Siemens Aktiengesellschaft

Infineon Technologies Ag

Manfred Bruckmann

Benno Weis

Heinz Mitlehner

Olaf Simon

Eric Baudelot

Hubert Schierling

Dietrich Stephani

Rainer Sommer

Rainer Marquardt

Leo Lorenz

Anton Pfauser

Axel Mertens

Walter Springmann

Michael Kaindl

Tomas Greif

Peter Stern

Hans-Georg K&ouml;pken

Christian Briesen

Marco Kaiser

Alois Wald

Gerhard Münzing

A frequency converter includes an intermediate circuit without any capacitors and an electronics which is supplied with power from a power supply device. The power supply device has a buffer capacitor which is disposed on an input side of the power supply device and connected electrically in parallel with the intermediate circuit. Connected to the buffer capacitor is a supply line in which a decoupling diode is disposed. A semiconductor adapted to be switched off is connected electrically back-to-back in parallel with the decoupling diode and has a control output which is connected to an output of an identification device for recognizing a power-line failure.

Frequency converter having an intermediate circuit without any capacitors

A method and a device for bridging temporary power outages in a matrix converter are disclosed. In the event of a detected power failure, the matrix converter is disconnected from the power line and changes into a buffer mode in which a determined actual capacitor voltage space vector is regulated to a predetermined space vector. When the power line is reestablished, the actual capacitor space vector is synchronized and the matrix converter is reconnected to the power line during the synchronization. This allows a conventional matrix converter to take advantage of kinetic load buffering.

Method and device for bridging brief power outages in a matrix converter

A controlled drive circuit for an analog controlled power semiconductor includes a digitally operating logic module, which has a control input receiving control signals from an A/D converter and a control output supplying processed control signals to a D/A module that converts the processed digital control signals signal to an analog or quasi-analog control variable that controls the power semiconductor.

Controlled drive circuit for an analog driven power semiconductor

A method for controlling a matrix converter with nine bidirectional power switches arranged in a 3&times;3 switch matrix is described. Switching states of a modulation period are each calculated with associated time intervals by using a space vector modulation method. According to the invention, these calculated switching states are each divided into switching states of an output phase of the matrix converter, with time intervals assigned to the switching states, wherein the time intervals and the output-phase-related switching states are placed into one-to-one correspondence. Depending on the measured input voltages, the output-phase-related switching states with associated time intervals are combined into a pulse train of a modulation period, so that a sequential commutation always occurs to a nearest input voltage. This significantly reduces the switching losses of a matrix converter.

Method for controlling a matrix converter

A method and a device for protecting a matrix converter is disclosed. The matrix converter has nine bi-directional circuit-breakers which are arranged in a 3&times;3 switch matrix. A highest potential is detected from all input and/or output potentials or from all input potentials and at least one output potential. Bi-directional circuit-breakers of the matrix converter are controlled when a predetermined threshold value is exceeded. This arrangement protects the entire matrix converter from overvoltages. The converter can be produced easily and cost-effectively.

Method for protection of a matrix converter against overvoltages, and an active overvoltage device

A low-inductivity busbar system for a matrix converter which includes a plurality of switch elements, in particular semiconductor switches, disposed in a 3&times;3 matrix. The matrix converter is connected on the network side by the busbar system to a plurality of capacitor elements for supply of three input voltage potentials to the matrix converter. The busbar system includes of a plurality of busbar sections disposed in two levels and isolated from one another.

Low-inductance busbar system for a matrix converter

A hybrid power MOSFET, comprising a MOSFET and a junction FET, the MOSFET and the junction FET being electrically connected in series is disclosed. In accordance with the present invention, the hybrid power MOSFET is provided with a device for reducing the change in the gate voltage of the junction FET. Thus, a hybrid power MOSFET is obtained in which high over-voltages no longer arise and whose EMC response is much improved.

