Alternating current and direct current integrated power supply system and control method

Abstract

The invention relates to an alternating-current and direct-current integrated power supply system and a control method, a power conversion unit comprises a parallel high-frequency rectification module, an inversion module and a communication power supply module, and a direct-current side is connected in parallel to a common direct-current bus; the energy storage unit realizes energy interaction between a storage battery pack and a bus through a bidirectional DC / DC converter, and a matched health monitoring circuit acquires internal resistance, temperature and voltage data in real time; the dynamic voltage support unit is formed by connecting a filter network and a transient suppression device in series and is directly connected with a bus to suppress voltage fluctuation caused by load abrupt change; the electromagnetic protection unit integrates an input-stage surge protector, a cabinet body grounding copper bar and an anti-interference device, so that the electromagnetic compatibility of the system is guaranteed; the intelligent control unit is combined with the communication bus through the main controller, and the functions of multi-mode power supply switching, energy storage unit temperature compensation charging and cooperative fault protection are achieved. The system meets the AC / DC load hybrid power supply requirement through the modular design and the cooperative control strategy, and improves the reliability and adaptability of the power supply system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power supply system control, in particular to an AC-DC integrated power supply system and a control method. BACKGROUND

[0002] The traditional AC-DC power supply system adopts a discrete architecture, and power conversion modules, energy storage devices and control units are independently configured, resulting in a large system size and a long energy conversion path. There is a lack of cooperative control mechanism among the modules, which easily causes bus voltage drop or overshoot when the load suddenly changes, affecting the normal operation of sensitive loads. In addition, the discrete design increases the maintenance complexity and is difficult to meet the demand of modern power electronic devices for high integration and fast response.

[0003] Existing energy storage unit management schemes mostly rely on single voltage monitoring, which cannot comprehensively evaluate the health status of the battery pack. The temperature compensation mechanism usually uses fixed coefficients to adjust the charging parameters, which cannot match the changes in battery characteristics in real time, resulting in frequent overcharging or undercharging. There is a lack of effective monitoring means for the change trend of the internal resistance of the battery, making it difficult to predict the capacity attenuation and shortening the actual service life of the battery pack.

[0004] The dynamic voltage support capability of the conventional power supply system is limited, and the filter network design does not fully consider the step characteristics of the load, which easily produces large voltage fluctuations under the action of impact current. The selection of transient suppression devices lacks matching design with the system impedance, and the suppression effect is limited by the response speed. At the same time, the electromagnetic protection measures mostly focus on input protection, and lack of system-level solutions for signal interference and ground potential shift problems between modules, affecting the overall electromagnetic compatibility performance. SUMMARY

[0005] In order to solve the above problems, the present application provides an AC-DC integrated power supply system and a control method, characterized by comprising: a power conversion unit, comprising a high-frequency rectification module, an inverter module and a communication power supply module arranged in parallel, the AC input end of the high-frequency rectification module being connected to an external AC power supply; the DC sides of the high-frequency rectification module, the inverter module and the communication power supply module being connected in parallel to a common DC bus; an energy storage unit, comprising a battery pack, a bidirectional DC / DC converter and a health monitoring circuit; the low-voltage side of the bidirectional DC / DC converter being connected to the battery pack; the high-voltage side of the bidirectional DC / DC converter being connected to the common DC bus; the health monitoring circuit being electrically connected to the battery monomer; a dynamic voltage support unit, composed of a filter network and a transient suppression device in series; the input end of the filter network being directly connected to the common DC bus; the output end of the filter network being connected to a load power supply interface; The electromagnetic protection unit comprises an input stage surge protector connected in series at the AC input end of the high-frequency rectification module; a cabinet body grounding copper bar electrically connected to the negative pole of the public DC bus; and anti-interference devices integrated in the signal acquisition end of each module circuit board. The intelligent control unit comprises a main controller and a communication bus; the main controller is bidirectionally connected to the control interface of each module through the communication bus; and the signal acquisition end of the main controller is connected to the voltage and current sensors and the health monitoring circuit.

[0006] Further, the health monitoring circuit comprises: an internal resistance detection module with a measurement accuracy of ≤±0.1 mΩ; a temperature sensor array for real-time monitoring of the surface temperature of each storage battery; a voltage acquisition circuit with an accuracy of ≤±0.14%; and a capacity prediction module for estimating the remaining capacity based on a 0.1 discharge curve.

[0007] Further, the dynamic voltage support unit specifically comprises: When the load step increases, the transient suppression device releases stored energy to maintain the bus voltage ≥ 95% of the nominal value; When the load step decreases, the filter network absorbs excess energy to suppress the voltage peak ≤ 105% of the nominal value; The full-load output ripple coefficient is ≤0.1%.

[0008] Further, the intelligent control unit specifically comprises: The real-time comparison of the DC bus voltage and the set threshold value triggers the PID adjustment when the deviation is >±2.5%; When the AC input voltage is <85% of the rated value, a switching command is sent to the bidirectional DC / DC converter; The battery temperature data is received, the float voltage is calculated according to the compensation formula, and the high-frequency rectification module is sent.

[0009] Further, the public DC bus specifically comprises: The DC positive / negative poles of the high-frequency rectification module, the inverter module, and the communication power supply module are connected in parallel to the bus copper bar; The high-voltage side positive / negative poles of the bidirectional DC / DC converter are directly connected to the bus copper bar; The input end of the dynamic voltage support unit is connected to the bus copper bar through a fuse; When the battery pack is powered, 200% impact current discharge is supported, and the bus voltage ≥ 90% of the nominal value.

