System for reducing rotating speed of internal combustion engine in low-power section of generator set and generator set

Abstract

The utility model discloses a system for reducing the rotating speed of an internal combustion engine in a low power section of a generator set and the generator set, the generator set comprises the internal combustion engine, a permanent magnet synchronous motor, an AC-DC rectification unit and a DC-AC inversion unit, and the system comprises a power detection unit, a rotating speed control unit, a boost unit and a boost control unit; the power detection unit is used for detecting the output power of the alternating current output end of the DC-AC inversion unit, the rotating speed control unit is used for controlling the working state of a rotating speed control execution mechanism of the internal combustion engine according to the detected output power so that the internal combustion engine can work at the target rotating speed, and the boost control unit is used for collecting voltage signals of a direct current bus. And the working state of the boosting unit is controlled according to the collected voltage signal, and the boosting unit is used for boosting the input voltage of the DC-AC inversion unit to a target voltage value under the control of the boosting control unit. The power of the permanent magnet synchronous motor at a low rotating speed can be improved, so that the rotating speed of an internal combustion engine during low-power output is reduced, and oil consumption and noise are reduced.

Description

Technical Field

[0001] This utility model relates to the field of internal combustion engine generator set technology, and in particular to a system and generator set for reducing the speed of internal combustion engine in the low-power range of a generator set. Background Technology

[0002] In the speed-power characteristic curve of a gasoline internal combustion engine, the slope of the curve gradually decreases as the speed increases, while the slope of the speed-power characteristic curve of the paired permanent magnet synchronous motor gradually increases as the speed increases under rated voltage.

[0003] In current generator sets, the gasoline internal combustion engine and permanent magnet synchronous motor are typically designed and selected based on power matching at rated speeds. This results in the internal combustion engine having excess power at low speeds, while the permanent magnet synchronous motor experiences insufficient power at its rated voltage. This mismatch forces the internal combustion engine to maintain a higher speed when the generator set is outputting low power, leading to higher fuel consumption and noise, reducing the generator set's efficiency and user experience. Utility Model Content

[0004] This invention provides a system and generator set for reducing the speed of the internal combustion engine in the low-power range of a generator set, aiming to solve the problems of high internal combustion engine speed, high fuel consumption, and high noise when the generator set is at low power output.

[0005] The first objective of this invention is to provide a system for reducing the speed of the internal combustion engine in the low-power range of a generator set.

[0006] The above-mentioned objective of this utility model is achieved through the following technical solution:

[0007] A system for reducing the speed of an internal combustion engine in the low-power range of a generator set, the generator set including an internal combustion engine, a permanent magnet synchronous motor, an AC-DC rectifier unit, and a DC-AC inverter unit, wherein the internal combustion engine is driven by the permanent magnet synchronous motor to drive the permanent magnet synchronous motor to generate electricity, the power output terminal of the permanent magnet synchronous motor is connected to the AC input terminal of the AC-DC rectifier unit, the DC output terminal of the AC-DC rectifier unit is connected to the DC input terminal of the DC-AC inverter unit through a DC bus, and the AC output terminal of the DC-AC inverter unit is used to connect a load to supply power to the load;

[0008] The system includes a power detection unit, a speed control unit, a boost unit, and a boost control unit. The signal input terminal of the power detection unit is connected to the AC output terminal of the DC-AC inverter unit. The signal output terminal of the power detection unit is connected to the signal input terminal of the speed control unit. The signal output terminal of the speed control unit is connected to the speed control actuator of the internal combustion engine. The input terminal of the boost unit is connected to the end of the DC bus closest to the AC-DC rectifier unit. The output terminal of the boost unit is connected to the end of the DC bus closest to the DC-AC inverter unit. The control terminal of the boost unit is connected to the signal output terminal of the boost control unit. The signal input terminal of the boost control unit is connected to the DC bus.

