Method and device capable of achieving online dual-power smooth switching of grinding engineering vehicle
By using voltage synchronization control and dual closed-loop control between the inverter power supply and the diesel generator, the online dual-power smooth switching of the grinding engineering vehicle was realized, which solved the problems of accuracy deviation and high equipment failure rate caused by shutdown switching in the existing technology, and reduced equipment cost and failure rate.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHENGDU SITE ELECTRIC TECH CO LTD
- Filing Date
- 2026-03-04
- Publication Date
- 2026-05-15
AI Technical Summary
The existing dual-power supply method for grinding engineering vehicles requires a shutdown for switching, which leads to short circuit impact between power sources, resulting in workpiece accuracy deviation and high equipment failure rate. Furthermore, it lacks a pre-synchronization mechanism for voltage and phase.
The inverter power supply and diesel generator are controlled synchronously with voltage. Through dual closed-loop control of the inner current loop and the outer voltage loop, smooth online switching between the two power sources is achieved. Parallel operation is achieved by using a switching switch, and load power transfer is completed by linearly adjusting the inverter power supply current setpoint.
It achieves seamless switching, continuous power supply to the load, short interruption time, reduces equipment failure rate and maintenance costs, reduces the number of core components, and adapts to the spatial layout requirements of engineering vehicles.
Smart Images
Figure CN122052289A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power switching technology for grinding engineering vehicles, specifically to a method and apparatus for achieving smooth online switching between dual power sources for grinding engineering vehicles. Background Technology
[0002] Currently, grinding engineering vehicles are transitioning from the traditional single diesel power source to a dual-power system combining overhead contact line and diesel generator. The existing dual-power supply method uses the overhead contact line for power in energized areas and the diesel generator for power in de-energized areas. Because it employs two independent power supply units without coordinated control, switching requires first disconnecting the current power source and then starting the backup power source; essentially, it's a "power outage-restart" interrupted switching process.
[0003] This method lacks a pre-synchronization mechanism for voltage and phase, and direct parallel connection can lead to short-circuit impacts between power sources, necessitating a shutdown and switching, resulting in a 0.5-3 second interruption of the work load. For operations requiring continuous power supply, such as rail grinding, this method can cause irreversible effects such as workpiece accuracy deviations and decreased work quality. Furthermore, the voltage surges during switching can cause instantaneous electrical stress impacts on the diesel generator set and working mechanism, significantly increasing equipment failure rates over long-term use.
[0004] In summary, the existing power switching problem of grinding engineering vehicles has restricted the promotion and application of dual-power technology. Therefore, there is an urgent need in this field for a method that can achieve smooth online dual-power switching of grinding engineering vehicles. Summary of the Invention
[0005] To address the aforementioned shortcomings in the prior art, this invention provides a method and apparatus for smoothly switching between dual power sources online on a grinding engineering vehicle.
[0006] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: A method for achieving smooth online dual-power switching of a grinding engineering vehicle includes a first switching process of switching from diesel generator power supply to inverter power supply, and a second switching process of switching from inverter power supply to diesel generator power supply. The first handover process includes the following steps: The output voltage of the diesel generator and the load current of the grinding vehicle are collected in real time, and the output voltage of the inverter is controlled to synchronize with the output voltage of the diesel generator. When the output voltages of the two reach a synchronized state, the switching switch located at the output terminals of the two is closed to enable the two to operate in parallel. At the same time, the control mode of the inverter is switched to the current inner loop control mode, and its active current setpoint is set to zero. The active current setpoint of the inverter power supply is increased linearly from zero until its output current equals the load current of the grinding vehicle. When the output current of the inverter power supply is equal to the load current of the grinding engineering vehicle, the control switch is opened to disconnect the diesel generator and switch the control mode of the inverter power supply back to the voltage outer loop control mode to complete the first switching process. The second switching process includes the following steps: The output voltage of the diesel generator and the load current of the grinding vehicle are collected in real time, and the output voltage of the inverter is controlled to synchronize with the output voltage of the diesel generator. When the output voltages of the two reach a synchronized state, the control switch is closed to make the two run in parallel, the control mode of the inverter power supply is switched to the current inner loop control mode, and its active current setpoint is set to the load current of the grinding engineering vehicle. The active current setpoint of the control inverter power supply is reduced to zero from the load current of the grinding vehicle in a linear decreasing manner. Once the active current setpoint of the inverter power supply drops to zero, the control mode of the inverter power supply is switched to the voltage outer loop control mode to complete the second switching process.
