Device for producing a rotational position signal and a method for producing rotational position signals

A converter system comprising converters for controlling voltages of two or more winding systems of one or more electrical machines, wherein:

• the converters comprise devices so that each of the converters comprise one of the devices, each of the devices being suitable for producing a position signal indicative of rotational position of a resolver for detecting rotational position of the one or more electrical machines and each of the devices comprising:
• a signal transfer interface for receiving a first alternative signal and a second alternative signal, amplitudes of the first and second alternative signals being dependent on the rotational position of the resolver so that envelopes of the first and second alternative signals have a mutual phase shift,
• a processing system for generating the position signal at least partly on the basis of the amplitudes of the first and second alternative signals and a polarity of an excitation signal of the resolver, and
• a signal generator,
• wherein:
• each of the devices is configurable to operate in a first operational mode where the signal generator is configured to generate the excitation signal and the signal transfer interface is configured to transmit the excitation signal to the resolver and to transmit information indicative of the polarity of the excitation signal to the other devices, and
• each of the devices is configurable to operate in a second operational mode where the signal transfer interface is configured to receive the information indicative of the polarity of the excitation signal from one of the other devices and where the received information indicative of the polarity of the excitation signal is independent of operation of the signal generator,
• a first one of the devices is in the first operational mode and other ones of the devices are in the second operational mode,
• the converter system comprises first signal transfer paths for transferring the excitation signal generated by the first one of the devices to the resolver for detecting the rotational position of the one or more electrical machines and for transferring the information indicative of the polarity of the excitation signal from the first one of the devices to the other ones of the devices, and
• the converter system comprises second signal transfer paths for transferring the first and second alternative signals from the resolver to the devices.

An electrical drive system comprising:

• one or more electrical machines comprising two or more winding systems,
• a resolver for detecting rotational position of the one or more electrical machines, and
• a converter system comprising converters for controlling the one or more electrical machines, the converters comprising devices so that each of the converters comprise one of the devices, each of the devices being suitable for producing a position signal indicative of rotational position of the resolver and each of the devices comprising:
• a signal transfer interface for receiving a first alternative signal and a second alternative signal, amplitudes of the first and second alternative signals being dependent on the rotational position of the resolver so that envelopes of the first and second alternative signals have a mutual phase shift,
• a processing system for generating the position signal at least partly on the basis of the amplitudes of the first and second alternative signals and a polarity of an excitation signal of the resolver, and
• a signal generator,
• wherein:
• each of the devices is configurable to operate in a first operational mode where the signal generator is configured to generate the excitation signal and the signal transfer interface is configured to transmit the excitation signal to the resolver and to transmit information indicative of the polarity of the excitation signal to the other devices,
• each of the devices is configurable to operate in a second operational mode where the signal transfer interface is configured to receive the information indicative of the polarity of the excitation signal from one of the other devices and where the received information indicative of the polarity of the excitation signal is independent of operation of the signal generator,
• a first one of the devices is in the first operational mode and other ones of the devices are in the second operational mode,
• the converter system comprises first signal transfer paths for transferring the excitation signal generated by the first one of the devices to the resolver for detecting the rotational position of the one or more electrical machines and for transferring the information indicative of the polarity of the excitation signal from the first one of the devices to the other ones of the devices, and
• the converter system comprises second signal transfer paths for transferring the first and second alternative signals from the resolver to the devices.

A working machine comprising:

• a combustion engine, and
• an electromechanical power transmission chain between the combustion engine and one or more actuators of the mobile working machine,
• wherein the electromechanical power transmission chain comprises at least one electrical drive system comprising:
• one or more electrical machines comprising two or more winding systems,
• a resolver for detecting rotational position of the one or more electrical machines, and
• a converter system comprising converters for controlling the one or more electrical machines, the converters comprising devices so that each of the converters comprise one of the devices, each of the devices being suitable for producing a position signal indicative of rotational position of the resolver and each of the devices comprising:
• a signal transfer interface for receiving a first alternative signal and a second alternative signal, amplitudes of the first and second alternative signals being dependent on the rotational position of the resolver so that envelopes of the first and second alternative signals have a mutual phase shift,
• a processing system for generating the position signal at least partly on the basis of the amplitudes of the first and second alternative signals and a polarity of an excitation signal of the resolver, and
• a signal generator,
• wherein:
• each of the devices is configurable to operate in a first operational mode where the signal generator is configured to generate the excitation signal and the signal transfer interface is configured to transmit the excitation signal to the resolver and to transmit information indicative of the polarity of the excitation signal to the other devices,
• each of the devices is configurable to operate in a second operational mode where the signal transfer interface is configured to receive the information indicative of the polarity of the excitation signal from one of the other devices and where the received information indicative of the polarity of the excitation signal is independent of operation of the signal generator,
• a first one of the devices is in the first operational mode and other ones of the devices are in the second operational mode,
• the converter system comprises first signal transfer paths for transferring the excitation signal generated by the first one of the devices to the resolver for detecting the rotational position of the one or more electrical machines and for transferring the information indicative of the polarity of the excitation signal from the first one of the devices to the other ones of the devices, and
• the converter system comprises second signal transfer paths for transferring the first and second alternative signals from the resolver to the devices.

A method comprising:

• transferring a first alternative signal and a second alternative signal from a resolver to two or more converters controlling voltages of two or more winding systems of one or more electrical machines, amplitudes of the first and second alternative signals being dependent on rotational position of the resolver so that envelopes of the first and second alternative signals have a mutual phase shift,
• generating, at each of the converters, a position signal indicative of the rotational position of the resolver at least partly on the basis of the amplitudes of the first and second alternative signals and a polarity of an excitation signal of the resolver,
• generating the excitation signal at a first one of the converters, and
• transferring the excitation signal from the first one of the converters to the resolver and transferring information indicative of the polarity of the excitation signal from the first one of the converters to each of other ones of the converters.