BTS

BTS 2000 Fast Bus Transfer System is an advanced microprocessor based Bus Transfer System for Power Generation Utilities & Continuous Process Industries. By performing high speed motor bus transfers between two independent sources of power under prescribed safe system parameters, the Bus Transfer System provides continuity of power supply to the critical motors of a plant. This pre-empts any interruption to the processes running in the plant inspite of the contingency of the feeding source.

Aartech has more than 25 years of experience in deploying fast bus transfer system solutions and 300’s of installations to a variety of demanding system requirements. We work with switchgear manufacturers, EPC contractors, end users and their respective consultants to ensure end-to-end solutions for mission critical applications. We take responsibility for the entire value chain – design, engineering, system integration, manufacturing, supply, supervision of commissioning and after sales customer service requirements.

BTS 2000 is a proven solution in thermal power generation as well as nuclear power generation of ratings from 25MW captive power units right upto 800MW. It has been selectively used in hydro power generation units as well.

Many of the continuous process facilities including Metals, Petrochemical, Mining, Water Handling are finding rich benefit by use of these systems. Industrial requirements are generally more stringent and non-empirical, and the power quality, process sensitivity,interruption nature, reliability issues and system response need to be evaluated on a case-to-case basis to offer an appropriate solution.

BTS Brochure

BTS 2000 continuously interfaces with various switchgear and protective devices, and monitors various system conditions in real time. On initiation of a transfer on upstream protective relay operation, self detection of source failure, or a manual command – BTS 2000 checks pertinent system parameters for availability of suitably enabled transfer modes and issues direct trip/close control operations on concerned breakers with precision timing.  The breaker operations are also further monitored for their proper operation, else backup measures are immediately initiated.

BTS 2000 is generally customised to project specific requirements. While there may be certain product configurations that are similar if not identical between projects, there is always a need to ensure that the switchgear circuits are appropriately designed and integrated to match the bus transfer requirements.

The product range illustrated to the right are therefore meant to serve as a general reference while specifics may vary on a case to case basis.

Please mail your custom specific requirements along with a copy of your Single Line Diagram (SLD), Specifications (if any) and Operational Philosophy to bts@aartechsolonics.com . We would be happy to assist you with our recommendations in the best possible manner.

Fig. 2 shows a 3-breaker scheme employed to service two motor buses from two alternate sources. Each source feeds a single motor bus through its main incoming breaker. A tie breaker is provided for coupling the two motor buses.

A typical example is that of a process industry, serviced by two separate stations SOURCES I and II, each capable to meet the load on both the Buses I & II, off the grid. The SOURCE I transformer is connected through I/C- I incoming breaker to BUS I. Similarly, SOURCE II transformer is connected through I/C – II incoming breaker to BUS II. BUS I and BUS II are connected using the TIE breaker. There are several bus transfer scenarios depending upon the choice of the normal supply to the motor buses.

1. Normally closed TIE breaker: The entire motor bus comprising BUS I and BUS II is transferred between SOURCE I and SOURCE II.
2. Normally open TIE breaker: Each source supplies power to a single motor bus. In case of source failure, the motor bus connected to the failed source is transferred to the source through the TIE breaker.

Since process continuity is the prime consideration in industrial plants, automatic transfers determined by different auto-initiation criteria for source contingencies as well as source equipment failure conditions are employed. Manual transfers are commonly conducted during planned start-ups and shutdowns. Typical breaker-failure logics safeguard the motor buses from a permanent paralleling position.

The 2-breaker scheme is employed to service a single motor bus from two alternate sources. The normal source feeds the motor bus through the Main breaker, while the alternate source feeds the motor bus through the tie breaker.

A typical example is that of a thermal power plant, where the unit auxiliaries, such as boiler feed pumps, forced draft and induced draft fans, cooling water pumps, etc., are supplied through unit boards. The configuration in Fig. 1 shows a single unit board, although higher capacity units typically have two or more unit boards.

The unit board can be fed from two sources. The Unit Auxiliary Transformer (UAT) (normal source) supplies locally generated power to run the auxiliaries when the unit incoming breaker (UAT I/C) is closed. The station board (alternate source) supplies power to the auxiliaries from the grid when both tie breakers (TIE-1 and TIE-2) are closed, and UAT I/C is open.

During startup, the generator transformer breaker (GTB) is open until the generator is synchronized with the grid. Until then, the station board supplies the unit board. After the generator is synchronized, the unit board is transferred to the UAT so that the unit feeds its own auxiliaries. Such a transfer is referred to as a Station-to-Unit transfer. There are several prioritized and categorized unit tripping conditions such as generator trip, load throw off, turbine trip, boiler trip etc. along with UAT / GT transformer trips on differential, winding temperature, oil temperature etc. under which it is required to automatically transfer the unit board from the UAT to the station board. These transfers are referred to as Unit-to-Station transfers. Automatic transfers on unhealthy bus conditions determined by different auto-initiation criteria are also employed in order to constantly provide a healthy supply to the motor bus. Manual transfers are commonly conducted during planned start-ups and shutdowns.

Typical breaker-failure logic safeguards the unit board from a permanent paralleling condition. TIE-2 is a normally closed (NC) breaker, used as a backup measure to safeguard the unit from a dangerous generator back-feed condition, in case both TIE-1 and UAT I/C fail to open.