The sub-stations of the high speed railway connected to the high voltage three phase network, are considered as pollutant loads, disrupting power grids. The major problem of these sub-stations is the unbalance caused by the connection between two phases of high voltage network. This connection leads to an unbalanced current, this current is decomposed into two sequences (positive and negative), creating negative sequence voltage in different points of the network. The parallel VSI STATCOM is one of the modern compensation solutions for the negative sequence current. It allows injecting currents in the sub-station connection point in order to get a balanced network. This paper describes the structure, control strategy, and performance of a VSI STATCOM.

In this paper, we present a detailed procedure to determine the semiconductor losses for both structures of a shunt STATCOM (Static Compensator), STATCOM based on Current Source Inverter (CSI) and STATCOM based on Voltage Source Inverter (VSI), both used for voltage unbalance compensation. As a first step, we study the VSI-based STATCOM and the CSI-based STATCOM used in high speed railway substations. Then we analyze the design and the sizing of the unbalance compensator in order to obtain an unbalance factor that does not exceed the limits imposed by the standards or by the energy provider. Following that, we compare the performances obtained with both structures VSI-STATCOM and CSI-STATCOM, after calculating the semiconductor power losses in the STATCOM converters. Finally, we validate our approach by simulation over real data of unbalance compensation caused by the new high-speed railway in Morocco. We use the tools MATLAB / Simulink/Simpowersys for performing our simulations.

This article consists of studying the reliability of the Moroccan electricity grid as well as verifying the plan of production for 2030. To propose an adequate production plan for 2050, a production plan where renewable energies take a large place in the production park. Our objective is the planning and optimization of the Moroccan energy system with a strong integration of renewable energy sources or even 100% integration by guaranteeing the reliability of the electrical system. In this study, we evaluated the reliability of the Moroccan electricity grid in the presence of renewable electricity production based on the energy plan simulator supplemented by Monte Carlo simulations based on probabilistic approaches. The first part of this work consists of projecting demand for 2030-2050 and studying the impact of energy efficiency on forecasts. In the second part, we integrated the existing means of production and the projected demand on energy plan. In the third part we studied the reliability of the Moroccan electricity grid in the presence of the production of wind, solar photovoltaic (PV) and concentrated solar (CSP) electricity according to different stages of study (from 2017 to 2050).