Motor cooperative power supply control method of special vehicle auxiliary equipment

Abstract

The invention relates to the technical field of power supply control of electric vehicles, and discloses a motor cooperative power supply control method of special vehicle auxiliary equipment, which comprises the following steps of: multiplexing inherent switch harmonic waves of a motor inverter into a physical layer signal bearing own working condition intention, and broadcasting before power operation; other equipment controllers accurately decode the intention signal from a strong interference background through a self-adaptive noise cancellation and spectrum analysis technology, so that the predictive collaborative response of a physical level is realized; according to the invention, the problems of system cooperation passivity and large fluctuation of bus voltage caused by inherent millisecond delay of a traditional digital bus are solved, and the capability of efficient cooperative transmission of energy and information of the DC bus is improved.

Description

Technical Field

[0001] This invention relates to a method for motor-assisted power supply control of auxiliary equipment for special vehicles, belonging to the field of power supply control technology for electric vehicles. Background Technology

[0002] Currently, in the design of modern special vehicles, providing power to multiple motor-driven auxiliary equipment via a single DC bus has become a mainstream technology. Its advantages lie in its centralized structure and flexible energy dispatch. Simultaneously, to achieve coordinated operation among the auxiliary equipment, the system typically relies on an independent digital communication network, such as a controller area network (CAN bus), to transmit status information and control commands. This power and information separation architecture has provided effective support for the modular design and functional implementation of the system for a long time. However, as the tasks of special vehicles become increasingly complex and sophisticated, higher demands are placed on the speed and accuracy of coordinated response. At this point, [further development is needed]. While the technology appears mature, its inherent, long-accepted hidden costs begin to emerge. The information packaging, arbitration, and transmission processes inherent in digital communication networks create an unavoidable millisecond-level time delay between the controller's intention to perform a high-power action and the time when this intention is known by other system units, such as the main generator or energy storage unit. When a high-power motor is about to start or brake, the power supply system is always in a passive, reactive state of being aware of the situation after the fact. This persistent response time difference directly leads to significant fluctuations in the DC bus voltage. This is not only a temporary power quality problem but also causes cumulative physical damage to power electronic components, affecting the long-term reliability of the vehicle.

[0003] To shorten this response time difference, those skilled in the art typically consider two seemingly straightforward improvement paths: one is to replace the CAN bus with a higher bandwidth communication network, and the other is to add a larger and more complex physical filtering device to the DC bus. However, in-depth analysis reveals that the former will significantly increase the hardware cost, software complexity, and overall power consumption of the system, forming a cost barrier that hinders the popularization of the technology, while the latter will increase the dead weight and space occupation of the vehicle, which is extremely disadvantageous for a mobile platform. Therefore, these linear improvement ideas do not address the root of the problem, namely, that the physical medium for information interaction and the physical medium for energy transmission are artificially separated.

[0004] Specifically, existing technologies have the following shortcomings: 1. There is an inherent time delay in system coordination. This delay stems from the need for control information to be transmitted in an independent communication network, which can cause bus voltage surges and damage component lifespan; 2. Higher-level hardware used to mitigate time delays drastically increases system cost and complexity, lacking general engineering economics; 3. The high-frequency switching harmonics generated by the motor inverter itself contain the most immediate and accurate information about the motor's operating conditions and intentions, but these are all treated as noise that must be filtered out, resulting in a waste of the system's intrinsic information. Therefore, how to avoid using expensive high-speed communication networks or bulky physical filters, and instead utilize the system's existing physical carriers and intrinsic signals to construct a low-cost and efficient collaborative control information interaction method, thereby avoiding bus voltage fluctuations and component damage caused by response time differences, is the technical problem this invention aims to solve. Summary of the Invention

[0005] This invention provides a motor-assisted power supply control method for auxiliary equipment of special vehicles. Its main purpose is to solve the problems of response delay, bus voltage fluctuation and high coordination cost caused by the separation of control information and power transmission in the prior art.

[0006] To achieve the above objectives, this invention provides a motor cooperative power supply control method for auxiliary equipment of special vehicles. This method establishes a procedure on a DC bus that multiplexes the unavoidable switching harmonics of each motor controller from noise into zero-delay physical layer broadcast signals carrying their own operational intentions, and achieves predictive coordination through distributed spectrum interpretation. The method is applied to a power supply system comprising a DC bus, a main power supply unit, and multiple motor controllers. The method includes: The controller of the main power supply unit determines the background harmonic ripple characteristics corresponding to the current state from a pre-established noise model that characterizes the harmonic ripple characteristics of the main power supply unit under different operating states, based on its own real-time operating state, and broadcasts the background harmonic ripple characteristics as noise template information. When the first motor controller receives a condition change command, before executing the power operation corresponding to the condition change command, it first listens to the energy level of the harmonic communication frequency band on the DC bus through spectrum analysis. Only when the listened energy level is lower than the silence threshold will it control its own inverter to inject a characteristic harmonic signature that uniquely corresponds to the condition change command into the DC bus. At least one second device controller continuously monitors the DC bus signal and performs adaptive cancellation filtering on the monitored DC bus signal based on the received noise template information. Then, it performs spectrum analysis on the filtered signal to detect characteristic harmonic signatures. When a characteristic harmonic signature is detected, it adjusts its own operating state before voltage fluctuations caused by power operation occur on the DC bus.

