Method for transmitting electrical power between an energy supply grid and an energy consumer or energy generation unit coupled to the energy supply grid, said method comprising the following steps: - detecting at least one electrical variable of the energy supply grid, - determining a discrepancy between the electrical variable and a rated variable of the energy supply grid which is assigned to the electrical variable, and - controlling the power transmission on the basis of the discrepancy, wherein the electrical variable is a line frequency of the energy supply grid and the rated variable is a rated frequency of the energy supply grid, wherein a first control range between a first and a second threshold value (24, 26) for the electrical variable is defined in which the power transmission is changed on the basis of the discrepancy of the electrical variable, wherein the rated variable is outside the first control range, and a second control range between a third and a fourth threshold value (30, 32) for the electrical variable is defined in which the power transmission is changed on the basis of the electrical variable, wherein the rated variable is between the second control range and the first control range, characterized in that - the line frequency relative to the rated frequency is used to ascertain whether the energy supply grid is oversupplied or is overloaded, and the line frequency in the second control range means that an oversupplied energy supply grid is assumed and the line frequency in the first control range means that an overloaded energy supply grid is assumed; and - the power transmission is interrupted in the event of discrepancies of the electrical variable that exceed the first and/or second control range (28, 34), the decision made on the basis of the line frequency being verified using a measured line voltage. - detecting at least one electrical variable of the energy supply grid, - determining a discrepancy between the electrical variable and a rated variable of the energy supply grid which is assigned to the electrical variable, and - controlling the power transmission on the basis of the discrepancy, wherein the electrical variable is a line frequency of the energy supply grid and the rated variable is a rated frequency of the energy supply grid, wherein a first control range between a first and a second threshold value (24, 26) for the electrical variable is defined in which the power transmission is changed on the basis of the discrepancy of the electrical variable, wherein the rated variable is outside the first control range, and a second control range between a third and a fourth threshold value (30, 32) for the electrical variable is defined in which the power transmission is changed on the basis of the electrical variable, wherein the rated variable is between the second control range and the first control range, - the line frequency relative to the rated frequency is used to ascertain whether the energy supply grid is oversupplied or is overloaded, and the line frequency in the second control range means that an oversupplied energy supply grid is assumed and the line frequency in the first control range means that an overloaded energy supply grid is assumed; and - the power transmission is interrupted in the event of discrepancies of the electrical variable that exceed the first and/or second control range (28, 34), the decision made on the basis of the line frequency being verified using a measured line voltage.