Wind power system based on combined generator set

Abstract

The invention discloses a wind power system based on a combined generator set, which relates to the technical field of wind power systems and comprises an engine set, an intelligent control system and an energy storage device. The output power of the generator set is adjusted through the intelligent control system; the engine unit comprises a direct-drive permanent magnet generator, a doubly-fed induction generator and a small wind driven generator; the direct-driven permanent magnet generator and the double-fed induction generator are connected to a power grid in parallel, and the small wind driven generators serve as supplements and are distributed in an area which cannot be covered by the direct-driven permanent magnet generator and the double-fed induction generator. The intelligent control system comprises a wind speed monitoring module, an analysis module, a wind direction monitoring module, an adjustment module and a generator set operation mode decision module. According to the wind power system based on the combined generator set, the redundancy of the system is increased, and the problem that the efficiency of a single generator set is low at the non-optimal wind speed is solved; and meanwhile, the arranged system can adapt to a complex and changeable wind energy resource environment.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power systems, and in particular to a wind power system based on a combined generator set. Background Art

[0002] With the acceleration of global industrialization, the demand for energy is growing. At the same time, the excessive use of traditional fossil energy has brought about many environmental problems, such as climate change, air pollution, etc. In this context, the development and utilization of renewable energy has received extensive attention. Wind energy, as an abundant renewable energy, has huge development potential.

[0003] Wind power generation is an effective way to convert wind energy into electrical energy. However, existing wind power generation systems face some technical challenges. Most traditional wind power generation systems use a single type of generator set. This single-structure generator set has obvious limitations in dealing with complex and changeable wind energy resources. Wind energy resources are intermittent and unstable. Wind speed varies greatly in different geographical locations, seasons, day and night. For example, in some coastal areas, the wind speed may be high during the day and significantly reduced at night; in mountainous areas, the wind speed may change complexly due to the influence of terrain. For a single generator set, it is usually designed and optimized for a specific wind speed range. When the actual wind speed deviates from its optimal operating range, the power generation efficiency will drop significantly. Moreover, a single generator set may also have efficiency problems when facing different wind directions. Changes in wind direction may affect the force on the blades of the wind turbine generator set, thereby affecting its power generation efficiency. In addition, the reliability of a single generator set is also a problem. Due to its single structure, once a key component fails, the entire generator set may stop working, affecting the stability of power supply.

[0004] From the perspective of energy utilization, different types of generator sets have different characteristics. For example, direct-drive permanent magnet generators have the advantages of high efficiency and low maintenance costs. They can generate electricity stably at high wind speeds, but their power generation efficiency may be low at low wind speeds; while asynchronous generators may have relatively good power generation performance at low wind speeds, but there may be risks such as overload at high wind speeds. The existing wind power generation system has failed to fully utilize the advantages of different generator sets, resulting in the inability to maximize the utilization of wind energy resources. In terms of overall system performance, the existing wind power generation system lacks effective energy storage and intelligent control mechanisms. When the wind speed is high, excess electricity may be generated, but due to the lack of suitable energy storage devices, this excess electricity cannot be effectively stored, resulting in energy waste. At the same time, the lack of intelligent control makes it impossible for the system to adjust the power generation strategy in time according to the real-time changes in wind speed and wind direction.

[0005] In summary, in order to improve the utilization efficiency of wind energy and enhance the reliability and stability of wind power generation systems, it is of great practical significance to develop a wind power system based on a combined generator set. Summary of the invention

[0006] The purpose of the present invention is to provide a wind power system based on a combined generator set to solve the problems in the prior art that the existing wind power generation system fails to fully utilize the advantages of different generator sets, resulting in the inability to maximize the utilization of wind energy resources, and the existing wind power generation system lacks effective energy storage and intelligent control mechanisms.

