Multi-expansion valve intelligent control for refrigerant circuit system

Abstract

The control input represents a directional flow rate of refrigerant through the virtual refrigerant metering device. For a plurality of real, non-virtual refrigerant metering devices connected in parallel, a control input is determined for each refrigerant metering device based on a refrigerant flow characteristic of each refrigerant metering device to produce an individual flow rate through the refrigerant metering device that provides a total flow rate equal to a directional flow rate. A control signal is sent to the refrigerant metering device.

Description

Technical Field

[0001] The present disclosure generally relates to improved devices, systems, and methods for controlling expansion valves, e.g., by using an improved control process for a circuit that uses multiple electronic expansion valves. Background Art

[0002] Refrigerant systems are widely used, e.g., in buildings, vehicles, and appliances, in commercial, industrial, public, private, and home settings, for cooling, or for cooling and / or heating when operating as a heat pump. Generally, the basis of a refrigerant system includes compression of the refrigerant and expansion of the refrigerant. Compression of the refrigerant removes thermal energy from the compressed refrigerant using heat exchange, and expansion of the refrigerant moves thermal energy into the expanded refrigerant using heat exchange. For various refrigerant systems of various sizes, capacities, and facilities, there are various compressors and expansion valves of various designs, sizes, and refrigerant flow capacities, which can be well utilized with appropriate control. However, there is a continuing need for technological improvements in refrigeration systems, and it is in this context that the present embodiments arise. Summary of the Invention

[0003] Various embodiments of a refrigerant circuit system, a controller for a refrigerant circuit system, related methods of operating a refrigerant circuit system, and various aspects and features thereof are described herein. Embodiments utilize a virtual refrigerant metering device and control various numbers and types of real, non-virtual refrigerant metering devices based on the virtual refrigerant metering device.

[0004] Some embodiments include a method of operating a refrigerant circuit system. The method includes receiving a control input that represents a directed flow rate of refrigerant through a virtual refrigerant metering device. For each refrigerant metering device of a plurality of parallel-connected, real, non-virtual refrigerant metering devices of the refrigerant circuit system, the method includes determining a separate control input for the refrigerant metering device. The separate control input for the refrigerant metering device is determined at least in part based on the control input representing the directed flow rate and the refrigerant flow characteristics of the refrigerant metering device to produce a plurality of separate flow rates through the plurality of refrigerant metering devices, the plurality of separate flow rates providing a total flow rate that is substantially equal to the directed flow rate. The method includes sending a plurality of control inputs to the plurality of refrigerant metering devices based on the determination of the separate control inputs for the plurality of refrigerant metering devices.

[0005] Some embodiments include a controller. The controller includes one or more processors. The controller is configured to receive a control input that represents a directed flow rate of refrigerant through a virtual refrigerant metering device. The controller includes one or more outputs that are coupled to the one or more processors and are configured to communicatively couple to a plurality of real, non-virtual refrigerant metering devices that are connected in parallel. The controller includes a computer-readable storage medium that is coupled to the one or more processors, and the processor includes program instructions that, when executed by the one or more processors, cause the controller to receive a control input that represents a directed flow rate of refrigerant through the virtual refrigerant metering device. For each refrigerant metering device of the plurality of refrigerant metering devices, the program instructions also cause the controller to determine, at least in part based on the control input representing the directed flow rate and the refrigerant flow characteristics of the refrigerant metering device, a separate control input for the refrigerant metering device to produce a plurality of separate flow rates through the plurality of refrigerant metering devices that provide a total flow rate that is substantially equal to the directed flow rate. The program instructions also cause the controller to send, via the one or more outputs, one or more control inputs to the plurality of refrigerant metering devices based on the determined separate control inputs for the plurality of refrigerant metering devices.

[0006] Other aspects and advantages of these embodiments will become apparent from the following detailed description in conjunction with the drawings, which illustrate, by way of example, the principles of the described embodiments. Other embodiments can be readily designed in accordance with the teachings herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The described embodiments and their advantages can be best understood by reference to the following description in conjunction with the drawings. The drawings are not limited to any changes in form and detail that may be made by those skilled in the art to the described embodiments without departing from the spirit and scope of the described embodiments.

[0008] Figure 1 A refrigerant circuit system according to some embodiments is shown.

[0009] Figure 2 A refrigerant circuit system with a single expansion valve is shown.

[0010] Figure 3 A refrigerant circuit system with two expansion valves according to some embodiments is shown.

