Study On The Simultaneous Wireless Power And Data Transmission Technology Based On The Harmonic Communication

Compared with the traditional cable power supply method,wireless power transfer(WPT)technology,characterized by avoiding the security risks like electric spark and leakage caused by the poor connections between the plugs,has attracted wide attention.As a mature implementation in WPT technology,inductively coupled power transfer(ICPT)technology is characterized by its safety,reliability,flexibility,convenience,and a wide range of power transmission.It has been successfully applied in various fields such as automatic guided vehicles,electric vehicles,and wireless sensor networks.In most applications,communication between the primary side and the secondary side is usually required.For example,sending control messages to the sencondary side,monitoring the status of battery load,and feedback control of the output voltage,etc.,all these need to set up better communication mechanism between the primary and secondary side without effecting power transmission.Therefore,according to the requirments,simultaneous wireless power and data transmission technology based on the harmonic communication is proposed in this paper.The fundamental component in the system is employed to transmit power and harmonic components to transmit data.In the proposed technology,the fundamental and harmonic components are coupled on the primary side and decoupled through frequency selecting circuits on the secondary side.Meanwhile,the key parameters of the system are determined by crosstalk analysis between power and data transmission.Finally,the simultaneous transmission of power and data can be realized without interference.Firstly,according to the requirements for simultaneous transmission of power and data in practical applications,the common types of wireless power and data transmission technology in current ICPT systems are summarized and analyzed.And the basic principles and pros and cons of various technologies have been introduced in detail Given the shortcomings of current research status,the scheme for the simultaneous power and data transmission based on the harmonic carrier has been proposed.Then,two methods of frequency modulation and phase modulation are applied to the signal transmission scheme proposed in this paper,respectively.For frequency modulation,the model of power transmission,signal transmission,and efficiency are built.The crosstalk between power and data transmission is analyzed by taking the coil self-inductance and operating frequency as independent variables,and system parameters are designed according to the analysis results.For phase modulation,the half-cycle operating modes of the phase-shifted full-bridge inverter are mainly introduced,and the effect of the phase angles on various parameters of the system is analyzed in detail.Similarly,the interval of phase angles is also determined through the crosstalk analysis of the power channel and the data channel.Finally,the theoretical correctness and practical feasibility of the proposed technology under two modulation methods are verified with simulation and experiment.For frequency modulation,it is indicated that the baud rate of stable signal transmission is up to 5k Bd when the output power is 50 W.But the output voltage is silightly effected by data transmission in the experimental results.For phase modulation,the maximum baud rate can reach 7k Bd when the output power is 45 W,and the output voltage can keep stable when transmitting data.In the end,it is shown that data transmission is independent on the coil gap within a certain range in both experiments.67 figures,7 tables and 77 references are included in this thesis.