Main drive control method for glass factories

Abstract

A main drive control method for glass factories, comprising the following steps: (a) providing a first circuit breaker and a second circuit breaker on a power supply loop of an electrical motor, wherein one end thereof is respectively connected to two main drive electrical motors; (b) enabling the first circuit breaker to be connected to a municipal power supply and the second circuit breaker to be connected to a UPS power supply; and (c) enabling the first circuit breaker and the second circuit breaker to be interlocked via a mechanical interlocking mechanism, so that only one of the circuit breakers can be switched on during a normal operation. The main drive control method for glass factories solves the problem that the rotation speed of a main drive electrical motor is incorrect due to the interference on a signal.

Claims

1. A main drive control method with precise transmission and high reliability for glass factories, comprising: a) providing a first driving motor and a second driving motor; b) providing a municipal power supply and a UPS power supply; c) providing a first circuit switch for the first driving motor; wherein, when switching the first driving motor to the municipal power supply is switched on, the first driving motor to the UPS power supply is turned off, when switching the first driving motor to the UPS power supply is switched on, the first driving motor to the municipal power supply is turned off; d) providing a second circuit switch for the second driving motor; wherein, when switching the second driving motor to the municipal power supply turned on, the second driving motor to the UPS power supply is turned off; when switching the second driving motor to the UPS power supply turned on, the second driving motor to the municipal power supply is turned off, e) providing an interlocking device for the first circuit switch and second circuit switch respectively, the interlocking device has a first circuit breaker and a second circuit breaker, wherein, when the first circuit breaker is turned on the second circuit breaker is turned off, when the first circuit breaker is turned off the second circuit breaker is turned on during a normal operation, wherein, the first and second drive motors are provided with a frequency converter controlled by a computer respectively, an acceleration/deceleration button is arranged on a digital input port of each frequency converter, which is used to change a frequency of the frequency converter, to enable an manual speed adjustment for the first and second drive motors.

2. The main drive control method with precise transmission and high reliability of claim 1, wherein, a pulse signal is outputted from the frequency converter to a pulse display instrument.

3. The main drive control method with precise transmission and high reliability of claim 2, wherein, a frequency converter malfunction output relay is connected in series with a main contactor opening loop.

4. The main drive control method with precise transmission and high reliability of claim 1, wherein, the first and second driving motors have a control loop, which is installed in a control box, the two control boxes for the first and second driving motors are separated.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) By reference to the accompanying drawings and detailed illustration hereinafter, the above or other features and advantages can be better understood through:

(2) FIG. 1 is a principle diagram of 1# main drive control.

(3) FIG. 1A is an enlarged portion of the FIG. 1.

(4) FIG. 1B is another enlarged portion of the FIG. 1.

(5) FIG. 2 is a principle diagram of 2# main drive control.

(6) FIG. 2A is an enlarged portion of the FIG. 2.

(7) FIG. 2B is another enlarged portion of the FIG. 2.

(8) FIG. 3 is a lay-out diagram of a main drive operation platform of a central control room.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(9) Reference to accompanying drawings, this invention will be described in more details hereinafter. However, this invention may be implemented by various different forms and should not be explained as being limited by the provided embodiments herein. To the contrary, these embodiments are provided for sufficient and complete disclosure, and enable the skilled in the art to fully understand the scope of this invention.

(10) A main drive control method for glass factories according to an embodiment of this invention will be elaborated hereinafter.

(11) Firstly, a power supply loop of an electrical motor is provided with a first circuit breaker and a second circuit breaker, wherein, one end of the first circuit breaker and one end of the second circuit breaker are connected to two main drive electrical motors respectively. Then, the first circuit breaker is connected to a municipal power supply and the second circuit breaker is connected to a UPS power supply. And last, the first circuit breaker and the second circuit breaker are interlocked via a mechanical interlocking mechanism, so that only one of the two circuit breakers can be switched on during a normal operation.

(12) As shown in FIG. 1, a general main drive control for a glass factory uses computer control, which mainly outputs a signal of 420 mA by computer analog quantity and controls a frequency of a frequency converter so as to control a rotate speed of the main drive electrical motor. This method is easily to cause an interference on the signal of 420 mA, which brings an inaccuracy of rotate speed of the main drive electrical motor. Meanwhile, the two main drive electrical motors are power-supplied by the municipal power supply or the UPS power supply respectively; if any one of the municipal power supply and UPS power supply encounters a failure, the corresponding electrical motor will stop working, which may not meet the requirement that one electrical motor is for working and the other one is for hot standby. Therefore this invention changes the traditional main drive control circuit, which reflects in the circuits as shown in FIG. 1 and FIG. 2.

(13) In FIG. 1, QL11a and QL12a are main circuit breakers; FL1a is a mechanical interlock device of the main circuit breakers; KM11a is a main circuit contactor; UF11a is a frequency converter; KB11a is a frequency converter manipulator; L11a is a frequency converter reactor; SA1a is a change-over switch for remote control/body control; SS12a is a manual operating acceleration button; SS13a is a manual operating deceleration button; SF1a and SS1a are power-on and power-off manual operating buttons of the main circuit respectively; SF11a and SS11a are start and stop manual operating buttons of the frequency converter respectively; LV11a is a velocity pulse display instrument of the main circuit; KA11a is a frequency converter starting relay; KA12a and KA13a are a frequency converter running signal relay and a frequency converter fault signal relay respectively. In FIG. 2, QL21a and QL22a are main circuit breakers; FL2a is a mechanical interlock device of the main circuit breakers; KM21a is a main circuit contactor; UF21a is a frequency converter; KB21a is a frequency converter manipulator; L21a is a frequency converter reactor; SA2a is a change-over switch for remote control/body control; SS22a is a manual operating acceleration button; SS23a is a manual operating deceleration button; SF2a and SS2a are power-on and power-off manual operating buttons of the main circuit respectively; SF21a, 5521a are start and stop manual operating buttons of the frequency converter respectively; LV21a is a velocity pulse display instrument of the main drive; KA2la is a frequency converter starting relay; KA22a and KA23a are a frequency converter running signal relay and a frequency converter fault signal relay respectively.

