Multi-Channel DC Controller Zero-Crossing Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multi-channel DC converters face inefficiencies and increased complexity due to reliance on external timers and fixed pulse width modulation, leading to high switching losses, reverse recovery losses, and increased structural volume, particularly in bidirectional applications like solar inverters and battery management systems.
Innovation Solution
A multi-channel DC converter design where at least one current channel detects zero crossings, allowing a microcontroller to operate all channels at the gap limit, with time offsets divided by detected period time and the number of channels, eliminating the need for subordinate current control circuits and reducing ripple in output current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed pulse width modulation with external timers is used to control multi-channel DC converter, then control simplicity is improved, but switching losses and reverse recovery losses increase
Solution Approach 1:
The patent implements feedback control by detecting the actual current zero-crossing point and using this information to trigger the next switching operation. The microcontroller measures the period time of current zero crossings and adjusts switching timing based on real-time feedback, eliminating the need for external timers and fixed PWM while minimizing switching losses.
Solution Approach 2:
The patent transitions from static fixed-frequency PWM control to dynamic variable-frequency control. The switching frequency automatically adapts to the load conditions by detecting current zero-crossings, allowing the converter to operate at the gap limit under light loads (reducing switching losses) and maintain stability under heavy loads.
2Device complexity
If fixed frequency switching is used in multi-channel DC converter, then control simplicity is improved, but output current ripple increases
Solution Approach 1:
The patent uses periodic current zero-crossing detection to synchronize switching operations across multiple channels. By dividing the detected period time by the number of channels and applying appropriate time offsets, the system creates optimally phased periodic switching actions that cancel out individual channel ripples, producing smoother output current.
3Measurement precision
If subordinate current control circuits are used for each channel, then current control precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent merges all current control functions into a single microcontroller that centrally manages all current channels. The microcontroller detects current zero-crossings and calculates optimal switching timing for all channels, eliminating the need for separate control circuits while maintaining precise current control through centralized digital processing.
Solution Approach 2:
The microcontroller serves multiple functions: detecting current zero-crossings, measuring period time, calculating switching timing for all channels, and controlling all semiconductor switches. This universal control approach replaces multiple specialized control circuits, reducing complexity while maintaining precision.
4Stability of the object's composition
If operation away from gap limit is used for stability, then operational stability is improved, but switching losses and reverse recovery losses increase
Solution Approach 1:
The patent uses real-time feedback from current zero-crossing detection to maintain operation at the gap limit. By continuously monitoring when the current actually reaches zero and adjusting switching timing accordingly, the system remains stable at the optimal operating point rather than requiring a safety margin that would increase losses.
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 design achieves smoother output current with minimized switching losses and reduced ripple, enhancing efficiency and reducing component costs by operating at the gap limit with variable switching frequency, thus improving overall converter performance.
Implementation Method 1
at least one current channel has a device for detecting the current zero crossing, that the microcontroller detects the period time of the current zero crossings in this current channel
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A multi-channel DC controller is described, with a plurality of parallel current channels which are controlled by a microcontroller at a time offset to each other, wherein the current channels each have at least two semiconductor switches(T1, T2, T3, T4), by means of which they can be operated by the microcontroller either as a boost converter or as a buck converter, wherein at least one current channel has a device to detect the zero crossing of the current (W), wherein the microcontroller detects the periodicity of the zero crossing in this current channel, and wherein the microcontroller operates the DC controller of all current channels in critical conduction mode based on the detected periodicity.