[0007] Preferably, the characteristic harmonic signature is a narrowband harmonic current signal with a uniquely determined combination of center frequency and bandwidth, and the frequency of the harmonic communication band is higher than the frequency of the main harmonics generated by power transmission when the power supply system is operating normally.

[0008] Preferably, when the first motor controller detects that the energy level of the harmonic communication frequency band is not lower than the silence threshold, it abandons the current injection operation and, after a delay of a period of time generated by the pseudo-random number generator inside the first motor controller, re-executes the step of detecting the energy level of the harmonic communication frequency band on the DC bus through spectrum analysis.

[0009] Preferably, the adaptive noise cancellation filtering is implemented through an adaptive noise canceller. This adaptive noise canceller uses noise template information as a reference input and the monitored DC bus signal as the main input, and continuously adjusts its internal filter weight coefficients so that the output estimated noise signal approximates the actual shape of the background harmonic ripple in terms of morphology. The filtered signal... Obtained from the following formula: ,in, For the monitored DC bus signal, This is the estimated noise signal output by the adaptive noise canceller.

[0010] Preferably, the method further includes the step of assessing the health status of the transmitter: the second device controller and other receiver controllers in the system, while detecting the characteristic harmonic signature, quantify its spectral purity by calculating the ratio of the main lobe energy of the characteristic harmonic signature signal to the total energy of the signal; when more than a predetermined number of receiver controllers in the system consistently quantify that the spectral purity of the characteristic harmonic signature originating from the same first motor controller is continuously lower than the health status threshold within a continuous time period, a health status warning is generated for the first motor controller.

[0011] Preferably, the method further includes the step of monitoring the health of the shared channel of the power supply system: during the silent period when there is no characteristic harmonic signature injection on the DC bus, all controllers jointly and continuously obtain the background harmonic spectrum shape of the DC bus through spectrum analysis, and calculate the background harmonic energy entropy that characterizes the degree of disorder of the spectrum shape; compare the real-time background harmonic energy entropy with the pre-stored baseline entropy value representing the initial state of system health, and generate a power supply system health status warning when the cumulative change trend of the difference between the two exceeds the degradation judgment threshold.

[0012] Preferably, the second device controller adjusts its own working state as follows: if the second device controller is the controller of the main power supply unit, it adjusts the excitation current to increase the power output capability; if the second device controller is the controller of the energy storage unit, it controls the working state of its internal bidirectional converter to make it enter the pre-charging or pre-discharging preparation mode; if the second device controller is another motor controller, it reduces its own power consumption by reducing its inverter switching frequency or entering a preset standby mode.

[0013] Preferably, the method further includes a channel state self-calibration step: a controller is pre-designated as an echo reference point in the system; when the echo reference point detects the characteristic harmonic signature injected by the first motor controller, it immediately controls its own inverter to inject the same echo harmonic signature into the DC bus; other controllers determine the channel attenuation level between the first motor controller and themselves by calculating the ratio between the signal strength of the characteristic harmonic signature they receive and the signal strength of the echo harmonic signature, and adjust their own signal strength decision threshold for detecting the characteristic harmonic signature based on the channel attenuation level.

[0014] Preferably, the step of controlling its own inverter to inject a characteristic harmonic signature into the DC bus is specifically: by performing a preset micro-modulation on the pulse width modulation signal used to control the power switching transistors inside the inverter, which is not used for power control, to generate a current with a characteristic harmonic signature on the DC bus.

[0015] Preferably, spectrum analysis is achieved by performing a fast Fourier transform on the voltage signal or current signal of the DC bus to obtain the spectrum information of the DC bus signal in the harmonic communication frequency band.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention provides a method for enabling a DC bus to carry stable and clear intent information while functioning as an energy carrier. In systems with high-power main power supply units, the continuously changing operating state of these units introduces strong broadband harmonics into the bus. The intensity and form of these harmonics are unpredictable for other auxiliary electrical equipment. This method establishes a coordination mechanism whereby the controller of the main power supply unit broadcasts its harmonic characteristics under its current operating condition through another communication bus. Other controllers then process the bus signals they collect based on the received characteristic information. Before identifying any specific intent harmonic signature, the noise characteristics of the actively broadcast signal are separated. This allows the weak harmonic signatures carrying the intent of each motor's operating condition to be clearly displayed in the purified information background. The DC bus is thus transformed from a mixed medium where energy and information interfere with each other into a structured transmission environment where information channels and energy channels are independent and do not affect each other, ensuring a stable and reliable decision-making basis for subsequent coordinated actions.

