Nguyen Duc Tuyen

PV-Active Power Filter Combination Supplies Power to Nonlinear Load and Compensates Utility Current

The photovoltaic (PV) generation is increasingly popular nowadays, while typical loads require more high-power quality. Basically, one PV generator supplying to nonlinear loads is desired to be integrated with a function as an active power filter (APF). In this paper, a three-phase three-wire system, including a detailed PV generator, dc/dc boost converter to extract maximum radiation power using maximum power point tracking, and dc/ac voltage source converter to act as an APF, is presented. The instantaneous power theory is applied to design the PV-APF controller, which shows reliable performances. The MATLAB/SimpowerSystems tool has proved that the combined system can simultaneously inject maximum power from a PV unit and compensate the harmonic current drawn by nonlinear loads.

3-Phase 4-wire Shunt APF under non-ideal PCC voltage using Adaptive Notch Filter

In this paper, the 3-phase 4-wire Shunt Active Power Filter (ShAPF) dealing with non-ideal Point of Common Coupling (PCC) voltages will be presented. The instantaneous power theory is applied to design the ShAPF controller which shows reliable performances. The Adaptive Notch Filter (ANF) is proposed to process those non-ideal PCC voltage. The power balance among utility, load and ShAPF while applying ANF is explained in details. The simulation results of SimpowerSystems tool have proved that the ANF successfully facilitates the ShAPF in terms of compensating unbalanced/distorted current of loads under even without an ideal voltage circumstance.

Optimal Distributed Generation and capacitor coordination for power loss minimization

This paper describes the effectiveness of solving the coordination of Distributed Generation (DG) and capacitor simultaneously to minimize power loss in the distribution system. Previously, the solution is executed separately which means the coordination of DG is done without the presence of capacitor, and vice versa. Hence, possibility to obtain better results will be limited. A hybrid optimization based on Artificial Bee Colony (ABC) and Artificial Immune System (AIS) will be used to determine the optimal DG and capacitor coordination simultaneously. The proposed method was tested on a 33-bus test system with several cases studies by using MATLAB programming. The simulation results show that the simultaneous approach provides better power loss reduction and voltage profile enhancement compared to a separate analysis.

Modelling a SOFC Power Unit Using Natural Gas Fed Directly

Completed models covering dynamic characteristics of those types of DGs are not openly available. The necessary task is to study these dynamic models based on the literature and any available operational data on DGs. Simulation of various types of DGs in a suitable software environment is the key step in analyzing the dynamic characteristics of DGs and designing the control strategies. In fact, computer simulation plays a vital role in the design and analysis of power system. Designing power systems without computer simulation is extremely laborious, time consuming, error-prone and expensive. Especially, in the new research field as DGs, computer simulation in an industrial environment with regard to the time in shortening the overall design process as compared to assembling and testing the components in the laboratory and deciding on the optimum values for components and controller parameters.

An integrated function of photovoltaic generator supplying to nonlinear load: Active power filter

The PV generation is increasingly popular nowadays while typical loads require more high power quality. Basically, one PV generator supplying to nonlinear load is desired to be integrated with a function as an active power filter (APF). In this paper, the proposed three-phase three-wire system including PV generation, DC/DC boost converter to extract maximum radiation power by using MPPT and DC/AC converter to acts as an APF will be presented. The instantaneous power theory is applied to design the PV-APF controller which shows reliable performances. The Matlab/SimpowerSytem tool has proved that combined system can simultaneously inject maximum power from PV unit and compensate harmonic current drawn by nonlinear loads.

Reliable Impedance Islanding Detection for Power Distribution Systems with High Motor Penetration

Regarding to dispersed generation field, an islanding is known as a situation that those generators are disconnected from the utility feeders and a bunch of local loads being powered by them is isolated. Accordingly, anti-islanding schemes are used to immediately detect that phenomenon in facilitating the detachment the DG or adaptive controlling of autonomous operation. Negative-sequence impedance measurement is considered as a novel method of detecting electrical islands in DG networks. However, in the case of high induction motor penetration, this method might malfunction. Using two-round impedance measurement, this paper deals with that problem while making typical assessments on how the impedance tolerant values are selected and how these values vary with network configuration. The simulation in PSCAD/EMTDC and experiments validate the methodology.

Applying Adaptive Notch Filter in αβ-coordinate to improve 3-phase 4-wire shunt APF performance under non-ideal PCC voltage

In this paper, the 3-phase 4-wire Shunt Active Power Filter (ShAPF) dealing with non-ideal Point of Common Coupling (PCC) voltages will be presented. The Adaptive Notch Filter (ANF) processes those non-ideal PCC voltages directly in αβ-coordinate where instantaneous power theory is applied. The simulation results proved that the ANF successfully facilitates the ShAPF comparing to the conventional dq-filter method.

Shunt Active Power Filter for 3-phase 3-wire nonlinear load under unbalanced and distorted PCC voltage using Notch Adaptive Filter

In this paper, the 3-phase 3-wire Shunt Active Power Filter (ShAPF) dealing with non-ideal PCC voltage will be presented. The instantaneous power theory is applied to design the APF controller which shows reliable performances. The Adaptive Notch Filter (ANF) is proposed to deal with those unbalanced and distorted PCC voltage. The Matlab/SimpowerSystems tool has proved that the ANF successful facilitates the ShAPF in terms of compensating harmonics current of nonlinear loads even without balance voltage circumstance.

Optimal placement and sizing of SVC by using various meta-heuristic optimization methods

This paper presents comparison of three kinds of meta-heuristic optimization to determine location and sizing of Static Var Compensator (SVC). The optimization methods are Particle Swarm Organization (PSO), Improved Harmony Search (IHS) and Cuckoo Search Algorithm (CSA). The multi-objective function of this problem considers loss power, voltage deviation and operational cost of SVC. All of methods are tested on three types of IEEE power systems, such as 9-bus case, 30-bus case and 57-bus case. Results show that the CSA does not only gives better solution than others do, but it also has better performance, while the IHS is more effective than the version of PSO.

Analysis of current-controller in grid-connected and islanded mode for dispersed generation

An islanding is that the islanded entity including DGs and critical load disconnects from the utility and then, operates in the islanded mode. During that mode, the Power Electronic Interface of DGs not only has a role in keeping the Point of Common Couplings voltage within a required range, it also needs to make islanded frequency arbitrarily at normal values. This paper investigates the operation response while keeping the conventional current controller in some cases of typical islanded loads and then, validate feasibility of proposed current controller for the islanded entity dealing with transient-to-island mode. The islanding detection method by using negative-sequence impedances also facilitates the fast switching for the entire control scheme. The droop control mechanism is presented for inductive-reductive impedance.