可控硅调压式抽油机节能控制器的谐波合成

Analysis of harmonic wave composition from the pumping unit energy\|saving controller

从理论上研究了两个谐波源合成的谐波电流，给出两个谐波源合成的谐波电流有效值的计算公式，得出两台该种节能器在抽油机电机上应用时谐波的合成谐波电流与两台抽油机驴头悬点相对位置有关． 对更多抽油机接入节能器后，在抽油机的一个冲程内，同一网线上所有抽油机驴头悬点的位置可分成两个位置范围，一是使ｃｏｓ θｎ 为正值的位置范围，另一个是使ｃｏｓ θｎ 为负值的位置范围，且出现在这两个位置范围的概率应相等，即更多台抽油机电机接入控制器后，类似于两台抽油机电机接入控制器后的合成谐波电流的情况． 谐波合成情况测试是在丛式井上进行的， 测试结果与理论计算基本相同，合成谐波电流幅值小于国标限值．

A formula of effective harmonic current value combined by two harmonic sources is given theoretically. It is put forward that the composition results of harmonic wave are associated with the relative position of hanger of every pumping unit when two controllers are used on motors.When more than two controllers are used,within the time period of one stroke,the position of hanger of every pumping unit that is in the same power network can be divided into two ranges,one is the range in which cos θn of composition harmonic current is positive,the other is the range in which cos θn of composition harmonic current is negative, and the probability in the two ranges should be equal. It shows that harmonic wave composition situation, when more than two controllers are used, is similar to that when two controllers are used.Test of composition of harmonic wave is conducted on cluster wells.Test results tally with theory basically.The magnitude of compositon harmonic current is smaller than the limitation from national standard.