40 results about "Dc link voltage" patented technology

The invention discloses a control method and device for a quasi-Z-source network inverter circuit, an inverter and a medium. The control method comprises the following steps: firstly, acquiring a direct-current chain voltage of a quasi-Z-source network, an instantaneous output power of an IPM module and an input voltage of an alternating-current power supply access module; determining an initial reference current according to the instantaneous output power and the input voltage; then, according to the direct-current chain voltage and a preset voltage threshold value, current correction is determined; then, sampling the input voltage to obtain voltage phase information, and correcting the initial reference current according to the voltage phase information and the current correction amount to obtain target reference current; according to the embodiment of the invention, a target reference current is generated, a PWM modulation signal is generated according to the target reference current, and an IPM module is driven according to the PWM modulation signal, so that the inductive current of a first inductor reaches the target reference current, and therefore, the power factor of the Z-source network inverter circuit can be effectively improved under the condition that an alternating current power supply is used as input.

The invention relates to the technical field of high-voltage direct-current power transmission, and discloses a surplus power consumption control method and device for an island new energy system, and the method comprises the steps: monitoring the output energy and direct-current link voltage of a transmitting-end converter station, and carrying out the control of the surplus power consumption when the island new energy system has an alternating-current fault; controlling the receiving-end converter station to perform optimal distribution of receiving-end current and dynamic adjustment of a direct-current voltage reference value so as to preferentially absorb surplus power, and further raising output energy and direct-current link voltage; when it is detected that the output energy meets the energy requirement and the direct-current link voltage meets the voltage requirement, the sending-end converter station is controlled to correct an energy reference value so that the sending-end converter station can consume surplus power through new energy, and after the alternating-current fault is removed, the sending-end converter station and the receiving-end converter station are controlled to perform sequential energy release so that the surplus power can be eliminated. When the energy consumption device is not used, the consumption control of the surplus power of the system is realized through cooperative inertia response and sequential energy release.

This invention relates to a voltage limiting control method for a series-type offshore wind power DC collector system, comprising: superimposing a low-voltage DC link voltage control loop on the power control loop of the wind turbine generator-side converter, and obtaining a reference value for the d-axis component of the generator-side converter voltage. umsd_ref and q-axis component reference value umsq_ref The control signal for the generator-side converter is generated through sinusoidal pulse width modulation to maintain stable low-voltage DC link voltage while ensuring stable power output. The grid-side converter of the wind turbine adopts voltage / frequency control to obtain the d-axis reference value of the grid-side converter output voltage. uod _ ref and q-axis reference value uoq _ ref The grid-side converter control signal is generated by sinusoidal pulse width modulation. By setting the d-axis setpoint of the grid-side converter output voltage, the AC output voltage of the grid-side converter is limited, thereby controlling the DC output voltage of the wind turbine generator within the limit value.

A system may include a power component, the power component including at least one device processor configured to: obtain load data, wherein the load data comprises a power characteristic associated with at least one of a high-load element or a low-load element, obtain a trained power management artificial intelligence (AI) and / or machine learning (ML) model, based at least on the load data and the trained power management Al and / or ML model, infer a direct current (DC) link voltage adjustment, wherein the DC link voltage adjustment is correlated with a predicted load cycle parameter; and cause the power component to alter a DC link voltage from an initial level to an adjusted level based on the DC link voltage adjustment.

The invention discloses an open winding motor power decoupling control device and method based on a Z-source inverter, and relates to the technical field of motor control. The control device is controlled by a power supply hybrid open winding motor; the method comprises three core links: 1, direct-current chain voltage closed-loop control with a reference value updating link, wherein the amplitude of a direct-current chain can be dynamically stabilized only by sampling capacitor voltage; according to the Z-source inverter modulation strategy, specific switch switching points are calculated for different sectors, and harmonic interference introduced by straight-through vectors is restrained; and 3, separating active and reactive voltage components based on a power decoupling algorithm of vector coordinate operation to realize power distribution. According to the invention, the complexity of a control algorithm is simplified, the feedback input quantity is reduced, and the anti-interference capability and the operation stability of the system are improved.

Techniques are described to continuously calculate an inverter DC power of a synchronous machine, e.g., motor or generator, based on the individual phase currents, DC link voltage, and gate signals, which can be compared against the commanded mechanical power based of the estimated rotor speed and commanded torque. A controller can determine whether to shut down the inverter, such as the pulse width modulation (PWM), if the DC power is greater than a threshold value. Such a threshold can be defined to allow an acceptable position and speed estimation error margin.

