CN104696170A - Hybrid transmission wind power generation system - Google Patents

Abstract

The invention relates to a hybrid transmission wind power generation system, which includes an impeller, a speed-increasing planetary gear train, a flow splitting device, a synchronous generator and a speed-regulating hydraulic system, and the impeller is connected with an input shaft of the speed-increasing planetary gear train. The diverter device includes a first gear pair, a diverter planetary gear and a second gear pair, the first gear pair includes a meshed first gear and a second gear, and the diverter planetary gear includes a planet carrier, a sun gear , a planetary gear and a ring gear, the second gear pair includes a meshing third gear and a fourth gear. The speed regulating hydraulic system includes a variable hydraulic pump, a quantitative hydraulic motor, an accumulator and an oil tank. The hybrid transmission wind power generation system adopts the mechanical-hydraulic hybrid transmission mode, which integrates the high efficiency of mechanical transmission and the flexible transmission characteristics of hydraulic transmission, and the synchronous generator is connected with the sun gear of the distribution planetary gear, and the teeth of the distribution planetary gear The ring can avoid failure caused by high-speed rotation.

Description

A hybrid drive wind power generation system

technical field

The invention belongs to the field of wind power generation, and in particular relates to a hybrid transmission wind power generation system.

Background technique

The operating environment of the wind power generation system is complex, there are many working conditions under different loads, and the load value is variable, so that the speed and torque of the transmission components such as the gearbox and the impeller spindle fluctuate violently, resulting in frequent failures of the transmission device of the wind power generation system. Repair costs remain high. With the trend of large-scale wind power generation system and expansion of offshore wind power, the problem of operation and maintenance cost of wind power generation system becomes more prominent. According to statistics, the maintenance cost of gearbox failures in wind power generation systems is the highest, and the high incidence of gearbox failures occurs within 5 to 8 years after being put into operation, which is significantly different from the design life of wind power generation systems of 15 to 20 years. The operating life and maintenance cost of the wind power generation system, as well as the reliability of the transmission system are related to the development of the entire wind power industry.

For the grid-connected wind power generation system, the wind power generation system is required to have the function of "variable speed and constant frequency", that is, when the wind speed is lower than the rated value, the wind power generation system maintains the best energy capture state at all times; when the wind speed is higher than the rated value, the wind power The power generation system can maintain the generator speed at the rated value. At present, most gearbox-driven wind power generation systems use power electronic equipment to realize this function. The use of power electronic equipment not only increases the cost, but also generates power loss and injects harmful harmonic power into the grid.

In the existing wind power generation system, the hydraulic system is also used as its transmission device. The hydraulic transmission can effectively alleviate the fluctuation and impact of sudden wind load on the wind power generation system, and stabilize the power output. However, compared with gearbox transmission, the overall efficiency of hydraulic transmission is low. Moreover, the hydraulic pump connected to the impeller needs to have the characteristics of large displacement and low speed, which requires professional design and manufacture, which greatly increases the cost.

The invention patent with the publication number CN103277252A discloses a mechanical-hydraulic hybrid transmission for grid-connected wind power generation systems. The mechanical-hydraulic hybrid transmission directly connects the generator with the ring gear of the planetary gear train, resulting in the ring gear It needs to rotate at a high speed synchronously with the generator, and the high speed of the ring gear will easily cause the planetary gear train to malfunction and damage it.

Contents of the invention

The technical problem to be solved by the present invention is to provide a hybrid transmission wind power generation system. The hybrid transmission wind power generation system adopts a mechanical-hydraulic hybrid transmission mode, which integrates the high efficiency of mechanical transmission and the flexible transmission characteristics of hydraulic transmission, and the synchronous generator Connected with the sun gear of the diverting planetary gear, the ring gear of the diverting planetary gear can avoid failure caused by high-speed rotation.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A hybrid transmission wind power generation system includes an impeller, a speed-increasing planetary gear train, a flow splitting device, a synchronous generator and a speed-regulating hydraulic system, and the impeller is connected to an input shaft of the speed-increasing planetary gear train. The diverter device includes a first gear pair, a diverter planetary gear and a second gear pair, the first gear pair includes a meshed first gear and a second gear, and the diverter planetary gear includes a planet carrier, a sun gear , a planetary gear and a ring gear, the second gear pair includes a meshing third gear and a fourth gear. The speed regulating hydraulic system includes a variable hydraulic pump, a quantitative hydraulic motor, an accumulator and an oil tank.

The first gear is connected with the variable hydraulic pump, and the second gear is respectively connected with the output shaft and the planet carrier of the speed-up planetary gear train. The third gear is connected with the quantitative hydraulic motor, and the fourth gear and the ring gear are integrated and can rotate synchronously. The sun gear is connected with the synchronous generator.

Further, the inlet of the variable hydraulic pump is respectively connected with the outlet of the quantitative hydraulic motor and the oil tank, and the outlet of the variable hydraulic pump is respectively connected with the inlet of the quantitative hydraulic motor and the outlet of the accumulator. connected.