[0011] Figure 4 Module and parameter transfer in some embodiments of a refrigerant circuit system according to a virtual expansion valve is shown, where the refrigerant circuit operates, for example, as Figure 1 and Figure 3 shown for two expansion valves.

[0012] Figure 5A The operating values of two expansion valves for some embodiments in the stage 1 and stage 2 operating regions of a refrigerant circuit system are shown in the form of a curve graph.

[0013] Figure 5B Shown in the form of a curve graph are the operating values of two expansion valves for some embodiments that are alternatives to Figure 5A in the stage 1 and stage 2 operating regions of a refrigerant circuit system.

[0014] Figure 5C Shown in the form of a curve graph are the operating values of two expansion valves for some embodiments that are alternatives to Figure 5A and Figure 5B in the stage 1 and stage 2 operating regions of a refrigerant circuit system.

[0015] Figure 6 The operating values of two expansion valves for some embodiments in which a hysteresis path is used are shown in the form of a curve graph in the stage 1 and stage 2 operating regions of a refrigerant circuit system.

[0016] Figure 7 The operating values of two expansion valves for some embodiments in a refrigerant circuit system are shown in the form of a table and a curve graph.

[0017] Figure 8A The operating values of two expansion valves for some embodiments and an idealized target valve for modeling a virtual expansion valve are shown in the form of a table and a curve graph.

[0018] Figure 8B Shown in the form of a table and a curve graph are the operating values of two expansion valves for some embodiments that are alternatives to Figure 8A and an idealized target valve for modeling a virtual expansion valve.

[0019] Figure 8C Shown in the form of a table and a curve graph are the operating values of two expansion valves for some embodiments that are alternatives to Figure 8A and 8B and an idealized target valve for modeling a virtual expansion valve.

[0020] Figure 9 A flowchart of a method for operating a refrigerant circuit system according to some embodiments is shown.

[0021] Figure 10 An exemplary computing device according to some embodiments is shown. Detailed Description

[0022] This document describes various embodiments of a refrigerant circuit system with intelligent control using multiple metering devices. In some embodiments, the metering devices are various types of expansion valves, including electronic expansion valves, thermal expansion valves, externally equalized expansion valves, and internally equalized expansion valves. Real-world expansion valves behave in various ways, such as non-linear, inaccurate, and / or non-repeatable behavior of refrigerant flow relative to control settings, especially for low levels of refrigerant flow compared to the assumed ideal expansion valve with respect to the maximum flow capacity of a given expansion valve. By using multiple expansion valves in parallel, in some embodiments with the same size and flow characteristics and in some other embodiments with different sizes and flow characteristics, each valve can be operated within an appropriate range for precise and repeatable flow control. Also, in various embodiments, the system can compensate for the non-ideal operation of each real-world expansion valve and includes a control system that operates as if there were a single, wide-flow-range, ideal (or nearly so) virtual expansion valve, which can be referred to as a "virtual EXV", that controls the setting over the entire range of (one or more) metered refrigerant flows with a linear, repeatable, and precise flow response.

[0023] Figure 1 A refrigerant circuit system according to some embodiments is shown. In various embodiments, the refrigerant circuit system will be considered to include only a controller 100 with a control circuit and an electronic expansion valve (EXV) control module, configured to control two (or more) expansion valves, which will be considered the controller coupled to two expansion valves 30, 32 (as depicted, or more), which will be considered two heat exchangers 22, 24, which will be considered the entire climate control system 10, or other combinations of components.

[0024] As Figure 1 shown, the climate control system 10 includes a chiller unit, which is configured to cool or heat a conditioned space (e.g., the interior of an office building, retail store, convention center, industrial process, etc.). Thus, the climate control system 10 may be referred to herein as a "chiller unit".

[0025] The climate control system 10 includes a refrigeration assembly 20, which is configured to circulate a refrigerant to exchange heat between the conditioned space and the surrounding environment (e.g., the outdoor environment surrounding the conditioned space) to cool or heat the conditioned space. The refrigeration assembly may include a first heat exchanger 22 and a second heat exchanger 24. The first heat exchanger 22 is configured to exchange heat between the refrigerant and the working fluid 44 of the environmental heat exchange loop 40, and the second heat exchanger 24 is configured to exchange heat between the refrigerant and the working fluid 54 of the conditioned space heat exchange loop 50.

