WO2018141085A1

WO2018141085A1 - A temperature regulation system and a power regulation apparatus

Info

Publication number: WO2018141085A1
Application number: PCT/CN2017/072857
Authority: WO
Inventors: Chun Tak Jacky LAI; Yau Chung John Chan; Shun Cheung Ryan YEUNG; Chung Fai Norman Tse; Shu Hung Henry Chung
Original assignee: City University Of Hong Kong; Jacky Instruments Limited
Priority date: 2017-02-03
Filing date: 2017-02-03
Publication date: 2018-08-09
Also published as: CN110431359B; CN110431359A

Abstract

A temperature regulation system (100) for regulating the temperature of an enclosed space, the temperature regulation system (100) comprising a fan assembly (150), the fan assembly (150) comprising a fan (154) and a multi speed motor (152) coupled to the fan (154) and the multi speed motor (152) configured to drive the fan (154), a power regulation apparatus (200) in electrical communication with the multi speed motor (152), the power regulation apparatus (200) comprises a motor driver (220) and an occupancy sensor (302), the occupancy sensor (302) configured to detect an occupancy within the enclosed space and generate an occupancy signal being indicative of the detected occupancy, the power regulation apparatus (200) being configured to adjust the energy or power supplied to the multi speed motor (152) to control a speed of the multi speed motor (152) and a speed of the fan (154) based on the occupancy signal.

Description

A TEMPERATURE REGULATION SYSTEM AND A POWER REGULATION APPARATUS

TECHNICAL FIELD

The present disclosure relates to a power regulation apparatus and a temperature regulation system, in particular the present disclosure relates to a temperature regulation system that includes a power regulation apparatus wherein the power regulation apparatus controls power or energy supplied to one or more components of the temperature regulation system.

BACKGROUND

Temperature regulation systems are used commonly for regulating the temperature of a space such as for example a room, an office, a house and so on. Heating, ventilation and cooling (HVAC) systems are commonly used systems as temperature regulating systems. A thermostat apparatus is used to sense the thermal conditions of a space and provide a necessary signal to an air conditioning unit that is part of the HVAC system. Thermostats are in communication with one or more components of a HVAC system or a temperature regulation system.

Thermostats are generally are connected to and control the operation of fans or heating elements or heaters or valves within a temperature regulation system, such as for example an HVAC system. Typically, a thermostat senses the temperature of a space, and controls one or more components of an HVAC system to maintain the temperature of the space as close to a reference temperature as possible. The reference temperature is a temperature set point that is received from a user. Thermostats include various sensors and typically include bimetallic strips or thermistors. Typical thermostats are binary type controllers that are configured to control various components, such as fans or heating elements, to switch between an ON and OFF position. Such thermostats provide a limited operating range for the control of components in a temperature regulation system.

Line voltages are another example of thermostats that are used commonly in temperature regulation systems. In line voltage thermostats the system power is directly switched by the thermostat. Line voltage thermostats can be used to control motors that drive fans in a temperature regulation system. The fan, in a temperature regulation system, is selectively turned on or off by the thermostat depending on the temperature of the space in relation to a reference temperature. The speed of the fan is controlled using a switch.

In prior art systems, an inductive potential divider or a capacitive potential divider arrangement is used to control the fan speed.

An inductive potential divider is widely used to change the fan speed, especially for a multi speed motor that drives the fan. The voltage and current applied to the driving winding are varied by changing the connections with the thermostat. A thermostat including an inductive potential divider includes multiple input taps and a switch that can connect to one of multiple input taps. Each tap connects to an inductor. For example in a thermostat with three taps, one tap connects the supply to two inductors and the motor, a second tap connects the supply to one inductor and the motor and the third tap connects the supply directly to the motor. The fan speed is controlled by connecting to one of the taps. The inductors reduce the voltage received by the motor by acting as an impedance to the AC voltage received from the power supply.

Using only an inductive potential divider has a number of disadvantages. An inductive potential divider arrangement can only adjust the fan speed in a discrete manner and limits the choices of speeds to discrete speeds relating to the number of taps. In the three tap example the fan speed can only be low, medium or high. The size of the motor used with an inductive divider is large and bulky because of the inductive divider arrangement being integrated into the motor housing. Further the inductive divider arrangement introduces parasitic elements resulting in power quality degradation. The parasitic elements can cause motor temperature rise, introduce magnetic core losses and shorten the lifespan of the motor. Finally such an arrangement introduces additional losses and can increase the cost of the motor design.

A capacitive potential divider may be used in prior art thermostats to control the fan speed for a multi speed motor that drives the fan. The fan speed is varied by connecting the power source between a series of capacitors of predetermined value, which effectively limits the electrical power supplied to the motor. The capacitors are placed inside the motor housing or may be placed in the thermostat. The thermostat including a capacitive potential divider includes multiple input taps and includes a switch that can connect can connect to one of the plurality of input taps. Each tap connects to a capacitor or across a capacitor. For example in a thermostat with three taps, one tap connects the supply to two capacitors, a second tap connects the supply to one capacitor and the third tap connects the supply directly to the motor. The fan speed is controlled by connecting to one of the taps. The capacitors reduce the voltage received by the motor by functioning as an impedance to the AC voltage received from the power supply.

Using only a capacitive potential divider also presents a number of drawbacks. One drawback is that the capacitance values have to be carefully matched with the impedance of the motor to allow for efficient operation and control of the motor. Practically this is challenging to do as the manufacturer of a fan or motor rarely provides impedance information thus making capacitance matching difficult and often unfeasible. Further the capacitors can introduce parasitic elements that can result in losses. Capacitive potential dividers also only for discrete speed adjustment of the fan based on the configuration of taps that are selected.

It is an object of the present disclosure to provide a thermostat apparatus and/or a temperature regulation system, which will substantially ameliorate at least some of the deficiencies

It is to be understood that, if any prior art information is referred to herein, such reference does not constitute an admission that the information forms a part of the common general knowledge in the art.

SUMMARY OF THE INVENTION

In accordance with a first aspect, the present disclosure relates to a temperature regulation system for regulating the temperature of an enclosed space, the temperature regulation system comprising:

a fan assembly, the fan assembly comprising a fan and a multi speed motor coupled to the fan and the multi speed motor configured to drive the fan, a power regulation apparatus in electrical communication with the multi speed motor, the power regulation apparatus comprises: a motor driver and an occupancy sensor, the occupancy sensor configured to detect an occupancy within the enclosed space and generate an occupancy signal being indicative of the detected occupancy, the power regulation apparatus being configured to adjust the energy or power supplied to the multi speed motor to control a speed of the multi speed motor and a speed of the fan based on the occupancy signal.

In an embodiment the power regulation apparatus is configured to improve energy usage of the multi speed motor.

In an embodiment the power regulation apparatus comprises a motor driver, the motor driver being electrically coupled to the multi speed motor, the motor driver configured to generate a drive signal based on at least the occupancy signal and wherein the motor driver further providing the generated drive signal to the multi speed motor to control the speed of the multi speed motor.

In an embodiment the power regulation apparatus comprises a speed controller, the speed controlled being in electrical communication with the motor driver, the speed controller providing a reference signal to the motor driver, wherein the reference signal is based on a difference between a reference speed and a measured speed of the multi speed motor, the reference speed being based on at least the occupancy signal, and；

the motor driver configured to generate the drive signal based on the received reference signal.

In an embodiment the drive signal that is provided to the multi speed motor comprises a driving voltage and a driving frequency, the reference signal comprises a reference voltage and a reference frequency, and wherein the driving voltage and/or the driving frequency being adjusted based on the reference signal.

In an embodiment the motor driver receives a power supply signal from a power source, and wherein the motor driver generates the drive signal by modulating the received power signal based on the reference signal, and wherein the motor driver is configured to modulate the voltage, or the frequency, or the voltage and frequency of the power supply signal.

In an embodiment the driving voltage is adjusted based on the reference voltage and the driving frequency is adjusted based on the reference frequency.

In an embodiment the drive signal provided to the multi speed motor comprises a driving voltage and a driving frequency, and the motor driver is configured to provide a drive signal in one of the following modes:

a varying voltage with a constant frequency,

a varying frequency with a constant voltage,

a varying voltage with a varying frequency.

In an embodiment the speed controller comprises a comparator and a reference signal generator, the comparator configured to determine a speed error, wherein the speed error being the difference between the reference speed and the measured speed, and；

the reference signal generator configured to generate a reference signal based on the speed error.

In an embodiment the power regulation apparatus further comprises a speed sensor, the speed sensor arranged in electronic communication with the speed controller, the speed sensor configured to determine and transmit a measured speed to the speed controller, and wherein the measured speed corresponds to the motor speed.

In an embodiment the speed sensor is a tachometer that is configured to measure the instantaneous motor speed.

In an embodiment the occupancy sensor is configured to generate an occupancy signal in a first state or in a second state, the occupancy signal being in a first state if an occupant is detected in the enclosed space by the occupancy sensor, and the occupancy signal being in a second state if an occupant is not detected in the enclosed space by the occupancy sensor.

In an embodiment the power regulation apparatus comprises a reference speed generator, the reference speed generator configured to generate a reference speed based on the occupancy signal and a fan speed set point.

In an embodiment the power regulation apparatus further comprises a fan speed set point detection module, the fan speed set point detection module configured to generate a fan speed set point, the fan speed set point being a high, medium, low or off set point.

In an embodiment the fan speed set point detection module comprising at least a high speed detection path, a medium speed detection path and a low speed dete2tion path, and；

wherein the fan speed set point detection module generating a high fan speed set point if a signal is detected on a high speed detection path, or

wherein the fan speed set point detection module generating a medium fan speed set point if a signal is detected on the medium speed detection path, or

wherein the fan speed set point detection module generating a low fan speed set point if a signal is detected on the low speed detection path, or

the fan speed set point detection module generating an off set point if no signal is detected on any of the detection paths.

In an embodiment the reference speed generator is configured to receive a supply status signal, the supply status signal being a first state or a second state, wherein a first signal state corresponding to an activated power supply and a second signal state corresponding to a deactivated power supply, the supply status signal being received by the speed generator from either the fan speed set point detection module or directly from a power supply.