Further, the speed regulating hydraulic system further includes an overflow valve, a first one-way valve, a second one-way valve and a stop valve. The inlet of the first one-way valve is connected with the outlet of the variable hydraulic pump, and the outlet of the first one-way valve is respectively connected with the inlet of the quantitative hydraulic motor, the inlet of the relief valve, the stop The outlet of the valve is connected. The inlet of the second one-way valve communicates with the oil tank, and the outlet of the second one-way valve communicates with the inlet of the variable hydraulic pump and the outlet of the overflow valve respectively. The inlet of the cut-off valve communicates with the outlet of the accumulator.

Adopt the present invention to have following beneficial effect:

1. The hybrid transmission wind power generation system of the present invention adopts the mechanical-hydraulic hybrid transmission mode, realizes the shunt transmission of energy captured by the impeller, and has both the high efficiency of mechanical transmission and the flexible transmission characteristics of hydraulic transmission.

2. The hybrid transmission wind power generation system of the present invention adopts a speed-regulating hydraulic system, and by adjusting the displacement of the variable hydraulic pump, it achieves the effect of variable speed and constant frequency, and realizes the maximum power capture of wind energy and the effect of grid friendliness. At the same time, the speed-regulating hydraulic system reduces the system impact and torque fluctuation caused by sudden changes in wind speed or load, so that the hybrid drive wind power system can run smoothly, improve the mechanical transmission conditions, and reduce the failure rate of the gearbox.

3. The hybrid transmission wind power generation system of the present invention absorbs and releases energy through the accumulator in the speed-regulating hydraulic system, so as to cut peaks and fill valleys. On the premise of ensuring the stable operation of the hybrid drive wind power generation system, the overall energy utilization rate of the hybrid drive wind power generation system is improved.

4. In the hybrid transmission wind power generation system described in the present invention, the speed regulating hydraulic system adopts a closed hydraulic circuit, and the oil return of the hydraulic actuator is directly connected with the oil suction chamber of the variable hydraulic pump. The small fuel tank saves space, and at the same time reduces leakage and pollution.

Description of drawings

1 is a schematic diagram of a mechanical transmission structure of a hybrid transmission wind power generation system according to an embodiment of the present invention;

Fig. 2 is a working principle diagram of a speed regulating hydraulic system of a hybrid transmission wind power generation system according to an embodiment of the present invention;

Fig. 3 is a schematic diagram of power flow of a splitter device of a hybrid drive wind power generation system according to an embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

With reference to accompanying drawing 1 and accompanying drawing 2. A hybrid transmission wind power generation system, which includes an impeller 1, a speed-increasing planetary gear train 2, a flow splitter 30, a synchronous generator 4 and a speed-regulating hydraulic system 50, the input of the impeller 1 and the speed-increasing planetary gear train 2 shaft connected. The impeller 1 captures wind energy and drives the speed-up planetary gear train 2 to rotate, increasing the output speed of the speed-up planetary gear train 2 to a certain value. The speed-increasing planetary gear train 2 transmits energy to the synchronous generator 4 through the flow splitting device 30 and the speed-regulating hydraulic system 50, and the synchronous generator 4 outputs electric energy to the grid or loads.

The splitter device 30 includes a first gear pair 31, a splitting planetary gear 32 and a second gear pair 33, the first gear pair 31 includes a meshing first gear 311 and a second gear 312, the splitting planetary gear The gear 32 includes a planet carrier 321 , a sun gear 322 , a planetary gear 323 and a ring gear 324 , and the second gear pair 33 includes a third gear 331 and a fourth gear 332 that are engaged with each other.

The speed regulating hydraulic system 50 includes a variable hydraulic pump 51 , a quantitative hydraulic motor 52 , an accumulator 53 , an oil tank 54 , an overflow valve 55 , a first one-way valve 56 , a second one-way valve 57 and a stop valve 58 . The speed regulating hydraulic system 50 is a closed hydraulic circuit.

The first gear 311 is connected with the variable hydraulic pump 51 , and the second gear 312 is respectively connected with the output shaft of the speed-up planetary gear train 2 and the planet carrier 321 . The third gear 331 is connected with the quantitative hydraulic motor 52 , and the fourth gear 332 and the ring gear 324 are integrated and can rotate synchronously. The sun gear 322 is connected with the synchronous generator 4 .

The inlet of the first one-way valve 56 is connected with the outlet of the variable hydraulic pump 51, and the outlet of the first one-way valve 56 is respectively connected with the inlet of the quantitative hydraulic motor 52 and the outlet of the relief valve 55. The inlet and the outlet of the cut-off valve 58 are connected. The inlet of the second one-way valve 57 communicates with the oil tank 54, and the outlet of the second one-way valve 57 is connected with the inlet of the variable hydraulic pump 51, the outlet of the relief valve 55, the The outlets of the quantitative hydraulic motor 52 are connected. The inlet of the stop valve 58 communicates with the outlet of the accumulator 53 .

The function of the variable hydraulic pump 51: by adjusting the displacement of the variable hydraulic pump 51, the "variable speed and constant frequency" control effect of the hybrid transmission wind power generation system can be realized, and the maximum power capture of wind energy and the effect of grid friendliness can be realized.