[0010] Further, the power conversion unit converts alternating current into direct current through a high-frequency rectification module to supply the public direct current bus in a normal power supply mode; the direct current is output in three ways: converted into alternating current through an inversion module, converted into low-voltage direct current through a communication power module, and directly supplied to a direct current load through a dynamic voltage support unit; the surplus electric energy charges the battery pack through a bidirectional DC / DC converter; the intelligent control unit detects the failure of the alternating current interruption input and sends a discharge instruction to the bidirectional DC / DC converter; the battery pack electric energy is injected into the public direct current bus after being boosted through the bidirectional DC / DC converter; the bus electric energy maintains the power supply of the inversion module, the communication power module and the direct current load; the intelligent control unit compensates for voltage fluctuation instantaneously when detecting load mutation; the intelligent control unit adjusts the output power of the high-frequency rectification module or the bidirectional DC / DC converter within 20 ms.

[0011] A control method of an AC-DC integrated power supply system, characterized in that it comprises: S1. Multi-mode power supply control, real-time monitoring of alternating current input state, switching to energy storage unit power supply when voltage is continuously lower than threshold value, enabling dynamic current limiting to suppress impact current when detecting load mutation; S2. Energy storage unit health management, collecting battery internal resistance, voltage and temperature data, dynamically calculating floating voltage according to temperature and adjusting charging parameters, periodically performing capacity verification test; S3. Cooperative fault protection, monitoring the insulation state of the direct current bus, triggering an alarm when the resistance value is lower than the threshold value, and grading off the output when overloaded.

[0012] Further, the S1 specifically comprises: When the input voltage is continuously lower than 85% of the rated value, send a discharge instruction to the bidirectional DC / DC converter to control the battery pack electric energy to be injected into the public direct current bus after being boosted through the bidirectional DC / DC converter; When the load has a step change, the dynamic voltage support unit is enabled to suppress bus voltage fluctuation, so that the voltage is maintained within 95%-105% of the nominal value; Specifically, when the load step increases, control the transient suppression device to release energy to maintain the bus voltage ≥ 95% of the nominal value; when the load step decreases, control the filter network to absorb excess energy to suppress voltage spikes ≤ 105% of the nominal value; The proportional-integral-derivative controller adjusts the duty cycle of the power device so that the voltage fluctuation is ≤ ±2.5%.

[0013] Further, the S2 specifically comprises: The formula for calculating the float charge voltage Vfloat is: Vfloat=Vbase-k×(T-Tref), where the temperature compensation coefficient k ranges from 2 to 4, mV / ℃ / cell; Vbase is the reference float charge voltage, V / cell; T is the measured battery temperature, ℃; and Tref is the reference temperature, taken as 25℃. The float charge voltage adjustment includes: when the temperature is >40℃, Vfloat is reduced by 0.02-0.04V / cell; when the temperature is <0℃, Vfloat is increased by 0.03-0.05V / cell. Vfloat is calculated by the intelligent control unit and sent to the high-frequency rectification module; T is acquired by the temperature sensor in the health monitoring circuit; k and Tref are stored in the configuration parameters of the intelligent control unit. Periodically perform 0.1 discharge curve verification and update the predicted value of the remaining battery capacity; The calculated float charge voltage value is sent to the high-frequency rectifier module to adjust the battery charging parameters.

[0014] Furthermore, S3 also includes: When the DC bus resistance to ground is ≤25kΩ, an audible and visual alarm and passive contact output are triggered; when the load rate is 105%-125%, the system will continue to operate for 10 minutes and then switch to bypass power supply; when the load rate is 150% or a short circuit occurs, the output current is limited and the circuit breaker is triggered to trip. The output is cut off in stages as follows: when overloaded, the dynamic voltage support unit will compensate for voltage fluctuations first. After the compensation fails, the intelligent control unit will send a disconnection command to the circuit breaker within 5ms.

[0015] The beneficial effects of this invention are: This invention employs an integrated architecture design, where the DC sides of the high-frequency rectifier module, inverter module, and communication power supply module in the power conversion unit are connected in parallel to a common DC bus. Combined with the coordinated configuration of a bidirectional DC / DC converter and a battery pack, a unified platform for bidirectional energy flow is constructed. When the AC input is abnormal, the energy storage unit injects voltage into the DC bus via the bidirectional DC / DC converter, achieving seamless switching of the power supply mode. The dynamic voltage support unit absorbs excess energy through a filter network and releases stored energy through transient suppression devices. Combined with the real-time PID adjustment of the intelligent control unit, it suppresses bus voltage fluctuations within ±2.5% of the nominal value within 20ms during load step changes, solving the problems of large switching delays and slow voltage transient response in traditional systems. The high coupling of power conversion, energy storage management, and dynamic support modules eliminates redundant components in discrete systems, optimizing the energy conversion path. Modules interact directly via a common DC bus, reducing intermediate conversion losses and improving the response speed of each module during load changes. The system size is smaller than traditional solutions, meeting the requirements for high-density deployment.

