on the temperature rise curve of the above temperature rise process, the controller obtains the thermal response time constant of the wind turbine and its cooling system during the temperature rise process.

[0152] In some embodiments, the test method is implemented by using the power curve obtained from the sudden instantaneous reduction in power during wind turbine operation or testing, which is shown to indicate the turbine's operation to shutdown, and the corresponding wind turbine cooling curve.

[0153] like Figure 5 As shown, the wind turbine is controlled to instantly disconnect from the rated power Pe state and shut down, for example, in the event of a sudden grid trip or power outage. At this time, it decreases according to this exponential law. Based on... Figure 5 In the laboratory, the quality of an external cooling system can be determined, as well as whether the external cooling system matches the internal cooling channels of the wind turbine. Figure 5 The vertical axis represents the wind turbine power (kW) and the wind turbine temperature rise (K), and the horizontal axis represents time T; from time 0 to t0, the wind turbine power stabilizes at the rated power P. e During operation, the temperature rise of the wind turbine generator increases from the initial value Δτ0 and remains stable at the rated power P. e The corresponding steady-state temperature rise level, that is, from time 0 to t0, when the wind turbine operates at its rated power P e During continuous operation, the temperature rise reaches and remains stable at that power level after heat accumulation. At time t0, after the wind turbine's power instantaneously drops to 0, the temperature rise Δτ gradually decreases exponentially from its stable state, eventually reaching a stable temperature at t... ∞ The constant Δτ approaches the same as the ambient temperature. ∞ It fully presents the thermal response process of a wind turbine as its temperature rise decays to ambient temperature over time after it stops operating at rated power. This can be used to analyze the heat dissipation characteristics and thermal time constant of the cooling system under shutdown conditions.

[0154] In some embodiments, the test method includes the following steps:

[0155] When the wind turbine reaches its rated power and continues to operate at the rated power until the wind turbine reaches its steady-state temperature rise, the controller will implement shutdown control for the operating wind turbine while not cutting off the operation of the wind turbine's cooling system, keeping the cooling system in the same operating state as before the wind turbine was shut down.

[0156] Controlling the ratio of the wind turbine's heat dissipation rate to its heat capacity during the heating process. Constant, meaning the Reynolds number of the cooling medium flow is constant;

[0157] Obtain the power curve of the wind turbine and the corresponding cooling curve of the wind turbine over time;

[0158] Obtain the initial temperature and cooling rate of the wind turbine when it is operating at full power, and reduce it to the ambient temperature;

[0159] The thermal response time constant of the cooling process of the wind turbine is obtained based on the cooling process curve of the wind turbine described above.

[0160] like Figure 6 As shown, in Figure 6 In this state, when a fault occurs, i.e., the wind turbine is without power and the external cooling system is not operating (the cooling system is suddenly cut off), the shorter the time period from t0 to t1, the better. and The smaller the difference, the better. A momentary shutdown of the external cooling system and a momentary halt to heat generation does not mean the temperature will not rise. To protect the insulation material of the wind turbine and prevent damage, it should be ensured that... Low enough to make The increased value does not exceed the upper limit of the temperature tolerance of the wind turbine material. The smaller the better, the shorter the time from t0 to t1 the better.

[0161] In some embodiments, the test method includes the following steps:

[0162] After the wind turbine reaches its rated power and continues to operate at the rated power until the wind turbine reaches its steady-state temperature rise, the controller will shut down the wind turbine and disconnect the wind turbine's cooling system.

[0163] The controller acquires the power curve of the wind turbine and the cooling curve of the wind turbine corresponding to the power curve in time, the initial temperature of the wind turbine when the wind turbine is at full power, and the cooling rate of the wind turbine.

[0164] Until the temperature of the wind turbine generator drops to the ambient temperature, the controller obtains the thermal response time constant of the wind turbine generator cooling process based on the above cooling process curve.

[0165] In some embodiments, the controller implements the test method using the power curve obtained from wind turbine operation or testing, which shows a gradual decrease in power until shutdown, and the corresponding wind turbine cooling curve.

