Abstract: A method for determining a function of a capacitor of a passive filter circuit, which partially reduces line-conducted interference of an electrical device electrically coupled to a power supply system via the passive filter circuit. The passive filter circuit comprises the capacitor having a predefined capacitance value and a choke having a predefined inductance value. An electric capacitor voltage on the capacitor is detected. A connection voltage of the electrical device is detected. Spectral components are determined for the capacitor voltage and the connection voltage. The function of the capacitor is determined by analysing the spectral components in consideration of the inductance value of the choke by a statistical processing operation.

Abstract: In a method for operating an energy converter that couples a first supply network to a second supply network by converting electrical energy via a switch element, the switch element is operated in a switching operation and a supply-network current for one of the supply networks is adjusted depending on a comparison of the supply-network current with a reference current. In a first operating mode for the switching operation, an electrical voltage of one of the supply networks is set by a PWM method on the basis of the comparison, and a second operating mode is provided, in which the switch element is switched when, during the comparison, a difference between the supply-network current and the reference current is greater than a first predefined relative switching value and/or is smaller than a second predefined relative switching value, wherein the first and second operating modes are alternated during the operation.

Abstract: A method for determining a function of a capacitor of a passive filter circuit, which partially reduces line-conducted interference of an electrical device electrically coupled to a power supply system via the passive filter circuit. The passive filter circuit comprises the capacitor having a predefined capacitance value and a choke having a predefined inductance value. An electric capacitor voltage on the capacitor is detected. A connection voltage of the electrical device is detected. Spectral components are determined for the capacitor voltage and the connection voltage. The function of the capacitor is determined by analysing the spectral components in consideration of the inductance value of the choke by a statistical processing operation.

Abstract: In a method for operating an energy converter that couples a first supply network to a second supply network by converting electrical energy via a switch element, the switch element is operated in a switching operation and a supply-network current for one of the supply networks is adjusted depending on a comparison of the supply-network current with a reference current. In a first operating mode for the switching operation, an electrical voltage of one of the supply networks is set by a PWM method on the basis of the comparison, and a second operating mode is provided, in which the switch element is switched when, during the comparison, a difference between the supply-network current and the reference current is greater than a first predefined relative switching value and/or is smaller than a second predefined relative switching value, wherein the first and second operating modes are alternated during the operation.

Abstract: A method for regulating an AC output current of a converter having a DC voltage intermediate circuit and a semiconductor switch in a bridge circuit for converting a DC voltage of the DC voltage intermediate circuit into an AC output current. The AC output current is regulated by way of a direct hysteresis current regulation, in which an actual value of the AC output current is maintained within a hysteresis window around a set point value. Furthermore, a hysteresis width of the hysteresis window is modulated in order to adjust a frequency spectrum of the AC output current.

Abstract: The invention relates to a method for controlling phase currents (iU_WR1, iv_WR1, iw_WR1) of a three-phase inverter (WR1), the phase currents (iU_WR1, iv_WR1, iw_WR1) of the inverter (WR1) being controlled by way of a direct hysteresis current control and a selected phase of the inverter (WR1) being additionally switched depending on a zero system current (i0_WR1) of the inverter (WR1).

Abstract: In a method and a corresponding device for detecting phase failures in a converter, current regulators of a positive phase sequence system and current regulators of a negative phase sequence system are provided for the current control of the converter, wherein the current regulators of the positive phase sequence system and the current regulators of the negative phase sequence system each have an integrator, resulting, in the case of a network fault, in coupling of the integrators. At least one measured or calculated value is checked by a monitoring unit for a course that is typical of the coupling of the integrators, wherein the monitoring unit generates a fault signal if such a typical course is detected.

Abstract: In a method for operating an inverter system and a corresponding inverter system, which includes from the network filter to the inverter, values are determined using the data unit, and a value spectrum of the determined values is determined using an evaluation unit. The value spectrum is compared to a predetermined or predefinable limit spectrum using an assessment unit, and a switching frequency of the inverter can be adapted while in operation by using an adapter unit arranged downstream of the data unit, the evaluation unit and the assessment unit in the return path.

Abstract: A method for regulating an AC output current of a converter having a DC voltage intermediate circuit and a semiconductor switch in a bridge circuit for converting a DC voltage of the DC voltage intermediate circuit into an AC output current. The AC output current is regulated by way of a direct hysteresis current regulation, in which an actual value of the AC output current is maintained within a hysteresis window around a set point value. Furthermore, a hysteresis width of the hysteresis window is modulated in order to adjust a frequency spectrum of the AC output current.

Abstract: The invention relates to a method for controlling phase currents (iU_WR1, iv_WR1, iw_WR1) of a three-phase inverter (WR1), the phase currents (iU_WR1, iv_WR1, iw_WR1) of the inverter (WR1) being controlled by way of a direct hysteresis current control and a selected phase of the inverter (WR1) being additionally switched depending on a zero system current (i0_WR1) of the inverter (WR1).