[0009] The power detection unit is used to detect the output power of the AC output terminal of the DC-AC inverter unit;

[0010] The speed control unit is used to control the working state of the speed control actuator of the internal combustion engine according to the detected output power, so that the internal combustion engine operates at the target speed;

[0011] The boost control unit is used to acquire the voltage signal of the DC bus and control the working state of the boost unit according to the acquired voltage signal.

[0012] The boost unit is used to boost the voltage supplied by the DC bus to the DC input terminal of the DC-AC inverter unit to the target voltage value under the control of the boost control unit.

[0013] Preferably, the boost control unit includes a voltage detection module and a boost control module. The signal input terminal of the voltage detection module is connected to the DC bus as the signal input terminal of the boost control unit. The signal output terminal of the voltage detection module is connected to the signal input terminal of the boost control module. The signal output terminal of the boost control module is connected to the control terminal of the boost unit as the signal output terminal of the boost control unit.

[0014] The voltage detection module is used to detect the voltage signal of the DC bus and transmit the detected voltage signal to the boost control module;

[0015] The boost control module is used to control the boost unit to turn on or off based on the voltage signal detected by the voltage detection module.

[0016] Preferably, the voltage detection module includes a first voltage acquisition circuit and a second voltage acquisition circuit, wherein,

[0017] The signal input terminal of the first voltage acquisition circuit is connected to the end of the DC bus closest to the AC-DC rectifier unit, and the signal output terminal of the first voltage acquisition circuit is connected to the first signal input terminal of the boost control module. The first voltage acquisition circuit is used to detect the voltage signal of the DC output terminal of the AC-DC rectifier unit in real time and transmit the detected voltage signal to the boost control module.

[0018] The signal input terminal of the second voltage acquisition circuit is connected to the end of the DC bus closest to the DC-AC inverter unit, and the signal output terminal of the second voltage acquisition circuit is connected to the second signal input terminal of the boost control module. The second voltage acquisition circuit is used to detect the voltage signal of the DC input terminal of the DC-AC inverter unit when the boost unit is turned on, and transmit the detected voltage signal to the boost control module.

[0019] Preferably, the boost control module is used to control the boost unit to turn on or off based on the voltage signal detected by the first voltage acquisition circuit and the voltage signal detected by the second voltage acquisition circuit.

[0020] Preferably, when the boost control module controls the boost unit to turn on or off based on the voltage signal detected by the first voltage acquisition circuit and the voltage signal detected by the second voltage acquisition circuit, it is specifically used for:

[0021] The boost control module compares the voltage signal acquired by the first voltage acquisition circuit with the target voltage value. When the voltage signal acquired by the first voltage acquisition circuit is less than the target voltage value, the boost control module outputs a high level, and the control terminal of the boost unit enables the boost unit to turn on and enter the working state, so as to boost the voltage of the DC bus near the input terminal of the DC-AC inverter unit through the boost unit.

[0022] During the process of boosting the voltage of the DC bus near the input terminal of the DC-AC inverter unit by the boost unit, the boost control module compares the voltage signal acquired by the second voltage acquisition circuit with the target voltage value. When the voltage signal acquired by the second voltage acquisition circuit is greater than or equal to the target voltage value, the boost control module outputs a low level, and the control terminal of the boost unit is de-energized, causing the boost unit to shut down and exit the working state.

[0023] Preferably, the voltage detection module further includes a first filter circuit and a second filter circuit, wherein the first filter circuit is connected in parallel with the first voltage acquisition circuit, and the second filter circuit is connected in parallel with the second voltage acquisition circuit.

[0024] Preferably, the boost control module employs an MCU controller or a voltage comparator circuit.

[0025] Preferably, the DC bus includes a positive DC bus and a negative DC bus. One end of the positive DC bus is connected to the positive terminal of the DC output of the AC-DC rectifier unit, and the other end of the positive DC bus is connected to the positive terminal of the DC input of the DC-AC inverter unit. One end of the negative DC bus is connected to the negative terminal of the DC output of the AC-DC rectifier unit, and the other end of the negative DC bus is connected to the negative terminal of the DC input of the DC-AC inverter unit.

