Robust dead-beat current control for PWM rectifiers and active filters
12 Oct 1998-Vol. 35, Iss: 3, pp 613-620
TL;DR: In this paper, the authors analyzed the stability limitations of digital dead-beat current control applied to voltage-source three-phase converters used as pulsewidth modulation rectifiers and/or active filters.
Abstract: This paper analyzes the stability limitations of digital dead-beat current control applied to voltage-source three-phase converters used as pulsewidth modulation rectifiers and/or active filters. In these applications, the conventional control algorithm, as used in drive applications, is not sufficiently robust and stability problems may arise for the current control loop. The current loop is, indeed, particularly sensitive to any model mismatch and to the possibly incorrect identification of the model parameters. A detailed analysis of the stability limitations of the commonly adopted dead-beat algorithm, based on a discrete-time state-space model of the controlled system, is presented. A modified line voltage estimation technique is proposed, which increases the control's robustness to parameter mismatches. The results of the theoretical analysis and the validity of the proposed modification to the control strategy are finally verified both by simulations and by experimental tests.
Citations
More filters
TL;DR: The feasibility and great potential of FCS-MPC due to present-day signal-processing capabilities, particularly for power systems with a reduced number of switching states and more complex operating principles, such as matrix converters are found.
Abstract: This paper presents a detailed description of finite control set model predictive control (FCS-MPC) applied to power converters Several key aspects related to this methodology are, in depth, presented and compared with traditional power converter control techniques, such as linear controllers with pulsewidth-modulation-based methods The basic concepts, operating principles, control diagrams, and results are used to provide a comparison between the different control strategies The analysis is performed on a traditional three-phase voltage source inverter, used as a simple and comprehensive reference frame However, additional topologies and power systems are addressed to highlight differences, potentialities, and challenges of FCS-MPC Among the conclusions are the feasibility and great potential of FCS-MPC due to present-day signal-processing capabilities, particularly for power systems with a reduced number of switching states and more complex operating principles, such as matrix converters In addition, the possibility to address different or additional control objectives easily in a single cost function enables a simple, flexible, and improved performance controller for power-conversion systems
1,554 citations
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
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
TL;DR: In this article, the performance of linear controllers such as proportional-integral, proportional-resonant, and deadbeat (DB) controllers for grid-connected distributed power generation systems has been evaluated.
Abstract: This paper discusses the evaluation of different current controllers employed for grid-connected distributed power generation systems having variable input power, such as wind turbines and photovoltaic systems. The focus is mainly set on linear controllers such as proportional-integral, proportional-resonant, and deadbeat (DB) controllers. Additionally, an improved DB controller robust against grid impedance variation is also presented. Since the paper discusses the implementation of these controllers for grid-connected applications, their evaluation is made in three operating conditions. First, in steady-state conditions, the contribution of controllers to the total harmonic distortion of the grid current is pursued. Further on, the behavior of controllers in the case of transient conditions like input power variations and grid voltage faults is also examined. Experimental results in each case are presented in order to evaluate the performance of the controllers.
886 citations
TL;DR: A new and simple control scheme using predictive control for a two-level converter using a model of the system to predict the behavior of the output voltage for each possible switching state is presented.
Abstract: The use of an inverter with an output LC filter allows for generation of output sinusoidal voltages with low harmonic distortion, suitable for uninterruptible power supply systems. However, the controller design becomes more difficult. This paper presents a new and simple control scheme using predictive control for a two-level converter. The controller uses the model of the system to predict, on each sampling interval, the behavior of the output voltage for each possible switching state. Then, a cost function is used as a criterion for selecting the switching state that will be applied during the next sampling interval. In addition, an observer is used for load-current estimation, enhancing the behavior of the proposed controller without increasing the number of current sensors. Experimental results under linear and nonlinear load conditions, with a 5.5-kW prototype, are presented, verifying the feasibility and good performance of the proposed control scheme.
578 citations
References
More filters
TL;DR: In this paper, a voltage-sourced rectifier control scheme for use with AC/DC/AC variable speed drives is presented, which directly calculates the duration of time spent on the zero state and on each switching state adjacent to the reference vector, over a constant switching interval.
