The paper focuses on the implementation of Hybrid Active Power Filter (HAPF) to compensate harmonics and improve power quality. Development in smart grid technology created a higher demand for improved power quality. Harmonics are the main constraints for poor power quality. Adjustable-speed drives, switching power supplies, arc furnaces, electronic fluorescent lamp ballasts, lightning strike and L-G fault are the sources of poor power quality. Nonlinear loads are the major source of harmonics in modern power system. The problems associated with power quality are voltage sags, voltage swells, interruption, sustained interruptions, overvoltage, undervoltage, long-duration voltage variations, voltage imbalance and waveform distortion. To overcome these problems, it is motivated to design the HAPF. For power quality improvement, hybrid filter has better filtering properties as it eliminates both high and low order harmonics. The p-q method is used for harmonic suppression. The expected properties of shunt hybrid power filter have been confirmed by simulation test in MATLAB/Simulink.

The paper compares three adiabatic logic designs like Efficient Charge Recovery Logic (ECRL), Modified Energy Recovery Logic (MERL) and Positive Feedback Adiabatic Logic (PFAL). A 2:1 multiplexer is implemented using these design techniques and the results are compared in terms of rise time, fall time, transistor count, delay, slew rate, etc. The designed circuits are simulated using mentor graphics VLSI design software Pyxis _v10.5_5_201606075. From the results, it is found that the delay of PFAL-based circuits is better compared to ECRL and MERL.

The paper proposes a microstrip-fed Triangular Dielectric Resonator Antenna (TDRA) for 2.45 GHz frequency. Alumina is used as dielectric resonator having dielectric constant (er) of 9.8. The microstrip coplanar loop feeding mechanism is etched on the topside of FR402 substrate and dielectric resonator is placed on it. The proposed geometry achieves the return loss |s11| < –10 dB from 2.41 GHz to 2.52 GHz. The experimental results showed peak gain of 5.6 dBi at 2.46 GHz resonance frequency. The measured results are well in agreement with simulated results.

The Induction Generator (IG) wind turbine system uses Fixed Speed Wind Turbine (FSWT) system. Due to high dependence on reactive power, it bears achieving new wind grid code requirements. IG requires high reactive power during network disturbances. Nowadays, Flexible AC Transmission System (FACTS) devices are available in the market for compensation of reactive power of IG during network faults. The use of FACTS devices in wind system increases the total budget. So, we have to concentrate on new innovative kind of topology which is cost-effective and gives the exact solution to the problem. The new idea is to locate the Permanent Magnet Synchronous Generator (PMSG) near to IG and connect via underground cable at Power Cable Connects (PCC). It has the ability to fulfill the requirements of reactive power during network disturbances. When there is a fault on network reactive power, requirement of IG is fulfilled using a combination of it with PMSG to meet wind grid code requirement. Low Voltage Ride Through (LVRT) or fault ride through characteristic of FSWT IG is analyzed using Indian grid code. The simulation results clearly showed that the proposed topology might be a good solution to augment the LVRT requirement of fixed speed Wind Turbine Generating System (WTGS) and for achieving certain optimal operating performance and economic benefits. The proposed topology illustrates the defined reactive power and voltage retort, which maintains the FSWT IG system-based wind farm to ride through the grid fault without installation of any additional devices.

FACTS devices are important in controlling power in a line and voltage amplitude at steady state and dynamic conditions. They perform well in suppressing power system oscillations while improving the damping and are based on power electronics technology supported by advanced control techniques. The paper proposes a new device SEN Transformer (ST) to damp Low Frequency Oscillations (LFOs) considering the techno-economic feasibility. ST has conventional technology of transformers and tap changer settings. The operational speed of tap changer switching determines the response time of damping controller, which is quite adequate (with simple electronic switches) in most utility applications.