Direct-current power supply switching method based on current feedback closed-loop control

Abstract

The invention discloses a direct-current power supply switching method based on current feedback closed-loop control, and belongs to the technical field of direct-current power supply control, and the direct-current power supply switching method based on current feedback closed-loop control comprises the following steps: all steps realize signal interaction through an anti-interference bus and an isolation circuit; the method comprises the following steps: S1, multi-parameter acquisition and anti-interference processing: acquiring output voltage U, output current I, feeder insulation resistance R and core device temperature T of a main power supply and a standby direct-current power supply, and performing differential conditioning and anti-interference processing on acquired signals; s2, dual-core cooperative control: a main control unit performs data processing and fault pre-judgment, a logical operation unit operates an adaptive algorithm to realize current closed-loop adjustment, and the main control unit and the logical operation unit cooperate to ensure that the instruction response delay is less than or equal to 1 microsecond; s3, current pre-synchronization and seamless switching: adopting current pre-synchronization and switching logic of first on and then off; and S4, performing graded alarm and information feedback. The method has the advantages of fast response, no breakpoint and accurate judgment.

Description

Technical Field

[0001] This invention belongs to the field of DC power supply control technology, and particularly relates to a DC power supply switching method based on current feedback closed-loop control. Background Technology

[0002] As the control core of electronic equipment, the reliability of DC power supply directly determines the operational safety and data integrity of the equipment. Currently, mainstream DC power switching solutions generally suffer from three major technical bottlenecks: First, relying on mechanical switches for switching typically results in an action delay exceeding 10 milliseconds, failing to meet the instantaneous power supply requirements of high-frequency precision equipment and easily leading to data loss; second, typically employing the traditional logic of disconnecting before connecting, the load experiences millisecond-level power outages, making it difficult to adapt to equipment requiring continuous operation; third, usually triggering switching only through a single voltage or current threshold, it is susceptible to instantaneous interference such as grid fluctuations and load surges, leading to erroneous switching or missed fault detection.

[0003] To address the aforementioned issues, while existing improvement technologies attempt to shorten delays using high-speed semiconductor devices, they fail to resolve the problem of sudden current changes during switching. Some solutions incorporate multi-parameter monitoring, but lack quantitative control logic support, resulting in control accuracy that still cannot meet the demands of high-end applications. Therefore, developing a fast-response, seamless, and accurate power switching system has become an urgent industry need. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a DC power supply switching method based on current feedback closed-loop control, which has the advantages of fast response, no breakpoints, and accurate judgment, thus solving the problems of the prior art.

[0005] This invention is implemented as follows: a DC power supply switching method based on current feedback closed-loop control includes the following steps, in which each step achieves signal interaction with an anti-interference bus and an isolation circuit, forming a closed-loop control link:

[0006] S1. Multi-parameter acquisition and anti-interference processing: Acquire the output voltage U, output current I, feeder insulation resistance R, and core device temperature T of the main power supply and backup DC power supply, and perform differential conditioning and anti-interference processing on the acquired signals;

[0007] S2. Dual-core collaborative control: The main control unit performs data processing and fault prediction, while the logic operation unit runs an adaptive algorithm to achieve current closed-loop regulation. The two work together to ensure that the command response delay is ≤1μs.

[0008] S3. Current pre-synchronization and seamless switching: The current pre-synchronization and switching logic of turning on before turning off are adopted. The logic operation unit outputs control signals to drive the high-speed switching device to achieve seamless switching between the main power supply and the backup power supply.

[0009] S4. Graded Alarm and Information Feedback: Output graded early warning signals based on fault type, including local audible and visual prompts and remote information notifications, and simultaneously feed back the switching results to the main control unit to complete closed-loop control.

[0010] As a preferred embodiment of the present invention, the voltage acquisition in step S1 includes the following steps: building a voltage divider network and configuring the voltage division ratio to 50:1-200:1 according to the rated voltage of the main and backup power supplies; connecting an operational amplifier to amplify the weak signal after voltage division, with the amplification factor matching the voltage division ratio to output a standard analog signal; performing zero-point and gain calibration on the output signal to ensure that the acquisition accuracy is ≤±0.5% and the standard analog signal output range is 1V-5V.

