Doubly-fed wind generator rotor temperature measuring method

Abstract

The invention discloses a doubly-fed wind generator rotor temperature real-time measurement method, which comprises the following steps of: performing rotor wire embedding on a rotor; pre-embedding at least three temperature sensors; leading out a lead of the temperature sensor to carry out vacuum paint dipping on the rotor; the stator, the rotor, the end cover and the air cooler are installed in place; a fixed shaft prepared in advance is installed in a shaft hole of a slip ring of the generator; the temperature measuring slip ring is sleeved on the fixed shaft; a lead of the temperature sensor is connected with a temperature measuring slip ring fixed on the fixed shaft; the hot spot temperature of the non-driving end of the rotor is collected in real time through the temperature sensor, and real-time measurement of the temperature of the rotor is completed. The method can accurately evaluate the temperature of the local hot spot at the end part of the rotor, and avoids the risk that the rotor temperature exceeds a specified value to cause the operation of a defective product in a wind field.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature measurement of wind turbines, and in particular to a method for measuring the rotor temperature of a doubly-fed wind turbine. Background Art

[0002] Currently, as a kind of environmental-friendly energy, with the increasing shortage of modern energy, wind power is attracting more and more attention, and the investment in wind turbines is also increasing.

[0003] Generally, the middle part of the generator rotor has good ventilation and is called the cold end; while the non-driving end is wrapped with non-magnetic tape and other insulating filling materials due to structural reasons, resulting in poor ventilation and higher temperature, so it is called the hot end. The existing national standard method for measuring the generator rotor is the resistance method (average value method), which cannot truly reflect the local hot spot temperature at the end. Especially for the rotor end of a doubly-fed motor, due to the high coil heat load and poor ventilation and heat dissipation at the end, the local temperature at the end is very high, even exceeding the tolerance temperature of the insulating material, seriously affecting the service life of the generator, and even causing the rotor end to burn out, resulting in major faults that lead to the removal from the shelf. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for measuring the rotor temperature of a doubly-fed wind turbine, which can accurately evaluate the temperature of the local hot spot at the rotor end and avoid the risk of defective products operating in the wind farm due to the rotor temperature exceeding the specified value.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A method for real-time measuring the rotor temperature of a doubly-fed wind turbine includes:

[0007] Performing rotor winding on the rotor;

[0008] Axially embedding at least three temperature sensors inside the upper-layer coil at the non-driving end of the rotor;

[0009] Leading out the leads of the temperature sensors through the leads of the rotor and the shaft hole at the non-driving end of the generator shaft;

[0010] Wrapping non-magnetic tape on the surface of the upper-layer coil at the non-driving end of the rotor and performing vacuum impregnation on the rotor;

[0011] Thermally sleeving the stator matching the rotor into the generator frame, installing the rotor into the frame and inside the stator, installing an end cover at the end of the frame, and installing the air cooler of the generator on the top of the frame;

[0012] Installing a pre-prepared fixed shaft into the shaft hole of the slip ring of the generator and measuring the runout of the fixed shaft to ensure the concentricity between the fixed shaft and the slip ring.

[0013] The temperature measuring slip ring is sleeved on the fixed shaft by interference fit, and the runout of the temperature measuring slip ring is measured to ensure the concentricity between the temperature measuring slip ring and the special small shaft;

[0014] Connect the lead wire of the temperature sensor to the temperature measuring slip ring fixed on the fixed shaft;

[0015] The hot spot temperature at the non-driving end of the rotor is collected in real time through the temperature sensor to complete the real-time measurement of the rotor temperature.

[0016] Furthermore, the rotor winding of the rotor is as follows:

[0017] Put the insulating paper at the bottom of the rotor core slot, embed the lower layer coil of the rotor into the rotor core slot, place the interlayer insulation on the top surface of the lower layer coil, embed the upper layer coil into the rotor core slot, and place the slot wedge on the top surface of the upper layer coil.

[0018] Furthermore, the axial distances between the three temperature sensors and the slot opening of the rotor core slot are 100 - 150 mm, 200 - 250 mm, and 300 - 350 mm respectively, and each temperature sensor is fixed by conformable felt.

[0019] Furthermore, the temperature sensor is a PT100 temperature sensor.

[0020] Furthermore, use a non-taped winding machine to wind a 6 - 7 mm non-taped on the surface of the upper layer coil at the non-driving end of the rotor, and use impregnating varnish to impregnate the rotor under a preset temperature and pressure in a vacuum.

[0021] Furthermore, the contact surface between the air cooler and the machine base is tightly sealed with foam.

