Multi-level PFC Circuit Using Hybrid Devices for Voltage Handling

Solution Overview

Problem

Power factor correction (PFC) circuits used in AC to DC converters face challenges with high voltage applications, as existing diodes require high cost, high conduction losses, and low efficiency, especially when handling high voltage levels like 1200V.

Innovation Solution

The implementation of a multi-level AC to DC converter using hybrid devices with parallel current paths, where one path is faster switching and lower current rated, and the other is slower switching but higher current rated, along with control circuitry that generates switching signals based on AC and DC voltage levels to achieve efficient power factor correction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If high voltage diodes are used to handle 1200V levels, then the circuit can process high voltage, but the cost increases, conduction losses increase, and efficiency decreases

Engineering Contradiction:

Improvevoltage handling capabilityVSAvoidconduction losses

Core Design Contradiction:

TemperatureVSLoss of energy

Solution Approach 1:

The circuit segments the voltage handling function across multiple components. Instead of using a single high-voltage diode rated for 1200V, the invention uses two lower-voltage diodes (each rated for approximately 600V) in a multi-level configuration. This segmentation allows each diode to operate within its optimal voltage range, reducing conduction losses and improving overall efficiency while maintaining the capability to handle 1200V through the series arrangement of voltage levels.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention changes the voltage rating parameter of the diodes from high (1200V) to lower values (approximately 600V each). By selecting diodes with lower voltage ratings and arranging them in a multi-level topology, the system achieves the same voltage handling capability with reduced conduction losses and improved efficiency, as lower voltage-rated diodes typically have lower on-resistance and better conducting characteristics.

Inventive Principle:

Principle #35Parameter changes

2Temperature

If high voltage diodes are used to handle 1200V levels, then the circuit can process high voltage, but the cost increases

Engineering Contradiction:

Improvevoltage handling capabilityVSAvoidcost

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The circuit segments the voltage handling function across multiple components. Instead of using a single high-voltage diode rated for 1200V, the invention uses two lower-voltage diodes (each rated for approximately 600V) in a multi-level configuration. This segmentation allows each diode to operate within its optimal voltage range, reducing conduction losses and improving overall efficiency while maintaining the capability to handle 1200V through the series arrangement of voltage levels.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention replaces expensive high-voltage diodes with cheaper lower-voltage diodes. By using diodes with lower voltage ratings (approximately 600V) instead of expensive 1200V-rated diodes, the system reduces component cost while achieving the same functional outcome through the multi-level circuit topology. The lower-voltage diodes are typically more economical and have better performance characteristics for their operating range.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Temperature

If high voltage diodes are used to handle 1200V levels, then the circuit can process high voltage, but efficiency decreases

Engineering Contradiction:

Improvevoltage handling capabilityVSAvoidefficiency

Core Design Contradiction:

TemperatureVSProductivity

Solution Approach 1:

The circuit segments the voltage handling function across multiple components. Instead of using a single high-voltage diode rated for 1200V, the invention uses two lower-voltage diodes (each rated for approximately 600V) in a multi-level configuration. This segmentation allows each diode to operate within its optimal voltage range, reducing conduction losses and improving overall efficiency while maintaining the capability to handle 1200V through the series arrangement of voltage levels.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention changes the voltage rating parameter of the diodes from high (1200V) to lower values (approximately 600V each). By selecting diodes with lower voltage ratings and arranging them in a multi-level topology, the system achieves the same voltage handling capability with reduced conduction losses and improved efficiency, as lower voltage-rated diodes typically have lower on-resistance and better conducting characteristics.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10361626B2Multi-level power factor correction circuit using hybrid devices

Publication Date: 2019.07.23 HUAWEI DIGITAL POWER TECH CO LTD

AI summary

AC to DC converters, more specifically Power Factor Correction (PFC) circuits, using a multi-level waveform and hybrid devices are presented. From an AC voltage input a multi-level waveform is generated, which is used to generate high and low DC output voltage levels. The multi-level waveform is connected to the DC outputs through a corresponding intermediate node by an initial switch, and from the intermediate node to the corresponding output by a hybrid device. The hybrid device includes a first current path, such as a series connected switch-diode pair, in parallel with second current path of a relatively faster and lower current device, such as a diode. The resultant arrangement can use devices having lower voltage ratings relative to typical PFC circuit designs.