53 results about "Commutation cell" patented technology

The present invention provides a direct current circuit breaker and its implementation method, which includes the cutout circuit, the commutation circuit and the energy absorption circuit connected in parallel, wherein the cutout circuit includes cutout inductance and cutout unit connected in series, the commutation circuit includes commutation inductance, commutation unit and mechanical switch connected in series, commutation unit has a smaller on-resistance compared to cutout unit. The direct current circuit breaker topology of the present invention is novelty, concise, fully functional, easy to control and can flexible extend to apply to different voltage occasion. Through using power semiconductor switch module to cut off the current, It will have a quickly action, without generating electric arc, while the modular construction also reduces the consistency requirements of the power electronic component, and easy to realize the voltage-sharing of the power semiconductor in series, the capacitor included in the module also plays a role of limiting the current. Commutation circuit and cutout circuit through the full-bridge structure can realize the shunt, reduce the current stress of the power electronic component, and also reduce the component cost.

A method of control of the current and voltage switching trajectories of insulated gate power semiconductor switches, more specifically MOSFETs and insulated gate bipolar transistor devices (IGBTs), is disclosed. MOSFETs and IGBTs are used in switch mode power supplies because of their easy driving ability and their ability to handle high currents and voltages at high-switching frequencies. However, the switching trajectories for both types of devices are responsible for both common-mode electromagnetic emissions generated by the drain current waveform and power losses in the commutation cell. These two characteristics represent opposing design objectives for power converters. The current invention uses a hybrid voltage/current gate signal source with feedback of the gate charge (or discharge) current to dynamically and independently control the drain current and drain voltage of an insulated semiconductor device. The rate of change of drain current is controlled by the voltage source traversing the transconductance curve while the rate of change of the drain voltage is controlled by dynamic variations in the current source due to feedback.

The invention provides a parallel online automatic commutation device of a low-voltage load. The commutation device comprises a control circuit, an input module, a commutation switch module and an output module; and the control circuit receives a commutation phase sequence state instruction sent by a distribution and transformation terminal, calculates an operation instruction of the commutation switch module, and realizes online commutation of the low-voltage load. The invention also provides an operation method of the device. The operation method comprises that 1) the three-phase voltage of power grid, a current of the low-voltage load and a phase sequence state when the low-voltage load is connected to the power grid are collected; 2) the commutation phase sequence state instruction is calculated; and 3) the operation instruction of the device is calculated, and online commutation of the low-voltage load is realized. Compared with the prior art, the device and operation method thereof use an intelligent optimized algorithm to optimize and select the phase sequence state combination of the low-voltage load in a power distribution district, and change the low-voltage load randomly among phases A, B and C, and three-phase loads in the power distribution district are balanced.

The present disclosure introduces a gate driver used to drive a power electronic switch of a commutation cell. The gate driver comprises a turn-off current source connected to a gate of the power electronic switch and an additional current source. The additional current source is in parallel to the turn-off current source of the gate driver and is configured to control a collector to emitter voltage variation at turn off of the power electronic switch. A circuit combining the gate driver with a commutation cell having a power electronic switch, a circuit combining a pair of gate drivers with a leg having two commutation cells including two power electronic switches and a converter including such circuits are also disclosed.

An actuator for a vehicle transmission system, comprising:

• • an electrical machine comprising an armature and an inductor,
  • a static converter comprising a plurality of commutation cells, the static converter being arranged so as to electrically connect the electrical circuit of the armature to an electrical energy source, and
  • a system for controlling the commutation cells of the static converter, said system being configured so that the torque constant of the electrical machine can assume at least two different values depending on the control applied to said cells.

The invention discloses a device for converting balanced three-phase electric power into single-phase electric power, which comprises a plurality of electrified railway traction power supply devices which are composed of an electronic device and/or a motor transformer. The devices have the advantages of high efficiency, energy saving, low cost, easiness in manufacturing and so on, the capacity of power processed by the electronic device accounts for about 46% to 67%, the balanced three-phase electric power can be converted into the single-phase electric power, and better three-phase balance and high power factor can be obtained by negative sequence compensation and reactive power compensation, therefore, the commutation zone in the electrified railway can be canceled, so as to save the investment in railway construction, stabilize the train power supply, and improve the safety of train operation.

The present disclosure relates to a commutation cell and to a compensation circuit for limiting overvoltage across the power electronic switch of the commutation cell and for limiting a recovery current in a freewheel diode of the commutation cell. The power electronic switch has a parasitic emitter inductance. A variable gain compensation circuit generates a feedback from a voltage generated across the parasitic inductance of the emitter of the power switch at turn-on or turn-off of the power electronic switch. The compensation circuit provides the feedback to a control of the power electronic switch to reduce the voltage generated on the parasitic emitter inductance. A power converter including the commutation cell with the compensation circuit is also disclosed.

