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Hybrid-Vehicles
Insulation Testing on Hybrid Cars
The word „hybrid“ originated in the Greek culture and means „mixed from two sources”.
Therefore a hybrid vehicle is powered by two types of engines. The most common is the
combination of gasoline engine and electro motor with electric energy storage, such as
batteries, fuel cells or super-caps (capacitors).
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Technology
Hybrid Motors were developed to reduce the emission of gases that pollute the environment. The high output of CO2 gases is getting much attention in regards to climate
changes.
A vehicle with an average size engine has a CO2 output of 204 g/km, which has a volume
of approx. 109 liter CO2/km. A vehicle with a hybrid engine has a CO2 output of approx.
104 g/km, which translates into a volume of 55 liter CO2/km. The combination of electro
motor for short distances, such as city driving and high performance of a gas engine for
long distances, such as highway driving, promises an optimum use of energy.
Picture 1: Hybrid Motor of Toyota
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Safety is important
Any place where is electricity, there may be dangerous voltages for humans and therefore there are regulations for safe operation and service of hybrid vehicles. Hybrid vehicles have a power supply system of 12V or 24V to drive standard components, such as
radio etc. and a high energy system for electric operation with voltages up to 1000V DC.
GMC-I Gossen Metrawatt GmbH,
frdr/diko, Apr-08
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Hybrid-Vehicles
Therefore any work performed by specialists or drivers can eventually be dangerous.
Protective measures are designed to prevent access to electric conductors. Therefore it
requires that only specially trained personnel is authorized to perform repairs or modifications.
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Regulations / Testing
The following protective measures and tests have to be performed before initial usage
and also during regular service intervals:
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Protection against direct contact during charge and discharge work performed.
Protection against indirect contact during discharging of the battery in vehicle and
during charging of the drive battery.
Electrical Insulation and Voltage Conductance (Insulation Resistance between all
electrical components and the chassis)
Electrical Insulation of the battery (Insulation Resistance between battery polarities
and metal components, chassis)
Voltage at the capacitors
Protective Grounding of electrical components
Testing of the charge controllers
Testing of the electro motor (nominal voltage, power consumption, RPM)
There are many applicable standards and regulations that apply to electric powered vehicles, such as IEC, EN and VDE standards.
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Tools for Testing
In order to perform tests as mentioned above there are Insulation Resistance Testers,
Multimeters and Current Clamps for AC & DC signals required.
METRAhit ISO
The METRAHIT ISO is such a multi-function measuring instrument that performs measurements of Voltage VDC, Current IDC, Temperature and Resistance, but is also a full
function Insulation Resistance Tester with test voltages of 50-100-250-500-1000V selectable. Measurements can be logged by the Smart Data Logging function built-in and
data can be down-loaded via IR-USB Adapter to PC-Software METRAWin10 and further
handled on a PC.
For very accurate current measurements up to 10A the internal measurement function is
being used, which has a resolution of up to 1μA. For larger currents, such as motor starter current, a DC current clamp is connected. The transformation ratio is selectable in the
METRAHIT ISO and the actual current values are displayed correctly. The METRAHIT
ISO is battery powered and rugged and does perform well in tough applications.
The METRAhit ISO is used also for service and repairs of fork lifts and has proven itself
in bad environments. Other applications include testing of rechargeable batteries, insulation testing of power supply cables, temperature measurements as well as trouble shooting of electrical control devices.
GMC-I Gossen Metrawatt GmbH,
frdr/diko, Apr-08
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Hybrid-Vehicles
DC Current Clamps Z202A/Z202A/Z203A und Z13B
Picture 2: Current Clamp (AC+DC), Z201A from GMC-I
Picture 3: Current Clamp (AC+DC), Z13B from GMC-I
The current clamps of the Z201A family with different transformation ratios are ideal accessories for safe measurements of AC & DC current signals without splitting off the current conductors. Because of the high bandwidth from DC to 10 kHz and simple zero adjust by the push of a button they are an universal accessory for Multimeters and Power
Measurement Instruments. The Z13B Clamp is for high currents up to 600A with a very
wide opening.
GMC-I Gossen-Metrawatt offers a wide range of Test & Measurement Instruments for
your safety .
GMC-I Gossen Metrawatt GmbH,
frdr/diko, Apr-08
Seite 3 von 3