[0026] In some embodiments, the working fluid 54 of the conditioned space heat exchange loop 50 may include water (or a suitable water-containing mixture). The working fluid 54 may circulate between the second heat exchanger 24 of the refrigeration assembly 20 and the conditioned space heat exchange assembly 52 to exchange heat between the refrigerant and the conditioned space during operation. In some embodiments, the conditioned space heat exchange assembly 52 may include one or more heat exchangers (e.g., an air handler unit) configured to exchange heat between the working fluid 54 and the conditioned space. In some embodiments, the working fluid 54 may include a fluid other than water, such as, for example, air (e.g., air directly supplied to the conditioned space).

[0027] The working fluid 44 of the ambient heat exchange loop 40 may include water or other suitable water-containing mixtures, such as the water-containing mixture described above for the working fluid 54. Alternatively, the working fluid 44 may include air. Other working fluids may also be used. When the working fluid 44 is water, the cooler unit or climate control system 10 may be referred to as a "water-cooled" cooler unit, and when the working fluid is air, the cooler unit or climate control system 10 may be referred to as an "air-cooled" cooler unit. In any case, the working fluid 44 may circulate between the first heat exchanger 22 of the refrigeration assembly 20 and the ambient heat exchange assembly 42 to exchange heat between the refrigerant and the surrounding environment. In some embodiments, the ambient heat exchange assembly 42 includes one or more heat exchangers (e.g., a water cooling tower, a radiator, a finned fan cooler, etc.) configured to transfer heat between the surrounding environment and the working fluid 44. In some embodiments, such as in the case of an air-cooled cooler unit, the ambient heat exchange assembly 42 may be integrated and combined with the first heat exchanger 22 such that heat is directly exchanged between the refrigerant and an air stream that originates from and is supplied back to the surrounding environment.

[0028] In addition to the first heat exchanger 22 and the second heat exchanger 24, the refrigeration assembly may include a compressor 26 and a plurality of expansion valves 30, 32. The compressor 26 and the expansion valves 30, 32 may be in fluid communication with the first heat exchanger 22 and the second heat exchanger 24 along the refrigerant loop or circuit 28. During operation, the refrigeration assembly 20 may be operated to circulate the refrigerant in the Figure 1 first direction shown to transfer heat from the conditioned space (e.g., via the conditioned space heat exchange loop 50) to the surrounding environment (e.g., via the ambient heat exchange loop 40). Such an operation may be referred to herein as "cooling mode" operation.

[0029] Specifically, in Figure 1In the cooling mode operation shown, the refrigerant (which may be in a vapor or semi-vapor state) can be compressed by the compressor 26 and delivered via the refrigerant loop 28 to the first heat exchanger 22. Inside the first heat exchanger 22, heat is transferred from the refrigerant to the working fluid 44, which cools the refrigerant and at least partially condenses the refrigerant into a liquid. Thus, in the Figure 1 cooling mode operation, the first heat exchanger 22 may be referred to as a "condenser". Then, as previously described, heat is transferred from the heated working fluid 44 to the surrounding environment via the ambient heat exchange component 42 of the ambient heat exchange circuit 40.

[0030] Then, the condensed refrigerant is discharged from the first heat exchanger 22 and flows via the expansion valves 30, 32 to the second heat exchanger 24. The expansion valves 30, 32 may be arranged in parallel with each other along the refrigerant loop 28 between the first heat exchanger 22 and the second heat exchanger 24. Thus, during operation, the refrigerant flowing out of the first heat exchanger 22 is split and distributed between the expansion valves 30, 32. The expansion valves 30, 32 can be actuated to controllably expand and thus cool the refrigerant upstream of the second heat exchanger 24.

[0031] Then, the expanded and cooled refrigerant flows to the second heat exchanger 24. Inside the second heat exchanger 24, heat is transferred from the working fluid 54 to the refrigerant, which causes the refrigerant to evaporate (or at least partially evaporate). Thus, in the Figure 1 cooling mode operation, the second heat exchanger 24 may be referred to as an "evaporator". Then, the cooled working fluid 54 is used to cool the conditioned space via the conditioned space heat exchange component 52 of the conditioned space heat exchange circuit 50, as previously described.

