Nisha Kondrath

Audio-susceptibility of the inner-loop of peak current-mode controlled PWM DC-DC buck converter in CCM

A complete block diagram including feedforward gains to derive the audio-susceptibility for the inner-current loop of peak current-mode controlled PWM dc-dc converter operating in continuous conduction mode is proposed. Audio-susceptibility transfer functions without and with feed-forward gains along with required power-stage transfer functions are derived for peak current-mode controlled PWM dc-dc buck converter. The derived audio-susceptibility transfer functions are illustrated for given values of perturbation ratio using MATLAB.

Slope compensation and relative stability of peak current-mode controlled PWM dc-dc converters in CCM

Relative stability of the inner-current loop with slope compensation for peak-current mode controlled PWM dc-dc converters operating in CCM is analyzed. Expressions for required compensation slope and control current level to achieve a specified margin of stability are derived. Design procedure and Saber Sketch simulation results for a buck converter with the inner-current loop are presented to validate the theory presented.

Building secure and robust microgrids: an overview of technical and security concerns

Microgrids are modern, localised versions of the centralised utility grid. They have been gaining popularity due to the increased power demand and the development of various renewable resources. In this paper, we present the technical and security challenges faced by modern microgrid implementations in ensuring interoperability, reliability, and security in the network.

Microgrids: Technical and security recommendations for future implementations

Microgrids are modern, localized versions of the centralized utility grid. They have been gaining popularity due to the increased power demand and the development of various renewable resources. In this paper, we present technical and security recommendations for modern microgrid implementations to ensure interoperability, reliability, and security.

Output impedance of peak current-mode controlled PWM DC-DC converters with only inner loop closed in CCM

Different control loops employed in regulating deck converter outputs may have an effect on the output impedance of the converter. In this manuscript, the effect of the inner-current loop on the output impedance of a peak current-mode controlled PWM dc-dc converter with the outer-voltage loop open is investigated. Closed-loop output impedance including feed-forward gains with inner-current loop closed and outer-voltage loop open for peak-current mode controlled PWM dc-dc converters operating in CCM is derived. Bode plots of the closed-loop output impedance for PCM controlled PWM dc-dc buck and boost converters with inner-current loop only are illustrated using MATLAB simulations and are compared with the Bode plots of respective open-loop output impedances.

Bidirectional DC-DC converter topologies and control strategies for interfacing energy storage systems in microgrids: An overview

A microgrid is defined as a local electric power distribution system with diverse distributed generation (DG), energy storage systems, and loads, which can operate as a part of the distribution system or when needed can operate in an islanded mode. Energy storage systems play a key role in improving security, stability, and power quality of the microgrid. During grid-connected mode, these storage units are charged from various DG sources as well as the main grid. During islanded mode, DG sources along with the storage units need to supply the load. Power electronic interfaces between the microgrid buses and the storage units should be able to detect the mode of operation, allow seamless transition between the modes, and allow power flow in both directions, while maintaining stability and power quality. An overview of bidirectional converter topologies relevant to microgrid energy storage application and their control strategies will be presented in this paper.

Performance evaluation of SiC based bidirectional dc-dc buck-boost converter operating in CCM using temperature-dependent L3 spice model

Wide-band gap devices are gaining popularity in high-power, high-temperature applications such as hybrid/full electric vehicles. A 27 kW synchronous bidirectional pulse-width modulated (PWM) dc-dc buck-boost converter operating in continuous conduction mode (CCM) is designed. The designed converter is tested using Silicon Carbon (SiC) and Silicon (Si) devices at different temperatures using LTSpice simulations. Steady-state as well as switching transition performances are evaluated and compared for converters using SiC and Si devices.

Design and PSpice simulation of synchronous bidirectional PWM DC-DC buck-boost converter operating in CCM

Bidirectional pulse-width modulated dc-dc converters are popular in many applications such as rechargeable power supply units, where power flow in both directions is necessary. In this paper, the design of a synchronous bidirectional dc-dc buck-boost converter operating in CCM is presented. PSpice simulation results are shown to verify the designed converter operation and bidirectional power flow.

Control-to-output transfer function including feed-forward gains of peak current-mode controlled PWM DC-DC converters in CCM

A unified model including feed-forward gains to derive the control-to-output transfer function of peak current-mode controlled PWM dc-dc converters for CCM is presented. The control-to-output transfer functions for peak current-mode controlled PWM dc-dc buck-boost, boost, and buck converters are derived and illustrated for selected values of perturbation ratio using MATLAB. The proposed model is experimentally verified for peak current-mode controlled buck converter operating in CCM.