LCC Compensation Network Research Articles

A New ZVS Tuning Method for Double-Sided LCC Compensated Wireless Power Transfer System

This paper presents a new zero voltage switching (ZVS) tuning method for the double-sided inductor/capacitor/capacitor (LCC) compensated wireless power transfer (WPT) system. An additional capacitor is added in the secondary side of the double-sided LCC compensation network in order to tune the network to realize ZVS operation for the primary-side switches. With the proposed tuning method, the turn off current of the primary-side switches at the low input voltage range can be reduced compared with the previous ZVS tuning method. Consequently, the efficiency of the WPT at the low input voltage range is improved. Moreover, the relationship between the input voltage and the output power is more linear than that of the previous ZVS tuning method. In addition, the proposed method has a lower start-up voltage. The analysis and validity of the proposed tuning method are verified by simulation and experimental results. A WPT system with up to 3.5 kW output power is built, and 95.9% overall peak efficiency is achieved.

A Crossed DD Geometry and Its Double-Coil Excitation Method for Electric Vehicle Dynamic Wireless Charging Systems

Dynamic wireless charging technology can supply power for electric vehicle (EV) while it is in-motion. However, the system output stability is heavily influenced by the mutual inductance variation of the magnetic coupler, which is a major drawback of the EV dynamic wireless power transfer (EV-DWPT). This paper focuses on the primary coil design and its activating method. First, the LCC compensation network was adopted in both primary side and pick-up side of the system to achieve the constant primary current characteristic. Subsequently, a double-coil excitation method with the crossed-DD coil structure was proposed, which specifically concentrates on the feature of the dynamic mutual inductance. Simulation studies were carried out to prove the effectiveness of the proposed system. An EV-DWPT system prototype was performed to further verify the theoretical and simulation results.

Dynamic Wireless Power Transfer System for Electric Vehicles Employing Multiplexing LCC Modules With Individual Transmitters

Dynamic wireless power transfer (DWPT) of electric vehicles employing individual transmitters is getting popular owing to the advantages of high efficiency and less unwanted magnetic field emissions. However, too many power supply devices and passive components of compensation networks will make individual-transmitter-type DWPT systems under intense cost pressure for a long charging lane. Besides, circuit parameters of different transmitters will be different due to unignored component errors. Therefore, in this paper, a cost-reducing multiplexing LCC module (MLM) is proposed, and the effects of passive component errors are considered. An MLM makes unenergized transmitter work as a part of LCC compensation network resulting in no additional inductor. Simultaneously, one power inverter is shared by two transmitters in an MLM and 50% of inverters can be reduced. A novel distribution method and matched controlling storage of MLMs are proposed so that any two adjacent transmitters can be controlled independently and simultaneously. Due to passive component errors, unwanted reactive load will be placed on the inverter, and different transmitters will have different output power even in the same coupling and loading condition. A voltage adjustment method and a redistribution of passive components for MLMs are proposed to solve these problems. At last, a 6-kW-level laboratory scale prototype has been constructed and tested.

Crosstalk Study of Simultaneous Wireless Power/Information Transmission Based on an LCC Compensation Network

The effective simultaneous wireless transmission of power and information (SWTPI) is an issue of great interest. To reduce the crosstalk between power and information channels while increasing the transmission air gap and power level, we introduce an inductor–capacitor–capacitor (LCC) compensation network for an SWTPI system. First, the crosstalk between the power and information channels is analyzed. An effective parametric design method is then proposed for the LCC compensation network, which is analyzed theoretically to minimize the crosstalk. Finally, experiments are conducted at 1000 W and 115.2 kbps with an air gap of 100 cm to verify whether the proposed structure and design method of the LCC compensation network are suitable for the SWTPI.

A new integration method with minimized extra coupling effects using inductor and capacitor series-parallel compensation for wireless EV charger

Wireless electric vehicle charger has become increasingly popular because of its improved convenience and safety. The recently proposed inductor-capacitor-capacitor (LCC) compensated topology and bipolar magnetic coupler structure have promoted the comprehensive performance of the wireless power transfer (WPT) system. Furthermore, the idea of integrating the magnetic components in the LCC compensated WPT system has been proposed for reducing the bulk. However, the extra inter-couplings between the adjacent coils are also introduced, which complicates the parameters design and the characteristic analysis. In this paper, a new integration method is presented for wireless EV charger adopting LCC compensation networks along with bipolar coupler. The impact of the extra couplings is evaluated thoroughly through the circuit analysis and simulation. The finite element analysis (FEA) tool is utilized to evaluate the extra coupling effects of the compensated coils, which leads to the proposed integration coupler structure. The comparison of the unipolar and the bipolar as the compensated coils for the extra coupling minimizing is discussed considering the misalignment. At last, a prototype of the magnetic coupler with a size of 550mm×500mmhas been built and tested. A peak efficiency of 95% is achieved while transferring 6.6kW electric power from a DC power source to the load in the condition of 150mm vertical clearance.

