Reactive power in the power system negatively affects the operating mode of the electric network, additionally loading high-voltage lines and transformers, which leads to an increase in power losses, as well as to an increase in voltage drops. The influence of active and reactive power components of voltage in the network nodes is different and is overwhelmingly determined by the ratio of active and reactive components of the resistance elements of the electric system. In high-voltage networks, the reactive component of the resistance significantly exceeds the active component, and therefore the flow of reactive current through the network leads to a greater voltage drop than the flow of the active component of the current. The transfer of reactive power can lead to exceeding the normalized voltage range in the load nodes. To reduce power losses and voltage drop in the elements of the electric network, synchronous compensators (SC), static capacitor banks (SCB), static thyristor compensators (STC), controlled shunt reactors (CSR) can be used. The cost of production and transmission of active and reactive power are different, and when choosing the power of reactive power compensation means, it is necessary to take into account the costs and compare them with the resulting effect, which differs for large and small values of reactive power when this is reduced by the same amount. To assess the feasibility of application of compensatory devices, and to choose their type and locations of installation, relevant calculations are required. An empirical criterion is proposed for preliminary assessment of the technical feasibility of reactive power compensation. It enables to identify the network sections and nodes, which require reactive power compensation and should be considered in greater detail.
Active and Reactive Power Losses in Distribution Transformers
