A power conversion device includes a first inverter and a control circuit that controls an on/off operations of switches in the first inverter and diagnoses disconnection failures of n-phase windings, where n is an integer of three or more. The control circuit generates a control signal to turn off all of n low-side switches and n high-side switches, supplies the control signal to the n low-side switches and the n high-side switches and measures the n-phase voltages that change depending on patterns of on failures of the switches, and executes a first failure diagnosis to diagnose the on failures of the n low-side switches and the n high-side switches based on the measured n-phase voltages by referring to a table associating the patterns of the on failures of the switches with n-phase voltage levels.

The present invention provides an abnormality diagnosis system capable of identifying an abnormality occurrence site in a rotary electric machine by use of output of sensors mounted to a bearing of the rotary electric machine. The abnormality diagnosis system includes: a rotary electric machine that has a main shaft secured to a center of a rotor and supported by a bearing; a vibration sensor that measures a vibration value of the bearing; a speed sensor that measures a rotational speed value of the main shaft; and an abnormality diagnosis apparatus that diagnoses abnormality in the rotary electric machine based on the vibration value and the rotational speed value. The abnormality diagnosis apparatus includes: a database that records the vibration value, the rotational speed value, and measurement times of the vibration value and the rotational speed value, as a data group of one unit, the vibration value and the rotational speed value measured within a predetermined time period; and an abnormality determination section that makes determination of abnormality, if a first threshold is exceeded by a difference in maximum vibration value in one speed range of interest between a past data group and a newer data group of a plurality of data groups recorded in the database, and makes no determination of abnormality, even if the first threshold is exceeded by a difference in maximum vibration value outside the speed range of interest.

Electrical power system includes: one or more rotary electric machines, each mechanically coupled to a gas turbine engine spool; a set of converter circuits connected to the one or more rotary electric machines for conversion between alternating (ac) and direct current (dc), wherein one or more rotary electric machines and the set of converter circuits are arranged to output a number R≥2 of dc power channels, each dc power channel having a respective index r=(1, . . . , R); and a group of N dc load channels connected to the R dc power channels by a switching arrangement, wherein N>R and each dc load channel has a respective index n=(1, . . . , N). The switching arrangement is operable to connect a number Q≥1 of the N load channels to at least two different power channels of the R power channels.

Data exchange using fan unit signal lines is disclosed, including receiving a pulse width modulated (PWM) signal on a PWM signal line of a fan unit; detecting that a frequency of the PWM signal is outside a frequency range used to control a fan speed of a fan in the fan unit; selecting a data output based on the frequency of the PWM signal; and sending the data output on a tachometric signal line of the fan unit.

Data exchange using fan unit signal lines is disclosed, including receiving a pulse width modulated (PWM) signal on a PWM signal line of a fan unit; detecting that a frequency of the PWM signal is outside a frequency range used to control a fan speed of a fan in the fan unit; selecting a data output based on the frequency of the PWM signal; and sending the data output on a tachometric signal line of the fan unit.

Electric machine drive systems, and related electric machine embodiments, include technologies for providing redundancy of shaft information of one or more electric machines between converter controllers of the corresponding system. The converter controllers are configured to control operation of power converters, which control one or more electric machines. The disclosed technologies include establishing one or more communication buses between the converter controllers to share the shaft information, which may be based on analog signals from a single, common resolver and/or from different, redundant resolvers depending on the embodiment. For example, in some embodiments, converter controllers communicatively connected to the same resolver may include separate resolver-to-digital converters (RDCs) to provide redundancy of the RDCs.

A method for identifying a malfunction in an inverter-motor assembly, including a plurality of sequential diagnostic procedures each having the following steps: a step of initially configuring the inverter; a step of initially configuring the phase switches; a step of biasing the phases; a voltage measurement step in which the voltage of each phase is measured; a comparison step in which the voltage measurement of each phase is compared with an expected resultant value; and a step of identifying a malfunction when the voltage measurement of a phase differs from the expected resultant value.

An electrical power system includes: an electrical machine to output AC; DC electrical network; power electronics converter connected between the AC output of the electrical machine and the DC electrical network and having a phase leg having first and second branches respectively having first and second bi-directional MOSFETs; and controller controlling switching of the first and second bi-directional MOSFETs of each phase leg of the converter so that current is commutated between the phase leg first and second branches rectifying the AC input to DC to supply the DC electrical network with DC electrical power. The controller is responsive to a determination to the effect that there is a fault in the DC electrical network, to control the switching of each phase leg first and second bi-directional MOSFETs to switch the converter into a crow-bar configuration in which electrical machine current does not flow to the DC network.

A method of controlling a multi-phase electric machine includes implementing a first control method to control the operation of a six-phase machine that is configured as a combination of two three-phase machines. The method also includes determining whether a fault exists in the six-phase machine. In response to determining that the fault exists in the six-phase machine, the method includes implementing a second and different control method to control the operation of the six-phase machine.

A method of controlling a multi-phase electric machine includes implementing a first control method to control the operation of a six-phase machine that is configured as a combination of two three-phase machines. The method also includes determining whether a fault exists in the six-phase machine. In response to determining that the fault exists in the six-phase machine, the method includes implementing a second and different control method to control the operation of the six-phase machine.