This power conversion device comprises: a chopper that has a switching element, and bidirectionally converts a battery voltage and a DC link voltage using the switching element; an inverter that bidirectionally converts the DC link voltage and an AC voltage; and a control device that controls the inverter and the chopper. The control device can select, as an operating mode for controlling the chopper, one of a first mode in which the DC link voltage is controlled in accordance with a voltage command value by turning on / off the switching element, and a second mode in which the switching element is always in an on state. The control device reduces the voltage command value when the operating mode is shifted from the first mode to the second mode.

The invention discloses a control method, device and equipment for an energy storage converter of an electric vehicle charging station and a medium, and the method comprises the steps: measuring reactive power and actual voltage through a voltage regulation module, and obtaining reference voltage; inputting the reference voltage into an inertia control module, and determining a reference frequency through the inertia control module based on Q-V droop control; the reference voltage and the reference frequency are sent to a double-layer current and voltage inner loop controller, and the output voltage is determined through the double-layer current and voltage inner loop controller; the output voltage is input into a DC / DC module, a battery charging and discharging instruction is determined through the DC / DC module based on P-f droop control, and the two-stage electric vehicle charging station energy storage converter is controlled through the battery charging and discharging instruction. According to the invention, Q-V droop control is utilized by the inertia control module, the output frequency is adjusted according to the deviation of the DC link voltage, and a power grid is supported through capacitance inertia in a network construction mode; and the DC / DC module detects the DC link voltage deviation, and the voltage proportion controller realizes P-f droop control to ensure that the DC link voltage is adjusted within an allowable safety range, so that the energy storage converter can adjust energy storage and energy release in time when the power demand changes, and the energy storage efficiency is improved. And instability and unreliability of power supply are improved.

The present invention pertains to a power electronic converter, such as an inverter or converter, for an electric application such as a motor drive, electrolyzer or charger. The power electronic converter includes a DC link and an active front end (AFE) connected to grid via a filter and a grid board with a first inrush relay with a resistive device. The resistive device may be a resistor, more specifically an NTC resistor or a PTC thermistor. The grid board further includes a second inrush relay, wherein at least one of the inrush relays is controlled to engage or disengage during startup phase of the power electronic converter and during abnormal grid voltage conditions, such that the DC link is charged via the resistive device or by bypassing the resistive device, and such that the AFE is provided for boosting the DC link voltage to a save level and under controlled conditions. The invention also pertains to an electric motor drive according and a method for operating a power electronic converter.

Systems and apparatuses include one or more processing circuits comprising one or more memory devices coupled to one or more processors, the one or more memory devices configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: determine a pantograph bounce event based on an input voltage and an input voltage frequency; automatically disable a rectifier in response to determining the pantograph bounce event; record an instant DC link voltage at the time the rectifier is disabled; and set a reference DC voltage to the instant DC link voltage.

This improves the efficiency of the power converter while suppressing shocks and unstable operation during mode switching. [Solution] The power converter 1 has switching elements 41 and 42, and uses these switching elements to convert the battery voltage V BAT and DC link voltage V DC A chopper 4 that converts the voltage bidirectionally, and a DC link voltage V DC The system includes an inverter 5 that converts AC voltage bidirectionally, and a control device 8 that controls the inverter 5 and the chopper 4. The control device 8 controls the DC link voltage V by switching elements 41 and 42 on and off as an operating mode for controlling the chopper 4. DC The voltage command value V DCref It is possible to select either SW mode, which controls according to the voltage, or TH mode, which keeps the switching element 41 in a constantly ON state, and when the operation mode of the chopper 4 is switched from SW mode to TH mode, the voltage command value V DCref Reduce.

The present invention provides a power supply device for supplying, using a DC link voltage of a high-voltage unit of a semiconductor transformer, a control power to a transformer control unit for controlling the high-voltage unit, the power supply device comprising: a converter unit which includes a transformer unit and a switch connected in series to a primary side of the transformer unit, is connected to a DC link of the high-voltage unit, and is configured to convert the DC link voltage and output the converted DC link voltage to a transformer control unit; and a converter control unit configured to control on / off of the switch to convert the DC link voltage, wherein the converter unit comprises a first to a (n+1)th converter (wherein, n is an integer greater than or equal to 1) connected in series.

