JPH07231686A - Controller of common power source inverter device - Google Patents

Abstract

PURPOSE:To quicken the deceleration of motors, according to priority by outputting a deceleration rate down command, based on the priority being set for each motor when the full motor power is larger than the maximum regeneration tolerance of a common power source, and controlling each inverter by torque limit value when the full motor power is small than it. CONSTITUTION:In deceleration setting circuits 7a-7n, deceleration rates are set, according to the width of rate up and the width of rate down, so as to seek torque. Load torque operating circuits 9a-9n seek load torques TM1-TMn from the deviation between the torque and the motor load torque being sought with load torque operating circuits 5a-5n, and give them to a control circuit 15 so as to control inverters 2a-2n. Accordingly, it becomes possible to quicken the deceleration of a motor with high priority by setting the power limit to each motor so that it may not get over the tolerance of regeneration of the common power source 1, in a priority setting circuit 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a controller for a common power supply inverter device having a power limit circuit during deceleration of a plurality of common power supply type inverters.

[0002]

2. Description of the Related Art In a controller for a common power supply inverter device in which electric power is supplied from a common power source to a plurality of inverters and each inverter is controlled to drive each motor, each inverter drives each motor. In deceleration control, if the regenerative power of each motor is large, the regenerative power of the motor exceeds the allowable amount of the common power source. Therefore, increase the allowable amount of the common power source or, as shown in FIG. Accordingly, the inverters that control the operation of the plurality of electric motors 3a to 3n are controlled at a constant deceleration rate to uniformly change the deceleration time rate of the electric motors so that the regenerative power of the electric motors is reduced.

That is, _{P≤P CCNV} (1) P = _Tω = _Jωdω / dt (2) where P: regenerative power of electric motor, P _CCNV : regenerative allowance of common power source Power T: Torque of electric motor, J: Moment of inertia, ω: Angular velocity of electric motor dω / dt: Rate of change of angular velocity of electric motor Therefore, control is performed to _{reduce the} rate of change dω / dt of the electric motor to the regenerative allowable power P _CCNV of the common power source or less. _{Alternatively} , the regenerative allowable power P _CCNV of the common power source is increased to be less than the regenerative power of the motor.

[0004]

However, in such a conventional control apparatus for a common power supply inverter device, when the electric motor is decelerated by the limited regenerative power of the common power supply, a method for limiting the torque of the electric motor is used. Since it is necessary to uniformly change the deceleration rate of the electric motor, that is, to significantly extend the deceleration time, there is a problem that the deceleration is delayed during an emergency stop. On the contrary, if a regenerative device is installed for an emergency stop, it is uneconomical because it is an excessive facility that is rarely used normally.

The present invention has been made to solve the above problems, and accelerates the deceleration of the electric motors in priority order and further decelerates and stops under the maximum allowable regenerative power of the common power source. An object of the present invention is to provide a control device for a common power supply inverter device that can minimize time.

[0006]

In order to achieve the above object, the present invention provides a common power source for supplying electric power to a plurality of inverters and controlling each inverter to drive each electric motor. In the control device of the power supply inverter device, load torque calculating means for obtaining a load torque corresponding to the electric motor speed from the speed detection signal of each electric motor,
A deceleration rate is set for each electric motor, and deceleration rate output means outputs the deceleration rate when decelerating the electric motor, and a preset inertia moment of each electric motor and the deceleration rate output means when decelerating the electric motor. A motor torque calculation unit that calculates the torque by multiplying the deceleration rate and obtains the torque from the torque and the load torque calculated by the load torque calculation unit, and the motor torques calculated by the motor torque calculation unit and the motor torque. The deceleration motor power is calculated from the speed detection signal, the total power calculation means for calculating these deceleration motor powers to calculate the total motor power, the maximum regenerative allowance of the common power source and the total power calculated by the total power calculation means. A comparison means for comparing and a priority setting procedure in which the priority order of the deceleration order is set for each electric motor. When the total electric motor power is larger than the maximum regenerative allowance of the common power source by the comparison means, a deceleration rate reduction command is issued to the deceleration rate output means of the corresponding electric motor based on the priority order set by the priority order setting means. When the total electric motor power is less than the maximum regenerative allowance, the deceleration command means for outputting a deceleration rate increase command to the deceleration rate output means of the corresponding motor based on the priority order, and the maximum of the common power source. And a control means for distributing and controlling the torque limit value to each inverter when the total electric motor power is smaller than the regeneration allowable amount.

[0007]

In the controller of the common power supply inverter device having such a configuration, when decelerating each electric motor, the load torque is obtained from the speed detection signal of the electric motor during deceleration, and this load torque and the preset electric motor are used. The electric motor load torque is calculated from the torque obtained by multiplying the inertia moment of 1 by the deceleration rate. Then, the speed reduction motor power is obtained from the motor load torque and the speed detection signal of the motor, and the speed reduction motor power is summed up to calculate the total motor power.

