Analysis of the Core Function of PV Nodes in Static Var Compensator (SVG)

In the field of power system control, the PV node serves as the key control mode for the static var compensator (SVG), and plays a decisive role in maintaining the stability of the power grid voltage. So, what is the function of the PV node in the static var compensator (SVG)?

I. Control Principle of PV Nodes

The PV node mode of the Static Var Compensator (SVG) refers to maintaining the voltage at the connection point constant by controlling the reactive power output.

1. Voltage closed-loop regulation: Real-time detection of bus voltage, comparison with the set value, and generation of reactive power instructions.
2. Rapid response mechanism: The power unit based on IGBT can adjust reactive power output within milliseconds.
3. Multi-objective Coordination: Achieve voltage regulation while also considering auxiliary functions such as harmonic filtering.

When the system voltage fluctuates, the static var compensator (SVG) injects or absorbs reactive power rapidly through the PV node mode, thereby providing voltage support. This active regulation method significantly improves the efficiency compared to the passive response of traditional capacitor banks.

II. Application of New Energy Power Stations

The PV node function of the Static Var Compensator (SVG) is particularly crucial in the integration of new energy sources:

1. Voltage fluctuation suppression: Mitigating voltage fluctuations caused by sudden changes in the output of photovoltaic or wind power generation.
2. Low-voltage ride-through: Provides dynamic reactive power support during grid faults
3. Power factor correction: Optimizing reactive power distribution during power limitation operation
4. Resonance damping: Suppressing sub-synchronous oscillations caused by new energy power generation

The actual measurement of a 200MW photovoltaic power station shows that the static var compensator (SVG) equipped with PV node control can keep the voltage at the grid connection point within ±1% fluctuation.

III. Application of Industrial Power Distribution System

In industrial scenarios, the PV node functions address typical power quality issues:

1. Impact load compensation: Improvement of voltage flicker caused by rolling mills, electric arc furnaces, etc.
2. Voltage Sudden Drop Mitigation: Quality Assurance for Power Supply of Key Process Equipment
3. Harmonic environment operation: Maintain voltage regulation accuracy under distorted waveforms
4. Energy efficiency optimization: By precisely controlling the voltage, reduce line losses.