56results about How to "Avoid voltage spikes" patented technology

A vehicle generator control system detects a time point at which an electrical load is to be disconnected from the generator output, with the detection being achieved prior to that disconnection time point, and initiates a lowering of the generated current of the generator by an amount equal to the load current of that electrical load. The generated current of the generator is thereby reduced, by the time of the disconnection, to a value whereby substantially no voltage spike is produced in the generator output voltage.

The invention relates to a high-efficiency and low-cost forward-flyback DC-DC (direct current-direct current) converter topology. The forward-flyback DC-DC converter topology comprises a transformer, a main switch tube, a clamp circuit, a first rectification switch tube, a second rectification switch tube, an LC resonance circuit and an output capacitor, wherein a primary winding of the transformer is connected in series with the main switch tube between a first input end and a second input end; the clamp circuit consisting of a clamp capacitor and a clamp switch tube which are connected in series is connected in parallel with the primary winding or the main switch tube; a secondary winding of the transformer comprises a forward winding and a flyback winding; one end making the current flow into the primary winding is a dotted end of the primary winding; the secondary side of the transformer is connected in a manner that: the dotted end of the forward winding is connected to the first output terminal through the first rectification switch tube, and the dotted end of the flyback winding is connected to the second output terminal through the second rectification switch tube; the LC resonance circuit is connected to the first output terminal and the second output terminal and the unlike ends of the forward winding and the flyback winding so as to switch on or switch off the first rectification switch tube and the second rectification switch tube at zero current; and the output capacitor is connected between the first output terminal and the second output terminal.

An alternator (10) has a housing (11), a pair of opposed magnet end plates (12, 13) mounted within the housing (11) a coil plate (14) mounted in and held in position within the housing (11), between the pair of magnet end plates (12, 13). A drive shaft (15) is located within housing (11) and is coupled to the pair of magnet end plates (12, 13). Each magnet end plate (12, 13) has a plurality of permanent magnets (17) disposed thereon. The coil plate (14) has a plurality of magnet wire coils (not shown) embedded therewithin such that they can be seen from both sides of the coil plate (14). In use, turning of the drive shaft (15) causes the magnet end plates (12, 13) to move relative to the coil plate (14) thus exciting each magnet wire coil (not shown) on each side resulting in the generation of an alternating current therein.

The invention discloses an intelligent IGBT (insulated gate bipolar transistor) constant-current driving device. The intelligent IGBT constant-current driving device comprises an isolation DC (direct current)-DC module, a PLD (programmable logic device) digital control module, a DAC (digital-to-analog converter) module, a controlled constant-current source, a voltage comparison logic circuit, a gate-level current acquisition circuit and a current comparison logic circuit. A driving power source and a driving signal of a primary side control portion provide an isolated driving power source and a driving signal for a secondary side through the isolation DC-DC module, and an alarming signal of the secondary side provides an isolated alarming signal for the primary side through the isolation DC-DC module. Output ends of the driving signals, the voltage comparison logic circuit and the current comparison logic circuit are connected with an input end of a PLD digital signal, output of PLD is connected with input of the DAC module, outputs of the DAC module and a subtraction circuit are connected with input of the controlled constant-current source, and output of the controlled constant-current source is connected with gate level of IGBT. On the basis of PLD digital control, output of a control circuit can be regulated according to parameter differences of different types of IGBTs to realize optimal control of different series and different types of the IGBTs.

The invention discloses an isolated modular multi-level converter, which comprises three phase units linked to high-voltage direct current ports (PH, NH) in parallel; every phase unit is composed of upper and lower bridge arms; outgoing lines of electric joint points (N1, N2, N3) of the upper and lower bridge arms of three phase units are high-voltage alternating current ports (a, b, c) after linking with filter inductors in series; every bridge arm is composed of a single-grade high frequency isolating type submodule with high-voltage direct current side fault current blocking ability and a bridge-arm reactor Lm; the single-grade high frequency isolating type submodule comprises a front grade part, a high-frequency transformer part and a back grade part; the back grade part can block failed current when the high-voltage direct current side has short-circuited failure, thus the failure at the direct current side is removed. The converter structure is simple, and the converter has the advantages that the isolated modular multi-level converter is free from the high-voltage-free side capacitor and voltage-sharing control, and others; the high-voltage direct current side failure voltage can be rapidly cut off.

