Brushless Generator Sense Coils for Rotor Position Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing position sensing methods for rotor control in brushless synchronous generators, such as Hall Effect sensors, are costly and limited by operational parameters, leading to reduced accuracy and increased complexity in synchronization.
Innovation Solution
A three-phase electromagnetic device with power coils and sense coils, where sense coils are magnetically and electrically decoupled from power coils and separated by an air gap, allowing for precise determination of rotor position and speed using the induced currents, enabling accurate rectification of power current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Hall Effect sensors are used for rotor position sensing, then rotor position can be detected, but the system becomes expensive and complex with extra wires and assembly steps
Solution Approach 1:
The patent extracts the position sensing function from separate Hall Effect sensors and integrates it into the stator windings themselves. The sense coils are wound in the stator to detect rotor position through induced voltages, eliminating the need for external position sensors and their associated electronics, wires, and assembly steps.
Solution Approach 2:
The stator windings serve dual functions: power coils generate power current from the rotating magnetic field, while sense coils simultaneously detect rotor position and speed through induced voltages. This multi-functionality eliminates the need for separate sensing apparatus and reduces overall system complexity.
2Measurement precision
If Hall Effect sensors are used for rotor position sensing, then rotor position can be detected, but the cost increases due to sensor and electronics expense
Solution Approach 1:
The patent removes the expensive Hall Effect sensors and their associated electronics from the system. Position sensing is achieved using simple coils wound in the stator, which are standard electromagnetic components that are much cheaper to manufacture and install than specialized position sensors.
Solution Approach 2:
The sense coils use ordinary wire windings similar to power coils, replacing expensive, delicate Hall Effect sensors with simple, robust electromagnetic感应 elements that are inexpensive to manufacture and replace if needed.
3Measurement precision
If traditional position sensors are used, then rotor position can be sensed, but accuracy is limited by operational parameters
Solution Approach 1:
The sense coils are integrated into the stator windings and work across the full operational range of the generator without requiring separate calibration or adjustment for different operating conditions. The induced voltage in the sense coils naturally adapts to varying rotor speeds and positions, providing accurate sensing across all operational parameters.
Solution Approach 2:
The sense coils provide continuous feedback on rotor position and speed through induced voltages that naturally vary with rotor motion. This feedback is inherently adaptive to operational parameters, as the induced voltage magnitude and frequency automatically adjust to match the rotor's actual position and speed, ensuring accurate detection across the full operating range.
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 solution provides high-precision rotor position and speed determination, enabling efficient and accurate rectification of AC power to DC, reducing costs and complexity compared to traditional sensing methods.
Implementation Method 1
sense coils configured to generate a sense current as a second portion of the magnetic poles pass each of the sense coils due to the rotor rotation
Implementation Method 2
power coils configured to generate a power current as a first portion of the magnetic poles pass each of the power coils due to rotor rotation
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An electromagnetic device (10) is provided and includes a stator (20) defining a bore (21), a rotor (30) rotatable within the stator bore (21) and having permanent magnetic elements (33) disposed about an outer surface (32) thereof to define a series of magnetic poles (34), power coils (50) configured to generate a power current as a first portion of the magnetic poles (34) pass each of the power coils (50) due to rotor rotation and sense coils (60) configured to generate a sense current as a second portion of the magnetic poles (34) pass each of the sense coils (60) due to the rotor rotation.