Online Partial Discharge Monitoring System

Online Partial Discharge Monitoring System



1.    Introduction:

In recent years, transformer fires and explosions have occurred more and more and most of them stemmed from local discharges inside transformers and electrical equipment.

In medium and high voltage electrical equipment, insulation plays a very important role in the operation of electrical equipment. Most electrical equipment failures are caused by insulation failures stemming from the effects of partial discharges that occur on insulation over a long period of time. A partial discharge is an indication that a failure has occurred in the insulation. Therefore, early detection of this discharge will help assess the quality of the insulation, make plans to repair equipment, prevent serious incidents from occurring, save repair costs. equipment replacement.

Local discharges typically generate four types of signals:

ü  Sound

ü   Current.

ü   Radio Frequency.

ü  Light & Electro Magnetic.

2.    Power PD Solution

POWER  is an online diagnostic system with the ability to continuously detect, analyze and monitor localized discharge (PD) signals occurring in electrical equipment such as Ap Transformer, GIS equipment, and high cables. medium voltage, cabinet, engine, ...

When PD occurs internally, it is known that electrical and audio signals are generated simultaneously from PD. Our system uses:

ü  Acoustic Emission (AE) Sensor: to detect sound signal.

ü  High Frequency Current Transformer (HFCT)  Sensor: to detect current signal.

When partial discharge (PD) occurs inside electrical equipment (eg transformers), electromagnetic waves and light cannot propagate to the outside.

The PowerPD has integrated technology to detect PD simultaneously through acoustic signals (propagating in oil and metal environments) and high frequency currents (propagating according to the device housing to grounding). Once PD appears, the multifunction diagnostic device (PD-TP500A) will capture the signal and detect the exact location of the source PD..

The PD-TP500A system has 5 channels. The AE and HFCT sensors are connected to the device using a coax cable. The signals from the channels are measured simultaneously and the data is stored in the computer. The software will analyze the frequency of the signal, the duration of groups of pulses, spread the signal spectrum, the position of the PD. The data collected during the online continuous measurement will help analyze the development trend of the PD, export tabular data, display 2D - 3D graphs, count pulses.

Multi-function diagnostics PD - TP 500A combines with many types of sensors such as:

AE sensor:

+ Frequency: 80KHz-500KHz

HFCT100 / 140 sensor:

+ Frequency: 100KHz - 20MHz.

+ Inner / outer diameter: 100 / 140mm

 TEV capacitance sensor:

+ Frequency: 20MHz - 800MHz

 Ultra high frequency sensor UHF:

+ Frequency: 100MHz - 1500MHz.

Depend on each cases need to use the appropriate type of sensor.

3.    Applications

a.    Switchgears



b.   Medium to High Voltage Cable

220KV Underground cable Tao Dan – Nha Be.




c.    Transformer

Transformer T6-  HocMon 110kV  Substation– PTC4.




➤ Branch in Ha Noi
Room 201, 2nd Floor, 63 Vu Ngoc Phan Str., Lang Ha Ward, Dong Da Dist., Ha Noi City, Vietnam
➤ Branch in Da Nang
Room 602, 6rd Floor, S-HOME Building, No. 186 30/4 Str., Hai Chau Dist., Da Nang City, Vietnam
➤ Head office in Ho Chi Minh
234/7 Vuon Lai St., Phu Tho Hoa Ward , Tan Phu Dist., Ho Chi Minh City, Vietnam