In an embodiment the reference speed generator generating one of a high reference speed, a medium reference speed, a low reference speed, an ultra low reference speed or an off reference speed, wherein the high reference speed is generated if a high fan speed set point, a first state occupancy signal and a first state supply status signal are received, wherein the medium reference speed is generated if a medium fan speed set point, a first state occupancy signal and a first state supply status signal are received, wherein the low reference speed is generated if a low fan speed set point, a first state occupancy signal and a first state supply status signal are received, wherein an ultra low reference speed is generated if a first state supply status signal is received and a second state occupancy signal is received, and

wherein an off reference speed is generated if a second state supply status signal is received.

In an embodiment the supply status signal is generated by the fan speed set point detection module, the fan speed set point detection module further comprising a power supply status monitor configured to detect the status of a power supply and generate the supply status signal.

In an embodiment the temperature regulation system comprising a thermostat apparatus, the thermostat apparatus comprising a fan speed selector, the fan speed selector allowing a user to set a fan speed,

the thermostat apparatus further comprising a valve controller, the valve controller configured to receive a reference temperature and a measured temperature, the valve controller further configured to generate a valve actuation signal based in the difference between the reference temperature and measured temperature,

the power regulation apparatus being removably coupled to the thermostat apparatus and the multi speed motor, the power regulation apparatus receiving the fan speed set by the user and utilizing the fan speed set by the user to control operation of the multi speed motor.

In an embodiment the user set fan speed allowing a user to select three or more discrete fan speeds, the fan speed set point detection module being in electrical communication with the fan speed selector and the fan speed set point detection module detecting a user set fan speed and generating the fan speed set point, wherein the fan speed set point corresponding to the user set fan speed.

In an embodiment the power regulation apparatus is connected between the multi speed motor and the thermostat apparatus, the power regulation apparatus being removably connectable with the thermostat apparatus and the multi speed motor and wherein the power regulation apparatus comprising standard electrical connections to allow removable connection with the multi speed motor and the thermostat apparatus.

In an embodiment the temperature regulation system comprising；

a reservoir containing a thermal exchange material,a heat exchanger in fluid communication with the reservoir, wherein the heat exchanger is adapted to receive the thermal exchange material from the reservoir,a valve located between the heat exchanger and the reservoir, the valve being moveable between an open position and a closed position based on the valve actuation signal received by the valve, wherein in an open position the valve allows passage of the thermal exchange material from the reservoir to the heat exchanger and in a closed position the valve preventing passage of the thermal exchange material from the reservoir to the heat exchanger, the valve controller being in electronic communication with the valve and providing the valve actuation signal to control the valve, a temperature sensor located within the enclosed space and configured to measure the temperature of the enclosed space to generate a measure temperature, the temperature sensor being in communication with the thermostat apparatus and the valve controller and transmitting the measured temperature to the valve controller of the thermostat apparatus, the valve controller generating a valve actuation signal to move the valve to an open position if the measured temperature is higher than the reference temperature and the valve controller generating a valve actuation signal corresponding to move the valve to a closed position if the measured temperature is lower than the reference temperature.

In accordance with a second aspect, the present disclosure relates to a power regulation apparatus for use with or as part of a temperature regulation system for regulating temperature of an enclosed space, the temperature regulation system including a fan assembly that includes a fan and a multi speed motor connected to the fan and configured to drive the fan, the power regulation apparatus in electrical communication with the multi speed motor and the power regulation apparatus comprising: a motor driver and an occupancy sensor, the occupancy sensor configured to detect an occupancy within the enclosed space and generate an occupancy signal being indicative of the detected occupancy, the power regulation apparatus being configured to adjust power supplied to the multi speed motor to control a speed of the multi speed motor and a speed of the fan based on the occupancy signal.

In an embodiment the motor driver being electrically coupled to the multi speed motor, the motor driver configured to generate a drive signal based on at least the occupancy signal and wherein the motor driver further providing the generated drive signal to the multi speed motor to control the speed of the multi speed motor.

a varying voltage with a constant frequency,

a varying frequency with a constant voltage,

a varying voltage with a varying frequency.

In an embodiment the fan speed set point detection module comprising at least a high speed detection path, a medium speed detection path and a low speed detection path, and；

wherein an off reference speed is generated if a second state supply status signal is received or an off set point is received.

In an embodiment the occupancy sensor is an infrared sensor that is configured to detect movement within the enclosed space to determine occupancy or detect the number of occupants in the enclosed space.

In accordance with a third aspect the present disclosure relates to a power regulation apparatus for use with or as part of a temperature regulation system , wherein the temperature regulation system is configured to regulate the temperature of an enclosed space, the temperature regulation system comprising a fan and a multi speed motor connected to and driving the fan, the power regulation apparatus comprising:

one or more active electronic components being electrically coupled to a power supply and the one or more electronic components configured to receive a supply power, the one or more active electronic components being electrically coupled to the multi speed motor, the one or more electronic components configured to modulate the received supply power to generate a drive signal, and deliver the drive signal the multi speed motor, an occupancy sensor, the occupancy sensor configured to generate an occupancy signal, and wherein the one or more active electronic component configured to modulate the supply power and generate a drive signal based on the occupancy signal.

In an embodiment the power regulation apparatus is removably connectable to a thermostat apparatus, the power regulation apparatus is configured to receive a fan speed set point from the thermostat apparatus, and the one or more active electronic components of the power regulation apparatus being configured to generate a drive signal based on the fan speed set point and the occupancy signal.

In an embodiment one or more active electrical components of the power regulation apparatus being configured to generate a drive signal that comprises one of:

a varying voltage with a constant frequency, or

a constant voltage with a varying frequency, or

a varying voltage and a varying frequency.

In accordance with a fourth aspect the present disclosure relates to a method of regulating a temperature of an enclosed space using a temperature regulating system, wherein the temperature regulating system comprises a fan, a multi speed motor driving the fan, a thermostat apparatus providing a fan speed set point, a power regulation apparatus connected between the thermostat apparatus and the multi speed motor and in electronic communication with the thermostat apparatus and the multi speed motor, the method of regulating a temperature of an enclosed space comprising the steps of:

determining a fan speed set point, receiving an occupancy signal corresponding to an occupancy of the enclosed space from an occupancy sensor, determining a reference speed based on the fan speed set point and the received occupancy signal, determining a measured speed of the multi speed motor from a speed sensor, determining a difference between reference speed and the measured speed, generating a reference signal based on the difference between the measured speed and the reference speed, generating a drive signal based on the reference signal, transmitting the drive signal to the multi speed motor to drive the multi speed motor.

In an embodiment the drive signal is generated in one of the following modes:

a varying voltage with a constant frequency,

a varying frequency with a constant voltage,

a varying voltage with a varying frequency.

The term speed as used herein relates to rotational speed. The following specification will use the terms speed and rotational speed interchangeably. Rotational speed as defined herein relates to the rotational speed of the rotor that is part of the motor. The term motor speed is used to denote rotor speed i.e. rotational speed of the rotor and drive shaft of the motor. This may be equal to the rotational speed of the fan. The terms motor speed and rotor speed are interchangeably used in the following specification and mean the same.

The term power as used herein can relate to either the voltage or electrical power (voltage x current) or current supplied to the motor. The term power as used herein denotes a general energy supplied to the motor that encompasses voltage or current or electrical power.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings in which:

Figure 1 illustrates a temperature regulation system including a power regulation apparatus.

Figure 2 illustrates an electrical schematic of the power regulation apparatus that can be used with or as part of the temperature regulation system.

Figure 3 illustrates an electrical schematic of the motor driver that forms part of the thermostat apparatus.

Figure 4 illustrates an electrical schematic of the speed controller when the speed controller is functioning in a variable voltage constant frequency mode.

Figure 5 illustrates an electrical schematic of the speed controller when the speed controller is functioning in a constant voltage variable frequency mode.

Figure 6 illustrates an electrical schematic of the speed controller when the speed controller is functioning in a variable voltage variable frequency mode.

Figure 7 shows the fan speed set point detection module when generating an off set point.

Figure 8 shows the fan speed set point detection module when generating a high fan speed set point.

Figure 9 shows the fan speed set point detection module when generating a medium fan speed set point. Figure 10 shows the fan speed set point detection module when generating a low fan speed set point.

Figure 11 shows a flow chart illustrating the function of the reference speed generator to generate a reference speed.

Figure 12 shows a method of calibrating a speed sensor of the power regulating apparatus.

Figure 13 illustrates a graph of back EMF generated by a motor and square pulses generated at each zero crossing of the back EMF signal.

Figure 14 shows a method of regulating temperature of an enclosed space using a temperature regulation system, which includes the power regulation apparatus.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The present disclosure relates to a power regulation apparatus that is used as part of a temperature regulation system, such as for example a heating, ventilation and air conditioning system (aHVAC system) . The power regulation apparatus is used as part of the HVAC system and is configured to control one or more components of the HVAC system to regulate temperature in an enclosed space. The enclosed space may be a room, a house, a factory, a manufacturing space, a laboratory, a medical clinic, a hospital ward, an office, a building floor, a shop or any other such enclosed space. The power regulation apparatus can be used as part of a temperature regulation system that includes a thermostat apparatus. The power regulation apparatus can be retrofitted into any temperature regulation system and be used with any conventional thermostat.

The present disclosure relates to a power regulation apparatus for use with or as part of a temperature regulation system for regulating temperature of an enclosed space, the temperature regulation system including a fan assembly that includes a fan and a multi speed motor connected to the fan and configured to drive the fan, the power regulation apparatus in electrical communication with the multi speed motor and the power regulation apparatus comprising； a motor driver and an occupancy sensor, the occupancy sensor configured to detect an occupancy within the enclosed space and generate an occupancy signal being indicative of the detected occupancy, the power regulation apparatus being configured to adjust the energy or power supplied to the multi speed motor to control a speed of the multi speed motor and a speed of the fan based on the occupancy signal. The motor driver being electrically coupled to the multi speed motor, the motor driver configured to generate a drive signal based on a reference signal. The reference signal being based on a difference between reference speed and a measured speed of the multi speed motor. The reference speed being generated based on the occupancy signal and a fan speed set point. The fan speed set point may be pre‐set or may be inputted by a user.

