Real-time digital simulation and experimental verification of a D-STATCOM interfaced with a digital controller

This paper presents the implementation and experimental details of a real-time digital simulator designed for representing a Distribution Static Compensator (D-STATCOM) interfaced with a digital controller. Real-time simulation using conventional fixed time-step integration algorithms can lead to erroneous results due to the lack of synchronism between the simulator time-step and the discrete switching signals coming from the digital controller. The real-time simulation algorithm implemented in this paper overcomes the drawbacks of a fixed time-step algorithm. The real-time algorithm relies on precise registration of timing of the incoming discrete firing pulses and a subsequent correction procedure to calculate the system state. This approach has been implemented on a hybrid digital processing platform comprising of a Digital Signal Processor (DSP) and a Field Programmable Gate Array (FPGA). The platform represents both the power electronic system and the digital control system. Experimental results, for a 5 kV A D-STATCOM system, in verification of the real-time simulator results are also provided. (C) 2004 Elsevier Ltd. All rights reserved.