764 results about "Off time" patented technology

The invention provides a tumor treatment electric field system which comprises an electric field therapeutic instrument and at least two pairs of insulated electrodes electrically connected with the electric field therapeutic instrument. An alternating electric signal direction switching period, an AC voltage amplitude peak value of the alternating electric signal, working periods of the alternating electric signal, a continuous conduction time period t1 of the alternating electric signal in each working period and a preset specific voltage V are stored in the electric field therapeutic apparatus. The continuous conduction time period t1 comprises a switching-on time period t3, a switching-off time period t4 and conduction time periods located between the switching-on time period t3 and the switching-off time period t4, and the preset specific voltage V is an AC voltage amplitude value of the alternating electric signal in each conduction time period and is not greater than an AC voltage amplitude peak value; the AC voltage amplitude of an alternating electric signal applied by the electric field therapeutic apparatus is increased from 0 to the preset specific voltage V in a gradually increasing mode within a switching-on time period t3, and the gradually increasing mode at least comprises 20 first steps, so that electrical stimulation generated when the alternating electric signal is alternately applied between different pairs of insulated electrodes is reduced.

The invention discloses an energy storage system and a parallel operation control method thereof. The system comprises a battery cluster, a battery management system and an energy storage converter. The battery management system is respectively connected with the battery clusters and the energy storage converter, and the plurality of battery clusters are connected with the energy storage converter through the coupling circuit. Wherein a pre-charging equalization loop is arranged between the battery cluster and the energy storage converter, and the battery management system is used for controlling connection or disconnection of a circuit. The battery management system is also provided with a threshold module which is integrated with a plurality of parallel operation thresholds and is used for judging the switching-on or switching-off time of the contactor. By constructing a coupling system containing a pre-charging equalization loop, the problems of impact current and device damage caused by large inter-cluster voltage difference in the parallel operation process of a traditional multi-battery energy storage system are solved; and meanwhile, through a strategy of setting multiple parallel operation threshold values, targeted current balancing can be carried out according to different dynamic working conditions and electric energy parameter differences, the impact current is prevented from being too high, components are protected, and the operation stability of the system is improved.

The invention discloses a switching converter and a control circuit and a control method thereof. The control circuit determines the conduction time of a main power tube according to a comparison result between a loop error signal and a preset threshold voltage in a PFM mode, and determines the turn-off time of the main power tube according to a comparison result between a current sampling signal representing an inductive current and the threshold voltage. Therefore, the switching frequency can be adjusted by adjusting the time position of the pulse of the switching signal, the pulse width of the switching signal (namely, the conduction time in the switching period) is constant, and compared with a control scheme in the prior art, the switching converter provided by the embodiment of the invention has the advantages that the switching frequency can be adjusted by adjusting the time position of the pulse of the switching signal no matter the switching converter is in a PWM mode or a PFM mode; and the feedback voltage always fluctuates near the reference voltage, so that the problem that the output voltage is too high in the PFM mode is avoided, and the stability and efficiency of the system are improved.

The invention belongs to the field of integrated circuit design, and comprises a switch module and a co-frequency control module, the switch module comprises a power switch tube, and the co-frequency control module comprises a turn-on time control circuit, a turn-off time control circuit, a logic circuit and a driving circuit; the turn-on time control circuit generates a first control signal for controlling the turn-on time of the power switch tube; the turn-off time control circuit generates a second control signal for controlling the turn-off time of the power switch tube; the logic circuit performs logic operation on the first control signal and the second control signal to generate a third control signal; the driving circuit generates a driving signal based on the third control signal; the switch module controls the power switch tube to be switched on and switched off periodically according to the corresponding switching frequency based on the driving signal so as to convert the input voltage of the input power supply into the output voltage. According to the BUCK converter, the same-frequency control circuit is introduced, so that the fluctuation of the switching frequency of the BUCK converter controlled by the self-adaptive conduction time when the load changes can be effectively reduced.

An apparatus includes a PWM off time current sense circuit configured to generate a PWM off time current signal proportional to a current flowing through an inductor of a power converter when a high-side switch of the power converter is turned off and a low-side switch of the power converter is turned on, a PWM on time current rebuild circuit configured to construct an artificial inductor current signal using a voltage-controlled current source to charge a rebuild capacitor when the high-side switch of the power converter is turned on, and a feedback loop configured to adjust a current flowing through the voltage-controlled current source so as to force a saved voltage of the artificial inductor current signal to be equal to a saved voltage of the PWM off time current signal.

