264 results about "Conduction mode" patented technology

The invention belongs to the technical field of power distribution, and discloses a direct current transformer soft switch and a control method.The direct current transformer soft switch comprises a medium-voltage direct current bus and low-voltage direct current buses, the medium-voltage direct current bus is electrically connected with a modular multi-level multi-port direct current converter, and the modular multi-level multi-port direct current converter is electrically connected with a plurality of low-voltage direct current converters; the plurality of low-voltage direct-current converters are electrically connected with a low-voltage direct-current bus and are used for realizing bidirectional power transmission from medium-voltage direct current to low-voltage direct current; according to the method, the medium-voltage side inductance value is reduced, the medium-voltage side current ripple is enabled to pass zero, the M3DC operates in an approximate critical conduction mode, a constant valley current control strategy is adopted, the minimum value of the medium-voltage side inductance current is controlled to be constant under different working conditions, and then zero-voltage switching-on of a switching device in a wide operation range and zero-current switching-off of an anti-parallel diode are achieved.

A method of operating a PFC circuit. The method includes receiving an input voltage at an input terminal, controlling a current in an inductor via a first switch having a drain terminal, a source terminal and a gate terminal, where the inductor is coupled between the input terminal and the drain terminal and where during an on-time of the first switch the current in the inductor increases from substantially zero to a peak, during a first off-time of the first switch the current in the inductor decreases from the peak to substantially zero, and during a second off-time of the first switch the current in the inductor is substantially zero, generating a first reference voltage that is inversely proportional to a sum of the on-time and the first off-time of the first switch, and controlling the on-time of the first switch in response to the first reference voltage.

A system may include a multi-level power converter comprising a power inductor and a plurality of switches and a controller configured to control the plurality of switches such that the multi-level power converter generates a regulated output voltage from an input voltage to the multi-level power converter, monitor an average inductor current through the power inductor, and operate the multi-level power converter in one of a continuous conduction mode and a discontinuous conduction mode based on the average inductor current.

The utility model provides a liquid cooling assembly, a battery module and a battery pack. The liquid cooling assembly comprises a heat exchange unit and a connecting pipe set, the heat exchange unit comprises a plurality of heat exchange parts arranged at intervals in the X direction, a cylindrical battery column is installed between every two adjacent heat exchange parts, each heat exchange part is used for being connected with the cylindrical battery column in a heat conduction mode, each heat exchange part is provided with a conveying flow channel, and each conveying flow channel is provided with a liquid inlet and a liquid outlet; the connecting pipe set comprises a liquid inlet branch pipe and a liquid outlet branch pipe, the liquid inlet branch pipe sequentially communicates with the multiple liquid inlets, an inlet allowing cooling liquid to flow in is formed in the liquid inlet branch pipe, the inlet is far away from the two heat exchange parts located on the edge in the multiple heat exchange parts, and the liquid outlet branch pipe sequentially communicates with the multiple liquid outlets. And an outlet through which the cooling liquid flows out is formed in one end of the liquid outlet branch pipe, so that the pressure drop difference caused by the length difference of pipelines can be reduced, enough cooling liquid flow can be ensured to be obtained by each heat exchange part, and the uniformity of cooling liquid flow conveying is improved.

The invention discloses a zero-voltage turn-on circuit and a zero-voltage turn-on method of a switching tube in a switching power supply, and belongs to the technical field of circuits. In a critical conduction mode, when a low-side power tube is turned off, the rising edge zero-voltage starting circuit compares a switch node voltage with an input voltage or compares the switch node voltage with an output voltage under the control of a low-side gate driving voltage, outputs a high level to a high-side gate driving end when the switch node voltage is equal to the input voltage or the output voltage, and outputs a low level to a low-side gate driving end when the high level is equal to the output voltage. A high-side power tube is controlled through a high level to realize zero-voltage starting; in a critical conduction mode, when the high-side power tube is turned off, the falling-edge zero-voltage starting circuit compares an induced voltage with a pull-up resistor voltage under the control of a high-side gate driving voltage, outputs a high level to a low-side gate driving end when the induced voltage is equal to the pull-up resistor voltage, and controls the low-side power tube to realize zero-voltage starting through the high level. The induced voltage is equal to the sum of the pull-up resistor voltage and the switch node voltage. According to the invention, the transmission delay can be reduced.

