A Two-Level, 48-Pulse Voltage Source Converter for HVDC Systems


This paper deals with an analysis, modeling and control of a two level 48-pulse voltage source converter for High Voltage DC (HVDC) system. A set of two-level 6-pulse voltage source converters (VSCs) is used to form a 48-pulse converter operated at fundamental frequency switching (FFS). The performance of the VSC system is improved in terms of reduced harmonics level at FFS and THD (Total Harmonic Distribution) of voltage and current is achieved within the IEEE 519 standard. The performance of the VSC is studied in terms of required reactive power compensation, improved power factor and reduced harmonics distortion. Simulation results are presented for the designed two level multipulse converter to demonstrate its capability. The control algorithm is disused in detail for operating the converter at fundamental frequency switching.


Two-Level Voltage Source Converter

HVDC Systems


Fundamental Frequency Switching





Fig. 1 A 48-Pulse voltage source converter based HVDC system configuration



Fig. 2 Steady state performance of proposed 48-pulse voltage source converter

3 4

Fig. 3 Dynamic performance of proposed 48-pulse voltage source converter

 5 6

 Fig. 4 Waveforms and harmonic spectra of 48-pulse converter (a) supply voltage (b) supply current (c) converter voltage


A 48-pulse two-level voltage source converter has been designed, modeled and controlled for back-to-back HVDC system. The transformer connections with appropriate phase shift have been used to realize a 48-pulse converter along with a control scheme using a set of two level six pulse converters. The operation of the designed converter configuration has been simulated and tested in steady sate and transient conditions which have demonstrated the quite satisfactory converter operation. The characteristic harmonics of the system has also improved by the proposed converter configuration.


[1] J. Arrillaga, Y. H. Liu and N. R. Waston, “Flexible Power Transmission, The HVDC Options,” John Wiley & Sons, Ltd, Chichester, UK, 2007.

[2] Gunnar Asplund Kjell Eriksson and kjell Svensson, “DC Transmission based on Voltage Source Converter,” in Proc. of CIGRE SC14 Colloquium in South Africa 1997, pp.1-8.

[3] Y. H. Liu R. H. Zhang, J. Arrillaga and N. R. Watson, “An Overview of Self-Commutating Converters and their Application in Transmission and Distribution,” in Conf. IEEE/PES Trans. and Distr.Conf. & Exhibition, Asia and Pacific Dalian, China 2005.

[4] B. R. Anderson, L. Xu, P. Horton and P. Cartwright, “Topology for VSC Transmission,” IEE Power Engineering Journal, vol.16, no.3, pp142- 150, June 2002.

[5] G. D. Breuer and R. L. Hauth, “HVDC’s Increasing Poppularity”, IEEE Potentials, pp.18-21, May 1988.

A Two-Level 24-Pulse Voltage Source Converter with Fundamental Frequency Switching for HVDC System


This paper manages the execution investigation of a two-level, 24-beat Voltage Source Converters (VSCs) for High Voltage DC (HVDC) framework for power quality enhancement. A two dimension VSC is utilized to understand a 24-beat converter with least exchanging misfortune by working it at fundamental recurrence exchanging (FFS). The execution of this converter is contemplated on different issues, for example, consistent state activity, dynamic conduct, responsive power pay, control factor amendment, and sounds mutilation. Reproduction results are exhibited for a two dimension 24-beat converter to show its ability.



 Fig. 1 A 24-Pulse voltage source converter based HVDC system Configuration



Fig. 2 Synthesis of Stepped AC voltage waveform of 24-pulse VSC.



Fig. 3 Steady state performance of proposed 24-pulse voltage source Converter


Fig. 4 Dynamic performance of proposed 24-pulse voltage source converter



Fig. 5 Waveforms and harmonic spectra of 24-pulse covnerter i) supply voltage ii) supply current (iii) converter voltage


A two dimension, 24-beat voltage source converter has been structured and its execution has been approved for HVDC framework to enhance the power quality with major recurrence exchanging. Four indistinguishable transformers have been utilized for stage move and to understand a 24-beat converter alongside control conspire utilizing a two dimension voltage source converter topology. The enduring state and dynamic execution of the planned converter setup has been exhibited the very attractive task and found appropriate for HVDC framework. The trademark sounds of the converter framework has likewise enhanced by the proposed converter design with least exchanging misfortunes without utilizing additional sifting necessities contrasted with the ordinary 12-beat thyristor converter.