[0166] like Figure 7 As shown, the power output decreases linearly from the rated power Pe state to zero power. However, when the power of the wind turbine becomes 0, the temperature of the wind turbine is not 0 degrees Celsius; the wind turbine still experiences a certain temperature rise. That is, even when the wind turbine's power output drops to zero, the turbine is still generating heat. It's just that after time t1, the turbine stops generating heat. From t1 to... The shorter the discharge time, the better, which is equivalent to the gradual discharge of a capacitor, and the shorter the discharge time, the better. Figure 7 The vertical axis represents the wind turbine power P (kW) and the wind turbine temperature rise Δτ (kW), respectively, and the horizontal axis represents time T. Initially, the wind turbine operates at its rated power Pe, corresponding to a temperature rise of Δτ0. Subsequently, the wind turbine power decreases linearly from Pe, and the temperature rise changes accordingly. At time t1, the power drops to 0, at which point the wind turbine temperature rise is Δτ1. After t1, the wind turbine temperature rise gradually decreases exponentially from Δτ1, eventually reaching a maximum at time t2. ∞ The time approaches Δτ ∞ This process clearly demonstrates that after the wind turbine's power linearly decreases to zero, the temperature rise gradually decreases from Δτ1 to Δτ corresponding to the ambient temperature. ∞ The thermal response law can be used to analyze the thermal characteristics of wind turbines during the linear power decay stage and the heat dissipation efficiency of the cooling system for the waste heat of the wind turbine: if from Δτ1 to Δτ ∞ The shorter the decay time, the stronger the cooling system's ability to dissipate waste heat from the wind turbine. This is of great importance for optimizing the thermal management of the wind turbine after shutdown and ensuring the insulation performance and service life of the wind turbine.

[0167] In some embodiments, the testing method further includes the following steps:

[0168] The controller gradually reduces the power of the wind turbine generator according to a linear decreasing pattern until it shuts down at zero power, and obtains the power curve and the corresponding cooling curve.

[0169] The controller maintains the ratio of the wind turbine's heat dissipation rate to its heat capacity during the cooling process. Constant, meaning the Reynolds number of the cooling medium flow is constant;

[0170] The controller acquires the initial temperature of the wind turbine, and continues to operate the cooling system of the wind turbine after the wind turbine's power output drops to zero until the wind turbine's temperature drops to the ambient temperature.

[0171] The controller obtains the thermal response time constant of the wind turbine and its cooling system during the cooling process based on the cooling curve of the wind turbine.

[0172] like Figure 8As shown, the wind turbine power decreases linearly, and the cooling system cannot be shut off at t15 because of heat rebound. The wind turbine power P changes with time as follows: From time 0 to t1, the wind turbine power remains at the rated power Pe; from t1 to t3, the wind turbine power begins to decrease from the rated power Pe; from t3 to t5, the wind turbine power remains at a constant power value; from t5 to t7, the wind turbine power decreases again; from t7 to t9, the wind turbine power remains at another constant power value; from t9 to t... 11 During this period, the power output of wind turbines continued to decline; at t 11 To t 13 During this period, the power output of the wind turbine remained constant at a fixed value; at t 13 To t 15 During this period, the power output of the wind turbines decreased again; at t 15 Afterwards, the wind turbine power continued to decrease, eventually approaching 0. The temperature rise Δτ of the wind turbine changed with time as follows: Starting from time 0, the wind turbine temperature rise gradually increased from its initial value, reaching a peak at time t2; between t2 and t4, the wind turbine temperature rise began to decrease, reaching a certain stable temperature rise value at time t4, and remaining unchanged from t4 to t5; between t5 and t8, the wind turbine temperature rise continued to decrease, reaching another stable temperature rise value at time t8, and remaining unchanged from t8 to t9. 10 During this period, the stable temperature rise value remains constant; at t 10 To t 12 During this period, the temperature rise of the wind turbine decreased again, and at t 12 When the temperature reaches another stable temperature rise value, at t 12 To t 14 During this period, the stable temperature rise value remains constant; at t 14 To t 16 During this period, the temperature rise of the wind turbine continued to decrease, and eventually reached t 16 and thereafter approaching the ambient temperature rise Δτ ∞ .

[0173] The power output P of the wind turbine exhibits a step-like decreasing pattern, meaning that after each power decrease, there is a period of constant power maintenance before the next power decrease occurs, and the constant power value after each decrease gradually decreases. Specifically, this is manifested in the periods t2~t3, t5~t7, t9~t... 11 t 13 ~t 15 Within the same interval, the power output of the wind turbine decreases sequentially; in t3~t5, t7~t9, t 11 ~t 13Within the specified interval, the wind turbine power remains constant at the corresponding value for each stage. Ultimately, the wind turbine power reaches its maximum value at time t. 15 The temperature rise continues to decrease and approaches 0. The temperature rise Δτ of the wind turbine exhibits a step-like decrease, gradually approaching the ambient temperature rise. That is, after each decrease in temperature rise, there is a period of constant temperature rise, followed by another decrease. The constant temperature rise value after each decrease gradually decreases, eventually approaching the ambient temperature rise Δτ. ∞ Specifically, this manifests as follows: during t2~t4, t5~t8, t 10 ~t 12 t 14 ~t 16 Within the same range, the temperature rise of the wind turbine decreases sequentially; in t4~t5, t8~t 10 t 12 ~t 14 Within the specified intervals, the temperature rise of the wind turbine remains constant at the corresponding values ​​for each stage. Ultimately, the temperature rise reaches t... 16 It then continued to decrease and eventually stabilized at the ambient temperature rise Δτ. ∞ nearby.