The function of the accumulator 53: the accumulator 53 can absorb the system shock and torque fluctuation caused by the wind speed sudden change or the load change, alleviate the load fluctuation of the gear pair in the mechanical transmission, and reduce the pressure fluctuation of the hydraulic system. In addition, the accumulator 53 stores energy when the high wind speed captures too much energy, and releases energy when the low wind speed captures little energy, which plays a role in peak shaving and valley filling, and improves the energy utilization rate of the hybrid drive wind power generation system.

Refer to accompanying drawing 3. When the hybrid transmission wind power generation system is running, the splitter device 30 plays the role of splitting power (the dotted line in Fig. 3 shows power flow). The wind energy captured by the impeller 1 is transferred to the synchronous generator 4 through the planetary carrier 321, the planetary gear 323, and the sun gear 322 of the distribution planetary gear 32; in addition, the wind energy captured by the impeller 1 Wind energy, a small part of energy is transmitted to the synchronous generator 4 through the first gear pair 31 , the speed-regulating hydraulic system 50 , the second gear pair 33 , the ring gear 324 , the planetary gear 323 , and the sun gear 322 .

Therefore, the hybrid transmission wind power generation system mainly uses mechanical transmission of energy, supplemented by hydraulic transmission of energy. It not only retains the high-efficiency characteristics of mechanical transmission, but also introduces the flexible characteristics of hydraulic transmission, which can largely alleviate the fluctuation and impact of sudden wind load on the hybrid transmission wind power generation system, so that the hybrid transmission wind power generation system can run smoothly , improve the mechanical transmission conditions, and reduce the failure rate of the gearbox. While the speed-regulating hydraulic system 50 assists in energy transmission, it can also adjust the speed of the impeller so that it can operate at variable speeds to achieve maximum power capture control.

An example embodiment of the hybrid transmission wind power generation system is as follows:

The input rotational speed range of the impeller is 9.8 rpm to 17.3 rpm; the speed-increasing planetary gear train 2 adopts a structure of a first-stage planetary gear (a transmission ratio of 5.8) and a first-stage gear pair (a transmission ratio of 4.39); the first gear pair 31 The transmission ratio is 3, the transmission ratio of the distribution planetary gear 32 is 2, and the transmission ratio of the second gear pair 33 is 1; the displacement of the variable hydraulic pump 51 is adjusted so that the speed range of the variable hydraulic pump 51 is 750 rev/min to 1320 rev/min, correspondingly, the speed range of the quantitative hydraulic motor 52 is 90 rev/min to 375 rev/min, then the speed of the synchronous generator 4 can be operated at a rated speed of 1500 rev/min nearby.

Claims (3)

1. a hybrid transmission wind power generation system, it comprises impeller (1), speed-increasing planetary gear train (2), splitter (30), synchronous generator (4) and speed-regulating hydraulic system (50), described impeller (1) It is connected with the input shaft of the speed-increasing planetary gear train (2), and it is characterized in that: the diverter device (30) includes a first gear pair (31), a diverter planetary gear (32) and a second A gear pair (33), the first gear pair (31) includes a meshed first gear (311) and a second gear (312), and the distribution planetary gear (32) includes a planet carrier (321), a sun wheel (322), planetary gear (323) and ring gear (324), the second gear pair (33) includes the third gear (331) and the fourth gear (332) in mesh; the speed regulating hydraulic system (50) comprises a variable hydraulic pump (51), a quantitative hydraulic motor (52), an accumulator (53) and a fuel tank (54); The first gear (311) is connected with the variable hydraulic pump (51), and the second gear (312) is connected with the output shaft and the planet carrier (321) of the speed-up planetary gear train (2) respectively. connection; the third gear (331) is connected with the quantitative hydraulic motor (52), the fourth gear (332) and the ring gear (324) are integrated and can rotate synchronously; the sun A wheel (322) is connected to the synchronous generator (4). 2. A hybrid transmission wind power generation system according to claim 1, characterized in that: the inlet of the variable hydraulic pump (51) is connected to the outlet of the quantitative hydraulic motor (52) and the fuel tank (54) respectively. The outlet of the variable displacement hydraulic pump (51) is respectively connected with the inlet of the quantitative hydraulic motor (52) and the outlet of the accumulator (53). 3. A hybrid drive wind power generation system according to claim 2, characterized in that: said speed regulating hydraulic system (50) further comprises an overflow valve (55), a first one-way valve (56), a second One-way valve (57) and cut-off valve (58); the inlet of described first one-way valve (56) is connected with the outlet of described variable hydraulic pump (51), and the outlet of described first one-way valve (56) The outlet communicates with the inlet of the quantitative hydraulic motor (52), the inlet of the overflow valve (55) and the outlet of the shut-off valve (58) respectively; the inlet of the second one-way valve (57) communicates with The oil tank (54) is connected, and the outlet of the second check valve (57) is respectively connected with the inlet of the variable hydraulic pump (51) and the outlet of the overflow valve (55); The inlet of the valve (58) communicates with the outlet of said accumulator (53).