Thermal Cycling in Converter IGBT Modules with Different Cooling Systems in Pitch- and Active Stall-Controlled Tidal Turbines

This paper compares active and passive cooling systems in tidal turbine power electronic converters. The comparison is based on the lifetime of the IGBT (insulated gate bipolar transistor) power modules, calculated from the accumulated fatigue due to thermal cycling. The lifetime analysis accounts for the influence of site conditions, namely...

Tidal Turbine Generators

Recently, tidal stream turbines have become a preferable mode of harvesting tidal energy. The main issue for low utilization of tidal energy is the high levelized cost of energy (LCoE) from tidal stream turbines. A major reason for this is the high operation and maintenance costs for submerged installations. A possible way of minimizing the LCoE...

Electromechanical dynamics analysis of pole-piece rotors in pseudo direct-drive wind turbine generators

This paper analyses the electromechanical dynamics of the pole-piece rotors in a pseudo direct-drive wind turbine generator. The investigated generator has a rated power of 10 MW and was designed in the INNWIND.EU project. One way coupled finite element analysis (FEA) was used to calculate the rotor dynamic defections caused by...

Lifetime Analysis of IGBT Power Modules in Passively Cooled Tidal Turbine Converters

Thermal cycling is one of the major reasons for failure in power electronic converters. For submerged tidal turbine converters investigating this failure mode is critical in improving the reliability, and minimizing the cost of energy from tidal turbines. This paper considers a submerged tidal turbine converter which is passively cooled by...

Calculation of PWM-induced rotor-can losses in flooded generators

Improving availability of tidal turbines has been identified as a key area to lower the levelized cost of energy from tides. One of the approaches suggested to achieve high reliability is to use a flooded permanent magnet (PM) generator. Flooded PM generators are designed to operate with a seawater filled stator-rotor gap in the generator. Using...

Sliding mode control with neural network for active magnetic bearing system

A novel controller design procedure is proposed for a 5-degree-of-freedom (DOF) active magnetic bearing (AMB) system, based on sliding mode control (SMC) and neural network (NN). The SMC is used to achieve high robustness and fast response while the NN can compensate unmodeled uncertainty and external disturbance by on-line tuning algorithm. The...

A study on passive cooling in subsea power electronics

This paper proposes a simplified approach to model the thermal behavior of the insulated gate bipolar transistors (IGBTs) in a subsea power electronic converter. The models are based on empirical relations for natural convection in water, and IGBT datasheet values. The proposed model can be used in the design of subsea converters and in the...

Comparing different materials for rotor-can in flooded generators

Flooded Generators have been proposed as a possible solution to eliminate the risks due to the seal failure, and improve cooling in tidal stream turbine generators. In a flooded generator, the stator-rotor gap is filled with the seawater; this poses a serious corrosion risk to the material inside the generator. For this reason, a can or a...

Fast rotor loss calculations in fractional-slot permanent magnet machines

Permanent magnet machines with fractional slot windings are popular because of their shorter end windings, low cost and ease of manufacturing. On the other hand, fractional slot machines have higher eddy current losses in the rotor magnets and sleeve. An accurate calculation of these losses usually involves a time-stepped finite-element analysis...