Nabiullina on Friday at an economic conference in Sochi provided an explanation for her policy. She made it clear that she has no intention of softening her policy. Rather she intends to keep interest rates 3% above inflation for the indefinite future in order to purge the Russian economy of its long running inflation problem, one which extends back to the 1960s (though it was masked during the Soviet period by the Soviet practice of fixing prices), and which caused Russia to experience double-digit inflation continuously throughout the 1990s and 2000s, with a sustained fall in inflation to single figures only taking place since roughly 2010.
Nabiullina has made it clear that this is all part of a long term policy of moving the Russian economy away from a model based on consumption towards one centred on investment and manufacturing. The Central Bank explained its thinking back in November 2015 in the Guidelines it published to explain its monetary policy.
This is a policy framework which would be immediately familiar to the Bundesbank, from whom it appears to have been copied. The idea is that the combination of low inflation, low long term rates of interest, and positive real interest rates, will encourage long term saving and investment, increasing over time productivity and growth.