77 results about "Discontinuous conduction" patented technology

The invention discloses a buck-boost circuit-based mppt charging current backflow prevention control method, and relates to the technical field of switching power supplies, and the method comprises the steps: collecting a photovoltaic input voltage, a battery output voltage, and an inductive current flowing through an inductor; the current input power is calculated based on the photovoltaic input voltage and the inductive current, and the reference voltage is dynamically adjusted through an MPPT loop algorithm; pI voltage loop operation is carried out on the output voltage and the adjusted reference voltage, and expected charging current is generated; pI current loop operation is carried out on the expected charging current and the inductive current sampling value after proportionality coefficient adjustment, and a PWM duty ratio control signal is output to adjust the driving states of the four switching tubes; when the judgment circuit is in an intermittent conduction mode and meets critical conditions, a driving signal of the fourth switching tube is shielded, and only a body diode realizes a current path to prevent reverse flow of current; the battery current is effectively prevented from flowing backwards, and the system safety and the energy utilization efficiency are improved.

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 embodiment of the invention provides a method for controlling a DC / DC converter of a battery system, and the method comprises the steps: controlling the operation parameters of the DC / DC converter of the battery system based on the collected stack current IS of a battery stack of the battery system, so as to adjust the phase current of the DC / DC converter, and enabling a first DC / DC conversion unit and a second DC / DC conversion unit to be connected in parallel, according to the method, at least three operation intervals of the DC / DC converter are divided based on the collected stack current of the battery stack, so that in each operation interval, a first DC / DC conversion unit and / or a second DC / DC conversion unit only operate in one conduction mode, and the conduction modes comprise a continuous conduction mode and / or a discontinuous conduction mode (S1); the first phase current of the first DC / DC conversion unit or the second phase current of the second DC / DC conversion unit is selected as the AC injection current of the battery system on the basis of the conduction mode of the DC / DC conversion units (S2).

A system may include a power converter comprising a power inductor and a plurality of switches and a controller configured to control the power converter, including controlling the power converter in discontinuous conduction mode to magnetize and demagnetize the power inductor, wherein the controller is further configured to, in each switching cycle of the power converter, terminate a magnetization period of the power inductor based on a function dependent upon an output voltage of the power converter and a power inductor current flowing through the power inductor.

This application relates to modulator circuits (401, 501) for driving switching output stages (102) in a class-D amplifier system (400) or the like. The switching output stage (102) has an output node (105) and high-side and low-side switches (104H, 104L) for selectively connecting the output node to respective high-side and low-side voltages (VH, VL) and is configured to be operable in a continuous conduction mode of operation, in which there is always an output current flowing throughout a switching cycle and also in a discontinuous conduction mode of operation where there is a period in each switching cycle where there is no output current. The modulator circuit comprises a compensator (407, 408) operable to apply compensation, in the discontinuous conduction mode of operation, to at least partly compensate for a non-linearity when operating in the discontinuous conduction mode.

The invention relates to the technical field of vehicle charging, and discloses an electric vehicle boost charging method and circuit, a vehicle, a storage medium and a program product, an upper bridge arm power switch tube of a direct current boost charging circuit is integrated with a body diode, and the method comprises the following steps: obtaining a direct current charging current, and identifying whether a target charging scene is satisfied based on the direct current charging current; the charging current of the target charging scene is smaller than a preset current threshold; when the target charging scene is met, a power switch tube of the inverter is controlled in an intermittent conduction mode, and the intermittent conduction mode is used for controlling an upper bridge arm power switch tube to be kept closed in each control period of direct current charging and controlling a lower bridge arm power switch tube to be conducted for preset time. According to the invention, in a low-current boost charging scene, the heating of the magnetic ring is in a controllable range, and continuous charging is realized.

A method includes configuring a power conversion system to operate in a discontinuous conduction mode, wherein the power conversion system comprises a power conversion apparatus connected between an input voltage bus and an output voltage bus, and a controller electrically coupled to the power conversion apparatus, detecting a switching frequency of the power conversion apparatus, and turning on a low-side switch of the power conversion apparatus once the switching frequency of the power conversion apparatus is less than a predetermined audio frequency threshold.

Embodiments relate to a voltage regulator. The voltage regulator can include plural phase blocks. The plural phase blocks can include a single-stage multi-phase series capacitor buck converter configured to operate at a boundary between continuous conduction mode and discontinuous conduction mode.

