Stand-alone power system

About: Stand-alone power system is a research topic. Over the lifetime, 8650 publications have been published within this topic receiving 192397 citations. The topic is also known as: Stand-alone photovoltaic power system.

Electric Vehicle Mobility in Transmission-Constrained Hourly Power Generation Scheduling

Abstract: The proposed approach evaluates the effect of integrating a large number of electric vehicles (EVs) on power grid operation and control. The EV fleets could serve as electricity load when drawing energy from the grid and as energy storage (vehicle-to-grid) when delivering energy to the grid. The paper considers two operating modes for EV fleets which are consumer-controlled and grid-controlled. The power grid generation mix represents a multitude of units including thermal, hydro, and wind. The paper considers the impact of EV battery utilization on offsetting the hourly variability of wind generation units in transmission-constrained power grids. The paper considers charging/discharging schedule of EV batteries and consumer driving requirements on the optimal hourly transmission-constrained commitment and dispatch of generation units in the day-ahead scheduling. The hourly solution of the proposed method will minimize the cost of supplying the hourly load while satisfying the temporal constraints of individual components in power grids.

Voltage recovery of grid-connected wind turbines after a short-circuit fault

Abstract: A simulation model of a MW-level wind turbine with dynamic slip control and pitch control is developed in the simulation tool of PSCAD/EMTDC and stability investigations are carried out with respect to a short circuit fault in the external power system. After the fault has been cleared, the voltage at the wind turbine terminal has to be re-established, and the wind turbine should restore its normal operating condition. Controlling the generator slip and pitch angle can adjust the electromagnetic torque and the aerodynamic torque of wind turbine, which helps to rebuild the voltage at the wind turbine terminal. Simulation results prove that dynamic slip control and pitch control are effective methods to improve the voltage and maintain power system stability.

A Multilevel Medium-Voltage Inverter for Step-Up-Transformer-Less Grid Connection of Photovoltaic Power Plants

Abstract: Recently, medium (0.1-5 MW) and large (>5 MW) scale photovoltaic (PV) power plants have attracted great attention, where medium-voltage grid connection (typically 6-36 kV) is essential for efficient power transmission and distribution. A power frequency transformer operated at 50 or 60 Hz is generally used to step up the traditional inverter's low output voltage (usually ≤400 V) to the medium-voltage level. Because of the heavy weight and large size of the power frequency transformer, the PV inverter system can be expensive and complex for installation and maintenance. As an alternative approach to achieve a compact and lightweight direct grid connection, this paper proposes a three-phase medium-voltage PV inverter system. The 11-kV and 33-kV PV inverter systems are designed. A scaled down three-phase 1.2-kV test rig has been constructed to validate the proposed PV inverter. The experimental results are analyzed and discussed, taking into account the switching schemes and filter circuits. The experimental results demonstrate the excellent feature of the proposed PV inverter system.