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This paper relies on the development of a model for an urban electric transportation system. This model is used to simulate the system operation both in normal and abnormal (short circuit) regimes. The simulation results are compared with the results of some theoretical studies presented in the technical literature and also with some experimental results. Unlike the theoretical idealized studies our...
There is a need to develop new control strategies for interconnecting Renewable Energy Sources (RES) to the power system due to the ever increasing penetration of RES and in particular for wind power systems (WPS). The control strategies are typically based on a fast and accurate detection of the phase angle of the grid voltage which may be estimated by using a Phase-Locked Loop (PLL) control circuit...
This paper describes the operation of modular multilevel converter (MMC). A control method of adding the feed-forward current is introduced. Another strategy of removing the second harmonic current is also described in order to improve the arm currents. Simulation results based on a detailed PSIM model prove the effectiveness of the two methods. The paper presents principle of parameters selection...
This paper is on wind energy conversion systems with full-power converter and permanent magnet synchronous generator. Different topologies for the power-electronic converters are considered, namely matrix and multilevel converters. Also, a new fractional-order control strategy is proposed for the variable-speed operation of the wind turbines. Simulation studies are carried out in order to adequately...
Three phase Phase-Locked-Loop is an important part of active power filter. In order to improve the behaviors of the conventional PLL system (CPLL), a novel control method of variable gain nonlinear PI controller based three phase PLL system (NLPLL) is proposed in this paper. As the proportional gain and integral gain of the nonlinear PI controller can adapt variety of the phase error, the schematic...
Because of the operation characters of power system, high-power electronic devices, such as active power filter (APF), could not be tested fully in field before commissioning. To solve this problem, the hardware-in-the-loop system (HIL) which is comprised of real-time digital simulator (RTDS) and the APF is used to test the functionality and performance of the APF in place of the real system. We introduce...
The Static Synchronous Compensator (STATCOM) is a shunt device using power electronics to control power flow and improve transient stability on power grids. A model of a 100Mvar GTO-based STATCOM on a 500kV transmission system is built and its dynamic response is simulated. The GTO-based STATCOM consists of a 48-pulse three-level inverter and its control system. The simulating result shows that the...
This work attempts to explain reactive power consumption in a line commutated HVDC transmission system and suggests a possible solution to reduce it. A series injection strategy has been formulated using voltage-source converters and the effects have been simulated indicating a significant reduction in reactive power consumption by the converter terminal and consequently that supplied by the source...
This paper is on wind energy conversion systems with full-power converter and permanent magnet synchronous generator. Different topologies for the power-electronic converters are considered, namely matrix and two-level converters. Also, a new fractional-order control strategy is proposed for the variable-speed operation of the wind turbines. Simulation studies are carried out in order to adequately...
The paper presents a nonlinear control strategy for single-phase active power filter applying exact feedback linearization theory, since this technique has been successfully applied to other area of power electronic. Using the state-space average modeling method, a nonlinear affine mode of single-phase shunt active power filter is set up. It is testified that the model is satisfied with the condition...
In recent years, with the rapid development of the power electronic technology, various power electronic devices and nonlinear elements, especially of many kinds of rectifier and switcher, are applied widely in power system. Harmonics have produced serious adverse effects in the equipment of power generators and distribution system, and of their control and protection, as well as the users and the...
At present, there are two kinds of the high voltage and large capacity inverter, namely multilevel and multi-pulse inverters. In this paper, multi-pulse inverters are classified into two types according to the interphase transformer configuration. At first, the fundamental and harmonic voltage amplitude expressions of two types of the multi-pulse inverter are proposed and used to analyze the relationship...
With the proliferation of nonlinear loads as power electronics equipment, the disadvantage of harmonics is more and more, which influence quality of power grid. Active power filter is a new harmonics restraint method comparing with passive filter, which is a power electronics device. This paper inspects harmonics current based on three-phase circuit instantaneous reactive power theory and simulates...
The total harmonic distortion (THD) monitoring is an important challenge in the industrial and office building environment. The IEEE-519 and IEC 61000-3 standards limit the individual harmonics current as well as the THD for nonlinear power electronic loads. A harmonic current distortion comparative study of a classical three-phase rectifier diode (TPRD) and rectifier with near sinusoidal currents...
When connecting the grid-connected power electronics systems to the utility system, one of the most important aspects to be considered is the synchronization with the grid system in phase and frequency. The synchronized speed and accuracy depend on the technology used in the phase-looked loop (PLL) system. Different kinds of PLL technologies have been published in recent years. A novel PLL structure...
Static power converters produce harmonics due to the nature of the conversion process. This paper will investigate two variations of current mode control for three-phase power converters ensuring reduced harmonic pollution and power factor improvement. The first method employed uses a Fryze current reference and the second method utilises a balanced three-phase sinusoidal reference. Both control techniques...
This paper is concerned with the design and simulation of a pulse width modulation (PWM) rectifier for three-phase Permanent Magnetic motor drive. Based on the mathematical model of PWM rectifier, the dual-close-loop engineering design with decoupled feed-forward control is applied in the 3-phase voltage source rectifier. The objective to be reached is to realize unity power factor at the input ac...
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