Wisconsin Alumni Research Foundation

Caterpillar Inc.

Thomas Merlin Jahns

Bulent Sarlioglu

Renato Amorim Torres

Hang Dai

Mustafa Guven

Robert Donald Lorenz

Seok-hee Han

Ayman Mohamed Fawzi EL-Refaie

Metin Aydin

Seok Hee Han

Takhiro Suzuki

Jeihoon Baek

Shihong Park

Shih-Chin Yang

Woongkul Lee

A switching circuit includes a reverse-voltage-blocking (RB) commutation switch, a first inverter leg, and a second inverter leg. The first inverter leg includes a first dual-gate bidirectional (DGBD) and a second DGBD switch connected in series. The second inverter leg includes a third and a fourth DGBD switch connected in series. A pair of the first DGBD switch, the second DGBD switch, the third DGBD switch, and the fourth DGBD switch that are in different inverter legs of the first inverter leg and the second inverter leg are configured to switch between a first DGBD on-state and a second DGBD on-state when in an inverting operating mode. A current with a positive or a negative polarity is conducted when in the first DGBD on-state. When in the second DGBD on-state, a reverse voltage is blocked by and a current with a positive polarity is conducted through the respective DGBD switch.

Current source inverter using bidirectional switches with bidirectional power flow capability

A switching circuit for a current source inverter includes a first inverter leg, a second inverter leg, and a controller. The first inverter leg includes a first reverse-voltage-blocking (RB) switch, a second RB switch, and a third RB switch that are connected in series between a first bus line and a second bus line. The second inverter leg includes a fourth RB switch, a fifth RB switch, and a sixth RB switch are connected in series between the first bus line and the second bus line. The controller is configured to control a switch between an on-state and an off-state for each RB switch. When in the on-state, a reverse voltage is blocked by a respective RB switch, and a current with a positive polarity is conducted through the respective RB switch. When in the off-state, a voltage and the current are blocked by the respective RB switch.

Balanced current-source inverter

A switching circuit includes a diode, a semiconductor switch, and a first bidirectional switch. The semiconductor switch is configured to conduct a first current from a second terminal to a third terminal of the semiconductor switch when a first on-state signal is sent to a first terminal of the semiconductor switch. An anode of the diode is connected to the second terminal of the semiconductor switch, and a cathode of the diode is connected to the third terminal of the semiconductor switch. The first bidirectional switch includes a first terminal, a second terminal connected to the anode of the diode, and a third terminal and is configured to conduct a second current from the second terminal to the third terminal or from the third terminal to the second terminal when a second on-state signal is sent to the first terminal of the first bidirectional switch.

Current source inverter with bi-directional switches

A permanent magnet motor for position sensorless drive operation provides a stator design that exhibits a saliency (machine asymmetric) functionally dependent on rotor position as caused by periodic magnetic saturation of stator structure. This saturation property is caused by rotor zigzag leakage flux from surface permanent magnets. The stator structure may be designed to further saturate from zigzag leakage flux to provide greatest spatial saliency in the quadrature phase for motor position sensorless position estimation. The position, velocity, and shaft torque can be extracted by measuring the phase current from the stator coil of permanent magnet motor.

Permanent magnet motor with stator-based saliency for position sensorless drive

An electric machine includes a rotor having at least one pole pair, the at least one pole pair including a first magnetic pole and a second magnetic pole having opposite polarities. The first magnetic pole may include a first inner radial permanent-magnet layer and a first outer radial permanent-magnet layer. The second magnetic pole may include a second inner radial permanent-magnet layer and a second outer radial permanent-magnet layer. An outer end of the first inner radial permanent-magnet layer and an outer end of the second inner radial permanent-magnet layer may be separated by an angle of between about 27 and about 55 electrical degrees. The electric machine may also include a stator having a stator core with an odd number of stator slots per pole pair of the rotor.

Electric machine

A rotor for an electric machine includes a rotor core constructed of magnetically-permeable material. The rotor core may include a first cavity having a first curved end portion and a second cavity having a first curved end portion disposed adjacent the first curved end portion of the first cavity. The rotor may also include a permanent-magnet cluster. The permanent-magnet cluster may include a permanent-magnet layer that substantially magnetically isolates a portion of the rotor core disposed inside the permanent-magnet cluster from portions of the rotor core disposed outside the permanent-magnet cluster. The permanent-magnet layer may include one or more permanent-magnet pieces disposed in the first cavity and one or more permanent-magnet pieces disposed in the second cavity.

Rotor having multiple permanent-magnet pieces in a cavity

An inverter phase leg with shoot-through protection that may be used in inverters includes a high side semiconductor switch and a low side semiconductor switch which are connected across DC supply lines and which have an output node between them. A series diode or connector switch is connected between the output node and the low side switch, and the junction between the diode or connector switch and the low side switch is electrically connected directly to the gate of the high side switch. If the low side switch is still conducting at the time that the high side switch receives a command to turn on, the gate of the high side switch will be biased so that the switch is held off until current stops flowing through the low side switch and, conversely, if the high side switch is still on at the time that the low side switch is turned on, the gate of the high side switch will be biased to insure its immediate turn-off, thereby preventing a shoot-through condition under which the high side and low side switches are turned on at the same time.

Growing community of inventors

Madison, WI, United States of America

Thomas Merlin Jahns