US 2003/0165071 A1 · Open-loop and closed-loop control method for a three-point converter with active clamped switches, and apparatus for this purpose

Abstract

An open-loop and closed-loop control method is proposed for a single-phase or polyphase three-point converter which is connected to a DC voltage intermediate circuit, having two series-connected main switches/inverse diodes between each DC voltage connection and each load connection. The common junction point of the two inner main switches forms the load connection. An active clamped switch with an inverse diode is connected between each common junction point of an inner main switch and an outer main switch and the center tap of the DC voltage intermediate circuit. As a result of which, two possible paths are formed for connecting a load connection to the center tap. Irrespective of the direction of the load current, at least one of the two active clamped switches (T5, T6) is connected to the center tap together with at least one inner main switch for connection of a load connection. The provides a circuit that can carry the current deliberately through the upper path, the lower path, or through both paths, to the center tap during a null state.

Claims18

Dependent claims

An open-loop and closed-loop control method, which comprises:

providing a three-point converter for connecting a DC voltage intermediate circuit having a positive DC voltage connection, a center tap, and a negative DC voltage connection, to three load connections, the three-point converter having:
two series-connected main switches/inverse diodes connected between each of the DC voltage connections and each of the load connections, and
two inner main switches sharing a common junction point, the common junction point forming one of the load connections,
an active clamped switch with an inverse diode connected between each common junction point of an inner main switch and an outer main switch and the center tap to form an upper path and a lower path for connecting respective load connections to the center tap;
and
irrespective of a direction of a load current, connecting at least one of the two active clamped switches to the center tap together with at least one of the inner main switches for connecting to one of the load connections, in order to carry the current deliberately through at least one of the upper path and the lower path, to the center tap during a null state.

3 more elements

An open-loop and closed-loop control apparatus, comprising:

a three-point converter for connecting a DC voltage intermediate circuit having a positive DC voltage connection, a center tap, and a negative DC voltage connection, to three load connections, the three-point converter including:
two series-connected main switches/inverse diodes connected between each of the DC voltage connections and each of the load connections, and
two inner main switches sharing a common junction point, the common junction point forming one of the load connections, and
an active clamped switch with an inverse diode connected between each common junction point of an inner main switch and an outer main switch and the center tap to form an upper path and a lower path for connecting respective load connections to the center tap,
said switches and diodes being semiconductors having phase currents and boundary layer temperatures;
and
a modulator producing switching state commands;
and
a temperature regulator and automatic drive device for forming control signals for the semiconductor switches from the switching state commands of said modulator, the phase currents, and the boundary layer temperatures of said semiconductors.

6 more elements

Dependencies are inferred from the claim text.

Open-loop and closed-loop control method for a three-point converter with active clamped switches, and apparatus for this purpose

Life of this patent

Open-loop and closed-loop control method for a three-point converter with active clamped switches, and apparatus for this purpose

Life of this patent

Abstract

Claims18