Low-temperature heating fan unit based on back-up power supply and starting control method thereof

Abstract

The invention discloses a low-temperature heating fan unit based on a back-up power supply and a starting control method thereof, and belongs to the field of wind power generation. A super capacitor module is arranged in the variable pitch cabinet, and a plurality of uniformly distributed low-voltage heaters are buried in gear oil. The super capacitor module is electrically connected with the voltage stabilizer, the voltage stabilizer is electrically connected with one ends of the power supply lines through the slip rings, and the other ends of the power supply lines are electrically connected with the low-voltage heaters respectively. When the unit is shut down or the power grid is powered off, the super-capacitor module supplies power to the low-voltage heater to heat the gear oil so as to keep the gear oil at a certain temperature in a low-temperature environment. The multiple low-pressure heaters are evenly arranged at all positions in the gearbox, gear oil can be globally and evenly heated at low temperature, and gear oil aging caused by local heating is avoided; and when the unit has a starting condition, the unit is started and connected to the grid, so that the low-temperature turning time of the unit is shortened, the power generation loss caused by waiting is reduced, and the benefit of a wind power plant is improved.

Description

Technical Field

[0001] The invention relates to a low-temperature heating fan unit based on a backup power supply and a start-up control method, belonging to the technical field of wind power generation. Background Art

[0002] With the increasing capacity of wind turbines, variable pitch control and variable speed constant frequency advanced wind power technologies have become the mainstream control methods for wind turbines. Since wind energy is a low-density energy source with unstable and random characteristics, control technology is the key to the safe and efficient operation of wind turbines. Therefore, the development of generator systems and advanced control technologies that are suitable for wind power conversion, reliable operation, high efficiency, good control and power supply performance are the key to the promotion and application of wind power generation.

[0003] Low temperature has a great impact on the unit. In northern my country, the lowest temperature in winter can reach below -40 degrees Celsius, which is also the time of the year when the wind speed is the highest. However, the minimum operating temperature of wind turbines is designed to be above -20 degrees Celsius, and the mechanical properties of the composite materials of blade components will change at low temperatures, and vibration will cause structural damage, making it difficult to achieve matching output power.

[0004] Among them, one of the mechanical parts that is most affected by the winter temperature is the gearbox. The oil cavity of the existing gearbox or external oil tank is generally a cavity with a single structure, in which the lubricating oil is stored and used to lubricate and cool the lubricated parts. The lubricating oil has a characteristic that its viscosity increases continuously as the temperature decreases. When the gearbox is in a low temperature environment, the viscosity of the lubricating oil is too large to be normally used for splash lubrication or forced lubrication of the lubricated parts. Therefore, a heating device is set in the oil cavity of the gearbox or the external oil tank. Under low temperature conditions, the gearbox needs to heat the lubricating oil by a heating device before working to reduce the viscosity of the lubricating oil. When the lubricating oil in the gearbox reaches a certain temperature, the viscosity of the lubricating oil is reduced to a certain value, and the oil pump that draws the lubricating oil can work normally, and the gearbox can also enter a normal working state. At this time, the wind turbine can start normally. In the prior art, electric heating is generally used to heat the gear oil. However, the current electric heater has the following disadvantages:

[0005] 1) The heater in the existing fan is generally a 220V AC heater. Due to its high power, the gear box needs to rotate (impeller rotates) to circulate the gear oil during heating. Otherwise, local heating will accelerate the aging of the gear oil. During the fan shutdown period, there may be no wind, blade icing, etc., which may cause the fan to be unable to rotate or not rotate. Therefore, there are certain risks in directly starting the existing electric heater at this time.

