148 results about "Current loop control" patented technology

The invention discloses an active damping control system for improving the output impedance of a current source type inverter, which comprises a current loop control loop, an active damping branch and an improved phase-locked loop, and is characterized in that the difference value of reference current and feedback network access current passes through a current controller to form the current loop control loop; the voltage of the grid-side inductor is fed back to the output of the current loop through the virtual resistor link to form a damping branch, and the voltage of the common coupling point enters the traditional phase-locked loop link through the low-pass filter and forms an improved phase-locked loop through phase compensation. The optimal feedback coefficient of the damping branch is designed according to the optimal damping ratio, the low-pass filter parameters are designed according to the phase at the maximum resonant frequency, the reasonable proportional gain link is designed according to the improvement of the output impedance amplitude, the resonance of the current source type inverter can be effectively inhibited, the output impedance of the inverter is increased, and the output impedance of the inverter is improved. And the quality of the network access current of the current source type inverter and the stability margin of the current source type inverter in a weak power grid are improved, and the stability of the system is improved.

The invention belongs to the technical field of new energy, and particularly relates to a fault voltage ride-through optimization method and system for a network construction type energy storage converter. Carrying out positive and negative sequence separation and Clark-Park coordinate transformation on the three-phase power grid voltage and the inversion current, calculating active power and reactive power of the network-forming type energy storage converter, and carrying out power loop control to obtain three-phase reference voltage and angular velocity; performing voltage loop control, and dynamically adjusting a positive sequence active current and a positive sequence reactive current according to whether a low-voltage-crossing indication signal exists or not; performing positive-sequence current loop control and negative-sequence current loop control, and then performing inverse Clark-park conversion to obtain positive-sequence three-phase reference voltage and negative-sequence three-phase reference voltage; and superposing the positive-sequence three-phase reference voltage and the negative-sequence three-phase reference voltage for PWM (Pulse Width Modulation). According to the invention, when the power grid voltage is unbalanced due to a fault, the oscillation of the direct current side voltage and power caused by the negative sequence component is eliminated, and the power angle stability is improved and the fault current is suppressed by dynamically adjusting the related reference value during the fault voltage ride-through period.

The invention discloses a vehicle control method and system. The vehicle comprises a motor, a battery and a controller. The controller is connected between the battery and the motor, and the controller is used for converting electric power output by the battery; the control method of the vehicle is executed by the controller. The vehicle control method comprises the steps that when the duration that the output current of a battery is larger than the maximum current of the battery reaches a first preset duration, a current limiting adjustment strategy is started; and circularly executing the steps of determining a target regulating variable according to the current-limiting regulation strategy, regulating the maximum output value of a speed loop control strategy of the motor according to the target regulating variable, determining a target current according to the regulated maximum output value and the speed loop control strategy, and controlling the rotating speed of the motor according to the target current and a current loop control strategy. And the duration for starting the current-limiting adjustment strategy reaches a second preset duration. According to the technical scheme, components and a battery can be better protected, it is guaranteed that the motor does not run slowly, and therefore running of a vehicle is guaranteed.

The invention relates to a permanent magnet synchronous motor current loop control method which is executed by a vehicle and comprises the following steps: acquiring real-time current passing through a permanent magnet synchronous motor stator winding of the vehicle under a three-phase static coordinate system; converting the real-time current under the three-phase static coordinate system into a d-axis current and a q-axis current under a two-phase rotating coordinate system; generating a d-axis voltage signal and a q-axis voltage signal according to the d-axis current, the q-axis current, the rotating speed of the motor and the current command; performing decoupling operation on the d-axis voltage signal and the q-axis voltage signal to obtain a d-axis command voltage and a q-axis command voltage; obtaining an overcurrent fault flag bit according to the d-axis current and the q-axis current; determining PWM switching frequency and current loop PI controller parameters based on the rotating speed of the motor; and controlling a permanent magnet synchronous motor current loop in the vehicle according to the d-axis voltage signal, the q-axis voltage signal, the overcurrent fault flag bit, the PWM switching frequency and the parameters of the current loop PI controller.

