Engine power generation system and its control method

Abstract

This invention provides an engine-generator system and its control method. The control method includes acquiring the generator feedback speed and engine reference speed detected at the zero-crossing point or natural commutation point of the generator winding; obtaining a voltage regulation variable using a PID algorithm based on the generator feedback speed and the engine reference speed; adjusting the charging voltage based on the voltage regulation variable; determining the current generator torque based on the generator feedback current; obtaining a current regulation variable using a PID algorithm based on the current generator torque and the engine reference torque; adjusting the charging current based on the current regulation variable; acquiring the current charging / electricity demand and the generator feedback voltage; and adjusting the charging load based on the current charging / electricity demand and the generator feedback voltage.

Description

Technical Field

[0001] This invention relates to the field of engine power generation technology, and particularly to an engine power generation system and its control method. Background Technology

[0002] With social progress and increased public awareness of environmental protection and energy conservation, "low-carbon, environmentally friendly, and green" travel and lifestyles are gradually attracting significant attention. Research into efficient, environmentally friendly, and energy-saving engine power generation has garnered considerable interest from manufacturers worldwide.

[0003] In traditional engine-generator systems, the engine and generator are relatively isolated from each other. The engine is usually set to one or a few fixed speeds, which is not well matched with torque and generator feedback. Summary of the Invention

[0004] To address the existing technical problems, this invention provides an engine power generation system capable of coordinating efficient and energy-saving control of the generator and engine.

[0005] To achieve the above objectives, the technical solution of this invention is implemented as follows:

[0006] An engine power generation control method, comprising:

[0007] The generator feedback speed and engine reference speed are detected at the zero-crossing point or natural commutation point of the generator winding. The voltage regulation variable is obtained by using a PID algorithm based on the generator feedback speed and the engine reference speed. The charging / consumption voltage is adjusted according to the voltage regulation variable.

[0008] The current torque of the generator is determined based on the generator feedback current. A PID algorithm is used to obtain the current adjustment variable based on the current torque of the generator and the engine reference torque. The charging / consumption current is adjusted based on the current adjustment variable.

[0009] Obtain the current charging / power demand and generator feedback voltage, and adjust the charging load according to the current charging / power demand and generator feedback voltage.

[0010] The method further includes:

[0011] Based on the current charging / electricity demand and engine speed, the generator voltage is adjusted, and voltage boosting or bucking is performed as needed.

[0012] The method further includes:

[0013] The generator feedback current is obtained by acquiring the phase current of the generator winding and the current charging current detected by the current detection circuit, and the generator feedback current is obtained based on the phase current and the current charging current.

[0014] The method further includes:

[0015] Based on the engine's constant fuel consumption curve, determine the engine reference speed and engine reference torque under optimal fuel consumption, and use the engine reference speed and engine reference torque as reference target values ​​for control.

[0016] The method further includes:

[0017] Based on the current charging / electricity demand, the starter motor and fuel pump of the engine are controlled to start and stop. The processor in the generator system is connected to the starter motor, throttle, and fuel pump of the engine via control lines.

[0018] The engine power generation control method provided in the above embodiments adjusts the charging voltage and current of the generator and the charging load by comprehensively considering the engine reference speed and engine reference torque, current charging / electricity demand, and intelligently adjusting and adapting the engine speed and torque so that the engine can keep working in the optimal fuel consumption range. In this way, by coordinating the engine and generator to fully meet the charging electricity demand, the goal of high efficiency and energy saving control is achieved.

[0019] An engine-generator system includes an engine, a generator system connected to the engine, and a battery management system connected to the generator system. The generator system includes a generator connected to the engine via a connecting shaft, a processor, a rectifier circuit connected between the processor and generator windings, a voltage feedback circuit and a current detection circuit connected between the rectifier circuit and the processor. The rectifier circuit includes an upper bridge arm circuit and a lower bridge arm circuit corresponding to each of the generator windings. The upper bridge arm circuit is a chopper circuit, and the lower bridge arm circuit is a switching circuit connected between the processor and the chopper circuit. The chopper circuit includes upper bridge elements corresponding to each of the generator windings, and the switching circuit includes lower bridge elements connected to the upper bridge elements. The upper bridge elements are silicon controlled rectifiers (SCRs) or field-effect transistors (FETs), and the lower bridge elements are FETs, diodes, or SCRs.

[0020] The generator's rotor is a pure permanent magnet rotor, and its stator is a single winding.

[0021] The generator operates in either a power generation mode or an electric mode. In the electric mode, the generator is used to start the engine or assist the axle.