[0174] In some embodiments, the testing method further includes the following steps:

[0175] The controller gradually reduces the wind turbine power in a segmented linear reduction mode. This segmented linear reduction mode means that after each segment of linear power reduction, the wind turbine is kept at a constant power level until its temperature drops to a new steady-state value. Then, the power is reduced again following the linear reduction pattern, and the wind turbine continues to operate at the reduced power level until its temperature drops to a new steady-state value. This continues until the wind turbine reaches zero power and its cooling system continues to operate.

[0176] The controller maintains the ratio of the wind turbine's heat dissipation rate to its heat capacity during the cooling process. Constant, meaning the Reynolds number of the cooling medium flow remains constant until the temperature of the wind turbine drops to the ambient temperature;

[0177] The controller obtains the thermal response time constant of the entire cooling process of the wind turbine and its cooling system based on the cooling curve of the wind turbine's cooling process described above.

[0178] like Figure 9 As shown in the figure, the vertical axis represents the wind turbine power P (including rated power Pe and zero power P0) and the wind turbine temperature rise Δτ (including initial related temperature rise and steady-state temperature rise Δτ). ∞The horizontal axis represents time T. Initially, the wind turbine operates stably at its rated power Pe, corresponding to a specific temperature rise state. Subsequently, the wind turbine power exhibits a distinct sawtooth-like downward trend, with multiple fluctuations in power, gradually decreasing from the rated power Pe to zero power P0. Simultaneously, the wind turbine temperature rise also decreases continuously along with the sawtooth-like power fluctuations, experiencing small temperature fluctuations due to power fluctuations, ultimately reaching a stable temperature at time t. ∞ The steady-state temperature rise Δτ is always stable at the level corresponding to zero power P0. ∞ This curve fully presents the thermal response process of the wind turbine's temperature rise gradually decreasing from the rated power operating level to the zero-power steady-state temperature rise when the wind speed at the wind farm experiences a sawtooth-like decline in power. It can be used to analyze the dynamic heat dissipation performance of the cooling system for the wind turbine's waste heat under this condition: if the temperature rise fluctuation is small and the decay rate is fast during the power reduction process, it indicates that the cooling system has strong adaptability to random power fluctuations; otherwise, optimization of the cooling system's response efficiency or heat dissipation capacity is needed. Simultaneously, the final steady-state temperature rise Δτ... ∞ It can serve as a key indicator of the thermal balance state of a wind turbine under zero-power conditions, used to assess whether the long-term heat dissipation effect of the cooling system under low-power or shutdown conditions meets the requirements for insulation protection and lifespan assurance of the wind turbine. Alternatively, Figure 9 The power curve in the calculation is not smooth. When using it, the average value filtering method can be used to obtain a continuously smoothed approximate power curve, and the calculation can be performed with the help of the smoothed approximate power curve.

[0179] In some embodiments, the testing method further includes the following steps:

[0180] When the wind turbine is in wind farm operation mode, the wind speed decreases continuously from the rated wind speed, and the wind turbine's operating power also decreases accordingly from the rated power. While the wind speed changes randomly from high to low, the overall decreasing trend of the wind speed decreases to below the wind turbine's starting wind speed for a period of time.

[0181] Alternatively, by using a process controller to adjust the pitch of the wind turbine and gradually reduce the turbine's circumferential torque, the mechanical energy input transmitted from the wind turbine to the wind turbine generator shaft system can be reduced accordingly until zero power is achieved, thereby reducing the temperature of the wind turbine generator to a stable state or consistent with the ambient temperature.

[0182] The controller maintains the ratio of the wind turbine's heat dissipation rate to its heat capacity during the cooling process. Constant, meaning the Reynolds number of the cooling medium flow is constant;

[0183] The controller acquires the cooling curve of the wind turbine corresponding to the time of the power curve reduction process.

[0184] The controller acquires the initial temperature of the wind turbine, the steady-state temperature drop value of the wind turbine and the temperature drop rate during the above process;

[0185] The controller obtains the thermal response time constant of the temperature drop process of the wind turbine and the cooling system thereof according to the above temperature drop process curve.

