Harmonic Analysis and Controller Design of 15 kV SiC IGBT-Based Medium-Voltage Grid-Connected Three-Phase Three-Level NPC Converter
TL;DR: In this article, the harmonic performance and current distortion of the grid-connected, three-level neutral point clamped converter using 15 kV silicon carbide Insulated Gate Bipolar Transistor (IGBTs) are investigated.
Abstract: Cascaded converters are generally used for medium-voltage (MV) grid-connected applications due to the limitation in the voltage rating of available silicon (Si) power devices. These converters find application in active power filters, STATCOM or as the active front end converters for solid state transformers at the distribution voltage levels. The high voltage wide bandgap semiconductor devices have enabled the grid connected operation of noncascaded converters. This results in high power density, less number of switching devices, and high efficiency for three-phase MV grid interface. This also results in control simplicity without the need for complex dc bus balancing algorithms otherwise needed for cascaded converters. However, such noncascaded, grid-connected converters introduce challenges in maintaining power quality at low currents. This paper investigates the harmonic performance and current distortion of the grid-connected, three-level neutral point clamped converter using 15 kV silicon carbide Insulated Gate Bipolar Transistor (IGBTs). A suitable control scheme for stable harmonic compensation is proposed. The challenges and control performance are explained through frequency domain analysis, simulations, and experimental validation on a developed prototype of the three-phase converter up to 4.16 kV, three-phase MV grid-connected operation.
Citations
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TL;DR: Simulation results show that the proposed strategy is applicable and effective for reactive power and harmonic compensation with an optimal rating of the APF under ideal and non-ideal grid conditions.
6 citations
01 Dec 2019
TL;DR: Experimental and numeric results verify the impacting of the two methodologies design in a five-level flying capacitor inverter.
Abstract: This work evaluates two capacitors design methodologies for Flying Capacitors Inverters. The first design methodology is developed through analysis of one switching period of the flying capacitor inverter. The second one analyses a complete output period of the inverter using the double Fourier series. Bolt methodologies use of the Phase-Shift Pulse Width Modulation. Experimental and numeric results verify the impacting of the two methodologies design in a five-level flying capacitor inverter.
5 citations
Cites background from "Harmonic Analysis and Controller De..."
...The simplicity design allows its widely used by the industry, particularly in motor drives and power systems applications [6], [7]....
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TL;DR: Based on the big triangular carrier equivalence method, the harmonic characteristics of a single phase neutral-point-clamped (NPC) cascaded inverter are calculated by double Fourier transform and voltage harmonics expressions of 5-level, 9-level and 13-level output waveforms as discussed by the authors.
Abstract: An advanced traction power supply system based on a single phase neutral-point-clamped (NPC) cascaded inverter is studied. The big triangular carrier equivalence method in double coordinate system is proposed, which can reduce one coordinate system, thus simplifying the calculation. Based on the big triangular carrier equivalence method, the harmonic characteristics of a single phase NPC cascaded inverter are calculated by double Fourier transform and voltage harmonics expressions of 5-level, 9-level and 13-level output waveforms are derived. Finally, the performance and calculated results of the proposed method were verified by simulations and experiments. The result provides a theoretical basis for further studies on traction network resonance.
5 citations
TL;DR: In this article , the authors provide a comprehensive review of the cutting-edge medium voltage inverter technology from the perspectives of structural analysis, model development, major findings, research gaps, and their applications in grid integration of renewable energy sources and grid decarbonization.
3 citations
TL;DR: In this paper , the coupling effect among the controllers of hybrid repetitive controller is revealed, showing clear physical meaning, thus the mechanism resulting in the instability problem and delay effect is addressed clearly.
Abstract: Static var generator (SVG) is mostly utilized under polluted grid conditions with certain power quality problems, of which the grid disturbance will lead to the distortion of grid-side current. Hybrid repetitive controller (RC), as an effective method to suppress periodic distortion of grid-connected converters and to improve the dynamic response of conventional RC, has been adopted in existing approaches. However, the physical meaning of existing modeling based on the small gain theorem is not clear. Besides, the conventional design method is difficult to reveal the stability domain and to obtain an optimized repetitive gain, which influences the anti-disturbance performance. In this article, the coupling effect among the controllers of hybrid RC is revealed, showing clear physical meaning, thus the mechanism resulting in the instability problem and delay effect is addressed clearly. Different from existing methods, a simpler design principle is proposed, and a universal stability domain analysis for hybrid RC can be directly obtained and ensure a maximized repetitive gain. A proportional, resonant, and RC (PR-RC) is given as an example to improve the dynamic response of the SVG under $a$ – $b$ – $c$ coordinate. Experimental results demonstrate the correctness and effectiveness of the coupling analysis and parameter design.
