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Variable speed wind turbine with full scale converter or so-called type-D wind turbine generator worldwide installation has been significantly increased in the last few years. Voltage Swell in the grid side may cause the wind turbine to be disconnected from the grid. In this paper, STATCOM is applied to improve the high voltage ride through capability of type-D wind turbine during voltage swell in the grid side. Simulation is carried out using MATLAB/Simulink software. Results show that STATCOM can significantly improve the high voltage ride through (HVRT) capability of type-D wind turbine and prevents it from being disconnected from the grid during certain level of voltage swell in the grid side.

With the rapidly growing interest in smart grid technology, plug-in electric vehicles (PEVs) are expected to become more popular as low emission replacement for the petroleum based vehicles. Significant PEVs charging activities will mostly take place in customer's premises, public or corporate car parks and electric charging stations. Therefore, utilities are concern about the possible detrimental impacts of these sizeable and unpredictable loads on the performance of distribution grids. Based on a recently proposed real-time smart load management (RT-SLM) control strategy, this paper focuses on the impact of uncoordinated and coordinated PEVs charging on substation transformer loading, system losses and voltage profile. Detailed simulations are performed on a 449 node smart grid system consisting of the modified IEEE 23 kV distribution system serving 4 charging stations and 22 low voltage residential networks populated with PEVs.

This paper presents an improvement method for future smart electricity grid performance using high efficiency solar cells. The smart grid offers several advantages for the connection of solar (renewable) energy sources to provide an efficient operation and better performance of the power systems. Finite-difference time domain (FDTD) method is employed to simulate the transmission, reflection and absorption of high efficiency solar cell structures. Simulation results show that the reflection loss is reduced with the use of nanostructures compared with the flat type substrates. Therefore, the proposed solar cells will inject more energy into the electricity grid and hence improving its overall performance.

Variable speed wind turbine with full scale converter or so-called Type-D wind turbine generator worldwide installation has been significantly increased in the last few years. Voltage sag in the grid side may cause the wind turbine to be disconnected from the grid. In this paper, effect of STATCOM on the low voltage ride through capability of Type-D wind turbine during voltage sag in the grid side is studied. Simulation is carried out using MATLAB/Simulink software. Results show that STATCOM can significantly improve the voltage profile at the Point of Common Coupling (PCC) and improve the capability of Type-D wind turbine and prevents it from being disconnected from the grid during certain level of voltage sag in the grid side.

The amount of wind turbine connected to the power grid has significantly increased during the last decade. This has resulted in essential need to establish grid codes. Previously, wind turbine generators (WTGs) were allowed to be disconnected from the network during any disturbance at the grid side to avoid WTGs from being damaged. However, lately, the transmission system operators (TSOs) require WTGs to be stayed connected to provide support to the grid during fault. This new requirement has been regulated in the new grid codes. In this paper, the super conducting magnetic energy storage (SMES) unit is used to enhance the high voltage ride through (HVRT) capability of DFIG based WTG during voltage swell events at the grid side. Two new grid codes are used to verify the ability of the SMES unit to avoid the WTG from being disconnected from the grid.

The ability of variable speed wind turbines technology to optimally tracking the power from wind energy has become the main reason of their popularity compared with the fixed speed wind turbines. In the earlier stage of connecting wind turbines (WTs) to the existing electricity grids, WTs were allowed to be disconnected from the grid in case of grid faults which might lead to the damage of the turbines. However, recently, the transmission system operators (TSOs) require to maintaining the connection of WTs with the grid to support the grid during fault and to assure the continuity of power supply. This requirement has been compiled in new grid codes in several countries. In this paper, super conducting magnetic energy storage (SMES) unit is used with two different types of variable speed wind turbine generators to comply with Spain grid codes. Results show that the low-voltage-ride-through (LVRT) of Type-3 and Type-4 wind turbine generators are significantly improved when SMES unit is connected to the system.

This paper investigates the application of STATCOM to stabilize the torsional oscillations of sub-synchronous resonance (SSR) of a wind energy conversion system (WECS). The IEEE system-1 of the second benchmark model for computer simulation of subsynchronous resonance is adopted with integrating aggregated induction generator-based wind turbine to perform the study. A small signal analysis is conducted to study the impact of the series compensation levels and torsional dynamics on system stability. EMTDC/PSCAD is used to simulate the system under study. Due to its simplicity, robustness and ease of implementation, a proportional integral (PI) controller along with auxiliary feedback signals are used to control the inverter firing angle to control the reactive power exchange between the AC system and the STATCOM. The performance of the controller is tested in steady state as well as transient conditions.

Due to the significant increase in non linear loads and the worldwide trend to establish smart grids, harmonic level in the electricity grids is significantly increased. In addition to their impact on power quality, harmonic currents can have a devastating effect on power system protection performance especially on the operation of over current relays which are designed to operate efficiently at the fundamental frequency. The distorted waveform will affect the operation of the over current rely and may cause the relay to trip under normal operating conditions. To solve this problem, power passive and active filters are employed to eliminate the harmonics and purify the relay operational signal. Passive filters are not cost effective choice to solve this issue. On the other hand, active filters are more complex and need proper and complicated controller. This paper introduces a new and simple approach for adaptive filter design. This approach is economic, compact and very effective in eliminating harmonics in the grid. It can be easily attached with any protective relay to improve its performance. Application of the proposed filter design to improve the performance of over current relays in the IEEE-30 bus system with heavy penetration of non-linear loads is investigated.