519 results about "Flying capacitor" patented technology

In accordance with some embodiments of the present disclosure, a multi-level power converter circuit includes a flying capacitor, a balancing capacitor to control a voltage across the flying capacitor, a plurality of converter switches, a control switch coupled between the flying capacitor and the balancing capacitor, and control circuitry to open and close the control switch based on states of at least two converter switches of the plurality of converter switches. In some embodiments, the multi-level power converter is a three-level buck converter, and the balancing capacitor maintains a voltage across the flying capacitor to be within a threshold range of half the input voltage of the buck converter. In some embodiments, a method for operating the multi-level power converter includes using control circuitry to operate the plurality of converter switches and the control switch to selectively couple the balancing capacitor to either side of the flying capacitor.

The invention provides a control method of a four-level hybrid clamping converter, and the core principle is to select a switching state which minimizes a cost function through a model predictive control (MPC) strategy. The topological structure and the working principle of the 4L-HCC converter are deeply researched, a traditional MPC control strategy is adopted, the charging and discharging process of the capacitors is accurately controlled, voltage fluctuation of the direct-current bus capacitor and the flying capacitor at low frequency and zero frequency is effectively restrained, safe operation of the capacitors, switches and other elements is guaranteed, and the stability and reliability of the converter are improved. By reasonably designing the cost function, the converter can output high-quality electric energy under different working conditions, the distortion of load voltage and current is reduced, the requirements of application scenes with high requirements on electric energy quality, such as motor driving and renewable energy power generation grid connection, are met, and the performance of the system is comprehensively improved.

A reconfigurable flying capacitor multilevel input stage accepts a wide range of input voltages. The input stage divides and inverts a DC input voltage. Generally, output voltage regulation is achieved by adjusting the power switches' duty ratio in the input stage for non-resonant converters and by adjusting the switching frequency for resonant converters.

According to some embodiments, a multi-level power converter, includes an output terminal, a reference terminal, an inductor, a flying capacitor, a first switching stage including a first switch connected to the output terminal and connected to the flying capacitor at a first node, and a second switch connected to the flying capacitor at a second node and connected to the reference terminal, a second switching stage including a third switch connected to the first node and the inductor, and a fourth switch connected to the inductor and the second node, and a pre-charge unit connected to the flying capacitor and the output terminal and configured to pre-charge the flying capacitor based on a voltage at the output terminal during a start-up cycle of the multi-level power converter.

Systems and methods for supplying power (both active and reactive) at a medium voltage from a DCSTATCOM to an IT load without using a transformer are disclosed. The DCSTATCOM includes an energy storage device, a two-stage DC-DC converter, and a multi-level inverter, each of which are electrically coupled to a common negative bus. The DC-DC converter may include two stages in a bidirectional configuration. One stage of the DC-DC converter uses a flying capacitor topology. The voltages across the capacitors of the flying capacitor topology are balanced and switching losses are minimized by fixed duty cycle operation. The DC-DC converter generates a high DC voltage from a low or high voltage energy storage device such as batteries and / or ultra-capacitors. The multi-level, neutral point, diode-clamped inverter converts the high DC voltage into a medium AC voltage using a space vector pulse width modulation (SVPWM) technique.

A voltage source multi-level converter topology and a control method thereof. The voltage source multi-level converter topology includes two groups of half-bridge circuits, two groups of flying capacitors and a plurality of switches. Each group of half-bridge circuits include two direct-current connection ends, and outputs of the two groups of half-bridge circuits are both connected, through a switch, to the two groups of flying capacitors that are in series. A neutral point of a connection between the two groups of flying capacitors is connected to an alternating-current end through two switches that are in reverse series, and an overall positive electrode and an overall negative electrode of the two groups of flying capacitors that are in series are respectively connected to the alternating-current end through switches.

The invention discloses a flying capacitor voltage prediction method based on a neural network. The method comprises the following steps: S10, collecting a switching signal, an output voltage and a capacitor voltage true value of a flying capacitor multi-level converter FCMC in a no-load to full-load operation process through a model prediction controller MPC; s20, a double-layer feed-forward neural network is constructed, a defined input vector and a defined output vector are recorded, the input vector comprises a switching signal and an output voltage at the current moment and a flying capacitor voltage estimated value at the previous moment, and the output vector is the flying capacitor voltage estimated value at the current moment; s30, repeating the step S10 and the step S20 by taking different capacitor voltages as initial conditions; s40, performing off-line training on the neural network by using a back propagation algorithm BP, optimizing network weight and bias, and enabling network output to approach real voltage of flying capacitor operation at the moment; and S50, deploying the trained neural network to an FPGA controller, and estimating the flying capacitor voltage online in real time in combination with a model predictive control MPC algorithm.