[0016] The health monitoring circuit achieves high-precision assessment of battery status through multi-parameter fusion monitoring via an internal resistance detection module, temperature sensor array, and voltage acquisition circuit, combined with a capacity prediction algorithm based on a 0.1C discharge curve. The intelligent control unit dynamically calculates the float charge voltage compensation value based on temperature data, lowering the float charge voltage by 0.02-0.04V / cell in high-temperature environments and raising it by 0.03-0.05V / cell in low-temperature environments, effectively suppressing battery gas evolution and sulfation. Periodic capacity verification testing calibrates the capacity prediction model through constant current discharge, optimizing battery lifespan from the source of the charge / discharge strategy. Energy storage unit health management employs a multi-dimensional parameter monitoring and dynamic compensation mechanism, achieving accurate assessment of the battery pack status through the fusion analysis of internal resistance, temperature, and voltage data. The temperature compensation coefficient is dynamically adjusted based on real-time temperature rise data, avoiding overcharging or undercharging caused by fixed parameters. Combined with the capacity prediction model, this extends the battery pack's cycle life and maintenance intervals.

[0017] The electromagnetic protection unit reduces the impact of electromagnetic interference on signal acquisition through three levels of protection: input surge protector, cabinet grounding copper busbar, and anti-interference devices. The intelligent control unit monitors the DC bus insulation status in real time, triggering audible and visual alarms and passive contact output when the resistance to ground is ≤25kΩ. Overload protection employs a strategy of priority compensation and graded output cutoff using the dynamic voltage support unit: after 105%-125% load rate for 10 minutes, bypass power supply is switched; at 150% load rate or in the event of a short circuit, current is limited first before triggering the circuit breaker tripping, and disconnection is completed within 5ms after compensation failure. This mechanism achieves precise fault isolation while ensuring continuous power supply, preventing system downtime due to protection malfunctions. The dynamic voltage support unit, combined with the impedance matching design of the filter network and the fast response characteristics of transient suppression devices, controls the bus voltage fluctuation range within ±3% of the nominal value during load step changes. The electromagnetic protection system covers input surge suppression, signal isolation between modules, and ground potential equalization, enabling the system to maintain stable operation in complex electromagnetic environments. The overall immunity meets the Level 4 requirements of the IEC 61000-4-5 standard. Attached Figure Description

[0018] Fig. 1 This is a schematic diagram of the overall structure of an integrated AC / DC power supply system. Fig. 2 This is a flowchart of a control method for an integrated AC / DC power supply system. Detailed Implementation

[0019] The following is in conjunction with the appendix Figs. 1-2 The preferred embodiments of the present invention will be described in detail so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more explicit definition of the scope of protection of the present invention.

[0020] An AC-DC integrated power supply system, a power conversion unit, comprising a high-frequency rectification module, an inverter module and a communication power module arranged in parallel, the AC input end of the high-frequency rectification module is connected to an external AC power supply; the DC side of the high-frequency rectification module, the inverter module and the communication power module is connected in parallel to a common DC bus; the high-frequency rectification module adopts a three-phase bridge topology, the AC input end thereof is connected to the external AC power supply through a copper busbar, and the DC output end thereof is connected in parallel to the common DC bus through a low-inductance bus. The inverter module adopts a full-bridge IGBT structure, and the DC input end thereof is connected to the positive and negative copper bars of the common DC bus through fast connection terminals. The communication power module is a Buck-Boost topology, and the DC input side thereof is connected to the common DC bus through an anti-reverse connector. The DC sides of the three modules adopt a star grounding structure on the bus copper bars, and the negative poles are uniformly connected to the cabinet grounding copper bar. When the high-frequency rectification module converts 380V AC into 220V DC, the inverter module converts DC into 220V AC output, and the communication power module generates 48V DC output, and the three outputs are electrically isolated.

[0021] An energy storage unit, comprising a battery pack, a bidirectional DC / DC converter and a health monitoring circuit; the low-voltage side of the bidirectional DC / DC converter is connected to the battery pack; the high-voltage side of the bidirectional DC / DC converter is connected to the common DC bus; the health monitoring circuit is electrically connected to the battery pack monomer; the battery pack is composed of 104 2V valve-regulated lead-acid batteries connected in series, and the positive and negative poles are connected to the low-voltage side port of the bidirectional DC / DC converter through a flame-retardant cable. The bidirectional DC / DC converter adopts a dual-active-bridge topology, and the high-voltage side port is directly lapped on the common DC bus through a copper busbar. The voltage acquisition wire harness of the health monitoring circuit is connected in parallel to the positive and negative poles of each battery through shielded twisted pair wires, the internal resistance detection module contacts the battery pole through a four-wire Kelvin connection method, and the temperature sensor array is attached to the surface groove of the battery shell and transmits data to the intelligent control unit through an RS485 bus.

[0022] A dynamic voltage support unit, which is composed of a filter network and a transient suppression device in series; the input end of the filter network is directly connected to the common DC bus; the output end of the filter network is connected to the load power supply interface; the filter network is composed of an LC second-order low-pass filter, and the input end is welded to the positive copper bar of the common DC bus. The transient suppression device is a parallel combination of a metal oxide varistor and a super capacitor, and its discharge circuit is connected in series with the filter network. When the load step increases and causes the bus voltage to drop, the super capacitor releases energy through an IGBT switch; when the load step decreases, the inductive element of the filter network absorbs excess energy, and the capacitive element suppresses voltage spikes. The output end is connected to the load interface through an EMI filter, forming a bidirectional energy buffer channel.

