Current Hysteresis Control of a Single Phase Integrated Battery Charger With Active Power Decoupling

Abstract

In today’s world, electric vehicles are starting to get more prominence in the automobile sector. Electric Vehicles (EVs) have a smaller carbon footprint and hence a lesser impact on climate. The number of EVs currently in use is lesser when compared to the number of Internal Combustion Engine (ICE) based vehicles. Typically, there are two types of chargers for EVs: off-board chargers and onboard chargers. With off-board chargers, the vehicle needs to be connected to an external charging circuitry, and one setback is the non-availability of a charging network. Onboard chargers have the charger circuit as a part of the EV. Integrated chargers are a type of onboard chargers that will use a single circuit to charge the battery and drive the motor. This will reduce the size, weight, and cost of the charger and reduce the EV’s charging time. In this paper, a novel single-phase integrated battery charger is discussed. Using a single-phase-based system for charging decreases the dependence on charging stations, as the EV can be charged by connecting to any single-phase grid available in households or industries. Single-phase grid-connected systems often suffer from second harmonic ripple power on the DC link. With the help of an active decoupling technique, the excess energy can be stored in one of the motor windings. Hence, the second harmonic oscillation of power on the DC side can be eliminated. For the control of current in the decoupling winding, a hysteresis controller is implemented in this work. The hysteresis controller is easy to implement, provides inherent short circuit protection, and ensures that the decoupling current is within the specified limits. The simulation results for the system are also presented in the paper.