Self-organized power grid distributed cooling fan system for special vehicle and control management method of self-organized power grid distributed cooling fan system

Abstract

The invention discloses a self-organized power grid distributed cooling fan system for a special vehicle and a control management method of the self-organized power grid distributed cooling fan system. The self-organized power grid distributed cooling fan system mainly comprises a plurality of electric drive fans based on a permanent magnet synchronous motor form, a flywheel generator and a motor controller. The system adopts a digital and integrated design scheme and a power flow prediction technology so as to ensure the stability of the self-assembled direct-current power grid, meanwhile, each fan can independently regulate the speed according to working conditions and efficiently operate, and the system is compact in installation size and can be arranged in a distributed mode.

Description

Technical Field

[0001] The present invention relates to the field of special vehicle electrical technology, and in particular to a self-organizing power grid distributed cooling fan system for special vehicles and a related control and management method. Background Art

[0002] For a long time, the power source of the cooling fan of special vehicles is mainly provided by the engine through mechanical power take-off mechanisms such as belts and gears or hydraulic mechanisms. Among them, the speed of the cooling fan usually changes linearly with the speed of the engine and cannot be adjusted automatically. It has the characteristics of low precision, slow response and low efficiency for the cooling needs of high-power diesel engines.

[0003] With the development of special vehicle electrification technology, a large number of new electronic and electrical equipment are used in special vehicles. In addition to the heat dissipation demand of diesel engines, there is also a heat dissipation demand for high-power electronic and electrical equipment.

[0004] While the heat dissipation power has increased, there has also been a problem with the spatial distribution of heat dissipation requirements caused by the layout of electronic and electrical equipment: based on the air duct design principle, the heat dissipation cooling fan needs to be arranged at the edge of the power compartment to achieve the best heat dissipation effect, and the diesel engine and gearbox that need heat dissipation must be installed in the middle of the power compartment, and high-power electronic and electrical equipment are usually installed at the edge of the power compartment. The belts, gears, hydraulic pump motors, etc. of the traditional heat dissipation cooling fan power transmission occupy a large space and are in mechanical form, which cannot be flexibly arranged and cannot take into account the heat dissipation needs of new electrified special vehicles. Summary of the invention

[0005] In order to solve the distributed heat dissipation needs of new electrified special vehicles, and in view of the size constraints and power layout characteristics of the power compartment, the present invention adopts an electric transmission solution based on a permanent magnet synchronous motor, and provides a digital distributed heat dissipation fan system for special vehicles based on a high-voltage DC self-organizing grid, which is mainly composed of several electric transmission fans based on a permanent magnet synchronous motor, a flywheel generator and a motor controller. It can self-stabilize the DC grid network without battery or supercapacitor energy storage voltage stabilization, and each fan can independently adjust the speed and run, with fast response, high precision, and control strategy adaptive to complex working conditions. The whole system has a compact installation volume, high power density, high operating efficiency, and can be distributed.

[0006] The self-organizing power grid distributed cooling fan system for special vehicles provided by the present disclosure includes:

[0007] Several electric transmission cooling fans based on permanent magnet synchronous motors, flywheel generators, motor control devices, generator power components and fan motor power components, including:

[0008] The AC end of the generator power component is connected to the AC end of the flywheel generator, and the AC end of the fan motor power component is connected to the corresponding AC end of the fan motor;

[0009] The DC end of the generator power component and the DC end of the fan motor power component are connected to the high-voltage DC busbar to form a high-voltage DC self-organizing power grid;

[0010] The flywheel generator rotates coaxially with the vehicle engine, and the generated AC power is transmitted to the generator power component. The generator power component is switched on and off in an orderly manner under the control of the motor control device, and outputs a stable DC voltage to the DC busbar; the DC busbar outputs high-voltage DC power to each fan motor power component, and the inverter outputs three-phase AC current to the three-phase winding of each fan motor; each fan motor power component is switched on and off in an orderly manner under the control of the motor control device, and each fan motor is controlled to operate independently at a speed regulation.

[0011] Furthermore, the DC self-organizing power grid adopts a 600V high voltage system.

[0012] Furthermore, the power component adopts an IGBT power module component.