[0017] 2. This method further introduces a distributed, decentralized channel access order. When multiple motor controllers may have collaborative needs at similar times, any controller will use its own spectrum analysis capabilities to listen to the harmonic frequency band to be used before injecting its harmonic signature. Only when the frequency band is in a silent state will the controller perform the injection operation. If it detects that the channel is already occupied, it will delay for a non-fixed time determined by itself before trying again. This "listen first, then speak, and retreat if there is a conflict" access method transforms the situation where multiple harmonic signatures may overlap and become unreadable due to high-density concurrent commands into an ordered, time-divided intention broadcast sequence. The system's collaborative capability is therefore no longer limited by the number and frequency of concurrent commands, and it can still maintain clear and stable information interaction even in complex and high-intensity operating scenarios.

[0018] 3. The spectrum analysis and information interaction mechanism established by this method, in addition to fulfilling its main collaborative control function, also provides a health status assessment approach for the entire power supply system. During the quiet window period when there is no active harmonic signature broadcasting in the system, all controllers can continuously monitor the overall morphological changes of the background harmonic spectrum of the DC bus. By tracking its long-term slow evolution trend, it can detect the early physical characteristic degradation of key passive components such as large-capacity filter capacitors due to aging. At the same time, in each successful harmonic signature interaction, all receiver controllers, in addition to interpreting its intent information, also evaluate the spectral purity of the signature. A signature quality that is continuously declining from a specific transmitter and is jointly confirmed by multiple receivers reflects that the health of the power semiconductor devices at that transmitter is changing. Thus, this method uses the same set of hardware and core algorithms, time-division multiplexing in time, to construct a two-dimensional diagnostic system: firstly, monitoring the public health of the shared channel, and secondly, assessing the individual health of independent nodes. This allows some hardware degradation processes that are not easy to measure directly and are gradual to be detected in advance in the form of clear early warning information. Attached Figure Description

[0019] Figure 1 This is a flowchart of the predictive collaborative control based on harmonic communication of the present invention. Figure 2 This is a system architecture diagram of the shared bus for harmonic information and power in this invention; Figure 3 This is a comparison diagram of the bus voltage response under load impact according to the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] This invention discloses a motor-assisted power supply control method for auxiliary equipment of special vehicles, applied to a power supply system comprising a DC bus, a main power supply unit, and multiple motor controllers. This method establishes a physical layer intent prediction and coordinated response procedure by encoding and broadcasting the switching harmonics generated by each motor controller during power conversion, and then having other device controllers perform distributed decoding. The main stages of this procedure include: the main power supply unit broadcasting its background harmonic ripple characteristics as a noise template; the intent-initiating motor controller injecting characteristic harmonic signatures after performing channel access control; and other device controllers performing adaptive noise cancellation and spectrum analysis to decode the intent and achieve predictive self-adjustment of their operating states. In a specific application scenario, such as a heavy engineering vehicle equipped with multiple sets of motor-driven auxiliary equipment including a main boom, slewing platform, and hydraulic pump station, all auxiliary equipment is powered by a high-power diesel generator as the main power supply unit, supplied through a shared DC bus. In such systems, maintaining the stability of the DC bus voltage is a crucial consideration for system operation; however, the main power supply unit... When the main power supply unit operates under different loads, it injects high-intensity, wide-spectrum harmonic ripple into the bus. This ripple constitutes a significant structural noise source for devices that need to interact with weak signals. To address this, the method of this invention is configured such that the controller of the main power supply unit first queries and determines the background harmonic ripple characteristics corresponding to the current state from a noise model pre-built in its non-volatile memory, based on its real-time monitored operating state parameters such as rotational speed and load rate. This noise model is a data structure that maps the discrete operating state range of the main power supply unit to a set of parameters describing the frequency points and corresponding amplitudes of the main harmonic ripples in that state. The controller then uses this set of background harmonic ripple characteristics containing frequency and amplitude information as noise template information and periodically broadcasts it through the vehicle's controller area network, i.e., the CAN bus. Since the rate of change of the operating conditions of the main power supply unit is usually lower than the transmission rate of the CAN bus, this method can provide the entire network with near-real-time reference information about the main interference sources with low communication overhead, thereby providing the necessary prior conditions for subsequent signal purification processing.

