CN201043512Y - Low wind speed started inner rotor type wind driven generator - Google Patents

Abstract

A low wind speed starting inner rotor type wind power generator uses a windmill to start a generator to generate electricity; the windmill includes five to six wide plate-shaped unit blades, which are evenly spaced and arranged around an impeller, and the diameter of the impeller accounts for at least one-half of the length of the unit blade; the generator is an inner rotor type, has the characteristics of low rotor inertia and low cogging torque, and the generator outputs a high voltage, which is then adjusted to a specific voltage value by a back-end conversion system. Accordingly, the utilization rate of wind energy can be improved, and the generator can be started in a low wind speed wind environment, and has the characteristics of stable operation, low rotor inertia and low cogging torque. The cost of using renewable energy at the back end can be reduced.

Description

Inner Rotor Wind Turbine Started at Low Wind Speed

technical field

The utility model is related to wind power generation equipment, more specifically, it is an inner rotor type wind power generator capable of starting at low wind speed.

Background technique

In view of the oil crisis in the late 1970s, many European and American countries began to seek energy outlets, and the most active one was Denmark. Since the early 1980s, the Danish government has been very keen to support wind power generation. Therefore, Denmark now has the world's most proud The fan industry has even replaced fishery as the second largest export commodity. The country's wind power generation reached 16% of electricity consumption by the end of 2000, and the Danish government even plans to increase wind power to 50% by 2030. Germany started to legislate in 1991, stipulating that the price of wind power should be 90% of the final user's price. After the legislation, wind power developed rapidly and even came from behind. By the end of 2000, Germany had installed more than 9,000 wind turbines, and the annual installed capacity in 2000 reached 1670MW, exceeding the sum of all traditional power generation in Germany and ranking first in the world.

Looking at the structure of Taiwan's power generation industry, in 1999, 67.3% of electricity came from thermal power, 26.8% from nuclear power, and 5.9% from hydropower. The economic benefits of nuclear power generation have always been doubted by many advanced countries. Take the United Kingdom, the United States, and Germany as examples. After the liberalization of the electricity industry, many nuclear power plants were automatically shut down because the economic benefits were too low. If economic benefits are excluded, the nuclear waste generated by nuclear power generation and nuclear power plant accidents are more likely to bring endless disasters to future generations. As for thermal power generation, due to dependence on imported oil, it has related impacts on national security and economic independence, and the environmental pollution it causes cannot be underestimated. Although hydropower currently only accounts for a single-digit proportion of use in my country, the damage to the natural environment and river dredging should also be carefully evaluated.

To change the structure of the power generation industry, wind power generation is a feasible solution. According to the evaluation of scholars and experts, Taiwan, for example, is an area with excellent wind energy potential. In addition to losing autonomy and independence due to excessive dependence on individual energy sources, it is more in line with the long-term strategy of sustainable development.

Below we will briefly introduce the principle of wind power generation.

Simply speaking, wind power generation is to convert the wind energy into mechanical energy by turning the blades through the wind energy, and then use the generator to convert the mechanical energy into electrical energy, and then use the battery to store the energy. Therefore, wind power generation equipment mainly includes two parts: windmill and generator. According to the combination of windmill and generator, wind turbines can be roughly divided into inner rotor type and outer rotor type.

The so-called outer rotor type, simply put, is a structure in which the rotor rotates outside the stator. The impeller is driven by the wind to rotate the outer rotor, so that the rotor and the stator move relative to each other to generate electric energy, which is rectified and output by the rear rectifier. This type of windmill is represented by the Rutland 913 manufactured by the British Marlec company.

The so-called inner rotor type is a structure in which the rotor rotates inside the stator. The impeller is driven by the wind to rotate the inner rotor, so that the relative movement of the rotor and the stator generates electric energy, which is rectified and output by the rear rectifier. This type of windmill is represented by the AIR403 type manufactured by Southwestern Company of the United States. Compared with the above-mentioned external rotating wind generators, the internal rotor wind generators have a smaller windmill inertia and are relatively easier to start. However, at present, most of the wind turbines above 1KW used in various countries adopt the external rotation type.

