Voltage/Current Doubler Converter for an Efficient Wireless Charging of Electric Vehicles With 400V and 800V Battery Voltages

The lithium-ion battery of an electric vehicle (EV) is typically rated at either 400 or 800 V. When considering public parking infrastructures, EV wireless chargers must efficiently deliver electric power to both battery options. This can be normally achieved by regulating the output voltage through a dc-dc converter at the cost of higher...

Design Trade-Offs Between the Coupled Coils’ Inductance and the Series-Series Compensation Capacitance for EV Wireless Charging Systems

Nowadays, inductive power transfer (IPT) with magnetic resonance is the most used method for high-power wireless battery charging applications. Once the topology of the compensation network and the operating frequency are selected, there are infinite combinations of the circuit equivalent inductance and compensation capacitance values resonating...

Interoperability of the Voltage/Current Doubler Converter Employing Bipolar Pads with the SAE J2954 VA WPT2/Z2 for EV Wireless Charging

This paper investigates the interoperability of the proposed voltage/current doubler (V/I-D) converter used for wireless charging of electric vehicles (EVs), which achieves high efficiency when charging both 400V and 800V batteries at the same power. Nominally, the V/I-D converter employs bipolar pads (BPP) at both the primary and the secondary...

Continuous Reduced-Order Dynamic Model Based on Energy Balancing for Inductive Power Transfer Systems

Resonant circuits are commonly used in inductive power transfer (IPT) systems for the charging of electric vehicles because of the high power efficiency. Transient behaviors of the resonant circuits, which play a significant role in the design and analysis of IPT systems, are cumbersome to model analytically because of the high-order. This...

Inductive Power Transfer based on Variable Compensation Capacitance to Achieve an EV Charging Profile with Constant Optimum Load

Wireless charging must be highly efficient throughout the entire battery charging profile to compete in the electric vehicle (EV) industry. Thus, optimum load matching is commonly used: it operates at the equivalent load that maximizes the efficiency, which depends on the coil's alignment. In this article, the optimum load is made independent...

Auto-Resonant Detection Method for Optimized ZVS Operation in IPT Systems With Wide Variation of Magnetic Coupling and Load

In wireless charging systems, the H-bridge converter's switching frequency is set close to the system's natural resonance for achieving optimized zero voltage switching (ZVS). Variations to the system's natural resonance are commonly tracked by following the changes in the resonant current's polarity, i.e., current zero-crossings. The main...

Design of Misalignment Tolerant Control for an Inductive Charger with V2G Possibilities

Since the power transfer efficiency in inductive power transfer (IPT) systems is directly related to the coupling of the transformer, coil misalignment can drastically decrease the efficiency. In this paper a misalignment tolerant control scheme is proposed which tracks the maximum power transfer efficiency point under misalignment. It does this...

Analysis of Magnetic Field Emissions in Inductive Power Transfer EV Chargers Following Reference Designs in SAE J2954/2019

This paper aims to investigate the radiated magnetic field by 11 kW inductive power transfer (IPT) systems used for the charging of electric vehicles. Two reference designs suggested by SAE J2954 are studied. Both designs are analysed to obtain the coils winding currents, and 3D FEM models are built in COMSOL without considering the car chassis,...

Electric Vehicle Charging Based on Inductive Power Transfer Employing Variable Compensation Capacitance for Optimum Load Matching

In inductive power transfer applications, it is possible to ensure high efficiency of the main coils by operating at the optimum load. Since the optimum load depends on the coupling between the main coils, the operation needs to be adapted to match this case at different alignment conditions. This paper proposes a method to keep the optimum load...

Compensation Network for a 7.7 kW Wireless Charging System that Uses Standardized Coils

Industrial wireless charging systems use standardized coils to guarantee interoperability between different manufacturers. In combination with these coils, the compensation network can still be designed and optimized. This paper explains the step-by-step design of the compensation network for a 7.7 kW wireless charging system (power class WPT2),...

Auto-resonant Control of the H-Bridge Resonant Converter for Inductive Power Transfer Applications

In inductive power transfer applications that use resonant compensation networks, the commonly employed H-bridge inverter should be kept operating in soft-switching to ensure high power efficiency and low irradiated electromagnetic noise. To achieve so, the zero-crossing detection circuit for the resonant current or voltage must be fast and...

Comparative Study of Foreign Object and Misalignment in Inductive Power Transfer Systems

This paper aims to identify the difference between foreign object (FO) and misalignment in terms of their influence on inductive power transfer (IPT) systems. This is performed through magnetic and equivalent circuit analysis of the mutual inductance, primary input impedance, charging pad terminal impedance and current harmonics. Experiment...