A switching converter with adjustable on-time is presented. The switching converter includes an inductor coupled to a power switch; a pulse generator generating a pulsed signal to switch the power switch and a controller. The pulsed signal has an on-time adjustable between a first value and a second value, the first value being shorter than the second value. The controller identifies a mode of operation between a continuous conduction mode and a discontinuous conduction mode and sets the on-time to the second value when a continuous conduction mode is identified. The controller also measures a duration between successive inductor current pulses, compares the duration with a first threshold value and maintains the on-time to the second value as long as the duration is less than the first threshold value. When the duration increases above the first threshold value the controller sets the on-time to the first value.

The present application relates to air conditioner detection technical field, propose a kind of air conditioner electrolytic capacitor health on-line detection method and system, the air conditioner electrolytic capacitor health on-line detection method includes collecting the voltage ripple signal of DC-DC step-down converter output in air conditioner, and detects the zero-crossing time of first time through direct current average voltage in a switching cycle, obtains first zero-crossing time;At the switching on starting moment or switching off moment of switching cycle, single sampling is carried out to output voltage ripple signal, and sampling voltage value is obtained;According to the running state of DC-DC step-down converter, it is judged that DC-DC step-down converter is currently in continuous conduction mode or discontinuous conduction mode;Based on the judgment result, corresponding capacitor parameter calculation model is selected, and the capacitance value and equivalent series resistance of output capacitor are calculated;The capacitance value and equivalent series resistance calculated are compared with preset threshold value, and if exceed threshold value, then trigger capacitor health state early warning.

The invention discloses a detection-free zero-voltage switching-on method based on a full-bridge inverter intermittent current mode, and relates to a power electronic converter. The micro inverter works in an inductive current intermittent conduction mode, zero-voltage switching-on of a switching tube can be realized on the basis of not adding any additional device and auxiliary circuit, and the efficiency of the inverter is effectively improved. The traditional scheme generally depends on a sampling circuit to detect a resonance current zero crossing point between an inductor and a switch tube shunt capacitor to determine the turn-on time, so that the hardware complexity is increased, and the zero-voltage turn-on effect depends on the reliability of a detection circuit. And when the switching frequency is relatively high, the inherent delay characteristic of the sampling circuit can limit the zero-voltage switching-on realization effect. The invention provides a zero-voltage turn-on moment determination strategy based on inverter behavior modeling in an intermittent conduction mode, a detection circuit is not needed, and the zero-voltage turn-on moment can be accurately determined only through discrete time control by a controller after modeling, so that full-period soft switching is realized, and the hardware complexity is reduced.

An integrated circuit including a buck converter having an integrator and a shunt resistor is described. The buck converter may operate in a continuous conduction mode (CCM) and a discontinuous conduction mode (DCM). The integrator may be coupled to the buck converter to generate an output voltage based on adjustment of a detected voltage across a load of the buck converter within range of a reference voltage. The shunt resistor may be coupled to the integrator configured to maintain the output voltage of the integrator during the DCM.

This disclosure relates to a system (1400) comprising an input voltage node (1442) configured to provide an input voltage (VIN). The system (1400) also includes a load (R). LOAD A switching converter (1450, 1460) coupled between the input voltage node (1442) and the load (RLOAD). The switching converter (1450, 1460) is configured to provide an output voltage (VOUT) to the load (RLOAD) based on the input voltage (VIN). LOAD The switching converters (1450, 1460) include a gate driver circuitry (1430) and a current-mode control circuitry (1470) coupled to the gate driver circuitry (1430). The current-mode control circuitry (1470) is configured to output control signals to the gate driver circuitry (1430) according to different operating modes, wherein the current-mode control circuitry (1470) is configured to adjust a threshold (I) for switching between discontinuous conduction mode (DCM) and power-saving mode (PSM). PSM *).

Provided is a spring connector capable of suppressing occurrence of discontinuous conduction due to vibration and impact. This spring connector comprises: a tube; a contact pin, the tip of which protrudes from the opening of the tube; and a spring that presses the contact pin toward the protruding direction. The tube has, on the outer periphery thereof, a through hole that exposes a portion of the contact pin in a direction substantially perpendicular to the protruding direction of the tube. An elastic member that presses, in the substantially vertical direction, the exposed portion of the contact pin exposed from the through hole is attached to the outer periphery of the tube.