[0022] Furthermore, when any motor controller in the system, such as the first motor controller of the main boom, receives a command to change the operating condition to full-power lifting, it needs to reliably notify other units in the system of this power consumption intention so that they can coordinate a response. To achieve this, the first motor controller does not immediately adjust the main power output of its inverter, but first executes a channel access control procedure. It uses the fast Fourier transform analysis unit built into its microcontroller to perform a fast energy listening on a preset harmonic communication frequency band with a frequency higher than the main harmonic frequency of the system's normal power transmission, such as 100kHz-200kHz. The detected energy level is then compared with a preset silence threshold. This silence threshold is determined during the self-calibration phase of the system's first power-on by collecting the background noise baseline of the harmonic communication frequency band when there is no active injection signal and taking a specific multiple of its peak value, such as 1.5 times. If the detected energy level... If the energy level is below the silence threshold, it indicates that the channel is idle. The controller then controls its own inverter to perform a preset micro-modulation on the pulse width modulation signal used to control its internal power switches, which is not used for power control. This micro-modulation injects a characteristic harmonic signature that uniquely corresponds to the full-power start-up command into the DC bus. This characteristic harmonic signature is a narrowband harmonic current signal with a uniquely determined combination of center frequency and bandwidth. Its energy is low, but it has a recognizable shape in the spectrum, thus completing the physical layer broadcast of its own operating condition intention. Correspondingly, if the energy level is found to be not lower than the silence threshold during the channel listening step, it indicates that the channel is occupied. At this time, the first motor controller abandons the injection operation and delays for a random time between 5 and 50 microseconds generated by its internal pseudo-random number generator before returning to the listening step. This access mechanism helps to avoid harmonic signal collisions and information aliasing that may occur when multiple intentions are executed concurrently.

[0023] All other device controllers in the system, such as the main power supply unit controller, energy storage unit controller, or the second device controller of the slewing platform, require no hardware modifications. They only continuously sample and monitor the DC bus voltage or current signal at a high frequency in software. Upon receiving noise template information broadcast by the main power supply unit, they construct and run an adaptive cancellation filter in real time within their respective microcontrollers. This filter uses the received noise template information as a reference input and the real-time monitored DC bus signal as its main input. It continuously adjusts its internal filter weights according to the least mean square algorithm, dynamically tracking and approximating the actual background harmonic ripple on the bus in terms of morphology. Thus, these controllers can obtain a purified signal by subtracting the estimated noise signal output by the filter from the monitored original bus signal. The mathematical relationship can be expressed as follows: ,in, For the monitored DC bus signal, The estimated noise signal is the output of the adaptive noise canceller, and This refers to the signal whose background noise has been suppressed after filtering. The controller then processes this purified signal. By performing a Fast Fourier Transform, specific characteristic harmonic signatures can be detected within a preset harmonic communication frequency band. When a full-power ramp-up harmonic signature with a center frequency of, for example, 150kHz is detected, these controllers become aware of the impending power demand in the system and adjust their own operating state before voltage fluctuations occur on the DC bus caused by the actual power operation of the first motor controller. Specifically, if the second device controller is the controller of the main power supply unit, it can adjust its excitation current to prepare for increasing power output capability; if it is the controller of the energy storage unit, it can adjust its internal circuit state to prepare for releasing electrical energy to the bus; and if it is another motor controller operating under light load, it can adjust its operating mode to temporarily reduce its own power consumption.

[0024] It should be noted that the information interaction mechanism established in this invention can be reused, without conflict, to assess the health status of the system. Firstly, it monitors the health of the shared channel. During the silent period when there are no characteristic harmonic signatures injected into the DC bus, all controllers can continuously obtain the spectral morphology of the background harmonics of the bus through spectrum analysis and calculate the background harmonic energy entropy, which characterizes the degree of disorder in the spectral morphology. By comparing the real-time background harmonic energy entropy with a baseline entropy value stored in the initial health state of the system, when the cumulative change trend of the difference between the two exceeds a preset degradation judgment threshold, the system can generate a power supply system health status warning. Secondly, it assesses the individual health of the transmitter. When the second device controller and other receiver controllers in the system detect a characteristic harmonic signature, they can also calculate in parallel the ratio of the main lobe energy of the signature signal to the total energy of the signal, thereby quantifying its spectral purity. When the system... If more than a predetermined number of receiving controllers consistently quantify the spectral purity of the characteristic harmonic signature originating from the same first motor controller within a continuous time period, a health status warning can be generated for that first motor controller. Furthermore, to address the uncertainty of channel attenuation caused by dynamic changes in the vehicle's electrical topology, this method can further configure a channel state self-calibration step. By pre-designating a controller with a fixed electrical location as an echo reference point in the system, when this echo reference point detects any characteristic harmonic signature, it injects the same echo harmonic signature into the bus. Other controllers then determine the degree of channel attenuation between themselves and the signal initiator by calculating the ratio of the signal strength of their received original characteristic harmonic signature to that of the echo harmonic signature. Based on this attenuation degree, they dynamically adjust their own signal strength decision threshold for detecting harmonic signatures to improve the reliability of information interaction in variable electrical environments.

