Accumulate And Research Electromagnetic Interference Of Electronic Computer Field In Hydropower Plants

Waterpower was an economical clean power generation. Hydropower plants could convert water potential energy and kinetic energy into electricity. As an economy developed, the demand for electricity was getting greater and greater. Hydroelectric power stations were increasing, and whose installed capacity was following to increase. For the purpose of safety and economic power generation, hydropower plants need monitor tens of thousands of signal, which caused the function of kinds of auto control equipment to be more complicated. Because there was high frequency electromagnetic field interference, frequency magnetic field interference, lightning over-voltage interference and electrostatic field interference, etc. in hydropower plants, the issue of computer monitoring system interference should be considered seriously, to meet the relevant standards and anti-jamming capability of the actual equipment requirements, and to make sure the computer monitoring system reliable operation after put it into production. Currently some medium-sized hydropower plants which used computer monitoring system have emerged some outstanding problems that due to the electromagnetic interference the normal work was affected in varying degrees.Based on the analysis of the electromagnetic interference of electronic computer field, two aspects have been mainly researched, these were computational method of steady-state frequency magnetic disturbance and computational method of short circuit transient and high frequency electromagnetic field interference. The maximal intensity of the magnetic field of plant rooms may exceed the allowable value through study in the rated open bus operation state. So the environment electric field strength calculus and observational were needed. The shell of unconnected closed bus only had the function of eddy. It had no decrement on the electric magnetic field out of the shell. So it can’t content the environment. The connected split phase closed bus mainly based on the joint action of the circulation and eddy of the outer case which dented the electric magnetic field out of the shell, and both the normal and the short-circuit electric magnetic field is below the standard value without consideration of the shielding measures in plant rooms. The external high-frequency signal made the computer error, so it’s important to prevent high frequency electric magnetic field disturbing computer system.In combination with the above theory, in this paper electromagnetic interference has been calculated to take Qiaogong hydroelectric power station of Guangxi for an example. The chosen locations for calculation were respectively relay protection rooms, computer rooms, the electromagnetic environment of central control rooms, cable rooms, bus well and sided machine screens. Some problems were discussed in design of circuits in Qiaogong hydroelectric power station by calculation. According to the hidden danger in projection and combining theory analysis some conclusive views on the question of shielding in hydropower plants were put forward in this paper.