The invention is suitable for the technical field of GPU testing, and provides a software and hardware combined GPU automatic testing method and system, which comprises a hardware platform and a software platform, and is characterized in that the software platform is used for setting a voltage source output voltage value, power-on time and power-off time of the hardware platform, obtaining current, voltage and temperature data fed back by the hardware platform, and sending the current, voltage and temperature data to the hardware platform; associating the data with the automatic test GPU performance, and establishing a GPU test fault case database; and the hardware platform is used for providing power for the GPU, controlling power-on and power-off of the GPU and a power supply voltage value of the GPU according to the setting of the software platform, reading real-time current, voltage and temperature data near a GPU pin and feeding back the real-time current, voltage and temperature data to the software platform. According to the method, automatic testing of the GPU is achieved in a software and hardware combination mode, data graphical analysis can be achieved, abnormal problems occurring in the testing process can be positioned by comparing analysis results, and the GPU detection efficiency is improved.

The invention relates to an intelligent identification and conversion control method for a charging interface of a multi-standard charging pile in the field of new energy automobiles, and the method comprises the steps: carrying out the mode matching analysis of interface physical feature data and communication signal feature data, and obtaining a preliminary classification result of the type of a charging interface device; according to the loading result of the communication configuration parameters, obtaining a confirmation feedback signal of successful protocol switching; judging whether the load demand data conforms to a rated output power range of a charging interface device or not; according to the authorization instruction, current intensity data including a peak value and an average level and voltage level data including a fluctuation amplitude in the charging process are monitored in real time; if the current intensity data or the voltage level data exceed a preset safety threshold value, power supply connection is disconnected, and a circuit path is cut off; and generating a power-off record log containing abnormal fluctuation data and a power-off moment according to a result of disconnecting the power supply connection.

The embodiment of the invention provides a control method and control circuit of a half-bridge flyback converter, a chip and power supply equipment. The control method comprises the steps that when the half-bridge flyback converter works in a free resonance state, in a first switching period, the second primary switching tube is controlled to be switched on so that the half-bridge flyback converter can exit from the free resonance state, after a preset switching-on duration, the second primary switching tube is controlled to be switched off so that excitation current can be negative current, and the half-bridge flyback converter can be switched off. And the half-bridge flyback converter enters the free resonance state again, and the first primary switch tube is controlled to be switched on at the moment which is separated from the switching-off moment of the second primary switch tube by odd number times of the free resonance half cycle, so that the valley bottom of the first primary switch tube is switched on, the efficiency of the half-bridge flyback converter can be improved, and the service life of the half-bridge flyback converter is prolonged. And the peak stress when the secondary switch tube is turned off can be reduced, so that the EMI of the half-bridge flyback converter is improved.

The present invention provides a control circuit of an isolated power supply and an isolated power supply. A secondary side controller in the control circuit can turn on and off a synchronous rectifier based on a voltage from a secondary side winding, enabling adaptive turn-on and turn-off control of the synchronous rectifier. Specifically, when the voltage from the secondary side winding reaches a second predetermined voltage, an instruction for turning off the synchronous rectifier is provided. The second predetermined voltage is adjusted based on a comparison between a time interval for the previous switching period and a predetermined reference interval. In this way, a delay from a turn-off time of the synchronous rectifier to a turn-on time of a primary transistor switch is substantially maintained at the predetermined reference interval. This prevents cross-conduction of the primary and secondary side circuits, ensuring safe operation of the isolated power supply.

The invention provides an IGBT (Insulated Gate Bipolar Translator) turn-off time measuring method, system, equipment and medium, and belongs to the field of power semiconductor device testing technology and state monitoring, and the method comprises the following steps: firstly, selecting 20% Vdc and 80% Vdc as turn-off initial measuring points, secondly, carrying out first error correction by adopting a linear estimation method, and finally, carrying out second error correction by adopting a linear estimation method; performing linear fitting on the voltage difference Vce data through a least square method to obtain initial turn-off time; and finally, aiming at systematic deviation caused by inherent concavity and convexity characteristics of the voltage curve, performing secondary error correction by adopting a convex hull algorithm, acquiring a lower envelope line of the ic-tOFF relation curve through an Andriw algorithm, and identifying and eliminating the problem of Overestimation of the turn-off time based on a convex hull accurate point set. According to the invention, accurate measurement of the turn-off time of the IGBT under the condition of low sampling rate is realized, the hardware cost is significantly reduced, and a reliable technical basis is provided for IGBT state monitoring and life prediction.

