Controller Modes for Charge Quantization Error Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electronic systems with switching power converters face challenges in reducing charge quantization errors, leading to power fluctuations and light flicker in constant current loads like LEDs, especially when dimmers are used, as they struggle to accurately control the charge delivered during each half-line cycle of the supply voltage.

Innovation Solution

A controller that operates a switching power converter in multiple modes, switching between a normal mode and an error reduction mode to finely tune the peak current and charge delivery, increasing granularity in error reduction mode to minimize excess charge and power fluctuations by adjusting the peak current based on unpushed charge, previous cycle charge, and conduction time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a switching power converter operates in normal mode with fixed charge pushing cycles, then the control structure is simple, but charge quantization errors occur leading to power fluctuations and light flicker

Engineering Contradiction:
Improvecharge delivery accuracyVSAvoidcontrol mode complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The controller dynamically switches between normal mode and error reduction mode based on real-time charge delivery requirements. In error reduction mode, the controller adjusts the peak current with increased granularity by considering unpushed charge, previous cycle charge, and conduction time, thereby adapting the control precision to the specific operating conditions to minimize quantization errors without maintaining high complexity in all conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the control parameters dynamically by introducing error reduction mode that modifies peak current determination based on unpushed charge, previous cycle charge, and conduction time. This parameter adaptation allows the system to achieve higher charge delivery accuracy when needed while maintaining simpler operation during normal conditions

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the controller increases granularity in error reduction mode to minimize charge quantization errors, then charge delivery precision improves, but control complexity increases

Engineering Contradiction:
Improvecharge measurement precisionVSAvoidcontroller complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The controller applies different control strategies to different operational scenarios: normal mode for standard conditions and error reduction mode for conditions requiring higher precision. The error reduction mode locally enhances measurement precision by considering unpushed charge, previous cycle charge, and conduction time, rather than applying high complexity uniformly across all operating conditions

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically transitions between control modes based on operational needs, increasing granularity and precision only when charge quantization errors are detected or anticipated, thereby achieving high measurement precision when needed while maintaining simpler control during normal operation

Inventive Principle:
Principle #15Dynamics

3Stability of the object's composition

If the system uses multi-mode operation to reduce charge quantization errors, then power fluctuation is reduced, but the control algorithm becomes more complex

Engineering Contradiction:
Improvepower stabilityVSAvoidcontrol algorithm complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The control algorithm changes parameters dynamically by switching between normal mode and error reduction mode. In error reduction mode, it adjusts peak current determination using unpushed charge, previous cycle charge, and conduction time, thereby stabilizing power delivery by reducing charge quantization errors without maintaining complex algorithms in all operating conditions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system dynamically adapts its control strategy based on real-time conditions, activating error reduction mode only when needed to reduce charge quantization errors and stabilize power delivery. This dynamic approach achieves power stability while limiting the average complexity of the control algorithm

Inventive Principle:
Principle #15Dynamics

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

The multi-mode operation effectively reduces charge quantization errors, minimizing power fluctuations and light flicker by ensuring a more precise control of charge delivery to the load, even at low phase cuts of the supply voltage, thereby enhancing the stability of the power provided to constant current loads.

Implementation Method 1

A switching power converter is controlled by a controller... converts power from voltage supply 102 into power usable by load 104

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

When control signal CSo opens switch 108, the primary voltage V P and secondary voltage Vs reverse the indicated polarities, and diode 120 is forward biased. When diode 120 is forward biased, the secondary side current is flows through the diode 120 to charge capacitor 122

Methodology Applied
Scientific EffectElectromagnetic energy transformation: Electromagnetic Induction

Data Source

PatentEP2973969B1Quantization error reduction in constant output current control drivers
Publication Date: 2021.05.12 SIGNIFY HOLDING BV
  • EP2973969B1 patent drawingFigure 1
  • EP2973969B1 patent drawingFigure 2
  • EP2973969B1 patent drawingFigure 3

AI summary

An electronic system and method includes a controller to control a switching power converter in at least two different modes of operation, a normal mode and an error reduction mode. The controller controls an amount of charge pushed (i.e. delivered) by the switching power converter to a load to reduce a charge quantization error. The charge quantization error represents an amount of charge pushed to the load beyond a target charge amount. The controller determines an amount of charge to be pushed to the load. Based on the amount of charge to be pushed to the load, the controller generates a current control signal that controls a current control switch in the switching power converter. Determination of the control signal depends on whether the controller is operating in normal mode or error reduction mode. The controller attempts to reduce the charge quantization error to avoid power fluctuations.