class: center, middle # EE-464 STATIC POWER CONVERSION-II # Multi Level Inverters ## Ozan Keysan ## [keysan.me](http://keysan.me) ### Office: C-113
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Tel: 210 7586 --- # Effect of Blanking (Dead) Time
### There has to be off time between swithcing instants to present short circuit of Vd (can be up to \\(2-3 \mu s\\)) --- # Effect of Blanking (Dead) Time
--- # Effect of Blanking (Dead) Time
## Results in non-linearity in the voltage output ### [Reading assignment for curious students](https://ieeexplore.ieee.org/abstract/document/9102428) --- # Effect of Blanking (Dead) Time -- ## \\( | \Delta V\_o | = \dfrac{2 t\_{\Delta}}{T\_s} V\_d\\) ### Always reduce the output voltage magnitude wrt. current direction
--- # Effect of Blanking (Dead) Time
--- # Multi-Level Inverters -- - ### Used commonly in high power (MW, kV) converters -- - ### Increases output voltage capacity -- - ### Minimizes THD even with low switching frequencies -- - ### Reduce EMI due to lower voltage steps --- # Two-Level Inverter Waveform
--- # Multi-Level Inverter Waveforms
### Three level, ### Five Level, ### and Seven Level voltage Output Waveforms --- # H-Bridge Inverters
--- # H-Bridge Inverters ### Three Level (unipolar) PWM Output
--- ## H-Bridges can be connected in series for higher voltages
--- ## What are the voltage levels? -- : 2Vdc, Vdc, 0, -Vdc, -2Vdc
### Specific harmonics can be elimination by proper \\(\alpha\_1, \alpha\_2\\) --- # Five-Series Cascaded H-Bridge Inverters ### How many voltage levels?
--- # 11-Level Cascaded H-Bridge Inverters
--- ## 11-Level Cascaded with Five Separate Sources
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- ### Diode-clamped (a.k.a. neutral-clamped) - ### Capacitor-clamped (a.k.a. flying-capacitors) --- # Multi-level Inverter Topologies
--- # Diode Clamped Multi-level Inverters --
### Five-level diode clamped inverter (Neutral Point Clamped (NPC)) --- ## Five-level diode clamped inverter ## Voltage Levels: Vdc
--- ## Five voltage-level diode clamped inverter ## Voltage Levels: 0
--- ## Five voltage-level diode clamped inverter ## Voltage Levels: Vdc/2
--- ## Even Higher Voltage Levels -- ### 3 voltage sources cascaded
--- ## Even Higher Voltage Levels ### 5-Photovoltaic panels connected in series
--- ## Even Higher Voltage Levels ## Switching States: Can you find the pattern? --
### A set of five switches is on at any time --- ## Even Higher Voltage Levels ## Line-to-line voltage
--- ## Alternate PWM Techniques
--- # N-Level Cascaded H-Bridge Inverters ## Five-level Output Voltage Waveform (fc=3kHz)
--- # Multi-Level SVPWM
--- # Multi-level SVPWM ## 3-Level
--- # Multi-level SVPWM ## 5-Level
--- # Multi-level SVPWM ## Voltage Vectors of a 6-Level Inverter
--- # Further Reading - ### [Multilevel Inverter – Types & Advantages](https://www.elprocus.com/multilevel-inverter-types-advantages/) - ### [Introduction to MultiLevel Inverters](https://docplayer.net/34231342-Introduction-to-multilevel-inverters-rijil-ramchand-associate-professor-nit-calicut.html) - ### [Multilevel Inverters](http://shodhganga.inflibnet.ac.in/bitstream/10603/16448/7/07_chapter%202.pdf) - ### [Multilevel Inverters: A Survey of Topologies, Controls, and Applications](https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=1021296) - ### [Multilevel Power Converters ](https://pdfs.semanticscholar.org/049a/a38514290aa78070abe1cd03a8b4a66edd73.pdf) --- ## You can download this presentation from: [keysan.me/ee464](http://keysan.me/ee464)