Abstract: A converter (101) for driving an electric machine whose stator windings are changeable to be in a low-speed configuration or in a high-speed configuration includes a converter stage (102) for supplying stator voltages to the stator windings, and a control system (103) that controls the stator windings to be in the low-speed configuration or in the high-speed configuration. The control system deactivates the converter stage during a change between the low-speed configuration and high-speed configuration and limits torque of the electric machine so that a torque limit is higher when the stator windings are in the low-speed configuration than when the stator windings are in the high-speed configuration. As the torque limit is changed when the number of series connected turns of the stator windings is changed, unwanted current transients can be reduced.

Abstract: A control device (101) for controlling a power converter (109) is configured to form a frequency droop value based on electric power supplied by the power converter to an alternating current system, decrease a frequency control value by the frequency droop value, form a power control value based on a target value of the electric power, increase the frequency control value by the power control value, and supply the frequency control value to the power converter to control alternating voltage frequency of the power converter. The electric power is driven to a value at which a combined effect of the frequency droop value and the power control value makes the alternating voltage frequency of the power converter to be the same as operating frequency of the alternating current system. Thus, the electric power can be controlled by changing the power control value.

Abstract: A device-system comprises parallel operating devices (105-107) for driving an operating quantity towards a target value, and a control system for controlling each device at least partly based on a device-specific integral term relating to a time integral of a device-specific error signal that is indicative of a deviation of the operating quantity from the target value. The control system comprises a stabilizing system that computes an arithmetic average of the device-specific integral terms and corrects the device-specific integral terms towards the computed arithmetic average. The correction of the device-specific integral terms makes it possible to avoid unwanted drifts in the device-specific integral terms in a situation where there are differences between the device-specific error signals. The devices can be peers to each other and thus redundancy is achieved because one device can be removed from or added to the device-system without actions from the other devices.

Abstract: An electric system of an electromechanical power transmission chain is provided that includes a first capacitive circuit, converter equipment between the first capacitive circuit and an electric machine, a second capacitive circuit, and a direct voltage converter between the first and second capacitive circuits. The electromechanical power transmission chain is a parallel transmission chain where the electric machine is mechanically connected to a combustion engine and to one or more actuators. The electric system includes a control system for controlling the direct voltage converter in response to changes in a first direct voltage of the first capacitive circuit and for controlling the converter equipment in response to changes in a second direct voltage of the second capacitive circuit. The first direct voltage is kept on a predetermined voltage range whereas the second direct voltage is allowed to fluctuate in order to respond to peak power needs.

Abstract: A control device (101) for controlling a power converter (109) is configured to form a frequency droop value based on electric power supplied by the power converter to an alternating current system, decrease a frequency control value by the frequency droop value, form a power control value based on a target value of the electric power, increase the frequency control value by the power control value, and supply the frequency control value to the power converter to control alternating voltage frequency of the power converter. The electric power is driven to a value at which a combined effect of the frequency droop value and the power control value makes the alternating voltage frequency of the power converter to be the same as operating frequency of the alternating current system. Thus, the electric power can be controlled by changing the power control value.

Abstract: A device-system comprises parallel operating devices (105-107) for driving an operating quantity towards a target value, and a control system for controlling each device at least partly based on a device-specific integral term relating to a time integral of a device-specific error signal that is indicative of a deviation of the operating quantity from the target value. The control system comprises a stabilizing system that computes an arithmetic average of the device-specific integral terms and corrects the device-specific integral terms towards the computed arithmetic average. The correction of the device-specific integral terms makes it possible to avoid unwanted drifts in the device-specific integral terms in a situation where there are differences between the device-specific error signals. The devices can be peers to each other and thus redundancy is achieved because one device can be removed from or added to the device-system without actions from the other devices.

Abstract: A power converter for an electric power system comprises a switching circuit (102) for supplying, in a first operating mode of the power converter, voltages for driving a rotating electric machine. The power converter comprises a contactor system (110) and a controller (109) for using, in a second operating mode of the power converter, the switching circuit and at least one of windings (115) of the rotating electric machine as a voltage-decreasing direct voltage converter between direct voltage terminals of the power converter. Therefore, the switching circuit of the power converter can be utilized both for driving the rotating electric machine and, for example, for charging a battery element connected to a direct voltage terminal of the power converter.

