Integrated Fault Ride Through Circuit in Electric Power Generators
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Solution Overview
Problem
Existing electric power generators often require separate fault ride through circuits external to the generator, which complicates cooling, integration, and compliance with grid code requirements, leading to potential failures during grid faults.
Innovation Solution
Integrating the fault ride through circuit within the electric power generator, allowing it to utilize the generator's cooling system and enabling compact, rigid, and impregnated brake resistance designs, eliminating the need for separate enclosures and support structures, and positioning the circuit on the stator core for efficient cooling and operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the fault ride through circuit is positioned external to the generator, then the generator structure remains simple, but the cooling system complexity increases and integration becomes difficult
Solution Approach 1:
The fault ride through circuit is integrated within the generator structure, specifically positioned on the outer surface of the stator core. This merging allows the circuit to utilize the generator's existing cooling system through cooling channels or air gaps, eliminating the need for separate external cooling arrangements and reducing overall system complexity.
2Ease of manufacture
If the brake resistance is made separate and non-impregnated, then manufacturing is easier, but the structural rigidity and compactness decrease
Solution Approach 1:
The brake resistance is impregnated with insulation varnish or resin to create a composite structure. This impregnation process combines the electrical resistance material with binding agents, providing both electrical functionality and mechanical rigidity, allowing the brake resistance to be securely mounted on the stator core surface.
3Temperature
If the fault ride through circuit is integrated within the generator, then cooling efficiency improves, but the available space within the generator decreases
Solution Approach 1:
The fault ride through circuit is positioned on the outer surface of the stator core, utilizing the radial dimension of the generator structure. This placement allows the circuit to access cooling airflow or cooling channels that pass through or along the stator core, providing efficient cooling without occupying valuable internal space that would be needed for the rotor or stator windings.
4Reliability
If separate enclosures and support structures are used for the fault ride through circuit, then the circuit is well-protected, but the overall device complexity and cost increase
Solution Approach 1:
The generator's stator core and its supporting structures serve multiple functions: they provide the magnetic circuit for power generation, structural support for the entire assembly, and a mounting surface for the fault ride through circuit. This multi-functionality eliminates the need for separate enclosures and support structures, reducing complexity while maintaining protection and structural integrity.
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
The integrated fault ride through circuit ensures the generator meets grid code requirements, maintains synchronism during faults, and reduces complexity and costs by leveraging the generator's cooling and manufacturing processes, while providing a compact and efficient solution.
Implementation Method 1
a brake resistance configured to absorb electric power produced by the electric power generator during a fault condition
Implementation Method 2
allowing it to utilize the generator's cooling system
Data Source
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AI summary
The electric power generator comprises a rotor (100) being rotatable around a longitudinal centre axis (X-X) of rotation and comprising a rotor winding (111), and a stator (200) surrounding the rotor (100). The stator (200) comprises a stator core (210) with a stator winding (211) and a stator frame (220) surrounding the stator core (210). The generator comprises further a connection space (250) formed in connection with the stator frame (220), a fault ride through circuit (500) comprising a brake resistance (510) and a switch (520), the switch (520) being configured to by-pass the brake resistance (510) in normal operation and to connect the brake resistance (510) in series with the stator winding (211) in a fault ride through situation in order to consume electric power produced by the electric power generator (400) during a period of at least 250 ms required by grid code requirements so that the electric power generator (400) maintains its synchronism during this period of 250 ms. The fault ride through circuit (500) is positioned within the electric generator (400) between the connection space (250) of the electric generator (400) and the stator winding (211).