A Novel LCC HVDC Transmission Technology Based on the Static Var Generator and Filter

The line commuted converter (LCC) has some drawbacks, such as the big harmonic current flowing through the converter transformer, and high dependence on the AC system voltage. Some scholars believe that LCC-HVDC is difficult to adapt to the scenario of weak AC systems. The high voltage direct current transmission based on the voltage source converter (VSC-HVDC) is suitable for the weak AC system. However, in the face of a large-scale and long-distance energy transmission, its problems such as high cost, low component ratings are becoming increasingly prominent. In this paper, a novel SLCC HVDC transmission technology based on the Static Var Generator and Filter (SVF) is proposed. The SVF is installed between the converter transformer and the LCC to compensate the reactive power and to attenuate harmonic current generated by the LCC. The superiority of SLCC is verified by PSCAD/EMTDC simulation in aspects as steady operation, fault ride-through, harmonic and dynamic voltage control, etc. The research shows that SLCC technology has the advantages of large capacity, low cost and high flexibility, which can effectively improve the performance of LCC-HVDC system.