1-9. (canceled)
10. A method of controlling a polyphase electrical machine by at least two polyphase inverters in parallel, each inverter comprising a number of branches equal to a number of phases of the electrical machine, and each branch comprising two power switches connected in series between two opposite terminals of a DC electrical power supply and connected to opposite sides of a point that is connected to an electrical phase of the electrical machine,
the method comprising:
controlling the inverters by pulse-width modulation so as to control switching of the power switches, and detecting an inverter branch fault;
wherein in response to detecting an inverter branch that is faulty, the faulty branch is isolated, the phase of the electrical machine corresponding to the faulty branch is powered by the or each other corresponding inverter branch, and the pulse-width modulation control is modified, or to make the power switches of the or each other corresponding inverter branch conductive in succession and without switching while the absolute value of the phase current concerned is greater than or equal to a threshold lying in a range of 80% to 120% of
n
–
1
n
\ue89e
I
ma
\ue89e
\ue89e
x
,
wherein n is the number of inverters and Imax is the absolute value of the maximum phase current, and while continuing to generate substantially sinusoidal voltage on each phase of the machine.
11. A method according to claim 10, for controlling a three-phase electrical machine by two three-phase inverters in parallel, wherein during each period of the phase current corresponding to the faulty inverter branch, the power switches of the corresponding other inverter branch are made conductive in succession and without switching for about \u2153 of the period.
12. A method according to claim 10, wherein the faulty inverter branch is isolated by opening a branch isolator switch connected between the inverter branch and the corresponding phase of the electrical machine.
13. A method according to claim 10, wherein the faulty inverter branch is isolated by inhibiting the driver circuits of the power switches of the faulty branch.
14. A method according to claim 11, wherein the faulty inverter branch is isolated by opening a branch isolator switch connected between the inverter branch and the corresponding phase of the electrical machine.
15. A method according to claim 11, wherein the faulty inverter branch is isolated by inhibiting the driver circuits of the power switches of the faulty branch.
16. A device for controlling a polyphase electrical machine, the device comprising:
at least two polyphase inverters in parallel, each inverter comprising a number of branches equal to a number of phase currents to be delivered, and each branch comprising two power switches connected in series between two opposite terminals of a DC electrical power supply and connected to opposite sides of a point connected to a respective phase current output terminal;
a control circuit for controlling the inverters by pulse-width modulation, controlling switching of the power switches; and
a system for detecting faults of the inverter branches and connected to the control circuit;
wherein, in response to detection of a faulty inverter branch, the control circuit of the inverters is configured to:
isolate the faulty inverter branch so that the current of the corresponding phase is delivered by the or each corresponding other inverter branch; and
modify the pulse-width modulation or to make the power switches of the or each corresponding other inverter branch conductive in succession and without switching while the absolute value of the phase current in question is greater than or equal to a threshold lying in a range of 80% to 120% of
n
–
1
n
\ue89e
I
ma
\ue89e
\ue89e
x
,
wherein n is the number of inverters and Imax is the absolute value of the maximum phase current, and while continuing to generate a substantially sinusoidal voltage on each phase of the machine.
17. A device according to claim 16, for controlling a three-phase electrical machine by two three-phase inverters in parallel, wherein, in response to detecting a faulty inverter branch, the control circuit of the inverters is configured to modify the pulse-width modulation, or to cause the power switches of the corresponding other inverter branch to be conductive in succession and without switching for respective durations equal to about \u2153 of the period of the phase current.
18. A device according to claim 16, further comprising respective isolating switches connected to each of the inverter branches to be configured to isolate any inverter branch selectively from the corresponding phase current outlet.
19. A device according to claim 16, wherein the power switches of the inverter branches are controlled via driver circuits and the inverter control circuit is arranged to respond to detecting a faulty branch by inhibiting the operation of the driver circuits of the power switches of the faulty branch.
20. A device according to claim 17, further comprising respective isolating switches connected to each of the inverter branches to be configured to isolate any inverter branch selectively from the corresponding phase current outlet.
21. A device according to claim 17, wherein the power switches of the inverter branches are controlled via driver circuits and the inverter control circuit is arranged to respond to detecting a faulty branch by inhibiting the operation of the driver circuits of the power switches of the faulty branch.
22. A system for starting an aeroengine, the system comprising:
a polyphase electrical machine controlled to operate in motor mode to drive a shaft of the engine; and
a device according to claim 16 for controlling the polyphase electrical machine.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A tool, comprising;
a wrench;
an inclinometer integrated with the wrench; and
an electronic indicator operatively coupled to the inclinometer, indicating when a predetermined rotation is met or indicating when a contrary rotation direction is occurring.
2. The tool of claim 1, wherein the inclinometer is a digital inclinometer and the indicator is a digital display displaying a first display color light when a correct rotation direction is occurring and displaying a second display color light when the contrary rotation direction is occurring.
3. The tool of claim 2, wherein the first display color light is a green light and the second display color light is a red light.
4. The tool of claim 1, wherein the indicator is at least one light emitting diode that displays a plurality of different color lights.
5. The tool of claim 1, wherein the indicator is at least one light emitting diode displaying a first color light and at least a second color diode displaying a second color light.
6. The tool of claim 1, wherein the wrench is an Allen wrench.
7. The tool of claim 1, wherein the wrench is a socket wrench.
8. The tool of claim 1, wherein the inclinometer is affixed to a first member and the wrench is affixed to a second member, wherein the first member rotates relative to the second member and the inclinometer provides a measure of the relative rotation between the first and second members.
9. The tool of claim 1, wherein the wrench comprises a shaft and a power source forming a portion of the shaft.
10. The tool of claim 9, wherein the power source is a battery for powering at least one of the inclinometer or the indicator.
11. The tool of claim 1, wherein the tool adjusts threaded rods of an Ilizarov apparatus.
12. A tool, comprising:
a shaft for applying torque;
an inclinometer integrated with the shaft;
a memory storing computer instructions, the memory coupled to the inclinometer; and
a processor communicatively coupled to the memory, wherein the processor, responsive to executing the computer instructions, performs operations comprising:
generating a signal indicating when a predetermined rotation is met or when a contrary rotation direction is occurring.
13. The tool of claim 12, wherein the tool comprises an indicator operatively coupled to the inclinometer.
14. The tool of claim 12, wherein the indicator is a digital display operatively coupled to the inclinometer and wherein the computer instructions when executed by the processor performs operations comprising generating the signal indicating when the predetermined rotation is met and generating the signal when the contrary rotation direction is occurring.
15. The tool of claim 12, wherein, the indicator is a display coupled to a computing device remote from the inclinometer.
16. The tool of claim 12, comprising computer instructions, which when executed by the processor performs operations comprising generating an audible alert when the predetermined rotation is met or when the contrary rotation direction is occurring.
17. The tool of claim 12, comprising computer instructions, which when executed by the processor performs operations comprising enabling a calendaring and reminder alert function for a subsequent predetermined rotation.
18. The tool of claim 12, comprising computer instructions, which when executed by the processor performs operations comprising generating a user interface for programming the predetermined rotation and for programming a schedule for performing a number of the predetermined rotations within a predetermined time frame.
19. The tool of claim 18, further comprising a wireless interface for coupling the processor to a computing device coupled to a display.
20. A method of operating a tool, comprising:
rotating a member of the tool, the tool having an inclinometer integrated with the member;
indicating when a predetermined rotation is met by rotating the member; and
indicating when a contrary rotational direction is occurring by rotating the member in a counter-indicated direction.