53results about How to "Reduce the voltage rating" patented technology

In an AC link type boosting device, DC terminals of two voltage inverters are connected each other in series in additive polarity and plural AC terminals of each of the voltage inverters are connected to a transformer. The two voltage type inverters are AC linked to each other via the transformer. An external voltage applied between the DC terminals of the AC link type booster is divided by the voltage-type inverters.

An interleaved flyback converter device with leakage energy recycling includes: two flyback converters and an input power. Each flyback converter includes a capacitor, a switch, two diodes, and a transformer. The input power is connected to the capacitors of the two flyback converters respectively. By using the capacitors as input voltage, the two flyback converters are provided with lower voltage rating. The diodes are used to recycle leakage energy directly, and to clamp voltage on power components. Therefore, in addition to enhancing efficiency via recycling leakage energy, the two flyback converters have lower switching losses due to lower switching voltage.

The present invention relates to a solid state lighting system comprising at least one light emitting semiconductor device (LEDstr), at least one driving means (LEDdr) for driving a predetermined current through the at least one light emitting semiconductor device (LEDstr). The lighting system furthermore comprises a first voltage supplying unit (PS1) coupled to provide a first supply voltage (Vbus1) to a first side of the at least one light emitting semiconductor device, and a second voltage supplying unit (PS2) coupled to provide a second supply voltage (Vbus2) for the at least one light emitting semiconductor device. The first and the second supply voltages (Vbus1, Vbus2) are selected to optimize the voltage drop across the at least one light emitting semiconductor device (LEDstr).

A 3-phase uninterruptible power supply (UPS) including first, second, and third AC/DC converters, a DC/DC converter, and at least one DC/AC converter coupled to multiple electrical buses. The first, second, and third AC/DC converters each being configured to receive AC power and to provide multiple DC signals to the multiple electrical buses. The DC/DC converter being configured to convert DC voltages present on the multiple electrical buses to a DC voltage that can be used to charge a battery. The DC/AC converter being configured to receive DC power from the multiple electrical buses and to provide an AC output. The 3-phase UPS being configured such that when suitable AC power is provided to the AC/DC converters, the DC/DC converter is configured to charge a battery, and when suitable AC power is not provided to the AC/DC converters, the DC/DC converter is configured to provide DC power to the multiple electrical buses using power provided by the battery.

The invention discloses a multi-power-source rail vehicle and a main and auxiliary transmission system and method thereof. The multi-power-source rail vehicle comprises a power supply system, an intermediate direct-current link, a traction inverter, a traction motor and an auxiliary system which are sequentially connected, and the power supply system comprises a diesel generator power supply system, a power grid power supply system and a power battery power supply system; and the auxiliary system is connected to the power battery power supply system. The auxiliary system takes power from the power battery power supply system. The invention breaks through the inherent operation modes of internal combustion and electric locomotives. When the railway vehicle runs on an electrified line, the locomotive can be powered by a contact power grid; and when running on a non-electrified line, the power is supplied by the power battery and the diesel generator set. And the grid section and the non-grid section are effectively connected, so that the electrochemical section and the non-electrochemical section achieve an integrated mode. Meanwhile, the auxiliary system is connected to the power battery power supply system, and the voltage class of the power battery loop is lower than that of the intermediate direct-current link, so that the voltage-withstanding class of the auxiliary system isreduced.

The invention discloses an isolated double half-bridge ANPC active bridge three-level DC/DC converter, which comprises two half-bridge ANPC active bridges, an inductor and a transformer. The two half-bridge ANPC active bridges are connected to the two sides of the transformer respectively. Each half-bridge ANPC active bridge circularly outputs a positive level, a zero level, a negative level and azero level. When energy flows from the primary side to the secondary side of the DC/DC converter transformer, the half-bridge ANPC active bridge circuit on the input side of the DC/DC converter is inan inversion state, and the half-bridge ANPC active bridge circuit on the output side of the DC/DC converter is in a rectification state. When energy flows from the secondary side to the primary sideof the DC/DC converter transformer, the half-bridge ANPC active bridge circuit on the input side of the DC/DC converter is in a rectification state, and the half-bridge ANPC active bridge circuit onthe output side of the DC/DC converter is in an inversion state. The voltage stress borne by each switching tube in each half-bridge ANPC active bridge is half of the bus voltage. Low voltage withstanding level, low cost and low switching loss of a switching device are realized through an ANPC three-level circuit.

