In　this　article,　a　robust　wireless　power　transfer　(WPT)　system　considering　a　wide　variation　in　load　resistance　and　coupling　coefficient　is　proposed　for　electric　vehicles　charging.　Here,　a　new　implementation　of　the　parity-time　(PT)-symmetric　circuit　using　a　phase　synchronization　method　is　presented,　in　which　a　power-adjustable　negative　resistor　is　constructed　only　by　a　single-stage　inverter.　Moreover,　based　on　the　PT-symmetric　circuit,　a　control　strategy　that　does　not　require　dual-side　communication　and　extra　dc-dc　converters　is　developed　for　battery　charging.　Theoretical　analysis　shows　that　constant　current　(CC)　and　constant　voltage　(CV)　outputs　independent　of　load　and　position　can　be　achieved,　and　the　charging　mode　can　be　switched　automatically.　A　scaled-down　prototype　with　an　8-A　charging　current　and　a　120-V　charging　voltage　is　built　to　verify　the　feasibility　of　the　proposed　method.　Experimental　results　demonstrate　that　within　the　transfer　distance　of　10-25　cm,　the　CC/CV　outputs　can　be　maintained　during　the　charging　process.