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EP-4318936-B1 - ROTATING ELECTRICAL MACHINE CONTROL DEVICE

EP4318936B1EP 4318936 B1EP4318936 B1EP 4318936B1EP-4318936-B1

Inventors

  • SAHA, SUBRATA
  • NISHIMURA, KEISUKE
  • KAWAMURA, Kyohei

Dates

Publication Date
20260506
Application Date
20220208

Claims (5)

  1. A rotating electrical machine control device (10), which drives and controls a rotating electrical machine (8) by performing switching control of a plurality of switching elements (3) constituting an inverter (30) that is connected to a DC power supply (4) and is connected to the rotating electrical machine (8) to convert power between DC and multiple-phase AC, and comprises at least asynchronous pulse-width modulation control and synchronous five-pulse control as control systems of the inverter (30), the asynchronous pulse-width modulation control being a control system in which the switching elements (3) are controlled by a plurality of switching pulses output based on a carrier that is not synchronized with rotation of the rotating electrical machine (8), the synchronous five-pulse control being a control system in which the switching elements (3) are controlled by the switching pulses output five times in one cycle of an electrical angle in synchronization with the rotation of the rotating electrical machine (8), and based on operation regions set by a relationship between torque and a rotational speed of the rotating electrical machine (8), the control system of the inverter (30) being selected, wherein a five-pulse region, which is an operation region where the synchronous five-pulse control is selected, is set on a side where the rotational speed of the rotating electrical machine (8) is higher and the torque is larger than in a PWM region, which is an operation region where the asynchronous pulse-width modulation control is selected, characterized in that a region boundary between the five-pulse region and the PWM region has a first boundary (K21) and a second boundary (K22), the second boundary (K22) is set on a side where the rotational speed of the rotating electrical machine (8) is higher and the torque is larger than at the first boundary (K21), when an operating point defined by the relationship between the torque and rotational speed of the rotating electrical machine (8) changes from a state in which the asynchronous pulse-width modulation control is being executed, and crosses the second boundary (K22), the control system is shifted from the asynchronous pulse-width modulation control to the synchronous five-pulse control, when the operating point changes from a state in which the synchronous five-pulse control is being executed, and crosses the first boundary (K21), the control system is shifted from the synchronous five-pulse control to the asynchronous pulse-width modulation control, the second boundary (K22) is set such that the number of the switching pulses per unit rotational speed by the asynchronous pulse-width modulation control immediately before the operating point crosses the second boundary (K22) is smaller than the number of the switching pulses per the unit rotational speed by the synchronous five-pulse control immediately after the operating point crosses the second boundary (K22), and the first boundary (K21) is set such that the number of the switching pulses per the unit rotational speed by the synchronous five-pulse control immediately before the operating point crosses the first boundary (K21) is smaller than the number of the switching pulses per the unit rotational speed by the asynchronous pulse-width modulation control immediately after the operating point crosses the first boundary (K21).
  2. The rotating electrical machine control device (10) according to claim 1, wherein the first boundary (K21) and the second boundary (K22) are set such that an interval between the first boundary (K21) and the second boundary (K22) becomes longer as a DC link voltage, which is a voltage on a DC side of the inverter (30), becomes higher.
  3. The rotating electrical machine control device (10) according to claim 1 or 2, wherein in the inverter (30), an arm for one AC phase is configured by a series circuit of an upper stage side switching element and a lower stage side switching element, in order not to cause the switching pulse for the upper stage side switching element and the switching pulse for the lower stage side switching element of the same arm to be simultaneously in an effective state that causes the switching element to make a transition to an on-state, a dead time, when both the switching pulses are in a non-effective state, is provided, and dead time compensation, for compensating for a decrease in an actual modulation rate due to the dead time with respect to a command value of a modulation rate indicating a power conversion rate between DC and AC, can be executed, the dead time compensation is executed when the operating point is in the PWM region, while the dead time compensation is not executed when the operating point is in the five-pulse region, and a region, where the dead time compensation is not executed even when the operating point is the PWM region, is set closer to the first boundary (K21) than to the second boundary (K22).
  4. The rotating electrical machine control device (10) according to claim 3, wherein a compensation value in the dead time compensation is set, as moving from the first boundary (K21) side to the second boundary (K22) side, to gradually become smaller as the modulation rate becomes larger.
  5. A rotating electrical machine control device (10), which drives and controls a rotating electrical machine (8) by performing switching control of a plurality of switching elements (3) constituting an inverter (30) that is connected to a DC power supply (4) and is connected to the rotating electrical machine (8) to convert power between DC and multiple-phase AC, and comprises at least asynchronous pulse-width modulation control and synchronous five-pulse control as control systems of the inverter (30), the asynchronous pulse-width modulation control being a control system in which the switching elements (3) are controlled by a plurality of switching pulses output based on a carrier that is not synchronized with rotation of the rotating electrical machine (8), the synchronous five-pulse control being a control system in which the switching elements (3) are controlled by the switching pulses output five times in one cycle of an electrical angle in synchronization with the rotation of the rotating electrical machine (8), and based on operation regions set by a relationship between torque and a rotational speed of the rotating electrical machine (8), the control system of the inverter (30) being selected, wherein a five-pulse region, which is an operation region where the synchronous five-pulse control is selected, is set on a side where the rotational speed of the rotating electrical machine (8) is higher and the torque is large than in a PWM region, which is an operation region where the asynchronous pulse-width modulation control is selected, characterized in that the asynchronous pulse-width modulation control is a discontinuous pulse width modulation control and the control system is switched between the asynchronous pulse-width modulation control and the synchronous five-pulse control, wherein the control system is switched for each phase of the multiple-phase AC at a region boundary between the five-pulse region and the PWM region, the asynchronous pulse-width modulation control and the synchronous five-pulse control at the region boundary are modulation systems including a fixed period (θf) in which the switching element is fixed to an on-state or an off-state for each phase of the multiple-phase AC, the control system is switched in the fixed period (θf) in the control system after being switched to or is switched at a time point when a voltage waveform of each of the multiple-phase AC intersects with an amplitude center of the voltage waveform, and in a case where the multiple phases are N phases, N being a natural number of 2 or more, the switching of the control system in each phase is performed by differentiating by every n/N or 2n/N in terms of an electrical angle for switching the switching pulse.