[0022] Furthermore, the fixed shaft is installed in the shaft hole of the slip ring by three-point hole positioning, and then the runout of the fixed shaft is measured with a dial indicator to ensure the concentricity between the fixed shaft and the rotating shaft.

[0023] Furthermore, the fixed shaft is made of stainless steel and its diameter matches the diameter of the shaft hole of the slip ring.

[0024] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0025] The measurement method of the present invention can accurately measure the hot spot temperature at the end of the rotor, which is beneficial to evaluating the rotor temperature rise, ensuring that the end temperature of the rotor does not exceed the temperature resistance value of the insulating material during operation, avoiding the major failure of the generator rotor burnout and causing the generator to be taken off the shelf, and can effectively ensure the 20-year full-cycle operation life of the generator. Description of the Drawings

[0026] Figure 1 It is a schematic diagram of the installation of the temperature sensor in the measurement method of the present invention.

[0027] Figure 2 It is a schematic structural diagram of the fixed shaft of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] like Figure 1 , Figure 2 As shown, this embodiment provides a real-time measurement method for the rotor temperature of a doubly-fed wind turbine generator, comprising:

[0030] S1, inserting the rotor 6 into the rotor; the details are as follows:

[0031] Place insulating paper at the bottom of the rotor core slot, and embed the lower coil of rotor 6 into the rotor core slot, place interlayer insulation on the top of the lower coil, and embed the upper coil into the rotor core slot, and place slot wedges on the top of the upper coil.

[0032] S2. At least three temperature sensors 1 are embedded in the axial direction inside the upper coil at the non-driving end of the rotor 6. In this embodiment, three temperature sensors 1 are arranged as an example. The axial distances between the three temperature sensors 1 and the slots of the rotor core slots are 100-150 mm, 200-250 mm and 300-350 mm respectively, and each temperature sensor 1 is fixed with conformable felt.

[0033] S3, lead the lead of the temperature sensor 1 through the lead of the rotor 6 and the shaft hole of the non-driving end of the generator shaft 9;

[0034] S4, winding a non-weft tape on the surface of the upper coil at the non-driving end of the rotor 6, and performing vacuum varnishing on the rotor 6; the details are as follows:

[0035] A 6-7 mm slatted tape is wound around the surface of the upper coil at the non-driving end of the rotor 6 using a slatted tape winding machine, and the rotor 6 is vacuum dipped in varnish at a preset temperature and pressure using a varnishing pot.

[0036] S5. Heat-shrink the stator 4 that matches the rotor 6 into the inner part of the generator housing 5, install the rotor 6 into the inner part of the housing 5 and locate it inside the stator 4. Install the end cover 7 at the end of the housing 5, install the air cooler 8 of the generator on the top of the housing 5, and use foam to press and seal the contact surface between the air cooler 8 and the housing 5.

[0037] S6. Install the pre-prepared fixed shaft 2 into the shaft hole of the slip ring 10 of the generator, and measure the runout of the fixed shaft 2 to ensure the concentricity between the fixed shaft 2 and the slip ring. Specifically as follows:

[0038] Install the fixed shaft 2 into the shaft hole of the slip ring by using three-point hole positioning, and then use a dial indicator to measure the runout of the fixed shaft 2 to ensure the concentricity between the fixed shaft 2 and the rotating shaft 9.

[0039] S7. Sleeve the temperature-measuring slip ring 3 on the fixed shaft 2 by interference fit, and measure the runout of the temperature-measuring slip ring 3 to ensure the concentricity between the temperature-measuring slip ring 3 and the special small shaft.

[0040] S8. Connect the lead wire of the temperature sensor 1 to the temperature-measuring slip ring 3 fixed on the fixed shaft 2.

[0041] S9. Real-time collect the hot spot temperature at the non-driving end of the rotor 6 through the temperature sensor 1 to complete the real-time measurement of the temperature of the rotor 6.

[0042] The temperature sensor in this embodiment is a PT100 temperature sensor, which has Class A accuracy, can effectively avoid electromagnetic interference, ensure the reliability of the temperature, and reduce errors.

[0043] The fixed shaft is made of stainless steel, and its diameter matches the diameter of the shaft hole of the slip ring.

[0044] The maximum rotational speed of the temperature-measuring slip ring can reach 5000 revolutions per minute.