[0006] 2) After the power grid is out of power for a long time, the heater cannot work normally due to lack of power, and the gear oil cannot be heated during the downtime. After the unit is powered on, it takes a long time from starting heating to starting the wind turbine and connecting to the grid. This time will seriously affect the batch start time of the wind turbines, and then affect the power generation and power generation time of the wind turbine generator set. Calculated as 30 minutes for each wind turbine, and 50 wind turbines in the wind farm, the generator time affected in a single time is 50*0.5=25 hours. Summary of the invention

[0007] In order to solve the above-mentioned problems that currently exist, the present invention provides a low-temperature heating fan unit based on a backup power supply and a startup control method, and the technical solution is as follows:

[0008] As one aspect of the present invention, a low-temperature heating fan unit based on a backup power supply is provided, comprising: a supercapacitor module, a slip ring, a power supply line, a low-voltage heater, a voltage stabilizer, a gear box and a hub; the low-voltage heater is evenly buried in the gear oil of the gear box, the supercapacitor module is located inside the pitch cabinet of the hub, the supercapacitor module is electrically connected to the voltage stabilizer, the voltage stabilizer is electrically connected to one end of several power supply lines through the slip ring, and the other end of each power supply line is electrically connected to one of the low-voltage heaters.

[0009] Furthermore, it also includes a timing controller, one end of which is electrically connected to the voltage regulator, and the other end of which is electrically connected to each of the low-voltage heaters, and the timing controller is used to generate an intermittent switching signal to control the conduction and disconnection of the power supply circuit of the low-voltage heater.

[0010] Furthermore, the number of the timing controllers is the same as the number of the low-voltage heaters, and each timing controller is connected to a corresponding low-voltage heater to control the on and off of the power supply circuit corresponding to the low-voltage heater.

[0011] Furthermore, it also includes a remote controller, a remote switch is arranged inside the timing controller, the remote switch is a normally-off switch, one end of the remote controller is electrically connected to the voltage regulator, and the other end of the remote controller is electrically connected to the timing controller, and the remote controller is used to remotely control the remote switch to start or shut down the timing controller.

[0012] Furthermore, a contactor is provided between the supercapacitor module and the voltage stabilizer, and the normally closed contact of the contactor is controlled by a main control controller inside the pitch cabinet to connect or disconnect the power supply circuit of the supercapacitor module.

[0013] Furthermore, the supercapacitor module can output a DC voltage of 24V or 48V through a voltage stabilizer.

[0014] As another aspect of the present invention, a startup control method of a low-temperature heating fan unit based on a backup power supply is provided, which is applied to the above-mentioned low-temperature heating fan unit based on a backup power supply, comprising:

[0015] S100, when the power supply grid of the fan unit is powered off and the temperature is lower than a preset temperature, connecting the power supply line between the supercapacitor module and the low-voltage heater power supply;

[0016] S200, heating the gear oil by the low-pressure heater.

[0017] Furthermore, step S100 includes:

[0018] S110, when the power supply grid of the fan unit is powered off and the temperature is lower than the preset temperature, the main controller controls to connect the power supply circuit of the supercapacitor module;

[0019] S120, determining whether the remote controller turns off control of the timing controller;

[0020] S130, if yes, control the remote switch in the timing controller to close through the remote controller; if no, the timing controller controls the remote switch to be turned on and off alternately according to a preset time interval;

[0021] S140, the low-pressure heater intermittently heats the gear oil under the control of the timing controller;

[0022] S150, when the fan unit and the remote controller are powered on, the main controller controls the contactor to power off, disconnects the supercapacitor module power supply circuit, and turns off the low-voltage heater;

[0023] S160, determining whether the gear oil temperature is greater than a threshold;

[0024] S170: If yes, start the fan unit;

[0025] S180, if not, start the AC heater to heat the gear oil, start the low-temperature cranking function, and repeat steps S160 to S180 until the fan unit start conditions are met and then start the fan unit.

[0026] The beneficial effects of the present invention are:

[0027] (1) When the unit is powered off and cannot be heated, the supercapacitor module is used to heat the gear oil to keep the gearbox at a certain temperature. When the unit is ready to start, it can be started directly, thereby reducing the waiting time for turning and increasing the power generation of the unit;

[0028] (2) Since it is a low-voltage system, no inverter circuit is required, which can reduce the number of components and volume of the system. At the same time, the system is directly powered by the supercapacitor module, which can effectively solve the problem of gear oil heating when the unit is not powered on.

