JPH0984379A - Common power source inverter controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an economical common power source inverter controller by selecting deceleration sequence of motors from a total output value of motors and a deceleration rate to use the common power source only in one direction even when an inverter group which requires regenerative braking is included in the inverter group which does not require regenerative braking. SOLUTION: Speed w1 of each motor is detected by a speed detector 2 and is then input to a power calculating circuit 3 and a deceleration command calculating circuit 6. Each inverter 4 calculates an output torque T1 of each motor 1 and then input to a power calculating circuit 3 and each power calculating circuit 3 calculates an output capacity P1 of each motor 1 and inputs it to the deceleration command calculating circuit 6. Moreover, the power calculating circuit 3 also inputs an output J1 of an inertia moment setting circuit 10 and an output of a deceleration pattern setting circuit 5 to the deceleration command calculating circuit 6. The circuit 6 calculates a total output of the motor 2 which continues operation to obtain the possible deceleration capacity of motor 1 which is decelerated by the regenerative braking to output it to the inverter 4 by selecting a deceleration sequence command 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a common power supply inverter control device having a plurality of common power supply type inverter devices.

[0002]

2. Description of the Related Art In a common power supply type inverter device, when a motor load is driven by a plurality of inverter devices, an inverter device group that requires regenerative braking when decelerating the load and an inverter device group that does not Separate power supplies were provided. Since a common power supply for the inverter device group that requires regenerative braking needs power regeneration, an antiparallel connection thyristor converter has been used.

[0003]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention An inverter device group that requires regenerative braking and an inverter device group that does not need regenerative braking are separately supplied with a common power source. It became big and complicated and uneconomical. Further, since the antiparallel connection thyristor converter is used as a common power source of the inverter device group which requires regenerative braking, the power factor is deteriorated.

The present invention solves the above-mentioned problems, and even if an inverter device group that does not require regenerative control includes an inverter device that requires regenerative braking, it uses only a one-way common power supply and is economical. It is intended to provide a common power supply inverter control device.

[0005]

SUMMARY OF THE INVENTION A common power supply inverter control device of the present invention is a common power supply for exchanging a transformed voltage with a DC voltage and supplying a common power supply to a plurality of inverter devices connected in parallel, and an inverter device. Speed detector for detecting the rotation speed of the electric motor driven by the motor, and power calculation for calculating the output capacity of the electric motor from the rotation speed detected by the speed detector and the output torque of the electric motor obtained by the output current of the inverter device. Circuit, inertia moment setting circuit that presets the moment of inertia of the load, deceleration pattern setting circuit that presets the deceleration pattern of the inverter device, and output addition that calculates the total output value of the motor by adding the outputs of the power calculation circuit Circuit, deceleration rate calculation circuit that calculates the deceleration rate from the rotation speed of the motor and the set value of the deceleration pattern setting circuit. When it is characterized in that a deceleration command calculation circuit which outputs a deceleration order command to the selected inverter deceleration sequence of the motor from the motor output sum and the deceleration rate.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a common power supply inverter control device of the present invention will be described. In FIG. 1, a common power source 8 is a device that converts an AC voltage into a DC voltage and supplies a common power source to a plurality of inverter devices 4 connected in parallel, and a smoothing capacitor connected to the load side of the common power source 8. A smoothing circuit 7 smoothes the pulsating flow of the DC voltage.
The speed detector 2 is directly connected to the electric motor 2, and the rotational speeds w ₁ and w of the electric motor 1 driven by the inverter device 4 are connected.
_It is a detector that detects _i . The power calculation circuit 3 is connected to the speed detector 2 and the inverter device 4, and the output torque T ₁ of the electric motor 1 obtained by the rotational speeds w ₁ and w _i detected by the speed detector 2 and the output current of the inverter device 4. , T _i , the output capacitances P ₁ , P _i of the electric motor 1 are calculated. The inertia moment setting circuit 10 is a circuit for presetting the load inertia moments J ₁ and J _i . The deceleration pattern setting circuit 5 is a circuit that presets the deceleration pattern of the inverter device 4. Output adder circuit 11
Is a circuit for adding the outputs of the power calculation circuit 3 to calculate the total output value of the motor. The deceleration rate calculation circuit 12 is a circuit that calculates the deceleration rate from the rotation speed of the electric motor 1 and the set value of the deceleration pattern setting circuit 5. Deceleration command calculation circuit 6
Is a circuit for selecting the deceleration order of the electric motor 1 from the total output value of the electric motor and the deceleration rate and outputting the deceleration order command 9 to the inverter device 4.

That is, the speed of each electric motor 1 is detected by the speed detector 2 attached to each electric motor. The output torques T ₁ and T _i of the respective electric motors 1 are calculated by the respective inverter devices 4. Then, the output speeds P ₁ and P _{i of the} electric motor 1 are calculated by the power calculation circuit 3 from the rotational speeds w ₁ and w _i of the electric motor ₁ and the output torques T ₁ and T _{i as} follows: T ₁ × w ₁ = P ₁ T _i × w _i = P _i The relationship between preset load inertia moments J ₁ and J _i and deceleration torques Td ₁ and Td _i required for deceleration and deceleration rate dw / dt is as follows.