Abstract: An electric system of an electromechanical power transmission chain is provided that includes a first capacitive circuit, converter equipment between the first capacitive circuit and an electric machine, a second capacitive circuit, and a direct voltage converter between the first and second capacitive circuits. The electromechanical power transmission chain is a parallel transmission chain where the electric machine is mechanically connected to a combustion engine and to one or more actuators. The electric system includes a control system for controlling the direct voltage converter in response to changes in a first direct voltage of the first capacitive circuit and for controlling the converter equipment in response to changes in a second direct voltage of the second capacitive circuit. The first direct voltage is kept on a predetermined voltage range whereas the second direct voltage is allowed to fluctuate in order to respond to peak power needs.

Abstract: An electric system of an electromechanical power transmission chain is provided that includes a first capacitive circuit, converter equipment between the first capacitive circuit and one or more electric machines, a second capacitive circuit, and a direct voltage converter between the first and second capacitive circuits. The electric system includes a control system for controlling the direct voltage converter in response to changes in first direct voltage of the first capacitive circuit and for controlling the converter equipment in response to changes in second direct voltage of the second capacitive circuit. The control of the first direct voltage is faster than the control of the second direct voltage so as to keep the first direct voltage on a predetermined voltage range and to allow the second direct voltage to fluctuate in order to respond to peak power needs.

Abstract: An electromechanical power transmission chain comprises an electric machine (110) mechanically connectable to a combustion engine (111) and to one or more actuators (114) to be driven, an energy-storage (118) for storing electric energy, converter equipment (115) for driving the electric machine in a torque controlled mode when transferring electric energy between the electric machine and the energy-storage, and a device (101) for producing a torque reference for the electric machine. The device produces a control value based on electric energy stored by the energy-storage so that the control value is a decreasing function of the stored electric energy, and produces the torque reference based on a difference between the control value and a control signal indicative of torque produced by the combustion engine.

Abstract: A power converter for an electric power system comprises a switching circuit (102) for supplying, in a first operating mode of the power converter, voltages for driving a rotating electric machine. The power converter comprises a contactor system (110) and a controller (109) for using, in a second operating mode of the power converter, the switching circuit and at least one of windings (115) of the rotating electric machine as a voltage-decreasing direct voltage converter between direct voltage terminals of the power converter. Therefore, the switching circuit of the power converter can be utilized both for driving the rotating electric machine and, for example, for charging a battery element connected to a direct voltage terminal of the power converter.

Abstract: A device (101) for producing a position signal indicative of rotational position of a resolver is presented. The device comprises a signal transfer interface (102) for receiving first and second alternative signals, and a processing system (103) for generating the position signal on the basis of the amplitudes of the first and second alternative signals and the polarity of an excitation signal of the resolver. The device is configurable to operate in a first operational mode where a local signal generator (104) generates the excitation signal and the device transmits the excitation signal to the resolver. The device is configurable to operate also in a second operational mode where the device receives information indicative of the polarity of the excitation signal from another device. Thus, devices of the kind described above can be used in a system where many converters are driving separate windings systems of an electrical machine.

Abstract: The invention relates to an injected laser (200) comprising an optical amplifying medium (2) arranged inside a triggered laser cavity (3), the optical amplifying medium (2) having a spectral amplifying band. According to the invention, the injected laser (200) includes an optical phase-modulation device (20), arranged between the injection source (11) and the laser cavity (3), the optical phase-modulation device (20) being configured to periodically modulate as a function of time a phase of the monochromatic continuous laser radiation (10) at a modulation frequency (fm) equal to a natural integer multiple of the free spectral range (FSR) of the laser cavity (3), so that the phase-modulated injection source generates a polychromatic injection radiation (120).