[0013] Furthermore, the system also includes:

[0014] A current sensor assembly, used to collect operating current signals of the AC phase current of the flywheel generator and the fan motor;

[0015] Voltage sensor assembly, used to collect voltage signals between the positive and negative lines of the DC busbar;

[0016] The current signal and the voltage signal are used to be transmitted to the motor control device for control instruction resolution.

[0017] Furthermore, the system also includes: a high-voltage relay and a discharge resistor, which are used to discharge the high-voltage charge after the generator stops generating electricity, wherein:

[0018] The normally closed contact of the high-voltage relay is connected to the positive line of the DC busbar, the normally open contact is connected to one end of the bleeder resistor, and the other end of the bleeder resistor is connected to the negative line of the DC busbar;

[0019] After the generator stops generating electricity, the motor control device controls the high-voltage relay to close, and the discharge resistor discharges the remaining charge until it is below the safe voltage.

[0020] A power generation control method applied to the above system, for outputting a stable DC voltage to a DC busbar, comprises the following steps:

[0021] The flywheel generator is driven by the engine and outputs three-phase AC power from the three-phase winding to the generator power component;

[0022] The voltage sensor component collects the actual DC voltage of the DC busbar and compares it with the set power generation voltage. The difference is adjusted by the PI regulator and output to the given AC and DC axis current.

[0023] The current sensor component collects the three-phase current value, and obtains the actual AC and DC axis current through coordinate transformation. The actual AC and DC axis current is compared with the given AC and DC axis current. The difference is adjusted by the PI regulator to output the AC and DC axis voltage.

[0024] The AC and DC axis voltages are transformed into three-phase AC voltages, which are then calculated by space vector pulse width modulation to obtain a three-phase voltage PWM switching waveform, which is input into the generator power component and then output to the three-phase winding of the flywheel generator to generate a three-phase current.

[0025] Through the above-mentioned current and voltage double closed-loop PI control, the motor control device controls the generator power components to be opened in an orderly manner, and stabilizes the output voltage at the required power generation voltage;

[0026] The rotor position required for the coordinate transformation is obtained by calculating the three-phase current values ​​collected by the current sensor assembly using position sensorless rotor position detection.

[0027] A fan motor speed control method applied to the above system comprises the following steps:

[0028] The flywheel generator is driven by the engine, and outputs three-phase AC power from the three-phase winding to the generator power component:

[0029] The current sensor component collects the three-phase current value, and uses the position sensorless rotor position detection to calculate the rotor position and speed, and compares them with the given speed. The difference is adjusted by the PI regulator and the given AC and DC axis current is output;

[0030] The three-phase current values ​​collected by the current sensor assembly are transformed into actual AC and DC axis currents through coordinate transformation. After being compared with the given AC and DC axis currents, the difference is adjusted by the PI regulator to output AC and DC axis voltages.

[0031] The AC and DC axis voltages are transformed into three-phase AC voltages, and then the three-phase voltage PWM switching waveform is calculated by space vector pulse width modulation, which is input into the fan motor power component and then output to the three-phase winding of the fan motor to generate three-phase current.

[0032] Through the above-mentioned current and speed double closed-loop PI control, the motor control device can control the fan motor power components to be opened in an orderly manner, thereby stabilizing the output speed at the required speed.

[0033] A self-organizing power grid power management method applied to the above system comprises the following steps:

[0034] 1) Start:

[0035] When the engine is started and ignited, the main shaft drives the flywheel generator to rotate. When the engine speed is greater than the lowest stable speed value n1 of the engine, the soft starter establishes the self-organized grid voltage to a certain value U1, and then starts to enable the fan speed regulation operation;

[0036] 2) Voltage stabilization operation:

[0037] After the engine is started, the flywheel generator generates electricity stably, and each fan motor operates at a stable speed. If the DC voltage drops below a certain value U2 due to a significant increase in load, 600V>U2>U1, the fan motor operates at a reduced rating, and the given speed is limited to no more than a certain value n2;

[0038] 3) Shutdown:

[0039] When the engine stops, the output of the flywheel generator and the generator power component is stopped first, that is, power generation is stopped;

[0040] When the generator speed is lower than a certain value n3, that is, after power generation stops, each fan motor power component blocks the output.

[0041] Furthermore, the method further comprises the following steps:

[0042] After stopping power generation, the motor control circuit controls the relay to close, and uses the discharge resistor to discharge the remaining charge until it is below the safe voltage.

