Kenneth A. Conner

Uniform Voltage Distribution Control for Series Connected DC–DC Converters

This paper investigates applications of current-mode, shared-bus commercial-off-the-shelf (COTS) dc-dc converters to power system architectures configured as parallel-input, series-output (PISO) and series-input, parallel-output (SIPO). By employing a PISO (or SIPO) architecture, current-mode COTS converters can transform their system input voltage to higher (or lower) system output voltage, provide ease and flexibility of power expansion, and preserve system efficiencies equal to those of standalone converters. Nonuniform output (or input) voltages still exist within a PISO (or SIPO) power system using identical converters when the system lacks proper distribution control of the series connected output (or input) voltages-and thus, system reliability suffers from thermal overstress to the converters that contribute a greater portion of the output power. Through unified approaches of voltage distribution control for the PISO and SIPO architectures, a series-connected converter power system attains robust stability and reliability. Two effective approaches to uniform voltage distribution control-the central-limit and maximum-limit voltage distribution-will be discussed. Both computer simulation and experimental prototypes validate both of the uniform voltage distribution power converter architectures.

Uniform Voltage Distribution Control for Paralleled-Input, Series-Output Connected Converters

This paper extends the application of current-mode, shared-bus converters to power system architectures configured as Parallel-Input, Series-Output (PISO). By employing a PISO interconnect method, current-mode commercial-off-the-shelf (COTS) dc-dc converters can deliver higher output voltages, provide flexible options for power system expansion, and preserve system efficiencies equal to that obtained from standalone converters. However, without proper control, non-uniformly distributed voltages occur due to converter component mismatch. System reliability suffers as a result of thermal overstress to the converters that contribute a greater portion of the output power. Conversely, robust system stability and uniform output voltage distribution among series-connected converters is realized through output voltage distribution control. Through both computer simulation and experimental prototype, the uniform voltage distribution power converter architecture is validated and successfully applied during power converter burn-in testing whereby converter load energy is recycled to the power system input, resulting in 49% to 80% conservation of energy

Uniform voltage distribution control for series-input parallel-output, connected converters

This paper extends the application of current-mode, shared-bus converters to power system architectures configured as series-input, parallel-output (SIPO). By employing a SIPO interconnect method, current-mode commercial-off-the-shelf (COTS) dc-dc converters can transform higher input voltages into low output voltages, provide flexible options for power system expansion, and preserve system efficiencies equal to that obtained from standalone converters. However, without proper control, converter internal component mismatch cause the input voltage to be non-uniformly distributed. System reliability suffers as a result of thermal overstress to the converters that contribute a greater portion of the input power. Conversely, robust system stability and uniform input voltage distribution among series-connected converters is realized through input voltage distribution control. Through computer simulation and experimental prototype the uniform voltage distribution power converter architecture is validated and successfully applied

High-voltage-input, low-voltage-output, series-connected converters with uniform voltage distribution

This paper presents a power system consisting of current-mode, shared-bus converters configured as Series-Input, Parallel-Output (SIPO). These current-mode commercial-off-the-shelf (COTS) dc-dc converters transform a 1kV system input voltage into a 5V output with up to 500 Watts of power. The SIPO power system provides for system expansion and preserves the standalone converters efficiency of over 80%. Uniform input voltage distribution control improves power system reliability by distributing thermal stresses equally among the series-connected converters. Furthermore, robust system stability and uniform input voltage distribution among series-connected converters is realized without control conflict. A computer simulation and an experimental 1 kV 500 W prototype were successfully implemented to validate the uniform voltage distribution power converter architecture.

Uniform Voltage Distribution Control for Series Connected DC-DC Converters

This paper investigates applications of current-mode, shared-bus commercial-off-the-shelf (COTS) dc-dc converters to power system architectures configured as parallel-input, series-output (PISO) and series-input, parallel-output (SIPO). By employing a PISO (or SIPO) architecture, current-mode COTS converters can transform their system input voltage to higher (or lower) system output voltage, provide ease and flexibility of power expansion, and preserve system efficiencies equal to those of standalone converters. Nonuniform output (or input) voltages still exist within a PISO (or SIPO) power system using identical converters when the system lacks proper distribution control of the series connected output (or input) voltages-and thus, system reliability suffers from thermal overstress to the converters that contribute a greater portion of the output power. Through unified approaches of voltage distribution control for the PISO and SIPO architectures, a series-connected converter power system attains robust stability and reliability. Two effective approaches to uniform voltage distribution control-the central-limit and maximum-limit voltage distribution-will be discussed. Both computer simulation and experimental prototypes validate both of the uniform voltage distribution power converter architectures.