Generator circuit control system

Abstract

The invention discloses a generator circuit control system, which comprises a rectification filter circuit, a driving isolation circuit and a power amplification circuit, the rectification filter circuit and the driving isolation circuit are connected with the power amplification circuit, and the driving isolation circuit comprises two driving control circuits and can output positive excitation and negative excitation. According to the generator circuit control system provided by the invention, the excitation circuit is driven by using the two paths of PWM, positive excitation can be output, and negative excitation can also be output, so that the problem that the output voltage change range is too large when a large inertia load is suddenly loaded, especially suddenly unloaded, of an existing generator can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit control, and more specifically, to a generator circuit control system. Background Art

[0002] Currently, most of the existing generator digital voltage regulation technologies use a single-channel PWM (Pulse Width Modulation) drive to control the excitation circuit to output positive excitation to provide a positive current to the excitation winding, thereby achieving regulation and control of the power supply output voltage.

[0003] Although the above-mentioned existing digital voltage regulation technology can also adjust the output voltage in time when the generator is loaded or unloaded, it can only stabilize the output voltage by reducing the PWM duty cycle to zero so that the excitation current also becomes zero when unloading, especially when the load is large. This method can meet the transient index requirements for voltage regulation rate and recovery time when a small load is suddenly unloaded, but it cannot restore the output voltage to the rated target value in time when a large load is suddenly unloaded, thereby failing to meet the transient index requirements of voltage regulation. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention innovatively provides a generator circuit control system, which can solve the technical problem in the prior art that the voltage regulating system cannot adjust the voltage in time when a large load is suddenly unloaded.

[0005] To achieve the above technical objectives, the present invention discloses a generator circuit control system, comprising: a rectifier filter circuit, a drive isolation circuit and a power amplifier circuit, wherein the rectifier filter circuit and the drive isolation circuit are connected to the power amplifier circuit, wherein:

[0006] The drive isolation circuit includes two drive control circuits, which can output positive excitation and negative excitation.

[0007] Furthermore, the rectification and filtering circuit includes a three-phase rectifier bridge and an electrolytic capacitor, the three-phase rectifier bridge is used to connect the output end of the generator, the three-phase rectifier bridge is connected to the electrolytic capacitor, and the electrolytic capacitor is connected to the power amplifier circuit.

[0008] Furthermore, the power amplifier circuit includes a plurality of MOS transistors, wherein the positive electrode of the DC power output by the rectifying and filtering circuit is connected to the MOS transistor Q1 and the MOS transistor Q2, and the positive electrode of the DC power output by the rectifying and filtering circuit is connected to the drain electrodes of the MOS transistor Q1 and the MOS transistor Q2;

[0009] The negative electrode of the DC power output by the rectifying and filtering circuit is grounded and connected to the MOS transistor Q3 and the MOS transistor Q4. The negative electrode of the DC power output by the rectifying and filtering circuit is connected to the source electrodes of the MOS transistor Q3 and the MOS transistor Q4.

[0010] Furthermore, the source of the MOS transistor Q1 is connected to the drain of the MOS transistor Q3, and a positive output F+ of the excitation power is formed between the source of the MOS transistor Q1 and the drain of the MOS transistor Q3.

[0011] Furthermore, the source of the MOS transistor Q2 is connected to the drain of the MOS transistor Q4, and a negative electrode output F- of the excitation power is formed between the source of the MOS transistor Q2 and the drain of the MOS transistor Q4.

[0012] Furthermore, the drive isolation circuit includes a first drive control circuit, and the first drive control circuit includes a transistor Q5, an optical coupler D5 and a transistor Q6, wherein:

[0013] The base of the transistor Q5 is used to connect to the first signal source, the power source VCC1 is connected to the positive electrode of the light emitting diode of the optical coupler D5 via the resistor R1, the negative electrode of the light emitting diode of the optical coupler D5 is connected to the negative electrode of the transistor Q5, and the emitter of the transistor Q5 is grounded;

[0014] The power source VCC2 is connected to the collector of the phototransistor of the optocoupler D5, the emitter of the phototransistor of the optocoupler D5 is connected to the base of the transistor Q6, and is grounded through the resistor R2;

[0015] The power source VCC2 is also connected to the collector of the transistor Q6, and the emitter of the transistor Q6 is grounded via a resistor R3.