The invention relates to a filter element comprising a filter medium (10) extending between two end caps (12, 14) that are respectively connected to an associable end region (16, 18) of the filter medium (10), supported at least on one side on a supporting tube (20). The fact that at least one of the end caps (14) and / or at least one end region (16, 18) of the filter medium (10) comprises a contacting device (22) and / or the respective end cap (14) itself or parts thereof are embodied in such a way as to derive the electrostatic charges especially occurring during the operation of the filter element, ensures that the charge generated on the filter medium (Meshpack) by tribo-electrical effects can escape towards a mass point or a mass site via the contacting device (22) or the respective end cap (14).

The invention discloses a drive circuit of a silicon carbide semiconductor field effect transistor. The drive circuit comprises a PWM control circuit, a drive signal amplification circuit, a turn-offcircuit, a gate shunt circuit and a current change rate control circuit, wherein the gate shunt circuit is switched on when the turn-off circuit works to perform shunt of the gate current of a SiC MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) and accelerate the switch-off of the SiC MOSFET; the SiC MOSFET is switched off when the drain-source voltage of the SiC MOSFET is increased toa preset value; the current change rate control circuit is switched off when the drain-source voltage of the SiC MOSFET is increased to the preset value to reduce the leakage current change rate. Thegate shunt circuit is arranged to perform shunt of the gate output current in the SiC MOSFET switch-off process and speed up the decreasing speed of the gate-source voltage so as to improve the switch-off speed of the SiC MOSFET; and besides, in the switch-off process of the SiC MOSFET, the switch-off of the current change rate control circuit reduces the leakage current change rate so as to reduce the voltage peak when the SiC MOSFET is switched off, the two circuits cooperatively act to achieve the voltage reduction speed and the low-voltage peak of the high gate-source voltage and ensure the safety operation of the SiC MOSFET.

The invention discloses a high-frequency link technology-based isolation type modular multi-level converter. The converter adopts a three-phase system structure and consists of single-stage high-frequency isolation type sub modules; the converter comprises three phase units connected between high-voltage direct current ports PH and NH in parallel; each phase unit consists of upper and lower bridgearms; the electric connecting point N1, N2 and N3 outgoing lines of the upper and lower bridge arms of the three phase units are connected with a filtering inductor in series to form high-voltage alternating current ports a, b and c; each bridge arm consists of n novel single-stage type high-frequency isolation type sub modules and a bridge arm electric reactor Lm; each single-stage type high-frequency isolation type sub module comprises a front-stage part, a high-frequency transformer part and a back-stage part; and the alternating current side of the front-stage part is connected with the primary side of the high-frequency transformer. By virtue of a combination of the high-frequency link technology and the modular multi-level technology, capacitor supporting and voltage-sharing controlon the high-voltage side of each module are not needed; and meanwhile, the problems of secondary side current conversion, voltage spike and the like of the conventional single-stage type converter are overcome.

The invention discloses a high-frequency isolated multi-low voltage DC bus collecting photovoltaic medium voltage grid-connected power generation system comprising a plurality of arrays of concentrated photovoltaic battery packs, and an array of each concentrated photovoltaic battery pack and an isolated modular cascade converter module group corresponding to three phases are connected in parallel. The system has the advantages of solving the problem of three-phase power imbalance caused by partial shadow; achieving the independent MPPT control and improving the power generation efficiency; reducing the DC side voltage and improving the stability and the safety; improving the system scalability and the redundancy; eliminating or reducing secondary power fluctuation of an independent capacitor at the low-voltage DC bus connecting portion, thereby greatly reducing the size of the individual capacitor at the low-voltage DC bus connecting portion.