Wind turbines mainly use wind energy to generate electricity, so windmills are the main body receiving wind, so the design of windmills is closely related to the application of wind energy. As shown in Figure 1, the windmill generally connects the blades with an impeller. The blades are three-leaf blades with long strips. The area of the impellers only accounts for a very small part of the main body of the windmill. The swept area is mainly composed of wind blades, so to increase the ability of wind blades to capture wind energy, the main method is to increase the length of the blades. According to structural mechanics, the structural strength of the long-striped fan blade is not stable, and it is prone to bending when exposed to wind, and the situation of swaying by the wind is more serious, resulting in unstable cutting wind. In addition, in the swept area of the above-mentioned windmill, the space between the three wind blades accounts for the vast majority, and most of the wind will pass through the space between the wind blades without acting on the wind blades. superior. Generally speaking, these types of windmills have the ability to capture wind energy and poor utilization, so they should be installed in areas with good wind, long wind season, high average wind speed, strong and continuous wind, and low wind power cannot be achieved. The target of the wind speed start.

Whether the wind turbine is easy to start, in addition to the structure of the windmill, the rotor inertia and cogging torque of the generator are also one of the determining factors.

Regarding the rotor inertia, analyze it with J=1/4GD ² relational formula [G is the rotor weight (KG), D is the rotor diameter (m)], it can be proved that the rotor diameter determines the rotor inertia, the cylindrical rotor with the same weight, the smaller the rotor diameter Or, the smaller the rotor inertia, the easier it is to start. Therefore, the diameter of the rotor of the inner rotor type generator is smaller than that of the outer rotor type, so it is easier to start. In other words, when the windmill is loaded with a rotor with high inertia, it will make the windmill less susceptible to wind start.

Regarding cogging torque, the rotor of a permanent magnet generator or electric motor has a tendency to align with the stator in a certain direction, and this tendency produces an oscillating torque called cogging or cogging torque (cogging torque). For permanent magnet motors, the cogging torque has a direct influence on the starting wind speed of the windmill rotation. The generator with high cogging torque will have a little bit of cogging, and the start-up at low speed will not be smooth. The starting wind speed of the relative windmill must be pulled high.

From the above analysis, it can be seen that it is necessary to design a wind turbine with better functions to solve the problems of difficulty in starting at low wind speed and poor utilization of wind energy. Next, further discussion will be made on the above-mentioned voltage output of the wind power generator.

The wind turbine has a generator device independent of the rear end of the windmill, which basically integrates the generator and the rectifier into a nacelle. In the stage of forming a wind turbine, it is necessary to confirm the specific voltage (such as 12V, 24V, 36V, 48V) adopted by the back-end power storage system or power supply load system, and then select a power generation device that can output the specific voltage . For example, if the power storage system is DC24V, you can only choose to output DC24V power generation equipment. That is to say, replacing the power generation equipment as a means of responding to different voltage outputs makes the construction cost of wind turbines very high, but the voltage output and application range are limited by ratings. The cost of end-use renewable energy becomes expensive, which is not economical.

Contents of the invention

The purpose of the utility model is to provide an inner-rotor wind power generator started at low wind speed, so as to overcome the defects of the above-mentioned traditional structure, achieve the effect of improving the utilization rate of wind energy, starting and running stably in a wind environment with low wind speed.

In view of the above analysis, when designing the wind power generator of the present utility model, there are many aspects such as the ability of the wind blade to extract wind energy, the structural strength of the windmill, the utilization rate of wind energy, the inertia of the generator rotor, the cogging torque, the starting wind speed, and the voltage output. involved.

An inner rotor type wind power generator started at low wind speed, comprising a windmill, a generator, a carbon brush slip ring combination unit, and an empennage; the windmill mainly includes an impeller and unit blades assembled around the impeller; The generator includes a rotor for receiving the mechanical energy transmitted by the impeller to generate electric energy, which is connected with the impeller; the carbon brush slip ring combination unit is connected with the power transmission wire of the generator; the generator and the carbon brush slip ring The combined unit is arranged in a nacelle; the empennage includes a connecting rod connected and fixed to the bottom of the nacelle; it is characterized in that:

The above-mentioned impeller is a disc structure, and its outer periphery is provided with a joint edge for the assembly of the above-mentioned unit blades; the end of the unit blade combined with the joint edge is provided with a joint groove, and the joint edge is embedded in the joint groove. The blade has several fixing elements and is fixed on the joint edge;

The diameter of the impeller accounts for more than half of the blade length of the unit;

The above-mentioned unit blades are plate-shaped and have more than five blades, which are grouped on the joint edge of the impeller at even intervals.

