An absolutely self-excited generator

Abstract

The present invention belongs to the field of automotive AC generators, and in particular relates to an absolute self-excited generator. An absolute self-excited generator includes an AC generator, the rotor of which is driven to rotate by an engine, and is characterized in that it also includes a start indication circuit, a detector, and a regulator. The negative pole of the start indication circuit is grounded and the positive pole is connected to the output end of the AC generator. The detector detects and obtains the current rotor speed signal of the rotor and sends it to the regulator; the regulator receives the current rotor speed signal, opens the self-excited circuit when the current rotor speed reaches the self-excited speed value, and outputs a stable excitation current to the rotor. Only the B+ line needs to be connected, and there is no need to consider the impact of external circuit design and the quality of the wiring itself on the generator, which facilitates the downstream assembly process and solves the matching problem with the outside.

Description

Technical Field

[0001] The invention belongs to the field of automobile alternating current generators, and in particular relates to an absolute self-excited generator. Background Art

[0002] The voltage buildup process of existing automotive AC generators requires external excitation when the voltage is below the battery voltage. Once the voltage reaches or exceeds the battery voltage, the generator switches to self-excitation. For this reason, the generator requires at least two wires. One is the B+ battery wire, through which the generator's electricity is used to power the vehicle's electrical appliances and charge the battery. This wire carries a high current and is thicker. The other is the L pre-excitation wire, which provides the generator with a pre-excitation current or voltage signal.

[0003] The B+ and L lines on existing automotive alternators must be connected, which can impact the alternator due to external wiring design and wiring quality issues. In particular, the L line's connection to the charging indicator light on the instrument panel can provide varying pre-excitation current and voltage levels to the alternator, depending on the indicator's specifications and the instrument panel's wiring characteristics. This can lead to uncertainty in the generator's initial speed, and often compatibility issues between the alternator and the vehicle's instrument panel. Furthermore, since automotive parts and components are sourced from different suppliers during vehicle assembly, the degree of compatibility between these parts can impact the overall assembly process and quality. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a generator that is only connected to the B+ line and nothing else, so that after detecting the corresponding rotor signal, the regulator is turned on to control the generator to perform absolute self-excited power generation.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] An absolute self-excited generator includes an AC generator, the rotor of which is driven to rotate by an engine. It is characterized in that it also includes a start indication circuit, a detector and a regulator. The negative pole of the start indication circuit is grounded and the positive pole is connected to the output end of the AC generator. The detector detects and obtains the current rotor speed signal of the rotor and sends it to the regulator; the regulator receives the current rotor speed signal, opens the self-excitation circuit when the current rotor speed reaches the self-excitation speed value, and outputs a stable excitation current to the rotor.

[0007] Preferably, the detector is an active sensor for detecting the rotational speed of the rotor, including a Hall sensor and an optical speed sensor.

[0008] Preferably, the detector is connected to the battery or the control circuit.

[0009] Preferably, the power consumption of the detector does not exceed the leakage current requirement of the automobile generator.

[0010] Preferably, the detector is a passive detection device for detecting the rotor speed.

[0011] Preferably, the detector is a magnetoelectric sensor, which includes a moving coil magnetoelectric sensor or a magnetoresistive magnetoelectric sensor, and a detection protrusion is provided on the rotating shaft of the rotor relative to the moving coil magnetoelectric sensor or the magnetoresistive magnetoelectric sensor.

[0012] Preferably, the detector is a miniature permanent magnet induction generator, which is arranged inside the AC generator. The induction coil of the miniature permanent magnet induction generator and the permanent magnet embedded in the rotor cut the magnetic lines to generate an induction signal, and the output end of the miniature permanent magnet induction generator is connected to the generator speed detection signal unit of the regulator.

[0013] Preferably, the regulator is a computer-controlled regulator, comprising the generator speed signal detection unit, a judgment unit, a switch unit and a regulation output unit;

[0014] The generator speed signal detection unit is configured to receive the current rotor speed signal;

[0015] The judgment unit is configured to judge whether the speed value of the current rotor speed signal is greater than or equal to the self-excitation speed value, and if so, to generate a self-excitation control signal to control the switch unit to open the self-excitation circuit and output an excitation current to the rotor; if not, to control the switch unit to remain in a closed state and to send a control signal to the generator speed detection unit;

[0016] The switch unit is used to open the self-excitation circuit to perform absolute self-excitation power generation;

[0017] The regulating output unit is used to deliver the excitation current to the rotor.