[0029] (3) Since a low-temperature heater is used and intermittent heating is adopted, the aging effect on the gear oil is relatively small;

[0030] (4) Evenly arranging multiple low-pressure heaters in the gear oil can achieve relatively uniform heating of the gear oil in a non-circulating state;

[0031] (5) The present invention has a wide range of applications and can be applied to various situations such as power outage, low ambient temperature, no wind or low wind, etc. The method of the present invention can also be used when the grid is powered on. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 is a structural diagram of a low-temperature heating fan unit based on a backup power supply provided by an embodiment of the present invention;

[0034] Figure 2 It is a circuit control schematic diagram of a low-temperature heating fan unit based on a backup power supply provided by an embodiment of the present invention;

[0035] Figure 3 is an intermittent power supply timing diagram provided by an embodiment of the present invention;

[0036] Figure 4 It is a flow chart of a method for starting and controlling a low-temperature heating fan unit based on a backup power supply provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0037] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0038] Embodiment 1:

[0039] Since all the lubricating oil in the gearbox is stored in this cavity, under low temperature conditions, the heater arranged in the cavity of the gearbox or external oil tank needs to heat all the lubricating oil to the expected temperature in order to complete the preheating of the gearbox. Limited by the surface power of the heater, the volume of the oil cavity and the amount of oil in the oil cavity, it takes a long time and more energy to heat all the lubricating oil in the oil cavity to the expected temperature. The preheating efficiency is low and the energy consumption is high. In other words, in winter, after the unit is shut down for a long time, it is first necessary to low-temperature crank the unit and heat the gear oil. The time is generally at least more than 30 minutes, which affects the start-up time of the wind turbine. With the increase in the number of wind turbines in the wind farm, the loss of power generation for the entire wind farm cannot be underestimated.

[0040] Based on the above reasons, the embodiment of the present invention provides a low-temperature heating fan unit based on a backup power supply, such as Figure 1 As shown, it includes: a super capacitor module 101, a nacelle 102, a slip ring 103, a power supply line 104, a low-pressure heater 105, a gear box 106, a hub 107, a blade 108, and a voltage regulator 109. The super capacitor module 101 is electrically connected to the voltage regulator 109, and the voltage regulator 109 is electrically connected to one end of a plurality of power supply lines 104 through the slip ring 103, and the other end of each power supply line 104 is electrically connected to a low-pressure heater 105. Among them, the low-pressure heater is buried in the gear oil of the gear box 106 and is evenly distributed in multiple positions in the gear oil. The super capacitor module 101 is located inside the pitch cabinet in the hub 107, and is used to provide a backup power supply for the pitch system. When the power grid has electricity, the charger in the pitch system can charge the super capacitor. The slip ring 103 connects the power supply lines and communication lines of the pitch cabinet in the nacelle 102 and the hub 107. When the power grid loses power in winter, the supercapacitor module 101 can output a DC voltage of 24V or 48V through the voltage stabilizer 109, and the power supply line 104 provides working power to each low-voltage heater 105 through the slip ring 103, so that each low-voltage heater 105 starts working to heat the gear oil in the gear box 106 at a low temperature.

[0041] Furthermore, if Figure 2 As shown, the low-temperature heating fan unit based on the backup power supply provided by the embodiment of the present invention also includes a timing controller, one end of the timing controller is electrically connected to the voltage stabilizer 109, and the other end of the timing controller is electrically connected to each low-voltage heater 105. The timing controller is powered by a supercapacitor module and is used to generate an intermittent switching signal to control the connection and disconnection of the power supply line 104 of the low-voltage heater 105. The switch state of the timing controller is disconnected by default. When the power supply grid of the fan unit is powered off or the temperature is low, the timing controller is started to generate an intermittent control signal to control the low-voltage heater 105 to intermittently heat the gear oil. Intermittent heating can prevent the gear oil from being burned or over-oxidized due to long-term local heating.

[0042] Furthermore, the number of timing controllers can be set to be the same as the number of low-voltage heaters, and each timing controller independently controls a low-voltage heater. In actual use, the low-voltage heaters can be turned on in a targeted manner, or some low-temperature heaters can be turned on according to the degree of cooling.

[0043] Furthermore, the low-temperature heating fan unit based on the backup power supply provided in the embodiment of the present invention includes not only a timing controller, but also a remote controller, one end of the remote controller is electrically connected to the voltage regulator 109, and the other end is electrically connected to the timing controller. The remote controller is powered by a supercapacitor module, and the remote controller can remotely control the remote switch inside the timing controller to start and shut down the timing controller, which is convenient for the staff to perform remote maintenance and improve work efficiency. The remote switch inside the timing controller is disconnected by default.