A Hybrid Switched Capacitor Converter (HSCC) topology is presented that is suitable for high conversion ratio Point-of-Load (PoL) applications. The topology specifically targets 48V to 1V power delivery in space-based high-performance computing systems, where size and weight are important considerations, along with device de-rating for radiation tolerance. One implementation merges an initial 2:1 switched capacitor conversion stage with a symmetric dual inductor hybrid (SDIH) conversion stage, reaping benefits of both. The SDIH stage offers reduced component count and an excellent switch stress figure of merit, while the initial 2:1 voltage reduction stage significantly reduces the volume of flying capacitors, enabling compact size and low weight.

Provided in the present invention is a multi-level isolated buck type DC / DC converter, comprising two transformers, wherein a primary side of each transformer is provided with a single winding, and a secondary side thereof is provided with two windings; the primary sides of the two transformers are connected in series and are then connected to an LLC resonant circuit, so as to implement isolation and voltage regulation; the other side of the LLC resonant circuit is connected to a flying-capacitor-clamped five-level half-bridge switch network, so as to reduce voltage stress; and the secondary sides of the two transformers are each sequentially connected to a rectifier bridge and a buck circuit, output ends of the two buck circuits are in interleaved parallel connection, and the buck circuits are responsible for closed-loop voltage stabilization regulation, thereby realizing high-gain buck of the converter. Compared with conventional LLC converters, the present invention can significantly reduce voltage stress, can achieve a wider input voltage range and high-gain buck, and can significantly reduce switching loss and improve the efficiency of the converter.

A charge pump includes a flying capacitor; a push-pull driver connected to a first end of the flying capacitor; a first switch provided between the first end of the flying capacitor and a first reference conductor; a second switch provided between a second end of the flying capacitor and the first reference conductor; and a third switch provided between the second end of the flying capacitor and an output terminal. The push-pull driver includes a fourth switch and a fifth switch, each of the fourth switch and the fifth switch having a first end connected to the first end of the flying capacitor. The fourth switch has a second end connected to a second reference conductor, the second reference conductor being different from the first reference conductor. The fifth switch has a second end connected to the first reference conductor.

A DC-DC converter for converting an input voltage at an input node, the converter comprising: first and second inductor nodes for connection of an inductor therebetween; first and second flying capacitor nodes for connection of a flying capacitor therebetween; a first switching network for selectively connecting the first flying capacitor node to each of the input node and the first inductor node; a second switching network for selectively connecting the second flying capacitor node to each of the input node and a reference voltage node; and reservoir circuitry, comprising: first and second reservoir capacitor nodes for connection of a reservoir capacitor therebetween; a third switching network for selectively connecting the first reservoir capacitor node to each of the first and second flying capacitor nodes; a fourth switching network for selectively connecting the second reservoir capacitor node to each of the second flying capacitor node and the reference voltage node.

A first converter includes first to fourth switching elements connected in series from a reference node toward a node fed with an input voltage, a flying capacitor, an intermediate capacitor, and a first inductor. The intermediate capacitor is provided between a connection node between the second and third switching elements and the reference node. The second converter includes a switching output stage connected to the connection node between the second and third switching elements, and a second inductor. A control circuit produces an output voltage lower than the input voltage by controlling the states of the switching elements and of the switching output stage.

A power supply device includes a three-level converting circuit, a dual path hybrid converting circuit and an auxiliary switch circuit. The three-level converting circuit includes a flying capacitor for three-level operation, and generates an intermediate voltage based on an input voltage, a plurality of first control signals and the flying capacitor. The dual path hybrid converting circuit includes a first path, a second path, an inductor in the first path and a hybrid capacitor in the second path, and generates an output voltage based on the intermediate voltage, a second control signal, the inductor and the hybrid capacitor. The auxiliary switch circuit controls current flow through the hybrid capacitor based on a third control signal. The power supply device operates based on a four-phase scheme or a six-phase scheme depending on an operation mode.

A vehicle system includes a first battery pack connected to a second battery pack via a flying capacitor multi-level inverter. The fling capacitor inverter has multiple inverter legs, with each inverter leg being arranged in a flying capacitor topology. A three phase motor is connected to the inverter. A controller connected to the motor and the inverter. The controller includes a memory storing instructions configured to cause the controller to control the inverter as a direct current (DC)-DC converter such that a circulating current passes through the motor, the first battery pack and the second battery pack.

An example apparatus to control a power stage circuit includes: programmable circuitry configured to: generate, in response to an instruction from an external controller, a pulse in a first local clock signal, the pulse in the first local clock signal generated when a fly capacitor in the power stage circuit has discharged for a discharge period that is less than a threshold amount of time; and generate a pulse in a second local clock signal after the fly capacitor has charged for a charge period, wherein a length of the charge period is based on the length of the discharge period.

