JP2000217367A - Current control circuit, inverter controller, inverter and power converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure high reliability by sealing the conductive part of the backward loop of feedback from a current detector to a summing point hermetically without exposing to the outer atmosphere. SOLUTION: An encoder 2 is built in an AC servo motor 1 while combining a pole position sensor 2-1 and a rotational position sensor 2-2 for the rotor of the AC servo motor 1 compositely wherein a current control section 7 and a PWM control section 8 constitute a forward loop. A current detector 11 for the AC servo motor 1 detects a current from the lower arm of an inverter main circuit and delivers a signal to a current detecting circuit 10. It is negative fed back at a summing point 12-3 and a rearward current feedback loop is constituted. Signal conductive parts of the forward and rearward loops of a current feedback loop are enclosed so that they do not touch the outer air. Since short circuit with an adjacent lead terminal is eliminated, reliability can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor driving device for driving a motor, and more particularly, to a motor driving device for detecting a motor current and implementing a feedback control therein to determine a position, a speed, a current, a torque and the like. The present invention relates to a motor driving device suitable for control.

[0002]

2. Description of the Related Art With the development of microprocessors, motor control devices used in general industrial machines have shifted from conventional analog control to digital control using a microcontroller. Components used for printed circuit boards are also changed from transistors to integrated circuit ICs (Integrated Cir
cuit), and then switched to a medium-scale integrated circuit MSI, a large-scale integrated circuit LSI, and a very large-scale integrated circuit VLSI.
The use of ICs (Application Specific ICs), custom LSIs, gate arrays, and the like according to customer specifications has led to the miniaturization of control devices. The package of these digital ICs has been further downsized by being surface-mounted on a printed circuit board. In addition, as the high-density integration of these ICs has progressed, the number of lead terminals (number of pins) of the IC has exceeded 100 pins, and the pitch of the lead terminals has been reduced from the conventional 2.54 mm to a half pitch. 1.27 mm, also called 1.27.
Those having a pitch of 00 mm, 0.8 mm, and 0.75 mm are used. More recently, 0.5 mm pitch lead packages have been used. In accordance with this, the conductor pattern interval of the printed circuit board is also 2.54m.
In recent years, a design has been promoted in which one conductor pattern is passed between one pin and three pins or three or more pins are passed between m lead pitches, and high mounting as a printed circuit board is progressing.

On the other hand, as a power source for performing variable speed operation of general industrial machines, a speed sensorless vector control for driving an induction motor, which is an AC motor by an inverter, and a vector control with a speed sensor are used. AC servo motors with built-in position and speed sensors for processing machines, assembling machines, textile machines, looms, robots, and the like have been actively used in processing and assembling sites due to demands for automation and labor saving. These basic controls are position, speed, current, and torque control.Recently, demands for faster line speed and faster tact time have led to vector control of induction motors, in which the motor current is reduced by a torque component proportional to the torque. High-speed current control is performed by separating the current into a magnetic flux and a current perpendicular to the torque. Also AC
In the case of a servo motor, a rotating field synchronous motor that uses a permanent magnet for the rotor performs high-speed current control by detecting the position of the permanent magnet with a magnetic pole position detector. Controls instantaneous values.

[0004] The place where these AC motor control devices are installed is in a control panel installed near a motor at an assembly site or a processing site, and the surrounding environment includes cut metal scraps, cutting oil, and a tire processing plant. In this case, dust containing carbon processed tires floats, and in textile factories and loom factories, cotton dust is floating. These dusts and cotton dust gradually adhere to the printed circuit board in the control device. At the loom factory, the water jet method, in which the weft yarn of an automatic loom that knits the warp and weft yarns, uses water to handle water, so the surrounding humidity increases, and as the temperature rises and falls, condensation forms on the motor control circuit printed circuit board. . An integrated circuit is mounted on the printed board, and the above-described components having a narrow lead pitch are mounted. For this reason, carbon-containing dust and cotton dust adhering to the printed circuit board over a long period of time cover the leads of the integrated circuit.

[0005] The operation of the AC motor is started every morning in the morning, and the temperature inside the control panel rises with the operation, and the operation is stopped at night, the temperature inside the control panel falls, and the outside temperature also falls. As a result, the air in the control panel warmed during the day increases in humidity and condenses at night with dust containing carbon and cotton dust adhering to the printed circuit board at a critical temperature or lower. The next day, at the start of the morning operation, if electricity is supplied in a state of condensation with dust and cotton dust, an electrical short may occur between the leads of the integrated circuit. This occurs frequently in the rainy season when the humidity is high, but in the case of a water jet type loom that uses water, it occurs regardless of the season. For this reason, the motor control circuit malfunctions, and in some cases, the semiconductor element of the inverter main circuit may be damaged.

Next, the lead terminals of the integrated circuit mounted on the printed circuit board of the AC servo motor control circuit for controlling the position, speed, current, and torque are adjacent to the lead terminals due to the adhesion of dust and cotton dust and condensation. Describe the effect of a short between two leads. FIG.
FIG. 1 shows a control block diagram of an AC servo motor according to a conventional embodiment. 1 is an AC servo motor, 2 is an encoder that combines a magnetic pole position sensor 2-1 for detecting the magnetic pole position of the rotor of the AC servo motor and a rotational position sensor 2-2 for detecting the rotational position of the AC servo motor. And built in the AC servo motor. 3
Is position control, 5 is speed control, 7 is current control, 8 is PWM
(Pulse Width Modulation) The control operation unit forms a forward loop. 4 is a position counter circuit, 6 is a speed calculation circuit, and 10 is a current detection circuit, which constitute a backward loop of a position, speed and current feedback loop, respectively. Reference numeral 9 denotes a magnetic pole position calculation circuit that inputs the magnetic pole position sensor 2-1 and the rotation position sensor 2-2 of the rotor of the AC servo motor 1 and calculates a magnetic pole position. Reference numeral 13 denotes an inverter main circuit including a driver for driving the switching element and a control power supply circuit for the driver. Among them, the inverter main circuit is mounted in a power module molded with a resin such as an epoxy resin. 11 is a current detector, A
The current flowing through the C servo motor is detected and fed back to the current detection circuit 10. In addition, 12-1 to 12
-3 is an addition point for adding the command signal and the feedback signal. With a sign, + means addition and-means subtraction. In the figure, the command signal is + and the feedback is-, so that a negative feedback feedback circuit is formed.

The control circuit of the AC servo motor is mounted on a logic printed circuit board 19 and includes a microprocessor C
PU, ROM (Read Only Memory), RAM (Random A)
ccess memory), an A / D converter (analog / digital converter), various LSIs, and electronic components such as interface components, and is shown in a range surrounded by a frame 19 in FIG. The pitch of the lead terminals of the components used in these components is a high-density package of about 0.5 to 0.8 mm.

Here, three types of feedback loops of position, speed, and current (or torque) are formed, and the responsiveness of each feedback loop generally becomes faster as the loop is formed inside. Thus, a stable control system with less overshoot and undershoot is configured. In the case of speed control, the response is set four to six times higher than the position control response, and the current control response is set four to six times higher than the speed control response. Therefore, when software processing is performed by the microprocessor CPU, the current operation loop is generally the fastest in the software operation cycle, then the speed feedback loop, and the position feedback is generally the slowest processing.