[0016] The emitter of the transistor Q6 is also connected to the gates of the MOS transistor Q1 and the MOS transistor Q4 of the power amplifier circuit.

[0017] Furthermore, the drive isolation circuit includes a second drive control circuit, and the second drive control circuit includes a transistor Q7, an optical coupler D6 and a transistor Q8, wherein:

[0018] The base of the transistor Q7 is used to connect to the first signal source, the power source VCC1 is connected to the positive electrode of the light emitting diode of the optical coupler D6 via the resistor R4, the negative electrode of the light emitting diode of the optical coupler D6 is connected to the negative electrode of the transistor Q7, and the emitter of the transistor Q7 is grounded;

[0019] The power source VCC2 is connected to the collector of the phototransistor of the optocoupler D6, the emitter of the phototransistor of the optocoupler D6 is connected to the base of the transistor Q8, and is grounded through the resistor R5;

[0020] The power source VCC2 is also connected to the collector of the transistor Q8, and the emitter of the transistor Q8 is grounded via a resistor R6.

[0021] The emitter of the transistor Q8 is also connected to the gates of the MOS transistors Q2 and Q3 of the power amplifier circuit.

[0022] The beneficial effects of the present invention are:

[0023] The generator circuit control system provided by the present invention utilizes a dual-channel PWM drive excitation circuit, which can output both positive excitation and negative excitation, thereby solving the problem of excessively large output voltage variation range of existing generators when a large inertia load is suddenly added or especially suddenly unloaded. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A structural block diagram of a generator circuit control system according to an embodiment of the present invention is shown;

[0025] Figure 2 A schematic diagram of a rectifier and filter circuit and a power amplifier circuit according to an embodiment of the present invention is shown;

[0026] Figure 3 A schematic diagram of a driving isolation circuit according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0027] The generator circuit control system provided by the present invention is explained and illustrated in detail below in conjunction with the accompanying drawings of the specification.

[0028] In the field of generator technology, digital voltage regulation is an important link in its operation that cannot be ignored. Its performance is directly related to whether the operation of the generator system is safe and stable, and also determines the generator's ability to recover the output voltage when it is unloaded or suddenly adds or removes a large inertia load. One of the most important links in digital voltage regulation technology is to provide real-time and reasonable excitation current to the excitation winding of the generator, thereby achieving the regulation and control of the power output, so that the generator output voltage is always kept at the target voltage.

[0029] The generator circuit control system provided by the present invention utilizes a dual-channel PWM drive excitation circuit, which can output both positive excitation and negative excitation, thereby solving the problem of excessively large output voltage variation range of existing generators when a large inertia load is suddenly added or especially suddenly unloaded.

[0030] In some embodiments, the present invention provides a generator circuit control system, such as Figure 1As shown, it includes: a rectifier and filter circuit, a drive isolation circuit and a power amplifier circuit, the rectifier and filter circuit and the drive isolation circuit are connected to the power amplifier circuit, wherein the drive isolation circuit includes two drive control circuits that can output positive excitation and negative excitation.

[0031] Rectification and filtering circuit: The three-phase AC voltage of the generator main output is used as input, which is converted into a DC voltage with large ripple after passing through a three-phase bridge rectifier, and then filtered by an electrolytic capacitor to become a relatively stable DC voltage as an excitation power supply for output;

[0032] Drive isolation circuit: takes the two PWM signals output by the CPU as input, and outputs them as drive signals after being isolated by optical couplers and driven and amplified;

[0033] Power amplifier circuit: The DC voltage output by the rectifier and filter circuit is used as the excitation power supply, and the PWM signal output by the PWM drive isolation circuit is used as the drive signal. After power conversion by four power MOS tubes connected in series and parallel, a regular forward (reverse) pulsating current is output to the excitation winding.

