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In order to meet the trend of miniaturization, large capacity and intelligence of the current vacuum circuit breaker, a new model of three-phase disc rotation vacuum circuit breaker has been proposed, in which the main circuit distribution was changed from the same direction to the opposite. Besides, some adjustments were made to the position of operating mechanism. The electric field distribution...
A design gauge pressure of an eco-friendly gas insulated switchgear (GIS) with an application of vacuum interrupters (VIs) ranges from 0.1 to 0.3MPa. Therefore, a high differential pressure is imposed on bellows of the VIs, which increases the fatigue failure risk of the bellows after cycles of operations. Although, there are some empirical equations recommended by the Chinese National Standard GB/T...
A numerical model was developed to simulate dynamic behavior of metallic vapor from the electrode in a reduced-pressure arc using the moving particle semi-implicit (MPS) model and the finite volume model (FVM) as a trial. The reduced-pressure arc plasma can be seen, for example, for vacuum arc deposition or vacuum circuit breaker. The developed model solves Naiver Stokes equations and the energy equations...
This paper deals with the computer modeling of a low-current vacuum arc with an external axial magnetic field taking into account the secondary plasma occurred due to anode sputtering by fast ions from cathode spot. The described hybrid model treats the electrons as a massless fluid and ions as macroparticles. The macroparticle dynamic is calculated with the use of PIC method. Ion-ion and ion electron...
In this paper, an investigation of arc root behavior on a pair of parallel electrodes is presented. An effective filtering method is introduced to allow the clear observation of arc root behavior. The position of the arc root is identified and tracked by a multi-objective dynamic tracing algorithm. Thus the trajectories and the speeds of arc roots can be obtained. The results show that the movement...
Recently, the self-blast principle of extinguishing the arc by the blast pressure which is generated by the arc itself has been widely applied to the high voltage circuit breaker. In the self-blast principle, the pressure relief valve fitted on the piston is opened to release excessive pressure in the compression volume during high current interruption. The design of the pressure relief valve operation...
SF6 has been widely used as insulating and arc-extinguishing medium in power equipment. Under discharges, lower fluorides of sulfur generated by the dissociations of SF6 will react with unavoidable moisture and oxygen to form corrosive byproducts (etc., SOF2, SO2F2, SOF4). These byproducts will reduce the insulating and arc-quenching capacity of SF6 power equipment, so it is necessary to study their...
In recent type tests, a 252kV SF6 self-blast circuit breaker re-ignites several times after interruption. In order to solve this problem, through CFD simulation of the gas flow field in the interrupter on load, the pressure, temperature and velocity after current zero are analyzed carefully. The conclusion is that, due to the upstream pressure decreased quickly after current zero and will lower than...
As a new actuator driven by Ampere force, Electro Magnetic Force driving Actuator (EMFA) is applicable to medium-high-voltage system with powerful output force, long stoke, simple structure and high reliability. In the paper, a new type of EMFA for 126kV VCB with single break is proposed on the basis of the mature manufacturing technology of 126kV vacuum interrupter. The model of EMFA is established...
The circuit breaker is an important part of control and protection in the power system. Mechanical failure is the main fault of circuit breakers, and the loosening of fasteners is one of the typical mechanical faults. The self-loosening of bolted joints is closely related to the vibration, especially transverse vibration. There is strong vibration while the circuit breakers are opened and closed....
In order to evaluate the insulation condition of gas insulated switchgear (GIS) by using the ultra-high frequency (UHF) method, attempt to estimate PD current using the finite difference time domain (FDTD) method was carried out. The influence of PD current parameters and the position of measuring point on the received electromagnetic (EM) waves was studied. The EM waves received by using UHF sensors...
The movable contact of conventional air circuit breaker (ACB) includes multiple parallel contacts. The arc motion process directly affects the breaker capacity of ACB. Therefore, it is important to study the arc motion process of multiple parallel contacts model. A three-dimensional (3D) magneto-hydro-dynamic (MHD) model of air arc plasma is built to investigate the arc motion process. The anode of...
More Electric Aircraft (MEA) is a promising aircraft, replacing air pressure system, hydraulic systems and mechanical systems by power system. Nevertheless, the increase of electrical equipment inevitably leads to more problems in aircraft safety problems, of which the arc fault has a great influence. This manuscript is aimed at series arc in because it's not easy to detect. To solve the problem of...
It is well known that over-voltage induced by re-ignition is dangerous for the safety and stable operation of power system. The objective of this paper is to determine the effect of load parameters on multiple re-ignitions due to dielectric breakdown in vacuum circuit breakers after interruption of small inductive currents at short gaps. A sheath development model was used to analyze the dielectric...
Electromagnetic force simulation of isolation knife switch was done by simulation software. The phase angle difference of three phases was 120°, current amplitude was applied in one of three phases respectively for three times simulation. The electromagnetic force of number 4 contact finger of middle phase was tensile force without conductive bridge model, and that of number 4, number 10, number 16...
Accurate temperature-rise prediction in gas insulated switchgears (GIS) is necessary to reduce the number of heat-run tests during the product development process. An electromagnetic-thermal-fluid coupled model using computational fluid dynamics (CFD) is developed to predict the temperature-rise of a 110-kV three phase GIS in common tank type. The GIS includes the three-position isolation/ground switch...
The erosion of contact material is one of the critical failure mechanisms in switch devices. Thus it is important to study the characteristics of contact erosion. In this paper, a two-dimensional magnetic hydrodynamics (MHD) is established to get physical characteristics of the molten pool in cathode. Gas dynamics and statistical methods are then used for the calculation of the vaporization rates...
The paper presents an innovative design scheme of the removable metal-enclosed switchgear, in which the three-phase main circuits are longitudinal layout if looking from the front of the cabinet, and the main circuit is mainly composed of tubular conductors, with a linear moving disconnector on each side of the vacuum interrupter. The reasons for this design and the ways to achieve it are discussed...
Now the switchgear is extensively used in the power grid. The temperature rise of switchgear issues have attracted people's great attention. The heat production and dissipation effect of the main circuit conductor is be taken into consideration comprehensively. The heat generated by the main circuitis is calculated by thermo-electricity coupled analysis. The key issue in thermal analysis of switchgear...
This paper studied the optimization of the shunt release electromagnet based on Ansoft maxwell finite element simulation. The minimum size as the optimization target by taking into account the electromagnet force and temperature rise limit. In this study the electromagnetic force is calculated using finite element simulation, demand of temperature rise limit is satisfied by limiting the maximum current...
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