Multi-Active-Bridge Converter Phase-Shift Control for Low-Loss ZVS
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing control methods for multi-port active-bridge (MAB) converters fail to maintain high efficiency at low power levels and do not determine optimal phase shift values in real-time, leading to suboptimal performance and increased system losses.
Innovation Solution
A method for controlling the switches of a multi-port active-bridge converter that involves a sweep between 0 and π of the value of the internal phase shift of a so-called reference port, and, for each value of the internal phase shift of a so-called reference port, calculating internal and external phase shifts to minimize reactive power exchange and total losses, and updating switching commands based on optimized phase shift values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If existing control methods (EPS modulation or disturbance and observe) are used, then the converter can operate, but efficiency is not optimal at low power levels and total losses increase
Solution Approach 1:
The control method dynamically adjusts the internal phase shift of the reference port based on real-time operating conditions. Instead of using fixed phase shift values, the system continuously optimizes the internal phase shift to minimize total losses at any given power level, making the converter adaptive to varying load conditions and maintaining high efficiency across the entire operating range.
Solution Approach 2:
The invention changes the control parameters by introducing an optimized internal phase shift for the reference port in addition to the external phase shifts. This parameter modification allows the system to minimize reactive power exchange and reduce total losses, particularly at low power levels where conventional methods fail to maintain optimal efficiency.
2Extent of automation
If conventional control methods are used, then switching commands can be generated, but optimal phase shift values are not determined in real-time
Solution Approach 1:
The control system implements a feedback mechanism that continuously monitors the operating state of the converter and adjusts the internal phase shift of the reference port accordingly. This real-time feedback enables the system to determine optimal phase shift values dynamically, ensuring minimal losses and maximum efficiency without requiring complex manual intervention or pre-computed lookup tables.
Solution Approach 2:
The converter performs self-optimization by automatically adjusting its own phase shift parameters based on its operating conditions. The control system uses the measured power and voltage to calculate and apply the optimal internal phase shift, making the system self-regulating and eliminating the need for external optimization tools or complex control architectures.
3Device complexity
If the internal phase shift is fixed at zero (EPS modulation), then the control system is simple, but reactive power exchange is not minimized and losses increase
Solution Approach 1:
The control method performs preliminary optimization by calculating the optimal internal phase shift value before executing the switching commands. This pre-calculation based on measured power and voltage allows the system to minimize reactive power exchange in advance, reducing losses without adding complex real-time computation during the switching cycle.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a method for controlling the switches of a multi-active-bridge converter, the method comprising the steps of: a) performing a sweep between 0 and π of the value of the internal phase shift (α1) of a so-called reference port, and, for each value of the internal phase shift (α1) of the reference port, the following substeps: a1) for each of the n-1 different ports of the reference port, calculate the internal phase shift (αi); a2) for each of the n-1 different ports of the reference port, calculate the external phase shift (φi); a3) calculate a set of at least one power parameter including the total losses of the converter (Ptotal losses) and, optionally, the number of switches of the converter in ZVS condition; a4) determining an optimized value of the internal phase shift (α1,OPT) of the reference port; b) updating the switching commands of the switches.