In one embodiment, an apparatus includes a surge voltage blocker circuit to couple between a distribution grid network and a grid-side power converter of a power conversion system. The surge voltage blocker circuit may include a plurality of series-coupled AC switch circuits, each including: a bidirectional switch formed of a first power transistor and a second power transistor; and a transient voltage suppression device coupled in parallel with the bidirectional switch.

A power conversion device includes: a switching circuit; a signal generator to generate a switching signal of a switching element based on a first instruction value; a current controller to generate a second instruction value based on a deviation between a current target value and the current flowing through the switching circuit such that the current flowing through the switching circuit approaches the current target value; an operation mode detector to detect an operation mode based on the first instruction value; and a compensator to adjust the second instruction value so as to compensate a gain between the deviation and an amount of a change in the current of the switching circuit. The compensator adjusts the second instruction value so as to suppress a change in the gain based on the operation mode, and outputs the first instruction value.

A method for controlling a power module includes: configuring N cells in cascade connection, where N is a positive integer equal to or greater than 2, each cell comprising a bidirectional switching unit and a non-controlled rectifier bridge, the bidirectional switching unit being connected to central points of two bridge arms of the non-controlled rectifier bridge; controlling each cell to operate in one of three operating modes of a modulation mode, a bypass mode and a non-controlled rectifying mode, wherein in the N cells, m1 cells operate in the bypass mode, where 0≤m1≤M1, m2 cells operate in the non-controlled rectifying mode, where 0≤m2≤M2, m3 cells operate in the modulation mode and can realize power factor correction, where 0<m3; wherein m1+m2+m3=N, M1 is the allowable number of cells for bypass in the system, and M2 is the allowable number of cells for non-controlled rectification in the system.

A power conversion system for electrically driven mobility device includes a first energy storage device and a second energy storage device having a voltage output lower than a voltage of the first energy storage device, a relay having one terminal connected to the first energy storage device, a DC link capacitor connected to the other terminal of the relay, a first DC converter provided between the DC link capacitor and the second energy storage device and capable of bidirectional voltage conversion, and a controller configured to control the first DC converter to convert a level of the voltage of the second energy storage device and to apply the voltage having the converted level to the capacitor before switching of the relay from an off state to an on state to charge the DC link capacitor to a preset voltage or higher, and then to switch the relay to the on state.

An energy conversion apparatus, a power system, and a vehicle are provided. The energy conversion apparatus includes a motor coil (11) and a bridge arm converter (12). The bridge arm converter (12) is connected to an external battery (200) and an external charging port (10). The motor coil (11) is connected to the external charging port (10), and the motor coil (11) includes a plurality of phase windings, each phase winding includes N coil units, first ends of the N coil units of each phase winding are connected together and then connected to a corresponding phase bridge arm of the plurality of phase bridge arms, and second ends of coil units in each phase winding are connected to second ends of corresponding coil units in other phase windings and then selectively connected to the charging port (10).

This application discloses an energy conversion apparatus, a power system, and a vehicle. The energy conversion apparatus includes: an inductor (12), where an end of the inductor is connected to an external charging port (2); a bridge arm converter (13), connected between an external battery (3) and the external charging port (2), where the bridge arm converter (13) includes a first phase bridge arm (131), a second phase bridge arm (132), and a third phase bridge arm (133) connected in parallel, and the other end of the inductor (12) is connected to the first phase bridge arm (131); a voltage transformation unit (14), where an input end of the voltage transformation unit is respectively connected to the second phase bridge arm (132) and the third phase bridge arm (133); and a first bidirectional H-bridge (15), connected between an output end of the voltage transformation unit (14) and the external battery (3).

An energy conversion device is provided, including a motor coil (11), a bridge arm converter (12), and a bidirectional bridge arm (13). The bridge arm converter (12) is connected to the motor coil (11) and the bidirectional bridge arm (13). The motor coil (11), the bridge arm converter (12), and the bidirectional bridge arm (13) are all connected to an external charging port (10). Both the bridge arm converter (12) and the bidirectional bridge arm (13) are connected to an external battery 200. The motor coil (11), the bridge arm converter (12), and the external charging port (10) form a DC charging circuit for charging the external battery 200. The motor coil (11), the bridge arm converter (12), the bidirectional bridge arm (13), and the external charging port (10) form an AC charging circuit for charging the external battery (200). The motor coil (11), the bridge arm converter (12), and the external battery (200) form a motor drive circuit.

The present invention relates to a power transmission in a DC-DC converter, in particular a phase-shifted full-bridge DC-DC converter from the secondary side to the primary side. In particular, an additional switching state which can reduce the power dissipation of the switching elements in the DC-DC converter, is provided.

Proposed is a method for accurately predicting an overcurrent flowing inside an isolated bidirectional DC-DC converter even without using a current sensor on primary and secondary sides of a transformer. In the converter according to the present disclosure, an average value of the inductor current is calculated after deriving inflection point current values by respectively modeling a current waveform for an inductor current of the transformer. A secondary side output current average value is calculated by comparing the calculated average value of the inductor current with a secondary side capacitor current average value of the converter at no load. Next, an error between the secondary side output current average value and an actually measured secondary side output current is calculated, and the inflection point current values of the current waveform are updated using a gain for reducing the error through PI control, whereby the overcurrent may be predicted.

An isolated DC-DC converter includes a transformer, a full-bridge switching circuit, a protective circuit, a control unit, an inductor, and an output circuit. The isolated DC-DC converter includes a first voltage detection unit that detects a voltage value between a first conductive path and a second conductive path, and a first current detection unit that detects a current value of the inductor. The control unit determines at least one of a first dead time and a second dead time on the basis of the voltage value detected by the first voltage detection unit and the current value detected by the first current detection unit, using a method that increases the dead time as the voltage value increases and reduces the dead time as the current value increases.