JP2005102394A - Control method for double winding ac motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control method that stably exchanges at high speed data between both inverters that control a double winding AC motor by transmission. <P>SOLUTION: The control method for the double winding AC motor drives the double winding AC motor 8 in which a first inverter power part 1 is connected to a first winding of the AC motor having double windings, and a second inverter power part 6 is connected to a second winding of the AC motor having the double windings. First and second transmission chips 4, 5 are mounted on first and second control boards 2, 3 that feed drive signals to the inverters, the transmission chips are connected with each other via a single transmission path 7, a variety of data such as a d-axis current command, a q-axis current command, a d-axis voltage command, a q-axis voltage command, a frequency command and a phase angle are set on the transmission chips at the first control board side, and transmitted to the second board side by transmission at high speed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control method for an inverter device that drives an AC motor having a double winding with two inverters.

  FIG. 6 is a block diagram of the “AC motor feeding system” disclosed in Patent Document 1, and shows an example of a multiplexing system that increases the capacity by combining a plurality of inverter devices 121 and 122. Each pole pair group U 1, V 1, W 1 and U 2, V 2, W 3 is driven by power feeding from separate inverter devices 121, 122. The conventional inverter for driving these double-winding AC motors is composed of two inverters 1 and 2 as shown in FIG. 5, and each inverter 1 and 2 is insulated from each other by the motor 8 to generate a magnetomotive force having the same phase. A method of supplying power to each of the double windings is adopted. In this method, in order to avoid the electromagnetic interference phenomenon generated between the windings, a method is adopted in which the voltage phases between the two windings are made to be the same or kept at a constant phase difference. 6, information is exchanged between the first and second control boards 2 and 3 between the first and second AI / AO circuits 9 and 10 via the analog signal circuit 11. ing.

Japanese Patent Publication No. 8-8791 (pages 2 and 3, FIG. 1)

However, the amount of information exchanged between conventional inverters usually includes a plurality of information such as a voltage command, a current command, or a frequency command, and the analog circuit for that is complicated, and adjustment of offset, drift, etc. is troublesome. Therefore, the conventional double-winding AC motor control device has a problem that a circuit for avoiding the interference phenomenon between the windings is complicated and adjustment is troublesome.
Therefore, the present invention has been made in view of such problems, and it is possible to simplify the circuit for exchanging information between inverters to avoid the interwinding interference phenomenon, and to omit the adjustment work. An object of the present invention is to provide a control device for a double-winding AC motor.

In order to solve the above-mentioned problem, the invention described in claim 1 comprises first and second inverter power units and first and second control boards for supplying gate drive signals to the respective power units. The output of the first inverter power unit is connected to the first winding of an AC motor having a double winding that is insulated from each other and generates a magnetomotive force of the same phase, and the output of the second inverter power unit is the double In the control method of a double-winding AC motor that drives and controls the double-winding AC motor connected to the second winding of the AC motor having windings, each of the first and second control boards has digital data First and second transmission chips for performing high-speed transmission are mounted, these transmission chips are connected by a single transmission path, and data exchange between the first and second inverters is performed by the transmission path. Conducted through As the data exchanged between the inverters, various data such as a d-axis current command, a q-axis current command, a d-axis voltage command, a q-axis voltage command, a frequency command, and a phase angle are calculated on the first control board side, and Transmission data calculation step set on the first transmission chip, and transmission of various data calculated in the transmission data calculation step by the CPU in the first control board by the link transmission procedure that defines the communication procedure between PCs When the high-speed data transmission step for transmitting to the second control board side and the data transmission by the high-speed data transmission step are completed, the first and second control chips respectively receive the first and second control boards. Data synchronization scan that synchronizes the shared data by simultaneously starting transmission interrupt scanning for the CPUs And a data update step in which the transmission data is reflected and updated by a control calculation of a current control scan first started by the CPU of each control board after the interrupt scan is activated in the data synchronization step. The second embodiment is characterized in that the voltage phase difference between the second inverters is adjusted to zero and the synchronous operation is performed.
According to a second aspect of the present invention, in the transmission data calculation step, the speed control scan in a speed control scan, a current control scan, and a transmission interrupt scan that the CPU in the first control board has as a control cycle. The d-axis current command, the q-axis current command, the d-axis voltage command, the q-axis voltage command, the frequency command, and the phase angle are calculated and set on the first transmission chip. It is said.
According to a third aspect of the present invention, in the high-speed data transmission step, when the various data is set on the transmission chip by the transmission data calculation step, transmission is started by the CPU in the first control board. Then, the set various data are transmitted at high speed by a link transmission procedure on the current control scan and the current interrupt scan of the transmission interrupt scan that the CPU in the second control board has as a control cycle. .
According to a fourth aspect of the present invention, in the data synchronization step, when transmission of the various data to the second control board is completed, an interrupt signal is sent to the data synchronization step from the first transmission chip. An interrupt is generated from the CPU of one control board and the CPU of the second control board from the second transmission chip, and a transmission interrupt scan is activated to ensure synchronization of both the first and second inverters. It is characterized by.
As described above, according to the control method of this double-winding AC motor, it is possible to transmit a plurality of information exchanges with a single signal line, simplify the circuit, and also provide analog-specific characteristics. Since there is no offset or drift, adjustment work can be omitted.