[0007] Furthermore, the inverter power supply adopts dual closed-loop control with an outer voltage loop and an inner current loop.
[0008] Furthermore, the dual closed-loop control of the voltage outer loop and the current inner loop is specifically implemented as follows: The voltage outer loop compares the Parker transform component of the inverter output voltage with the voltage setpoint to obtain the first error. The first error is then adjusted by a PI (Proportional-Integral) to generate the active current setpoint and determine the reactive current setpoint. The current inner loop compares the actual active current and the actual reactive current with the active current setpoint and the reactive current setpoint, respectively, to obtain the second error. The second error is then adjusted by a PI to generate a reference voltage vector. The reference voltage vector undergoes an inverse Parker transform to obtain the inverse Parker variable of the reference voltage vector. The inverse Parker variable of the reference voltage vector is then modulated by SVPWM (Space Vector Pulse Width Modulation) to generate a switching signal for dual closed-loop control of the voltage outer loop and the current inner loop.
[0009] Furthermore, depending on the different operating modes of the inverter and diesel generator, the voltage setpoint, current setpoint, and angle used for Parker transformation are adaptively switched. Specifically: when the inverter or diesel generator is running independently, the voltage setpoint is a fixed value, and the angle used for Parker transformation is generated by the inverter itself; when the inverter and diesel generator are running in pre-synchronous mode, the voltage setpoint is taken from the output voltage of the diesel generator, and the angle used for Parker transformation locks the output voltage phase of the diesel generator; when the inverter and diesel generator are running in parallel, the voltage outer loop is disconnected, the active current setpoint is taken from the load current of the grinding vehicle, and the angle used for Parker transformation locks the output voltage phase of the diesel generator.
[0010] Furthermore, the synchronization state includes an amplitude difference of less than or equal to 2% between the inverter output voltage and the diesel generator output voltage, and a phase difference of less than 5 degrees between the inverter output voltage and the diesel generator output voltage.
[0011] Furthermore, the output voltage of the inverter power supply is synchronized with the output voltage of the diesel generator. The specific process is as follows: the output voltage of the diesel generator is collected in real time and determined as the given voltage of the outer loop of the inverter power supply. By adjusting the output frequency of the inverter power supply, the amplitude difference and phase difference between the output voltage of the inverter power supply and the output voltage of the diesel generator are reduced to within the preset threshold.
[0012] Furthermore, the switching device uses a thyristor.
[0013] A device for implementing the above method, enabling smooth online switching between dual power sources for a grinding engineering vehicle, includes an inverter power supply unit, a switching unit, and a voltage and current acquisition unit. The inverter power supply unit is used in the first switching process to control the output voltage of the inverter power supply to synchronize with the output voltage of the diesel generator. After the output voltages of the two power supplies are synchronized, the control mode of the inverter power supply is switched to the current inner loop control mode, and its active current setpoint is set to zero. Then, the active current setpoint of the inverter power supply is controlled to increase from zero in a linear increment until its output current equals the load current of the grinding vehicle. Then, the control mode of the inverter power supply is switched back to the voltage outer loop control mode to complete the first switching process. The inverter power supply unit is used in the second switching process to control the output voltage of the inverter power supply to synchronize with the output voltage of the diesel generator. After the output voltages of the two power supplies are synchronized, the control mode of the inverter power supply is switched to the current inner loop control mode, and its active current setpoint is set to the load current of the grinding vehicle. The active current setpoint of the inverter power supply is controlled to decrease from the load current of the grinding vehicle in a linear decrease to zero. After the active current setpoint of the inverter power supply drops to zero, the control mode of the inverter power supply is switched back to the voltage outer loop control mode to complete the second switching process. The switching unit is used in the first switching process to control the switching switches located at the output terminals of both the inverter and the diesel generator to close, so that they can operate in parallel, after the output voltage of the inverter and the output voltage of the diesel generator reach a synchronized state. When the output current of the inverter equals the load current of the grinding vehicle, the switching switch is controlled to open, disconnecting the diesel generator. The switching unit is used in the second switching process to control the switching switch to close, so that they can operate in parallel, after the output voltage of the inverter and the output voltage of the diesel generator reach a synchronized state. The voltage and current acquisition unit is used to acquire the output voltage of the diesel generator and the load current of the grinding engineering vehicle in real time during the first and second switching processes.