[0026] The positive terminal of the boost unit's input is connected to the end of the DC positive bus closest to the AC-DC rectifier unit, and the negative terminal of the boost unit's input is connected to the end of the DC negative bus closest to the AC-DC rectifier unit. The positive terminal of the boost unit's output is connected to the end of the DC positive bus closest to the DC-AC inverter unit, and the negative terminal of the boost unit's output is connected to the end of the DC negative bus closest to the DC-AC inverter unit.

[0027] The system also includes an anti-backflow diode, which is connected to the DC positive bus, with the positive terminal of the anti-backflow diode connected to the positive terminal of the input of the boost unit and the negative terminal of the anti-backflow diode connected to the positive terminal of the output of the boost unit.

[0028] Preferably, the boost unit employs a Boost converter circuit.

[0029] The second objective of this invention is to provide a generator set.

[0030] The second objective of this utility model is achieved through the following technical solution:

[0031] A generator set includes the system described in the first object of this utility model for reducing the speed of the internal combustion engine in the low-power range of the generator set.

[0032] The beneficial effects of this utility model are as follows:

[0033] 1. By increasing the power of the permanent magnet synchronous motor at low speeds, the internal combustion engine does not need to maintain high speeds when outputting low power, thereby effectively reducing fuel consumption and improving the fuel economy of the generator set;

[0034] 2. The reduction in internal combustion engine speed directly reduces noise generation during operation, providing users with a quieter operating environment and improving the user experience;

[0035] 3. The matching performance between the permanent magnet synchronous motor and the internal combustion engine in the low power range has been optimized, making the operation of the entire generator set more stable and reliable, and reducing the possibility of system fluctuations and failures caused by power mismatch. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of a system for reducing the speed of an internal combustion engine in the low-power range of a generator set, according to one embodiment of the present invention.

[0038] Figure 2 This is a power characteristic curve of the generator set under various operating conditions. Detailed Implementation

[0039] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0040] In the embodiments provided by this utility model, it should be understood that the disclosed methods and systems can be implemented in other ways. The system embodiments described below are merely illustrative. For example, the division of units and modules is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or modules can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or modules, and can be electrical, mechanical, or other forms.

[0041] In addition, each functional unit in the various embodiments of this utility model can be integrated into a single processor, or each unit can be a separate device, or two or more units can be integrated into a single device; each functional unit in the various embodiments of this utility model can be implemented in hardware or in the form of hardware plus software functional units.

[0042] Those skilled in the art will understand that all or part of the steps of the following method embodiments can be implemented by program instructions and related hardware. The aforementioned program instructions can be stored in a computer-readable storage medium. When the program instructions are executed, they perform the steps of the following method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, read-only memory (ROM), magnetic disks, or optical disks.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" or "several" means two or more, unless otherwise explicitly specified.

[0044] like Figure 1 As shown, this utility model embodiment provides a system for reducing the speed of the internal combustion engine in the low-power range of a generator set.

[0045] Specifically, the generator set includes an internal combustion engine 100, a permanent magnet synchronous motor 200, an AC-DC rectifier unit 300, and a DC-AC inverter unit 400. The internal combustion engine 100 is driven by the permanent magnet synchronous motor 200 to generate electricity. The power output terminal of the permanent magnet synchronous motor 200 is connected to the AC input terminal of the AC-DC rectifier unit 300. The DC output terminal of the AC-DC rectifier unit 300 is connected to the DC input terminal of the DC-AC inverter unit 400 through a DC bus. The AC output terminal of the DC-AC inverter unit 400 is used to connect to the load and supply power to the load.

[0046] Specifically, the system for reducing the speed of the internal combustion engine in the low-power range of the generator set includes a power detection unit 1, a speed control unit 2, a boost unit 3, and a boost control unit. The signal input terminal of the power detection unit 1 is connected to the AC output terminal of the DC-AC inverter unit 400. The signal output terminal of the power detection unit 1 is connected to the signal input terminal of the speed control unit 2. The signal output terminal of the speed control unit 2 is connected to the speed control actuator of the internal combustion engine 100. The input terminal of the boost unit 3 is connected to the end of the DC bus near the AC-DC rectifier unit 300. The output terminal of the boost unit 3 is connected to the end of the DC bus near the DC-AC inverter unit 400. The control terminal of the boost unit 3 is connected to the signal output terminal of the boost control unit. The signal input terminal of the boost control unit is connected to the DC bus.

