Where the Wind meets the Grid
There is a reason Southern States unique and purpose built products are strongly entrenched and widely used in new wind farm construction and collector station upgrades. The reason so many wind farms use Southern States products is that they solve the toughest problems in their application.
Wind power generators are large induction motors which can degrade power quality on the grid. Capacitor banks are a major part of the compensation schemes to correct for this degradation. But switching capacitor banks can itself cause problems with voltage transients (electronics frying voltage spikes) and restrikes (like lightning strikes to the capacitor bank). More and more wind farm developers and designers are switching to the CapSwitcher which was designed by utilities and industry experts and employs a simple reliable approach to eliminate those problems and work right every time.
Long underground cables connecting turbines with the collector station require switched shunt reactors to maintain voltage levels. Switching reactors can cause significant problems with reignitions (lightning strikes on the reactor) and contact failure (shortened life of the switcher). The RLSwitcher was also specially design only for reactor switching and to solve these problems and is already deployed in many new wind farms.
In most cases even though the wind power is generated at 34.5 kV, the system voltage of the grid interconnect is normally a higher kV; thus a power transformer is required to step up the generated voltage to the grid interconnect voltage. This power transformer will need a protective device, and the typical choices of a power transformer protective device are either a circuit switcher or a set of power fuses (Typically for primary side protection if the power transformer is less than 15 MVA then power fuses are used and if it is 15 MVA or more a circuit switcher is used). Southern States full line of power fuses and full line of horizontal and vertical circuit switchers is well suited for the wide variety of configurations and challenges of wind farm transformer protection.
Since wind power is an intermittent power source, it is desirable to be able to quickly and simply disconnect this source from the grid when the wind is not blowing. This is ideally done via single point switching without the need for complex switching schemes. Southern States' LLS® Load and Line Switcher supplied on a vertical break disconnect switch was designed for reliable single point switching of loads, lines, and loops all equally well; providing great convenience and versatility.
Other Southern States products can also be applied at the wind farm. No-load disconnect switches can be furnished to provide visual isolation points on the capacitor banks and on both the primary and secondary side of the power transformer. Ground switches can be applied to ground the capacitor banks.
Air core reactor being switched by an RLSwitcher at a midwest wind farm