A single-phase PWM rectifier direct-current side boost type active filter circuit control method based on a duty ratio feed-forward single current loop is characterized by comprising the following steps that inductive current of an active filter circuit is collected; collecting the direct current side current of the single-phase PWM rectifier; the method comprises the following steps: extracting a DC side current secondary pulsation component of a PWM rectifier as a reference current of an active filter circuit, performing high-pass filtering on the acquired inductive current of the active filter circuit to filter out a DC component, then subtracting the reference current, and enabling a deviation value to pass through a controller to obtain a current loop control component; the control component per unit of the current loop is added with the voltage control duty ratio Dv of the support capacitor of the active filter circuit for modulation to obtain a control signal of a corresponding switch tube. According to the method, a support capacitor voltage sampling circuit and a control loop of a traditional boost active filter circuit are omitted, the system hardware cost is reduced, the reliability is improved, and the control loop is simplified. The method is suitable for all active filter control which adopts a boost type active filter circuit for filtering on the direct current side, and applicable systems comprise single-phase rectification, single-phase inversion, multi-phase rectification, multi-phase inverters and the like.

The invention discloses a power current loop control method for seamless switching of grid-connected and off-grid modes of an energy storage PCS, and the method achieves the seamless switching of the two control modes through the dynamic adjustment of a power reference value of an inverter, the merging of a PQ-controlled current loop and a Vf-controlled current loop, and the introduction of a PQ-controlled reference current into a Vf control loop. The method specifically comprises the following steps: detecting voltage, current and phase parameters in grid-connected and off-grid states, and calculating corresponding power; when the switching signal is received, the grid-connected active power is adjusted to an off-grid preset value through a PI controller; switching an inverter control mode within a power error allowable range, and introducing a PQ reference current to a Vf voltage loop; and control mode switching and switch state change are completed in sequence. According to the method, the problems of voltage fluctuation and current sudden change during switching in a traditional method are effectively solved, bidirectional seamless switching can be realized without reducing zero output power, dependence on an additional energy storage system is reduced, and the operation stability of the micro-grid is improved.

The application belongs to the technical field of motor drive control, and discloses a permanent magnet synchronous motor current loop control method based on a predictive nonlinear active disturbance rejection, which comprises the following steps: step 1, establishing a permanent magnet synchronous motor control system model considering time delay; step 2, establishing a current loop extended state observer with time delay compensation; and step 3, designing a nonlinear current feedback control law based on finite time convergence. The application establishes a discrete domain extended model for the current loop of the permanent magnet synchronous motor, and proposes a high-performance nonlinear active disturbance rejection current control method for the permanent magnet synchronous motor. The high-frequency response current controller designed by the application is composed of a predictive extended state observer and a nonlinear current feedback control law, and can solve the problem that the frequency response of the permanent magnet synchronous motor drive is limited due to the digital delay in the motor digital control system and the low-pass filter delay in the current feedback channel, and improve the anti-disturbance performance when the motor parameters change.

The invention discloses a servo driver based on a heterogeneous computing architecture, and relates to the field of servo drive control, and the servo driver comprises a first processing unit which is configured to execute an upper-layer control loop and a real-time communication protocol of a servo system; the second processing unit is a heterogeneous processor integrated with a processing system and programmable logic, the processing system is used for executing system management and man-machine interaction tasks, and the programmable logic is configured to realize lower-layer current loop control, pulse width modulation signal generation and hardware acceleration calculation; and the high-speed parallel data interface is connected with the first processing unit and the second processing unit and is used for realizing bidirectional interaction of the control data and the state data. According to the scheme, through collaborative optimization of a heterogeneous computing architecture and a hardware acceleration mechanism, the comprehensive performance of the servo driver is remarkably improved.

The invention discloses a method for suppressing input three-phase harmonic current of ship power supply equipment, which comprises the following steps of: firstly, determining the times and loop parameters of specific harmonic current needing to be compensated by a PFC (Power Factor Correction) unit of the power supply equipment under the working condition by combining a CE101 test chart and the size of an array load, so that harmonic current control participates in the existing PFC current loop control; therefore, the content of the input harmonic current is adjusted to be lower than the CE101 limit value. On the basis of a PFC digital control unit of original equipment, a control method for suppressing input of three-phase harmonic current is added, and an electric reactor or an active power filter (APF) device is omitted, so that the problem that part of sub-harmonic current exceeds a CE101 limit value is solved.