This total electric motor power is compared with the maximum regenerative allowance of the common power source, and when the total electric motor power is greater than the maximum regenerative allowance of the common power source, the corresponding electric motor is given to the corresponding electric motor based on the priority order set for each electric motor. To output a deceleration rate reduction command, and when the total motor power is less than the maximum regenerative allowance, it outputs a deceleration rate increase command to the corresponding motor based on the priority order, and all motors exceed the maximum regenerative allowance of the common power source. When the power is small, the torque limit value is distributed to each inverter for control.

Therefore, by setting a large torque limit value for a motor having a high deceleration priority and a small torque limit value for a motor having a low priority, deceleration of a motor having a high priority can be accelerated. After that, motors with lower priorities can be decelerated more quickly.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing a configuration example of a control device for a common power supply inverter device according to the present invention. In FIG. 1, 1
Is a common power source, 2a to 2n are a plurality of inverters to which electric power is respectively supplied from the common power source 1, and 3a to 3n are electric motors whose operation is controlled by the inverters 2a to 2n, respectively.

Further, 4a to 4n are speed detectors for detecting the speeds of the electric motors 3a to 3n, and 5a to 5n are speed detectors 4a.
4n is a calculation circuit for calculating the load torque of each electric motor from the speed detected by 4n.

On the other hand, 6a to 6n are electric motors 3a to 3n in advance.
Load J, that is, a load setter in which the moment of inertia is set, 7a to 7n are deceleration rate setters that output deceleration rates within a rate range set according to a rate increase / decrease command, and 8a to 8n are load setters. A multiplication circuit for multiplying the load J set in 6a to 6n by the deceleration rate output from the deceleration rate setters 7a to 7n, and 9a to 9n are arithmetic circuits 5.
a deviation between the torque T ₁ through T _n determined by the load torque T _L1 through T _Ln of the obtained motor multiplying circuit 8a~8n in A～5n, this as the load torque T _M1 through T _Mn of the motor It is a load torque calculation circuit for outputting.

Further, 10 a to 10 n is the load torque calculating power circuit 9a~9n with the determined load torque T _M1 through T _Mn and speed detector motor than the rate of the detected motor 3a~3n by 4a to 4n P ₁ power calculation circuit for calculating a to P _n, 11 is the total power calculation circuit for obtaining the power P _x of the total motor from the power P ₁ to P _n obtained by the power calculation circuit 10 a to 10 n, 12 in full power operation circuit 11 The obtained power P _x of all electric motors is compared with the maximum regenerative allowance P _{CONV of the} common power source 1, and if P _x > P _CONV , a lowering command is output, and if P _x <P _CONV , a raising command is output. Circuit.

Further, 13 is a priority setting circuit in which priorities are set in the order of the motors requiring fast deceleration among the motors 3a to 3n, and 14 is a comparison circuit 12 for P _x <.
If it is determined that P _CONV and the raising command is input, the rate raising command of each electric motor is output based on the priority set by the priority setting circuit 13, and if P _x > P _CONV It is a raising / lowering command circuit that outputs a rate lowering command of each electric motor based on the priority when it is judged and the lowering command is input.

Further, 15 is a load torque calculation circuit 9a-9.
It is a control circuit for controlling each of the inverters 2a to 2n so that the load torques T _{M1 to} T _Mn input from n are obtained. When the raising / lowering instruction circuit 14 receives the raising instruction from the comparison circuit 12 as shown in FIG.
The maximum power P _MAX (i) of the corresponding motor is compared with the current power P (i) based on the priority set in 3, and if the current power is smaller than the maximum power, the i-th motor Command the rate increase range to the corresponding motor to increase the power of. In addition, the comparison circuit 12
When the lowering command is received, the minimum power P of the corresponding electric motor is based on the priority set by the priority setting circuit 13.
_min (i) is compared with the current power P (i), and when the current power is larger than the minimum power, the rate reduction range is instructed to the corresponding motor in order to reduce the power of the i-th motor.

Next, the operation of the control device for the common power inverter device configured as described above will be described. Now, in order to decelerate the electric motors 3a to 3n from the operation-controlled state by the plurality of inverters 2a to 2n to which electric power is respectively input from the common power source 1, the speed detectors 4a to 4n.
The speed detection signals of the decelerating electric motors 3a to 3n detected by 4n are input to the load torque calculation circuits 5a to 5n,
Here the load torque T _L1 through T _Ln is calculated. At this time a reduction rate that is output from the set load J ₁ through J _n and deceleration rate setter 7a~7n each motor is multiplied by the multiplier 8a~8n torque T ₁ through T _n sought , The torques T _{1 to} T _n and the load torque calculation circuit 5a
The motor load torques T _{M1 to} T _Mn are obtained from the deviation from the motor load torques T _{L1 to} T _Ln obtained in 5n.

The motor load torques T _{M1 to} T _Mn are input to the control circuit 15, while the power arithmetic circuits 10a to 10a are input.
Each motor 3 detected by speed detectors 4a to 4n
The motor powers P _{1 to} P _n are obtained by multiplying the speeds a to 3n, and these are input to the total motor power calculation circuit 11.

