Method for using phases of control voltage and current to measure vector of circuit protection device

Abstract

The invention discloses a method for using phases of control voltage and current to measure a vector of a circuit protection device. The method of the invention comprises steps of applying current on a primary side of a circuit of a CT and applying voltage on a primary side of a PT when a circuit breaker, an isolation switch and a PT isolation switch are disconnected, regulating magnitudes and phases of voltage and current, making magnitudes and phases of voltage and current which are displayed on a relay protection device are constant with that of the applied voltage and current, increasing the voltage and current phase by phase and detecting whether a secondary value of each phase of the relay protection device is constant with a primary value. The method for using phases of control voltage and current to measure the vector of the circuit protection device respectively applies the circuit voltage and current, makes an experiment device small in volume, light in weight, simple in operation, less in investment and high in efficiency, finishes phase determination of a protection device before a project is put into production when a circuit transmits power, does not need to install a temporary protection device when the project is put into protection, reduces an operation amount, does not need to change an operation mode, reduces investment of labor and material resources, and improves reliability of power grid safe operation.

Description

technical field [0001] The invention relates to the technical field of power systems, in particular to a method for measuring vectors of line protection devices by using control voltage and current phase. Background technique [0002] The power industry standard "Inspection Regulations for Relay Protection and Power Grid Safety Automatic Devices" clearly requires: "8.2.2. For devices that are newly installed or have a large change in the equipment circuit, they must be tested with primary current and working voltage before they are put into operation. inspection and judgment." [0003] The content of the inspection mainly includes: measuring the amplitude and phase relationship of voltage and current, measuring the differential current of differential protection, checking the unbalanced output of the phase sequence filter, etc. [0004] However, in the process of actual project commissioning, in order to determine the side phase of the protection device, it is necessary to ...

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Problems solved by technology

[0004] However, in the process of actual project commissioning, in order to determine the side phase of the protection device, it is necessary to consider the arrangement of various power grid operation modes, the power transmission components must have a certain load, and temporary protection and circuit breakers need to be added in series. Therefore, when there are many equipment in production, the power grid The arrangement of the operation mode is complicated, and there are many equipment operations at one time. It is necessary to install temporary protection and calculate the fixed value of temporary protection. The workload of secondary protection and safety automatic device phase measurement is heavy, which affects the efficiency and safety of production.

[0005] The current relay protection tester is only used for the functional test of the relay protection device itself. It is a test tool for secondary operations. The output voltage is low, the current is small, and the capacity is limited. It can only be used in PT (potential transformer voltage transformer) and The CT (Current Transformer Current Transformer) secondary circuit adds voltage and current, and does not have the ability to apply voltage and current to the primary side of PT and CT. Therefore, it cannot detect the correctness of the wiring between the primary and secondary circuits of PT and CT. Moreover, the secondary side equipment is generally charged, so it is necessary to install temporary protection, which poses a great danger to the operator, and the workload of setting calculation is large, there are many switching operations, and it is difficult to arrange the load

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