Totem-pole Power Factor Correction Research Articles

Design and Verification of a Bridgeless Totem-Pole Power Factor Corrector

A power factor corrector (PFC) is a device whose job is to improve the power factor of a device. Several connections of semiconductor converters are used for this purpose; one of them is the bridgeless totem-pole power factor correction converter (BLTP-PFC). The bridgeless totem-pole power factor correction converter (BLTP-PFC) is known for its advantages, including its simple topology, low interference capability, high efficiency, and environmental friendliness. Initially, this article focuses on a single-phase PFC, precisely the principle of operation of the BLTP-PFC converter and its simulation verification. Finally, an experimental prototype of an interlaced totem-pole bridgeless PFC converter is designed to verify the correctness and effectiveness of the proposed method.

A Combined MPC and PI Control Strategy for Bidirectional Interleaved Totem Pole PFC Converters in Electric Vehicle G2V and V2G Applications

This paper presents an optimized control strategy for a bidirectional interleaved totem pole Power Factor Correction (PFC) converter, employing a combination of Model Predictive Control (MPC) and a Proportional-Integral (PI) controller. The converter’s mathematical model is used to implement the MPC, which ensures a unit power factor during both Grid-to-Vehicle (G2V) and Vehicle-to-Grid (V2G) operations. Meanwhile, the PI controller regulates the DC-side voltage. It is worth noting that the MPC’s design eliminates the need for a comparator to generate the Pulse Width Modulation (PWM) signal, simplifying the control architecture. The proposed control technique’s effectiveness is validated through various simulation scenarios in both G2V and V2G power transfer modes, demonstrating satisfactory performance. This integrated approach provides a robust solution for efficient energy management and high-quality power conversion in bidirectional PFC converters.

Variable-Frequency Control for Totem-Pole Bridgeless Power Factor Correction Converter to Achieve Zero-Voltage Switching Without Zero-Crossing Detection Circuits

The totem-pole bridgeless power factor correction (PFC) converter, known for its advantages including simple topology, capability for zero-voltage switching (ZVS), and low common mode interference, presents an opportunity to enhance the efficiency and environmental friendliness of power systems. However, these converters have issues such as ZVS, requiring zero-crossing detection (ZCD) under circuits’ critical continuous mode (CRM) or additional auxiliary resonant circuits, resulting in increased circuit costs and control complexity. Therefore, this paper proposes a variable switching frequency digital control method to achieve ZVS under a wide operating range without ZCD circuits. At the same time, under the premise of ZVS, an interleaved parallel scheme is adopted to further minimize the current ripple and enhance the quality of the current waveform. Finally, an experimental 2 kW two-phase interleaved totem-pole bridgeless PFC converter prototype is designed to verify that the proposed method is correct and effective. The experimental prototype can reach an efficiency of 97.78%.

Multipurpose Design of Optimized Current Controller for Bridgeless Totem-Pole Power Factor Correction Converters

Multipurpose Design of Optimized Current Controller for Bridgeless Totem-Pole Power Factor Correction Converters

Modeling and Control Simulation of Power Converters in Automotive Applications

This research introduces a model-based approach for the analysis and control of an onboard charger (OBC) system for contemporary electrified vehicles. The primary objective is to integrate the modeling of SiC/GaN MOSFETs electrothermal behaviors into a unified simulation framework. The motivation behind this project stems from the fact that existing literature often relies on finite element method (FEM) software to examine thermal dynamics, necessitating the development of complex models through partial derivative equations. Such intricate models are computationally demanding, making it difficult to integrate them with circuit equations in the same virtual environment. As a result, lengthy wait periods and a lack of communication between the electrothermal models limit the thorough study that can be conducted during the design stage. The selected case study for examination is a modular 1ϕ (single phase) onboard computer (OBC). This system comprises a dual active bridge (DAB) type DC/DC converter, which is positioned after a totem pole power factor correction (PFC) AC/DC converter. Specifically, the focus is directed toward a 7 kW onboard computer (OBC) utilizing high-voltage SiC/GaN MOSFETs to ensure optimal efficiency and performance. A systematic approach is presented for the assessment and selection of electronic components, employing circuit models for the totem pole power factor correction (PFC) and dual active bridge (DAB) converter. These models are employed in simulations closely mimicking real-world scenarios. Furthermore, rigorous testing of the generated models is conducted across a spectrum of real-world operating conditions to validate the stability of the implemented control algorithms. The validation process is bolstered by a comprehensive exploration of parametric variations relative to the nominal case. Notably, each simulation adheres to the recommended operational limits of the selected components and devices. Detailed data sheets encompassing electrothermal properties are provided for contextual reference.

