Since it has been observed in some cases to upgrade or upgrade GE turbine control systems, instead of using the specialized control system manufactured by General Electric Company, PLCs manufactured by SIEMENS company have been suggested, so we have made a brief comparison between these two options. The familiarity of more and more experts in this field is provided to help make the right decision
Technical specifications of the control system and its governing logic
By comparing the coding part and implementing its control logic in both SIEMENS and GE options, you will easily understand that this part in SIEMENS PLC is very, very difficult and complex, and therefore may cause many problems for turbine control. One of the reasons for its complexity is that SIEMENS PLC is used to control a wide range of equipment, both general and non-specialized. Examples of these PLCs have been seen from cnc machines to special rotating devices, which requires time, cost, design and complete implementation. Control logic is about everything, which in practice causes complexity in the algorithm and confuses the user and frequent references to SIEMENS references. While coding and implementing control logic in the GE control system is easy and because it is designed exclusively and in a completely specialized way to control the turbine, it controls the turbine in the best possible way and in practice is very userfriendly.
Rendering control system
The GE control system consists of three fully specialized control sections with separate and at the same time coordinated function. These three sections, named R, S, T, each with separate power modules, separate CPU and input and output boards, have practically provided the highest protection factor in the GE control system. (Coefficient two of three with 67% return)
However, the existence of two control sections in SIEMENS control systems actually includes a coefficient of one of the two rattan systems with only 50% redundancy.
Ability and cost of control system repair
Despite the general parts on the GE control system component cards, the system maintenance cost is practically very low.
Also, the operation of the system with the least depreciation and high useful life has greatly reduced the cost of repairing and maintaining the system.
However, the presence of multiple ASIC components in SIEMENS cards that are both not repairable and face many breakdowns, in practice, imposes a high cost of repair and maintenance on the system and the consumer.
Hardware control system
Turbine synchronization card:
Synchronous card is one of the most important control components of the turbine control system. This is well defined in the GE control system with a separate specialized card for this task called the VTUR card.
The connection of this card with the central processor and the way of receiving and sending information under the defined protocols, has enabled one of the highest coefficients of performance assurance and accuracy of the control system.
Synchronization in the proposed SIEMENS systems does not have a special card or module and another system must be purchased for this purpose.
Instantaneous monitoring and permanent control of turbine vibration and analysis of all relevant criteria, and finally guidance and issuance of appropriate commands is one of the most sensitive tasks of the turbine control system.
In the GE control system, this task is performed by the VVIB card in a completely specialized way. The received information is processed by this card and transmitted to the main processor through VME bus.
This is important in the SIEMENS system without a special vibration section or module and for this another system must be purchased.
VALVE control card:
In the GE control system, the servo control card (SERVO), which is a terminal board for connecting circuits and transmits VSVO card data, is specialized in control of the valves. Due to the TRIPLE GE control system, this card is perfectly suitable for designed turbine valves.
Such a task does not exist in the SIEMENS system in a specialized and independent way, and sometimes due to the two-part system
The control and triple input of the control valves also causes the valves to fail.
Turbine protection card:
The protection control section of a turbine is the most important part in discussing the protection of a control system, in which GE has a specialized card (VPRO card). This card is responsible for protecting the entire system and preventing SHUT DOWN of all R, S, T slots.
The SIEMENS control system does not have a protection card and it is not possible to provide it.
The important point is that if the control is lost from the control system, there is no protection for the turbine and it will cause severe damage to the turbine.
Control system software:
The software used in the GE control system includes toolbox and cimplicity, which are very userfriendly, and their superiority over the software used in the SIEMENS control system is fully evident from the point of view of control system experts.
The software used in SIEMENS PCS7 is the general software for any type of PLC.