초록 ▼

The invention relates to a circuit with a variable rotational speed to be used particularly in a wind power plant, comprising a double fed asynchronous generator (DASM), a crow-bar, an additional resistor (R15) and a converter. In order to meet the requirements of the network provider, whereby a par

The invention relates to a circuit with a variable rotational speed to be used particularly in a wind power plant, comprising a double fed asynchronous generator (DASM), a crow-bar, an additional resistor (R15) and a converter. In order to meet the requirements of the network provider, whereby a particularly permanent coupling to the network should be ensured so that the wind power plant can start up and stabilize the network during and after medium voltage short circuit in the network, the additional resistor can be regulated with the aid of a fast switch in such a way that the converter can be provisionally disconnected at least partly in case of a short circuit in the network. The rotor current is momentarily assumed by the additional resistor and disconnected after the rotor short circuit current dies out so that the converter can be subsequently connected once again and so that it can supply the desired active short circuit current to the network.

대표청구항 ▼

The invention claimed is: 1. Circuit arrangement which is intended in particular for use in a variable rotation speed wind energy installation, comprising a double-fed asynchronous generator, an additional resistor and a converter, characterized in that the additional resistor can be controlled by

The invention claimed is: 1. Circuit arrangement which is intended in particular for use in a variable rotation speed wind energy installation, comprising a double-fed asynchronous generator, an additional resistor and a converter, characterized in that the additional resistor can be controlled by means of a switch such that the converter can be at least temporarily disconnected in the event of a network short circuit, in order for the rotor current to be taken over in the short term by means of the additional resistor, and can be connected to the network again for active injection of a short-circuit current after the rotor short-circuit current has decayed. 2. Circuit arrangement according to claim 1, characterized in that the converter can be connected below a rotor inverter rated current once the rotor short-circuit current has decayed. 3. Circuit arrangement according to claim 1, characterized in that the circuit arrangement has two or more resistors which can be connected dependent on one another or independently of one another. 4. Circuit arrangement according to claim 1, characterized by a two-point regulator for controlling the additional resistor. 5. Circuit arrangement according to claim 1, characterized in that the switch is controlled by pulse-width modulation at a fixed clock frequency. 6. Circuit arrangement according to claim 1, characterized in that the switch is controlled by a P regulator, a PI regulator or a PID regulator. 7. Circuit arrangement according to claim 1, characterized in that the additional resistor is a component of a crow bar. 8. Circuit arrangement according to claim 7, characterized in that the active switch is controlled directly by the crow bar. 9. Circuit arrangement according to claim 8, characterized in that the crow bar switch is controlled directly by the converter control board. 10. Circuit arrangement according to claim 1, characterized in that, in the event of a network short circuit, a capacitive current or an inductive current is supplied to the short circuit. 11. Circuit arrangement according to claim 1, characterized in that, in the event of a network short circuit, no wattless component is transmitted to the short circuit. 12. Circuit arrangement according to claim 1, characterized in that an additional impedance is briefly inserted in the stator circuit in order to limit the stator and rotor current. 13. Circuit arrangement according to claim 12, characterized in that a high-speed contactor is inserted in the stator circuit in parallel with the resistor. 14. Circuit arrangement according to claim 12, characterized in that at least one thyristor with natural commutation is inserted in the stator circuit in parallel with the resistor. 15. Circuit arrangement according to claim 1, characterized in that a regulated resistor is operated on the intermediate circuit of the converter. 16. Circuit arrangement according to claim 7, characterized in that a regulated resistor is operated both in the crow bar and in the intermediate circuit of the converter. 17. Circuit arrangement according to claim 1, characterized in that, when the network voltage returns, the rotor inverter is switched off, and the overcurrent is passed through the controllable resistor and, once the overcurrent has decayed, the controlled resistor is disconnected and the rotor inverter actively carries the rotor current. 18. Circuit arrangement for use in a variable rotation speed wind energy installation comprising a double-fed asynchronous generator, an additional resistor and a converter, wherein the rotor inverter is switched off when the network voltage rises, and the overcurrent is passed through the controllable resistor and, once the overcurrent has decayed, the controlled resistor is switched off and the rotor inverter actively carries the rotor current.