The present disclosure further relates to a temperature regulation system for regulating the temperature of an enclosed space, the temperature regulation system comprising； a fan assembly, the fan assembly comprising a fan and a multi speed motor coupled to the fan and the multi speed motor configured to drive the fan, a power regulation apparatus in electrical communication with the multi speed motor, the power regulation apparatus comprises； a motor driver and an occupancy sensor, the occupancy sensor configured to detect an occupancy within the enclosed space and generate an occupancy signal being indicative of the detected occupancy, the power regulation apparatus being configured to adjust the energy or power supplied to the multi speed motor to control a speed of the multi speed motor and a speed of the fan based on the occupancy signal.

Exemplary embodiments of the temperature regulating system and power regulation apparatus will be described with reference to the drawings.

Referring to figure 1 there is illustrated a temperature regulation system 100 that is used to regulate the temperature of an enclosed space 102. The system 100 includes an inlet duct 110 and an outlet duct 112 that in fluid communication with each other. Return air 114 is sucked in through the inlet duct 110 and supply air 116 is delivered via the outlet duct. Air within the enclosed space 102 can be circulated through the temperature regulation system 100 to maintain the temperature of the enclosed space 102 at a selected or predetermined reference temperature.

The temperature regulation system 100 further comprises a passage 120 that is positioned between the inlet duct 110 and the outlet duct 112. The passage 120 includes an inlet opening 122 in fluid communication with the inlet duct 110 and an outlet opening 124 in fluid communication with the outlet duct 112. The passage 120 may include an inlet manifold (not illustrated) that is positioned at the inlet opening that can connect to multiple inlet ducts. The passage 120 may further include an outlet manifold (not illustrated) that is positioned at the outlet opening 124 that can connect to multiple outlet ducts.

Referring again to figure 1, the temperature regulation system 100 further includes a heat exchanger 130, a reservoir 140 that is configured to hold a thermal exchange material and a fan assembly 150. As shown in figure 1 the heat exchanger 130 and the fan assembly 150 are positioned within the passage 120 such that air from the inlet opening 122 passes over and across the heat exchanger 130 and into the fan assembly 150. The heat exchanger 130 is configured to facilitate thermal energy exchange between the air and the heat exchanger 130. In the illustrated embodiment of figure 1, the heat exchanger 130 is configured to cool the air pass across the heat exchanger 130. The fan assembly 150 is configured to impart a driving pressure onto the air received into the fan assembly 150. The fan assembly 150 is configured to push cooled air out of the outlet duct 112 as supply air 116.

As shown in figure 1, the temperature regulation system 100 comprises a filter 160 that is disposed downstream of the inlet duct 110 and downstream of the inlet opening 122. The filter 160 is located upstream of the heat exchanger 130 and the fan assembly 150. The filter 160 is a dust filter such as for example a HEPA filter. The filter 160 is configured to filter out particulate matter such as dust, air borne particles, hair and other particulate matter from the air passing through the passage 120. The filter 160 prevents or reduces the amount of particulate matter such that the fan assembly 150 does not get blocked or cease up during operation.

The heat exchanger 130 will be described in more detail now. The heat exchanger 130, as shown in figure 1, is a shell and tube type heat exchanger. The heat exchanger 130 comprises a hollow shell 132 that houses a coiled tube 134. The coiled tube 134 is a single tube that includes a plurality of U bends, as seen in figure 1. In the illustrated embodiment the tube 134 comprises seven U bends but alternatively may include any suitable number of U bends depending on the size of heat exchanger required and the amount of heat exchange required. The coiled tube 134, and in particular the section of the coiled tube 134 that includes the U bends defines a heat transfer area 139. The air passing through the passage 120 is cooled as is passes through the heat transfer area 139 i.e. as the air passes across the U bends in the coiled tube 134.

The heat exchanger 130 further comprises an inlet tube section 136 and an outlet tube section 138. The inlet tube section 136 is connected to and in fluid communication with the coiled tube 134 at one end and enters the shell 132 from one side. The outlet tube section 138 is connected to and in fluid communication with the coiled tube 134 at an opposing end to the inlet tube section 136. The outlet tube section 138 exits the shell 132 from an opposing side to the inlet of the inlet tube section 136. As shown in figure 1, the inlet tube section 136 and outlet tube section 138 may be integrally formed with the coiled tube section 134. Alternatively the inlet tube section 136 and the outlet tube section 138 may be separate tubes that are connectable to the coiled tube 134.

The heat exchanger 130 is in fluid communication with the reservoir 140. The inlet tube section 136 and the outlet tube section 138 connect to the reservoir. A fluid pathway is formed between the reservoir 140 to the coiled tube 134 via the inlet tube section 136 and the outlet tube section 138. The reservoir is adapted to receive and hold a thermal exchange material. In the illustrated embodiment of figure 1, the thermal exchange material is chilled water. The chilled water is transferred into the thermal exchanger 130 and cools the air passing across the thermal exchanger 130. The chilled water is introduced into the coiled tube 134 via the inlet tube section 136 and returned to the reservoir 140 via the outlet tube section 138. The chilled water flows through the inlet tube section 136, the coiled tube 134, the outlet tube section 138 and back to the reservoir 140.

The system 100 includes a valve 170 that is located on the inlet tube section 136. The valve 170 is located between the heat exchanger 130 and the reservoir 140. The valve 170 being selectively moveable between an open position and a closed position. When the valve 170 is in an open position the valve 170 allows passage of the thermal exchange material from the reservoir 140 to the heat exchanger 130. In a closed position the valve 170 prevents the passage of the thermal exchange material from the reservoir 140 to the thermal exchanger 130. In the illustrated example the valve 170 is an electronically controlled valve such as a solenoid valve.

The valve 170 receives an actuation signal that includes state information including an ON state and an OFF state, the ON state causes the valve to move to an open position and the OFF state causes the valve to move to a closed position. In an open position the solenoid valve allows chilled water to flow from the reservoir 140 to the heat exchanger 130 and in a closed position the valve 170 prevents flow of the chilled water from the reservoir 140 to the heat exchanger 130.

The fan assembly 150 will be described in more detail with respect to figure 1. The fan assembly 150 comprises a motor 152 and a fan 154. The motor 152 is electrically connected to the fan 154 and mechanically coupled to the fan 154 by a drive shaft. The motor 152 is configured to drive the fan 154 at a speed. The motor 152 is a multi‐speed motor and the motor 152 is configured to rotate the fan at a selected rotational speed. The multi speed motor 152 is a rotational motor that generates a rotational or rotary movement. Speed as defined within this specification refers to rotational speed. The fan 154 includes a plurality of fins. The fan 154 may include any suitable number of fins to create a driving pressure to push the air out of the outlet duct 112.

The temperature regulation system 100 comprises a thermostat apparatus 190. The thermostat apparatus 190 is in electrical communication with the valve 170 and provides the valve with an actuation signal. The thermostat apparatus 190 is in electrical communication with a power regulation apparatus 200. The power regulation apparatus 200 is in electrical communication with the multi speed motor 152 and drives the multi speed motor. The thermostat apparatus 190 is in electrical communication with the power regulation apparatus 200. The power regulation apparatus regulates or controls the power delivered to the multi speed motor 152. The power regulation apparatus 200 controls or regulates at least the voltage and/or the frequency of the voltage provided to the motor 152. The power regulation apparatus 200 directly supplies power to the motor 152. The power regulation apparatus 200 is removably connectable to the thermostat apparatus 190. The power regulation apparatus 200 comprises appropriate connections or interfaces or interfacing circuitry to allow removable connection with the thermostat apparatus 190 and the multi speed motor 152. The power regulation apparatus 200 is retrofittable with any thermostat apparatus 190, in particular any conventional thermostat apparatus. The thermostat apparatus 190 acts as a front end interface for the user to input settings such as fan settings and a reference temperature, while the power regulation apparatus controls power (i.e. at least voltage) or energy supplied to drive the motor. The power regulation apparatus 200 controls the speed of the motor based on the user input and based on the occupancy of the enclosed space 102.

Referring to figure 1, the thermostat apparatus 190 includes a user interface 192. The user interface 192 is located within the enclosed space 102 and accessible by a user or person. In one example thermostat apparatus 190 may be disposed on a wall in the space or on any other suitable structure such that a user can access the thermostat apparatus 190. The user interface 192 allows a user to set a reference temperature for the space 102. The reference temperature is the temperature that is desired in the space 102. The user interface 192 is configured to be in electrical communication with one or more components of the thermostat apparatus 190. The user interface 102 also allows a user to set a fan speed via the user interface. The fan speed set by the user is used by the power regulation apparatus 200 to control the multi speed motor to control the motor in a more efficient manner.

The temperature regulation system further includes a temperature sensor 180. The temperature sensor 180 measures the temperature of the room and feeds this value into the thermostat apparatus 190. The measured temperature value is used by the thermostat to at least generate a valve actuation signal. The valve actuation signal is generated based on a difference between a reference temperature (i.e. user set temperature) and the measured temperature from the temperature sensor 180. The fan speed may also be modified by the thermostat 190 based on the difference between a measured temperature and a reference temperature. The fan speed value determined by the thermostat 190 is utilized by the power regulation apparatus 200 in combination with an occupancy signal generated by the occupancy sensor 302 to generate a drive signal to control and drive the motor 152.

The power regulation apparatus 200 comprises an occupancy sensor 302. The occupancy sensor 302 as shown in figure 1 and figure 2 is a separate unit that is mounted in the enclosed spaced 102. The occupancy sensor 302 is configured to detect or determine an occupancy of the enclosed space 102 and generate an occupancy signal corresponding to the detected occupancy. The occupancy sensor 302 may be an infrared sensor that can detect the occupancy of the enclosed space. The occupancy sensor 302 is configured to generate the occupancy signal in a first state or in a second state, the occupancy signal being in a first state if an occupant is detected in the enclosed space by the occupancy sensor 302 and the occupancy signal being in a second state if an occupant is not detected in the enclosed space 102. The occupancy sensor 302 generates a binary occupancy signal. The occupancy signal can be in a first state e.g. YES or POSITIVE or HIGH when there is one or more occupants detected within the enclosed space. The occupancy signal is in a second state e.g. NO or NEGATIVE or LOW when there is no occupant detected in the enclosed space 102. The occupancy sensor 302 may be an infrared sensor or a laser sensor that can detect the presence of one or more occupants in the enclosed space.

