二相负荷有功电度计量的办法（Method for measuring active power of two phase load）

二相负荷有功电度计量的办法（Method for measuring active power of two phase load） 二相负荷有功电度计量的办法(Method for measuring active power of two phase load) Phase load power measuring phase load power measurement Huaiyin Power Supply Bureau of Jiangsu province Ruan Hongtai A power meter, wrong type 1. shipbuilding, machinery factory and other electric welder for more, the power rate is low, welding habits will be measured separately, it is possible. The three single-phase active watt hour meter is connected into a three-phase four wire connection, the measurement is feasible. But when welding work, the power rate is generally very low. At this time, only three of the electricity meter single-phase watt hour meter is not the same, is only three meter aluminum wheel rotation speed is not the same, one fast, one slow or reverse, this phenomenon is normal, but many County Bureau staff, feel unbelievable, that where the reverse is wrong meter. This is to separate the three meter run (such as the use of three-phase four wire three element meter there would not be such a phenomenon) without theoretical analysis and calculation on the chaos caused by measuring error change wiring. 2. single-phase electric high, although the Department of phase electricity meter but current transformer and voltage transformer is to complete three-phase electric wiring, because did not grasp the measurement principle of the connecting way, wrong about that phase power three-phase electric wiring, plus the connection coefficient (human 2 / 3 2003). In this measurement Bureau has reached a number of years. The loss of hundreds of thousands of electricity. 3. three-phase electricity and three-phase four wire measurement method with electric confusing error with 3 * 380 volt three-phase watt hour meter to two yuan for the measurement of three-phase unbalanced load line four. The 3 x 380 volt three-phase two element and 3 x 380 / 220 volt three-phase four wire three element electric meter principle is not clear, the leakage of electricity in multiple phase. The 4. phase load connection mode, because they do not grasp the advantages and disadvantages of the related wiring and wiring of the corresponding coefficients, some think that compared several kinds of wiring, wiring table go faster. The three-phase two element table current series parallel connection voltage, but lost the connection coefficient (1 / 2), caused by error of electric meter. 5. for the new watch factory DT1 type three-phase four wire two element with negative current coil power meter can be used to measure the three-phase four wire unbalanced load, especially the single-phase electric welder load with the concept of comprehensive measurement is not clear. Because of this phase into the voltage meter, and that can not be used for measuring error of three-phase four wire with alternating load (such as welding) and separate metering equipment, this construction is troublesome and time-consuming, labor and materials. Two, voltage meter fault analysis 1. three meter and a single-phase load (such as electric welding machine) the situation: 2. when the AB phase and C phase is connected with the electric welder without load The above results, the power rate is less than 0.5, a table with the actual power consumption had no effect, the total power did not reduce. The meter is transferred completely depends on the rate of reversal of power, therefore can not arbitrarily change the wiring. The two element is a three-phase three-phase voltage phase current conditions of electricity metering three-phase load, From the wiring diagram and principle analysis formula is visible in this table, the phase current into the table, counting the three-phase load power, but between phase and zero line connected with the load, through the phase current meter free, there is no turning force, the table does not turn, then although load. But without electricity, it could not be used to measure the three-phase four wire unbalanced load. 4, three-phase two element current meter, phase diagram and phase voltage series, coil, analysis of connection: when the AB phase indirect measurement See W`=2W1, such a connection times more than the actual amount of the meter, the wiring should be multiplied by the coefficient 1/2 of collecting electricity. Which is the correct. The actual three-phase two element meter fully integrated measurement of three-phase and two-phase load. 5, DT type three-phase four wire two element analysis and current coil with negative electricity metering: DT features: phase voltage into no separate electromagnetic components, while the phase current is poured into, from the I into the coil, is divided into two parts: report of A, C two core and coil electromagnetic components with A and C two winding to the contrary, in order to obtain additional torque. When under special circumstances, such as AB or BC in the same phase with arbitrary load and quantitative analysis: (1) AAB on the interphase load such as electric welding machine: The above three kinds of circumstances, in any two indirect load when the power meter is the product of two phase voltage and current and power car rate angle cosine. So whether the three-phase load balance and imbalance or any two electricity rate, etc. can correctly measure the level of. So there is no need to separate meter electric welding machine load. Three, phase load correct measurement circuit 1. phase separate measurement of load diagram: 2. Three phase load diagram and integrated wiring Four, conclusion In the presence of phase load electricity metering problems were analyzed and calculated. It explains why the wrong power meter, and to prevent some kinds of wiring diagrams do not occur in the future similar error proposed the correct measurement. From the above analysis and fault meter power, if you can master various types of meter structure, measuring principle and connection of vector analysis and calculation, the error can be avoided. Load measurement wiring scheme phase is varied, when the power supply or special needs measurement, separate meter, should first use figure 6 or 9 connection, as a result of the user's specific situation without special needs, can be used in the three-phase four line table comprehensive measurement, or the total amount of three-phase three wire heald. The other according to the different categories and needs decide which ensure the measurement is correct and reliable connection. Can also take further measures such as: construction installation diagram, and unified with different categories of electrical wiring method.