[0186] In some embodiments, the test method is implemented through the power curve obtained from the operation or test of the wind turbine and the corresponding temperature rise curve.

[0187] As Figure 10 shown, the test can be carried out in a workshop. Three temperature rise curves, curve 1, curve 2 and curve 3, respectively correspond to three different external cooling systems, or correspond to three working conditions of one external cooling system, for example, the flow rate of the cooling medium is different at different rotating speeds. The three curves correspond to different time constants, and a shorter time constant is better. If the curves correspond to three working conditions of one external cooling system, the cooling effect of working condition one is the best, and the cooling effect of working condition three is the worst. M is mass, C is specific heat, that is, heat generation is constant, Q is heat generation. The intersection points of the three tangent lines and the steady-state temperature rise correspond to three time constants T1, T2 and T3. In Figure 10 , the horizontal coordinate is time t, and the vertical coordinate is wind turbine power P and temperature rise Δτ. There are an initial temperature rise Δτ0 and a steady-state temperature rise Δτ that finally approaches ∞ . The three temperature rise curves 1, 2 and 3 respectively correspond to three different external cooling systems, or correspond to the cooling effects of the same external cooling system under three different working conditions (for example, the flow rate of the cooling medium is different at different rotating speeds). The intersection points of the tangent lines of the three temperature rise curves and the steady-state temperature rise Δτ ∞ respectively correspond to time constants T1, T2 and T3, and satisfy T1<T2<T3. A shorter time constant indicates that the system reaches a steady state faster, that is, the cooling effect is better. Therefore, if the three temperature rise curves correspond to three working conditions of the same external cooling system, the working condition corresponding to curve 1 has the best cooling effect, while the working condition corresponding to curve 3 has the worst cooling effect. In the above process, the heat generation of the wind turbine remains constant, the heat generation is Q, the mass of the wind turbine is m, the specific heat capacity is c, so the contribution rate q / mc of heat generation to temperature rise is a constant value.

[0188] Specifically, the test method further comprises the following steps:

[0189] During the temperature rise process, the controller keeps the ratio of the heat dissipation rate of the wind turbine to the heat capacity of the wind turbine constant, that is, the Reynolds number of the cooling medium flow is constant, and keeps the ratio of the heat loss power of the wind turbine to the heat capacity of the wind turbine constant;

[0190] The controller obtains the temperature rise curve of the wind turbine, and according to the temperature rise curve , , values and relational expression (3) determines the thermal response time constant of the temperature rise process of the wind turbine .

[0191] In some embodiments, the controller implements the experimental method through the power curve obtained from the operation or test of the wind turbine and the corresponding temperature drop curve.

[0192] As shown in Figure 11 , T1 is the shortest, the curve reflects the strongest cooling capacity, and T3 reflects the worst cooling capacity. In Figure 11 , the abscissa is time t, and the ordinate is temperature rise Δτ. The figure includes the initial temperature rise Δτ0 and the ambient temperature rise that is finally approached . Under the condition that both hA / mc and q / mc remain constant, starting from time t0, the temperature rise of the wind turbine decreases from Δτ0, forming three temperature rise curves 1, 2 and 3, the tangents of which correspond to time constants T1, T2 and T3 respectively, where T1<T2<T3. A shorter time constant indicates that the cooling system attenuates the temperature rise faster, so curve 1 corresponds to the strongest cooling capacity; a longer time constant means a slower cooling speed, so curve 3 corresponds to the worst cooling capacity. Finally, all three temperature rise curves gradually decrease and approach the ambient temperature rise . The time constants T1, T2 and T3 can be determined by geometric construction: at time t0, draw tangents to temperature rise curve 1, curve 2 and curve 3 respectively, extend the tangent of each curve at t0 to intersect with the horizontal straight line corresponding to the ambient temperature rise . The time intervals between t0 and the projection points of the intersection points of each tangent and the horizontal straight line on the time axis are defined as the corresponding time constants T1, T2 and T3 respectively. In summary, the time constant is determined by the intersection position of the tangent of the temperature rise curve at t0 and the straight line corresponding to the ambient temperature rise .

