What exactly do EMI, EMS, EMC mean? Is there a demand for lithium batteries?

　　The electromagnetic radiation problem of electronic products has attracted more and more attention. I believe that most of them are familiar with the term EMC (electromagnetic compatibility). However, similar professional terms such as EMI and EMS often appear in front of everyone. They seem They are all related to radiation protection (electromagnetic radiation). So, what are the similarities and differences between them?

　　EMI (Electro Magnetic Interference) refers to the phenomenon that electronic equipment (interference source) interferes with other electronic equipment through electromagnetic waves. For example, when we are watching TV, there will be snow noise on the TV screen when someone is using household appliances such as a hair dryer.

　　What's more serious is that if electromagnetic interference signals hinder the medical electronic equipment that is monitoring the condition or the aircraft that is flying, it will cause unimaginable consequences. Judging from these examples, it is as if electronic devices have an invisible "attack power" that disrupts and destroys the normal operation of other electronic devices.

　　From the perspective of "attack", there are two main types: conducted interference and radiated interference. Conducted interference refers to the interference source coupling (interference) the signal on its own electrical network to another electrical network through a conductive medium (such as wires). The most common example is that the power supply in our computer will affect the electricity network at home. When the computer is turned on, the lights in the home may be dimmed. This is more obvious on computers with inferior-brand power supplies.

　　Radiation interference is often referred to as electromagnetic radiation for short. It refers to the interference source coupling (interference) the signal on its own electrical network to another electrical network through space. Excessive electromagnetic radiation can cause impact and damage to the human body. The "radiation" that people often worry about refers to this part of electromagnetic radiation interference.

　　EMS (Electro Magnetic Susceptibility) refers to the ease with which electronic equipment is exposed to electromagnetic energy from the outside, causing its own performance to decline. For example, it is also interfered by a hair dryer or an electric shaver. Snow noise appears on the screen of some TV sets, but some TV sets are safe and sound. This shows that in the case of being "attacked" by electromagnetic interference, the former's "defensive power" is lower; while the latter's "defensive power" is higher.

　　EMC (Electro Magnetic Compatibility) refers to the ability of the electromagnetic energy generated by electronic equipment to neither interfere with other electronic equipment, nor to interfere with the electromagnetic energy of other electronic equipment. Therefore, EMC includes the requirements of EMI and EMS: on the one hand, the electromagnetic interference generated by electronic equipment in the environment in the normal operation process cannot exceed a certain limit, that is, EMI; on the other hand, the electronic equipment is required to the electromagnetic interference that exists has a certain degree of anti-interference ability, namely EMS.

　　Specifically, when conducting EMC tests on electronic equipment, the relevant standards stipulate the maximum value of EMI and the minimum value of EMS, just like limiting the "attack power" to a lower level and requiring the "defense power" to be at a higher level.

　　So how to choose qualified products? In fact, the regulations have already prepared for us. Since 1996, the European Community has made regulations on its unified market: any electrical and electronic equipment without the "CE" certification mark shall not enter the European Community market.

　　Although lithium batteries do not have EMI requirements, they are usually used with electronic products such as PCM and BMS. Engineers must take this into consideration when designing.

　　Lithium-ion battery (LIB) has become the main energy storage solution in modern social life. Among them, lithium iron phosphate batteries are a perfect replacement for lead-acid batteries, and they are the first choice for grid-connected peak shaving, off-grid energy storage, photovoltaic energy storage, UPS, data center and other industries.