[0025] Example 1: This example illustrates the operation and effects in a specific application scenario involving multi-task concurrency and strong electrical interference. In a fully electrically driven automated port, a rail-mounted container gantry crane is operating. The crane's main power supply unit, main hoisting motor, trolley travel motor, and auxiliary trolley travel motor are all connected to the same high-voltage DC bus. During a certain operating cycle, a condition that tests the stability of the bus occurs: the main hoisting motor controller receives a full-speed hoisting command for a fully loaded container, and within a similar microsecond window, the trolley travel motor controller also receives a full-speed translation command. This condition not only means that the two high-power motors are about to simultaneously request a considerable starting current from the bus, but also that the two motor controllers have a high probability of simultaneously attempting to broadcast their operating intentions to the harmonic channel, potentially causing information collisions. When this condition occurs, the crane's main power supply unit controller is continuously broadcasting the background harmonic ripple characteristics of its current state via the CAN bus according to its own operating load. All other controllers in the system... The controllers of both the main hoisting motor and the trolley travel motor have received this noise template information and processed the monitored DC bus signal using their respective adaptive cancellation filters. This maintains a harmonic communication channel that suppresses the main background noise, providing a high signal-to-noise ratio decision-making basis for the subsequent channel listening operations performed by the main hoisting and trolley travel motor controllers. When the two operating condition change commands are issued, the main hoisting motor controller and the trolley travel motor controller simultaneously prepare to inject their respective characteristic harmonic signatures. Before performing the injection operation, they both perform energy listening on the harmonic communication frequency band. Due to a slight physical time difference, the main hoisting motor controller completes its listening before the trolley travel motor controller. It detects that the channel energy is below the silence threshold and then injects the characteristic harmonic signature representing heavy-load start-up. Immediately afterwards, when the trolley travel motor controller performs its listening, it detects the harmonic energy injected by the main hoisting motor, whose energy level is higher than the silence threshold. Therefore, it abandons this injection and starts its internal pseudo-random timer to enter a short random silence waiting period.

[0026] Within tens of microseconds after the main hoisting motor injects its characteristic harmonic signature, all other controllers in the system, including the main power supply unit, energy storage unit, and trolley travel motor, detect this heavy-load start signature from the bus signal after adaptive cancellation filtering. The main power supply unit controller increases its power output before a significant change in bus voltage occurs, and the energy storage unit prepares to release energy. Subsequently, the main hoisting motor begins to draw a large current. Because the power supply side has entered a prepared state in advance, the DC bus voltage only experiences a slight dip within the allowable range before stabilizing, avoiding voltage instability that could be caused by response delay. After the random silent waiting period of the trolley travel motor controller ends... It relistens to the channel, and when the channel has returned to silence, it successfully injects its own characteristic harmonic signature. The system units then respond to its request a second time in a coordinated manner. This operating mode transforms a resource competition that could lead to bus disturbances and information conflicts into an ordered, time-division coordinated response sequence based on physical layer channel access rules. This enables the parallel operation of high-power energy transmission and weak intent information transmission on a single DC bus physical medium. During the entire concurrent operation, the DC bus voltage of the crane is maintained within the preset operating range, and both the main hoisting motor and the trolley traveling motor start smoothly without any controller protective shutdown events caused by voltage fluctuations.

[0027] Example 2: To objectively verify the effectiveness of the aforementioned technical solution in suppressing DC bus voltage fluctuations, this example constructs a hardware-in-the-loop test platform to simulate a multi-motor power supply system for special vehicles. This platform consists of a programmable DC power supply simulating the main power supply unit, a high-power programmable electronic load simulating the main crane motor, and two physical motor controllers configured with the method of this invention and existing technologies, respectively. A high-speed data acquisition system synchronously monitors the voltage and current of the DC bus. The experiment aims to quantitatively compare the differences in key performance indicators between the system using the cooperative control method of this invention and the system using the traditional CAN bus communication cooperative method when subjected to the same instantaneous high-power load impact. The key parameters of the test platform are set as follows: the nominal voltage of the DC bus is set to 600V; the instantaneous load impact setting needs to strike a balance between reproducibility and representativeness. For this purpose, the programmable electronic load is set to linearly increase the current step from unloaded state to 200A within 10ms. This parameter is used to simulate the common process of a high-power motor starting from standstill to full load. Its value is selected based on the analysis of the starting current curves of commonly used motors in this field; for the sample group of this invention, the characteristic harmonic signature used to broadcast the intention of heavy-load start is set to a center frequency of 150kHz. This frequency is chosen to avoid the low- and medium-frequency harmonics generated by the main power supply unit and the motor inverter during normal power conversion, so as to obtain a higher communication signal-to-noise ratio.