[0047] The power detection unit 1 is used to detect the output power of the AC output terminal of the DC-AC inverter unit 400;

[0048] The speed control unit 2 is used to control the working state of the speed control actuator of the internal combustion engine 100 according to the detected output power, so that the internal combustion engine 100 operates at the target speed;

[0049] The boost control unit is used to acquire the voltage signal of the DC bus and control the working state of the boost unit 3 according to the acquired voltage signal;

[0050] The boost unit 3 is used to boost the voltage supplied from the DC bus to the DC input terminal of the DC-AC inverter unit 400 to the target voltage value under the control of the boost control unit.

[0051] The working principle of the system for reducing the speed of the internal combustion engine in the low-power range of the generator set in this embodiment is as follows:

[0052] When the generator set is working, the internal combustion engine 100 drives the permanent magnet synchronous motor 200 to rotate. The permanent magnet synchronous motor 200 outputs three-phase AC power to the AC-DC rectifier unit 300. The AC-DC rectifier unit 300 converts the AC power into DC power and outputs it to the DC-AC inverter unit 400. The DC-AC inverter unit 400 converts the DC power into the AC power required by the load. During generator set operation, power detection unit 1 detects the output power of the AC output terminal of DC-AC inverter unit 400. Speed ​​control unit 2 controls the working state of the speed control actuator (such as throttle valve, fuel injector, etc.) of internal combustion engine 100 according to the detected output power, so that internal combustion engine 100 operates at the target speed, avoiding excessive speed of internal combustion engine 100, which would lead to high fuel consumption and high noise. In order to maintain the output power of generator set at a low speed to meet the load demand, boost control unit collects the voltage signal of DC bus and controls the working state of boost unit 3 according to the collected voltage signal. Under the control of boost control unit, boost unit 3 boosts the voltage of DC bus supplied to DC input terminal of DC-AC inverter unit 400 to the target voltage value.

[0053] Because the permanent magnet synchronous motor 200 can output more power when the output voltage is lower at the same speed; for example, when the output voltage is T1, it can output power P1, and when the output voltage is adjusted to T1*70%, it can output power P1*130%.

[0054] like Figure 2 As shown, to ensure that the overall output voltage of the generator set does not drop, for example, when the rated voltage of the motor (i.e., permanent magnet synchronous motor 200) is designed to be 150V, when the speed of the engine (i.e., internal combustion engine 100) / motor (horizontal axis) drops below 2600rpm, the output power of the motor cannot meet the required power while maintaining the voltage at no less than 150V, while the engine power can meet the required power and has a surplus. At this time, when the motor output voltage reaches 110V, the motor output power can meet the required power.

[0055] To solve the problem of low generator set output voltage caused by low motor output voltage, this invention adds a boost unit 3. When the output voltage of the AC-DC rectifier unit 300 is detected to be lower than the target voltage, the boost control unit is enabled, so that the output voltage of the AC-DC rectifier unit 300 is boosted to the target voltage through the boost unit 3, thereby enabling the output voltage of the DA-AC inverter unit to reach the rated value.

[0056] It should be noted that in this embodiment, the power detection unit 1 detects the output power of the AC output terminal of the DC-AC inverter unit 400 (i.e., the output power of the generator set), and the speed control unit 2 controls the working state of the speed control actuator of the internal combustion engine 100 according to the detected output power, so that the internal combustion engine 100 operates at the target speed. Specifically, when the power detection unit 1 detects that the output power of the generator set is lower than a preset power threshold (i.e., when the generator set enters a preset low power range), the speed control unit 2 controls the working state of the speed control actuator of the internal combustion engine 100 according to the pre-constructed power-speed curve of the low power range, so that the speed of the internal combustion engine 100 is lower than the speed at the same power in the prior art, avoiding the internal combustion engine 100 speed being too high when the generator set is outputting low power, thereby effectively reducing the fuel consumption and noise of the internal combustion engine 100.

