This paper proposes a fully distributed control methodology for secondary control of AC microgrids. The control framework includes three modules: voltage regulator, reactive power regulator, and active power/frequency regulator. The voltage regulator module maintains the average voltage of the microgrid distribution line at the rated value. The reactive power regulator compares the local normal...

A piecewise-linear bandagp reference (BGR) with high power supply rejection ratio (PSRR) and low temperature coefficient is designed for analogue and mixed signal systems in this paper. By adopting LDO regulator, the designed high PSRR piecewise-linear BGR achieves well performances and has a simple architecture. Simulation results show that the PSRR of the designed piecewise-linear BGR with LD...

A detailed model of wind power station, including Double Fed Induction Generator, DFIG is presented in this paper. Two control mechanisms are included in the model. The inner control system uses stator flux oriented control for the rotor side converter and grid voltage vector control for the grid side converter. The outer control system is used for wind turbine pitch angle. PSCAD/EMTDC is us...

This paper presents a comprehensive approach for the design of UPFC controllers (i.e. power flow controller, DC voltage regulator and damping controller) for a multimachine system. UPFC controllers have been designed in the presence of conventional PSS. The interaction between the UPFC controllers and PSS has been studied. Investigations reveal that the system damping gets adversely affected wi...

A voltage regulator is developed to extend the operation range of a electrostatic actuator using a displacement feedback. The feedback actuator system can be used for continuous position tracking of step, ramp, or harmonic voltage signals. The electrostatic actuator is composed of a micro-cantilever beam electrode above a fixed electrode. The voltage difference between the two electrodes is reg...

This paper mainly studies the main circuit topology, the working principle, modulation technique and control strategy of the STATCOM based on H-bridge. The STATCOM direct power control algorithm based on the virtual flux is used to control the AC side reactive power compensation, and in accordance with the principle of conservation of power, the DC side voltage imbalance factors are analyzed, a...

The mixed power flow analysis method decreases the computational complexity and achieves a high level of simulation accuracy. The mixed approach combines the ac with the dc power flow models, depending on the area of interest. The accurate ac model is used in the study area of interest to obtain high simulation accuracy, while the approximate dc model is used in the remainder of the system to r...

This paper describes the problem of voltage sags and swells and its severe impact on sensitive loads and introduces a new solution for doubly fed induction generators to stay connected to the grid during voltage sags. The main idea is to increase the stator voltage to a level that creates the required flux to keep the rotor side converter current below its transient rating. To accomplish this g...

Literature survey shows that generally studies are made assuming the fact that there is no interaction between LFC and AVR loops. But the Automatic Voltage Regulation (AVR) and Load Frequency Control (LFC) loops are not in truest sense non-interacting. Practically, during dynamic perturbations some interactions between these two control loops exist. Interaction exists in opposite direction of t...

The capability of regulating power flow in Nigerian Grid System using UPFC is the main focus in this paper. Consequently, three control methods, namely, voltage control through shunt compensation, real power flow control through quadrature voltage injection and reactive power flow control through in-phase voltage injection for the UPFC were examined in order to improve the transient stability o...