[0014] The beneficial effects of this invention are as follows: (1) This invention achieves parallel connection by synchronizing the voltages of the two power supplies first, then closing the switching switch, and switching the inverter power supply to current control mode. Then, by linearly adjusting the current setpoint of the inverter power supply, the load power is smoothly transferred between the two power supplies. Finally, the unloaded power supply is disconnected to complete the switching. The whole process realizes seamless and smooth switching between the inverter power supply and the diesel generator. The load power supply is continuous during the switching process, and the interruption time is much lower than the equipment sensing threshold. This solves the problem of accuracy deviation and quality degradation caused by power supply interruption in continuous operations such as rail grinding. (2) Compared with the existing online switching scheme that requires multiple stages of "AC-DC-AC" conversion, the present invention directly realizes parallel connection and power transfer on the AC side through the inverter power supply, without the need for additional configuration of special modules such as rectifier cabinet, DC bus, and fast DC circuit breaker. This significantly reduces the number of core components used in the method of the present invention, reduces equipment cost, lightens weight, and shrinks size, and can better adapt to the limited carrying space and layout requirements of engineering vehicles. (3) Through the linear adjustment mechanism of the current inner loop, the load power of the grinding engineering vehicle can be smoothly transferred between the two power sources, avoiding voltage surges and current impacts during the switching process. This not only eliminates the instantaneous electrical stress damage to the diesel generator windings, engine and grinding motor control module, but also effectively extends the service life of the core equipment and reduces the failure rate and maintenance costs. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of a method for achieving smooth online switching between dual power sources for a grinding engineering vehicle. Figure 2 This is a schematic diagram of a dual closed-loop control process consisting of an outer voltage loop and an inner current loop. Figure 3 This is a schematic diagram of a device that enables smooth online switching between dual power sources for a grinding engineering vehicle. Detailed Implementation
[0016] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.
[0017] like Figure 1 As shown, a method for achieving smooth online dual-power switching of a grinding engineering vehicle includes a first switching process of switching from diesel generator power supply to inverter power supply, and a second switching process of switching from inverter power supply to diesel generator power supply.
[0018] The first handover process includes steps A1-A4, as follows: A1. Real-time acquisition of the output voltage of the diesel generator and the load current of the grinding vehicle, and control the output voltage of the inverter to achieve synchronization with the output voltage of the diesel generator.
[0019] In an optional embodiment of the present invention, the inverter power supply employs dual closed-loop control consisting of an outer voltage loop and an inner current loop.
[0020] The dual closed-loop control of the voltage outer loop and the current inner loop is as follows: The voltage outer loop compares the Parker transform component of the inverter output voltage with the voltage setpoint to obtain the first error. The first error is then adjusted by a PI controller to generate the active current setpoint and determine the reactive current setpoint. The current inner loop compares the actual active current and the actual reactive current with the active current setpoint and the reactive current setpoint, respectively, to obtain the second error. The second error is then adjusted by a PI controller to generate a reference voltage vector. The reference voltage vector undergoes an inverse Parker transform to obtain the inverse Parker variable of the reference voltage vector. The inverse Parker variable of the reference voltage vector is then modulated by SVPWM to generate a switching signal for dual closed-loop control of the voltage outer loop and the current inner loop.
[0021] Based on the different operating modes of the inverter and diesel generator, this invention adaptively switches the voltage setpoint, current setpoint, and Parker transformation angle. Specifically: when the inverter or diesel generator is running independently, the voltage setpoint is a fixed value, and the Parker transformation angle is generated by the inverter itself; when the inverter and diesel generator are running in pre-synchronous mode, the voltage setpoint is taken from the output voltage of the diesel generator, and the Parker transformation angle locks the output voltage phase of the diesel generator; when the inverter and diesel generator are running in parallel, the voltage outer loop is deactivated, the active current setpoint is taken from the load current of the grinding vehicle, and the Parker transformation angle locks the output voltage phase of the diesel generator.
