Electronic Theses and Dissertation

Peningkatan integrasi distributed generation (DG) berbasis energi terbarukan menimbulkan tantangan baru dalam upaya mempertahankan kestabilan di sistem distribusi, terutama saat terjadi gangguan tegangan. Penelitian ini mendesain dan menguji sistem kendali daya reaktif untuk voltage source converter (VSC) pada DG agar dapat aktif mendukung kestabilan tegangan sesuai aturan jaringan (grid code) dengan menginjeksikan arus reaktif proporsional terhadap tingkat penurunan tegangan. Meode yang digunakan meliputi pemodelan DG, perancangan kendali arus reaktif pada kerangka referensi dq yang diperoleh melalui transformasi Park, dan simulasi model terhadap gangguan tiga fasa simetris dengan tiga level penurunan tegangan menggunakan MATLAB/Simulink. Hasil simulasi menunjukkan bahwa kendali mampu menjaga tegangan pada titik koneksi DG di kisaran 0.9 pu pada penurunan tegangan 0.8 pu dan sekitar 0.7 pu pada penurunan tegangan 0.5 pu, keduanya di atas batas kritis dan pulih cepat pasca gangguan. Namun, pada penurunan ekstrem 0.2 pu, kendali masih belum mampu menghilangkan fluktuasi besar pada tegangan dan arus, meskipun kinerjanya lebih baik dibandingkan tanpa kendali.

Kata kunci: daya reaktif, voltage source converter, inverter, aturan jaringan, kestabilan tegangan

The increasing integration of renewable energy–based distributed generation (DG) introduces new challenges in maintaining stability within distribution systems, especially during voltage disturbances. This study designs and evaluates a reactive power control system for the voltage source converter (VSC) in DG to actively support voltage stability in compliance with grid codes requirements, by injecting reactive current proportional to the voltage drop level. The methodologys includes modeling the DG, designing reactive current control in the dq reference frame obtained through Park’s transformation, and simulating the model under symmetrical three-phase faults with three levels of voltage sag using MATLAB/Simulink. Simulation results indicate that the proposed controller is capable of maintaining the voltage at the DG connection point around 0.9 pu under a 0.8 pu voltage sag and approximately 0.7 pu under a 0.5 pu voltage sag, both above the critical treshold and with rapid post-fault recovery. However, under an extreme 0.2 pu voltage sag, the controller is unable to eliminate fluctuation in voltage and current, although its performance remains superior compare to without reactive power support controller. Keywords: reactive power, voltage source converter, inverter, grid code, voltage stability