Performance Analysis of a Multiport Converter Based D-STATCOM for Dynamic Reactive Power Compensation in Distribution Systems

In general, the rapid and efficient reactive power compensation is receiving increasing attention as power distribution systems develop to address voltage instability, power quality degradation, and dynamic load variations. This paper proposes the design and performance analysis of a D-STATCOM connected with multiport converter topology (MCT) for distributing voltage regulation and reactive power support at a medium-voltage level. The main purpose is to reduce voltage sags, increase power factor and keep the DC link stable with load changing by the conventional reactive power compensation with low dynamic response and weak adaptability. The reference current generation and modulated switching are implemented in the control scheme to inject or absorb reactive power dynamically by using real-time bus voltage deviations. Extensive simulation results are conducted through MATLAB/Simulink for analysing the performance of the proposed control scheme at steady state and under different load-change operation conditions on a 25 kV, 100 MVA distribution network with variable resistive-inductive-purely resistive loads. The simulation results show that the voltage is well regulated at the key points, and the voltage profiles are also close to 1 pu in value with a stable DC-link cam response of voltage and accuracy in tracking for reference current under transient and steady-state conditions. Based on the above results, it is evident that the control strategy successfully compensates reactive power, which has an immediate response without overshoot, verifying the effectiveness of the proposed control system. Results confirm the viability of topology in distribution-level power quality enhancement and its applicability in smart grids, renewable integration and industrial power systems.