[0034] In some embodiments, Figure 2 As shown, the rectifier filter circuit includes a three-phase rectifier bridge and an electrolytic capacitor. The three-phase rectifier bridge is used to connect the output end of the generator, the three-phase rectifier bridge is connected to the electrolytic capacitor, and the electrolytic capacitor is connected to the power amplifier circuit. The three-phase AC voltage of the main output of the generator is used as input, and after passing through the three-phase rectifier bridge U1, it becomes a DC voltage with a large ripple, and then after filtering by the electrolytic capacitor C1, it becomes a relatively stable DC voltage as an excitation power supply for output. In this embodiment, the rectifier filter circuit adopts a three-phase rectifier bridge that can input high voltage and output large current, which can meet the requirements of large excitation current output; a high-voltage electrolytic capacitor is used for voltage filtering, so that it can output a relatively stable DC voltage as an excitation power supply input. Optionally, for the rectifier and filter circuit, the input voltage of the three-phase rectifier bridge selected must meet the withstand voltage requirements of the three-phase AC voltage of the main output of the generator, and its output current must also meet the requirements of the rated excitation current of the generator. For example, the rectifier bridge model is: SKBPC3516; the withstand voltage of the DC filter capacitor must also meet the withstand voltage requirements of the excitation power supply voltage after rectification by the rectifier bridge, for example, the filter capacitor model is: LS227M450O30RR0VH2SP0.

[0035] In some embodiments, Figure 2As shown, the power amplifier circuit includes a plurality of MOS transistors, wherein the positive electrode of the DC power output by the rectifying and filtering circuit is connected to the MOS transistor Q1 and the MOS transistor Q2, and the positive electrode of the DC power output by the rectifying and filtering circuit is connected to the drain electrodes of the MOS transistor Q1 and the MOS transistor Q2. In this embodiment, four MOS transistors are included, namely, the MOS transistor Q1, the MOS transistor Q2, the MOS transistor Q3 and the MOS transistor Q4, wherein the negative electrode of the DC power output by the rectifying and filtering circuit is grounded and connected to the MOS transistor Q3 and the MOS transistor Q4, and the negative electrode of the DC power output by the rectifying and filtering circuit is connected to the source electrodes of the MOS transistor Q3 and the MOS transistor Q4.

[0036] Optionally, the source of the MOS tube Q1 is connected to the drain of the MOS tube Q3, and a positive output F+ of the excitation power is formed between the source of the MOS tube Q1 and the drain of the MOS tube Q3; the source of the MOS tube Q2 is connected to the drain of the MOS tube Q4, and a negative output F- of the excitation power is formed between the source of the MOS tube Q2 and the drain of the MOS tube Q4. In this embodiment, four power MOS tubes connected in series and parallel are used to convert the excitation power supply so that it can output a forward or reverse pulsating current, thereby providing a DC excitation power input to the exciter. Optionally, the MOS tube must meet the withstand voltage requirements of the excitation power supply voltage after rectification by the rectifier bridge, and its continuous current must also meet the requirements of the rated excitation current of the generator. For example, the MOS tube model that can be selected is: STF26NM60N.

[0037] In some embodiments, Figure 3 As shown, the drive isolation circuit includes a first drive control circuit, which includes a transistor Q5, an optical coupler D5 and a transistor Q6, wherein the base of the transistor Q5 is used to connect to the first signal source, the power supply VCC1 is connected to the positive electrode of the light-emitting diode of the optical coupler D5 via a resistor R1, the negative electrode of the light-emitting diode of the optical coupler D5 is connected to the negative electrode of the transistor Q5, and the emitter of the transistor Q5 is grounded; the power supply VCC2 is connected to the collector of the photosensitive transistor of the optical coupler D5, the emitter of the photosensitive transistor of the optical coupler D5 is connected to the base of the transistor Q6, and is grounded through a resistor R2; the power supply VCC2 is also connected to the collector of the transistor Q6, the emitter of the transistor Q6 is grounded via a resistor R3, and the emitter of the transistor Q6 is also connected to the gates of the MOS transistors Q1 and Q4 of the power amplifier circuit.