[0011] As a preferred embodiment of the present invention, the current acquisition in step S1 includes the following steps: selecting a closed-loop current sensor and matching the sensor range according to the load current range; filtering and level conditioning the sensor output signal to eliminate high-frequency interference; transmitting the conditioned signal in two paths, one for real-time adjustment and the other for data monitoring, with sensor acquisition accuracy ≤ ±0.5%, linearity error ≤ ±0.5%, and the conversion coefficient between output and input current can be configured as needed.

[0012] As a preferred embodiment of the present invention, the current pre-synchronization control in step S3 includes the following steps: real-time calculation of the main and backup power supply current deviation e= - ,in, Real-time current of the main power supply This is for backup power supply current; the logic unit calls an adaptive PID algorithm to dynamically configure the proportional coefficient according to the load type. Integral coefficient With differential coefficients Through formula Calculate the current regulation amount ΔI; continuously output the regulation signal to the backup power supply until |e|≤50mA triggers the switching permission, and |e|≤20mA is judged as the synchronization is completed. The sampling period of the PID algorithm is configured to be 50μs-200μs. Among them, the PID coefficients are dynamically adapted according to different load characteristics such as resistive and inductive to ensure that there is no overshoot during the regulation process.

[0013] As a preferred embodiment of the present invention, the seamless switching in step S3 includes the following steps: after receiving the switching command, the logic operation unit configures the turn-on-off timing parameters according to the load power; S32. the backup power high-speed switch is turned on first according to the configured timing, and the main power high-speed switch is turned off after an interval of 1μs-20μs, ensuring that the switching overlap time is 5μs-15μs; the load voltage fluctuation ΔU during the switching process is monitored in real time, and ΔU is kept ≤±2% through current pre-synchronization control. ,in are the rated output voltages of the main power supply and the backup power supply;

[0014] The voltage fluctuation ΔU is predicted and controlled by the following formula:

[0015]

[0016] where is the rated current of the load. By optimizing the current deviation the fluctuation control target is achieved to ensure that the voltage fluctuation meets the relevant requirements of power quality.

[0017] Preferably, in the present invention, the insulation resistance acquisition in step S1 includes the following steps: generating a sinusoidal detection signal with a frequency of 500 Hz - 2 kHz and a peak-to-peak value (the difference between the positive peak value and the negative peak value of the signal) of 0.5 V - 2 V; injecting the detection signal into the power supply feeder through an isolation coupling circuit to avoid interfering with the main power supply circuit; synchronously collecting the signal amplitudes of the positive and negative poles of the power supply to the ground, and calculating the insulation resistance R in combination with a reference resistor; setting two-level thresholds, where a fault is triggered when R ≤ 300 kΩ, and a warning is triggered when 300 kΩ < R ≤ 500 kΩ.

[0018] Preferably, in the present invention, the fault prediction in step S2 includes the following steps: establishing a multi-parameter threshold library, setting the voltage threshold to 0.8U - 1.15U, the current threshold to ≤1.2I, and the temperature threshold and the insulation resistance threshold are configured as required; continuously collecting parameter data for 3 to 5 sampling periods to exclude single instantaneous interference;

[0019] Comparing the parameters with the threshold library, and judging the fault type in combination with the parameter change trend to generate corresponding control instructions.

[0020] Preferably, in the present invention, the temperature acquisition in step S1 includes the following steps: arranging temperature-sensitive elements on the surfaces of high-speed switches and power devices; measuring the resistance value of the elements at the standard temperature to establish a resistance-temperature correspondence curve; real-time collecting the resistance signals of the elements and converting them into temperature values, triggering the heat dissipation control in advance when the temperature reaches the warning threshold, and starting the switching process when the temperature reaches the fault threshold.

[0021] Preferably, in the present invention, the dual-core cooperation in step S2 includes the following steps: the master control unit and the logic operation unit complete the communication protocol matching during initialization and set the data interaction format; the master control unit pushes the collected data and the fault prediction results to the logic operation unit in real time, and the push period ≤ 10 μs; the logic operation unit feeds back the adjustment instructions and the execution status to the master control unit, the dual-core data interaction rate ≥ 100 Mbps, and the signal acquisition accuracy of the logic operation unit ≥ 12 bits.

