**3. Power flow in WPT system**

**T**he block diagram of the Power flow in WPT system becomes as shown in **Figure 6**. RF inverter converts the frequency of the power. Typically, RF inverter also converts the voltage of the power. Considering that the power is P = VI and the impedance is Z = V/I, the RF inverter also converts the impedance of the power. The rectifier in Rx side also changes the frequency of the power.

• High-frequency inverter converts the DC power to high frequency AC in the primary side. On the secondary side, the high-frequency AC energy is rectified to DC power and filtered to create a ripple free current that can charge the battery of EVs. The resonant frequency of the compensation topologies and coils determine the required switching frequency of the inverters. Usually used

• Compensation networks are located between the high-frequency inverter and the primary coil in the ground assembly (GA), while between the secondary coil and the rectifier in the vehicle assembly (VA). **Table 2** summaries these

inductance relationships for the basic compensation topologies SS, SP, PS, and PP are given in **Figure 8**. An optimal selection operation of the compensation topology based on the economics of the system is proposed in [18]. It concludes that SS and SP-compensation networks are the most appropriate topologies for high-power WPT systems. In addition, SS compensation needs less copper than

• Communication links. Evenly important to the power transfer system is the

communication to the GA grid connection to manage demand upon grid status.

communication link between GA and VA. This also contains the

resonance frequencies for WPT EV-chargers are within a range of

*(a) The base components of a WPT system for (b) EV charging system.*

*Wireless Power Charging in Electrical Vehicles DOI: http://dx.doi.org/10.5772/intechopen.96115*

networks and their efficiency. Power transfer efficiency with mutual

20–100 kHz [17].

**Figure 7.**

**35**

the other compensation networks.