This disclosure proposes a flyback converter, and a control circuit and a control method thereof. The control method comprises: working in a discontinuous conduction mode while the load state is light load; working in a boundary conduction mode while the load state is heavy load; working in a hybrid conduction mode while the load state is between light load and heavy load. A hybrid conduction mode cycle comprises N switching cycles, with the first N-1 switching cycles working in the boundary conduction mode while the Nth switching cycle working in the discontinuous conduction mode. Each switching cycle in the hybrid conduction mode cycle is controlled to work in the boundary conduction mode or the discontinuous conduction mode according to a set maximum value of the hybrid conduction mode cycle and a set first duty cycle. Each switching cycle in the hybrid conduction mode is adaptively control, thereby improving system efficiency.

The invention discloses a multi-magnetic-core variable inductor control method based on illumination adjustment and application of the multi-magnetic-core variable inductor control method in a boost converter. The method comprises the following steps: acquiring external illumination intensity information in real time through an illumination sensor arranged in an environment, and transmitting the acquired illumination data to a controller; and the controller controls the excitation current of the control winding in the multi-magnetic-core variable inductor according to a preset illumination threshold value, so that the equivalent inductance value of the variable inductor is adjusted. Dynamic switching of the boost converter among a continuous conduction mode (CCM), a boundary conduction mode (BCM) and a discontinuous conduction mode (DCM) is realized by adjusting an inductance value so as to adapt to different illumination conditions and load requirements. According to the method, the dynamic response capability, the maximum power point tracking efficiency and the overall energy conversion efficiency of the photovoltaic system under different irradiation intensities can be improved, and the method has good environment adaptability and wide application prospects.

A method and related apparatus for performing discontinuous conduction mode (DCM) pulse control of a buck converter to reduce inductor loss is provided. The method may include performing multi-pulse control on the buck converter, causing the buck converter to operate in DCM; and during performing the multi-pulse control on the buck converter to cause the buck converter to operate in the DCM, generating a plurality of pulses per cycle to cause an inductive current of an inductor within the buck converter to be boosted multiple times and then reduced to reduce the inductor loss.

A single-inductor multi-output DC-DC converter includes a regulation circuit that controls a switch to alternately charge at least two capacitors associated with at least two DC output voltages via a single inductor from a DC input port. The regulation circuit determines whether the DC-DC converter operates in continuous conduction mode (CCM) or discontinuous conduction mode (DCM). In CCM mode, the regulation circuit regulates the charging duty cycle of a first output voltage and generates an initial charging duty cycle for each of the other output voltages by scaling the first output voltage duty cycle. In DCM mode, the regulation circuit independently regulates the charging duty cycle of each output voltage and stores each duty cycle to be used for the next charging period of the same output voltage. The regulation circuit detects and handles undershoot and overshoot conditions to accelerate recovery at the output port.

The power stage circuit comprises a switching circuit, a driving circuit and a bootstrap circuit. The switching circuit includes a low-side switch and a high-side switch coupled to a switching node. The driving circuit is coupled to the switching circuit and drives the low-side switch and the high-side switch to be switched on alternately. The bootstrap circuit is coupled to the switching circuit and the driving circuit, and comprises a bootstrap capacitor and a pre-charging circuit. When both the low-side switch and the high-side switch are turned off, the bootstrap capacitor is charged when the voltage difference between the two ends of the bootstrap capacitor is lower than a first preset limiting voltage value, and is discharged when the voltage difference is higher than a second preset limiting voltage value, so that the voltage difference is maintained within a preset voltage range. The voltage difference between the two ends of the bootstrap capacitor is maintained within the preset voltage range in the discontinuous conduction mode, so that the driving circuit can drive the high-side switch to be switched into the conduction state when the high-side switch needs to be conducted subsequently, and the problem that the high-side switch cannot be conducted due to excessive discharge of the bootstrap capacitor is solved. Therefore, the method has the advantages of high stability and the like.