FIG. 15 shows an embodiment of a general external protection mode, which is an AC servomotor 1, an encoder 2, and an external protection device 18 provided outside the AC servomotor control device 20. When the AC servo motor malfunctions, a protection system suitable for the machine is installed with a device for ensuring the safety of workers. These sensors include an acceleration sensor 14, an over-speed sensor 15, and right and left edge sensors 16 attached to both ends of the operating range. If the operating range of the specified machine is exceeded, the signals from these sensors are input to the protection processing circuit 17 for preventing runaway, and the AC servomotor is stopped. Further, safety measures such as turning off the main circuit power supply and further operating a mechanical brake are performed by the external protection device 18. Generally, AC servo motor 1, encoder 2, and AC servo motor controller 20
Are manufactured by electric manufacturers as general-purpose products, and set makers purchase these electric products and perform mechanical design, and install an external protection system for the entire system including electric and mechanical devices.

FIG. 16 shows an internal circuit diagram of an embodiment of a power module used in a conventional AC servomotor control device. The AC power supply is connected to the R, S, and T terminals, and is converted from AC to DC by the diode rectifier 43. A current limiting resistor (not shown) is connected to the terminals PP and P1 outside the power module, and a smoothing capacitor (not shown) is connected between the terminals P1 and N to limit the rush current flowing through the smoothing capacitor when the AC power is turned on. Limit with resistance. The DC voltage smoothed by the smoothing capacitor is applied to the switching element S
The antiparallel circuit of u, Sv, Sw, Sx, Sy, Sz (such as a power transistor) and diodes Du, Dv, Dw, Dx, Dy, Dz is 6
AC is output by applying on / off control of a base or a gate of each switching element, which is applied to an inverter circuit 45 configured as a set, and an AC servo motor (not shown) connected to output terminals U, V, W Drive.
The energy regenerated from the AC servomotor is stored in a smoothing capacitor connected between P1 and N, and together with a discharge resistor connected between P1 and BR terminals (not shown) when the DC voltage rises, together with a regenerative braking circuit. The switching element 44 is turned on, and the regenerative energy is consumed by the discharge resistor. The gate inputs of the seven switching elements of the regenerative braking circuit and the inverter circuit are supplied from a driver circuit external to the power module. This gate terminal G
U, EU, GV, EV, GW, EW and GX, GY, G
Z, GB, and E are power modules 22 shown in FIG.
As shown in (1), the lead terminals are thin and are arranged at a narrow pitch. On the other hand, the main circuit terminal is a thick lead terminal, the space between the main circuit terminals is wide, and the dust passes through. The lead terminals penetrate the main circuit printed circuit board according to the terminal position of the power module 22 and are electrically connected by soldering. The lead pitch of the gate terminals of the main circuit printed circuit board is the same. When power is supplied in a dew condensation state with dust and cotton dust just like the lead pitch of an integrated circuit, a short circuit may occur between the leads of the gate terminal of the power module.

FIG. 17 is an exploded structural view of an embodiment of a conventional AC servo motor control device. Reference numeral 22 denotes the power module described with reference to FIG. 19 is a logic printed board, and 23 is a main circuit printed board. 24 is a power module 22
And a cover covering the two printed circuit boards 19 and 23. The cover has a ventilation hole 39 so that the air heated in the apparatus can be discharged to the outside by natural air cooling. The main circuit connector 26 attached to the main circuit printed circuit board 23 and the logic printed circuit board 19
Are provided with through holes 40, 41, and 42 for letting the input / output connector 37 and the encoder connector 38 attached to the outside.

The logic printed circuit board 19 corresponds to 1 in FIG.
The figure shows the components mounted in the frame surrounded by 9, one microprocessor (CPU) 31 for controlling and calculating the position, speed, current (torque), etc., and the current of the AC servo motor from analog. A / D converter 32 for converting to digital, gate array 33, ROM (Read Only)
Memory) 34, interface IC 35, RAM (Ra
ndom Access Memory) 36 and the like.

The main circuit printed circuit board 23 includes a current limiting resistor between the P-P1 terminals of the output of the diode rectifier 43 for converting an AC to a DC, a smoothing capacitor 25 connected between the P1-N terminals, and an AC servo motor 1. The main circuit components such as two current detectors 11 for detecting the current of the power supply are mounted. The switching transformer 27 and the switching power supply IC 29 constituting the control power supply circuit and the signal output from the PWM control A drive circuit driven by the driver IC, an interface IC 30 for exchanging an interface with the main circuit, and the like are mounted. As described above, various integrated circuit components are mounted on the logic printed board 19 and the main circuit printed board 23 in FIG.
These IC, LSI, VLSI, gate array, ASI
A high-density package having a lead pitch of about 0.5 to 0.8 mm is adopted for C.

Next, the operation in the case where the lead terminals of an integrated circuit mounted on a printed circuit board are short-circuited between adjacent lead terminals due to the adhesion of dust and cotton dust and dew condensation will be described. When adjacent lead terminals are short-circuited, the adjacent lead terminals may be at a logic power supply of 5 V (fixed to a high level H potential), a common 0 V (fixed to a low level L potential), another It may be a signal line (H potential and L potential mixed), but simply a logic power supply 5V (fixed to H potential)
And the common 0 V (fixed to the L potential).

In general, the operation when the signal of the automatic control loop having feedback is short-circuited to the common 0 V line will be examined. In FIG. 14, addition point 1
When the position feedback signal θf, the speed feedback signal Nf, and the current feedback signal If of the backward signals, which are the negative feedback signals of 2-1 to 12-3, are short-circuited to the 0 V line of the common potential, the command signals θref and Nref are provided. , Iref, actual position, speed, current
Feedback control works so that (torque) follows the command value.

First, when the position feedback signal .theta.f of the position control loop is short-circuited to the 0V line, it is determined that it has actually reached the position but has not reached the command position, and accelerates. However, since the position feedback signal is short-circuited to the 0V line, the normal position is not fed back, and acceleration continues to run away. However, if the current control loop is operating normally, the current of the AC servomotor is limited to the maximum value or less, and the external protection device 1
8, the AC servo motor 1, the encoder 2, and the AC servo motor controller 20 are not damaged.

Next, when the speed feedback signal Nf of the speed control loop is short-circuited to the 0V line, it is determined that the speed has actually reached the speed but not reached the command speed, and the speed is increased. However, since the speed feedback signal is short-circuited to the 0V line, the normal speed is not fed back and the speed continues to increase, resulting in runaway. Again,
If the current control loop is operating normally, the current of the AC servo motor is limited to the maximum value or less, and the AC servo motor 1, the encoder 2, and the AC servo motor controller 2
0 is not damaged.

Next, when the current feedback signal If of the current control loop is short-circuited to the 0 V line, it is determined that the current actually reaches the current but does not reach the command current, and increases instantaneously. However, since the current feedback signal is short-circuited to the 0V line, the normal current does not feed back and continues to increase, instantaneously exceeding the maximum current, becoming an overcurrent, and there is no time for the AC servo motor to accelerate, thus protecting the overcurrent detection circuit. The operation is performed, the switching element of the inverter main circuit shuts off the base, and the AC servo motor controller 20 trips. At this time, a large current flows through the switching element of the power module 22 up to a saturation current determined by the current amplification factor of the switching element, and the overcurrent detection circuit operates to shut off. At this time, the temperature inside the switching element is rising,
If the operation is repeated in a state where the internal temperature has not decreased, the switching element is damaged by thermal fatigue.

The response time in the position control loop and the speed control loop is the acceleration / deceleration time for the actual machine to move. The acceleration / deceleration time is the inertia moment of the AC servo motor and the inertia of the machine converted into the motor shaft. It is proportional to the sum of moments and inversely proportional to the difference between motor torque and load torque. Therefore, the response is slow due to the moment of inertia of the machine. As described above, in order to construct a stable control system with less overshoot and undershoot,
The responsiveness is a current loop, a speed loop, and a position loop in the descending order. Therefore, the response time of the position loop and the speed loop is designed to be slower than the response time of the current loop. For this reason, acceleration sensors, overspeed sensors,
With the right and left edge sensors attached to both ends of the operating range so as not to deviate from the operating range, detection and protection were possible without time delay. For example, the set maker is electricity,
External protection device 18 for the whole system including the machine
The acceleration sensor 14, the over speed sensor 15, which is installed on the machine side, the right edge sensor and the left edge sensor 16 attached to both ends of the operating range,
Since it prevented runaway and secured the safety of human life and protected the machine, it was possible to protect the AC servo motor.

