In the modern world of technology, the cascaded DC-DC converters with multiple output configurations are contributing a dominant part in the DC distribution systems and DC micro-grids. An individual DC-DC converter of any configuration exhibits complex non-linear dynamic behavior resulting in instability. This paper presents a cascaded system with one source boost converter and three load converters including buck, Cuk, and Single-Ended Primary Inductance Converter (SEPIC) that are analyzed for the complex non-linear bifurcation phenomena. An outer voltage feedback loop along with an inner current feedback loop control strategy is used for all the sub-converters in the cascaded system. To explain the complex non-linear dynamic behavior, a discrete mapping model is developed for the proposed cascaded system and the Jacobian matrix's eigenvalues are evaluated. For the simplification of the analysis, every load converter is regarded as a fixed power load (FPL) under reasonable assumptions such as fixed frequency and input voltage. The eigenvalues of period-1 and period-2 reveal that the source boost converter undergoes period-2 orbit and chaos whereas all the load converters operate in a stable period-1 orbit. The proposed configuration eliminates the period-2 and chaotic behavior from all the load converters and is also validated using simulation in MATLAB/Simulink and experimental results.

The technology of modern power systems is revolutionizing as renewable energy sources are being integrated with electric power grids. In the form of inverters, power electronic converters are becoming an integral part of power systems due to their massive demand for grid integration of photovoltaic (PV) systems. Existing multilevel inverter topologies either require an output filter to get a sinusoidal voltage or generate a higher number of output voltage levels at the expense of many hardware resources. This paper presents a new single-phase 81-level inverter configuration with the name given as ‘Modified W-Type Multilevel Inverter’. The proposed inverter configuration uses only eighteen power switches and four DC voltage sources to generate an 81-level output voltage approaching a sinusoidal waveform without an output filter. The general design equations are developed to calculate the number of switches, the number of voltage levels, and the number of DC sources for the proposed configuration. Loss and efficiency analysis is carried out that verifies a good practical efficiency of the proposed inverter configuration during the dynamic operation. A comparative analysis with the existing MLI topologies is also carried out that validates the effectiveness and novelty in reducing parts count and higher number of voltage levels. The proposed topology offers 1.04% total harmonic distortion of the output voltage which is within the benchmarks specified for grid integration without any filter requirements. The proposed inverter configuration is simulated in MATLAB/Simulink, and the results are validated by the design and development of a hardware prototype.

Index Terms -Time-domain measurements, Track and hold amplifier, virtual sampling Frequency, Non-Linear devices.

To address the challenge of the phase calibration of modulated RF and microwave signals or the response of a linear or nonlinear system under modulated excitation, a nextgeneration comb generator is characterized. The latter allows kHz-level modulation tones in addition to the GHz-level RF and microwave tones, while still exhibiting an acceptable power level for each tone. This comb generator includes a PRBS generator, two dividers and a logical "and" operation to trigger the internal pulse generating unit. The pulse generator is characterized using a calibrated sampling oscilloscope. Depending upon the mode of operation this generator could be operated using a plentitude of possible values for every setting (input frequency, divider value, PRBS length). Each setting results in a different amplitude and phase spectrum. In practice it is impossible to characterize this pulse generator and provide a spectral phase dataset for every possible setting of each mode. To address this problem it is investigated if it is feasible to mathematically obtain the complete amplitude and phase spectrum of each possible setting by just using the characterized information of a single pulse. The amplitude and phase characteristic obtained by the measured and predicted spectrum are analyzed and compared. In this paper this technique will be applied to a comb generator operating under divider or PRBS mode.