Stator Winding Layout Without Neutral Bus Bars in Wind Generators

Solution Overview

Problem

Existing electrical machines, particularly large segmented machines like wind turbine generators, require complex neutral connections via bus bars, increasing cost, weight, and installation time, and suffer from circulating currents and inefficiencies due to shared neutral points.

Innovation Solution

A stator wiring arrangement where coils are grouped into phases with internal connections within each group but no connections between groups, eliminating the need for a neutral bus bar and allowing phase-shifted currents, thereby simplifying construction and reducing weight and losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a common neutral connection (bus bar or wire) is used to connect parallel coil groups, then the electrical machine can share total current across groups, but the system experiences increased weight, cost, and installation time

Engineering Contradiction:

Improvecurrent sharing capabilityVSAvoidweight of neutral connection

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The invention extracts and removes the common neutral connection (bus bar or wire) from the electrical machine system. Each parallel coil group is equipped with its own independent neutral connection, eliminating the need for a shared neutral path. This directly addresses the contradiction by removing the heavy common neutral connection while preserving current sharing capability through independent group connections.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention segments the neutral connection system by providing separate neutral connections for each parallel coil group instead of a single common neutral connection. This segmentation allows each group to independently manage its current return path, eliminating the need for a heavy common bus bar while maintaining the ability to share total current across all groups.

Inventive Principle:

Principle #1Segmentation

2Reliability

If a common neutral connection (bus bar or wire) is used to connect parallel coil groups, then the electrical machine can share total current across groups, but the system experiences increased cost and installation time

Engineering Contradiction:

Improvecurrent sharing capabilityVSAvoidinstallation time

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The invention extracts and removes the common neutral connection (bus bar or wire) from the electrical machine system. Each parallel coil group is equipped with its own independent neutral connection, eliminating the need for a shared neutral path. This directly addresses the contradiction by removing the heavy common neutral connection while preserving current sharing capability through independent group connections.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention segments the neutral connection system by providing separate neutral connections for each parallel coil group instead of a single common neutral connection. This segmentation allows each group to independently manage its current return path, eliminating the need for a heavy common bus bar while maintaining the ability to share total current across all groups.

Inventive Principle:

Principle #1Segmentation

3Power

If parallel coil groups share a common neutral connection, then total current can be distributed across groups, but circulating currents cause losses and inefficiencies

Engineering Contradiction:

Improvetotal current capacityVSAvoidcirculating current losses

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The invention extracts and removes the common neutral connection (bus bar or wire) from the electrical machine system. Each parallel coil group is equipped with its own independent neutral connection, eliminating the need for a shared neutral path. This directly addresses the contradiction by removing the heavy common neutral connection while preserving current sharing capability through independent group connections.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention segments the neutral connection system by providing separate neutral connections for each parallel coil group instead of a single common neutral connection. This segmentation allows each group to independently manage its current return path, eliminating the need for a heavy common bus bar while maintaining the ability to share total current across all groups.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentEP3550699B1Winding design arrangement for an electrical machine and wind turbine generator

Publication Date: 2025.10.08 SIEMENS GAMESA RENEWABLE ENERGY AS

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AI summary

It is described an winding design arrangement (100) for an electrical machine (230), the arrangement comprising: multiple first coils (101a, 101b, 101c) for providing multiple phases (A, B, C); at least multiple second coils (103a, 103b, 103c) for providing the multiple phases (A, B, C), wherein, at respective one ends (107) of the coils, any of the multiple first coils (101a, 101b, 101c) is electrically disconnected from any of the multiple second coils (103a, 103b, 103c).