TY - JOUR
T1 - Theoretical minimum DC-link capacitance in PWM converter-inverter systems
AU - Gu, B. G.
AU - Nam, K.
PY - 2005/1
Y1 - 2005/1
N2 - In the PWM converter-inverter system, if the converter current control is fast enough to match the inverter power at all instants, then no current flows through the DC-link capacitor, making the DC-link voltage constant, even with a very small DC-link capacitance. A matching control method making the capacitor current zero suggests the possibility of using a tiny DC-link capacitor. However, in practice, a certain amount of capacitance is required, since the matching control itself is not perfect and there are one-step delays in the PWM. In this work, the authors investigate a theoretical low bound of the DC-link capacitance, considering an extreme case in which the DC-link voltage rises to a maximum value in a single PWM period. Utilising the optimisation technique, the theoretical minimum capacitance is found to be the one that limits the voltage rise below a certain threshold value. Analytical calculation results are compared with MATLAB simulation results.
AB - In the PWM converter-inverter system, if the converter current control is fast enough to match the inverter power at all instants, then no current flows through the DC-link capacitor, making the DC-link voltage constant, even with a very small DC-link capacitance. A matching control method making the capacitor current zero suggests the possibility of using a tiny DC-link capacitor. However, in practice, a certain amount of capacitance is required, since the matching control itself is not perfect and there are one-step delays in the PWM. In this work, the authors investigate a theoretical low bound of the DC-link capacitance, considering an extreme case in which the DC-link voltage rises to a maximum value in a single PWM period. Utilising the optimisation technique, the theoretical minimum capacitance is found to be the one that limits the voltage rise below a certain threshold value. Analytical calculation results are compared with MATLAB simulation results.
UR - http://www.scopus.com/inward/record.url?scp=15044352923&partnerID=8YFLogxK
U2 - 10.1049/ip-epa:20040980
DO - 10.1049/ip-epa:20040980
M3 - Article
AN - SCOPUS:15044352923
SN - 1350-2352
VL - 152
SP - 81
EP - 88
JO - IEE Proceedings: Electric Power Applications
JF - IEE Proceedings: Electric Power Applications
IS - 1
ER -