A 21-level (line-to-line) BTB system based on series connection of sixteen converter-cells for power flow control: experimental verifications by a 200-V, 10-kW laboratory system

Abstract

A 21-level (line-to-line) self-commutated BTB (back-to-back) system based on series connection of sixteen converter-cells has attractive features as follows: i) Both active and reactive powers can be controlled independently even in transient states, ii) The BTB system produces almost sinusoidal voltage at the AC side without performing PWM (pulse-width-modulation) control, so that no harmonic filter is required, iii) The BTB system provides an active-power response as high as 3 ms. This work presents experimental verifications of the self-commutated BTB system for the purpose of achieving power flow control in transmission systems. Experimental results obtained by a 200-V 10-kW laboratory prototype confirm effectiveness and validity of both the proposed system configuration and control strategy developed in this paper.