RE: MVA, MVAR & MW ? Barrie66 (Electrical) 10 Nov 05 17:44 I can make those turbines produce the torque, but I struggle to understand what you EE's do with it to ship it. PS: As I stated in one of the other threads, I am trying to comprehend this as an ME. Is something done at the power plant to correct, effect or change either of those conditions?Īnd, since the power companies are beginning to bill for the effects of reactive power, isn't it in the Utilities interest to not correct the PF? You get the picture, purely resistive load, approaching unity power factor. What happens when all those workers turn off their motor driven machines at the end of the work day and go home and turn on their electric space heaters, coffee pots, toasters, ovens, and lights. Since power factor is a function of load, reactive load, and VARS is a function of the PF, (if that is not right correct me right away) in a hypothetical system, a power plant supplies power to a grid that has lots of installed horse power, electric motors, creating a significant lagging power factor, and hence a given amount of VARS. Now, I have a purely theoretical question. They did not deal with what actually happened at the power station, however. This is an interesting thread in light of a couple of recent threads on reactive power. RE: MVA, MVAR & MW ? rmw (Mechanical) 10 Nov 05 16:26 I guess these days the system controllers spread the VAR loads around much better than we did in the old days.
Power world simulator generator mva and kv generator#
During the night on light system loads, the voltage would rise and we would have to import VARs by lowering the generator volts and during peak periods on high system loads, raise the generator volts and export VARs to maintain nominal voltage on the 132kV feeder. The power plant I operated, was on the end of a 132kV spur line some 120 miles from the main 330kV interconnected system, and the voltage used to vary substantially over 24hrs. This generally mean't that the voltage on the outgoing line was had to be kept at its nominal kV. Each power station on the grid had to maintain its voltage within given parameters. When I was working as a power plant operator shortly after graduating in the early 60s. By raising the machine volts the generator will export VARs to the system and conversely by decreasing the machine volts VARs will be imported to the generator. RE: MVA, MVAR & MW ?īEPC13 explained it correctly however, it may be clearer to simply state that an MVAR meter in a power plant is a center zero device. This increases the magnetic coupling of the rotor to the stator and increases the MVAR output. That is to raise MVAR output you excite the machine more by increasing the current in the field (rotor). You adjust the MVAR output of the machine by adjusting the exciter of the machine. This tries to speed up the machine against the grid and produces more power. This usually means more steam to the turbine. You adjust the MW of the machine with the amount of torque you apply to the input shaft of the machine. They are not exportable therefor you either have local generation or capacitor banks provide them. MVARs are the result of the magnetic coupling needed to produce work with a machine. You adjust the MVAR of the machine to adjust grid voltage in the local area. You adjust the MW of a plant based on the load on the grid. It is actually called the power triangle. If you remember your Circuit II course MVA is the Square Root of MW^2+MVAR^2. MVA is the aparant power, MW is the real power and, MVAR is reactive power.
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