Wind Turbine Generator Heating via Dual Three-Phase Short-Circuiting
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Solution Overview
Problem
Existing wind energy systems face challenges in reducing the duration of the heating operation for the generator after a longer standstill, leading to prolonged downtimes and potential damage from moisture accumulation.
Innovation Solution
The proposed procedure involves a two-phase heating operation for the wind energy system generator, utilizing a first three-phase system and a second three-phase system with switches to manage short-circuiting and heating, prioritizing the three-phase system with the worst insulation for initial heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a generator heater is used to heat the generator after prolonged downtime, then moisture is removed from the generator, but the heating period lasts several hours causing loss of profit and lost productivity
Solution Approach 1:
The patent segments the three-phase system into two separate three-phase systems (first and second), each with its own switch. By alternately short-circuiting phases from different systems, the heating process is divided into multiple phases that can be executed more efficiently, reducing total heating time while maintaining moisture removal effectiveness.
Solution Approach 2:
The patent implements periodic switching between the first and second three-phase systems. The controller alternates between short-circuiting phases in the first system and phases in the second system, creating a periodic heating action that maintains high heat output throughout the process while reducing overall duration compared to continuous heating of a single system.
2Power
If short-circuit heating is used to generate heat through short-circuit current, then heating is achieved, but the heat generation is insufficient requiring long heating periods
Solution Approach 1:
The patent merges the heating capability of two separate three-phase systems into a coordinated heating process. By alternately activating short-circuiting in both systems, the total heat generation capability is effectively doubled compared to using a single system, thereby reducing the time required to achieve the necessary heating for moisture removal.
3Reliability
If the generator is left idle after prolonged downtime, then maintenance and wind availability issues occur, but continuous operation prevents moisture accumulation
Solution Approach 1:
The patent implements a preliminary rapid heating phase that quickly raises the generator temperature to prevent moisture condensation. This preliminary action allows the generator to be returned to service faster after downtime, minimizing the loss of time while ensuring adequate protection against moisture accumulation during the transition from idle to operational state.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces the heating time by maximizing heat output through strategic short-circuiting and prioritization of heating based on insulation values, thereby minimizing downtime and preventing damage from moisture.
Implementation Method 1
The rotor (16) is configured to generate a magnetic field and, during rotation, to inject an electric current into the first three-phase system and the second three-phase system of the stator
Implementation Method 2
The short-circuit current leads to heat generation due to the resistances present in the windings
Data Source
Figure 1
Figure 2~3
Figure 4~6
AI summary
The invention relates to a method for operating a wind turbine generator (12) in heating mode, wherein the wind turbine generator (12) has a rotor (16) and a stator (14), and the stator (14) has a first three-phase system (32a) with three first phases (36a, 36b, 36c) and a second three-phase system (32b) with three second phases (36d, 36e, 36f). The rotor (16) is configured to generate a magnetic field and, during rotation with the magnetic field, to induce an electric current in the first three-phase system (32a) and the second three-phase system (32b).The first three-phase system (32a) has at least one first switch (54a, 54b, 54c, 54d, 54e, 54f, 64) for short-circuiting the first strands (36a, 36b, 36c) in a closed state (60) and for letting the first strands (36a, 36b, 36c) run freely in an open state (56) and the second three-phase system (32b) has at least one second switch (54a, 54b, 54c, 54d, 54e, 54f, 64) for short-circuiting the second strands (36d, 36e, 36f) in a closed state (60) and for letting the second strands (36d, 36e, 36f) run freely in an open state (56).The heating operation comprises a first phase (70), in which, during the first phase (70), the first switch (54a, 54b, 54c, 54d, 54e, 54f, 64) is switched to the closed state (60) and the second switch (54a, 54b, 54c, 54d, 54e, 54f, 64) is switched to the open state (56), or the first switch (54a, 54b, 54c, 54d, 54e, 54f, 64) is switched to the open state (56) and the second switch (54a, 54b, 54c, 54d, 54e, 54f, 64) is switched or remains switched. The invention further relates to a wind turbine generator system (10) comprising a wind turbine generator (12) and a wind turbine (100).