[0193] In some embodiments, the test method further comprises the following steps:

[0194] During the temperature drop process, keep the ratio of the heat dissipation rate of the wind turbine to the heat capacity of the wind turbine constant, that is, the process controller controls the flow of the cooling medium in the cooling system to maintain a constant Reynolds number in the pipeline, and keeps the ratio of the heat loss power of the wind turbine to the heat capacity of the wind turbine constant during the process when the aforementioned ratio is constant;

[0195] The controller obtains the cooling curve of the wind turbine and calculates the temperature rise value of the process in the cooling curve. Initial value New steady-state values Numerical values ​​and relational expressions (3) Determine the thermal response time constant of the cooling process of the wind turbine.

[0196] like Figure 12 As shown, there are three cooling curves with dimensionless vertical axes, calculated by dividing the temperature rise by the initial temperature rise and the current power by the rated power. The temperature drop from 1 to 0.368°C has a characteristic feature, with the intersection point being T2. The time taken for the temperature to drop to 0.368°C of the rated temperature rise is the time constant of the cooling process. Obtaining the cooling time constants of the three different cooling systems allows us to determine which system is better or worse. The goal is to maximize the cooling capacity of the cooling system to achieve optimal performance. A smaller T1 indicates stronger cooling capacity.

[0197] The purpose of this invention is to address the process by which a wind turbine generates heat (or produces heat), causing a temperature rise, and then uses a cooling system to suppress this temperature rise and control it within the allowable temperature range of the wind turbine's insulating components (or insulating materials) and magnetic components. This process is essentially a typical thermodynamic system. The invention establishes a dynamic thermal path for this heat generation and cooling dynamic system. This is achieved by using sensors (including temperature sensors and power sensors) in the forward channel of the process controller, and by employing a specialized algorithm based on this information, to acquire the dynamic characteristics of the thermodynamic system during the cooling transition of the heat source. This results in a test method and apparatus for identifying the thermodynamic dynamic transfer relationship between the wind turbine's power and temperature rise, as well as the dynamic real-time performance of its cooling system, throughout the entire cooling process.

[0198] This invention provides a test method and apparatus for identifying the relationship between the power output and temperature rise of a wind turbine generator and the performance of its cooling system. For the thermodynamic dynamic system of heat generation and cooling in a wind turbine generator, a mathematical description is first performed to… This concept centrally represents the losses generated during the electromechanical energy conversion process within a wind turbine generator, which are ultimately transferred or transferred as heat energy. Specifically, it represents the heat energy generated within the wind turbine generator per unit time. Here, c represents the specific heat capacity of the physical heat source components within the wind turbine generator; m represents the mass of these components (such as the armature winding and its impregnated insulating varnish, magnetic poles, and permanent magnet poles); h represents the surface heat transfer coefficient (or surface heat dissipation coefficient) of these components; and A represents the surface heat dissipation area of ​​these components. This represents the temperature rise of the physical heat source components inside a wind turbine relative to the surrounding medium. According to the principle of energy conservation, this is the amount of heat generated by the heat source per unit time. It should be equal to the heat (or thermal energy) transferred out or dissipated from the heat source within the same time period. ), plus the heat (or thermal energy) absorbed by the heat source ),Right now: + = ,here , , Since both are known functions of time, the general solution of this differential equation is:

[0199] Equation (1)

[0200] exist and When constant, and with initial conditions: , Then the general solution above is expressed as equation (2).

[0201] In the formula, It is the initial temperature rise of the physical heat source components inside the wind turbine relative to the surrounding medium;

[0202] It is a steady-state temperature rise, that is The temperature rise, denoted as ;

[0203] It is the time constant of the wind turbine when it heats up, denoted as It is a characteristic number with the dimension of time, which reflects the ratio between the heat capacity of the wind turbine's heat source body and its heat dissipation capacity during the temperature change process of the wind turbine.

[0204] Organize it into a form that reflects the characteristics of a temperature rise transition process:

[0205] Equation (3).

[0206] When the process controller monitors the internal heat source and cooling medium of the wind turbine to ensure that their temperatures are the same, that is, when the initial temperature rise is zero, The above relation (3) becomes Relation (4), It is the time constant of the wind turbine when it heats up, denoted as It is a characteristic number with the dimension of time, which reflects the ratio between the size of the heat source body itself and its heat dissipation capacity during the temperature change of the internal heat source of the wind turbine.

