Control of rectifier systems

Claims

The switching element and the circuit breakers, as well as the auxiliary or reserve groups, are each connected to a switching relay. This ensures that when the overvoltage returns and the power is switched on, all rectifier groups are initially activated. Afterwards, the auxiliary or reserve groups automatically switch off again after an adjustable period if not needed. The drawing serves to explain the invention in more detail. Fig. > shows an older control system for Rectifier systems, while Fig. 2 shows an embodiment of a new 'Self-control' for rectifier systems of the above-mentioned type is illustrated. Figure 3 shows three groups I, II, and III of rectifiers ii, 2-2, and 3-3. Each rectifier group is assigned one of the circuit breakers 4, 5, and 6. In this case, group I is considered the primary group; groups II and III form the first and second auxiliary or reserve groups. The timer 7 acts on the circuit breaker 4 of the primary group I, while the switching relays 8 and 9 act on the circuit breakers 5 and 6 of rectifier groups II and III. The primary rectifier group I is switched on first, while the other rectifier groups (reserve groups) switch on and off as needed at a later time, depending on the load, by means of the delayed switching relays 8 and 9. Each rectifier group is assigned a restart device 10, 11, and 12, which attempts to restart that group several times when the circuit breaker of the respective group trips.In the event of a sudden overload, the circuit breaker 4 of the primary rectifier group I is switched off before the first auxiliary or reserve group II is switched on by its switching relay 8. Only the switching device 10 for the primary group I is activated, and only this primary rectifier group is switched on again. Since the overload may persist, this process repeats itself. The primary rectifier group I then becomes blocked after several unsuccessful attempts to switch it on again, meaning that this rectifier group I becomes unusable for the operation of the rectifier system, even though there is no inherent operational cause for this. As mentioned above, it can happen that the initial switch-on of the system by the timer 7 results in such a high load that the circuit breaker 4 of the primary group I trips again immediately. According to Fig. 2, which shows an embodiment of the invention, rectifier groups I to III are equipped with a single, common rectification device 13. The rectification device 13 is connected to the circuit breakers 4, 5, and 6. The timer 7 acts on the circuit breakers 4, 5, and 6 simultaneously. The circuit breakers 5 and 6 are also connected to the switching relays 8 and 9. According to this embodiment, when the overvoltage returns and the system is switched on by the timer 7, all rectifier groups I to III are initially put into operation. The reserve groups II and III can switch themselves off automatically after an adjustable time if not needed. The new switching arrangement, besides the advantage that only one restart device is required for all groups, has the particularly advantageous feature that, both when switched on by the timer and after switching on when the previously absent overvoltage returns, all auxiliary or reserve groups are checked. This means that all components of the auxiliary rectifiers are activated, at least briefly, so that any faults in the system can be detected in time. This ensures that the value of the auxiliary groups as reserve groups can be recognized in a timely manner.Furthermore, if the leading group is tripped by an overcurrent, the common restarting device also ensures the automatic activation of all reserve groups. This means that after an overcurrent occurs that has tripped circuit breaker 4, the load is initially distributed across all rectifier groups intended for operation, thus preventing unnecessary blocking of the leading rectifier group. The new 1x0 switching arrangement also offers the advantage of particularly simple and clear cable routing. Patent claim: Control of rectifier systems, in particular self-control of rectifier substations, which are equipped with several rectifier substations with a common rectification device that automatically adjust themselves depending on the load. 640873 switching-off rectifier groups, characterized in that the AC-side protection switches (4, 5, 6) of all rectifier groups^ (I, II, III) are connected on the one hand to the restarting device (13) common to all rectifier groups, on the other hand to the switching element which may be designed as a time switch (7) and the protection switches of the auxiliary or reserve groups are also each connected to a switching relay. This includes r sheet drawings