[0018] Preferably, when the judgment unit further includes a re-judgment subunit, when the speed value of the current rotor speed signal is inconsistent with the self-excitation speed value, it is used to judge whether the speed value of the current rotor speed signal is less than the self-excitation speed value. If the judgment result is yes, a detection frequency acceleration signal is sent to the generator speed detection unit to speed up the acquisition of the current rotor speed signal; if the judgment result is no, a detection frequency stop signal is sent to the generator speed detection signal unit to no longer acquire the current rotor speed signal until the current rotor speed signal is acquired again after the engine is shut down.

[0019] Preferably, the control signal includes the accelerated detection frequency signal and the stopped detection frequency signal.

[0020] By implementing the above technical solution, the present invention has the following advantages:

[0021] The present invention integrates a detector between the rotor and the regulator. This detector detects rotor information and compares it with the preset self-excitation value in the regulator. Once the required value is met, the generator's self-excitation circuit is immediately activated, entering self-excitation power generation mode. Simply connecting the B+ line eliminates the need to consider external wiring design and wiring quality issues that could affect the generator, facilitating downstream assembly and eliminating external compatibility issues. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a block diagram of a generator in parallel excitation under the existing technology.

[0023] Figure 2 This is the excitation circuit diagram of the existing automobile AC generator.

[0024] Figure 3 This is the block diagram of the generator in this application under absolute self-excitation conditions.

[0025] Figure 4 This is the excitation circuit diagram of the generator in this application under absolute self-excitation conditions.

[0026] Figure 5 This is a block diagram of the regulator in this application.

[0027] Figure 6 This is a block diagram of the judgment unit in this application. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to specific examples and experimental data. It should be understood that the embodiments of the present invention are intended only to illustrate the present invention and not to limit the present invention. Various substitutions and modifications made according to common technical knowledge and customary means in the art without departing from the technical concept of the present invention are intended to be included within the scope of the present invention.

[0029] like Figure 1The figure shows a block diagram of a conventional generator in parallel excitation. Existing generator 1' requires external pre-excitation. The excitation process is as follows: ignition switch on → charging indicator 2' illuminates → generator 1' receives a pre-excitation current or voltage signal → engine 1' starts → generator 1' rotor rotates to a certain speed and generates electricity → voltage at terminal L' establishes, charging indicator 2' turns off → generator switches to self-excitation. However, since most manufacturers collaborate with upstream and downstream suppliers, generator manufacturers do not consider the selection and production of the charging indicator 2' circuit. For example, if the L line is connected to the charging indicator circuit of an external instrument, different pre-excitation current strengths or voltage types will be provided to the generator depending on the indicator's specifications and the characteristics of the instrument circuit. This can lead to uncertainty in the initial generating speed of generator 1', which in turn can cause problems in matching generator 1' with the vehicle's instrument cluster.

[0030] like Figure 2 The figure shows the excitation circuit diagram of a conventional automotive AC generator, including a charging indicator light 2', rotor 11', rectifier bridge 12', stator 13', regulator 6', battery 4', and ignition switch 3'. The single arrow represents the self-excitation circuit, while the double arrow represents the pre-excitation (external excitation) circuit. It also shows that the excitation circuit after starting is affected by the charging indicator light 2'. For example, if the voltage of the charging indicator light 2' is too low, after self-excitation, the voltage across the charging indicator light 2' will not balance due to the low voltage of the charging indicator light 2' itself, and the light will continue to be turned off, causing leakage. National standards have strict requirements for leakage current in automotive alternators, and excessive leakage current can cause serious safety issues. Example 1

[0031] like Figure 3-Figure 4 As shown, an absolute self-excited generator includes an AC generator 1, whose output unit B+ is connected to a battery 4 and an onboard electrical appliance 5. The AC generator's rotor 11 is controlled by the engine and rotates in conjunction with the engine. The AC generator also includes a detector 7 and a regulator 6. The negative electrode of a start-up indication circuit is grounded, and the positive electrode is connected to the output terminal of the AC generator. Through the cooperation of the detector 7 and the regulator 6, the regulator 6 determines the current rotor speed received. When the current rotor speed reaches the self-excitation speed value, the self-excitation circuit is activated and excitation current is output to the rotor, causing the AC generator 1 to enter a self-excitation state and continuously generate electricity. Figure 4 The single arrow in the figure represents the absolute self-excitation circuit of the AC generator 1. No pre-excitation is required during the process, and no pre-excitation current is required. This reduces the need for the AC generator in traditional technology to connect the L line of the external pre-excitation current. It only needs to connect the B+ line at the output end, and connect to the battery and on-board electrical appliances through the B+ line.

[0032] The detector 7 detects and obtains the current rotor speed signal of the rotor and transmits it to the regulator 6. Upon receiving the current rotor speed signal, the regulator 6 activates the self-excitation circuit when the current rotor speed reaches the self-excitation speed value, thereby stabilizing the rotor in its current rotational state. During this process, the regulator 6 receives the current rotor speed signal, determines the current rotor speed, and controls the switch unit to activate the self-excitation circuit for absolute self-excitation power generation when it determines that the current rotor speed has reached the self-excitation speed value.