[0044] Furthermore, a contactor can be set between the supercapacitor module 101 and the voltage regulator 109. The normally closed contacts of the contactor are controlled by the main controller inside the pitch cabinet. When the unit is powered on or the supercapacitor module 101 is not needed for power supply, the main controller can directly disconnect the supercapacitor module power supply circuit.

[0045] Embodiment 2:

[0046] The embodiment of the present invention provides a startup control method of a low-temperature heating fan unit based on a backup power supply, which is applied to the above-mentioned low-temperature heating fan unit based on a backup power supply, such as Figure 4 As shown, including:

[0047] Step (1), when the power supply grid of the fan unit is powered off and the temperature is lower than a preset temperature, the main control controller controls the power supply circuit of the supercapacitor module to be connected;

[0048] Specifically, the normally closed contact of the contactor can be controlled by the main controller. When the power supply grid of the fan unit is powered off, the climate temperature and the ambient temperature are low, causing the gearbox temperature to be lower than the preset temperature, the lubricating oil may condense and the supercapacitor module is required to supply power. The main controller controls the contactor to be powered and connects the supercapacitor module power supply circuit; when the fan unit is powered on and the supercapacitor module is not required to supply power, the main controller controls the contactor to be powered off and disconnects the supercapacitor module power supply circuit. The preset temperature can be set according to the actual situation.

[0049] It should be understood that when the power supply grid of the fan unit is not cut off and only the temperature drops, the power supply circuit of the supercapacitor module can also be connected to start the low-voltage heater.

[0050] Step (2), determining whether the remote controller turns off control of the timing controller;

[0051] Specifically, the remote controller can control the connection and disconnection of the timing controller through a remote control switch, such as 5G, Bluetooth, etc.

[0052] Step (3), if yes, control the remote switch in the timing controller to close by the remote controller; if no, the timing controller controls the remote switch to be turned on and off alternately according to a preset time interval;

[0053] Step (4), the low-pressure heater intermittently heats the gear oil under the control of the timing controller;

[0054] Specifically, this step refers to Figure 3 The control sequence shown in FIG. 1 is used to intermittently heat the gear oil. Specifically, the control sequence is as follows: the remote switch is in the disconnected state by default. When the remote switch is closed, the timing controller starts to control the on and off of the power switch on the power supply line. Figure 3 As shown, at t0, the line is connected, and the low-voltage heater starts to work and heats the gear oil; after the timing time is reached, at t1, the line is disconnected, and the low-voltage heater stops working. After the line is disconnected for a predetermined time, at t2, the line is reconnected, and at t3, the line is disconnected again, and the cycle repeats. When the remote controller remotely disconnects the remote switch inside the timing controller, such as at t4, the timing control signal disappears immediately, and the power switch on the power supply line is disconnected, and the supercapacitor module no longer provides working power for the low-voltage heater. Intermittent heating can prevent the gear oil from being burned or over-oxidized due to long-term local heating.

[0055] Step (5), when the fan unit and the remote controller are powered on, the main controller controls the contactor to power off, disconnects the supercapacitor module power supply circuit, and turns off the low-voltage heater;

[0056] Step (6), determining whether the gear oil temperature is greater than a threshold;

[0057] Step (7), if yes, start the fan unit to run;

[0058] Step (8), if not, start the AC heater to heat the gear oil, start the low-temperature cranking function, and repeat steps (6) to (8) until the fan unit start-up conditions are met and then start the fan unit.

[0059] Specifically, after the main control controller of the wind turbine generator is powered on, it can detect the temperature of the gear oil and determine whether to start the unit directly or continue heating according to the current temperature value. If the temperature of the gear oil is not greater than the threshold value, during the period when the unit is powered on, since the unit has AC power supply, the main control controller can control the execution of step (8) to heat the gear oil by using an AC heater and a method of circulating the gear oil.