A charging device, in particular for supplying electrical energy to at least a first energy storage unit and a second energy storage unit, comprises a control device and a mains connection for connecting to a mains power supply. The charging device comprises a rectifier, a power factor correction filter, a preset device with an isolated DC-DC converter and a capacitor for generating an isolated DC link voltage, wherein the preset device comprises at least a first interface and a second interface, wherein each adapter device comprises an adapter interface for connecting to the at least first interface or second interface of the preset device, and wherein each adapter device comprises a fine tuning device with an interface means for connecting to an energy storage unit, and wherein each fine tuning device comprises an adjusted and non-isolated DC-DC converter, so that a power value can be provided at the first interface means and / or the second interface means, and wherein the power value at the first interface means and / or the second interface means corresponds to at least a portion of the total power.

The invention relates to a method of operating an inverter, a controller, a computer program and an inverter system. The inverter (20) comprises a DC link having a DC link capacitor (26), and the inverter is configured for converting a three-phase AC voltage generated by the generator into a DC link voltage to be applied to the DC link capacitor (26). The method comprises: receiving a power reference value representative of power to be provided by the generator; determining an estimated mechanical frequency of the generator; determining a harmonic component of the estimated mechanical frequency; determining a torque reference value from the power reference value and the determined harmonic component, wherein the torque reference value represents a torque to be generated by the generator; generating a switching signal for the inverter according to the determined torque reference value; and operating the inverter by providing the switching signal to the inverter.

This motor drive device comprises: a converter that selectively executes a rectification operation for converting AC power inputted from an AC power supply to DC power and outputting the DC power to a DC link, and a regeneration operation for converting the DC power of the DC link to AC power and returning the AC power to the AC power supply when a DC link voltage exceeds a regeneration start voltage; an inverter that, in accordance with a motor drive command, selectively executes an active drive operation for converting the DC power of the DC link to AC drive power and supplying the AC drive power to a motor, and a regeneration operation for converting AC regenerative power from the motor to DC power and returning the DC power to the DC link; and a converter control unit that controls the operation of the converter. The converter control unit changes the regeneration start voltage in accordance with information related to the motor drive command.

A power converter system is provided and includes a power converter having a first converter that includes at least a controllable semiconductor switch having a threshold voltage and a gate voltage for normal on-state conduction, DC terminals connected to a DC link, and AC terminals, a controller of the system supplies current to the first converter for short circuiting by controlling the switches to create a short circuit path through the converter that carries the current. At least one switch in a short circuit path is operated with modified on-state conduction to increase conduction losses by applying a modified gate voltage less than the gate voltage for normal on-state conduction, the modified gate voltage equals the threshold voltage plus x volts, where x ranges from 100 mV to 4 V, and when the converter is short-circuited, the DC link voltage is less than that during a normal switching operation.

The invention relates to a method for braking a power tool, which is a battery-operated power tool and can be connected to at least one first power supply and a second power supply so as to be supplied with electrical energy. The electric energy released when the power tool is braked is fed back to the first power supply device and / or the second power supply device of the power tool. The power supplies are connected in series, and the method may include actively controlling the DC link voltage, where a limit value UZwitchenkreis, Limit of the DC link voltage is less than the sum of limit values UAkkuppack, Limit of the voltages of the power supplies. In a second aspect, the invention relates to a power tool for performing the braking method.

A method for controlling an electrical converter is provided. The invention relates to an electrical converter comprising a main stage adapted to convert a DC voltage into an intermediate voltage having at least two voltage classes, and a filter cell stage having filter cells for each phase of the main stage, the main stage comprising a DC link, and each filter unit is adapted to add or subtract the unit voltage of the filter unit to the intermediate voltage. The method comprises the following steps: determining a first optimized pulse pattern of the primary stage and a second optimized pulse pattern of the filter unit from optimized pulse patterns calculated offline, the first optimized pulse pattern comprising a switching time of the primary stage on the next calculation window (); and wherein the second optimized pulse pattern comprises a switching time of the filter unit on the next calculation window (); determining a midpoint potential (VNP) based on the measured lower DC link voltage and the measured upper DC link voltage of the DC link; determining a first balance signal for the primary stage based on the determined midpoint potential (VNP), determining a second balance signal for the filter cell based on a measured cell voltage of the filter cell; determining a first differential mode voltage from the first balanced signal; determining a second differential mode voltage from the second balanced signal; determining a first voltage change from the first balanced signal and the second differential mode voltage; determining a second voltage change ([delta] UAF, abc) from the second balanced signal and the first differential mode voltage; adjusting the first optimized pulse pattern by moving a switching time of the first optimized pulse pattern on the next calculation window based on the first voltage change, and adjusting the second optimized pulse pattern by moving a switching time of the second optimized pulse pattern on the next calculation window based on the second voltage change; determining a reference flux trajectory on the next computational window based on the adjusted first and second optimized pulse patterns; and controlling the electrical converter based on the determined reference flux trajectory and the adjusted first and second optimized pulse patterns.

