Proceedings Article•
A comparative study of predictive current control for three-phase voltage source inverters based on switching frequency and current error
15 Sep 2011-pp 1-8
TL;DR: A modification of the predictive current control is presented for decoupling the switching frequency from the sampling frequency, thus the performance of the system is improved and the switching Frequency is kept controlled.
Abstract: Conventional linear current control with pulse width modulation and predictive current control for a three phase voltage source inverter are compared in this paper based on the ripple of current for a range of switching frequencies. Predictive current control allows to improve the performance by increasing the sampling frequency, but the resulting switching frequency can also make the semiconductors to operate out of their thermal limits. Behavior of the predictive control scheme for a range of switching frequencies is presented. A modification of the predictive current control is presented for decoupling the switching frequency from the sampling frequency, thus the performance of the system is improved and the switching frequency is kept controlled.
Citations
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TL;DR: The predictive current control is applied to the grid-side NPC converter as part of a wind energy conversion system, in order to fulfill the LVRT requirements, and DC-link neutral-point balance is achieved by means of the predictive control algorithm.
Abstract: The low-voltage ride through (LVRT) requirement demands the wind power plants to remain connected to the grid in the presence of grid voltage dips, actively helping the network overall control to keep network voltage and frequency stable. Wind power technology points to increase power ratings. Hence, multilevel converters, as for example, neutral-point- clamped (NPC) converters, are well suited for this application. Predictive current control presents similar dynamic response and reference tracking than other well-established control methods, but working at lower switching frequencies. In this paper, the predictive current control is applied to the grid-side NPC converter as part of a wind energy conversion system, in order to fulfill the LVRT requirements. DC-link neutral-point balance is also achieved by means of the predictive control algorithm, which considers the redundant switching states of the NPC converter. Simulation and experimental results confirm the validity of the proposed control approach.
173 citations
Cites background or methods from "A comparative study of predictive c..."
...Some other control objectives such as the reduction of the number of commutations [19], [23] or an imposed load current spectrum [24], which are interesting for high-power systems,...
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...However, the FCS-MPC can achieve better performance than the SVM by using a proper weight in the quality function for controlling the switching frequency [19] or the current spectrum [24]....
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...Higher THD is found for the FCS-MPC, as previously detailed in [19]....
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...Notice that the number of commutations can be even more reduced by including an additional term in the quality function [19], [23], also providing some degree of decoupling between the sampling and the switching frequencies....
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TL;DR: In this paper, a model-predictive control of medium voltage, grid-tied four-level diode-clamped inverter for use in high-power wind energy conversion systems is presented.
Abstract: In this paper, a model-predictive control of medium voltage, grid-tied four-level diode-clamped inverter for use in high-power wind energy conversion systems is presented. The control objectives such as regulation of net dc-link voltage, reactive power generation to meet the grid operator request, dc-link capacitor voltages balancing, and switching frequency minimization are included in the cost function. The latter objective is an important requirement for high-power converters, and this has been achieved without any modifications to the software or hardware configuration. The future behavior of the grid currents and dc-link voltages is predicted for all the possible switching states using the discrete-time model of the inverter, dc-link, inductive filter, and grid. The switching state that minimizes the cost function has been chosen and applied to the inverter directly. During different operating conditions, the switching frequency is regulated between 750 and 850 Hz with the help of a lookup-table-based weighting factor, and thus, the proposed methodology appears as a promising tool to control the high-power grid-tied inverters. The results obtained through the MATLAB simulations on 4 MVA/4000 V system and dSPACE DS1103-based experiments on 5 kW/208 V prototype are in a close relationship and thus validate the proposed control strategy.
117 citations
13 May 2013
TL;DR: In this paper, the authors present a model predictive current control method for current source inverters (CSI) following the duality with VSI, which is based on the discrete prediction model of the system, including the converter and output filter.
Abstract: This paper presents a novel model predictive current control method for current source inverters (CSI) following the duality with voltage source inverters (VSI) The method is based on the discrete prediction model of the system, including the converter and output filter The model is used to predict how the system variables will behave for each switching state of the converter The predictions are evaluated using a cost function that weights the level of accomplishment of the control goals The switching state with the best performance is then generated The proposed algorithm predicts the output currents (including the output filter capacitors), ensuring sinusoidal current generation without the need for cascaded control loops, coordinate transformations, and modulation schemes found in traditional solutions In addition, low switching frequency is imposed by including a new term in the cost function Simulation results validate the proposed control scheme, with performance comparable to the traditional solutions, especially in terms of the current and voltage harmonic distortion
30 citations
01 Nov 2013
TL;DR: A new predictive control strategy for current source rectifiers which allows an effective control of source and load currents is presented and the feasibility of the proposed method is verified by MATLAB/Simulink software.
Abstract: A new predictive control strategy for current source rectifiers which allows an effective control of source and load currents is presented in this paper. This method uses the commutation states of the converter in the subsequent sampling time according to an optimization algorithm given by a cost function and the discrete system model. The two control goals are: (a) regulation of dc-link current according to an arbitrary reference, and (b) a good tracking of the source current to its sinusoidal reference. The feasibility of the proposed method is verified by MATLAB/Simulink software.
22 citations
Cites methods from "A comparative study of predictive c..."
...The FCS-MPC has been introduced for matrix converters [8], [9], active front ends [10], and twolevel and multilevel inverters [11], [12]....
