摘要:
A control apparatus for an AC rotary machine includes a control circuit, a power converter, a current detector, and a voltage detector. The control circuit includes: an activation current instruction unit which generates a current instruction for activation; and a start phase setting unit which sets an initial rotation phase for activation control, based on the rotation direction of the AC rotary machine just after activation and on the polarity of current detected by the current detector just after activation. Thus, the current amplitude and torque shock just after activation control is started can be reduced, and assured and stable reactivation is allowed without causing the protection operation.
摘要:
A control apparatus for an AC rotary machine includes a control circuit, a power converter, a current detector, and a voltage detector. The control circuit includes: an activation current instruction unit which generates a current instruction for activation; and a start phase setting unit which sets an initial rotation phase for activation control, based on the rotation direction of the AC rotary machine just after activation and on the polarity of current detected by the current detector just after activation. Thus, the current amplitude and torque shock just after activation control is started can be reduced, and assured and stable reactivation is allowed without causing the protection operation.
摘要:
An object is to provide a magnetic-pole position detection apparatus for synchronous machines that allows a desired accuracy of magnetic-pole position detection regardless of variation in DC voltage of a DC voltage source. Calculation means (2a) changes a pulse width (tp) and a pulse-quiescent width (tn) in accordance with a DC voltage detection value (Vdc), using a pulse width determination section (22a), such that a desired accuracy of magnetic-pole position detection can be obtained regardless of variation in DC voltage of a DC voltage source (5). The calculation means (2a) also performs control such that a sampling timing is fixed at the end point of the pulse width (tp) of voltage vectors regardless of the DC voltage detection value (Vdc).
摘要:
An object is to provide a magnetic-pole position detection apparatus for synchronous machines that allows a desired accuracy of magnetic-pole position detection regardless of variation in DC voltage of a DC voltage source. Calculation means (2a) changes a pulse width (tp) and a pulse-quiescent width (tn) in accordance with a DC voltage detection value (Vdc), using a pulse width determination section (22a), such that a desired accuracy of magnetic-pole position detection can be obtained regardless of variation in DC voltage of a DC voltage source (5). The calculation means (2a) also performs control such that a sampling timing is fixed at the end point of the pulse width (tp) of voltage vectors regardless of the DC voltage detection value (Vdc).
摘要:
An electric power conversion apparatus includes a converter 1 for rectifying ac electric power, a series-connected set, of capacitors 2A and 2B, connected to the dc side of the converter, an inverter 3 for, by setting one end of the series-connected capacitor set to a high-potential level, the other end of the set to a low-potential level, and a connection point between the capacitors to a medium-potential level, selecting any one of the levels and outputting three-phase ac, an inverter control unit 4 for controlling the inverter 3, and a voltage measurement device 8 for measuring a capacitor voltage Vdc as a voltage between both ends of the series-connected set, of the capacitors 2A and 2B; and the inverter control unit 4 further includes a beatless control unit 21 for controlling a modulation factor γ in response to the capacitor voltage Vdc, and a frequency fixing unit 22 for fixing to a command value the frequency of an ac voltage outputted from the inverter 3.
摘要:
A power converter includes: a converter (1) which rectifies an AC power; capacitor series assemblies (2A, 2B) connected to the DC side of the converter; an inverter (3) which assumes that one end of the capacitor series assemblies is at a high potential, the other end is at a low potential, and a series connection point is at an intermediate potential and selects one of the high potential, the intermediate potential, and the low potential for output of a 3-phase AC; an inverter control unit (4) which controls the inverter (3); and a voltage measuring device (8) which measures a capacitor voltage Vdc as a voltage between the both ends of the capacitor series assemblies (2A, 2B). The inverter control unit (4) has a beatless control unit (21) which controls the modulation ratio γ in accordance with a capacitor voltage Vdc and a frequency fixation unit (22) which fixes the frequency of the AC voltage outputted by the inverter (3) to an instruction value.
摘要:
A control apparatus for an AC rotating machine that can reliably and stably start up an AC rotating machine, particularly a synchronous motor using a permanent magnet, in position-sensorless vector control thereof, includes: a steady speed calculator that calculates, during steady state control of the AC rotating machine, a rotation angular frequency of the AC rotating machine based on an AC current and voltage commands; and a start-up speed calculator that calculates, during start-up control within a predetermined period after the AC rotating machine has been started up, the rotation angular frequency of the AC rotating machine based on the AC current and the voltage commands. The control apparatus corrects during the start-up control current commands so that the AC voltage amplitude of the voltage commands will be a constant value not more than the maximum output voltage of a power converter.
摘要:
A control apparatus for an AC rotating machine that can reliably and stably start up an AC rotating machine, particularly a synchronous motor using a permanent magnet, in position-sensorless vector control thereof, includes: a steady speed calculator that calculates, during steady state control of the AC rotating machine, a rotation angular frequency of the AC rotating machine based on an AC current and voltage commands; and a start-up speed calculator that calculates, during start-up control within a predetermined period after the AC rotating machine has been started up, the rotation angular frequency of the AC rotating machine based on the AC current and the voltage commands. The control apparatus corrects during the start-up control current commands so that the AC voltage amplitude of the voltage commands will be a constant value not more than the maximum output voltage of a power converter.
摘要:
A control apparatus for an AC rotary machine includes: a current detection section detecting current from a power converter to the AC rotary machine; and a control section generating a three-phase AC voltage instruction to the power converter, based on current detected by the current detection section and a torque instruction. The control section includes: an observer calculating a magnetic flux estimated value of the AC rotary machine, based on detected current and the voltage instruction; a current instruction calculation unit calculating current instruction values on rotational two axes, based on the torque instruction and the magnetic flux estimated value from the observer; and a voltage instruction calculation unit calculating the voltage instruction, based on the current instruction values from the current instruction calculation unit and the magnetic flux estimated value from the observer.
摘要:
A control apparatus for an AC rotary machine includes: a current detection section detecting current from a power converter to the AC rotary machine; and a control section generating a three-phase AC voltage instruction to the power converter, based on current detected by the current detection section and a torque instruction. The control section includes: an observer calculating a magnetic flux estimated value of the AC rotary machine, based on detected current and the voltage instruction; a current instruction calculation unit calculating current instruction values on rotational two axes, based on the torque instruction and the magnetic flux estimated value from the observer; and a voltage instruction calculation unit calculating the voltage instruction, based on the current instruction values from the current instruction calculation unit and the magnetic flux estimated value from the observer.