A New 3-phase Buck-Boost Unity Power Factor Rectifier with Two Independently Controlled DC Outputs (original) (raw)
Related papers
2018 IEEE International Power Electronics and Application Conference and Exposition (PEAC), 2018
Battery chargers supplied from the three-phase mains are typically realized as two-stage systems consisting of a three-phase PFC boost-type rectifier with an output DC link capacitor followed by a DC/DC buck converter if boost and buck functionality is required. In this paper, a new modulation scheme for this topology is presented, where always only one out of three rectifier half-bridges is pulse width modulated, while the remaining two phases are clamped and therefore a higher efficiency is achieved. This modulation concept with a minimum number of active half-bridges, denoted as 1/3 rectifier, becomes possible if in contrast to other modulation schemes the intermediate DC link voltage is varied in a six-pulse voltage fashion, while still sinusoidal grid currents in phase with their corresponding phase voltages and a constant battery output voltage are obtained. In this paper, a detailed description of the novel 1/3 rectifier's operating principle and the corresponding control structure are presented and the proper closed loop operation is verified by means of a circuit simulation. Finally, the performance gain of the 1/3 rectifier control scheme compared to conventional modulation schemes is evaluated by means of a virtual prototype system.
The Essence of Three-Phase PFC Rectifier Systems—Part II
IEEE Transactions on Power Electronics, 2014
In the first part of this paper, three-phase power factor correction (PFC) rectifier topologies with sinusoidal input currents and controlled output voltage are derived from known single-phase PFC rectifier systems and/or passive three-phase diode rectifiers. The systems are classified into hybrid and fully active pulsewidth modulation boost-type or buck-type rectifiers, and their functionality and basic control concepts are briefly described. This facilitates the understanding of the operating principle of three-phase PFC rectifiers starting from single-phase systems, and organizes and completes the knowledge base with a new hybrid three-phase bucktype PFC rectifier topology denominated as SWISS Rectifier. Finally, core topics of future research on three-phase PFC rectifier systems are discussed, such as the analysis of novel hybrid buck-type PFC rectifier topologies, the direct input current control of buck-type systems, and the multi-objective optimization of PFC rectifier systems. The second part of this paper is dedicated to a comparative evaluation of four rectifier systems offering a high potential for industrial applications based on simple and demonstrative performance metrics concerning the semiconductor stresses, the loading and volume of the main passive components, the differential mode and common mode electromagnetic interference noise level, and ultimately the achievable converter efficiency and power density. The results are substantiated with selected examples of hardware prototypes that are optimized for efficiency and/or power density.
2004
A three-phase boost+buck PWM rectifier system formed by series connection of a boost-type rectifier input stage and a DC/DC buck converter output stage and a threephase buck+boost PWM rectifier system comprising a threeswitch rectifier input stage with integrated DC/DC boost converter output stage are presented and comparatively evaluated. Both systems are characterized by sinusoidal input current and wide output voltage control range. Analytical expressions for the calculation of the current stresses on the power components and results of transistor switching loss measurements are provided as guidelines for the system design. Furthermore, the overall efficiency, the loss contributions and the volume and weight of the main components are given for 6kW rated system output power at 400V rms line-to-line input. In combination with an assessment of the realization effort this provides a basis for the selection of the appropriate topology for an industry application. I.
2001
In this paper the experimental analysis of a three-phase three-switch buck+boost PWM rectifier with unity power factor is discussed. The output voltage and the output current control are realized using a digital signal processor where a modulation scheme is employed which does provide minimum switching losses and minimum input capacitor voltage ripple rms value. The control design which is based on an equivalent DC/DC converter and state-space averaging is discussed briefly. Finally, the efficiency, the power factor, and the total harmonic distortion and the low-frequency harmonics of the mains current are gained in dependency on the output power by measurements on a 5 kW prototype of the system.
IEEE Transactions on Industrial Electronics, 2005
In this paper the reliable operation of a three-phase three-switch buck-type PWM unity power factor rectifier with integrated boost output stage under heavily unbalanced mains, i.e. mains voltage unbalance, loss of one phase, short circuit of two phases or earth fault of one phase is investigated theoretically and experimentally. The analytical calculation of the relative on-times of the active switching states and of the DC link current reference value is treated in detail for active and deactivated boost output stage. Based on the theoretical considerations a control scheme which allows to control the system for any mains condition without changeover of the control structure is described. Furthermore, digital simulations as well as experimental results are shown which confirm the proposed control concept for different mains failure conditions and for the transition from balanced mains to a failure condition and vice versa. The experimental results are derived from a 5kW prototype (input voltage range (208. .. 480)V rms line-to-line, output voltage 400V DC of the rectifier system, where the control is realized by a 32-bit digital signal processor.