A power supply control method, a power supply and a computer program product are applied to the technical field of power supplies, and the power supply control method comprises the following steps: obtaining a target output value and a target limit value of a current configuration; acquiring a voltage value measured by the current circuit and a current value measured by the current circuit; if the source working mode is satisfied, determining a feedback time relationship between the current loop control module and the voltage loop control module; if the feedback time of the current loop control module is less than the feedback time of the voltage loop control module, controlling to reach a current limit value or a current output value in the target output value and the target limit value; and on the contrary, the voltage loop control module controls to reach the voltage limit value or the voltage output value in the target output value and the target limit value. Because the control module with short feedback time can be switched to control the power supply output, the voltage switching and the current switching can be smoothly carried out, thereby avoiding the occurrence of overtuning and inflection points.

The invention discloses an internal model control-based network construction type full-power wind power converter control method. The method comprises the following steps of: acquiring a control quantity of a network construction type full-power wind power converter; determining an active power current given value by using preset internal model control according to the control quantity; determining a modulation voltage of a wind power converter machine side converter according to an active power current given value by utilizing current loop control; utilizing direct-current voltage synchronous control, and outputting a control synchronous angle according to the control quantity; by means of voltage and current double-loop control, output control output voltage is output according to the control quantity; and realizing machine-side converter control of the wind power converter according to the modulation voltage, and realizing grid-side converter control of the wind power converter according to the control synchronization angle and the control output voltage.

A power supply control method, power supply, and computer program product are applied to the power supply technology field. The power supply control method includes: obtaining a currently configured target output value and a target limit value; obtaining a currently measured voltage value and a currently measured current value of the circuit; if a source operating mode is satisfied, determining the feedback time relationship between a current loop control module and a voltage loop control module; if the feedback time of the current loop control module is less than the feedback time of the voltage loop control module, controlling the current to reach the current limit value or current output value between the target output value and the target limit value; otherwise, controlling the voltage to reach the voltage limit value or voltage output value between the target output value and the target limit value based on the voltage loop control module. Because the power supply output can be controlled by switching to a control module with a shorter feedback time, voltage and current switching can be performed smoothly, thereby avoiding overshoot and inflection points.

The invention relates to the technical field of robots, in particular to a bodybuilding robot joint module motor electrical zero point confirmation method, which comprises the following steps: randomly setting an initial electrical zero point, executing a current loop in a short pulse mode to control motor rotation, giving a forward rated current at an isqref end, substituting the forward rated current into a q-axis current PI controller to calculate to obtain Usqref, and determining the initial electrical zero point; performing inverse Park conversion on the Usqref to obtain Ualpha, obtaining Ua, Ub and Uc through an SVPWM (Space Vector Pulse Width Modulation) algorithm, and finally inputting the Ua, Ub and Uc to three phases of the motor to drive the motor to rotate so as to complete primary current loop control; and meanwhile, the feedback of the real encoder is detected. According to the method, zero point confirmation of the motor in a full-load range is ensured, compared with a pre-positioning method, the method has a wider application range, and the accurate zero point confirmation can ensure the adaptive capacity of the robot in a complex and dynamic environment.

The present invention discloses a control method, device, motor, storage medium and processor for a motor. The method includes: in the field weakening control system of the motor, a single q-axis current regulator is adopted to freely switch between field weakening traction and braking control under field weakening conditions; in the control system of the single q-axis current regulator, a field weakening compensation module is added to perform field weakening compensation processing on the d-axis and q-axis currents of the motor; and an out-of-control limiting and compensation module is added to perform out-of-control limiting and compensation processing on the field weakening current of the motor to obtain the voltage vector angle of the field weakening control system of the motor; according to the voltage vector angle and the maximum stator voltage of the motor, the dq-axis reference voltage vector of the motor is determined to drive and control the system where the motor is located. With this solution, by adopting a single current loop control structure in the field weakening control of a permanent magnet synchronous motor and using a limiting method and a current compensation method for field weakening control, the stability of the control system of the permanent magnet synchronous motor can be improved.

The embodiment of the invention relates to a direct-current voltage conversion circuit control method and device, electronic equipment and a storage medium. The method comprises the following steps: acquiring a sampling voltage and a preset number of sampling currents; determining a voltage error value between the set voltage and the sampling voltage; determining a voltage loop control parameter based on the voltage error value, and determining a first control quantity by using the voltage loop control parameter; determining a set current value based on the first control quantity and the input voltage values of the preset number of voltage conversion branches; and for each voltage conversion branch in the preset number of voltage conversion branches, calculating the current error value by using the current loop control parameter to obtain a second control quantity, and generating a control signal for performing pulse width modulation on the voltage conversion branch based on the second control quantity. According to the embodiment of the invention, the output voltage and current can be more rapidly stabilized, the stability of the voltage and current is better, and the environmental adaptability and the anti-interference performance are better.

