阅读说明：本技术 一种三相交流发电机宽范围短路限流装置 (Wide-range short-circuit current limiting device of three-phase alternating-current generator ) 是由 刘振 李伟强 张璟华 何跃 闫军部 于 2019-11-08 设计创作，主要内容包括：本申请提供了一种三相交流发电机宽范围短路限流装置，包括将所述三相交流发电机的主发电压经半波整流后分为第一输出端及第二输出端，所述第一输出端的电位高于所述第二输出端的电位，所述第一输出端通过低相或门连接于NPN型三极管V86的基级，所述第二输出端通过高相或门连接于PNP型三极管V87的基级，三极管V86的发射极与三极管V87的发射极相连，三极管V87处于常通状态，三极管V86的集电极连接有短路限流比较器，用于在三极管V86的集电极输出高电平时，判定为短路故障，进而调节励磁以限制短路电流。本发明不仅能够有效的将短路电流限制在要求范围内，而且可调性好，调节范围宽，节约了成本，减小了体积和重量，提升了可靠度。(The application provides a three-phase alternator wide region short circuit current-limiting device, include with three-phase alternator's main electricity generation is pressed and is divided into first output and second output after the half-wave rectification, the electric potential of first output is higher than the electric potential of second output, first output is connected in NPN type triode V86's base level through low looks OR gate, the second output is connected in PNP type triode V87's base level through high looks OR gate, and triode V86's projecting pole links to each other with triode V87's projecting pole, and triode V87 is in the normal open state, and triode V86's collecting electrode is connected with current-limiting short circuit comparator for when triode V86's collecting electrode output high level, judge short-circuit fault, and then adjust the excitation in order to limit short-circuit current. The invention not only can effectively limit the short-circuit current within the required range, but also has good adjustability and wide adjusting range, saves the cost, reduces the volume and the weight and improves the reliability.)

1. The utility model provides a three-phase alternating current generator wide region short circuit current limiting device which characterized in that includes:

the three-phase alternating-current generator is characterized in that a main generating voltage of the three-phase alternating-current generator is divided into a first output end and a second output end after half-wave rectification, the potential of the first output end is higher than that of the second output end, the first output end is connected to the base level of an NPN type triode V86 through a low-phase OR gate, the second output end is connected to the base level of a PNP type triode V87 through a high-phase OR gate, an emitter of a triode V86 is connected with an emitter of a triode V87, the triode V87 is in a normally-on state, a collector of the triode V86 is connected with a short-circuit current-limiting comparator, and when a collector of the triode V86 outputs a high level, the short-circuit fault is judged, and.

2. The wide-range short-circuit current-limiting apparatus of claim 1, wherein the second output terminal is connected to a power source through a sliding resistor, and the base of the transistor V87 is connected to the sliding terminal of the sliding resistor, and the sliding resistor is used for adjusting the base potential of the transistor V87.

3. The wide-range short-circuit current-limiting device of a three-phase alternating current generator as claimed in claim 1, wherein the base and emitter of the transistor V86 are connected to each other, and a capacitor C47 is provided in the connection circuit.

4. The wide-range short-circuit current-limiting apparatus of claim 1, wherein the emitter of the transistor V87 is connected to a 12V power source through a resistor, and the collector of the transistor V87 is grounded.

5. The apparatus as claimed in claim 2, wherein the base of the transistor V86 is adjusted to 5V by a resistor and the base of the transistor V87 is adjusted to 4.2V by a power supply and a sliding resistor to turn on the transistor V86 during normal operation of the three-phase ac generator.

Technical Field

The invention belongs to the technical field of generator control, and particularly relates to a wide-range short-circuit current limiting device of a three-phase alternating-current generator.

Background

With the continuous expansion of the aviation field, the aviation power generation system is more and more important, and the demand is more and more. When the short circuit phenomenon occurs in the generator, the generator is required to continue to work but the short circuit current is limited within a specific range. In the traditional mode, a current sensor is adopted to sample the current of the output end of the generator so as to judge whether a short circuit occurs or not and when the output current of the generator needs to be limited. This approach is based on current sampling, which increases the weight and volume of the product design and is costly. The current sensor with large volume and weight can not be used when the volume and weight have special requirements, so that the current of the generator in short circuit is limited by adopting a circuit without the current sensor, and the generator can continuously work when the short circuit phenomenon occurs.

