An open phase detection system for a power conversion system includes a phase difference abnormality detection unit, an amplitude difference abnormality detection unit, and an open phase determination unit. The phase difference abnormality detection unit outputs a phase difference abnormality signal when an absolute value of a phase difference between a current flowing through a reactor and a current flowing through a capacitor is equal to or smaller than a phase threshold value. The amplitude difference abnormality detection unit outputs an amplitude difference abnormality signal when an absolute value of a value based on an amplitude difference between the current flowing through the reactor and the current flowing through the capacitor is equal to or smaller than an amplitude threshold value. The open phase determination unit outputs an open phase signal when receiving inputs of both the phase difference abnormality signal and amplitude difference abnormality signal.

A method for determining an interrupted motor phase of an electric motor having at least three windings by means of a control unit is disclosed, wherein voltages induced in the windings are determined on outer conductors of the electric motor by means of at least one measuring unit, wherein the measuring unit is connected to at least one outer conductor of the electric motor via at least one resistor, the induced voltages of the outer conductors of the electric motor are compared with one another, and an interrupted motor phase is registered if the induced voltage differs or if a frequency of the induced voltage differs. A control unit, a computer program and a machine-readable storage medium are also disclosed.

A controller and a plurality of driver circuits may be configured to operate selectively either in a normal mode or in a diagnostic mode. In the normal mode, the controller is configured to transmit a drive signal to each driver circuit via a corresponding drive signal line. Each driver circuit is configured to drive corresponding switching element(s) in response to the drive signal and is further configured to output a failure signal when the driver circuit detects a failure related to the corresponding switching element(s). In the diagnostic mode, the controller is configured to sequentially transmit a request signal to the driver circuits via their corresponding drive signal lines, and each driver circuit is configured to output the failure signal in response to the request signal in a case of having detected the failure during operation in the normal mode.

A motor protector and a method for operating the same. The motor protector includes: a power supply unit adapted to receive electric power from power supply lines of a motor to power the motor protector; a measuring unit adapted to measure electric parameters of the motor; and a controller configured to at least perform steps of: receiving from the measuring unit the electric parameters; determining, based on the electric parameters, whether the motor experiences a first failure related to overheating of the motor; enabling, in accordance with determination of the first failure of the motor, the power supply unit to power a closing mechanism of the motor protector after a predetermined time, thereby closing the closing mechanism to power the motor by the power supply lines; determining, based on the electric parameters, whether the motor experiences a second failure different from the first failure; and enabling, in accordance with determination of the second failure of the motor, the power supply unit to stop powering the closing mechanism. Hence, the motor protector can discriminate types of the motor failures and adopt corresponding measures for different failures.

A fault-tolerant power system architecture for aircraft electric propulsion. The fault-tolerant systems continue to operate in the event of the failure of (or one or more faults within) some component. The fault-tolerant design enables the system to continue its intended operation, possibly at a reduced level, rather than failing completely, when some part of the system fails. When a turn-to-turn fault in an AC motor is detected, a motor controller will short three top or three bottom switches in the inverter together (effectively shorting the associated stator windings) to divert fault current from the motor windings to the motor controller, where cooling is available. Also, when a fault in or at the input to a motor controller is detected, the motor controller cuts off power to the motor by issuing a command that causes an upstream contactor with high-voltage DC bus input to open.

A motor drive system can detect a misconnection. A motor drive system for driving a motor including a plurality of stator windings includes: an inverter that converts a DC voltage supplied from a DC voltage source into an AC voltage and applies the AC voltage to the motor; a connection switching device that is disposed between the inverter and the motor and can switch a connection state of the stator windings; and a controller that performs abnormality determination on a connection state of the connection switching device on the basis of a current value of a current flowing in each of the stator windings.

A method for detecting an imbalance in a synchronous motor drive, the method including reading an output voltage signal, and extracting a signature of a parameter imbalance from the output voltage signal. The parameter imbalance is in the synchronous motor drive. Responsive to extracting the signature of the parameter imbalance, the method further includes identifying a certain parameter having the parameter imbalance based on an operating condition of a synchronous motor controlled by the synchronous motor drive, and determining at least one phase of the synchronous motor in which the certain parameter is manifesting the parameter imbalance.

A motor drive control device driving a motor having a first system coil and a second system coil, the motor drive control device comprising: a first drive circuit controlling energization of the first system coil; a second drive circuit controlling energization of the second system coil; a first temperature sensor detecting a temperature of the first drive circuit; a second temperature sensor detecting a temperature of the second drive circuit; and a signal output circuit outputting an output signal concerning whether or not any one of the first system coil and the second system coil is in an open state, based on a detection result by the first temperature sensor and a detection result by the second temperature sensor.

An apparatus is disclosed that in one embodiment includes a circuit configured to selectively activate a transistor. The circuit is further configured to assert a signal when the circuit detects an electrical short between terminals of the transistor or when the circuit detects the transistor does not conduct current while the transistor is activated by the circuit. The circuit is further configured to output another signal, which is set to a first state or a second state. The other signal is set to the first state when the circuit detects the electrical short. The other signal is set to the second state when the circuit detects the transistor does not conduct current while activated.

Fault-tolerant electrical drive systems and methods of maintaining electrical balance or continuing operation of a rotary electric machine under a fault condition are provided. One such system comprises: a rotary electric machine comprising pn phases having a common connection point, where p is a prime number and n is an integer greater than or equal to 1; a drive circuit module having pn phase drive circuits and a reserve drive circuit; and a contactor module. The contactor module comprises: pn phase contactors each of which is operable to connect one of the pn phases of the rotary electric machine to a respective one of the pn phase drive circuits; and a phase fault contactor operable to connect the reserve drive circuit to the common connection point.