[0033] The detector 7 is connected to the generator phase signal detecting unit of the regulator 6 and is an active sensor for detecting the rotation speed of the rotor, including a Hall sensor and an optical speed sensor.

[0034] Since the Hall effect sensor and optical speed sensor require electricity during operation, they can be directly connected to the battery 4 and powered by the battery 4, provided that the leakage current requirement of the vehicle generator is not exceeded. The power consumption of the detector should not exceed the leakage current requirement of the vehicle generator. When used on vehicles without a main power switch or other types of construction machinery, the leakage current standard for vehicle generators, such as JB / T 6710-2006, must be considered.

[0035] In addition, when the car has a main power switch or is used on other types of engineering machinery, the leakage problem caused by the Hall sensor and optical speed sensor requiring electricity when working (when the car is not started) can be ignored.

[0036] In this application, the applicant, drawing on actual production experience, proposes an improvement to the generator's requirement for simultaneous connection to both the B+ and L lines. By adding a detector 7 between the rotor 11 and the regulator 6, the detector 7 detects rotor information and compares it with the preset self-excitation value preset in the regulator 6. Once the required value is met, the self-excitation circuit of the AC generator 1 is immediately activated, entering self-excitation power generation mode. Simply connecting the B+ line eliminates the need to consider the impact of external circuit design and wiring quality issues on the generator, facilitating downstream assembly and resolving external matching issues.

[0037] On the other hand, the start-up condition of the regulator can be freely set without considering the influence of other external circuits. As long as the self-excitation regulation is achieved, the self-excitation circuit can be turned on to perform absolute self-excitation power generation. Example 2

[0038] Based on Example 1, the difference from Example 1 is that:

[0039] The detector 7 is a passive detection device for detecting the rotor speed.

[0040] The detector 7 is a magnetoelectric sensor, which includes a moving coil magnetoelectric sensor or a magnetoresistive magnetoelectric sensor. A detection protrusion is provided on the rotating shaft of the rotor relative to the moving coil magnetoelectric sensor or the magnetoresistive magnetoelectric sensor.

[0041] A magnetoelectric speed sensor consists of an iron core, a magnet, and an induction coil. When the object being measured rotates, the sensor's coil generates magnetic lines of force, which are then cut by the rotating gears. Due to the change in magnetic resistance, the magnetic circuit generates an electromotive force within the induction coil. A moving-coil magnetoelectric sensor, in which the center coil is the moving component, is essentially a speed sensor capable of directly measuring linear or angular velocity. A magnetoresistive sensor operates based on the magnetoresistive effect. Its core consists of a piece of permanent magnetic metal material whose resistance changes with the external magnetic field. This change in the external magnetic field is used to measure changes in the object's condition. Magnetoresistive sensors offer high precision, high sensitivity, high resolution, excellent stability and reliability, non-contact measurement, and a wide temperature range, enabling both dynamic and static measurements. Example 3

[0042] Based on Example 1, the difference from Example 2 is that:

[0043] The detector 7 is a miniature permanent magnet induction generator, which is arranged inside the AC generator. The induction coil of the miniature permanent magnet induction generator and the permanent magnet embedded in the rotor cut the magnetic lines to generate an induction signal. The output end of the miniature permanent magnet induction generator is connected to the generator speed detection signal unit of the regulator.

[0044] The micro permanent magnet induction generator is placed in the magnetic field of the AC generator 1. The AC generator 1 generates an induced current through electromagnetic efficiency, which passes through the micro permanent magnet induction generator. The rotor in the micro permanent magnet induction generator rotates, generating its own induced current. The induced current is input into the regulator 6. When the induced current matches the preset induced current value in the regulator 6, the self-excitation circuit is opened. Since the induced current is proportional to the rotor speed, the induced current generated by the micro permanent magnet induction generator can be used to convert the current rotor speed of the rotor 11. The detection end of the micro permanent magnet induction generator is used to detect the current rotor speed of the rotor. The information transmitting end of the micro permanent magnet induction generator is connected to the generator speed detection signal unit of the regulator.

[0045] Furthermore, when the rotor 11 in the AC generator 1 is not driven to rotate by the engine, the micro permanent magnet induction generator does not work, so no power consumption is generated and no leakage problem is caused to the entire vehicle. Example 4

[0046] Based on Examples 1, 2, and 3, the differences from Examples 1, 2, and 3 are:

[0047] like Figure 5-Figure 6 As shown, the regulator is a computer-controlled regulator, including a regulating output unit, the generator speed detection signal unit, a judgment unit, and a switch unit;

[0048] The generator speed signal detecting unit is configured to receive the rotor speed signal. Furthermore, the generator speed signal detecting unit can proactively request the current rotor speed signal from the detector 7. The generator speed signal detecting unit can request the current rotor speed signal from the detector 7 at a frequency that is set initially or according to specific requirements in the control signal.

