19 Eylül 2012 Çarşamba

Wind News: Utility models wind plants and hydro to spot integration problems

Wind News: Utility models wind plants and hydro to spot integration problems

A Canadian utility committed to using renewable energy, mainly hydroelectric and wind power, says it conducts simulations of its far-flung equipment to smooth power flow to the grid. Hydro-Québec engineers also say simulations forecast power output and ensure safe, reliable operation of the overall power system.
Another task for the simulations is to determine how much equipment, such as static VAR compensators, will be needed when new wind farms are connected to the power network. “Without accurate models, we risk installing millions of dollars’ worth of unnecessary equipment or not having the equipment needed to meet reliability and production goals,” says Denis Laurin, the utility’s manager of technological innovation.
The utility’s additional challenge is to model the control system and power output of a single turbine, simulate the 70 to 100 turbines of a single wind farm to validate an aggregation method for modeling, and then simulate the interaction of wind farms with the power-system network.
“Accurate modeling is essential for planning investments and detecting situations that cause outages,” says Richard Gagnon, researcher at Institute de recherche d’Hydro-Québec. “We can simulate power electronics, mechanics, and control systems in one model and they respond like the units in the field.” Gagnon says turbine models include control systems, machines, power electronics, and measurement systems. Generating C code lets them use the models to study the integration of new wind farms into power system networks.
For accurate simulation results, the utility must model transient stability and electromagnetic transients, which accounts for electromechanical phenomena and transients. Such models help engineers understand the dynamic interaction between the electrical modes of the network and the wind power plants.
Gagnon says his team models individual turbines and entire wind farms using MATLAB Simulink  and SimPowerSystems from MathWorks Inc, (mathworks.com).  They use Simulink Coder to generate code, which they incorporate into Hypersim, Hydro-Québec’s multiprocessor real-time simulation environment.
To study stability, the utility simulates turbine mechanics using a two-mass system model in Simulink that accounts for the pitch of the blade and torsional effects, among other details. One recent model assembled an entire wind farm of 73 individual turbines and the collector network that links them.
In the resulting real-time environment, the team performed hundreds of simulations with varying operating conditions, wind speeds, and fault scenarios. Their aggregate wind farm model predicted the same voltage and current outputs at the real world connection between the wind farm and power system. The utility is using simulation results to guide the planning of new wind-power plants that will add 4,000 MW of capacity to its power system.
Hydro-Québec engineers use Mathworks  Simulink and SimPowerSystems to model and simulate individual wind turbines and entire wind farms. The utility uses Simulink Coder to generate code, which they run in Hypersim, Hydro-Québec’s multiprocessor simulation environment. WPE