The application discloses an inverter grid-connected current harmonic suppression method and system, collects inverter bridge arm current and grid-connected point voltage, carries out operation on the inverter bridge arm current and the grid-connected point voltage to obtain grid-connected current, carries out harmonic suppression on the grid-connected current through a harmonic suppression ring to obtain harmonic suppression ring output value, obtains feedforward value of the grid-connected point voltage and fundamental wave current loop control output value, takes a negative value of the harmonic suppression ring output value and superimposes the feedforward value of the grid-connected point voltage and the fundamental wave current loop control output value, obtains modulation voltage of the inverter, carries out PWM modulation on components of the modulation voltage to generate a switching signal for driving the grid-connected inverter to work. The application estimates the grid-connected current, suppresses specific harmonics in the grid-connected current, makes the grid-connected current harmonic suppression effect better, adopts feedforward on the grid-connected point voltage, makes the inverter have better dynamic performance and stability under strong grid or weak grid, and reduces the grid-connected current harmonic suppression difficulty.

The invention discloses a permanent magnet synchronous motor control parameter self-tuning method and system based on frequency domain analysis. The method comprises the steps of current loop control including a PI link, a delay link and a motor model; offline optimization: extracting bandwidth and phase margin indexes of a current loop, and establishing a relationship between control gain and response and stability indexes to reversely solve optimal kp and ki parameters; and online index optimization: in the operation process, the steady-state error of the current is compared with a preset error threshold value, and motor control parameter optimization is carried out according to a comparison result. Based on a current motor vector control architecture, optimization of control parameters can be realized through frequency domain modeling, frequency domain index analysis and the like, so that the control effect of the motor is improved, and meanwhile, the use requirements of the vehicle are met.

The invention discloses a power conversion circuit, which comprises a main power converter of which the output end is connected with the output end of the power conversion circuit through a first detection resistor, and is used for providing a first current; the output end of the auxiliary power converter is connected with the output end of the power conversion circuit through a second detection resistor, and the auxiliary power converter is used for providing second current; the feedback regulation circuit is used for generating a regulation signal according to the first current and the second current and providing the regulation signal to a current loop control pin of the auxiliary power converter; therefore, the ratio of the current value between the second current provided by the auxiliary power converter and the first current is equal to the ratio of the resistance value between the first detection resistor and the second detection resistor, so that the requirement of heavy-load current can be met only by two power converters.

The application discloses a motor system efficiency improving system, device and vehicle permanent magnet synchronous motor. The motor system efficiency improving system comprises a CAN communication transceiving module, a torque coordination module, a variable frequency control module and a motor control module. The application receives instruction information sent by a vehicle controller through the CAN communication transceiving module, analyzes the instruction information, processes the analyzed instruction information through the torque coordination module, obtains target instruction information, processes the target instruction information through the variable frequency control module, obtains frequency information and current loop control parameter information, switches the motor control mode according to the target instruction information through the motor control module, and improves the motor efficiency according to the frequency information and the current loop control parameter information. The application realizes closed-loop control of the motor according to the current loop control parameter information through the motor control module, and improves the motor efficiency according to the frequency information.

The invention provides an aviation permanent magnet generator power control system and method, and the method comprises the steps: enabling a result obtained after the difference value between a given rotating speed and feedback power from a power calculation module passes through a PI controller to serve as the input of a current loop control signal, and enabling an output value of a modulation ratio weak magnetic module to serve as the input of the current loop control signal, two-phase current sampling is carried out through a phase current detection circuit, a dq rotating coordinate system is obtained through Clarke and Park conversion, a first result is obtained through subtracting an input and a feedback value of a current loop, a second result is obtained through subtracting the input and the feedback value of the current loop, and the first result is output through a current PI controller. And a second result is output through a current PI controller, a sum is obtained through Park inverse transformation, six paths of control signals are output through an SVPWM module to drive an inverter to work, and a generator outputs target power. The method can be used for power control of any aviation permanent magnet power generation control system.