In the all-motor power calculation circuit 11, the all-motor power P _{1 to} P _n is added to obtain the all-motor power P _X, which is input to the comparison circuit 12. The comparison circuit 12 compares the maximum regenerative allowance P _{CONV of} the common power source 1 with the total electric motor power P _X, and if P _x > P _CONV , the lowering command, P
_{If x} <P _CONV , the raising command is given to the raising and lowering command circuit 14, respectively.

When the raising / lowering command circuit 14 receives the raising command from the comparison circuit 12, as shown in FIG. In order to increase the power of the electric motor in order, the rate increase range is instructed to the deceleration rate setting circuits 7a to 7n, and when the lowering command is received, the electric motor is decreased in order of decreasing priority. The rate reduction range is instructed to the deceleration rate setting circuits 7a to 7n.

In the deceleration rate setting circuits 7a-7n,
Rate gains, rate sets the deceleration rate according to the reduction rate, the reduction rate multiplier 8a~8n the load setter 6a~6n set to load J ₁ through J _n and multiplying by the torque T ₁ through T _{Find n} . Furthermore, the electric motor is determined by the load torque calculating circuit 5a~5n the torque T ₁ through T _n by the load torque calculation circuit 9a~9n load torque T _L1 through T _Ln
The load torques T _{M1 to} T _Mn are obtained from the deviation from the above and are applied to the control circuit 15 to control the inverters 2a to 2n.

Therefore, the priority setting circuit 13 sets the priority order of the deceleration order for each electric motor so as not to exceed the regeneration allowable amount of the common power source 1, and further sets the power limit for the priority order. As a result, it becomes possible to accelerate deceleration of the electric motor having a high priority.

That is, ΣPi (where i = 1 to n) ≦ P _CONV (3) Pi = Tiωi = Jidωi / dtωi (4) where Pi is the value of each motor. Power, torque limit P _CONV is the regenerative allowable power of the common power source, Ti is the torque of each motor, Ji is the load (inertia moment) of each motor, ωi is the angular velocity of each motor, and dωi / dt is the angular velocity change of each motor. Is the rate.

In the above formulas (3) and (4), the limit of the torque Ti of the electric motor may be reduced so that the sum ΣPi of the electric powers of the electric motors does not exceed the regenerative allowable power of the common power source 1. Therefore, the deceleration of the electric motor can be accelerated by setting the limit value of the torque Ti to a small value for the electric motor having a high priority set in the order of quick deceleration.

[0024]

As described above, according to the present invention, under the maximum allowable regenerative power of the common power supply, the deceleration of the motors is accelerated in the priority order, and the deceleration stop time of all the motors is minimized. It is possible to provide a control device for the common power supply inverter device.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a controller for a common power inverter device according to the present invention.

FIG. 2 is an explanatory diagram of a raising / lowering command circuit in the same embodiment.

FIG. 3 is an explanatory diagram in the case of decelerating a plurality of electric motors in a conventional controller for a common power supply inverter device.

[Explanation of symbols]

1 ... Common power source, 2a-2n ... Inverter, 3a-3
n ... motor, 4a-4n ... speed detector, 5a-5n
...... Load torque calculation circuit, 6a to 6n ...... Load setter,
7a to 7n ... deceleration rate setter, 8a to 8n ... multiplier, 9a to 9n ... motor load torque calculation circuit, 10a
-10n ... motor power arithmetic circuit, 11,000 electric motor power arithmetic circuit, 12 ... comparison circuit, 13 ... priority setting circuit, 14 ... down command circuit, 15 ... control circuit.

Claims (1)

[Claims] 1. A speed detection signal for each electric motor in a controller for a common power supply inverter device, which supplies electric power from a common power supply to a plurality of inverters and controls each inverter to drive each electric motor. Load torque calculating means for obtaining a load torque according to the electric motor speed, deceleration rate setting means for setting a deceleration rate for each electric motor and outputting the deceleration rate when the electric motor is decelerated, and for each preset electric motor. Motor torque calculating means for calculating a torque by multiplying the inertia moment and the deceleration rate output from the deceleration rate output means during deceleration of the electric motor to obtain a torque, and obtaining a motor torque from the torque and the load torque obtained by the load torque calculating means. And from each motor torque obtained by this motor torque calculation means and the speed detection signal of the motor A total power calculating means for calculating the reduction motor power and summing the reduction motor powers to calculate the total electric motor power, and a comparing means for comparing the maximum regenerative allowable amount of the common power source and the total power calculated by the total power calculating means. And priority setting means for setting the priority order of the deceleration order for each electric motor, and the priority setting means when the total electric motor power is larger than the maximum regenerative allowable amount of the common power source by the comparison means. Output a deceleration rate lowering command to the deceleration rate setting means of the corresponding motor based on the priority order, and when the total electric motor power is smaller than the maximum regenerative allowance, the deceleration rate of the corresponding motor based on the priority order. Decreasing / increasing command means for outputting a deceleration rate increasing command to the setting means, and when the total electric motor power is smaller than the maximum regenerative allowance of the common power source Controller of the common power inverter device is characterized in that a control means for controlling to distribute the torque limit value to the inverter.