[0032] Although not shown, in some embodiments, the refrigeration assembly 20 can circulate the refrigerant in a second direction opposite to the Figure 1 refrigerant loop 28 shown, so as to transfer heat from the surrounding environment to the conditioned space via the ambient heat exchange circuit 40 and the conditioned space heat exchange circuit 50. Such an operation may be referred to herein as a "heating mode" operation, and the refrigeration assembly 20 configured to operate in the heating mode may be referred to as a "heat pump". During the heating mode operation of the refrigeration assembly 20, the first heat exchanger 22 can be used as an "evaporator" (which evaporates the refrigerant), while the second heat exchanger 24 can be used as a "condenser" (which condenses the refrigerant).

[0033] As previously described, in the Figure 1During operation of the cooler unit or climate control system 10 shown, refrigerant can expand controllably through expansion valves 30, 32. In some embodiments, each of expansion valves 30, 32 can be electrically actuated (e.g., by a controller such as controller 100 described in more detail herein) between a fully closed position, a fully open position, and a plurality of positions between the fully closed and fully open positions. Thus, expansion valves 30, 32 can both be referred to herein as "electric expansion valves" (EXVs).

[0034] Additionally, in some embodiments, compressor 26 can be a variable speed compressor configured to operate at a plurality of operating speeds to vary the cooling (or heating) capacity of the cooler unit or climate control system 10. Accordingly, the positions of expansion valves 30, 32 can be adjusted based on the operating speed of compressor 26 (and other factors) to accommodate varying flow rates of refrigerant along refrigerant loop 28 and ensure efficient operation of the cooler unit or climate control system 10.

[0035] The non-ideal behavior and operation of real-world expansion valves are compensated for in various embodiments of the system. Described below are control algorithms for some embodiments that can be applied to different expansion valve sizes determined for a particular cooling or heat exchanger device and system. Generally, sizing of the system, including selection of expansion valve sizes for two or more expansion valves in the system, involves determining the maximum refrigerant flow rate for the facility and system and idealized expansion valve characteristics. In some embodiments, the idealized expansion valve characteristics are represented in the system in the form of a virtual refrigerant metering device, which can be a virtual expansion valve. The selected refrigerant metering device can be an expansion valve that operates in the system according to the virtual expansion valve. Thus, in some embodiments, a real, non-virtual refrigerant metering device or expansion valve operates as if there were a single, idealized expansion valve, e.g., a virtual expansion valve. In some embodiments, as further described below in an example system with example control involving case, the control is parameterized. In various embodiments, the developed, parameterized control for a particular, selected, real-world expansion valve models the real, parallel-connected expansion valves as a single, idealized expansion valve, a virtual expansion valve, and is embedded in controller 100 having a control circuit and an EXV control module. Aspects and features thereof are further described below with reference to Figures 2 - 8C 、 Figure 9 a flowchart (for a method or algorithm) and Figure 10 an example of Figure 10 illustrates an example computing device that, in some examples, is the same as or similar to the control circuit discussed herein. Example system involvement and technical solutions

[0036] In one example, the feature development requirement is for an RTWF (Rotary Twin Water-cooled F cooler), water-cooled unit that controls an EXV to maintain the condenser refrigerant level above the sub-cooler section. Products using condenser sub-cooling, suction superheat, or evaporator level control are also envisioned. Considering an RTWF unit that controls an EXV to maintain a desired condenser refrigerant level, it is generally possible to choose between two different EXV sizes based on the customer-stated functional conditions. However, in cases where there are fewer restrictions between a somewhat undersized and a normal-sized EXV selection, the normal-sized one is chosen, resulting in a refrigerant flow control problem in the circuit when the required circuit capacity is low (e.g., inaccuracy in refrigerant flow regulation when the EXV opening is below 10% of the wide-open position). For example, during an operation requiring low refrigerant flow, the normal-sized EXV opening can remain in the lower part of the control curve, and thus the imprecision in refrigerant flow regulation causes this problem. Therefore, for better refrigerant flow controllability, an undersized EXV can be used for operating conditions with lower required refrigerant flow, while a normal-sized EXV can be used for achieving higher and maximum refrigerant flows.

[0037] Accordingly, in some embodiments, a technical solution to the refrigerant flow regulation problem is to install a normal-sized EXV and an undersized EXV in parallel and control them in such a way that the undersized EXV is used in the lower part of the control curve and the normal-sized EXV is used in the upper part of the control curve. In some embodiments, this is accomplished using dual-stage control that operates the two EXVs in a low-flow regime and a high-flow regime, which may be referred to herein as Stage 1 and Stage 2. In some embodiments, the operation is transparent to the circuit EXV control system such that the operation of the two (or more) EXVs is treated as a single EXV control based on a virtual EXV. Control Systems for Real and Virtual EXVs

[0038] In some embodiments, the control system exhibits the ideal EXV behavior, such as a virtual EXV, from a closed valve to a wide-open valve, but is physically implemented (installed, connected, or coupled in parallel) using two real EXVs. In some embodiments, the system compensates for the inaccuracies of each real EXV as much as possible, thereby making the circuit refrigerant flow more reliable, especially when the refrigerant circuit is traveling at low flow, such as in a low-flow regime or Stage 1 of dual-stage control.

