»Functionality and safety are
dovetailed perfectly.«
Walter Schossig,
expert in energy
supply protection and
control technology
Interview
The next level of functionality – increased safety
Test connector system for protection
and secondary technology
Talking about the special requirements of grid protection technology in high and mediumvoltage switchgear: Walter Schossig, an expert in energy supply protection and control
technology, and Markus Schade, Global Industry Manager Energy and Utilities at Weidmüller.
In Detail
Makig operating power grids easy and
safe: WIPRO makes testing simple
WIN! As populations and
economies grow worldwide,
so does the amount of energy
required. What does this mean for
Weidmüller?
Schade: Day in, day out, our
customers in the energy industry are
working on new or more efficient forms
of energy generation. One major issue
that the sector is having to deal with
is the trend towards decentralising
energy generation. This can be in
the form of wind and photovoltaic
systems, but also combined heat
and power plants such as gas power
stations and district heating plants.
Work here is focused on extending
the grid technology to transmit and
distribute the energy generated
remotely. For grid operators, this means
providing additional substations for the
decentralised generators to feed in to.
Weidmüller’s products have been used
in this field for decades – for example,
with products that make it easier to
commission and maintain substations.
WIN! What are the key issues for
commissioning and maintenance?
Schossig: Protective relays are
fitted in high and medium voltage
substations to detect overloads, earth
faults and short circuits. If certain limits
are exceeded, the relays trigger circuit
breakers. To ensure the protective
function, the protective relays must
be tested before commissioning in
accordance with DIN VDE 0105 and
other industry guidelines such as the
code of practice for protective systems.
This applies to new substations
and when making changes to and
extending existing substations. Regular
testing is also needed during operation.
Test terminal strips for test devices
and protective relays are needed for
to ensure that tests are carried out
correctly. Weidmüller has developed
several practical solutions for this
purpose.
WIN! What does the test
involve?
Schossig: The protective relay is
measured by inputting certain levels
of current, voltage, impedance and
frequency and testing the output
signals. In the past, test equipment
was attached to the protective relay
itself; later the test parameters were
supplied via a terminal strip. But
there was always the risk that the
test equipment would be connected
incorrectly or the tester would forget
to close the pulse or transformer
circuits once the test was complete.
This resulted in unplanned tripping,
more time being spent on testing the
protective relays, protection failure and
even risks for staff and transformers if
the jumpers in the terminal strip were
wrongly connected. For example, if a
test device is incorrectly connected, it
can cause system components in the
transmission or distribution grid to fail.
This represents a major risk to supply
security for consumers. To make testing
economical while improving security,
protection specialists in transmission
and distribution grids and power
stations have developed connection
circuits with test terminal strips and
test connectors.
WIN! What product solutions has
Weidmüller developed in this area?
Schade: We are a partner in industrial
connectivity and over many decades
have provided practical products for
testing protective equipment. Our test
isolating terminals offer a range of
connection technologies which have
consistently proved themselves on the
market.
We always keep pace with the very
latest developments; we have worked
closely with customers in the energy
market to advance and optimise this
concept. The end result is our POCON
test connector system, with a defined
number of connection points, which
allows for rapid, error-free testing and
measuring of transformers during
operation. Through our ongoing
dialogue with power station and grid
operators, we are always taking on
board new practical requirements
and building those findings into new
product developments. In response
to the need for more flexible and
adaptable test systems, we have
developed the new test terminal
strip WIPRO (Weidmüller Interface
for Protection Relay). The modular
structure with up to 22 connection
points means the device can cover all
circuits.
WIN! What makes the WIPRO so
special?
Schade: To start with there is the
modular base unit with a choice
of installation method, either on a
mounting rail or wall, and connection
technology – a choice of clamping
yoke or tension spring. Users can select
whichever options suit their needs.
Service technicians use coding
elements to set up the test adapters
for different circuits, then simply plug
the right connector with the test
device into the base unit and testing
can begin. Once it is plugged in,
the automatic lock in the base unit
prevents the test connector coming
loose during protective relay testing.
Integrated connection protection with
a lead seal means that any incorrect
In Detail
rewiring of the test terminal strip can
be identified straight away.
system availability. Functionality and
safety are dovetailed perfectly.
WIPRO also has three early break
contact stages, keeping it one step
ahead. Certain tripping paths can
therefore be deactivated just before
the transformer short circuits and the
voltage transformer is isolated.
WIN! What other product
solutions does Weidmüller provide
for the energy generation and
transmission sector?
WIN! To what extent do these
product features satisfy reallife requirements and industry
standards?
Schossig: To a great extent! The
features of the WIPRO mean that
protection tests can be set up without
disconnecting any wires. The system
therefore vastly improves the reliability
of protective systems. Safe testing
during operation also provides major
benefits – both in terms of safety and
distributor housings to suit customer
requirements. In addition to these
products and solutions, what clearly
sets our developments apart is the
extraordinarily close relationships we
have with our customers.
Schade: Numerous Weidmüller
products are used in this area, such as
our electronics products. Transformer
stations provide DC voltage for
emergency power supplies. Our
PRO-M Series power supplies can use
either 110 V DC or 220 V DC and
convert them to 24 V DC. We also
offer signal converters and isolators
such as the WAVE TTA, which features
configurable input and output signals
for universal use. To complete the
portfolio, we provide services such
as application-specific assembly of
In addition to the WIPRO test terminal strip,
Weidmüller’s product range includes a wide range
of other connectivity solutions for energy providers.
Field
Circuit breaker
Switchgear
Field wiring
Protection technology
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Pre-assembled Klippon® enclosures for use in outdoor applications
WIPRO test connector system
Connection systems: heavy duty connectors, cable glands and feedthrough
Cabinet components: power supply, separation and conditioning of signals, industrial Ethernet communication, overvoltage protection
Station control
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