HVC – Applications in Hospitals

 

Modern hospitals are equipped with large and expensive medical instruments such as MRI, DSA, spiral CT, and high-frequency gamma knife. They also have numerous lighting points using electronic tri-color energy-saving light sources (high neutral current), many frequency converters for water circulation and wastewater treatment, and operating rooms with purification systems and uninterruptible power supply systems. These devices have high requirements for power quality, but they also become sources of harmonics, laying a practical foundation for harmonic mitigation.

 

 

The main power quality problem in the hospital is harmonic pollution. The main lighting circuit, uninterruptible power supply (UPS), and frequency converters in the water supply circulation system are the primary sources of harmonics, generating 3rd, 5th, 7th, 11th, 13th, and higher harmonics. Furthermore, due to uneven distribution of single-phase high-power equipment, the neutral (N) line has a large harmonic current. Harmonics can cause malfunctions in medical instruments, ranging from minor data errors, blurred graphics, and information loss to severe hardware damage and software impacts. This is particularly detrimental to instruments monitoring human bioelectrical signals and equipment in the ICU and operating rooms.

 

 

A graded protection system of "active filter (L-HTS800A) + passive harmonic protector (L-HTS300)" is adopted, combined with harmonic current calculation (k1=0.7, k2=0.5, THDi=20%), and the equipment configuration is as follows:

Shanghai Changzheng Hospital:

Local load S=4×2000KVA, equipped with 4 sets of L-HTS800A-4/200A/380V filters for main bus harmonics, and 35 L-HTS300 protection precision devices.

Dongguan Taixin Hospital:

Local load S=4×1600KVA, 4 sets of L-HTS800A-4/200A/380V (installed at the rear end of the reactive power compensation device on the transformer outgoing side) filters for main bus harmonics, and 28 L-HTS300 protection precision devices.

Beijing Armed Police General Hospital:

Local load S=2×2500KVA, 2 sets of L-HTS800A-4/250A/380V (installed at the rear end of the reactive power compensation device on the transformer output side) to filter the main bus harmonics, 30 L-HTS300 protection precision equipment.

 

 

Analysis From a direct benefit perspective, it can reduce medical instrument malfunctions, avoid delays in diagnosis and treatment and duplicate examinations caused by data errors and equipment damage, ensure the stable operation of equipment in critical scenarios such as ICUs and operating rooms, and reduce the risk of patient treatment. From an indirect benefit perspective, it can reduce equipment maintenance and replacement costs, extend the service life of instruments, reduce losses caused by hospital operational interruptions due to equipment failures, improve hospital diagnostic and treatment efficiency and service quality, and ensure the normal medical order of the hospital.