[0022] As a preferred embodiment of the present invention, data storage and parameter display include the following steps: configuring a storage module to store data according to operating parameters, fault information, and switching records, with a storage duration of ≥1 year; the local display module refreshes core parameters such as U, I, T, and R in real time, and uses a graphical interface to display the parameter change trend; and supports the retrieval of historical data through local operation or remote commands, which facilitates fault tracing and system optimization.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] The traditional 10-millisecond switching latency is compressed to less than 50 microseconds, improving the response speed by 200 times and adapting to the needs of high-frequency precision equipment. Through current pre-synchronization technology, voltage fluctuations during switching are controlled within ±2%, completely eliminating power supply interruptions and ensuring continuous equipment operation. The judgment mechanism based on multi-parameter thresholds and continuous cycle verification effectively avoids false or missed judgments caused by instantaneous interference. The hierarchical alarm and remote feedback functions are adapted to unattended scenarios, reducing operation and maintenance costs and shortening fault handling time. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the steps of the DC power supply switching method based on current feedback closed-loop control provided in an embodiment of the present invention;

[0026] Figure 2 This is a flowchart illustrating the DC power supply switching method based on current feedback closed-loop control provided in an embodiment of the present invention. Detailed Implementation

[0027] To further understand the invention's content, features, and effects, the following embodiments are provided, and detailed descriptions are given in conjunction with the accompanying drawings.

[0028] The structure of the present invention will now be described in detail with reference to the accompanying drawings.

[0029] like Figures 1 to 2 As shown, the DC power supply switching method based on current feedback closed-loop control provided in this embodiment of the invention includes the following steps, each step of which achieves signal interaction with an anti-interference bus and an isolation circuit to form a closed-loop control link:

[0030] S1. Multi-parameter acquisition and anti-interference processing: Acquire the output voltage U, output current I, feeder insulation resistance R, and core device temperature T of the main power supply and backup DC power supply, and perform differential conditioning and anti-interference processing on the acquired signals;

[0031] S2. Dual-core collaborative control: The main control unit performs data processing and fault prediction, while the logic operation unit runs an adaptive algorithm to achieve current closed-loop regulation. The two work together to ensure that the command response delay is ≤1μs.

[0032] S3. Current pre-synchronization and seamless switching: Adopting current pre-synchronization and the switching logic of "first on then off", the logic operation unit outputs a control signal to drive the high-speed switching device to act, achieving gapless switching between the main power supply and the standby power supply;

[0033] S4. Hierarchical alarm and information feedback: Based on the fault type, a hierarchical early warning signal is output, including local audible and visual prompts and remote information notifications. At the same time, the switching result is fed back to the main control unit to complete the closed-loop control.

[0034] The voltage acquisition in step S1 includes the following steps: Build a voltage divider network, and configure the voltage division ratio as 50:1 - 200:1 according to the rated voltages of the main and standby power supplies; Connect an operational amplifier to amplify the weak signal after voltage division, and the amplification factor matches the voltage division ratio to output a standard analog signal; Perform zero-point and gain calibration on the output signal to ensure the acquisition accuracy ≤ ±0.5%, and the standard analog signal output range is 1V - 5V. The output voltage of the DC power supply is usually relatively high (such as 24V, 48V), which exceeds the conventional acquisition range (1V~5V) of the control unit. Therefore, it is necessary to first attenuate the high voltages of the main power supply and the standby power supply into weak signals in proportion through the voltage divider network; Then, utilize the signal amplification ability of the operational amplifier to boost the weak signal to the standard range for the control unit to accurately identify; The zero-point and gain calibration is to eliminate the inherent errors of the circuit, ensure that the acquired value and the actual voltage have a linear correspondence relationship, and guarantee the accuracy of subsequent fault judgment and adjustment.

[0035] The current acquisition in step S1 includes the following steps: Select a closed-loop current sensor and match the sensor range according to the load current range; Filter and level-condition the signal output by the sensor to eliminate high-frequency interference; Transmit the conditioned signal in two paths, one for real-time adjustment and the other for data monitoring. The acquisition accuracy of the sensor ≤ ±0.5%, the linearity error ≤ ±0.5%, and the conversion coefficient between the output and input currents can be configured as required.