The invention relates to the technical field of wind power equipment, in particular to a wind turbine generator variable pitch control system and method.The wind turbine generator variable pitch control system comprises a half-control rectification loop, a driver direct-current bus, an inversion alternating-current loop and a super-capacitor module, and the half-control rectification loop is connected with a three-phase alternating-current power grid; the driver direct-current bus is connected with the half-control rectification loop, the inversion alternating-current loop is connected with the driver direct-current bus, and the inversion alternating-current loop controls the pitch angle of the paddle through the motor; the super capacitor module is connected with the half-control rectification loop and the positive electrode end of the driver direct-current bus. The super capacitor module is connected with the driver direct-current bus in parallel through a circuit with a relay. According to the variable-pitch control system, loop switching of connection of the super-capacitor module is carried out through on-off of the relay, the function of a traditional independent charger is replaced through loop switching of the super-capacitor module, a brake resistor and a bleeder circuit are not needed, and therefore the cost, the fault rate and the design and installation difficulty of the variable-pitch control system are reduced, and the size of the system is reduced.

The invention discloses a brushless direct-current motor control system and a brushless direct-current motor controller adopting the same, which realize a current loop and generate a motor driving signal through hardware circuit design, cancel a rotating speed loop and a corresponding motor rotating speed measurement module, and only reserve a position loop in embedded software. The resource overhead of the embedded processor is greatly reduced, so that embedded software can bear more other work tasks, the hardware design is simplified, the product cost is reduced, and the volume and the weight of a product are favorably compressed. Moreover, according to a current loop control strategy, an existing PWM control mode is improved into current direct control, the system complexity is further reduced, the design is simplified, EMI electromagnetic interference noise in the device can be reduced, smoother rotating motion can be provided, the tiny jitter defect of a PWM driving mode at the zero-current intersection position is avoided, and the reliability of the device is improved. And a hardware circuit control mode also has the advantages of simplicity, high efficiency and quick response.

This application discloses a current loop control method, related devices, and a permanent magnet synchronous motor (PMSM), relating to the field of motor control. By feeding forward a disturbance voltage characterizing the voltage change caused by parameter variations in the PMSM, an ideal stator current equation is obtained. The transfer function of the PMSM is obtained by combining the vector expressions of stator voltage and stator current in an orthogonal coordinate system. The first current loop transfer function is determined by combining the first controller transfer function. The coefficient values ​​of each control element are determined by tuning the first current loop transfer function. Then, based on the obtained second controller transfer function and the compensation term for the current loop delay, a control voltage calculation model corresponding to the target coordinate axis is determined. The first control voltage is determined based on the control voltage calculation model and fused with the disturbance voltage to obtain the final control voltage. This achieves high-precision current decoupling control of the PMSM, improving control accuracy and efficiency.

The invention provides a control method and a controller of an uninterruptible power supply (UPS), the control method is used for controlling the UPS to switch from a mains supply mode to a battery mode, the control method comprises voltage loop control and current loop control, the voltage loop control provides a current control signal based on the comparison of a bus voltage sampling value and a bus voltage given value of the UPS, and the current loop control provides a current control signal based on the comparison of the bus voltage sampling value and the bus voltage given value of the UPS. The current loop control provides a PWM control signal for operation of the battery mode based on a comparison of a battery current sampling value and a current given value, and the control method comprises the following steps: in a first control period of the current loop control, determining the current given value based on the current control signal and a battery current calculated value, the battery current calculation value is in direct proportion to the inversion output power of the UPS; and determining the current set value only based on the current control signal in a subsequent control period of the current loop control, the current control signal of each control period in the subsequent control period being directly related to the current set value of the previous control period.

The invention discloses a manipulator cooperative control system and method based on a servo motor, and relates to the technical field of manipulator control, and the method comprises the following steps: injecting a frequency-adjustable reference excitation signal into a servo driver ground wire of each servo shaft in a manipulator, and constructing a coupling observation basic sequence; when reference excitation signal injection is executed, ground wire instantaneous potentials of servo drivers of all servo shafts are synchronously collected in parallel, and a complete multi-shaft potential response matrix is constructed based on a coupling observation basic sequence. According to the method, the frequency-adjustable excitation signal is introduced, sparse cross-correlation and adaptive Kalman filtering are combined, identification and modeling of a cross-axis potential interference path are realized, and servo current loop control parameters are dynamically corrected, so that parasitic current interference is effectively inhibited, synchronism, stability and anti-interference robustness of multi-axis cooperative control are improved, and the method is suitable for large-scale popularization and application. The problems of response lagging and out-of-step of a traditional method are solved.

