1Why power outages

There are two unavoidable reality in the information age: mains cannot provide stable power supply for precision electronic equipment, but the user is accountable for the normal operation of equipment and safety operation. Although based on computer information network development, but the instantaneous power would cause loss of data. Is more dangerous, if the computer power failures when storing files, may lead to a previously written to the file and even the entire hard disk data loss, continued writing web servers are especially sensitive to your disk.

With various high-tech electronic and intelligent equipment application wide generalization, they have raised new requirement to the power supply quantity and quality. Medical systems, financial systems, transportation, telecommunications, aerospace, and other important sectors of the management and operation level if there is a second power can cause huge losses to the government image, the state and people's life and property.

Some people think that: the utility is always continuous steady except occasional blackouts accidents. In fact, as a public power grid of the tens of thousands of loads connected to the mains above, some of the larger perceptual, capacitive, switching power supply and other nonlinear load get electricity from the grid, not only will in turn worsen quality of power supply, power grid waveform distortion or frequency drift or direct. In addition, some accidents, such as earthquake, lightning, power transmission and transformation system open circuit or short circuit, will direct damage or destruction of high precision equipment and even life-threatening. For example, hospital, bank, subway, spaceflight Ricky in the computer system of data signals in power at work, can cause memory information wiped out hard disk data loss, even directly cause operation failure, system failure, such as parking car crashes, failed launch serious consequences. Concrete such as the electrocardiogram machine in the hospital, intensive monitoring by the bed and the whole body spiral CT scan and magnetic resonance imaging (MRI), breathing machine, pacemakers, dialysis machine, ultrasonic diagnostic apparatus, electronic medical equipment, such as the high frequency electricity knife if because of the power to suspend the work, the effect of it would be fatal for patients.

2Why the leakage

Wire and cable will appear different degrees of aging, and thus the leakage in the power supply and distribution system, not only a waste of energy, more serious can cause electrical fires. Electrical fire accident tops in all the fire accident, proportion and it has a rising trend.  

Electrical fire reason mainly has: short-circuit, overload, poor contact, leakage, lamps and lanterns and electric heating appliance ignition. In recent years, caused by leakage fire occur repeatedly, the concealment of the fire is more than a short circuit caused by the fire, it is difficult to find out the real reason after fire (concealed by short circuit such as illusion), so its harm is greater.

Under certain conditions of insulation damage electrical wiring to close to the material or equipment (threading tube metal shell, electrical device, wet wood, etc.) will happen leakage, leakage can make local material charged, cause fatal electric shock hazard or produce spark, arc and high temperature, which caused the fire.

In addition, for the purpose of measurement, diagnosis and treatment of the special environment of the hospital, the patient often, and a variety of medical electrical equipment together, leakage current can be ground into the operating room, ICU, CCU of medical electrical equipment in the traditional method of TN - S power supply system, make the patient's skin resistance is punctured, the patient often lost or reduce leakage defense capability due to the loss of sense of pain, especially all kinds of electrode, sensor, or pipeline directly inserted into the patient in the patient in the operation or under anesthesia, when there are 10 μa leakage current directly through the patient's heart, will cause electric shock accidents to the patient, a serious threat to the safety of life, and even directly cause the patient to electrocution. Usually adopted in the construction of leakage protection switch, its action response value is mA level (such as: 30 mA), far cannot satisfy the needs of the medical field, so how to protect patients from the leakage accident damage becomes more and more important.

3Why to appear interference electricity

Along with the advancement of science, computer, electrocardiogram machine, CT, MRI, network monitoring host, DCS, PLC, frequency conversion device, UPS, advanced instrument, rectifier, switches, servers, axle is apart from the counting device, a storage device, signal processing system, vehicle control system and other advanced equipment widely used in hospital, bank, subway, high-speed rail, aviation, spaceflight, stadium, etc, the nonlinear load will produce surge, pulse, electromagnetic interference, such as higher harmonic power pollution. These headed by higher harmonic power pollution, in turn, will cause great pollution to the equipment and power system, such as voltage instability caused by (surge phenomena), the controller misoperation, frequency conversion device overvoltage trip, burn out SCR, computer data system, control system, signal system due to the higher harmonic interference and error causing misoperation caused directly deal to stop, data disorder, operation failure, parking car crashes and other accidents. The harm produced by high order harmonic pollution has seriously affect the safe and reliable operation of the equipment, make frequent accidents, therefore have to find a kind of theoretical science, stable operation, energy conservation and environmental protection solutions to eliminate the harmonic pollution.       

Modern medical institutions to improve the health level, and constantly introducing new and more sophisticated medical equipment such as MRI, CT, high-frequency electric knife, electrocardiogram machine, bed intensive care instrument, etc., these devices for power supply high quality requirements because they all have high-end computer components and a large number of high sensitive micro-electronic components. Operators often encountered in the work for the advanced medical instruments and equipment failure due to these devices contain higher harmonic in the power supply circuit, light data errors, blurred images, the information is missing, disrupted work, suddenly damaged or hardware and software have been hit, equipment can't continue to work normally. Especially in the biological electrical signal equipment, such as heart eeg machine, monitor, direct contact with human body such as ultrasonic diagnostic instrument equipment, because the signal is very weak, if higher harmonic interference, will be on the test results such as waveform, graphics, image distortion of superposition a similar to certain lesions (harmonic), in turn, misdiagnosis, at the same time also can cause micro electric shock, serious when there is danger. Specific performance in:

    1)The operating room

In the operating room with electric knife, defibrillator, electrocardiogram machine, etc., harmonic pollution will cause the electrocardiogram machine output data change and γcounter software failure, etc.

     2)Intensive care unit

Treatment in ICU provide support to the patient, must be in the vicinity of the patient at the same time put and USES a number of medical equipment, such as ecg monitor, multi-function breathing machine, electrocardiogram machine, pacemakers, etc. Harmonic pollution is serious and complex, more harmonic purification measures should be taken.

    3)Radiotherapy department

Radiotherapy in portable radiation dose measurement system (such as room rate meter, calibration, etc.) if suffer higher harmonic interference, they embedded electronic components may record the noise and change the data output.

    4)Medical imaging room

γcounting instrument, mobile X-ray machine and so on easy to change the data output by higher harmonic interference.

    5)Hospital information network system

Characteristics of the medical determine hospital information network system must be stable running 24 hours without clearance. Higher harmonic pollution makes the intelligent system equipment to produce error, wrong words.if, produce false action; Often appear when running the program runs, data errors and time errors, crash, restart, a cause can even make the whole network paralysis.