What industrial electronics are.
The effects of EMI on industrial electronics.
The EMC standards for industrial electronics.
The advantages of factory automation include reduced operation costs, increased efficiency of operation, and improved product quality and safety. Industrial electronics play a vital role in automation; components such as power electronic devices, sensors, actuators, meters, integrated circuits, and semiconductors are used for industrial automation. In harsh industrial environments, such as chemical, semiconductor, energy, petroleum, mining, and transportation industries, the EMC in industrial electronics-based systems is important--even a small glitch in a sensor can lead to temporary shutdowns and devastating financial losses. In this article, we will explore industrial electronics, their vulnerability to electromagnetic interferences, and the standards for EMC in industrial electronics.
What Are Industrial Electronics?
“Industrial electronics” is an umbrella term that covers the electrical and electronic devices, equipment, and components used in industrial environments. Industrial electronic elements can range from small passive components to heavy machinery. Items that fall under the category of industrial electronics include:
- Power electronic switches
- Integrated circuits
- RF circuits
Industrial electronics engineering deals with the control, instrumentation, installation, signal processing, fault detection, maintenance, and automation systems in industries. Part of the job of an industrial electronics engineer is to mitigate electromagnetic interference (EMI), as all industrial electronic systems are subject to EMI, which hinders the efficient and reliable operation of these industries.
The Effects of EMI on Industrial Electronics
Let’s use the effects of EMI on analog sensors, a widely used component in industrial electronics, as an example of the general effects EMI can have on industrial electronics.
Analog sensors are employed in industries to measure quantities such as temperature, pressure, flow, position, voltage, and current. They are indispensable parts of factory automation and control systems. These sensor signals are compared with a reference to start, continue, or end an operation. In the presence of electromagnetic interference, sensor readings are manipulated and can end up in the wrong control system operation.
EMI effects on analog sensors can be classified into two types:
1) Intentional or unintentional EMI
2) Low power or high power EMI
Some examples of unintentional high-power EMI sources are transformers or lightning. Intentional EMI injects faults by corrupting the digital logic and causes inappropriate or erratic system operations. Since analog sensor signals are in millivolt and milliwatt power levels, they are vulnerable to low power EMIs. An EMI-injected sensor reading can even bring the automated industrial systems into a temporary shutdown, causing financial loss. To prevent these issues, engineers should carefully adhere to the standards for EMC in industrial electronics when designing these systems.
Standards for EMC in Industrial Electronics
It is important to protect industrial electronic systems from electromagnetic interference in order to ensure the reliable operation of the system. To achieve this, industrial electronic systems need to comply with EMC standards. The most popular EMC standards concerning industrial environments are IEC 61000-6-1 and IEC 61000-6-2. The former standard reviews the immunity requirements for light industrial environments, whereas the latter standard reviews the general industrial environment. There are also EMC standards that provide guidelines for limiting emissions from industrial systems. Standards IEC 61000-6-3 and IEC 61000-6-4 deal with the emissions from light and generic industrial environments.
Here, we break down these four standards in greater detail:
IEC 61000-6-1 is the generic EMC immunity requirement that applies to electrical and electronic equipment used in light-industrial locations as well as residential and commercial locations. It covers the immunity requirements for frequencies up to 400GHz.
IEC 61000-6-2 is an international standard that gives the EMC immunity requirements for frequencies up to 400 GHz. It is applicable to electrical and electronic equipment used in industrial locations.
IEC 61000-6-3 is a generic EMC emissions standard that applies to electrical and electronic equipment. A part of this standard handles the emissions requirements of equipment used in light-industrial environments. Conducted and radiated emissions up to 400GHz are considered under this standard.
IEC 61000-6-4 contains the international standard for emissions requirements from electrical and electronic equipment existing in both indoor and outdoor industrial environments. This standard is applicable to equipment outside the scope of IEC 61000-6-3. The emissions requirements within the range of 9 kHz to 400 GHz are covered under this standard.
As industries become more technology-driven, the chances of EMI increase drastically in automated manufacturing and processing systems. Ensuring the EMC of industrial electronics and compliance with EMC standards is critical to mitigating EMI. Cadence’s suite of design and analysis tools can help you design your industrial electronics-based systems in an electromagnetically immune way.