Experimentation of voltage regulation infrastructure on LV network using an OLTC with a PLC communication system

Abstract

The energy transition comes along with an increase of voltage variations especially on the LV (Low Voltage) network due to photovoltaic (PV) generation influence. In the scope of the French smart grid demonstrator GreenLys, and in order to limit these variations, an OLTC (On Load Tap Changer) has been experimented in a secondary substation in Lyon since November 2015. It has been associated through PLC (Power Line Communication) with several voltage sensors wisely placed on the LV network to get a precise vision of the voltage on the network fed by the transformer. This paper describes the voltage regulation infrastructure implemented and its main outcomes.

Accurate Assessment of Decoupled OLTC Transformers to Optimize the Operation of Low-Voltage Networks

“…Once again, the use of both the traditional and novel MV volt/var control solutions mentioned above has been intensively proposed in the most current literature, but it is not applied in practice [20][21][22][23][24][25][26][27][28][29][30][31]. The use of OLTC transformers in secondary distribution substations is currently the closest to realizing an LV reality [19,[32][33][34][35]. This paper focuses on this last point: the use of OLTC MV/LV transformers (OLTCST) to control voltage in LV networks.…”

“…Depending on the technology, two different methods of operating an OLTCST are possible: (1) a synchronized tap change among the three phases or (2) decoupled control [32]. Most previous works have dealt with uniform and common tap positions for all three phases of the MV/LV-controlled transformer (3P-OLTCST) [19][20][21]28,30,31,[33][34][35], but increasingly, more tap position settings among transformer phases are being proposed (1P-OLTCST) [24,25,29,32,36]. Decoupled control is obviously a great deal more attractive for LV networks because of their unbalanced nature.…”