[0028] The experiment was conducted in two groups: a control group using a traditional CAN bus for collaborative control, and a prototype group using the harmonic collaborative power supply control method of this invention. In the control group, the programmable DC power supply only compensated for the output voltage through its internal adjustment circuit after detecting an actual change in the bus current; its collaborative information relied on a simulated CAN bus signal with millisecond-level delay. In the prototype group, the programmable electronic load controller injected a 150kHz characteristic harmonic signature into the DC bus within a specific time window before performing a current step operation; the programmable DC power supply controller was equipped with harmonic signature detection and pre-response capabilities. Under the same load impact conditions, a significant difference was observed when comparing the dynamic process of the bus voltage in the two groups. The voltage in the control group experienced a sharp drop to 58.4V, and the time required for it to recover to 98% of the stable threshold was [not specified in the original text]. The response time was 125.6 ms, reflecting the limitation of its collaborative response time by the approximately 1850.5 μs communication delay of the CAN bus. In contrast, the voltage of the sample group of this invention only showed a gentle dip of 11.3V, with a voltage recovery time of 41.5 ms, and its collaborative response time was shortened to 85.2 μs. This improvement stems from the fact that the main power supply unit can receive the power consumption intention through the harmonic signature propagated by the physical layer within a microsecond window before the programmable electronic load actually consumes a large current, and start increasing the power output in advance, thereby actively canceling most of the upcoming load impact. The test results show that under the same load impact conditions, the power supply system using the method of this invention has a lower DC bus voltage drop amplitude and recovery time compared to the system using traditional CAN bus collaboration. This improvement in voltage stability helps to reduce the working stress of power electronic components in the system and improve the operational reliability of the vehicle power supply system.

[0029] Example 3: This example combines Figures 1 to 3 This document describes a method for coordinated power supply control of an auxiliary device for a special vehicle, such as... Figure 1As shown, the process begins with any motor controller receiving a condition change command and then executing a listen-before-speak channel access mechanism. This involves listening to the harmonic communication frequency band. If the channel is detected as idle, a characteristic harmonic signature is injected to broadcast the intended condition. If the channel is detected as occupied, the controller relistens after a delay to avoid information aliasing. Simultaneously, other controllers in the system continuously monitor the bus signal and accurately identify this intended signal from a strong interference background through adaptive noise cancellation and spectrum analysis decoding techniques. This enables predictive coordinated response, adjusting the controller's operating state before power disturbances occur, ultimately achieving the goal of stable bus voltage and efficient coordination. Furthermore, the process reuses an information interaction mechanism to provide endogenous health status assessment, including shared channel health monitoring to monitor shared channel aging and transmitter individual health assessment to evaluate the status of individual devices. The entire process relies on using the DC bus as a medium for the fusion of energy and cyber-physical layers.

[0030] like Figure 2 As shown, the main power supply unit broadcasts real-time background harmonic characteristics via the CAN bus based on its internal noise model. Various controllers connected to the DC bus (DCBUS) work collaboratively. The first motor controller, upon receiving the command, performs operations 1. channel listening and 2. signature injection. The second equipment controller and energy storage unit controller, among others, continuously monitor the bus. Upon receiving the noise template broadcast by the main power supply unit, they utilize an adaptive cancellation filter, according to the formula... The signal is purified and then the signature is detected by FFT spectrum analysis. Once the signature is detected, a series of actions are executed, including 3. Signature detection, 4. Pre-response, 5. Cooperative control, etc., to finally achieve the goal of 6. Stabilizing the bus. This architecture uses distributed intelligence to upgrade the traditional DC bus into a system that has both power transmission and high-speed information interaction capabilities.

[0031] like Figure 3 As shown in the figure, the horizontal axis represents time. The left vertical axis represents the bus voltage. The right vertical axis represents the load current. When a step impact occurs on the dotted line in the load current diagram, the bus voltage under the control of the dashed line in the traditional CAN bus method diagram experiences a sharp drop and a slow recovery process. In contrast, the bus voltage under the control of the solid line in the harmonic communication method diagram of this invention only experiences a dip with a very small amplitude and a rapid recovery. This shows that the present invention has significant technical advantages in suppressing bus voltage fluctuations through predictive collaborative response.

[0032] Example 4: This example illustrates the systematic calibration procedure for the key models and thresholds involved in the aforementioned method. To ensure the operational reliability of the coordinated power supply control method, a standardized offline calibration and online self-calibration procedure must be performed before a special vehicle leaves the factory for the first time or after deep maintenance. This procedure first calibrates the noise model of the main power supply unit in a controlled test environment. The unit is then run stably at multiple preset discrete load points from idle to full load through a standard operating condition cycle program. At each load point, a high-bandwidth spectrum analyzer is used to collect the harmonic ripple data output to the DC bus and record it. Several frequency points with significant energy and their corresponding amplitudes within the harmonic communication band are identified. These load point harmonic characteristic data pairs are stored in the non-volatile memory of the main power supply unit controller in the form of a lookup table, thus constructing a noise model reflecting the harmonic ripple characteristics of the unit under different operating states. Subsequently, the system enters the health state baseline learning phase. With all auxiliary equipment of the vehicle in a silent state, all controllers jointly analyze the background harmonic spectrum of the DC bus at this time and obtain the baseline entropy value through a standardized background harmonic energy entropy calculation process. This process specifically involves dividing the monitored harmonic communication band into... Each of the equal-width frequency panes is used to calculate the frequency of each pane. Internal signal energy ,pass Calculate the energy percentage of each pane, and finally use the formula Obtain the baseline entropy value characterizing the initial health state of the system. The degradation threshold associated with this baseline entropy value is set when the background harmonic energy entropy calculated in real time is lower than this value for multiple consecutive sampling periods. When it reaches 80%, an early warning is triggered.