The invention discloses a high-frequency link technology-based isolated modular cascaded converter, which is capable of achieving conversion from low voltage DC to high voltage DC. Single-phase and three-phase topological structures of the converter are formed by single-stage high-frequency isolation modules, wherein the three-phase structure can be in star connection or delta connection; each module comprises an upper submodule and a lower submodule; and each submodule comprises four parts, namely a front-stage active H bridge, a high-frequency transformer, a back-stage active H bridge and avoltage clamping circuit. The high-frequency link technology-based isolated modular cascaded converter belongs to single-stage power conversion, so that high voltage sides of various modules do not need to be supported by a capacitor any more; and compared with a two-stage modular cascaded converter, the high-frequency link technology-based isolated modular cascaded converter has the advantages that use of the capacitor can be reduced, the volume and the cost of a device are reduced, and meanwhile, the problems, such as secondary side current commutation and voltage spike of a traditional single-stage converter are solved.

The invention discloses a high-transformation ratio bidirectional DC / DC converter based on a coupling inductor, and belongs to the field of power electronics. The bidirectional DC / DC converter comprises a high-voltage power supply end VH, a low-voltage power supply end VL, a high-voltage filter capacitor CH, a low-voltage filter capacitor CL, a high-transformation ratio boost-buck structure composed of an intermediate capacitor C1, a coupling inductor T, a first switch tube S1 and a body diode D1 thereof, a third switch tube S3 and a body diode D3 thereof, a fourth switch tube S4 and a body diode D4 thereof and an active clamping circuit consisting of a clamping capacitor C2, a second switch tube S2 and a body diode D2 of the second switch tube S2. The high-transformation ratio bidirectional DC / DC converter is simple in circuit structure and can realize the higher voltage transformation ratio, the voltage stress of a switching device is small, and the circuit loss is reduced.

A switch circuit capable of preventing voltage spike, includes an input end for receiving an input voltage, an output end for outputting an output voltage, a switch unit for controlling an electrical connection between the input end and the output end according to a control signal, a protection unit for generating the control signal according to an input current passing through the input end, and a first parasitic transistor for controlling an electrical connection between a second end and a third end according to the control signal, wherein when the input current is greater than a threshold value, the switch unit turns off electrical connection between the input end and the output end according to the control signal, and the first parasitic transistor turns on electrical connection between the second end and the third end of first parasitic transistor according to the control signal to reduce variation of input current.

The invention relates to an output dynamic regulation circuit of a low dropout regulator (LDO). A digital circuit is combined with an analog circuit, a load control circuit generates control signals according to changing of load, and a dynamic output control circuit in the LDO can dynamically control assemblies designed proportionally and with different current output capabilities to output required current. The load control circuit can control changing of the load and LDO output current at the same time to achieve dynamic fast accurate matching of the load and required current. When the load changes, the circuit can adjust the magnitude of the output current so as to meet output requirements and eliminates impact on output voltage when the load changes suddenly. Meanwhile, the output dynamic regulation circuit adopts an interlaced wire distribution technology to place the dynamic output control circuit and an LDO output circuit at intervals, improves responding speed of the output circuit, reduces interference on the LDO circuit caused by power source noises and improves performance of the LDO circuit.

The invention relates to a forward-flyback two-way DC-DC converter, composing a forward transformer by coupling secondary and primary windings; composing a flyback transformer by coupling another secondary and primary windings, where the two secondary windings are connected in series with the two switches tubes, respectively, and then connected in parallel with a DC power supply. The two primary windings are connected in series and then connected in parallel with a DC power supply through rectifier / inverter. It uses active clamping, RCD clamping, LCD clamping, ZVT and other techniques to compose a family of two-way converter topologies. It uses the forward transformer and a coupling inductance together to transmit energy, solving the defect in using transformer leakage inductance or coupling inductance to transmission energy; avoids the peak problem in current topologies in existing techniques; has the advantages of small current ripple, implementing soft switch for each switch tube, etc.