Switched capacitor power converter circuitry configured to receive an input voltage and to output an output voltage, the switched capacitor power converter circuitry comprising: a switch network; a flying capacitor coupled to the switch network; and an output capacitor coupled to an output node of the switch network, wherein the switched capacitor power converter circuitry is operable in: a first mode in which the switch network operates at a fixed duty cycle; and a second mode in which the switch network operates at a variable duty cycle based on a predetermined flying capacitor charging threshold and a predetermined flying capacitor discharging threshold.

An interleaved flying capacitor multi-level converter includes a plurality of arms and a phase-shift PWM generation circuit. Each arm includes a flying capacitor multi-level circuit having an upper arm and a lower arm coupled at a middle node. The upper arm includes a plurality of serially coupled upper arm switches and the lower arm includes a plurality of serially coupled lower arm switches. One capacitor is correspondingly coupled between every two upper arm switches and every two lower arm switches. The phase-shift PWM generation circuit generates a plurality of switch control signals to respectively control the plurality of upper arm switches and the plurality of lower arm switches.

A power factor correction (PFC) converter includes an inductor to electrically connect to an alternating current (AC) source, a first set of switches to be electrically connected to a terminal of the inductor at one end and to a negative output terminal at an opposite end, and a second set of switches to be electrically connected to the terminal of the inductor at one end and to a positive output terminal at an opposite end. An output voltage of the PFC converter is between the positive output terminal and the negative output terminal. Two or more flying capacitors are connected between different pairs of adjacent ones of the first set of switches and corresponding adjacent ones of the second set of switches. A controller controls duty cycle of the first set of switches and the second set of switches based on balancing voltages of the two or more flying capacitors.

Effective, efficient, and compact circuits and corresponding methods that enable startup of a multi-level (M-level) converter cell to ensure that driver circuits for power transistors are adequately powered in order to be able to switch the power transistors ON and OFF, and to ensure that all fly capacitors are pre-charged to a target voltage level before enabling operational mode switching of the M-level converter cell. Embodiments utilize the power available from a battery connected to an M-level converter cell and operate a converter cell in a boost mode to repeatedly transfer charge from the battery to one or more fly capacitors until a respective target voltage is reached for each fly capacitor.

Circuits and methods are provided that more effectively and efficiently implement multi-level converter circuits. Power switch circuitry may be implemented to selectively route a first voltage between a first terminal and a second terminal. The first terminal may be electrically couplable to a supply voltage and the second terminal may be electrically couplable to a load, such as a battery. The integrated circuit further includes control circuitry configurable to generate a second voltage from the first voltage by selectively operating the power switch circuitry to charge and / or discharge one or more capacitors. A startup sequence may include charging a high-side voltage with a battery, pre-charging one or more fly capacitors and boot capacitors using the battery, operating in a 2-level mode, and transitioning to one or more multi-level modes.

The utility model discloses a direct-current converter based on an asymmetric three-level bridge arm circuit, which comprises a direct-current bus, the asymmetric three-level bridge arm circuit connected with the direct-current bus in parallel, a resonance circuit, an isolation transformer and a rectifying circuit, the asymmetric three-level bridge arm circuit comprises a voltage dividing capacitor, a clamping circuit, a flying capacitor C3 and a half-bridge inverter. According to the direct-current converter, the connection points of the resonant circuits are changed, so that voltage sharing of the voltage-dividing capacitors is realized, the problem of neutral point imbalance caused by characteristic difference of a driving chip and a switching tube in the traditional half-bridge three-level converter is effectively solved, and the direct-current converter is higher in response speed and higher in control precision.

A pre-bias voltage control circuit includes a flying capacitor, a voltage sensor, and a voltage controlled current source. The voltage sensor is used to generate a sensed capacitor voltage according to a capacitor voltage across the flying capacitor, and includes an inverting input terminal coupled to the flying capacitor, a non-inverting input terminal coupled to the flying capacitor, and an output terminal for outputting the sensed capacitor voltage. The voltage controlled current source is used to charge and discharge the flying capacitor, and includes a reference terminal for receiving a reference voltage, an input terminal coupled to the output terminal of the voltage sensor, a current output terminal coupled to the flying capacitor, and a current return terminal coupled to the flying capacitor. The voltage controlled current source generates a source current to charge the flying capacitor when the sensed capacitor voltage falls below the reference voltage.

Circuits and methods are provided that more effectively and efficiently implement multi-level converter circuits. According to some aspects, a method is disclosed herein. In an embodiment, the method includes providing a supply voltage to a power converter, wherein the pow-er converter is selectively configurable in one of a plurality of states, and wherein the power converter comprises a fly capacitor. In an embodiment, the method further includes generating a sample of a voltage across the fly capacitor using a sensing circuit to yield a voltage sample, wherein a target voltage across the fly capacitor is a fraction of the supply voltage; computing a difference between the voltage sample and the target voltage; and sending the difference to a state selector configured to select from the plurality of states based on the difference.