Disclosure of Invention

In order to solve at least one of the above technical problems, the present application provides a wide-range short-circuit current limiting device for a three-phase ac generator, including:

the three-phase alternating-current generator is characterized in that a main generating voltage of the three-phase alternating-current generator is divided into a first output end and a second output end after half-wave rectification, the potential of the first output end is higher than that of the second output end, the first output end is connected to the base level of an NPN type triode V86 through a low-phase OR gate, the second output end is connected to the base level of a PNP type triode V87 through a high-phase OR gate, an emitter of a triode V86 is connected with an emitter of a triode V87, the triode V87 is in a normally-on state, a collector of the triode V86 is connected with a short-circuit current-limiting comparator, and when a collector of the triode V86 outputs a high level, the short-circuit fault is judged, and.

Preferably, the second output terminal is connected to a power supply through a sliding resistor, and a base of the transistor V87 is connected to a sliding terminal of the sliding resistor, and the sliding resistor is used for adjusting a base potential of the transistor V87.

Preferably, the base and emitter of the transistor V86 are connected to each other, and a capacitor C47 is provided in the connection circuit.

Preferably, the emitter of the transistor V87 is connected to a 12V power supply through a resistor, and the collector of the transistor V87 is grounded.

Preferably, when the three-phase ac generator is in normal operation, the base of the transistor V86 is adjusted to 5V by a resistor, and the base of the transistor V87 is adjusted to 4.2V by a power supply and a sliding resistor, so that the transistor V86 is turned on.

The wide-range short-circuit current limiting device of the three-phase alternating-current generator limits the short-circuit current when the short-circuit phenomenon occurs to the alternating-current generator based on the principle of sensitive three-phase unbalanced voltage so as to ensure that the motor can continue to work, reduce the volume and weight of a product, save the cost and increase the reliability.

Drawings

Fig. 1 is a circuit diagram of a wide-range short-circuit current limiting device of a three-phase alternating-current generator.

Detailed Description

In order to make the implementation objects, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the accompanying drawings in the embodiments of the present application. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all embodiments of the present application. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present application, and should not be construed as limiting the present application. All other embodiments obtained by a person of ordinary skill in the art without any inventive work based on the embodiments in the present application are within the scope of protection of the present application. Embodiments of the present application will be described in detail below with reference to the drawings.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience in describing the present invention and for simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be taken as limiting the scope of the present invention.

Referring to fig. 1, the wide-range short-circuit current limiting device for a three-phase ac generator mainly includes:

the three-phase alternating-current generator is characterized in that a main generating voltage of the three-phase alternating-current generator is divided into a first output end and a second output end after half-wave rectification, the potential of the first output end is higher than that of the second output end, the first output end is connected to the base level of an NPN type triode V86 through a low-phase OR gate, the second output end is connected to the base level of a PNP type triode V87 through a high-phase OR gate, an emitter of a triode V86 is connected with an emitter of a triode V87, the triode V87 is in a normally-on state, a collector of the triode V86 is connected with a short-circuit current-limiting comparator, and when a collector of the triode V86 outputs a high level, the short-circuit fault is judged, and.

Referring to fig. 1, the three-phase ac generator three-way voltage POR _ A, POR _ B, POR _ C has a first potential through a first-level voltage drop (R50-R52) after passing through V54-V56, and is connected to the base of the transistor V86 through an or gate (V48-V50), the three-way voltage POR _ A, POR _ B, POR _ C has a second potential through a second-level voltage drop (R53-R55), and is connected to the 12V power supply through an or gate (V51-V53), while passing through a sliding resistor RP4, the sliding end of the sliding resistor RP4 is connected to the base of the transistor V87, the transistor V87 is different from the transistor V86, the transistor V87 is an emitter follower, the collector of the transistor V87 is Grounded (GND), so that the transistor V87 is in a normally-on state, i.e., the base of the transistor V87 is at the same potential as the emitter, and the emitter of the transistor V87 is connected to the 12V power supply through a, the base level potential of the triode V87 is adjustable, which is the key to achieving the wide-range adjustable design of the present application, and specifically, returning to the triode V86, since the emitter thereof is connected with the emitter of the triode V87, that is, the emitter of the triode V86 is adjustable, after the base level of the triode V86 is determined, the emitter of the triode V86 is adjusted to achieve the adjusting function.