A power switching circuit includes a driving signal part, a first switch element, a second switch element, a first driving circuit and a second driving circuit. The first driving circuit includes a first resistor and a first connection branch, which are connected between a positive driving signal terminal of the driving signal part and a first driving terminal of the first switch element, respectively. The second driving circuit includes a third resistor and a second connection branch, which are connected between the positive driving signal terminal and the second driving terminal of the second switch element, respectively. In a same switching cycle, the turn-on time of the first switch element is earlier than the turn-on time of the second switch element and the turn-off time of the first switch element is earlier than the turn-off time of the second switch element.

The invention provides a power-on and power-off control method and device, electronic equipment and a storage medium, and the method comprises the steps: obtaining module enabling input which is used for indicating power-on or power-off; determining each target power supply to be controlled and a control time sequence of each target power supply from each power supply based on the module enabling input, and generating a trigger signal and an expected output for each target power supply; and determining a first target power supply to be controlled based on the control time sequence among the target power supplies, sending a trigger signal to the first target power supply, and sending a trigger signal to the next target power supply after the output of the first target power supply is consistent with the expected output, thereby overcoming the defect that the power-on and power-off time sequence control of the complex equipment in the traditional scheme depends on an external circuit. The power-on and power-off control circuit has the advantages that the defects of difficulty in accurate control in the prior art are overcome, accurate control of any power-on and power-off time sequence can be realized without a complex circuit, simplicity, high efficiency and accuracy of a control process can be guaranteed, and sleep and sleep functions of equipment can be compatible.

The invention discloses an LED open circuit protection control system and a control method thereof. The circuit comprises a logic control module, a constant turn-on time module, a driving module, an NMOS tube MN1, an NMOS tube MN2, an inductor L, a current sampling resistor Rsense, a capacitor C2, an operational amplifier OP2, an error amplifier EA, a comparator CMP1, a loop compensation network, a switch S1, a filter network, a selector MUX, an operational amplifier OP1, a PMOS tube MP1, a minimum turn-off time detection circuit, an output overvoltage detection circuit, an AND gate AND1 and a phase inverter INV1. When the output LED is in an open circuit, the output voltage of the error amplifier EA is clamped at a proper voltage value required by normal operation of the system, so that the problem of inductive current peak during fault removal in the prior art is solved, and the reliability of the system is improved.

The invention discloses a power modulation method and system for an all-solid-state power supply, and belongs to the technical field of pulse power. The method comprises the following steps: converting a target waveform into a multi-level discrete waveform, and segmenting the multi-level discrete waveform into a plurality of continuous sub-waveforms according to polarity; for each sub-waveform, identifying all level switching moments, obtaining a time-level number corresponding relation, and generating a corresponding switching action time sequence matrix; the row index of the switching action time sequence matrix corresponds to the level number, the odd-numbered columns store the turn-on time parameters of the switching devices under the corresponding level number, and the even-numbered columns store the turn-off time parameters of the corresponding switching devices; and converting the switching action time sequence matrix into period counting based on an FPGA main clock, and generating a corresponding driving pulse signal by the FPGA according to time sequence data so as to control a switching device in the all-solid-state power supply and carry out power modulation. High-real-time and high-precision control on the switch of the solid-state power supply is realized, and the effect of arbitrary waveform power modulation is realized.

The invention discloses an intelligent integrated power supply, and particularly relates to the field of power supply intelligent control, the intelligent integrated power supply comprises a power supply body, the input end of the power supply body is connected with a main power supply and a standby power supply in parallel, the output end of the power supply body is connected with load equipment, and a super capacitor buffer module is arranged in the power supply body; the super capacitor buffer module is connected in parallel between the main power supply and the standby power supply, and an intelligent prediction control unit is further arranged in the power supply body and used for predicting the expected power-off time of the power supply body when the power supply input is switched next time. And if the predicted expected power-off time is less than the maximum buffer time of the super-capacitor buffer module, starting the super-capacitor buffer module to supply power and executing a power input switching action, otherwise, activating the standby power supply in advance. According to the invention, the problem of instantaneous power failure in the switching process is solved through a power supply seamless switching scheme in which the super capacitor buffer module and the intelligent prediction algorithm cooperate.

