Direct repetitive control of SPWM inverter for UPS purpose
13 May 2003-IEEE Transactions on Power Electronics (Institute of Electrical and Electronics Engineers (IEEE))-Vol. 18, Iss: 3, pp 784-792
TL;DR: In this paper, a novel repetitive controller directly combined with an open loop SPWM inverter is presented, which achieves low THD% (1.4-1.7%) with nonlinear loads and fast error convergence (3-5 fundamental periods).
Abstract: A novel repetitive controller directly combined with an open loop SPWM inverter is presented in this paper. To cope with the high-resonant peak of the open loop inverter that may cause instability, a zero-phase-shift notch filter other than the inverse transfer function of the inverter or a conventional second-order filter is incorporated in the controller. The proposed method has good harmonic rejection and large tolerance to parameter variations. To further reduce the steady-state error, a low-pass-filter Q(z) algorithm is applied. The DC bias problem is also taken into consideration and solved with the repetitive controller itself. The method is implemented with a digital signal processor and achieves low THD% (1.4%-1.7%) with nonlinear loads and fast error convergence (3-5 fundamental periods). It proves to be a cost-effective solution for common UPS products where high-quality output voltage is more stressed than fast dynamic response.
Citations
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Book•
01 Jan 2006TL;DR: This book presents the reader, whether an electrical engineering student in power electronics or a design engineer, a selection of power converter control problems and their basic digital solutions, based on the most widespread digital control techniques, to give a basic, introductory knowledge of thedigital control techniques applied to power converters.
Abstract: This book presents the reader, whether an electrical engineering student in power electronics or a design engineer, a selection of power converter control problems and their basic digital solutions, based on the most widespread digital control techniques. The presentation is primarily focused on different applications of the same power converter topology, the half-bridge voltage source inverter, considered both in its single- and three-phase implementation. This is chosen as the test case because, besides being simple and well known, it allows the discussion of a significant spectrum of the most frequently encountered digital control applications in power electronics, from digital pulse width modulation (DPWM) and space vector modulation (SVM), to inverter output current and voltage control, ending with the relatively more complex VSI applications related to the so called smart-grid scenario. This book aims to serve two purposes: (1) to give a basic, introductory knowledge of the digital control techniques applied to power converters; and (2) to raise the interest for discrete time control theory, stimulating new developments in its application to switching power converters.
537 citations
Cites background from "Direct repetitive control of SPWM i..."
...However, the interested reader can find much useful information in technical papers such as [12] or [13]....
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TL;DR: In this article, the q-axis current reference has been modified to achieve constant torque in order to improve current tracking in the presence of periodic reference signals and disturbances, where the application of repetitive techniques to the current control in a field-oriented PMSM drive is proposed.
Abstract: The paper deals with the torque-ripple reduction in a permanent magnet synchronous motor (PMSM) drive with distorted back electromotive force. A smooth torque is obtained by tracking a modified current reference which is periodic over one-sixth of the electrical time period in the synchronous reference frame. An accurate tracking involves, however, very high current loop bandwidth, which is usually not achievable with conventional linear controllers. In order to improve current tracking in the presence of periodic reference signals and disturbances, the paper proposes the application of repetitive techniques to the current control in a field-oriented PMSM drive, where the q-axis current reference has been modified to achieve constant torque. The paper investigates the advantages and pitfalls of the method, through a mathematical analysis and an experimental validation obtained on a laboratory prototype. Particular emphasis is placed on the adjustments that have been specifically studied to enhance the overall system performance.
270 citations
Cites background from "Direct repetitive control of SPWM i..."
...Moreover, stability of the repetitive controller can be improved by adding a delay of – samples at the output of the regulator, which is equivalent to a leading time of samples for the periodic frequencies [16]....
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...A sufficient condition for the system stability is [16]...
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TL;DR: This paper deals with the design of an SRF multiloop control strategy for single-phase inverter-based islanded distributed generation systems and presents a step-by-step systematic design procedure based on a frequency response approach.