The operation in the case where the signal in the loop is short-circuited to the 5 V line at which the signal in the loop becomes H level in the feedback system will be examined.

The position feedback signal θf, speed feedback signal Nf, and current feedback signal If added at the minus points of the addition points 12-1 to 12-3 are H level 5
When a short circuit occurs at the V line, that is, at the maximum value in the positive direction, feedback control is performed so that the actual position, speed, and current (torque) follow the command signals θref, Nref, and Iref according to the command values.

First, in the position control loop, since the maximum positive position is fed back even though it has actually reached the designated position, it is determined that the vehicle has gone too far, and acceleration is performed in the reverse direction. However, the position feedback signal is H level 5V
Due to the short circuit, the regular position is not fed back and continues accelerating in the reverse direction and runs away.

Next, in the speed control loop, although the speed actually reaches the command speed, the speed exceeds the command speed, it is determined that the speed has reached the maximum speed, the speed is reduced, and the speed is further accelerated in the reverse direction.
However, since the speed feedback signal is short-circuited to the 5V line, the normal speed is not fed back, and the vehicle continues to accelerate in the reverse direction, resulting in a runaway state. However, as in the case where the feedback signal is short-circuited to the 0V line, if the current control loop is operating normally, the current of the AC servo motor is limited to the maximum value or less. AC servo motor controller 2
0 is not damaged. Further, an external protection device 18 for the entire system is manufactured, and the runaway is performed by the acceleration sensor 14, the overspeed sensor 15, and the right edge sensor and the left edge sensor 16 attached to both ends of the operation range installed on the machine side. Prevention and ensuring the safety of human life,
Since the protection of the machine is performed, the protection of the AC servomotor can be performed.

Next, in the current control loop, although the current has actually reached the command current, it is determined that the current has reached the maximum current, and the current decreases instantaneously, and still increases beyond the negative maximum current on the opposite polarity side. I do. However, since the current feedback signal is short-circuited to the 5V line, the normal current is not fed back, but continues to increase to the negative side and instantaneously becomes an overcurrent. If this is repeated, the switching element is instantaneously damaged due to thermal fatigue.

The magnetic pole position sensor 2 of the encoder 2
-1 and disconnection of the output line to the rotational position sensor 2-2 and the AC servo motor controller 20 are detected by
JP-A-44262 discloses a method of using a pulse encoder that outputs both a reference pulse and an inverted pulse obtained by inverting the reference pulse. Disconnection was detected by sum. Thereby, the encoder 2 and A
The disconnection of the encoder output line with the C servo motor control device 20 is detected instantaneously at the same time as the disconnection, so that the machine cannot run out of control.

Next, the addition points 12-1 to 12- in FIG.
The case where the loop is short-circuited to the L level and the H level on the forward loop side from 3 will be described.

When the outputs of the position control calculator 3 and the speed control calculator 5 are short-circuited to the L level, the speed command Nref and the current command Iref become zero. When the output of the position control calculator 3 is short-circuited, the speed of the AC servomotor is reduced and stopped. Further, when the output of the speed control calculation unit 5 is short-circuited, the AC servomotor is free-run and is not damaged.

Next, when a short circuit occurs at the H level, the speed command Nref and the current command Iref go to the H level. When the output of the position control calculation unit 3 is short-circuited, the motor is operated at the maximum speed. When the output of the speed control calculation unit 5 is short-circuited, the maximum current flows and the AC servomotor accelerates, but the external protection device 18 can work to protect. .

Next, the output of the current control unit 7 is at L level,
Consider the case of shorting to a level. If the output of the current control unit 7 is short-circuited to the L level, a free run is performed.
When short-circuited to the H level, the voltage command becomes maximum, the current exceeds the maximum current, and an overcurrent occurs, causing a trip. At this time, the temperature inside the switching element is rising, and if the internal temperature is not lowered, the switching element is damaged due to thermal fatigue.

When a short circuit occurs between the pins at the output of the PWM control calculation unit 8, the PWM signal normally turns on and off the upper arm switching element and the lower arm switching element alternately. The short circuit between the smoothing capacitors causes an arm short circuit. In this case as well, the switching element is damaged by thermal fatigue when repeated.

As described above, the position control loop and the speed control loop have the lead terminals of the integrated circuit on the printed circuit board where dust and cotton dust adhere and condensate. As a result, even if a short circuit occurs, the AC servo motor is controlled to the maximum current or less. Power module is not damaged. If the printed circuit board dries, it may operate normally again. However, in the current control loop, dust and cotton dust adhere to the leads of the integrated circuit, and as a result of condensation, the maximum current is instantaneously exceeded, and if this is repeated, the power module will be damaged by thermal fatigue. For this reason, only the current control loop is most sensitive to power module damage, and if installed in a bad environment and condensed, there is a significant risk of damage.

According to JP-A-6-169578, since a printed circuit board is mounted on a power module and is not hardened by epoxy or the like, an IC
There is a possibility that dust and cotton dust will adhere between the lead terminals and cause dew condensation. For this reason, a portion with a narrow lead pitch is not sufficiently protected against short-circuit. Also, according to Japanese Patent Application Laid-Open No. 9-229772, position control, speed control, and current control are processed by a microprocessor CPU, and since current feedback data runs in a data bus of another loop, dust and cotton dust are removed. When dew adheres to the microprocessor CPU, A / D converter, or printed circuit board and forms dew, a short circuit occurs because the pitch of the lead terminals or the interval between conductor patterns on the printed circuit board is narrow. No consideration was given to this.

[0033]

SUMMARY OF THE INVENTION In the case of general industrial machines,
A control panel containing an AC servo motor control device is installed near a production site or a processing site. Even if it has a dustproof structure to prevent dust and cotton dust from entering the control panel,
If the control panel door is opened during regular inspections and periodic inspections, dust and cotton dust will adhere to the logic board and main circuit board of the AC servo motor control device in the control panel if the operation is started for a long time. come. In the rainy season when the humidity increases, dew condensation may occur on the printed circuit board. Therefore, even in such a case, failures such as breakage of the AC servo motor control device that cannot be recovered are eliminated, and a highly reliable product is manufactured.

In this case, the purpose is not to be damaged, and if it is not damaged, safety can be ensured by the external protection circuit even if an abnormality occurs in the operation of the machine. If the condensation dries,
In addition, since the device operates normally, if the external protection operation is activated, the device can be returned to the original operation if the dust and cotton dust are removed and cleaned.

[0035]

Means for Solving the Problems As means for solving these problems, the conductive portion of the backward loop of the feedback from the current detector to the summing point is sealed without contacting the outside atmosphere. As one of the methods, it is mounted in a power module made by molding with a resin such as an epoxy resin, and sealed so that dust and cotton dust are not exposed to the outside. Therefore, the current detector is detected inside the power module.

