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Journal ArticleDOI

Three-Dimensional Pulse Width Modulation Techniques for Three-Phase Four Leg Voltage Source Converters

15 Sep 2020-Vol. 5, Iss: 3, pp 153-158
TL;DR: In this paper, a new control strategy to improve the performance of shunt active power filter (SAPF) in three-phase four-wire system when operating under an unbalanced system is presented.
Abstract: This paper presents a new control strategy to improve the performance of shunt active power filter (SAPF) in three-phase four-wire system when operating under an unbalanced system. A control method based on the instantaneous power theory have been used and discussed. On the other side, a threedimensional hysteresis current controller is used to track the compensated current references. This scheme requires the service of a phased-locked loop (PLL) to make the system insensitive to the distortions that are generally present in the utility voltages. The performance of the proposed topology under the used control approach has been finally discussed through the obtained simulation results.

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Citations
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Journal ArticleDOI
01 Feb 2021
TL;DR: In this paper, a combined sliding mode space vector modulation control of the shunt active power filter using robust harmonic extraction method is presented to improve the power quality such as current harmonics and reactive power compensation due to the nonlinear loads and unbalanced voltage source.
Abstract: This paper presents a combined sliding mode space vector modulation control of the shunt active power filter using robust harmonic extraction method to improve the power quality such as current harmonics and reactive power compensation due to the non-linear loads and unbalanced voltage source. To verify the validity of the analysis and the feasibility of the proposed control method a set of simulation tests have been conducted using Matlab/Simulink. A comparison between the conventional instantaneous powers method (PQ) used for harmonic extracting and the new PQ based on a multivariable extraction filter demonstrates the superiority of the proposed control scheme.

4 citations

References
More filters
Journal ArticleDOI
TL;DR: In this article, a comparative analysis between results from applications of the p-q and the pq-r theories in shunt active power filters for three-phase four-wire systems is presented.
Abstract: This paper presents a comparative analysis between results from applications of the p-q and the p-q-r theories in shunt active power filters for three-phase four-wire systems, discussing aspects related to the influence of the system voltage in the control methods that calculate the compensating currents. It is shown that in some cases, a preprocessing of the system voltage is required if the goal is to achieve sinusoidal compensated currents. On the other hand, when the goal is to compensate zero-sequence current, the need of energy storage elements in the active filter is discussed. In this case, if zero-sequence components are present simultaneously in the system voltage and load current, they produce zero-sequence power flow, and the control methods based on both theories must contain additional calculations to allow the elimination of energy storage elements in the active filter. A control strategy based on the p-q theory is proposed to eliminate the neutral current without the need of energy storage elements, with the advantage of avoiding the extra transformation from alphabeta0 to pqr coordinates that is needed in the p-q-r theory. Simulation results are presented for the purpose of comparing the performance of both control methods.

123 citations


"Three-Dimensional Pulse Width Modul..." refers methods in this paper

  • ...There are fourteen non-zero space voltage vectors (NZSVV) and two zero space voltage vectors (ZSVV) as shown in Fig1 [11-13] The reference current obtained by (9) can be written with the space vector representation as follows: ref ref ref reff f f fi i i i j i k (09) The same representation can be given to the measured active filter current: f f f fi i i i j i k (10) The reference current is represented in space voltage vector as shown in Fig 2, the tip of the reference current reffi is located at the centre of a three dimensional cube, while the tip of the measured active filter current fi can be located in any cube of the eight small cubes as illustrated in Fig 3....

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  • ...There are fourteen non-zero space voltage vectors (NZSVV) and two zero space voltage vectors (ZSVV) as shown in Fig1 [11-13]...

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Journal ArticleDOI
TL;DR: A novel three-phase parallel grid-connected multilevel inverter topology with a novel switching strategy is proposed to feed a microgrid from renewable energy sources (RES) to overcome the problem of the polluted sinusoidal output in classical inverters and to reduce component count.
Abstract: In this paper, a novel three-phase parallel grid-connected multilevel inverter topology with a novel switching strategy is proposed. This inverter is intended to feed a microgrid from renewable energy sources (RES) to overcome the problem of the polluted sinusoidal output in classical inverters and to reduce component count, particularly for generating a multilevel waveform with a large number of levels. The proposed power converter consists of $n$ two-level $(n+1)$ phase inverters connected in parallel, where $n$ is the number of RES. The more the number of RES, the more the number of voltage levels, the more faithful is the output sinusoidal waveform. In the proposed topology, both voltage pulse width and height are modulated and precalculated by using a pulse width and height modulation so as to reduce the number of switching states (i.e., switching losses) and the total harmonic distortion. The topology is investigated through simulations and validated experimentally with a laboratory prototype. Compliance with the $\text{IEEE 519-1992}$ and $\text{IEC 61000-3-12}$ standards is presented and an exhaustive comparison of the proposed topology is made against the classical cascaded H-bridge topology.