[0007] To achieve the above-mentioned object, the present invention provides a wind power system based on a combined generator set, comprising a generator set, an intelligent control system and an energy storage device; the output power of the generator set is adjusted by the intelligent control system; The generator set includes a direct-drive permanent magnet generator, a doubly-fed induction generator and a small wind turbine generator; the direct-drive permanent magnet generator and the doubly-fed induction generator are connected to the power grid in parallel, and the small wind turbine generator is used as a supplement and distributed in areas that are not covered by the direct-drive permanent magnet generator and the doubly-fed induction generator; The intelligent control system includes a wind speed monitoring module, an analysis module, a wind direction monitoring module, an adjustment module, and a generator set operation mode decision module; the wind speed monitoring module collects wind speed data through a wind speed sensor (such as an ultrasonic anemometer or a mechanical anemometer) installed near the generator set; the ultrasonic anemometer measures wind speed based on the principle that the speed of ultrasonic waves in the air is affected by wind speed; the mechanical anemometer measures wind speed based on the relationship between the speed of the wind cup or propeller and the wind speed. The collected wind speed data is then transmitted to the analysis module; the wind direction monitoring module detects wind direction data through a wind direction sensor (such as a wind vane) and transmits it to the analysis module, which adjusts the blade angle of the generator set through the adjustment module according to the wind direction data; the generator set operation mode decision module determines the operation mode of the generator set based on the wind speed and wind direction data and the power-wind speed characteristic curve of the generator set.

[0008] Preferably, the direct-drive permanent magnet generator directly converts wind energy into electrical energy, and its rotor uses permanent magnets and the stator is an armature winding; when the wind wheel drives the rotor to rotate, according to the law of electromagnetic induction, an induced electromotive force is generated in the stator winding to complete power generation.

[0009] Preferably, the stator winding of the doubly-fed induction generator is directly connected to the grid, and the rotor winding is connected to the grid through a frequency converter; based on the principle of induction motors, when a current of a certain frequency is passed through the rotor winding through the frequency converter, a rotating magnetic field is generated in the rotor, which interacts with the stator magnetic field to complete energy conversion.

[0010] Preferably, the analysis module uses a sliding average algorithm to smooth the collected wind speed data, and the processing process is as follows: Assume that the collected wind speed data sequence is , choose a sliding window size of ,in, is a positive integer and , for the data points, , No. The sliding average of the data points The calculation expression is as follows: ; In the formula, Indicates Wind speed data.

[0011] Preferably, the blade angle is adjusted based on aerodynamic principles to optimize the ratio of lift to drag, thereby capturing the maximum wind energy. The calculation expression is as follows: ; ; ; In the formula, is the proportionality constant, is the lift of the blade, represents the resistance of the blade, Indicates wind speed, represents the chord length of the blade, represents the angle of attack of the blade (i.e. the angle between the blade angle and the wind direction), represents the air density, is the lift coefficient, represents the drag coefficient, Indicates wind direction.

[0012] Preferably, the expression of the power-wind speed characteristic curve of the direct-drive permanent magnet generator is as follows: ; In the formula, , , are constants determined according to the characteristics of the direct-drive permanent magnet generator, respectively representing the coefficients related to the power-wind speed characteristic curve of the direct-drive permanent magnet generator, the direct-drive permanent magnet generator at a wind speed of The basic power output at the time, the wind speed reference value of the direct-drive permanent magnet generator, Represents the power-wind speed characteristic curve of the direct-drive permanent magnet generator.

[0013] Preferably, the expression of the power-wind speed characteristic curve of the doubly-fed induction generator is as follows: ; In the formula, , are constants determined according to the characteristics of the doubly-fed induction generator, representing the proportional coefficient and the offset constant respectively. Represents the power-wind speed characteristic curve of the doubly-fed induction generator.