According to the present invention, by exchanging data between two inverters according to the link transmission procedure, the exchange circuit can be simplified to one transmission line, and the data is handled as a digital quantity. This has the effect of eliminating the trouble of adjusting the drift.
Further, since the data is updated by the interrupt process at the end of transmission, there is an effect that the data update synchronization of the two inverters can be ensured.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram of a control device to which a control method for a double-winding AC motor of the present invention is applied.
FIG. 2 is a control block diagram of the control device shown in FIG.
FIG. 3 is a transmission time chart of the CPU of the control board shown in FIG.
FIG. 4 is a flowchart of the transmission control shown in FIG.
In FIG. 1, this control device comprises two inverter power units 1 and 6 and two control boards 2 and 3 for supplying a gate drive signal to each of the power units. The outputs of the inverter power unit 1 are isolated from each other. The output of the inverter power unit 6 is connected to the second winding of the AC motor 8 having a double winding. This double winding AC motor 8 is driven and controlled. Also, transmission chips 4 and 5 are mounted on the two control boards 2 and 3, respectively. These transmission chips are connected by a single transmission line 7, and data between the two inverters 1 and 6 is transferred. The exchange is performed through the transmission path 7.
In this case, data transmission between the control board 2 and the control board 3 is performed by, for example, an “FA network between upper cells”, “a communication network between intermediate PCs (or PC links)”, “lower” Data sharing type with a high-speed internal bus by PC link (inter-CPU communication procedure, N-to-N token passing, etc.) For example, the transmission chips 4 and 5 are PC link modules, and the transmission path 7 corresponds to an FA bus, a coaxial cable, and the like.

  In FIG. 2, 12 is a speed controller, 13 is a torque limiter and outputs a q-axis current command Iqref 25, 14 is a slip frequency calculator, 15 is a q-axis current controller for the first winding, and 16 is the first volume. A d-axis current controller for line 17 is a voltage command calculator, which calculates and outputs a q-axis voltage command 28 and a d-axis voltage command 29 from a q-axis current command Iqref 25, a d-axis current command Idref 26, and a frequency command 24. Reference numeral 18 denotes a first winding phase calculator that calculates a phase by an integrator, and outputs a phase angle 27. Reference numeral 19 denotes a first winding three-phase voltage command calculator, and reference numeral 20 denotes a first winding current feedback calculator that outputs Iqfb and Idfb by coordinate conversion. 21 is a PWM signal generator for the first winding, 22 is an inverter power unit for the first winding, 23 is a speed detector, 24 is a frequency command, 25 is a q-axis current command, 26 is a d-axis current command, 27 is a phase angle, 28 is a q-axis voltage command, and 29 is a d-axis voltage command.

  On the other hand, for the second winding, 30 is a q-axis current controller for the second winding, 31 is a d-axis current controller for the second winding, 32 is a phase calculator for the second winding, Reference numeral 33 denotes a second winding three-phase voltage command calculator, reference numeral 34 denotes a second winding current feedback calculator, and reference numeral 35 denotes a second winding PWM signal generator. Reference numeral 36 denotes an inverter power unit for the second winding, and as data, a d-axis current command 26, a q-axis current command 25, a d-axis voltage command 29, a q-axis voltage command 28, a frequency command 24, and a phase angle 27 are transmitted. The operation is performed with the voltage phase difference between the two inverters set to 0 by transmitting from one inverter to the other inverter.

Next, the operation will be described with reference to the drawings.
As shown in FIG. 3, the CPU in the control board (6) for the second winding has at least a speed control scan (37), a current control scan (38), and a scan (39) activated by a transmission interrupt. There are three scans. The d-axis current command (26), q-axis current command (25), d-axis voltage command (29), q-axis voltage command (28), frequency command (24), phase angle (27) of the transmission data shown in FIG. ) Is calculated (43) by the CPU speed control scan (37) on the control substrate 2 for the first winding and set (44) in the transmission chip 4 for the first winding (FIGS. 3 and 4 Sl).
On the other hand, the CPU on the control board (3) for the second winding includes at least two scans of a current control scan (41) and a scan (42) activated by a transmission interrupt. The six control data d-axis current command (26), q-axis current command (25), d-axis voltage command (29), q-axis voltage command (28) to the transmission chip (4) for the first winding. When the setting of the frequency command (24) and the phase angle (27) (44) is completed, the transmission is started (40) by the CPU in the control board (2) for the first winding, and the link transmission (46). Then, bidirectional data transmission / reception is performed (S2 in FIGS. 3 and 4). Upon completion of data transmission / reception, the first winding transmission chip (4) transfers to the CPU on the first winding control board (2), and simultaneously the second winding transmission chip (5) transfers the second winding. The CPU on the control board (3) is interrupted, and the transmission interrupt scans (39, 42) are started simultaneously in each CPU (S3, S4 in FIGS. 3 and 4). In each transmission interrupt scan (39, 42), the six control data used in the calculation (45, 48) of the current control scan (38, 41) are updated (47, 49) (FIGS. 3 and 4). S5, S6).
As a result, the transmission data is reflected from the control calculation (45, 48) of the current control scan (38, 41) that starts first after the transmission interrupt scan (39, 42) started simultaneously in each CPU. As a result, the reflection timing of the transmission data is shifted only within the scan time of the current control scan (38, 41), so that the synchronization of the control data update (47, 49) can be ensured.