[0045] Use the measurement method of the present invention and the traditional resistance method for test comparison, and the test results are shown in Table 1 below:

[0046]

[0047] Table 1 Test comparison between the measurement method of the present invention and the traditional resistance method

[0048] As can be seen from Table 1, there is a large difference in the temperature rise measured by the traditional resistance method and the measurement method of the present invention. Although the temperature rise of the traditional resistance method meets the requirement of the protocol of 90K and also meets the actual use requirements, theoretically the highest operating temperature of the rotor in summer will not exceed the temperature resistance value of 180°C of the Class H insulation material and will not cause the failure of the rotor end to burn out, but in the actual wind farm, there has already been a failure of the rotor to burn out due to the high temperature at the rotor end. The traditional resistance method has great defects and cannot accurately evaluate the highest temperature of the rotor.

[0049] However, the measurement method of the present invention measures that the temperature rise of the hottest point exceeds the required value of 90K in the protocol, and the highest operating temperature in summer has also exceeded the temperature resistance value of 180°C of the insulating material. The measurement method of the present invention has obtained the highest temperature of the rotor during the test, and can accurately evaluate the rotor temperature in advance, avoid the failure of the rotor end burning in the wind field, and avoid the serious consequence of the generator being taken off the shelf, and can effectively ensure the safe operation and full-cycle service life of the generator.

[0050] The above is only a preferred embodiment of the present invention for patent, but the protection scope of the present invention for patent is not limited thereto. Any person skilled in the art within the scope disclosed by the present invention for patent, according to the technical solution and inventive concept of the present invention for patent, makes equivalent substitutions or changes, all belong to the protection scope of the present invention for patent.

Claims

1. A real-time measurement method for the rotor temperature of a doubly-fed wind turbine generator, characterized in that: include, Carry out rotor embedding on the rotor; At least three temperature sensors are embedded in the upper coil at the non-driving end of the rotor along the axial direction; Lead the lead of the temperature sensor through the lead of the rotor and the shaft hole of the non-driving end of the rotating shaft of the generator; Winding a non-weft tape on the surface of the upper coil at the non-driving end of the rotor, and vacuum impregnating the rotor; The stator matching the rotor is shrink-fitted into the generator frame, the rotor is installed into the frame and positioned inside the stator, the end cover is installed at the end of the frame, and the air cooler of the generator is installed on the top of the frame; Install the prepared fixed shaft into the shaft hole of the generator slip ring, and measure the runout of the fixed shaft to ensure the concentricity of the fixed shaft and the slip ring; The temperature measuring slip ring is mounted on the fixed shaft through interference fit, and the runout of the temperature measuring slip ring is measured to ensure the concentricity of the temperature measuring slip ring and the special small shaft; Connect the lead wire of the temperature sensor to the temperature measuring slip ring fixed on the fixed shaft; The temperature sensor is used to collect the hot spot temperature at the non-driving end of the rotor in real time to complete the real-time measurement of the rotor temperature.

2. The method for real-time measurement of rotor temperature of a doubly-fed wind turbine generator according to claim 1, characterized in that: The rotor embedding is specifically as follows: Place the insulating paper at the bottom of the rotor core slot, and embed the lower coil of the rotor into the rotor core slot, place the interlayer insulation on the top of the lower coil, and embed the upper coil into the rotor core slot, and place the slot wedge on the top of the upper coil.

3. The real-time temperature measurement method of a doubly-fed wind turbine generator rotor according to claim 1, characterized in that: The axial distances between the three temperature sensors and the slot openings of the rotor core slots are 100-150 mm, 200-250 mm and 300-350 mm respectively, and each temperature sensor is fixed with conformable felt.

4. The method for real-time measurement of rotor temperature of a doubly-fed wind turbine generator according to claim 3, characterized in that: The temperature sensor is a PT100 temperature sensor.

5. The method for real-time measurement of rotor temperature of a doubly-fed wind turbine generator according to claim 1, characterized in that: A 6-7 mm slatted tape is wound on the surface of the upper coil at the non-driving end of the rotor using a slatted tape winding machine, and the rotor is vacuum impregnated with paint at a preset temperature and pressure using a paint pot.

6. The method for real-time measurement of rotor temperature of a doubly-fed wind turbine generator according to claim 1, characterized in that: The contact surface between the air cooler and the base is sealed with foam compression.

7. The real-time temperature measurement method of a doubly-fed wind turbine generator rotor according to claim 1, characterized in that: The fixed shaft is installed in the shaft hole of the slip ring using three-point hole positioning, and then the runout of the fixed shaft is measured using a thread gauge to ensure the concentricity of the fixed shaft and the rotating shaft.

8. The method for real-time measurement of rotor temperature of a doubly-fed wind turbine generator according to claim 1, characterized in that: The fixed shaft is made of stainless steel, and its diameter matches the diameter of the shaft hole of the slip ring.

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