Converter arrangement and method for operating a converter arrangement
A converter arrangement comprises a converter with a first side and a second side, a first connection line connected to the first side of the converter, a short-circuit switch connected to the first connection line, and a controller having a terminal coupled to the converter and an output connected to a control terminal of the short-circuit switch. A method for operating a converter arrangement comprises providing a detection signal by a converter, receiving the detection signal by a controller, providing a set signal to a short-circuit switch by the controller in case the controller determines a fault of the converter by evaluating the detection signal, and setting the short-circuit switch in a conducting state by the set signal.
1 . A converter arrangement, comprising:
a converter with a first side and a second side,
a first connection line connected to the first side of the converter,
a short-circuit switch connected to the first connection line,
a controller having a terminal coupled to the converter and an output connected to a control terminal of the short-circuit switch,
a further first connection line connected to the second side of the converter,
an auxiliary short-circuit switch connected to the further first connection line, and a machine coupled to the second side of the converter via the further first connection line,
wherein the converter is configured to provide a detection signal,
wherein the controller is configured to receive and evaluate the detection signal, and
wherein upon detection of a converter internal fault, the controller triggers fast shorting of the first side via the short-circuit switch and blocks converter pulses simultaneously, driving currents to zero and making full converter blocking voltage available on the machine side.
2 . The converter arrangement according to claim 1 ,
wherein the short-circuit switch comprises an ultrafast switch.
3 . The converter arrangement according to claim 1 ,
wherein the short-circuit switch includes a crowbar.
4 . The converter arrangement according to claim 1 ,
wherein the short-circuit switch connects the first connection line to an earth terminal.
5 . The converter arrangement according to claim 1 ,
wherein the converter arrangement includes a second connection line connected to the first side of the converter, and
wherein the short-circuit switch is coupled to the first connection line and to the second connection line.
6 . The converter arrangement according to claim 1 , wherein the converter is configured to provide the detection signal, wherein the controller is configured to receive the detection signal at the terminal of the controller and to provide a set signal to the control terminal of the short-circuit switch in case a fault is detected by evaluation of the detection signal, and wherein the short-circuit switch is configured to be set in a conducting state by the set signal.
7 . The converter arrangement according to claim 1 ,
wherein the converter arrangement comprises a first circuit breaker and a transformer,
wherein the first circuit breaker is coupled via the transformer to the first connection line, and
wherein the controller comprises a further output connected to a control terminal of the first circuit breaker.
8 . The converter arrangement according to claim 1 ,
wherein the controller is coupled to the auxiliary short-circuit switch for providing an additional set signal to the auxiliary short-circuit switch.
9 . The converter arrangement according to claim 1 ,
wherein the converter arrangement comprises a current sensor configured to measure a current of the further first connection line, and
wherein an output of the current sensor is connected to an input of the auxiliary short-circuit switch.
10 . The converter arrangement according to claim 1 ,
wherein the converter is implemented as an AC/AC converter and includes a modular multi-level converter.
11 . The converter arrangement according to claim 1 , wherein the controller is configured to block the converter pulses within less than 4 milliseconds of detecting the converter internal fault.
12 . The converter arrangement according to claim 1 , wherein the converter comprises a modular multi-level converter having phase legs with a voltage blocking capability configured to cover a sum of AC voltages at both the first side and the second side.
13 . The converter arrangement according to claim 1 , wherein the controller is configured to:
trigger the short-circuit switch to create a short circuit on the first side, wherein short circuit currents are limited by a transformer short circuit impedance; and
trip a main circuit breaker on the first side.
14 . The converter arrangement according to claim 1 , wherein the controller is configured to detect the converter internal fault by:
analyzing internal voltages and currents of the converter;
combining different signals representing the internal voltages and currents; and
generating a set signal to trigger the short-circuit switch based on the analyzing and combining.
15 . The converter arrangement according to claim 1 , wherein the controller is configured to:
detect the converter internal fault by evaluating a maximum available phase-leg voltage compared to a present voltage across a phase-leg of the converter; and
trigger the short-circuit switch when the maximum available phase-leg voltage is less than the present voltage across the phase-leg.
16 . A method for operating a converter arrangement, comprising
providing a converter with a first side and a second side,
providing a detection signal by the converter,
receiving the detection signal by a controller,
providing a set signal to a short-circuit switch by the controller in case the controller determines a fault of the converter by evaluating the detection signal, and
setting the short-circuit switch in a conducting state by the set signal, wherein the converter arrangement comprises
a further first connection line connected to the second side of the converter,
an auxiliary short-circuit switch connected to the further first connection line, and
a machine coupled to the second side of the converter via the further first connection line,
wherein upon detection of a converter internal fault, the controller triggers fast shorting of the first side via the short-circuit switch and blocks converter pulses simultaneously, driving currents to zero and making full converter blocking voltage available on the machine side.
17 . The method according to claim 16 ,
wherein the detection signal includes at least one information of a group comprising:
a measurement of a DC voltage of the converter,
a measurement of an AC voltage of the converter,
a measurement of a current of the converter,
a measurement of a present voltage across a phase-leg of the converter,
an information of a status of a cell of the converter,
an information of a status of a phase-leg of the converter, and
an information of a detected light generated by an arc.
18 . The method according to claim 16 ,
wherein the controller determines the fault of the converter by performing at least one evaluation of a group comprising:
comparing a DC voltage of the converter with an AC voltage of the converter,
comparing a maximum available phase-leg voltage with a present voltage across a phase-leg of the converter,
comparing a current of the converter with a predetermined value,
comparing a number of cells of the converter with a status indicating a short-circuit with a predetermined number,
determining a presence of a phase-leg of the converter with a status indicating out-of-order, and
determining a presence of an arc.
19 . The method according to claim 16 , wherein upon detection of a sustained machine side short circuit after the fast shorting of the first side, the controller is configured to trigger the auxiliary short-circuit switch after a delay.