Through the analysis, the base and the emitter of the triode V86 are respectively related to the potential of the first output end and the potential of the second output end, the two potentials are compared on the base and the emitter of the triode V86, during normal operation, the three-phase voltage is balanced, the voltage difference between the base and the emitter of V86 is constant, at the moment, the base potential is higher than the emitter potential, the V86 is conducted, the collector outputs low level, and no short circuit phenomenon occurs. When a short-circuit fault occurs to a certain phase of the generator, the phase voltage is reduced, the voltage difference between the base electrode and the emitter electrode of the V86 is reduced to be lower than the voltage drop during the conduction, and therefore the V86 is cut off. Whether a short-circuit fault occurs is judged by the output level of the collector of V86, if V86 is cut off, the collector is at a high level and is judged to be short-circuited, the later stage can output a control wave through a comparison circuit to adjust excitation so as to limit short-circuit current, and meanwhile, the limit range of the short-circuit current can be adjusted through a potentiometer RP 4.

For example, during normal operation, the base voltage of V86 is 5V, RP4 is adjusted to make the emitter voltage of V87 be 4.2V, and V86 be conductive (normally, when the difference between the base voltage and the emitter voltage of transistor V86 selected in this example is greater than or equal to 0.7V, this is conductive), so that the collector of V86 outputs a low level, that is, the 4-pin low level of comparator N5A in fig. 1, at this time, the 2-pin output end of the comparator is a high level, short-circuit current limiting protection is not enabled, otherwise, if the system has a short-circuit fault, the base voltage of V86 drops to 4V, the emitter voltage of V87 drops to 3.7V, at this time, the difference between the base voltage and the emitter voltage of transistor V86 is less than 0.7V, V86 is not conductive, the 4-pin high level of comparator N5A, and the corresponding 2-pin output end is a low level.

It should be noted that, when the voltage of the V86 base is decreased to 4V, the voltage of the emitter of the V87 is decreased to 3.7V, not to 3.2V, because of the voltage dividing effect of the resistor such as R53, and the voltage drop of the low phase or gate (V51-V53, the low voltage is selected) circuit is smaller than the voltage drop of the high phase or gate (V48-V50, the high voltage is selected).

As further explained with respect to the wide range adjustment of the present application, the conduction condition of the transistor V86 is determined, for example, 0.7V, the base voltage of the transistor V86 is determined, for example, 5V, and in one embodiment, if the sliding resistor RP4 is adjusted to make the base voltage of the transistor V87 be 4.3V, and the difference between the base voltage and the emitter of the transistor V86 is exactly 0.7V, it can be considered that the transistor V86 is conductive, and if a short circuit occurs, the difference between the base voltage and the emitter of the transistor V86 is immediately decreased to be below 0.7V, so that the transistor V86 is not conductive and a short-circuit current-limiting protection signal is sent; in another embodiment, if the sliding resistor RP4 is adjusted to make the base of the transistor V87 be 4V, the difference between the base and the emitter of the transistor V86 be 1V, and the transistor V86 is turned on, and if a short circuit occurs, the difference between the base and the emitter of the transistor V86 is gradually reduced from 1V to below 0.7V, and then a short-circuit current-limiting protection signal is sent out, thereby implementing a wide-range short-circuit signal adjustment.

When the alternating current generator is in single-phase-to-ground or interphase short circuit condition, the short-circuit current can be effectively limited within the required range, and the method has good adjustability and wide adjusting range. Meanwhile, the cost is greatly saved, the size and the weight are reduced, and the reliability is improved.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.