An electronic control circuit for electric regenerative power take-off and operation method thereof

Abstract

A control circuit for electric regenerative power take-off includes: instant voltage and current sensors for connecting to power connection of a synchronous generator for capturing a triphasic voltage and a triphasic current, respectively; voltage-based and current-based direct-quadrature (DQ) transform calculators outputting an equivalent two phase DQ tensor of a three vector triphasic voltage of the captured voltage and an equivalent two phase DQ tensor of a three vector triphasic current of the captured current, respectively; a current-based DQ controller outputting desired active-power and reactive-power voltages for the power controller; a phase-locked loop (PLL) for defining the operation angle of the power converter; processor switching between 1.sup.st and 2.sup.nd operation stages in order to engage or disengage the power converter from the synchronous generator, and to synchronize the PLL with the captured voltage using Q output from either the voltage-based DQ transform calculator or the current-based DQ controller.

Claims

1. An electronic control circuit for an electric regenerative power take-off device comprising a synchronous generator (synchronous motor), a power converter (inverter) and a power bus connecting the power converter to the generator, the circuit comprising: an instant voltage sensor connectable to the power bus for capturing the synchronous generator triphasic voltage (V_motor); an instant current sensor connectable to the power bus for capturing the synchronous generator triphasic current (I_motor); a voltage-based direct-quadrature (DQ) transform calculator arranged to output an equivalent two phase DQ-D and Q, tensor (Vd_motor, Vq_motor) of three voltage vectors of the captured triphasic voltage (V_motor); a current-based direct-quadrature, DQ, transform calculator arranged to output an equivalent two phase DQ-D and Q, tensor (Iq, Id) of three current vectors of the captured triphasic current (I_motor); a current-based direct-quadrature, DQ, controller (Id controller, Iq controller) configured to output setpoint active-power and reactive-power voltages (Vd, Vq) for the power converter from the outputted DQ tensor of the current-based DQ transform calculator; a phase-locked loop (PLL) configured to define an operation angle of the power converter and comprising a phase input; an electronic data processor arranged to switch from a 1.sup.st operation stage to a 2.sup.nd operation stage, wherein: the 1.sup.st stage comprises disengaging the power converter from the synchronous generator and synchronizing the PLL with the captured triphasic voltage by switching the PLL phase input to the voltage-based DQ transform calculator, and the 2.sup.nd stage comprises engaging the power converter from the synchronous generator and synchronizing the PLL with the captured triphasic voltage by switching the PLL phase input to the outputted DQ tensor output Q (Vq_motor) of the current-based DQ controller.

2. The electronic control circuit according to claim 1, wherein the electronic data processor is configured to set, during the 1.sup.st stage, an active-power setpoint voltage of the current-based DQ controller (Id Controller) equal to the outputted DQ tensor output D (Vd_motor) of the voltage-based DQ transform calculator and to set a reactive-power setpoint voltage of the current-based DQ controller (Iq Controller) equal to zero.

3. The electronic control circuit according to claim 1, further comprising a voltage-based DQ inverse transform calculator arranged to output an instant converter-driving voltage (V_inverter) from the PLL-defined operation angle, and from the setpoint active-power and reactive-power voltages (Vd, Vq) of the current-based DQ controller (Id controller, Iq controller).

4. The electronic control circuit according to claim 1, wherein the PLL is configured to output the operation angle to the current-based DQ transform calculator.

5. The electronic control circuit according to claim 1, wherein the electronic data processor is configured to change from the 1.sup.st stage to the 2.sup.nd stage when the outputted DQ tensor output Q (Vq_motor) of the voltage-based DQ transform calculator is below a predetermined threshold.

6. The electronic control circuit according to claim 1, wherein the electronic data processor is configured to engage or disengage the power converter from the synchronous generator by using power converter semiconductor switches that drive the synchronous generator voltage.

7. The electronic control circuit according to claim 1, wherein the instant voltage sensor comprises an analogue-to-digital converter.

8. The electronic control circuit according to claim 1, wherein the instant current sensor comprises an analogue-to-digital converter.

9. The electronic control circuit according to claim 1, wherein the phase-locked loop, PLL, comprises a control system configured to generate an output signal whose phase is related to the phase of an input signal.

10. (canceled)

11. The electric regenerative power take-off device according to claim 1, further comprising a synchronous generator (synchronous motor), a power converter (inverter) and a power bus connecting the power converter to the generator.

12. The electronic control circuit according to claim 11, wherein a vehicle traction shaft drives the synchronous generator.

13. A method for operating an electronic control circuit for an electric regenerative power take-off device comprising a synchronous generator (synchronous motor), a power converter (inverter) and a power bus connecting the power converter to the generator, the circuit comprising: an instant voltage sensor connectable to the power bus configured to capture the synchronous generator triphasic voltage (V_motor); an instant current sensor connectable to the power bus and configured to capture the synchronous generator triphasic current (I_motor); a phase-locked loop (PLL) to define an operation angle of the power converter and comprising a phase input; an electronic data processor; the method comprising, using the electronic data processor: calculating a voltage-based direct-quadrature (DQ) transform to output an equivalent two phase DQ-D and Q, tensor (Vd_motor, Vq_motor) from three voltage vectors of the captured triphasic voltage (V_motor); calculating a current-based DQ transform calculator to output an equivalent two phase DQ-D and Q, tensor (Iq, Id) from three current vectors of the captured triphasic current (I_motor); using a current-based DQ controller (Id controller, Iq controller) for outputting setpoint active-power and reactive-power voltages (Vd, Vq) for the power converter from the outputted DQ tensor of the current-based DQ transform calculator; switching from a 1.sup.st operation stage to a 2.sup.nd operation stage, wherein: the 1.sup.st stage comprises disengaging the power converter from the synchronous generator and synchronizing the PLL with the captured triphasic voltage by switching the PLL phase input to the voltage-based DQ transform calculator, and the 2.sup.nd stage comprises engaging the power converter from the synchronous generator and synchronizing the PLL with the captured triphasic voltage by switching the PLL phase input to the outputted DQ tensor output Q (Vq_motor) of the current-based DQ controller.