The present disclosure relates to sample-and-hold techniques for reading charger current in discontinuous conduction mode. The current monitoring system may include a sample-and-hold circuit to generate a sample-and-hold signal (S / H signal), where the S / H signal corresponds to a peak value of a current in the charging circuit during a switching period of the charging circuit. The system may also include a first analog-to-digital channel (ADC channel) for sampling the S / H signal; and a second ADC channel configured to sample a current in the charging circuit. The system may then determine an average current of the charging circuit based on the first ADC channel when the charging circuit is operating in the discontinuous conduction mode, and determine an average current of the charging circuit based on the second ADC channel when the charging circuit is operating in the continuous conduction mode.

The invention discloses a control method, device and equipment for a four-switch buck-boost converter, and the method comprises the steps: obtaining the current input voltage and output voltage of the four-switch buck-boost converter, and generating a loop regulation quantity based on the output voltage and reference voltage after passing through a loop; the control period of the inductive current of the four-switch buck-boost converter is obtained; when the control period is smaller than or equal to a threshold value, the four-switch buck-boost converter is adjusted to be in a fixed-frequency intermittent conduction mode, and the time of the second stage of the inductive current is adjusted according to the loop adjusting quantity, so that the output voltage is kept stable; when the control period is larger than a threshold value, the four-switch buck-boost converter is adjusted to be in a frequency conversion continuous conduction mode, and the time of the first stage of the inductive current is adjusted according to the loop adjusting quantity, so that the output voltage is kept stable. According to the invention, ZVS can be realized while the difference of gains in different modes is reduced and the difficulty of loop design is reduced, and the optimal efficiency can be ensured.

A switching regulator includes: a power stage circuit configured to operably control a power switch therein according to a pulse width modulation signal to switch an inductor coupled to a phase node, so as to convert an input voltage to an output voltage; and a control circuit configured to operably determine an equivalent capacitance adjustment procedure to enter or sustain an enabled state according to a phase node voltage at the phase node at an inductor magnetization start time point in a discontinuous conduction mode (DCM) to adjust an equivalent capacitance at the phase node, so as to reduce a voltage across the power switch at another inductor magnetization start time point after the equivalent capacitance adjustment procedure.

The invention provides a high-efficiency single-mode Buck-Boost DC-DC converter, and the converter comprises a power switch group which is used for controlling the duty ratio outputted in each period through controlling the conduction time of the power switch group; the flying capacitor is used for alternately bearing multiplied input voltage and storing energy of the input voltage in different phases of the power switch group; and the output filtering unit is used for filtering the multiplied input voltage according to the duty ratio and then taking the multiplied input voltage as an output voltage, or releasing energy stored in each period and outputting the voltage. According to the invention, in a mode of supporting continuous conduction, continuous transmission of inductive current is realized by alternately switching energy paths, and in a non-continuous conduction mode, reverse current is blocked during light load, and light load efficiency is improved. The method has the advantages that the inductive current is continuous, mode switching is not needed, the inductive current is reduced in the Boost mode, the inductive conduction loss can be remarkably reduced, and the efficiency is improved.

Power efficiency can be optimized in a direct current (DC)-DC converter in discontinuous conduction mode (DCM) if a transition from a state of decreasing inductor current to a state of zero inductor current occurs as close as possible to the decreasing inductor current reaching zero. The timing of a zero current indication is affected by a voltage offset and a propagation delay of a comparator. A DC-DC converter, including a control circuit for accurate detection of zero inductor current, is disclosed. A control circuit calibrates an offset voltage for a load, stores a corresponding offset value, and in response to powering the load, provides an offset voltage to the comparator based on the stored offset value. In some examples, the control circuit determines an offset voltage and stores an offset value for each voltage and switch width combination. Using stored offset values increases accuracy of zero inductor current detection.

The techniques and circuits described herein include a solution for multi-mode current control of pulse width modulation (PWM) converters. In some aspects, a slope control circuit (116) is used to simulate a current through an inductor (102) as a voltage across a switched capacitor (144) during a discharge phase. A slope control voltage (134) is used to modify a slope of the simulated current waveform relative to the actual inductor current waveform. The converter may selectively operate in a continuous conduction mode (CCM), a discontinuous conduction mode (DCM), or a transition mode (TM), respectively, depending on whether the magnitude of the modified slope is greater than, less than, or equal to the actual slope.