The present invention belongs to the technical field of matrix converters, and discloses a three-phase four-leg three-level direct matrix converter and an SVPWM modulation method. The topology consists of 24 bidirectional switches and 8 flying capacitors. Each of the four legs A, B, C, and N includes 9 output switching states and 6 output voltages. There are a total of 6561 switching states, and the output phase line voltages altogether include six output voltages. The present invention proposes a novel SVPWM modulation method. This method mainly transforms the control of the output voltage from the conventional αβ coordinate system to the abc coordinate system, while the input current is still modulated separately in the αβ coordinate system. The biggest advantage of using the abc coordinate system is that through coordinate translation, the three-level modulation can be simplified to two-level modulation, greatly reducing the increase in algorithm complexity caused by the increase in the number of levels.

The invention relates to a four-level flying capacitor converter (4L-SFC) based on a model predictive control algorithm, the converter defines a single target cost function to control an output current, and capacitor voltage balance is realized by reconstructing a phase voltage level selected by a 4L-SFC inverter. According to the method, the voltage of the flying capacitor is balanced by reconstructing the phase voltage level selected by the 4L-SFC converter, so that the calculated amount is relatively low; compared with a traditional FCS-MPC, a plurality of switch states are applied in the converter, and therefore current distortion is reduced.

A system may include a multi-level power converter comprising a plurality of switches, a power inductor electrically coupled to the plurality of switches, and a flying capacitor coupled to the plurality of switches, wherein the plurality of switches are controllable among a plurality of switch configurations in order to generate an output voltage from an input voltage received by the multi-level power converter. The system may also include a flying capacitor voltage control loop configured to, based on an error signal between a measurement of a flying capacitor voltage across terminals of the flying capacitor and a flying capacitor reference voltage, generate switch control signals for switching among the plurality of switch configurations in order to regulate the flying capacitor voltage and a compensator configured to apply compensation to the flying capacitor voltage control loop based on a measurement of an inductor current flowing through the power inductor.

A circuit suitable for use with a multi-level power converter cell that (1) charges boot capacitors at startup to a sufficient level to power level shifters and drivers that control the power switches within the cell, (2) pre-charges each fly capacitor to a target voltage, (3) provides a shut-down and / or a standby mode of operation that enables a quick re-start of operation, and (4) balances fly capacitor voltages when the fly capacitor(s) is / are not actively charge-balanced. One embodiment includes a first switchable current source coupled between a fly capacitor and an input voltage; a second switchable current source coupled between the fly capacitor and a reference potential; and a third switchable current source coupled in parallel with the fly capacitor; wherein the switchable current sources are configured to charge the fly capacitor in a first mode of operation, and to discharge the fly capacitor in a second mode of operation.

A buck-boost converter for converting an input voltage at an input node into an output voltage at an output node, the converter comprising: first and second inductor nodes for connection of an inductor therebetween; a first converter stage coupled between the input node and the first inductor node; and a second converter stage coupled between the second inductor node and the output node, wherein one or more of the first converter stage and the second converter stage comprises a switching network, comprising: a first switch for selectively connecting a first flying capacitor node to a stage input node; a second switch for selectively connecting the first flying capacitor node to a stage output node; a third switch for selectively connecting a second flying capacitor node to the stage output node; and a fourth switch for selectively connecting the second flying capacitor node to a reference voltage, the first and second flying capacitor nodes for connection of a flying capacitor therebetween.

A modular multilevel flying capacitor (MMFC) converter that seamlessly integrates features of flying capacitor converter and conventional modular multilevel converters. The converter achieves higher voltage and power handling capabilities, along with substantial cost, weight, and size reductions for High Voltage DC (HVDC) systems as the MMC arms within the MMFC converter only sustain half of the full DC voltage. Therefore, the required number of expensive submodules is halved, and size and weight of the total capacitors can be significant reduced, irrespective of the submodule topologies, whether the submodules contain half-bridge or full-bridge switch poles or T-type converter submodule or full-bridge T-type converter submodule or any other submodule topologies. The switches for MMC submodules can be implemented with any type of fully controllable switches made of any types of semiconductor materials.

A charge pump control circuit, comprising an internal reference voltage generator configured to generate a programmable reference voltage ramp, and a control circuit coupled to the internal reference voltage generator. The control circuit configured to control current of a charge pump circuit driving a load by controlling a duty cycle of a transfer phase of the charge pump circuit during a gain-up stage according to a first comparison between the programmable reference voltage ramp and an output voltage across an output capacitor of the charge pump circuit, and a second comparison between a fly capacitor reference voltage and a fly capacitor voltage of a fly capacitor of the charge pump circuit.