The invention discloses a drive control circuit for large-scale optical switch signal switching. Control drive design on a silicon photon optical switch array is achieved through hardware model selection and circuit design, FPGA logic design and upper computer control optimization. The circuit comprises an overvoltage / anti-reverse connection protection circuit, an FPGA driving power supply circuit, an HV high-voltage conversion circuit, a feedback voltage regulation circuit, a high-voltage driving circuit and FPGA conduction logic. According to the invention, channel conduction data is generated by using a PC and upper computer software, so that a programmable modified optical switch conduction mode is realized, optical signal adjustable mode switching is realized, and signal low-loss interaction of a signal switching center is satisfied. Micromechanical voltage is adopted to drive the optical switch unit, and the problems that a traditional thermo-optical switch is high in power requirement, serious in heat dissipation requirement and the like can be solved; and the expansion capability limitation of high-voltage signals is solved through the serial-parallel conversion voltage driving module, and the function of driving the large-scale optical switching switch array is realized.

A switch control method is applied to a hybrid voltage converter including a switched capacitor unit and a freewheeling unit. The method including obtaining the output current of the hybrid voltage converter, when the output current is greater than a first current threshold, controlling the switches in the hybrid voltage converter to operate in parallel conduction mode, when the output current is less than the first current threshold, controlling the switches in the hybrid voltage converter to operate in sequential conduction mode. When the switches operate in parallel conduction mode, N switches in the switched capacitor unit are controlled to turn on and off with the same duty cycle and a phase shift of 360 / N degrees. When the switches operate in sequential conduction mode, each switch in the switched capacitor unit is controlled to conduct individually with the same duty cycle in sequence.

A power factor correction (PFC) control circuit includes a pulse-width modulation (PWM) circuit configured to control a switch of a switching power converter. The PFC control circuit further includes a mode control circuit configured to select a conduction mode from a plurality of conduction modes for the switching power converter based at least in part on an output power of the switching power converter and to control a beginning of a switching cycle of the switching power converter based on the selected conduction mode. In addition, the PFC control circuit includes a current regulation circuit configured to provide a regulation signal to the PWM circuit to regulate an average coil current of the switching power converter in each of the plurality of conduction modes.

A method for charging a battery pack via an offboard energy source uses an interleaved boost converter and closed-loop control. The energy source outputs a charging current via a DC charge port during a direct current fast-charging (DCFC) process. A controller detects a voltage disparity condition in which a voltage capability of the battery pack exceeds a voltage capability of the energy source. In response to this condition, a rise of the charging current over time is recorded as a current trajectory and an open-loop equivalent time constant is extracted from the current trajectory. A time constant of the PI control block is set substantially equal to the equivalent time constant. The PIM is controlled in closed-loop using proportional-integral control. The charging current is controlled in a continuous current conduction mode during the DCFC process.

A power converter incorporating a synchronous rectifier implements adaptive turn-off voltage control for fast turn-off of the synchronous rectifier in the continuous conduction mode. In some embodiments, the synchronous rectifier turn off detection threshold is adaptively changed as a function of the detected operation mode of the power converter. In response to detecting the power converter being operated in the continuous conduction mode, the synchronous rectifier turn off detection threshold is set to a voltage value farther away from zero volt as compared to the nominal turn off detection threshold. In this manner, the synchronous rectifier can be turned off earlier while in the continuous conduction mode. When the synchronous rectifier can be turned off quickly, large reverse current or negative current as well as large drain voltage spike at the synchronous rectifier can be avoided. The reliability of the synchronous rectifier and the power converter is improved.

A power converter includes a plurality of power stages configured to generate an output current that has an output voltage based on an input current that as an input voltage a control circuit coupled to the plurality of power stages. The control circuit is configured to control operation of the plurality of power stages. The control circuit includes a plurality of constant-on-time loops for the plurality of power stages. The power converter is configured to operate in a single-phase mode or a multiphase mode. A first power stage of the plurality of power stages supports a continuous conduction mode and a discontinuous conduction mode when the power converter operates in the single-phase mode.

