Abstract: The invention provides a method and an apparatus for estimating an RMS current (Ic,rms) of an intermediate circuit capacitor (CZWK) for a complete system of a battery (1), an inverter (9) and an N-phase electrical machine (6), wherein, in the complete system, the inverter (9) converts a DC power received from the battery (1) for the purpose of energizing the electrical machine with N phase currents, and wherein the RMS current (Ic,rms) of the intermediate circuit capacitor to be estimated is calculated according to a calculation rule which is supplied with predefined switching times (tLow,off, tHigh,off) of the N phases of the electrical machine, measured phase currents (ISu, ISv, ISw) of N-1 phases or N phases of the electrical machine and a predefined battery direct current (IBatt) as input variables. This makes it possible to exactly estimate the RMS current (Ic,rms) of an intermediate circuit capacitor for any desired pulse patterns for controlling the inverter.

Abstract: The invention relates to a method for estimating a temperature contribution of an inverter used to energize an electrical machine, in particular a synchronous machine. The method comprises the steps for calculating oscillating temperature swings of components of the inverter; and determining, as the estimated temperature contribution (?T(?), ?Ti(?), (?Td(?)) of the inverter, an upper envelope of an amplitude of a sum of the calculated oscillating temperature swings. The method according to the invention or an apparatus designed to carry out the method can be expanded for the purpose of estimating a temperature or a complete temperature contribution of the inverter and is provided, in particular, for use in an electric vehicle or a hybrid vehicle having an electrical drive without a variable speed gear in order to estimate the operating temperature of vehicle drive power electronics accommodated therein.

Abstract: The invention provides a method and an apparatus for estimating an RMS current (Ic,rms) of an intermediate circuit capacitor (CZWK) for a complete system of a battery (1), an inverter (9) and an N-phase electrical machine (6), wherein, in the complete system, the inverter (9) converts a DC power received from the battery (1) for the purpose of energizing the electrical machine with N phase currents, and wherein the RMS current (Ic,rms) of the intermediate circuit capacitor to be estimated is calculated according to a calculation rule which is supplied with predefined switching times (tLow,off, tHigh,off) of the N phases of the electrical machine, measured phase currents (ISu, ISv, ISw) of N-1 phases or N phases of the electrical machine and a predefined battery direct current (IBatt) as input variables. This makes it possible to exactly estimate the RMS current (Ic,rms) of an intermediate circuit capacitor for any desired pulse patterns for controlling the inverter.

Abstract: The invention relates to a method for estimating a temperature contribution of an inverter used to energize an electrical machine, in particular a synchronous machine. The method comprises the steps for calculating oscillating temperature swings of components of the inverter; and determining, as the estimated temperature contribution (?T(?), ?Ti(?), (?Td(?)) of the inverter, an upper envelope of an amplitude of a sum of the calculated oscillating temperature swings. The method according to the invention or an apparatus designed to carry out the method can be expanded for the purpose of estimating a temperature or a complete temperature contribution of the inverter and is provided, in particular, for use in an electric vehicle or a hybrid vehicle having an electrical drive without a variable speed gear in order to estimate the operating temperature of vehicle drive power electronics accommodated therein.

Abstract: The invention relates to a method for operating an electrical machine (1) controlled by an inverter (2), wherein the inverter (2) comprises half-bridge branches (10-U, 10-V, 10-W) having power components in the form of controllable power switching elements (3) and power diodes (4) respectively connected in parallel therewith, wherein each of the half-bridge branches (10-U; 10-V; 10-W) is arranged on a separate semiconductor module (11-U; 11-V; 11-W), which are arranged jointly on a baseplate (12), wherein the phase currents (1_U, 1_V, 1_W) flowing through the half-bridge branches (10-U, 10-V, 10-W), the voltages present at the power components and temperatures (t_Sens_U, t_Sens_V, t_Sens_W) on the semiconductor modules (11-U, 11-V, 11-W) are determined, from the current (1_U; 1_V; 1_W) respectively flowing at a power component and from the voltage respectively present a power loss (P) is calculated for each of the power components, from the power losses (P) a relevant temperature swing (?t; ?t_Sens) is determ

Abstract: The invention relates to a method for operating an electrical machine (1) controlled by an inverter (2), wherein the inverter (2) comprises half-bridge branches (10-U, 10-V, 10-W) having power components in the form of controllable power switching elements (3) and power diodes (4) respectively connected in parallel therewith, wherein each of the half-bridge branches (10-U; 10-V; 10-W) is arranged on a separate semiconductor module (11-U; 11-V; 11-W), which are arranged jointly on a baseplate (12), wherein the phase currents (1_U, 1_V, 1_W) flowing through the half-bridge branches (10-U, 10-V, 10-W), the voltages present at the power components and temperatures (t_Sens_U, t Sens_V, t_Sens_W) on the semiconductor modules (11-U, 11-V, 11-W) are determined, from the current (1_U; 1_V; 1_W) respectively flowing at a power component and from the voltage respectively present a power loss (P) is calculated for each of the power components, from the power losses (P) a relevant temperature swing (?t; ?t_Sens) is determ

Abstract: A method for operating an inverter, wherein the inverter can be connected to a DC voltage source on the input side for the purpose of electrical energy supply, wherein the inverter has a plurality of controllable switches which are switched alternately in order to provide a polyphase electric current on a corresponding plurality of phase lines of the inverter, in particular in order to supply an electric machine with electric current in polyphase fashion, wherein at least one electrical variable of at least one of the phase lines and at least one switch-on time of at least one of the controllable switches are detected and an input current is determined on the basis of the detected variables.