[0022] The generator system further includes a current regulator or load regulator connected between the processor and the battery management system.

[0023] Wherein, the generator is a three-phase generator, and the chopper circuit includes a first thyristor, a second thyristor, and a third thyristor respectively connected to the A-phase coil, B-phase coil, and C-phase coil of the three-phase generator winding; or, the chopper circuit includes a single field-effect transistor or two field-effect transistors connected in reverse series to the A-phase coil, B-phase coil, and C-phase coil of the three-phase generator winding respectively.

[0024] The switching circuit includes a first switch, a second switch, and a third switch that are respectively connected to the first thyristor, the second thyristor, and the third thyristor. The processor is connected to the first switch, the second switch, and the third switch through a switch driving circuit. The first switch, the second switch, and the third switch are all field-effect transistors.

[0025] The engine-generator system provided in the above embodiment includes an engine, a generator system connected to the engine, and a battery management system connected to the generator system. The engine is connected to the generator via a coupling. The generator system obtains the charging power demand in real time through the battery management system. The rectifier circuit includes upper bridge arm circuits and lower bridge arm circuits connected to each phase of the generator winding. By setting the switching circuit in the lower bridge arm of each phase winding, the conduction or disconnection of the branch formed by the chopper circuit and the switching circuit can be adjusted accordingly. The on / off time of the thyristor and the switching circuit can be adjusted to adjust the current output current and the current rectified voltage, so that the generator system can coordinate the engine and the generator to fully meet the charging power demand, achieving the purpose of high efficiency and energy saving control. Attached Figure Description

[0026] Figure 1 This is a logic block diagram of an engine power generation system in one embodiment;

[0027] Figure 2 A schematic diagram of an engine-generator system provided in one embodiment;

[0028] Figure 3 This is a schematic diagram of a generator system in one embodiment;

[0029] Figure 4 This is a schematic diagram of the generator system in another embodiment;

[0030] Figure 5 This is a flowchart of an engine power generation control method in one embodiment;

[0031] Figure 6 This is a logic diagram of a generator power generation control method in one embodiment;

[0032] Figure 7 This is a schematic diagram of the universal characteristics of the constant fuel consumption rate line used to adjust the engine in one embodiment.

[0033] Figure 8 This is a graph showing the overall efficiency of the system. Detailed Implementation

[0034] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] 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 in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to limit the ways in which the invention may be implemented. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0036] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] Please see Figure 1 and Figure 2The engine-generator system includes an engine 20, a generator system connected to the engine 20, and a battery management system 30 connected to the generator system. The generator system includes a generator 10 connected to the engine 20 via a coupling, a processor 12, a rectifier circuit connected between the processor 12 and the generator windings, a voltage feedback circuit 14 and a current detection circuit 13 connected between the rectifier circuit and the processor 12. The rectifier circuit includes an upper bridge arm circuit and a lower bridge arm circuit connected to each corresponding part of the generator windings. The upper bridge arm circuit is a chopper circuit 15, and the lower bridge arm circuit is a switching circuit 16 connected between the processor 12 and the chopper circuit 15. The chopper circuit 15 includes upper bridge elements connected to each corresponding part of the generator windings, and the switching circuit 16 includes lower bridge elements connected to the upper bridge elements. The upper bridge elements are thyristors or field-effect transistors, and the lower bridge elements are field-effect transistors, diodes, or thyristors.

[0039] In the above embodiment, the engine 20 is connected to the generator 10 via a coupling. The generator system obtains the charging power demand in real time through the battery management system 30. The rectifier circuit includes upper and lower bridge arm circuits connected to each corresponding phase of the generator winding. By setting the switch circuit 16 in the lower bridge arm of each phase winding, the conduction or disconnection of the branch formed by the chopper circuit 15 and the switch circuit 16 can be adjusted accordingly. The on / off time of the thyristor and the switch circuit 16 can be adjusted to adjust the current output current and the current rectified voltage, so that the generator system can coordinate the engine 20 and the generator 10 to fully meet the charging power demand, achieving the purpose of high efficiency and energy saving control. Secondly, by setting the switch circuit 16 in the lower bridge arm of each phase winding, the opening or closing of the switch circuit 16 can adjust the conduction or disconnection of the branch formed by the chopper circuit 15 and the switch circuit 16 accordingly, thereby reducing the losses caused by voltage drop in the chopper circuit 15 and the switch circuit 16 during the positive and negative half-cycles of each phase current.