Wherein, the unit blades are in the number of six blades, which are arranged on the joint edge of the impeller at even intervals.

Wherein, the above generator is a low rotor inertia generator.

Wherein, the above-mentioned generator is a low cogging torque type generator.

Wherein, the wind power generator is a generator with a three-phase 80v voltage output.

Wherein, the wind generator further includes a back-end conversion system for adjusting the output voltage of the wind generator.

Wherein, the back-end conversion system is a transformer.

Wherein, the back-end conversion system also includes a rectifier.

The diameter of the impeller accounts for at least one-half of the length of the blades of the unit, so that when it is started, the large area of the impeller blocks the wind and guides the wind to each blade to increase its starting performance; When the blade length is the same, the design of the large impeller increases the sweeping area of the windmill, thus increasing the utilization rate of wind energy; the above-mentioned unit blades are in the shape of a wide plate in proportion to their length and width, and are evenly spaced by five to six blades The ground group is set at the joint edge of the impeller; the above-mentioned generator is an inner rotor type, and has the characteristics of low rotor inertia and low cogging torque; the above-mentioned wind power generator adopts high rated voltage output, and is adjusted by a rear-end conversion system Voltage.

Functions and beneficial effects of the utility model include:

The wind power generator of the utility model belongs to the inner rotor type wind power generator.

The windmill of the utility model can increase the utilization rate of wind energy, and can be started in a wind environment with low wind speed.

The windmill of the utility model has the effect of improving stable operation.

The generator of the utility model has the characteristics of low rotor inertia and low cogging torque.

The wind power generator of the utility model can reduce the cost of utilizing renewable energy at the rear end.

The detailed purpose and function will be described in detail later.

Description of drawings

Fig. 1: It is the plan view of the windmill of conventional wind power generator.

Fig. 2: is the exterior view of the utility model wind power generator.

Fig. 3: is the side view of the utility model wind power generator.

Fig. 4: is the three-dimensional exploded view of the windmill of the utility model.

Figure 5: It is a side view of the windmill of the utility model and a schematic diagram of the internal assembly of the generator.

Fig. 6: is the bottom view of the utility model, showing the state of the bottom of the wind generator.

Detailed ways

The hardware equipment of the present utility model is first introduced below, and then the characteristics and effects of the present utility model are discussed in detail on the basis of the hardware equipment.

hardware device

As shown in the figure, the wind power generator of the present invention includes a windmill 20 , a generator 30 , a carbon brush slip ring combination unit 40 , and an empennage 50 . The windmill 20 mainly includes an impeller 21 and unit blades 22 assembled on the impeller 21 . The rotor 31 of the generator 30 is connected to the impeller 21 and receives the mechanical energy transmitted by the impeller 21 to generate electrical energy. The carbon brush slip ring combination unit 40 is connected to the power transmission wire 34 of the generator 30 to output the electric power generated by the generator 30 . The generator 30 and the carbon brush slip ring combination unit 40 are arranged in a nacelle 32 . The empennage 50 is connected and fixed to the bottom of the nacelle 32 by a connecting rod 51 . The empennage 50 is affected by the wind, so that the windmill 20 and the above-mentioned nacelle 32 are turned to a direction that can effectively receive the wind.

The design of the above-mentioned empennage 50 makes the nacelle 32 and the windmill 20 a mechanism that is rotated by the wind, which makes the power transmission wire 34 of the above-mentioned generator face the problem of entanglement, so the carbon brush slip ring combination unit 40 is used to solve it. The carbon brush 41 in the carbon brush slip ring combination unit 40 is connected with the power transmission wire 34 of the generator 30, and the copper ring 42 is then pivotally sleeved outside a fixed shaft 43, and the nacelle 32 can rotate around the fixed shaft 43, and the carbon brush 41 produces a fixed relationship with the nacelle 32 by the connector 44, and the carbon brush 41 that rotates with the nacelle 32 contacts the fixed copper ring 42, and the electric energy is transmitted to the copper ring 42, and the copper ring 42 is connected to the power transmission wire 45 in addition, and the power transmission The wire 45 penetrates into the fixed shaft 43 and extends outwardly out of the nacelle 32 . In this way, no matter how the nacelle 32 rotates, the power transmission wire 45 is not affected, and there is no problem of wire entanglement.