Efficiency and PF Improving Techniques with a Digital Control for Totem-Pole Bridgeless CRM Boost PFC Converters

A totem-pole bridgeless boost converter is one of the most promising topologies for the power factor correction (PFC) stage in high-power applications due to its high efficiency and small number of components. However, due to the totem-pole structure of the field-effect transistor (FET), very high switching loss occurs via the reverse recovery current of the body diode. To solve these problems, critical mode (CRM) control is a good solution to achieve the valley switching technique. With valley switching of CRM control, the switching loss decreases drastically with decreasing turn-on voltage. But, although the CRM control enables valley switching, it is hard to make an exact valley switching control with general zero-voltage detection circuits. In addition, when a frequency limitation scheme is applied to prevent a very high frequency, the switch can operate with hard switching at the boundary of the frequency limitation. Furthermore, the CRM boost PFC has a low PF and high total harmonic distortion (THD) under light-load conditions due to the large negative current resulting from resonance between the inductor and parasitic capacitance. It becomes worse at near-zero input voltage since the resonance current becomes larger near zero-input voltage. Therefore, in this paper, a totem-pole bridgeless boost PFC converter with high efficiency, high PF, and low THD is developed using TMS320F28377 by Texas Instruments. Based on the basic digital structure of the totem-pole bridgeless converter, the proposed controls help with exact valley switching, PF and THD improvement, and frequency limitation. The prototype converter is verified using 90–264 VAC input voltages and 450 V/3.3 kW output specifications.

Thermal design and performance evaluation of GaN power stage in a 4-level totem-pole PFC

Low voltage Gallium Nitride (GaN) power devices are enabling the development of single-phase multi-level power factor correction (PFC) converters for high power density designs due to their superior figure-of-merit. However, despite their lower power losses compared to Si MOSFETs, it is still challenging to remove a few watts of power loss from small packages, which presents a barrier for using GaN in high power converters. To address this issue, this study establishes a 3-D thermal model for chip-scale package GaN devices, and analyses various heat sinking methods for a power stage of a single-phase 4-level PFC structure using the finite element method. The thermal performances of GaN devices with different layouts, board types, and thermal via patterns have been analyzed and verified experimentally on a power stage of a 4-level GaN PFC rated for 3.7 kW, where each of the six GaN devices dissipates 2.3 W.

Digitalized Control Algorithm of Bridgeless Totem-Pole PFC with a Simple Control Structure Based on the Phase Angle

Compared to the conventional boost power factor correction (PFC) converter, a totem-pole bridgeless PFC has high efficiency because it does not have an input diode rectifier stage, but a current spike may occur when the polarity of the grid voltage changes. This paper proposes a digital control algorithm for bridgeless totem-pole PFC with a simple control structure based on the phase angle of grid voltage. The proposed algorithm has a PI-based double-loop control structure and performs DC-link voltage and input inductor current control. Rectifying switches operate based on the proposed rectification algorithm using phase angle information calculated through a single-phase phase-locked loop (PLL) to prevent current spikes. The feed-forward duty ratio value is calculated according to the polarity of the grid voltage and added to the double-loop controller to perform appropriate power factor control. The performance and feasibility of the proposed control algorithm are verified through a 3 kW hardware prototype.

