Precision switching for carrier based PWM

A voltage source converter station including a multilevel voltage source converter, for conversion of electrical power between AC and DC, and a control system, the voltage source converter comprises a plurality of switching cells including switchable semiconductors, and the control system comprises at least one main control unit for providing a voltage reference signal to a plurality of included cell control units, each cell control unit using carrier based pulse width modulation for controlling the switching of a respective cell, wherein the main control unit is communicatively connected to the cell control units and provides the reference voltage signal to each cell control unit and each cell control unit creates a switching signal to each respective switching cell using the reference voltage signal and a carrier signal to effectuate the conversion characterized in that

• each of the cell control units process signals at a higher frequency than the main control unit, wherein each cell control unit includes a reference signal reconstruction unit, for adapting the voltage reference signal to the higher frequency of the cell control unit, which signal reconstruction unit is adapted to provide a reconstructed reference voltage signal by interpolating sampling values of the reference voltage signal.