The utility model windmill 20, its impeller 21 is a disc structure, its outer periphery is provided with a joint edge 23 whose thickness is thinner than the disc thickness, and the joint edge 23 is used for the assembly of the above-mentioned unit blades 22 . An engaging groove 24 is formed at the combined end of the unit blade 22 and the joint edge 23 , the joint edge 23 is inserted into the joint groove 24 , and the unit blade 22 is fixed on the joint edge 23 by a plurality of fixing elements 25 .

Features and functions

The wind power generator of the utility model belongs to the inner rotor type wind power generator

As shown in the figure, the wind power generator of the present invention is known to be a power generation structure in which the rotor rotates inside the stator, so the present invention belongs to the inner rotor type wind power generator. Based on the analysis of J=1/4GD ² , it can be proved that the diameter of the rotor determines the inertia of the rotor. The smaller the diameter of the rotor, the smaller the inertia of the rotor, and the easier it is to start. Therefore, the diameter of the rotor of the inner rotor type generator is smaller than that of the outer rotor type, so the utility model adopts the inner rotor type generator and has the advantage of being easy to start.

The windmill of the utility model can improve the utilization rate of wind energy, and can be started in a wind environment with low wind speed.

The windmill of the utility model includes a disk-shaped impeller and six unit blades combined with the edge of the impeller. The radius of the circular area swept by the windmill is the sum of the impeller radius and the length of a unit blade. It can be seen from the figure that the radius of the impeller and the length of the unit blade each occupy a corresponding proportion of the radius of the area of the swept circle. The swept area of the windmill is composed of the impeller and the unit blade, and the wind-receiving structure of the windmill is the unit blade. The amount of wind energy captured is directly proportional to the area of the windmill that receives the wind. The utility model uses a large-diameter impeller to increase the swept area of the windmill, thereby increasing the utilization rate of wind energy. Furthermore, the unit blades of the windmill of the utility model are wide-plate type, and each unit blade receives wind with an enlarged area, and the wind receiving area increases, so that the utilization rate of wind energy of the windmill is further improved. The unit blades are combined with six blades around the impeller, and the multi-blade pattern is matched with the wide plate area to maintain an appropriate wind-receiving distance between the unit blades. This distance maintains good gas flow, so most of the Part of the wind force acts on the impeller and the unit blades, and the loss of unused wind energy passing through the space is reduced, so the utilization rate of wind energy is increased. Under the complementary effect of the impeller and the unit blades, the windmill of the utility model can greatly improve the utilization rate of wind energy, so the purpose of starting and turning the windmill at a low wind speed can be realized.

The windmill of the utility model has the effect of improving stable operation

The utility model constitutes the radius of the sweeping area of the windmill with the sum of the impeller radius and the length of a unit blade. As stated in the above paragraph and the drawing of the utility model, the radius of the impeller and the length of the unit blade respectively occupy the radius of the sweeping area. Quite proportional. In other words, relative to the whole windmill, the impeller of the present utility model is a structure with a large area ratio. The impeller constitutes the center of mass of the windmill so that it has a stable center of gravity. Function, so that the windmill can rotate stably, reduce the situation of shaking, and the relative rotation noise can be greatly reduced. According to structural mechanics, wide-plate unit blades can exhibit better structural strength, and are not easy to bend or shake when exposed to wind, so they can cut wind stably. The windmill of the utility model has an impeller for stabilizing the center of gravity and unit blades for stably cutting wind, so it has the effect of increasing stable operation.