[0023] The electromagnetic protection unit comprises an input stage surge protector connected in series at the AC input end of the high-frequency rectification module; a cabinet body grounding copper bar electrically connected to the negative pole of the common DC bus; and an anti-interference device integrated at the signal acquisition end of each module circuit board. The input stage surge protector is a cascade structure of a gas discharge tube and a TVS diode, which is connected in series at the rear end of the AC input circuit breaker of the high-frequency rectification module. The cabinet body grounding copper bar is made of tin-plated red copper plate and connected to the negative pole of the common DC bus and the metal frame of the cabinet through a braided copper cable. The anti-interference device comprises a magnetic ring common mode choke coil and an RC filter circuit, which are integrated at the PCB signal acquisition terminal of the power conversion unit and the energy storage unit to suppress high-frequency conducted interference.

[0024] The intelligent control unit comprises a main controller and a communication bus. The main controller is bidirectionally connected to the control interface of each module through the communication bus. The signal acquisition end of the main controller is connected to the voltage and current sensors and the health monitoring circuit. The main controller communicates with the control interface of each module through the CAN bus: sends the voltage set value to the high-frequency rectification module and receives the charge and discharge state code of the bidirectional DC / DC converter. The voltage sensor is a Hall effect device connected across the positive and negative poles of the common DC bus. The current sensor is a closed-loop fluxgate type and is sleeved on the bus copper bar. The data of the health monitoring circuit is processed by an AD conversion chip and then transmitted to the SPI interface of the main controller through optical coupling isolation.

[0025] The health monitoring circuit comprises: An internal resistance detection module with a measurement accuracy of ≤±0.1 mΩ; a temperature sensor array for real-time monitoring of the surface temperature of each storage battery; a voltage acquisition circuit with an accuracy of ≤±0.14%; and a capacity prediction module for estimating the remaining capacity based on a 0.1 discharge curve.

[0026] The dynamic voltage support unit specifically comprises: When the load step increases, the transient suppression device releases stored energy to maintain the bus voltage ≥ 95% of the nominal value; When the load step decreases, the filter network absorbs excess energy to suppress the voltage spike ≤ 105% of the nominal value; The full-load output ripple coefficient is ≤ 0.1%.

[0027] The intelligent control unit specifically comprises: Real-time comparison of the DC bus voltage with the set threshold value, deviation > ± 2.5% to trigger PID adjustment; Detection of AC input voltage < 85% of the rated value to send switching instructions to the bidirectional DC / DC converter; Receiving battery temperature data, calculating the float voltage according to the compensation formula and sending it to the high-frequency rectification module.

[0028] The common DC bus specifically comprises: High-frequency rectifier module, inverter module, and communication power module are connected to the bus copper bar in parallel respectively. The high-voltage side of the bidirectional DC / DC converter is directly connected to the bus copper bar. The input end of the dynamic voltage support unit is connected to the bus copper bar through a fuse. Support 200% impact current discharge when the battery pack is powered, and the bus voltage is ≥ 90% of the nominal value.

[0029] The bus copper bar adopts a laminated design: the positive electrode is a silver-plated copper bar, and the negative electrode is a bare copper bar, which are separated by a polyimide insulating film. The DC positive electrode of the high-frequency rectifier module and the inverter module is connected to the positive copper bar in parallel through a copper cable; the negative electrode of the communication power module is directly screwed to the negative copper bar. The high-voltage side of the bidirectional DC / DC converter is connected to the bus using a copper-aluminum composite transition joint. The input end of the dynamic voltage support unit is connected through a fast-melting fuse, and the rated current of the fuse is 150% of the maximum impact current.

[0030] In normal power supply mode, the power conversion unit converts AC power into DC power through the high-frequency rectifier module and delivers it to the public DC bus; the DC power is output in three ways: converted into AC power by the inverter module, converted into low-voltage DC power by the communication power module, and directly supplied to the DC load by the dynamic voltage support unit; the excess power is used to charge the battery pack through the bidirectional DC / DC converter; the intelligent control unit detects the failure of AC interruption input and sends a discharge command to the bidirectional DC / DC converter; the battery pack power is injected into the public DC bus after being boosted by the bidirectional DC / DC converter; the bus power maintains the power supply of the inverter module, the communication power module, and the DC load; the intelligent control unit compensates for voltage fluctuations instantaneously when detecting load mutations; the intelligent control unit adjusts the output power of the high-frequency rectifier module or the bidirectional DC / DC converter within 20ms.

[0031] A control method of an AC / DC integrated power supply system, comprising: S1. Multi-modal power supply control, real-time monitoring of AC input state, switching to energy storage unit power supply when voltage is continuously below threshold, enabling dynamic current limiting to suppress impact current when detecting load mutations; S2. Energy storage unit health management, collecting battery internal resistance, voltage, and temperature data, dynamically calculating float voltage according to temperature and adjusting charging parameters, periodically performing capacity verification test; S3. Cooperative fault protection, monitoring the insulation state of the DC bus, triggering an alarm when the resistance value is below the threshold, and grading off the output when overloaded.