A Unified Differential Mode Noise Estimation Method and Filter Size Comparison in Single-Phase Multileg and Multilevel Totem-Pole PFC Converters

Wide band-gap power devices have enabled single-phase totem-pole (TP) power factor correction (PFC) converter designs to be switched at several tens of kHz under hard-switching and hundreds of kHz under soft-switching. It is straight-forward to analyze and compare the volume of boost inductor for TP PFC converters having multi-leg and multi-level configurations operating under continuous-conduction-mode (CCM) and critical-conduction-mode (CrM) at various switching frequencies; however, the impact of topology and switching frequency selections remains unchallenged for generated differential mode (DM) noise. This paper proposes a unified and generalized DM noise estimation method for multi-leg, and multi-level TP PFC converters operated under both CCM and CrM operation modes. The method has been verified with simulation results obtained from various TP PFC topologies, as well as experimental results obtained from single-leg CCM and 4-Level CCM TP PFC converters. The empirically determined boxed sizes of DM filters have been compared among various TP PFC topologies, and the best switching frequency for each topology has been determined with the integration of boost inductor volume comparison.

SR Control With Zero Current Detection Delay Compensation for GaN CRM Totem-Pole PFC Rectifier

An SR control with ZCD delay compensation is proposed to reduce the high reverse inductor current and input current distortion caused by the zero current detection (ZCD) delay in critical mode totem-pole power factor correction (PFC). The basic idea of the proposed control is to calculate the SR turn-off instant considering the ZCD delay. Accurate operation model in VOT control is analyzed with ZCD delay compensation to realize the proposed control. A prototype of 2 kW GaN CRM totem-pole PFC converter is built to verify the proposed control. The total harmonic distortion (THD) with full load decreases to 3% by mitigating the current distortion caused by the ZCD delay, 1.6% lower than that before compensation. The high reverse inductor current near the zero-crossing of input voltage is avoided since the length of the zero-current platform is shortened by 87.5%. The prototype achieves 99% efficiency at full load (2 kW) and a power density of 120 W/inch <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> .

High-Efficiency Interleaved Totem-Pole PFC Converter With Voltage Follower Characteristics

High power density, efficiency, control simplification, and robustness are highly demanded for power factor correction (PFC) converters. This paper proposes a totem-pole rectifier based on the switching cell with switching frequency modulation (SC-SFM). The SC-SFM features interleaved operation, soft commutation, and resistive characteristics with continuous conduction in the input inductor. The converter operates without needing sensors and a control loop for the current. Unlike conventional solutions or some sensorless converters, the converter does not require a fast control loop to shape the current since the current naturally follows the input voltage. Only one output voltage sensor and one input half-line cycle detector are required to achieve unitary power factor and regulated DC output voltage. A detailed analysis of the converter operation, including the operating principle, mathematical analysis, a small signal model, and control method, is presented, including the differences in operation from the conventional PFC rectifier with the diode bridge. Experimental results evaluate a 1-kW prototype with different switch technologies (IGBT, SiC, and GaN).

Improved Control Strategies for Totem-Pole PFC With True Full Range ZVS Operation

Zero voltage switching (ZVS) of power semiconductor devices is an effective way to improve the efficiency and power density of the power electronic converters with extremely high switching frequency. This article aims to analyze and realize the true full-range ZVS operation of a totem-pole power factor correction circuit. The available ZVS control strategies are investigated, and the conditions for the realization of full-range ZVS operation are analyzed. It is revealed that the existed control strategies did not consider the influence of the dead-time, resulting in the failure of ZVS operation in some input voltage ranges. To address this issue, two feasible retrofitted control strategies, namely the turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> current optimization control and the adaptive dead-time control, are proposed. The merits and drawbacks of the two control strategies are carefully analyzed and compared. It is found that the adaptive dead-time control can not only achieve the true full range ZVS but also significantly reduce the loss of the freewheeling diodes. The design consideration of key parameters is discussed. Finally, the feasibility of the proposed control and the correctness of the theoretical analyses are verified by simulation and experiment.

