1. The rendering of the hospital area
Peking University People's Hospital has included the construction of the hospital area as an important part of its spatial strategy in the overall development plan of the "One, Two, and Three Projects" (focusing on the comprehensive development of the hospital, grasping the two basic points of basic medical quality and innovative medical technology, and implementing the three major strategies of talent, discipline, and space). Space strategy is a necessary foundation for the development of hospitals and a necessary requirement for hospitals to reach a new level of development. The under construction hospital area and the northern hospital area are important spatial expansions for the hospital to adapt to the new situation of reform, cooperate with the overall strategic deployment of national and municipal governments, take medical needs as the guide, and leverage the hospital's unique disciplines and medical resource advantages.
The construction and use of this hospital area will not only meet the medical needs of patients in the southeast of Beijing, but also become the core of regional medical care in Xianghe County, Dachang County, Sanhe City, Langfang City, Hebei Province, and Wuqing District of Tianjin City. It will contribute to promoting the coordinated development of Beijing Tianjin Hebei and the strategic deployment of relieving non capital functions.
2. Existing problems
A large number of advanced medical equipment such as MRI, CT machines, X-ray machines, blood dialysis machines, as well as various energy-saving lighting equipment, variable frequency air conditioning, elevator equipment, etc., have been put into use in large quantities. It brings harmonic and three-phase imbalance problems to medical institutions, which can easily lead to medical accidents.
Main typical loads
Ventilation equipment: In order to save energy, the hospital adopts variable frequency fans and air conditioning. The frequency converter is a very typical harmonic source, with a current distortion rate of over 33%, which will generate a large number of (6n ± 1) harmonics such as 5, 7, 11, 13, etc;
Lighting equipment: Due to the use of a large number of energy-saving fluorescent lamps inside the hospital, a large amount of harmonic current will be generated. When the fluorescent lamps are connected to a three-phase four wire load, a large third harmonic current will flow on the neutral line;
Electronic medical precision equipment: Large electronic medical equipment in large hospitals is generally powered by switch mode power supplies, which will generate (2n ± 1) harmonics such as 3, 5, 7, and 9;
Computers and UPS power supply: Currently, hospitals are managed by computer networks, and there are many computers. In addition, servers and other data storage systems must be equipped with backup power supplies such as UPS. The switching power supply and UPS of personal computers are both harmonic sources, which can generate a large number of (2n ± 1) harmonics such as 3, 5, 7, and 9.
The harmonic characteristics of the hospital power distribution system are shown in the table below:
Main hazards: Due to the presence of harmonics, operators often encounter malfunctions in these advanced medical instruments and equipment during work, ranging from data errors, blurred images, information loss, interference in work, to sudden hardware damage, software impact, and inability to continue normal operation of the equipment. Especially for instruments and equipment that detect the bioelectrical signals of the human body, such as electrocardiographs, electroencephalographs, electrocardiogram monitors, ultrasound diagnostic devices, and other instruments and equipment that directly contact the human body, due to the very weak signal, if disturbed, a distortion (harmonic) similar to certain lesions will be superimposed on the detection results such as waveforms, graphics, and images, causing misdiagnosis and also causing micro electric shocks.
3. Reactive power compensation design
3.1 Reactive Power Compensation Design
Based on the load type and transformer capacity of the People's Hospital of Peking University, the reactive power compensation design capacity configuration between the incoming cabinet and the load is as follows:
3.2 Product Introduction
The SFR-M series intelligent dynamic harmonic suppression reactive power compensation module from Jiangsu Sifel Electric is an integrated reactive power compensation product specifically designed for harmonic and power factor problems in 0.4KV low-voltage distribution networks with severe harmonic pollution. It achieves power factor improvement, effective harmonic suppression, reduces line loss, and improves power quality.
The intelligent dynamic harmonic suppression reactive power compensation module includes: DSP digital processing circuit, highly integrated detection, control, protection, display unit, zero crossing switching module, discharge and air cooling unit, filtering reactor, low-voltage filtering power capacitor, and functional module operation status indication circuit. This series of modules is a new generation of dynamic filtering and compensation equipment for 0.4KV low-voltage distribution networks. It is suitable for frequent load changes and high voltage qualification requirements in electric fields. The total time for judging switching and switch action is ≤ 20ms. It is a typical integrated dynamic tracking and compensation module.
3.3 Technical parameters
3.4 Module System Diagram
4. Project summary
The SFR-M series intelligent dynamic harmonic suppression reactive power compensation module of Jiangsu Sifel Electric can achieve efficient harmonic filtering. At the same time, series reactors are equipped in the compensation module to limit the closing inrush current of the compensation branch and suppress harmonics.
