Protective circuit of a control and protection switch

Abstract

The invention relates to a protective circuit of a control and protection switch. The circuit comprises: a microprocessor circuit, a signal acquiring circuit, a power supply circuit, an input circuit, a drive circuit, an output control circuit, a human-computer interface circuit and a communication circuit. The circuit has a plurality of protection functions such as overload, phase failure, underload, imbalance and the like, as well as the display function of nixie tubes and the communication function of field buses, and can form a digital control and protection switch capable of communicating together with the main body of the control and protection switch. The protective circuit of the control and protection switch adopts few elements, effectively realizes the protection, control, measurement and display functions of the control and protection switch by reasonable connection, and has communication function. The circuit is simple in connection and high in anti-interference performance, and has the advantages of small volume and high reliability when used in the control and protection switch.

Description

technical field [0001] The invention relates to a protection circuit for a control and protection switch, belonging to the technical field of low-voltage electrical appliances. Background technique [0002] Control and protection switch (CPS) is a new product of low-voltage electrical appliances. CPS realizes integrated, internally coordinated control and protection functions on a single structural product, and can replace circuit breakers (fuse), contactors, Overload (or overcurrent, phase failure) protection relays, starters, isolators and many other traditional discrete devices can be widely used in automated centralized control systems. The control and protection switch (CPS) has a variety of structural forms, such as contactor-based, isolating switch-based, circuit breaker-based, etc., but there are roughly three forms of realization of the protection part: using bimetallic strips, using Analog circuits, using digital circuits. [0003] Patent No. 01238478.X is a util...

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Problems solved by technology

[0003] Patent No. 01238478.X is a utility model patent "an integrated control and protection switching device". Its phase failure, overload, and overcurrent are realized by thermal magnetic modules, and thermal protection is realized by bimetallic strips. There is a precision Low, difficult to set, poor reliability, and difficult to carry heavy loads;

[0004] The invention patent with the publication number CN 1988098A "Control Device for Digital Control and Protection of Switching Appliances" discloses a CPS control device, the protection of which is realized by an embedded microprocessor, but the man-machine interface uses potentiometers and buttons, which is not very friendly , and no communication function

[0005] The patent for invention with the publication number CN 101047084A "Control Device for Intelligent Control and Protection of Switching Appliances" discloses a CPS control device. Its protection uses a 32-bit embedded processor with relatively complete functions, but its man-machine interface requires an external , the circuit structure is more complicated and the cost is higher

[0006] The patent for invention disclosed as CN 1996695A "Multifunctional circuit for controlling and protecting switchgear" and the patent for invention "Controlling and protecting circuit for controlling and protecting switchgear" with publication number CN 101217231A both disclose a CPS circuit, but both There is no human-machine interface module, and the short-circuit protection is realized through the circuit, which reduces the reliability of the short-circuit protection

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