[0207] The process controller controls the wind turbine to quickly shut down from the operating state, internal heat source The above relation (3) becomes Relation (5) It is the time constant of the internal heat source of the wind turbine being cooled, denoted as . It is a characteristic number with the dimension of time, representing the ratio between the heat capacity of the wind turbine's heat source and its heat dissipation capacity during the temperature change process. For At this particular moment, the exponents in the above relations (4) and (5) will equal -1. Therefore, the corresponding This specific time, or time constant, represents the completion of 63.2% (i.e., the maximum possible range of change) of the unsteady-state process of cooling the heat source inside the wind turbine, or the remaining 36.8% from the final equilibrium state. This is related to the heat capacity of the internal heat source of the wind turbine. The smaller the value, the lower the resistance to heat transfer between the cooling channels and the cooling medium inside the wind turbine's internal heat source. The lower the heat transfer rate (i.e., the lower the heat transfer rate between the cooling channels and the cooling medium inside the wind turbine's heat source), the better. The higher the temperature of the wind turbine, the smaller the time constant of its cooling channels and cooling system, and the more sensitive the internal heat source of the wind turbine is to temperature changes in the cooling medium.

[0208] The above provides a detailed description of the test method and apparatus for identifying the relationship between wind turbine power and temperature rise and cooling system performance, as provided in the embodiments of the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention; the descriptions of the embodiments above are merely for the purpose of helping to understand the method of the present invention. The motion states of the wind turbine and the electric motor are reversible, and it can also be used for transformers.

[0209] This invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described method. This invention also provides a computer device, such as... Figure 13As shown, the system includes one or more processors 301, a communication interface 302, a memory 303, and a communication bus 304. The processors 301, communication interface 302, and memory 303 communicate with each other via the communication bus 304. The memory 303 stores computer programs; the processors 301 execute the programs stored in the memory 303 to implement the steps of the aforementioned method. The processor 301 can be a general-purpose processor, including a central processing unit (CPU), a network processor, etc.; it can also be a digital signal processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The memory 303 can include a large-capacity memory for data or instructions. The memory 303 can include a hard disk drive, a floppy disk drive, flash memory, an optical disk drive, a magneto-optical disk drive, a magnetic tape drive, or a universal serial bus drive, or a combination of two or more of these. The memory 303 is a non-volatile solid-state memory. The communication bus 304 includes hardware, software, or both, for coupling the aforementioned components together.

[0210] For those skilled in the art, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A method for testing the performance of a wind turbine generator body and its internal and external cooling systems, characterized in that, include: S1: Start the wind turbine and its cooling system. The wind turbine is started and operated by a prime mover, an electric motor, or a wind turbine in electric motor operation mode. S2: The power of the wind turbine is controlled by the prime mover or electric motor to increase from the initial state to the rated power, and the power curve and the corresponding motor temperature rise curve are recorded during this process; S3: Control the test conditions during the heating process to keep the ratio of the heat dissipation rate to the heat capacity of the wind turbine constant; S4: Based on the temperature rise curve, obtain the steady-state temperature rise parameters and temperature rise variation parameters used to characterize the thermal properties of the wind turbine generator; S5: Calculate the thermal response time constant of the cooling system of the wind turbine generator based on the temperature rise curve, the steady-state temperature rise parameter, and the temperature rise change parameter; S6: Determine the performance of the wind turbine body and its internal and external cooling systems based on the thermal response time constant.

2. The method according to claim 1, characterized in that, The method of increasing the power of the wind turbine in step S2 is a continuous linear growth mode, specifically including: continuously increasing the power of the wind turbine from the initial power to the rated power at a constant power increase rate.

3. The method according to claim 2, characterized in that, Step S2 specifically includes: gradually increasing the power of the wind turbine according to a piecewise linear growth pattern, and obtaining a power curve and a temperature rise curve of the wind turbine corresponding to the power curve; wherein, the piecewise linear growth pattern in step S2 is implemented according to the following steps: S2.1: Increase the power of the wind turbine to an initial power level and maintain the operation at the initial power level; S2.2: Continuously operate and monitor the temperature rise of the wind turbine until the temperature rise of the wind turbine reaches the steady-state value corresponding to the current power level; S2.3: Upgrade the power of the wind turbine to the next higher power level; S2.4: Repeat steps S2.2 and S2.3 until the power of the wind turbine reaches the rated power, and continue to operate until the temperature rise reaches the final steady-state temperature rise under the rated power. During the entire step-by-step power increase process from step S2.1 to step S2.4, record the power curve and the corresponding wind turbine temperature rise curve. Step S3 specifically includes: maintaining the ratio of the wind turbine's heat dissipation rate to its heat capacity during the heating process. The ratio of the heat loss power of the wind turbine to its heat capacity should be kept constant. Constant; Step S4 specifically includes: obtaining the initial temperature of the wind turbine at each stage of the segmented power increase or segmented temperature increase process, and the steady-state temperature rise of the wind turbine at the corresponding power level; Step S5 specifically includes: based on the temperature rise value in the temperature rise curve of the wind turbine generator. Initial temperature The value of steady-state temperature rise and relation Determine the thermal response time constant of the temperature rise process of a wind turbine generator. .