Although the utility model emphasizes the large-area impeller, the quality of the impeller also has its necessity to be considered, so as to avoid the situation that the static mass of the impeller is too large and the resulting inertia is too large and it is difficult to start. Under the conditions of the same diameter and the same unit blades, the low-wind starting experiments were carried out on the impellers weighing 2kg, 1.3kg and 0.8kg respectively. The 1.3kg impeller can get an expected low starting wind speed, and the 2kg impeller must be started at a higher than expected wind speed. The wind speed can only be started by the wind force, which is not in line with the expectation of low wind speed start. On the contrary, the starting wind speed of 0.8kg is larger than that of 1.3kg, and the starting wind speed does not decrease proportionally because the static mass becomes smaller. Therefore, in this experimental data, the performance of the 1.3kg impeller is better.

The generator of the utility model has the characteristics of low rotor inertia and low cogging torque.

The utility model adopts a permanent magnet generator, and whether the permanent magnet wind generator is easy to be started, in addition to the windmill structure, the rotor inertia and the cogging torque of the generator are also one of the determining factors.

Regarding the rotor inertia, analyze it with J=1/4GD ² relational formula [G is the rotor weight (KG), D is the rotor diameter (m)], it can be proved that the rotor diameter determines the rotor inertia, the cylindrical rotor with the same weight, the smaller the rotor diameter Or, the smaller the rotor inertia, the easier it is to start. The utility model sets the diameter of the rotor of the generator to be 32mm, the thickness of the magnet is 3mm, and the total length is 99mm. According to the deduction of the rotor inertia formula above, it can be seen that the generator of the present invention has the characteristics of low rotor inertia, the generator itself is easy to start, and the low inertia rotor reduces the load of the windmill, making it easier to start the windmill by the wind.

Regarding cogging torque, as mentioned in the previous art column, the rotor of a permanent magnet generator or electric motor has a tendency to align with the stator in a certain direction, and this tendency produces an oscillating torque called Cogging torque or cogging torque. For permanent magnet motors, the cogging torque has a direct influence on the starting wind speed of the windmill rotation, and the generator with high cogging torque will have a little bit of cogging, which will cause the problem of poor start-up and rotation at low wind speeds. Looking at the solution to this problem from the point of view that the magnetic field lines have a tendency to align, the structure of integer slots is likely to produce the alignment of the rotor magnet and the stator slot teeth, that is, at a certain angle, the induction of the magnet and the slot teeth produces the largest magnetic flux chain, resulting in a steady-state force balance, so there will be a jerk when turning. Therefore, one of the ways to reduce the cogging is to reduce the drop of the induced flux linkage. The method can use the method of fractional slots to reduce the chance of alignment between the magnet and slot teeth, and can also deliberately increase the number of poles and slots. For example, 8 poles and 9 slots, by dividing the space angle of 360 degrees by the least common multiple of the number of magnetic poles and the number of stator slots, it can be known that the period of 8 poles and 9 slots is 5 degrees, and the mechanical angle of the sudden rotation is small. Significantly improved.

The generator of the utility model has the characteristics of low inertia rotor and low cogging torque, which can reduce the load of the windmill and make the windmill and the generator easy to start.

The utility model belongs to a light wind starting type wind power generator

The utility model can be started in a wind environment with low wind speed by combining the windmill with improved wind energy utilization rate with the generator with low rotor inertia and low cogging torque. Because the starting wind speed of the Rutland 913 type of British Marlec Company is below 2.5m/s, the model structure of the utility model is better than the former, so the estimated starting wind speed is about below 2m/s, which belongs to light wind starting. However, the starting wind speed of the known low-wind generator is about 3-4m/s, which belongs to the wind-driven generator started by light wind. It can be explained that the starting wind speed of the utility model is lower than that of the conventional low-wind start-up wind generators, so the location of installing wind generators is no longer limited to areas with good wind, and the freedom of location selection is higher.

