DC Generator Damper Winding Removal and Rectifier Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Synchronous generators experience high peak fault currents due to fluctuations in air gap flux caused by sudden load changes, which can lead to oscillations and instability in DC power generation systems.
Innovation Solution
A DC power generation system with a generator having reduced or eliminated damper windings, coupled with a controller that adjusts the firing angle of the rectifier array based on oscillation components of the DC power output to mitigate peak fault currents, using a rectifier controller that filters and compensates measurement signals to generate an oscillation correction signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If damper windings are included in the generator to reduce air gap flux fluctuations, then generator stability is improved, but peak fault output current increases due to reduced dq axis reactance
Solution Approach 1:
The patent removes the damper windings from the generator rotor, extracting the source of the cancellation magnetic field that causes reduced dq axis reactance. This elimination directly addresses the harmful effect of high peak fault current while maintaining generator stability through alternative control means.
Solution Approach 2:
The patent implements a control system that uses feedback from DC power output measurements to adjust the firing angle of the rectifier array. The controller detects oscillation components in the DC output and dynamically adjusts rectifier operation to compensate for the absence of damper windings, thereby maintaining stability without the harmful peak fault current effect.
2Stability of the object's composition
If damper windings are used to cancel air gap flux oscillations, then torque pulsations are reduced, but the cancellation magnetic field reduces dq axis reactance causing high short circuit current
Solution Approach 1:
The patent extracts and removes the damper windings that create the problematic cancellation magnetic field. By eliminating this component, the system prevents the reduction of dq axis reactance that leads to high short circuit currents, while torque stability is maintained through the rectifier control system.
Solution Approach 2:
The rectifier array and controller serve as an intermediary system to achieve torque stability without relying on damper windings. The controller acts as a mediator that processes DC power output signals and adjusts rectifier firing angles to compensate for fluctuations, replacing the traditional damper winding function through electronic control.
3Productivity
If the rectifier array operates with high peak fault current, then power conversion continues, but system stability deteriorates due to oscillation components in DC power output
Solution Approach 1:
The control system performs preliminary action by adjusting the rectifier firing angle in response to detected oscillation components before these oscillations can significantly impact system stability. The controller continuously monitors DC power output and proactively modifies rectifier operation to prevent instability while maintaining power conversion.
Solution Approach 2:
The patent implements dynamic control of the rectifier array by continuously adjusting the firing angle based on real-time DC power output measurements. This dynamic adjustment allows the system to maintain stability under varying load conditions and during fault events, replacing the static damping function of traditional damper windings with an adaptive electronic control system.
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 reduces peak fault output currents and stabilizes the DC power generation by minimizing the cancellation magnetic field and adjusting the rectifier operation, thereby enhancing system stability and reducing transient inductance.
Implementation Method 1
The generator may be configured to generate an alternating current (AC) power output in response to an excitation
Implementation Method 2
The rectifier array may be configured to convert the AC power output to a DC power output in response to a control signal
Data Source
AI summary
Technologies for reducing peak fault output current in a DC power generation system include a generator having a reduced damper winding and a controller to control a rectifier array to generate a DC power output. In some embodiments, the generator may have no damper windings, may have damper windings including a reduced number of damper bars, and/or may have damper windings having separated end ring mounts for each damper bar. The controller is configured to control the rectifier array so as to reduce oscillations of the DC output that may be due to the reduced damper windings. To do so, the controller is configured to generate the control signal based on an oscillation component of the DC power output. For example, the controller may generate an oscillation correction signal based on the DC power output and adjust a firing angle set point of the rectifier array based on the oscillation correction signal.