[0033] The spectral purity health status threshold used to assess the health status of the transmitter is set through another calibration process. During the commissioning phase, a controller injects a reference characteristic harmonic signature with a spectral shape close to the ideal, generated by a high-precision signal source, into the bus. At this time, all receiver controllers quantify the spectral purity of the reference signal, take the average of multiple measurements as 98.5%, and set 85% of this average as the health status threshold. Through the above process, each model and threshold mentioned in the previous implementation is given a clear physical meaning and a reproducible calibration method. After completing all offline calibration and online self-calibration, the cooperative power supply control system of this special vehicle has a known quantified initial state. All subsequent health status monitoring and diagnosis in actual operation will be based on the comparison with this initial state.

[0034] Example 5: This example describes the adaptive configuration of the collaborative power supply control method when applied to different vehicle platforms, as well as the integration verification procedure when adding auxiliary equipment during the system life cycle. Before deploying the method of this invention on a new model of special vehicle platform, a basic survey of harmonic channel characteristics and signature set design procedure must be performed. This procedure first collects the inherent background harmonic noise spectrum of the DC bus under the vehicle's preset operating conditions, including idling and high load conditions, and identifies several high-frequency bands with background noise energy below a preset threshold as candidate harmonic communication frequency bands. Subsequently, within the selected frequency bands, a set of candidate characteristic harmonic signatures with intervals in center frequency and bandwidth is defined, and cross-correlation analysis is performed through offline simulation to evaluate the probability that any signature will be misidentified as another signature under the conditions of signal attenuation and phase distortion. Finally, a set of characteristic harmonic signatures with the lowest cross-correlation coefficient and the highest identification separation degree in the electrical environment of this specific vehicle platform is selected and solidified as the communication protocol followed by all controllers on this model of vehicle.

[0035] When a vehicle already equipped with the method of this invention needs to have a new auxiliary electrical device installed, a field compatibility verification and channel evaluation process must be performed to maintain the operational integrity of the existing harmonic cooperative communication. This process involves independently running the new device while keeping the vehicle's existing equipment silent, and allowing it to traverse its main operating modes. During this period, all configured controllers in the vehicle jointly monitor and record whether the harmonic noise generated by the new device overlaps spectrally with any signature in the pre-defined set of characteristic harmonic signatures. If the monitoring results show that its noise spectrum does not interfere with the existing harmonic communication frequency band, the device is considered compatible. If its noise energy exceeds the silence threshold of a certain communication frequency, the system can generate an incompatibility warning, or, in a system with dynamic spectrum allocation capabilities, reassign the operating condition intent corresponding to the interfered characteristic harmonic signature to an uncontaminated backup harmonic communication frequency, thereby maintaining the operational integrity of the cooperative control system.

[0036] Example 6: This example aims to supplement the explanation of the optimization selection procedure for key control parameters in the cooperative control method. In order to determine the value of the silence threshold in the "listen first, speak later" mechanism to optimize the balance between channel utilization and communication reliability, an offline calibration of the receiver's operating characteristics needs to be performed. This calibration is carried out in a controllable noise environment. First, a background noise signal with known power spectral density and amplitude is injected into the DC bus to simulate the vehicle's electrical environment. Then, a reference characteristic harmonic signature signal with a power gradient from high to low is injected on the noise background. At the receiver controller side, the missed detection rate of the reference signal and the false judgment rate of the simple background noise are recorded simultaneously under different silence threshold settings. By analyzing these two sets of mutually constraining data, an energy value that minimizes the sum of the missed detection rate and the false judgment rate is finally selected as the silence threshold of the system at this background noise level.

[0037] To set the step size factor for the minimum mean square algorithm in adaptive cancellation filtering. To ensure both rapid convergence and algorithm stability, another parameter optimization process is required. This process is conducted in an offline simulation environment, where a background harmonic ripple signal derived from a noise model is superimposed with a standard characteristic harmonic signature signal as the algorithm's input. Then, within a preset interval, the step size factor is adjusted iteratively. The values ​​are recorded, and the estimated noise signal output by the algorithm is recorded for each value. The root mean square error between the filter and the real background harmonic ripple signal is calculated to determine the time required for convergence to a steady state. Ultimately, the filter is selected to minimize this convergence time without causing oscillations in the filter coefficients. The value serves as the fixed working parameter for this algorithm. To address sudden strong electromagnetic interference events that vehicles may encounter during operation that are not originating from their own power supply system, this method also includes an online identification and response logic for abnormal noise environments. During communication silence, in addition to calculating the background harmonic energy entropy, all controllers continuously monitor the total energy level of the harmonic communication frequency band. When the total energy level rises to an abnormally high level far exceeding the historical baseline and the noise model prediction within a short period of time, and its spectral shape does not match any defined characteristic harmonic signature, the system determines that it has encountered external strong electromagnetic interference. In this state, all controllers will suspend any new characteristic harmonic signature injection operations until the total energy level is detected to return to the normal range. After that, the system will automatically lift the above restrictions and restore the normal cooperative communication mode.