Abstract: In a method and to a corresponding device for detecting phase failures in a converter, current regulators of a positive phase sequence system and current regulators of a negative phase sequence system are provided for the current control of the converter, wherein the current regulators of the positive phase sequence system and the current regulators of the negative phase sequence system each have an integrator, resulting, in the case of a network fault, in coupling of the integrators. At least one measured or calculated value is checked by a monitoring unit for a course that is typical of the coupling of the integrators, wherein the monitoring unit generates a fault signal if such a typical course is detected.

Abstract: In a method for operating an inverter system and a corresponding inverter system, which includes from the network filter to the inverter, values are determined using the data unit, and a value spectrum of the determined values is determined using an evaluation unit. The value spectrum is compared to a predetermined or predefinable limit spectrum using an assessment unit, and a switching frequency of the inverter can be adapted while in operation by using an adapter unit arranged downstream of the data unit, the evaluation unit and the assessment unit in the return path.

Abstract: In a method for synchronizing a feed voltage with a network voltage of an electrical energy supply network, a property of the feed voltage can be determined on the basis of a static characteristic curve. The static characteristic curve is compared to the property of the feed voltage of a feed power received by the electrical energy supply network at the applied feed voltage. The property of the feed voltage is adjusted to a specified value when a limit current of the feed power is reached.

Abstract: A supply device supplies electrical current provided by at least one current source to an electrical grid, the supply device having at least one current converter that can be electrically coupled to the current source and at least one connection device which is electrically coupled to an electrical line via an input connection and electrically coupled to the current converter via the line. The connection device is designed to be electrically coupled on the output side to the electrical grid and to adapt an electrical voltage at the input connection to an electrical voltage of the electrical grid at the output side.

Abstract: In a method for synchronizing a feed voltage with a network voltage of an electrical energy supply network, a property of the feed voltage can be determined on the basis of a static characteristic curve. The static characteristic curve is compared to the property of the feed voltage of a feed power received by the electrical energy supply network at the applied feed voltage. The property of the feed voltage is adjusted to a specified value when a limit current of the feed power is reached.

Abstract: A method and an apparatus for setting a feedback power of a converter clocked at a fundamental frequency on the power supply side are disclosed. The converter includes a bridge circuit equipped with controllable semiconductor switches, wherein the semiconductor switches are clocked at the fundamental frequency depending on a desired direction of a power flow through the bridge circuit. Drive signals for the semiconductor switches are derived from the clock pulses at the fundamental frequency and a switch-on delay which depends on a DC link voltage of a DC link connected to the converter. The switch-on delay is determined based on a predetermined characteristic curve that depends on the DC link voltage.

Abstract: A method for operating a line-side fundamental-frequency-clocked converter is disclosed. The converters has a bridge circuit with, for example three, upper and, for example three, lower semiconductor switches, which are connected to respective positive and negative terminals of a DC link circuit. Center taps of connected pairs of the upper and lower semiconductor switches are connected to the line voltage phases. Two upper or two lower semiconductor switches are simultaneously activated during fundamental frequency operation for a predetermined time period before or after a natural trigger instant of the semiconductor switches caused by a line voltage angle. An estimated line voltage angle for clocking the semiconductor switches is tracked based on two phase currents measured while the two upper or two lower semiconductor switches are simultaneously active.

Abstract: The invention relates to a method for reducing the idle current requirement of a base frequency clocked supply side converter (1) on idle and with low motor loads, provided with controllable semiconductors (T1,T2,T3,T4, T5,T6), wherein the base frequency clocking of the semiconductor switches (T1,T2,T3,T4,T5,T6) occurs depending on the desired direction of flow of power. A converter (1) for carrying out said method is also disclosed.

Abstract: A method for operating a line-side fundamental-frequency-clocked converter is disclosed. The converters has a bridge circuit with, for example three, upper and, for example three, lower semiconductor switches, which are connected to respective positive and negative terminals of a DC link circuit. Center taps of connected pairs of the upper and lower semiconductor switches are connected to the line voltage phases. Two upper or two lower semiconductor switches are simultaneously activated during fundamental frequency operation for a predetermined time period before or after a natural trigger instant of the semiconductor switches caused by a line voltage angle. An estimated line voltage angle for clocking the semiconductor switches is tracked based on two phase currents measured while the two upper or two lower semiconductor switches are simultaneously active.

Abstract: A method and an apparatus for setting a feedback power of a converter clocked at a fundamental frequency on the power supply side are disclosed. The converter includes a bridge circuit equipped with controllable semiconductor switches, wherein the semiconductor switches are clocked at the fundamental frequency depending on a desired direction of a power flow through the bridge circuit. Drive signals for the semiconductor switches are derived from the clock pulses at the fundamental frequency and a switch-on delay which depends on a DC link voltage of a DC link connected to the converter. The switch-on delay is determined based on a predetermined characteristic curve that depends on the DC link voltage.