A VARIABLE SPEED COMPRESSOR BASED AC SYSTEM AND CONTROL METHOD

Abstract

The present disclosure relates to the field of air conditioning technology. In particular, it involves a control method and control system based on a variable speed AC compressor.

Claims

1. A variable speed AC (meaning cooling or heating) control system comprises: speed control calculation unit, database unit, operation data acquisition unit, wherein the speed control calculation unit readjusts the compressor speed of F based on selecting any of three parameters from the compressor load current change of I, refrigerant high pressure change of Pc, refrigerant low pressure change of Pe, in conjunction with change of time t since at different variable speed the compressor is run.

2. The variable speed AC control system according to claim 1, wherein the database unit is for storing data from actual compressor cycle, the compressor on timing t, the average outdoor temperature and the average compressor speed; and the data storage unit stores the compressor speed regression model; and the data storage unit provides to the speed control calculation unit those data.

3. The variable speed AC control system according to claim 2, wherein the speed control calculation unit calculates the individual coefficient values as weight factors that would favor increase or decrease compressor speed by default setting amount.

4. The variable speed AC control system according to claim 3, wherein the speed control calculation unit further evaluates the regression model by adding up the terms that would favor increase speed as well as decrease speed, and based on the net value, chooses to increase or decrease the compressor speed by the default setting amount.

5. The variable speed AC control system according to claim 4, wherein the speed control calculation unit tests whether the compressor speed is higher than the default speed, and if so, decrease the compressor speed; and the amount of increase or decrease default setting can be set by user or by remote server.

6. The variable speed AC control system according to claim 5, wherein after operation cycle is finished, the system tests whether the operation cycle is completed ahead of target timing as having adequate output or inadequate output conversely, and based on comparing similar multiple operation cycle performances, determines whether the similar operation cycle speed should be increased or decreased by default setting, as well as updates the database with the results.

7. A variable speed AC (meaning both cooling and heating) control method, comprising: receiving default setting of run time t, and selecting any of three parameters of compressor regression model from compressor current change of I as A.sub.1, refrigerant high pressure change of Pc as A.sub.2, refrigerant low pressure change of Pe as A.sub.3, in conjunction with change of time t since at different variable speed compressor is run as A.sub.4; based on the outdoor temperature and the default run time t, setting a target compressor speed; running compressor until the target compressor speed is achieved, then running it one speed control timing cycle; and based on evaluating the regression model, readjusting whether that the compressor speed should be increased or decreased by default setting amount.

8. The variable speed AC control method according to claim 7, wherein the readjusting step evaluates the regression model by adding up the terms that would favor increasing speed as well as decreasing speed, and based on the net value, chooses to increase or decrease the compressor speed by the default setting amount.

9. The variable speed AC control method according to claim 8, wherein the readjusting step calculates the individual coefficient values as weight factors that would favor increasing or decreasing compressor speed.

10. The variable speed AC control method according to claim 9, wherein the readjusting step tests whether the compressor speed is higher than the default speed, and if so, decreases the compressor speed; and the amount of increase or decrease default setting can be set by user or by remote server.

11. The variable speed AC control method according to claim 10, further comprising: after operation cycle is finished, testing whether the operation cycle is completed ahead of the target timing as having adequate output or inadequate output conversely, and based on comparing similar multiple operation cycle performances, determining whether the similar operation cycle speed should be increased or decreased by default setting, and recording operation cycle parameters into database.

12. A non-transitory computer-readable medium having stored thereon a set of computer-executable instructions for causing a first device to perform steps comprising: receiving default setting of run time t, and selecting any parameter(s) of compressor regression model from compressor current change of I as A.sub.1, refrigerant high pressure change of Pc as A.sub.2, refrigerant low pressure change of Pe as A.sub.3, in conjunction with of time t since at different variable speed compressor is run as A.sub.4; based on the outdoor temperature and the default run time t, setting a target compressor speed; running compressor until the target compressor speed is achieved, then running it one speed control timing cycle; and based on evaluating the regression model, readjusting whether that the compressor speed should be increased or decreased by default setting amount.