A Novel Interleaved Parallel Cascaded Three-Level PFC With Low Inductance Volt-Second and Low Common-Mode Noise

Interleaved parallel cascaded multilevel technology is an attractive approach for converters to achieve high efficiency, high-power density, and high modularity. In this letter, a novel single-phase interleaved parallel cascaded three-level (IPC-TL) power factor correction (PFC) converter is proposed. It is formed by cascading two interleaved parallel totem-pole PFC cells. The proposed topology exhibits the merits of lower inductance volt-second and inductor current ripples, lower common-mode noise, and lower control cost, compared with the traditional IPC-TL topology. A laboratory-scale experimental prototype is developed to verify the effectiveness of the proposed topology.

Input Impedance Modeling and Experimental Validation of a Single-Phase PFC in the D-Q Frame

This article models and characterizes the input impedance of a single-phase totem-pole power factor correction (PFC) converter in a virtual synchronous reference (d-q) frame. Due to the dc voltage controller, its d-d channel impedance behaves like a negative resistor, and the cascaded dc–dc converter load reduces its gain and phase at low frequency. Both are detrimental to system stability. The proposed impedance model can be employed to analyze instability issues. As examples, the low-frequency stability of a single-phase and a three-phase four-wire system is analyzed using the model. It is found that the single-phase system will confront the issue of settling to an operating point before any small-signal instability occurs. Whereas in a four-wire system, high neutral line inductance or high dc voltage control bandwidth could lead to small-signal instability. The impedance modeling results are validated by experiments.

Research on Single-Phase and Three-Phase Compatible Isolated On-Board Charger and Control Technology

This paper presents a single-phase and three-phase compatible isolated on-board charger for electric vehicles. The charger is compatible with the single-phase and three-phase AC voltage input and is composed of two-stage circuits. Based on the three-phase six-switch power factor correction (PFC) circuit, by switching on and off, the front stage is transformed into a cascade topology of a totem-pole PFC circuit and boost circuit. The rear stage is a full-bridge LLC resonant converter. In the single-phase or three-phase working mode, the front-stage control strategy is a double closed-loop control. The current inner loop controller is improved for the three-phase six-switch PFC circuit. The PI controller and repetitive controller are connected in parallel to form the current inner loop compound controller, which can effectively reduce the total harmonic distortion of the input current. By using simulation software MATLAB/Simulink, the circuit model was built. The simulation results verify the correctness of the theoretical analysis.

Totem-Pole PFC Reliability and Performance Improvement With Advanced Controls

Totem-pole power factor correction (PFC) is a simple and highly efficient topology. It is being widely used in high-density and high-efficiency power supply design. However, engineers still face many design challenges, including PFC current reversing prevention at input voltage drop, lightning surge protection, current harmonic reduction, and ac crossover current spike elimination. These challenges are not closely related to each other and there is no single control that can solve all the design issues. This article reviews the main design challenges and provides comprehensive solutions to these issues. Most of the solutions are novel or are used for the first time in PFC control. These solutions are integrated into the industry’s first continuous conduction mode (CCM) totem-pole PFC analog controller IVCC1102 <xref ref-type="bibr" rid="ref1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[1]</xref> . A 2.5 kW SiC-based totem-pole PFC prototype <xref ref-type="bibr" rid="ref1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[1]</xref> is built to demonstrate the robustness and performance improvement with the proposed solutions.

Adaptive Observer Design for a Bidirectional AC/DC totem pole PFC Power Converter

In this paper, we propose a nonlinear observer for a single-phase bidirectional AC/DC totem-pole power factor correction (PFC) converter intended to be used in wireless power transfer (WPT) chargers for electric vehicles (EVs). This converter is gaining a lot of interest recently as it entails power losses reduction which is a key desirable factor in WPT chargers. Secondly after introduction, its operating principle during grid to vehicle (G2V) and vehicle to grid (V2G) power transfer modes is presented. Thirdly, an overall mathematical model governing all the operating modes of the converter is elaborated. Fourthly, a nonlinear observer-based Kalman Like technique is designed for estimating the involved state variables and also the converter's parameters. Finally, it was shown, using simulation results, that the estimated state variables match well the measured ones which verify the accuracy of the proposed observer. It is worth noting that the designed observer is a cost-effective solution since it requires only one measurement which is chosen as the grid current.

