Concept of reactive power The active power is used to keep the normal operation of appliances,converting electrical energy into other forms(mechanical,light or heat) Reactive power is used to exchange energy (electric field and magnetic field).It does not do work,but just help exchange the energy.Any appliances that have coils would consume reactive power. Reactive power is not useless!Motor needs to build up a magnetic field,driving mechanical movements; Transformer needs to build up magnetic field, helping induction of voltage. 电力拿镜广城洲量写控制四川省童点实验蜜 家电网电力系统广域测量与控制四川省重点实验室 Concept of reactive power  The active power is used to keep the normal operation of appliances, converting electrical energy into other forms (mechanical, light or heat)  Reactive power is used to exchange energy (electric field and magnetic field). It does not do work, but just help exchange the energy. Any appliances that have coils would consume reactive power.  Reactive power is not useless! Motor needs to build up a magnetic field, driving mechanical movements; Transformer needs to build up magnetic field, helping induction of voltage