[0043] Compared with the prior art, the beneficial effects of the present invention are: (1) the fully controlled rectifier output end of the AC power generated by the flywheel generator and the DC input end of the electric drive fan are integrated, and the high-voltage busbar and filter capacitor group are shared, which reduces the volume and weight and improves the power density;

[0044] (2) The selected cooling fans are based on permanent magnet synchronous motors and use electric transmission, which can be distributed according to the optimal heat dissipation position;

[0045] (3) The use of permanent magnet synchronous motor drive control technology has greatly improved the response speed and speed regulation accuracy of the cooling fan. Each fan can independently adjust the speed according to the working conditions and operate efficiently.

[0046] (4) The system has a complete self-organizing network power management strategy, which can maintain the internal DC voltage stability without the need for high-power energy storage devices such as supercapacitors or high-voltage power batteries. The system can operate reliably and the cost and maintenance difficulty are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above and other objects, features and advantages of the present disclosure will become more apparent through a more detailed description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present disclosure.

[0048] Figure 1 is an exemplary distributed cooling fan system according to the present disclosure;

[0049] Figure 2 is a schematic diagram of a power generation control method according to the present disclosure;

[0050] Figure 3 A schematic diagram of a fan motor speed control method according to the present disclosure;

[0051] Figure 4 A method for starting power generation for the system;

[0052] Figure 5 It is the method of voltage stabilization operation of the system;

[0053] Figure 6 It is a method for system shutdown and charge discharge. DETAILED DESCRIPTION

[0054] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0055] The present disclosure provides a self-organizing power grid distributed cooling fan system for special vehicles, which is used to provide distributed air cooling for engines, gearboxes, and high-power electronic and electrical equipment when the special vehicles are operating normally.

[0056] In one exemplary embodiment, the system includes:

[0057] 1 flywheel generator, multiple electric drive fan motors, multiple filter capacitors, multiple current sensors, 1 voltage sensor, 1 high-voltage relay, 1 bleeder resistor, 1 set of high-voltage busbars, multiple IGBT power modules, and motor control devices and other components.

[0058] (1) Structural principle

[0059] The fan system adopts an integrated design method. The generator is designed as a flywheel and compactly installed between the diesel engine and the gearbox for coaxial transmission. The generated AC power is connected to the DC power grid through the motor control device (preferably DSP digital motor controller), and then the inverter drives each electric drive cooling fan to operate independently at a controlled speed.

[0060] The cooling fan system consists of a high-voltage busbar assembly, a filter capacitor assembly, a generator IGBT power module assembly, a fan motor IGBT power module assembly, a voltage sensor assembly, a current sensor assembly, a DSP digital motor control circuit assembly, a high-voltage contactor assembly, and a discharge resistor assembly;

[0061] The system connects the DC end of the generator IGBT power module assembly that realizes the rectification and output of the generator's electric energy in parallel with the DC end of the fan IGBT power module assembly that realizes the speed regulation of the cooling fan through a high-voltage busbar assembly (the positive line of the DC busbar connects the positive pole of the generator power assembly and the fan motor power assembly; the negative line of the DC busbar connects the negative pole of the generator power assembly and the fan motor power assembly). It can stabilize the self-organized power grid and drive the three cooling fans to independently regulate their speeds according to their respective working conditions, thereby accurately matching the cooling power with the cooling demand and greatly improving the operating efficiency.

[0062] Preferably, the system DC group power grid adopts a 600V high voltage system, which reduces the current of the IGBT power module and also reduces the performance requirements for the filter capacitor components. Therefore, smaller power devices can be selected, the power circuit volume is compressed, and the power density is increased.

[0063] As a preferred method, a high-voltage charge discharge circuit is also provided. Since there is no energy storage system such as a battery or supercapacitor, the discharge circuit can be used to completely discharge the high-voltage charge in the self-assembled power grid when the system is shut down to ensure electrical and personnel safety. At the same time, combined with the fan motor charge discharge operation strategy, the high-voltage electricity can be quickly discharged to a safe voltage.

