Noise (electrical noise): Refers to radio frequency interference (RFI), electromagnetic interference (EFI), and various other high-frequency interferences. The operation of motors, the actuation of relays, the functioning of motor controllers, radio transmissions, microwave radiation, and electrical storms can all induce noise. 　　

Frequency variation: This refers to the variation of the mains frequency exceeding 3Hz, primarily due to the unstable operation of the emergency generator or the supply of power from a frequency-unstable source.

Brownout: refers to a situation where the effective value of the mains voltage is lower than the rated value and persists for a prolonged period of time. The causes of brownout include: the startup and application of large equipment, switching of main power lines, starting of large motors, and line overload.

Power failure: Refers to a situation where the municipal power supply is interrupted and lasts for at least two cycles to several hours. The causes may include: circuit breaker tripping on the line, interruption of municipal power supply, and grid failure.

SNMP: It is the English abbreviation for Simple Network Management Protocol. Its significance lies in enabling computers and peripheral devices to connect directly to the network without going through a computer, and allowing the network system to manage them. High-end UPSs usually come with optional SNMP network management interfaces, making it easy to connect the UPS to the network.

IGBT: It is the English abbreviation for Insulated Gate Bipolar Transistor. IGBT is a type of power transistor. UPS designed using this transistor can effectively enhance product performance, offering various advantages such as good power quality, high efficiency, low heat loss, low noise, compact size, and long product lifespan.

Isolation transformer: When instruments and equipment are used in conjunction with general UPS, issues such as equipment damage or malfunctions often arise due to the zero-to-ground voltage caused by electrical characteristics. To avoid such situations, some high-end UPSs are designed with isolation transformers specifically to address this issue. Through special design and coordination, the output zero-to-ground voltage can be made less than 1 volt, thus preventing the aforementioned problems. In addition, it also has functions such as noise filtering.

AVR: It is the English abbreviation for Automatic Voltage Regulation. AVR refers to automatic voltage adjustment, which means that the UPS adjusts the coil turns of the internal output transformer or processes the power electronic components according to the input voltage, achieving a wide mains input range and stable output voltage characteristics for the UPS.

Power regulation rate: The voltage regulation accuracy of the output terminal when the input changes.

Communication protocol: The rules that interconnected devices adhere to when exchanging data.

SNMP: The abbreviation of Simple Network Management Protocol, which is mainly used for monitoring, fault diagnosis, and control of TCP/IP networks, and provides a simple network management protocol for user data programming.

Input frequency range: The standard frequency of China's power grid is 50Hz. UPS allows a certain range of variation in the mains frequency. Within this range, UPS synchronizes and tracks the mains frequency. If it exceeds this range, it outputs at its own frequency.