METHOD FOR CONTROLLING AN ELECTRONIC POWER CONVERTER THAT IS CONNECTED TO A DIRECT-CURRENT SOURCE

摘要

The invention relates to a method for controlling an electronic power converter (9), which is connected to a direct-current source (12), comprises power conductor switches (10a...10f) that can be deactivated and which is designed to supply a distribution network (2) with three-phase voltage. According to said method, the currents that flow through the respective power semiconductor switches (10a...10f) are measured, whereby current values that are respectively assigned to the power semiconductor switches (10a...10f) are obtained, the current values are sampled and the sampled current values are digitised to obtain digital current values, the latter being checked by a logic that is implemented in a control unit for the presence of an excess current condition. If no excess current condition is detected, the power semiconductor switches (10a...10f) are activated and deactivated with the aid of a nominal operation controller and if an excess current condition is detected, at least the power semiconductor switches with assigned digital current values that fulfil the excess current condition are deactivated after a pulse block has expired. For the digital current values that fulfil the excess current condition, all power semiconductor switches (10a...10f), which are connected to the positive direct-current connection, are activated and all power semiconductor switches, which are connected to the negative direct-current connection are deactivated or vice versa. For the digital current values that do not fulfil the excess current condition, The power semiconductor switches (10a...10f) are controlled once again by the nominal operation controller.