Abstract: Control of three-phase power converters in the synchronous reference frame (SRF) is now a mature and well-developed research topic. However, for single-phase converters, it is not as well established as three-phase applications. This paper deals with the design of an SRF multiloop control strategy for single-phase inverter-based islanded distributed generation systems. The proposed controller uses an SRF proportional-integral controller to regulate the instantaneous output voltage, a capacitor current shaping loop in the stationary reference frame to provide active damping and improve both transient and steady-state performances, a voltage decoupling feedforward to improve the system robustness, and a multiresonant harmonic compensator to prevent low-order load current harmonics to distort the inverter output voltage. Since the voltage loop works in the SRF, it is not straightforward to fine tune the control parameters and evaluate the stability of the whole closed-loop system. To overcome this problem, the stationary reference frame equivalent of the voltage loop is derived. Then, a step-by-step systematic design procedure based on a frequency response approach is presented. Finally, the theoretical achievements are supported by experimental results.
234 citations
TL;DR: In this article, a grid-connected boost-half-bridge photovoltaic (PV) microinverter system and its control implementations are presented, where a plug-in repetitive current controller based on a fourth-order linear-phase IIR filter is proposed to regulate the grid current.
Abstract: This paper presents a novel grid-connected boost-half-bridge photovoltaic (PV) microinverter system and its control implementations. In order to achieve low cost, easy control, high efficiency, and high reliability, a boost-half-bridge dc-dc converter using minimal devices is introduced to interface the low-voltage PV module. A full-bridge pulsewidth-modulated inverter is cascaded and injects synchronized sinusoidal current to the grid. Moreover, a plug-in repetitive current controller based on a fourth-order linear-phase IIR filter is proposed to regulate the grid current. High power factor and very low total harmonic distortions are guaranteed under both heavy load and light load conditions. Dynamic stiffness is achieved when load or solar irradiance is changing rapidly. In addition, the dynamic behavior of the boost-half-bridge dc-dc converter is analyzed; a customized maximum power point tracking (MPPT) method, which generates a ramp-changed PV voltage reference is developed accordingly. Variable step size is adopted such that fast tracking speed and high MPPT efficiency are both obtained. A 210 W prototype was fabricated and tested. Simulation and experimental results are provided to verify the validity and performance of the circuit operations, current control, and MPPT algorithm.
225 citations
Cites background from "Direct repetitive control of SPWM i..."
...effective solution for elimination of periodic harmonic errors and has been previously investigated and validated in the uninterruptible power system (UPS) systems [16]–[24], active...
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TL;DR: In this article, a plug-in repetitive control scheme was proposed to solve the problem of even-order harmonics in the circulating currents in a modular multilevel converter (MMC), which combines the high dynamics of PI controller and good steady-state harmonic suppression of the repetitive controller.
Abstract: In a modular multilevel converter (MMC), the interaction between switching actions and fluctuating capacitor voltages of the submodules results in second- and other even-order harmonics in the circulating currents. These harmonic currents will introduce extra power loss, increase current stress of power devices, and even cause instability during transients. Traditional methods for circulating current harmonic suppression have problems such as limited harmonic rejection capability, limited application area, and complex implementation. This paper presents a plug-in repetitive control scheme to solve the problem. It combines the high dynamics of PI controller and good steady-state harmonic suppression of the repetitive controller, and minimizes the interference between the two controllers. It is suitable for multiple harmonic suppression, easy to implement, and applicable for both single-phase and three-phase MMCs. Simulation and experimental results on a single-phase MMC inverter proved the validity of the proposed control method.
201 citations
Cites background from "Direct repetitive control of SPWM i..."
...Smaller magnitude of H(e) indicates larger stability margin, faster error convergence, and better steady-state harmonic suppression [23]....
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...is most desirable for the repetitive controller design [23]....
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...As indicated in [23], slope sections in the gain curve pose potential threats for stability of the repetitive control system....
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References
More filters
Book•
01 Jan 1986
TL;DR: This introductory book provides an in-depth, comprehensive treatment of a collection of classical and state-space approaches to control system design and ties the methods together so that a designer is able to pick the method that best fits the problem at hand.
Abstract: From the Publisher:
This introductory book provides an in-depth, comprehensive treatment of a collection of classical and state-space approaches to control system designand ties the methods together so that a designer is able to pick the method that best fits the problem at hand. It includes case studies and comprehensive examples with close integration of MATLAB throughout the book. Chapter topics include an overview and brief history of feedback control, dynamic models, dynamic response, basic properties of feedback, the root-locus design method, the frequency-response design method, state-space design, digital control, and control-system design. A basic reference for control systems engineers.
