How to reduce distribution
transformer technical losses

Transformers are significant loss-making components in the power grid. The key to providing a reliable and affordable electricity supply to consumers is through minimising energy losses in transformers. A bonus for utilities is an increase in revenue with the same input of power, as the energy saved is energy generated.

In Africa, a persistent challenge is the high rate of failure of distribution transformers, which leads to the complete shut down in distribution networks. The leading causes are the improper quality of the materials used for manufacturing of transformers, overloading at sites, theft of oil and copper from transformers, and inadequate grid protection systems.

The focus should be on bringing in significant improvement in the design, process, and quality of the distribution transformers by selecting reliable manufactures in addition to measures taken to strengthen the distribution networks.

Presenting the case for energy efficient amorphous metal distribution transformers

According to Toshiba, there are four significant challenges for African utilities

  1. Shortage of Power generation capacity,
  2. electrification for the rural area and
  3. shortage of necessary funding.
Due to resource-constraints, the company proposes that utilities prioritise increasing grid efficiency by minimising energy losses in transformers. This solution will further save on investments to new power generation systems, and such savings can be utilised for additional electrification programmes.

It is this underlying effort – always deliver a value chain for customers by providing energy-efficient products that result in savings – that is the driving force behind Toshiba’s success.

For utilities who continue to battle with technical losses, Toshiba proposes energy-efficient amorphous metal distribution transformers. Available from its state-of-the-art manufacturing facility based in India, these transformers are ideal for the reduction of technical losses.

Amorphous metal distribution transformers are highly reliable and competitive when evaluated on a life-cycle cost basis. Detailed in Figure 1 are the benefits of using amorphous transformers.
table 1
Figure 1: Typical loss, TOC and efficiency comparison of energy efficient transformers (AMDT vs. CRGO) (The above losses mentioned are for illustration purpose only)
The investment needed versus the AMDT lifespan cost savings

As an example, in a network installed with 10,000 units of amorphous transformers instead of cold-rolled grain-oriented (CRGO), the additional investment on AMDT will be 8% (approx.) per transformer, when compared with conventional CRGO transformer. The additional investment percentage will vary depending on the rating of the transformer.

The estimated savings obtained in using 10,000 AMDT units during the lifespan of the transformer:

  • Savings in electricity consumption cost of $1.2 million per year.
  • Savings in the usage of power generation capacity of 2.41MW.
  • Reduction in CO2 emissions of 5,926MT per year.
  • The payback period using AMDT is three years.

Considering transformers have a typical lifespan of 25 years, utilities and their customers will benefit from the monetary savings in electricity consumption, usage of power generation capacity, and reduction in CO2 emissions. These benefits gained by installing AMDTs in the network will also boost the T&D sector in Africa.

The evidence is clear, AMDTs are energy-efficient, and with aluminum winding have numerous advantages in terms of reduction of capital expenditure and overcoming vandalism, as there is no copper inside.

table 2
Figure 2: Energy and money saved in using amorphous transformers
Toshiba’s distribution transformers facilities and plans
Toshiba’s manufacturing facility in India, the Toshiba Transmission & Distribution Systems (TTDI), is primed to cater to the global T&D sector’s requirements. The TTDI amorphous plant is equipped with unique infrastructure, which includes automatic and semi-automatic processes, a one-of-a-kind in the world.

TTDI is proud to have sophisticated ultra-modern manufacturing facilities, and state-of-the-art testing and manufacturing equipment for the fabrication, assembly and testing of amorphous metal core distribution transformers with total quality control process mechanisms meeting International Quality Standards.

Toshiba has always been at the forefront of promoting and delivering the best technologies and practices globally. We extend our support at every stage of asset management for distribution utilities, under our Total Asset Management Initiative. This support starts from the pre-tendering stage in incorporating the best technical specifications, manufacturing and testing practices. This initiative culminates in the post-landing control to ensure secure product delivery and support in training utilities’ workforce in the use and maintenance of products.
Supply record of Toshiba’s transformers across the globe
table 3
This article was originally published on ESI Africa 2019 Issue 4 https://www.esi-africa.com/tag/2019-issue-4/