[0014] Preferably, the generator set operation mode decision module determines the operation mode of the generator set according to the wind speed and wind direction data and the power-wind speed characteristic curve of the generator set. Specifically, in the wind power system of the combined generator set, when the wind speed is low, the double-fed induction generator is started, mainly because its power generation efficiency at low wind speed is relatively high; as the wind speed increases, considering the advantages of the direct-drive permanent magnet generator at high wind speed, the analysis module determines whether to start the direct-drive permanent magnet generator for auxiliary operation or make it the main power generation equipment according to the characteristic curves of the two and the current wind speed. The specific process is as follows: The optimal wind speed range of the direct-drive permanent magnet generator is set to , the optimal wind speed range of the doubly-fed induction generator is ,in ; when When only the doubly fed induction generator is started, the output power is calculated according to the power-wind speed characteristic curve of the doubly fed induction generator. ; when When the doubly-fed induction generator operates normally, at the same time, according to the relationship between wind speed and the starting threshold of the direct-drive permanent magnet generator, it is determined whether to start the direct-drive permanent magnet generator for auxiliary operation; if the direct-drive permanent magnet generator is started, and the output power is calculated according to the power-wind speed characteristic curve of the direct-drive permanent magnet generator, , at this time the total output power of the system ; when When the direct-drive permanent magnet generator is the main power generation equipment, the doubly-fed induction generator adjusts the operation mode according to the system requirements and its own state. The output power is calculated according to the power-wind speed characteristic curve of the direct-drive permanent magnet generator. According to the power-wind speed characteristic curve of the doubly-fed induction generator, the output power is calculated as , then the total system output power ; when When the direct-drive permanent magnet generator is regulated by the intelligent control system to adapt to the high wind speed state, the output power is calculated according to the power-wind speed characteristic curve of the direct-drive permanent magnet generator. The doubly-fed induction generator adjusts its operating state according to the system requirements. The output power is calculated based on the power-wind speed characteristic curve of the doubly-fed induction generator. , total system output power .

[0015] Preferably, the working state of the energy storage device is as follows: When the total output power of the power generation system Greater than load power When the excess power Stored in an energy storage device; energy storage state of the energy storage device satisfy ,in is the initial energy storage state; when When To fill the power gap, .

[0016] Preferably, the energy storage device uses a lithium-ion battery. During the charging process, lithium ions are deintercalated from the positive electrode material, migrate to the negative electrode through the electrolyte and are embedded in the negative electrode material; during the discharging process, lithium ions are deintercalated from the negative electrode and migrate to the positive electrode through the electrolyte.

[0017] Therefore, the present invention adopts the above-mentioned wind power system based on the combined generator set, which has the following beneficial effects: (1) Combining different types of generator sets can take advantage of the strengths of each generator set under different wind speed conditions, avoiding the problem of low efficiency of a single generator set under non-optimal wind speeds, thereby improving overall power generation efficiency; (2) The intelligent control system used can adjust the operating mode and blade angle of the generator set according to changes in wind speed and direction, so that the system can adapt to the complex and changing wind energy resource environment and effectively respond to high wind speed, low wind speed and wind direction changes; (3) The combination of multiple generator sets increases the redundancy of the system. When a generator set fails, other generator sets can continue to work, reducing the risk of the entire system shutting down due to the failure of a single generator set and improving the reliability of the system; (4) Through the installation of energy storage devices, the storage and release of electric energy can be effectively managed, avoiding the waste of electric energy when there is excess wind energy. At the same time, it can provide supplementary electric energy when there is insufficient wind energy, thus achieving optimal energy management.

[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The overall architecture diagram of a wind power system based on a combined generator set of the present invention. DETAILED DESCRIPTION

[0020] The following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] See also Figure 1 , a wind power system based on a combined generator set, comprising a generator set, an intelligent control system and an energy storage device; the output power of the generator set is adjusted by the intelligent control system; The generator group includes a direct-drive permanent magnet generator, a doubly-fed induction generator and a small wind turbine generator; the direct-drive permanent magnet generator and the doubly-fed induction generator are connected to the power grid in parallel, and the small wind turbine generators are distributed in areas that are not covered by the direct-drive permanent magnet generator and the doubly-fed induction generator as a supplement. The electric energy they generate is also converted into alternating current through power electronic equipment such as inverters, and then incorporated into the power grid of the entire wind power system. In specific work, small wind turbine generators are set up as needed and their power is calculated; the direct-drive permanent magnet generator directly converts wind energy into electrical energy, and its rotor uses permanent magnets and the stator is an armature winding; when the wind wheel drives the rotor to rotate, according to the law of electromagnetic induction, an induced electromotive force is generated in the stator winding to complete power generation. The stator winding of the doubly-fed induction generator is directly connected to the power grid, and the rotor winding is connected to the power grid through a frequency converter; based on the principle of induction motor, when a certain frequency current is passed through the rotor winding through the frequency converter, a rotating magnetic field is generated in the rotor, which interacts with the stator magnetic field to complete energy conversion.