Minimization of the DC current ripple of a three-phase buck-boost PWM unity power factor rectifier
2002
The modulation of a novel three-phase three-switch buck-type unity power factor rectifier with integrated DC/DC boost converter output stage is optimized concerning the ripple amplitude of the buck-boost inductor current. This is achieved by coordination of the switching operation of the buck input stage and of the boost output stage. A comparative evaluation of different modulation schemes does identify a modulation scheme which simultaneously does provide minimum DC current ripple and minimum input filter capacitor voltage ripple at minimum switching losses and/or maximum pulse frequency. All theoretical considerations are for operation in a wide input voltage range and are verified by simulations and by measurements on a DSP-controlled 5 k W prototype of the system.
IEEE Transactions on Industrial Electronics, 2007
Connecting three-phase rectifier systems in parallel shows many advantages as compared to a single rectifier system with higher output power, such as higher reliability, smaller current and voltage ripple components, lower filtering effort, or higher system bandwidth. However, current unbalance or circulating currents can occur for modular design. In this paper, the parallel connection of two three-phase three-switch bucktype unity-power-factor pulsewidth-modulation rectifier systems is experimentally investigated for a 10-kW digital-signalprocessor-controlled prototype. A space vector modulation scheme is employed showing all the advantages of an interleaved operation. Three control schemes for active dc-link current balancing are described employing an additional freewheeling state that allows to influence the rate of change of the dc-link currents and can therefore be used for dc-link current balancing. The control schemes differ concerning control action and additional switching losses. Simulation and experimental results confirm the theoretical considerations: The dc-link current-balancing capability of the different control methods is compared, and the influence of the additional freewheeling state on switching losses and operation behavior is investigated. The most advantageous control method, which employs a hysteresis controller and shows limited switching losses, is selected. The analysis of the mains behavior shows an improvement as compared to a single rectifier operation.
Control of a single-stage three-phase boost power factor correction rectifier
2016 IEEE Applied Power Electronics Conference and Exposition (APEC), 2016
Advances in power electronics are enabling More Electric Aircrafts (MEAs) to replace pneumatic systems with electrical systems. Active power factor correction (PFC) rectifiers are used in MEAs to rectify the output voltage of the three-phase AC-DC boost converter, while maintaining a unity input power factor. Many existing control strategies implement PI compensators, with slow response times, in their voltage and current loops. Alternatively, computationally expensive nonlinear controllers can be chosen to generate input currents with high power factor and low total harmonic distortion (THD), but they may need to be operated at high switching frequencies due to relatively slower execution of control loop. In this work, a novel control strategy is proposed for a three-phase, singlestage boost-type rectifier that is capable of tight and fast regulation of the output voltage, while simultaneously achieving unity input power factor, without constraining the operating switching frequency. The proposed control strategy is implemented, using one voltage-loop PI controller and a linearized transfer function of duty-ratio to input current, for inner loop current control. A 1.5 kW three-phase boost PFC prototype is designed and developed to validate the proposed control algorithm. The experimental results show that an input power factor of 0.992 and a tightly regulated DC link voltage with 3% ripple can be achieved.
TURKISH JOURNAL OF ELECTRICAL ENGINEERING & COMPUTER SCIENCES
For some industrial converter applications such as battery chargers, a DC/DC converter is needed to step down the high DC (direct current) voltages generated by PWM (pulse with modulated) rectifiers to lower voltage levels such as 110V/220V. These both complicate the design and decrease the efficiency. In this paper, a novel topology that includes a step-down transformer and a novel control algorithm is proposed. The proposed current, which is synchronized, look-up table based, sinusoidal PWM control method (CS-LUT-SPWM method) using switching frequency-oriented synchronization (SWFOS) results in a very fast PWM generation and stable operation. Finally, a new thyristor-based start-up circuit providing safe operation when there is energy black out is proposed. A 32-kW converter has been designed, built, and tested to prove the concepts. The proposed converter has an efficiency higher than 94%, an input current total harmonic distortion (THDi) less than 5%, and a power factor closer to 0.99. Theoretical calculations and experimented results show that proposed converter has better efficiency (94%-96%) compared to classical PWM boost rectifiers with a series DC/DC converter topology (92%) in the literature. Fast PWM control algorithm, less complexity, low switching noises, one-stage conversion circuit, and novel start-up circuit are other advantages of the proposed converter.
Journal of power electronics
This paper presents an improved three-phase PFC power rectifier with a three-phase diode rectifier cascaded four-switch boost converter. Its operating principle contains the operating principle of two conventional three-phase PFC power rectifiers: one switch boost converter type and a two switch boost converter type. The operating characteristics of the four switch boost converter type three-phase PFC power rectifier are evaluated from a practical point of view, being compared with one switch boost converter type and two switch boost converter topologies.