GB2318431A - Control for fan of ventilating, air-conditioning or air extraction apparatus - Google Patents

Control for fan of ventilating, air-conditioning or air extraction apparatus Download PDF

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Publication number
GB2318431A
GB2318431A GB9621664A GB9621664A GB2318431A GB 2318431 A GB2318431 A GB 2318431A GB 9621664 A GB9621664 A GB 9621664A GB 9621664 A GB9621664 A GB 9621664A GB 2318431 A GB2318431 A GB 2318431A
Authority
GB
United Kingdom
Prior art keywords
fan
motor
speed
control system
signal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB9621664A
Other versions
GB9621664D0 (en
Inventor
Jeremy Davies
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nuaire Ltd
Original Assignee
Nuaire Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nuaire Ltd filed Critical Nuaire Ltd
Priority to GB9621664A priority Critical patent/GB2318431A/en
Publication of GB9621664D0 publication Critical patent/GB9621664D0/en
Publication of GB2318431A publication Critical patent/GB2318431A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P5/00—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
    • F24F11/32—Responding to malfunctions or emergencies
    • F24F11/38—Failure diagnosis
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/70—Control systems characterised by their outputs; Constructional details thereof
    • F24F11/72—Control systems characterised by their outputs; Constructional details thereof for controlling the supply of treated air, e.g. its pressure
    • F24F11/74—Control systems characterised by their outputs; Constructional details thereof for controlling the supply of treated air, e.g. its pressure for controlling air flow rate or air velocity
    • F24F11/77—Control systems characterised by their outputs; Constructional details thereof for controlling the supply of treated air, e.g. its pressure for controlling air flow rate or air velocity by controlling the speed of ventilators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2110/00—Control inputs relating to air properties
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
    • H02P6/04—Arrangements for controlling or regulating the speed or torque of more than one motor
    • H02P2006/045—Control of current
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
    • Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Power Engineering (AREA)
  • Control Of Positive-Displacement Air Blowers (AREA)
  • Air Conditioning Control Device (AREA)

Abstract

The control system comprises means 16 for providing a signal representing the desired speed of the fan in accordance with one or more sensed parameters, means 14 for supplying electrical current to an electrical motor 12 driving the fan and dependent on the desired speed signal, and means D for sensing the actual speed of the fan. The control system is arranged to alter the electrical voltage or current supplied to the motor according to any difference between the desired speed and the actual speed of the fan. The motor may be an induction motor. If the difference persists above a predetermined value for more than a predetermined time, a further change is made to the voltage or current supplied to the motor in the sense required to reduce the difference.

Description

FAN CONTROL SYSTEM The present invention relates to a control system for a fan of a ventilating, air-conditioning or air extraction apparatus.
It is known to provide control systems which seek to adjust the fan speed of ventilating, air conditioning or air extraction apparatus, in accordance with senses parameters, such as temperature or humidity. Typically the fan is driven by an induction motor, which is controlled by altering the voltage applied to its field windings. However, when the voltage is reduced, often this does not result in the required reduction in speed, because the load on the motor is insufficient to increase the "slip" of the motor (i.e. the difference between the synchronous speed and actual speed of the motor).
We have now devised a control system which overcomes the drawback outlined above.
In accordance with the present invention, there is provided a control system for a fan of a ventilating, airconditioning or air extraction apparatus, the control system comprising means for providing a signal representing the desired speed of the fan in accordance with one or more sensed parameters, means for supplying electrical current to an electrical motor driving the fan and dependent on said desired speed signal, and means for sensing the actual speed of the fan, the system being arranged to alter the electrical voltage or current supplied to the motor according to any difference between the desired speed and actual speed of the motor.
Preferably the system comprises a comparator for comparing the desired speed signal with a signal representing the actual speed of the fan, to provide an error signal which is used to control the current or voltage supplied to the motor.
Preferably the system is arranged so that if the error signal persists above a predetermined value for more than a predetermined time, a further change is made to the electrical current or voltage supplied to the motor, in the sense required to reduce the error signal.
An embodiment of the present invention will now be described by way of example only and with reference to the accompanying drawing, the single figure of which is a schematic block diagram of a fan control system in accordance with the invention.
Referring to the drawing, a fan 10 of a ventilating, air conditioning or air extraction system is driven by an induction motor 12. A power control unit 14 supplied a.c.
power to the motor 12: the voltage of this a.c. power is varied according to a control signal applied to the unit 14.
One or more sensors S are provided and sense parameters such as the temperature and humidity of the room or other space which the ventilating, air conditioning or air extraction system acts upon. The sensors S are connected to a controller 16, which is arranged to deliver an output signal, dependent on the input signals from sensors S, representing the desired fan speed.
A sensor D is also provided, e.g. a Hall effect device, to sense the actual speed of the fan or of the motor shaft, to provide a corresponding output signal. A comparator 18 receives the "desired speed" signal from the controller 16 and the "actual speed" signal from the fan speed sensor D, to provide an error signal which is applied to the power control unit 14.
The control unit 14 is arranged to alter the voltage of the a.c. power supplied to the motor 12 in accordance with the error signal which it receives from the controller 16, in the sense required to reduce or eliminate the error signal.
In operation therefore, if a change in the room temperature or some other room condition is sensed, such that the controller 16 determines that a change in fan speed is required, then a new "desired speed" signal will be provided by controller 16, initially producing an error signal to which the control unit will respond in order to alter the voltage level of the a.c. power supplied to the motor 12. The actual motor speed should then alter to become equal to the desired speed.
However, the power control unit 14 is preferably arranged so that if the error signal persists at greater than a predetermined value for greater than a predetermined time period, a further reduction (or increase) is made in the voltage of the a.c. power supplied to the motor: this may be repeated until the actual speed of the fan becomes more or less equal to the desired speed, and the error signal is eliminated.
It will accordingly be appreciated that the control system which has been described will be effective in maintaining the fan speed more or less equal to the desired speed at all times. If in particular a reduction in the fan speed is demanded, the voltage supplied to the motor will be reduced (in successive steps if necessary) until the actual fan speed reduces to that required.