It is a block diagram of the control apparatus with which the control method of the double winding alternating current motor of this invention is applied. It is a control block diagram of the control apparatus shown in FIG. It is a transmission time chart of CPU of the control board shown in FIG. 4 is a flowchart of data transmission control shown in FIG. It is a block diagram of the conventional double winding alternating current motor control apparatus. It is a block diagram of the electric power feeding system of the conventional alternating current motor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st inverter power part 2 1st control board 3 2nd control board 4 1st transmission chip 5 2nd transmission chip 6 2nd inverter 7 Transmission path 8 Double winding alternating current motor 9 1st AI / AO circuit 10 Second AI / AO circuit 11 Analog signal circuit 12 Speed controller 13 Torque limiter 14 Slip frequency calculator 15 q-axis current controller 16 for the first winding d-axis current controller 17 for the first winding Voltage command calculator 18 First winding phase calculator 19 First winding three-phase voltage command calculator 20 First winding current feedback calculator 21 First winding PWM signal generator 22 First winding Inverter power unit 23 speed detector 24 frequency command 25 q-axis current command 26 d-axis current command 27 phase angle 28 q-axis voltage command 29 d-axis voltage command 30 q-axis current controller 31 for second winding second winding D-axis current controller 32 second winding phase calculator 33 second winding three-phase voltage command calculator 34 second winding current feedback calculator 35 second winding PWM signal generator 36 second Winding inverter power unit 37 First winding speed control scan 38 First winding current control scan 39 First winding transmission interrupt scan 40 Transmission start 41 Second winding current control scan 42 Second winding Transmission interrupt scan 43 Control data calculation 44 Control data setting 45 First winding control calculation 46 First winding / second winding link transmission 47 First winding control data update 48 Second winding control calculation 49 Second Winding control data update

Claims (4)

The first and second inverter power units and the first and second control boards that supply gate drive signals to the respective power units, and the outputs of the first inverter power units are insulated from each other and are in phase with each other. Connected to the first winding of the AC motor having a double winding for generating magnetic force, and the output of the second inverter power unit is connected to the second winding of the AC motor having the double winding. In the control method of the double winding AC motor that drives and controls the double winding AC motor,
First and second transmission chips for performing high-speed transmission of digital data are mounted on the first and second control boards, respectively, and these transmission chips are connected by a single transmission line. Data exchange between the second inverters is performed via the transmission line, and d-axis current command, q-axis current command, d-axis voltage command is transmitted on the first control board side as data exchanged between the inverters. A transmission data calculation step of calculating various data such as a q-axis voltage command, a frequency command and a phase angle and setting the first data on the first transmission chip, and the various data calculated in the transmission data calculation step A high-speed data transmission step in which transmission in the link transmission procedure stipulating the communication procedure between PCs is started from the CPU in the control board and transmitted to the second control board When the data transmission in the high-speed data transmission step is completed, the transmission interrupt scan is simultaneously started and shared by the CPUs of the first and second control boards from the first and second transmission chips, respectively. A data synchronization step for synchronizing data, and a data update step in which the transmission data is reflected and updated by a control calculation of a current control scan first started by the CPU of each control board after the start of the interrupt scan in the data synchronization step. And controlling the voltage phase difference between the first and second inverters to zero and performing a synchronous operation.   The transmission data calculation step includes the d-axis current command, the q-axis on the speed control scan among the speed control scan, current control scan, and transmission interrupt scan that the CPU in the first control board has as a control cycle. 2. The double winding according to claim 1, wherein various data such as a current command, a d-axis voltage command, a q-axis voltage command, a frequency command and a phase angle are calculated and set on the first transmission chip. AC motor control method.   In the high-speed data transmission step, when the various data is set on the transmission chip in the transmission data calculation step, the CPU in the first control board starts transmission and the CPU in the second control board The double winding according to claim 1 or 2, wherein the set various data are transmitted at high speed by a link transmission procedure on a current control scan in a current control scan and a transmission interrupt scan included in the control cycle. AC motor control method.   In the data synchronization step, when the transmission of the various data to the second control board is completed, an interrupt signal is sent to the CPU of the first control board from the first transmission chip and the second control board. 4. An interrupt is applied from the transmission chip to the CPU of the second control board, and a transmission interrupt scan is activated to ensure synchronization of both the first and second inverters. A control method for a double-winding AC motor according to claim 1.

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