Fly-back Power Supply Hold-up Capacitor Charging

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Solution Overview

Problem

Existing hold-up capacitor charging methods require additional complex circuitry, such as boost converters and multi-winding transformers, leading to increased size, weight, and power consumption, which complicates electrical power systems.

Innovation Solution

A hold-up capacitor charging circuit using a fly-back power supply with a voltage boosting charge pump circuit and a fly-back circuit, which boosts the charging voltage without additional complex components, utilizing a few discrete components to charge the hold-up capacitor efficiently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additional complex circuitry such as boost converters or multi-winding transformers is used to charge the hold-up capacitor, then the hold-up capacitor can be charged, but the system size, weight, and power consumption increase

Engineering Contradiction:
Improvehold-up capacitor charging capabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The existing fly-back power supply circuit is made to perform dual functions: its primary function of powering the load and an additional function of charging the hold-up capacitor. The controller selectively activates different operational modes of the fly-back circuit to charge the hold-up capacitor during normal operation and discharge it during voltage dips, eliminating the need for separate dedicated charging circuitry.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The fly-back power supply circuit serves itself by using its own operational cycles to charge the hold-up capacitor. During normal operation, the fly-back circuit naturally generates voltage spikes during switching that are used to charge the hold-up capacitor, and during voltage dips, the same circuit reverses direction to discharge the capacitor back into the system.

Inventive Principle:
Principle #25Self-service

2Reliability

If additional complex circuitry such as boost converters or multi-winding transformers is used to charge the hold-up capacitor, then the hold-up capacitor can be charged, but the system size and weight increase

Engineering Contradiction:
Improvehold-up capacitor charging capabilityVSAvoidsystem weight
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The existing fly-back power supply circuit is made to perform dual functions: its primary function of powering the load and an additional function of charging the hold-up capacitor. The controller selectively activates different operational modes of the fly-back circuit to charge the hold-up capacitor during normal operation and discharge it during voltage dips, eliminating the need for separate dedicated charging circuitry.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The dedicated hold-up capacitor charging circuitry is extracted and removed from the system. Instead of having separate boost converters or additional transformer windings, the patent extracts the charging function and integrates it into the existing fly-back circuit's operational modes, thereby eliminating unnecessary components and reducing overall system weight.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If additional complex circuitry such as boost converters or multi-winding transformers is used to charge the hold-up capacitor, then the hold-up capacitor can be charged, but power consumption increases

Engineering Contradiction:
Improvehold-up capacitor charging capabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The fly-back power supply circuit serves itself by using its own operational cycles to charge the hold-up capacitor. During normal operation, the fly-back circuit naturally generates voltage spikes during switching that are used to charge the hold-up capacitor, and during voltage dips, the same circuit reverses direction to discharge the capacitor back into the system.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The hold-up capacitor charging occurs continuously during normal operation through the natural switching cycles of the fly-back circuit, rather than requiring separate continuous power consumption from dedicated charging circuitry. The capacitor is charged during each switching cycle and discharged only when needed during voltage dips, maintaining continuous useful action without additional power overhead.

Inventive Principle:
Principle #20Continuity of useful action

4Duration of action of stationary object

If the hold-up time is increased by storing more energy in the hold-up capacitor, then the system can operate longer during power failures, but the capacitor size and charging requirements increase

Engineering Contradiction:
Improvehold-up timeVSAvoidcapacitor charging circuit complexity
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The existing fly-back power supply circuit is made to perform dual functions: its primary function of powering the load and an additional function of charging the hold-up capacitor. The controller selectively activates different operational modes of the fly-back circuit to charge the hold-up capacitor during normal operation and discharge it during voltage dips, eliminating the need for separate dedicated charging circuitry.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solution reduces system complexity and size by effectively increasing the energy stored in the hold-up capacitor, allowing for a longer hold-up time without the need for additional circuitry, and efficiently supplies power during voltage reductions.

Implementation Method 1

a voltage boosting charge pump circuit and a fly-back circuit, which boosts the charging voltage

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

hold-up capacitor charging circuit using a fly-back power supply

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3499702B1Hold-up capacitor charging using fly-back power supply
Publication Date: 2021.09.01 HAMILTON SUNDSTRAND CORP
  • EP3499702B1 patent drawingFigure 1
  • EP3499702B1 patent drawingFigure 2
  • EP3499702B1 patent drawingFigure 3

AI summary

Aspects include a hold-up capacitor charging circuit for a power supply. The hold-up capacitor charging circuit (10) includes a voltage boosting charge pump circuit (20) with a hold-up capacitor (24) electrically coupled to a voltage source (26). The hold-up capacitor charging circuit also includes a fly-back circuit (40). The fly-back circuit includes a transformer (42) with a primary winding electrically coupled to the voltage source and a secondary winding electrically coupled to a load. A switch (44) is electrically coupled to the primary winding and the voltage boosting charge pump circuit. A controller (48) is operable to open and close the switch to control energy transfer from the primary winding to the secondary winding and charge the hold-up capacitor responsive to voltages of the voltage source, the voltage boosting charge pump circuit, and a reflected voltage of the secondary winding at the primary winding.