[0039] In various embodiments, the virtual EXV may model one, two, or more real metering devices of a real expansion valve as an idealized, single virtual metering device, which may be a virtual expansion valve. In some embodiments, the control system generates control for each of one or more real metering devices, such as one or more expansion valves, operating within a defined operating range, which provides the overall operation of the system as if operating an idealized, single virtual metering device or virtual expansion valve.

[0040] Then, for some embodiments, the goal is to develop a dual EXV system (e.g., two real EXVs) with dual-stage control (e.g., having operation in a low-flow regime or stage 1 and a high-flow regime or stage 2) to enhance loop refrigerant flow controllability, especially for low-flow regimes. Figure 3 Details of the dual-stage control of the dual electronic EXV system are further described hereinafter to enhance loop refrigerant flow controllability, especially for low-flow regimes. Flow coefficient

[0041] In some embodiments, one principle of the control system is to work with a defined ideal Cv (see below) versus percentage opening curve (for the idealized, virtual EXV) and control the physical EXV to follow that ideal curve as smoothly as possible. Based on an EXV model algorithm specification, the size of the valve is determined based on the "flow coefficient", which is commonly designated as Cv. Cv is more appropriately called the "volume flow coefficient" because its application directly provides volumetric flow rate rather than mass flow rate. The flow equation using Cv allows the estimation of flow rate for pressure drops and fluid densities different from the test conditions.

[0042] Each qualified EXV has its own Cv versus percentage opening curve, which is used by the control to define the EXV opening based on the estimated refrigerant mass flow rate required through the actuator, which may be referred to as the directed refrigerant flow. The Cv versus percentage opening curve is a specific example characteristic curve of the refrigerant flow characteristics of the refrigerant metering device. In this case, the characteristic curve manages the refrigerant flow rate of the refrigerant through the refrigerant metering device. For example, see Figure 7 where the Cv, which is a variable flow coefficient indicating refrigerant flow, is associated with the "position" or expansion valve opening expressed as a percentage value.

[0043] Embodiments can use a single qualified EXV, two identical or equivalent qualified EXVs (e.g., the same Cv curve), two different qualified EXVs (e.g., different Cv curves), or multiple EXVs in various combinations of the same, equivalent, or different components (and one or more corresponding Cv curves). In various embodiments, the refrigerant circuit system and its controller and related methods can use these various numbers of EXVs with or without dual-stage control (e.g., utilizing different portions of one or more Cv curves and their weighting). Integrate feature software into the controller

[0044] In some embodiments, software integration is used to combine the various features or aspects of the embodiments in the system. It should be understood that variations can use software executed on processors, firmware, hardware, and combinations thereof, and in particular, the components or features of the system can be implemented in various such modules in various combinations (e.g., software modules, hardware modules, firmware modules, etc.). For example, specific features or aspects of the system or its operation can be implemented in one or more modules or such hardware, software, etc.

[0045] For condenser liquid level control, the application software (loaded into the controller) controls the EXV by sending a flow coefficient value (related to the EXV wide-open Cv) to the extended software module. In various embodiments, the extended software module converts the flow coefficient value into an EXV opening (or percentage of position) and applies the converted flow coefficient value to the real EXV(s). For some embodiments of the dual EXV case where two real EXVs are used, the same opening value based on the double wide-open Cv is applied to the two EXVs. For some other embodiments of the dual EXV case, different opening values are applied to the two EXVs. For some other embodiments of the dual EXV case, different opening values are applied to the two EXVs in one operating range (e.g., low flow) and different additional opening values are applied to the two EXVs in another operating range (e.g., higher flow) for dual-stage control. For some other embodiments of the dual EXV case, different opening values are applied to the two EXVs in one operating range (e.g., low refrigerant flow) and the same opening value is applied to the two EXVs in one operating range (e.g., higher refrigerant flow) for dual-stage control.

