VOLTAGE stability may be improved by various CONTROL functions. In this paper, it is shown that how HIGH SIDE VOLTAGE CONTROL (HIVC) may be employed for this purpose. Two test systems, namely a 22- bus and IEEE U8-bus systems are used to demonstrate the proposed tuning strategy for HSVC CONTROL parameters.

A common method for CONTROLling a group of parallel converters in decentralized CONTROL strategy structure in an island microgrid, the use is the droop-down characteristics of frequency ω-P and VOLTAGE E-Q. However, the problem with using this method is that the reactive power is not properly distributed (in proportion to the capacity of the micronutrients) between the micronutrients, which may lead to overload in the converters. Microgrids may also suffer from dynamic stability problems such as power fluctuations, which can be increased by switching between active and reactive power CONTROL. To avoid this problem, the X / R ratio of transmission lines is an important parameter that should be carefully conSIDEred in the design of micronutrient CONTROLlers. By linearizing and simplifying conditions, the CONTROL system conversion function model becomes a single input-single output system, which is efficient enough to show the relationship between CONTROL parameters such as slope of droop characteristics and derivative sentences, virtual impedance, and VOLTAGE CONTROLlers. Using this model, stability conditions for different parameters are analyzed. Also, to improve power distribution stability, common droop strategies are modified by adjusting the slope as well as adding nonlinear sentence sections. This approach reduces the coupling between active and reactive power CONTROL and reduces the dependence of power distribution on grid parameters such as the X / R ratio. To evaluate the reliability of the proposed model, the simulation results in a sample island microgrid in MATLAB software are presented.

To evaluate the effect of nitrogen and water withholding in vegetative growth stage of corn on efficacy of nicosulfuron and 2,4-D+ MCPA an experiment was conducted as a factorial arrangement in a randomized complete block design with three replications at Tarbiat Modares University in 2017. The first factor contained four treatments including application of nicosulfuron, 2,4-D+ MCPA, weed free and weed infested as CONTROL. The second factor consisted of normal irrigation and water withholding from 4 to 8 leaf stage. Third factor contained either urea application or no fertilizer application. Normal irrigation and nitrogen fertilizer application significantly increased nicosulfuron and 2,4-D+ MCPA efficacy in weed CONTROL and total weed dry weight decreased to 341 and 361 g.m-2 respectively compared 1370 g.m-2 as weed infested. Nicosulfuron and 2,4-D+ MCPA reduced weed total dry weight significantly under irrigation withholding. Grain yield increased with application of nitrogen and nicosulfuron. Grain yield was HIGHer with application of 2,4-D+ MCPA than nicosulfuron without nitrogen application under irrigation withholding. Application of nicosulfuron with nitrogen application provided satisfactory weed CONTROL and increased grain yield.

Severe VOLTAGE fluctuations at different points of the network are the main concerns of the widespread low-VOLTAGE electrical energy distribution networks. In particular, small industrial loads and rural consumers in remote geographical areas, which are fed by long lines, always experience great VOLTAGE drops. The use of common distribution transformers equipped with off-load tap changers has not been effective in solving this problem due to issues such as lack of access to all network points for operators, the need to de-energize the line during tap change, and the successive and unpredictable load changes. Therefore, the use of transformers with automatic VOLTAGE adjustment at different points of distribution networks has attracted much attention. The present research aimed to implement a simple solid-state VOLTAGE REGULATOR (SSVR) in the low power range to automatically eliminate severe VOLTAGE fluctuations. In this research, a solid-state VOLTAGE REGULATOR with a rated power of 5 KVA was designed and built to automatically compensate for the VOLTAGE of a small group of home customers (who have a severe VOLTAGE drop due to the distance from the distribution post). The results of the measurements showed that this equipment can limit the VOLTAGE changes to 220±3%, while it does not affect the power quality. In addition, various hardware and software protections were designed for the device built against network disturbances and abnormal consumer functions.

Electricity distribution network delivers VOLTAGE 220V to single phase customers. In weak distribution system, the length of feeders is long so the end of feeders is faced with excessive VOLTAGE drop. Compensating for this VOLTAGE drop by constructing medium VOLTAGE power system and installing new distribution substations is not cost effective. Especially in rural areas where the prospect of development and increase in subscribers is unlikely. Therefore, other flexible and low-cost solutions should be conSIDEred. In this research, to compensate for VOLTAGE drop, a small group of home subscribers who have VOLTAGE drop due to their distance from the distribution substation, a semi-industrial model of solid-state VOLTAGE REGULATOR is designed and manufactured. In this structure, dry autotransformers with nominal power of 15KVA will be used as single-phase (or three-phase). The low-VOLTAGE autotransformer taps are changed by the use of triac semiconductor switches with VOLTAGE closed-loop CONTROL. To show the efficiency of this method, a 500VA laboratory sample was made using 12 triacs with 40A rated current, from which successful results were obtained. The measurement results show that this equipment can limit the VOLTAGE changes to the range of 0.95 to 1.05 of the nominal value while also not affecting the quality of power. The semi-industrial version of this VOLTAGE REGULATOR has been manufactured and successfully tested, in which appropriate protection functions are embedded for operational use in power systems.

This paper presents a low quiescent current low-dropout VOLTAGE REGULATOR (LDO) with CONTROLled pass transistor which can work either with on-chip or off-chip output capacitor. The pass transistor of the proposed LDO has lower width in low load condition and has HIGHer width for moderate to heavy load current and the LDO topology transforms between a two-stage structure in low load current and a three-stage one in moderate to HIGH load current. The proposed LDO topology is designed and simulated in HSPICE in a 0.35 mm CMOS process to provide a 2.8 V output VOLTAGE for a 3 V input VOLTAGE and is capable to deliver a stable output current in the range of 0-100 mA to the load with a 100 pF on-chip output capacitor while its quiescent current is only 7.5 mA. Without using the adaptively-CONTROLled pass transistor, the maximum output variations of the LDO to the 0-100 mA load transient is 540 mV and its settling time is 11 ms, while using this technique decreases the output VOLTAGE variations and settling time to 280 mV and 6.5 ms, respectively.

The objective of this work is to meet the variations of the electrical energy needs by modifying the conventional topology of the conversion chain, at the same time to improve the operation of the photovoltaic system. This article focuses on improving the performance and efficiency of photovoltaic systems connected to the AC grid, through the use of advanced CONTROL algorithms (Sliding Mode CONTROL SMC and Fuzzy Logic CONTROL FLC) for the CONTROL of DC/DC and DC/AC power conditioners. The CONTROL of the DC/DC converter allows the pursuit of the maximum power point MPPT of the photovoltaic generator with a view to a better utilization of the photovoltaic generator. The inverter CONTROL system is used to inject synchronized sinusoidal output current to the power grid and to improve the quality of energy injected into the grid. The original idea of this work is based on the insertion of a DC/DC BOOST VOLTAGE REGULATOR in the conversion chain (between the battery and the inverter) to adjust the VOLTAGE transfer of the DC bus. This technique allows the provision of AC VOLTAGE for the sufficiency of the energy required by the CONTROL according to the need of the load.