13. The non-transitory computer-readable medium according to claim 12, wherein the readjusting step evaluates the regression model by adding up the terms that would favor increasing speed as well as decreasing speed, and based on the net value, chooses to increase or decrease the compressor speed by the default setting amount.

14. The non-transitory computer-readable medium according to claim 13, wherein the readjusting step calculates the individual coefficient values as weight factors that would favor increasing or decreasing compressor speed.

15. The non-transitory computer-readable medium according to claim 14, wherein the readjusting step tests whether the compressor speed is higher than the default speed, and if so, decreases the compressor speed; and the amount of increase or decrease default setting can be set by user or by remote server.

16. The non-transitory computer-readable medium according to claim 15, further comprising: after operation cycle is finished, testing whether the operation cycle is completed ahead of the target timing as having adequate output or inadequate output conversely, and based on comparing similar multiple operation cycle performances, determining whether the similar operation cycle speed should be increased or decreased by the default setting, and recording operation cycle parameters into database.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1 shows a system diagram of the new variable AC unit implementation of this disclosure.

[0023] FIG. 2 shows a flow diagram in cooling mode of the new variable AC unit implementation of a first embodiment of this disclosure.

[0024] FIG. 3 shows several control plots created by the new variable AC control unit through self-learning in the first embodiment of this disclosure.

[0025] FIG. 4 shows a flow diagram in heating mode of the new variable AC unit implementation of the first embodiment of this disclosure.

[0026] FIG. 5 shows a flow diagram in cooling mode of the new variable AC unit implementation of a second embodiment of this disclosure.

[0027] FIG. 6 shows a flow diagram in heating mode of the new variable AC unit implementation of the second embodiment of this disclosure.

[0028] FIG. 7 shows a flow diagram in cooling mode of the new variable AC unit implementation of a third embodiment of this disclosure.

[0029] FIG. 8 shows a flow diagram in heating mode of the new variable AC unit implementation of the third embodiment of this disclosure.

[0030] FIG. 9 shows a flow diagram the new variable AC unit implementation of a fourth embodiment of this disclosure.

[0031] FIG. 10 shows a control plot created by the new variable AC control unit through self-learning in the fourth embodiment of this disclosure.

[0032] FIG. 11 shows a flow diagram of the new variable AC unit implementation of a fifth embodiment of this disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

First Embodiment

[0033] FIG. 1 is the variable speed AC control system configuration diagram of the first embodiment, comprises: speed control calculation unit 1, database unit 2, operation data acquisition unit 3 and network communication module 4, wherein

[0034] the speed control calculation unit 1 is for setting an initial target speed of the compressor based on current outdoor temperature and default compressor run time t, and after achieving the initial target speed, readjusting the speed; and

[0035] database unit 2, for storing and providing from actual compressor cycle, the compressor on timing t, the average outdoor temperature and the average compressor speed, which are needed by the speed control calculation unit 1 when starting; and

[0036] the operation data acquisition unit 3, for collecting sensor data generated by the outdoor unit, including the outdoor temperature, outdoor unit high/low pressure saturation temperatures, compressor speed, compressor current; and

[0037] the network communication unit 4 is used to get weather forecasts results from a remote server, used to obtain in advance ambient temperature.

[0038] This embodiment works on estimating the relationship on how the changing compressor current I affects the changing indoor temperature, and based on the estimation, adjust the compressor speed.

[0039] FIG. 2 shows flow diagram of a new fuzzy control method in cooling mode of the present disclosure, comprises: [0040] a. receiving default setting of run time t; [0041] b. based on the outdoor temperature and the default run time t, setting a target compressor speed; [0042] c. running compressor until the target compressor speed is achieved, then running it one speed control timing cycle; [0043] d. comparing the present compressor current I and that (I) from the prior speed control timing cycle, if II, meaning the indoor temperature has not decreased, then increasing the compressor speed by a default value X, but if on the other hand, I>I, meaning the indoor temperature has decreased, then further testing whether the current speed>default speed, in order to decrease the current speed by default value X if so, or leave the current speed unchanged if not; [0044] e. running the compressor one speed control timing cycle before returning to step d; [0045] f. when receiving compressor off signal, recording the actual compressor on time of t, actual average outdoor temperature and actual average speed from the compressor on period into data storage unit for self-learning purpose.