[0046] In addition, it should be understood that the directed flow rates discussed herein can be sent and / or received from various sources. For example, as described above with respect to Figure 1The climate control system discussed can set the directed flow rate for one or more EXVs based on various conditions associated with the refrigeration system, such as requested demand, ambient conditions, overheating, etc. Based on these conditions, the directed flow rate can be set by a given controller. Additionally, the processes discussed herein for controlling the EXV to achieve or attempt to achieve the directed flow rate can be utilized by the same controller, or in some examples, additional controllers, software modules, etc. can interface with the controller providing the directed flow rate.

[0047] By way of example, a first controller in the climate control system can determine the directed flow rate through one or more EXV valves. That is, the directed flow rate can be for the refrigerant within the refrigeration system, and it can be based on the cooling load requested by the conditioned space. The first controller can encode the directed flow rate into a control input. In some examples, this control input provided by the first controller can be directed to control a system with a single EXV to achieve the directed flow rate. Other control inputs can also be utilized / determined by the controller. Additionally, in some examples, a second controller can be communicatively coupled to the first controller and receive the control input. The second controller can utilize one or more of the processes described herein to control the position of one or more EXV valves, potentially obtaining a flow rate approximately the same as the directed flow rate. In these examples, separating the controller for determining the directed flow rate, such as the desired refrigerant flow rate, from the control for implementing the EXV control to achieve that flow rate can have various advantages. For example, this can allow these more advanced EXV controls to be implemented into existing systems that utilize only a single EXV valve and / or have different controls, thereby improving the overall performance of the system without significant changes. These and other advantages can also be achieved. Single expansion valve

[0048] Figure 2 A refrigerant circuit system having a single expansion valve 62 is shown. Referring to Figure 2 , the expansion software module 60 processes the received flow coefficient and determines the valve position, which is communicated to the EXV 62. In some embodiments, this control is performed according to an algorithm described in more detail below.

[0049] In some embodiments, to make the main EXV control software with dual-stage EXV control (e.g., condenser liquid level control) transparent, the expansion software module shows a virtual EXV and converts its flow coefficient into personalized inputs for the opening of two EXVs, which will be applied to the physical EXV with a smooth transition between the low-stage valve (LSV) and the high-stage valve (HSV) (see Figure 3 ). Dual expansion valve and virtual EXV

[0050] Figure 3Shows a refrigerant circuit system with two expansion valves 66, 68 according to some embodiments. The extended software module 64 includes a virtual EXV, which is used to determine the LSV position and HSV position when processing the received flow coefficient. The extended software module 64 communicates the LSV position to the low-level valve EXV 66 and the HSV position to the high-level valve EXV 68.

[0051] Some embodiments of the virtual EXV are described below. In some embodiments, the virtual EXV is defined based on the wide-open (or 100% open) Cv (Max Cv) parameter according to the loop maximum capacity, and as it will follow an ideal curve, the following equation shows the linear and proportional behavior of the virtual EXV. CV = RampCoef * Opening(%) with RampCoef = MaxCV / 100 Or Opening(%) = (CV * 100) / MaxC

[0052] In an example of "Ideal SEHI-400", for example, a specific real flow control valve is modeled by a micro control system, where MaxCv = 14.5: Opening(%) = (Cv / 14.5) * 100 = 6.897 * Cv As modeled above, for the idealized virtual EXV, the percentage of the expansion valve opening is linearly proportional to the refrigerant flow rate, which is modified by the ramp coefficient, and when the maximum refrigerant flow rate is reached, the expansion valve opening will reach 100%. Two-stage control

[0053] What is described below is applicable to Figure 4 Some embodiments of two-stage control. Here, two real expansion valves are used, one expansion valve operates as a low-level valve (LSV), and the other expansion valve operates as a high-level valve (HSV), where the combination of the expansion valves operates as a virtual expansion valve using bipolar control. Figure 4 Shows the module and parameter transfer in some embodiments of a refrigerant circuit system where two expansion valves are operated according to a virtual expansion valve, for example, as Figure 1 and Figure 3 shown. In various embodiments, these modules are embedded in the controller 100 (see Figure 1 ) or distributed in two or more physical controllers or embedded in the EXV control module, etc.