[0064] Preferably, a DSP digital motor control circuit is used to receive the distributed cooling working conditions sent by the host computer, and the flywheel generator phase current and fan motor phase current collected by the current sensor component and the self-organizing grid voltage collected by the voltage sensor component are calculated, and the generator IGBT power component is controlled to be switched on and off in an orderly manner according to a given switch duty cycle, and a stable voltage of the self-organizing grid is output; each fan motor IGBT power component is controlled to be switched on and off in an orderly manner according to a given switch duty cycle, and each fan motor is driven to operate at a controlled speed; and when the generator stops, the high-voltage contactor component is controlled to connect the discharge resistor component to discharge the high-voltage charge.

[0065] Further specific structural examples are shown in the attached Figure 1 As shown:

[0066] The cooling fan system consists of three electric drive fan motors (fan motor F1, fan motor F2, fan motor F3), a flywheel generator G1, a power generation IGBT power module assembly M1, a fan IGBT power module assembly M2, a fan IGBT power module assembly M3, a fan IGBT power module assembly M4, a filter capacitor group C, a high-voltage busbar BUS, a voltage sensor assembly LV, a current sensor assembly LA, a high-voltage relay T, a discharge resistor R, and a DSP motor control circuit.

[0067] The DC ends of the power generation IGBT power module assembly M1, the fan IGBT power module assembly M2, the fan IGBT power module assembly M3, and the fan IGBT power module assembly M4 are all connected to the high-voltage busbar BUS to form a high-voltage DC self-organizing power grid:

[0068] The "+" poles of the filter capacitor group C, the power generation IGBT power module assembly M1, the fan IGBT power module assembly M2, the fan IGBT power module assembly M3, and the fan IGBT power module assembly M4 and the "1" point (normally closed point) of the high-voltage relay T are all connected to the positive line of the DC busbar BUS;

[0069] The “-” poles of the filter capacitor group C, the power generation IGBT power module assembly M1, the fan IGBT power module assembly M2, the fan IGBT power module assembly M3, and the fan IGBT power module assembly M4 and the “2” point of the discharge resistor R are all connected to the negative line of the DC busbar BUS;

[0070] The "2" point (normally open point) of the high-voltage relay T is connected to the "1" point of the discharge resistor R.

[0071] The three-phase AC ends of the power generation IGBT power module assembly M1, the fan IGBT power module assembly M2, the fan IGBT power module assembly M3, and the fan IGBT power module assembly M4 are respectively connected to the three-phase AC ends of the flywheel generator G1, the fan motor F1, the fan motor F2, and the fan motor F3.

[0072] The current sensor assembly LA collects the working current signals of the AC phase currents of the four motors, and the voltage sensor assembly LV collects the voltage signals between the positive and negative lines of the DC busbar BUS, and transmits them to the DSP control circuit for calculation. The DSP control circuit sends control instructions to the power generation IGBT power module assembly M1, the fan IGBT power module assembly M2, the fan IGBT power module assembly M3, and the fan IGBT power module assembly M4 according to the calculation results, and sends a close / open instruction to the high-voltage relay T.

[0073] (2) System power generation control method

[0074] During power generation operation, the flywheel generator is driven by the engine and outputs three-phase AC power from the three-phase winding to the power generation IGBT power module. The current sensor component collects the three-phase current signal and sends it to the DSP control circuit. The DSP control circuit calculates the amplitude, frequency, and phase of the three-phase AC power, and after coordinate transformation and space vector pulse width modulation, obtains the current rotor position of the flywheel generator and performs current and voltage dual closed-loop PI control. According to the difference between the given voltage and the actual power generation voltage, the PWM waveform duty cycle of the power generation IGBT power module is calculated and adjusted in real time, so as to stably output a DC voltage consistent with the given voltage to the positive and negative lines of the DC bus BUS.

[0075] As attached Figure 2 As shown, a power generation control strategy based on a DSP control circuit specifically includes the following steps:

[0076] 1) The actual DC voltage of the DC bus collected by the voltage sensor component is compared with the given power generation voltage, the difference is adjusted by the PI regulator, and the output is the given AC and DC axis current.

[0077] 2) The three-phase current values ​​collected by the current sensor assembly are transformed into actual AC and DC axis currents. After being compared with the given AC and DC axis currents, the difference is adjusted by the PI regulator to output AC and DC axis voltages.

[0078] 3) The AC and DC axis voltages are transformed into three-phase AC voltages through coordinate transformation, and then the three-phase voltage PWM switching waveform is obtained through space vector pulse width modulation calculation, which is input into the power generation IGBT power module and then output to the three-phase winding of the flywheel generator to generate three-phase current.