Hybrid power MOSFET

A method and an apparatus for turning off a cascode circuit comprising a series circuit formed by a low-blocking-capability and high-blocking-capability semiconductor switch, are described. When a turn-off command arrives, the gate voltage of the low-blocking-capability semiconductor switch is controlled in such a way that its drain voltage is held constant in the active range of the low-blocking-capability semiconductor switch. Consequently, an impermissible overvoltage at high potential of the cascode circuit at low potential is detected and actively limited.

Method and device for disconnecting a cascode circuit with voltage-controlled semiconductor switches

A method for controlling positive or negative freewheeling paths of the phases of a matrix converter with nine bidirectional power switches arranged in a 3&times;3 switch matrix is described. Each power switch has two back-to-back series-connected semiconductor switches. Those semiconductor switches are actuated that have the most positive/negative line voltage to provide a negative/positive freewheeling path capable of carrying a negative/positive load current. The matrix converter can be immediately disconnected if an error is detected or if the matrix converter is inadvertently switched off, without damaging the matrix converter.

Method for controlling freewheeling paths in a matrix converter

Method and apparatus for controlling a turn-off power converter valve having at least two series connections. Each non-latching power semiconductor switch of this power converter valve has an active collector-emitter limiting circuit. When a rising edge of a drive signal that is provided arrives, a predetermined value of the reference limited voltage of the active collector-emitter limiting circuit is decreased to a low value and is increased to the predetermined value again during a turn-off operation. Using a switch-on command, it is possible to balance the voltage sharing on the non-latching power semiconductor switches of a turn-off power converter valve having at least two series connections.

Method and device for controlling a power converter valve that can be turned off and has at least two series circuits

A hybrid power MOSFET having a low blocking-capability MOSFET and a high blocking-capability junction FET is disclosed. In accordance with the present invention, this cascode circuit has at least two high blocking-capability junction FETs which are electrically connected in parallel and whose gate connections are respectively electrically conductively connected to the source connection of the low blocking-capability MOSFET by means of a connecting line. Thus, a hybrid power MOSFET for a high current-carrying capacity is obtained whose design technology has been considerably simplified on account of the use of only one control line and n&plus;1 chips.

Hybrid power MOSFET for high current-carrying capacity

A low-inductive busbar arrangement for a three-point phase module of a polyphase three-point power converter is provided. At least one turn-off semiconductor switched being provided for each switch of this three-point phase module and at least one diode being provided for each of the two neutral point diodes. Connection busbars of this three-point-phase module are distributed between three busbar planes of the low-inductive busbar arrangement, which are mutually electrically insulated from one another in each case with insulation layer and are arranged in a plan-parallel manner. A low-inductive busbar arrangement for a three-point phase module is thus obtained which has three busbar planes, irrespective of the series connection number.

Provision of a low-inductive rail for three-point phase module

The invention provides a method by which losses are reduced during the commutation of a free-running, driven power converter valve (T ) of an invertor phase ( ) to a current-accepting power converter valve (T ) of said invertor phase ( ). The current-accepting power converter valve (T ) is switched on at the beginning of the commutation process and the free-running, driven power converter valve (T ) is rapidly switched off as soon as the value of its drain voltage (U ) is zero.

Method for reducing losses during the commutation process

The present invention relates to an active overvoltage protection apparatus for a bidirectional power switch which has two back-to-back in series connected semiconductor switches in the &ldquo;common collector mode&rdquo; topology. The overvoltage protection apparatus has a diode network which is linked to gate and emitter connections of the bidirectional power switch in the in such a manner as to provide a voltage clamping circuit for each of the semiconductor switches in the bidirectional power switch.

Active overvoltage protection apparatus for a bidirectional power switch in common collector mode

A circuit arrangement for precharging the capacitor connected to the output of a line-commutated power converter is described, where an element which limits the charging current of the capacitor to a level which is largely independent of the charging voltage is connected between a direct voltage output of the power converter and the respective terminal of the capacitor.

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Nürnberg, Germany

Manfred Bruckmann