[0054] At a high level, the system determines a directional flow rate of refrigerant based on a control input and then encodes the directional flow rate in a separate control input for a refrigerant metering device, one operating as an LSV and the other as an HSV. More specifically, at a module level, the virtual MaxCv / 100 module 70 receives a flow coefficient, determines an EXV Cv parameter value, and passes the EXV Cv parameter value to the LSV and HSV weighting logic module 72. The LSV and HSV weighting logic module 72 also receives a virtual EXV opening parameter value, which applies the aforementioned weighting to the virtual EXV opening parameter value to determine LSV Cv and HSV Cv for the two expansion valves. The LSV Cv is communicated to the 100 / LSV MaxCv module 74, which determines %FC LSV and communicates it to the LSV UniEXV driver module 76 to control the low-stage expansion valve. The HSV Cv is communicated to the 100 / HSV MaxCv module 74, which determines %FC HSV and communicates it to the HSV UniEXV driver module 76 to control the low-stage expansion valve.

[0055] Continuing reference Figure 4 , for a two-stage, dual EXV control, the %FlowCoef should be converted back to a virtual EXV Cv (VEXVCv), which will be split into two Cvs (one for the LSV and the other for the HSV, considering that two parallel Cvs can be added to give a total Cv), then converted to %FlowCoefLSV and %FlowCoefHSV, and applied to the relevant physical EXVs. Thus, Figure 4 the modules and parameter passing in

[0056] illustrate a controller for some embodiments of a refrigerant circuit that receives a virtual EXV opening as an input representing the directional flow rate of refrigerant through a virtual refrigerant metering device, applies weighting to operate one EXV as a low-stage valve and the other EXV as a high-stage valve, and generates separate control inputs for two real, non-virtual EXVs or refrigerant metering devices. Figure 2 . Alternatively, for embodiments using a single EXV control, the %FlowCoef from the main EXV control (e.g., condenser level control) is converted to %opening and applied to a single physical EXV (see, for example, Figure 2 ). In various embodiments, for a single EXV, the control can be single-stage or two-stage. LSV and HSV weighting logic

[0057] The weighted logic link is between a virtual optimal or ideal actuator, such as a virtual refrigerant metering device or a virtual EXV, and two real (non-optimal) actuators, such as a real, non-virtual refrigerant metering device or EXV. Additionally, in a particular system embodiment (e.g., see Figures 4 - 8C and Figure 9 flowchart), the parameterized implementation of such an algorithm controls the real EXV in a way that ensures following the virtual EXV curve with the lowest possible latency and without or with low continuity, since in some embodiments, the loop EXV control is based on incremental PID. In some embodiments, it is desirable to avoid perturbation effects that can lead to unintended refrigerant flow behavior as much as possible.

[0058] In some embodiments, there are two or more different control phases (e.g., see Figures 5A - 6 phase 1 and phase 2 in Figures 8A - 8C and also see Figures 5A - 8C alternatives in Figure 4 ). Examples of weights for controlling the phases are discussed below with reference to such as the weights of the LSV and HSV weighted logic module 72 in

[0059] For these examples, at any point on the horizontal axis, the sum of these two weights (for the two expansion valves) adds up to the value "1". In parametric terms, this means that the sum of the weights at any given operating point in any control phase is normalized to "1", or equivalently, to 100%. More specifically, for a dual EXV embodiment, at any operating point, the weight on the LSV plus the weight on the HSV adds up to "1". The weights applied to the corresponding Cv curve or the characteristic curve of the refrigerant metering device are mapped to the ideal characteristic curve of the virtual refrigerant metering device and vice versa. Figures 5A - 5C Three versions of the dual-stage operation of two real, non-virtual expansion valves or refrigerant metering devices are described below with reference to

[0060] Figure 5A for various embodiments of a refrigerant circuit system or its controller, and related methods. These embodiments feature one EXV operating as a low-stage expansion valve or LSV, and the other EXV operating as a high-stage expansion valve or HSV, as a dual EXV operation. The embodiments have operations and parameters similar to dual-stage operation in phase 1, and operations and parameters different from dual-stage operation in phase 2.The operating values of two expansion valves in the stage 1 and stage 2 operating regions of a refrigerant circuit system are shown in the form of a curve graph for some embodiments. For the weight LSV82 of the low-stage expansion valve, it is a stable "1" value throughout stage 1, and then, across stage 2, it linearly decreases from there to "0". For the weight HSV84 of the high-stage expansion valve, it is a stable "0" value throughout stage 1, and then across stage 2, it linearly increases from there to "1". Thus, the system performs two-stage operation of the two EXVs using these weighting functions, one operating as the low-stage expansion valve and the other as the high-stage expansion valve.

