#SVC FILTER DESIGNER MANUAL#
#SVC FILTER DESIGNER SERIES#

Similar devices include the static synchronous compensator (STATCOM) and unified power flow controller (UPFC).Purpose:The goals of this research were to compare tilt and caval penetration rates of the Günther Tulip (Cook Medical, Bloomington, IN) and Greenfield (Boston Scientific, Marlborough, MA) inferior vena cava (IVC) filters, and assess the difficulty of Tulip retrieval based on filter tilt, dwell time and caval wall penetration. However, static VAR compensators are more expensive than mechanically switched capacitors, so many system operators use a combination of the two technologies (sometimes in the same installation), using the static VAR compensator to provide support for fast changes and the mechanically switched capacitors to provide steady-state VARs. They are, in general, cheaper, higher-capacity, faster and more reliable than dynamic compensation schemes such as synchronous condensers. For this reason they are often operated at close to their zero-point in order to maximize the reactive power correction they can rapidly provide when required. The main advantage of SVCs over simple mechanically switched compensation schemes is their near-instantaneous response to changes in the system voltage. The disc-shaped semiconductors, usually several inches in diameter, are usually located indoors in a 'valve house'.

#SVC FILTER DESIGNER SERIES#

The dynamic nature of the SVC lies in the use of thyristors connected in series and inverse-parallel, forming 'thyristor valves'). In some static VAR compensators for industrial applications such as electric arc furnaces, where there may be an existing medium-voltage busbar present (for example at 33 kV or 34.5 kV), the static VAR compensator may be directly connected in order to save the cost of the transformer.Īnother common connection point for SVC is on the delta tertiary winding of Y-connected auto-transformers used to connect one transmission voltage to another voltage. This reduces the size and number of components needed in the SVC, although the conductors must be very large to handle the high currents associated with the lower voltage. Generally, static VAR compensation is not done at line voltage a bank of transformers steps the transmission voltage (for example, 230 kV) down to a much lower level (for example, 9.0 kV).

#SVC FILTER DESIGNER MANUAL#

Remote supervisory control and manual adjustment of the voltage set-point are also common. Voltage regulation is provided by means of a closed-loop controller. More complex arrangements are practical where precise voltage regulation is required. Since the filters themselves are capacitive, they also export MVARs to the power system. Chopping reactive load into the circuit in this manner injects undesirable odd-order harmonics and so banks of high-power filters are usually provided to smooth the waveform. Thyristors, like all semiconductors, generate heat and deionized water is commonly used to cool them. The thyristors are electronically controlled. Thyristor-switched capacitor (TSC), shown with delta connection In industrial applications, SVCs are typically placed near high and rapidly varying loads, such as arc furnaces, where they can smooth flicker voltage. By connecting the thyristor-controlled reactor, which is continuously variable, along with a capacitor bank step, the net result is continuously variable leading or lagging power. Under inductive (lagging) conditions, the capacitor banks are automatically switched in, thus providing a higher system voltage. If the power system's reactive load is capacitive (leading), the SVC will use thyristor controlled reactors to consume VARs from the system, lowering the system voltage.

In transmission applications, the SVC is used to regulate the grid voltage.

Connected near large industrial loads, to improve power quality ('industrial SVC').

Connected to the power system, to regulate the transmission voltage ('transmission SVC').

The SVC is an automated impedance matching device, designed to bring the system closer to unity power factor.

Prior to the invention of the SVC, power factor compensation was the preserve of large rotating machines such as synchronous condensers or switched capacitor banks. A static VAR compensator has no significant moving parts (other than internal switchgear). SVCs are part of the flexible AC transmission system device family, regulating voltage, power factor, harmonics and stabilizing the system. A static VAR compensator ( SVC) is a set of electrical devices for providing fast-acting reactive power on high-voltage electricity transmission networks.

Svc filter designer