The invention relates to a resonant converter, which comprises a primary side switch circuit; the resonant cavity comprises a transformer, a primary winding and a secondary winding, and the primary winding is electrically connected to the primary switching circuit; the secondary side switching circuit is electrically connected to the secondary side winding and comprises a first switching bridge arm and a second switching bridge arm, and a phase shift angle exists between the first switching bridge arm and the second switching bridge arm; wherein secondary side current flowing through the secondary side winding selectively works in a forced continuous conduction mode, a continuous conduction mode or a critical conduction mode according to the operation of the primary side switching circuit and the secondary side switching circuit; and the control circuit is used for adjusting the switching frequency and the phase shift angle of the primary side switching circuit and the secondary side switching circuit when the secondary side current flowing through the secondary side winding works in a forced continuous conduction mode or a continuous conduction mode, so that the secondary side current flowing through the secondary side winding is gradually adjusted to work in a critical conduction mode. And the actual voltage gain value of the resonant converter is controlled at the default voltage gain value.

The utility model discloses a deicing device which is used for deicing a battery replacing vehicle, a battery pack of the battery replacing vehicle is installed at the bottom of a vehicle body through a locking mechanism so that quick replacement of the battery pack can be achieved, the deicing device comprises a movable vehicle body and an electromagnetic heating unit installed on the vehicle body, and the electromagnetic heating unit can generate an alternating electromagnetic field on the periphery of the electromagnetic heating unit; the machine body can move to the bottom of a vehicle body of the battery changing vehicle and enables the bottom of the vehicle body and / or the locking mechanism to be heated under the action of the alternating electromagnetic field of the electromagnetic heating unit so as to conduct deicing operation on the bottom of the vehicle body and / or the locking mechanism. Heat for hot melting of the ice layer comes from heat energy generated by the locking mechanism and / or the vehicle body, and the heat energy is transmitted into the ice layer in a direct contact solid conduction mode, so that the transmission loss of the heat energy from the locking mechanism and / or the vehicle body to the ice layer is greatly reduced, the ice layer receives the heat from the locking mechanism and / or the vehicle body to a large extent, and the service life of the ice layer is prolonged. And the ice melting efficiency is greatly improved.

The invention relates to an operation mode control technique for a power factor correction circuit. A power factor correction (PFC) control circuit includes a pulse width modulation (PWM) circuit configured to control a switch that switches a power converter. The PFC control circuit also includes a mode control circuit configured to select a conduction mode from a plurality of conduction modes for the switching power converter based at least in part on an output power of the switching power converter, and controlling a start of a switching cycle of the switching power converter based on the selected conduction mode. Further, the PFC control circuit includes a current regulation circuit configured to provide a regulation signal to the PWM circuit to regulate an average coil current of the switching power converter in each of the plurality of conduction modes.

The invention discloses a spreader control hydraulic circuit, a reachstacker hydraulic control system and a reachstacker, belonging to the technical field of reachstackers. The spreader control hydraulic circuit includes a leveling cylinder, a leveling valve group and an oil supply port P1; the leveling valve group includes a first leveling valve, a second leveling valve and a reversing control valve; when the first leveling valve and the second leveling valve are simultaneously conducted, the spreader performs adaptive leveling under the action of gravity; the reversing control valve is provided with a first conduction mode and a second conduction mode; by switching the first conduction mode and the second conduction mode through the reversing control valve, the tilting direction of the spreader is switched. The invention can enable the spreader to perform adaptive leveling and switch the tilting direction of the spreader, reducing the lifting difficulty.

The invention discloses a trapezoidal wave current soft switching method of an interleaving DC-DC converter, which is used for a two-phase interleaving bidirectional DC-DC converter based on a coupling inductor and a multi-phase interleaving converter thereof, and is characterized in that an inductive current adopts a trapezoidal wave mode, so that the converter works in an approximate critical conduction mode; a fixed switching frequency control or hybrid control method is adopted, so that the device can work in a Buck mode and can also work in a Boost mode. The method for realizing the soft switching is characterized in that the parasitic capacitance or the external resonant capacitor of the switching tube is discharged to be zero under the resonance action of the inductor and the capacitor in the dead zone time when the upper bridge arm switch and the lower bridge arm switch are alternately switched on, so that the zero-voltage switching-on of all the switching tubes is realized. And each phase current sharing control is adopted in the multi-phase interleaving parallel topological structure. According to the invention, the problems of large current peak value and high turn-off loss of a traditional triangular wave current mode are solved, the output ripple current is reduced, a soft switching method is provided, the switching loss is reduced, and the conversion efficiency of the converter is improved.

