Statcom, Current sampling and voltage sampling

Current and Voltage Sampling in STATCOM

Static Synchronous Compensator (STATCOM) is a device used for dynamic reactive power compensation and voltage stabilization in power systems. Accurate current and voltage sampling are crucial for the proper functioning of STATCOM, ensuring it provides the necessary reactive power compensation and voltage regulation.

Current Sampling in STATCOM

• Purpose of Current Sampling:

Real-Time Monitoring: Current sampling helps in real-time monitoring of the current flowing through the power system. This enables the STATCOM to respond promptly to changes in load conditions.

Control Feedback: The sampled current data is used in the control algorithms of STATCOM to adjust its output and provide the required reactive power compensation.

• Sampling Methods:

Current Transformers (CTs): CTs are commonly used to measure AC current. They provide a scaled-down version of the current flowing through the primary circuit, making it safe and manageable for measurement and analysis.

Hall Effect Sensors: These sensors are used for both AC and DC current measurements. They are known for their high accuracy and are capable of providing real-time current data.

• Sampling Precision:

High Precision Requirement: Accurate current sampling is essential for precise control of reactive power. High-precision sensors ensure the reliability of the sampled data.

• Filtering and Noise Reduction: Filtering techniques are employed to remove noise and high-frequency components from the sampled data, ensuring accurate and stable current measurements.

Voltage Sampling in STATCOM

• Purpose of Voltage Sampling:

Voltage Control: Voltage sampling is used to monitor the system voltage and ensure that STATCOM can effectively regulate the voltage levels.

Fault Detection: Real-time voltage monitoring helps in detecting faults such as over-voltage or under-voltage conditions, enabling prompt corrective actions.

• Sampling Methods:

Voltage Transformers (VTs): VTs step down the high system voltage to a lower, safer level suitable for measurement and analysis.

Voltage Dividers: Resistor or capacitor voltage dividers are used to reduce the voltage to a measurable level. These are typically used in conjunction with other measuring equipment.

• Sampling Precision:

High Resolution: High-resolution voltage sampling is necessary to capture small voltage variations accurately.

Signal Conditioning: Signal conditioning circuits, including amplifiers and filters, are used to enhance the quality of the sampled voltage signal by removing noise and ensuring stability.

Integration of Current and Voltage Sampling in STATCOM

• Synchronous Sampling:

Coordinated Processing: Current and voltage sampling must be synchronized to provide accurate real-time data for control algorithms. This coordination ensures precise calculation of reactive power and effective voltage regulation.

Phase Correction: Any phase difference between current and voltage signals must be corrected to ensure accurate power factor calculation and compensation.

• Data Processing:

Real-Time Analysis: Sampled current and voltage data are processed in real-time to determine the reactive power requirements and voltage deviations.

Control Algorithms: The processed data is fed into control algorithms that adjust the STATCOM’s output, maintaining the desired power factor and voltage levels.

• System Feedback:

Closed-Loop Control: STATCOM operates in a closed-loop control system, where continuous feedback from current and voltage sampling helps in maintaining the stability and performance of the power system.

Adaptive Control: The system adapts to changes in load conditions and system disturbances, ensuring reliable operation.

Current and voltage sampling are critical components of STATCOM operation, enabling accurate monitoring and control of reactive power and voltage levels. High-precision sensors, synchronous sampling, and advanced data processing techniques ensure that STATCOM can respond effectively to dynamic changes in the power system, enhancing stability, efficiency, and power quality.