The SIPROTEC 7UM511 is a numerical generator protection relay. The provided protection functions meet the requirements of small, medium-sized and large generators. This numerical relay is the basic device in each unit connection scheme. The device can be supplemented by the 7UT51 differential protection units.

Note : Successive product = 7UM61

The SIPROTEC 7UM512 is a numerical generator protection relay. The relay provides a practical combination of protection functions for generators. The unit contains all the protection functions required for small generators, such as emergency generators or private power plants. As the relay features directional earth-fault protection, it is frequently applied in direct connection of the generator to a busbar. Combined with the devices 7UM511 and 7UT511 it meets the protection requirements of medium-sized generators. The unit is also a module in comprehensive protection systems for large generators based on the 7UM51 range.

Note : Successive product = 7UM62

The SIPROTEC 7UM515 is a numerical protection relay which is mainly used for larger generators in block connection. In the majority of cases it is used in combination with other relays from the 7UM51 and 7UT51 series. In such combinations, some functions can be used to provide redundant generator protection systems.

Note : Successive product = 7UM62

The SIPROTEC 4 7UM61 protection relay can do more than just protect. They also offer numerous additional functions. Be it earth faults, short-circuits, overloads, overvoltage, overfrequency or underfrequency, protection relays assure continued operation of power stations. The SIPROTEC 4 7UM61 protection relay is a compact unit which has been specially developed and designed for the protection of small and medium-sized machines. They integrate all the necessary protection functions and are particularly suited to the protection of

• Hydro and pumped-storage generators
  
• Co-generation stations
  
• Private power stations using regenerative energy sources such as wind or biogases
  
• Diesel generator stations
  
• Gas-turbine power stations
  
• Industrial power stations
  
• Conventional steam power stations.
  

The integrated programmable logic functions (continuous function chart CFC) offer the user high flexibility so that adjustments can easily be made to the varying power station requirements, on the basis of special system conditions. The flexible communication interfaces are open for modern communication architectures with the control system.

This device is a new member of the SIPROTEC 4 family. The 7UM6- devices are available as 7UM611 (1/3 19'' width) and as 7UM612 (½ 19'' width). Both devices have an identical scope of functions. The 7UM612 has more binary inputs and outputs and is thereby also applicable as back-up protection for larger power stations.

The SIPROTEC 4 7UM62 includes all necessary protection functions for large synchronous and asynchronous motors and for transformers. The integrated programmable logic functions (continuous function chart-CFC) offer the user a high flexibility so that adjustments can easily be made to the varying power station requirements on the basis of special system conditions. The flexible communication interfaces are open for modern communication architectures with the control system.

The following basic functions are available for all versions:
Current differential protection for generators, motors and transformers, stator earth-fault protection, sensitive earth-fault protection, stator overload protection, overcurrent-time protection (either definite-time or inverse-time), definite-time overcurrent protection with directionality, undervoltage and overvoltage protection, underfrequency and overfrequency protection, overexcitation and underexcitation protection, external trip coupling, forward-power and reverse-power protection, negative-sequence protection, breaker failure protection, rotor earth-faults protection ( f n , R -measuring), motor starting time supervision and restart inhibit for motors.

The 7UM62-devices are available as 7UM621 (½ 19'' width) and as 7UM622 (1/1 19'' width). Both devices have an identical scope of functions. The 7UM622 has more binary inputs and outputs and is thereby applicable especially for larger power stations.

The tripping matrix 7UW50 is a component of the Siemens numerical generator protection system. The tripping matrix provides a transparent, easily programmable facility for combining output commands of the trip outputs of individual protection devices with plant items such as the circuit-breakers, de-excitation etc. The matrix was developed for marshalling tripping commands of large power station. With its help, the tripping schematic can be temporarily changed, e.g., on the basis of a generator circuit-breaker revision. If the software matrix incorporated in each generator protection unit is used for marshalling the tripping commands, the marshalling in the protection units must be changed for this purpose.

The new device is intended as a supplement to our substation systems and for use in individual applications. It features two voltage inputs (U; Ux) to which a variety of functions have been assigned. While input U serves all of the implemented functions, input Ux is exclusively dedicated to the voltage protection functions. The scope of functions can be selected from three ordering options (see MLFB code).

The numerical SIPROTEC 7VE51 synchronizing unit is used to synchronize networks and generators. In the operating mode "Paralleling of synchronous networks" the frequency difference measurement is performed with extremely high accuracy. When a frequency difference is not detected during an extended period of time, then the networks are considered to be in synchronism and a larger switching angle can be permitted. When synchronizing generators, it is of advantage to automatically adjust the speed to the network frequency and the generator voltage to the network voltage. For this purpose, a model with integrated frequency and voltage matching is available.

The synchronizing unit can be delivered in two versions: The 7VE511 unit is the smaller model and contains 2 parameter blocks for the synchronizing points (circuit-breakers) but does not include a frequency matching unit. The 7VE512 unit is the larger model and contains 6 parameter blocks for the synchronizing points (circuit-breakers) and one integrated frequency and voltage matching unit.