Design electrical power distribution network efficiently in PC !

With the software tool Simaris design electrical power distribution can be planned easily, quickly, and safely. The versions 6 offers electrical planners, installers, and control cabinet manufacturers even more functionality and provides improved support throughout the project cycle, from planning and configuration to installation and documentation of the systems.

Due to ever higher requirements for the equipping of nonresidential and industrial buildings as well increased expectations regarding the safety of the systems and the system documentation, electrical power distribution planning is becoming ever more costly and complex. 

The Simaris software tools, by professionals for professionals, provide support for the planning of power distribution systems in buildings.

For example, the planner can use Simaris design to carry out a system calculation based on the specifications found in the project requirements and use that to dimension the equipment according to accepted engineering practice and applicable standards (VDE, IEC), from the medium-voltage infeed to the connected devices.

Simaris design provides support for the calculation of short-circuit currents, load flow and distribution, voltage drops, and energy balance. Simaris design is also helpful in the selection of the equipment that is actually required (e.g., medium-voltage switchgear and protective devices, transformers, generators, and low-voltage switchgear and protective devices), as well as for conductor dimensioning (i.e., for the dimensioning of cables, conductors, and bus bars).

Download Simaris design software from Siemens site.

Motor starting calculation by MS Excel spread sheet.

A motor starting case study for any given electrical network can be performed by reduced the network to a smaller equivalent network consisting of a source (generator / grid), the starting motor (largest motor), other large running motor and a lumped load.

This MS Excel based spread sheet is based on this concept and present a small model of electrical network that can be adapted for such motor starting case studies.

This is very helpful especially for quick checks as follows:

1. What is the largest motor size that can be started with a given generator rating
2. What should be the rating of the generator (or nos of generator operated in parallel) for a given load and largest motor size
3. Knowing voltage drop during starting conditions for given motor details and hence deciding the key parameter during design (say max allowable starting current)
4. Deciding the cable size / number of runs etc.

The spread sheet performs an iterative calculation based on pre-start load inputs and starting motor data. Detailed analysis may be performed with the help of available software.

Download the Motor starting calculation by MS Excel spread sheet

How to select generator for your industry?

This is a major decision to select a generator for captive power because it will acts as a heart for your industry. So consider the following technical facts to ensure maximum efficiency as well as up time. Also consider all technical data regarding maximum 90% of load for safe and economical operation.  Collect the bellow data according  and compare among them to make the decision.                       

                 

        Technical Data                  

                                               

                S.L          Description

                1              Electrical output(KW) at 400V,1500 RPM,50 Hz P.F=0.92

                2              Minimum Gas pressure required(PSI)   

                3              Lube oil Consumption(L/MWH)

                4              Gas Consumption(Nm3/h)         

                5              Fuel efficiency  

                6              Electrical Efficiency         

                7              Thermal Efficiency          

                8              Total Expenditure up to major overhauling(USD)             

                9              Total downtime upto major overhauling(Hours)               

                10            Cost/KHW          

                11            Emission Values (NOx )

         

                                      

 Durientg operation of generator you will get some energy form exhaust and jacket water which can be used co-generation purpose. so this is also an imposrtant issue who able to ensure maximum heat recovery.          

           

                                    

                                               

                Co-Generation Data                      

                                               

                Engine cooling water circuit                       

                                               

                S.L          Description         

                1              Hot water flow (m3/H) 

                2              Hot water outlet from engine(0C)           

                3              Hot water Inle to engine(0C)     

                4              Maximum allowable pressure drop in PHE(PSI) 

                                               

                Exhaust  gas circuit                         

                                               

                S.L          Description         

                1              Exhaust Gas flow(Kg/Hr)             

                2              Exhaust Gas temperature(0C)   

                3              Maximum allowable exhaust pressure drop (mmWC)    

                                               

             

        Commercial Data                             

                                               

                S.L          Description       

                1              Price /Unit(USD)             

                2              Warranty(Yrs)   

                3              Free Maintenance Spare parts (Set)       

                4              Delivery Period(Month) 

                                  

Calculation of total Expenditure up to major overhauling" must inculde Engine operational cost(Gas Consumption,lube oil consumption,maintenance parts and service ),overhauling parts  and servicing cost. Total downtime up to major overhauling" will include downtime for maintenance and      

overhauling.        

If you want to add something comment here .
 

                 

Factors to select a power transformer.

To Select the Right power Transformer, First Determine the following things:

• Three Phase or Single Phase ,according to load
• Primary voltage, which is the available voltage
• Secondary voltage required by load equipment
• Frequency (in Hz)
• KVA load  with possible future increases factored in 0.20
• Is the transformer to be used indoors or outdoors?
• Is the transformer to be floor or wall-mounted?
• Is an auto transformer or a double-wound transformer required?
• Insulation Type (Liquid-Filled or Dry Type)
• Low-Loss Core Material
• Regulation
• Voltage Taps
• Cooling system
• Temperature Class

The manufacturers of transformers recommend that the connected wattage not exceed 90% of the Transformer's rated wattage. For example, don't connect more than 450 watts to a 500 watt transformer.

Nominal Data of a power transformer:

Description	Unit	Data
Rating Voltages	kV	11/0.4
Power rating	KVA	1000
On Load /Off Load Tapping	kV	03 Position
Coupling	-	Star/Star
Vector Group	-	Yyn0
Frequency	Hz	50
Maximum Oil Temperature	K	40
Hot Spot Winding Temperature	K	65
Temperature Class		A
No Load Loss	kW	1
Full Load Loss	kW	3
No-Load Current	%	0.4