[0057] The decrease in engine speed will cause the output voltage of the permanent magnet synchronous motor 200 to decrease, which will cause the output voltage of the generator set to the load to be lower than the rated voltage, thus affecting the normal operation of the load. Therefore, in order to ensure that the output voltage of the generator set can meet the load requirements at low speeds, after the speed of the internal combustion engine 100 is reduced according to the preset power-speed curve, the voltage signal of the DC bus is collected by the boost control unit. When the output voltage of the AC-DC rectifier unit 300 is detected to be lower than the target voltage, the boost control unit enables the output voltage of the AC-DC rectifier unit 300 to be boosted to the target voltage through the boost unit 3, so that the output voltage of the DA-AC inverter unit reaches the rated voltage.

[0058] This embodiment increases the power output of the permanent magnet synchronous motor 200 to the load at low speeds, so that the internal combustion engine 100 does not need to maintain a high speed when the power output is low, thereby effectively reducing fuel consumption and improving the fuel economy of the generator set.

[0059] In one embodiment, the boost control unit includes a voltage detection module and a boost control module 42. The signal input terminal of the voltage detection module is connected to the DC bus as the signal input terminal of the boost control unit, and the signal output terminal of the voltage detection module is connected to the signal input terminal of the boost control module 42. The signal output terminal of the boost control module 42 is connected to the control terminal of the boost unit 3 as the signal output terminal of the boost control unit.

[0060] The voltage detection module is used to detect the voltage signal of the DC bus and transmit the detected voltage signal to the boost control module 42;

[0061] The boost control module 42 is used to control the boost unit 3 to turn on or off based on the voltage signal detected by the voltage detection module.

[0062] In this embodiment, the boost control unit is equipped with a voltage detection module and a boost control module 42. The voltage detection module detects the voltage signal of the DC bus in real time and transmits the detected voltage signal to the boost control module 42. The boost control module 42 controls the boost unit 3 to turn on or off according to the voltage signal detected by the voltage detection module, thereby realizing the automatic control of the boost unit 3 to turn on and off according to the voltage of the DC bus.

[0063] In one embodiment, the voltage detection module includes a first voltage acquisition circuit 411 and a second voltage acquisition circuit 412, wherein...

[0064] The signal input terminal of the first voltage acquisition circuit 411 is connected to the end of the DC bus closest to the AC-DC rectifier unit 300, and the signal output terminal of the first voltage acquisition circuit 411 is connected to the first signal input terminal of the boost control module 42. The first voltage acquisition circuit 411 is used to detect the voltage signal of the DC output terminal of the AC-DC rectifier unit 300 in real time and transmit the detected voltage signal to the boost control module 42.

[0065] The signal input terminal of the second voltage acquisition circuit 412 is connected to the end of the DC bus closest to the DC-AC inverter unit 400, and the signal output terminal of the second voltage acquisition circuit 412 is connected to the second signal input terminal of the boost control module 42. The second voltage acquisition circuit 412 is used to detect the voltage signal of the DC input terminal of the DC-AC inverter unit 400 when the boost unit 3 is turned on, and transmit the detected voltage signal to the boost control module 42.

[0066] The boost control module 42 is used to control the boost unit 3 to turn on or off based on the voltage signal detected by the first voltage acquisition circuit 411 and the voltage signal detected by the second voltage acquisition circuit 412.

[0067] In this embodiment, the voltage detection module sets up a first voltage acquisition circuit 411 and a second voltage acquisition circuit 412. The first voltage acquisition circuit 411 detects the voltage signal at the DC output terminal of the AC-DC rectifier unit 300 in real time and transmits the detected voltage signal to the boost control module 42. The second voltage acquisition circuit 412 detects the voltage signal at the DC input terminal of the DC-AC inverter unit 400 when the boost unit 3 is turned on and transmits the detected voltage signal to the boost control module 42. Thus, the boost control module controls the boost unit 3 to turn on or off according to the voltage signal detected by the first voltage acquisition circuit 411 and the voltage signal detected by the second voltage acquisition circuit 412.

