Control circuit based on excitation generator

Abstract

The utility model provides a control circuit based on an excitation generator, which acquires the frequency of the output voltage of a target excitation generator through a frequency acquisition module, can accurately represent the rotating speed of the target excitation generator through the frequency of the output voltage, and converts the frequency into a direct-current rotating speed voltage signal through a frequency-to-voltage conversion module; the rotating speed voltage signal is compared with different reference signals through three comparison units of the rotating speed segmentation module, so that a current rotating speed interval can be distinguished; the combined output of the three comparison units is identified and converted through a decoder of the winding selection control module, and three control signals respectively corresponding to the current rotating speed interval can be provided at three output ends of the decoder. The control circuit based on the excitation generator can effectively realize respective starting control of the three groups of excitation windings of the target excitation generator, does not need a high-cost analog-to-digital converter and a high-cost digital signal processor, and can effectively reduce the control cost of the excitation generator.

Description

Technical Field

[0001] This utility model relates to the field of excitation generator technology, and in particular to a control circuit based on an excitation generator. Background Technology

[0002] When weapons and electrical equipment travel with a vehicle, they require uninterrupted power supply. To ensure that these equipment remains in a state of readiness at all times while the vehicle is in motion, the generator must maintain a stable voltage output even as the vehicle's speed changes.

[0003] Existing vehicle-mounted generators are generally excitation generators, which, in conjunction with an excitation controller, regulate the excitation current to provide different excitation magnetic fields and, depending on the engine speed, provide a stable voltage output. However, the adjustment range of the excitation controller is limited, and the vehicle-mounted excitation generator is connected to the vehicle's engine drive, resulting in a wide range of vehicle speed variations, which makes the excitation controller's ability to adapt insufficient. Therefore, in existing technologies, vehicle-mounted excitation generators are generally equipped with multiple sets of excitation windings with different numbers of turns, allowing selection of different excitation windings according to the current speed range, thereby enhancing excitation regulation capabilities and adapting to the wide speed range of the engine.

[0004] In existing technologies, the speed of a generator is generally acquired by various sensors such as encoders and electronic tachometers. The acquired data is converted from analog to digital and then processed by digital signal processing (at least a 12-bit analog-to-digital converter is required depending on the engine speed range, and the number of bits in the digital signal processing must be corresponding) to obtain the speed. The excitation winding is then switched and controlled based on the speed. The implementation cost of high-bit analog-to-digital converters and digital signal processors is relatively high. Utility Model Content

[0005] Therefore, the purpose of this utility model is to provide a control circuit based on an excitation generator to solve the problem of high cost of excitation winding switching control equipment for excitation generators in the prior art.

[0006] This utility model provides a control circuit based on an excitation generator, comprising: a frequency acquisition module, a frequency-to-voltage conversion module, a speed segmentation module, and a winding selection control module connected in sequence.

[0007] The frequency acquisition module includes a generator voltage signal input terminal connected to the voltage output terminal of the target excitation generator, and the frequency signal output terminal of the frequency acquisition module is connected to the frequency signal input terminal of the frequency-to-voltage conversion module.

[0008] The speed segmentation module includes three comparison units, and the input terminal of each comparison unit is connected to the speed voltage signal output terminal of the frequency to voltage conversion module.

[0009] The winding selection control module includes a decoder. The output terminals of the three comparison units are respectively connected to the three input terminals of the decoder, and the three output terminals of the decoder are respectively connected to the control terminals of the three winding enable control switches of the target excitation generator.

[0010] Optionally, the frequency acquisition module includes a first operational amplifier, the non-inverting input of the first operational amplifier is the input terminal of the generated voltage signal, the inverting input of the first operational amplifier is used to connect a reference signal, a first resistor is connected between the inverting input terminal and the output terminal of the first operational amplifier, a first capacitor is connected in parallel with the first resistor, and the output terminal of the first operational amplifier is the output terminal of the frequency signal.

[0011] Optionally, a second resistor and a second capacitor are connected in series between the frequency signal output terminal and the frequency signal input terminal, and a third resistor is also connected in series between the frequency signal input terminal and ground, and a third capacitor is connected in parallel with the third resistor.

[0012] Optionally, the comparison unit includes a hysteresis comparator and a transistor. The base of the transistor is connected to the output terminal of the hysteresis comparator, the collector of the transistor is connected to a standard voltage source through a pull-up resistor, the emitter of the transistor is grounded, and the collector of the transistor is the output terminal of the comparison unit.

