7results about How to "Reduce inrush current" patented technology

The application discloses a control method and device of an inverter circuit and an inverter system, and belongs to the inverter field. The control method of the inverter circuit comprises the following steps: in the case that a grid performs a grid-connection and off-grid action, the minimum common-mode voltage between the neutral line and the protection ground line on the output side of the inverter is acquired; based on the number of point positions corresponding to the minimum common-mode voltage in the same power frequency cycle and the system delay time length, the target delay time length is determined; the system delay time length is determined based on at least one of the communication delay time length and the mechanical delay time length; after the target delay time length, the relay attraction instruction is issued; the relay attraction instruction is used for instructing the closing of the switching element. The control method of the inverter circuit can reduce the impact current generated in the moment of the closing of the contact, slow down the arc erosion of the relay, and prolong the service life of the relay.

The utility model relates to the field of switching circuits, in particular to a PMOS (P-channel Metal Oxide Semiconductor) switching circuit, which is characterized in that a source electrode of a PMOS tube Q1 is connected with an input voltage end Vi n, and a drain electrode is connected with a load output end Vout; a base electrode of the triode Q2 receives the switching signal through a control signal end PWR, and an emitting electrode of the triode Q2 is grounded; the first divider resistor R1 is connected between the grid electrode of the PMOS tube Q1 and an input voltage end Vi n; the second divider resistor R2 is connected between the grid electrode of the PMOS tube Q1 and the collector electrode of the triode Q2; the first capacitor C1 is connected between the grid electrode and the source electrode of the PMOS tube Q1; the resistance value ratio of the first divider resistor R1 to the second divider resistor R2 is 1: 3 to 1: 5, the capacitance value of the first capacitor C1 is 10 nF to 100 nF, and the load capacitance C2 does not exceed 470 [mu] F. The voltage division ratio of R1 / R2 is matched with the capacitor C1, so that the conduction time of the PMOS is prolonged, the instantaneous charging current peak value of the load capacitor C2 is remarkably reduced, voltage drop is avoided, and the stability of the system is guaranteed.

The invention provides a converter control method and device, control equipment and a converter, and belongs to the technical field of power supplies. The converter comprises at least two inversion modules; a communication module is arranged between the midpoints of the DC buses of every two adjacent inversion modules, and the communication module comprises a first switch and a first buffer unit which are connected in parallel; the method comprises the following steps: acquiring a midpoint potential of a direct-current bus of each inversion module; for every two adjacent inversion modules, if the midpoint potentials of the DC buses of the two inversion modules are not equal, a first buffer unit between the two inversion modules is controlled to be switched on, and after the first buffer unit is switched on, a first switch between the two inversion modules is controlled to be switched on. According to the method, zero-sequence circulating current between the inversion modules can be avoided, carrier synchronization control in advance in a software control method and strict synchronization of a control process are not needed, and the control process is relatively simple.

The invention discloses an energy storage inverter power grid pre-charging control method and an energy storage inverter system.The energy storage inverter power grid pre-charging control method comprises the steps that when it is detected that no direct-current power source is input into the energy storage inverter system, a pre-charging relay and a first live wire relay are closed, and a direct-current bus of an energy storage inverter is pre-charged through a power grid; the second live wire relay and the null line relay are kept disconnected; when the energy storage inverter meets the pre-charging completion condition, an adjusting loop is started, the adjusting loop is used for enabling the phase difference of the output voltage of the energy storage inverter to be transited to a second angle from a first angle, so that the phase difference of the output voltage of the energy storage inverter is close to the phase difference of the power grid side voltage, and the impact current at the moment of grid connection can be reduced; when the energy storage inverter meets the grid connection condition, the second live wire relay is closed, the pre-charging relay is disconnected, and the zero line relay is closed, so that the energy storage inverter is connected to the grid.

This application relates to the technical field of frequency converters, and in particular to a braking-boost integrated frequency converter and control method for multiplexing switching devices. It includes a rectifier, an inverter, and a DC link, and further includes: a reactor, one end of which is connected to the positive output terminal of the rectifier; a reconfiguration unit, comprising a switching switch, a freewheeling diode, a multiplexing switch, and a braking resistor, wherein the multiplexing switch is connected between the moving end of the switching switch and the negative bus, the switching switch having a first stationary end and a second stationary end, the first stationary end being connected to the other end of the reactor, the anode of the freewheeling diode being connected to the first stationary end, the cathode of the freewheeling diode being connected to the positive bus, and the second stationary end being connected to the positive bus via the braking resistor; and a controller, used to acquire the bus voltage, and when the bus voltage is higher than a preset braking threshold, control the moving end to close to the second stationary end and output a pulse width modulation signal to the multiplexing switch so that the braking resistor and the multiplexing switch form a chopper circuit. This application can solve the defect of easy shoot-through during load switching and achieve safe multiplexing of devices.

A DC-DC converter includes a current limiting device and a capacitor. The first interface is coupled to the capacitor and is configured to be coupled to a second interface that supplies an input voltage. The first interface is further configured to couple the input voltage to the capacitor through the current limiting device and then couple the input voltage to the capacitor bypassing the current limiting device. The first interface may include pins of unequal lengths, where a longer pin is connected to the capacitor through a current limiting device and a shorter pin is connected to the capacitor bypassing the current limiting device.

The utility model provides a soft start circuit and an input circuit of a charging power supply module. The soft start circuit comprises a switch unit, a first resistor, a second resistor and a rectification unit. As the input end of the EMI filter in the charging power supply module is connected to the alternating current power grid through the first switching device, one port of the soft start circuit is connected to the two ends of the first switching device, and the other port is connected with the bus, the charging power supply module can be switched on and off by controlling the switching unit. When the first switching device is disconnected and the EMI filter is disconnected from the power grid, the soft start circuit supplies power to the auxiliary power supply connected with the bus, meanwhile, reactive loss generated by the X capacitor is not introduced, and the stability of the circuit and the signal can be ensured through processing of the first resistor, the second resistor and the rectifying unit; during startup, the switch unit can charge the capacitor in the EMI circuit firstly, so that the impact current of the power grid side is reduced, and the safety of the first switch device is ensured.