Design of a GaN Totem-Pole PFC Converter Using DC-Link Voltage Control Strategy for Data Center Applications

In today’s power industry, a compact and highly efficient power converter is the main component for server power applications. The objective of this paper is to propose a totem-pole power factor correction (PFC) converter with DC-link voltage control strategies for data center applications. Gallium Nitride High Electron Mobility Transistors (GaN HEMTs) are also used to increase power density and conversion efficiency without the reverse recovery loss. With the derived equations of the converter loss, the dc-bus voltage control strategy is proposed to improve the conversion efficiency. Furthermore, this paper proposes the hold-up time extension method to increase the DC bus voltage under heavy load conditions. The reduction of the DC link capacitor capacitance is achievable, and the power factor can be improved in a wide range. A 2.9-kW GaN totem-pole PFC prototype is developed and fabricated to verify this paper’s theoretical analysis. As demonstrated in the prototype’s experimental results, the tested peak efficiency is 98.5% and the tested total harmonic distortion (THD) is less than 3%.

Electro-Thermal Model-Based Design of Bidirectional On-Board Chargers in Hybrid and Full Electric Vehicles

In this paper, a model-based approach for the design of a bidirectional onboard charger (OBC) device for modern hybrid and fully electrified vehicles is proposed. The main objective and contribution of our study is to incorporate in the same simulation environment both modelling of electrical and thermal behaviour of switching devices. This is because most (if not all) of the studies in the literature present analyses of thermal behaviour based on the use of FEM (Finite Element Method) SWs, which in fact require the definition of complicated models based on partial derivative equations. The simulation of such accurate models is computationally expensive and, therefore, cannot be incorporated into the same virtual environment in which the circuit equations are solved. This requires long waiting times and also means that electrical and thermal models do not interact with each other, limiting the completeness of the analysis in the design phase. As a case study, we take as reference the architecture of a modular bidirectional single-phase OBC, consisting of a Totem Pole-type AC/DC converter with Power Factor Correction (PFC) followed by a Dual Active Bridge (DAB) type DC/DC converter. Specifically, we consider a 7 kW OBC, for which its modules consist of switching devices made with modern 900 V GaN (Gallium Nitrade) and 1200 V SiC (Silicon Carbide) technologies, to achieve maximum performance and efficiency. We present a procedure for sizing and selecting electronic devices based on the analysis of behaviour through circuit models of the Totem Pole PFC and DAB converter in order to perform validation by using simulations that are as realistic as possible. The developed models are tested under various operating conditions of practical interest in order to validate the robustness of the implemented control algorithms under varying operating conditions. The validation of the models and control loops is also enhanced by an exhaustive robustness analysis of the parametric variations of the model with respect to the nominal case. All simulations obtained respect the operating limits of the selected devices and components, for which its characteristics are reported in data sheets both in terms of electrical and thermal behaviour.

A Variable Inductor Controlled Single-Stage AC/DC Converter for Modular Multi-Channel LED Driver

Light-emitting diodes (LEDs) are widely used in street lighting, landscape lighting, liquid crystal display (LCD) backlighting, healthcare, etc. As an important part of LED lighting products, LED driver plays a vital role in maintenance costs reduction, energy saving and lifetime prolongation. In this paper, a single-stage LED driver is proposed, which is integrated by a totem-pole bridgeless power factor correction (PFC) unit and several modular LCL-T resonant rectifiers. The totem-pole bridgeless PFC unit and the LCL-T resonant rectifiers are integrated by sharing switches, which can simplify the circuit and reduce the system cost. The output current can be regulated by applying the variable inductor control. Constant duty cycle and fixed switching frequency operation can be achieved as well. The operating principle and the performance of the proposed converter are analyzed in this paper. In addition, a precise parameter design method is proposed by considering the high-order harmonics. At last, an experimental prototype is established to validate the proposed parameter design and variable inductor control method.