Alternatively the occupancy sensor 302 may be a camera. In an alternative form the occupancy sensor 302 may generate an occupancy signal that is continuous and corresponds to the number of occupants in the enclosed space 102. For example the occupancy signal may increase in magnitude or frequency as the number of occupants increases.

Referring to figures 2 to 12 the power regulation apparatus 200 will be described in more detail. Figure 2 shows an electrical schematic of the thermostat apparatus 190 and power regulation apparatus 200. The thermostat apparatus 190 may be a conventional thermostat apparatus. The power regulation apparatus 200 is electrically connected or in electrical communication with the thermostat apparatus 190. The thermostat apparatus 190 is configured for use with or as part of the temperature regulation system 100. The power regulation apparatus 200 is also configured for use with or as part of the temperature regulation system 100. The thermostat apparatus 190 is electrically coupled to a power supply 210 is an AC power supply. The power regulation apparatus 200 is also electrically coupled to an AC power supply 210. In the illustrated embodiment the power supply 210 is a mains power supply that generates an alternating current and an alternating voltage. The voltage is generated at a specified frequency.

The power regulation apparatus 200 is connected directly to the mains power. The power regulation apparatus 200 is configured to generate a drive signal by modulating the power supply signal received from the power supply 210. The power regulation apparatus 200 is configured to generate a drive signal in one of the following modes:

a. a varying voltage with a constant frequency,

b. a varying frequency with a constant voltage,

c. a varying voltage with a varying frequency.

The power regulation apparatus 200 comprises at least a motor driver that is configured to generate a drive signal in one of the above listed modes.

Referring to figure 2, the power regulation apparatus 200 further comprises a motor driver 220 that is electrically coupled to and configured to control the multi speed motor 152. The motor driver 220 generates and provides a drive signal to the multi speed motor 152. The thermostat apparatus 190 comprises a speed controller 230 in electronic communication with the motor driver 220 and provides a reference signal to the motor driver 220. The reference signal is based on a difference between a reference speed and a measured speed of the motor. The drive signal is generated based on the reference signal from the speed controller 230. The thermostat apparatus further comprises a speed sensor 240 in electronic communication with the speed controller. The speed sensor 240 determines the speed of the motor and provides feedback of the motor speed (i.e. the measured speed) to the speed controller 230. The power regulation apparatus 200 further includes a fan speed set point detection module 250 and a reference speed generator 270. The fan speed set point detection module 250 is in electrical communication with the thermostat apparatus 190. In particular the fan speed set point detection module detects the fan speed set at the thermostat apparatus 190 and provides the fan speed to reference speed generator 270. The reference speed generator 270 uses the fan speed set point and the occupancy signal from the occupancy sensor 302, to generate a reference speed and provide the reference speed to the speed controller 230. The speed controller utilizes the reference speed to generate a drive signal. The drive signal is based at least partially on the occupancy signal and the fan speed set point.

The components of the thermostat apparatus 190 described are disposed in a casing 194. The components of the power regulation apparatus are also positioned within a casing 260. The casing 260 may be a metal or plastic casing. The thermostat apparatus 190 and casing 194 may be mounted on a wall within the enclosed space for access by the user to input a reference temperature and fan speed. The power regulation apparatus 200 and the casing 260 may be mounted on a wall next to the thermostat 190 or may be mounted elsewhere within the space 102.

The thermostat apparatus 190 further includes a valve controller 199. The valve controller 199 is a hardware controller that is in electronic communication with the valve 170. The valve controller is configured to receive a reference temperature and a measured temperature. The valve controller 199 is configured to determine a difference between the reference temperature and measured temperature and generate an error signal. The valve controller 199 is further configured to generate a valve actuation signal based on the error signal i.e. based on the difference between the measured temperature and the reference temperature. The valve actuation signal causes the valve to move between either an open position or a closed position. When the valve 170 is in an open position the thermal exchange material within the reservoir e.g. chilled water or coolant can flow into the heat exchanger. When the valve 170 is in a closed position the thermal exchange material does not flow into the thermal exchanger. The valve controller is configured to deliver a signal to open the valve if the measured temperature is less than the reference temperature. Alternatively the valve controller 199 may deliver an actuation to open based on the size of the error signal e.g. if the error signal is greater than a threshold.

As stated above the motor driver 220 provides a drive signal to the multi speed motor 152. The drive signal comprises a driving voltage and a driving frequency. The reference signal generated by the speed controller 230 comprises a reference voltage (labelled V_ref) and a reference frequency (labelled f_ref) . The driving voltage or the driving frequency or both are adjusted based on the reference signal. In particular the driving voltage is adjusted based on the received reference voltage V_ref and the driving frequency is adjusted based on the reference frequency f_ref. Specifically the motor driver is configured to provide a drive signal in one of the following modes:

a. a varying voltage with a constant frequency (VVCF mode) ,

b. a varying frequency with a constant voltage (CVVF mode) ,

c. a varying voltage with a varying frequency (VVVF mode) .

The speed of the multi speed motor 152 is based on the received driving voltage and the driving frequency. The motor driver 220 modulates the received power supply based on the reference signal to generate a drive signal, specifically the motor driver 220 being configured to modulate the voltage or frequency or both of the power supply signal.

The motor driver 220 is also electrically coupled to the power supply 210 and configured to receive a power signal from the power supply 210. The motor driver 220 is directly connected to the multi speed motor such that all the voltage of the drive signal is delivered to the multi speed motor 152. As seen in figure 2 there may be a built in potential divider assembly within either the power regulation apparatus 200 or in the motor 152. The potential divider is bypassed and unused in the currently illustrated embodiment. Alternatively the outputs of the motor driver may be coupled to a switch that interconnects to the potential divider in the motor 152 to provide additional speed control to the motor. The currently illustrated embodiment does not use the potential divider and controls speed by varying the voltage or frequency of the supply to the motor, thereby reducing the overall components, losses due to using passive components and reduces any parasitic resistances or voltages introduced due to passive components such as the potential divider.

The motor driver 220 may include an inverter, cycloconverter, or a power flow controller. The motor driver 220 includes components depending on the cost of hardware implementation, power rating, heat dissipation, magnitude or noise and size constraints.

Figure 3 shows an embodiment of the motor driver 220. Figure 3 shows a schematic diagram of the motor driver 220. The motor driver 220 includes a switching network 221 that includes power electronics such as Triacs, Diodes, Power MOSFETS etc. These components are organized together to form an electrical switching network 221. The switching network effectively acts as an actuator to shape the motor voltage and its corresponding frequency. The switching network 221 is operated based on a gate signal that is generated by a driver feedback controller 224. The gate signals define the switching pattern of the switching network 221, such that the switching network outputs the appropriate driving signal including a driving voltage and a driving frequency.

The motor driver 220 further includes a passive network comprising passive elements such as capacitors and/or inductors. The passive network is connected to the switching network. The passive network acts as a low pass filter to smooth out pulsating voltage and current as well as improving the EMI performance. The passive network also reduces voltage spikes that may induced due to the coils in the motor 152.

The motor driver 220 comprises a command signal generator 222. The command signal generator 222 comprises appropriate circuitry to generate a command signal that is defined as V_cmd (t) that is provided to a voltage comparator 223. The command signal is generated based on a received reference signal, and specifically based on a received reference voltage V_ref and a reference frequency f_ref. The reference signal is generated by the speed controller 230 and provided to the command signal generator 222. The command signal V_cmd (t) generated is different for each driving signal mode. Table 1 below shows a relationship between the drive signal mode and the command signal.

TABLE 1:

f_N is a nominal frequency of the motor in Hz, and V_n is the nominal RMS voltage of the motor in Volts.

In VVCF mode, the motor control engine only varies the motor voltage V_Motor, while the frequency of the motor f_Motor is kept as the same as the nominal frequency of the motor f_N. In CVVF mode, the motor control engine only varies the motor frequency f_Motor, while the motor voltage V_Motoris kept as the same as the nominal RMS voltage of the motor V_N. In VVVF mode, the motor control engine varies both motor voltage and frequency. Typically, the ratio between the motor voltage V_Motor and frequency f_Motor is maintained as the same as the ratio between the motor nominal voltage V_Nand nominal frequency f_N to achieve constant flux operation, i.e.

As shown in figure 3, the motor driver 220 further comprises a motor driver comparator 223. The motor driver comparator 223 generates an error signal ε_v that is provided to a driver feedback controller 224. The error signal is the difference between the command voltage signal V_cmd (t) and a sampled motor voltage V_motor. The driver feedback controller 224 comprises appropriate circuitry and the driver feedback controller 224 is configured to suppress the error signal to zero. The driver feedback controller 224 outputs an appropriate switching pattern i.e. gate signals that are delivered to the switching network 221. The driver feedback controller 224 may be a PID controller or any other suitable controller.

The power regulation apparatus 200 further comprises a speed controller 230 in electronic communication with the motor driver 220, as illustrated in figure 2. The speed controller 230 is further configured to provide a reference signal to the motor driver 220. The reference signal is based on the difference between a reference speed and a measured speed of the multi speed motor 152. The reference speed is generated by the reference speed generator 270. The reference speed is based at least on the occupancy of the space 102 i.e. the occupancy signal. The reference speed is based on the occupancy signal and a fan speed set point. The fan speed set point is based on the selected fan speed by a user at the thermostat apparatus 190.

The speed controller 230 is configured to map the reference speed (i.e. a reference motor speed) to the reference signal. In particular the speed controller 230 is configured to map the reference speed ω_ref to the reference voltage V_ref and reference frequency f_ref. Depending on the type of motor driver 220 the speed controller 230 can generate an appropriate reference voltage and an appropriate reference frequency. The speed controller 230 comprises a speed controller comparator 231 and a reference feedback controller 232. The comparator 231 and reference feedback controller 232 operation is described with reference to figures 4, 5 and 6.

Figure 4 shows an arrangement of a speed controller 230 when the motor driver 220 functions in a VVCF (variable voltage constant frequency) mode. Figure 4 is a schematic view of the internal modules of the speed controller 230. As shown in figure 4, the comparator 231 receives a reference speed and a measured speed. The speed controller 230 receives a reference speed from the reference speed generator 270 and receives a measured speed is received from a speed sensor 240. The comparator 231 generates a speed error signal ε_ω. The reference feedback controller 232 receives the speed error signal and generates an appropriate reference voltage signal V_ref. The reference feedback controller is configured to compensate for the speed error by varying the motor voltage set point i.e. by varying the reference voltage. The reference frequency f_ref and hence frequency of the motor are kept constant. The reference frequency is set to a nominal frequency f_N. The nominal frequency in the embodiment of figure 4 may be mains frequency e.g. 50Hz or any other suitable frequency.