[0022] Synchronization is defined as the amplitude difference between the inverter output voltage and the diesel generator output voltage being less than or equal to 2%, and the phase difference between the inverter output voltage and the diesel generator output voltage being less than 5 degrees.
[0023] This invention controls the output voltage of the inverter power supply to achieve synchronization with the output voltage of the diesel generator. The specific process is as follows: the output voltage of the diesel generator is collected in real time and determined as the given value of the outer loop of the inverter power supply voltage. By adjusting the output frequency of the inverter power supply, the amplitude difference and phase difference between the output voltage of the inverter power supply and the output voltage of the diesel generator are reduced to within a preset threshold.
[0024] like Figure 2 As shown, this invention detects the inverter output voltage by sampling the inverter's AC voltage. , , After Parker transformation, the Parker transformation component of the inverter output voltage is obtained. The abc / dq transformation is converted to the Parker transformation, and the Parker transformation components of the inverter output voltage are compared. With voltage setpoint The first error is obtained, and the first error is used to generate the active current setpoint after passing through the PI regulator. When the inverter operates at unity power factor, the system outputs active power, thus determining the reactive current setpoint. The value is zero. This invention obtains the amplitude and phase information of the diesel voltage by sampling the AC voltage of the diesel engine, and then detects the three-phase AC current through an AC current sensor. , , The actual active current is then obtained through the Parker transformation. With actual reactive current The actual active current and actual reactive current are compared with the given values of active current and reactive current, respectively, to obtain the second error. After obtaining the second error, the reference voltage vector can be obtained through the PI regulator. The reference voltage vector is then subjected to an inverse Parker transformation, and the dq / abc transformation is converted to an inverse Parker transformation to obtain the inverse Parker variable of the reference voltage vector. The inverse Parker variable of the reference voltage vector is then modulated by SVPWM to generate a switching signal, which controls the on-off state of the switching transistors in the converter, thereby realizing the control of the AC voltage and current of the inverter power supply, and performing dual closed-loop control of the voltage outer loop and the current inner loop.
[0025] Specifically, voltage setpoint Active current setpoint * and adaptive switching of the angle θ used in the Parker transformation, when the inverter or diesel generator is running independently, the voltage setpoint For fixed Active current setpoint * represents the output of the outer voltage loop. The angle θ used in the Parker transformation is the angle generated by the inverter itself. When the inverter is in the pre-synchronization stage, the voltage setpoint is... The output voltage of the diesel generator is obtained by Parker transformation. Active current setpoint * represents the output of the outer voltage loop. The angle θ used in the Parker transformation locks the phase of the diesel generator's output voltage. When the inverter and diesel generator are running in parallel, the outer voltage loop is not operating, and the active current setpoint of the inner current loop is... *Load current sampled from the grinding vehicle and processed by Parker transformer. The angle θ used in the Parker transformation locks the phase of the diesel generator's output voltage.
[0026] A2. When the output voltages of the two reach a synchronized state, the switch located at the output terminals of the two is closed to enable them to operate in parallel. At the same time, the control mode of the inverter is switched to the current inner loop control mode, and its active current setpoint is set to zero.
[0027] Specifically, the switching device uses a thyristor.
[0028] A3. The active current setpoint of the control inverter power supply is increased linearly from zero until its output current equals the load current of the grinding vehicle.
[0029] A4. When the output current of the inverter power supply is equal to the load current of the grinding engineering vehicle, the control switch is opened to disconnect the diesel generator and switch the control mode of the inverter power supply back to the voltage outer loop control mode to complete the first switching process.
[0030] The second switching process includes steps B1-B4, as follows: B1. Real-time acquisition of the output voltage of the diesel generator and the load current of the grinding vehicle, and control the output voltage of the inverter to achieve synchronization with the output voltage of the diesel generator.
[0031] B2. When the output voltages of both reach a synchronized state, the control switch is closed to enable them to operate in parallel, the control mode of the inverter power supply is switched to the current inner loop control mode, and its active current setpoint is set to the load current of the grinding engineering vehicle.
[0032] B3. The active current setpoint of the control inverter power supply is reduced to zero from the load current of the grinding vehicle in a linear decreasing manner.
[0033] B4. When the active current setpoint of the inverter power supply drops to zero, switch the control mode of the inverter power supply to the voltage outer loop control mode to complete the second switching process.
