The transformer includes a core. The transformer includes a first rectifier voltage connection winding wound on the core operable to conduct with the first rectifier voltage connection. The transformer includes a second rectifier voltage connection winding wound on the core operable to conduct with the second rectifier voltage connection, the second rectifier voltage connection winding operable to form a first magnetic flux with the first rectifier voltage connection winding. The transfer includes a first rectifier return connection winding wound on the core operable to conduct with the first rectifier return connection. The transformer includes a second rectifier return connection winding wound on the core operable to conduct with the second rectifier return connection, the second rectifier return connection winding operable to form a second magnetic flux with the first rectifier return connection winding and operable to form a net flux with the first rectifier voltage connection winding.

The transformer includes a core. The transformer includes a first rectifier voltage connection winding wound on the core operable to conduct with the first rectifier voltage connection. The transformer includes a second rectifier voltage connection winding wound on the core operable to conduct with the second rectifier voltage connection, the second rectifier voltage connection winding operable to form a first magnetic flux with the first rectifier voltage connection winding. The transfer includes a first rectifier return connection winding wound on the core operable to conduct with the first rectifier return connection. The transformer includes a second rectifier return connection winding wound on the core operable to conduct with the second rectifier return connection, the second rectifier return connection winding operable to form a second magnetic flux with the first rectifier return connection winding and operable to form a net flux with the first rectifier voltage connection winding.

A rectifier assembly includes: a mounting base; and one or more rectification modules configured to be received in the mounting base, each rectification module including: an electronic network including one or more electronic elements configured to convert alternating current (AC) electrical power at an input of the rectification module to direct current (DC) electrical power at an output of the rectification module. Each of the one or more rectification modules is configured to be electrically connected to a DC bus of a driving apparatus that is separate from and independent of the rectifier assembly.

An auto-transformer rectifier system comprising an 18-pulse (or multiple of 18-pulse) autotransformer rectifier unit ATRU having three, or a multiple of three, diode bridge rectifiers and a balancing resistor to balance the power flow through the diode bridge rectifiers, wherein the balancing resistor has a variable resistance, and further comprising a controller configured to identify imbalances between power flows of the respective diode bridge rectifiers and to adjust the resistance of the balancing resistor in response to the detected imbalance.

A system for protecting a vehicle inverter from overvoltage includes a first inverter having switching elements and converting energy from an energy storage device into AC power. A first motor is driven by receiving the converted AC power. A second inverter is connected in parallel with the first inverter, includes a switching elements, and converts energy from the energy storage device into AC power. A second motor is driven by receiving the converted AC power. A first capacitor is connected in parallel between the first inverter and the energy storage device and stores electric energy of the first motor during regenerative braking. A controller turns off a relay connecting the energy storage device and the motor when a voltage of the first capacitor is equal to or greater than a predetermined voltage and operates the switching elements in the inverters in response to first and second current commands.

A system for protecting a vehicle inverter from overvoltage includes a first inverter having switching elements and converting energy from an energy storage device into AC power. A first motor is driven by receiving the converted AC power. A second inverter is connected in parallel with the first inverter, includes a switching elements, and converts energy from the energy storage device into AC power. A second motor is driven by receiving the converted AC power. A first capacitor is connected in parallel between the first inverter and the energy storage device and stores electric energy of the first motor during regenerative braking. A controller turns off a relay connecting the energy storage device and the motor when a voltage of the first capacitor is equal to or greater than a predetermined voltage and operates the switching elements in the inverters in response to first and second current commands.

A system for protecting a vehicle inverter from overvoltage includes a first inverter having switching elements and converting energy from an energy storage device into AC power. A first motor is driven by receiving the converted AC power. A second inverter is connected in parallel with the first inverter, includes a switching elements, and converts energy from the energy storage device into AC power. A second motor is driven by receiving the converted AC power. A first capacitor is connected in parallel between the first inverter and the energy storage device and stores electric energy of the first motor during regenerative braking. A controller turns off a relay connecting the energy storage device and the motor when a voltage of the first capacitor is equal to or greater than a predetermined voltage and operates the switching elements in the inverters in response to first and second current commands.

A power conversion device connected in parallel to a second power conversion device including power conversion circuitry that performs power conversion by changing a connection state between first multiple lines on a primary side and second multiple lines on a secondary side, baseline selection circuitry that selects one of the second multiple lines on the secondary side as a baseline and partial modulation control circuitry that controls the power conversion circuitry to maintain a state in which the baseline is connected to one of the first multiple lines on the primary side and to change a connection state between other second multiple lines on the secondary side and the first multiple lines on the primary side, wherein the baseline selection circuitry switches a line selected as the baseline based on a switching timing used by second baseline selection circuitry of the second power conversion device to select a second baseline.

A zero-sequence blocking transformer includes a first core part around which is wound a first winding and a second core part around which is wound a second winding, and a third core part to create an additional leakage flux path. The concept of this disclosure can be applied to any known core structure by adding an additional leakage flux component part. In the case of a known toroidal core, the additional component part may be a rod of magnetic material fitted into the gap between the two windings to intentionally create an additional leakage flux path. Alternatively, an EE core geometry can be used and the additional leakage flux path is created by forming an air gap or adding a magnetic material insert in the leg which does not carry a winding.

It is therefore an objective of the invention to provide an apparatus for conversion between AC power and DC power. The apparatus includes a first power conversion circuit having a first AC side and a first DC side, at least one second power conversion circuit each having a second AC side and a second DC side; and at least one choke having a first terminal, a second terminal and at least one third terminal, wherein the first terminal is arranged to be electrically coupled to a phase of the AC power, and the second terminal and the at least one third terminal are electrically coupled to respective same phases of the first AC side of the first power conversion circuit and the second AC side of the at least one second power conversion circuit. Moreover, the choke includes a first common-mode choke and a first differential-mode choke, wherein: the first common-mode choke and the first differential-mode choke are electrically coupled in series via a first group of coil ends of the first common-mode choke and a first group of coil ends of the first differential-mode choke, and a second group of coil ends of one of the first common-mode choke and the first differential-mode choke are electrically coupled to the first terminal of the choke, and a second group of coil ends of the other are respectively electrically coupled to the second terminal and the at least one third terminal of the choke. The first common-mode choke can help provide high inductance to the high-frequency components of the common-mode current, which flows from the AC power source, since the impedance of the common-mode choke and the differential-mode choke depends on frequency on the same scale as inductance. The advantages of using the common-mode choke is that it provides twice the inductance of separate inductor design due to the coupling effect. Therefore it filters the common-mode current more effectively or the inductance size can be reduced for a given current ripple requirement.