Loading patent…
AssigneeSiemens Aktiengesellschaft
InventorMichael Braun
Estimating the term…
In an inverter, the phase, frequency and amplitude of the output voltage are determined by the switching signals for the inverter switches. By means of the switches which can be actuated by the same switching signals, the measured values corresponding to the phase currents are pulse width-modulated. The instantaneous values of the phase power formed thereby are optionally added to form the total active power sum. A characteristic stage can weight the sum signal with the reciprocal value of the voltage drive of the inverter, so that a signal is produced which is proportional to the active current. In a similar manner, also the reactive current can be determined by means of switches if the phase of the measured phase currents is shifted by .pi./2.
Apparatus for determining the instantaneous power of at least one phase of a load connected inverter having at least one switch coupled to the phase, particularly a pulsed inverter, comprising switch means and means for providing a measurement signal corresponding to the phase current of the inverter to the switch means, the switch means being actuated by a switching signal, which determines the switching state of the at least one switch of the inverter coupled to the phase, a signal corresponding to the instantaneous power of the phase being generated at the output of said switch means.
Dependencies are inferred from the claim text.