What will be the consequences if the busbar switch is connected directly?
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The secondary load is powered by sections A and B. Under normal conditions, the busbar is disconnected. What would happen if both circuit breakers of the transformers remained closed and the busbar were connected as well?
How can two transformers with identical parameters be connected in parallel to meet the requirements for parallel operation? Conditions for parallel operation: ① The same wiring configuration； ② The transformation ratio difference must not exceed ±0.5% ； ③ The short-circuit voltage value must not exceed ±10% ； ④ The capacity ratio of the two transformers should not exceed 3:1. Once the above conditions are met and before connecting in parallel, it is sufficient to use a multimeter to verify the phase sequence. Generally, power supply companies do not allow parallel connection as this can easily lead to \"loop formation,\" causing the protection devices to fail or resulting in widespread accidents.
It depends on how the operation mode is specified! When it comes to connecting to the network office, approval from the network office’s scheduling department is also required!
Based on the design of control systems, interlock devices are usually installed; for example, it is not possible to close the switch if both circuit breakers are in the closed position. If there is no interconnection, the two transformers operate in parallel. According to the specifications, it is acceptable as stated on the 2nd floor. But the short-circuit current will double, so you need to verify whether your equipment can handle it. If the conditions for parallel operation are not met, the transformer will overheat, which is dangerous for the equipment.
If the interlock is functioning properly, it should not be possible to close it. To force it closed manually, one needs to consider the power parameters of the relevant system; if it can be closed, then it’s a matter of the magnitude of the impact.
The high-voltage power distribution cabinet is equipped with a three-lock two-key interlock system; if power is supplied to both stage 1 and stage 2, the busbar switch cannot be activated.
Such operation is feasible; it is known as parallel operation of two transformers. During design, the two transformers must meet the conditions for parallel operation. Those that do not meet the requirements cannot operate in parallel.
I’m not from an electrical engineering background, and it seems pretty risky to do this without any proper design.
It seems the second floor has misled many people! What the original poster is asking is what will happen if all three switches – the two inputs of the busbar and the one for sectioning – are closed at the same time. It has nothing to do with being connected in parallel with a transformer! When three switches are closed simultaneously, we generally refer to this as closing a loop. Whether a loop can be formed depends mainly on whether the two power supplies belong to the same power system Has the higher level been closed? Because it involves an asynchronous issue as well as a problem with crossing power. If the two power supplies are not part of the same system, closing the sectionalizer may result in asynchronous switching, leading to system disturbances or even equipment damage. Even within the same power supply system, the load may be unbalanced. When the sectionalizer is closed, part of the external load current may flow in through one power supply and out through another, causing the incoming switch of the former supply to become overloaded.