[0036] The insulation resistance acquisition in step S1 includes the following steps: Generate a sinusoidal detection signal with a frequency of 500Hz - 2kHz and a peak-to-peak value of 0.5V - 2V; Inject the detection signal into the power supply feeder through an isolation coupling circuit to avoid interfering with the main power supply loop; Synchronously collect the signal amplitudes of the positive and negative poles of the power supply to the ground, and calculate the insulation resistance R in combination with a reference resistor; Set two levels of thresholds, a fault is triggered when R ≤ 300kΩ, and a warning is triggered when 300kΩ < R ≤ 500kΩ.

[0037] The temperature acquisition in step S1 includes the following steps: Arrange temperature-sensitive elements on the surfaces of high-speed switches and power devices; Measure the resistance value of the elements at the standard temperature and establish a resistance-temperature correspondence curve; Real-time collect the resistance signals of the elements and convert them into temperature values. When the temperature reaches the warning threshold, the heat dissipation control is triggered in advance, and when the temperature reaches the fault threshold, the switching process is started.

[0038] The fault prediction in step S2 includes the following steps: establishing a multi-parameter threshold library, setting the voltage threshold to 0.8U-1.15U, the current threshold to ≤1.2I, and configuring the temperature threshold and insulation resistance threshold as needed; continuously collecting parameter data for 3 to 5 sampling cycles to eliminate single instantaneous interference; comparing the parameters with the threshold library, determining the fault type based on the parameter change trend, and generating corresponding control commands.

[0039] The dual-core collaboration in step S2 includes the following steps: the main control unit and the logic operation unit complete the communication protocol matching and set the data interaction format during initialization; the main control unit pushes the collected data and fault prediction results to the logic operation unit in real time, with a push period of ≤10μs; the logic operation unit feeds back the adjustment instructions and execution status to the main control unit, with a dual-core data interaction rate of ≥100Mbps and a logic operation unit signal acquisition accuracy of ≥12 bits.

[0040] The current pre-synchronization control in step S3 includes the following steps: real-time calculation of the main and backup power supply current deviation e= - ,in, Real-time current of the main power supply This is for backup power supply current; the logic unit calls an adaptive PID algorithm to dynamically configure the proportional coefficient according to the load type. Integral coefficient With differential coefficients Through formula Calculate the current regulation amount ΔI; continuously output the regulation signal to the backup power supply until |e|≤50mA triggers the switching permission, and |e|≤20mA is judged as the synchronization is completed. The sampling period of the PID algorithm is configured to be 50μs-200μs. Among them, the PID coefficients are dynamically adapted according to different load characteristics such as resistive and inductive to ensure that there is no overshoot during the regulation process.

[0041] The seamless handover in step S3 includes the following steps: After receiving the handover command, the logic unit configures the turn-on-off timing parameters according to the load power; S32. The backup power high-speed switch is turned on first according to the configured timing, and the main power high-speed switch is turned off after an interval of 1μs-20μs, ensuring that the handover overlap time is 5μs-15μs; the load voltage fluctuation ΔU during the handover process is monitored in real time, and ΔU is kept ≤±2% through current pre-synchronization control. ( (Rated output voltage of main power supply and backup power supply).

[0042] Voltage fluctuation ΔU is predicted and controlled using the following formula:

[0043]

[0044] In the formula To optimize the current deviation for the rated load current. To achieve the goal of fluctuation control and ensure that voltage fluctuations meet the relevant power quality requirements.

[0045] Data storage and parameter display include the following steps: Configure the storage module to store data according to operating parameters, fault information, and switching records, with a storage duration of ≥1 year; The local display module refreshes core parameters such as U, I, T, and R in real time and displays parameter change trends using a graphical interface; Historical data can be retrieved through local operation or remote commands, facilitating fault tracing and system optimization.

[0046] The switching method of the present invention will be described in detail below with reference to typical application scenarios. In this embodiment, the rated output voltage of the main power supply and the backup DC power supply is U=24V, the rated current of the load is I=1A, and the load is the power supply company's distribution network DTU terminal (equivalent impedance 24Ω).