The invention discloses the research of a model predictive current control method for an open-winding permanent magnet synchronous motor, which belongs to the technical field of permanent magnet synchronous motor model predictive current control. The method is characterized in that the research adopts the open-winding permanent magnet synchronous motor which maintains the stator and rotor structure characteristics of a permanent magnet synchronous motor; and the neutral point of a winding is opened to form the open-winding permanent magnet synchronous motor to increase the output voltage of aconverter. The core idea of the model predictive current control method is to predict the current state quantity of a system at the next moment, and has the advantages of rapid dynamic response and the like. The model predictive current control method is applied to the current loop control system of the open-winding permanent magnet synchronous motor. According to the principle that the dq0 axis current error value is the smallest in vector screening, the zero-sequence current of the open-winding permanent magnet synchronous motor is effectively suppressed.

A control chip of a primary-side feedback switch power source comprises a voltage control unit (101), an RS trigger (102), a chopper unit (103), a driving unit (104), a current control unit (105) and three pins VDD, GND and OUT. The pin OUT outputs to drive an external switch tube after the chopper unit (103) is amplified by the driving unit (104), the voltage control unit (101) and the current control unit (105) are respectively connected with an S end and an R end of the RS trigger (102) respectively to control the chopper unit (103) through the RS trigger. The control chip is characterized in that the pin VDD is used as a feedback voltage collecting point, and the pin OUT is used as a primary-side current signal collecting point. The control chip of the primary-side feedback switch power source solves the problems of high withstand voltage and cost and non-flexible application of a control chip in the prior art.

A inverter of push ¿C pull normal shock three ¿C level DC is prepared as connecting two ends of clamping capacity separately to crossover point of isolation transformer primary winding and three ¿C level branch ad well as crossover point of isolation transformer primary winding b and three ¿C level branch b, connecting the crossing capacity to connection point of power switching tubes on two three ¿C level branches, connecting isolation transformer secondary winding to rectifying and filtering circuit.

The invention discloses a photovoltaic power generation high-voltage DC transmission device and a method thereof. The photovoltaic power generation high-voltage DC transmission device comprises a plurality of photovoltaic units which are connected in series, a plurality of DC-DC converters, a plurality of energy storage units, a plurality of first local controllers, a second local controller and acentral controller. The serially connected photovoltaic units are in circuit connection with the input end of a high-voltage grid-connected inverter. The output end of the high-voltage grid-connectedinverter is connected with an AC power grid. The input ends of the plurality of DC-DC converters are connected with the output ends of the photovoltaic units in the one-to-one correspondence mode. The plurality of energy storage units are connected with the output ends of the plurality of DC-DC converters in the one-to-one correspondence mode. The plurality of first local controllers are connected with the control ends of the plurality of DC-DC converters in the one-to-one correspondence mode. The first local controllers are used for controlling each photovoltaic unit to run at a maximum power point thereof under the preset current of a high-voltage bus. The second local controller is connected with the control end of the high-voltage grid-connected inverter. According to the invention, the DC-DC converters are not directly connected with a high-voltage DC bus, so that the cost is reduced. The power generation efficiency is improved. Meanwhile, the generation of the hot spot phenomenon is avoided as much as possible.

