Servo control system

There are provided a drive unit 50 having a connection part 52 while driving a motor 61, a control unit 40 having a connection part 48 while receiving a command from a host controller 30 and sending a command to the drive unit 50, a rack for providing a back panel 80 having connected parts 84, 85 for removably making electrical connection to the connection parts 48, 52 while accommodating the control unit 40 and the drive unit 50, and a DC voltage conversion part 14 for converting a DC voltage into an output using an AC voltage as an input while being provided in the back panel 80, and the drive unit 50 is provided with a capacitor 58 while being connected to an output of the DC voltage conversion part 14, and an inverter 59 for converting the DC voltage into an AC voltage based on the command.

What is claimed is:

1. A servo control system comprising:

a plurality of motors for driving a plurality of controlled targets;

a plurality of drive units having a first connection part, for driving the motors;

a control unit having a second connection part, for receiving a command from a host controller and sending a command to the drive unit;

a rack including a back panel having a connected part for removably electrically connecting to the first and second connection parts, the rack accommodating the control unit and the drive unit; and

a DC voltage conversion part for converting an AC voltage as an input into a DC voltage as an output, the DC voltage conversion part disposed in the back panel,

wherein the drive unit has:

a capacitor having a predetermined capacitance value determined based on a rated capacity of the motor driven by the drive unit and connected in parallel with an output of the DC voltage conversion part; and

an inverter part for converting a DC voltage into an AC voltage based on a command; and

the capacitor has a capacitance value in which an allowable ripple current is larger than a ripple current flowing through the capacitor at a time of a rated load of the motor and electric power is supplied to the motor with respect to an instantaneous power failure of predetermined of the AC voltage.

2. The servo control system according to claim 1, further comprising a capacitor unit having an add-on capacitor connected in parallel with the capacitor and having a third connection part removably electrically connected to the connected part of the back panel.

3. A servo control system comprising:

a plurality of motors for driving a plurality of controlled targets;

a drive unit having a first connection part, for driving the motors;

a control unit having a second connection part, for receiving a command from a host controller and sending a command to the drive unit;

a rack including a back panel having a connected part for removably electrically connecting to the first and second connection parts, the rack accommodating the control unit and the drive unit;

a DC voltage conversion part for converting an AC voltage as an input into a DC voltage as an output, the DC voltage conversion part disposed in the back panel;

voltage detection means for generating a signal when a DC voltage value of the DC voltage conversion part reaches a predetermined value;

switching means connected to an output of the DC voltage conversion part through a resistor, the switching means for performing on-off control based on the presence or absence of a signal from the voltage detection means;

first calculation means for calculating consumption energy consumed in the resistor based on the on time of the switching means and the DC voltage value;

second calculation means for calculating storage energy stored in the capacitor and the add-on capacitor based on a predetermined voltage rise value of the DC voltage of the DC voltage conversion part and a capacitance value of the total sum of the capacitor and the add-on capacitor and for comparing a value of the consumption energy with a value of the storage energy; and

display means for displaying a result of the comparison means,

wherein the dive unit has:

a capacitor having a predetermined capacitance value determined based on a rated capacity of the motor driven by the drive unit and connected in parallel with an out put of the DC voltage conversion part; and

an inverter part for converting a DC voltage into an AC voltage based on a command.

4. The servo control system according to claim 3, further comprising:

a capacitor unit having an add-on capacitor connected in parallel with the capacitor and having a third connection part removably electrically connected to the connected part of the back panel;

third calculation means calculating storage energy stored in the capacitor and the add-on capacitor based on a predetermined voltage rise value of the DC voltage of the DC voltage conversion part and a capacitance value of the total sum of the capacitor and the add-on capacitor and for comparing a value of the consumption energy with a value of the storage energy, in place of the second calculation means; and

display means for displaying the capacitance value.

5. The servo control system according to claim 3, further comprising:

identification number generation means for detecting that the first connection part of the drive unit and the third connection part of the capacitor unit are electrically connected to the connected part and for generating identification numbers associated with capacitance values of the capacitors provided in the drive unit and the capacitor unit;

detection means for detecting an identification number of the identification number generation means;

fourth calculation means calculating the total sum of capacitance values of the capacitor and the add-on capacitor from the identification number of the detection means and for calculating the storage energy value running short and calculating a capacitance value of a capacitor to be added when the consumption energy value obtained by the first calculation means is higher; and

display means for displaying the capacitance value.