From the summation point of the current control to the gate terminal of the switching element,
Seal without touching the outside atmosphere. One method is to mount a conductive part of the forward loop from the current control addition point to the gate terminal of the switching element in a power module made by molding with a resin such as epoxy resin, and remove dust and cotton dust. Seal so as not to be exposed to the outside. By sealing in this way,
Gate terminals GU, EU, GV, EV, GW, EW and G
Since the terminals of X, GY, GZ, GB, and E can be handled as signals inside the power module, it is not necessary to provide these terminals as terminals coming out of the power module. Therefore, it is no longer necessary to provide the lead terminals at a narrow pitch on the gate terminals standing at a narrow pitch and the printed circuit board corresponding to the gate terminals, and the problem of short-circuit due to dust and cotton dust is eliminated.

In the conventional centralized control in which the position control, the speed control, the current control, and the interface processing are concentrated on one microprocessor, the current loop cannot be separated. Therefore, in the present invention, the distributed processing is performed by dividing the current loop and the other position control, speed control, and interface processing into two parts. Therefore, the current control loop including the current feedback is constituted by another sub-microprocessor and both are mounted in a power module made by molding with a resin such as an epoxy resin.

The system clock signals of the main and sub microprocessors are not shared, but are individually owned for decentralization.

Further, as a preferred embodiment of the present invention, in order to reduce the number of control signal input / output terminals of the power module, a signal of serial communication is transmitted between the main microprocessor and the sub microprocessor in the power module. Send and receive data to minimize the number of input / output terminals. The input and output are separated from each other by a signal at which the power module is not damaged even if the lead terminals are short-circuited, that is, by a current command (Iref). In addition, a current command limiter is provided for the current command,
Even if an excessive voltage is input, it should be less than the maximum current value.

Further, as a preferred embodiment of the present invention, the magnetic pole position data is such that a signal outputted from an encoder is received by a main microprocessor and transferred to a power module by serial communication. The control operation cycle of the sub-microprocessor of the current control loop is calculated earlier than the position, speed, and interface processing cycles. Therefore, the magnetic pole position data is interpolated by the sub-microprocessor at the calculation cycle faster than the main microprocessor cycle. And current control is performed.

[0041]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention can be widely applied to a motor drive device having a current control loop in a control circuit. For the sake of simplicity, first, an embodiment of an AC servo motor control device will be described in detail. explain.

FIG. 1 shows the overall configuration of the AC servo motor control device, and FIG. 2 shows the internal configuration of the power module 122.
Shown in 1 is an AC servo motor, 2 is an encoder built in the AC servo motor, and the encoder 2 has a magnetic pole position sensor 2-1 and a rotation position sensor 2-2.

Reference numeral 31-2 denotes a main microprocessor (CP
In U), position control and speed control of the AC servo motor 1 and exchange with an external interface are performed. The external interface circuit 68 includes an analog input / output interface (AIO) 69, a digital input / output interface (DIO) 70, a serial communication interface (SIO) 67, and the encoder 2. There is an encoder interface circuit 66 for inputting the second signal. A ROM (Read Only M) is provided around the main microprocessor 31-2.
emory) 34, RAM (Random Access Memory) 36,
There is a nonvolatile memory (EEPROM) 58 and the like. The switching power supply circuit 65 receives a control power supply from outside, controls a logic power supply such as the main microprocessor 31-2, a control power supply for an analog circuit, an encoder power supply supplied to an encoder, and a power module logic supplied to a logic circuit of the power module 122. Supply 15V power. Note that the digital input / output interface 70 and the serial communication interface 67 are insulated from the logic circuit of the main microprocessor 31-2 for noise suppression. Power module logic power supply 15V, 0V
Has the same common as the N potential from the inverter circuit, and is electrically insulated from other power supplies. The transmission and reception of signals between the main microprocessor 31-2 and the power module 122 are performed by serial communication, and the serial communication synchronous clock SCK and the first serial data RXD are transmitted from the main microprocessor 31-2 to the power module 122 through the inverter gate 59. Transmits the power module 122 to the main microprocessor 31-2,
Is the serial communication synchronous clock S
The signal is received through the inverter gate 59 in synchronization with CK. These serial data are electrically insulated by the photocoupler 63 in the power module and transmitted.

The P, N1, N,
The smoothing capacitor 25, the current limiting resistor 48, and the discharging resistor 49 connected to the BR terminal constitute a part of a main circuit outside the power module.

FIG. 2 shows the detailed configuration of the power module 122.
Will be described.

The three-phase AC power supply is connected to the R, S, and T terminals, and is converted by a diode rectifier 43 from AC to DC.

A current limiting resistor 48 is connected to the terminals N1-N, and a smoothing capacitor 25 is connected between the PN terminals. The rush current flowing through the smoothing capacitor 25 when the AC power is turned on is limited by the current limiting resistor 48. Restrict. After the charging of the smoothing capacitor 25, the thyristor 50 is fired to short-circuit the current limiting resistor 48, and is turned on. Smoothing capacitor 25
DC voltage smoothed by the switching elements Su, Sv, S
An inverter circuit 45 is configured using six antiparallel circuits of w, Sx, Sy, Sz and diodes Du, Dv, Dw, Dx, Dy, Dz,
AC servo motor 1 connected to output terminals U, V, W
Drive.

The energy regenerated from the AC servo motor is temporarily stored in a smoothing capacitor 25 connected between P and N, and when the DC voltage rises to a certain voltage, the switching of the regenerative braking circuit 44 is performed. The element is turned on, and is consumed by the discharge resistor 49 connected between the P-BR terminals.

The regenerative braking circuit 44 converts the PN voltage into a resistance R
1, the voltage is divided and detected by R2, the voltage / frequency conversion is performed by the V / F converter 54, and the converted voltage is input to the sub-microprocessor 31-1.
/ F converter 54 voltage / frequency relationship and resistors R1, R
The DC voltage is known from the relationship of the division ratio of 2. When the DC voltage rises to a certain voltage, the sub-microprocessor 31-1 sends an ON signal to the regenerative braking drive circuit 60 to make the switching element of the regenerative braking circuit 44 conductive. When the regenerative energy is consumed by the discharge resistor 49 and the PN voltage drops, the sub microprocessor 31-1 outputs an off signal to the regenerative braking drive circuit 60.

The current of the AC servo motor 1 is supplied to the current detecting shunt resistors SH1, S1 on the N side of the inverter circuit 45.
It is detected by the voltage between both ends of H3. This voltage is amplified by the amplifiers 52-1 and 52-2, and the two A / D (analog / digital) converters 3 with sample hold are provided.
At 2-1 and 32-2, they are converted into digital signals at the same time. This digital data is alternately passed through the sub-microprocessor 31- through the D-type flip-flop 57.
Serial transfer to 1 and input. The A / D conversion timing, the data select, and the output of the serial synchronization clock signal are performed by the sub microprocessor 31-1. The sub microprocessor 31-1 is the main microprocessor 3
1-2, the current command data Iref and the two A /
It calculates from the values detected by the D converters 32-1 and 32-2, calculates the difference from the current feedback If (Iref-If), performs the current control calculation and the PWM control calculation, and supplies the driver IC 28 with the data for six. It outputs a PWM signal. The driver IC 28 performs level conversion of the gate signals of the six switching elements of the inverter circuit, and drives the switching elements of the inverter circuit 45.

The protection circuit 53 of the inverter main circuit section includes upper and lower arms formed by an overvoltage detection OV between the inverter DC voltages PN, an undervoltage detection UV between PN, and shunt resistors SH1, SH2, SH3 for detecting the current of the inverter. The switching element overheat OH is detected by detecting the overcurrent OC and the temperature rise near the switching element and output to the sub microprocessor 31-1. Sub microprocessor 31-1
In response to these detections, the driver IC 28
Emergency cutoff of the M signal causes a free run, and then the alarm content is reported to the main microprocessor 31-2. The nonvolatile memory 58 stores the winding resistance, inductance, induced voltage constant, output, rating and maximum rotation speed, maximum torque, number of poles of the AC servo motor 1, the number of poles, the proportionality of encoder resolution and current control, the integration constant, and the like as a power supply. This data is used to store the data even when the power is turned off. When the power is turned on next time, these data are read and used for normal control.

