Three main ways of reactive power compensation

Three main ways of reactive power compensation
1. Centralized compensation
Basic principle: Install parallel capacitor banks in the high and low voltage distribution lines or substation busbars of the power system to regulate the reactive power of the entire power grid.
Advantages: Small investment, can globally improve power factor, reduce reactive power losses of main transformers and transmission lines.
Disadvantages: The compensation accuracy is low, and overcompensation (reactive power reversal) may occur during light loads, resulting in increased energy loss.
Applicable scenarios: Industrial substations or large distribution systems with small load fluctuations.
2. Group compensation (decentralized compensation)
Basic principle: Install capacitor groups in groups at the low-voltage side of distribution transformers or distribution panels in user workshops to compensate for local areas or equipment.
Advantages: The compensation is more targeted, which can reduce low-voltage side line losses and improve the quality of power supply voltage.
Disadvantages: Multiple sets of capacitors need to be coordinated for control, equipment maintenance costs are high, and capacity configuration needs to be matched with the load.
Applicable scenarios: scenarios where the load distribution is scattered and fluctuates greatly (such as between factory and mining cars).
3. On site compensation (single machine compensation)
Basic principle: Directly parallel capacitors near a single inductive load (such as an electric motor or transformer) to achieve "on-site balancing" of reactive power.
Advantages: The highest compensation efficiency can eliminate reactive power losses at the end of distribution lines, reducing line losses by over 90%.
Disadvantages: Large equipment investment, capacitors need to be switched synchronously with the load, and high requirements for control technology.
Applicable scenarios: Inductive load scenarios with frequent start stop of high-power motors, welding machines, etc. (such as cement plants, water plants).