Online condition monitoring device (OLM2) on high voltage Circuit Breakers
Edwiin
02/13/2025
This device is capable of monitoring and detecting various parameters according to the specifications outlined:
SF6 Gas Monitoring:
- Utilizes a specialized sensor for measuring SF6 gas density.
- Capabilities include measuring gas temperature, monitoring SF6 leak rates, and calculating the optimal date for refilling.
Mechanical Operation Analysis:
- Measures operational times for closing and opening cycles.
- Evaluates primary contacts separation speed, damping, and contact overtravel.
- Identifies signs of mechanical deterioration, such as increased friction, corrosion, breakage, spring fatigue, wear on linkage rods, and damping issues.
Recharging Motor Performance:
- Monitors motor supply voltage, current, and consumed energy.
- Detects defects in motors or limit switches and measures spring travel.
Hydraulic Operating Mechanism:
- Tracks pump motor operating time.
- Identifies internal and external leaks and monitors threshold pressure within the hydraulic system.
Switching Operations:
- Measures current during breaking operations.
- Assesses primary contact wear and arc duration.
Auxiliary and Control Circuits:
- Checks the continuity of operating coils, measures coil current, voltage, resistance, and armature operation time and energy consumption.
- Monitors auxiliary supply voltage and ensures heater integrity.
Anti pumping function in circuit breakers operating mechanism
The anti - pumping function stands as a crucial characteristic of control circuits. In the absence of this anti - pumping function, assume that a user connects a maintained contact within the closing circuit. When the circuit breaker is closed onto a fault current, the protective relays will promptly trigger a tripping action. However, the maintained contact in the closing circuit will attempt to close the breaker (once again) onto the fault. This repetitive and dangerous process is referred to
Edwiin
02/12/2025
Ageing phenomena of current pass blades in high voltage disconnector switch
This failure mode has three primary origins:Electrical Causes: The switching of currents, such as loop currents, can lead to localized wear. At higher currents, an electric arc may burn at a specific spot, increasing the local resistance. As more switching operations occur, the contact surface wears down further, causing an increase in resistance.Mechanical Causes: Vibrations, often due to wind, are the main contributors to mechanical aging. These vibrations cause abrasion over time, leading to
Edwiin
02/11/2025
Initial Transient Recovery Voltage (ITRV) for high voltage circuit breakers
Transient Recovery Voltage (TRV) stress similar to that encountered during a short-line fault can also occur due to the busbar connections on the supply side of a circuit breaker. This specific TRV stress is known as Initial Transient Recovery Voltage (ITRV). Given the relatively short distances involved, the time to reach the first peak of ITRV is typically less than 1 microsecond. The surge impedance of the busbars within a substation is generally lower compared to that of overhead lines.The f
Edwiin
02/08/2025
Typical transient recovery voltage waveshapes under fault conditions
Transient Recovery Voltages (TRVs) caused by fault current interruptions are typically categorized into three types of waveshapes: exponential, oscillatory, and sawtoothed. Additionally, significant TRV conditions can be classified under two main scenarios:Short Circuit Current Interruption: This is the simplest scenario involving the interruption of a symmetrical, rated-frequency short-circuit current. Since this current naturally reduces to zero at least once every half cycle, it represents th
Edwiin
02/07/2025