[0032] S1 specifically includes: When the input voltage is continuously lower than 85% of the rated value, a discharge instruction is sent to the bidirectional DC / DC converter, and the battery pack electric energy is injected into the common DC bus after being boosted by the bidirectional DC / DC converter; When the load occurs a step change, the dynamic voltage support unit is enabled to suppress the bus voltage fluctuation, so that the voltage is maintained within the range of 95%-105% of the nominal value; specifically, when the load step increases, the transient suppression device is controlled to release energy, so that the bus voltage is maintained to be greater than or equal to 95% of the nominal value; when the load step decreases, the filter network is controlled to absorb excess energy, so that the voltage peak is suppressed to be less than or equal to 105% of the nominal value. The proportional-integral-derivative controller adjusts the duty cycle of the power device, so that the voltage fluctuation is less than or equal to ±2.5%.

[0033] The main controller continuously samples the AC input voltage. When the voltage is lower than 85% of the rated value for 3 power frequency periods, a PWM enable signal is sent to the bidirectional DC / DC converter, and the battery discharge mode is switched. When the load suddenly changes, the dynamic voltage support unit responds within 0.5 ms, and the PID controller adjusts the phase shift angle of the high-frequency rectification module, so that the power adjustment is completed within 20 ms. The impact current is limited to be less than or equal to 20% of the rated value by the pre-charge resistance.

[0034] S2 is specifically: The formula for calculating the float voltage Vfloat is: Vfloat=Vbase-k×(T-Tref), wherein the temperature compensation coefficient k is in the range of 2-4 mV / ℃ / monomer, Vbase is the reference float voltage, V / monomer, T is the measured battery temperature, ℃, and Tref is the reference temperature, taken as 25℃; The float voltage adjustment includes: when the temperature is greater than 40℃, the Vfloat is lowered by 0.02-0.04V / monomer; when the temperature is less than 0℃, the Vfloat is raised by 0.03-0.05V / monomer; The Vfloat is calculated by the intelligent control unit and sent to the high-frequency rectification module; the T is collected by the temperature sensor in the health monitoring circuit; the k and Tref are stored in the configuration parameters of the intelligent control unit; The 0.1 discharge curve verification is periodically performed to update the remaining capacity prediction value of the battery; The calculated float voltage value is sent to the high-frequency rectification module to adjust the battery charging parameters.

[0035] The temperature sensor collects the battery surface temperature every 10 seconds. When the temperature is greater than 40℃, the reference float voltage Vbase is lowered by 0.03V / monomer step by step; when the temperature is less than 0℃, the Vbase is raised by 0.04V / monomer step by step. The capacity verification test is automatically performed every month: the bidirectional DC / DC converter is controlled to discharge at a constant current of 0.1C for 10 hours, and the voltage curve is recorded to correct the capacity prediction model.

[0036] S3 also includes: When the DC bus resistance to ground is less than or equal to 25kΩ, trigger the audible alarm and passive contact output; when the load rate is 105%-125%, continue to run for 10 minutes and then switch to bypass power supply; when the load rate is 150% or short-circuit, limit the output current and trigger the circuit breaker to trip, and the specific output is: when overloaded, the dynamic voltage support unit compensates for voltage fluctuations first, and when compensation fails, the intelligent control unit sends a disconnect command to the circuit breaker within 5ms. The insulation monitoring module calculates the DC bus impedance to ground in real time. When the impedance is less than or equal to 25kΩ, the main controller triggers the dry contact signal to start the audible alarm. When the load rate is 105%-125%, the timer starts a 10-minute countdown, and after the time is up, the static switch is controlled to bypass the power supply. When the load is greater than or equal to 150%, the IGBT current limiting circuit is activated instantly, and the shunt trip device is actuated to disconnect the output circuit breaker. The dynamic voltage support unit prioritizes voltage compensation during the initial overload period, and triggers the circuit breaker to open within 5ms when compensation fails.

[0037] In the power conversion unit, the high-frequency rectification module uses a three-phase full-bridge topology structure, with a switching frequency set to 20kHz. The IGBT device is selected based on the peak load current and safety margin to ensure a conversion efficiency of ≥90%. The LC filter is configured at the output end of the inverter module, with an inductance value designed according to the load current rate of change of 0.5A / μs, and a capacitance value selected as 10μF / kW. The output waveform is sinusoidalized through SPWM modulation, with a total harmonic distortion of ≤3%. An isolation transformer is added to the output end of the communication power supply module, with a primary-to-secondary turns ratio of 1:1 and a withstand voltage rating of DC500V, ensuring electrical isolation from the common DC bus. Specifically, in the power conversion unit, the high-frequency rectification module efficiency test is conducted under the conditions of load rate 25%, 50%, 75%, 100%, and input voltage 380V±10%. The synchronous rectification technology is used, with an IGBT switching frequency of 20kHz. The magnetic circuit design is optimized to reduce iron loss, ensuring a full-load efficiency of ≥92%. The inverter module output waveform is achieved through SPWM modulation, with a carrier frequency of 10kHz and a modulation ratio of 0.8. The total harmonic distortion is ≤3%, and the output end is configured with a 10μH inductor and a 470μF capacitor to form an LC filter to suppress switching ripple. An isolation transformer is added to the output end of the communication power supply module, with a primary-to-secondary turns ratio of 1:1 and a withstand voltage rating of DC500V, ensuring electrical isolation from the common DC bus.

