Inherently Decoupled Dc-Link Capacitor Voltage Control of Multilevel Neutral-Point-Clamped Converters
<p>Functional schematic of an <span class="html-italic">n</span>-level NPC converter leg.</p> "> Figure 2
<p>Examples of four-level NPC leg topologies. (<b>a</b>) Transistor clamped. (<b>b</b>) Reduced transistor clamped or π-type. (<b>c</b>) Diode clamped. (<b>d</b>) Reduced diode clamped.</p> "> Figure 3
<p>Proposed optimum control configuration for <span class="html-italic">n</span> levels.</p> "> Figure 4
<p>Control configuration in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] (four-level case).</p> "> Figure 5
<p>System diagram of a four-level, three-phase NPC grid inverter.</p> "> Figure 6
<p>Complete control block diagram of a four-level, three-phase grid inverter. (<b>a</b>) Decoupled structure following [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>]. (<b>b</b>) Proposed simplified decoupled structure.</p> "> Figure 6 Cont.
<p>Complete control block diagram of a four-level, three-phase grid inverter. (<b>a</b>) Decoupled structure following [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>]. (<b>b</b>) Proposed simplified decoupled structure.</p> "> Figure 7
<p>System diagram of the three-phase, four-level NPC dc–ac converter employed in the simulations and in the experimental verification.</p> "> Figure 8
<p>Simulation results under unbalanced initial capacitor voltages of a four-level, three-phase system. Conditions: <span class="html-italic">V</span><sub>dc</sub> = 150 V, <span class="html-italic">m</span> = 0.5, <span class="html-italic">C</span> = 155 µF, R = 10 Ω, L = 10 mH, switching frequency <span class="html-italic">f</span><sub>s</sub> = 5 kHz, and <span class="html-italic">G</span><sub>c</sub>(<span class="html-italic">s</span>) = 0.02/[1 + <span class="html-italic">s</span>/(1000π)]. (<b>a</b>) Control disabled. (<b>b</b>) Control in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] without decoupling. (<b>c</b>) Proposed inherently decoupled control from <a href="#electronics-13-02671-f003" class="html-fig">Figure 3</a>, which is exactly equivalent to the control in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] with decoupling.</p> "> Figure 9
<p>Simulation results under ramp variations of the <span class="html-italic">v</span><sup>*</sup><sub>C2</sub> and <span class="html-italic">v</span><sup>*</sup><sub>C3</sub> commands of a four-level, three-phase system. Conditions: <span class="html-italic">V</span><sub>dc</sub> = 150 V, <span class="html-italic">m</span> = 0.5, <span class="html-italic">C</span> = 155 µF, R = 10 Ω, L = 10 mH, switching frequency <span class="html-italic">f</span><sub>s</sub> = 5 kHz, and <span class="html-italic">G</span><sub>c</sub>(<span class="html-italic">s</span>) = 0.02/[1 + <span class="html-italic">s</span>/(1000π)]. (<b>a</b>) Capacitor voltage command values. (<b>b</b>) Control in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] without decoupling. (<b>c</b>) Proposed inherently decoupled control from <a href="#electronics-13-02671-f003" class="html-fig">Figure 3</a>, which is exactly equivalent to the control in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] with decoupling.</p> "> Figure 10
<p>Simulation results under ramp variations of the <span class="html-italic">v</span><sup>*</sup><sub>C1</sub> and <span class="html-italic">v</span><sup>*</sup><sub>C4</sub> commands of a five-level, five-phase system. Conditions: <span class="html-italic">V</span><sub>dc</sub> = 200 V, <span class="html-italic">m</span> = 0.5, <span class="html-italic">C</span> = 200 µF, R = 10 Ω, L = 10 mH, <span class="html-italic">f</span><sub>s</sub> = 5 kHz, <span class="html-italic">G</span><sub>c</sub>(<span class="html-italic">s</span>) = 0.02/[1 + <span class="html-italic">s</span>/(1000π)]. (<b>a</b>) Capacitor voltage command values. (<b>b</b>) Control in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] without decoupling. (<b>c</b>) Proposed inherently decoupled control from <a href="#electronics-13-02671-f003" class="html-fig">Figure 3</a>, which is exactly equivalent to the control in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] with decoupling.</p> "> Figure 11
<p>Simulation results under ramp variations of the <span class="html-italic">v</span><sup>*</sup><sub>C1</sub>, <span class="html-italic">v</span><sup>*</sup><sub>C2</sub>, <span class="html-italic">v</span><sup>*</sup><sub>C5</sub>, and <span class="html-italic">v</span><sup>*</sup><sub>C6</sub> commands of a seven-level, five-phase system. Conditions: <span class="html-italic">V</span><sub>dc</sub> = 300 V, <span class="html-italic">m</span> = 0.5, <span class="html-italic">C</span> = 270 µF, R = 10 Ω, L = 10 mH, <span class="html-italic">f</span><sub>s</sub> = 5 kHz, <span class="html-italic">G</span><sub>c</sub>(<span class="html-italic">s</span>) = 0.02/[1 + <span class="html-italic">s</span>/(1000π)]. (<b>a</b>) Capacitor voltage command values. (<b>b</b>) Control in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] without decoupling. (<b>c</b>) Proposed inherently decoupled control from <a href="#electronics-13-02671-f003" class="html-fig">Figure 3</a>, which is exactly equivalent to the control in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] with decoupling.</p> "> Figure 12
