Abstract:
PROBLEM TO BE SOLVED: To specify a method for operating a converter circuit, and reduce thereby a harmonic component in system voltages of an AC voltage system connected with the converter circuit. SOLUTION: In the converter circuit which has a converter 2 having a large number of drivable power semiconductor switches and has a three-phase AC voltage system 1, the drivable power semiconductor switches are driven by means of a drive signal S A formed from a control signal S R , and the control signal S R is formed by adjusting an H-th harmonic component i NH of system currents to a system current set point value i NHref . In order to reduce a harmonic component in the system voltages, the system current set point value i NHref is formed by adjusting an H-th harmonic component of system voltages to a predeterminable system voltage set point value u NHref , the control difference from the H-th harmonic component of the system voltages and the system voltage set point value u NHref being weighted by a system impedance y NH determined with respect to the H-th harmonic component. COPYRIGHT: (C)2010,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To make substantially constant an intermediate circuit voltage by a three-point DC voltage middle circuit. SOLUTION: A converter circuit facility is the one for matching a variable DC voltage to a drive circuit, making a drive signal, and having a three-point DC voltage middle circuit (2). The three-point DC voltage middle circuit (2) is made of a first capacitor (3) and a second capacitor (4) connected in series with it, one connection of the first capacitor (3) forms the upper connection (5) of the three-point DC voltage middle circuit (2), the first capacitor (3) forms a center point connection (6) at the junction with the second capacitor (4), and one connection of the second capacitor (4) forms the lower connection (7) of the three-point DC voltage intermediate circuit (2).
Abstract:
PROBLEM TO BE SOLVED: To reduce a harmonic component in an alternating-current system voltage connected to a converter circuit. SOLUTION: The converter circuit has a converter unit 1 with a plurality of drivable power semiconductor switches and is connected to a three-phase alternating-current main line system, the drivable power semiconductor switches are driven by a driving signal formed from a control signal S R , and the control signal S R is formed by adjusting an H-th harmonic component i NH of the system current to a system current set point value i NHref and specifies a method to actuate the converter circuit regarding H as 1, 2, 3, .... In order to reduce the harmonic component of system voltage, the system current set point value i NHref is formed by adjusting the absolute value of an H-th harmonic component u NH of the system voltage to the absolute value of a prescribable system voltage set point value u NHref . COPYRIGHT: (C)2009,JPO&INPIT
Abstract:
The invention specifies a method for operating a converter circuit, the converter circuit having a converter unit (2) with a large number of drivable power semiconductor switches and with a three--phase electrical AC voltage system, in which the drivable power semiconductor switches are driven by means of a drive signal (SA) formed from a control signal ((SR), and the control signal (SR) is formed by adjusting an H-th harmonic component of system currents (i NH) to a system current setpoint value (i NHref), where H=1, 2, 3, .... In order to reduce a harmonic component in the system voltages, the system current setpoint value (i NHref is formed by adjusting an H-th harmonic component of system voltages (u NH) to a predeterminable system voltage setpoint value (U NHref), the control difference (U nHdiff) from the H-th harmonic component of the system voltages (U NH) and the system voltage setpoint value (U NHref) being weighted by a system impedance (Y NH) determined with respect to the H-th harmonic component. In addition, the invention specifies an apparatus for implementing the method.
Abstract:
The invention specifies a method for operating a converter circuit, the converter circuit having a converter unit (2) with a large number of drivable power semiconductor switches and with a three--phase electrical AC voltage system, in which the drivable power semiconductor switches are driven by means of a drive signal (SA) formed from a control signal ((SR), and the control signal (SR) is formed by adjusting an H-th harmonic component of system currents (i NH) to a system current setpoint value (i NHref), where H=1, 2, 3, .... In order to reduce a harmoni c component in the system voltages, the system current setpoint value (i NHref is formed by adjusting an H-th harmonic component of system voltages (u NH) to a predeterminable system voltage setpoint value (U NHref), the control difference (U nHdiff) from the H-th harmonic component of the system voltages (U NH) and the system voltage setpoint value (U NHref) being weighted by a system impedance (Y NH) determined with respect to the H-th harmonic component. In addition, the invention specifies an apparatus for implementing the method.
Abstract:
The method involves operating a converter circuit which has an inverter (2) with a variety of controllable power switches and is connected to a three-phase alternating current electric power (1). The current power being a H-th harmonic component of mains power (UNH) is formed of a predetermined power. An error signal is provided from the H-system harmonic component of mains power and the power is weighted with respect to the H-th harmonic component network impedance (yNH). An independent claim is included for device for carrying out the method.
Abstract:
An invertor having a plurality of invertor bridges which operate in parallel and whose output voltages are summed. The invertor bridges are driven with pulse duration modulation according to an auxiliary control voltage. The auxiliary control voltages of the individual invertor bridges have a constant phase difference between one another. The output voltages of the bridges are summed by a center tap which is grounded by a ground connection. Effective suppression of the common-mode current distortion is achieved by having the switch arranged in the ground connection.
Abstract:
An invertor having a plurality of invertor bridges which operate in parallel and whose output voltages are summed. The invertor bridges are driven with pulse duration modulation according to an auxiliary control voltage. The auxiliary control voltages of the individual invertor bridges have a constant phase difference between one another. The output voltages of the bridges are summed by a center tap which is grounded by a ground connection. Effective suppression of the common-mode current distortion is achieved by having the switch arranged in the ground connection.