Annual damage rate of capacitor bank

What happens if a capacitor bank fails?

V. INTERNAL OVERVOLTAGE AND ITS APPLICATION IN SETTING THE UNBALANCE PROTECTION ELEMENTS A failure in a capacitor bank causes an internal overvoltage inside the bank (see Fig. 9 and Fig. 10). This overvoltage may cause more failures, which in turn creates even higher overvoltage, and eventually, leads to a cascading failure.

Why do capacitor bank voltages and currents unbalance in per-unit values?

We achieved this simplicity by working in per-unit values. It is apparent that an unbalance in capacitor bank voltages and currents is a result of a difference between the faulted and healthy parts of the bank. As such, the per-unit voltage or current unbalance is independent of the absolute characteristics of the faulted and healthy parts.

How many capacitor banks were installed in 1985 to 2008?

The study includes 9 vendors for whom the Capacitor Banks are installed during the period of early installation in 1985 till 2008. Analyzing the available Capacitor Failure data of all vendors, over the banks lifetime. 5/9 of these vendors.

What are the underlying equations of a capacitor bank?

Because capacitor bank equations are linear and there is no mutual coupling inside the bank, the underlying equations for the calculations are simple: the unit reactance ties the unit voltage and current while Kirchhoff’s laws tie all voltages and currents inside the bank. However, solving these underlying equations by hand is tedious.

What is a capacitor bank?

Capacitor Banks are installed to provide capacitive reactive compensation and power factor correction. A capacitor unit is the building block of any shunt capacitor bank. The capacitor unit is made up of individual capacitor elements, arranged in parallel/series connected groups.

Are capacitor banks reliable?

The failure rates in Table 1 are high, much higher than most distribution equipment. Capacitor banks are complicated, they have a lot of equipment to fail. Yet, failure rates should be significantly better than this. An EPRI survey on capacitor reliability found wide differences in utilities’ experience with capacitors (EPRI 1001691, 2002).