2 citations
References
More filters
TL;DR: Current control techniques for three-phase voltage-source pulsewidth modulated converters, including bang-bang (hysteresis, delta modulation) controllers and predictive controllers with on-line optimization are reviewed.
Abstract: The aim of this paper is to present a review of current control techniques for three-phase voltage-source pulsewidth modulated converters. Various techniques, different in concept, have been described in two main groups: linear and nonlinear. The first includes proportional integral (stationary and synchronous) and state feedback controllers, and predictive techniques with constant switching frequency. The second comprises bang-bang (hysteresis, delta modulation) controllers and predictive controllers with on-line optimization. New trends in current control-neural networks and fuzzy-logic-based controllers-are discussed, as well. Selected oscillograms accompany the presentation in order to illustrate properties of the described controller groups.
2,086 citations
"Harmonic Analysis and Controller De..." refers methods in this paper
...This method is considered unsatisfactory because it cannot completely eliminate the steady-state errors [24], [25]....
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TL;DR: In this paper, the presence of steady-state limit cycles in digitally controlled PWM converters is discussed, and conditions on the control law and quantization resolution for their elimination are suggested.
Abstract: This paper discusses the presence of steady-state limit cycles in digitally controlled pulse-width modulation (PWM) converters, and suggests conditions on the control law and the quantization resolution for their elimination. It then introduces single-phase and multi-phase controlled digital dither as a means of increasing the effective resolution of digital PWM (DPWM) modules, allowing for the use of low resolution DPWM units in high regulation accuracy applications. Bounds on the number of bits of dither that can be used in a particular converter are derived. Finally, experimental results confirming the theoretical analysis are presented.
735 citations
03 Oct 1999
TL;DR: In this article, a technique for interpreting the stationary/rotating frame transformations as modulation processes in the Laplace domain is presented, which moves the control function from one part of the frequency spectrum to another.
Abstract: Stationary frame linear PI current regulators are conventionally regarded as unsatisfactory for AC systems because they cannot eliminate steady state errors. Consequently, synchronous frame regulators are perceived to be superior, since they achieve zero steady state error by acting on DC signals in a rotating frame of reference. However, a synchronous frame regulator is more complex, and requires in particular a way of transforming a measured stationary frame AC current (or error) to rotating frame DC quantities, and transforming the resultant control action back to the stationary frame for implementation. This paper presents a technique for interpreting the stationary/rotating frame transformations as modulation processes in the Laplace domain which move the control function from one part of the frequency spectrum to another. The technique is used to compare stationary and synchronous frame PI regulators on a common basis to better understand the advantages of a synchronous frame regulator, and then to develop a new form of stationary frame resonant regulator which achieves zero steady state error without requiring the complex transformations of a synchronous frame regulator. The performance of this new regulator is evaluated and found to be equivalent to that of the synchronous frame PI regulator.
672 citations
"Harmonic Analysis and Controller De..." refers background or methods in this paper
...second-order model of the PR controller is not straightforward and is prone to higher error in fixed point implementation [25]....
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...This method is considered unsatisfactory because it cannot completely eliminate the steady-state errors [24], [25]....
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TL;DR: In this article, a hybrid system consisting of a proportional integral (PI) controller plus a generic hth harmonic resonant controller implemented in a frame rotating at the n th harmonic frequency is discussed in detail.
Abstract: Voltage source inverters connected to the grid in applications such as active rectifiers, active filters, uninterruptible power supplies, and distributed generation systems need an optimal ac current control. To obtain zero steady-state error at the fundamental frequency (i.e., unity power factor), the use of a standard integrator in a rotating frame is as effective as the use of a resonant controller in a stationary frame. However, the grid voltage harmonics influence the current controller and generate current harmonics unless several integrators in multiple rotating frames or resonant compensators in a stationary frame are adopted. In this letter, a hybrid system consisting of a proportional integral (PI) controller plus a generic hth harmonic resonant controller implemented in a frame rotating at the n th harmonic frequency is discussed in detail. The hth harmonic controller is able to decrease both the (h - n)th and (h + n)th harmonics, while the PI controller is able to decrease other harmonics if the synchronization phase signal adopted for the frame transformation is unfiltered. It is demonstrated that the use of a PI and sixth harmonic resonant compensator is effective for both positive and negative sequence fifth and seventh harmonics; hence, four harmonics are compensated with the proportional integral-resonant (PI-RES) controller implemented in a synchronous frame. Simulation and experimental tests validate the proposed analysis
662 citations
"Harmonic Analysis and Controller De..." refers background in this paper
...A proportional-resonant (PR) controller or a PI-resonant controller can be used in the stationary reference frame for each lower order harmonic to be eliminated [27], [26]....
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01 Jan 2006
583 citations
"Harmonic Analysis and Controller De..." refers background in this paper
...A proportional-resonant (PR) controller or a PI-resonant controller can be used in the stationary reference frame for each lower order harmonic to be eliminated [27], [26]....
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