1 ” Group is exploded ” Phenomenon
As everyone knows, it connects the main protection of the trouble within the single condenser in the condenser bank in parallel to fuse one under high pressure. The whole group fuse and one phase fuse all as condenser of taking place, fuse it is one that connect piece of the intersection of continuation and some times, call this phenomenon ” Group is exploded ” . Once as happening in our bureau ” Group is exploded ” The phenomenon, cause 9 condensers to withdraw to run. ” Group is exploded ” The phenomenon mainly has the following characteristics:
1The outdoor condenser bank happens ” Group is exploded ” And then visual examination can find, fuse piece protect, in charge of surface discharge, boil, decrease, and protect the tube and link with line of end.
2Whether connect the reactor in series and can happen ” Group is exploded ” .
3No matter which kind of wiring knows takes place ” Group is exploded ” ,Statistical data indicate triangular wiring person take place probability to be relatively more.
4″ Group is exploded ” Take place in the abominable climate weather more or put it into operation while operating finishing.
5Adjusting the condenser capacity can’t be prevented either ” Group is exploded ” .
6″ Group is exploded ” While happening, in most instances protect will not act, so the circuit breaker does not trip.
2 ” Group is exploded ” Reason
1Fuse one and melt and bring up the rear, the line of end can’t break away from with protecting the tube. The fuse box used at present mainly gushes out the chasing type, require it to melt and bring up the rear, the line of end should be able to break away from and protect managing reliably. Otherwise protect the voltage born on the tube:
Fuse one while running while fusing, it is that the worker in the fracture both ends resumes voltage to protect the voltage that the tube bears frequently, the condenser bank wired as to the star, this voltage is a voltage maximum of 2 times of phases; The condenser bank wired as to the triangle, this voltage is a voltage maximum of 23 times of phases. Puncture at the some components remaining the voltage and disappearing as the intersection of trouble and condenser, is the voltage maximum of the looks and 3 phase voltage maximums respectively that star and triangular wiring condenser bank protect the voltage that the tube bears while running.
When the condenser bank is operated to put into operationing, fusing one that if already there is the condenser in advance fuses and not finds, the situation that its thread of end has not broken away from exists, generally speaking, remain the voltage and already disappear on the trouble condenser, so the condenser bank in star and triangular wiring protects and bears the voltage maximum of 2 times of phases and 23 times of phases voltage maximum separately on the tube.
Under the above-mentioned voltage function, holding if meets the severe weather in the outdoor fuse box, may be produced and discharged and caused it to burn and decrease along protecting and managing the surface. Cause at the same time and produce high frequency and discharge in the electric current to the trouble condenser with other condensers of its parallel connection, lead to the fact, cross, shed and fuse, produce seriously ” Group is exploded ” . In the condenser bank wired on the triangle, this electric current only reflection may be caused and exactly organized the fusing of the condenser within the triangle.
2The specified electric current choice of the fuse box is too small. While choosing the specified electric current of the fuse box, should consider cooperating with specified electric current of the condenser.
It allow condenser work for a long time at 1.3IN,it and allow by electric capacity allowance of the values as -5-10. So in operation, some condenser job electric current can reach 11* 13 =143 specified electric current. Therefore IEC549 stipulates: Specified electric current and ratio in the specified electric current of condenser of circuit breaker should be greater than 143 times. GB3983-85 ” connects the condenser in parallel ” the standard stipulates for 1.5- 1.6 times, former Ministry of Water Conservancy and Electric Power SDJ25-85 stipulates it is 1.5- 2.0 times. But is happening ” Group is exploded ” In the condenser bank of the phenomenon, there are some of this ratios only 1.35-1.37, some are even smaller. Foundation statistics indicate, China for producing specified electric current of the fuse box exceeds 20 offsetting the majority, consider this factor, recommend the electric current to suitable for 1.7- 1.8.
3It is relatively bad to make and give up performance the fuse box. The fuse box should not be fired again while turning on and breaking the fixed holding electric current, otherwise absorbed again after one group in a lot of condensers running in parallel is cut off, will cause the condenser operated with it in parallel to discharge to it. This discharges in electric current to exceed the fuse box to resist the ability of pouring greatly, thus make it fuse, produce ” Group is exploded ” .
4The harmonic wave is produced ” Group is exploded ” . Because commutate non-linear power consuming apparatuses such as the apparatus, silicon controlled rectifier, electric arc furnace,etc. in the transformer substation, make the harmonic wave increase constantly. After the harmonic electric current enters the condenser, it is increased that the electric current is urgent in the return circuit, thus cause the condenser to cross and load, the delay time to exceed in its time, will fuse in a large amount, take shape ” Group is exploded ” Phenomenon.
3 ” Group is exploded ” Prevention
1Select the fuse box with better performance for use. While choosing the fuse box, should choose to be open to break of good performancely, the specialized fuse box not fired again.
2Adopt the single platform to protect the fuse box, and notice the grade of its voltage should be suitable.
3Choose the fuse box to compare with specified electric current of the condenser correctly. Should carry out according to SDJ25-85 regulation.
4Choose to connect the induction reactance value of the reactor in series correctly.
5Adopt star-shaped wiring. In order to reduce ” Group is exploded ” The quantity that the fuse box fuses, the condenser bank should try hard to adopt star-shaped wiring.