A power carrier signal coupling circuit, connected to a three-phase alternating current, AC, power line, comprising: a first power carrier signal coupling channel, comprising a first capacitor; and a second power carrier signal coupling channel, comprising a second capacitor, wherein a phase of the three-phase AC power line serves as a common channel, the first power carrier signal coupling channel is arranged between the common channel and one of two phases of the three-phase AC power line other than the common channel, the second power carrier signal coupling channel is arranged between the common channel and the other of the two phases of the three-phase AC power line other than the common channel, and a power carrier signal is coupled into the first power carrier signal coupling channel and the second power carrier signal coupling channel, wherein the power carrier signal coupling circuit further comprises: a signal transceiver; a coupling transformer, comprising a primary winding, a first secondary winding and a second secondary winding, wherein a first terminal of the first secondary winding is connected to the signal transceiver, a second terminal of the first secondary winding is connected to a first terminal of the second secondary winding, and a second terminal of the second secondary winding is connected to the signal transceiver; and a first transient voltage suppressor diode, wherein a cathode of the first transient voltage suppressor diode is connected to the common channel, and an anode of the first transient voltage suppressor diode is connected to the two phases of the three-phase AC power line other than the common channel, wherein a first terminal of the first capacitor is connected to one of the two phases of the three-phase AC power line other than the common channel, a second terminal of the first capacitor is connected to a first terminal of the primary winding, a first terminal of the second capacitor is connected to the other of the two phases of the three-phase AC power line other than the common channel, a second terminal of the second capacitor is connected to the first terminal of the primary winding, and a second terminal of the primary winding is connected to the common channel. a first power carrier signal coupling channel, comprising a first capacitor; and a second power carrier signal coupling channel, comprising a second capacitor, wherein a phase of the three-phase AC power line serves as a common channel, the first power carrier signal coupling channel is arranged between the common channel and one of two phases of the three-phase AC power line other than the common channel, the second power carrier signal coupling channel is arranged between the common channel and the other of the two phases of the three-phase AC power line other than the common channel, and a power carrier signal is coupled into the first power carrier signal coupling channel and the second power carrier signal coupling channel, wherein the power carrier signal coupling circuit further comprises: a signal transceiver; a coupling transformer, comprising a primary winding, a first secondary winding and a second secondary winding, wherein a first terminal of the first secondary winding is connected to the signal transceiver, a second terminal of the first secondary winding is connected to a first terminal of the second secondary winding, and a second terminal of the second secondary winding is connected to the signal transceiver; and a first transient voltage suppressor diode, wherein a cathode of the first transient voltage suppressor diode is connected to the common channel, and an anode of the first transient voltage suppressor diode is connected to the two phases of the three-phase AC power line other than the common channel, wherein a first terminal of the first capacitor is connected to one of the two phases of the three-phase AC power line other than the common channel, a second terminal of the first capacitor is connected to a first terminal of the primary winding, a first terminal of the second capacitor is connected to the other of the two phases of the three-phase AC power line other than the common channel, a second terminal of the second capacitor is connected to the first terminal of the primary winding, and a second terminal of the primary winding is connected to the common channel. a signal transceiver; a coupling transformer, comprising a primary winding, a first secondary winding and a second secondary winding, wherein a first terminal of the first secondary winding is connected to the signal transceiver, a second terminal of the first secondary winding is connected to a first terminal of the second secondary winding, and a second terminal of the second secondary winding is connected to the signal transceiver; and a first transient voltage suppressor diode, wherein a cathode of the first transient voltage suppressor diode is connected to the common channel, and an anode of the first transient voltage suppressor diode is connected to the two phases of the three-phase AC power line other than the common channel, wherein a first terminal of the first capacitor is connected to one of the two phases of the three-phase AC power line other than the common channel, a second terminal of the first capacitor is connected to a first terminal of the primary winding, a first terminal of the second capacitor is connected to the other of the two phases of the three-phase AC power line other than the common channel, a second terminal of the second capacitor is connected to the first terminal of the primary winding, and a second terminal of the primary winding is connected to the common channel.