[0068] In one embodiment, when the boost control module 42 controls the boost unit 3 to turn on or off based on the voltage signal detected by the first voltage acquisition circuit 411 and the voltage signal detected by the second voltage acquisition circuit 412, it is specifically used for:

[0069] The boost control module 42 compares the voltage signal acquired by the first voltage acquisition circuit 411 with the target voltage value. When the voltage signal acquired by the first voltage acquisition circuit 411 is less than the target voltage value (indicating that after the generator set enters the low-power range, the speed is controlled to decrease, resulting in the output voltage of the permanent magnet synchronous motor 200 being too low, and the overall output voltage of the generator set not meeting the requirements, requiring a boost), the boost control module 42 outputs a high level. The control terminal of the boost unit 3 is enabled, turning on the boost unit 3 and putting it into operation. This allows the boost unit 3 to boost the voltage at the input terminal of the DC bus near the DC-AC inverter unit 400.

[0070] During the process of boosting the voltage of the DC bus near the input terminal of the DC-AC inverter unit 400 by the boost unit 3, the boost control module 42 compares the voltage signal collected by the second voltage acquisition circuit 412 with the target voltage value. When the voltage signal collected by the second voltage acquisition circuit 412 is greater than or equal to the target voltage value (indicating that the output voltage of the generator set has reached the target voltage required after boosting by the boost unit 3), the boost control module 42 outputs a low level, and the control terminal of the boost unit 3 is de-energized, causing the boost unit 3 to shut down and exit the working state.

[0071] It should be noted that in this embodiment, the boost control module 42 adopts an MCU controller or a voltage comparator circuit. The boost control module 42 controls the boost unit 3 to turn on or off based on the voltage signal detected by the first voltage acquisition circuit 411 and the voltage signal detected by the second voltage acquisition circuit 412. This process does not involve any modification to the computer program itself and can be implemented by controlling the comparator device or comparator in the comparator circuit through the MCU.

[0072] In one embodiment, the voltage detection module further includes a first filter circuit 413 and a second filter circuit 414. The first filter circuit 413 is connected in parallel with the first voltage acquisition circuit 411, and the second filter circuit 414 is connected in parallel with the second voltage acquisition circuit 412. By setting the first filter circuit 413 and the second filter circuit 414, the voltage signals acquired by the first voltage acquisition circuit 411 and the second voltage acquisition circuit 412 are more accurate and reliable, thereby ensuring the accurate switching of the boost unit 3. Specifically, in this embodiment, both the first filter circuit 413 and the second filter circuit 414 are implemented using filter capacitors.

[0073] In one embodiment, the DC bus includes a positive DC bus and a negative DC bus. One end of the positive DC bus is connected to the positive terminal of the DC output of the AC-DC rectifier unit 300, and the other end is connected to the positive terminal of the DC input of the DC-AC inverter unit 400. One end of the negative DC bus is connected to the negative terminal of the DC output of the AC-DC rectifier unit 300, and the other end is connected to the negative terminal of the DC input of the DC-AC inverter unit 400.

[0074] The positive terminal of the input of boost unit 3 is connected to the end of the DC positive bus closest to the AC-DC rectifier unit 300, and the negative terminal of the input of boost unit 3 is connected to the end of the DC negative bus closest to the AC-DC rectifier unit 300. The positive terminal of the output of boost unit 3 is connected to the end of the DC positive bus closest to the DC-AC inverter unit 400, and the negative terminal of the output of boost unit 3 is connected to the end of the DC negative bus closest to the DC-AC inverter unit 400.