The invention provides a power battery system, a series-parallel connection control method, a movable carrier and a storage medium, and relates to the technical field of power batteries, the system comprises a control module, a switch module and N battery packs; the switch module is electrically connected with the control module and each battery pack respectively; the control module is used for responding to the charging and discharging control strategy and sending a series-parallel connection control signal to the switch module, and the series-parallel connection control signal comprises a series connection signal, a parallel connection signal or a series-parallel connection signal; and the switch module is used for entering a target conduction mode according to the control signal, so that the battery packs are connected according to a target connection mode, and the target connection mode comprises a series connection mode, a parallel connection mode or a series-parallel connection mode. The compatibility of the power battery system is improved by controlling the series-parallel connection mode of the battery packs in the power battery system.

The utility model discloses an unattended crude oil handover metering system, which is characterized in that a first density totalizer is arranged on the basis of a traditional dynamic handover system to detect the density of crude oil on line, and the first density totalizer adopts metering equipment for measuring the density of the crude oil on line by using electrical characteristics; crude oil density can be mutually verified through a capacitance mode and an electric conduction mode, the accuracy of crude oil density detection is improved, compared with other density metering equipment, the measured density error is small, and a parameter verification assembly is arranged on the basis of a traditional dynamic handover system. A second flow meter, a second temperature transmitter, a second pressure transmitter, a second water content meter and a second density integrating instrument are arranged on the verification pipeline, the front end of the verification pipeline is connected with a calibration crude oil tank through an oil supply pipe, calibrated crude oil is adopted, it can be avoided that metering devices of the same kind go wrong at the same time, and the accuracy of the verification process is guaranteed.

The invention relates to a switched mode power supply (SMPS). A switched mode power supply includes: a first switch coupling a first node receiving a supply voltage to a second node supplying an output voltage; and a second switch coupling a third node receiving the reference voltage to the second node. The comparator is used for comparing the output voltage with the comparison voltage. When the switched mode power supply is operating in the pulse skipping mode, the comparator generates an output signal indicating that the output voltage is higher than the comparison voltage during a portion of the on phase of the first switch. Once the output voltage is below the comparison voltage, the switched mode power supply transitions from the pulse skip mode to the continuous conduction mode.

The invention provides a vehicle with a welded bus bar connector. In a high voltage vehicle electronic system, an electronic component having a tab is welded to a bus bar using pulsed laser welding. Each tab is welded to the bus bar by an array of welds. Each spot welding portion includes an inner region formed in a pinhole mode by laser welding and an outer region formed in a conduction mode by laser welding. The density of energy applied to the inner region is between ten and twenty times higher than the density of energy applied to the outer region.

This application discloses a power conversion device, a converter control method, and a system, belonging to the field of converter control technology. It includes: a condition identification module that monitors the voltage characteristics at the switching nodes of the converter and outputs an intermittent conduction mode enable signal; a frequency dithering modulation module that generates an instantaneous switching frequency based on a preset center frequency; a voltage closed-loop control module that determines a reference duty cycle based on the deviation between the converter's output voltage and a target reference voltage; and a feedforward compensation module that corrects the reference duty cycle based on the preset center frequency, the instantaneous switching frequency, and the intermittent conduction mode enable signal to obtain a corrected duty cycle. This application, through digital control and simple hardware, effectively eliminates low-frequency output voltage ripple caused by frequency dithering in intermittent conduction mode while retaining the significant electromagnetic interference reduction advantage of frequency dithering technology. It features low hardware cost, high system stability, and fast dynamic response.

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).

The invention relates to the technical field of power electronic component manufacturing and advanced composite material application, in particular to a 3D inductor based on the Ampere's law and a method thereof. The three-dimensional precise interlocking winding comprises a functional composite framework, a three-dimensional precise interlocking winding and a magnetic core assembly, according to the system, a framework is formed by compositing a heat-conducting insulating substrate and soft magnetic powder, and air gaps between winding layers are physically filled through step-shaped positioning ribs; the core is that a low-thermal-resistance export path is established by utilizing the high heat conduction characteristic of the framework, and a heat conduction mode is converted from coil-to-air to coil-to-framework; the gradient difference between the core temperature and the surface temperature in the coil is effectively reduced through the embedded heat dissipation array, the heat dissipation problem under the high power density is solved, and the device performance is remarkably improved.

