Synchronous Generator Tunable Notch Filter Voltage Ripple
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Solution Overview
Problem
Existing electrical power generating systems for vehicles using synchronous generators suffer from voltage ripple in the output voltage due to the nature of power processing during rectification, which is not effectively mitigated by current technologies.
Innovation Solution
The system employs multiple stator armature windings with rectifiers and tunable notch filters, including variable inductors and auto-tuning notch filter control, to reduce voltage ripple by phase shifting the three-phase voltages and using capacitors and inductors to filter the DC voltages, thereby minimizing the size of diodes and capacitors and reducing active power switch usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a synchronous generator with rectifier is used to generate electric power, then electric power can be generated for the vehicle, but voltage ripple is present in the output voltage
Solution Approach 1:
The patent divides the single three-phase voltage system into multiple independent three-phase voltage systems (first, second, third armature windings). Each winding is connected to its own rectifier and filter circuit, allowing independent processing and ripple reduction through parallel operation.
Solution Approach 2:
The patent combines multiple rectified DC voltage outputs into a single unified DC output. The filtered voltages from parallel armature windings are merged at the DC bus, achieving ripple cancellation through phase shifting while maintaining high power output.
2Object-generated harmful factors
If traditional filtering methods are used to reduce voltage ripple, then voltage ripple can be reduced, but the size of diodes and capacitors increases
Solution Approach 1:
The patent employs variable inductors with magnetically controllable inductance values that can be dynamically adjusted based on operating conditions. This allows the filter to adapt to different load and speed conditions, maintaining effective ripple filtering while minimizing component size across varying operating ranges.
Solution Approach 2:
The patent changes the electrical parameters of the filter components by using variable inductance values and phase shifting angles. By adjusting the phase shift between multiple armature windings and varying the inductor values, the system optimizes filtering performance without requiring large fixed-size components.
3Object-generated harmful factors
If multiple armature windings with phase shifting are used, then voltage ripple is reduced, but device complexity increases
Solution Approach 1:
The patent designs the multiple armature windings to serve dual functions: power generation and ripple reduction. The same windings that generate electrical power also provide phase-shifted voltages for ripple cancellation, eliminating the need for separate filtering systems and reducing overall complexity.
Solution Approach 2:
The system uses its own generated power to control the variable inductors and phase shifting mechanisms. The control windings are energized from the generated output, making the system self-regulating and reducing external control complexity.
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 configuration results in reduced voltage ripple, smaller filter sizes, and lower weight, leading to improved packaging and efficiency in generating a stable DC output voltage with reduced DC bus capacitance.
Implementation Method 1
A first variable inductor may be configured to filter at least one of the first DC voltage, the second DC voltage, and a DC output voltage
Implementation Method 2
The electric power generating system may further comprise a first tunable notch filter comprising, a capacitor, and the first variable inductor
Implementation Method 3
a first rectifier configured to rectify the first three-phase voltage received from the first armature winding, and a second rectifier configured to rectify the second three-phase voltage
Implementation Method 4
a first armature winding configured to generate a first three-phase voltage in response to rotation of the rotor, and a second armature winding configured to generate a second three-phase voltage
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
A synchronous generator (110) may comprise a rotor (190) and a stator (192). The stator (192) may comprise a first armature winding (102) configured to output a first three-phase voltage, a second armature winding (104) configured to output a second three-phase voltage, and a first variable inductor (L1), wherein the first variable inductor (L1) is tunable in response to a rotational frequency of the rotor (190).