Optimising out put of DG SETS

Mr. Chandmal Goliya BE (Elect.)
has more than four decades
experience in the field of
Electrical & Electronic
Test & Measuring Instruments.

Electricity is becoming a scarce & costly commodity day by day. Due to improper planning & lack of new Power Stations & low efficiency in the output of the existing Power Stations there is shortage of electricity. While industry should not suffer due to the shortage but at the same time due to non availability of electricity, production out put of the industry is affected. To cover the shortage, industry has to resort to setting of alternate means of energy to full fill their requirement.

One of the means the industry resorts to is installing Diesel Generator Set in their plant for meeting their electricity supply demand. These D.G. sets run on diesel fuel which is also expensive resulting in high unit cost. For the industry to be profitable one of the aspects is to control the cost of the input such as raw material, salary & wages, over heads etc. & DG set is no exception. If operating cost of the DG set are kept under control, the profitability of the company can increase. To control the cost related to DG set, the load connect to the DG set must be monitored & only essential load must be switched ON as required for the smooth running of the factory. Also losses due to heat should be reduced & the load Power Factor should be 0.9 or above.

Some of the solutions for the above problems are as follows:
Heat loss control by thermal imaging camera
A Thermal Imaging Camera can detect the hot spots in the DG systems, whether it is the hood V type air filter or exhaust pipe choke or the intake air or any other point where heat losses are high. By identifying such hot spots, proper action can be taken to reduce the heat losses.

Power factor control
Power factor below 1.0 requires a utility to generate more than the minimum VA necessary to supply the real power (watts). This increaseds generation and transmission costs 1.4 times the current. This causes extra load on the DG set leading to consumption of more fuel. To reduce the fuel cost & optimize the load, the load Power Factor plays a significant role. For maintaining the Power Factor to 1.0 appropriate value of capacitors must be installed along with an APFC Relay. The Power Factor can be maintained near unity by installing appropriate value of capacitors on the load side & controlling the operation of the capacitor with Automatic Power Factor Controller. By improving the power factor it reduces the load burden on the Diesel Generator.

Maximum demand control
Many times in the factory there are low priority loads connected, such as air conditioners, passage lights, fountains, ground lights etc. To control the disconnection of such loads it is necessary to have Maximum Demand Controller to be connected on the load side. With proper programming, it disconnects the non essential load not required. Maximum Demand is calculated & billed by a KW Demand meter which records the highest KW consumed in one 15 or 30 minute period over a monthly billing cycle. The purpose of controlling the maximum Demand is not to exceed the contracted maximum demand. One way to achieve this is to shed non-critical loads such as Lights, Compressors, Air conditioners, Pumps, Fans, Shredders, Refrigerators etc. By installing MDC we can keep the Demand under control & consequently reduce fuel consumption.

Vibration control
If the DG set is installed properly with proper anti vibration mounts the vibration will be minimized. If there is vibration it will affect the efficiency of the DG set resulting is more losses. DG sets should be mounted rigidly on the ground so that there is no vibration. Vibration leads to quicker wear & tear of the bearings, shafts and can lead to misalignments. This results in lower efficiency and lower load capacity. Hence by regular checks for vibration, the efficiency will be enhanced.

Sound level control
“As per Pollution Control Board the sound level emitted from DG set should not exceed 70 dBa at a distance of one meter. Sound level meters should be installed for monitoring & recording the sound level so that there is compliance with the law. In conclusion, by implementing the above recommendations maximum output can be obtained with high efficiency resulting profits for the user.

For more information
Mr. Chandmal Goliya, Kusam Electrical Industries Ltd.
E-mail: [email protected]