Matrix Converter Phase Voltage Correlation Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing matrix converter techniques require complex processes for generating PWM pulses, leading to increased computation and distortion in input and output current waveforms, especially at low loads, resulting in reduced power conversion efficiency.
Innovation Solution
A matrix converter with a bidirectional switch circuit and controller that performs virtual AC/DC conversion processes based on phase voltage correlations, using different carrier waveform patterns to generate switching patterns for direct AC power conversion without matrix operations, thereby simplifying the conversion process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If virtual rectifier and virtual inverter PWM pulse generation methods are used, then AC power conversion is achieved, but computation amount increases significantly due to matrix operations and carrier wave modulation
Solution Approach 1:
The patent extracts and eliminates the matrix operation step from the conventional virtual rectifier-virtual inverter control method. By directly generating PWM pulses based on phase voltage correlations without performing matrix conversions, the computation amount is significantly reduced while maintaining the AC-AC power conversion function.
Solution Approach 2:
Instead of following the conventional approach of converting voltage vectors to current vectors through matrix operations, the patent inverts the control logic by directly utilizing phase voltage correlations to generate switching patterns. This reversal of the control sequence eliminates complex computations.
2Power
If conventional PWM pulse generation with matrix operations is used, then voltage conversion is achieved, but input and output current waveform distortion increases especially at low loads
Solution Approach 1:
The patent removes the matrix operation process that causes waveform distortion. By directly generating PWM pulses based on phase voltage correlations, the method eliminates the source of distortion while maintaining voltage conversion capability across all load conditions.
3Adaptability or versatility
If maximum-intermediate phase selection is used in carrier period, then phase selection flexibility is provided, but pulse width becomes narrow at low loads leading to switching time issues
Solution Approach 1:
The patent inverts the phase selection approach by not relying on maximum-intermediate phase selection during carrier periods. Instead, it directly determines switching patterns based on instantaneous phase voltage correlations, ensuring adequate pulse widths are maintained regardless of load conditions.
4Power
If complex matrix operations and carrier wave modulation are performed, then AC power conversion control is achieved, but power conversion efficiency decreases due to increased computational burden
Solution Approach 1:
The patent extracts and eliminates the computationally intensive matrix operations and complex carrier wave modulation processes. By using direct phase voltage correlation-based PWM generation, the computational burden is reduced, thereby improving power conversion efficiency while maintaining full control capability.
Data Source
Figure 1
Figure 2(a)~2(c)
Figure 3
AI summary
Disclosed is a matrix converter (1) that directly converts input three-phase AC power into three-phase AC power and outputs the converted three-phase AC power to a load (LD) . The matrix converter includes: a bidirectional switch circuit (10) that switches on or off the supply of the three-phase AC power to the load; and a controller (20) that performs different virtual AC/DC conversion processes according to a plurality of modes which are divided depending on magnitude correlation between respective phase voltages in the input three-phase AC power, with respect to the input three-phase AC power, selects two phases from the input three-phase AC power, and generates switching patterns of the bidirectional switch circuit so as to perform the different DC/AC conversion processes according to the plurality of modes with respect to line voltages of the two selected phases.