Figure 5 shows an arrangement of a speed controller 230 when the motor driver 220 functions in a CVVF (constant voltage variable frequency) mode. Figure 5 is a schematic view of the internal modules of the speed controller 230. As shown in figure 5, the comparator 231 receives a reference speed and a measured speed. In this mode, the comparator generates an error signal based on the difference between a received reference speed and a measured speed. The reference feedback controller 232 generates an appropriate reference frequency f_ref. The reference feedback controller compensates for the speed error signal by varying the reference frequency f_ref. The reference voltage V_ref is kept constant, which is a nominal motor voltage V_n.

Figure 6 shows an arrangement of the speed controller 230 when the motor driver 220 functions in a VVVF (variable voltage variable frequency) mode. Figure 6 is a schematic view of the internal modules of the speed controller 230. Referring to figure 6, the comparator 231 generates an error signal that relates to the difference between a reference speed and a measured speed. The reference feedback controller 232 compensates for the speed error by varying the motor set point voltage i.e. reference voltage V_ref and the set point frequency i.e. reference frequency f_ref. The ratio between the reference voltage and reference frequency is kept constant, which may be the same as the ratio between the motor nominal voltage V_N and a nominal frequency f_N to achieve a constant flux operation.

As discussed earlier with reference to figure 2, power regulation apparatus 200 comprises a speed sensor 240. The speed sensor 240 is configured to provide a motor speed ω (i.e. fan speed) signal to the speed controller 230. In an embodiment the speed sensor 240 comprises a tachometer. The tachometer may be positioned in the fan assembly 150. The tachometer may be positioned in the motor 152 or on the fan 154 or on the drive shaft that connects the motor to the fan. The tachometer is configured to measure the speed of the motor (or fan) and returns a measured speed value in revolutions per min. The tachometer measures the actual rotational speed of the motor. Preferably the speed sensor 240 comprises a tachometer. Alternatively if a tachometer is not available then a back EMF detection can be used. The back EMF detection process is described later in the description of alternative embodiments. Preferably a direct speed sensor is used such as a tachometer or accelerometer.

As seen in figure 2 the power regulation apparatus 200 is connected to a conventional thermostat apparatus 190. The conventional thermostat apparatus includes a supply switch 196. The supply switch controls power supply to the fan speed set point detection module 250. The thermostat 190 further includes a fan speed selector 198. The fan speed selector 198 is provided as part of the user interface 192 and may be a switch or a series of buttons. The fan speed selector 198 allows for discrete fan speed selections. In the exemplary embodiment of figure 2 the fan speed selector 198 allows three fan speed selections, HIGH, MED, LOW (i.e. high, medium, low) . The fan speed selector 198 allows a user to select a desired fan speed. Alternatively the fan speed selector may allow for two or more discrete fan speeds to be selected. The fan speed selector may alternatively be a knob or a remote control unit allowing a user to select any desired fan speed. In a further alternative example the fan speed selector 198 may be automatically controlled by a separate fan speed controller (not illustrated) within the thermostat apparatus 190. The fan speed selection may be defined based on a difference between the measured room temperature T_room and a reference temperature i.e. a desired or set temperature T_ref. The fan speed selector 198 is in electrical communication with the fan speed set point detection module 250.

The fan speed set point detection module 250 determines an appropriate fan speed set point. Referring to figures 7 to 10, there is illustrated an embodiment of the fan speed set point detection module 250 and the components thereof. Figures 7 to 10 shows an exemplary architecture of the fan speed set point detection module 250. The fan speed set point detection module 250 is electrically coupled to the fan speed selector 198, and forms a detection circuit 252 with the fan speed selector 198. The detection circuit 252 is a complete circuit. The fan speed set point detection module 250 is configured to generate a fan speed set point, wherein the fan speed set point can be high, medium, low or off. The fan speed set point detection module 250 comprises a plurality of detection paths. In the illustrated embodiment the fan speed detection module 250 comprises three

detection paths

254, 256, 258 that form part of the detection circuit. The three

detection paths

254, 256, 258 correspond to a high, medium or low speed detection. The fan speed set point detection module 250 also comprises a plurality of resistors 259 in that are used to zero the voltage in the circuit. The resistors 259 are substantially high resistance or high magnitude resistors. The

detection paths

254, 256, 258 are electrically connected to the fan speed selector 198. The fan speed set point detection module generates an off or zero set point if no signal is detected on any of the detection paths. This occurs if the mains supply switch 196 is in an OFF position thereby breaking the circuit from the mains power. Figure 7 shows a circuit arrangement for an off or zero speed set point.

Figure 8 shows a circuit arrangement when the fan speed set point detection module 250 determines a high fan speed set point. The fan speed set point detection module 250 generates a high fan speed set point if a signal is detected on the high speed detection path 254. The speed selector 198 selects a high speed which causes the speed selector to connect the high speed detection path 254 to the power supply 210. Figure 9 shows a circuit arrangement when the fan speed set point detection module 250 determines a medium or med fan speed set point. The fan speed set point detection module 250 generating a med fan speed set point if a signal is detected on the med speed detection path 256. Figure 10 shows an arrangement of the fan speed detection module 250 when it determines a low fan speed set point. The fan speed set point detection module 250 generates a low fan speed set point if a signal is detected on the low speed detection path 258.

The reference speed generator 270 is a hardware unit that comprises appropriate active electronic components to process received signals and output a reference speed to the speed controller 230. The reference speed generator 270 is configured to receive a supply status signal, the supply status signal being in a first state or a second state, wherein a first signal state corresponds to an activated power supply and a second signal state corresponds to a deactivated power. The supply status signal may be part of the speed set point outputted by the speed set point detection module 250. The fan speed set point detection module 250 may comprise a power supply status monitor configured to detect the status of a power supply and generate the supply status signal and transmit the status to the reference speed generator 270. Alternatively there may be a direct connection between the power supply and the reference speed generator 270. In the case of a direct connection to the power supply, the supply status signal is received at the reference speed generator 270.

The reference speed generator 270 generates a reference speed based on the state of the supply status signal, the speed set point received from the fan speed set point detection module 250 and the occupancy signal received from the occupancy sensor 302. The reference speed generator 270 processes the received signals and generates one of a high reference speed, a medium reference speed, a low reference speed, an ultra low reference speed or an off reference speed.

The reference speed generator generates a high reference speed is generated if a high fan speed set point, a first state occupancy signal and a first state supply status signal are received. A medium reference speed is generated if a medium fan speed set point, a first state occupancy signal and a first state supply status signal are received. A low reference speed is generated if a low fan speed set point, a first state occupancy signal and a first state supply status signal are received. An ultra low reference speed is generated if a first state supply status signal is received and a second state occupancy signal is received, and an off reference speed is generated if a second state supply status signal is received.

Figure 11 shows a flow chart illustrating the function of the reference speed generator 270 to generate a reference speed. Referring to figure 11, the method 1100 implemented by the reference speed generator begins at step 1101. At step 1102, the reference speed generator 270 checks the supply status i.e. if the supply is ON or OFF. If No then an off reference speed or zero reference speed is generated. If yes at step 1102, the method proceeds to step 1104. At step 1104, the reference speed generator processes the occupancy signal to determine if there is at least one occupant depending on the state of the occupancy signal. If No i.e. no occupants in the space 102, then the ultra low reference speed is outputted by the reference speed generator 270. If Yes at step 1104, the method proceeds to step 1106. At step 106 the reference speed generator checks if a high speed set point has been received. If Yes then a high reference speed is generated. If no then the method proceeds to step 1108 where the reference speed generator 270 checks if a med speed set point signal has been received. If Yes then a med reference speed is outputted. If no then at step 1110 the reference speed generator 270 outputs a low reference speed. The reference speed generator 270 is configured to multiplex the speed set point inputs. The method 1100 is executed by the reference speed generator 270 regularly at a set period for example the method is repeated every millisecond or every microsecond. The method 1100 may be stored as computer readable and executable instructions in a local memory unit of the reference speed generator 270. The reference speed generator includes a processor or processing circuitry that is configured to execute the stored instructions and execute method 1100 at the regular period.

Referring again to figure 2, the power regulation apparatus 200 further includes an AC load current sensor 272 (I_AC) . This sensor measures the current drawn by the motor driver 220. The AC load current sensor 272 may generate an alarm or disable the motor driver 220 if the current drawn is below a first threshold or greater than a second threshold. The AC load current sensor is any suitable type of current sensor such as for example a resistive current sensor or a Hall effect IC current sensor.

The power regulation apparatus 200 further includes an AC grid voltage sensor 274. The AC grid voltage sensor 274 measures the grid voltage V_AC and provides the grid voltage to the motor driver 220. The AC grid voltage sensor 274 is useful if a power factor corrector is used in the motor driver. Based on the sampled voltage the RMS (root mean square) grid voltage and grid frequency are determined. The AC grid voltage sensor 274 is any suitable voltage sensor, such as for example a non‐isolated resistive divider network with a differential amplifier. Alternatively the AC grid voltage sensor 274 may be implemented using isolated methods, such as optically isolated sigma‐delta modulator, a voltage transformer based voltage sensor or a linear optocoupler or any other suitable sensor.

The power regulation apparatus 200 further includes an AC motor voltage sensor 276. The AC motor voltage sensor 276 is configured to measure a motor voltage V_motor. It provides the motor voltage value or signal to the motor driver 220 and the speed sensor. Based on the sampled voltage signal, the RMS motor voltage and frequency to be supplied to the motor are determined. The AC motor voltage sensor 276 may be implemented as any suitable voltage sensor. For example the AC motor voltage sensor 276 may include a sensor that is similar in structure and function as the AC grid voltage sensor 274.

As shown in figure 2, the power regulation apparatus 200 comprises an AC load current sensor 278. The AC load current sensor 278 measures the motor current I_motor drawn by the motor 152. Operation of the motor driver 220 will be disabled if the motor current I_motor rating exceeds its power rating to protect the motor driver 220.

