Single phase ground fault definition

Three-phase electric power system,only in the insulation between the phase conductors and ground (to appear.Broadly,single-phase earth fault,including single phase grounding short circuit,single phase grounding short circuit is a special phenomenon of single phase ground fault,only the transformer neutral point grounding system will be.Narrowly speaking,single-phase earth fault and single-phase grounding short circuit are two concepts.One is a failure,is an accident.Power system www.dongfeng-motor.com fault and accident is divided in narrow sense.Refers to the one-phase ground fault line (electric) any phase without load and earth wire connected directly,in the 380/220 power supply system or other grounding system.

due to the transformer neutral is grounded,and grounding resistance is very small,wire (electric) any phase without load ground connected directly,and instant will produce very big current,burn out the wire,power distribution equipment or tripping,etc.,so is a serious accident,one-phase ground fault power system is to avoid as far as possible.In power system,there are many places not grounded system power supply,such as dust,inflammable and explosive special field,such as our country all 6-10 kv,35 kv power supply system,etc.,is the neutral point grounding are used or through big resistance earthed power system,this system after the single phase grounding,because there is no loop or that do not produce a large current in the pumps circuit without earth current or large

grounding current,so does not affect the normal operation of the system.Although does not affect the

normal operation of the system,single phase grounding is a failure,in order to guard against ground

for the extension of two phase ground or make the grounding device further damage,such ac alternators 220v as rules of single- phase earth fault happened,to find out the reason,in 2 hours to make processing,2 hours to check out reason or can't handle,would power outage after processing.

Permanent magnet brushless motor is a little electrical engineer

As is known to all, the motor in our life are everywhere: from home appliances to the industry; Used cars to aviation, motor can be said to be the household appliance, apparatus, the core perkins diesel generator component of traffic construction machinery and industrial equipment. For a long time, high energy consumption, low efficiency, material consumption big asynchronous motor and excitation generator of traditional motor has been the main force that ACTS as a way of energy conversion. (see electrical engineer) pointed out that the permanent magnet brushless dc motor (BLDC) motors and permanent magnet brushless generator is in recent years, with the rapid development of electronic technology and a new type of motor. Brushless motor with a set of electronic commutation device to replace the mechanical brush motor reversing device, retained the has a broad and smooth brush ac motor electric 65kw dc motor performance of speed adjustment, at the same time there to overcome the mechanical commutator brush dc motor with a series of shortcomings, so is widely used in various fields, such as: computer floppy disk drive, the robot of artificial intelligence, CD machine, air conditioner, electric vehicles and aviation, spaceflight, shipping, etc. Except brushless motor brushless dc motor have advantages, also has the characteristic such as high energy density, high efficiency. At the same time, modern power electronic technology, the development of permanent magnetic materials and amorphous materials and provides convenient conditions for the development of brushless motor, drive the permanent magnet brushless motor in high performance, low power consumption, high power density, thus has a strong vitality and development prospects. Traditional industry cost pressure, the cost is not high www.facebook.com/guohong.trading but better performance of motor for technology promotion, increasing product competitiveness. For high-end permanent magnet brushless motor in the traditional industry overall upgrade carve out an innovative way.