[0013] Optionally, a Zener diode is connected in series between the output of the hysteresis comparator and the base of the transistor.

[0014] Optionally, a fourth resistor, a fourth capacitor, and a variable resistor are provided between the reference signal input terminal of the hysteresis comparator and the reference signal source. The fourth resistor and the variable resistor are connected in series between the reference signal source and ground. The movable terminal of the variable resistor is connected to the reference signal input terminal of the hysteresis comparator, and the fourth capacitor is connected in parallel across the variable resistor.

[0015] Optionally, the three outputs of the decoder are each connected to a standard voltage source via a resistor.

[0016] The control circuit based on the excitation generator provided by this utility model includes: a frequency acquisition module, a frequency-to-voltage conversion module, a speed segmentation module, and a winding selection control module connected in sequence. The frequency acquisition module acquires the frequency of the output voltage of the target excitation generator, and the frequency of the output voltage can accurately represent the speed of the target excitation generator. The frequency-to-voltage conversion module converts the frequency into a DC speed voltage signal. The speed voltage signal is compared with different reference signals by three comparison units of the speed segmentation module to distinguish the current speed range. When the current speed is in different speed ranges, the output signal combination state of the three comparison units is different. The winding selection control module's decoder performs identification and conversion, and can provide three control signals corresponding to the current speed range at the three output terminals of the decoder to control the three sets of excitation windings of the target excitation generator to be activated respectively. The control circuit based on the excitation generator of this invention converts the rotational speed of the target excitation generator into a DC speed voltage signal. Then, the speed voltage signal is compared with the corresponding reference signal through three comparison units to obtain the current speed range. The combinational logic signals output by the three comparison units are then converted by a decoder to obtain three control signals for the separate activation of the three sets of excitation windings. This can effectively realize the separate activation control of the three sets of excitation windings of the target excitation generator without the need for high-cost analog-to-digital converters and digital signal processors, thus effectively reducing the control cost of the excitation generator. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the main module structure of the control circuit based on the excitation generator in an embodiment of this utility model;

[0018] Figure 2 This is a circuit diagram of the frequency acquisition module of the control circuit based on the excitation generator in an embodiment of the present invention;

[0019] Figure 3 This is a circuit diagram of a comparison unit in the control circuit based on the excitation generator in an embodiment of this utility model.

[0020] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this utility model. Detailed Implementation

[0021] To facilitate understanding of this utility model, a more complete description of it will be given below with reference to the accompanying drawings. Several embodiments of this utility model are shown in the drawings. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this utility model will be more thorough and complete.

[0022] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] To address the high cost of existing excitation winding switching control equipment for excitation generators, this invention provides a control circuit based on an excitation generator. It acquires the frequency of the output voltage of the target excitation generator through a frequency acquisition module, accurately representing the generator's rotational speed. A frequency-to-voltage conversion module converts the frequency into a DC speed voltage signal. This speed voltage signal is compared with different reference signals by three comparison units in a speed segmentation module to distinguish the current speed range. A decoder in a winding selection control module identifies and converts the combined outputs of the three comparison units, providing three control signals corresponding to the current speed range at the decoder's three output terminals. This effectively enables separate activation control of the three excitation windings of the target excitation generator, eliminating the need for high-cost analog-to-digital converters and digital signal processors, thus significantly reducing the control cost of the excitation generator.

[0025] Specifically, please refer to Figure 1 , Figure 2 and Figure 3 In this embodiment, the control circuit based on the excitation generator is connected in sequence to a frequency acquisition module 10, a frequency-to-voltage conversion module 20, a speed segmentation module 30, and a winding selection control module 40.

[0026] The frequency acquisition module 10 includes a generator voltage signal input terminal connected to the voltage output terminal of the target exciter generator, which converts the sinusoidal voltage signal into a square wave frequency signal. The frequency signal output terminal of the frequency acquisition module 10 is connected to the frequency signal input terminal of the frequency-to-voltage conversion module 20, so that the frequency signal can be converted into a DC speed voltage signal through the frequency-to-voltage conversion module 20.

[0027] The faster the target excitation generator rotates, the higher the speed voltage signal becomes, which can be achieved by the frequency-to-voltage conversion module 20 using the LM2917 conversion chip.

[0028] The speed segmentation module 30 includes three comparison units. The input terminal of each comparison unit is connected to the speed voltage signal output terminal of the frequency to voltage conversion module 20. When the speed voltage signal reaches the comparison threshold of the three comparison units, the module can provide the corresponding logic signal output.