A rectifier includes digital timers to control FET switching rather than direct measurement of current and / or voltage. The digital timers control turn-off time to compensate for a delay produced by comparators in the rectifier. The digital timers are adjusted over multiple cycles to arrive at a turn-off time that produces zero current turn-off. The digital timers may be periodically or continuously readjusted based on a preceding set of cycles. Adaptive turn-off via digital timers is useful for discontinuous conduction mode suppression.

The present application provides a tumor electric field treatment system. The tumor electric field treatment system comprises an electric field treatment device and two pairs of the insulated electrodes electrically connected to the electric field treatment device. The AC signal controller is configured to generate control signals with respective time periods and at least two cyclically switched output states. The AC signal generator is configured to generates an alternating electric signal, and according to the output state of the control signals generated by the AC signal controller, cyclically and alternately apply the generated alternating electric signal to the insulated electrodes in pairs, so as to alternately generate alternating electric fields between the two pairs of insulated electrodes. The alternating electric signal applied to the insulated electrodes in pair have respective continuous on-time periods, and each continuous-on time period comprises an initial switching-on time period, an intermediate on-time period and a final switching-off time period. During the switching-on time period, the AC voltage value of the alternating electric signal applied to the insulated electrodes in pair rises from 0 to a specific voltage at a constant speed. During the switching-off time period, the AC voltage value of the alternating electric signal applied to the insulated electrodes in pair decreases from a specific voltage to 0 at a constant speed.

The invention belongs to the technical field of DC-DC converters, and particularly relates to a buck-boost single-inductor three-output DC-DC converter. The converter comprises a power tube, a divider resistor, a comparator, a control logic module, a turn-on time generation module, a self-adaptive turn-off time module and a current detection module. The power tube is used for a buck-boost topological structure of a traditional DC-DC converter; each path of output voltage of the converter is fed back to the comparator after passing through the divider resistor, and a duty ratio signal of the energy distribution switch is generated in the control logic, so that the power tubes are conducted in sequence; the turn-on time generation module is used for controlling the turn-on time of the system and generating a duty ratio signal of an energy generation switch in control logic, and the turn-on time generation module comprises peak current control and self-adaptive phase control; the steady-state switching frequency of the system is controlled by the self-adaptive turn-off time module; the current detection module detects inductive current information. The method has good key indexes such as cross modulation, response speed, conversion efficiency and the like.

A direct current to direct current (DC-DC) converter can include a chip embedded integrated circuit (IC), one or more switches, and an inductor. The IC can be embedded in a PCB. The IC can include driver, switches, and PWM controller. The IC and / or switches can include eGaN. The inductor can be stacked above the IC and / or switches, reducing an overall footprint. One or more capacitors can also be stacked above the IC and / or switches. Vias can couple the inductor and / or capacitors to the IC (e.g., to the switches). The DC-DC converter can offer better transient performance, have lower ripples, or use fewer capacitors. Parasitic effects that prevent efficient, higher switching speeds are reduced. The inductor size and overall footprint can be reduced. Multiple inductor arrangements can improve performance. Various feedback systems can be used, such as a ripple generator in a constant on or off time modulation circuit.

The invention discloses an anti-saturation equivalent virtual impedance grid-forming type SVG fault current-limiting control method, which comprises the following steps of: inverting a direct current into an alternating current through an inverter, and filtering high-frequency harmonics through a filter to obtain a sine wave alternating current meeting a grid-connected requirement. A three-phase alternating current signal is collected in real time, coordinate transformation is carried out through a Park transformation module, and a modulation signal is obtained. The modulation signal is compared with a triangular carrier signal, a driving signal is generated, the on-off time of a power switching device of the inverter is controlled, the amplitude and phase of output voltage and current are adjusted, accurate control over the output power of the grid-connected inverter is achieved, and the power grid access requirement is met. According to the method, the limitation of traditional fixed parameters is broken through, and the robustness of the system to a complex fault scene is improved. In addition, manual intervention or a complex mode switching program is not needed, automatic smooth transition between different working conditions can be achieved, and powerful technical guarantee is provided for stable operation of a power grid.

