GWPD-S-TEV TEV Partial Discharge Sensor

1. GWPD-S-TEV TEV Partial Discharge Sensor – Product Introduction

• The GWPD-S-TEV TEV partial discharge sensor is an online monitoring device that integrates signal acquisition, processing and data communication. It is primarily intended for partial discharge monitoring in metal-enclosed switchgear.
• When insulation defects within the equipment give rise to partial discharge, high-frequency electromagnetic signals are generated. These signals can couple through enclosure seams, openings and other discontinuities, producing detectable TEV signals on the outer surface of the earthed metal enclosure. The GWPD-S-TEV acquires these signals through capacitive coupling, providing data for identifying suspected partial discharge activity and tracking changes over time.
• Wireless and wired versions are available to suit site power supplies, communication arrangements and monitoring network requirements. Internal or wireless power-frequency synchronisation provides a reference for analysing partial discharge signals in relation to the power-frequency cycle. Measurement data are transmitted to the monitoring system through the associated communication network to support equipment condition assessment and maintenance planning.

2. GWPD-S-TEV TEV Partial Discharge Sensor – Product Functions

The GWPD-S-TEV TEV partial discharge sensor provides the following functions:

TEV Partial Discharge Detection: A detection bandwidth of 3–100 MHz and a detection dynamic range of 0–60 dBmV enable the GWPD-S-TEV to acquire transient earth voltage signals associated with partial discharge activity on metal enclosure surfaces.

Wireless and Wired Versions:

• Wireless version: Supports LoRaWAN communication, with a wireless transmission distance of at least 600 m in open-area conditions. Suitable for locations where communication cabling is difficult to install.
• Wired version: Uses an RS-485 communication interface. Suitable for centralised monitoring installations with external power supplies and communication cabling.

Low Power Consumption and Long Battery Life: The wireless version of the GWPD-S-TEV incorporates a lithium thionyl chloride battery with a nominal battery life of more than six years. Actual battery life depends on the acquisition interval, data transmission frequency, operating temperature and wireless communication conditions.

Power Supply Options:

• Wireless version: Powered by an internal lithium thionyl chloride battery.
• Wired version: Available with 5 V DC or 12 V DC supply configurations. An optional AC power supply module accepts an input of 85–264 V AC.

Environmental Protection: The GWPD-S-TEV has an IP66 protection rating and an operating temperature range of −40 to +85 °C. Installation arrangements should suit the environmental conditions at the monitoring location.

Power-Frequency Synchronisation: Supports internal or wireless power-frequency synchronisation, providing a phase reference for partial discharge analysis.

3. GWPD-S-TEV TEV Partial Discharge Sensor – Technical Specifications

The technical specifications of the GWPD-S-TEV TEV partial discharge sensor are listed below:

4. GWPD-S-TEV TEV Partial Discharge Sensor – Operating Principle

The GWPD-S-TEV TEV partial discharge sensor uses transient earth voltage (TEV) detection technology. Its operating process is as follows:

• Partial Discharge Generation: Partial discharge within metal-enclosed switchgear, such as discharge in insulation voids or surface discharge, produces fast current pulses and high-frequency electromagnetic signals.
• Signal Coupling: High-frequency electromagnetic signals generated by partial discharge can couple through enclosure seams, openings and other discontinuities, producing detectable TEV signals on the outer surface of the earthed metal enclosure. Signal propagation and detection performance depend on factors including enclosure construction, earthing arrangements and sensor location.
•  Signal Acquisition: The GWPD-S-TEV is installed on a suitable metal enclosure surface and acquires TEV signals through capacitive coupling, without connection to the primary high-voltage circuit.
•  Signal Processing and Conversion: The acquired signals undergo internal signal conditioning and digital processing to produce measurement data for the monitoring system.
• Data Transmission: The wireless version transmits data through a LoRaWAN network and an associated gateway. The wired version transmits data through an RS-485 interface and associated data acquisition equipment.
•  Condition Analysis and Alarming: The monitoring system evaluates measurement results, trends, background interference and power-frequency phase information to assist in identifying suspected partial discharge activity. The data support insulation condition assessment and early warning. Abnormal results should be investigated through repeat measurements on site or complementary diagnostic methods.
• TEV amplitude is expressed in dBmV and supports trend analysis and comparative assessment under comparable measurement conditions. It does not directly represent apparent charge in pC, and amplitude alone should not be used to determine the severity of an insulation defect.

5. GWPD-S-TEV TEV Partial Discharge Sensor – Applications

The GWPD-S-TEV TEV partial discharge sensor is primarily intended for metal-enclosed equipment with suitable TEV signal coupling paths:

• High-Voltage Switchgear / Ring Main Units: Monitors TEV signals on enclosure surfaces to assist in identifying suspected internal partial discharge activity and tracking changes over time.
•  Cable Branch Boxes / Cable Termination Boxes: Where suitable metal enclosures and signal coupling paths are available, the GWPD-S-TEV can assist in monitoring partial discharge activity associated with cable terminations and related insulation components.
• Monitoring Retrofits: The wireless version reduces communication cabling requirements, making it suitable for retrofit projects in substations and electrical distribution rooms where cable installation is restricted.
• Distributed Remote Monitoring: Associated gateways and monitoring software enable data aggregation and remote access across multiple monitoring points, supporting monitoring in distributed electrical distribution rooms and unattended substations.
• State Grid IoT Sensor Integration Projects: Supports monitoring data integration through the applicable communication specification, associated gateways and project-specific platform interfaces.