High voltage improves the power factor

For a factory that has already been built and put into operation, where the main transformers rated at 220 or 110 kV stepped down to 10 kV, as well as the 10 kV and low-voltage electrical equipment, have all been determined, the only way to improve the power factor on the 10 kV side is by adding reactive power compensation devices. Increasing the reactive power compensation for both the 10 kV level and the 0.4 kV level will improve the power factor of the high-voltage 10 kV power grid. Given that your power factor has already reached 0.93, which meets the basic requirements of the local power company, there is no need for further investment in additional high- and low-voltage reactive power compensation.

We have a transformation from 220 to 10 KV, and we are considered heavy electricity consumers, using around 800 million kWh of electricity each year. So the management assigned a task to find ways to improve the power factor; even a slight improvement can yield significant benefits. Are you saying that this increase in economic value is not significant?

Based on an operating rate of 8,000 hours per year, your factory’s annual electricity consumption is 800 million kWh; therefore, its load should be around 100,000 kilowatts, making it indeed a heavy electricity user. Methods for your factory to improve the power factor: (1) Improve the natural power factor of rotating equipment and avoid overloading them; this certainly requires process adjustments, and sometimes such adjustments are not possible. This method is effective but in practice not feasible. (2) Improve the power factor of the high-voltage and low-voltage power supply systems by enhancing operational management. In a factory of this size, reactive power compensation devices for high-voltage and low-voltage systems are essential in the design phase, and design firms carry out calculations accordingly. Generally, they set a value of 0.95, with the actual capacity for reactive power compensation being higher than that. For high-voltage and low-voltage reactive power compensation devices, compensation starts automatically when the value is below 0.95, and it stops automatically when the value exceeds 0.98. Through the above measures, your factory’s electricity consumption will decrease somewhat.

Improving the power factor does not save on electricity costs, as the charges are based on the active power consumed. However, a higher power factor helps to reduce the amount of reactive power that needs to be generated by power plants. The electricity supply company has a metric related to this – a fee based on power factor adjustments; generally, if the power factor is below 0.9, a penalty is applied, while a value above 0.9 results in a reward. It is recommended to aim for a power factor of 0.95 in order to obtain the highest possible reward. For specific details, please refer to your electricity supply contract

That’s the case; I want to raise it from 0.93 to 0.95, and I’m not sure what good methods there are.

Just invest in capacitors – what else can be done?