What is meant by circulating current?
When two substations are conected through a switch, there may be a voltage difference between the sites. When the switch is closed, creating a parallel, it is said that current flows between the sub stations, known as ‘circulating current’.
What is circulating current in power electronics?
Module synchronization- All inverter module connected in parallel should have the same output voltage, frequency and phase. If the output voltage of modules are not equal a current flow from the module with the higher voltage to the lower voltage that current is known as crosscurrent or circulating current.
What is circulating current formula?
Conceptually, it really is as simple as Ohm’s Law: I = V/R. Of course that is an over simplification, but it is the same concept applied to three phase AC systems. Now let’s take a deeper dive into how to calculate circulating current.
What is meant by circulating current in transformer?
Above, the circulating currents are the current flowing at no load in the high and low voltage windings absent of exciting currents. Full load current is the current flowing in the transformer with a load connected, absent of exciting and circulating currents.
What is circulating current protection?
Circulating Current Protection (CCP) is used as the diameter protection in one and half breaker Substation. CCP is used to protecting area between Current Transformer (CT) at bay line and CT at circuit breaker in between diameter (AB: B or AB: A as shown in Fig. 1).
Why does circulating current flow in paralleling?
These unequal no-load voltages (unequal tap positions) will cause a circulating current to flow through the parallel connected transformers. … So, the difference in current between the currents through these two impedances is basically the circulating current as it is not seen outside these parallel impedances.
What causes circulating current in dual converters?
What causes circulating current in dual converters? Explanation: In case of practical dual converters, the voltages from both the converter circuits though equal in magnitude is out of phase. This indifference in voltages causes circulating currents to flow.
What is circulating current in dual converter?
There is an instantaneous voltage difference at the DC terminals of the two converters. It produces enormous circulating current between the converters and that will flow through the load. Therefore, in the practical dual converter, it is necessary to control the circulating current.
How do you reduce circulation current?
There are mainly two ways to eliminate or reduce the ZSCC flow: (i) breaking the route of CC flow by introducing physical devices such as an isolation transformer or common mode inductor or (ii) by proper control methods.
What is neutral circulating current?
The circulating current is driven by the voltage induced on the neutral from the phase conductor. Circulating currents are worse with larger conductors and with wider separation between cables. Two configurations are given: (1) cables in separate ducts and (2) all three cables in the same duct.