4. A method for testing the performance of a wind turbine generator body and its internal and external cooling systems, characterized in that, include: S1': Under natural wind conditions at the wind farm, start the prime mover of the wind turbine, i.e., the wind turbine or wind power unit, so that the motor in the wind turbine starts running from the starting wind speed; S2': By taking advantage of the natural change process of the wind speed in the wind farm randomly increasing to the rated wind speed, the output power of the wind turbine is increased from the initial power to the rated power, and the power curve and the corresponding temperature rise curve of the wind turbine are recorded throughout the process. S3': During the power increase and temperature rise process, the ratio of the heat dissipation rate to the heat capacity of the wind turbine is kept constant by adjusting the externally connected cooling system other than the wind turbine body. S4': Based on the temperature rise curve, obtain the steady-state temperature rise of the wind turbine after reaching its rated power and the temperature rise rate during the heating process; S5': Calculate the thermal response time constant of the wind turbine body and its internal and external cooling systems based on the temperature rise curve of the wind turbine, the steady-state temperature rise and the temperature rise rate obtained in step S4'; S6': Determine the performance of the wind turbine body and its internal and external cooling systems based on the thermal response time constant.

5. The method according to claim 4, characterized in that, It also includes the following steps: After the wind turbine generator reaches its rated power and continues to operate at the rated power until the wind turbine generator reaches its steady-state temperature rise, the wind turbine generator is shut down while the external cooling system other than the wind turbine generator body is not shut down, and the cooling system is kept in the same operating state as before the wind turbine generator was shut down. Controlling the ratio of the wind turbine's heat dissipation rate to its heat capacity during the heating process. Constant; Obtain the power curve of the wind turbine and the cooling curve of the wind turbine corresponding to the power curve in time, the initial temperature and cooling rate when the wind turbine is operating at full power, and reduce it to the ambient temperature; The thermal response time constant of the wind turbine cooling process is obtained from the cooling curve of the wind turbine.

6. The method according to claim 4, characterized in that, It also includes the following steps: Once the wind turbine's output reaches the rated power and continues to operate at the rated power until the wind turbine reaches its steady-state temperature rise, the wind turbine is shut down while the external cooling system connected to the wind turbine is disconnected. The power curve of the motor and the time-related cooling curve of the motor, the initial temperature of the motor when the motor is at full power, and the cooling rate of the motor are obtained. Until the motor temperature drops to the ambient temperature, the thermal response time constant of the motor cooling process is obtained from the motor cooling process curve.

7. The method according to claim 4, characterized in that, It also includes the following steps: The motor operating power is gradually reduced according to a linear decreasing pattern until it stops at zero power, and the power curve and the corresponding cooling curve are obtained during this process. During the motor cooling process, the ratio of the motor's heat dissipation rate to its heat capacity should be controlled and maintained. Constant; The initial temperature of the motor at the start of the cooling process is obtained, and the cooling system continues to run until the motor temperature drops to the ambient temperature after the motor power drops to zero. Based on the cooling curve of the motor cooling process, the thermal response time constant of the motor and the cooling system of the motor during the cooling process is obtained.

8. The method according to claim 4, characterized in that, It also includes the following steps: The motor operating power is gradually reduced using a piecewise linear power reduction mode. This mode involves: first, reducing the motor power to an initial power level and maintaining constant operation, continuously monitoring the motor temperature until it reaches the steady-state value corresponding to the current power level; then, reducing the power to the next lower power level and maintaining constant operation, again monitoring and waiting for the temperature to drop to the new steady-state value corresponding to that power level; repeating this process of reducing power and waiting for the temperature to reach the corresponding steady-state value until the motor power drops to zero; after the motor power drops to zero, the cooling system continues to operate until the motor temperature drops to ambient temperature; during the motor cooling process, the ratio of the motor's heat dissipation rate to its heat capacity is controlled and maintained. Maintain a constant temperature until the motor temperature drops to ambient temperature; Based on the cooling curve of the motor cooling process, the thermal response time constant of the entire cooling process of the motor and its cooling system is obtained.

