FEM-Based Virtual Prototyping and Design of Third Harmonic Excitation System for Low-Voltage Salient-Pole Synchronous Generators

Abstract

Virtual prototyping is a method used for the prediction of electrical machine parameters during the design stage, thus reducing the development time and cost for new machines. Based on the simulated results of the virtual prototype, the design is fine-tuned and finalized. In synchronous generators, the design of a third harmonic excitation (THE) winding is done based on the third harmonic flux generated in the air gap of the machine. Estimating the amplitude of the third harmonic flux in the air gap of a machine accurately by conventional design procedures is difficult due to the complex geometry of the machine and the nonlinear characteristics of the magnetic materials. In this paper, accurate prediction of the third harmonic flux in the air gap is done by the finite-element method, and prototyping of the machine is virtually done with the third harmonic winding inserted into the stator slots. Based on the electromotive force induced per turn, the design of the third harmonic winding is finalized, and an experimental machine with THE is developed. The effect of the THE in reducing the total harmonic distortion across the main output terminals of the generator is analyzed, and the experimental results show close agreement with the simulation results.Index Terms-Finite-element method (FEM), synchronous generators, third harmonic excitation (THE), total harmonic distortion (THD), triplen harmonics, virtual prototyping.

Improved Damper Cage Design for Salient-Pole Synchronous Generators

“…Although these 'classical' electrical machines have been extensively studied and implemented, today there is an interest in revamping their design and development, partly due to the ever-increasing requirements in terms of power quality standards, efficiency and grid compliance and partly due to advances in materials and manufacturing techniques. Also, the significant improvements in the computational resources allow the utilisation of modern design techniques and tools such as multi-physics modelling [3] and virtual prototyping [4].…”

Damper cage loss reduction and no-load voltage THD improvements in salient-pole synchronous generators

“…Important aspects of such generators include a high power-to-weight ratio, high efficiency and a low cost per kVA output [1]. Another critical aspect is the requirement for very low harmonic content in the output voltage.…”

Feasibility analysis of auxiliary winding for condition monitoring of wound field brushless synchronous generators

“…1 shows schematic of the WFSG with auxiliary winding. The auxiliary winding is commonly used in the low power WFSGs such as less than 5MVA for exciting the rotor field and for high power generators a separate permanent magnet generator is used to generate power for field excitation [3]- [4]. In this paper the auxiliary winding voltage is selected for investigating its suitability for condition monitoring, because of some of the key features of auxiliary winding voltage which assist in condition monitoring of the WFSG.…”

“…The voltage across the short circuited turns ( ) in a-b-c reference frame is given by (3) The auxiliary winding voltage in the rotor reference frame is given by (4) The voltage induced in the auxiliary winding in the a-b-c frame can then be defined as (5) Where,…”