[0038] When the PWM1A signal output by the CPU is at a high level, transistor Q5 is turned on, the light-emitting diode at the front end of the optocoupler is turned on and emits light, the photosensitive transistor at the rear end of the optocoupler is turned on, and transistor Q6 is turned on. At this time, the PWM1 signal output is also at a high level; when the PWM1A signal output by the CPU is at a low level, transistor Q5 is turned off, the light-emitting diode at the front end of the optocoupler D5 is turned off and does not emit light, the photosensitive transistor at the rear end of the optocoupler D5 is turned off, and transistor Q6 is turned off. At this time, the PWM1 signal output is also at a low level.

[0039] like Figure 3 As shown, the drive isolation circuit includes a second drive control circuit, and the second drive control circuit includes a transistor Q7, an optical coupler D6 and a transistor Q8, wherein the base of the transistor Q7 is used to connect to the first signal source, the power supply VCC1 is connected to the positive electrode of the light emitting diode of the optical coupler D6 via the resistor R4, the negative electrode of the light emitting diode of the optical coupler D6 is connected to the negative electrode of the transistor Q7, and the emitter of the transistor Q7 is grounded; the power supply VCC2 is connected to the collector of the photosensitive transistor of the optical coupler D6, the emitter of the photosensitive transistor of the optical coupler D6 is connected to the base of the transistor Q8, and is grounded through the resistor R5; the power supply VCC2 is also connected to the collector of the transistor Q8, the emitter of the transistor Q8 is grounded via the resistor R6, and the emitter of the transistor Q8 is also connected to the gates of the MOS transistors Q2 and Q3 of the power amplifier circuit. Optionally, the conduction characteristics of the optocoupler D5 (D6) should be good, that is, the delay time before and after should be small, and must meet the requirement of being less than the corresponding time of the PWM output frequency. For example, the optocoupler model is: PC817C.

[0040] When the PWM2A signal output by the CPU is at a high level, transistor Q7 is turned on, the light-emitting diode at the front end of the optocoupler D6 is turned on and emits light, the photosensitive transistor at the rear end of the optocoupler D6 is turned on, and the transistor Q8 is turned on. At this time, the PWM2 signal output is also at a high level; when the PWM2A signal output by the CPU is at a low level, transistor Q7 is turned off, the light-emitting diode at the front end of the optocoupler D6 is turned off and does not emit light, the photosensitive transistor at the rear end of the optocoupler D6 is turned off, and the transistor Q8 is turned off. At this time, the PWM2 signal output is also at a low level.

[0041] When PWM1 is at a high level and PWM2 is at a low level, MOS tubes Q1 and Q4 are turned on, and Q2 and Q3 are turned off. At this time, the excitation current flows from F+ to F-, and positive excitation is output; when PWM1 is at a low level and PWM2 is at a high level, MOS tubes Q2 and Q3 are turned on, and Q1 and Q4 are turned off. At this time, the excitation current flows from F- to F+, and negative excitation is output.

[0042] The method designed by the present invention for solving the problem of voltage overshoot caused by sudden load unloading of a generator is mainly used in the field of digital voltage regulation technology of generators. Its dynamic response speed and static stability must be high, so two PWM drives are cleverly used to control four power MOS tubes connected in series and parallel with each other. The excitation power supply can be converted into power according to different load conditions of the generator, so that it can output forward or reverse pulsating current to act on the exciter to offset the change of the output voltage of the generator being too low or too high when a large inertia load is suddenly added or unloaded.

[0043] The method designed by the present invention for solving the voltage overshoot caused by sudden load unloading of a generator has simple circuit design, fast dynamic response speed and strong practicality.

[0044] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0045] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the description of this specification, the description with reference to the terms "this embodiment", "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any at least one embodiment or example. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0047] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0048] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and simple improvements made to the essential contents of the present invention should be included in the protection scope of the present invention.

