Wiring method of current loop of main transformer protection for side-band operation

Abstract

The invention discloses a wiring method of a current loop of main transformer protection for side-band operation. According to the invention, a switch CT current, a main transformer casing tube CT current are respectively and independently introduced into a main transformer protection apparatus; During the operation process, the main transformer protection simultaneously monitors two sets of current loops; when a CT open circuit phenomenon occurs in any set of the current loop, both of the two sets of the current loops emit alarm information; and an input is sent into a main transformer protection CPU by utilizing an auxiliary node of an operating handle, so that an operating state of the transformer protection is distinguished. And on the normal operating condition, the transformer protection uses the switch CT current; and on the side-band operation condition, the main transformer protection uses the main transformer casing tube CT current. Therefore, it is no need for an operator to operate a current loop; the operation is simple and time for withdrawal of main transformer protection is short; besides, system operation reliability and operation security are substantially improved as well as the operation is convenient; and system operational reliability is substantially enhanced; moreover, in both the normal operation and side-band operation conditions, reliable monitoring is carried out on the switch CT current and the main transformer casing tube CT current; if there is a phenomenon of a CT open circuit, the operator can take measurements to deal with it timely.

Description

[0001] technical field [0002] The invention belongs to the technical field of main transformer protection, and in particular relates to a main transformer protection current loop wiring method capable of side-band operation. Background technique [0003] In the power system, there is often an operation mode in which the main transformer is connected in series with the side bus. At this time, the operator needs to switch the current circuit used by the protection device in the main transformer protection cabinet from the switch CT to the main transformer bushing CT, which has the following disadvantages: the operation process is complicated, and the current switching connection is easy to wear, which may lead to open circuit of CT , endangering the life safety of the operating personnel; due to the cumbersome operation steps, the operation time of the operating personnel is long, and the time for the main transformer protection to exit is correspondingly prolonged, which...

AI Technical Summary

Problems solved by technology

At this time, the operator needs to switch the current circuit used by the protection device in the main transformer protection cabinet from the switch CT to the main transformer bushing CT, which has the following disadvantages: the operation process is complicated, and the current switching connection is easy to wear, which may lead to open circuit of CT , endangering the life safety of the operating personnel; due to the cumbersome operation steps, the operation time of the operating personnel is long, and the time for the main transformer protection to exit is correspondingly prolonged, which affects the reliability of the system operation; after too many current switching operations, poor contact is prone to occur. It not only endangers the life of operating personnel and equipment safety, but also easily causes unstable operation of the device; under normal operation, the protection current circuit does not monitor the CT current of the main transformer bushing, and does not monitor the switch CT current under sideband operation. , even if there is a CT open circuit, the operator has no way of knowing, and the operation is very blind and dangerous

Images