[0022] The intelligent control system includes a wind speed monitoring module, an analysis module, a wind direction monitoring module, an adjustment module, and a generator set operation mode decision module; the wind speed monitoring module collects wind speed data through a wind speed sensor (such as an ultrasonic anemometer or a mechanical anemometer) installed near the generator set; the ultrasonic anemometer measures wind speed based on the principle that the speed of ultrasonic waves in the air is affected by wind speed; the mechanical anemometer measures wind speed based on the relationship between the speed of the wind cup or propeller and wind speed. The collected wind speed data is then transmitted to the analysis module; the analysis module uses a sliding average algorithm to smooth the collected wind speed data, and the processing process is as follows: Assume that the collected wind speed data sequence is , choose a sliding window size of ,in, is a positive integer and , for the data points, , No. The sliding average of the data points The calculation expression is as follows: ; In the formula, Indicates Wind speed data; The wind direction monitoring module detects wind direction data through a wind direction sensor (such as a wind vane) and transmits it to the analysis module. The analysis module adjusts the blade angle of the generator set through the adjustment module according to the wind direction data; the blade angle is adjusted based on the aerodynamic principle to achieve the optimal ratio of lift to drag, thereby capturing the maximum wind energy. The calculation expression is as follows: ; ; ; In the formula, is the proportionality constant, is the lift of the blade, represents the resistance of the blade, Indicates wind speed, represents the chord length of the blade, represents the angle of attack of the blade (i.e. the angle between the blade angle and the wind direction), represents the air density, is the lift coefficient, represents the drag coefficient, Indicates wind direction.

[0023] The generator set operation mode decision module determines the operation mode of the generator set according to the wind speed and wind direction data and the power-wind speed characteristic curve of the generator set; among them, the expression of the power-wind speed characteristic curve of the direct-drive permanent magnet generator is as follows: ; In the formula, , , are constants determined according to the characteristics of the direct-drive permanent magnet generator, respectively representing the coefficients related to the power-wind speed characteristic curve of the direct-drive permanent magnet generator, the direct-drive permanent magnet generator at a wind speed of The basic power output at the time, the wind speed reference value of the direct-drive permanent magnet generator, Represents the power-wind speed characteristic curve of the direct-drive permanent magnet generator.

[0024] The expression of the power-wind speed characteristic curve of the doubly fed induction generator is as follows: ; In the formula, , are constants determined according to the characteristics of the doubly-fed induction generator, representing the proportional coefficient and the offset constant respectively. Represents the power-wind speed characteristic curve of the doubly-fed induction generator.

[0025] The generator set operation mode decision module determines the operation mode of the generator set according to the wind speed and wind direction data and the power-wind speed characteristic curve of the generator set. Specifically, in the wind power system of the combined generator set, when the wind speed is low, the double-fed induction generator is started, mainly because its power generation efficiency at low wind speed is relatively high; as the wind speed increases, considering the advantages of the direct-drive permanent magnet generator at high wind speed, the analysis module determines whether to start the direct-drive permanent magnet generator for auxiliary operation or make it the main power generation equipment according to the characteristic curves of the two and the current wind speed. The specific process is as follows: The optimal wind speed range of the direct-drive permanent magnet generator is set to , the optimal wind speed range of the doubly-fed induction generator is ,in ; when When only the doubly fed induction generator is started, the output power is calculated according to the power-wind speed characteristic curve of the doubly fed induction generator. ; when When the doubly-fed induction generator operates normally, at the same time, according to the relationship between wind speed and the starting threshold of the direct-drive permanent magnet generator, it is determined whether to start the direct-drive permanent magnet generator for auxiliary operation; if the direct-drive permanent magnet generator is started, and the output power is calculated according to the power-wind speed characteristic curve of the direct-drive permanent magnet generator, , at this time the total output power of the system ; when When the direct-drive permanent magnet generator is the main power generation equipment, the doubly-fed induction generator adjusts the operation mode according to the system requirements and its own state. The output power is calculated according to the power-wind speed characteristic curve of the direct-drive permanent magnet generator. According to the power-wind speed characteristic curve of the doubly-fed induction generator, the output power is calculated as , then the total system output power ; when When the direct-drive permanent magnet generator is regulated by the intelligent control system to adapt to the high wind speed state, the output power is calculated according to the power-wind speed characteristic curve of the direct-drive permanent magnet generator. The doubly-fed induction generator adjusts its operating state according to the system requirements. The output power is calculated based on the power-wind speed characteristic curve of the doubly-fed induction generator. , total system output power .

