Switch network of a multilevel power converter architecture

Abstract

A power converter provides a pyramidal structure of switches communicating between a capacitive divider at the base of the pyramid and a terminal at the top of the pyramid to provide a transformation of a relationship between current and voltage in power transferred between the capacitive divider and the terminal at the top of the pyramid while providing reduced electrical interference and electrical rate of change (dv / dt).

Description

CROSS REFERENCE TO RELATED APPLICATIONBACKGROUND OF THE INVENTION[0001]The present invention relates to electrical circuits for power conversion, for example, between different voltages and / or between AC and DC power, and in particular to a multilevel architecture for power converters that can provide improved power conversion of high voltages.[0002]Conventional power conversion, for example, converting between different levels of AC power, may employ a transformer having inductively linked coils that transform input AC voltage to output AC voltage according to the turns ratio of coils.[0003]For many applications, and in particular applications related to renewable energy including windfarms, electric vehicles, and photovoltaic arrays, transformer systems are unacceptably bulky, expensive, and inflexible. Windfarms and photovoltaic arrays may need to transform between low-voltage AC or DC to medium voltage grid power (2 kV to 35 kV) while recharging systems for electric vehicles may...

AI Technical Summary

Benefits of technology

[0007]The present invention provides a power converter using a pyramid architecture that limits the voltage difference handled by each switch to reduce electromagnetic interference and high dv / dt. The pyramid design permits asynchronous operation of the switches eliminating the criticality of switch synchronization allowing the switching speed and duty cycle to be adjusted, for example, to reduce EMI and to improve power-sharing among semiconductor devices.

Problems solved by technology

For many applications, and in particular applications related to renewable energy including windfarms, electric vehicles, and photovoltaic arrays, transformer systems are unacceptably bulky, expensive, and inflexible.

Rapid switching of high voltages by solid-state devices can create problems of generating electromagnetic interference and high dv / dt (voltage change rate) such as can be damaging to electrical insulation on motors and the like.

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