In the current energy ecosystem, the need for a Hybrid Appliance Load Monitoring System (HALMS) to establish a smarter grid and energy infrastructure is undeniable. The increasing popularity of the Internet of Things (IoT) has suddenly pushed the demand for smart and connected devices. This review introduces the term smart plug as a device that uses IoT for establishing HALMS. These smart plugs are a handy solution to make the so-called ‘dumb’ devices smart. The strategy of smart plugs to enhance the energy management experience in connected spaces is presented. This study extensively highlights the current smart plug technologies and the relevant activities and limitations that need to overcome the requirements of HALMS.

Moisture measurement and control is very essential for gas-insulated switchgear (GIS). For safe and reliable operation, the moisture inside GIS needs to be kept within the prescribed limit. This paper presents a capacitive sensor for traces of moisture measurement in SF6 gas used in GIS. The sensor is fabricated using fluorine doped tin-oxide (FTO) glass as the base substrate and silver as upper electrode. A thin film of porous alumina (Al2O3) is used as a sensing layer for detecting the presence of moisture at ppm scale. The performance of the presented sensor is experimentally validated for different moisture concentrations in SF6 gas. The sensor shows a good sensitivity (0.238 pF/ppm) with linear characteristics (±2.05 %) over the moisture range of 246-725 ppm. The response of the fabricated sensor is very accurate (±0.84 %), with low hysteresis (±0.32%) and highly repeatable (±0.013%). All the data of the fabricated sensor are obtained experimentally that validate its use for an effective moisture measurement in GIS where, the live conductors and other electrical equipment are surrounded by SF6 gas. The cost effectiveness of the sensor is ensured because of its simple fabrication process and robust design.

This paper presents a RH smart humidity sensor fabricated using poly vinyl alcohol (PVA) as sensing film deposited on polyimide substrate. This sensor detects change in capacitance due to presence of humidity in gas insulated switchgear (GIS) application. The initial tests are conducted using moist nitrogen gas with different percentage relative (% RH). The performance of designed PVA sensor was experimentally validated and it is noticed that the sensor possesses good sensitivity with linear characteristics over the range of 0- 20% suitable for industrial practices. Further, other parameters of the sensors such as reproducibility test, transient response analysis, linearity analysis, impedance response, and dissipation factor were also conducted to test the stability and effectiveness of the designed sensor. COMSOL Multiphysics is also used to validate the design aspects of the sensor with the fabricated one. The uniqueness of the fabricated sensor is that it is demonstrated good sensitivity profile along with the excellent linear response for the measurement of low RH values. The cost effectiveness of the sensor ensures due to simple fabrication process, use of inexpensive materials and 100% yield ratio.

Fault ride through (FRT) capability is an essential practice as per the present grid code demands for grid‐connected renewable energy‐based distributed energy resources. Studies on FRT capability for grid‐connected hybrid systems are rarely found. This study considers a wind energy conversion system and a fuel cell system interconnected at a common dc bus. It proposes a new feed‐forward‐based FRT control scheme for the inverter control where new current references in dq ‐axis frame are derived by tracking the positive sequence power. The newly derived references are fed forward to the input of the current regulator of the voltage source inverter. Second, fuzzy logic‐based current controllers are suggested to improve the tracking capability of the current references in the inverter control scheme so as to enhance the FRT capability of the hybrid system as a whole. The proposed feed‐forward‐fuzzy control scheme for achieving an enhanced FRT capability is compared with the conventional dq current control and feed‐forward FRT control for various grid voltage sag tests, where the performance of the combined feed‐forward‐fuzzy control is found better. The validation of the proposed FRT control scheme is performed in MATLAB‐Simulink environment.

This paper presents a system to monitor the presence of trace moisture in SF6 gas insulated switchgear (GIS) employing a micro-cantilever sensor. The main objective of the proposed system design is to continuously monitor the moisture concentration inside the GIS for enhanced safety. Microcantilever-based sensors reduce the overall size of the measurement system as well as enhance the measurement accuracy and sensitivity. A new system approach is proposed to detect trace moisture by monitoring the change in Q-factor of the microcantilever. It makes the measurement of resonant frequency of the microcantilever easier to implement and analyze. The system is made Internet of Things (IoT) enabled using Raspberry Pi. It allows easy local and remote accessibility of sensor data. The usefulness of the proposed system lies in its continuous monitoring ability, compact nature, and easy integration and accessibility, which are some of the essential and current requirements of the smart grid environment.

Power generation from a grid-integrated renewable energy generator embedded with backup sources to form a hybrid energy system possesses convincing features of high efficiency and zero emissions. Control for felicitating apt power sharing and for providing ancillary services such as low voltage ride through (LVRT) is necessary for the compliance of grid codes. However, the simultaneous control coordination for meeting these control objectives is challenging due to the dynamic nature of renewable generators and utility grid. Hence, this paper proposes an integrated power management strategy (PMS) and LVRT control scheme for such systems. A wind energy conversion system backed up by a battery energy storage system, proton exchange fuel cell, and electrolyzer is considered in this work. A reduced rule-based power management control scheme is proposed for the considered system where the request made by the grid operator is kept in priority. Further, a dynamic current feed-forward based LVRT control scheme based on negative sequence current minimization is presented for the grid-interfaced inverter. The inverter control is coupled with an inherent mode selection capability between the grid feeding mode and LVRT mode in order to realize the proposed integrated control objectives. The validation of the proposed PMS and LVRT control is justified by detailing relevant mathematical control models and also by realizing practical case scenarios such as variable wind speed, load demand, grid power request, and occurrences of balanced and unbalanced voltage sag. The obtained simulation results show the cordial response of the system with the proposed control strategies.