Multi-Channel Generator with Rotating Power Converters
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Solution Overview
Problem
Generator output voltage variations due to sudden load changes and rotational speed fluctuations in variable frequency generators, leading to unstable power delivery.
Innovation Solution
A multi-channel generator system with a generator control unit (GCU) and rotating power converters, which includes high-side and low-side switches and diodes, allows independent control of each channel to regulate the main field winding current, maintaining near constant voltage through feedback and PWM control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a permanent magnet generator with belt-type interface is used, then mechanical energy conversion is achieved, but sudden load changes cause sudden changes in generator speed and output voltage variations occur
Solution Approach 1:
A controlled rectifier is introduced as an intermediary device between the permanent magnet generator and the load. This rectifier includes controllable switches that can independently control the current flowing to different output channels, thereby stabilizing the output voltage despite speed variations caused by load changes
Solution Approach 2:
The invention changes the electrical parameters by using controllable rectifier switches to independently regulate the current in each phase winding. By adjusting the conduction angle and timing of each switch, the output voltage and current can be controlled to remain stable despite variations in generator speed
2Power
If a wound field synchronous machine with exciter section is used, then output voltage regulation is achieved, but the architecture complexity increases
Solution Approach 1:
The invention merges the functions of the permanent magnet generator and the controlled rectifier into a single integrated system. The permanent magnet generator provides the magnetic field, while the controlled rectifier with independently controllable switches provides the voltage regulation function, eliminating the need for a separate exciter section
Solution Approach 2:
The invention replaces the mechanical exciter system with an electrical control system. Instead of using a separate exciter generator to provide field current, the patent uses electronically controlled rectifier switches to regulate the current in the stator windings, thereby achieving voltage regulation without the mechanical complexity of a wound field synchronous machine
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 system effectively stabilizes generator output voltage by regulating current to the main field winding, mitigating sudden voltage changes and ensuring consistent power delivery despite load and speed variations.
Implementation Method 1
generators convert mechanical energy to electrical energy via the interaction of rotating magnetic fields and coils of wire
Implementation Method 2
The AC voltage provided by the permanent magnet portion is rectified and selectively applied to the exciter winding
Implementation Method 3
The exciter field current interacts with the rotating exciter armature windings to provide an AC voltage
Implementation Method 4
A rotating rectifier rectifies the AC voltage and supplies the DC voltage to a main field winding
Implementation Method 5
Rotation of the motive power shaft and the main field winding induces three-phase AC output voltage on the main generator armature winding
Data Source
Figure 1
Figure 1
AI summary
A generator system includes a generator 52 haying a stationary portion 60 and a rotating 61. The generator includes an exciter field winding 62 disposed on the stationary portion. A first channel includes a first main field winding 72 and a first main field power converter 78 disposed on a rotating portion. The first main field power converter selectively delivers voltage from the exciter winding the first main field winding. A second channel includes a second main field winding 74 and a second main field power converted 80 disposed on the rotating portion. The second main field power converter selectively delivers voltage from the exciter winding to the second main field winding. A generator control unit is connected to the first channel and the second channel. The generator control unit monitors an output voltage at each of the first channel and the second channel and generates the first and second control signals based on the output voltage.