[0047] 1. The specific implementation of the switching method is as follows:

[0048] 1.1 Step S1: Multi-parameter acquisition and anti-interference processing

[0049] Voltage Acquisition: Based on the 24V rated voltage in this scenario, the voltage divider network ratio is configured as 100:1 (99kΩ and 1kΩ resistor combination), the operational amplifier amplification factor is set to 10, and a 2.4V standard signal is output. After differential conditioning and zero-point calibration, the acquisition error is controlled within ±0.5% before being transmitted to the main control unit.

[0050] Current acquisition: A closed-loop current sensor is used, with a conversion coefficient k=0.1V / A. When the load current I=1A, the sensor outputs a 0.1V signal; the signal is transmitted in two paths: one path is directly sent to the logic unit for PID regulation, and the other path is sent to the main control unit after opto-isolation for data recording, achieving dual protection for control and monitoring.

[0051] Insulation resistance acquisition: Following the insulation resistance acquisition method described above, a 1kHz, 1V peak-to-peak sinusoidal signal is generated and coupled to the power supply feeder via an isolation transformer. When U1=0.4V and U2=0.6V are acquired, R=5MΩ (normal range) is calculated based on the 1MΩ reference resistor; when U1=0.1V and U2=0.9V, R=125kΩ, triggering an insulation fault signal.

[0052] Temperature acquisition: A temperature-sensitive element is attached to the surface of the high-speed switching device. At 25℃, the resistance is 10kΩ and the temperature coefficient B=3950K. When the element temperature rises to 85℃, the resistance drops to about 1.6kΩ. The main control unit identifies the resistance change through a voltage divider circuit, calculates the change, and outputs an overheat warning signal.

[0053] 1.2 Step S2: Dual-core collaborative control

[0054] Dual-core configuration: The main control unit uses a high-performance processor with a main frequency of ≥400MHz, and the logic operation unit uses a high-speed logic chip with a built-in 12-bit acquisition module. The two communicate through a high-speed bus with a speed of ≥100Mbps, and the instruction response latency is stable within 0.8μs.

[0055] Current pre-synchronization control: Performed according to the steps of claim 4, for the 1A resistive load in this scenario, the PID coefficients are configured as follows: =0.6、 =0.15、 =0.08 (compliant with standard PID parameter configuration), sampling period 100μs. Assuming main power supply current I=1A, initial backup power supply current I=0.8A, after calculating deviation e=0.2A, output PWM adjustment signal, increase I to 0.98A within 100μs, at which point e=0.02A≤20mA, determine synchronization completed and feedback "ready" signal.

[0056] 1.3 Step S3: Current pre-synchronization and seamless switching:

[0057] Based on the load characteristics of this scenario, the switching sequence is configured as follows: At time t0, the command is received; at t0+1μs, the backup power switch is turned on; at t0+11μs, the main power switch is turned off, with an overlap time of 10μs. =0.02A, substituting into the voltage fluctuation formula, we get ΔU=24V×(0.02A / 1A)=0.48V, with a fluctuation range of 1.8%, which meets the control target of ≤±2% and achieves seamless power supply.

[0058] 1.4 Step S4: Tiered Alarm and Information Feedback

[0059] The fault thresholds in the fault prediction steps trigger tiered alarms: When 300kΩ≤R≤500kΩ or 70℃≤T≤85℃, the local green indicator light flashes at a frequency of 1Hz, and the display shows "Parameter Abnormality Warning"; when R<300kΩ, T≥85℃ or I>1.2I, the red indicator light stays on, the buzzer sounds an intermittent alarm at a frequency of 1Hz, and the remote communication module sends an SMS to the maintenance terminal with the content "Fault Type: Overcurrent; Time: XXX; Current Current: 1.28A", with an SMS sending delay of ≤100ms. After the switch is completed, the execution module sends a "Switch Successful" signal back to the main control unit to update the system's operating status.

[0060] 2. Complete switchover procedure example (main power overcurrent fault)

[0061] t1=0ms: Step S1 collects the main power supply current I=1.3A>1.2I, and the main control unit starts fault counting;

[0062] t2=2ms: After three consecutive sampling cycles confirming the overcurrent fault, the main control unit generates a "master to standby" command and sends it to the logic operation unit;

[0063] t3=3ms: The current pre-synchronization control of the logic operation unit in step S2 is used to adjust the backup power supply current.