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24 Dec 2012
TL;DR: The proposed algorithm predicts the output terminal voltages (includes the output filter capacitors), ensuring sinusoidal voltage generation without the need of cascaded control loops, coordinate transformations and modulation schemes found in classic solutions.
Abstract: This paper presents a novel model predictive control method for current source converters (CSC) following the duality with voltage source converters (VSC). In VSC the predictive control is applied to the output current, while in this work the CSC is controlled through the output voltage. The method is based on the discrete prediction model of the system, including the converter and output filter. The model is used to predict future behavior of the system variables for each switching state of the converter. The predictions are evaluated in a cost function that weights the level of accomplishment of the control goals. The switching state with best performance is then generated. The proposed algorithm predicts the output terminal voltages (includes the output filter capacitors), ensuring sinusoidal voltage generation without the need of cascaded control loops, coordinate transformations and modulation schemes found in classic solutions. In addition, low switching frequency is imposed by including the switching frequency in the cost function. Simulation results show a preliminary validation of the proposed control scheme, with comparable performance to the classical solutions, especially in terms of the current and voltage harmonic distortion.
17 citations
References
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TL;DR: A simple classification of the most important types of predictive control is introduced, and each one of them is explained including some application examples.
Abstract: Predictive control is a very wide class of controllers that have found rather recent application in the control of power converters. Research on this topic has been increased in the last years due to the possibilities of today's microprocessors used for the control. This paper presents the application of different predictive control methods to power electronics and drives. A simple classification of the most important types of predictive control is introduced, and each one of them is explained including some application examples. Predictive control presents several advantages that make it suitable for the control of power converters and drives. The different control schemes and applications presented in this paper illustrate the effectiveness and flexibility of predictive control.
1,389 citations
"A comparative study of predictive c..." refers background in this paper
...Predictive control has attracted much attention in recent years for power converters and drives due to several advantages: Good dynamic response, straightforward inclusion of non-linearities and restrictions in the model and in the control [ 4 ]....
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TL;DR: The results show that the predictive method controls very effectively the load current and performs very well compared with the classical solutions.
Abstract: This paper presents a predictive current control method and its application to a voltage source inverter. The method uses a discrete-time model of the system to predict the future value of the load current for all possible voltage vectors generated by the inverter. The voltage vector which minimizes a quality function is selected. The quality function used in this work evaluates the current error at the next sampling time. The performance of the proposed predictive control method is compared with hysteresis and pulsewidth modulation control. The results show that the predictive method controls very effectively the load current and performs very well compared with the classical solutions
1,387 citations
"A comparative study of predictive c..." refers background or methods in this paper
...This control strategy presents variable switching frequency that depends on the sampling frequency and the operating conditions [5]....
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...This scheme has been used for the control in a three-phase inverter [5], three-level neutral point clamped inverter [6], matrix converters [7, 8], induction machines [9], rectifiers [10], and other applications, achieving a simple and flexible control with good performance....
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18 Nov 2008
TL;DR: In this article, a Powerpoint presentation on predictive control in power electronics and drives is presented, where the areas discussed include predictive control, power electronics, power drive, cascaded control structure, nonlinear control system, switching system, etc.
Abstract: The article consists of a Powerpoint presentation on predictive control in power electronics and drives. The areas discussed include: predictive control; power electronics; power drive; cascaded control structure; nonlinear control system; switching system; etc. etc.
1,073 citations
TL;DR: A new predictive strategy for current control of a three-phase neutral-point-clamped inverter does not require any kind of linear controller or modulation technique, achieving a different approach to control a power converter.
Abstract: A new predictive strategy for current control of a three-phase neutral-point-clamped inverter is presented. The algorithm is based on a model of the system. From that model, the behavior of the system is predicted for each possible switching state of the inverter. The state that minimizes a given quality function is selected to be applied during the next sampling interval. Several compositions of are proposed, including terms dedicated to achieve reference tracking, balance in the dc link, and reduction of the switching frequency. In comparison to an established control method, the strategy presents a remarkable performance. The proposed method achieves comparable reference tracking with lower switching frequency per semiconductor and similar transient behavior. The main advantage of the method is that it does not require any kind of linear controller or modulation technique, achieving a different approach to control a power converter.
545 citations
"A comparative study of predictive c..." refers methods in this paper
...This scheme has been used for the control in a three-phase inverter [5], three-level neutral point clamped inverter [ 6 ], matrix converters [7, 8], induction machines [9], rectifiers [10], and other applications, achieving a simple and flexible control with good performance....
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TL;DR: A predictive control algorithm that uses a state-space model of an induction machine with time-varying components improving the accuracy of state prediction and a high degree of flexibility is obtained with the proposed control technique due to the online optimization algorithm.
Abstract: In this paper, we present a predictive control algorithm that uses a state-space model. Based on classical control theory, an exact discrete-time model of an induction machine with time-varying components is developed improving the accuracy of state prediction. A torque and stator flux magnitude control algorithm evaluates a cost function for each switching state available in a two-level inverter. The voltage vector with the lowest torque and stator flux magnitude errors is selected to be applied in the next sampling interval. A high degree of flexibility is obtained with the proposed control technique due to the online optimization algorithm, where system nonlinearities and restrictions can be included. Experimental results for a 4-kW induction machine are presented to validate the proposed state-space model and control algorithm.
432 citations