[0038] The bidirectional DC / DC converter of the energy storage unit adopts a bidirectional Buck-Boost topology, the voltage on the high-voltage side matches the nominal value 220V of the public DC bus, the voltage range on the low-voltage side is 180-260V, and it is suitable for the float / charge state of the battery pack. The internal resistance detection module is realized by the 0.1 kHz AC injection method, the sampling frequency is 1 kHz, and after band-pass filtering and RMS calculation, the internal resistance resolution reaches 0.01 mΩ. The temperature sensor array adopts NTC thermistors, which are arranged 5 mm below the battery pole, with a measurement error of ≤±1℃, a data acquisition period of 10s, and a moving average filtering process. Specifically, the temperature rise test of the bidirectional DC / DC converter of the energy storage unit is carried out under the condition of an environmental temperature of 40℃ and a load rate of 100%, the junction temperature of the key components IGBT is ≤125℃, and the inductance temperature rise is ≤60K, which adopts forced air cooling, the air duct design is based on fluid mechanics simulation, the air inlet speed is 2m / s, and the hot air is discharged through the rear exhaust fan. The internal resistance detection module adopts the 0.1 kHz AC injection method, the injection current amplitude is 1A, after band-pass filtering and RMS calculation, the internal resistance resolution reaches 0.01 mΩ, the sampling frequency is 1 kHz, and the data is processed by moving average filtering to suppress noise interference.

[0039] The filter network of the dynamic voltage support unit is composed of a 10mH inductor and a 4700μF electrolytic capacitor to form an LC low-pass filter, the cutoff frequency is 50Hz, and the switching ripple is suppressed. The transient suppression device selects a varistor, the current capacity is 5kA, the response time is ≤1ns, and it is connected in series at the output end of the filter network. When the load step increases, the varistor releases the pre-stored charge by conduction, and maintains the bus voltage ≥209V; when the step decreases, the inductance energy is absorbed by the capacitor, and the voltage peak is ≤231V. Specifically, the response time test of the dynamic voltage support unit is realized by suddenly applying a load step, the load jumps from 50% to 100%, the voltage fluctuation is ≤±2.5%, and the response time is ≤5ms. The filter network is composed of a 10mH inductor and a 4700μF electrolytic capacitor to form an LC low-pass filter, the cutoff frequency is 50Hz, and the switching ripple is suppressed. The transient suppression device selects a varistor, the current capacity is 5kA, the response time is ≤1ns, and it is connected in series at the output end of the filter network, when the load step increases, the varistor releases the pre-stored charge by conduction, and maintains the bus voltage ≥209V; when the step decreases, the inductance energy is absorbed by the capacitor, and the voltage peak is ≤231V.

[0040] The input stage surge protector of the electromagnetic protection unit adopts an SPD module, with a maximum current capacity of 40 kA, and is connected in a Kelvin method to ensure a residual voltage of ≤1.5 kV. Conductive paste is applied at the bolt connection, with a contact resistance of ≤0.1 mΩ. Anti-interference devices are integrated with common-mode inductors at the signal acquisition end, with ferrite selected as the magnetic core material, a suppression frequency range of 10 MHz-1 GHz, and a differential-mode filter capacitor selected as 0.1 μF / 250 V. Specifically, the residual voltage test of the surge protector of the electromagnetic protection unit is based on the IEC 61643-1 standard, with a residual voltage of ≤1.5 kV under an 8 / 20 μs waveform, a connection method of Kelvin, a lead length of ≤50 mm to reduce lead inductance. The cabinet grounding copper bar is made of T2 red copper, with a cross-sectional area of 50 square millimeters, and conductive paste is applied at the bolt connection, with a contact resistance of ≤0.1 mΩ to ensure a residual voltage lower than the voltage level of the device. Anti-interference devices are integrated with common-mode inductors at the signal acquisition end, with ferrite selected as the magnetic core material, a suppression frequency range of 10 MHz-1 GHz, and a differential-mode filter capacitor selected as 0.1 μF / 250 V to reduce conducted interference.

[0041] The main controller of the intelligent control unit is based on an ARM Cortex-M4 core, with 12-bit ADC and PWM output channels configured, a communication bus using CAN2.0B protocol, and a baud rate of 500 kbps. The PID regulation algorithm uses incremental PID, with a proportional coefficient Kp=0.8, an integral time Ti=0.1 s, and a differential time Td=0.01 s, and the parameters are set by the Ziegler-Nichols method. The step response test has an overshoot of ≤5% and a regulation time of ≤200 ms. When calculating the battery float voltage, the temperature compensation coefficient k is taken as 3 mV / ℃ / monomer, and the reference voltage Vbase is 2.25 V / monomer. The data is transmitted to the high-frequency rectification module through an I2C bus, with a sampling period of 10 s and moving average filter processing.

[0042] The power conversion unit is in normal power supply, the high-frequency rectification module output is connected in parallel through the bus copper bar, the cross-sectional area of the copper bar is 100 square millimeters, the contact surface is silver plated, and the contact resistance is less than or equal to 0.05 mΩ. The inverter module and the communication power module are connected to the bus through a fast fuse, the rated current of the fuse is configured according to 1.5 times the capacity of the module, and the action time is less than or equal to 1 ms. The input end of the dynamic voltage support unit is connected to the bus through a 30A fuse, and the short-circuit protection response time is ensured to be less than or equal to 1 ms. When the battery pack is discharged, the bidirectional DC / DC converter adopts voltage mode control, the duty cycle adjustment range is 20%-80%, and the step-up ratio is 1:1.2. The output voltage precision is less than or equal to ±0.5%.