Abstract: A voltage-sourced rectifier control scheme for use with AC/DC/AC variable speed drives is presented. A control scheme is derived that directly calculates the duration of time spent on the zero state and on each switching state adjacent to the reference vector, over a constant switching interval, in order to drive the line current vector to the reference vector. In addition, under transient conditions, when deadbeat control is not possible, a control scheme is presented that ensures that the line current vector is driven in the direction of the reference current vector. The current reference for the rectifier controller is derived from the bus voltage error and a feedforward term based on the estimated converter output power. The proposed space vector-based rectifier regulator is shown to exhibit improved harmonic and transient performance over existing per-phase duty cycle prediction methods, especially at modulation indices near unity. The deadbeat control of the rectifier input current is accomplished every half-cycle with constant switching frequency while still symmetrically distributing the zero state within the half-cycle period. >
337 citations
TL;DR: In this article, a new control technique based on dead beat control theory to obtain a nearly sinusoidal PWM inverter output voltage is described, which inherently provides very good voltage regulation, phase positioning, and compensation for load disturbances and nonlinear loads.
Abstract: A new control technique based on dead beat control theory to obtain a nearly sinusoidal PWM inverter output voltage is described. The closed-loop digital feedback system measures the output and controls the inverter switches to generate the required pulsewidth-modulated (PWM) pattern to produce low total harmonic distortion (THD) sinusoidal output voltage. This scheme inherently provides very good voltage regulation, phase positioning, and compensation for load disturbances and nonlinear loads. A theoretical analysis, computer simulation, and experimental results for a single-phase bridge inverter controlled by an Intel 8086 microprocessor-based system is presented.
313 citations
TL;DR: In this article, a technique based on deadbeat control theory is proposed to obtain a nearly sinusoidal PWM (pulsewidth-modulated) inverter output voltage using only a voltage sensor.
Abstract: A technique based on deadbeat control theory is proposed to obtain a nearly sinusoidal PWM (pulsewidth-modulated) inverter output voltage using only a voltage sensor. The closed loop sampled-data feedback scheme inherently results in very fast response to load disturbance and nonlinear load, producing low total harmonic distortion. Parameter estimation of the plant provides a type of self-tuning of the proposed controller. A theoretical analysis, simulation, and experimental results are presented for a single-phase PWM inverter controlled by an Intel 8086 microprocessor. >
287 citations
TL;DR: New method of high performance current and/or voltage control of three phase PWM inverter, especially suitable for high speed switching devices such as Transistor and BIMOS is proposed.
Abstract: A novel method for microprocessor control of three-phase sinusoidal-voltage pulse-width-modulated (PWM) inverters is proposed. First, the discretized state equations of the inverter main circuit on the d-q frame are derived. An algorithm for dead beat control with a current minor loop that constrains the inverter current within the safety limit is subsequently developed. To compensate the computing time delay, a second-order prediction method and a novel discretization method using twice the time of the sampling period have been adopted. This method is especially suitable for inverters using high-speed switching devices and digital signal processors. The validity of the control system has been demonstrated by precise simulation using a hybrid computer. >
272 citations
06 Oct 1996
TL;DR: Algorithms for directly implementing a predictive current controller in a microprocessor for load situations where the back-EMF is both known and unknown are presented.
Abstract: The three major approaches for regulating current in hard switched inverters are ramp comparison, hysteresis control and predictive current control. Of these three, predictive current control offers the potential for achieving more precise current control with minimum distortion and harmonic noise, but is generally more difficult to implement and usually must be matched to a specific load. Also, errors caused by computational delays create further problems in a real system. This paper presents algorithms for directly implementing a predictive current controller in a microprocessor for load situations where the back-EMF is both known and unknown. The algorithms fully compensate for sampling delays and discretisation errors, and are simple enough to be readily implemented in a practical system. Both simulation and experimental results are presented as confirmation of the approach presented.
228 citations
"Robust dead-beat current control fo..." refers background or methods in this paper
...More generally, the presence of model mismatches or, in case of a correctly identified model’s structure, of parameter uncertainties and/or variations can cause stability problems to the current control loop, in particular, when a line voltage estimation strategy is adopted, as reported in [2]....
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...In the more recent versions [2] of the dead-...
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...Anyway, similar problems arise also when there is a parameter mismatchbetween the modeled inverter inductance and the actual one [2]....
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