A grid-connected converter comprising a power factor controller (PFC) for control of flow of power from a grid supply to a load via a DC link, by switching of at least one active component, which converter including: a voltage controller receiving a link voltage VDC at the DC link and generating a feedback control signal for input to the PFC controller from the link voltage, which voltage controller including: a notch filter tuned to a nominal grid frequency; and a proportional (P) + lead lag compensator.

Electrical circuits, systems, and methods for protecting a turbo alternator from an overspeed condition are presented. The turbo alternator may be part of a cryocooler. A system may include a brake circuit to provide voltage clamping on a DC link of the turbo alternator in case of a failure of a controller of the system to maintain the DC link voltage. If the turbo alternator speed is left uncontrolled, the DC link voltage may excessively increase. The turbo alternator may then reach an overspeed condition and destroy itself, such as by bearing failure. The brake circuit may prevent the turbo alternator from such an overspeed condition by operating in view of the DC link voltage. The brake circuit need not require any external input for control and it may be powered from the DC link bus.

The embodiment of the present application provides a kind of power conversion system and control method, power conversion system includes multiple power modules, each power module contains first port, second port and third port, wherein, the first port of each power module is connected with external device respectively, the second port of each power module is independent of each other, as independent port output power, the third port of each power module is connected in parallel to form a power bus, and, the power of the third port of each power module flows bidirectionally.Therefore, when the load of output port is unbalanced, the power bus formed by the third port in parallel realizes the power scheduling between multiple power modules, so that the power input by each power module through the first port is as equal as possible, reduce or eliminate the problem of DC link voltage sharing caused by load imbalance.

A transformer module and a solid-state transformer are disclosed. The transformer module includes an AC-DC converter, a DC-DC converter, and a controller. The AC-DC converter receives AC voltage and includes a first arm, a second arm, and a DC link. The first arm has a plurality of first switches. The DC link is used to generate a DC link voltage. The DC-DC converter receives the DC link voltage and includes a plurality of second switches. The controller is used to: detect a first detection signal from the AC-DC converter and a second detection signal from the DC-DC converter; decrease the DC link voltage via the second switches in response to an abnormal state of the first detection signal; and decrease the DC link voltage via the first switches in response to an abnormal state of the second detection signal.

The invention relates to an electric machining device (10) with a housing (14), an output mechanism (38) for a tool (32) for machining a workpiece, an electric motor (12) for driving the output mechanism (38), and an intermediate circuit electronics (42) for generating a rectified intermediate circuit voltage (U). IC ) from a supply voltage (U S ) of the processing device (10) and a power electronics unit (38) for controlling the electric motor (12) by means of a voltage derived from the intermediate circuit voltage (U IC ) generated motor voltage signal (U M ), wherein the power electronics (38), the DC link electronics (42) and the electric motor (12) form a drive train (44) which is housed in the casing (14) together with at least part of the output mechanism (28). It is proposed that a converter circuit (48) be connected upstream of the DC link electronics (42), which is derived from the supply voltage (U S) a dynamically adjustable setpoint of the DC link voltage (U IC ) provides.

A method (300) of operating a battery charging circuit (100) for charging a battery (104) is described. The method (300) includes controlling (302) the battery charging circuit (100) to operate in a first mode to output a direct current (DC) current at a first voltage less than or equal to a predefined threshold and controlling (304) the battery charging circuit (100) to operate in a second mode to output the DC current at a second voltage greater than the predefined threshold. In the first mode, the AC-to-DC converter (110) is controlled to regulate a DC link voltage across a DC link capacitor (112) and the DC-to-DC converter (120) is configured to output the DC current at the first voltage. In the second mode, the AC-to-DC converter (110) is controlled to output the DC current and the DC-to-DC converter (120) is bypassed to equalize the DC link voltage with the second voltage.