The invention provides a triple phase shift control method and control device for a dual-active bridge circuit, and the dual-active bridge circuit comprises three-level plus three-level, three-level plus two-level, and two-level plus three-level. The method comprises the following steps: selecting a circuit structure according to the voltage ranges of an input voltage source and an output voltage source of the dual-active bridge circuit and the withstand voltage range of a switching tube; judging phase shift modes, including a step-down triple phase shift mode and a step-up triple phase shift mode; according to the equivalent voltage of the input voltage source, the equivalent voltage of the output voltage source and the closed-loop control quantity of the dual-active bridge circuit, calculating corresponding triple phase shift angles in different phase shift modes; and performing phase shift control according to the triple phase shift angle. According to the method, a proper dual-active bridge circuit topology is selected according to different voltage levels, the voltage withstand level of a switching tube is reduced, the combination mode is flexible, the cost is saved, triple phase shift control is adopted for the selected topology, the switching-on loss of the switching tube can be reduced, and the working efficiency of the dual-active full-bridge circuit is improved.

A power grid voltage supporting type modularized active power filter and a control algorithm are provided and belong to an active power filter and a control algorithm. The topology of the active power filter is a serial combination structure of a power grid voltage supporting portion and an active filtering portion. Each phase of the power grid and voltage support portion consists of n power grid voltage supporting module units connected in series, and each unit consists of an H-bridge circuit and a shunt capacitor; and the active filtering portion consists of m active filtering module units connected in parallel, and each unit consists of a three-phase full-bridge circuit, an AC filtering inductor and a shunt capacitor. The power grid voltage supporting portion adopts a carrier phase-shifting modulation technique to track a grid-side voltage of a common coupling point, so as to reduce voltage demands at the DC side of the active portion; and the active filtering portion adopts an improved current prediction technique to track a harmonic current, so as to be adapted to the power grid voltage supporting structure. The algorithm has the advantages of low costs, high reliability, strong universality, and easy extension, and can be widely used in harmonic treatments in high voltage and high power occasions such as petroleum mining and precision manufacturing and tiny weak power grids.

A flexible on-load voltage regulator of an integrated flexible AC power transmission device comprises a main voltage regulator (10), a voltage regulation transformer (20), a flexible AC power transmission electronic device (30) and a controller (40), wherein a tap is arranged on a high-voltage side, connected with a power grid, of the main voltage regulator (10), the main voltage regulator (10) is connected with the voltage regulation transformer (20) through the tap, the voltage regulation transformer (20) shares a part of winding of the main voltage regulator (10), the voltage regulation transformer (20) is connected with the flexible AC power transmission electronic device (30), the flexible AC power transmission electronic device (30) is connected with the controller (40), the controller (40) is used for simultaneously sampling the voltage of the power grid and a filter current output from the flexible AC power transmission electronic device for feedback control according to a given voltage regulation instruction, the obtained driving pulse instruction is generated to a required compensation voltage, the required compensation voltage is sent to the main voltage regulator (10) through the voltage regulation transformer (20), the voltage of the high-voltage side of the main transformer (10) is changed, and stepless and rapid regulation on the voltage of a load side is further achieved.

The invention relates to an energy taking circuit used in series with a power module equalizing resistor. A capacitor positive pole of a power unit is taken as a voltage input end HVin, and two powersupply power sources VOUT1 and VOUT2 are outputted. A voltage equalizing resistor, a first full control switching device, a rectifier diode, a first voltage sampling circuit, a driving circuit, a starting circuit, a starting capacitor, a storage capacitor, a second voltage sampling circuit, a main control circuit, a power conversion circuit and a power supply diode are included. The energy takingcircuit is independent of an original energy taking power source on a power module, when the original energy taking power source fails, standby power supply can be provided for a bypass contactor trigger circuit of the power unit to ensure reliable implementation of the contactor bypass action. The energy taking circuit is connected with a power unit capacitor after being connected in series withthe equalizing resistor, voltage withstanding levels of a full control device and the storage capacitor are reduced, and design convenience is high. The energy taking circuit is advantaged in that thecircuit principle is concise, reliability is high, the VOUT1 and VOUT2 dual power source output function is achieved, and flexible application is achieved.