# Single-Phase, Bidirectional, 7.7 kW Totem Pole On-Board Charging/Discharging Infrastructure
## 1 Introduction  
In the fast-growing, emission-free transportation revolution, the participation of electric vehicles (EVs) has increased exponentially. EVs are rapidly becoming an essential facet in the drive for attaining sustainable energy goals. In this regard, the expansion of the transportation revolution is being carried out by offering a versatile choice of EV chargers and charging infrastructures for end users. The choices of the EV charging infrastructures are classified based on the power levels, such as level 1, level 2, and level 3 [1, 2]. Amongst all levels, level-2 is best suited to single-phase and mid-range power applications. On the other hand, the charging infrastructure is constructed in terms of component placement, such as out-board and in-board placement--known as off-board and on-board, respectively [3]. Among both infrastructures, off-board charging has an advantage over on-board charging in terms of weight, space, and cost constraints. However, off-board chargers have the risk of vandalism and added clutter in an urban environment, as identified by [PERSON] et al. in [4]. However, the advancement in power electronics made it possible to overcome some problems, such as size, weight, and cost constraints for the on-board charging infrastructure [5]. At the same time, the on-board charging infrastructure has added advantages when it works in bidirectional mode. In a bidirectional charging infrastructure (BDCI), power flow is from the grid to the battery and vice versa. Additionally, the connected batteries have also been used to support the grid as an energy storage system in load-demand management and reactive power compensation [6, 7]. However, the charging and discharging performance depends upon the components used in the on-board BDCI. A BDCI consists of the grid, two bidirectional converters, and the EV/EVs. The first bidirectional converter is connected with the grid, which works as a rectifier (AC-DC) and an inverter (DC-AC) in grid-to-vehicle (G2V) and vehicle-to-grid (V2G) mode,respectively. The rectifier is used for the power factor correction (PFC) in G2V mode and the inverter is used to feedback the power from EV to the grid in V2G mode. On the other hand, the second bidirectional DC-DC converter is connected between DC-link of the first bidirectional converter and EV, which works in buck and boost mode, as shown in Figure 1. The buck and boost mode of the bidirectional DC-DC converter always depends upon the voltage level of the EV and DC-link. However, the first bidirectional converter plays a significant role in BDCI, ensuring its size, efficiency, power density, and harmonic content. In this direction, many researchers have proposed their contributions in resolving issues such as size, efficiency, power density, topology, and harmonic content. [PERSON] et al. [8] represented every aspect of EV's existence, such as the source of energy types, charging technologies, and emerging issues. In [9], [PERSON] et al. explained that the continuous conduction mode (CCM) eliminates the input current distortion, which is very much required to improve the power factor (PF). With respect to the grid-side converter topology, the authors in [10; 11; 12; 13] presented various bridge-less PFC topologies which reduce the overall conduction loss by reducing the number of rectifiers essentially eliminating the diode bridge rectifier that conducts the current from the input to the output. Similarly, in [14; 15; 16; 17; 18], the authors presented various topologies of PFC to obtain high efficiency as well as PF. Amongst various topologies, a bridge-less topology, i.e., totem pole, attracted enormous attention from researchers due to low conduction losses, less switching devices, and low common mode electromagnetic interferences (EMI). Authors have achieved an improved efficiency, power density, and power factor with fewer switching components, but are unable to present a bidirectional functionality of the power converter.