Description

TECHNICAL FIELD The present invention relates to a rotating electrical machine control device that drives and controls a rotating electrical machine by performing switching control of a plurality of switching elements constituting an inverter that is connected to a DC power supply and is connected to the rotating electrical machine to convert power between DC and multiple-phase AC. BACKGROUND ART As disclosed in JP 2006-81287 A (Patent Literature 1), asynchronous modulation control that is not synchronized with rotation of a rotating electrical machine and synchronous modulation control that is synchronized with the rotation of the rotating electrical machine are known as control systems when the rotating electrical machine is driven and controlled via an inverter. Generally, the asynchronous modulation control is executed in an operation region where the rotational speed of the rotating electrical machine is low, while the synchronous modulation control is executed in an operation region where the rotational speed is high. A typical example of the synchronous modulation control is one-pulse control (rectangular wave control) in which one pulse is output in one cycle of an electrical angle, and a typical example of the asynchronous modulation control is so-called pulse-width modulation control. When the control system is switched between the asynchronous pulse-width modulation control and the one-pulse control, a shock may be caused in the rotating electrical machine due to harmonic components included in the pulse in the one-pulse control. Therefore, when the control system is switched from the asynchronous pulse-width modulation control to the one-pulse control, the control system is switched to the one-pulse control through five-pulse control and three-pulse control in which harmonic components are fewer than in the one-pulse control. In this method, however, it is necessary to generate many modulation patterns, such as one pulse, three pulses, and five pulses, in the synchronous modulation control, and there is a possibility that the control becomes complicated and the cost of the rotating electrical machine control device may be increased. Therefore, in Patent Literature 1, synchronous one-pulse control and synchronous five-pulse control are provided as the synchronous modulation control, and the rotating electrical machine control device is simplified. In combination with the asynchronous modulation control, the rotating electrical machine control device can switch the control system from the asynchronous modulation control to the synchronous one-pulse control through the synchronous five-pulse control, and can switch the control system from the synchronous one-pulse control to the asynchronous pulse-width modulation control through the synchronous five-pulse control. CITATION LIST PATENT LITERATURE Patent Literature 1: JP 2006-81287 A Document JP 2017 - 005810 A discloses a rotary electric machine control device, which has asynchronous modulation in which modulation pulse is in asynchronous with rotation of a rotary electric machine, and a synchronous modulation in which modulation pulse is in synchronous with rotation of the rotary electric machine. In accordance with an operating condition including rotating speed of at least a rotary electric machine, the rotary electric machine control device switches a modulation system during a transient period prescribed on the basis of a voltage phase indicating relations among three phase AC voltages. The transient period is set to a period of a voltage phase, in which the signal level of one phase among the three phase AC voltages is fixed to a high or low level and, during the period in which the signal level of this one phase is fixed, two phase modulation is brought about, in which the signal levels of the other two phases change. SUMMARY OF INVENTION TECHNICAL PROBLEMS Here, a case, where the control system is switched between the asynchronous pulse-width modulation control and the synchronous five-pulse modulation control, will be considered. In the asynchronous pulse-width modulation control, a pulse is generated based on a carrier independent of the rotational speed of the rotating electrical machine. When it is assumed that n pulses are generated in one cycle of the electrical angle of the rotating electrical machine at a certain rotational speed and when the rotational speed is doubled, the one cycle of the electrical angle of the rotating electrical machine is halved, and thus the number of generated pulses is n/2. That is, the resolution of the carrier is lowered with respect to the electrical angle. For example, while the rotating electrical machine is performing a regenerative operation, and when the rotational speed of the rotating electrical machine decreases and the control system is switched from the synchronous five-pulse control to the asynchronous pulse-width modulation control, pulses are generated in synchronization with the rotation o