A description of the multi speed motor 152 will be described below. In the VVCF mode the voltage V_s (i.e. supplied voltage) , from the motor driver 220, is adjusted to adjust the speed (i.e. rotational speed) of the motor 152 and hence the rotational speed of the fan 154. In VVCF mode the motor driver 220 varies the voltage and maintains a constant frequency. The motor speed is increased by increasing the voltage supplied to the motor 152, and the motor speed is reduced by reducing the supplied voltage to the motor 152. The torque applied to the motor 152 is proportional to the supply voltage V_s that is supplied to the motor 152.

In CVVF mode, the speed of the motor 152 is controlled by adjusting the supply frequency f_S. The torque produced by the motor is increased by reducing the supply frequency. However the synchronous speed of the motor is reduced leading to the speed reduction of the motor 152 and hence a speed reduction of the fan 154. However varying the supply frequency only, to control the speed of the motor 152 can have the problem of higher conductive loss due to increased current being drawn by the motor because of an increase in reactance. Further the increase in frequency only, will also cause an increase in magnetic flux leading to an increased magnetic saturation resulting in high current. The increased current can cause overheating if the load current exceeds the rated current.

To reduce the speed of the motor or rotor with the supply frequency, the supply voltage should also be reduced to prevent magnetic saturation. CVVF mode is seldom used due to the magnetic saturation issue. Therefore VVVF mode is more preferable to the CVVF mode to control the motor if a variable frequency is required. The mode used by the motor driver 220 is dependent on the type of multi speed motor 152 that is used. In the VVVF mode the ratio between the supply voltage V_S and the supply frequency f_S is held constant and hence the magnetic flux is approximately constant. In the VVVF mode the speed of the motor or rotor can be controlled by adjusting the supplied frequency or by adjusting the supplied voltage or both.

The power regulation apparatus 200 varies the electrical conditions of the motor without using a potential divider or such passive components. The motor driver 220 is connected directly to the stator winding of the motor 152 so that losses associated with a divider network are eliminated. Further the power regulation apparatus 200 as described is configured to allow speed control across a wider speed range, based on the voltage and frequency supplied to the motor 152 by the motor driver 220. The power regulation apparatus 200 as described herein is advantageous the apparatus 200 allows a broad range of speeds. The only limitation on an achievable speed are mechanical factors of the motor such as friction, weight etc.

As described earlier the speed sensor 240 includes a tachometer or any other suitable sensor that determines the rotational speed of the motor (i.e. the rotor or fan) . The speed sensor 240 comprises a lookup table that relates the motor speed ω with the supply voltage (V) and supply frequency (f) . The supplied voltage and supplied frequency are supplied by the motor driver 220. The lookup table created can be stored in the speed controller 230 or in the motor driver 220. The lookup table may alternatively be stored in a memory unit that is in communication with either the speed controller 230 or the motor driver 220. The lookup table is created during a speed sensor calibration process. Figure 12 shows an embodiment of the calibration method. The calibration method 1200 shown in figure 12 is a calibration method that relates to a tachometer speed sensor. The method is executed by the speed sensor 240.

Referring to figure 12, the method begins at step 1202 wherein the calibration is initialized. The user can initiate the calibration method via the user interface 192. Alternatively the speed controller or motor driver or some other suitable component is configured to initiate the calibration process during start up.

At step 1204 the set point of the motor driver 220 is set to max. At step 1204 the speed controller 230 is configured to provide a reference signal that comprises a maximum value reference voltage and a maximum value reference frequency. The motor driver 220 consequently generates a drive signal that includes a maximum value voltage and a maximum value frequency.

At step 1206 the speed sensor 240 (in this example a tachometer) is configured to read out the rotational speed of the motor (i.e. rotor or fan) . At step 1208 a lookup table is created by the speed controller or the motor driver. At step 1208 the driving voltage value, the driving current value and the driving frequency value that relate to the measured rotational speed are stored in the table. The driving voltage, driving current and driving frequency are stored such that they relate to and are linked to the measured rotational speed.

At step 1210 the reference signal (i.e. the reference voltage and reference frequency) are decremented. This causes a corresponding decrement in the driving signal (i.e. driving voltage and/or driving frequency) . The parameters that are decremented are based on the mode of the motor driver 220. At step 1212 a check for if the set point is greater than the minimum threshold value is performed. The check can be performed by the speed controller 230 or the motor driver 220. If the reference signal value and/or the driving signal value is less than a minimum threshold then the calibration process is complete, as shown at step 1214. The thermostat apparatus 190 resumes normal operation. If the reference signal value and/or driving signal value is greater than the minimum threshold then the method proceeds to step 1216 where the drive signal is transmitted to the motor 152 and the method awaits until the motor 152 reaches a steady state. Once steady state is reached the method proceeds to repeat steps 1206‐1212 until the calibration method is complete. The minimum threshold value is different for each mode of the motor driver. The table below illustrates the ratios of the maximum (Max) drive voltage and frequency, the minimum threshold values (Min) and the step size for decrementing (Step‐size) . These values are denoted as ratios of a nominal voltage V_N and frequency f_N. See table 2 below:

Table 2.

Figure 14 shows a further embodiment of a method 1400 for regulating the temperature of a space using a temperature regulation system that comprises a thermostat apparatus, a power regulation apparatus and at least a multi‐speed motor. The power regulation apparatus is in electronic communication with the multi speed motor and controls the power i.e. voltage or frequency or energy delivered to the motor. The power regulation apparatus is removably connected to the thermostat apparatus. The method of regulating the temperature comprises a plurality of steps as will be described with reference to figure 14. The method 14 is implemented by the power regulation apparatus 200. The method begins at step 1402 that comprises determining a fan speed set point. The fan speed set point can be determined by the fan speed set point detection unit 250. Step 1404 comprises receiving an occupancy signal from the occupancy sensor 302. The occupancy signal corresponds to the occupancy of the enclosed space 102. Step 1406 comprises determining a reference speed based on the fan speed set point and the received occupancy signal. Step 1406 can be executed by the reference speed generator 270. The method proceeds to step 1408. Step 1408 comprises determining a measured speed of the multi speed motor. The measured speed of the motor is determined using the speed sensor 240. Step 1410 comprises determining a difference between a reference speed and the measured speed at the speed controller 230. Step 1412 comprises generating a reference signal based on the difference between the measured speed and the reference speed. The reference signal comprises a reference voltage and a reference frequency. Step 1412 is executed by the speed controller 230. Step 1414 comprises generating a drive signal based on the reference signal. The motor driver 220 is configured to generate the drive signal and execute step 1414. Step 1416 comprises transmitting the drive signal to the multi speed motor to drive the multi speed motor. The method 1400 is repeated to continuously control the motor speed to regulate the temperature in the enclosed space 102.

The power regulation apparatus 200 is advantageous because it efficiently controls the power supplied to the motor 152. The power regulation apparatus 200 acts as an energy saver and provides improved control to the motor while reducing errors, parasitic effects and maintains a true sinusoidal voltage output to the motor. The presence of the speed sensor helps to regulate the rotational speed with higher precision and helps to detect stalling. The motor driver and construction of the power regulation apparatus 200 further helps to drive the motor in a stepless manner which reduces temperature fluctuations in the space 102. The power regulation apparatus 200 is also advantageous because it improves the energy efficiency of the system and improves energy or power usage of by the motor. The power regulation apparatus 200 allows improved control of the motor because a conventional thermostat 190 controls temperature by controlling the valve. This is because a user sets the fan speed and the efficiency of the motor at the selected med and low fan speeds is poor. The power regulation apparatus 200 is advantageous because it can be retrofitted to any thermostat apparatus and is connected in series with the thermostat 190 and the motor 152 to improve operation of the motor. The power regulation apparatus 200 directly supplied the required power e.g. voltage and frequency to the motor terminals hence reducing losses associated with passive electronic components and parasitic elements in the circuit. The power regulation apparatus 200 also improves the operation of the motor since it detects the occupancy of the space 102 with an occupancy signal. When there is no person in the space 102, the fan is maintained on at a very low speed to ensure air flow within the space and avoid odors. This minimal air supply and minimal motor speed also helps the motor to operate more efficiently since the motor does not need to constantly switch on and off. Further the system does not need to drive the motor to overcome interia since it is already spinning at a low speed when there is no occupant. This improves the temperature control and energy usage of the motor.

Some alternative embodiments will now be described in more detail.

In an alternative embodiment the heat exchanger 130 comprises a plate type heat exchanger that includes a plurality of plates located adjacent each other. In a further alternative the heat exchanger may be a plate and shell type heat exchanger, or a phase change heat exchanger or a micro‐channel heat exchanger or a direct contact heat exchanger or a pass over heat exchanger or any other suitable heat exchanger that can be used to cool air through the passage 120.

In an alternative embodiment the thermal exchange material is a coolant such as a hydraulic fluid. The thermal exchange material may comprise a fluid or gas or liquid coolant. The thermal exchange material is preferably a fluid that is cooler than the operating temperature range of the room. The thermal exchange material is configured to cool air flowing across the heat exchanger. In a further alternative embodiment the thermal exchange material may be a hot fluid or hot gas that is configured to heat air flow across the heat exchanger.

In an alternative embodiment the valve 170 is a proportional valve. The proportional valve includes a moveable member that can move between an open position and a closed position. The moveable member can also be moved between any intermediate position between the open and closed position such that the moveable member can be partially open. The proportional valve allows any suitable or predetermined volume of thermal exchange material to be delivered to the heat exchanger. The actuation signal, generated by the valve controller, comprises position information for the moveable member. The actuation signal causes the moveable member to move to a predetermined position between a fully open position and a fully closed position. The valve member position information is related to a temperature difference between the reference temperature and measured temperature. The valve member position information may be predetermined and stored in a look up table. The temperature controller is configured to generate an actuation signal with the appropriate valve member position information based on the difference between the reference temperature and the measured temperature. The temperature controller is configured to select the valve member position information from the look up table and encode it into the actuation signal.

In a further alternative embodiment the valve 170 may be any other suitable electronically activated valve such as an electromechanical check valve or an electromechanical butterfly valve or any other type of electronically activated or controllable valve. In an alternative embodiment the temperature regulation system 100 may comprise a plurality of valves between the reservoir and the thermal exchanger.