Claims (4)

Claims
1) A control system for a fan of a ventilating, airconditioning or air extraction apparatus, said control system comprising means for providing a signal representing the desired speed of said fan in accordance with one or more sensed parameters, means for supplying electrical current to an electrical motor driving said fan and dependent on said desired speed signal, and means for sensing the actual speed of said fan, said control system being arranged to alter the electrical voltage or current supplied to said motor according to any difference between said desired speed and said actual speed of said fan.
2) A system as claimed in claim 1, comprising a comparator for comparing said desired speed signal with a signal representing the actual speed of said fan, to provide an error signal which is used to control the current or voltage supplied to said motor.
3) A system as claimed in claim 2, arranged so that if said error signal persists above a predetermined value for more than a predetermined time, a further change is made to the electrical current or voltage supplied to said motor, in the sense required to reduce said error signal.
4) A control system substantially as herein described with reference to the accompanying drawings.
GB9621664A 1996-10-17 1996-10-17 Control for fan of ventilating, air-conditioning or air extraction apparatus Withdrawn GB2318431A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9621664A GB2318431A (en) 1996-10-17 1996-10-17 Control for fan of ventilating, air-conditioning or air extraction apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9621664A GB2318431A (en) 1996-10-17 1996-10-17 Control for fan of ventilating, air-conditioning or air extraction apparatus

Publications (2)

Publication Number Publication Date
GB9621664D0 GB9621664D0 (en) 1996-12-11
GB2318431A true GB2318431A (en) 1998-04-22

Family

ID=10801586

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9621664A Withdrawn GB2318431A (en) 1996-10-17 1996-10-17 Control for fan of ventilating, air-conditioning or air extraction apparatus

Country Status (1)

Country Link
GB (1) GB2318431A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000026586A1 (en) * 1998-10-30 2000-05-11 Daewoo Electronics Co., Ltd. Air curtain generator for refrigerator
EP1026452A2 (en) * 1999-02-08 2000-08-09 Adrianus Jacobus Zwaan Ventilating system
WO2005124474A3 (en) * 2004-06-14 2006-03-09 Ogd V Hvac Inc Adaptable hvac; ac motor speed, air temperature and air quality control system
EP1854201A4 (en) * 2005-02-16 2015-09-16 Texas Instruments Inc Programmable closed loop fan control

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2114325A (en) * 1982-02-05 1983-08-17 Sunbeam Corp Motor speed control circuit
EP0117558A2 (en) * 1983-02-28 1984-09-05 Hitachi, Ltd. Method and apparatus for controlling PWM inverter
US4544852A (en) * 1981-08-26 1985-10-01 Papst-Motoren Gmbh & Co. Kg Circuit arrangement for monitoring speed of a drive motor
GB2239107A (en) * 1989-12-04 1991-06-19 John Barrie Timmons Motor control system
GB2249848A (en) * 1990-08-24 1992-05-20 Nippon Denso Co Control apparatus for air-conditioner

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4544852A (en) * 1981-08-26 1985-10-01 Papst-Motoren Gmbh & Co. Kg Circuit arrangement for monitoring speed of a drive motor
GB2114325A (en) * 1982-02-05 1983-08-17 Sunbeam Corp Motor speed control circuit
EP0117558A2 (en) * 1983-02-28 1984-09-05 Hitachi, Ltd. Method and apparatus for controlling PWM inverter
GB2239107A (en) * 1989-12-04 1991-06-19 John Barrie Timmons Motor control system
GB2249848A (en) * 1990-08-24 1992-05-20 Nippon Denso Co Control apparatus for air-conditioner

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000026586A1 (en) * 1998-10-30 2000-05-11 Daewoo Electronics Co., Ltd. Air curtain generator for refrigerator
GB2358908A (en) * 1998-10-30 2001-08-08 Daewoo Electronics Co Ltd Air curtain generator for refrigerator
GB2358908B (en) * 1998-10-30 2003-04-16 Daewoo Electronics Co Ltd Air curtain generator for refrigerator
EP1026452A2 (en) * 1999-02-08 2000-08-09 Adrianus Jacobus Zwaan Ventilating system
NL1011238C2 (en) * 1999-02-08 2000-08-10 Zwaan Adrianus J Ventilation system.
EP1026452A3 (en) * 1999-02-08 2000-08-30 Adrianus Jacobus Zwaan Ventilating system
WO2005124474A3 (en) * 2004-06-14 2006-03-09 Ogd V Hvac Inc Adaptable hvac; ac motor speed, air temperature and air quality control system
JP2008502876A (en) * 2004-06-14 2008-01-31 オージーディー・ヴィ−エイチヴィエーシー・インコーポレーテッド Adaptable HVAC; AC motor speed, air temperature, and air quality control device
US7797080B2 (en) 2004-06-14 2010-09-14 Ogd V-Hvac Inc. Opto-programmed HVAC controller
US7899579B2 (en) 2004-06-14 2011-03-01 Ogd V-Hvac, Inc. Adaptable HVAC; AC motor speed, air temperature and air quality control system
EP1854201A4 (en) * 2005-02-16 2015-09-16 Texas Instruments Inc Programmable closed loop fan control

Also Published As

Publication number Publication date
GB9621664D0 (en) 1996-12-11

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WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)