The invention discloses a surge current suppression circuit of a spacecraft switch control path. A parallel branch is formed by connecting a resistor and a relay contact in series, and two ends of the parallel branch are connected with two ends of a power switch K1 contact in parallel. The relay drive circuit is located at the front end of the power switch drive circuit, the positive end of the secondary bus is connected with the positive end of a coil of a relay switch K2 through a current-limiting resistor, and the negative end of the coil of the relay switch K2 is directly connected with a drive signal end. The power switch driving circuit adopts an MOS tube driving circuit to perform on-off control and adopts a triode delay circuit to perform delay control, the positive end of the secondary bus is connected with the s pole of an MOS tube, the d pole of the MOS tube is connected with the positive end of a coil of the power switch K1 through a current-limiting resistor of the power switch K1, and the negative end of the coil of the power switch K1 is directly connected with the negative end of the secondary bus. When the driving signal is a closing instruction, the relay contact is closed before the power switch contact; and when the driving signal is a turn-off instruction, the relay contact is disconnected before the power switch contact.

The invention provides a push-pull switching power supply topological structure. The problem that energy of magnetic inductance in a transformer must be maintained on a secondary side when a traditional push-pull switching power supply is in dead time is solved. To maintain the energy of the magnetic inductance, a follow current conduction circuit must be formed on the secondary side of the transformer. For a push-pull circuit, two rectifier diodes are usually used to achieve the purpose, but the premise to ensure the reliable conduction of the diodes is that a load large enough must be available to generate a forward current that can be sufficiently reliably conducted. In addition, in an instant when an inverter switch tube of the push-pull circuit, a very high voltage spike is generateddue to the leakage inductance of the transformer, and a switching tube buffer circuit is usually used to solve the problem. According to the push-pull switching power supply topological structure, a magnetic inductance magnetic inductance circuit is added on a primary side, to maintain the energy of the magnetic inductance on the primary side, so that the voltage spike can be generated in an instant of switching tube turn-off, and the burden on the buffer circuit is reduced.

The invention relates to a special-purposed logic current type separation and link unipolar PWM method of an AND-OR gate construction. According to the method, a circuit topology of a single-phase high-frequency link matrix rectifier uses an LC type filter in the input side and an L type filter in the output side, so that the topology is a current type topology; modulation aimed at the single-phase high-frequency link matrix rectifier all uses current type modulation methods; and in a current type unipolar PWM signal generation link, two low-frequency driving signals and two high-frequency driving signals are generated, and four driving signals generated by current type PWM modulation and high-frequency square waves in 1 / 2 switching frequency are combined logically via special-purposed logic current type separation and link modulation of the AND-OR gate construction, and a driving signal for driving a pre-stage single-phase matrix converter of a high-frequency transformer of the single-phase high-frequency link matrix rectifier is obtained. Thus, a conversion problem of a bidirectional switch tube of the pre-stage matrix converter of the high-frequency transformer of the single-phase high-frequency link matrix rectifier is solved.

The invention belongs to the technical field of frequency converters and relates to a driving and protecting circuit for an inversion module. The circuit comprises a driving circuit, an overvoltage clamping circuit, a gate voltage reduction circuit, a soft turn-off circuit and an overcurrent protection circuit; the gate voltage of the inversion module is clamped to be in a specific voltage range through the overvoltage clamping circuit, and therefore, the problem that the inversion module is damaged due to over-high gate voltage in case of over-high current is solved; the gate voltage of the inversion module is reduced through the gate voltage reduction circuit; and the soft turn-off circuit performs soft turn-off on the inversion module before a driving optocoupler is not blocked; under the condition that the gate voltage reduction circuit or the soft turn-off circuit works, overlarge current signals can be fed back to an upper computer controller through an isolation optocoupler, anddriving signals are blocked, and therefore, the inversion module is prevented from repeatedly performing overlarge current protection on the inversion module. Compared with an intelligent optocouplerdriving circuit, the driving and protecting circuit of the invention is lower in cost. Compared with a common optocoupler driving circuit, the driving and protecting circuit is more stable and reliable.

