Delta Electronics (shanghai) Co., Ltd

Wenfei Hu

Cheng Lu

Hong Tao Liu

Hongyang Wu

Baihui Song

Wen Ju Zhang

Tao Xia

Ling Shi

Hong Liu

Yong Tao

Jie Kong

Wen Zhang

The application discloses a resonant converter and a method for controlling the same. The resonant converter includes: a resonant tank, a first circuit electrically connected to a first end of the resonant tank, and a second circuit electrically connected to a second end of the resonant tank; the first circuit including at least one primary switch, the second circuit including at least one controllable switch, and controlling the at least one controllable switch according to a secondary initial switching frequency, such that the second circuit outputs power, adjusting a secondary switching frequency of the at least one controllable switch according to the secondary initial switching frequency and a signal reflecting the power of the second circuit, such that the secondary switching frequency of the second circuit follows a primary switching frequency of the first circuit.

Resonant converter and method for controlling the resonant converter

The application provides a cascade system distributed control method and device. The method including: taking an output of a closed-loop control for regulating an AC current of the power module as a reference value of a bridge arm voltage; according to the reference value of the bridge arm voltage to obtain an amplitude of the bridge arm voltage, taking the amplitude of the bridge arm voltage as a feedback signal, and after closed-loop control and regulation together with the AC current of the power module, adjusting the reference value of the bridge arm voltage; and controlling the bridge arm voltage according to the reference value of the bridge arm voltage, wherein in at least one working mode of the cascade system, a change of parameters reflecting an active current has a monotonic relation with a change of the amplitude of the bridge arm voltage.

Non-communication distributed control method and device for cascade system

The disclosure discloses a method for estimating parameters of a resonant converter. The resonant converter has first, second port, and a resonant tank that includes an equivalent resonant capacitor and an equivalent resonant inductor, the method including: estimating a second voltage estimation value of the second port, an equivalent resonant capacitor estimation value, and/or an equivalent resonant inductor estimation value of the resonant converter according to a first voltage of the first port, an equivalent resonant capacitor voltage and an equivalent resonant inductor current of at least three effective points, wherein the points have different coordinates on a state plane of the equivalent resonant capacitor voltage and the equivalent resonant inductor current, and are on a state trajectory formed by the equivalent resonant capacitor voltage and the equivalent resonant inductor current, and the points are not central symmetric about a center of the state trajectory.

Method for estimating parameters of resonant converter, method for controlling resonant converter and resonant converter

A method for controlling a distributed power conversion system comprises: configuring N control units for controlling N power modules of the system respectively, wherein each of the control units is configured to execute: step S, generating a first variable Qreflecting respective module serial numbers R according to a coordination variable; step S, generating a second variable Qreflecting the optimal operating number M of the modules; and step S, comparing the first variable Qand the second variable Q, wherein, when the first variable Qis greater than the second variable Q, the corresponding power module stops; and when the first variable Qis less than or equal to the second variable Q, the corresponding power module runs.

Device and method for controlling distributed power conversion system

Embodiments of the present disclosure provide a power conversion system and a control method. The power conversion system includes multiple power modules, and each power module includes a first port, a second port, and a third port, where the first port of each power module is connected to an external device, second ports of the power modules are independent of each other and used as independent ports to output power, third ports of the power modules are connected in parallel to form a power bus and power flow of the third port of each power module is bidirectional.

Power conversion system and control method

The application provides a dispersed carrier phase-shifting method and system. The method includes connecting at least two power modules to form a modular system; each power module including a control module for sampling at least twice a common state variate, signs of slopes of the common state variate at a first and second sampling time are opposite, and a reference time of the first sampling time for each control module is the same; and regulating a carrier frequency of the power module according to a relative size between a sampled values at the first and second sampling time. According to embodiments herein, carrier phase-shifting of modular system may be implemented without communication between respective modules. Under closed-loop control, optimal carrier phase-shifting can be automatically achieved under various duty ratios, thereby having good stability.

Dispersed carrier phase-shifting method and system

The application provides a method for controlling a PFC circuit including a diode bridge arm, DNPC bridge arm and capacitor group connected in parallel. The control method includes: switching working mode of the PFC circuit back and forth between first mode and third mode via second mode in each switching cycle when positive half cycle of a modulation wave is modulated, and switching working mode of the PFC circuit back and forth between sixth mode and fourth mode via fifth mode in each switching cycle when negative half cycle of the modulation wave is modulated. The durations of the second and fifth modes are as short as possible, thereby decreasing a current flowing into or out from midpoint of the capacitor group, and reducing voltage fluctuation at the midpoint. The application further provides a PFC circuit using the control method and a power conversion device having the PFC circuit.

