Preamble
From the last four blogs, we now have a good understanding of power flow in AC systems. We found that there is a component of AC power flow which is oscillatory. In other words, a part of the power that flows back and forth from the source and load every cycle. We called it the “Reactive Power”.
The reactive power plays a major role in the design of AC transmission systems and in the economic operation of AC power systems. Interestingly, the reactive power is not only relevant for electric utilities, but it is also relevant for the consumer.
Consumers can reduce their power bills by reducing the ‘consumption’ of reactive power. Quite often, many consumers are unaware or unconcerned about this issue. This may be because of the simpler tariff structure used by some utilities to reduce metering and billing costs. In other words, the consumer is billed only for active power (kW) demand and active energy (kWh) consumption. In such cases, the utility absorbs the cost of inefficiency due to reactive power flows.
The modern ‘market-based’ electric utilities cannot afford to absorb the cost of consumer inefficiency. Hence, the tariff structure is designed to penalise the low power factor loads. This provides an incentive for the customers to improve the load power factor.
In addition, in the case of large industrial sites such as mines, it is possible to reduce the power loss within their distribution system by locating the power factor correction (PFC) equipment as close to the loads as possible.
This blog illustrates the advantages of installing PFC capacitors with a practical case study.