Circulating Current Suppression Control in Surrogate Network of MMC- HVDC System
Naini Raju Manchala1, Sree Devi J2, Raja Shekar P Mandi3, Meera K.S4

1Naini Raju M, Ph.D Degree, Department of Electrical Engineering, VTU Belgaum (Karnataka), India.
2Smt. J Sree Devi, Joint Director, Power Systems Division (PSD), CPRI, Bengaluru (Karnataka), India.
3Dr. Raja Shekar P. Mandi, Director, Department of Electrical and Electronics Engineering, REVA University, (Karnataka), India.
4Meera K S, Addional Director, Power System Division (PSD), CPRI, Bangalore (Karnataka), India.
Manuscript received on 23 February 2020 | Revised Manuscript received on 06 March 2020 | Manuscript Published on 18 March 2020 | PP: 29-34 | Volume-8 Issue-6S March 2020 | Retrieval Number: F10060386S20/2020©BEIESP | DOI: 10.35940/ijrte.F1006.0386S20
Open Access | Editorial and Publishing Policies | Cite | Mendeley | Indexing and Abstracting
© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (

Abstract: Modular multilevel converter consists of hundreds of submodules (SMs) like half bridge and full bridge converters etc. These hundreds of SMs and electrical nodes poses challenges while computing electromagnetic transients (EMTs). This problem becomes more complex while computed in real-time. To overcome this, an equivalent topology to model MMC arm/valve called surrogate network is utilized. But, the major ambiguity integrated with surrogate network model is SM capacitor voltage balancing. This leads to variation in voltage among the three phases which are parallel and produces circulating current between the three phases. A control circuitry is proposed in this paper to suppress/minimize circulating currents between the phases. Apart from circulating current suppression, the ‘ac’ output voltage is also enhanced at the converter with this proposed controller. Simulation is carried out in RSCAD software using RTDS simulator.
Keywords: Modular Multilevel Converter (MMC). Surrogate Network. Circulating Currents in MMC.
Scope of the Article: RFID Network and Applications