In an alternative embodiment the fan assembly comprises a fan, a linear motor and a crank assembly. The linear motor is connected to the fan via the crank assembly to drive the fan in a rotary or rotational motion. A linear motor can be used instead of a standard rotational motor since a linear motor may be smaller or may be easier to control. In this alternative embodiment the fan assembly may also include a linear “fan” in the form of a piston or plunger that is driven by the motor. The linear piston or plunger imparts pressure onto the air flow to push chilled air out of the outlet duct 112.

In a further alternative embodiment the motor driver 220 may include a power factor corrector. The power factor corrector may be implemented as a hardware module comprising a plurality of electronic circuit components. The electronic circuit components may be analog or digital electronic components. Alternatively the power factor corrector may be implemented as a software module within the motor driver 220. The power factor corrector is used to correct for power factors due to the supply being an alternating power (i.e. alternating current and voltage) , which alternates at a particular frequency.

In an alternative embodiment the speed sensor 240 is configured to determine or predict the measured speed (i.e. motor speed) based on back EMF generated by the multi speed motor 152. Due to mechanical inertia in the motor 152 and fan 154, the rotor of the motor continues rotating for several cycles and generates a back EMF that can be detected. Figure 13 shows a graph of the back EMF (i.e. back voltage) that is generated by the motor 152. The speed sensor 240 comprises a zero crossing detector that is configure to detect a zero crossing of the back EMF signal. A square pulse is generated during zero crossing points, as seen in figure 13. The period of the back EMF equals the time duration between two consecutive rising edge signals. The rotational speed can be estimated using the following formula:

ω_m＝ω

ω_m is the mechanical rotational speed of the rotor in rad s‐1,

t_b is the measured period of back‐EMF in s,

P is the number of motor pole‐pair.

The speed sensor 240 is configured to generate a measured speed using the above formula. The speed sensor 240 generates a signal that includes information that denotes the speed of the motor. The speed that is estimated using the back EMF method is the rotational speed of the motor 152. For back EMF detection of speed the speed sensor 240 may be calibrated using a similar method to that described in figure 12. The method of calibration comprises the steps of initializing the calibration, adjusting the reference signal (reference voltage and reference frequency) to a maximum value. Following this any power to the motor is switched off such that the motor functions as a generator generating a back EMF. The rotational speed of the motor is estimated using the formula above that relates speed to the period of the back EMF. A lookup table is created that relates the driving voltage, driving current and driving frequency to the rotational speed. The reference voltage and reference frequency are decremented by a step size, thus causing the driving voltage and driving frequency to be decremented too. The calibration method checks if the reference voltage and/or reference frequency is less than a minimum threshold. If no then the calibration process is ended once a specific number of decrements have taken place. If yes, then a driving signal is supplied to the motor and the system waits until the motor returns to a steady state before repeating the process. Other calibration methods are also contemplated.

In the foregoing specification the components of the thermostat apparatus and any sub components such as comparators, generators, controllers etc may be implemented with analog electronic parts such as resistors, inductors, capacitors, opamps, MOSFETS, transistors and so on. Alternatively the thermostat apparatus and any sub components such as comparators, generator, controllers etc may be implemented with digital electronic components such as logic gates. In a further alternative some or all of these components may be implemented as software modules that are stored in a memory unit and executed by a hardware processor residing in the thermostat apparatus casing. The thermostat apparatus may comprise a non‐transitory computer readable medium such as a memory unit, that comprises computer readable instructions that are executable by a processor.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a, " "an" and "the" are intended to include plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" or "comprising, " when used in this specification, specify the presence of stated features, integers, steps, operations, elements components and/or groups or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups or combinations thereof.

As used herein, the term "and/or" includes any and all possible combinations or one or more of the associated listed items, as well as the lack of combinations when interpreted in the alternative ( "or" ) .

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and claims and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well‐known functions or constructions may not be described in detail for brevity and/or clarity.

It will be understood that when an element is referred to as being "on, " "attached" to, "connected" to, "coupled" with, "contacting, " etc., another element, it can be directly on, attached to, connected to, coupled with and/or contacting the other element or intervening elements can also be present. In contrast, when an element is referred to as being, for example, "directly on, " "directly attached" to, "directly connected" to, "directly coupled" with or "directly contacting" another element, there are no intervening elements present. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed "adjacent" another feature can have portions that overlap or underlie the adjacent feature.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

A temperature regulation system for regulating the temperature of an enclosed space, the temperature regulation system comprising:

a fan assembly, the fan assembly comprising a fan and a multi speed motor coupled to the fan and the multi speed motor configured to drive the fan,

a power regulation apparatus in electrical communication with the multi speed motor, the power regulation apparatus comprises:

a motor driver and an occupancy sensor,

the occupancy sensor configured to detect an occupancy within the enclosed space and generate an occupancy signal being indicative of the detected occupancy,

the power regulation apparatus being configured to adjust the energy or power supplied to the multi speed motor to control a speed of the multi speed motor and a speed of the fan based on the occupancy signal.
A temperature regulation system in accordance with claim 1, wherein the power regulation apparatus is configured to improve energy usage of the multi speed motor.
A temperature regulation system in accordance with claim 1, wherein the power regulation apparatus comprises a motor driver,

the motor driver being electrically coupled to the multi speed motor,

the motor driver configured to generate a drive signal based on at least the occupancy signal and wherein the motor driver further providing the generated drive signal to the multi speed motor to control the speed of the multi speed motor.
A temperature regulation system in accordance with claim 1, wherein the power regulation apparatus comprises a speed controller,

the speed controlled being in electrical communication with the motor driver,

the speed controller providing a reference signal to the motor driver, wherein the reference signal is based on a difference between a reference speed and a measured speed of the multi speed motor,

the reference speed being based on at least the occupancy signal, and；

the motor driver configured to generate the drive signal based on the received reference signal.
A temperature regulation system in accordance with claim 4, wherein the drive signal that is provided to the multi speed motor comprises a driving voltage and a driving frequency, the reference signal comprises a reference voltage and a reference frequency, and wherein the driving voltage and/or the driving frequency being adjusted based on the reference signal.
A temperature regulation system in accordance with claim 4, wherein the motor driver receives a power supply signal from a power source, and wherein the motor driver generates the drive signal by modulating the received power signal based on the reference signal, and wherein the motor driver is configured to modulate the voltage, or the frequency, or the voltage and frequency of the power supply signal.
A temperature regulation system in accordance with claim 4, wherein the driving voltage is adjusted based on the reference voltage and the driving frequency is adjusted based on the reference frequency.
A temperature regulation system in accordance with claim 1, wherein the drive signal provided to the multi speed motor comprises a driving voltage and a driving frequency, and the motor driver is configured to provide a drive signal in one of the following modes:

a varying voltage with a constant frequency,

a varying frequency with a constant voltage,

a varying voltage with a varying frequency.
A temperature regulation system in accordance with claim 4, wherein the speed controller comprises a comparator and a reference signal generator,

the comparator configured to determine a speed error, wherein the speed error being the difference between the reference speed and the measured speed, and；

the reference signal generator configured to generate a reference signal based on the speed error.
A temperature regulation system in accordance with claim 4, wherein the power regulation apparatus further comprises a speed sensor, the speed sensor arranged in electronic communication with the speed controller, the speed sensor configured to determine and transmit a measured speed to the speed controller, and wherein the measured speed corresponds to the motor speed.
A temperature regulation system in accordance with claim 10, wherein the speed sensor is a tachometer that is configured to measure the instantaneous motor speed.
A temperature regulation system in accordance with claim 1, wherein the occupancy sensor is configured to generate an occupancy signal in a first state or in a second state, the occupancy signal being in a first state if an occupant is detected in the enclosed space by the occupancy sensor, and the occupancy signal being in a second state if an occupant is not detected in the enclosed space by the occupancy sensor.
A temperature regulation system in accordance with claim 4, wherein the power regulation apparatus comprises a reference speed generator, the reference speed generator configured to generate a reference speed based on the occupancy signal and a fan speed set point.
A temperature regulation system in accordance with claim 1, wherein the power regulation apparatus further comprises a fan speed set point detection module, the fan speed set point detection module configured to generate a fan speed set point, the fan speed set point being a high, medium, low or off set point.
A temperature regulation system in accordance with claim 13, wherein the fan speed set point detection module comprising at least a high speed detection path, a medium speed detection path and a low speed detection path, and；

wherein the fan speed set point detection module generating a high fan speed set point if a signal is detected on a high speed detection path, or

wherein the fan speed set point detection module generating a medium fan speed set point if a signal is detected on the medium speed detection path, or

wherein the fan speed set point detection module generating a low fan speed set point if a signal is detected on the low speed detection path, or

the fan speed set point detection module generating an off set point if no signal is detected on any of the detection paths.
A temperature regulation system in accordance with claim 12, wherein the reference speed generator is configured to receive a supply status signal, the supply status signal being a first state or a second state, wherein a first signal state corresponding to an activated power supply and a second signal state corresponding to a deactivated power supply, the supply status signal being received by the speed generator from either the fan speed set point detection module or directly from a power supply.
A temperature regulation system in accordance with claim 15, wherein the reference speed generator generating one of a high reference speed, a medium reference speed, a low reference speed, an ultra low reference speed or an off reference speed,

wherein the high reference speed is generated if a high fan speed set point, a first state occupancy signal and a first state supply status signal are received,

wherein the medium reference speed is generated if a medium fan speed set point, a first state occupancy signal and a first state supply status signal are received,

wherein the low reference speed is generated if a low fan speed set point, a first state occupancy signal and a first state supply status signal are received,

wherein an ultra low reference speed is generated if a first state supply status signal is received and a second state occupancy signal is received, and

wherein an off reference speed is generated if a second state supply status signal is received.
A temperature regulation system in accordance with claim 17, wherein the supply status signal is generated by the fan speed set point detection module, the fan speed set point detection module further comprising a power supply status monitor configured to detect the status of a power supply and generate the supply status signal.
A temperature regulation system in accordance with claim 1, wherein the temperature regulation system comprising a thermostat apparatus,

the thermostat apparatus comprising a fan speed selector, the fan speed selector allowing a user to set a fan speed,