[0038] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for motor-assisted power supply control of auxiliary equipment for special vehicles, characterized in that, The method is applied to a power supply system comprising a DC bus, a main power supply unit, and multiple motor controllers, and includes: The controller of the main power supply unit determines the background harmonic ripple characteristics corresponding to the current state from a pre-established noise model that characterizes the harmonic ripple characteristics of the main power supply unit under different operating states, based on its own real-time operating state, and broadcasts the background harmonic ripple characteristics as noise template information. When the first motor controller receives a condition change command, before executing the power operation corresponding to the condition change command, it first listens to the energy level of the harmonic communication frequency band on the DC bus through spectrum analysis. Only when the listened energy level is lower than the silence threshold will it control its own inverter to inject a characteristic harmonic signature that uniquely corresponds to the condition change command into the DC bus. At least one second device controller continuously monitors the DC bus signal and performs adaptive cancellation filtering on the monitored DC bus signal based on the received noise template information. Then, it performs spectrum analysis on the filtered signal to detect characteristic harmonic signatures. When a characteristic harmonic signature is detected, it adjusts its own operating state before voltage fluctuations caused by power operation occur on the DC bus.

2. The method for motor-assisted power supply control of auxiliary equipment for special vehicles according to claim 1, characterized in that, A characteristic harmonic signature is a narrowband harmonic current signal with a unique combination of center frequency and bandwidth. The frequency of the harmonic communication band is higher than the frequency of the main harmonics generated by power transmission when the power supply system is operating normally.

3. The method for motor-assisted power supply control of auxiliary equipment for special vehicles according to claim 1, characterized in that, When the first motor controller detects that the energy level of the harmonic communication band is not lower than the silence threshold, it abandons the current injection operation and, after a delay of a period of time generated by the pseudo-random number generator inside the first motor controller, re-executes the step of detecting the energy level of the harmonic communication band on the DC bus through spectrum analysis.

4. The method for motor-assisted power supply control of auxiliary equipment for special vehicles according to claim 1, characterized in that, Adaptive noise cancellation filtering is implemented through an adaptive noise canceller. This adaptive noise canceller uses noise template information as a reference input and the monitored DC bus signal as the main input, continuously adjusting its internal filter weight coefficients to make the output estimated noise signal approximate the actual shape of the background harmonic ripple. The filtered signal... Obtained from the following formula: ,in, For the monitored DC bus signal, This is the estimated noise signal output by the adaptive noise canceller.

5. The method for motor-assisted power supply control of auxiliary equipment for special vehicles according to claim 1, characterized in that, The method further includes the step of assessing the health status of the transmitter: the second device controller and other receiver controllers in the system, while detecting the characteristic harmonic signature, quantify its spectral purity by calculating the ratio of the main lobe energy of the characteristic harmonic signature signal to the total energy of the signal; when more than a predetermined number of receiver controllers in the system consistently quantify that the spectral purity of the characteristic harmonic signature originating from the same first motor controller is continuously lower than the health status threshold within a continuous time period, a health status warning is generated for the first motor controller.

6. The method for motor-assisted power supply control of auxiliary equipment for special vehicles according to claim 1, characterized in that, The method further includes the step of monitoring the health of the shared channel of the power supply system: during the silent period when there is no characteristic harmonic signature injection on the DC bus, all controllers jointly and continuously obtain the background harmonic spectrum shape of the DC bus through spectrum analysis, and calculate the background harmonic energy entropy that characterizes the degree of disorder of the spectrum shape; compare the real-time background harmonic energy entropy with the pre-stored baseline entropy value representing the initial state of system health, and generate a power supply system health status warning when the cumulative change trend of the difference between the two exceeds the degradation judgment threshold.

7. The method for motor-assisted power supply control of auxiliary equipment for special vehicles according to claim 1, characterized in that, The second equipment controller adjusts its own working state as follows: if the second equipment controller is the controller of the main power supply unit, it adjusts the excitation current to increase the power output capability; if the second equipment controller is the controller of the energy storage unit, it controls the working state of its internal bidirectional converter to make it enter the pre-charge or pre-discharge preparation mode; if the second equipment controller is another motor controller, it reduces its inverter switching frequency or enters the preset standby mode.

8. The method for motor-assisted power supply control of auxiliary equipment for special vehicles according to claim 1, characterized in that, The method further includes a channel state self-calibration step: a controller is pre-designated as an echo reference point in the system; when the echo reference point detects the characteristic harmonic signature injected by the first motor controller, it immediately controls its own inverter to inject the same echo harmonic signature into the DC bus; other controllers determine the channel attenuation level between the first motor controller and themselves by calculating the ratio between the signal strength of the characteristic harmonic signature they receive and the signal strength of the echo harmonic signature, and adjust their own signal strength decision threshold for detecting the characteristic harmonic signature based on the channel attenuation level.

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