[0029] The winding selection control module 40 includes a decoder. The outputs of the three comparison units are respectively connected to the three inputs of the decoder, and the three outputs of the decoder are respectively connected to the control terminals of the three winding enable control switches of the target excitation generator. The decoder can be a 74LS138 decoder, which can realize 3-to-8-wire decoding control. The specific decoding rules are programmable and can meet the functional requirements of this application.

[0030] In a specific example, the speed range can be divided into a first speed range, a second speed range, and a third speed range in ascending order. With digital signal logic as a reference, when the target excitation generator's speed is in the first speed range, the second speed range, and the third speed range, the output logic combinations of the three comparison units are 000, 100, and 110, respectively. Correspondingly, the output logic combinations of the three output terminals of the winding selection control module 40 are 100, 010, and 001, respectively, which correspond to the individual activation control of the three sets of excitation windings. This can effectively distinguish the speed range in which the current speed is located and control the activation of the corresponding set of excitation windings.

[0031] To achieve frequency acquisition, such as Figure 2 As shown, in this embodiment, the frequency acquisition module 10 mainly includes a first operational amplifier U1. The non-inverting input terminal of the first operational amplifier U1 is the generator voltage signal input terminal, and the inverting input terminal of the first operational amplifier U1 is used to input a reference signal. A first resistor R1 is connected between the inverting input terminal and the output terminal of the first operational amplifier U1. A first capacitor C1 is connected in parallel with the first resistor R1. The output terminal of the first operational amplifier U1 is the frequency signal output terminal. The reference signal can be selected as half of the output voltage amplitude of the target excitation generator, which can effectively monitor the frequency of the output voltage.

[0032] To reduce the impact of DC interference on the subsequent frequency-to-voltage signal conversion, in this embodiment, a second resistor R2 and a second capacitor C2 are connected in series between the frequency signal output terminal of the frequency acquisition module 10 and the frequency signal input terminal of the frequency-to-voltage conversion module 20. A third resistor R3 is also connected in series between the frequency signal input terminal and ground, and a third capacitor C3 is connected in parallel with the third resistor R3.

[0033] To avoid the influence of speed oscillation on speed detection, in this embodiment, as follows: Figure 3 As shown, the comparison unit includes a hysteresis comparator 31 and a transistor Q1. The base of transistor Q1 is connected to the output of the hysteresis comparator 31, and the collector of transistor Q1 is connected to a standard voltage source (providing a logic high level, 5V in this embodiment, but the actual voltage can be selected according to the actual specifications of the decoder) through a pull-up resistor R6. The emitter of transistor Q1 is grounded, and the collector of transistor Q1 is the output of the comparison unit. Through comparison by the hysteresis comparator 31, the output state is maintained when the input signal reaches the lower limit of comparison but not the upper limit; when the input signal reaches the upper limit of comparison and fluctuations do not drop below the lower limit, the output remains in the flipped state. This prevents false triggering of the flip when the input signal fluctuates, avoiding output fluctuations caused by frequent switching of the excitation winding, and thus improving the output stability of the excitation generator.

[0034] When the speed voltage signal is less than the corresponding reference signal, the hysteresis comparator 31 outputs a high level, the transistor Q1 is turned on, the collector is pulled down to ground potential, and the output logic of the comparator unit is 0; when the speed voltage signal is greater than the corresponding reference signal, the output logic of the comparator unit is 1.

[0035] To improve the control stability of transistor Q1, in this embodiment, a Zener diode D1 is connected in series between the output of the hysteresis comparator 31 and the base of transistor Q1, which can improve the standardization of its base drive voltage and ensure the reliability of switch control.

[0036] The reference signal is typically provided by a bandgap reference circuit or a voltage regulator circuit to ensure its stability. To reduce the cost of the bandgap reference circuit and meet the different reference signal requirements of different comparison units, in this embodiment, the reference signal is multiplexed. Simultaneously, a fourth resistor R4, a fourth capacitor C4, and a variable resistor R5 are provided between the reference signal input terminal of the hysteresis comparator 31 and the reference signal source. The fourth resistor R4 and the variable resistor R5 are connected in series between the reference signal source and ground. The movable end of the variable resistor R5 is connected to the reference signal input terminal of the hysteresis comparator 31, and the fourth capacitor C4 is connected in parallel across the variable resistor R5. The three comparison units can adjust the corresponding resistance value of the variable resistor R5 according to their specific needs to meet the different comparison requirements of the three comparison units.

