Single-Stage Isolated and Bidirectional Three-Phase Series-Resonant AC–DC Converter: Modulation for Active and Reactive Power Control

Abstract

Single-stage isolated and bidirectional (SSIB) AC–DC converters have a high potential for future solid-state transformers and smart battery chargers due to their reduced volume and high efficiency. However, there is a research gap for SSIB reactive power injection. This article introduces an SSIB three-phase AC–DC converter composed of three low frequency rectifiers linked by tiny film capacitors with a quad-active-bridge series-resonant (QABSR) DC–DC. A novel QAB modulation is proposed to solve three issues: (1) Three DC inputs with high ripple compensation, (2) active–reactive power injection, and (3) minimization of high-frequency (HF) transformers currents. The rectified grid voltages were modulated by time-variant duty ratio (DR) angles. In contrast, the DC source was modulated by a fixed DR (FDR) angle along with a phase-shift angle which changes according to the grid current amplitude. A constant HF current amplitude with minimum value was obtained. It is shown that the HF current amplitude is increased for reactive power injection. Hence, the FDR angle was used to compensate for this increase. Active and reactive power control were validated in a 2 kW prototype. Compared with other structures, tiny DC-link capacitors and smaller L filters were used. Moreover, higher efficiency (96%) and smaller grid currents THDi (3%) were obtained.

Overview on Battery Charging Systems for Electric Vehicles

“…The particular configuration selected hinges on the specific application prerequisites and the desired performance outcomes. Within DC-DC power converters, the choice of transformer configuration can significantly influence voltage and current levels, as well as the overall efficiency and power density of the converter [141][142][143]. In general, the DAB converter, in both its single-phase and three-phase configurations, is an advanced solution for on-board chargers in electric vehicles.…”

Impact of Heat Pump and Cogeneration Integration on Power Distribution Grids Based on Transition Scenarios for Heating in Urban Areas

“…The results in Section 3.3 show that a reinforcement of the cables in the grid to reduce the over line-loading still remains a high amount of under-voltage buses. As PV systems are connected to the grid through power electronic inverters, they could be able to inject reactive power into the grid, even when no solar irradiation and therefore no active power is available (see [15,16]). Scenario 1 with a full heat pump solution is adapted in a way that the photovoltaic systems inject reactive power into the grid based on their capacity S i and active power P i (t) derived from available solar irradiation at at time-step i according to:…”

A Survey on Multi-Active Bridge DC-DC Converters: Power Flow Decoupling Techniques, Applications, and Challenges

“…The secondary windings of the transformers are connected to the third H-bridge which behaves as a voltage bus, and hence each of the ports can have independent power flow controls. Figure 23b illustrates the proposed topology of a triple transformer resonant QAB converter in [80], where the common port contains a series LC resonant circuit. In addition to discussing topologies and methods for decoupling power flow at the circuit level, the research presented in [189] emulated a negative inductance to eliminate the effect of the leakage inductance of the common port winding.…”

“…Since a three-port MAB converter or triple active bridge (TAB) converter can meet the requirements in many applications, it is the most explored type of MAB converter [77]. However, depending on the application, adding more active bridges to achieve a higher number of ports has been proposed, resulting in the quadruple active bridge (QAB) [12,17,23,39,40,43,[46][47][48][49]51,52,[54][55][56][60][61][62]70,[78][79][80][81][82][83][84][85][86][87][88][89][90], penta active bridge (PAB) [41], 6-port [91], 10-port [75], and 12-port [35,92,93] MAB converters. Although adding more ports can provide potential advantages over the DAB converter, converter analysis becomes more complicated, and a research gap arises between the conventional DAB and the various MAB converters.…”

“…A similar topology, that consists of three full H-bridges, is proposed in [31] to supply loads in a bipolar DC distribution grid. The work in [80] combines a series-connected triple transformer-based MAB resonant converter with three H-bridge inverters to create a DC to three-phase structure and HF three-phase decoupling is implemented to reduce interaction.…”