[0043] In the multi-modal power supply control, the AC input voltage monitoring is realized through a true RMS sensor, the sampling period is 1 ms, and when the voltage is lower than 85% of the rated value for 2 cycles, a switching instruction is triggered. The dynamic current limiting function is realized through current loop control, the current limiting threshold is set to 200% of the rated current, the response time is less than or equal to 50μs, and a hysteresis comparator is used. When the energy storage unit is healthy managed, the capacity verification test is performed once a month, the discharge current is 0.1C10, the terminal voltage is 1.8V / cell, and the test data is uploaded to the monitoring system through the RS485 bus.

[0044] In the cooperative fault protection, the DC bus insulation monitoring adopts a balanced bridge method, a 50Hz / 1mA test current is injected, and when the resistance to ground is less than or equal to 25kΩ, an alarm signal is output through a passive contact. When the overload is 105%-125%, the dynamic voltage support unit preferentially compensates, after the compensation fails, the main controller sends a breaking instruction to the circuit breaker within 5ms, and the tripping time of the circuit breaker is less than or equal to 1ms. In the characteristic curve configuration, the current limiting threshold is set to 3 times the rated current, and the action time is less than or equal to 2ms. Specifically, in the cooperative fault protection, the DC bus insulation monitoring adopts a balanced bridge method, a 50Hz / 1mA test current is injected, and when the resistance to ground is less than or equal to 25kΩ, an alarm signal is output through a passive contact with a contact capacity of DC220V / 5A. When the overload is 105%-125%, the dynamic voltage support unit preferentially compensates, after the compensation fails, the main controller sends a breaking instruction to the circuit breaker within 5ms, and the tripping time of the circuit breaker is less than or equal to 1ms. The characteristic curve configuration is that the tripping time is less than or equal to 2s at 150% load. When short-circuit protection is performed, the current limiting threshold is set to 3 times the rated current, the action time is less than or equal to 2ms, the magnetic blow arc extinguishing technology is adopted, and the breaking reliability is ensured. In the power conversion unit, the high-frequency rectification module efficiency test is performed under the conditions of load rate 25%, 50%, 75%, 100% and input voltage 380V±10%, the synchronous rectification technology is adopted, the IGBT switching frequency is 20kHz, the iron loss is reduced through the optimization of the magnetic circuit design, and the full-load efficiency is greater than or equal to 92%. The inverter module output waveform is realized through SPWM modulation, the carrier frequency is 10kHz, the modulation ratio is 0.8, the total harmonic distortion is less than or equal to 3%, the output end is provided with an LC filter composed of a 10μH inductor and a 470μF capacitor, and the switching ripple is suppressed. An isolation transformer is additionally arranged at the output end of the communication power supply module, the primary and secondary turns ratio is 1:1, the withstand voltage grade is DC500V, and the electrical isolation with the public DC bus is ensured.

[0045] Any example of the present application can be implemented as an independent technical solution, or can be combined with other examples. All patents and publications mentioned in the present application indicate that these are the disclosed technologies in the art, and the present application can use them. All patents and publications cited herein are also listed in the references, and each publication is specifically and individually referred to. The present application can be implemented without any element or elements, one limitation or multiple limitations, and the limitations are not specifically mentioned herein. The terms and expressions used herein are for description, not for limitation, and there is no intention to indicate that the terms and expressions described herein exclude any equivalent features, but it can be understood that any suitable changes or modifications can be made within the scope of the present application and the claims. It can be understood that the described examples of the present application are examples and features in some embodiments, and any general person skilled in the art can make some changes and modifications based on the essence of the present application description, and these changes and modifications are also considered to be within the scope of the present application and the scope limited by the independent claims and the dependent claims.

Claims

1. An AC / DC integrated power supply system characterized by comprising: It comprises: a power conversion unit comprising a high-frequency rectification module, an inverter module and a communication power module arranged in parallel, the AC input end of the high-frequency rectification module being connected to an external AC power supply; the DC side of the high-frequency rectification module, the inverter module and the communication power module being connected in parallel to a common DC bus; an energy storage unit comprising a battery pack, a bidirectional DC / DC converter and a health monitoring circuit; the low-voltage side of the bidirectional DC / DC converter being connected to the battery pack; the high-voltage side of the bidirectional DC / DC converter being connected to the common DC bus; and the health monitoring circuit being electrically connected to the battery pack monomer; a dynamic voltage support unit composed of a filter network and a transient suppression device in series; the input end of the filter network being directly connected to the common DC bus; and the output end of the filter network being connected to a load power supply interface; an electromagnetic protection unit comprising an input stage surge protector connected in series at the AC input end of the high-frequency rectification module; a cabinet grounding copper bar electrically connected to the negative pole of the common DC bus; and an anti-interference device integrated in the signal acquisition end of each module circuit board; an intelligent control unit comprising a main controller and a communication bus; the main controller being bidirectionally connected to the control interface of each module through the communication bus; and the signal acquisition end of the main controller being connected to the voltage and current sensors and the health monitoring circuit.

2. The AC-DC integrated power supply system according to claim 1, wherein The health monitoring circuit comprises: Internal resistance detection module, measurement accuracy ≤±0.1 mΩ; temperature sensor array, real-time monitoring of the surface temperature of each battery; voltage acquisition circuit, accuracy ≤±0.14%; capacity prediction module, based on 0.1 Discharge curve estimates remaining capacity.

