Nijan Yogal

All around the world, new plans and strategies are being implemented for installing energy-efficient wind turbines in order to increase renewable energy capacities and meet the demand for clean energy. Advances in wind turbine technologies and their extremely sophisticated systems have led to an increasing need for proper efficiency determination methods, both in the field and on test benches, to keep up with the accelerated deployment of wind turbines around the globe. This paper examines the feasibility and practicability of new wind turbine efficiency determination methods on test benches that are based on international standards for electrical machines. Test methods and the static calibration certificates of the employed specialised instruments and sensors were used to evaluate the efficiency and associated measurement uncertainties in ambient conditions. Furthermore, the results were compared with those obtained through the innovative iso-efficiency method, which comprehensively maps the wide operating range of wind turbines.

In this paper, the efficiency of a 2.75 MW nacelle drivetrain on a test bench was determined traceably at various load points. For this purpose, so-called transfer standards for mechanical and electrical power measurement were additionally installed and integrated into the nacelle drivetrain. As torque measurement contributes greatly to the overall uncertainty, the static torque calibration was expanded to include additional influences present under rotation. An overall system efficiency of 89% was measured in the high torque and high speed range. The relative expanded measurement uncertainty for efficiency determination was between 0.30% and 0.72% over the entire operating range. Both the efficiency and the relative expanded measurement uncertainty were calculated for each operating point.

Permanent magnet synchronous machines (PMSMs) fed with frequency converter faces higher order harmonics signals which results higher eddy current losses in permanent magnets (PMs). This eddy current losses in the PMs leads to overheating causing irreversible demagnetization of PMs during the operation of the machines. One of the goals in machine design for the safe operation is to measure the total eddy current loss and minimize overheating of PMs. In this paper, measurement methods with a focus on measurement sensors and a finite element method (FEM) simulation for the eddy current loss (i.e. PM loss) of PMSMs are presented and compared.

Rotating electric machine test benches used for testing electric drive systems in the automotive industry consist of different kinds of sensors a |

High energy‐efficient permanent magnet synchronous machines (PMSMs) with low manufacturing costs and easy controllability are in high demand for the automotive and aerospace industries and in explosive environments (hazardous areas) like mines and the petrochemical industries. In explosive environments, the high surface temperature of PMSMs, due to magnetic losses and the irreversible demagnetisation of permanent magnets (PMs), could be a source of ignition leading to explosions. Therefore, this paper presents magnetic losses of a PMSM, which will help engineers to design robust machines with a high tolerance to explosive environments. Analytical calculations and finite element method (FEM) simulations of the magnetic losses of a PMSM are presented and compared with measured values from testing a PMSM.