Abstract:
[Problem] In a pseudo-current source inverter which drives a motor at a high speed, a current phase adjustment is assured and facilitated to perform a field-weakening control or suppress a terminal voltage saturation at a time of the high-speed motor drive.[Means For Solving Problem]A phase advance correction is carried out for a magnetic flux phase information from which a 120 degree conduction pattern is obtained with a motor terminal voltage as a reference phase. The phase advance correction includes the correction of differentiating the terminal voltage detection signals of the motor, the adjustment of enlarging the phase advance correction quantity in a case where the motor load current is large, and delays the gate signals of the 120 degree conduction pattern in accordance with the speed estimation value through a delay counter and carries out the phase advance correction as the rising edge timing of the subsequent gate signal at the subsequent step phase. Furthermore, the error correction is carried out for the phase advance correction quantity in accordance with a variation tendency of the speed estimation value and a detection value of a direct current of the inverter.
Abstract:
A motor drive device including a battery 10; switching elements 15 and 16 which are connected in series with a condenser C2 having a voltage Vdc resulting from an increase action of battery voltage and which are operated in a chopper control; a reactor L2 whose one end is connected with a common connection point of the switching elements 15 and 16; and an inverter 19 for driving a PM motor 20 which is connected between another end of the reactor L2 and a negative-pole terminal of the battery 10. In such a motor drive device, an electrical power W is determined based on the voltage Vdc of positive-side point P of the condenser C2, a current Idc flowing in the reactor L2, and a switching duty d1 of the switching element 15 which satisfies a condition of 0≦d1≦1, i.e., is determined by calculating Vdc·d1·Idc.
Abstract:
Disclosed is a current source inverter device which controls the power factor in an arbitrarily configurable manner without a magnetic pole position detector. The device is provided with a current source inverter; a motor supplied with alternating current power from the current source inverter; and a control means which detects the terminal voltage of the motor, calculates the motor's internal induced voltage and the motor current that flows in the motor based on the detected terminal voltage, and controls the current source inverter. The control means calculates the phase difference (θc) between the terminal voltage and the motor current, the phase difference (θx) between the motor current and the internal induced voltage, and the phase difference (θv) between the terminal voltage and the internal induced voltage. An adjustment angle (θα), which is the error in the phase difference between the motor current and the internal induced voltage when the set value of the phase difference (θx) is θy, is obtained from the conditional equation θα=θv−θy−θc.
Abstract:
[Task] A high-speed driving is possible, a utilization of a power supply having a low voltage is possible, and a regeneration is easy to be carried out.[Means to solve the task] A first buck-boost chopper portion is provided on an output side of a battery 10 to boost a voltage across battery 10 during a drive of a motor, a second buck-boost chopper portion is provided on an output side of the first buck-boost chopper portion to boost the voltage from an inverter portion 20 during a regeneration, inverter portion 20 of a 120-degree conduction current source inverter is provided on the output side of the second buck-boost chopper portion, and a motor 38 is provided on an output side of inverter portion 20.
Abstract:
[Problem] In a pseudo-current source inverter which drives a motor at a high speed, a current phase adjustment is assured and facilitated to perform a field-weakening control or suppress a terminal voltage saturation at a time of the high-speed motor drive. [Means For Solving Problem] A phase advance correction is carried out for a magnetic flux phase information from which a 120 degree conduction pattern is obtained with a motor terminal voltage as a reference phase. The phase advance correction includes the correction of differentiating the terminal voltage detection signals of the motor, the adjustment of enlarging the phase advance correction quantity in a case where the motor load current is large, and delays the gate signals of the 120 degree conduction pattern in accordance with the speed estimation value through a delay counter and carries out the phase advance correction as the rising edge timing of the subsequent gate signal at the subsequent step phase. Furthermore, the error correction is carried out for the phase advance correction quantity in accordance with a variation tendency of the speed estimation value and a detection value of a direct current of the inverter.
Abstract:
In a torque ripple suppression control effected by a periodicity disturbance observer, it is necessary to consider plant fluctuation and fluctuation of plant characteristics caused by over time usage. Thus, improvement for robustness to an identification model error has been required. For fulfilling this requirement, there is provided a system that includes a phase correction amount calculation portion 11 that derives a phase correction amount by calculating a phase of a vector trajectory drawn by a frequency component of the periodicity disturbance, a gain correction amount calculation portion 12 that derives a gain correction amount by calculating a progress speed of the vector trajectory drawn by the frequency component of the periodicity disturbance and comparing the calculated progress speed with a threshold value and a rotation vector calculation portion 13 that derives a system identification model correction value by multiplying the phase correction amount by the gain correction amount and corrects the system identification model of a periodicity disturbance observer portion 14 based on the system identification model correction value.
Abstract:
A periodic disturbance observer determines real part I^An and imaginary part I^Bn of an estimated current including a periodic disturbance, from value of identification identifying a system transfer function of an nth order torque ripple frequency component from a command torque to a detected torque value, with a one-dimensional complex vector having a real part P^An and an imaginary part P^Bn, a cosine coefficient TAn, a sine coefficient TBn, and the real part P^An and imaginary part P^Bn of the system transfer function; subtracts command compensating current IAn* and IBn* obtained through pulsation extracting filter GF, respectively, from the real part I^An and imaginary part I^Bn of the estimated current, and thereby determines estimated periodic disturbance current real part dI^An and imaginary part dI^Bn to cancel the periodic disturbance current.
Abstract:
[Object] The present invention provides a space vector modulation method for an AC-AC direct conversion device, which can convert input and output waveforms into sine waves and reduce the number of times of switching at an inter-sector shift.[Means to Solve] A vector state in which a line voltage of multi-phase AC output is expanded onto a two-phase static αβ coordinates is defined. Simple harmonic oscillation vector axes of a sector where an output voltage command value vector Vo* exists are defined as an X axis and a Y axis. Maximum/middle/minimum vectors in each axis, a zero vector that is an intermediate voltage of a phase voltage, and one rotation vector that is present in the sector, are set as base vectors. A switching selection pattern formed by a combination of four vectors among these vectors, which satisfies predetermined conditions, is determined by a selection means 15. On the basis of power source voltage information and output current information, an inverse matrix operation for the four vectors is executed by a duty operation means 14, and a duty solution of the four vectors is determined, then the input and output waveforms are simultaneously converted into the sine waves by the determined duties.