[0034] like Figure 3 As shown, a device for implementing the above method, enabling smooth online switching between dual power sources for a grinding engineering vehicle, includes an inverter power supply unit, a switching unit, and a voltage and current acquisition unit.
[0035] In an optional embodiment of the present invention, the inverter power supply unit is used in the first switching process to control the output voltage of the inverter power supply to reach a synchronized state with the output voltage of the diesel generator. After the output voltages of the two power supplies reach a synchronized state, the control mode of the inverter power supply is switched to the current inner loop control mode, and its active current setpoint is set to zero. Then, the active current setpoint of the inverter power supply is controlled to increase from zero in a linear increment until its output current equals the load current of the grinding vehicle. The control mode of the inverter power supply is then switched back to the voltage outer loop control mode to complete the first switching process. In the second switching process, the inverter power supply unit is used to control the output voltage of the inverter power supply to reach a synchronized state with the output voltage of the diesel generator. After the output voltages of the two power supplies reach a synchronized state, the control mode of the inverter power supply is switched to the current inner loop control mode, and its active current setpoint is set to the load current of the grinding vehicle. The active current setpoint of the inverter power supply is controlled to decrease from the load current of the grinding vehicle in a linear decrease to zero. After the active current setpoint of the inverter power supply drops to zero, the control mode of the inverter power supply is switched to the voltage outer loop control mode to complete the second switching process.
[0036] In an optional embodiment of the present invention, the switching unit is used to control the switching switches located at the output terminals of the inverter power supply to close in the first switching process after the output voltage of the inverter power supply and the output voltage of the diesel generator reach a synchronized state, so that the two can operate in parallel. When the output current of the inverter power supply is equal to the load current of the grinding engineering vehicle, the switching unit is controlled to open to disconnect the diesel generator. The switching unit is used to control the switching switch to close in the second switching process after the output voltage of the inverter power supply and the output voltage of the diesel generator reach a synchronized state, so that the two can operate in parallel.
[0037] In an optional embodiment of the present invention, the voltage and current acquisition unit is used to acquire the output voltage of the diesel generator and the load current of the grinding vehicle in real time during the first switching process and the second switching process.
[0038] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of this invention.
Claims
1. A method for achieving smooth online switching between dual power systems for a grinding engineering vehicle, characterized in that, It includes a first switching process for switching from diesel generator power supply to inverter power supply, and a second switching process for switching from inverter power supply to diesel generator power supply; The first handover process includes the following steps: The output voltage of the diesel generator and the load current of the grinding vehicle are collected in real time, and the output voltage of the inverter is controlled to synchronize with the output voltage of the diesel generator. When the output voltages of the two reach a synchronized state, the switching switch located at the output terminals of the two is closed to enable the two to operate in parallel. At the same time, the control mode of the inverter is switched to the current inner loop control mode, and its active current setpoint is set to zero. The active current setpoint of the inverter power supply is increased linearly from zero until its output current equals the load current of the grinding vehicle. When the output current of the inverter power supply is equal to the load current of the grinding engineering vehicle, the control switch is opened to disconnect the diesel generator and switch the control mode of the inverter power supply back to the voltage outer loop control mode to complete the first switching process. The second switching process includes the following steps: The output voltage of the diesel generator and the load current of the grinding vehicle are collected in real time, and the output voltage of the inverter is controlled to synchronize with the output voltage of the diesel generator. When the output voltages of the two reach a synchronized state, the control switch is closed to make the two run in parallel, the control mode of the inverter power supply is switched to the current inner loop control mode, and its active current setpoint is set to the load current of the grinding engineering vehicle. The active current setpoint of the control inverter power supply is reduced to zero from the load current of the grinding vehicle in a linear decreasing manner. Once the active current setpoint of the inverter power supply drops to zero, the control mode of the inverter power supply is switched to the voltage outer loop control mode to complete the second switching process.
2. The method for achieving smooth online dual-power switching of a grinding engineering vehicle according to claim 1, characterized in that, The inverter power supply adopts dual closed-loop control with an outer voltage loop and an inner current loop.