[0064] t4=3.1ms: The backup power supply current I rises to 1.28A, current synchronization is completed, and a "ready" signal is fed back;

[0065] t5=3.100001ms: Execute step S3 to turn on the high-speed switch of the backup power supply;

[0066] t6=3.100011ms: The main power high-speed switch is disconnected, and the switching is complete (total delay 32μs).

[0067] t7=3.2ms: Execute step S4, trigger overcurrent alarm and remotely send fault information, and send the switching result back to the main control unit.

[0068] It should be noted that, regarding The explanation is as follows:

[0069]

[0070] Input quantity: Current deviation between main power supply and backup power supply ( Real-time current of the main power supply (This refers to the current actual current of the backup power supply).

[0071] Calculation basis: PID coefficients dynamically configured according to load type (resistive load) Inductive load .

[0072] Output format: ΔI is converted into a current regulation command for the backup power supply by adjusting the duty cycle of the PWM signal (PWM frequency 10kHz, duty cycle adjustment accuracy 0.1%).

[0073] At the power company's distribution network DTU terminal ( In resistive load scenarios, Its function is manifested in three steps:

[0074] 1. Initial Deviation Correction: In case of main power supply failure initial current of backup power supply Current deviation Calculated using the formula The logic unit outputs PWM instructions to rapidly increase the backup power supply current. , The deviation decreased as the value increased to 0.92A. ;

[0075] 2. Dynamic fine-tuning of sampling: Second sampling period , Calculated The backup power supply current further increased to 0.968A; third cycle , Stable at (Synchronous completion of interval values);

[0076] 3. Ensure seamless handover: because With precise adjustment, the current difference between the main and backup power supplies is controlled within an extremely small range. During switching (with a turn-on-then-off timing sequence), there will be no sudden current change, which is consistent with the voltage fluctuation formula. Ultimately, the voltage fluctuation is only .

[0077] Traditional methods lack a ΔI regulation stage and rely solely on threshold triggering for direct switching, leading to excessive current differences and voltage surges. This application utilizes ΔI to achieve dynamic current calibration for load adaptation, upgrading switching from passive triggering to active pre-synchronization. This is the core of the current pre-synchronization PID adaptive regulation mechanism and a key technical means to achieve zero-disruption, low-fluctuation switching.

[0078] In the seamless switching technology solution of this patent, ΔI (current regulation amount) is the core means of controlling ΔU (voltage fluctuation amount). ΔU is the direct manifestation of the ΔI regulation effect. The two are quantitatively correlated through the current difference, forming a correlation that "precise adjustment of ΔI leads to a reduction in the current difference, which in turn leads to ΔU being controlled". This correlation is mathematically defined through the voltage fluctuation formula, which is the core logic for achieving "low fluctuation seamless switching".

[0079] ΔI is used to dynamically adjust the backup power supply current, changing the current difference between the primary and backup power supplies. It is calculated and output by a PID algorithm, in the form of a PWM duty cycle command. ΔU is used to measure the power supply stability during switching and is a technical target parameter, which must meet the requirement of ≤2%. It is quantified and calculated using the voltage fluctuation formula.

[0080] The relationship between ΔI and ΔU is as follows:

[0081] 1. Mathematical Bridge: The voltage fluctuation formula is as follows:

[0082]

[0083] (Rated voltage of main and backup power supplies, such as 24V) (The rated load current, such as 1A) is a fixed value for the scenario and does not change with adjustment; The difference between the main and backup power supplies is the only dynamic variable that directly determines the current. Size. Its core function is to change (Backup power supply current), indirect control Ultimately achieved Precise control.

[0084] Specifically, control The steps are as follows: (According to the power company) Taking a resistive load scenario as an example, the complete logic chain is as follows:

[0085] first step: Directly change the backup power supply current : It is the current adjustment command output by the logic unit to the backup power voltage regulation module—such as the initial main power supply current. backup power Current difference At this point, the PID algorithm calculates... The logic unit uses PWM signals (duty cycle boosting) to increase the duty cycle. Control the backup power supply to make The current difference decreased to 0.08A when the current increased from 0.8A to 0.92A.

[0086] Step 2: The current difference is directly determined by the formula. :because It is a fixed value. According to the formula, when the initial current difference is 0.2A, (Exceed The target cannot be switched directly); After adjustment, when the current difference is 0.08A, (Approaching the target). Then... Fine-tuning When the current rises to 0.98A, and the current difference is 0.02A, satisfy (Technical requirements).

