The detection of generator amature superpotential action and protection circuit
Technical field
The utility model relates to a kind of overvoltage detection circuit, the detection of particularly a kind of generator amature superpotential action and protection circuit.
Background technology
The superpotential source in synchronous generator rotor loop mainly contains switching overvoltage, stator outlet short circuit that phase conversion overvoltage, stator side or rotor-side switch on and off that controllable silicon rectifying bridge produces produce or to be struck by lightning etc. when producing slip over-voltage and stator threephase load asymmetric operation when producing fault overvoltage, generator asynchronous operation and produces asymmetric superpotential etc.
At present, use in the rotor over-voltage protection design of controllable silicon jumper, judge that the method for overvoltage action generally uses overcurrent relay, Hall element or current sensor etc.But these determination methods are very high to the requirement on devices gathering voltage or electric current, and device is serially connected with major loop, needs to carry out type selecting according to different capabilities to device, and circuit structure is complicated, and inconvenience is installed, debugging.
Utility model content
The technical problems to be solved in the utility model is that the circuit structure judging overvoltage action is complicated in order to overcome in prior art, the defect of inconvenience debugging etc., provides a kind of simple and reliable for structure, detection and protection circuit that accurately can detect the action of generator amature superpotential.
The utility model solves above-mentioned technical matters by following technical proposals:
The testing circuit of a kind of generator amature superpotential action, its feature is, this testing circuit comprises one first current-limiting resistance, one second current-limiting resistance, one the 3rd current-limiting resistance, one the 4th current-limiting resistance, one first diode, one second diode, one first stabilivolt, one second stabilivolt and a photoelectrical coupler
One end of this first current-limiting resistance is electrically connected with one end of a de-excitation resistance, the other end of this first current-limiting resistance is connected with the anode of this second diode and the cathodic electricity of this second stabilivolt respectively, one end of this second current-limiting resistance is electrically connected with the other end of this de-excitation resistance, the other end of this second current-limiting resistance is connected with the anode of this first diode and the cathodic electricity of this first stabilivolt respectively, the negative electrode of this first diode is electrically connected with the negative electrode of this second diode and one end of the 3rd current-limiting resistance respectively, the other end of the 3rd current-limiting resistance is electrically connected with the anode of the input side of this photoelectrical coupler, the negative electrode of the input side of this photoelectrical coupler is electrically connected with the anode of this first stabilivolt and the anode of this second stabilivolt respectively, the collector of the outgoing side of this photoelectrical coupler is electrically connected with the positive pole of a direct supply, the emitter of the outgoing side of this photoelectrical coupler is electrically connected with the output terminal of this testing circuit and one end of the 4th current-limiting resistance respectively, the other end of the 4th current-limiting resistance is connected with the negative electricity of this direct supply.
In this programme, the DC voltage exported by a rectifier bridge provides field voltage to generator, and generator amature is electrically connected with de-excitation resistance by an on-off circuit.When generator amature there is forward superpotential, this on-off circuit forward conduction; When generator amature there is negative sense superpotential, this on-off circuit reverse-conducting.Wherein, this on-off circuit is available circuit.
When generator amature normally runs, this on-off circuit disconnects, the output terminal output low level of this testing circuit.
When voltage when on-off circuit forward conduction and on de-excitation resistance is increased to certain value, de-excitation resistance, the first current-limiting resistance, the second diode, the 3rd current-limiting resistance, photoelectrical coupler, the first stabilivolt and the second current-limiting resistance form series loop, the output terminal of testing circuit exports high level, and its voltage magnitude is the magnitude of voltage of this direct supply.
When voltage when on-off circuit reverse-conducting and on de-excitation resistance is increased to certain value, de-excitation resistance, the second current-limiting resistance, the first diode, the 3rd current-limiting resistance, photoelectrical coupler, the second stabilivolt and the first current-limiting resistance form series loop, the output terminal of testing circuit exports high level, and its voltage magnitude is the magnitude of voltage of this direct supply.
By the level detecting output terminal, testing circuit of the present utility model judges whether generator amature occurs superpotential, circuit structure is simple, and utilize photoelectrical coupler to realize electrical isolation, circuit safety is reliable simultaneously.
Preferably, the voltage of this direct supply is 15V ~ 24V.When generator amature occurring superpotential, the output terminal of the utility model testing circuit exports the DC voltage of 15V ~ 24V.
Preferably, this photoelectrical coupler is Low speed photo coupling mechanism.Photoelectrical coupler makes the output of testing circuit and only has optically-coupled between power supply and detected object, there is not electrical connection.
Preferably, the resistance of this first current-limiting resistance and this second current-limiting resistance is equal.
The utility model also provides the protection circuit of a kind of generator amature superpotential action; its feature is; comprise testing circuit as above, one first controllable silicon and one second controllable silicon; this the first silicon controlled anode and this second silicon controlled negative electrode are all electrically connected with one end of this de-excitation resistance, and this first silicon controlled negative electrode is electrically connected with this second silicon controlled anode.
In this programme, the DC voltage exported by a rectifier bridge provides field voltage to generator, and generator amature is electrically connected with de-excitation resistance by two controllable silicons parallel with one another.When generator amature occurring forward superpotential, controlling the second silicon controlled control pole and making this second controlled silicon conducting; When generator amature occurring negative sense superpotential, controlling the first silicon controlled control pole and making this first controlled silicon conducting.Wherein, the first controllable silicon and the second silicon controlled control extremely can to send trigger pip by microprocessor chips such as single-chip microcomputers and control, and also can be controlled by hardware circuit.
