Medical power supply control circuit meeting EMC and safety standards

Abstract

The present invention discloses a medical power supply control circuit meeting EMC and safety standards. An isolation power supply employs a multi-level filter structure and is configured to filter out ultraharmonics in a power grid from the circuit through a ship-type switch, an isolated transformer and a surge protector in order and restrict a surge voltage possibly generated in a thunder and lightning condition in a range which can be accepted by a device and a system. Usage of the isolation transformer ensures safety of operators. A solid-state relay controls power supply input of a driver, and the input end of the driver is provided with an EMI filter and a 10MH reactor, so that motor interference generated between the driver and peripheral devices is reduced, and the driver has a good electromagnetic compatibility. The driver outputs SPWM modulated waves and filters the SPWM modulated waves to approximate sine waves through a sine filter, and finally the approximate sine waves access the motor. The power supply control circuit meets the medical EMC and safety standards can pass GB9706.1-2007 standard and YY0505-2012 standard and detection and national related product standards.

Description

[technical field] [0001] The invention relates to the field of medical power supplies, in particular to a medical power supply control circuit in compliance with EMC and safety standards. [Background technique] [0002] In medical equipment, when it comes to some special medical equipment, many conventional power supplies do not meet the medical grade EMC and safety standards, and cannot pass the GB9706.1-2007 standard and YY0505-2012 standard and testing, and national related products standard. After the national YY0505-2012 standard and GB9706.1-2007 standard are enforced, EMC and certification in medical equipment are very difficult. [0003] There are many reasons why the existing power supply equipment does not meet the requirements, for example: ① Mains interference is a common interference when using electronic equipment. Due to various factors, high-frequency noise interference signals can be generated on the AC power grid. These high-frequency interference signals ...

AI Technical Summary

Problems solved by technology

③There are high-frequency harmonics in the output of the power drive (inverter), which increases the loss of power cables and motors; at the same time, extremely high dv / dt will cause radiation interference of several MHz

[0004] The power noise filter cannot effectively suppress the surge generated in the power grid

According to the requirements of the Chinese national standard GB / T12668.3, electronic equipment needs to meet the requirements of electromagnetic interference and anti-electromagnetic interference. Simple noise filtering alone cannot ensure good electromagnetic compatibility.

According to the national standard YY0505 standard and GB9706.1-2007 standard, medical electrical equipment has higher EMC and safety requirements, and the modulation method and dv / dt electric frequency filter are not ideal for suppressing the interference on the output side of the driver.

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