A kind of anti-overvoltage measurement and control device
Technical field
The utility model belongs to the automatic control technology of power system field, especially relates to a kind of anti-overvoltage measurement and control device.
Background technology
Along with the progress of electric power science and technology information technology, net capacity constantly enlarges, and more and more higher to the fail safe and the reliability requirement of Automation of Electric Systems operation, the automation of transformation substations is the most basic automated system.Easily cause overvoltage on the electrical network during switching of main equipment operating state, be because when power circuit broke down, primary current was huge, needs moment need discharge huge electric current, when primary equipment insulation or imperfect earth, the primary side alternating voltage secondary device of playing a reversed role, secondary device will produce very high voltage, when taking place to puncture, will be with the form discharge of electric current, threaten personal safety, damage secondary device, cause serious consequence.
Measure and control device is the core apparatus of electric substation automation system wall, be that the basis from the safe and reliable operation of automated system is combined by realization transformer station, measure and control device integrates multiple functions such as AC sampling, remote signalling, distant arteries and veins, remote control, be mainly used in power plant/electric substation's wall and power distribution network switching station/ring main unit high-voltage electrical equipment control, measurement, signal, communicate by letter, failure logging etc., it is combined into an integrated apparatus with various functional modules.At present, transformer station measurement and control device, be integrated circuit modules, working earthing is the reference potential of module work, therefore, its operating voltage is low, withstand voltage insulation level to high potential is lower, easily produces alternating voltage secondary device of playing a reversed role, and causes the secondary device fault, the accident potential safety hazard is buried in the safe operation of the equipment of giving, even seriously injures equipment operation management personnel's personal safety.
Summary of the invention
For addressing the above problem, the purpose of this utility model provides a kind of anti-overvoltage measurement and control device, prevents alternating voltage secondary device of playing a reversed role, and causes the secondary device fault.
For achieving the above object, the utility model adopts following technical scheme:
Described anti-overvoltage measurement and control device, it mainly is made up of analog input circuit, dsp processor and peripheral circuit thereof, switching value input circuit, switching value output loop; One overvoltage lightning protection circuit is in parallel with switching value remote signalling input circuit, between switching value remote control output loop and the secondary control loop direct current relay is installed and isolates.
Described anti-overvoltage measurement and control device; its overvoltage lightning protection circuit comprises lightning arrester, discharge resistance, current-limiting resistance, photoelectrical coupler and relay; lightning arrester one end is connected with mechanism case place primary equipment auxiliary contact; the other end is through discharge resistance ground connection; and be connected with the photoelectrical coupler input with diode by current-limiting resistance in parallel, photoelectric coupler output end with connect the measure and control device positive supply after relay is connected.
Owing to adopt aforesaid technical scheme, the utlity model has following superiority:
This anti-overvoltage measurement and control device, it is simple in structure, cost of manufacture is low, and is easy and simple to handle, isolates by switch amount input circuit, switching value output loop, effectively prevent alternating voltage secondary device of playing a reversed role, cause the secondary device fault, result of use is good, has improved the monitoring system of electric substation reliability effectively, eliminate accident potential, improved the entire system security performance.The utility model also can be used in other Automatic monitoring systems such as railway, space flight.
Description of drawings
Fig. 1 is the circuit theory diagrams of measure and control device anti-overvoltage remote signalling input circuit of the present invention;
Fig. 2 is the structured flowchart of measure and control device anti-overvoltage control loop operation of the present invention.
Embodiment
Below in conjunction with accompanying drawing the utility model is described in further detail.
Anti-overvoltage measurement and control device described in the utility model, it mainly is made up of analog input circuit, dsp processor and peripheral circuit thereof, switching value input circuit, switching value output loop.
As shown in fig. 1; described anti-overvoltage measurement and control device; its switching value remote signalling input circuit is in parallel with the overvoltage lightning protection circuit; the overvoltage lightning protection circuit comprises lightning arrester BLQ; discharge resistance R1; current-limiting resistance R2; photoelectrical coupler OC1 and relay K 1; lightning arrester BLQ one end is connected with mechanism case place primary equipment circuit breaker (or disconnecting link) auxiliary contact XJ; the other end is through discharge resistance R1 ground connection; and by diode in series D1; D2 and current-limiting resistance R2 are in parallel to be connected with photoelectrical coupler OC1 input, photoelectrical coupler OC1 output with connect the measure and control device positive supply after relay K 1 is connected.
When carrying out acquisition process in the dsp processor of switching value remote signals by switching value input circuit input measure and control device, at first through the remote signals of active input circuit, auxiliary contact XJ by primary equipments such as mechanism case place circuit breakers, if voltage is less than 500V, then lightning arrester BLQ does not work, and the overvoltage lightning protection circuit is not worked; If voltage is greater than 500V; lightning arrester BLQ works (there is certain time-delay in switching value remote signalling input circuit); directly discharge by discharge resistance R1 when voltage is big; and make photoelectrical coupler OC1 by certain electric current; starting relay K1; relay normally closed contact k1 disconnects, and measure and control device has effectively been protected in the high voltage input of cut-off switch amount remote signalling input circuit.
As shown in Figure 2, described anti-overvoltage measurement and control device, its remote control output loop and secondary control loop are isolated by direct current relay K2 contact, and the anti-overvoltage measurement and control device utilizes self unnecessary control output contact YK6 to link to each other with direct current relay K2.
When measure and control device receives the prefabricated order of remote control, at first should control export the YK6 closure, start direct current relay K2, k2 action in direct current relay contact is with secondary breaker tripping and closing control loop 1,3,33 connect, and start once-through operation mechanism, carry out branch, the closing operation of equipment such as circuit breaker or isolating switch; After straighforward operation was finished, the YK6 contact disconnected, and direct current relay K2 returns, and contact k2 disconnects, and isolated secondary control loop;
When manual operation, the observing and controlling of measure and control device screen need carry out five anti-permissions, plug five preventing keys after, will operate the connection of positive electricity loop, just can carry out manual operation; After plugging five preventing keys, five anti-auxiliary contact JS closures directly start direct current relay K2 with secondary control loop 1,3, and 33 connect, and can carry out manual operation; When manual operation finish extract five preventing keys after, five anti-auxiliary contact JS return, secondary control loop is isolated in direct current relay K2 involution.