Abstract: An electromechanical power transmission chain comprises an electric machine (110) mechanically connectable to a combustion engine (111) and to one or more actuators (114) to be driven, an energy-storage (118) for storing electric energy, converter equipment (115) for driving the electric machine in a torque controlled mode when transferring electric energy between the electric machine and the energy-storage, and a device (101) for producing a torque reference for the electric machine. The device produces a control value based on electric energy stored by the energy-storage so that the control value is a decreasing function of the stored electric energy, and produces the torque reference based on a difference between the control value and a control signal indicative of torque produced by the combustion engine.

Abstract: A working machine includes a combustion engine (101), an electromechanical power transmission chain (102) between the combustion engine and one or more actuators (109) of the working machine, an electrical connector system (103) for connecting to an external electrical power network (110), and an electronic power converter (104) for transferring electrical energy from the electromechanical power transmission chain to the external electrical power network and from the external electrical power network to the electromechanical power transmission chain. The working machine can be used as an auxiliary power plant for increasing reliability and capacity of power supply. On the other hand, the working machine can be energized merely by the external electrical power network when the capacity of the electrical power network is sufficient and when it is more cost-effective to use the electrical power network than to use the combustion engine.

Abstract: An electronic power converter includes a storage circuit (101) capable of storing electrical energy that is determined by an electrical quantity, voltage or current, of the storage circuit. The electronic power converter includes an electronic power converter stage (102) connected to the storage circuit and a regulator (103) for controlling the electronic power converter stage to regulate the electrical quantity at least partly on the basis of deviation of the electrical quantity from its reference level. The regulator is configured to weight the deviation with a first gain coefficient when the deviation is positive, and to weight the deviation with a second gain coefficient when the deviation is negative. The first gain coefficient has a value different from that of the second gain coefficient because the reference level is typically not in the middle of the allowed range of variation of the electrical quantity.

Abstract: A device (101) for producing a position signal indicative of rotational position of a resolver is presented. The device comprises a signal transfer interface (102) for receiving first and second alternative signals, and a processing system (103) for generating the position signal on the basis of the amplitudes of the first and second alternative signals and the polarity of an excitation signal of the resolver. The device is configurable to operate in a first operational mode where a local signal generator (104) generates the excitation signal and the device transmits the excitation signal to the resolver. The device is configurable to operate also in a second operational mode where the device receives information indicative of the polarity of the excitation signal from another device. Thus, devices of the kind described above can be used in a system where many converters are driving separate windings systems of an electrical machine.

Abstract: A mobile working machine includes an energy source, a storage circuit for storing electrical energy, a first electronic power converter stage between the storage circuit and the energy source, an electrical machine for driving actuators, a second electronic power converter stage between the storage circuit and the electrical machine, and a control system for controlling the first electronic power converter stage responsive to the power taken by the second electronic power converter stage from the storage circuit, the control system providing a control signal path from the storage circuit to the first electronic power converter stage. The signal processing properties of the control signal path are dependent on the electrical energy stored by the storage circuit in order to allow the electrical energy to vary, but within desired limits, so as to reduce the peak power taken from the energy source.

Abstract: A working machine includes a combustion engine (101), an electromechanical power transmission chain (102) between the combustion engine and one or more actuators (109) of the working machine, an electrical connector system (103) for connecting to an external electrical power network (110), and an electronic power converter (104) for transferring electrical energy from the electromechanical power transmission chain to the external electrical power network and from the external electrical power network to the electromechanical power transmission chain. The working machine can be used as an auxiliary power plant for increasing reliability and capacity of power supply. On the other hand, the working machine can be energized merely by the external electrical power network when the capacity of the electrical power network is sufficient and when it is more cost-effective to use the electrical power network than to use the combustion engine.

Abstract: An electronic power converter includes a storage circuit (101) capable of storing electrical energy that is determined by an electrical quantity, voltage or current, of the storage circuit. The electronic power converter includes an electronic power converter stage (102) connected to the storage circuit and a regulator (103) for controlling the electronic power converter stage to regulate the electrical quantity at least partly on the basis of deviation of the electrical quantity from its reference level. The regulator is configured to weight the deviation with a first gain coefficient when the deviation is positive, and to weight the deviation with a second gain coefficient when the deviation is negative. The first gain coefficient has a value different from that of the second gain coefficient because the reference level is typically not in the middle of the allowed range of variation of the electrical quantity.