A converter (1) for operating an LED load is provided. The converter (1) comprises an actively switched power factor correction, PFC, circuitry (104-112), having a control circuitry (2-4) for controlling a switch (105) of the PFC circuitry (104-112). The control circuitry (2-4) is configured to control a switch-on timing of the switch (105) such that an output voltage (113, Vbus) of the PFC circuitry (104-112) is feedback-controlled in accordance with a nominal value (201). In a discontinuous conduction mode, DCM, the control circuitry (2-4) is configured to control an actual value (204, Toff_act) of the switch-on timing of the switch (105) in one or more switching cycles to be a time of a valley of a voltage across the switch (105) succeeding a nominal value (302, Toff_nom) of the switch-on timing of a control algorithm implemented by the control circuitry (2-4). The control circuitry (2-4) is further configured to control the actual value (204, Toff_act) of the switch-on timing of the switch (105) in one or more subsequent switching cycles being subsequent to the one or more switching cycles to be a time of a valley of the voltage across the switch (105) preceding the nominal value (302, Toff_nom) of the switch-on timing. This reconciles valley switching and avoidance of visible light flicker.

Functional electrical stimulation devices and methods of operating the same are described. For example, a device includes a high-efficiency power boost circuit configured to step a low battery voltage to a boosted output voltage, an open-loop charge pump circuit coupled to the power boost circuit to further increase the boosted voltage, and a switched capacitor output stage to generate high-slew-rate, charge-balanced stimulation pulses. The switched capacitor stage may produce symmetric or asymmetric bi-phasic pulses with adjustable amplitudes, widths, and frequencies over an operating range. The boost and charge pump stages may operate in discontinuous conduction and discontinuous voltage modes to achieve soft switching and improved efficiency at high conversion ratios. The devices may be incorporated into wearable electrical stimulators using textile electrodes. Methods are also provided for operating the power boost circuit, the charge pump circuit, and the switched capacitor stage to deliver controlled stimulation to electrically excitable tissue.

The present invention relates to the field of switching power supplies and discloses a flyback converter. Based on an existing trailing-edge non-complementary flyback active clamp circuit, an auxiliary winding and a rectifier are added to the primary side of the flyback converter. This circuit is used to transfer a portion of the transformer's energy to the clamp capacitor via the rectifier when the transformer transfers energy to the secondary side after the main power switch is turned off, thereby increasing the charging voltage of the clamp capacitor and enabling the clamp capacitor to store more energy. When the clamp switch is turned on, the energy of the clamp capacitor is transferred to the primary leakage inductance, thereby ensuring that the energy stored in the primary leakage inductance is sufficiently large. When the clamp switch is turned off, the leakage inductance current can resonate the junction capacitance voltage of the main power switch to zero, thereby achieving zero-voltage switching of the main power switch. While the present invention enables lossless absorption of leakage inductance energy, it also simplifies the control method for zero-voltage switching of the main power switch, enabling the main power switch to achieve zero-voltage switching in both continuous conduction mode and discontinuous conduction mode.

The invention discloses a single-stage isolated AC-DC converter with a wide gain range and a modulation method thereof.The converter comprises a power frequency full-bridge circuit module, an FSBB converter module and an LLC resonant converter module which are connected in sequence, and each of the FSBB converter module and the LLC resonant converter module comprises two bridge arms which are connected in parallel; each bridge arm comprises two branches which are connected in parallel and formed by connecting two switching tubes in series, and the inductor is connected to a common node between the two bridge arms of the FSBB converter module in series; in the LLC resonant converter module, a primary winding of a transformer is connected in parallel with an excitation inductor and then connected in series with a common node between two bridge arms, and a resonant inductor is connected in series with a resonant capacitor and then connected in parallel with the excitation inductor to form a resonant cavity; the modulation method comprises the following steps: implementing a simplified frequency conversion control strategy on the FSBB converter module, performing fixed-frequency control in an intermittent conduction mode during light load, and performing frequency conversion control in a continuous conduction mode during heavy load; pulse frequency modulation control is carried out on the LLC resonant converter module; according to the invention, high-efficiency energy conversion in a wide input and output range is realized.

A system may include a power converter comprising a power inductor and a plurality of switches and a controller configured to control the power converter, including controlling the power converter in discontinuous conduction mode to magnetize and demagnetize the power inductor, wherein the controller is further configured to, in each switching cycle of the power converter, terminate a magnetization period of the power inductor based on a function dependent upon an output voltage of the power converter and a power inductor current flowing through the power inductor.