The wind power generator of the utility model can reduce the cost of using renewable energy at the back end

The wind power generator of the utility model adopts a three-phase high rated voltage output above 80V, and then converts it into AC or DC with a specific lower voltage through a back-end conversion system (transformer and rectifier). According to the relationship of P (power) = I (current) × V (voltage), when the power is the same, the higher the voltage, the lower the current; and the transmission capacity of the line is proportional to the square of the voltage. If the voltage is doubled, the transmission capacity quadrupled its original size. Therefore, for the same transmission capacity, a higher voltage only requires a smaller current. According to the relationship between V (voltage) = I (current) × R (resistance), when the resistance is fixed and the current decreases, the voltage generated on the cable The drop (voltage loss) is also reduced. According to the relationship between P (heating power or copper loss) = I ² (current square) × R (resistance), the current drop represents the heat generated by the resistance of the cable during power transmission. Losses or copper losses are reduced accordingly. Therefore, the wind power generator of the utility model has the power transmission characteristics of small voltage drop, small copper loss, and small heat loss.

The wind turbine with high rated voltage output can use the means of changing the back-end conversion system (transformer, rectifier) to cope with the specific voltage of the back-end power storage system or power consumption system. To put it simply, a wind turbine can match different power storage systems or power consumption systems. The only difference lies in the replacement of the back-end conversion system (transformer, rectifier). This replacement is easy to implement and low in cost. Therefore, The construction cost of wind power generation can be greatly reduced, and the cost of using renewable energy at the back end can be reduced, which is in line with economic benefits.

Based on the above descriptions about the hardware structure and functional characteristics, it can be seen that the utility model has indeed broken through the stereotype of the traditional type of wind power generator, and exhibited a novel shape and multiple advanced functions, which proves that the utility model is indeed a practical one. Although the utility model is illustrated with a preferred embodiment in the drawings, those skilled in the art can make various changes without departing from the spirit and category of the utility model. The above-mentioned embodiments are only used to illustrate the utility model, and are not intended to limit the scope of the utility model. All modifications or changes that do not violate the spirit of the utility model belong to the patent scope of the utility model.

Claims (8)

1. the one kind low internal rotor type wind-driven generator that wind speed starts comprises a windmill (20), a generator (30), a carbon brush slip-ring combining unit (40) and an empennage (50); The unit blade (22) that this windmill mainly comprises an impeller (21) and is mounted on this impeller (21) periphery; This generator comprises the rotor (31) that is used to accept the mechanical energy that this impeller (21) transmitted and produces electric energy, and it is connected with this impeller (21); This carbon brush slip-ring combining unit (40) is connected with the transmission pressure (34) of this generator (30); This generator (30) and this carbon brush slip-ring combining unit (40) are arranged in the cabin (32); This empennage (50) comprises a connecting rod (51), and it is connected and fixed on bottom, this cabin (32); It is characterized in that:

Above-mentioned impeller (21) is a disc structure, and its periphery is established a trip edge (23) that supplies above-mentioned unit blade (22) group to establish; This unit blade (22) is provided with an engaging groove (24) with the end of this trip edge (23) combination, and this trip edge (23) embed in this engaging groove (24), and this unit blade (22) has plurality of fixed element (25), and is fixed on this trip edge (23);

The diameter of this impeller (21) accounts for more than 1/2nd of this unit blade (22) length;

Said units blade (22) is tabular, and has the above quantity of five leaves, and its ground, equispaced group is located on the trip edge (23) of this impeller (21).

2. the internal rotor type wind-driven generator that low according to claim 1 wind speed starts is characterized in that this unit blade (22) is the quantity of six leaves, and its ground, equispaced group is located on the trip edge (23) of this impeller (21).

3. the internal rotor type wind-driven generator that low according to claim 1 wind speed starts is characterized in that above-mentioned generator (30) is a low rotor inertia generator.

4. the internal rotor type wind-driven generator that low according to claim 1 wind speed starts is characterized in that above-mentioned generator (30) is the generator of low cogging torque.

5. the internal rotor type wind-driven generator that low according to claim 1 wind speed starts is characterized in that this wind-driven generator is a three-phase 80v voltage output type generator.

6. the internal rotor type wind-driven generator that starts as low wind speed as described in the claim 5 is characterized in that, this wind-driven generator comprises that more one is used for rear end converting system that the output voltage of this wind-driven generator is adjusted.

7. the internal rotor type wind-driven generator that starts as low wind speed as described in the claim 6 is characterized in that this rear end converting system is a transformer.

8. the internal rotor type wind-driven generator that starts as low wind speed as described in the claim 7 is characterized in that this rear end converting system also comprises a rectifier.

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