[0026] The working status of the energy storage device is as follows: When the total output power of the power generation system Greater than load power When the excess power Stored in an energy storage device; energy storage state of the energy storage device satisfy ,in is the initial energy storage state; when When To fill the power gap, Among them, the energy storage device uses a lithium-ion battery. During the charging process, lithium ions are deintercalated from the positive electrode material, migrate to the negative electrode through the electrolyte and embed into the negative electrode material; during the discharging process, lithium ions are deintercalated from the negative electrode and migrate to the positive electrode through the electrolyte.

[0027] Therefore, the present invention adopts the above-mentioned wind power system based on the combined generator set. Through the combination of multiple generator sets, it not only increases the redundancy of the system, but also avoids the problem of low efficiency of a single generator set under non-optimal wind speed; in addition, the intelligent control system adopted can adjust the operating mode and blade angle of the generator set according to changes in wind speed and wind direction, so that the system can adapt to the complex and changeable wind energy resource environment; finally, through the setting of the energy storage device, it can effectively manage the storage and release of electric energy, avoiding the waste of electric energy when wind energy is in excess, and at the same time providing supplementary electric energy when wind energy is insufficient, thereby realizing the optimal management of energy.

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A wind power system based on a combined generator set, characterized in that: It includes a generator set, an intelligent control system and an energy storage device; the output power of the generator set is adjusted through the intelligent control system; The generator set includes a direct-drive permanent magnet generator, a doubly-fed induction generator and a small wind turbine generator; the direct-drive permanent magnet generator and the doubly-fed induction generator are connected to the power grid in parallel, and the small wind turbine generator is used as a supplement and distributed in areas that are not covered by the direct-drive permanent magnet generator and the doubly-fed induction generator; The intelligent control system includes a wind speed monitoring module, an analysis module, a wind direction monitoring module, an adjustment module and a generator set operation mode decision module; The wind speed monitoring module collects wind speed data through a wind speed sensor installed near the generator set; the collected wind speed data is then transmitted to the analysis module; the wind direction monitoring module detects wind direction data through a wind direction sensor and transmits it to the analysis module, and the analysis module adjusts the blade angle of the generator set through the adjustment module according to the wind direction data; the generator set operation mode decision module determines the operation mode of the generator set according to the wind speed and wind direction data and the power-wind speed characteristic curve of the generator set.

2. A wind power system based on a combined generator set according to claim 1, characterized in that: The direct-drive permanent magnet generator directly converts wind energy into electrical energy. Its rotor uses permanent magnets and its stator is an armature winding. When the wind wheel drives the rotor to rotate, according to the law of electromagnetic induction, an induced electromotive force is generated in the stator winding to complete power generation.

3. A wind power system based on a combined generator set according to claim 2, characterized in that: The stator winding of the doubly-fed induction generator is directly connected to the grid, and the rotor winding is connected to the grid through a frequency converter. Based on the principle of induction motors, when a current of a certain frequency is passed through the rotor winding through the frequency converter, a rotating magnetic field is generated in the rotor, which interacts with the stator magnetic field to complete energy conversion.

4. A wind power system based on a combined generator set according to claim 3, characterized in that: The analysis module uses a sliding average algorithm to smooth the collected wind speed data. The processing process is as follows: Assume that the collected wind speed data sequence is , choose a sliding window size of ,in, is a positive integer and , for the data points, , No. The sliding average of the data points The calculation expression is as follows: ； In the formula, Indicates Wind speed data.

