Transmitter unit and method for coupling an electrical transmission signal into a dc voltage line

A photovoltaic inverter comprising a transmitter circuit for coupling an electrical transmission signal into a DC voltage line, the transmitter circuit comprising two output terminals between which the electrical transmission signal is applied and which are configured to connect to a coupling circuit in the DC voltage line, wherein the transmitter circuit comprises an amplifier circuit comprising a clocked amplifier, and wherein an amplitude of the transmission signal is proportional to a supply voltage of the clocked amplifier,

• wherein the transmitter circuit comprises a compensation circuit which is configured to detect the amplitude of the transmission signal via a differential voltage measurement at the two output terminals and to set the supply voltage of the clocked amplifier depending on the amplitude of the transmission signal, and
• wherein the transmitter circuit is configured to couple the electrical transmitter signal into the DC voltage line, wherein a DC bus comprises the DC voltage line, and the DC bus connects the photovoltaic inverter to at least one photovoltaic generator for electrical power exchange.

A method for coupling a transmission signal into a DC voltage line, wherein the transmission signal is applied between two output terminals which are connected to a coupling circuit in the DC voltage line, comprising:

• generating the transmission signal using an amplifier circuit with a clocked amplifier, wherein the transmission signal comprises an amplitude that is proportional to a supply voltage of the clocked amplifier,
• detecting the amplitude of the transmission signal via a differential voltage measurement at the output terminals using a compensation circuit, and
• setting the supply voltage of the clocked amplifier based on the detected transmission signal amplitude using the compensation circuit.