the thermostat apparatus further comprising a valve controller, the valve controller configured to receive a reference temperature and a measured temperature, the valve controller further configured to generate a valve actuation signal based in the difference between the reference temperature and measured temperature,

the power regulation apparatus being removably coupled to the thermostat apparatus and the multi speed motor, the power regulation apparatus receiving the fan speed set by the user and utilizing the fan speed set by the user to control operation of the multi speed motor.
A temperature regulation system in accordance with claim 19, wherein the user set fan speed allowing a user to select three or more discrete fan speeds, the fan speed set point detection module being in electrical communication with the fan speed selector and the fan speed set point detection module detecting a user set fan speed and generating the fan speed set point, wherein the fan speed set point corresponding to the user set fan speed.
A temperature regulation system in accordance with claim 19, wherein the power regulation apparatus is connected between the multi speed motor and the thermostat apparatus, the power regulation apparatus being removably connectable with the thermostat apparatus and the multi speed motor and wherein the power regulation apparatus comprising standard electrical connections to allow removable connection with the multi speed motor and the thermostat apparatus.
A temperature regulation system in accordance with claim 19, wherein the temperature regulation system comprising；

a reservoir containing a thermal exchange material,

a heat exchanger in fluid communication with the reservoir, wherein the heat exchanger is adapted to receive the thermal exchange material from the reservoir,

a valve located between the heat exchanger and the reservoir, the valve being moveable between an open position and a closed position based on the valve actuation signal received by the valve, wherein in an open position the valve allows passage of the thermal exchange material from the reservoir to the heat exchanger and in a closed position the valve preventing passage of the thermal exchange material from the reservoir to the heat exchanger,

the valve controller being in electronic communication with the valve and providing the valve actuation signal to control the valve,

a temperature sensor located within the enclosed space and configured to measure the temperature of the enclosed space to generate a measure temperature, the temperature sensor being in communication with the thermostat apparatus and the valve controller and transmitting the measured temperature to the valve controller of the thermostat apparatus,

the valve controller generating a valve actuation signal to move the valve to an open position if the measured temperature is higher than the reference temperature and the valve controller generating a valve actuation signal corresponding to move the valve to a closed position if the measured temperature is lower than the reference temperature.
A power regulation apparatus for use with or as part of a temperature regulation system for regulating temperature of an enclosed space, the temperature regulation system including a fan assembly that includes a fan and a multi speed motor connected to the fan and configured to drive the fan, the power regulation apparatus in electrical communication with the multi speed motor and the power regulation apparatus comprising:

a motor driver and an occupancy sensor,

the occupancy sensor configured to detect an occupancy within the enclosed space and generate an occupancy signal being indicative of the detected occupancy,

the power regulation apparatus being configured to adjust power supplied to the multi speed motor to control a speed of the multi speed motor and a speed of the fan based on the occupancy signal.
A power regulation apparatus in accordance with claim 23, wherein the power regulation apparatus is configured to improve energy usage of the multi speed motor.
A power regulation apparatus in accordance with claim 23, wherein the motor driver being electrically coupled to the multi speed motor,

the motor driver configured to generate a drive signal based on at least the occupancy signal and wherein the motor driver further providing the generated drive signal to the multi speed motor to control the speed of the multi speed motor.
A power regulation apparatus in accordance with claim 23, wherein the power regulation apparatus comprises a speed controller,

the speed controlled being in electrical communication with the motor driver,

the speed controller providing a reference signal to the motor driver, wherein the reference signal is based on a difference between a reference speed and a measured speed of the multi speed motor,

the reference speed being based on at least the occupancy signal, and；

the motor driver configured to generate the drive signal based on the received reference signal.
A power regulation apparatus in accordance with claim 26, wherein the drive signal that is provided to the multi speed motor comprises a driving voltage and a driving frequency, the reference signal comprises a reference voltage and a reference frequency, and wherein the driving voltage and/or the driving frequency being adjusted based on the reference signal.
A power regulation apparatus in accordance with claim 26, wherein the motor driver receives a power supply signal from a power source, and wherein the motor driver generates the drive signal by modulating the received power signal based on the reference signal, and wherein the motor driver is configured to modulate the voltage, or the frequency, or the voltage and frequency of the power supply signal.
A power regulation apparatus in accordance with claim 26, wherein the driving voltage is adjusted based on the reference voltage and the driving frequency is adjusted based on the reference frequency.
A power regulation apparatus in accordance with claim 23, wherein the drive signal provided to the multi speed motor comprises a driving voltage and a driving frequency, and the motor driver is configured to provide a drive signal in one of the following modes:

a varying voltage with a constant frequency,

a varying frequency with a constant voltage,

a varying voltage with a varying frequency.
A power regulation apparatus in accordance with claim 26, wherein the speed controller comprises a comparator and a reference signal generator,

the comparator configured to determine a speed error, wherein the speed error being the difference between the reference speed and the measured speed, and；

the reference signal generator configured to generate a reference signal based on the speed error.
A power regulation apparatus in accordance with claim 26, wherein the power regulation apparatus further comprises a speed sensor, the speed sensor arranged in electronic communication with the speed controller, the speed sensor configured to determine and transmit a measured speed to the speed controller, and wherein the measured speed corresponds to the motor speed.
A power regulation apparatus in accordance with claim 32, wherein the speed sensor is a tachometer that is configured to measure the instantaneous motor speed.
A power regulation apparatus in accordance with claim 23, wherein the occupancy sensor is configured to generate an occupancy signal in a first state or in a second state, the occupancy signal being in a first state if an occupant is detected in the enclosed space by the occupancy sensor, and the occupancy signal being in a second state if an occupant is not detected in the enclosed space by the occupancy sensor.
A power regulation apparatus in accordance with claim 26, wherein the power regulation apparatus comprises a reference speed generator, the reference speed generator configured to generate a reference speed based on the occupancy signal and a fan speed set point.
A power regulation apparatus in accordance with claim 23, wherein the power regulation apparatus further comprises a fan speed set point detection module, the fan speed set point detection module configured to generate a fan speed set point, the fan speed set point being a high, medium, low or off set point.
A power regulation apparatus in accordance with claim 36, wherein the fan speed set point detection module comprising at least a high speed detection path, a medium speed detection path and a low speed detection path, and；

wherein the fan speed set point detection module generating a high fan speed set point if a signal is detected on a high speed detection path, or

wherein the fan speed set point detection module generating a medium fan speed set point if a signal is detected on the medium speed detection path, or

wherein the fan speed set point detection module generating a low fan speed set point if a signal is detected on the low speed detection path, or

the fan speed set point detection module generating an off set point if no signal is detected on any of the detection paths.
A power regulation apparatus in accordance with claim 35, wherein the reference speed generator is configured to receive a supply status signal, the supply status signal being a first state or a second state, wherein a first signal state corresponding to an activated power supply and a second signal state corresponding to a deactivated power supply, the supply status signal being received by the speed generator from either the fan speed set point detection module or directly from a power supply.
A power regulation apparatus in accordance with claim 35, wherein the reference speed generator generating one of a high reference speed, a medium reference speed, a low reference speed, an ultra low reference speed or an off reference speed,

wherein the high reference speed is generated if a high fan speed set point, a first state occupancy signal and a first state supply status signal are received,

wherein the medium reference speed is generated if a medium fan speed set point, a first state occupancy signal and a first state supply status signal are received,

wherein the low reference speed is generated if a low fan speed set point, a first state occupancy signal and a first state supply status signal are received,

wherein an ultra low reference speed is generated if a first state supply status signal is received and a second state occupancy signal is received, and

wherein an off reference speed is generated if a second state supply status signal is received or an off set point is received.
A power regulation apparatus in accordance with claim 38, wherein the supply status signal is generated by the fan speed set point detection module, the fan speed set point detection module further comprising a power supply status monitor configured to detect the status of a power supply and generate the supply status signal.
A power regulation apparatus in accordance with claim 23, wherein the occupancy sensor is an infrared sensor that is configured to detect movement within the enclosed space to determine occupancy or detect the number of occupants in the enclosed space.
A power regulation apparatus for use with or as part of a temperature regulation system , wherein the temperature regulation system is configured to regulate the temperature of an enclosed space, the temperature regulation system comprising a fan and a multi speed motor connected to and driving the fan, the power regulation apparatus comprising:

one or more active electronic components being electrically coupled to a power supply and the one or more electronic components configured to receive a supply power,

the one or more active electronic components being electrically coupled to the multi speed motor,

the one or more electronic components configured to modulate the received supply power to generate a drive signal, and deliver the drive signal the multi speed motor,

an occupancy sensor, the occupancy sensor configured to generate an occupancy signal, and wherein the one or more active electronic component configured to modulate the supply power and generate a drive signal based on the occupancy signal.
A power regulation apparatus in accordance with claim 42, wherein the power regulation apparatus is removably connectable to a thermostat apparatus, the power regulation apparatus is configured to receive a fan speed set point from the thermostat apparatus, and the one or more active electronic components of the power regulation apparatus being configured to generate a drive signal based on the fan speed set point and the occupancy signal.
A power regulation apparatus in accordance with claim 42, wherein one or more active electrical components of the power regulation apparatus being configured to generate a drive signal that comprises one of:

a varying voltage with a constant frequency, or

a constant voltage with a varying frequency, or

a varying voltage and a varying frequency.
A method of regulating a temperature of an enclosed space using a temperature regulating system, wherein the temperature regulating system comprises a fan, a multi speed motor driving the fan, a thermostat apparatus providing a fan speed set point, a power regulation apparatus connected between the thermostat apparatus and the multi speed motor and in electronic communication with the thermostat apparatus and the multi speed motor, the method of regulating a temperature of an enclosed space comprising the steps of:

determining a fan speed set point,

receiving an occupancy signal corresponding to an occupancy of the enclosed space from an occupancy sensor,

determining a reference speed based on the fan speed set point and the received occupancy signal,

determining a measured speed of the multi speed motor from a speed sensor,

determining a difference between reference speed and the measured speed,

generating a reference signal based on the difference between the measured speed and the reference speed,

generating a drive signal based on the reference signal,

transmitting the drive signal to the multi speed motor to drive the multi speed motor.
A method of regulating a temperature in accordance with claim 45, wherein the drive signal is generated in one of the following modes:

a varying voltage with a constant frequency,

a varying frequency with a constant voltage,

a varying voltage with a varying frequency.