MV semiconductors => high losses =>limits switching frequency & power throughput & grid harmonics MV => high energy => limits size of passives=> shorter time constant =>dynamic operation, requires fast action These MV drives are challenged by: Low switching frequency => low control bandwidth => difficult to meet control objectives High losses => Limits power throughput (Arshad) High power can be achieved by increasing the voltage. The Advantages and Disadvantages of increasing voltage are: Disadvantages Advantages . High dv/dt Smaller cross sectional area of cable More complex insulation concept - Cost effective drive set-up- Less familiarity of plant electricians Circuit breakers of lower current rating and drive service personnel with effective drive setup medium voltage levels Lower rms current, lower conduction losses Higher efficiency (Arshad) Benefits of SiC to drives include: SiC switching losses are very flat with switching frequency: Higher output power compared to Si at f_sw = const. Crossover point above critical switching frequency (LV) Si: P_losses = P_cond + P_sw (40%) (60%) SiC: P_losses=P_cond + P_sw (60%) (40%) (Arshad) For MV drives SiC Diode technology brings a definite benefit in reducing the turn-on switching losses of the semiconductor switch. ABB see the hybrid Si+SiC power modules as a promising entry point for SiC in MW applications, but limited by the Si operating temperature Full SiC modules show an additional reduction in losses compared to hybrid technology, but are limited mainly by their low current rating and over voltages due to the fast unipolar SiC switch (Arshad) Aii.b. Manufacturers Challenges A long list of items were identified that required additional R&D work to resolve.
MV semiconductors => high losses =>limits switching frequency & power throughput & grid harmonics MV => high energy => limits size of passives=> shorter time constant =>dynamic operation, requires fast action These MV drives are challenged by: Low switching frequency => low control bandwidth => difficult to meet control objectives High losses => Limits power throughput (Arshad) High power can be achieved by increasing the voltage. The Advantages and Disadvantages of increasing voltage are: Disadvantages Advantages . High dv/dt More complex insulation concept Smaller cross sectional area of cable - Cost effective drive set-up- Less familiarity of plant electricians and drive service personnel with medium voltage levels Circuit breakers of lower current rating effective drive setup Lower rms current, lower conduction losses Higher efficiency (Arshad) Benefits of SiC to drives include: SiC switching losses are very flat with switching frequency: Higher output power compared to Si at f_sw = const. Crossover point above critical switching frequency (LV) Si: P_losses = P_cond + P_sw (40%) (60%) SiC: P_losses=P_cond + P_sw (60%) (40%) (Arshad) For MV drives SiC Diode technology brings a definite benefit in reducing the turn-on switching losses of the semiconductor switch. ABB see the hybrid Si+SiC power modules as a promising entry point for SiC in MW applications, but limited by the Si operating temperature Full SiC modules show an additional reduction in losses compared to hybrid technology, but are limited mainly by their low current rating and over voltages due to the fast unipolar SiC switch (Arshad) Aii.b. Manufacturers Challenges A long list of items were identified that required additional R&D work to resolve.
Proceedings-of-HMW-VSD-Motor-Technology-Workshop-1.docx