The invention provides a hydraulic control circuit. The hydraulic control circuit comprises a main oil circuit (1), an automatic reversing unit (2) and an oil tank (3), wherein the main oil circuit (1) is provided with an oil inlet (I) and an oil outlet (O); the automatic reversing unit (2) is connected in series with the oil tank (3) and is in side joint with the main oil circuit (1); when the flow value of the oil inlet (I) of the main oil circuit (1) is smaller than a predetermined value, the automatic reversing unit (2) is switched on to ensure that inlet oil of the main oil circuit (1) passes through the automatic reversing unit (2) and flows back to the oil tank (3); and when the flow value of the oil inlet (I) of the main oil circuit (1) reaches the predetermined value, the automatic reversing unit (2) is switched off to ensure that the inlet oil of the main oil circuit (1) flows to the oil outlet (O). The invention also provides a hydraulic motor control system, which controlsa hydraulic motor mainly through the hydraulic oil control circuit. The technical scheme can ensure that the main oil circuit provides a required initial flow value outwards through the oil outlet thereof.

There is disclosed a method and a circuit arrangement for the feedback of commutation energy in three-phase current drive systems with a current intermediate circuit converter. Commutation energy is released at each commutation in the inverter. The commutation unit ensures that the released energy is directly fed back to the current intermediate circuit in two steps. In the first step, the commutation energy is fed into the commutation capacitor by a rectifier circuit (diode bridge and three triacs). In the second step, the commutation energy is fed directly from the commutation capacitor into the current intermediate circuit by means of three semiconductors (first RIGBT, second RIGBT, diode) so that the current of the intermediate circuit flows through the capacitor over a controlled period of time.

The invention discloses a marine large-power brushless direct current motor commutation process control device. The device includes a direct voltage source, a three-phase full-bridge inverter and six electric power transistors, wherein the three-phase full-bridge inverter is formed by connecting six power tubes in series two by two and then connecting the power tube in parallel, and the six power tubes are connected with the six electric power transistors in parallel in one-to-one correspondence; and the three-phase full-bridge inverter is connected with a permanent magnet brushless direct current motor. The invention also discloses a large-power brushless direct current motor commutation process control method, at the starting moment of a commutation process, the electric power transistor connected in parallel with a power tube that is switched off in the three-phase full-bridge inverter is switched on, and the other five electric power transistors are switched off; and at the finishing moment of the commutation process, all the six electric power transistors are switched off. The marine large-power brushless direct current motor commutation process control device and control method are relatively low in hardware cost, an original operation control mode of a brushless direct current motor does not need to be changed, and software implementation is simple.

The invention relates to an electric steering engine electrical failure rapid detection circuit and method. The electric steering engine electrical failure rapid detection circuit is formed by a first single-pole single-throw switch S1 to a fourth single-pole single-throw switch S4, a first double-pole single-throw switch S5 to a sixth double-pole single-throw switch S10, a diode D1, a first light emitting diode D2 to a tenth light emitting diode D11, a resistor R1 to a resistor R10 and an electric connector plug (1). The electric steering engine electrical failure rapid detection method can be used for failure detection on a stator winding of a motor in an electric steering engine, a motor Hall reversing unit of the electric steering engine and a position sensor in the electric steering engine. Before the steering engine is powered on and runs, whether broken wires, staggered wires and short-circuit wires exist in the electric steering engine can be detected, damage caused by blind power-on work to related circuits and members is avoided, rapid electrical failure detection and accurate positioning of a known breakdown steering engine are achieved, the whole detection process is rapid, efficient, simple, and the detection circuit and method are high in universality.

The present disclosure relates to a compensation circuit for independently controlling turn-on and turn-off of a power electronic switch through a gate driver. The compensation circuit includes a circuit path sampling a first portion of a voltage induced across an inductance of the power electronic switch at turn-on. Another circuit path samples a second portion of the voltage induced across the inductance of the power electronic switch at turn-off. The compensation circuit further includes a gate driver reference connection configured to respectively supply the sampled portions of the voltage during turn-on and turn-off of the power electronic switch. A compensation circuit controlling a first power electronic switch in parallel with a second power electronic switch, a commutation cell and a power converter having a pair of parallel legs, in which each power electronic switch is provided with the compensation circuit, are also disclosed.

The invention discloses a multi-level photovoltaic grid-connected inverter with an isolation transformer. The multi-level photovoltaic grid-connected inverter comprises a power source, a preposed DC/DC converter, a high-frequency SPWM (sinusoidal pulse width modulation) modulation circuit, a high-frequency isolation transformer, a rectification unit, a filtering and inverting unit, a first capacitor and a second capacitor, wherein the power source is connected with the first capacitor in parallel; the preposed DC/DC converter is connected with the first capacitor in parallel and is connected with the second capacitor in parallel; the high-frequency SPWM modulation circuit is connected with the second capacitor in parallel, and is connected with the rectification unit through the high-frequency isolation transformer; the rectification unit is connected with the filtering and inverting unit; and the high-frequency isolation transformer is formed by a first inductor and a second inductor in coupling. With the adoption of the multi-level photovoltaic grid-connected inverter with the isolation transformer, the loss of switch devices is reduced as far as possible; and high conversion efficiency is achieved.