In communication with the main microprocessor 31-2, the serial communication synchronous clock SCK and the first serial data RXD are received by the photocoupler 63 while being electrically insulated. Second, such as alarm data and status monitor
Is transmitted through the inverter gate 59 and the photocoupler 63 in synchronization with the serial communication synchronous clock SCK.

When the serial communication synchronization clock SCK is fixed at the “L” level, the clock synchronization signal abnormality detection circuit 47 detects the abnormality by measuring the time, and shuts off the output of the inverter circuit. The control power supply abnormality detection circuit 7
2 is a control power supply 15V, 5V, 0V in the power module
, The sub-microprocessor 31-1 is reset and the seven switching elements of the inverter circuit 45 and the regenerative braking circuit 44 are turned off.

FIG. 3 shows an embodiment of an AC according to the present invention.
FIG. 2 shows a control block diagram of a servo motor control device.

The difference from the control block diagram of FIG.
2 and a speed / position control system included in the frame 119. The main microprocessor 31-2 performs the operations of the position control 3 and the speed control 5 in the frame of 119, the processing of the position counter 4, the speed operation circuit 6, and the magnetic pole position operation circuit 9, and executes the current command Ire.
f, the magnetic pole position signal data and the like are transferred to the power module 122 by serial communication.

The sub microprocessor 31-1 in the power module 122 includes a current control 7, a PWM control 8,
The current detection circuit 10 and the current command limiter 71 share control of the current control loop of the AC servo motor 1. Then, the switching element of the inverter main circuit 13 is driven. Further, it sends monitor data of the alarm / status monitor circuit 46 and the like to the main microprocessor 31-2.

Next, FIG. 4 illustrates a current detection time chart according to the present invention.

FIG. 4A shows the U-phase motor current of the output of the inverter circuit 45 in FIG. 2 (the positive direction of the current is indicated by the arrow Iu in FIG. 1). The motor current detecting shunt resistor SH1 is inserted between the lower arm switching element and the N terminal. At the timing when the switching element of the lower arm of the positive half cycle of the U-phase motor current is turned on, the current does not flow through the switching element of the lower arm, but the current flows through the diode connected in parallel with the switching element. A current flows upward through the shunt resistor SH1 from the N side. At the timing when the lower half-cycle switching element of the U-phase motor current is turned on, a current flows through the lower-arm switching element. At this time, a current flows downward to the N side in the current detection shunt resistor SH1. Flows. The voltage across the current detecting shunt resistor SH1 is shown in FIG. The voltage between both ends is amplified by the amplifier 52-1 and is converted to the A / D converter 32.
-1 is input. The A / D converter has a built-in sample-hold circuit, and FIG. 4C shows the output waveform of the sample-hold circuit inside the A / D converter 32-1. Although the above description has been made for the U phase, the same applies to the W phase. As can be seen from FIG. 4, the motor current can be detected by sampling and holding with the current detecting shunt resistor of the lower arm.

Next, FIG. 5 shows a time chart of A / D converter current detection according to the present invention, with reference to the internal configuration diagram of the power module shown in FIG.

FIG. 5A shows the sub microprocessor 31-.
1 to the A / D converters 32-1 and 32-2.
It shows a waveform that outputs the conversion start signal CONV. The CONV signal is output in synchronization with a carrier frequency for generating a PWM signal, and the A / D converters 32-1 and 32-2 sample and hold the signals of the amplifiers 52-1 and 52-2 at the same time with the rising signal. Then, the A / D conversion is started upon completion of the sample hold. During the A / D conversion, as shown in FIG. 5B), the BUSY signal is output from the A / D converters 32-1 and 32-2, and the two signals are ORed by the OR gate 56. The fact that conversion is in progress is transmitted to the sub microprocessor 31-1. When the conversion is completed, the BUSY signal goes to L level, and the sub-microprocessor 31-1 receives the select signals SEL1 (select the A / D converter 32-1) and SEL2 (A / D) in order to receive data from each A / D converter. The D converter 32-2 is supplied with the selection signal) alternately as shown in c) and d) of FIG. Next, the sub microprocessor 31-
Numeral 1 outputs a synchronous clock signal SCLK, takes a logical product of the above-mentioned select signal and the AND gate 55, and sends it to each A / D converter. A / D converters 32-1 and 32-2
Is synchronized with the synchronous clock signal SCLK, and f) in FIG.
As shown in g), the digitally converted current data is sent to the D-type flip-flop 57 as a serial signal,
The timing is output to the SDATA terminal of the sub microprocessor 31-1 at the same timing. The digitally converted current data is selected by the select signals SEL1 and SEL2, and the U-phase current data and the W-phase current data are arranged in this order (h in FIG. 5).
And the data transfer is completed.

FIG. 6 is a timing chart showing serial communication between the main and sub microprocessors according to the present invention, with reference to FIG. Assuming that the speed control calculation cycle of the main microprocessor 31-2 is tasr and the current control calculation cycle of the sub-microprocessor 31-1 is tacr, the current control calculation tacr performs faster processing. This was mentioned earlier. Also,
The system clocks of the main microprocessor 31-2 and the sub-microprocessor 31-1 are operated by different crystal oscillators in order to perform distributed processing, and each processing is of an asynchronous system. The serial communication synchronous clock SCK is output from the main microprocessor 31-2 to the sub microprocessor 31-1 as shown in FIG. When data is not transmitted, the standby state is at H level, and the first serial data RXD of FIG. 6B is transmitted in synchronization with the serial communication synchronization clock SCK during the oscillation state.

On the other hand, in the sub-microprocessor 31-1, the A / D converters 32-1 and 32-3 for current detection described above are used.
2-2, the A / D conversion start signal CO as shown in FIG.
NV is output in synchronization with the carrier frequency. The current command Iref sent from the main microprocessor 31-2,
The transfer time of the magnetic pole position data of the AC servo motor takes time to transfer the data, and is represented by a delay time td in FIG. Therefore, the data update reflected by the sub microprocessor 31-1 is after the delay time td. In the current command data Iref, as shown in FIG.
Current control operation cycle tacr of sub microprocessor 31-1
Uses the same data until the data is updated.

Next, since the magnetic pole position detection data is updated at intervals of tasr by the main microprocessor 31-2, the current control operation cycle of the sub microprocessor 31-1 is changed.
Need to recalculate to tacr. In e) of FIG. 6, the magnetic pole position data is not used with the same data until the data is updated by the main microprocessor 31-2.
In the figure, it is obtained by interpolation with a straight line. Specifically, time t1-0
When the data was updated in, the previous t0-0 and the current t1-0
Extend the straight line connecting the data of each time t1-1, t1-2, t1-3
The data is interpolated and controlled as shown by black circles. Similarly, when the data is updated at the time t2-0, a straight line connecting the data of the previous t1-0 and the data of the current t2-0 is extended, and as shown at each time t2-1 ... Is controlled by interpolation.

As described above, the magnetic pole position data indicates that the motor is constantly rotating, so even when the motor is accelerating or decelerating,
Assuming that the vehicle is accelerating and decelerating at the same inclination as the previous time, if the control is finely controlled, the vehicle can be operated more smoothly.

Also, the feedback of the magnetic pole position signal and the rotation position signal of the encoder is fed back not to the power module but to the speed and position control side, so that the serial communication with the power module requires a minimum number of I / O terminals. Because of the configuration, the reliability against dust and cotton dust adhesion and corrosion is greatly improved.