The invention discloses a full-bridge converter with a freewheeling path. The full-bridge converter comprises a full-bridge bridge arm 1, a DC blocking capacitor 2, an energy transfer transformer 3, an energy main output path 4 and an energy freewheeling path 5. The full-bridge bridge arm is composed of four power switching devices. The DC blocking capacitor 2 and the primary winding of the energytransfer transformer 3 are connected in series and connected with the center of the leading arm and the lagging arm of the full-bridge bridge arm respectively. The energy main output path 4 is composed of a main secondary winding of the transformer 3, four rectifier diodes and a main filtering inductor. The energy freewheeling path 5 is composed of an auxiliary secondary winding of the transformer 3, four rectifier diodes, a pi-type filter, a resonant capacitor and a freewheeling clamping diode. The energy main output path 4 and the energy freewheeling path 5 are connected in parallel. According to the full-bridge converter with freewheeling path, the defects of large voltage stress, loss of duty ratio, large circulation loss and the like of a rectifier diode existing in a traditional full-bridge converter are overcome; and the wide range of the output voltage from zero to the maximum gain can be realized.

The invention discloses a multi-module parallel input circuit for reverse connection prevention, overvoltage and undervoltage protection and isolation startup and shutdown. The multi-module parallel input circuit comprises a reverse connection prevention circuit, an overvoltage protection circuit, an undervoltage protection circuit, a multi-power-supply-module parallel input circuit and an isolation startup and shutdown circuit. The circuit has the advantage of realizing the functions of reverse connection prevention, overvoltage and undervoltage protection and isolation startup and shutdown. A reverse connection prevention circuit is realized by using a PMOS transistor and a voltage stabilizing tube, so that the module is prevented from being damaged by reverse connection input. The voltage stabilizing tube and the triode are used for realizing an overvoltage and undervoltage protection circuit, and the module can still work normally when normal voltage is input again after overvoltage and undervoltage; and the module is ensured not to work outside the specified range of the input voltage. The optocoupler is used for realizing isolation between module input ground and startup and shutdown control ground, thereby ensuring stable and reliable operation of the circuit. The circuit structure is simple, and the component cost is economical. And the expensive cost of the traditional voltage sampling for an operational amplifier chip and an independent source is avoided. Therefore, the efficiency of the whole machine is also improved.

The invention relates to a switching tube protection circuit and a switching device, the protection circuit comprises a sampling circuit, an absorption buffer loop and a processing circuit, the sampling circuit is connected with a first end and a second end of a switching tube, the absorption buffer loop is connected with the first end and the second end of the switching tube, and the processing circuit is connected with a control end of the switching tube, the sampling circuit and a control device. When the voltages of the first end and the second end of the switching tube are too high, the switching tube can be switched off through the processing circuit, and the voltage is absorbed by the absorption buffer loop, so that a voltage peak between the first end and the second end of the switching tube is avoided, the effect of protecting the switching tube is achieved, and the operation reliability of the switching tube is improved.

A system and method for controlling switching in an AC-AC converter is disclosed. A controller for the AC-AC converter determines a direction of current flow on supply lines that provide AC power to the AC-AC converter and determines a switching pattern for each of a plurality of line-side switches and each of a plurality of floating-neutral side switches in the AC-AC converter based on the determined direction of current flow on each of the supply lines. The controller causes the line-side switches and the floating-neutral side switches to operate in an ON or OFF condition according to the determined switching pattern, such that a controlled current flow is output from the AC-AC converter. The controller also implements a safe-switching routine when transitioning from a first switching pattern to a second switching pattern that prevents a non-zero current from being interrupted during the transitioning between the first and second switching patterns.