9. The method according to claim 4, characterized in that, It also includes the following steps: When the wind turbine is in operation at the wind farm, cooling is achieved to bring its temperature down to a stable state or match the ambient temperature through the following methods: First, the wind speed naturally decreases from the rated wind speed to below the turbine's starting wind speed, causing the wind turbine's operating power to decrease from the rated power to zero. Second, the turbine's pitch is adjusted to reduce its output torque, thereby reducing the mechanical energy input to the wind turbine's shaft system until the turbine's operating power reaches zero. During this cooling process, the ratio of the wind turbine's heat dissipation rate to its heat capacity is controlled and maintained. Constant; Obtain the cooling curve of the wind turbine corresponding to the time of the accompanying power reduction process; Based on the cooling curve, the initial temperature of the wind turbine, the steady-state cooling value of the wind turbine, and the temperature drop rate are obtained at the beginning of the cooling process. Based on the cooling curve, the initial temperature, the steady-state cooling value of the wind turbine generator, and the temperature drop rate, the thermal response time constant of the cooling process of the wind turbine generator and its cooling system is obtained.

10. A testing system for the performance of a wind turbine generator body and its internal and external cooling systems, characterized in that, The system performs the method according to any one of claims 1-3, the system comprising: The start control module is used to start the prime mover corresponding to the wind turbine, drive the wind turbine, and start the externally connected cooling system of the wind turbine. The power control module is used to control the power of the wind turbine to increase from the initial state to the rated power, and to record the power curve and the corresponding wind turbine temperature rise curve during the process. The test condition control module is used to control the test conditions during the heating process so that the ratio of the heat dissipation rate to the heat capacity of the wind turbine remains constant. The parameter acquisition module is used to acquire steady-state temperature rise parameters and temperature rise variation parameters that characterize the thermal properties of the wind turbine based on the temperature rise curve. The calculation module is used to calculate the thermal response time constant of the cooling system of the wind turbine generator based on the temperature rise curve, the steady-state temperature rise parameter, and the temperature rise change parameter. A cooling performance determination module is used to determine the performance of the cooling system based on the thermal response time constant.

11. The system according to claim 10, characterized in that, The wind turbine is replaced by an engine, electric motor, gearbox or other transmission device, diesel engine, gasoline engine, bearing, power battery and its power battery assembly, capacitor, resistor or inductor.

12. A testing system for the performance of a heat-generating equipment body and its internal and external cooling systems, characterized in that, The system includes: The start control module is used to start the prime mover corresponding to the heat-generating equipment, drive the heat-generating equipment, and start the cooling system externally connected to the heat-generating equipment. The power control module is used to control the power of the heat-generating equipment to increase from the initial state to the rated power, and to record the power curve and the corresponding temperature rise curve of the heat-generating equipment during this process. The test condition control module is used to control the test conditions during the heating process so that the ratio of the heat dissipation rate to the heat capacity of the heat-generating equipment remains constant. The parameter acquisition module is used to acquire steady-state temperature rise parameters and temperature rise change parameters that characterize the thermal properties of the heat-generating equipment based on the temperature rise curve. The calculation module is used to calculate the thermal response time constant of the cooling system of the heat-generating equipment based on the temperature rise curve, the steady-state temperature rise parameter, and the temperature rise change parameter. A cooling performance determination module is used to determine the performance of the cooling system based on the thermal response time constant.

13. A testing system for the performance of a heat-generating equipment body and its internal and external cooling systems, characterized in that, include: The prime mover start control module is used to start the prime mover used to drive the heat-generating equipment in a natural environment, and to start the external cooling equipment matched with the heat-generating equipment. The flow rate of the cooling medium used by the external cooling equipment increases from zero. The operation status recording module is used to record the power curve and the corresponding temperature rise curve of the heat-generating equipment during the entire process of the output power of the heat-generating equipment increasing from the initial power to the rated power, by taking advantage of the natural change process of the wind speed in the natural environment randomly increasing to the rated wind speed. The cooling system control module is communicatively connected to an external cooling system other than the heat-generating equipment body. It is used to control the externally connected cooling system during the power increase and temperature rise process so that the ratio of the heat dissipation rate to the heat capacity of the heat-generating equipment remains constant. The temperature rise parameter extraction module is used to obtain the steady-state temperature rise of the heat-generating equipment after it reaches its rated power and the temperature rise rate during the heating process, based on the temperature rise curve recorded by the operating status recording module. The thermal response time constant calculation module is used to calculate the thermal response time constant of the heat-generating equipment body and its internal and external cooling systems based on the temperature rise curve, the steady-state temperature rise and temperature rise rate obtained by the temperature rise parameter extraction module; The cooling performance evaluation module is used to determine the performance of the heat-generating equipment body and its internal and external cooling systems, as well as whether the temperature rise process has self-balancing capability, based on the thermal response time constant obtained by the thermal response time constant calculation module.

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