[0040] In this embodiment, the lower bridge element in the switching circuit 16 is preferably a field-effect transistor (FET). Compared with a diode, using a FET can reduce the on-state voltage drop and improve power generation efficiency.

[0041] The generator 10 is a three-phase generator. The chopper circuit 15 includes a first thyristor SCR1, a second thyristor SCR2, and a third thyristor SCR3, respectively connected to the A-phase coil, B-phase coil, and C-phase coil of the three-phase generator windings. The switching circuit 16 includes a first switch, a second switch, and a third switch, respectively connected to the first thyristor SCR1, the second thyristor SCR2, and the third thyristor SCR3. The processor 12 is connected to the first switch, the second switch, and the third switch via a switch drive circuit. The first switch, the second switch, and the third switch are all field-effect transistors. The processor 12 includes multiple input / output terminals. The switching circuit 16 is connected between the input / output terminals of the processor 12 and the chopper circuit 15. For ease of description and distinction, the multiple input / output terminals connected to the processor 12 and the switching circuit 16 are respectively labeled as the seventh input / output terminal I / O7, the eighth input / output terminal I / O8, and the ninth input / output terminal I / O9. The first switch is connected between the seventh input / output terminal I / O7 and the first thyristor SCR1; the second switch is connected between the eighth input / output terminal I / O8 and the second thyristor SCR2; and the third switch is connected between the ninth input / output terminal I / O9 and the third thyristor SCR3. When the processor 12 detects that the phase voltage of the generator winding is in the positive half-cycle of a sine wave through the commutation detection circuit 17, the processor 12 outputs a chopping control signal to regulate the voltage by switching the thyristor on the corresponding upper bridge arm. When the processor 12 detects that the phase voltage is at the commutation point through the commutation detection circuit 17, it outputs drive signals through the first, second, and third input / output terminals respectively to open the switch of the corresponding lower bridge arm. The branch formed by the thyristor and the corresponding switch is then connected, thereby reducing the loss caused by voltage drop and improving rectification efficiency. In some embodiments, the chopper circuit 15 includes a single field-effect transistor connected to the A-phase coil, B-phase coil, and C-phase coil of the three-phase generator winding, respectively; or the chopper circuit 15 includes field-effect transistors connected in reverse series to the A-phase coil, B-phase coil, and C-phase coil of the three-phase generator winding, respectively.

[0042] In another alternative embodiment, please refer to Figure 3The first switch includes a first field-effect transistor Q1 and a second field-effect transistor Q2 connected in parallel; the second switch includes a third field-effect transistor Q3 and a fourth field-effect transistor Q4 connected in parallel; and the third switch includes a fifth field-effect transistor Q5 and a sixth field-effect transistor Q6 connected in parallel. The use of multiple field-effect transistors connected in parallel with each corresponding switch in the lower bridge arm circuit significantly increases the on-state current when the field-effect transistors are turned on, thereby further reducing losses and improving rectification efficiency. The processor 12 includes multiple feedback terminals. For ease of description and differentiation, the feedback terminal connected to the voltage feedback circuit 14 is designated as the first feedback terminal AD1, and the feedback terminal connected to the current detection circuit 13 is designated as the second feedback terminal AD2. The processor 12 can detect the current output of the rectifier circuit in real time through the current detection circuit 13 and the current output voltage of the rectifier circuit in real time through the voltage feedback circuit 14. When the commutation detection circuit 17 detects that the phase voltage is in the positive half-cycle of the sine wave, it outputs a matching chopper control signal to the thyristor of the corresponding phase upper bridge arm for voltage regulation based on the voltage feedback of the rectifier output and the current detection value of the output.

[0043] Optionally, the commutation detection circuit 17 includes multiple circuits, each corresponding to one phase of the generator winding. The processor 12 includes multiple input / output terminals, and the commutation detection circuit 17 is connected between the input / output terminals of the processor 12 and the generator winding. For ease of description and distinction, the multiple input / output terminals connected to the chopper drive circuit are labeled as the seventh input / output terminal, the eighth input / output terminal, and the ninth input / output terminal. The commutation detection circuit 17 includes a first input / output terminal I / O1, a second input / output terminal I / O2, and a third input / output terminal I / O3 connected to the processor 12, and connected to Hall sensors or windings A, B, and C. By setting up commutation detection circuits 17 that correspond one-to-one with each phase, the commutation point and positive / negative half-cycles of each phase can be independently detected and judged, improving control accuracy.