[0079] 4) The rotor position required for coordinate transformation is obtained by calculating the three-phase current values ​​collected by the current sensor assembly through the position sensorless rotor position observer in the software.

[0080] 5) After the current and voltage dual closed-loop PI control, the DSP control circuit can control the orderly opening of the power generation IGBT power module, thereby stabilizing the output voltage at the required power generation voltage.

[0081] (3) Fan motor speed control method

[0082] When the fan motor is driven to operate at a speed control mode, high-voltage DC is output from the DC busbar to each fan IGBT power module, and the inverter outputs three-phase AC current to the three-phase winding of the fan motor. The current sensor component collects the three-phase current signal and sends it to the DSP control circuit. The DSP control circuit calculates the amplitude, frequency, and phase of the three-phase AC power, and after coordinate transformation and space vector pulse width modulation, obtains the current rotor position of the fan motor, and performs dual closed-loop PI control of current and speed. According to the difference between the given speed and the actual speed, the PWM waveform duty cycle of the fan IGBT power module is calculated and adjusted in real time, so as to stably output the fan speed consistent with the given speed.

[0083] As attached Figure 3 As shown in the figure, the fan motor speed control strategy process based on DSP control circuit is:

[0084] 1) The three-phase current values ​​collected by the current sensor assembly are solved by the position sensorless rotor position observer to obtain the rotor position and speed, which are compared with the given speed, and the difference is adjusted by the PI regulator to output the given AC and DC axis currents.

[0085] 2) The three-phase current values ​​collected by the current sensor assembly are transformed into actual AC and DC axis currents. After being compared with the given AC and DC axis currents, the difference is adjusted by the PI regulator to output AC and DC axis voltages.

[0086] 3) The AC and DC axis voltages are transformed into three-phase AC voltages through coordinate transformation, and then the three-phase voltage PWM switching waveform is obtained through space vector pulse width modulation calculation, which is input into the fan IGBT power module and then output to the three-phase winding of the fan motor to generate three-phase current.

[0087] 4) The rotor position required for coordinate transformation is obtained by calculating the three-phase current values ​​collected by the current sensor assembly through the position sensorless rotor position observer in the software.

[0088] 5) After the current and speed dual closed-loop PI control, the DSP control circuit can control the fan IGBT power module to be turned on in an orderly manner, thereby stabilizing the output speed at the required speed.

[0089] (4) Self-organizing power grid power management method

[0090] The cooling fan system has a self-assembled high-voltage power grid inside. There are no large-capacity energy storage devices such as supercapacitors or high-voltage power batteries in the system. In order to ensure the stability of the self-assembled power grid, it is necessary to carry out targeted power management of the power grid in the system to prevent load changes from causing power grid fluctuations, triggering overvoltage and overcurrent protection, and causing the fan cooling system to lose function. In addition, the primary energy source of this cooling fan system is the mechanical energy provided by the rotation of the engine main shaft. The fluctuation and imbalance of the power grid will cause the torque of the flywheel generator to change, and may also generate negative torque that reverses the engine. In severe cases, it may cause the engine to reverse and shut down.

[0091] 1) Start-up strategy

[0092] As attached Figure 4 As shown:

[0093] When the engine is started, the main shaft drives the generator to rotate. When the generator speed is greater than the power generation speed n1, the soft starter establishes the grid voltage to U1 and starts to enable the fan speed regulation operation. This prevents the current shock caused by the increase in load during the starting process and also prevents the engine starting torque from increasing, which increases the difficulty of ignition.

[0094] When the engine is started, the main shaft drives the flywheel generator to rotate, and the generator speed is in a 1:1 relationship with the engine speed. When the engine speed is greater than a certain speed (here refers to the lowest stable speed of a high-power diesel engine, which is usually called the engine idle speed. It varies slightly from one diesel engine to another, usually around 800 rpm. The reason why it can only start to generate electricity at this speed is that the dynamic process from no power generation to power generation requires the generator speed to be as stable as possible. When the engine speed is lower than the lowest stable speed, it may have surge and other phenomena, and the speed may repeatedly have an unstable process of falling and rising, resulting in the generator speed being unstable, and entering the power generation state may fail), when the value n1, the soft starter establishes the self-organizing grid voltage to a certain value U1, and starts to enable the fan speed regulation operation;