[0075] The system also includes an anti-backflow diode 5, which is connected to the DC positive bus. The positive terminal of the anti-backflow diode 5 is connected to the positive terminal of the input of the boost unit 3, and the negative terminal of the anti-backflow diode 5 is connected to the positive terminal of the output of the boost unit 3. By setting the anti-backflow diode 5, the backflow of the current output from the boost unit 3 after boosting is prevented from flowing back to its input terminal, thereby better ensuring the normal and stable operation of the system.

[0076] In one embodiment, boost unit 3 employs a boost circuit. The boost circuit uses an inductor, an energy storage element, as an intermittent power source, connected in series with the input power supply to achieve voltage boosting. The boost circuit includes components such as inductors, capacitors, and power switching transistors. When boosting the voltage output from the AC-DC rectifier unit 300 through the boost circuit, the voltage output to the DC bus can be controlled by controlling the on-time of the power switching transistor. The specific circuit structure of the boost circuit is prior art and will not be described in detail here.

[0077] This utility model embodiment also provides a generator set, including the generator set transient power compensation system in any of the above embodiments.

[0078] The generator set in this embodiment has the same working principle and technical effect as the transient power compensation system of the generator set in the above embodiment, and will not be described again here.

[0079] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0080] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this invention.

[0081] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly using hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0082] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A system for reducing the speed of an internal combustion engine in the low-power range of a generator set, characterized in that, The generator set includes an internal combustion engine, a permanent magnet synchronous motor, an AC-DC rectifier unit, and a DC-AC inverter unit. The internal combustion engine is driven by the permanent magnet synchronous motor to generate electricity. The power output terminal of the permanent magnet synchronous motor is connected to the AC input terminal of the AC-DC rectifier unit. The DC output terminal of the AC-DC rectifier unit is connected to the DC input terminal of the DC-AC inverter unit through a DC bus. The AC output terminal of the DC-AC inverter unit is used to connect to the load and supply power to the load. The system includes a power detection unit, a speed control unit, a boost unit, and a boost control unit. The signal input terminal of the power detection unit is connected to the AC output terminal of the DC-AC inverter unit. The signal output terminal of the power detection unit is connected to the signal input terminal of the speed control unit. The signal output terminal of the speed control unit is connected to the speed control actuator of the internal combustion engine. The input terminal of the boost unit is connected to the end of the DC bus closest to the AC-DC rectifier unit. The output terminal of the boost unit is connected to the end of the DC bus closest to the DC-AC inverter unit. The control terminal of the boost unit is connected to the signal output terminal of the boost control unit. The signal input terminal of the boost control unit is connected to the DC bus. The power detection unit is used to detect the output power of the AC output terminal of the DC-AC inverter unit; The speed control unit is used to control the working state of the speed control actuator of the internal combustion engine according to the detected output power, so that the internal combustion engine operates at the target speed; The boost control unit is used to acquire the voltage signal of the DC bus and control the working state of the boost unit according to the acquired voltage signal. The boost unit is used to boost the voltage supplied by the DC bus to the DC input terminal of the DC-AC inverter unit to the target voltage value under the control of the boost control unit.

2. The system for reducing the speed of the internal combustion engine in the low-power range of a generator set according to claim 1, characterized in that, The boost control unit includes a voltage detection module and a boost control module. The signal input terminal of the voltage detection module is connected to the DC bus as the signal input terminal of the boost control unit. The signal output terminal of the voltage detection module is connected to the signal input terminal of the boost control module. The signal output terminal of the boost control module is connected to the control terminal of the boost unit as the signal output terminal of the boost control unit. The voltage detection module is used to detect the voltage signal of the DC bus and transmit the detected voltage signal to the boost control module; The boost control module is used to control the boost unit to turn on or off based on the voltage signal detected by the voltage detection module.