The invention discloses an electric bridge circuit used for an inverter or a rectifier, and relates to the technical field of power electronics. The electric bridge circuit comprises a first switch, asecond switch, a third switch and a fourth switch which are connected in series and electrically connected between positive and negative direct current voltage sources, wherein the first switch and the second switch are in anti-parallel connection with a first diode; the first switch and the second switch at least comprise a combined field effect transistor; the third switch and the fourth switchare in anti-parallel connection with a second diode; the third switch and the fourth switch at least comprise a combined field effect transistor; the combined field effect transistor comprises a highvoltage withstand field effect transistor and a low voltage withstand field effect transistor with electrically connected sources or drains. Parasitic diodes in the combined field effect transistor are in series-opposing connection, so that the access of a follow current in the parasitic diodes is blocked, so that switch loss and spike voltage caused by the follow current are reduced.

A high-voltage feed-through contains a securing flange for securing the high-voltage feed-through to a wall. The securing flange contains a retaining part and a moving part, wherein the moving part is mounted relative to the retaining part such that it can rotate in relation to a longitudinal direction of the high-voltage feed-through. An electrical device contains a fluid-tight housing and the high-voltage feed-through. A device connection part is provided for receiving and contacting the high-voltage feed-through.

A high-efficiency and low-cost forward and flyback DC-DC converter topology. The topology of the forward and flyback DC-DC converter includes a transformer, a main switch tube, a clamping circuit, a first and a second rectifier switch tube, an LC resonance circuit and an output capacitor. The primary winding of the transformer is connected in series with the main switch tube in the first and second rectifier switches. Between the second input terminal and the second input terminal, a clamping circuit composed of a clamping capacitor and a clamping switch tube connected in series is connected in parallel with the primary winding or the main switching tube, and the secondary winding of the transformer includes a forward winding and a flyback winding, so that The end of the current flowing into the primary winding is the same-named end of the primary winding. The connection of the secondary side of the transformer is as follows: the same-named end of the forward winding is connected to the first output terminal through the first rectifier switch tube, and the same-named end of the flyback winding is connected to the first output terminal through the first rectifier switch. The two rectifier switches are connected to the second output terminal, and the LC resonant circuit is connected to the first and second output terminals and the opposite ends of the forward and flyback windings so that the first and second rectifier switches can realize zero-current switching, and the output A capacitor is connected between the first and second output terminals.

The invention discloses an isolated high-light load efficiency low-output voltage high-current switch power source which comprises an active clamping primary switching circuit (1), an insulating transformer (2), a synchronous rectification circuit (3), an output filter circuit (5), an output sample circuit (6), an error magnification isolation circuit (7), a pulse width modulation control circuit(10), an auxiliary follow current pipe (4), a load sensing circuit (8) and an isolation driver circuit (9). The invention greatly lowers the light load power consumption of the switching converter, and has the advantages of simple structure, low cost and high reliability.

A system architecture for an active chassis system in a motor vehicle has a vehicle electrical system with a first subsystem and a second subsystem. The first subsystem has a first voltage level that is lower than a second voltage level of the second subsystem (14). At least one electric assembly unit for an active chassis element and at least one control device are provided. The electric assembly unit and the control device are supplied with the second voltage level. A vehicle having a system architecture of this kind is also described.

A system and method for controlling switching in an AC-AC converter is disclosed. A controller for the AC-AC converter determines a direction of current flow on supply lines that provide AC power to the AC-AC converter and determines a switching pattern for each of a plurality of line-side switches and each of a plurality of floating-neutral side switches in the AC-AC converter based on the determined direction of current flow on each of the supply lines. The controller causes the line-side switches and the floating-neutral side switches to operate in an ON or OFF condition according to the determined switching pattern, such that a controlled current flow is output from the AC-AC converter. The controller also implements a safe-switching routine when transitioning from a first switching pattern to a second switching pattern that prevents a non-zero current from being interrupted during the transitioning between the first and second switching patterns.