Default Runtime t Determination

[0046] The default compressor on time t can be set according to user's preference. But it can also be set by a remote server. Also, t can be calculated based on a fixed compressor power.

Default Compressor Speed Adjustment Increment X

[0047] In this embodiment, the default compressor speed adjustment increment X can be set according to user's preference. But it can also be set by a remote server. The effect of this value being large is to speed up the compressor speed adjustment in order to search a stable compressor speed. But the abrupt temperature change can become uncomfortable to the users. Therefore, this value can be set smaller if that is the case. On the other hand, setting this value small can prolong the search for the stable compressor speed.

Compressor Speed Adjustment Cycle Timing

[0048] The compressor speed adjustment timing can be set by the users or by a remote server so the compressor speed can be adjustede.g. every 120 seconds.

Self-Learning by Average Outdoor Temperature and Compressor Speed

[0049] In the self-learning process, the average outdoor temperature can be calculated by weighted method. For example, when compressor on timing is 50 min, during which temperatures were at 33 for 15 min, 34 for 30 min, and 35 for 5 min, then the average temperature is (15/50)33+(30/50)34+(5/50)35=33.8. Similarly, average compressor speed during 50 min runtime for the sequence of 50 Hz for 10 min, 48 Hz for 30 min and 46 Hz for 10 min is: (10/50)50 Hz+(30/50)48 Hz+(10/50)46 Hz=48 Hz.

[0050] In this embodiment, based on fuzzy control method, and after accumulating enough test runs for self-learning, FIG. 3 shows the plots from the data. Every time when the compressor starts, looking up from the plots, one can determine the target compressor speed.

[0051] However, because the compressor stop signal can be triggered by the user, not because after the desired temperature has been achieved, in such situation, the learned runtime average temperature/compressor on timing/average compressor speed relationship would not be accurate. For this particular data set, its effect can be offset by taking an average from all the observed data sets, or be eliminated by excluding the unreliable dataset. For example, when running under speed of 48 RPS, timings of 40 min, 50 min, 60 min, 55 min and 65 min can be averaged to offset the chance when one of them was caused by user's shut off.

[0052] FIG. 4 shows flow diagram of a new fuzzy control method in heating mode of the present disclosure, comprises: [0053] a. receiving default setting of run time t; [0054] b. based on the outdoor temperature and the default run time t, setting a target compressor speed; [0055] c. running compressor until the target compressor speed is achieved, then running it one speed control timing cycle; [0056] d. comparing the present compressor current I and that (I) from the prior speed control timing cycle, if II, meaning the indoor temperature has not increased, then increasing the compressor speed by a default value X, but if on the other hand, I<I, meaning the indoor temperature has increased, then further testing whether the current speed>default speed, in order to decrease the current speed by default value X if so, or leave the current speed unchanged if not; [0057] e. running the compressor one speed control timing cycle before returning to step d; [0058] f. when receiving compressor off signal, recording the actual compressor on time of t, actual average outdoor temperature and actual average speed from the compressor on period into data storage unit for self-learning purpose.

Second Embodiment

[0059] Similar to the first embodiment, this embodiment works on estimating the relationship on how the changing compressor high pressure Pc affects the changing indoor temperature, and based on the estimation, adjust the compressor speed.