[0037] To facilitate the standardization of control signals, the three outputs of the decoder are each connected to a standard voltage source via a resistor, serving as a voltage reference for the logic high level of the control signals.

[0038] The winding selection control module 40 of this invention provides three control signals that are respectively connected to the control terminals of the three activation controllers of the three sets of excitation windings of the target excitation generator. The activation controller is, for example, a control switch on the excitation current loop. Furthermore, the design focus of the control circuit based on the excitation generator in this application lies in the frequency acquisition module 10, the frequency-to-voltage conversion module 20, the speed segmentation module 30, and the winding selection control module 40. The structure of the target excitation generator and the activation controllers of the excitation windings are not particularly limited.

[0039] The control circuit based on the excitation generator provided by this utility model includes: a frequency acquisition module, a frequency-to-voltage conversion module, a speed segmentation module, and a winding selection control module connected in sequence. The frequency acquisition module acquires the frequency of the output voltage of the target excitation generator, which can accurately represent the speed of the target excitation generator. The frequency-to-voltage conversion module converts the frequency into a DC speed voltage signal. The speed voltage signal is compared with different reference signals by three comparison units of the speed segmentation module to distinguish the current speed range. When the current speed is in different speed ranges, the output signal combination of the three comparison units is different. The winding selection control module's decoder identifies and converts the signals, providing three control signals corresponding to the current speed range at the decoder's three output terminals to control the three sets of excitation windings of the target excitation generator to be activated separately. This effectively realizes the separate activation control of the three sets of excitation windings of the target excitation generator without the need for high-cost analog-to-digital converters and digital signal processors, thus effectively reducing the control cost of the excitation generator.

[0040] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0041] The embodiments described above are merely illustrative of several specific implementations of this utility model, and while the descriptions are detailed, they should not be construed as limiting the scope of protection of this utility model. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the scope of protection of this utility model. Therefore, the scope of protection of this utility model patent should be determined by the appended claims.

Claims

1. A control circuit for an excitation generator, characterized by include: The frequency acquisition module, frequency-to-voltage conversion module, speed segmentation module, and winding selection control module are connected in sequence. The frequency acquisition module includes a generator voltage signal input terminal connected to the voltage output terminal of the target excitation generator, and the frequency signal output terminal of the frequency acquisition module is connected to the frequency signal input terminal of the frequency-to-voltage conversion module. The speed segmentation module includes three comparison units, and the input terminal of each comparison unit is connected to the speed voltage signal output terminal of the frequency to voltage conversion module. The winding selection control module includes a decoder. The output terminals of the three comparison units are respectively connected to the three input terminals of the decoder, and the three output terminals of the decoder are respectively connected to the control terminals of the three winding enable control switches of the target excitation generator.

2. The field-based generator control circuit of claim 1, wherein, The frequency acquisition module includes a first operational amplifier. The non-inverting input of the first operational amplifier is the input terminal of the generated voltage signal. The inverting input of the first operational amplifier is used to connect a reference signal. A first resistor is connected between the inverting input and the output terminal of the first operational amplifier. A first capacitor is connected in parallel with the first resistor. The output terminal of the first operational amplifier is the output terminal of the frequency signal.

3. The control circuit for an excitation generator according to claim 1 or 2, characterized by A second resistor and a second capacitor are connected in series between the frequency signal output terminal and the frequency signal input terminal. A third resistor is also connected in series between the frequency signal input terminal and ground. A third capacitor is also connected in parallel with the third resistor.

4. The field-based generator control circuit of claim 1, wherein, The comparison unit includes a hysteresis comparator and a transistor. The base of the transistor is connected to the output terminal of the hysteresis comparator, the collector of the transistor is connected to a standard voltage source through a pull-up resistor, the emitter of the transistor is grounded, and the collector of the transistor is the output terminal of the comparison unit.

5. The field-based generator control circuit of claim 4, wherein, A Zener diode is connected in series between the output of the hysteresis comparator and the base of the transistor.

6. The field-based generator control circuit of claim 4, wherein, A fourth resistor, a fourth capacitor, and a variable resistor are provided between the reference signal input terminal of the hysteresis comparator and the reference signal source. The fourth resistor and the variable resistor are connected in series between the reference signal source and ground. The movable terminal of the variable resistor is connected to the reference signal input terminal of the hysteresis comparator. The fourth capacitor is connected in parallel across the variable resistor.

7. The field-based generator control circuit of claim 1, wherein, The three outputs of the decoder are each connected to a standard voltage source via a resistor.

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