All the equipment connected to the power utility system is designed to be used within the voltage range. Voltage drop exists in each part of the system. Consumers who are electrically connected to the primary distribution feeder near to the substation will have maximum voltage levels compared to consumers who are located at the tail end or far end of the distribution (higher voltage drops attributes to the poor voltage levels). But for satisfactory operation of the electrical equipment voltage levels to these types of equipment should be within the operational range. Therefore in order to provide supply voltage within prescribed limits, some voltage correction or voltage control measures should be taken.
Voltage Control Methods
Some of the methods available to achieve voltage control at the distribution end of the power system are explained below:
- By operating grid or main sub-distribution on load/offload tap changing arrangement of the transformer.
- By the addition of extra feeders. This reduces the load carrying of the feeder and hence results in reduced voltage drop and improve regulation.
- By increasing the conductor sizes of the existing conductors. This reduces the losses in the conductor resulting in the improvement in the voltage profile.
- By rearranging the system and transfer loads.
- By balance load between different phases.
- Converting the single-phase system or single wire earth return system to three phase system.
- By adding distribution transformer capacity.
- By altering tap settings on the distribution transformers.
- Providing line drop compensators such as shunt capacitors for improving the power factor and series capacitors for improving the voltage profiles and stability of the system. Switching on and off these devices whenever they are necessary.
- By installing voltage regulators on the distribution side.
- Increase distribution voltage levels.