4,267 citations
Book•
01 Jan 1991
TL;DR: In this paper, the authors provide an in-depth, comprehensive treatment of a collection of classical and state-space approaches to control system design, and tie the methods together so that a designer is able to pick the method that best fits the problem at hand.
Abstract: From the Publisher:
This introductory book provides an in-depth, comprehensive treatment of a collection of classical and state-space approaches to control system designand ties the methods together so that a designer is able to pick the method that best fits the problem at hand. It includes case studies and comprehensive examples with close integration of MATLAB throughout the book. Chapter topics include an overview and brief history of feedback control, dynamic models, dynamic response, basic properties of feedback, the root-locus design method, the frequency-response design method, state-space design, digital control, and control-system design. A basic reference for control systems engineers.
990 citations
TL;DR: In this article, a two-layer controller consisting of a tracking controller and a repetitive controller is proposed to improve both the transient and steady-state responses of a closed-loop regulated pulsewidth-modulated (PWM) inverter for high-quality sinusoidal AC voltage regulation.
Abstract: This paper proposes a new control scheme based on a two-layer control structure to improve both the transient and steady-state responses of a closed-loop regulated pulse-width-modulated (PWM) inverter for high-quality sinusoidal AC voltage regulation. The proposed two-layer controller consists of a tracking controller and a repetitive controller. Pole assignment with state feedback has been employed in designing the tracking controller for transient response improvement, and a repetitive control scheme was developed in synthesizing the repetitive controller for steady-state response improvement. A design procedure is given for synthesizing the repetitive controller for PWM inverters to minimize periodic errors induced by rectifier-type nonlinear loads. The proposed control scheme has been realized using a single-chip digital signal processor (DSP) TMS320C14 from Texas Instruments. A 2-kVA PWM inverter has been constructed to verify the proposed control scheme. Total harmonic distortion (THD) below 1.4% for a 60-Hz output voltage under a bridge-rectifier RC load with a current crest factor of 3 has been obtained. Simulation and experimental results show that the DSP-based fully digital-controlled PWM inverter can achieve both good dynamic response and low harmonics distortion.
279 citations
"Direct repetitive control of SPWM i..." refers background in this paper
...In [7] and [ 8 ], repetitive control are combined with deadbeat control and least-square-error state-feedback control, respectively, with these instantaneous feedback control schemes serving as the inner loops....
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...The simplest choice of is a close-to-unity constant, typically 0.95 [ 8 ]....
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TL;DR: In this paper, a repetitive voltage compensation technique that generates a high quality sinusoidal output voltage from a single-phase pulse width modulation (PWM) inverter used for uninterruptible power supplies is described.
Abstract: A repetitive voltage compensation technique that generates a high-quality sinusoidal output voltage from a single-phase pulse width modulation (PWM) inverter used for uninterruptible power supplies is described. A repetitive control technique eliminates the steady-state error in the distorted output voltage caused by cyclic loads. The proposed PWM inverter system uses microprocessor-based closed-loop digital feedback with a sinusoidal reference. The PWM pattern is determined at every sampling instant by the proposed algorithm, implemented by a microprocessor using a set of detected output voltages and the reference signals through one cycle. The system has low distortion and very fast response for AC phase-controlled loads. >
231 citations
AXA1
TL;DR: In this article, a real-time space-vector-based control strategy for three-phase uninterruptible power supply systems powering nonlinear and unbalanced loads is presented.
Abstract: In this paper, a new real-time space-vector-based control strategy is presented for three-phase uninterruptible power supply systems powering nonlinear and unbalanced loads The proposed control strategy generates the inverter reference and gating signals in closed loop and guarantees high-quality output voltages at the load terminals The approach, which is implemented on a digital signal processor, adapts to a wide variation of nonlinear and unbalanced load conditions without specific knowledge of the output filter (L-C) component values Analysis and experimental results on a 10-kVA prototype are presented The results show that the output voltage is restored at heavy nonlinear and unbalanced load
144 citations
"Direct repetitive control of SPWM i..." refers methods in this paper
...A nearly parameter-independent method is proposed in [ 10 ], in which a zero-phase-shift low-pass FIR filter is placed in the feedback path to block off any frequency components above and around the resonance frequency of the output filter, thus safeguarding system stability....
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