Electric power consumption control system

• US 8,866,420 B2
• Filed: 01/20/2011
• Issued: 10/21/2014
• Est. Priority Date: 01/29/2010
• Status: Active Grant

• Current Assignee: Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: Mishina, Shunji
• Primary Examiner(s): Leykin, Rita
• Application Number:
  US13/504,887
• Publication Number:
  US 20120261989A1
• Time in Patent Office: 1,370 Days
• Field of Search: 700/174, 700/33, 700/173, 700/34, 318/561, 318/571, 318/560, 318/34, 318/63, 318/64, 318/66, 318/67, 318/68, 307/35, 307/125, 307/126
• US Class Current: 318/255
• CPC Class Codes: G05B 19/416 characterised by control of velocity, acceleration or deceleration G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/32021 Energy management, balance and limit power to tools
• CPC Class Codes: G05B 2219/34314 Slow down, limit speed for energy saving
• CPC Class Codes: H02J 2310/60 Limiting power consumption in the network or in one section of the network, e.g. load shedding or peak shaving
• CPC Class Codes: H02J 3/14 by switching loads on to, or off from, network, e.g. progressively balanced loading
• CPC Class Codes: Y02P 70/10 Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

Disclosed is an electric power consumption control system for a factory where a plurality of machine tools (Mi, Mp1, Mp2) are installed. A machine tool (Mi) is provided with a control device (10) whereby either the rotational acceleration/deceleration (Pi) for the motor for the machine tool and/or the rotational speed (Si) thereof is controlled on the basis of information regarding electric power consumption (Wt) in the factory so that electric power consumption will not exceed a specified value (We). This electric power consumption control system is also provided with electric power detection instruments (11, 12, 13) and an electric power monitoring instrument (20) which measure the electric power consumption of all the machine tools installed in the factory, thereby obtaining the electric power consumption of the factory, and provide information regarding the electric power consumption to the control device of the machine tool equipped with the control device.

Claims

1. An electric power consumption control system for a facility in which a plurality of industrial machines each causing a motor to rotationally drive are installed, wherein

only one of the industrial machines includes controlling means for controlling at least one of a rotational acceleration/deceleration speed Pi and a rotational speed Si of the motor of the one industrial machine, on the basis of information on an electric power consumption Wt of the facility, in such a way that the electric power consumption Wt becomes equal to or less than a specified value We, and

the electric power consumption control system comprises electric power monitoring means for obtaining the electric power consumption Wt of the facility by measuring each of electric power consumptions of all of the industrial machines installed in the facility and for providing the information on the electric power consumption Wt to the controlling means of the industrial machine including the controlling means.

2. The electric power consumption control system according to claim 1, wherein, when at least one of the rotational acceleration/deceleration speed Pi and the rotational speed Si of the industrial machine including the controlling means is less than a steady state value Pin, Sin, the controlling means of the industrial machine including the controlling means controls the motor of the industrial machine including the controlling means, on the basis of information indicating that the electric power consumption Wt continuously falls below the specified value We for a specified time period Te2, in such a way that the at least one of the rotational acceleration/deceleration speed Pi and the rotational speed Si is raised until any one of following conditions is satisfied:

the at least one of the rotational acceleration/deceleration speed Pi and the rotational speed Si reaches the steady state value Pin, Sin; and

the electric power consumption Wt reaches the specified value We.

3. The electric power consumption control system according to claim 1, wherein

the industrial machine including the controlling means is a machine tool for machining a workpiece by moving a tool and the workpiece relative to each other,

the rotational acceleration/deceleration speed Pi is an acceleration/deceleration speed Pi of a positioning and feeding motion, and

the rotational speed Si is a feeding speed Si of the positioning and feeding motion.

4. The electric power consumption control system according to claim 3, wherein the controlling means of the machine tool including the controlling means further controls an acceleration/deceleration speed Ri of a rotating motion of a main spindle of the machine tool on the basis of the information on the electric power consumption Wt in such a way that the electric power consumption Wt becomes equal to or less than the specified value We.

5. The electric power consumption control system according to claim 4, wherein the controlling means of the machine tool including the controlling means further controls the motor of the machine tool including the controlling means on the basis of information indicating that the electric power consumption Wt continuously exceeds the specified value We for the specified time period Te1, in such a way that the acceleration/deceleration speed Ri of the machine tool including the controlling means is reduced until the electric power consumption Wt becomes equal to or less than the specified value We.

6. The electric power consumption control system according to claim 4, wherein, when the acceleration/deceleration speed Ri of the machine tool including the controlling means is less than a steady state value Rin, the controlling means of the machine tool including the controlling means controls the motor of the machine tool including the controlling means on the basis of information indicating that the electric power consumption Wt continuously falls below the specified value We for the specified time period Te2, in such a way that the acceleration/deceleration speed Ri is raised until any one of following conditions is satisfied:

the acceleration/deceleration speed Ri reaches the steady state value Rin; and

the electric power consumption Wt reaches the specified value We.

7. The electric power consumption control system according to claim 1, wherein the controlling means of the industrial machine including the controlling means controls the industrial machine in such a way that an average value of the electric power consumption Wt during a specified time period becomes equal to or less than the specified value We.

8. The electric power consumption control system according to claim 1, wherein the controlling means of the industrial machine including the controlling means controls the motor of the industrial machine including the controlling means on the basis of information indicating that the electric power consumption Wt continuously exceeds the specified value We for a specified time period Te1, in such a way that at least one of the rotational acceleration/deceleration speed Pi and the rotational speed Si of the industrial machine including the controlling means is reduced until the electric power consumption Wt becomes equal to or less than the specified value We.