Predictive Current Mode Control Research Articles

Digital Predictive Current-Mode Control for Asymmetrical Half-Bridge LED Constant-Current Driver

In this paper, we propose three advanced digital predictive current-mode control (DPCC) algorithms based on a simplified estimation method of duty cycle lost time for asymmetric half-bridge (AHB) LED constant-current driver. They are the digital predictive peak current mode control(DPPCC) algorithm based on leading-edge modulation, the digital predictive quasi-valley current mode control(DPqVCC) algorithm based on trailing-edge modulation, and the digital predictive quasi-average current mode control(DPqACC) algorithm based on double-edge modulation. Simulation and experimental results demonstrate that the three DPCC algorithms can effectively offset the effect of delay on digital control performance, which confirms the superiority of DPqACC. When the DPqACC is applied, the series-load-jump transition times are below 4.5 ms, the maximum load adjustment rate is 0.5%/ V, and the output current can be tuned continuously between 0.3 A and 4.5 A with the longest transition time of 1 ms. Moreover, the three DPCC algorithms are capable of compensating for low-frequency ripples due to the rapid regulation speed of the inner loop. With the electrolytic capacitance removed without additional ripple compensation, the maximum peak-to-peak value of the low-frequency secondary ripple is 0.1163 A (2.91%) when the input is 400 53sin(2ω <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>lin</i></sub> <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</i> ) V and the output is 4 A. This approach provides an excellent solution for the digital design of low-ripple AC-DC LED constant-current drivers without electrolytic capacitance.

Digital Predictive Current-Mode Control of Three-Level Flying Capacitor Buck Converters

This article investigates the use of digital predictive current-mode control (DPCMC) in dc-dc three-level flying capacitor (3LFC) buck converters. In particular, stability and flying capacitor (FC) balancing properties of predictive peak, average, and valley current-mode controllers are studied when operated in single- and multisampled modes. A variant of the multisampled DPCMC obtained through a fast-update of the duty cycle command is also disclosed and analyzed. Results indicate that single-sampled DPCMC is always stable, and that fast-update approaches can strongly improve the converter dynamic response. Multisampled controllers are also shown to be inherently more robust than single-sampled ones against timing mismatches in the control signals, resulting in a smaller FC voltage imbalance. The analysis is validated in simulation and experimentally on a 500 kHz, 12-1.5 V, 500 mA 3LFC buck case study.

An Active Partial Switching Method in Tertiary Loop for a High-Efficiency Predictive Current-Mode Control PFC Converter

This paper proposes a novel active partial switching method for a boost power factor correction (PFC) converter, based on the predictive current mode control to achieve both current shaping capability and high power conversion efficiency. This method consists of a controller that maintains a switching stop angle near the peak voltage of the input voltage by means of output voltage control, and an adaptive current shaper that adjusts the switching stop period near the zero voltage of the input voltage based upon the load condition. The proposed method shows good PFC performance and high efficiency even under various disturbances such as input voltage and load fluctuations. Moreover, it has the advantage that it is possible to achieve high efficiency even under conditions of output voltage exceeding the peak value of the input voltage. For sequential explanation, this paper illustrates the design of the controller based on the frequency-domain response and provides theoretical analysis of the proposed method. Finally, to verify the effectiveness of the proposed method, experimental results are presented based upon a 2.4 kW boost PFC converter prototype.

A Digital Predictive Current-Mode Controller for a Single-Phase High-Frequency Transformer-Isolated Dual-Active Bridge DC-to-DC Converter

This paper presents predictive current-mode control for a single-phase high-frequency transformer-isolated dual-active bridge dc-to-dc converter. The predictive control algorithm increases the bandwidth of the current loop of the converter which enables tracking of the current reference within one switching cycle. The paper further demonstrates that the application of the predictive control algorithm can remove transient dc offset from the current in high-frequency isolation transformer within one switching cycle. Direct control of the converter current protects the transformer from saturation even at transient conditions. The control algorithm has been implemented on an experimental setup and transient tests have been performed to validate controller performance. Since the predictive control algorithm is dependent on the measured value of the leakage inductance of the transformer, a compensator has been implemented to improve the parameter insensitivity of the proposed controller.

Boost Compensator for Predictive Current Mode Control of High Power Factor Boost Rectifier

This paper presents the design of the Boost compensator for a predictive current mode control of high power factor boost rectifier. The general features are no input voltage sensing, no use of multiplier, and no inner current loop regulator. The switching principle of the controller is predictive, as the actual current equals the reference current at the ending of the switching period. This switching law will extend the range of the continuous conduction mode (CCM) of operation. boost compensator is designed by using k-factor approach with the help of low frequency small signal model of the boost rectifier switched by the predictive current mode control. Simulation results on a 400W boost rectifier are presented.

Parameter Tuning Method for Digital Power Converter With Predictive Current-Mode Control

The objective of this paper is to present an online parameter tuning method for digital power converter with predictive current-mode control. The proposed method can effectively deal with the issues caused by variation of inductance, input voltage drift, and voltage drop caused by DCR. The proposed online parameter tuning method is based upon adding an additional current sampling between two pulsewidth-modulated outputs. Neither an additional sensor nor system parameter is required for the realization of the proposed method. Moreover, the effects of inductance variation, input voltage drift, and voltage drop caused by DCR are analyzed. It will be shown that inductance variation and DCR result in dc offset of the inductor current, and input voltage drift and DCR deteriorate the performance of both steady-state and transient responses. It will be confirmed by simulation and experimental results that these effects can be dealt with by using the presented online parameter tuning method. Experimental results will be presented to fully support the theoretical analysis.

Novel fast-acting predictive current mode controller for power electronic converters

A proposed general-purpose fast-acting controller with predictive current mode control suitable for power electronic converters is described. The predictive controller regulates the converter output voltage or current with respect to a demand signal, and implements true average current mode control. A four-quadrant single-phase DC/AC converter supplying a variety of loads, including live loads and high crest factor loads, with high di/dt, is used to demonstrate the performance of the controller. Simulation and practical results are presented for this converter.

New optimal predictive current mode control technique for bilevel quantum series resonant convertors

A new optimal predictive current mode control technique is proposed to improve the performance of a bilevel quantum series resonant convenor. With this technique, the fast transient response with negligible overshoot and the minimised current ripple with reduced offset current can be available.