[0044] Optionally, the generator system further includes a chopper drive circuit connected between the processor 12 and the chopper circuit 15. The processor 12 outputs a PWM chopper control signal to the chopper drive circuit, which controls the switching of the thyristors on each phase upper bridge arm. The processor 12 includes multiple input / output terminals, and the chopper drive circuit is connected between the input / output terminals of the processor 12 and the chopper circuit 15. For ease of description and distinction, the multiple input / output terminals connected to the chopper drive circuit are designated as the fourth input / output terminal I / O4, the fifth input / output terminal I / O5, and the sixth input / output terminal I / O6. Optionally, the rectifier circuit further includes a switch drive circuit connected between the processor 12 and each switch. The processor 12 outputs drive signals to the switch drive circuit through the seventh input / output terminal I / O7, the eighth input / output terminal I / O8, and the ninth input / output terminal I / O9, respectively, which controls the opening or closing of the switches on each phase lower bridge arm.

[0045] The rotor of generator 10 is a pure permanent magnet rotor. Magnets can be surface-mounted or embedded permanent magnets (IPMs). The stator is a single-winding unit, requiring no excitation, resulting in a simple and efficient structure. Optionally, the processor 12 in the generator system is connected to the starter motor, throttle, and fuel pump of engine 20 via control lines. The throttle can be linear, two-speed, or single-speed. Linear throttle refers to a throttle that changes linearly, achieved by an electronic governor, electronic throttle control, or adjustable electronic fuel injection. Two-speed throttle means the throttle only has idle and maximum speed settings, controlled by a solenoid valve. During start-up and shutdown, the throttle is in idle speed mode; as the throttle reaches maximum, the load is correspondingly adjusted to maximum to maintain optimal speed. Single-speed throttle means the throttle is always at maximum; after start-up, the load is correspondingly adjusted to maximum, and shutdown is achieved by stopping the fuel pump.

[0046] Optionally, the generator operates in either a power generation mode or an electric operation mode. In the electric operation mode, the generator is used to start the engine or assist the axle. The generator can switch between different operation modes to meet the needs of more application scenarios.

[0047] Optionally, the generator system further includes a current regulator or load regulator connected between the processor 12 and the battery management system 30. When the torque of the engine 20 exceeds the optimal torque of the engine 20, the current regulator can be a current limiter, and the generator system limits the current through the current limiter. The battery management system 30 is correspondingly connected to the battery array 11 and can determine the number of batteries connected according to the current charging / power consumption demand.

[0048] Optionally, the commutation detection circuit 17 can be a zero-crossing detection circuit, which detects the zero-crossing information of the phase voltages of the generator windings and determines the phase relationship of the voltages of the three-phase windings (A, B, and C) based on the detected zero-crossing information. Optionally, the commutation signal detected by the commutation detection circuit 17 can also be a natural commutation point signal, which refers to a position 30 degrees ahead of the zero-crossing position of the relative electromotive force. The commutation detection circuit 17 can use a Hall sensor (Hall element) for detection. For example, when the commutation signal is a zero-crossing signal, the commutation detection circuit 17 can use a Hall element installed at the zero-crossing position of the electromotive force in each phase winding; when the commutation signal is a natural commutation point signal, the commutation detection circuit 17 can use a Hall element installed 30 degrees before the zero-crossing position of the electromotive force. Optionally, the commutation detection circuit 17 can also use a voltage acquisition circuit to acquire the phase voltages of the three-phase windings, compare the phase voltages with the three-phase center point voltages to obtain the zero-crossing point or the natural commutation point.

[0049] Optionally, the generator system further includes a phase current detection circuit 13 connected in series with the lower bridge element of one phase of the generator winding. In this embodiment, the phase current detection circuit 13 includes a sampling resistor connected in series with the lower bridge element corresponding to the A-phase winding.

[0050] Please see Figure 4 Each bridge component can be two N-channel MOSFETs with opposite drain and source connections, providing boost and buck functions during power generation. When driving a motor, this circuit can be used for PWM speed control. In this case, Q4, Q5, and Q6 are continuously conducting, and speed control is achieved through the PWM control of six MOSFETs: A0, A', B0, B', C0, and C'.

[0051] Please see Figure 5 and Figure 6 In another aspect, this application also provides an engine power generation control method applied to a processor, the method comprising:

[0052] S101, acquire the generator feedback speed and engine reference speed detected at the zero-crossing point or natural commutation point of the generator winding, obtain the voltage regulation variable using a PID algorithm based on the generator feedback speed and the engine reference speed, and adjust the charging voltage or the voltage of the electricity used based on the voltage regulation variable.

