Segmented Waveform Converter for Variable Speed Engine Frequency Control
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Solution Overview
Problem
Existing variable speed generators face challenges in maintaining constant output frequency, leading to inefficient engine operation, increased wear, and fuel consumption, as they require fixed engine speeds to compensate for varying loads, which is not necessary for power supply.
Innovation Solution
The implementation of a segmented waveform converter, specifically a synchronous inverter system with a controlled field alternator, allows for the conversion of AC signals to change frequency and voltage efficiently, enabling engine speed adjustment while maintaining constant output frequency through advanced switching and filtering techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the engine speed is maintained at fixed rated speed to provide constant output frequency, then the output frequency stability is improved, but the fuel consumption and engine wear increase due to unnecessary operation at high speed during light loads
Solution Approach 1:
The patent changes the operating parameters of the engine by allowing speed variation within a range rather than maintaining a fixed speed. The control system adjusts engine speed based on load conditions, changing the speed parameter dynamically to optimize fuel consumption while maintaining acceptable output frequency through converter control
Solution Approach 2:
The system transitions from a static fixed-speed operation to a dynamic variable-speed operation. The engine speed is made adjustable and responsive to load conditions, enabling the system to adapt its operating point continuously rather than remaining at a single fixed point
2Loss of energy
If the engine speed is reduced at light loads to decrease fuel consumption and wear, then the energy efficiency is improved, but the output frequency becomes unstable
Solution Approach 1:
The power converter acts as an intermediary between the engine and the electrical load. It decouples the direct relationship between engine speed and output frequency, allowing the engine to operate at variable speeds while the converter maintains stable frequency output through its control mechanisms
Solution Approach 2:
The control system uses feedback to monitor engine speed and load conditions, automatically adjusting the engine operating point to optimize fuel consumption while maintaining acceptable performance. The converter control also uses feedback to maintain output frequency stability despite engine speed variations
3Loss of energy
If a conventional frequency converter is used to allow variable engine speed, then the fuel consumption decreases, but the device complexity and cost increase
Solution Approach 1:
The power converter is designed to perform multiple functions: frequency conversion, voltage regulation, and engine control. By integrating these functions into a single system rather than using separate dedicated devices, the overall complexity is reduced while achieving the desired fuel efficiency improvements
Solution Approach 2:
The patent combines the frequency conversion function with the engine control function in a single integrated system. Rather than using a conventional frequency converter as a separate device, the control mechanisms are merged into the power conversion system itself, reducing component count and system 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 solution reduces engine wear, fuel consumption, and noise emissions by allowing engine speed to decrease at light loads, while maintaining efficient power supply and minimizing total harmonic distortion (THD) in the output voltage.
Implementation Method 1
a controlled field alternator and a segmented waveform converter, the output of which is connected to a load
Data Source
Figure 1A~1B
Figure 2
Figure 3A~3B
AI summary
An apparatus includes a controlled field alternator or utility source of electrical power, a segmented waveform converter, and a controller. The source of electrical power is configured to generate a polyphase signal. The synchronous inverter includes multiple switches connected between the polyphase signal of the source of electrical power and an output filter. The controller is configured to provide a control signal for the switches based on measured electrical quantities associated with the output filter and may provide a field control signal to the controlled field alternator. The apparatus may be applied to a vehicle, a lawnmower, a zero turn radius lawnmower, or another type of machine.