Note that ts is a value representing a calculation time delay for converting the magnetic pole position data into a calculation cycle of the sub microprocessor 31-1.

FIG. 7 shows an AC according to an embodiment of the present invention.
FIG. 2 shows an exploded structural view of the servo motor control device.

Reference numeral 122 denotes a power module, a backward loop, a forward loop, and a current control feedback loop.
Sub-microprocessor 31-1, driver IC 28, current detection A / D converter 32, current command limiter, etc.
-1, 32-2 are built-in. Its internal configuration is shown in Fig. 2.
As shown in FIG. The power module is mounted on the cooling fins 21 and the generated heat can be radiated to the outside by natural cooling with the cooling fins.
The printed circuit board 119 includes a main microprocessor 31-2,
ROM 34, RAM 36, serial communication interface 67 nonvolatile memory 58, IC such as analog input / output interface 69, LSI and smoothing capacitor 25, switching transformer 27, main circuit connector 26 for connecting AC power supply and motor output, input / output connector 37, The encoder connector 38 and the like are mounted. These parts are the parts except the power module 122 shown in FIG.
Performs position and speed control calculations. A cover 124 covers the power module 122 and the logic printed board 119. The cover has a ventilation hole 139 so that the air heated in the apparatus can be discharged to the outside by natural air cooling. Further, through holes 140, 141 and 142 for opening the main circuit connector 26, the input / output connector 37, and the encoder connector 38 attached to the logic printed circuit board 119 to the outside are provided in the front. As described above, the power module 122 incorporates a current control loop including an IC, an LSI, a gate array, and the like having a narrow lead pitch, and is sealed so as not to be exposed to an external atmosphere.

FIG. 8 shows an embodiment A according to the present invention.
2 shows a structure of a power module of the C servo motor control device. The power module 122 uses a metal base 75 that also functions as a heat radiator, forms an insulating layer (not shown) thereon, and then forms an inverter main circuit 45 including a switching element and a diode thereon and the shunt resistors SH1 to SH1 for current detection. SH3, regenerative braking circuit 44, diode rectifier 43, thyristor 50, voltage dividing resistors R1, R2, etc. are mounted, and power module logic printed circuit board 73 is further mounted.
Is implemented inside. In FIG. 8, the arrangement of components is indicated by broken lines. Further, these are subjected to insulation sealing with a mold resin or an equivalent product. The components shown in the frame of the power module 64 in FIG. 2 are mounted on the power module logic printed board 73. Terminals on the mold resin are denoted by the same reference numerals as the reference numerals attached to the terminals in the frame 122 in FIG. The module 122 is used by being attached to the cooling fins 21 of the inverter device through the attachment holes 74.

FIG. 9 is a control block diagram of an AC servo motor control device according to another embodiment of the present invention. The current control loop of the power module 122 is the same as that of FIG. 3, but the logic printed circuit board 119 has a torque control configuration instead of a position control and a speed control.

When controlling the tension of the winder, torque control of the AC servo motor is required. FIG. 9 shows that the torque command Tref of the AC servomotor is transferred from the main microprocessor 31-2 to the sub microprocessor 31-1 by serial communication, and the power module 122 controls the current.

1 is an AC servo motor, 2 is an encoder, a magnetic pole position sensor 2-1 for detecting the magnetic pole position of the rotor of the AC servo motor, and a rotational position sensor 2-2 for detecting the rotational position of the AC servo motor. It is built into the AC servo motor. Reference numeral 7 denotes a current control, and 8 denotes a PWM (Pulse Width Modulation) control calculation unit, each of which forms a forward loop. 1
Reference numeral 1 denotes a current detector for detecting the current of the AC servo motor 1, which detects the current from the lower arm of the inverter main circuit. This signal is sent to 10 current detection circuits, and 12-3
The negative feedback is fed back at the point of addition, and constitutes a backward loop current feedback. The details are shown in FIG.
6 and the description is omitted. A speed calculation circuit 6 monitors the speed of the AC servo motor 1. 9 is A
Magnetic pole position sensor 2-1 of rotor of C servo motor 1
And a rotation position sensor 2-2 to calculate a magnetic pole position. Reference numeral 79 denotes a runaway prevention circuit, which includes a comparison circuit 80 and a limiter circuit 81. The characteristic of the limiter circuit 81 is the torque-speed characteristic shown in FIG. 10, and the output Tb is zero in the section from the rotation speed N1 to the rotation speed N2 which is the torque control range.
4 has no effect.

When the load torque is smaller than the torque command Tref, for example, when the winding speed is out of the range of N1 to N2 when the winding machine runs out of control due to running out of material during tension control of the winding machine, The comparison circuit 80 operates, switches to proportional speed control, operates as a speed limiter, and prevents runaway.

FIG. 11 is a control block diagram of a speed sensorless vector inverter according to another embodiment of the present invention. An induction motor 84 has no speed sensor. The power module 122 has two current control loops. The current control loop controls the current that contributes to the torque, and the flux current control that is orthogonal to the current control.
It is calculated by -2. 8-1 is a vector synthesis PWM control circuit for performing PWM control by vector synthesis of the outputs of the torque current control and the magnetic flux current control, which are sent to the driver 13, control power supply circuit and inverter main circuit. The current detection is the same as in FIG. 9, but the current feedback is the torque current component It.
It is converted into a DC amount of the orthogonal component of f and the magnetic flux current component Imf.
Each DC feedback current is calculated at the summation point 12-
At steps 3 and 12-5, two current commands output from the current command limiter 71, that is, a torque current command It and a magnetic flux current command Im are compared to form negative feedback control. These controls are performed by the sub-microprocessor 31-1, and operate in accordance with commands from the main microprocessor 3-2 from the logic printed circuit board 119. The primary angular frequency ω1 of the input of the magnetic flux control circuit 83 depends on the torque current control 7− of the power module 122.
1 and is transferred by serial communication. ω1
Calculates the magnetic flux current command Im in the magnetic flux control circuit 83 and transfers it again to the power module 122 by serial communication. On the other hand, in the slip angular frequency calculation circuit 82, the power module 1
At 22, the torque current feedback Itf output from the current detection circuit 10-1 is transferred by serial communication, a slip angular frequency ωs proportional to the torque current feedback Itf is output, and a difference from the primary angular frequency ω1 is calculated. The feedback ωr = ω1−ωs is calculated. The difference between the speed command ωref and the speed feedback ωr is calculated at the addition point 12-6, and the speed control calculation is performed at 5-1. This output is transferred to the power module 122 by serial communication as a torque current command It, and the speed sensorless vector control is configured.

FIG. 12 is a diagram showing the internal configuration of a power module of a power-supply-side converter control device according to another embodiment of the present invention. When the power is turned on, the current from the power source passes from the AC power sources R, S, and T through the current limiting resistor RS, the harmonic absorption reactor ACL0, and the power coordination reactor ACL1,
It is rectified by the diode of the power supply side converter main circuit 151 and charges the smoothing capacitor 25. Smoothing capacitor 25
After charging is completed, the electromagnetic contactor Mg is turned on, and thereafter, power is supplied through the electromagnetic contactor Mg.

Next, the switching elements Su, Sv, Sw, Sx, Sy, Sz of the power supply side converter main circuit 151 receive the on / off signals from the gate terminals GU, GV, GW, GX, GY, GZ, and perform the PWM switching. Is started, the boost control is performed so that the PN output voltage becomes a constant voltage, and power is supplied from the power sources R, S, T to the loads P, N. Conversely, even when power is regenerated from the load side P, N to the R, S, T side through the power supply side converter main circuit 151, the P-N
The regenerated power is returned to the power supply, that is, a regenerative operation is performed so that the inter-voltage becomes a constant voltage.

