Comparison of permanent magnet synchronous and induction generator for a tidal current conversion system with onshore converters

Abstract

Tidal current conversion systems are moving towards commercialisation. Tidal energy developers are looking to optimise their systems by testing all the available options and taking advantage of the experience from the wind energy industry. The key focus of this paper is to compare an induction generator with a permanent magnet synchronous generator in a tidal current conversion system with onshore converters. The architecture of a tidal system with onshore converters is an option for tidal sites with small distances to shore as previous research has shown. In order to investigate the two generator technologies full resource-to-grid models in MATLAB/Simulink are developed. The analysis of these models compares generator efficiency, energy capture, losses at each stage, the cost and the maintenance for each system. Results show that the tidal system with PMSG is more efficient and generates fewer losses to transmit power onshore. In addition, since both systems tested are using a gearbox, the size, cost and maintenance of the PMSG are comparable to the reliable and cost-effective option of SCIG.

The effect of supercapacitors in a tidal current conversion system using a torque pulsation mitigation strategy

“…The generator controller is described in [32] and is based on zero d-axis current control with space vector modulation (ZDC SVM). The ZDC SVM control method for non-salient pole PMSG is based on the linear relationship between the stator current magnitude, is, and the electromagnetic torque, Te when the d-axis stator current of the generator is kept zero and the flux, λr, is kept constant.…”

Modelling, control and frequency domain analysis of a tidal current conversion system with onshore converters

“…Comparing the types of generators in tidal current applications is performed in two separate studies under different conditions [59], [60]. In [59] authors compare all the types of generators that can be used in a tidal current system and summarise the advantages and disadvantages of each generator technology.…”

“…The discussion of the authors and the results presented in [59] are comprehensive but there is no reference in the research paper about the effect of the generator type in the power transmission system of the TCCS. In [60] researchers compare SCIG and PMSG in a TCCS with direct connection to shore using onshore power converters. Authors create a dynamic model of a TCCS in MATLAB/Simulink and set three criteria to compare the two designs.…”

“…This is also the case of the ZDC controller for the PMSG. The block diagram of the ZDC control method developed for the PMSG TCCS model is shown in Figure 3.13 and was published in [60]. The SVM method used to control the PMSG is similar to the one presented in Section 3.3.1.2 for the control of the SCIG.…”

“…The conference paper entitled "Modelling and control of tidal energy conversion systems with long distance converters" [88] discusses the resource-to-grid modelling of a single TCCS that uses SCIG with long distance controls which is presented in The conference paper entitled "Comparison of permanent magnet synchronous and induction generator for a tidal current conversion system with onshore converters" [60] compares the SCIG and the PMSG options for a resource-to-grid TCCS with long distance controls. The modelling and control of the generators are presented in Chapter 3 and the results from this study are linked to Chapter 5.…”