3. The system for reducing the speed of the internal combustion engine in the low-power range of a generator set according to claim 2, characterized in that, The voltage detection module includes a first voltage acquisition circuit and a second voltage acquisition circuit, wherein... The signal input terminal of the first voltage acquisition circuit is connected to the end of the DC bus closest to the AC-DC rectifier unit, and the signal output terminal of the first voltage acquisition circuit is connected to the first signal input terminal of the boost control module. The first voltage acquisition circuit is used to detect the voltage signal of the DC output terminal of the AC-DC rectifier unit in real time and transmit the detected voltage signal to the boost control module. The signal input terminal of the second voltage acquisition circuit is connected to the end of the DC bus closest to the DC-AC inverter unit, and the signal output terminal of the second voltage acquisition circuit is connected to the second signal input terminal of the boost control module. The second voltage acquisition circuit is used to detect the voltage signal of the DC input terminal of the DC-AC inverter unit when the boost unit is turned on, and transmit the detected voltage signal to the boost control module.

4. The system for reducing the speed of the internal combustion engine in the low-power range of a generator set according to claim 3, characterized in that, The boost control module is used to control the boost unit to turn on or off based on the voltage signal detected by the first voltage acquisition circuit and the voltage signal detected by the second voltage acquisition circuit.

5. The system for reducing the speed of the internal combustion engine in the low-power range of a generator set according to claim 4, characterized in that, When the boost control module controls the boost unit to turn on or off based on the voltage signal detected by the first voltage acquisition circuit and the voltage signal detected by the second voltage acquisition circuit, it is specifically used for: The boost control module compares the voltage signal acquired by the first voltage acquisition circuit with the target voltage value. When the voltage signal acquired by the first voltage acquisition circuit is less than the target voltage value, the boost control module outputs a high level, and the control terminal of the boost unit enables the boost unit to turn on and enter the working state, so as to boost the voltage of the DC bus near the input terminal of the DC-AC inverter unit through the boost unit. During the process of boosting the voltage of the DC bus near the input terminal of the DC-AC inverter unit by the boost unit, the boost control module compares the voltage signal acquired by the second voltage acquisition circuit with the target voltage value. When the voltage signal acquired by the second voltage acquisition circuit is greater than or equal to the target voltage value, the boost control module outputs a low level, and the control terminal of the boost unit is de-energized, causing the boost unit to shut down and exit the working state.

6. The system for reducing the speed of the internal combustion engine in the low-power range of a generator set according to claim 3, characterized in that, The voltage detection module further includes a first filter circuit and a second filter circuit, wherein the first filter circuit is connected in parallel with the first voltage acquisition circuit, and the second filter circuit is connected in parallel with the second voltage acquisition circuit.

7. The system for reducing the speed of the internal combustion engine in the low-power range of a generator set according to claim 2, characterized in that, The boost control module uses an MCU controller or a voltage comparator circuit.

8. The system for reducing the speed of the internal combustion engine in the low-power range of a generator set according to claim 1, characterized in that, The DC bus includes a positive DC bus and a negative DC bus. One end of the positive DC bus is connected to the positive terminal of the DC output of the AC-DC rectifier unit, and the other end is connected to the positive terminal of the DC input of the DC-AC inverter unit. One end of the negative DC bus is connected to the negative terminal of the DC output of the AC-DC rectifier unit, and the other end is connected to the negative terminal of the DC input of the DC-AC inverter unit. The positive terminal of the boost unit's input is connected to the end of the DC positive bus closest to the AC-DC rectifier unit, and the negative terminal of the boost unit's input is connected to the end of the DC negative bus closest to the AC-DC rectifier unit. The positive terminal of the boost unit's output is connected to the end of the DC positive bus closest to the DC-AC inverter unit, and the negative terminal of the boost unit's output is connected to the end of the DC negative bus closest to the DC-AC inverter unit. The system also includes an anti-backflow diode, which is connected to the DC positive bus, with the positive terminal of the anti-backflow diode connected to the positive terminal of the input of the boost unit and the negative terminal of the anti-backflow diode connected to the positive terminal of the output of the boost unit.

9. The system for reducing the speed of an internal combustion engine in the low-power range of a generator set according to any one of claims 1-8, characterized in that, The boost unit uses a Boost converter circuit.

10. A generator set, characterized in that, The system includes the system for reducing the speed of the internal combustion engine in the low-power range of a generator set as described in any one of claims 1-9.

Images