[0060] FIG. 5 shows a flow diagram of a new fuzzy control method in cooling mode of the present disclosure comprises: [0061] a. receiving default setting of run time t; [0062] b. based on the outdoor temperature and the default run time t, setting a target compressor speed; [0063] c. running compressor until the target compressor speed is achieved, then running it one speed control timing cycle; [0064] d. comparing the present compressor high pressure Pc and that (Pc) from the prior speed control timing cycle, if PcPc, meaning the indoor temperature has not decreased, then increasing the compressor speed by a default value X, but if on the other hand, Pc>Pc, meaning the indoor temperature has decreased, then further testing whether the current speed>default speed, in order to decrease the current speed by default value X if so, or leave the current speed unchanged if not; [0065] e. running the compressor one speed control timing cycle before returning to step d; [0066] f. when receiving compressor off signal, recording the actual compressor on time of t, actual average outdoor temperature and actual average speed from the compressor on period into data storage unit for self-learning purpose.

[0067] FIG. 6 shows a flow diagram of a new fuzzy control method in heating mode of the present disclosure, comprises: [0068] a. receiving default setting of run time t; [0069] b. based on the outdoor temperature and the default run time t, setting a target compressor speed; [0070] c. running compressor until the target compressor speed is achieved, then running it one speed control timing cycle; [0071] d. comparing the present high pressure Pc and that (Pc) from the prior speed control timing cycle, if PcPc, meaning the indoor temperature has not increased, then increasing the compressor speed by a default value X, but if on the other hand, Pc<Pc, meaning the indoor temperature has increased, then further testing whether the current speed>default speed, in order to decrease the current speed by default value X if so, or leave the current speed unchanged if not; [0072] e. running the compressor one speed control timing cycle before returning to step d; [0073] f. when receiving compressor off signal, recording the actual compressor on time of t, actual average outdoor temperature and actual average speed from the compressor on period into data storage unit for self-learning purpose.

Third Embodiment

[0074] Similar to the second embodiment, this embodiment works on estimating the relationship on how the changing compressor low pressure Pe affects the changing indoor temperature, and based on the estimation, adjust the compressor speed.

[0075] FIG. 7 shows a flow diagram of a new fuzzy control method in cooling mode of the present disclosure comprises: [0076] a. receiving default setting of run time t; [0077] b. based on the outdoor temperature and the default run time t, setting a target compressor speed; [0078] c. running compressor until the target compressor speed is achieved, then running it one speed control timing cycle; [0079] d. comparing the present compressor high pressure Pe and that (Pe) from the prior speed control timing cycle, if PePe, meaning the indoor temperature has not decreased, then increasing the compressor speed by a default value X, but if on the other hand, Pe>Pe, meaning the indoor temperature has decreased, then further testing whether the current speed>default speed, in order to decrease the current speed by default value X if so, or leave the current speed unchanged if not; [0080] e. running the compressor one speed control timing cycle before returning to step d; [0081] f. when receiving compressor off signal, recording the actual compressor on time of t, actual average outdoor temperature and actual average speed from the compressor on period into data storage unit for self-learning purpose.

[0082] FIG. 8 shows a flow diagram of a new fuzzy control method in heating mode of the present disclosure, comprises: [0083] a. receiving default setting of run time t; [0084] b. based on the outdoor temperature and the default run time t, setting a target compressor speed; [0085] c. running compressor until the target compressor speed is achieved, then running it one speed control timing cycle; [0086] d. comparing the present high pressure Pe and that (Pe) from the prior speed control timing cycle, if PePe, meaning the indoor temperature has not increased, then increasing the compressor speed by a default value X, but if on the other hand, Pe<Pe, meaning the indoor temperature has increased, then further testing whether the current speed>default speed, in order to decrease the current speed by default value X if so, or leave the current speed unchanged if not; [0087] e. running the compressor one speed control timing cycle before returning to step d; [0088] f. when receiving compressor off signal, recording the actual compressor on time of t, actual average outdoor temperature and actual average speed from the compressor on period into data storage unit for self-learning purpose.

Fourth Embodiment

[0089] In this embodiment, in addition to the similar routine shown in prior embodiments, specific finding of actual speed as adequate or inadequate would be collected into the data set.