[0053] Speed ​​feedback is obtained from the generator's zero-crossing or commutation detection. Speed ​​control can be based on PID processing of the reference speed and feedback speed, and the output voltage regulation variable is adjusted accordingly.

[0054] S103, determine the current torque of the generator based on the generator feedback current, obtain the current adjustment variable using a PID algorithm based on the current torque of the generator and the reference torque of the engine, and adjust the charging current or the current used for electricity according to the current adjustment variable.

[0055] In this method, the generator's torque and current are essentially proportional. Optionally, the method further includes: acquiring the phase current of the generator windings and the current charging current detected by the current detection circuit; and obtaining the generator feedback current based on the phase current and the current charging current. Thus, the current feedback is derived from the charging current and the phase current, and acquiring the phase current allows for more accurate torque calculation. Stabilizing the current further stabilizes the engine speed, resulting in more stable speed compared to adjusting the throttle alone, reducing fuel consumption, vibration and noise, and improving emissions.

[0056] S105, obtain the current charging / power consumption demand and the generator feedback voltage, and adjust the charging load according to the current charging / power consumption demand and the generator feedback voltage.

[0057] The processor can interact with the battery management system to switch the number and combination of battery arrays to be charged, thereby adjusting the charging load accordingly. Charging the battery arrays in batches results in a smaller charging load, while charging them simultaneously results in a larger charging load. By adjusting the number of battery packs being charged, the impedance and current of the charging circuit will also change accordingly.

[0058] The engine power generation control method provided in the above embodiments adjusts the generator's charging voltage and current, the voltage or current of the electricity used, and the charging load by comprehensively considering the engine's reference speed and torque, current charging / electricity demand, and intelligently adjusting and adapting the engine's speed and torque. This allows the engine to maintain operation within the optimal fuel consumption range. Thus, by coordinating the engine and generator to fully meet the charging and electricity demand, the method achieves efficient and energy-saving control. Furthermore, by coordinating the torque of the engine and generator, the engine's speed and torque are kept within the optimal fuel consumption range with minimal fluctuations, thus fully meeting the requirements.

[0059] The generator and control circuit can be integrated, resulting in high efficiency and high power density. Optionally, the method further includes: adjusting the generator voltage according to the current charging / electricity demand and engine speed, performing voltage boosting or bucking as needed. Adjusting the generator voltage based on the current charging / electricity demand and engine speed ensures appropriate adjustment of the charging voltage and keeps it within an optimal range. By adjusting the charging voltage, the charging current and the phase current of the generator windings can be changed accordingly.

[0060] Optionally, the method further includes: adjusting the output voltage by boosting or bucking it; boosting the voltage through PWM chopping of the lower bridge MOSFET at very low speeds; and bucking the voltage by controlling the conduction angle of the upper bridge thyristor when the electromotive force is too high. This ensures good power output over a wide speed range.

[0061] Optionally, the method further includes: determining the engine reference speed and engine reference torque at optimal fuel consumption based on the engine's constant fuel consumption curve, and using the engine reference speed and engine reference torque as reference target values ​​for control. Please refer to [link to relevant documentation]. Figure 7 To adjust the engine, a universal characteristic diagram of the constant fuel consumption curve is used. The most efficient constant fuel consumption line of 0.27 L / kWh is determined from the constant fuel consumption curve diagram, representing the optimal fuel consumption. The engine speed and torque are then adjusted within or around this constant fuel consumption line. The corresponding engine reference speed and engine reference torque can be obtained from the optimal fuel consumption region determined by the most efficient constant fuel consumption line.

[0062] By weighting the charging demand and optimal fuel consumption, the optimal torque can be obtained. Factors considered include: meeting charging needs promptly, protecting the battery (avoiding both over-discharging and over-charging), maintaining engine torque and speed within the optimal fuel consumption range, and stabilizing engine speed, charging current, and voltage as much as possible.

[0063] When the demand for charging increases or decreases, adjust the engine speed and torque to the optimal range, either at the maximum or minimum power level.

[0064] Optionally, the method further includes: controlling the starter motor and fuel pump of the engine to start and stop according to the current charging / electricity demand. The processor in the generator system is connected to the engine's starter motor, throttle, and fuel pump via control lines. By coordinating the control of the engine's starter motor and fuel pump, and automatically starting and stopping according to charging / electricity demand, the fuel supply system can be simplified. It can eliminate the need for electronically controlled throttle, electronic fuel injection, and electronically controlled fuel pumps, requiring only a simple throttle valve or mechanical pump. When the engine uses electronically controlled variable throttle, the optimal fuel consumption operating range can be expanded.

