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ABSTRACT
In this paper, a wireless charging system that can perform coil capacity optimization and dynamic protection is proposed for mobile robots. Poor wireless charging performance might be obtained because of the inability to achieve reliable capacity estimation and effective charging detection; therefore, in this study, suitable solutions were identified for capacity estimation and effective charging detection. First, resonance analysis was conducted on a systematic flexible coil design to maximize its charging capacity. Second, a dynamic protection mechanism was developed to handle unexpected charging mistakes caused by misalignment. Third, a pickup terminal feedback system integrated with a Bluetooth chip and microprocessor unit was embedded to maintain the requisite output voltage. This system was validated through simulations and hardware implementations. The experimental results indicate that a setup based on the proposed design delivers a power of 3.2 kW at an efficiency of 91.4%, which confirms the efficacy and feasibility of the proposed approach for robot charging.
CO EDITOR-IN-CHIEF:
Nomenclature
| ar | = | Turns ratio of the coil module |
| Cp and Cs | = | Compensated capacitances of the transmitter and receiver, respectively |
| Cf | = | Stabilized output filter capacitor |
| Dg1–Dg4 | = | Duty cycle signals of MOSFETs S1–S4, respectively |
| fo | = | Operation frequency |
| ga | = | Air gap between coils Lp and Ls |
| ip and is | = | Operation currents of coils Lp and Ls, respectively |
| Iin and Io | = | Input and output currents of the proposed system, respectively |
| Ip-t | = | Feedback signals of current ip in the phase-triggering format |
| Ip-f | = | Feedback signals of current ip in DC voltage format |
| iReq | = | Operation current of the equivalent load resistor |
| iCs | = | Operation current of the filter capacitor Cf |
| k | = | Coupling coefficient |
| Lp and Ls | = | Inductances of the transmitting coil and pickup coil, respectively |
| Mtr | = | Mutual inductance between coil Lp and coil Ls |
| Pin and Po | = | Input power and rated output power of the proposed WPT system, respectively |
| Req | = | Equivalent load resistance |
| S1–S4 | = | Silicon carbide n-channel MOSFETs of the full-bridge inverter |
| Vin and Vo | = | Input and output voltages of the proposed WPT system, respectively |
| vab and vab(rms) | = | Rectangular output voltage of the full-bridge inverter and its root-mean-square value, respectively |
| vp and vs | = | Operation voltages of coils Lp and Ls, respectively |
| vg1–vg4 | = | Driving signals of MOSFETs S1–S4, respectively |
| Vp-f and Vo-f | = | Feedback signals of voltages vp and Vo, respectively, in the DC voltage format |
| Vab-t | = | Feedback signals of voltage vab in the phase-triggering format |
| Ztol | = | Equivalent impedance of the compensation circuit |
| ηtr | = | Coupling efficiency between vab(rms) and vs |
| ɵt | = | Phase angle between Vab-t and Ip-t |
Disclosure statement
No potential conflict of interest was reported by the author(s).