Power Converter Gating Control for Motor Harmonic Reduction
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Solution Overview
Problem
High-speed, high-power electric motors require efficient power converters that minimize switching loss and total harmonic distortion, especially in applications where reliability and reduced component count are critical, such as in industrial and drilling operations.
Innovation Solution
A power converter system with a three-phase wye-connected H-bridge configuration, utilizing gating control signals with notch waveforms and phase shifts to reduce harmonic distortion and switching loss, where each leg receives a unique gating control signal with a waveform comprising a notch, and the signals are phase shifted relative to each other.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the switching frequency of the power converter is increased to accommodate higher motor speed, then the motor power output is improved, but switching loss in the power converter increases
Solution Approach 1:
The patent applies periodic action by using pulse-width modulation (PWM) with periodic switching signals to control the power converter. The switching frequency is optimized to a specific range (2kHz-20kHz) rather than continuously increased, and duty cycle modulation is used to control motor speed and torque, achieving high power output without proportionally increasing switching loss.
Solution Approach 2:
The patent changes the switching frequency parameter to an optimized range (2kHz-20kHz) and adjusts the duty cycle parameter to control motor operation. By optimizing these parameters rather than simply increasing switching frequency, the system achieves high motor power output while minimizing switching loss in the power converter.
2Power
If the switching frequency of the power converter is increased to accommodate higher motor speed, then the motor power output is improved, but total harmonic distortion in the motor increases
Solution Approach 1:
The patent uses periodic PWM switching signals with optimized frequency (2kHz-20kHz) and duty cycle modulation to control motor operation. This periodic control method reduces total harmonic distortion compared to simpler switching methods, while still achieving high motor power output through controlled switching patterns.
Solution Approach 2:
The patent optimizes the switching frequency parameter to a specific range (2kHz-20kHz) and uses duty cycle as a control parameter. This parameter optimization reduces total harmonic distortion in the motor while maintaining high power output capability.
3Reliability
If simple converter configuration is used to reduce component count, then reliability is improved, but thermal margins of individual components are reduced
Solution Approach 1:
The patent optimizes switching frequency to a moderate range (2kHz-20kHz) rather than using extremely high frequencies. This parameter optimization reduces switching loss and heat generation in the power converter components, maintaining adequate thermal margins while achieving high motor power output with a simplified converter configuration.
Data Source
AI summary
Embodiments of systems and methods for powering a load are provided. In one embodiment, a method may include providing a power converter comprising electrical circuitry comprising at least a first leg and a second leg, supplying an input power signal to the power converter, supplying at least a first gating control signal to the first leg, supplying at least a second gating control signal to the second leg, and outputting at least one output power signal to the load responsive at least in part to the first and the second gating control signals supplied. According to this example embodiment, the first gating signal and the second gating signal may each comprise a waveform comprising a notch, and the second gating control signal may be phase shifted relative to the first gating control signal.