3. The method for achieving smooth online dual-power switching of a grinding engineering vehicle according to claim 2, characterized in that, The dual closed-loop control of voltage outer loop and current inner loop is specifically controlled as follows: the voltage outer loop compares the Parker transformation component of the inverter output voltage with the voltage setpoint to obtain the first error, and generates the active current setpoint after PI adjustment of the first error, and determines the reactive current setpoint. The inner current loop compares the actual active current and actual reactive current with the given values of active current and reactive current, respectively, to obtain a second error. The second error is then PI-regulated to generate a reference voltage vector. The reference voltage vector is then subjected to an inverse Parker transformation to obtain the inverse Parker variable of the reference voltage vector. Finally, the inverse Parker variable of the reference voltage vector is modulated by SVPWM to generate a switching signal for dual closed-loop control of the outer voltage loop and the inner current loop.
4. The method for achieving smooth online dual-power switching of a grinding engineering vehicle according to claim 3, characterized in that, Depending on the operating modes of the inverter and diesel generator, the voltage setpoint, current setpoint, and Parker transformation angle are adaptively switched. Specifically: when the inverter or diesel generator is running independently, the voltage setpoint is a fixed value, and the Parker transformation angle is generated by the inverter itself; when the inverter and diesel generator are running in pre-synchronous mode, the voltage setpoint is taken from the output voltage of the diesel generator, and the Parker transformation angle locks the output voltage phase of the diesel generator; when the inverter and diesel generator are running in parallel, the voltage outer loop is deactivated, the active current setpoint is taken from the load current of the grinding vehicle, and the Parker transformation angle locks the output voltage phase of the diesel generator.
5. The method for smoothly switching between dual power sources online for a grinding engineering vehicle according to claim 1, characterized in that, Synchronization is defined as the amplitude difference between the inverter output voltage and the diesel generator output voltage being less than or equal to 2%, and the phase difference between the inverter output voltage and the diesel generator output voltage being less than 5 degrees.
6. The method for achieving smooth online dual-power switching of a grinding engineering vehicle according to claim 1, characterized in that, The process of controlling the output voltage of the inverter power supply to achieve synchronization with the output voltage of the diesel generator is as follows: the output voltage of the diesel generator is collected in real time and determined as the given voltage of the outer loop of the inverter power supply. The amplitude difference and phase difference between the output voltage of the inverter power supply and the output voltage of the diesel generator are reduced to within the preset threshold by adjusting the output frequency of the inverter power supply.
7. The method for smoothly switching between dual power sources online for a grinding engineering vehicle according to claim 1, characterized in that, The switching device uses a thyristor.
8. A device for implementing the method of any one of claims 1-7, enabling smooth online switching between dual power sources for a grinding engineering vehicle, characterized in that, It includes an inverter power supply unit, a switching unit, and a voltage and current acquisition unit; The inverter power supply unit is used in the first switching process to control the output voltage of the inverter power supply to synchronize with the output voltage of the diesel generator. After the output voltages of the two power supplies are synchronized, the control mode of the inverter power supply is switched to the current inner loop control mode, and its active current setpoint is set to zero. Then, the active current setpoint of the inverter power supply is controlled to increase from zero in a linear increment until its output current equals the load current of the grinding vehicle. Then, the control mode of the inverter power supply is switched back to the voltage outer loop control mode to complete the first switching process. The inverter power supply unit is used in the second switching process to control the output voltage of the inverter power supply to synchronize with the output voltage of the diesel generator. After the output voltages of the two power supplies are synchronized, the control mode of the inverter power supply is switched to the current inner loop control mode, and its active current setpoint is set to the load current of the grinding vehicle. The active current setpoint of the inverter power supply is controlled to decrease from the load current of the grinding vehicle in a linear decrease to zero. After the active current setpoint of the inverter power supply drops to zero, the control mode of the inverter power supply is switched back to the voltage outer loop control mode to complete the second switching process. The switching unit is used in the first switching process to control the switching switches located at the output terminals of both the inverter and the diesel generator to close, so that they can operate in parallel, after the output voltage of the inverter and the output voltage of the diesel generator reach a synchronized state. When the output current of the inverter equals the load current of the grinding vehicle, the switching switch is controlled to open, disconnecting the diesel generator. The switching unit is used in the second switching process to control the switching switch to close, so that they can operate in parallel, after the output voltage of the inverter and the output voltage of the diesel generator reach a synchronized state. The voltage and current acquisition unit is used to acquire the output voltage of the diesel generator and the load current of the grinding engineering vehicle in real time during the first and second switching processes.