At this time, the terminals R-1 and S-
1, the AC current of T-1 is detected by the current transformer CT, and the current feedback is performed. In this embodiment, similarly to FIG. 2, the current detecting shunt resistor on the N side of the power source converter main circuit 151 is used. It is detected by the voltage between both ends of SH1 and SH3. The current detection is the same as the time chart of FIG. 4 and the A / D converter current detection time chart of FIG. 5, and the power module 150 has a built-in current feedback circuit. In the AC servo motor, the magnetic pole position is detected by the encoder by the main microprocessor 31.
In the alternative, the power supply voltage phase is determined by the main microprocessor 31-2 and interpolated and determined by the sub microprocessor 31-1.

FIG. 13 shows an overall configuration diagram of a power supply side converter control device according to an embodiment of the present invention. As the load, the AC servo motor controller 155,
The AC servo motor 1 is connected, and the DC voltage between PN is controlled to a constant voltage. In FIG.
In the case of the C servo motor, the speed and the position are fed back by the encoder feedback. However, in the power converter control device, the power converter main circuit 1 is used.
The output 51 outputs the voltage across the smoothing capacitor 25 as feedback.

In the above embodiment, the AC servo motor control device in which the input / output of the power module is a three-phase AC has been described. The present invention can be similarly applied to the case of the same control device even in the case of the phase exchange. Further, the present invention can be similarly applied to an inverter device having a control system in which current control and other speed control are mixed even if it is not an AC servo motor control device (AC servo motor control device is also a kind of inverter device). Further, the present invention can be similarly applied to DC power receiving in which the diode rectifier 43 is unnecessary. Further, the present invention can be similarly applied to a case where a DC motor is driven by a DC output in which the inverter circuit 45 is replaced with a chopper circuit.

The embodiment of the present invention shown in FIGS.
It shows an embodiment, and it is needless to say that the present invention is not limited to this and can be changed without departing from the spirit of the invention.

The present invention exhibits a great effect in an environment where the amount of dust and cotton dust is high and the humidity is high, but the insulation between the conductors is deteriorated by a long-term use even in such a severe environment. This can be prevented by the present invention, so that the present invention can be widely applied to a general environment.

The above description has described that when the current control system malfunctions due to the influence of dust, cotton dust, etc., a serious accident or the like is caused, and it is important to improve the reliability of this portion. According to the above embodiment, the following effects are also obtained. That is, when the position or speed feedback control loop is changed to a control method that includes a request from the user or the like or a control control method (for example, an auto-tuning method in vector control) is changed, FIG. It is necessary to change the storage contents of the ROM 34 and the EEPROM 58 as storage means and other control circuit configurations. On the other hand, such a change hardly occurs in the current control control system and the main circuit. Therefore, if the current control system is integrated only or the current control system and the main circuit are integrated and modularized, the current control system can be used in common even if a change occurs in the upper level of the current control system. Therefore, there is an effect that it becomes suitable for mass production.

Further, according to the above-described embodiment, an upper-level dedicated CPU which is responsible for software which is a low-speed task but emphasizes functions such as overall management and usability, and a high-speed task software which realizes a high-speed response of current control. A dedicated CPU for current control and a dedicated CPU
The processing in the current control loop assigned to the current control dedicated CPU is modularized separately from the part,
Serial data is transmitted between U and the CPU dedicated to current control. This serial data transmission portion is composed of DC data (generally excitation (d-axis) and torque (q-axis) obtained as vector control internal signals from each phase data (three-phase data) for a conventional three-phase AC motor. D-q axis two-phase)
However, in the case of a permanent magnet type synchronous motor, since the excitation component is not controlled, Id = 0 and only one phase of the q-axis can be used, and the number of data is reduced. And serial transmission. Therefore, according to the above embodiment, the data transmission interface between the module in which the current control system is integrated and the upper-level dedicated CPU is greatly simplified, and the number of data transmission signals is reduced. There is also an effect that electrical insulation between a certain upper portion and a module portion having a current control dedicated CPU can be easily performed. This is more advantageous when, for example, a part of the controller 122 is integrated into a module to form an interface with another part (for example, between the position control system and the speed control system).

[0084]

As described above, according to the present invention, since the signal conductive portions of the forward loop and the backward loop of the current feedback loop do not come into contact with the outside air, there is no short circuit with the adjacent lead terminal. Further, since the current command is provided with a current limiter, the current command is limited to a maximum value or less even if an excessive input or short circuit occurs in the command input terminal, and the switching element of the inverter circuit is not damaged. Therefore, product reliability is greatly improved.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an AC servo motor control device according to an embodiment of the present invention.

FIG. 2 is an internal configuration diagram of a power module of an AC servo motor control device according to an embodiment of the present invention.

FIG. 3 is a control block diagram of an AC servo motor control device according to an embodiment of the present invention.

FIG. 4 is a current detection time chart according to the present invention.

FIG. 5 is an A / D converter current detection time chart according to the present invention.

FIG. 6 is a time chart of serial communication between the main and sub microprocessors according to the present invention.

FIG. 7 is an exploded structural view of an AC servo motor control device according to an embodiment of the present invention.

FIG. 8 shows a structure of a power module of an AC servo motor control device according to an embodiment of the present invention.

FIG. 9 is a control block diagram of an AC servo motor control device according to an embodiment of the present invention.

FIG. 10 is a speed torque characteristic diagram for explaining an embodiment according to the present invention.

FIG. 11 is a control block diagram of a speed sensorless vector inverter according to an embodiment of the present invention.

FIG. 12 is an internal configuration diagram of a power module of a power supply-side converter control device according to an embodiment of the present invention;

FIG. 13 is an overall configuration diagram of a power supply-side converter control device according to an embodiment of the present invention;

FIG. 14 is a control block diagram of an AC servo motor according to one embodiment of the related art.

FIG. 15 shows an embodiment of a general external protection mode.

FIG. 16 is an internal circuit diagram of a power module of an AC servo motor control device according to a conventional embodiment.

