Method of dc undervoltage regulation and/or dc overvoltage regulation for electric power converter, electric power converter, and dc microgrid

A method of a DC undervoltage regulation and/or a DC overvoltage regulation for an electric power converter, the method comprising:

• monitoring a DC voltage by the electric power converter;
• comparing the DC voltage to an undervoltage regulation limit and/or an overvoltage regulation limit defined at least by a user-specified or process-specified undervoltage limit and/or a user-specified or process-specified overvoltage limit, wherein, when the DC undervoltage regulation or the DC overvoltage regulation is in an inactivated state, the undervoltage regulation limit and/or the overvoltage regulation limit are/is at least partially, preferably completely, droop-compensated by utilizing an undervoltage drooping coefficient or an overvoltage drooping coefficient, respectively;
• activating the DC undervoltage regulation or the DC overvoltage regulation as a response to the DC voltage reaching the undervoltage regulation limit or the overvoltage regulation limit, respectively, for changing the DC undervoltage regulation or the DC overvoltage regulation into an activated state;
• regulating the DC voltage, when the DC undervoltage regulation or the DC overvoltage regulation is in the activated state, by adjusting loading of the electric power converter based on an undervoltage loading adjustment coefficient or an overvoltage loading adjustment coefficient, respectively, wherein the undervoltage loading adjustment coefficient and/or the overvoltage loading adjustment coefficient are/is based on a voltage difference between the undervoltage regulation limit or the overvoltage regulation limit, and the DC voltage, and based on the undervoltage drooping coefficient or the overvoltage drooping coefficient;
• and
• deactivating the DC undervoltage regulation or the DC overvoltage regulation when the DC voltage becomes higher than the user-specified or process-specified undervoltage limit or lower than the user-specified or process-specified overvoltage limit, respectively.