<p>Simulation results under ramp variations of the <span class="html-italic">v</span><sup>*</sup><sub>C2</sub> and <span class="html-italic">v</span><sup>*</sup><sub>C3</sub> commands of a four-level, three-phase system with unbalanced dc-link capacitor values. Conditions: <span class="html-italic">V</span><sub>dc</sub> = 150 V, <span class="html-italic">m</span> = 0.5, <span class="html-italic">C</span><sub>1</sub> = 155 µF, <span class="html-italic">C</span><sub>2</sub> = 186 µF, <span class="html-italic">C</span><sub>3</sub> = 124 µF, R = 10 Ω, L = 10 mH, switching frequency <span class="html-italic">f</span><sub>s</sub> = 5 kHz, and <span class="html-italic">G</span><sub>c</sub>(<span class="html-italic">s</span>) = 0.02/[1 + <span class="html-italic">s</span>/(1000π)]. (<b>a</b>) Capacitor voltage command values. (<b>b</b>) Control in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] without decoupling. (<b>c</b>) Proposed inherently decoupled control from <a href="#electronics-13-02671-f003" class="html-fig">Figure 3</a>, which is exactly equivalent to the control in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] with decoupling.</p> "> Figure 13
<p>Simulation results under unbalanced capacitor leakage currents of a four-level, three-phase system with a proportional compensator. Conditions: <span class="html-italic">V</span><sub>dc</sub> = 150 V, <span class="html-italic">m</span> = 0.5, <span class="html-italic">C</span> = 465 µF, R<sub>C1__leakage</sub> = 100 kΩ, R<sub>C2__leakage</sub> = 100 kΩ, R<sub>C3__leakage</sub> = 2 kΩ, R = 10 Ω, L = 10 mH, switching frequency <span class="html-italic">f</span><sub>s</sub> = 5 kHz, and <span class="html-italic">G</span><sub>c</sub>(<span class="html-italic">s</span>) = 0.02/[1 + <span class="html-italic">s</span>/(1000π)]. (<b>a</b>) Control disabled. (<b>b</b>) Control in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] without decoupling. (<b>c</b>) Proposed inherently decoupled control from <a href="#electronics-13-02671-f003" class="html-fig">Figure 3</a>, which is exactly equivalent to the control in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] with decoupling.</p> "> Figure 14
<p>Simulation results under unbalanced capacitor leakage currents of a four-level, three-phase system with a proportional–integral compensator. Conditions: <span class="html-italic">V</span><sub>dc</sub> = 150 V, <span class="html-italic">m</span> = 0.5, <span class="html-italic">C</span> = 465 µF, R<sub>C1__leakage</sub> = 100 kΩ, R<sub>C2__leakage</sub> = 100 kΩ, R<sub>C3__leakage</sub> = 2 kΩ, R = 10 Ω, L = 10 mH, switching frequency <span class="html-italic">f</span><sub>s</sub> = 5 kHz, and <span class="html-italic">G</span><sub>c</sub>(<span class="html-italic">s</span>) = [0.02 + 1/s]/[1 + <span class="html-italic">s</span>/(1000π)]. (<b>a</b>) Control disabled. (<b>b</b>) Control in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] without decoupling. (<b>c</b>) Proposed inherently decoupled control from <a href="#electronics-13-02671-f003" class="html-fig">Figure 3</a>, which is exactly equivalent to the control in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] with decoupling.</p> "> Figure 15
<p>Laboratory prototype of a three-phase, four-level NPC-based dc–ac converter.</p> "> Figure 16
<p>Experimental results under a ramp variation of the <span class="html-italic">v</span><sup>*</sup><sub>C2</sub> and <span class="html-italic">v</span><sup>*</sup><sub>C3</sub> commands of a four-level, three-phase system. Same conditions as in <a href="#electronics-13-02671-f009" class="html-fig">Figure 9</a>. (<b>a</b>) Control in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] without decoupling. (<b>b</b>) Proposed inherently decoupled control from <a href="#electronics-13-02671-f003" class="html-fig">Figure 3</a>, equivalent to the control in [<a href="#B5-electronics-13-02671" class="html-bibr">5</a>] with decoupling.</p> ">
Abstract
:1. Introduction
2. Inherently Decoupled Capacitor Voltage Balancing Control
3. Simulation and Experimental Results
4. Conclusions
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
References
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Garcia-Rojas, G.; Busquets-Monge, S.; Griñó, R.; Campos-Salazar, J.M. Inherently Decoupled Dc-Link Capacitor Voltage Control of Multilevel Neutral-Point-Clamped Converters. Electronics 2024, 13, 2671. https://doi.org/10.3390/electronics13132671
Garcia-Rojas G, Busquets-Monge S, Griñó R, Campos-Salazar JM. Inherently Decoupled Dc-Link Capacitor Voltage Control of Multilevel Neutral-Point-Clamped Converters. Electronics. 2024; 13(13):2671. https://doi.org/10.3390/electronics13132671
Chicago/Turabian StyleGarcia-Rojas, Gabriel, Sergio Busquets-Monge, Robert Griñó, and José M. Campos-Salazar. 2024. "Inherently Decoupled Dc-Link Capacitor Voltage Control of Multilevel Neutral-Point-Clamped Converters" Electronics 13, no. 13: 2671. https://doi.org/10.3390/electronics13132671