J ₁ × dw / dt = Td _i J _i × dw / dt = Td _i Here, the capacity Td required for deceleration is calculated by the deceleration command calculation circuit as follows.

Td · w = Pd The sum of the output capacities P ₁ and P _i of the electric motor 1 which continues the operation is calculated by the deceleration command calculation circuit 6.

Motor 1 for deceleration by deceleration command calculation circuit 6
Among these, those requiring regenerative braking and those not requiring regenerative braking are discriminated from the deceleration patterns of the inverter device 4 which are preset.

The output capacity P ₁ of the electric motor 1 which continues to operate,
The deceleration capacity Pd and the deceleration rate dw / dt of the electric motor group for regenerative braking so as not to exceed the sum of P _i are calculated by the deceleration command calculation circuit 6.

[0012]

[Equation 1] However, Pa _i is the electric power output of the electric motor which continues the operation, n is the number of electric motors to be decelerated, and Pd _i is the deceleration capacity.

The deceleration order is determined by the deceleration command calculation circuit 6 so that the inverter device 4 that does not require regenerative braking stops after all the inverter device groups that require regenerative braking have stopped.

That is, FIG. 1 shows a common power supply type inverter device in which a plurality of inverter devices 4 drive a motor load, and a speed detector 2 for detecting the speed of each motor 1.
And output speed P of the electric motor 1 from the speeds w ₁ and w _i detected by the speed detector 2 and the output torques T ₁ and T _{i of the} electric motor 1.
_1, P _i and power calculation circuit 3 for calculating the electric motor 1 of the output capacitance P _1, P inertia sum calculates the .SIGMA.P _M preset load _i moment J _1, J _i and the speed w ₁ of the motor 1 , W _i , the deceleration rate dw / dt is calculated, and the deceleration pattern setting circuit 5 of the preset inverter device 4 is calculated.
The control apparatus of the common power supply inverter which has the several inverter apparatus 4 provided with the deceleration command calculation circuit 6 which determines the deceleration order more is shown. The inverter device 4 is connected to the common power source 8 via the smoothing capacitor 7 and drives each electric motor 1. The speeds w ₁ and w _{i of the} respective motors 1
Is detected by the speed detector 2. Detected speed w
₁ and w _i are input to the power calculation circuit 3 and the deceleration command calculation circuit 6. In the inverter device 4, the output torques T ₁ and T _{i of the} electric motor 1 are calculated. The output torques T ₁ and T _i are input to the power calculation circuit 3. In the power calculation circuit 3, the output capacities P ₁ and P _{i of the} electric motor 1 are calculated from the speeds w ₁ and w _i and the output torques T ₁ and T _i . Calculated output capacity P
₁ and P _i are input to the deceleration command calculation circuit 6. The preset inertia moments J ₁ and J _{i of} the load and the deceleration pattern from the deceleration pattern setting circuit 5 of the inverter device 4 are input to the deceleration command calculation circuit 6.

The deceleration command calculation circuit 6 calculates the total output capacity Pa _m of the electric motor 1 which continues to operate. Thereby, the possible deceleration capacity P of the electric motor 1 decelerated by regenerative braking
d _n is obtained.

The deceleration rate dw / dt is calculated by the deceleration command calculation circuit 6 from the inertia moments J ₁ and J _i of the load of the electric motor 1 decelerated by the regenerative braking and the deceleration capacity Pd _n .

The deceleration sequence is determined by the deceleration command calculation circuit 6 so that the inverter device 4 which does not always require regenerative braking stops after the inverter device 4 which requires regenerative braking stops.

Deceleration rate dw / dt and deceleration order command 9
Is output from the deceleration command calculation circuit 6 to each inverter device 4.

[0019]

As described above, according to the present invention, even if the inverter device group that does not require regenerative braking includes the inverter device that requires regenerative braking, it is possible to use only the one-way common power source, which is economically common. In addition to realizing a power supply, it is possible to realize a high power factor and space saving.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a common power supply inverter control device showing an embodiment of the present invention.

[Explanation of symbols]

 1 Motor 2 Speed Detector 3 Power Calculation Circuit 4 Inverter Device 5 Deceleration Pattern Setting Circuit 6 Deceleration Command Calculation Circuit 7 Smoothing Capacitor 8 Common Power Supply 10 Inertia Moment Setting Circuit 11 Output Addition Circuit 12 Deceleration Rate Calculation Circuit

Claims (1)

[Claims] 1. A common power source for converting an AC voltage into a DC voltage and supplying a common power source to a plurality of inverter devices connected in parallel, and a speed detector for detecting a rotation speed of an electric motor driven by the inverter device. A power calculation circuit for calculating the output capacity of the electric motor from the rotational speed detected by the speed detector and the output torque of the electric motor obtained from the output current of the inverter device; A moment of inertia setting circuit for setting, a deceleration pattern setting circuit for presetting a deceleration pattern of the inverter device, an output addition circuit for adding outputs of the power calculation circuit to calculate a motor output total value, and a rotation of the motor. A deceleration rate calculation circuit for calculating a deceleration rate from the speed and the set value of the deceleration pattern setting circuit; A common power supply inverter control device comprising: a deceleration command calculation circuit that selects a deceleration sequence of the electric motor from a machine output total value and the deceleration rate and outputs a deceleration sequence command to the inverter device.