Magnetic Integration of LCC Compensation Topology with Minimized Extra Coupling Effects for Wireless EV Charger

Abstract Wireless electric vehicle charger has become increasingly popular because of its improved convenience and safety. The recently proposed doubled-sided LCC compensated topology and bipolar magnetic coupler structure have promoted the comprehensive performance of the wireless power transfer (WPT) system. Furthermore, the idea of integrating the magnetic components in the LCC compensated WPT system has been proposed for reducing the bulk. However, the extra inter-couplings between the adjacent coils are also introduced, which complicates the parameters design and the characteristic analysis. In this paper, a new integration method is presented for wireless EV charger adopting LCC compensation networks along with bipolar coupler. The impact of the extra couplings is evaluated through circuit analysis and simulation. The finite element analysis (FEA) tool is utilized to simulate the extra coupling effects of the compensated coil, which leads to the proposed integration coupler structure. At last, a 550 mm × 500 mm with a nominal 150-mm-gap and 6.6-kW-power prototype, has been built and tested. A peak efficiency of 95% from a DC power source to the load is achieved.

Applying <italic>LCC</italic> Compensation Network to Dynamic Wireless EV Charging System

Based on the wireless power transfer (WPT) technology, dynamic wireless charging of electric vehicle (EV) is gaining increasing attentions because it promotes the popularization of EV and also serves a new form of clean transportation. In this paper, we introduce the LCC compensation network to WPT system oriented for dynamic wireless EV charging application. First, characteristics of symmetrical T-type network, which is the origin of the favorable LCC compensation network, are summarized. Then, parametric design for both the LCC network used in the secondary side and the LCC network used in the primary side is elaborated theoretically. Furthermore, neighboring effects resulting from the combination of the LCC compensation network and the inevitable inter-coupling between adjacent segments are investigated. Finally, a two-segment LCC compensated dynamic EV charging system is built up and tested with both intra-segment and inter-segment experiments. Spatially averaged output power and dc-dc efficiency of the prototype are measured to be 2.34 kW and 91.3%, respectively. High consistency of the experimental results validates the correctness of the proposed analyses and parametric design method, as well as the suitability of applying LCC network in dynamic wireless EV charging applications.

Compact and Efficient Bipolar Coupler for Wireless Power Chargers: Design and Analysis

Compactness and efficiency are the two basic considerations of the wireless battery chargers for electric vehicles (EVs) and plug-in hybrid EVs. The double-sided LCC compensation topology for wireless power transfer (WPT) has been proved to be one of the efficient solutions lately. However, with the increase of the numbers of compensation components, the volume of the system may become larger, which makes it less attractive. To improve the compactness, a bipolar coupler structure with a compensation-integrated feature is proposed. The inductors of the LCC compensation networks are designed as planar-type and attached to the power-transferring main coils. Extra space and magnetic cores for the compensated inductors outside of the coupler are saved. The cost is that extra couplings between the compensated coils (inductors) and the main coils are induced. To validate the feasibility, the proposed coupler is modeled and investigated by 3-D finite-element analysis tool first. The positioning of the compensated coils, the range of the extra couplings, and the tolerance to misalignment are studied. This is followed by the circuit modeling and characteristic analysis of the proposed WPT topology based on the fundamental harmonic approximation. At last, a 600 mm × 600 mm with a nominal 150-mm-gap wireless charger prototype, operated at a resonant frequency of 95 kHz and a rated power of 5.6 kW has been built and tested. A peak efficiency of 95.36% from a dc power source to the battery load is achieved at rated operation condition.

A Double-Sided LCC Compensation Network and Its Tuning Method for Wireless Power Transfer

This paper proposes a double-sided LCC compensation network and its tuning method for wireless power transfer (WPT). With the proposed topology and its tuning method, the resonant frequency is irrelevant with the coupling coefficient between the two coils and is also independent of the load condition, which means that the system can work at a constant switching frequency. Analysis in frequency domain is given to show the characteristics of the proposed method. We also propose a method to tune the network to realize zero voltage switching (ZVS) for the Primary-side switches. Simulation and experimental results verified analysis and validity of the proposed compensation network and the tuning method. A wireless charging system with output power of up to 7.7 kW for electric vehicles was built, and 96% efficiency from dc power source to battery load is achieved.