115 citations


"Three-Dimensional Pulse Width Modul..." refers background in this paper

  • ...In Cartesian pqr coordinates, the system currents are defined in [8]....

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Journal ArticleDOI
TL;DR: Simple smooth hyperbolic voltage THD upper and lower bound approximations for single- and three-phase inverters with nearest synchronous switching are presented, valid for arbitrary modulation indices and uniformly distributed level counts and may practically serve as good reference values.
Abstract: Many recent multilevel inverter papers end up with voltage total harmonic distortion (THD) values obtained from numerical voltage spectrum calculations (measurements). Motivated by IEEE Standard 519, a part of the multilevel research community uses a limited harmonic count to evaluate the multilevel voltage quality. First, this causes significant voltage THD underestimation, particularly for relatively high frequency PWM. Second, for a three-phase star-connected balanced load with an isolated neutral and phase symmetric modulation strategy, the calculated load line and phase voltage THD become different. However, simple considerations show that line and phase voltage THDs are essentially the same in this case. It may be difficult to judge about the multilevel voltage quality given a numerically calculated (measured) voltage THD value that may be subject to computation errors. Presented are simple smooth hyperbolic voltage THD upper and lower bound approximations for single- and three-phase inverters with nearest synchronous switching. They are valid for arbitrary modulation indices and uniformly distributed level counts and may practically serve as good reference values.

82 citations


"Three-Dimensional Pulse Width Modul..." refers background in this paper

  • ...The four hysteresis comparator controls has been considered as a simplest control strategy but it suffers from a high frequency operation; generally the PWM is interested for the feeding and the control of induction electrical machine [6], particularly the three dimensional hysteresis PWM techniques presented in [7] uses eight switching vectors among the existing sixteen switching vectors....

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Journal ArticleDOI
TL;DR: This study presents a multiple harmonic elimination-based feedback controller for shunt hybrid active power filter to perform an effective harmonic compensation performance in a wide harmonic frequency band and the compensation performance is compared with conventional methods both theoretically and experimentally.
Abstract: This study presents a multiple harmonic elimination-based feedback controller for shunt hybrid active power filter (SHAPF) to perform an effective harmonic compensation performance in a wide harmonic frequency band. The conventional control methods presented for SHAPF cannot perform an adequate performance, because of the disturbances such as phase delays caused by controller methods and measurement circuitries, tolerances of passive filter components and supply voltage harmonics. In the proposed controller, the conventional feedback controller is improved by using supply side individual current harmonics which are extracted by the synchronous reference frame method. To prevent the performance degradation effects of disturbances, proportional-integral controllers are applied to each d and q components of individual current harmonics. The compensation performance of the proposed method is compared with conventional methods both theoretically and experimentally. The experimental results verify the advanced harmonic compensation performance of the proposed control method.

25 citations


"Three-Dimensional Pulse Width Modul..." refers background in this paper

  • ...Although three-phase four-wire active filters have been introduced in the 1980’s, the development is still in its infancy and no experimental prototype has been put in operation outside the universities [4] and in work of [5]....

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Journal ArticleDOI
TL;DR: In this article, a three-phase four-leg voltage source inverter (VSI) was designed and modelled separately for balanced/unbalanced linear/non-linear current control in three phase 4-leg power inverter.
Abstract: In this study, balanced/unbalanced linear/non-linear current control in three-phase four-leg voltage source inverter (VSI) is carried out by using modified p - q - r method instead of the classical p - q - r method, digital proportional integral derivative (PID) control rule and three-dimensional (3D) space vector pulse width modulation (3D SVPWM). For this purpose, three-phase four-leg power inverter and PWM signal generation circuits are designed and modelled separately. Even if the power source voltage is unsymmetrical, the proposed modified p - q - r method leads to measurement and to generating the instantaneous harmonic and reactive components of load current accurately. The performance of the classical p - q - r theory under non-ideal mains voltages is improved and the accuracy of the proposed modified p - q - r theory is demonstrated both through simulation and real-time application. Each phase of the three-phase four-leg VSI modelled directly in abc reference frame is decoupled from each other This simplifies the digital PID controller design significantly. Modelling of the whole system, modified p - q - r measurement and digital PID design steps are given in detail. Real-time experimental results for the designed three-phase four-leg VSI in stand-alone mode are compared with the simulation results.

20 citations


"Three-Dimensional Pulse Width Modul..." refers methods in this paper

  • ...To overcome this problem, the pqr theory need to preprocess the system voltages to be sinusoidal and balanced waveforms by using such as a PLL (phase locked loop) circuit [9], extracting only the forward-sequence component from the system voltages....

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  • ...To overcome this problem, this paper proposes to use a PLL in the control loop [9]....

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