The application discloses a single-input multi-output modular multi-port power supply and a control method thereof. The power supply comprises an AC-DC conversion module, a first DC conversion module comprising a plurality of parallel first DC conversion units for providing an output in a four-quadrant operation mode, a second DC conversion module comprising a plurality of parallel second DC conversion units for providing an output in a two-quadrant operation mode, and a third DC conversion module comprising a plurality of parallel third DC conversion units for providing an output in a single-quadrant operation mode. The input ends of the first DC conversion module, the second DC conversion module and the third DC conversion module are connected in parallel to a DC bus at the output end of the AC-DC conversion module. The control method performs collaborative optimization of voltage loop control parameters, current loop control parameters and power distribution coefficients by using a multi-objective evolutionary algorithm. The application effectively improves the flexibility, expandability and stability of the multi-port modular power supply.

The invention relates to a frequency converter control method, a frequency converter, a readable storage medium and a program product. The method comprises the following steps: acquiring a power supply phase current under an alpha-beta coordinate system; determining a power supply phase voltage according to the power supply phase current; acquiring a reference voltage and a bus voltage of the output end of the rectification inverter; performing voltage loop control according to the reference voltage and the bus voltage to obtain voltage loop current; performing power control according to the voltage loop current, the power supply phase voltage and the power supply voltage, and determining a reference phase current; the power supply voltage is determined according to the power supply phase voltage; performing current loop control according to the reference phase current and the power supply phase current to obtain a target phase voltage; the target phase voltage is used for adjusting the voltage output by the rectification inverter. By adopting the method, the voltage control is accurate.

The invention discloses a fault-tolerant control system and method for a high-resistance connection fault of a three-phase permanent magnet synchronous motor, and belongs to the field of synchronous motor control, the fault-tolerant control system comprises a rotating speed loop control module, a current loop control module and an SVPWM modulation module, the rotating speed loop control module comprises an encoder and a resonant sliding mode controller, and the rotating speed loop control module is used for obtaining a target current component; the current loop control module is used for generating a voltage control signal based on a current difference value between the target current component and the corresponding real-time current component; the SVPWM modulation module is used for driving the to-be-monitored three-phase permanent magnet synchronous motor to operate based on the generated voltage control signal. According to the fault-tolerant control system and method for the high-resistance connection fault of the three-phase permanent magnet synchronous motor, the resonant sliding mode controller is adopted in the rotating speed loop, the self-adaptive notch filter is introduced into the current loop, and the torque ripple and the rotating speed fluctuation of the three-phase permanent magnet synchronous motor under the high-resistance connection fault can be effectively inhibited without additional hardware, so that the fault tolerance of the high-resistance connection fault of the three-phase permanent magnet synchronous motor is improved. And the fault-tolerant performance and the operation stability of the motor are improved.

The invention provides a control system and an anti-disturbance method of an electromagnetic bearing, a rotor position outer ring is controlled by a non-singular fast terminal sliding mode controller, external disturbance borne by the system is estimated in real time by introducing a non-linear disturbance observer, and an estimation result is fed back to a position controller for compensation; the input of the position controller is the difference value between the given position and the feedback position of the magnetic bearing rotor, and the output value is the reference value of the current loop control current; a stator coil inner ring is controlled by a nonsingular fast terminal sliding mode controller, input values of the controller comprise a current bias value + a current reference value output by a position ring and a current bias value-a current reference value output by the position ring, and an output quantity is a driving PWM signal duty ratio of a magnetic bearing stator coil; driving the PWM signal to be output to the power amplifier; the power amplifier supplies power to the stator coil; the axial thrust load sudden change anti-disturbance capability can be enhanced, it is ensured that when the thrust load suddenly changes, the magnetic bearing maintains stable suspension of the rotor, and anti-disturbance control is achieved.

The application belongs to the technical field of electric power, and provides a DC micro-grid system and a secondary control method of the DC micro-grid. The voltage compensation module, the droop control module, the steady-state current distribution compensation module, the dynamic current distribution compensation module and the voltage and current loop control module of the DC micro-grid system work cooperatively to ensure the accurate distribution of load current among different distributed power generation units, and improve the power quality and robustness of the DC micro-grid. The DC micro-grid system introduces compensation voltage to be used for bus voltage recovery and offsetting the influence of line resistance on the steady-state current distribution accuracy. The voltage and current loop control module adopts a cascaded voltage and current loop control mode to ensure that the output voltage of the distributed power generation unit converter closely tracks the reference output voltage, so as to realize the accurate distribution of load current among the distributed power generation units and improve the power quality of the DC micro-grid.