A power supply system includes a first energy storage, a second energy storage, a power transmission circuit, and circuitry. The first energy storage outputs first output power to an electric load. The second energy storage outputs second output power to the electric load. The circuitry is configured to acquire a demand power to be supplied to the electric load. The circuitry is configured to acquire a remaining capacity value indicating remaining capacity in the second energy storage. The circuitry is configured to control the power transmission circuit to change a ratio of the first output power to the second output power to supply the demand power in accordance with the demand power and the remaining capacity value.

A power conversion system includes a hybrid power converter phase unit including three voltage inputs, a voltage output, a pair of outer switches between the voltage inputs and voltage output, and a pair of inner switches between the voltage inputs and the outer switches. The power conversion system includes a controller in electrical communication with the inner and outer switches. The controller is configured to selectively disable or enable the inner switches by switching the inner switches OFF or ON. A method includes selectively disabling or enabling inner switches in a hybrid power converter phase unit with a controller such that the hybrid power converter phase unit is a 3-level converter when the inner switches are ON and enabled in a 3-level mode and a 2-level converter when the inner switches are OFF and disabled in a 2-level mode.

A power conversion system includes a hybrid power converter phase unit including three voltage inputs, a voltage output, a pair of outer switches between the voltage inputs and voltage output, and a pair of inner switches between the voltage inputs and the outer switches. The power conversion system includes a controller in electrical communication with the inner and outer switches. The controller is configured to selectively disable or enable the inner switches by switching the inner switches OFF or ON. A method includes selectively disabling or enabling inner switches in a hybrid power converter phase unit with a controller such that the hybrid power converter phase unit is a 3-level converter when the inner switches are ON and enabled in a 3-level mode and a 2-level converter when the inner switches are OFF and disabled in a 2-level mode.

Circuitry for directly providing drive power to a BLDC motor having separated coils, comprising unipolar controlled current sources for supplying current to each of the separated coils; a controller, for controlling the level and phase of the unipolar controlled current sources; a polarity switch for converting the unipolar current to a bipolar (AC) current, supplied to the separated coils. The controller is adapted to shape the current being fed to the BLDC motor by the current source via the polarity switch, to be in phase with the back EMF sensed on the separated coils, and of a magnitude that corresponds to a required torque.

An electric motor has a stator defining multiple stator poles with associated electrical windings, and a rotor having multiple rotor poles. The rotor has flux barriers between adjacent rotor poles, the flux barriers each having a material with an electrical conductivity higher than the rotor pole material. The flux barriers are electrically isolated from one another external to the ferromagnetic material. Eddy currents are induced in the flux barrier to cause destructive interference of an impending magnetic field, such that the flux barrier effectively acts to inhibit magnetic flux during motor operation, which in some cases will result in a repulsive force that will act to increase an induced motive force on the rotor poles.

Ina power conversion system having a fixed pulse pattern modulation unit 2 that is configured to refer to tables storing therein pulse patterns that determine respective command voltage levels corresponding to phase information for each modulation ratio and to generate a gate signal g on the basis of a command modulation ratio d and a control phase θ and driving a power converter 3 on the basis of the gate signal g, the fixed pulse pattern modulation unit 2 is further configured to, when performing a pulse pattern transition, search for a proper post-transition table reference position and make a command voltage level follow a command voltage level of a post-transition pulse pattern. With this, the power conversion system that can perform the pulse pattern transition without current impulse and that can also be applied to a multi-level power converter having four levels or more can be provided.

An electric drive system is connected to power batteries and includes a bus, a three-level inverter circuit, a direct current (DC)-DC conversion circuit, and a controller. The bus includes a positive bus and a negative bus. The three-level inverter circuit includes a first bus capacitor and a second bus capacitor. The first bus capacitor is connected between the positive bus and a bus neutral point, and the second bus capacitor is connected between the negative bus and the bus neutral point. The DC-DC conversion circuit includes a first conversion circuit and a second conversion circuit, an input terminal of the first conversion circuit is connected in parallel to the first bus capacitor, and an input terminal of the second conversion circuit is connected in parallel to the second bus capacitor.

A three-level power conversion device includes a three-level converter and a three-level inverter. When the voltage unbalance at a neutral point of the three levels between a + side voltage and a − side voltage is greater than or equal to a threshold value, the three-level power conversion device changes the pulse width of a gate pulse at a specific timing of a gate pulse signal for operating a switching element of the three-level converter. The three-level power conversion device performs control so that the voltage at the neutral point approaches zero.

A three-level power conversion device includes a three-level converter and a three-level inverter. When the voltage unbalance at a neutral point of the three levels between a + side voltage and a − side voltage is greater than or equal to a threshold value, the three-level power conversion device changes the pulse width of a gate pulse at a specific timing of a gate pulse signal for operating a switching element of the three-level converter. The three-level power conversion device performs control so that the voltage at the neutral point approaches zero.

An electric drive system includes a rechargeable energy storage unit, a power inverter, an electric motor and a controller having a processor and tangible, non-transitory memory on which instructions are recorded. A transfer of electrical power between the rechargeable energy storage unit and the electric motor is governed by a pulse width modulation (PWM) switching frequency. The controller is configured to determine a current switching frequency based in part on a PWM type, a PWM switching frequency style and an inverter direct current voltage. A PWM scalar is determined based in part on the current switching frequency and a maximum value of a control reference frequency. The controller is configured to transmit a command signal to regulate the transfer of electrical power based in part on the PWM scalar, the PWM switching frequency being proportional to a product of the PWM scalar and the control reference frequency.