[0095] 2) Voltage stabilization operation strategy

[0096] As attached Figure 5 As shown:

[0097] After the engine is started, the flywheel generator generates electricity steadily, and each fan motor operates at a stable speed. Since the engine speed of special vehicles has been changing dynamically over a wide range during operation, and the engine speed will suddenly decrease when braking or shifting gears, the output power of the flywheel generator is also reduced accordingly due to the speed limit. If each fan motor still maintains a high speed, that is, the load is at a high level, the DC voltage inside the cooling fan system will be pulled down, which will increase the three-phase current of the flywheel generator and even reverse the engine.

[0098] Therefore, a fan derating operation strategy is designed:

[0099] If the DC voltage drops below a certain value U2 (600V>U 2> U1), the fan motor operates at a reduced rating and the given speed is limited to not more than a certain value n2.

[0100] By temporarily reducing the speed of the fan to the idle speed n2, the voltage on the high-voltage DC busbar is maintained stable, thereby preventing the reverse drag on the engine caused by the load being greater than the output capacity. The fan motor is derated to operate at an operating speed that can meet the power requirements even at the engine idle speed.

[0101] 3) Shutdown and charge discharge strategy

[0102] As attached Figure 6 As shown:

[0103] When the engine is shut down, if the fan motor is stopped first, it may cause the fan motor to generate electricity to the DC bus during inertial operation, causing the bus voltage to pump up and cause a fault. Therefore, it is necessary to stop the flywheel generator and the power generation IGBT module output first, that is, stop power generation. When the generator speed is lower than n3, after stopping power generation, each fan motor IGBT module blocks the output, the DSP control circuit controls the relay to pull in, and uses the discharge resistor to discharge the remaining charge until the safety voltage is below 36V.

[0104] The system described in this embodiment adopts a digital and integrated design solution, integrates the fully controlled rectifier output end of the AC power generated by the flywheel generator with the DC input end of the electric drive fan, and adopts power flow prediction technology to ensure the stability of the self-assembled DC power grid. At the same time, the permanent magnet synchronous motor drive control technology is used to greatly improve the response speed and speed regulation accuracy of the cooling fan, achieving the design goals of each fan independently regulating the speed according to the working conditions and operating efficiently, the system installation volume is compact, and it can be distributed.

[0105] The system has been verified many times on test benches and actual vehicles. It is mainly based on permanent magnet synchronous motor technology, multi-unit motor integrated control and self-organizing grid power management strategy. It can provide the vehicle with a compact flywheel generator, an integrated motor control system and a distributed installed cooling fan. It has high power density, high reliability, and fast fan speed response, and does not require supercapacitors or high-voltage power batteries.

[0106] The above technical scheme is only an exemplary embodiment of the present invention. For those skilled in the art, it is easy to make various types of improvements or modifications based on the application methods and principles disclosed in the present invention, and it is not limited to the method described in the above specific embodiment of the present invention. Therefore, the method described above is only preferred and does not have a restrictive meaning.

Claims

1. A self-organizing grid distributed cooling fan system for special vehicles, characterized in that: include: Several electric transmission cooling fans based on permanent magnet synchronous motors, flywheel generators, motor control devices, generator power components and fan motor power components, including: The AC end of the generator power component is connected to the AC end of the flywheel generator, and the AC end of the fan motor power component is connected to the corresponding AC end of the fan motor; The DC end of the generator power component and the DC end of the fan motor power component are both connected to the high-voltage DC busbar to form a high-voltage DC self-organizing power grid; The flywheel generator rotates coaxially with the vehicle engine, and the generated AC power is transmitted to the generator power component. The generator power component is switched on and off in an orderly manner under the control of the motor control device, and a stable DC voltage is output to the DC busbar; the DC busbar outputs high-voltage DC power to each fan motor power component, and an inverter outputs a three-phase AC current to the three-phase winding of each fan motor; each fan motor power component is switched on and off in an orderly manner under the control of the motor control device, and each fan motor is controlled to operate independently at a speed regulation.

2. The system according to claim 1, characterized in that The DC self-organizing power grid adopts a 600V high voltage system.