Positive progressive effect of the present utility model is: compared with prior art, by the level detecting output terminal, testing circuit of the present utility model judges whether generator amature occurs superpotential, circuit structure is simple, can detect whether generator amature has superpotential action exactly, the utility model utilizes photoelectrical coupler to realize electrical isolation simultaneously, and circuit safety is reliable.
Accompanying drawing explanation
Fig. 1 is the circuit diagram of the protection circuit of the generator amature superpotential action of the utility model embodiment.
Embodiment
Lift preferred embodiment below, and come by reference to the accompanying drawings clearlyer intactly the utility model to be described.
A protection circuit for generator amature superpotential action, as shown in Figure 1, comprises testing circuit, controllable silicon BG1 and controllable silicon BG2, and wherein, when switch S 1 closes, the DC voltage that rectifier bridge A11 exports provides field voltage to generator amature L.
The anode of controllable silicon BG1 and the negative electrode of controllable silicon BG2 are all electrically connected with one end of de-excitation resistance R10, and the negative electrode of controllable silicon BG1 is electrically connected with the anode of controllable silicon BG2, and the control pole of controllable silicon BG1 and the control of controllable silicon BG2 are extremely all electrically connected with control circuit A12.
This testing circuit comprises current-limiting resistance R1, current-limiting resistance R2, current-limiting resistance R3, current-limiting resistance R4, diode D1, diode D2, stabilivolt D3, stabilivolt D4 and photoelectrical coupler U1.
One end of current-limiting resistance R1 is electrically connected with one end of de-excitation resistance R10, the other end of current-limiting resistance R1 is connected with the anode of diode D2 and the cathodic electricity of stabilivolt D4 respectively, one end of current-limiting resistance R2 is electrically connected with the other end of de-excitation resistance R10, the other end of current-limiting resistance R2 is connected with the anode of diode D1 and the cathodic electricity of stabilivolt D3 respectively, the negative electrode of diode D1 is electrically connected with the negative electrode of diode D2 and one end of current-limiting resistance R3 respectively, the other end of current-limiting resistance R3 is electrically connected with the anode of the light emitting diode of the input side of photoelectrical coupler U1, the negative electrode of the light emitting diode of the input side of photoelectrical coupler U1 is electrically connected with the anode of stabilivolt D3 and the anode of stabilivolt D4 respectively, the collector of the triode of the outgoing side of photoelectrical coupler U1 is electrically connected with the positive pole P of direct supply, the emitter of the triode of the outgoing side of photoelectrical coupler U1 is electrically connected with the output terminals A of this testing circuit and one end of current-limiting resistance R4 respectively, the other end of current-limiting resistance R4 is electrically connected with the negative pole M of this direct supply.In the present embodiment, the negative pole M ground connection of direct supply.
In the present embodiment, control circuit A12 comprises BOD (Break Over Diode, breakdown diode).When generator amature L normally runs, BOD disconnects, the output terminals A output low level of testing circuit.
When generator amature L occurring forward superpotential, BOD conducting, trigger controllable silicon BG2 conducting, controllable silicon BG1 ends, and de-excitation resistance R10 is in parallel with generator amature L, de-excitation resistance R10 has electric current to flow through and produce pressure drop on de-excitation resistance R10.When the voltage on de-excitation resistance R10 increases within the specific limits, de-excitation resistance R10, current-limiting resistance R1, diode D2, current-limiting resistance R3, photoelectrical coupler U1, stabilivolt D3 and current-limiting resistance R2 form series loop, when photoelectrical coupler U1 conducting, current-limiting resistance R4 there is electric current to flow through and produce pressure drop on current-limiting resistance R4, the output terminals A of testing circuit exports high level, and its amplitude is the magnitude of voltage of direct supply.Wherein, the voltage on de-excitation resistance R10 constantly increases, until stabilivolt D4 conducting, the voltage on de-excitation resistance R10 is fixed, and the electric current flowing through photoelectrical coupler U1 is shunted by stabilivolt D4, avoids photoelectrical coupler U1 and occurs excess current thus cause device failure.
When inverse overvoltage appears in generator amature L, BOD conducting, trigger controllable silicon BG1 conducting, controllable silicon BG2 ends, and de-excitation resistance R10 is in parallel with generator amature L, de-excitation resistance R10 has electric current to flow through and produce pressure drop on de-excitation resistance R10.When the voltage on de-excitation resistance R10 increases within the specific limits, de-excitation resistance R10, current-limiting resistance R2, diode D1, current-limiting resistance R3, photoelectrical coupler U1, stabilivolt D4 and current-limiting resistance R1 form series loop, when photoelectrical coupler U1 conducting, current-limiting resistance R4 there is electric current to flow through and produce pressure drop on current-limiting resistance R4, the output terminals A of testing circuit exports high level, and its amplitude is the magnitude of voltage of direct supply.Wherein, the voltage on de-excitation resistance R10 constantly increases, until stabilivolt D4 conducting, the voltage on de-excitation resistance R10 is fixed, and the electric current flowing through photoelectrical coupler U1 is shunted by stabilivolt D4, avoids photoelectrical coupler U1 and occurs excess current thus cause device failure.
In the present embodiment, the voltage of direct supply is 24V, when output terminals A output amplitude testing circuit being detected is the high level of 24V, can judge superpotential forward or backwards appears in generator amature.
The structure of the utility model testing circuit is simple, can detect whether generator amature has superpotential action exactly, and the utility model utilizes photoelectrical coupler to realize electrical isolation simultaneously, and circuit safety is reliable.
Although the foregoing describe embodiment of the present utility model, it will be understood by those of skill in the art that these only illustrate, protection domain of the present utility model is defined by the appended claims.Those skilled in the art, under the prerequisite not deviating from principle of the present utility model and essence, can make various changes or modifications to these embodiments, but these change and amendment all falls into protection domain of the present utility model.