基于等效的视在功率计算新方法

Apparent power calculation based on equivalent scheme

在电力系统电压、电流波形畸变和不对称的条件下,目前视在功率求解还没有一种认可的方法,导致功率因数计算数值不一致。针对该问题,首先详细分析影响电能传输的因素,然后采用拉格朗日乘数法推导分析一种单等效视在功率计算方法,最后在考虑影响电能传输的不同因素条件下将所提方法分别与矢量视在功率、算数视在功率、双等效视在功率进行对比分析,以研究不同视在功率实际应用特性。算例结果表明,所提方法能够体现不同不利因素对电能传输的影响,且影响程度越大,功率因数越小。

Since there is no widely-acceptable method for calculating the apparent power of distorted or asymmetric voltage and current waveforms in power system,the calculated power factor is thus not consistent,aiming at which,the influencing factors of electric energy transmission are analyzed in detail and the single-equivalent apparent power calculation method derived from Lagrange multiplier method is proposed. With the consideration of different influencing factors,the proposed method is compared with the calculation methods of vector apparent power,arithmetic apparent power and double-equivalent apparent power respectively to research the practical application characteristics of different apparent powers. Case study shows that,the proposed method reflects the impacts of different unfavourable factors on electric energy transmission;the larger the impact is,the smaller the power factor will be.