SMA Solar Technology AG | Date: 2015-10-28
In order to measure a choke current through a choke, a flux density of a magnetic field which is emitted by the choke is consecutively measured at a sampling rate at a location which is fixed in relation to the choke. A magnetic bias of the choke is ascertained from the measurement values of the flux density at a known choke current which occurs during operation of the choke, wherein the choke current is known only in longer time intervals than the inverse value of the sampling rate during measurement of the flux density. The actual choke current is determined from the actual measurement values of the flux density taking into account the ascertained magnetic bias.
SMA Solar Technology AG | Date: 2015-01-30
The disclosure relates to a DC/DC converter including at least one clocked switching member and at least one inductor which is arranged between an input connection and an output connection of the DC/DC converter and is for intermediate storage of energy transferred by the DC/DC converter, wherein the inductor has a core with permanent magnetization. The DC/DC converter is configured for bidirectional operation, wherein, in a first energy transfer direction, the at least one switching member is switched in a first operating mode and, in a second energy transfer direction which is opposite to the first, the at least one switching member is switched in a second operating mode which deviates from the first. The disclosure also relates to an operating method for a DC/DC converter.
SMA Solar Technology AG | Date: 2015-01-13
To stabilize the grid voltage in a grid section which is connected to a higher-level grid via an apparatus having a variable voltage transformation ratio and which includes at least one energy consumption or generation unit, the voltage transformation ratio is changed in order to change a grid voltage level in the grid section. In at least in one mode of the method the grid voltage level is raised in order to counteract a rise in the grid voltage at the energy consumption or generation unit, or the grid voltage level is lowered in order to counteract a drop in the grid voltage at the energy consumption or generation unit. This is effectively possible since the power consumption or output of each energy consumption or generation unit in the grid section is controlled via a characteristic curve of the grid voltage present there.
SMA Solar Technology AG | Date: 2015-06-12
In order to protect reverse currents, several strings of a photovoltaic generator, which are connected in small groups respectively via a DC/DC-converter, parallel to a common DC voltage intermediate circuit, the current which flows over each of the DC/DC-converter is detected and if a reverse current is detected flowing through one of the DC/DC converters, the converter is stopped by controlling the DC/DC-converter.
SMA Solar Technology AG | Date: 2015-03-17
A method for converting DC power from a source into AC power by means of an inverter which includes three bridge branches, each having a phase output, is described. During grid-connected operation, the bridge branches are actuated in such a way that the AC power is fed, as three-phase grid-compliant power, into a grid. During emergency operation of the inverter, the AC power is provided as single-phase island grid by two of the three bridge branches at the phase outputs thereof, wherein the inverter is disconnected from the grid.