3. The system according to claim 1, characterized in that The power component adopts an IGBT power module component.

4. The system according to any one of claims 1 to 3, characterized in that: Also includes: A current sensor assembly, used to collect operating current signals of the AC phase current of the flywheel generator and the fan motor; Voltage sensor assembly, used to collect voltage signals between the positive and negative lines of the DC busbar; The current signal and the voltage signal are used to be transmitted to the motor control device for control instruction resolution.

5. The system according to claim 4, characterized in that Also includes: High-voltage relays and discharge resistors are used to discharge high-voltage charges after the generator stops generating electricity, including: The normally closed contact of the high-voltage relay is connected to the positive line of the DC busbar, the normally open contact is connected to one end of the bleeder resistor, and the other end of the bleeder resistor is connected to the negative line of the DC busbar; After the generator stops generating electricity, the motor control device controls the high-voltage relay to close, and the discharge resistor discharges the remaining charge until it is below the safe voltage.

6. A power generation control method applied to the system of any one of claims 1 to 5, for outputting a stable DC voltage to a DC bus, comprising the following steps: The flywheel generator is driven by the engine and outputs three-phase AC power from the three-phase winding to the generator power component; The voltage sensor component collects the actual DC voltage of the DC busbar and compares it with the set power generation voltage. The difference is adjusted by the PI regulator and output to the given AC and DC axis current. The current sensor component collects the three-phase current value, and obtains the actual AC and DC axis current through coordinate transformation. The actual AC and DC axis current is compared with the given AC and DC axis current. The difference is adjusted by the PI regulator to output the AC and DC axis voltage. The AC and DC axis voltages are transformed into three-phase AC voltages, which are then calculated by space vector pulse width modulation to obtain a three-phase voltage PWM switching waveform, which is input into the generator power component and then output to the three-phase winding of the flywheel generator to generate a three-phase current. Through the above-mentioned current and voltage double closed-loop PI control, the motor control device controls the generator power components to be opened in an orderly manner, and stabilizes the output voltage at the required power generation voltage; The rotor position required for the coordinate transformation is obtained by calculating the three-phase current values ​​collected by the current sensor assembly using position sensorless rotor position detection.

7. A fan motor speed control method applied to the system according to any one of claims 1 to 5, comprising the following steps: The flywheel generator is driven by the engine, and outputs three-phase AC power from the three-phase winding to the generator power component: The current sensor component collects the three-phase current value, and uses the position sensorless rotor position detection to calculate the rotor position and speed, and compares them with the given speed. The difference is adjusted by the PI regulator and the given AC and DC axis current is output; The three-phase current values ​​collected by the current sensor assembly are transformed into actual AC and DC axis currents through coordinate transformation. After being compared with the given AC and DC axis currents, the difference is adjusted by the PI regulator to output AC and DC axis voltages. The AC and DC axis voltages are transformed into three-phase AC voltages, and then the three-phase voltage PWM switching waveform is calculated by space vector pulse width modulation, which is input into the fan motor power component and then output to the three-phase winding of the fan motor to generate three-phase current. After the above-mentioned current and speed double closed-loop PI control, the motor control device can control the fan motor power components to be opened in an orderly manner, thereby stabilizing the output speed at the required speed.

8. A method for managing power in an ad hoc power grid applied to the system of any one of claims 1 to 5, comprising the following steps: 1) Start: When the engine is started and ignited, the main shaft drives the flywheel generator to rotate. When the engine speed is greater than the lowest stable speed value n1 of the engine, the soft starter establishes the self-organized grid voltage to a certain value U1, and then starts to enable the fan speed regulation operation; 2) Voltage stabilization operation: After the engine is started, the flywheel generator generates electricity stably, and each fan motor operates at a stable speed. If the DC voltage drops below a certain value U2 due to a significant increase in load, 600V>U2>U1, the fan motor operates at a reduced rating, and the given speed is limited to no more than a certain value n2; 3) Shutdown: When the engine stops, the output of the flywheel generator and the generator power component is stopped first, that is, power generation is stopped; When the generator speed is lower than a certain value n3, that is, after power generation stops, each fan motor power component blocks the output.

9. The method according to claim 8, further comprising the steps of: After stopping power generation, the motor control circuit controls the relay to close, and uses the discharge resistor to discharge the remaining charge until it is below the safe voltage.

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