5. A wind power system based on a combined generator set according to claim 4, characterized in that: Based on the principles of aerodynamics, the blade angle is adjusted to optimize the ratio of lift to drag, thereby capturing the maximum wind energy. The calculation expression is as follows: ； ； ； In the formula, is the proportionality constant, represents the lift of the blade, represents the resistance of the blade, Indicates wind speed, represents the chord length of the blade, represents the angle of attack of the blade, represents the air density, is the lift coefficient, represents the drag coefficient, Indicates wind direction.

6. A wind power system based on a combined generator set according to claim 5, characterized in that: The expression of the power-wind speed characteristic curve of the direct-drive permanent magnet generator is as follows: ； In the formula, , , are constants determined according to the characteristics of the direct-drive permanent magnet generator, respectively representing the coefficients related to the power-wind speed characteristic curve of the direct-drive permanent magnet generator, the direct-drive permanent magnet generator at a wind speed of The basic power output at the time, the wind speed reference value of the direct-drive permanent magnet generator, Represents the power-wind speed characteristic curve of the direct-drive permanent magnet generator.

7. A wind power system based on a combined generator set according to claim 6, characterized in that: The expression of the power-wind speed characteristic curve of the doubly fed induction generator is as follows: ； In the formula, , are constants determined according to the characteristics of the doubly-fed induction generator, representing the proportional coefficient and the offset constant respectively. Represents the power-wind speed characteristic curve of the doubly-fed induction generator.

8. A wind power system based on a combined generator set according to claim 7, characterized in that: The generator set operation mode decision module determines the operation mode of the generator set according to the wind speed and wind direction data and the power-wind speed characteristic curve of the generator set. Specifically, in the wind power system of the combined generator set, when the wind speed is low, the double-fed induction generator is started; as the wind speed increases, the analysis module determines whether to start the direct-drive permanent magnet generator for auxiliary operation or make it the main power generation equipment according to the characteristic curves of the two and the current wind speed. The specific process is as follows: The optimal wind speed range of the direct-drive permanent magnet generator is set to , the optimal wind speed range of the doubly-fed induction generator is ,in ; when When only the doubly fed induction generator is started, the output power is calculated according to the power-wind speed characteristic curve of the doubly fed induction generator. ; when When the doubly-fed induction generator operates normally, at the same time, according to the relationship between wind speed and the starting threshold of the direct-drive permanent magnet generator, it is determined whether to start the direct-drive permanent magnet generator for auxiliary operation; if the direct-drive permanent magnet generator is started, and the output power is calculated according to the power-wind speed characteristic curve of the direct-drive permanent magnet generator, , at this time the total output power of the system ; when When the direct-drive permanent magnet generator is the main power generation equipment, the doubly-fed induction generator adjusts the operation mode according to the system requirements and its own state. The output power is calculated according to the power-wind speed characteristic curve of the direct-drive permanent magnet generator. According to the power-wind speed characteristic curve of the doubly-fed induction generator, the output power is calculated as , then the total system output power ; when When the direct-drive permanent magnet generator is regulated by the intelligent control system to adapt to the high wind speed state, the output power is calculated according to the power-wind speed characteristic curve of the direct-drive permanent magnet generator. The doubly-fed induction generator adjusts its operating state according to the system requirements. The output power is calculated based on the power-wind speed characteristic curve of the doubly-fed induction generator. , total system output power .

9. A wind power system based on a combined generator set according to claim 8, characterized in that: The working status of the energy storage device is as follows: When the total output power of the power generation system Greater than load power When the excess power is stored in an energy storage device; Energy storage status of energy storage device satisfy ,in is the initial energy storage state; when When To fill the power gap, .

10. A wind power system based on a combined generator set according to claim 9, characterized in that: The energy storage device uses a lithium-ion battery. During the charging process, lithium ions are deintercalated from the positive electrode material, migrate to the negative electrode through the electrolyte and embed into the negative electrode material; during the discharging process, lithium ions are deintercalated from the negative electrode and migrate to the positive electrode through the electrolyte.

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