The invention relates to a battery charger (1), in particular for use as an on-board battery charger, for providing a battery charging voltage (VHV) on a high-voltage on-board electrical system (2) from a multi-phase supply system voltage of an AC supply system (3), comprising: - an AC / DC converter (6) designed to provide a DC link voltage (VZW) on the basis of the single-phase or multi-phase supply system voltage, - a DC / DC converter (8) designed to generate the battery charging voltage (VHV) on the basis of the DC link voltage (VZW); - a protective conductor (PE) which is capacitively coupled to at least the high-voltage on-board electrical system (3); - a compensation unit (12) for injecting a compensation current (Icomp) into the protective conductor (PE), which compensation current compensates for a leakage current in the protective conductor (PE), the compensation unit (12) having a control unit (121) in order to provide the compensation current (Icomp) depending on a common-mode voltage in the high-voltage on-board electrical system (3).

[Problem] To suppress the disadvantage that occurs with regard to the flow of a compensation current when a voltage of a power source of a noise canceller is lower than a DC link voltage of a power converter.[Solving means] A noise reduction circuitry includes a noise canceller that injects a compensation current into a power line or an earth to reduce a common mode noise current flowing to an alternating-current power source from a power converter including a switching element connected to the alternating-current power source through the power line and the earth, and a direct-current power source that supplies power to the noise canceller, and a voltage Vcc of the direct-current power source is less than ⅔ of a peak value of a DC link voltage of the power converter, and when a connection point between the power line and a path connecting the power line and the earth via the noise canceller is a first connection point, and a connection point between the path and the earth is a second connection point, when the compensated common mode noise current whose positive direction is a direction of flow from the alternating-current power source side to the first connection point and flowing through the power line on a side closer to the alternating-current power source than the first connection point is Ig(t), when the compensation current whose positive direction is a direction of flow from the alternating-current power source side to the first connection point and flowing through the path is Io(t), when an impedance of the path is Z1, when an impedance on a side closer to the alternating-current power source than the first connection point and the second connection point is Z2, and when V(t)=2*(Z1*Io(t)−Z2*Ig(t)), the voltage Vcc is set to be a maximum value of a quasi-peak value of V(t) or √2 times or more an effective value of V(t).

The present invention refers to a power supply unit for operating an electronic device in an explosion-proof area, comprising:a means (2) for providing a rectified input voltage (UE);a DC link capacitance (5) for buffering a DC link voltage;a phase section control (4) controlled to apply the rectified input voltage to the DC link capacitance (5) during a time period in which the rectified input voltage (UE) increases and is between a lower (Uu) and upper voltage threshold (Uo), and to disconnect the rectified input voltage from the DC link capacitance (5) in the remaining time periods;a converter circuit (7) configured to convert the DC link voltage (UZ) into an output voltage.

A process for transiently increasing performance of an electric motor includes boosting a DC link voltage of a rectifier-fed variable frequency drive of the electric motor by using an energy storage system. The energy storage system delivers power directly to a DC link of the variable frequency drive. The energy storage system can be at least one of a battery bank, capacitor bank and a flywheel. Feedback from the DC link is delivered to a DC link controller.

The present invention relates to a power converter and to a method for operating same, wherein the power converter is designed to receive two input potentials DC+ and DC−, the power converter comprising a first anti-interference capacitor in order to connect the input potential DC+ capacitively to earth, a second anti-interference capacitor in order to connect the input potential DC− capacitively to earth, a first voltmeter for measuring a first voltage drop Uyp across the first anti-interference capacitor, a second voltmeter for measuring a second voltage drop Uyn across the second anti-interference capacitor, and a calculation unit which is designed to determine a DC link voltage Uzk dropping between the input potential DC+ and the input potential DC− using the first voltage drop Uyp and the second voltage drop Uyn.

Intelligent UPS control for artificial intelligence (AI) loads is disclosed. For example, a system may include a power component including at least one device processor configured to obtain load data, where the load data includes power characteristics associated with at least one of high load elements or low load elements, obtain a trained power management artificial intelligence and / or machine learning (ML) model, and transmit the trained power management artificial intelligence and / or machine learning (ML) model to the device processor. Inferring a direct current (DC) link voltage adjustment based on at least the load data and the trained power management AI and / or ML model, where the DC link voltage adjustment is related to the predicted load cycle parameter; and causing the power component to change the DC link voltage from an initial level to an adjusted level based on the DC link voltage adjustment.