3. The AC-DC integrated power supply system according to claim 1, wherein The dynamic voltage support unit specifically comprises: When the load step increases, the transient suppression device releases stored energy to maintain the bus voltage ≥ 95% of the nominal value; When the load step decreases, the filter network absorbs excess energy to suppress the voltage peak ≤ 105% of the nominal value; The full-load output ripple coefficient ≤ 0.1%.

4. The AC-DC integrated power supply system according to claim 1, wherein The intelligent control unit specifically comprises: Real-time comparison of the DC bus voltage with the set threshold value, deviation > ± 2.5% triggers PID adjustment; When the AC input voltage < 85% of the rated value, send switching instructions to the bidirectional DC / DC converter; Receive battery temperature data, calculate the float voltage according to the compensation formula and send it to the high-frequency rectification module.

5. The AC / DC integrated power supply system according to claim 1, wherein The common DC bus specifically comprises: The DC positive / negative poles of the high-frequency rectification module, the inverter module and the communication power module are connected in parallel to the bus copper bar; The high-voltage positive / negative poles of the bidirectional DC / DC converter are directly connected to the bus copper bar; The input end of the dynamic voltage support unit is connected to the bus copper bar through a fuse; Support 200% impact current discharge when the battery pack is powered, and the bus voltage ≥ 90% of the nominal value.

6. The AC / DC integrated power supply system of claim 1, wherein The power conversion unit converts AC power into DC power through a high-frequency rectification module in a normal power supply mode, and the DC power is supplied to a common DC bus; the DC power is output in three ways: converted into AC power through an inversion module, converted into low-voltage DC power through a communication power module, and directly supplied to a DC load through a dynamic voltage support unit; the surplus power charges a battery pack through a bidirectional DC / DC converter; the intelligent control unit detects the failure of AC interruption input and sends a discharge instruction to the bidirectional DC / DC converter; the battery pack power is injected into the common DC bus after being boosted by the bidirectional DC / DC converter; the bus power maintains the power supply of the inversion module, the communication power module and the DC load; the intelligent control unit compensates for voltage fluctuation instantaneously when detecting load mutation; the intelligent control unit adjusts the output power of the high-frequency rectification module or the bidirectional DC / DC converter within 20ms.

7. A control method of an AC-DC integrated power supply system, applied to the AC-DC integrated power supply system of any one of claims 1-6, characterized in that, Comprise: S1. Multi-modal power supply control, real-time monitoring of AC input state, switching to energy storage unit power supply when voltage is continuously below threshold, enabling dynamic current limiting to suppress impact current when detecting load mutation; S2. Energy storage unit health management, collecting battery internal resistance, voltage and temperature data, dynamically calculating float voltage according to temperature and adjusting charging parameters, periodically performing capacity verification test; S3. Collaborative fault protection, monitoring DC bus insulation state, triggering alarm when resistance value is below threshold, grading off output when overloaded.

8. The control method of an AC-DC integrated power supply system according to claim 7, characterized by, The S1 specifically comprises: When the input voltage is continuously below 85% of the rated value, send a discharge instruction to the bidirectional DC / DC converter to control the battery pack power to be injected into the common DC bus after being boosted by the bidirectional DC / DC converter; When the load steps change, enable the dynamic voltage support unit to suppress bus voltage fluctuation, so that the voltage is maintained within 95%-105% of the nominal value; Specifically: when the load steps increase, control the transient suppression device to release energy to maintain the bus voltage ≥ 95% of the nominal value; when the load steps decrease, control the filter network to absorb excess energy to suppress voltage spikes ≤ 105% of the nominal value; The proportional-integral-derivative controller adjusts the duty cycle of the power device so that the voltage fluctuation is ≤ ± 2.5%.

9. The control method of an AC-DC integrated power supply system according to claim 7, characterized by, The S2 specifically comprises: The float voltage Vfloat calculation formula is: Vfloat=Vbase-k×(T-Tref), wherein the temperature compensation coefficient k has a value range of 2-4 mV / ℃ / monomer; Vbase is the reference float voltage, V / monomer; T is the measured battery temperature, ℃; Tref is the reference temperature, taken as 25℃; The float voltage adjustment includes: when the temperature > 40℃, Vfloat is lowered by 0.02-0.04V / monomer; when the temperature < 0℃, Vfloat is raised by 0.03-0.05V / monomer; Vfloat is calculated by the intelligent control unit and sent to the high-frequency rectification module; T is collected by the temperature sensor in the health monitoring circuit; k and Tref are stored in the configuration parameters of the intelligent control unit; Periodically perform 0.1 Discharge curve check, update battery remaining capacity prediction value; The calculated float voltage value is sent to the high-frequency rectification module to adjust the battery charging parameters.

10. The control method of an AC-DC integrated power supply system according to claim 7, characterized by, The S3 further comprises: When the DC bus resistance to ground is less than or equal to 25 kΩ, a sound-light alarm and passive contact output are triggered; when the load rate is between 105% and 125%, the device runs continuously for 10 minutes and then switches to bypass power supply; when the load rate is 150% or a short circuit occurs, the output current is limited and the circuit breaker is tripped, and the output is cut off in stages: when overloaded, the dynamic voltage support unit compensates for voltage fluctuations first; when compensation fails, the intelligent control unit sends a breaking command to the circuit breaker within 5 ms.

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