Saturday, October 30, 2010

Kenya receives sh.3.79 Billion to finance regional energy projects

Kenya has recently aquired  a 3.97billion loan form the African Development Bank. This is part of a regional grids of five countries.The five countries include Uganda, Burundi, DRC, Congo & Rwanda. Speaking during the signing ceremony, at The Treasury building, Finance minister Uhuru Kenyatta, said the project will enhance cross border sharing of electricity and development at low cost power resources. The loab deal was signed by AfDB representative: Mrs. Domina Buzingo.

This loan will facilitate:
  1. Upgrading of 769km of 220kV and 110kV Power lines.
  2. Construction & Reinforcement of 17 transformers to interconnect the grids of the Nile Equatorial Lake Countries.
  3. Construction of a 220kV double circuit transmission line from the border of Uganda to the substation at Lessos - which shall be expanded with additional transformers & switchgear
  4. Uganda - Rwanda interconnection, upgrading of the Burundi, DRC and Rwanda interconnection lines.
  5. Operational Costs.
One of the major potential sources of power is the Iinga Dam in DRC which has a potential of 40GW

Sunday, October 10, 2010

How your neighbourhood transformer works

Generally as one of the most preyed upon units in the electric industry, the domestic or neighborhood transformer serves a crucial role in ensuring that we get a constant flow of electricity.In the electric industry it is commonly referred to as a Step-down transformer since it does exactly that at all times besides protecting consumers.

The main purpose of these electrical machines is to provide a step-down mechanism for the incoming voltage from the primary substation, located away from consumers.It should be noted that it steps down voltage and steps up current to feed the consumer directly.It is the last in the line of machines that modify the voltage or current before going to small consumers.

In countries that use the BS 240/415V Standard, their transfomers usually receive and incoming supply of 11kV from the overhead feeders.It is then from this 11kV is is able to step it down to 240/415V 3phase voltage.
One major drawback of these machines is the heat energy generated therefore it does not operate at full efficiency.It is also prone to vandalism, because it houses a rather rare expensive oil that is used as a cooling mechanism. One good as advantage of this machine however is that it does not require regular maintenance and can withstand the weather elements as long as the mounting is mechanically sound.

The Star-Delta 3-phase Motor Starting Method

The Star Delta starting method is a motor starting mechanism that minimizes the large amount of starting current that motors draw in. The Star Delta, as the name suggests basically involves feeding the motor with 1/sq.root3 (58%) of the full load current until it attains speed then applying the full load current. This method is commonly referred to as "Soft Starting" the motor, For this to work the whole set-up requires 3 contactor i.e The Star Contactor, The Delta Contactor & The Main Contactor.However for the motor to be started in Star Delta, its internal connection at the terminal box has to be wired in Delta-giving it capability of receiving the full-load current at any instant.

Traditionally, in many regions there was a requirement that all motor connections be fitted with a reduced voltage starter for motors greater than 4KW 5HP.This was to curb the high inrush of starting currents associated with starting induction motors.
Advantages of this method is low or reduced cost as compared to other methods...

Saturday, October 9, 2010

KPLC opts for Non-Oil based transformers

The Kenya Power & Lighting Company (KPLC) , Kenya's largest power transmission and distribution company, has embarked on an initiative to replace its transformers with non-oil based types. This is in response to rampant vandalism of its convectional transformers.KPLC has ordered for 100 dry type transformers which are to be installed in Kiambu, Nyeri, Thika, Dagoretti Corner, Ruiru, Gatundu, Limuru and Kitengela towns which are prone to transformer theft.

The Reality
According to the firm's Operations and Maintenance manager, KPLC faces losses of  up to Ksh.600 Million per year and economy losses of Ksh.2 Billion.These vandalism cases are mainly transformer oil theft but in recent times they have involved to the entire unit itself! I must say that the thieves have upgraded their business indeed.How the thieves manage to offload the 200kg unit form the poles remains a mystery to me.It would require a crane to do the tedious job.