The invention discloses a workpiece reversing device and workpiece placing equipment provided with the same. The workpiece reversing device comprises a transmission unit for conveying a workpiece andan outputting mechanism, wherein the outputting mechanism is arranged on the transmission unit and comprises a plurality of outputting channels and reversing units arranged on the paths of the outputting channels; and the reversing units adjust the workpiece outputting direction. The outputting mechanisms are arranged on the transmission unit; when the workpieces are conveyed on the outputting channels, the reversing units adjust the direction during the conveying process, and conveying of the workpieces in the outputting channels is not delayed at the same time, so that the defect that the surface of the workpiece is worn when an external clamping device clamps the workpiece is overcome, and the situation that the workpiece quality is reduced due to clamping is avoided; and the reversingunits are arranged on the conveying paths of the outputting channels to avoid manual direction adjustment of the workpiece and increase the productivity of the workpiece.

The invention relates to a light-operated door magnetic sensor, which comprises a commutation unit, a voltage division unit and a voltage control unit, wherein the voltage control unit is connected with the voltage division unit and the commutation unit respectively; the voltage division unit is connected with the commutation unit; the commutation unit is provided with two connection terminals which are connected with a door control interface respectively; the voltage division unit is provided with a photosensitive device; the voltage of the connection point of the voltage control unit and the voltage division unit is reduced to turn off the voltage control unit in light environment; the voltage of the connection point of the voltage control unit and the voltage division unit is increased to turn on the voltage control unit in dark light environment. The light-operated door magnetic sensor can response to the light environment in a base station timely, the condition that a person opens a door to enter the base station or light is used can be effectively detected, and a power supply is not required to be mounted.

The present disclosure relates to a commutation cell configured for limiting switching overvoltage. The commutation cell includes a power electronic switch having a parasitic emitter inductance through which a voltage is generated upon turning off of the power electronic switch. The commutation cell also includes a dynamically controlled compensation circuit connected to the parasitic emitter inductance. The compensation circuit applies a controllable portion of the voltage generated through the parasitic emitter inductance at turn-off of the power electronic switch to control the voltage generated through the parasitic emitter inductance. A power converter comprising a pair of commutation cells and a compensation circuit of the commutation cell are also disclosed.

The invention relates to the technical field of electrical equipment, particularly a power grid direct supply-based high-power pulse power supply. The high-power pulse power supply comprises a 24-pulse wave uncontrollable rectifier, three-phase triple chopped wave units and a reversing unit, wherein the 24-pulse wave uncontrollable rectifier is used for converting the three-phase alternating current mains supply into three paths of direct current to be output to the three-phase triple chopped wave units; each three-phase triple chopped wave unit is corresponding to one path of direct current output of the 24-pulse wave uncontrollable rectifier, and used for converting the instable direct current voltage into a stable direct current voltage needed by a load and outputting the stable directcurrent voltage to one reversing unit separately; and the reversing unit is used for realizing reversing of positive and negative directions of the output current and outputting to a demagnetizing coil. By virtue of the high-power pulse power supply, the problem of current waveform distortion input on the grid side is solved, and the waveform quality of the output direct current voltage is ensured. Meanwhile, compared with a silicon controlled rectifier for rectifying, the 24-pulse wave uncontrollable rectifier improves the power factor of the apparatus, and in addition, direct current stability of a subsequent device is also ensured.

It is presented a voltage source converter comprising a first converter device. The first converter device comprises: a plurality of director valves, wherein each director valve comprises two anti-parallel thyristors provided in a bridge for switching between two states, the bridge being provided in at least one phase leg connected to two a first pair of direct current poles and comprising a midpoint connected to an alternating current, AC, terminal; and at least one commutation cell connected to a respective one of the at least one phase leg, wherein the commutation cell is controllable to reverse-bias a thyristor of at least one director valve of a connected phase leg when the thyristor is to stop conducting current. By providing anti-parallel thyristors in the director valves, greater control is possible. For instance the current between the DC poles can be turned off using the director valves.

The invention relates to a control circuit of a stainless domestic garbage disposer. The control circuit achieves integrated control through a micro-control unit and comprises a power supply changeover unit, an overload protection unit, an electromagnetic inverting unit and an inverting trigger unit. The power supply changeover unit enables accessed alternating currents to be converted into direct currents to be output. The micro-control unit receives electric signals triggered by the inverting trigger unit, and therefore the electromagnetic inverting unit is triggered and the direction of the output direct currents is changed. The overload protection unit enables overload signals to be fed back to the micro-control unit and achieves power-off protection. Through above mode, the control circuit of the stainless domestic garbage disposer comprises the power supply changeover unit, the electromagnetic inverting unit, the inverting trigger unit and the overload protection unit which are controlled by the micro-control unit, perfect operation to electrical apparatus elements is achieved, and the ideal function of automation is achieved.