The method for obtaining the sampled current and voltage of the reactive power compensation controller

The reactive power compensation controller is the core device for reactive power compensation in the power system. The accurate acquisition of sampled current and voltage by this controller directly affects the compensation effect and system stability. So, what are the methods for obtaining the sampled current and voltage of the reactive power compensation controller?

I. Current Sampling Method

1. Current transformer (CT) sampling

Installation location: Usually installed in the main circuit or the compensation branch.
Connection method: In a three-phase four-wire system, 3 CTs are used; in a three-phase three-wire system, 2 CTs are used (two-phase connection method)

2. Hall sensor sampling

Applicable scenarios: DC or AC systems
Technical features: Excellent isolation performance; Capable of measuring DC components; High requirements for temperature stability.

II. Voltage Sampling Method

1. Voltage Transformer (PT) sampling

Standard configuration: Rated voltage matches the system; accuracy class 0.2 or 0.5; secondary rated voltage is usually 100V.
Connection scheme: V-V connection (three-phase three-wire); Y-Y connection (three-phase four-wire).

2. Resistance Voltage Division Sampling

Applicable scenario: Low-pressure system
Key design points: Calculation of voltage division ratio; Selection of resistance temperature coefficient; Design of power margin.
Advantages: Low cost; Small size; No magnetic saturation problem.

3. Capacitor Voltage Division Sampling

Features: Suitable for high-frequency applications; Low power consumption; Good temperature stability.