[0087] Step 3: The adjustment precision determines Control effect: The calculation accuracy (dynamically configured by PID coefficients) The sampling period directly determines the control accuracy of the current difference, and thus determines... Fluctuation range: If Excessive adjustment (e.g., Kp being too large) ), It will rise to above 0.95A, and the current difference may widen in the reverse direction. , The current difference will rise to 2.4% (exceeding the target); if ΔI adjustment is insufficient (e.g., Ki is too small, resulting in ΔI=0.08A), the current difference will only decrease to 0.12A, and ΔU=2.88% (still not meeting the requirements). This patent ensures that ΔI adjustment has no overshoot and converges quickly through load-adaptive PID coefficients (e.g., Kp=0.6, Ki=0.15, Kd=0.08 for resistive loads), ultimately stabilizing ΔU at 1.8%.

[0088] The core mission of ΔI is to control ΔU to ≤2% by reducing the current difference. Within the threshold range, seamless switching is achieved. ΔU and ΔI are indirectly positively correlated (non-linear, as ΔI is the increment of the current difference adjustment), but can be accurately predicted using the voltage fluctuation formula: the adjustment range of ΔI determines the change range of the current difference, and the change range of the current difference directly determines the change range of ΔU. Traditional methods lack a ΔI adjustment stage, resulting in random fluctuations in the current difference (typically above 0.5A), leading to excessively large ΔU. This patent, however, precisely controls the current difference to ≤20mA through ΔI, thereby suppressing ΔU to 1.8%, solving the problem of excessive voltage fluctuations in traditional methods. In summary, ΔI is the means to control ΔU, and ΔU is the benchmark for verifying the effect of ΔI adjustment. The two are bound together by a mathematical formula to ensure the quantifiability and reproducibility of the technical solution, ultimately achieving the core technical goal of zero breakpoints and low fluctuations.

[0089] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0090] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A DC power supply switching method based on current feedback closed-loop control, characterized in that, The process includes the following steps, each of which interacts with an isolation circuit via an anti-interference bus to form a closed-loop control link: S1. Multi-parameter acquisition and anti-interference processing: Acquire the output voltage U, output current I, feeder insulation resistance R, and core device temperature T of the main power supply and backup DC power supply, and perform differential conditioning and anti-interference processing on the acquired signals; S2. Dual-core collaborative control: The main control unit performs data processing and fault prediction, while the logic operation unit runs an adaptive algorithm to achieve current closed-loop regulation. The two work together to ensure that the command response delay is ≤1μs. S3. Current pre-synchronization and seamless switching: The current pre-synchronization and switching logic of turning on before turning off are adopted. The logic operation unit outputs control signals to drive the high-speed switching device to achieve seamless switching between the main power supply and the backup power supply. S4. Graded Alarm and Information Feedback: Output graded early warning signals based on fault type, including local audible and visual prompts and remote information notifications, and simultaneously feed back the switching results to the main control unit to complete closed-loop control.

2. The DC power supply switching method based on current feedback closed-loop control according to claim 1, characterized in that, The voltage acquisition in step S1 includes the following steps: Set up a voltage divider network and configure the voltage divider ratio to 50:1-200:1 according to the rated voltage of the main and backup power supplies. The weak signal after voltage division is amplified by an operational amplifier, and the amplification factor is matched with the voltage division ratio to output a standard analog signal. Zero-point and gain calibration is performed on the output signal to ensure that the acquisition accuracy is ≤ ±0.5% and the standard analog signal output range is 1V-5V.

3. The DC power supply switching method based on current feedback closed-loop control according to claim 1, characterized in that, The current acquisition in step S1 includes the following steps: Select a closed-loop current sensor and match the sensor range according to the load current range; The sensor output signal is filtered and level-conditioned to eliminate high-frequency interference; The conditioned signal is transmitted in two paths: one for real-time adjustment and the other for data monitoring. The sensor acquisition accuracy is ≤ ±0.5%, the linearity error is ≤ ±0.5%, and the conversion coefficient between the output and input current can be configured as needed.