[0090] FIG. 9 shows a flow diagram of a new fuzzy control method in the present disclosure comprises: [0091] a. receiving default setting of run time t; [0092] b. based on the outdoor temperature and the default run time t, setting a target compressor speed; [0093] c. running compressor until the target compressor speed is achieved, then running it one speed control timing cycle; [0094] d. on outdoor temperature change, based on temp-speed lookup data, adjust compressor speed; [0095] e. when receiving compressor off signal, recording the actual compressor on time of t, actual average outdoor temperature and actual average speed from the compressor on period into data storage unit for self-learning purpose, and denote that when tt, the actual speed as adequate, or inadequate when t>t. [0096] f. further processing the multiple events on speed setting within a given temperature in the data storage, so that statistically, when actual speed adequate occurrence>inadequate occurrence, decrease the default speed for a given temperature by default X, or increase conversely.

[0097] FIG. 10 shows a plot of temperature vs. target starting speed from enough data points generated by the new fuzzy control method and after statistical modification based on adequate and inadequate occurrence.

Fifth Embodiment

[0098] In this embodiment, in addition to the similar routine shown in prior embodiments, a combined compressor current change of I, refrigerant high pressure change of Pc, refrigerant low pressure change of Pe, as well as the change of time t since compressor is on, are used as parameters of the speed change function F=f (I, Pc, Pe, t). The coefficients for the parameters can also be weight factors, having compressor current change of I as A.sub.1, refrigerant high pressure change of Pc as A.sub.2, refrigerant low pressure change of Pe as A.sub.3, as well as the change of time t since compressor is on as A.sub.4. These parameter weights each could be between 0% to 100%, but should satisfy A.sub.1+A.sub.2+A.sub.3+A.sub.4=100%.

[0099] FIG. 11 shows a flow diagram of a new fuzzy control method in the present disclosure comprises: [0100] a. receiving default setting of run time t, and the compressor regression model parameters on compressor current change of I as A.sub.1, refrigerant high pressure change of Pc as A.sub.2, refrigerant low pressure change of Pe as A.sub.3, as well as the change of time t since compressor is on as A.sub.4; [0101] b. based on the outdoor temperature and the default run time t, setting a target compressor speed; [0102] c. running compressor until the target compressor speed is achieved, then running it one speed control timing cycle; [0103] d. based on only compressor current change of I, calculating the value of this parameter that either would favor increase speed or decrease speed; [0104] e. based on only refrigerant high pressure change of Pc, calculating the value of this parameter that either would favor increase speed or decrease speed; [0105] f. based on only refrigerant low pressure change of Pe, calculating the value of this parameter that either would favor increase speed or decrease speed; [0106] g. when the current time has not reached the target run time t, then adding up all the favorable values of the parameters of A.sub.1, A.sub.2 and A.sub.3 that would increase compressor speed, as well as adding up all the favorable values of the parameters that would decrease compressor speed, and based on the increase of compressor speed sum value>decrease of compressor speed sum value, setting the compressor value higheror lower conversely; [0107] h. when the current time has reached the target run time t, then adding up all the favorable values of the parameters of A.sub.1, A.sub.2, A.sub.3 and A.sub.4 that would increase compressor speed (A.sub.4 being a parameter always favors increasing speed), as well as adding up all the favorable values of the parameters that would decrease compressor speed, and based on the increase of compressor speed sum value>decrease of compressor speed sum value, setting the compressor value higheror lower conversely; [0108] i. running the compressor one speed control timing cycle before returning to step d; [0109] j. when receiving compressor off signal, recording the actual compressor on time of t, actual average outdoor temperature and actual average speed from the compressor on period into data storage unit for self-learning purpose, and denoting that when tt, the actual speed as adequate, or inadequate when t>t; [0110] k. further processing the multiple events on speed setting within a given temperature in the data storage, so that statistically, when actual speed adequate occurrence>inadequate occurrence, decreasing the default speed for a given temperature by default X, or increasing conversely.