A New Control Scheme for Three-Phase Non-Isolated Grid Feeding PV Inverter

The use of control algorithms in inverter topologies is becoming more attractive for integration of wind and photovoltaic (PV) energy with a grid. Among the various inverters, the non-isolated inverter topology has gotten a huge attention for fixing the problem of leakage current issue with other inverters. In this paper, a linear control strategy is offered for the grid connected non-isolated PV inverter. The proposed scheme consists of a proportional resonance (PR) controller with lag compensator (LC). This controller offers lower oscillation in output grid current and better steady state performance for the grid-tied PV inverter systems. The analytical comparison of proposed control scheme and the other control strategies are mentioned in this work. The simulation results indicate the improvements of the performance for the proposed controller in terms of reference tracking ability, total harmonic distortion (THD), and the supplied dc bus voltages of the grid-injected PV inverter systems. This proposed controller can enhance the performance of the PV systems by reducing energy consumption during load change and faulty condition

Closed loop deep brain stimulation: an evolving technology

Deep brain stimulation is an effective and safe medical treatment for a variety of neurological and psychiatric disorders including Parkinson\u27s disease, essential tremor, dystonia, and treatment resistant obsessive compulsive disorder. A closed loop deep brain stimulation (CLDBS) system automatically adjusts stimulation parameters by the brain response in real time. The CLDBS continues to evolve due to the advancement in the brain stimulation technologies. This paper provides a study on the existing systems developed for CLDBS. It highlights the issues associated with CLDBS systems including feedback signal recording and processing, stimulation parameters setting, control algorithm, wireless telemetry, size, and power consumption. The benefits and limitations of the existing CLDBS systems are also presented. Whilst robust clinical proof of the benefits of the technology remains to be achieved, it has the potential to offer several advantages over open loop DBS. The CLDBS can improve efficiency and efficacy of therapy, eliminate lengthy start-up period for programming and adjustment, provide a personalized treatment, and make parameters setting automatic and adaptive

Development of a compact rectenna for wireless powering of a head-mountable deep brain stimulation device

Design of a rectangular spiral planar inverted-F antenna (PIFA) at 915 MHz for wireless power transmission applications is proposed. The antenna and rectifying circuitry form a rectenna, which can produce dc power from a distant radio frequency energy transmitter. The generated dc power is used to operate a low-power deep brain stimulation pulse generator. The proposed antenna has the dimensions of 10 mm × 12.5 mm × 1.5 mm and resonance frequency of 915 MHz with a measured bandwidth of 15 MHz at return loss of -10 dB. A dielectric substrate of FR-4 of εr = 4.8 and δ = 0.015 with thickness of 1.5 mm is used for both antenna and rectifier circuit simulation and fabrication because of its availability and low cost. An L-section impedance matching circuit is used between the PIFA and voltage doubler rectifier. The impedance matching circuit also works as a low-pass filter for elimination of higher order harmonics. Maximum dc voltage at the rectenna output is 7.5 V in free space and this rectenna can drive a deep brain stimulation pulse generator at a distance of 30 cm from a radio frequency energy transmitter, which transmits power of 26.77 dBm