14. A non-transitory storage medium comprising computer program instructions for implementing an electronic control circuit for electric regenerative power take-off, the computer program instructions including instructions which, when executed by a processor, cause the processor to carry out the method of claim 13.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The following figures provide preferred embodiments for illustrating the disclosure and should not be seen as limiting the scope of invention.

[0052] FIG. 1: Schematic representation of an embodiment of the system for dynamic electric regenerative power take-off comprising a synchronous generator (or motor, interchangeably), a power converter and electronic control circuit according to the prior art (1a) and according to the disclosure (1b).

[0053] FIG. 2: Schematic data flow representation of an embodiment of a system for dynamic electric regenerative power take-off comprising an electrical detector of frequency and angle of the synchronous generator (or motor, interchangeably) with DQ transform and PLL, arranged to connect the synchronous motor when motor-fed Vd is the same of the converter connections.

[0054] FIG. 3: Schematic data flow representation of an embodiment of a system for dynamic electric regenerative power take-off comprising an electrical detector of frequency and angle of the synchronous generator (or motor, interchangeably) with DQ transform and PLL, arranged to connect the synchronous motor when motor-fed Vd is the same of the converter connections.

[0055] FIG. 4: Schematic data flow representation of an embodiment of a system for dynamic electric regenerative power take-off comprising an electrical detector of frequency and angle of the synchronous generator (or motor, interchangeably) with DQ transform and PLL, with the synchronous motor already connected to the converter.

DETAILED DESCRIPTION

[0056] The present disclosure relates to a system for dynamic electric regenerative power take-off from a vehicle traction shaft, in particular a wheel axle or a transmission shaft, for a vehicle propelled by an internal combustion engine or for a trailer vehicle being towed by a tractor vehicle, comprising a synchronous electrical generator for coupling the vehicle traction shaft and an electrical converter for converting the generated AC power into DC power and controlling output voltage and current, and an operation method thereof, in particular for synchronizing a generator phase angle with a converter state of said system.

[0057] The present disclosure relates to an inverter voltage synchronisation mechanism for synchronous motors, eliminating the need for an encoder to find the motor position and speed.

[0058] In an embodiment, synchronous motors have internal voltage proportional to its speed (commonly known as back EMF). This voltage can be measured at the terminals of the motor if no load is applied to it.

[0059] In an embodiment, if the motor is connected to an inverter, this voltage can only be read when the inverter is idle (not switching).

[0060] In an embodiment, for intermittent inverter operation (either tractioning or regenerating), this solution makes it possible for the inverter to connect to the motor at any point of the motor operation.

[0061] In an embodiment, sensorless operation of synchronous machines is wide-spread, as is the use of voltage syncing algorithms (specially for grid-synced operation).

[0062] The electronic control circuit described in the present disclosure bridges both and enables the seamless transition from one mode to the other, even when the motor is already spinning.

[0063] In an embodiment, a DQ frame PLL used for syncing an inverter to the grid has the function of aligning the inverter's angle with the angle of the grid, so that the q component is near zero. In FIG. 2, the grid is replaced by a synchronous generator, which behaves exactly the same if the motor has sinusoidal output. For other motor outputs the PLL should be modified. On the other hand, a sensorless control of a motor uses the voltage from the inverter itself (Vq) to feed the PLL (see FIG. 4).

[0064] In an embodiment, FIG. 3 shows that algorithm bridges both states, so that the transition is seamless.

[0065] In an embodiment, before turning on the transistors, the output/integrators of the current controllers is tampered so that the output of Iq controller equals zero and the output of Id controller equals Vd_motor.

[0066] In an embodiment, on the moment the transistors start operation, Vq is fed to the PLL instead of Vq_motor and both current controllers start operating as usual.

[0067] The term comprising whenever used in this document is intended to indicate the presence of stated features, integers, steps, components, but not to preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0068] Flow diagrams of particular embodiments of the presently disclosed methods are depicted in figures. The flow diagrams illustrate the functional information one of ordinary skill in the art requires to perform said methods required in accordance with the present disclosure.

[0069] It is to be appreciated that certain embodiments of the disclosure as described herein may be incorporated as code (e.g., a software algorithm or program) residing in firmware and/or on computer useable medium having control logic for enabling execution on a computer system having a computer processor, such as any of the servers described herein. Such a computer system typically includes memory storage configured to provide output from execution of the code which configures a processor in accordance with the execution.

[0070] The code can be arranged as firmware or software, and can be organized as a set of modules, including the various modules and algorithms described herein, such as discrete code modules, function calls, procedure calls or objects in an object-oriented programming environment. If implemented using modules, the code can comprise a single module or a plurality of modules that operate in cooperation with one another to configure the machine in which it is executed to perform the associated functions, as described herein.

[0071] The disclosure should not be seen in any way restricted to the embodiments described and a person with ordinary skill in the art will foresee many possibilities to modifications thereof. The above-described embodiments are combinable. The following claims further set out particular embodiments of the disclosure.