[0049] The judgment unit is configured to judge whether the speed value of the rotor speed signal is greater than or equal to the preset speed value, and if so, to generate a self-excitation control signal to control the switch unit to open the self-excitation circuit and output an excitation current to the rotor; if not, to control the switch unit to remain in a closed state and to send a control signal to the sensor;

[0050] The switch unit is used to open the self-excitation circuit after being triggered to control the rotor to stabilize in the current rotation state;

[0051] The regulating output unit is used to deliver the excitation current to the rotor.

[0052] When the judgment unit also includes a re-judgment subunit, when the speed value of the current rotor speed signal is inconsistent with the self-excitation speed value, it is judged whether the speed value of the current rotor speed signal is less than the self-excitation speed value. If the judgment result is yes, a detection frequency acceleration signal is sent to the generator speed signal detection unit to speed up the acquisition of the current rotor speed signal; if the judgment result is no, a detection frequency stop signal is sent to the generator speed detection unit, and the current rotor speed signal is no longer acquired until the current rotor speed signal is acquired again after the engine is shut down.

[0053] The control signal includes the accelerated detection frequency signal and the stopped detection frequency signal.

Claims

1. An absolute self-excited generator, comprising an AC generator, wherein the rotor of the AC generator is driven by an engine, characterized in that: The device further includes a start indication circuit, a detector, and a regulator. The negative electrode of the start indication circuit is grounded and the positive electrode is connected to the output terminal of the AC generator. The detector detects and obtains a current rotor speed signal of the rotor and sends it to the regulator. The regulator receives the current rotor speed signal and opens the self-excitation circuit and outputs an excitation current to the rotor when the current rotor speed reaches a self-excitation speed value. The detector is a passive detection device for detecting the rotor speed; The detector is a magnetoelectric sensor, which includes a moving coil magnetoelectric sensor or a magnetoresistive magnetoelectric sensor. The rotor shaft is provided with a detection protrusion opposite to the moving coil magnetoelectric sensor or the magnetoresistive magnetoelectric sensor. The output unit B+ of the AC generator is connected to the battery and the onboard electrical appliances, the rotor of the AC generator is controlled by the engine and rotates along with the engine, and further includes the detector and the regulator; The negative pole of the start indication circuit is grounded and the positive pole is connected to the output end of the AC generator. Through the cooperation of the detector and the regulator, the regulator determines the current rotor speed received. After the current rotor speed reaches the self-excitation speed value, the self-excitation circuit is opened and the excitation current is output to the rotor, so that the AC generator enters the self-excitation state and generates electricity continuously.

2. The absolute self-excited generator according to claim 1, characterized in that: The detector is a miniature permanent magnet induction generator, which is arranged inside the AC generator. The induction coil of the miniature permanent magnet induction generator and the permanent magnet embedded in the rotor cut the magnetic lines to generate an induction signal. The output end of the miniature permanent magnet induction generator is connected to the generator speed detection signal unit of the regulator.

3. The absolute self-excited generator according to claim 2, characterized in that: The regulator is a computer-controlled regulator, comprising a generator speed signal detection unit, a judgment unit, a switch unit and a regulation output unit; The generator speed signal detection unit is configured to receive the current rotor speed signal; The judgment unit is configured to judge whether the speed value of the current rotor speed signal is greater than or equal to the self-excitation speed value, and if so, to generate a self-excitation control signal to control the switch unit to open the self-excitation circuit and output an excitation current to the rotor; if not, to control the switch unit to remain in a closed state and to send a control signal to the generator speed signal detection unit; The switch unit is used to open the self-excitation circuit to perform absolute self-excitation power generation; The regulating output unit is used to deliver the excitation current to the rotor.

4. The absolute self-excited generator according to claim 3, characterized in that: When the judgment unit also includes a re-judgment subunit, when the speed value of the current rotor speed signal is inconsistent with the self-excitation speed value, it is judged whether the speed value of the current rotor speed signal is less than the self-excitation speed value. If the judgment result is yes, a speed-up detection frequency signal is sent to the generator speed signal detection unit to speed up the acquisition of the current rotor speed signal; if the judgment result is no, a stop detection frequency signal is sent to the generator speed signal detection unit, and the current rotor speed signal is no longer acquired until the current rotor speed signal is acquired again after the engine is shut down.

5. The absolute self-excited generator according to claim 4, characterized in that: The control signal includes the accelerated detection frequency signal and the stopped detection frequency signal.

Images