Phase balancing refers to the process of equalising the load across the different phases of an electrical system.
Fluctuations in the electrical loads of a single phase can cause an uneven distribution of current in the three-phase conductors, resulting in an unequal decrease in voltage and the generation of an imbalanced phase-to-phase voltage.
The presence of an imbalanced voltage between phases poses a significant risk to the distribution feeder, particularly in the absence of adequate safeguards to mitigate the effects of stray voltage. Attaining a fully balanced system is challenging, but it is crucial to make diligent efforts to balance the phases in order to minimise harmonics
Phase voltage imbalance
In order to properly identify the imbalance voltage, it is essential to possess the knowledge on how to accurately calculate it.
In the event that the system functions with an imbalanced phase, the subsequent consequences will occur:
- The cables are overheating as a result of imbalanced line currents.
- Removal of the protective covers from the MCB, MCCB, fuses, and other components.
- Defects in the subterranean cables.
Phase balancing ensures equitable allocation of the load among the three-phase power lines in the system. In the event of an imbalance in the system, the feeder capacitor will be incorrectly utilised for the anticipated load demand of the system in the future. By achieving effective current balancing, the excessive current strain on the overloaded line or phase can be eliminated and transferred to the underloaded line or phase. This allows for accommodating future demand. Phase balancing enhances the feeder capacity and voltage quality of the system while minimising losses.
Group Loading
An excessive number of electrical networks may be accompanied by nonlinear loads that exhibit varying spectral characteristics. Classifying these loads into categories based on their similar harmonic spectrum facilitates the optimisation of the placement, installation, dimensions, and choice of harmonic filters.
Within a circuit network, various types of electrical components might be present, including resistive loads, inductive loads, and capacitive loads. Each of these components introduces different degrees of harmonics into the power systems. These loads are utilised in many fields. Modest amounts of power are consumed in household or residential loads. Electricity is also employed in commercial, industrial, and municipal sectors. These sections utilise power from various harmonics and can be categorised to minimise the spread of harmonics between sectors.
We possess various loads that consume distinct voltages. Various devices operate at different voltage levels, such as 208 V, 120 V, 240 V, and so on, and it is necessary to organise these loads effectively.
Key benefits of reducing harmonics
The article has presented six strategies that engineers can utilise to mitigate harmonics in power systems. The items encompass:
Network reconfiguration is a method used to decrease the presence of harmonics. Harmonics refer to the undesirable electrical currents or voltages that might disrupt the functioning of a network. During network reconfiguration, users who generate significant harmonics are discovered and classified based on the specific type of harmonics they produce.
An increase in supply mode stiffness indicates a stronger and more resilient electric supply node, which is determined by the ratio of the short circuit current to the load current. A higher stiffness of the AC system indicates an increased likelihood of a short circuit occurring.
- The use of multi-pulse converters, such as half and full-wave converters, aids in the elimination of harmonics by cancelling them out. The six-pulse converter is the most often used polyphase converter.
Series reactors are used to reduce harmonics in smelting and steel facilities.
Phase balancing is an effective technique for reducing harmonics. Unbalanced phase generates harmonics.
Load grouping refers to the practice of organising similar loads together. Electrical systems can include nonlinear loads with varying spectral content. Grouping these loads is useful for choosing and determining the appropriate size of harmonic filters.