How to Choose a Regulated Power Supply for Medical Equipment
With the advancement of technology, various precision medical diagnostic equipment such as spiral CT, magnetic resonance MR, DR, CR, DSA, ECT, linear accelerator, digital gastrointestinal machine, gamma knife, biochemical analyzer, color ultrasound, etc. have become the symbol of modern hospitals. At the same time, how to ensure the stable and reliable normal operation of these precision equipment has naturally become a focus of attention for medical related departments. So what are the reasons that affect the normal operation of these precision medical equipment?
We have identified the main cause of precision medical diagnostic equipment failures - power quality - through analysis of equipment failures in multiple hospitals
With the widespread application and development of power electronics technology, a large number of nonlinear loads have been added to the power supply system. From low-voltage small capacity household appliances to high-voltage large capacity industrial AC-DC conversion devices, such as electric arc furnaces, large rolling mills, electric locomotives, etc., not only generate a large number of high-order harmonics during operation, but also make voltage fluctuations, flicker, and three-phase imbalance increasingly serious. These adverse effects on the power grid not only reduce the reliability of the power supply and consumption equipment itself, but also seriously weaken and interfere with the economic operation of the power grid, causing "pollution" to the power grid. Below, we will analyze the impact of power supply quality on medical equipment based on practical experience:
1. Voltage fluctuation
This is a common problem in the power grid. The normal voltage fluctuation range of the power grid should be ≤ 10%, while in China, the voltage of the power grid usually exceeds this range, with a fluctuation range of ± 15% or even ± 20%, such as fluctuations caused by load fluctuations, fluctuations caused by other electrical equipment in the power grid when starting or stopping, fluctuations caused by certain electrical equipment with special working characteristics, peak and valley electricity consumption, etc. Continuous high or low voltage can cause faults in the power system of equipment, such as CT and other devices, which belong to the intermittent instantaneous working mode. During system scanning, the load increases rapidly, while during non scanning, the load is very light. The power grid must adapt to this working mode and always maintain normal power supply quality. Otherwise, the fuse may be blown, and in severe cases, the power system of the entire device may be damaged. This is the main reason for the frequent malfunctions of precision medical diagnostic equipment directly connected to the power grid.
2. Frequency offset
The frequency standard for China's power supply network is 50Hz. Due to the unstable operation of emergency generators or power supply from unstable frequency sources, it will have a significant impact on some medical equipment with high accuracy that requires mains frequency synchronization or benchmarking.
3. Power supply interference
The power supply interference can be divided into peak voltage, surge voltage, noise interference, odd harmonics, etc. These interferences are quite serious in China's power grid. Strong interference can cause damage to the circuit boards of medical equipment, disorder in computer control, instability of high-voltage systems, and endanger the entire machine.
4. Improper configuration of internal power supply system
With the development of hospitals, new electrical equipment is constantly being introduced, making it impossible for hospitals to continuously carry out power grid renovations. This results in too many loads connected to existing transformers, leading to insufficient capacity of the power supply transformers; The diameter of the power supply wire is too thin; There are devices that frequently start with high power or too many electrical devices connected in the same circuit. Due to the fact that precision medical diagnostic instruments typically contain a large number of electronic computers and large-scale integrated circuits, the machines themselves are highly sensitive to power sources. These power quality issues can cause computer crashes, data transmission errors, and even damage to equipment components.