[0060] The low-temperature heating fan unit startup control method based on backup power supply provided in the embodiment of the present invention, during the shutdown of the unit or the power outage of the power grid, supplies power to multiple preset low-voltage heaters through a supercapacitor module to heat the gear oil to maintain a certain temperature of the gear oil in a low-temperature environment. On the one hand, evenly arranging multiple low-voltage heaters in various places inside the gear box can perform global uniform low-temperature heating on the gear oil, thereby avoiding local heating and aging of the gear oil caused by local overheating; on the other hand, it can effectively deal with the situation of power outage of the power grid. When the unit meets the startup conditions, it can be directly started and connected to the grid, thereby reducing the low-temperature cranking time of the unit in a low-temperature environment, reducing the loss of power generation caused by waiting, and improving the efficiency of the wind farm.

[0061] Some steps in the embodiments of the present invention may be implemented using software, and the corresponding software program may be stored in a readable storage medium, such as a CD or a hard disk.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A low-temperature heating fan unit based on a backup power supply, characterized in that: include: A supercapacitor module, a slip ring, a power supply line, a low-voltage heater, a voltage stabilizer, a gear box and a wheel hub; the low-voltage heater is evenly buried in the gear oil of the gear box, the supercapacitor module is located inside the pitch cabinet of the wheel hub, the supercapacitor module is electrically connected to the voltage stabilizer, the voltage stabilizer is electrically connected to one end of several power supply lines through the slip ring, and the other end of each power supply line is electrically connected to one of the low-voltage heaters.

2. The low-temperature heating fan unit based on backup power supply according to claim 1 is characterized in that: It also includes a timing controller, one end of which is electrically connected to the voltage regulator, and the other end of which is electrically connected to each of the low-voltage heaters. The timing controller is used to generate an intermittent switching signal to control the conduction and disconnection of the power supply circuit of the low-voltage heater.

3. The low-temperature heating fan unit based on backup power supply according to claim 2 is characterized in that: The number of the timing controllers is the same as the number of the low-voltage heaters, and each timing controller is connected to a corresponding low-voltage heater to control the on and off of the power supply circuit corresponding to the low-voltage heater.

4. The low-temperature heating fan unit based on backup power supply according to claim 2 is characterized in that: It also includes a remote controller, a remote switch is arranged inside the timing controller, the remote switch is a normally-off switch, one end of the remote controller is electrically connected to the voltage regulator, and the other end of the remote controller is electrically connected to the timing controller, and the remote controller is used to remotely control the remote switch to start or shut down the timing controller.

5. The low-temperature heating fan unit based on backup power supply according to claim 4 is characterized in that: A contactor is provided between the supercapacitor module and the voltage stabilizer. The normally closed contact of the contactor is controlled by a main control controller inside the pitch cabinet to connect or disconnect the power supply circuit of the supercapacitor module.

6. The low-temperature heating fan unit based on backup power supply according to claim 1, characterized in that: The supercapacitor module can output a DC voltage of 24V or 48V through a voltage stabilizer.

7. A startup control method for a low-temperature heating fan unit based on a backup power supply, applied to a low-temperature heating fan unit based on a backup power supply as claimed in any one of claims 1 to 6, characterized in that: include: S100, when the power supply grid of the fan unit is powered off and the temperature is lower than a preset temperature, connecting the power supply line between the supercapacitor module and the low-voltage heater power supply; S200, heating the gear oil by the low-pressure heater.

8. The method according to claim 7, characterized in that The step S100 includes: S110, when the power supply grid of the fan unit is powered off and the temperature is lower than the preset temperature, the main controller controls the power supply circuit of the supercapacitor module to be connected; S120, determining whether the remote controller turns off control of the timing controller; S130, if yes, control the remote switch in the timing controller to close through the remote controller; if no, the timing controller controls the remote switch to be turned on and off alternately according to a preset time interval; S140, the low-pressure heater intermittently heats the gear oil under the control of the timing controller; S150, when the fan unit and the remote controller are powered on, the main controller controls the contactor to power off, disconnects the supercapacitor module power supply circuit, and turns off the low-voltage heater; S160, determining whether the gear oil temperature is greater than a threshold; S170: If yes, start the fan unit; S180, if not, start the AC heater to heat the gear oil, start the low-temperature cranking function, and repeat steps S160 to S180 until the fan unit start conditions are met and then start the fan unit.

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