The invention provides a rear-phase-cut single-live-wire type wall light modulator. The rear-phase-cut single-live-wire type wall light modulator comprises an MOS tube switch loop unit, a single-chip microcomputer control unit and a direct-current power supply unit. Wherein the direct current power supply unit comprises an alternating current voltage waveform acquisition circuit, a direct current voltage drop circuit, an overcurrent protection circuit and a filtering voltage stabilizing circuit. The single-chip microcomputer control unit comprises a single-chip microcomputer, a potentiometer, a triode Q6, a triode Q5 and a triode Q7, the PC2 end of the single-chip microcomputer is connected with the potentiometer, when the resistance value of the potentiometer changes, the voltage collected by the PC2 end changes, and the PA6 end of the single-chip microcomputer outputs different voltage signals to control the on-off of the triode Q6, the triode Q5 and the triode Q7 so as to adjust the on-off time of the MOS tube; the output end of the alternating current voltage waveform acquisition circuit is connected with a PC1 port of the single chip microcomputer to provide a phase reference; after alternating current passes through the direct current power supply unit, 5V direct current is output and is connected with a VDD end of the single chip microcomputer to supply power to the single chip microcomputer; the light modulator can stably modulate light at low brightness.

The invention relates to a boost type adjustable high-voltage reference source which comprises a Boost topological structure, a voltage doubling circuit and an output filter circuit. The Boost topological structure comprises an LC circuit, a switching circuit and a voltage feedback circuit; the LC circuit receives external input voltage, when the switching circuit is closed, the external input voltage flows through the inductor, and the inductor stores energy; when the switching circuit is disconnected, the inductor discharges to charge the LC circuit and the capacitor in the voltage doubling circuit, and the voltage at the two ends of the capacitor is increased, so that the output voltage is higher than the input voltage; the voltage doubling circuit reduces the voltage-withstanding requirement on the device through a multi-stage structure, and the output voltage is sent to the output filter circuit to be filtered and then output; and the voltage feedback circuit samples the output voltage of the voltage doubling circuit, compares the output voltage with the reference voltage, controls the on-off time of the switching circuit, and realizes closed-loop control of the output voltage. The problem that high reference voltage is generated under the condition of low power supply voltage is solved, circuit miniaturization and low power consumption are achieved through the Boost topological structure, and the requirement for device performance is lowered through the voltage doubling circuit.

The invention discloses a hybrid switch driving method based on model prediction junction temperature control, and the method comprises the steps: obtaining the real-time shell temperature value and junction temperature value of a Si IGBT device, and the real-time shell temperature value and junction temperature value of a SiC MOSFET device, constructing the relation between the junction temperature and the shell temperature of each device, and building a junction temperature prediction model and a loss prediction model of a hybrid switch, and constructing a cost function through the junction temperature prediction model and the loss prediction model, and controlling the on-off of the hybrid switch through the soft turn-off time corresponding to the minimum value of the cost function. Compared with the prior art, collaborative optimization of power loss is realized while junction temperature distribution between the Si IGBT and the SiC MOSFET device is balanced, that is, the power loss of the hybrid switch is reduced, and the stability and the operation efficiency of the hybrid switch are effectively improved.

The invention provides a step-down converter in a COT mode, the step-down converter comprises a main comparator, a conduction time generation module and a PWM generation module, the main comparator is used for comparing a feedback voltage with a reference voltage, the conduction time generation module is used for providing a conduction time signal of the COT mode, and the PWM generation module is set as follows: when the conduction time signal is changed from 0 to 1, the conduction time signal is converted from 0 to 1; judging whether the feedback voltage is smaller than reference voltage; and if the feedback voltage is less than the reference voltage, skipping the turn-off time to enable the high-side power tube to be continuously conducted until the feedback voltage is greater than or equal to the reference voltage, and turning off the high-side power tube of the buck converter. According to the buck converter in the COT mode, the output voltage of the main comparator serves as a judgment standard to judge whether the turn-off time is reduced or skipped, so that the turn-on time of a high-side power tube is prolonged, the output voltage obtains more power, and the buck converter in the COT mode is more beneficial to scenes needing more power.

The invention provides a control method for dead time of a power unit. The power unit comprises a power semiconductor device module and a driving module. The control method comprises the steps of obtaining a current value of the power unit; determining the turn-off time of the power semiconductor device module according to the current value and a preset relation table, wherein the preset relation table comprises a corresponding relation between the determined current value and the turn-off time based on the type of the power semiconductor device module; determining the dead time of the power semiconductor device module according to the turn-off time; and determining a driving pulse of the driving module according to the dead time, so that the driving pulse controls the power semiconductor device module to realize the dead time. According to the technical scheme of the invention, the dead time of the power semiconductor device module is automatically updated according to the current value of the power unit, and the probability of current short circuit caused by simultaneous conduction of two power switches in a bridge arm in the power semiconductor device module is reduced. And thus, the stability of equipment or a system comprising the power unit is improved.