(14) By setting acceleration/deceleration buttons on a digital input port of the frequency converter, and by changing frequencies of the frequency converter through operations of the acceleration and deceleration buttons, an adjustment of the main electrical motor speed is implemented. By providing two circuit breakers for the power loop of each electrical motor, namely, each electrical motor is connected to two power supplies, i.e., one is the municipal power supply and the other one is the UPS power supply, while the two circuit breakers are interlocked by a mechanical interlock mechanism, only one of the two circuit breakers can be switched on during normal operations, which guarantees that both two main drive electrical motors can operate normally if any one of the two power supplies encounters a power failure. To ensure that human error accidents or interference phenomenon will not be caused by a failure or maintenance of any one of the electrical motors, two control loops of the two electrical motors are respectively arranged in separate control boxes.

(15) To meet the requirement that both the main electrical motors could not stop working even if any one of the municipal power supply and UPS power supply encounters power failure, the power loop of each electrical motor is provided with two circuit breakers, namely, each electrical motor is connected to two power supplies, i.e., one is the municipal power supply and the other is the UPS power supply, while the two circuit breakers are interlocked by a mechanical interlock mechanism. During a normal operation, only one of the two circuit breakers can be switched on, which guarantees that both two main drive electrical motors can work properly even if one of the two power supplies encounters power failure.

(16) To meet the precision requirement of the speed adjustment, each electrical motor of the main drive is provided with a frequency converter. By setting acceleration/deceleration buttons on the digital input port of the frequency converter, and by changing frequencies of the frequency converter through operations of the acceleration and deceleration buttons, an adjustment of the main electrical motor speed is implemented.

(17) To directly and correctly reflect speeds of the main drive, a signal is pulse outputted from the frequency converter to a pulse display instrument to guarantee accuracy of the main drive speed.

(18) For flexible, convenient and direct manipulation, the start/stop button of the frequency converter, the acceleration/deceleration button, an indicator, and the pulse display instrument are all arranged integrally on an operation platform of the central control room, to satisfy functions of a remote start/stop control and a speed adjustment.

(19) To ensure cutting off the power supply in time when the frequency converter encounters a failure, a frequency converter malfunction output relay is in series with the main contactor opening loop to guarantee safety of the device and an operator when in fault.

(20) To avoid mis-operation and interference phenomenon if any one of the main drive electrical motors encounters a motor failure or maintenance, the control loop of each main electrical motor is set in separate control box respectively, as shown in FIG. 3.

(21) The control method is implemented by following steps: (what mentioned below is for 1# main drive; 2# main drive is the same as 1#) (1) Checking rotation direction of each electrical motor of the main drive to ensure that each electrical motor has correct rotation direction so as to meet process requirement; checking phase sequence consistency of the two power supplies in the control boxes so as to ensure that the phase sequences of the two power supplies are consistent. (2) During the normal operation, switching the change-over switch SA1a to a remote control position, manually operating the main circuit breaker switch QL11a or OL12a on, manually operating to switch the button SF1a on, switching on the main contactor KM11a, and then the main circuit being power on. a. Setting a corresponding frequency of the frequency converter based on a speed given by the technique, manually operating to switch the start button SF11a on, starting the main drive electrical motor, and then turning to the normal operation. b. If the speed of the main drive needs to be increased, manually inching the control button SS12a to accelerate the motor; observing the display instrument LV11a, and stopping acceleration when a target value is reached. c. If the speed of the main drive needs to be decreased, manually inching the control button SS13a to decelerate the motor; observing the display instrument LV11a, and stopping deceleration when a target value is reached. d. If the main drive needs to stop, manually operating the stop button SS11a to complete the stop. e. When the frequency converter works properly or encounters a failure, sending a operation or failure signal to the central control room for displaying on a computer system. (3) Body start/stop the main drive electrical motor: switching the change-over switch SA1a to a body control position, starting/stopping the main drive electrical motor by the frequency converter manipulator, and enabling speed adjustments of the main drive through frequencies set by the frequency converter manipulator.

(22) The main drive control method according to this invention overcomes inaccuracy of rotation rate of the main drive electrical motor caused by signal interference, satisfies requirement that none of the electrical motors stops working if any one of the municipal power supply and UPS power supply encounters a power failure; and meanwhile sets the two main drive control systems in separate control box respectively to avoid human error accidents caused by a failure or maintenance of any one of the electrical motors.

(23) Preferable embodiments of this invention have been described in details above. One should understand that the skilled in the art may make various modifications and changes according to the spirit of this invention without any creative work. All technical schemes achieved through logical analysis, deduction or a limited number of experiments based on existing technique by the skilled in the art shall be contained in the protection scope determined by the appending claims.