Powerformer ppt presented by b.yedukondalachari from pnc&viet in electrical & electronics engineering department.

1. Pnc&viet

2. Power requirement is increasing day by day
due to the maximum power utilization. In order to
meet this demand a large power has to be
generated in an efficient way. A new machine
namely “Powerformer” can do this. The
conventional plant generated voltage is limited to
30KV. This voltage is stepped up to a high voltage
level in the order of 800KV with the help of power
step-up transformers. The step-up transformer
imposes great drawbacks on the power plant,
starting from reduction in efficiency, high
maintenance costs, and more space less
availability.

3.  During the last century, a number of attempts
were made at developing a high-voltage
generator that could be connected directly to the
power grid, i.e. without going any step-up
transformer. The powerformer has opened a
new chapter in the generation and transmission
of electrical energy.

4.  Powerformer Concept
 Innovative Design
 The first Powerformer Installation
 Advantages of Powerformer

5.  Powerformer is a new machine, It is a 3-phase AC
generator with a rotor of conventional design.
 The difference compared with conventional generator lies
in the stator windings.
 In Powerformer stator winding consists of high-voltage
cables instead of today’s windings with a square cross-
section.
 By using high-voltage cables as generator stator winding, it
is possible to highly increase the generated voltage.
 The decisive difference between this design and present-
day technology is that Powerformer allows direct
connection to the high-voltage grid.

6. 1. Generator
2. Generator circuit breaker
3. Surge arrester
4. step-up transformer
5. Line circuit breaker

7.  This design implies the omission of the
generator circuit breaker, the high current bus
bar and the step-up power transformer from the
power plant, because Powerformer comprises
the functions of both generator and step-up
transformer as realized from above Figure
 As a consequence there is an increase up to
1.5% in total electric power efficiency compared
with today’s best designs, without using
superconductive materials.

8.  Powerformer has been designed with several
unique features that allow it to exceed the 30kV
limit, including a winding consisting of power
cables and an innovative stator design.

9.  The winding consists of a power cable with solid
insulation and two semiconducting layers, one
surrounds the conductor and the other outside
the insulation.
 The insulation material is cross-linked
polyethylene
 High-voltage power cables are used in winding.
 These cables used to many advantages over
conventional designs

12.  The stator of Powerformer consists of a
laminated core.
 These laminated core are built up from electrical
sheet.
 The winding is located in the slots formed by the
teeth, the cross section of the slots decreases .
The winding turn requires less cable insulation
the closer it is to the rotor.
 Each slot has circular bores at intervals, forming
narrow waists between the winding layers, as
shown in Figure below.

14.  The world’s first high-voltage generator based
on the new technology; a hydropower machine
is rated at 11 MVA, 45 kV, and 600 rpm. The
machine has already been tested in the factory
and installed at the Porjus Hydropower Center
on the Lule River in northern Sweden. The
machine is directly connected to the 45 kV
transmission power grids; its stator is shown in
below Figure

16. 1.It generates Low voltage
(<30kv)
1.It generates High voltage
(>>30kV)
2. High current 2. Low current
3. Stator has Short teeth 3. Stator Long teeth
4. High weight 4. Less weight
5. Mount winding is used 5. Thread cable is used
6. Impregnating windings 6. Extrusion type winding is used
7. High temperature 7. Low temperature

17.  higher efficiency
 low maintenance costs
 power transfer form generator to power
grid without going via the step-up
transformer
 better availability

18. ABB’s new high-voltage generator (Powerformer)
has been studied the new concept provides the
possibility to directly connect a rotating machine to the
high-voltage power grid without going any step-up
transformer. Powerformer is a high-voltage generator;
the limitation in its rated voltage is set solely by the AC
 Power cable and the cable accessories
(terminations and joints) used in its stator winding. This
means that Powerformer of voltage ratings up to 400 kV
can be realized, although has not been proved yet.