The invention discloses a load transient detection circuit of a COT Buck, a corresponding COT Buck and a switching power supply. The load transient detection circuit comprises an input end, three resistors connected in series, two comparators and a switched capacitor sampling hold circuit, wherein the input end is grounded after passing through the three resistors in sequence. A node between the input end and the first resistor and a node between the second resistor and the third resistor are connected to the input ends of the first comparator and the second comparator through a switched capacitor sampling hold circuit structure. Valley voltage information and peak voltage information of inductive current are obtained through the switched capacitor sampling hold circuit, whether a load is transiently changed or not is judged by comparing inductive current ripples with a valley value and a peak value, and it is guaranteed that the switching power supply has appropriate transient detection trigger threshold voltage under any load. According to an output signal of the load transient detection circuit, the COT Buck can increase the turn-on or turn-off time so as to enhance the transient response speed.

The invention provides a conduction time control circuit and a switch conversion system, and relates to the technical field of electrical control. For any sampling period, a ramp signal generation module in the turn-on time control circuit generates a ramp signal according to the input voltage; the peak value sampling module is used for acquiring the peak voltage of the ramp signal in the current sampling period; the error amplification module determines an error signal according to the peak voltage and the output voltage; the on-time generation module generates a state indication signal according to the error signal and the ramp signal, so that the charging module adjusts its own charging / discharging state according to the state indication signal to adjust the peak voltage of the ramp signal in the next sampling period, thereby improving the on-off time of a switching tube under the DC-DC converter. On the basis, on the basis of improving the accuracy of the on-off time of the converter, the problems of structural complexity and high power consumption of the control circuit can be reduced.

The invention relates to the technical field of output control, in particular to a COT-based constant voltage control method, device and equipment and a storage medium, and the method achieves the precise control of the total duration of a target period through the dynamic adjustment of the turn-off time on the basis of the fixed turn-on time, can quickly respond to the sudden change of a load, and improves the stability of the load. The overshoot or undershoot phenomenon of the output voltage is reduced; specifically, voltage information is sampled in real time within the period conduction time, and the turn-off time of the next period is immediately adjusted after the period is ended, so that error accumulation caused by delayed adjustment in a traditional control mode is avoided, the dynamic response capability to battery voltage fluctuation is enhanced, and the output precision is improved; besides, a strategy of synchronous opening and unified adjustment of turn-off time is adopted, so that the consistency of the turn-off time of multi-path output in a starting stage and a subsequent period is ensured, load change disturbance caused by asynchronous turn-off is avoided, and voltage rise deviation of a later turn-off channel is reduced.

The invention discloses a communication power supply load measurement and calculation and air switch control method and system based on service priority, and relates to the technical field of communication power supply intelligent management. Comprising the following steps: initializing and acquiring a load service priority list and a time threshold; monitoring an AC input state, switching to a standby power supply mode when the AC input state fails, and recording a power-off moment; a hybrid algorithm of ampere-hour integration and dynamic voltage calibration is adopted to measure the residual capacity of the storage battery in real time and with high precision, and residual power supply time is dynamically predicted; when the waiting time exceeds a first threshold value and the remaining power supply time is smaller than a second safety threshold value, a turn-off instruction is generated; and dynamically generating a turn-off sequence from low to high according to the service priority list, and iteratively executing turn-off and state re-evaluation until the endurance safety requirement of the core service is met. According to the invention, the problems of low control precision, incapability of distinguishing service priorities and low resource utilization rate in the prior art are solved, and accurate, intelligent and service-aware power management is realized.

The invention provides a direct-current circuit breaker and a control method thereof, and belongs to the technical field of direct-current middle-high voltage power system fault protection. The short circuit turn-off branch comprises a first capacitor and a first thyristor; the coupling commutation branch comprises a first inductor, a second inductor, a second thyristor and a third capacitor; the rated turn-off branch comprises a first resistor and a second capacitor; the first resistor, the second capacitor, the first capacitor and the second inductor are sequentially connected in series and then are connected with the main switch branch in parallel; the first inductor, the second thyristor and the third capacitor are sequentially connected in series, and the first inductor and the second inductor form mutual inductance. By controlling the on-off of the first thyristor, the first capacitor and the second capacitor are connected in series, the capacitance value is reduced, large-capacitance-value operation of a single group of capacitors is realized, and the problem that the on-off time of rated and lower low-current breaking is relatively long can be solved.