Siemens A1 User Manual
International English
Electromagnetic Compatibility
MICROMASTER Applications Handbook
29
6
Electromagnetic Compatibility (EMC)
6.1
What is EMC?
All electronic and electrical equipment generate unwanted signals. These signals
can be emitted from the product either via cables that are connected to the product
(Input, output, signal etc.) or via electromagnetic radiation ‘radio transmission’.
These signals can be received by other products (via the same routes) and can
interfere with the correct operation of the product.
can be emitted from the product either via cables that are connected to the product
(Input, output, signal etc.) or via electromagnetic radiation ‘radio transmission’.
These signals can be received by other products (via the same routes) and can
interfere with the correct operation of the product.
Control
Ouput
Supply
Emissions: Conducted and Radiated
Control
Ouput
Supply
Immunity: Conducted and Radiated
MICROMASTER
MICROMASTER
Figure 6-1
EMC. Emissions and Immunity
Any particular product gives out a certain level of emissions, and has a certain
level of immunity to incoming signals from other products. If the immunity of all
products is higher than their emissions, all is well. If this is not the case, severe
problems can occur, causing quality problems, damage, or in extreme cases injury.
level of immunity to incoming signals from other products. If the immunity of all
products is higher than their emissions, all is well. If this is not the case, severe
problems can occur, causing quality problems, damage, or in extreme cases injury.
Electromagnetic Compatibility concerns how equipment works together.
Electromagnetic Interference (EMI) refers to the unwanted signals themselves.
Electromagnetic Interference (EMI) refers to the unwanted signals themselves.
EMI has become a more serious problem recently as more electronic systems
(which may prove to have low immunity) are used in industrial applications, and as
power electronic products such as drives, generate high frequency signals which
can produce high levels of interference.
(which may prove to have low immunity) are used in industrial applications, and as
power electronic products such as drives, generate high frequency signals which
can produce high levels of interference.
6.2
Minimising the problem of EMI
EMI and EMC are much better understood than a few years ago, and most
manufacturers of electronic equipment take care during design and installation to
minimize emissions and maximize immunity. Siemens inverters are carefully
designed with this in mind, and optional filters can be specified (either built in or as
an external option) to reduce the emissions in the supply.
manufacturers of electronic equipment take care during design and installation to
minimize emissions and maximize immunity. Siemens inverters are carefully
designed with this in mind, and optional filters can be specified (either built in or as
an external option) to reduce the emissions in the supply.
Before describing the practical solutions to EMI, it is important to understand the
practical problems associated with EMC and inverters.
practical problems associated with EMC and inverters.