4. The DC power supply switching method based on current feedback closed-loop control according to claim 1, characterized in that, The current pre-synchronization control in step S3 includes the following steps: Real-time calculation of the main and backup power supply current deviation e= - ,in, Real-time current of the main power supply This is the backup power supply current; The logic unit calls the adaptive PID algorithm to dynamically configure the proportional coefficient according to the load type. Integral coefficient With differential coefficients Through formula Calculate the current regulation ΔI; The system continuously outputs a regulation signal to the backup power supply until |e|≤50mA triggers the switching permission, and |e|≤20mA determines that synchronization is complete. The PID algorithm sampling period is configured to be 50μs-200μs. The PID coefficients are dynamically adapted to different load characteristics, such as resistive and inductive loads, to ensure that there is no overshoot during the adjustment process.

5. The DC power supply switching method based on current feedback closed-loop control according to claim 4, characterized in that, The seamless transition in step S3 includes the following steps: After receiving the switching command, the logic unit configures the turn-on-then-off timing parameters according to the load power; S32. The backup power high-speed switch is turned on first according to the configured timing, and the main power high-speed switch is turned off after an interval of 1μs-20μs to ensure that the switching overlap time is 5μs-15μs. Real-time monitoring of load voltage fluctuation ΔU during the switching process, and current pre-synchronization control to ensure ΔU ≤ ±2%. ,in Rated output voltage of main power supply and backup power supply; Voltage fluctuation ΔU is predicted and controlled using the following formula: In the formula To optimize the current deviation for the rated load current. To achieve the goal of fluctuation control and ensure that voltage fluctuations meet the relevant power quality requirements.

6. The DC power supply switching method based on current feedback closed-loop control according to claim 1, characterized in that, The insulation resistance measurement in step S1 includes the following steps: A sinusoidal detection signal with a frequency of 500Hz-2kHz and a peak-to-peak value of 0.5V-2V is generated. The detection signal is injected into the power supply line through an isolation coupling circuit to avoid interference with the main power supply circuit. Synchronously acquire the signal amplitudes of the positive and negative terminals of the power supply to ground, and calculate the insulation resistance R by combining the reference resistance; Set two - level thresholds. A fault is triggered when R ≤ 300 kΩ, and a warning is triggered when 300 kΩ < R ≤ 500 kΩ.

7. The DC power supply switching method based on current feedback closed-loop control according to claim 1, characterized in that, The fault prediction in step S2 includes the following steps: Establish a multi - parameter threshold library. The voltage threshold is set to 0.8U - 1.15U, the current threshold is set to ≤1.2I, and the temperature threshold and insulation resistance threshold are configured as required; Continuously collect parameter data for 3 to 5 sampling periods to eliminate single - time transient interference; Compare the parameters with the threshold library, and combine the parameter change trend to judge the fault type and generate corresponding control instructions.

8. The DC power supply switching method based on current feedback closed-loop control according to claim 1, characterized in that, The temperature acquisition in step S1 includes the following steps: Arrange temperature - sensitive elements on the surfaces of high - speed switches and power devices; Measure the resistance value of the element at the standard temperature and establish a resistance - temperature correspondence curve; Real - time collect the resistance signal of the element and convert it into a temperature value. When the temperature reaches the warning threshold, trigger the heat dissipation control in advance, and start the switching process when the temperature reaches the fault threshold.

9. The DC power supply switching method based on current feedback closed-loop control according to claim 1, characterized in that, The dual - core collaboration in step S2 includes the following steps: Complete the communication protocol matching during the initialization of the main control unit and the logic operation unit, and set the data interaction format; The main control unit pushes the collected data and the fault prediction results to the logic operation unit in real - time, and the push period ≤ 10 μs; The logic operation unit feeds back the adjustment instructions and the execution status to the main control unit. The data interaction rate between the two cores ≥ 100 Mbps, and the signal acquisition accuracy of the logic operation unit ≥ 12 bits.

10. The DC power supply switching method based on current feedback closed-loop control according to any one of claims 1-9, characterized in that, Data storage and parameter display include the following steps: Configure a storage module to store data classified by operating parameters, fault information, and switching records, and the storage duration ≥ 1 year; The local display module refreshes the core parameters such as U, I, T, R in real - time and uses a graphical interface to display the parameter change trend; [[ID=

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