Claims

1. A generator circuit control system, characterized in that: include: A rectifier and filter circuit, a drive isolation circuit and a power amplifier circuit, wherein the rectifier and filter circuit and the drive isolation circuit are connected to the power amplifier circuit, wherein: The drive isolation circuit includes two drive control circuits, which can output positive excitation and negative excitation.

2. The generator circuit control system according to claim 1, characterized in that: The rectification and filtering circuit comprises a three-phase rectifier bridge and an electrolytic capacitor. The three-phase rectifier bridge is used to connect the output end of the generator. The three-phase rectifier bridge is connected to the electrolytic capacitor, and the electrolytic capacitor is connected to the power amplifier circuit.

3. The generator circuit control system according to claim 2, characterized in that: The power amplifier circuit includes a plurality of MOS transistors, wherein the positive electrode of the DC power output by the rectifying and filtering circuit is connected to the MOS transistor Q1 and the MOS transistor Q2, and the positive electrode of the DC power output by the rectifying and filtering circuit is connected to the drain electrodes of the MOS transistor Q1 and the MOS transistor Q2; The negative electrode of the DC power output by the rectifying and filtering circuit is grounded and connected to the MOS transistor Q3 and the MOS transistor Q4. The negative electrode of the DC power output by the rectifying and filtering circuit is connected to the source electrodes of the MOS transistor Q3 and the MOS transistor Q4.

4. The generator circuit control system according to claim 3, characterized in that: The source of the MOS transistor Q1 is connected to the drain of the MOS transistor Q3 , and a positive output F+ of the excitation power is formed between the source of the MOS transistor Q1 and the drain of the MOS transistor Q3 .

5. The generator circuit control system according to claim 4, characterized in that: The source of the MOS transistor Q2 is connected to the drain of the MOS transistor Q4, and a negative electrode output F- of the excitation power is formed between the source of the MOS transistor Q2 and the drain of the MOS transistor Q4.

6. The generator circuit control system according to claim 5, characterized in that: The drive isolation circuit includes a first drive control circuit, and the first drive control circuit includes a transistor Q5, an optical coupler D5 and a transistor Q6, wherein: The base of the transistor Q5 is used to connect to the first signal source, the power source VCC1 is connected to the positive electrode of the light emitting diode of the optical coupler D5 via the resistor R1, the negative electrode of the light emitting diode of the optical coupler D5 is connected to the negative electrode of the transistor Q5, and the emitter of the transistor Q5 is grounded; The power source VCC2 is connected to the collector of the phototransistor of the optocoupler D5, the emitter of the phototransistor of the optocoupler D5 is connected to the base of the transistor Q6, and is grounded through the resistor R2; The power source VCC2 is also connected to the collector of the transistor Q6, and the emitter of the transistor Q6 is grounded via a resistor R3. The emitter of the transistor Q6 is also connected to the gates of the MOS transistor Q1 and the MOS transistor Q4 of the power amplifier circuit.

7. The generator circuit control system according to claim 6, characterized in that: The drive isolation circuit includes a second drive control circuit, and the second drive control circuit includes a transistor Q7, an optical coupler D6 and a transistor Q8, wherein: The base of the transistor Q7 is used to connect to the first signal source, the power source VCC1 is connected to the positive electrode of the light emitting diode of the optical coupler D6 via the resistor R4, the negative electrode of the light emitting diode of the optical coupler D6 is connected to the negative electrode of the transistor Q7, and the emitter of the transistor Q7 is grounded; The power source VCC2 is connected to the collector of the phototransistor of the optocoupler D6, the emitter of the phototransistor of the optocoupler D6 is connected to the base of the transistor Q8, and is grounded through the resistor R5; The power source VCC2 is also connected to the collector of the transistor Q8, and the emitter of the transistor Q8 is grounded via a resistor R6. The emitter of the transistor Q8 is also connected to the gates of the MOS transistors Q2 and Q3 of the power amplifier circuit.

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