Wind turbine with modular generator-converter system and power distribution for optimized efficiency control in partial load operation

Abstract

Wind turbine with a total electrical output of at least 20 MW, characterized in that - the plant has several generators, each with a rated output of no more than 12 MW; - the generators are mechanically connected to the rotor shaft via a gearbox system with power sharing; - each generator is operated at a rated speed of at least 1000 rpm; - each generator is assigned a separate inverter; - each generator converter path can be switched on or off independently; - a central control system is in place which, in partial load operation, only activates the number of generator-converter paths required to meet the current power demand; - the control system is designed in such a way that the activated paths operate in the area of ​​highest efficiency.

Description

1. Title of the invention

[0001] Wind turbine with modular generator-converter system and power distribution for optimized efficiency control in partial load operation. 2. Technical field

[0002] The invention relates to wind turbines, in particular high-power offshore turbines. They have a total electrical output of at least 20 MW. The core of the invention is a modular architecture for generating and converting electrical energy. This architecture is based on distributing the power across multiple generator-converter units. 3. State of the art

[0003] In well-known inverter systems, a modular arrangement of power semiconductors is frequently used, particularly so-called IGBT modules (Insulated Gate Bipolar Transistors). These modules serve for internal load sharing and redundancy within a single inverter. They make it possible to relieve individual power modules or switch off sections of the inverter in the event of partial load or partial failure. However, the inverter as a whole remains operational, so high baseline losses still occur at low power levels. Independent switching on or off of inverter strings at the system level is not possible with such internal modules.

[0004] Wind turbines with a power output of 20 MW and above typically use a single generator that feeds into the grid via a central gearbox and a single converter train. However, this design has significant disadvantages: - In partial load operation, both the large generator and the large converter often operate outside their optimal operating ranges, which leads to increased conversion losses. - Furthermore, a failure of the converter or generator can lead to a complete standstill in power generation, as there is no redundancy.

[0005] Wind turbines of this power class typically use a single generator coupled to a central inverter. However, this design has its drawbacks. Under partial load, both the generator and the inverter often operate outside their optimal efficiency range. Furthermore, the failure of these central components can lead to a complete loss of power generation. Differentiation from the state of the art:

[0006] Known solutions rely either on a large generator with a single inverter or on an inverter with an internal modular structure. Both lead to disadvantages in partial load operation and in the event of individual component failure. While it would theoretically be possible to connect a single large generator with multiple inverter strings, this is rarely implemented in practice. The reasons for this are: - The generator's losses remain regardless of how many converters are active. - Synchronizing multiple inverters on a single generator is complex and expensive. Cabling and cooling costs increase significantly with such solutions.

[0007] The present invention differs in that it features complete modularization on both the generator and inverter sides. Several smaller generators are operated via a gearbox with power distribution. Each generator has its own dedicated inverter. This allows both generators and inverters to be flexibly switched on and off as needed. This optimizes overall efficiency, increases system availability, and minimizes losses, particularly under partial load. 4. Description of the invention

[0008] The invention proposes to distribute the electrical power generation of a wind turbine across multiple sub-generators. Each generator is connected to the rotor shaft via a power-sharing gearbox system. The generators operate at a rated speed of at least 1000 rpm. Each generator has its own inverter. The individual generator-inverter paths can be switched on or off independently. A central control system manages the activation of the modules based on the current power demand. This ensures that only the necessary number of modules are active at any given time to guarantee high overall efficiency. Unused modules remain in standby mode, serving either as a reserve for higher load demands or as redundancy in case of a malfunction. 5. Advantages of the invention - Higher overall efficiency through selective activation of the modules - Improved availability through redundant structure - More compact design due to higher rated speeds of the generators - Simplified maintenance thanks to modular structure - More efficient controllability through fine-tuned control

Claims

[1] Wind turbine with a total electrical output of at least 20 MW, characterized by , that - the plant has several generators, each with a rated output of no more than 12 MW; - the generators are mechanically connected to the rotor shaft via a gearbox system with power sharing; - each generator is operated at a rated speed of at least 1000 rpm; - each generator is assigned a separate inverter; - each generator converter path can be switched on or off independently; - a central control system is in place which, in partial load operation, only activates the number of generator-converter paths required to meet the current power demand; - the control system is designed in such a way that the activated paths operate in the area of ​​highest efficiency. [2] Plant according to claim 1, characterized by, that the rated speed of the generators is 1500 rpm. [3] Plant according to any one of the preceding claims, characterized by that the transmission system is designed as a multiple output with a planetary stage. [4] Plant according to any one of the preceding claims, characterized by that the inverters are housed in a common container using a pluggable modular design. [5] Plant according to any one of the preceding claims, characterized by that the control system uses a wind power model to determine the optimal operating condition. [6] Plant according to any one of the preceding claims, characterized by , that if one module fails, the remaining modules continue operation without interruption. [7] Plant according to any one of the preceding claims, characterized by that a central control unit is provided which coordinates all converters and has a common signal and communication interface. [8] Plant according to any one of the preceding claims, characterized by that the converters are designed as standardized modules with a maximum nominal power of 12 MW and are designed for parallel use in systems with a total power of at least 20 MW. [9] Plant according to any one of the preceding claims, characterized by that the converters are arranged in a spatially compact location close to the turbine or in a common housing in order to minimize the length of the electrical connecting cables. [10] Plant according to any one of the preceding claims, characterized by , that a control logic for dynamic load distribution is used, in which only a portion of the inverters are switched on at partial load and a uniform power distribution takes place at full load. [11] Plant according to any one of the preceding claims, characterized by that the converters use common infrastructure elements such as cooling systems, DC intermediate circuits or transformers. [12] Plant according to any one of the preceding claims, characterized by , ensuring that temperature monitoring and control of the switching frequency or load distribution guarantee that the inverters are operated with both high efficiency and maximum service life. [13] Plant according to any one of the preceding claims, characterized by that the generators can also have a rated output of up to 20 MW.