FIG. 17 is an exploded structural view of an AC servo motor control device according to a conventional embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... AC servo motor, 2 ... Encoder, 2-1 ... Magnetic pole position sensor, 2-2 ... Rotation position sensor, 3 ... Position control calculation part, 4 ... Position counter circuit, 5 ... Speed control calculation part, 5-1 ... Speed control calculation unit, 6 Speed calculation circuit, 7
Current control calculation section, 7-1 ... torque current control calculation section, 7-
2: magnetic flux current control calculation unit, 8: PWM control calculation unit, 8-
DESCRIPTION OF SYMBOLS 1 ... Vector synthesis PWM control calculation part, 9 ... Magnetic pole position calculation circuit, 10 ... Current detection circuit, 10-1 ... Current detection circuit, 1
1. Current detector, 12-1, 12-2, 12-3, 12
-4,12-5,12-6,12-7 ... adding unit, 13 ...
Driver, control power supply circuit and inverter main circuit, 14 ...
Acceleration sensor, 15 ... Over speed sensor, 16 ...
Right and left edge sensors, 17 ... Protection processing circuit, 18 ...
External protection device, 19: logic printed circuit board, 20: A
C servo motor control device, 21 ... cooling fin, 22 ...
Power module, 23 ... main circuit printed circuit board, 24,
124 cover, 25 smoothing capacitor, 26 main circuit connector, 27 switching transformer, 28 driver IC, 29 switching power supply IC, 30 main circuit interface IC, 31 microprocessor, 31
-1 ... Sub microprocessor, 31-2 ... Main microprocessor, 32 ... A / D converter, 32-1 ... U phase A
/ D converter, 32-2 ... W-phase A / D converter, 3
3 gate array, 34 ROM, 35 interface IC, 36 RAM, 37 input / output connector, 38
... Encoder connector, 39 ... ventilation hole, 40 ... main circuit connector through hole, 41 ... input / output connector through hole, 42 ... encoder connector through hole, 43 ... diode rectifier, 4
4 ... Regenerative braking circuit, 45 ... Inverter circuit, 46 ... Alarm / status monitor circuit, 47 ... Clock synchronization signal abnormality detection circuit, 48 ... Current limiting resistor, 49 ... Discharge resistor, 50
... thyristor, 51 ... temperature detector, 52-1 ... amplifier 1, 52-2 ... amplifier 2, 53 ... protection circuit, 54 ... V /
F converter, 55 AND gate, 56 OR gate, 57 D flip-flop, 58 non-volatile memory, 59 inverter gate, 60 drive circuit for regenerative braking, 61 thyristor drive circuit, 62 logic power supply circuit 63, photo coupler, 64, power module internal control circuit, 65, switching power supply circuit, 66
... Encoder interface circuit, 67 ... Serial communication interface circuit, 68 ... External interface circuit, 69 ... Analog input / output interface circuit, 7
0: digital input / output interface circuit, 71: current command limiter, 72: control power supply abnormality detection circuit, 73: power module logic printed circuit board, 74: mounting hole,
75: metal base, 79: runaway prevention circuit, 80: comparison circuit, 81: limiter circuit, 82: slip angular frequency calculation circuit, 83: magnetic flux control circuit, 84: induction motor, 119 ...
Logic printed circuit board, 120: AC servo motor control device, 122: power module, 139: ventilation hole,
140: through hole of main circuit connector, 141: through hole of input / output connector, 142: through hole of encoder connector, 150
... Power module, 151 ... Power supply converter main circuit, 152 ... Power module internal control circuit, 153 ...
Power supply side converter control circuit, 155: AC servo motor control device, R1 to R3: resistor, SH1 to SH3: shunt resistor for current detection, Mg: electromagnetic contactor, Rs: current limiting resistor, ACL0: harmonic absorption reactor, ACL1 ... Power coordination reactor, C0 ... Harmonic absorption capacitor, Du, D
v, Dw, Dx, Dy, Dz ... Diode, Su, Sv, Sw, Sx, S
y, Sz: Switching element.

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Masato Takase 7-1-1, Higashi-Narashino, Narashino-shi, Chiba Industrial Equipment Division, Hitachi, Ltd. (72) Inventor Juichi Ninomiya 4-6-1, Kanda Surugadai, Chiyoda-ku, Tokyo F-term in the Industrial Equipment Sales Division, Hitachi, Ltd. (reference) JJ15 JJ16 JJ17 JJ19 JJ28 LL07 LL12 LL22 LL30 LL33 LL41 LL55 MM01 MM02 MM03 MM06 MM10 MM20 PP02 PP03

Claims (8)

[Claims] 1. A control circuit for forming a current feedback control loop for controlling a current of a motor based on a current command and supplying a drive signal to a gate or a base of a switching element provided in an inverter main circuit, wherein a current detection of the motor is performed. A signal conducting portion of a backward loop from a point to an addition point for adding a feedback signal of the detected current to a current command, and a signal conducting portion of a forward loop from the addition point to the gate or the base drive signal are both externally connected. Current control circuit characterized by being sealed without touching the atmosphere. 2. A current control system constituting the current feedback control loop is provided with a current limiter circuit for limiting the magnitude of the current command, and the current limiter circuit is connected to the backward loop without touching an external atmosphere. 2. The current control circuit according to claim 1, wherein the current control circuit is sealed together with the signal conductive portion and the signal conductive portion of the forward loop. 3. A current control circuit forming a current feedback control loop and supplying a signal for driving a switching element, a signal portion up to an addition point for adding a current feedback signal to a current command, and the switching element from the addition point. A current control circuit characterized in that the signal portion up to the drive signal portion is sealed without contacting the outside atmosphere. 4. A current feedback control loop for forming at least a position or speed feedback control loop and controlling a current of the electric motor based on a current command obtained from the position or speed feedback control loop inside the feedback control loop. In the inverter control device configured to supply a drive signal to the gate or base of the switching element provided in the inverter main circuit, a feedback signal of the detected current is added to a current command from a current detection point of the motor. The signal conducting portion of the backward loop from the summing point and the signal conducting portion of the forward loop from the summing point to the gate or the base drive signal are both sealed without contacting the outside atmosphere, and the position or speed is sealed. Configure a feedback control loop A first microprocessor in position,
A second microprocessor in a portion constituting the current feedback control loop, and a system clock signal supplied independently to the first and second microprocessors; and a magnetic pole from a magnetic pole position detector of the electric motor. The position command and the rotational position data from the rotational position detector are configured to be fed back to the first microprocessor, and the current command and the magnetic pole are serially transmitted from the first microprocessor to the second microprocessor. The position data is transmitted or transferred, and the magnetic pole position data in the second microprocessor is obtained by interpolation between the previous magnetic pole position data from the first microprocessor and the current magnetic pole position data by interpolation. Inverter control device characterized by calculating the position. 5. A feedback control loop comprising at least a position or speed feedback control loop, wherein a current command obtained by said position or speed feedback control loop is received inside said feedback control loop, and an inverter main circuit switching element is provided based on said current command. In the inverter device that constitutes a current feedback control loop that drives and controls the current of the motor, a backward direction from a detection point of the motor current to an addition point where the polarity of the feedback signal of the detected current is inverted and added to the current command signal. A single phase in which two loops, a forward loop from the addition point to the gate or base drive signal of the inverter main circuit switching element, and an anti-parallel circuit in which at least the switching element and the diode are connected in parallel in the reverse direction are connected in series in two circuits Arm, multi-phase arm parallel A continuous inverter main circuit, a current limiter circuit that limits the current command, and an insulating element that electrically insulates and transmits a signal at an input portion of the current command are built in the power module and sealed together. Inverter device characterized by: 6. A first microprocessor at least in a portion forming a position or speed feedback control loop, a second microprocessor in a portion forming a current feedback control loop, and each of the first and second microprocessors. A system clock signal supplied independently to the microprocessor, and configured to feed back magnetic pole position data from the magnetic pole position detector of the electric motor and rotational position data from the rotational position detector to the first microprocessor; 6. The inverter device according to claim 5, wherein a current command and said magnetic pole position data are transferred from one microprocessor to a second microprocessor by serial communication. 7. An inverter apparatus comprising a current control system for controlling a current of a motor so as to match a current command, and configured to drive a switching element based on a signal of the current control system. From the current detection point of the motor connected to the output of the motor to the addition point where the feedback signal of the detected current is inverted and added to the addition point, and from the addition point to the gate or base drive signal of the inverter main circuit switching element. , A main circuit in which a single-phase arm in which at least two antiparallel circuits in which switching elements and diodes are connected in parallel in the reverse direction are connected in series, a multi-phase arm in parallel, and a current limiter for limiting a current command The power of the circuit and the insulating element for transmitting a signal while being electrically insulated at the input portion of the current command are both provided. Inverter that features that were sealed built into the module. 8. A main circuit for receiving a direct current or an alternating current and controlling the driving of a switching element to convert it into a direct current of an arbitrary voltage or an alternating current having an arbitrary voltage and frequency, and flowing to the main circuit based on a current command. A power feedback device including a current feedback control loop for controlling a current, a backward loop to an addition point for adding a current feedback signal to the current command, and a forward loop from the addition point to a drive signal portion of the switching element. When,
A power converter characterized in that the main circuit and both are molded and sealed with resin.