PFC circuit, control method thereof and power conversion device

A method for controlling a power conversion system includes: configuring a carrier period of the power modules, and configuring a phase shift of carrier waves of the adjacent power modules to be 2&#x3c0;/N; selecting M power modules to operate within the carrier period, where O&#x2264;M&#x2264;N, and providing a modulation wave to the power modules, an amplitude of the modulation wave being A/N of a carrier peak of the carrier waves; and comparing the value of the modulation wave with a value of the carrier wave of each of the power modules, respectively, wherein, when the value of the modulation wave is greater than the value of the carrier wave, the corresponding power module runs; when the value of the modulation wave is less than or equal to the value of the carrier wave, the corresponding power module stops.

Control device for power conversion system and its control method

The present disclosure provides a control method of a DC/DC converter and a related DC/DC converter. The control method allows for: detecting a difference between a first voltage and a second voltage; if an absolute value of the difference between the first voltage and the second voltage is greater than or equal to a preset value, reselecting desired operating states of respective switches in a 1-level state according to the difference between the first voltage and the second voltage and a direction of an average current from a fourth node to a first passive network in the 1-level state; and thus outputting a control signal to enable the voltage difference between the first capacitor and the second capacitor to be reduced, thereby effectively adjusting the neutral-point voltage balance of the DC/DC converter.

DC/DC converter and neutral-point voltage balance control method thereof

The present application provides a power converter and a power supply system, the power converter includes: a star/delta switching unit, a first power conversion unit, a second power conversion unit, a third power conversion unit, and a controller; AC terminals of the first power conversion unit, the second power conversion unit and the third power conversion unit are connected to a three-phase AC terminal through the star/delta switching unit, and DC terminals of the first power conversion unit, the second power conversion unit, and the third power conversion unit are connected to a DC power terminal; wherein the controller is configured to control the star/delta switching unit according to a signal reflecting a voltage of the DC power terminal, to form a star connection or a delta connection among the three-phase AC terminal and the first power conversion unit, the second power conversion unit and the third power conversion unit.

Power converter and power supply system

A DC/DC converter includes a first capacitor and a second capacitor coupled to a first node, a first switch and a second switch coupled between the first node and a second node, a third switch and a fourth switch coupled between the first node and a third node, a first passive network coupled between a fourth node and a fifth node, the first passive network connecting the fourth node and the fifth node in series to a primary winding of a transformer, and a secondary side circuit coupled to a secondary winding of the transformer; a control method of the DC/DC converter includes: adjusting a phase shift angle between control signals of the first switch and the fourth switch to reduce a voltage difference between the first capacitor and the second capacitor.

DC/DC converter and method for controlling phase shift angle thereof

A driving and controlling method and a circuit thereof are provided. The method includes: sending, by a primary controller, a first signal that includes a first type of pulse sequence and a second type of pulse sequence; receiving the first signal, by a secondary controller, and identifying a pulse type of the first signal; when a first type of pulse is detected, the secondary controller outputs multiple switching signals to respectively control multiple switching elements to turn off; when a second type of pulse is detected, the secondary controller outputs multiple switching signals to respectively control multiple switching elements to work as normal. A level of the first signal is maintained constant between the first type of pulse sequence and the second type of pulse sequence. The disclosure features cost-efficiency and low driving delay.

Driving and controlling method for switching element and circuit thereof

A DC/DC converter includes: a first capacitor and a second capacitor coupled to a first node; a five-port network coupled to the first to fifth nodes; a transformer electrically connected to the fourth and fifth nodes; and a secondary side circuit electrically connected to a secondary winding of the transformer and coupled to a load; the control method includes: controlling, when the load is less than a preset value, switching states of multiple switches in the secondary side circuit, causing the transformer to be short-circuited for at least a first time period during a phase of stopping energy transmission; and controlling switching states of multiple switches in the five-port network during the first time period, causing current to flow from the five-port network to the first node or flow from the first node to the five-port network.

DC/DC converter and control method thereof

The present disclosure provides a power electronic conversion unit and a power electronic conversion system. The power electronic conversion unit includes: two AC/DC subunits, AC ports of which are coupled in series to form a first port; two half-bridge subunits, DC ports of which are coupled to DC ports of the two AC/DC subunits, respectively; and a transformer, wherein two terminals of a primary winding of the transformer are coupled to a midpoint of bridge arms of the two half-bridge subunits. And a power electronic conversion system comprises a plurality of power electronic conversion units.

Growing community of inventors

Shanghai, China

Wenfei Hu