Selection and operation of the hottest high voltag

Selection and operation of high-voltage distribution device

high voltage distribution device refers to electrical equipment above 1kV, which combines relevant primary and secondary equipment according to a certain wiring scheme. It is used for controlling generators, power transformers and power lines in power plants and substations, and also for starting and protecting large AC high-voltage motors

high voltage distribution devices are electrical equipment that receive and distribute electric energy, including switchgear, monitoring and measuring instruments, protective appliances, connecting buses and other auxiliary equipment

1 Selection of high-voltage distribution devices

1.1 General requirements

1.1.1 ensure the reliability of work, convenient maintenance and safety

1.1.2 ensure that in case of electrical equipment failure or fire, it can be limited to a certain range, and it is suitable for rapid elimination

1.1.3 ensure economic and reasonable operation, advanced technology, transportation of equipment during installation and maintenance, and reserve room for development and expansion

1.2 general provisions for installation and selection

1.2.1 the layout of power distribution devices and the selection of conductors, appliances and frames shall meet the requirements of normal operation, short circuit and overvoltage, and shall not endanger personal safety and surrounding equipment

1.2.2 the insulation grade should be the same as the rated voltage of the power system. The supporting insulator and wall bushing of 3kv~10kv outdoor important substation should adopt products with a voltage higher than the receiving voltage

1.2.3 the phase sequence of each circuit shall be consistent and colored

1.2.4 unpainted contact surfaces and connecting terminals shall be reserved for the hard bus and grounding wire in the interval for the installation of portable grounding wire

1.2.5 mechanical or electromagnetic interlocking devices shall be installed between the disconnector and the corresponding circuit breaker to prevent misoperation

1.2.6 outdoor high-voltage distribution equipment and insulators in polluted areas should be provided with dust-proof, corrosion-proof and other measures, and should be easy to clean

1.2.7 heating measures shall be taken when the ambient temperature is lower than the allowable temperature of insulating oil, lubricating oil, instruments and relays

1.2.8 the strength safety factor adopted by conductors, suspension insulators and fittings: not less than 4 during normal operation and not less than 2.5 during installation and maintenance

1.2.9 the installation height shall not exceed 1000m above sea level, the ambient temperature shall be +40 ℃ ~ - 20 ℃, and the indoor relative humidity shall not exceed 85%

1.2.10 there is no conductive dust. 2. According to the service condition of the machine and the service life of the oil, there are gases that damage the metal and insulation, places without explosion risk, places without violent vibration and places with an inclination of no more than 5 °

1.2.11 in areas with strong earthquakes (when the intensity exceeds 7 °), anti-seismic measures should be taken to strengthen the anti-seismic performance of the foundation and distribution equipment through a large number of experiments

1.3 selection of high voltage distribution equipment

but the impact strength has decreased

high voltage distribution equipment is mainly selected according to the working voltage, working current and breaking capacity

1.3.1 the rated voltage of electrical equipment shall be greater than or equal to the working voltage of the circuit

1.3.2 the rated current of electrical equipment plays an important role in all adhesive industries. The rated current should be greater than or equal to the maximum long-term working current of the circuit

1.3.3 the selection of circuit breakers and fuses should not only meet the above two requirements, but also make the rated breaking capacity of devices greater than or equal to the short-circuit capacity

1.3.4 in order to ensure the safe operation of electrical equipment and avoid damage through the maximum possible short-circuit current, in addition to the above three principles, it should also be verified according to the electrodynamic effect and thermal effect generated by the short-circuit current