[0065] Optionally, the method further includes: combining the engine's fuel consumption efficiency curve and the generator's efficiency curve to obtain the overall system efficiency curve, and adjusting the torque and speed accordingly to ensure that the engine and generator operate within the system's maximum efficiency range. (See also...) Figure 8 .

[0066] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An engine power generation control method, characterized in that, A processor applied to an engine-generator system, wherein a rectifier circuit is connected between the processor and the generator windings; a current regulator or load regulator is connected between the rectifier circuit and the load; the method includes: The generator feedback speed and engine reference speed detected at the zero-crossing point or natural commutation point of the generator winding are obtained. A PID algorithm is used to obtain a voltage regulation variable based on the generator feedback speed and the engine reference speed. The charging voltage or the voltage of the electricity used is adjusted according to the voltage regulation variable. The voltage regulation is achieved through the rectifier circuit. The current torque of the generator is determined based on the generator feedback current. A PID algorithm is used to obtain the current adjustment variable based on the current generator torque and the engine reference torque. The charging current or the current used is adjusted based on the current adjustment variable. The current adjustment is achieved through the current regulator or load regulator. Obtain the current charging / power demand and generator feedback voltage, and adjust the charging load according to the current charging / power demand and generator feedback voltage.

2. The engine power generation control method as described in claim 1, characterized in that, The method further includes: Based on the current charging / electricity demand and engine speed, the generator voltage is adjusted, and voltage boosting or bucking is performed as needed.

3. The engine power generation control method as described in claim 1, characterized in that, The method further includes: The generator feedback current is obtained by acquiring the phase current of the generator winding and the current charging current detected by the current detection circuit, and the generator feedback current is obtained based on the phase current and the current charging current.

4. The engine power generation control method as described in claim 1, characterized in that, The method further includes: Based on the engine's constant fuel consumption curve, determine the engine reference speed and engine reference torque under optimal fuel consumption, and use the engine reference speed and engine reference torque as reference target values ​​for control.

5. The engine power generation control method as described in claim 1, characterized in that, The method further includes: Based on the current charging / electricity demand, the starter motor and fuel pump of the engine are controlled to start and stop. The processor in the generator system is connected to the starter motor, throttle, and fuel pump of the engine via control lines.

6. An engine-generated power system, characterized in that, The system includes an engine, a generator system connected to the engine, and a battery management system connected to the generator system. The generator system includes a generator connected to the engine via a connecting shaft, a processor for implementing the engine power generation control method according to any one of claims 1-5, a rectifier circuit connected between the processor and the generator windings, a voltage feedback circuit and a current detection circuit connected between the rectifier circuit and the processor, the rectifier circuit including an upper bridge arm circuit and a lower bridge arm circuit corresponding to each of the generator windings, the upper bridge arm circuit being a chopper circuit, and the lower bridge arm circuit being a switching circuit connected between the processor and the chopper circuit, the chopper circuit including upper bridge elements corresponding to each of the generator windings, and the switching circuit including lower bridge elements connected to the upper bridge elements, the upper bridge elements being thyristors or field-effect transistors, and the lower bridge elements being field-effect transistors, diodes, or thyristors.

7. The engine-generator system as described in claim 6, characterized in that, The generator has a pure permanent magnet rotor and a single-winding stator.

8. The engine-generator system as described in claim 6, characterized in that, The generator operates in either a power generation mode or an electric mode. In the electric mode, the generator is used to start the engine or assist the axle.

9. The engine-generator system as described in claim 6, characterized in that, The generator system also includes a current regulator or load regulator connected between the processor and the battery management system.

10. The engine-generator system as described in claim 6, characterized in that, The generator is a three-phase generator, and the chopper circuit includes a first thyristor, a second thyristor, and a third thyristor respectively connected to the A-phase coil, B-phase coil, and C-phase coil of the three-phase generator winding; or, the chopper circuit includes a single field-effect transistor or two field-effect transistors connected in reverse series to the A-phase coil, B-phase coil, and C-phase coil of the three-phase generator winding. The switching circuit includes a first switch, a second switch, and a third switch that are respectively connected to the first thyristor, the second thyristor, and the third thyristor. The processor is connected to the first switch, the second switch, and the third switch through a switch driving circuit. The first switch, the second switch, and the third switch are all field-effect transistors.

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