The present application belongs to the technical field of power semiconductor, and relates to an enhanced GaN longitudinal field effect transistor with reverse freewheeling capability. The main feature of the present application is that when etching a P-GaN layer, the P-GaN layer under a gate is reserved, so that the enhanced GaN longitudinal field effect transistor is realized, and meanwhile, part of the unetched P-GaN layer at the other end of the device is reserved to form contact with a source metal, so as to integrate a freewheeling diode with an anode and a source short-circuit and a cathode and a drain short-circuit. The freewheeling diode is only turned on in a reverse conduction mode, and is turned off in a forward conduction mode and a blocking mode, and does not affect the forward characteristics of the device. Compared with a freewheeling diode connected in reverse parallel outside the device, the present application reduces parasitic parameters, improves power density, and is simple in process and easy to implement.

The application relates to a critical conduction mode control method of a totem-pole PFC converter, which utilizes energy equivalence to determine the resonance process of inductor current at switching commutation, carries out totem-pole Boost inductor current value estimation, and on this basis, utilizes a current zero-crossing point prediction algorithm to calculate the turn-on and turn-off time to generate corresponding active tube-synchronous rectifier tube commutation dead time T d,f , synchronous rectification conduction time T SR , rectifier tube-active tube commutation dead time T d,r ; the PWM drive signals of high-speed switching tubes Q1 and Q2 are generated by T on , T d,f , T SR , T d,r ; the power frequency drive signals of low-speed switching tubes Q3 and Q4 are generated by comparing the input alternating voltage v ac with a hysteresis comparison loop and 0. The method can effectively get rid of the dependence on a current zero-crossing detection circuit and a current sensor, reduces the cost and improves the system stability.

A switched-mode power supply includes a first switch coupling a first node receiving a power supply voltage to a second node supplying an output voltage and a second switch coupling a third node receiving a reference voltage to the second node. A comparator functions to compare the output voltage with a comparison voltage. When the switched-mode power supply is operating in a pulse skipping mode, the comparator generates an output signal indicating that the output voltage is higher than the comparison voltage during part of the conduction phase of the first switch. The switched-mode power supply transitions from a pulse skipping mode to the continuous conduction mode as soon as the output voltage is lower than the comparison voltage.

A control apparatus includes a first signal generator configured to generate a first reset signal for determining an on-time of a high-voltage side switch of a first phase of a multi-phase power converter; a first comparator configured to generate a first set signal for determining a conduction moment of the high-voltage side switch of the first phase based on comparing the first current sensing signal and the voltage control signal; a first zero-crossing detection circuit configured to detect a zero-crossing point of the inductive current of the first phase; and a first phase bias voltage generator configured to generate a first bias voltage for configuring the first phase to exit the first continuous conduction mode when a zero crossing point of the inductive current of the first phase is detected.

The invention provides a power module and a gate control circuit. The power module provided by the invention comprises more than two bridge arm groups which are connected in parallel, the power module has a first conduction mode and a second conduction mode, and in the first conduction mode, the more than two bridge arm groups are conducted; and in the second conduction mode, one part of the more than two bridge arm groups is conducted, and the other part of the more than two bridge arm groups is turned off. According to the invention, the integration level of the power electronics can be improved, the power electronics are miniaturized, the power density is improved, and the production cost is reduced.

This invention provides a bidirectional transient voltage suppressor with low dynamic resistance and high surge capability, comprising: a heavily doped semiconductor substrate of a first conductivity type; a first epitaxial layer disposed on the substrate; a conduction modulation buried layer disposed on the first epitaxial layer; a second epitaxial layer disposed on the conduction modulation buried layer; a heavily doped first conductivity type region disposed on the second epitaxial layer; a first electrode disposed on the front side of the heavily doped first conductivity type region and a second electrode disposed on the back side of the substrate; the conduction modulation buried layer is disposed inside the double epitaxial body region and is configured to form a high-concentration conductivity modulation region of charge carriers under transient high current impact conditions, forming a body region-dominated conduction path between the first epitaxial layer and the second epitaxial layer, so that the conduction current changes from concentrated conduction in the PN junction region to a laterally extended and planar distributed overall conduction mode within the body region, thereby reducing the dynamic resistance of the device and improving the surge carrying capacity of the device.

The present invention relates to a power module and a gate control circuit. The power module according to the invention comprises at least two bridge-arm groups connected in parallel. The power module has a first conduction mode and a second conduction mode, wherein in the first conduction mode, all of the at least two bridge-arm groups are switched on; in the second conduction mode, some of the at least two bridge-arm groups are switched on and the other part of the at least two bridge-arm groups is switched off. The present invention makes it possible to increase the degree of integration of power electronics, miniaturize the power electronics, increase the power density, and reduce production costs.