A transceiver device adapted to be operatively coupled with a protection and control device for electric power distribution systems to provide wireless connectivity to said protection and control device, said transceiver device comprising: - a transceiver unit including a RF antenna; - a serial communication port adapted to be operatively coupled with a further corresponding serial communication port of said protection and control device; - a serial communication bus electrically connected between said serial communication port and said transceiver unit, said serial communication bus having a transmission line and a reception line, the transceiver device being configured such that in operation said transmission line takes a high-level voltage value (V H), when said transmission line is in a stand-by condition, and a low-level voltage value (V L), when said transmission line is in an active condition; - a battery unit; - a feeding unit adapted to feed said transceiver unit with a feeding voltage (V DD), said feeding unit comprising a first power supply stage electrically coupled with said battery unit to harvest electric power from said battery unit and a second power supply stage electrically coupled with the transmission line of said serial communication bus to harvest electric power from said transmission line, when said transmission line is in said stand-by condition and takes said high-level voltage value (V H); - wherein said feeding unit further comprises a voltage switching stage electrically connected with said first and second power supply stages (51, 52) to receive a first voltage (V 1) from said first power supply stage and a second voltage (V 2) from said second power supply stage, said voltage switching stage being adapted to select said first voltage (V 1) or said second voltage (V 2) as said feeding voltage (V DD) to feed said transceiver unit; characterised in that said transceiver unit is adapted to: - check an average value calculated over a predetermined time period, of said feeding voltage (V DD) received by said transceiver unit from said voltage switching stage; - make said voltage switching stage to select said second voltage (V 2) as said feeding voltage (V DD), if the average value of said feeding voltage is not lower than a threshold voltage value and - make said voltage switching stage to select said first voltage (V 1) as said feeding voltage, if the average value of said feeding voltage is lower than said threshold voltage value. - a transceiver unit including a RF antenna; - a serial communication port adapted to be operatively coupled with a further corresponding serial communication port of said protection and control device; - a serial communication bus electrically connected between said serial communication port and said transceiver unit, said serial communication bus having a transmission line and a reception line, the transceiver device being configured such that in operation said transmission line takes a high-level voltage value (V H), when said transmission line is in a stand-by condition, and a low-level voltage value (V L), when said transmission line is in an active condition; - a battery unit; - a feeding unit adapted to feed said transceiver unit with a feeding voltage (V DD), said feeding unit comprising a first power supply stage electrically coupled with said battery unit to harvest electric power from said battery unit and a second power supply stage electrically coupled with the transmission line of said serial communication bus to harvest electric power from said transmission line, when said transmission line is in said stand-by condition and takes said high-level voltage value (V H); - wherein said feeding unit further comprises a voltage switching stage electrically connected with said first and second power supply stages (51, 52) to receive a first voltage (V 1) from said first power supply stage and a second voltage (V 2) from said second power supply stage, said voltage switching stage being adapted to select said first voltage (V 1) or said second voltage (V 2) as said feeding voltage (V DD) to feed said transceiver unit; - check an average value calculated over a predetermined time period, of said feeding voltage (V DD) received by said transceiver unit from said voltage switching stage; - make said voltage switching stage to select said second voltage (V 2) as said feeding voltage (V DD), if the average value of said feeding voltage is not lower than a threshold voltage value and - make said voltage switching stage to select said first voltage (V 1) as said feeding voltage, if the average value of said feeding voltage is lower than said threshold voltage value.