[0061] Figure 5B The operating values of two expansion valves in the stage 1 and stage 2 operating regions of a refrigerant circuit system are shown in the form of a curve graph for Figure 5A some embodiments as an alternative to Figure 5A The stage 1 operation can be compared with the

[0062] weighting function of Figure 5A and 5B In stage 2, LSV86 decreases and HSV88 climbs until the weighting functions both reach the "0.5" value, where they remain for the remainder of stage 2. Note that in this example, 50% is the minimum weight of LSV86 and the maximum weight of HSV88. Figure 5C For some embodiments as an alternative to Figure 5A and Figure 5B The operating values of two expansion valves in the stage 1 and stage 2 operating regions of a refrigerant circuit system are shown in the form of a curve graph. The stage 1 operation can be compared with the weighting function of and In stage 2, LSV90 decreases to a value of "0.3" and HSV92 increases to a value of "0.7", where the weighting functions remain for the remainder of stage 2. Note that the two weighting functions cross each other, and the minimum weight of LSV90 is 30%. In the lower part of the virtual EXV curve (e.g., stage 1), only LSV90 is used: LSVCv = VEXVCv and HSVCv = 0 While VEXVCv is increasing, on HighLSVCv (related to LSV MaxCv), when VEXVCv = VEXVMaxCv, LSVCv will linearly decrease to 0 (LSV closed). Here, in this embodiment, the control system should not make LSVCv lower than LowLSVCv (related to the current VEXVCv). And, in this case, the control system should compensate for the virtual EXV Cv with HSVCv: LSVC = HighLSVCv * (MaxVEXVCv - VEXVCv) (MaxVEXVCv-HighLSVCv) In some embodiments, as described below, the control system does not allow the LSV 90 to be lower than LowLSVCv (which is related to the current VEXVCv and is shown here as the value "0.3" or 30%). LowLSVCv = VEXVCv * LSVMinWeight If LSVCv < LowLSVCv then LSVCV = LowLSVCv In some embodiments, the control system should not allow the HSV 92 to be higher than HighLSVCv (which is related to LSV MaxCv and is shown here as the value "0.7" or 70%). if LSVCv > HighLSVCv then LSVCV = HighLSVCv Compensate LSVCv with HSVCv HSVCV = VEXVCv - LSVCv

[0063] Empirically, in some embodiments for a real EXV actuator, the expansion valve may not move at an opening of 5%, and the Cv may be unstable at an opening of 10%. To avoid unstable refrigerant flow in the refrigerant circuit when the HSV starts to open, the system uses an HSV minimum opening parameter (default 5%), and a method that transitions as smoothly as possible from stage 1 to stage 2. An example of the parameters is given below. When in stage 2: If HSVCv < HSVCv (minimum opening) then { Force the HSV to its minimum opening HSVCV = HSVCv (minimum opening) Compensate HSVCv with SVCvLSVCV = VEXVCv - HSVCv } Two-stage, dual EXV operation and parameters with hysteresis

[0064] In some embodiments, when the EXV control moves from stage 2 to stage 1, the system has hysteresis so that if the EXV control adheres around the stage 1 and stage 2 boundary (sometimes stage 1 is called P1 and sometimes stage 2 is called P2), then "oscillating" HSV control (from 0% to the minimum opening) is not obtained. In some embodiments, the HSV is operated according to a hysteresis path, in some embodiments, the LSV is operated according to a hysteresis path, or in some embodiments, the HSV is operated according to one hysteresis path and the LSV is operated according to another hysteresis path (see Figure 6 ) to mitigate this oscillatory behavior. Figure 6 The operating values of two expansion valves in the stage 1 and stage 2 operating regions of a refrigerant circuit system are shown in the form of a curve graph for some embodiments in which a hysteresis path is used. In the hysteresis region, when the LSV 94 transitions from left to right in the curve graph, it follows the upper path, and when it transitions from right to left in the curve graph, it follows the lower path. In the hysteresis region, when the HSV 96 transitions from left to right in the curve graph, it follows the upper path, and when it transitions from right to left in the curve graph, it follows the lower path. In various embodiments, in the operation of the refrigerant metering device of the refrigerant circuit system or more specifically the controller, hysteresis, more specifically a hysteresis path, is provided by applying a weighting function to the characteristic curve. For example, this can be done through software integration. The parameters and algorithms are described below (and also see Figure 9 the flowchart).

[0065] When transitioning from stage 2 to stage 1, the HSV remains at the minimum opening, and when VEXVCv is less than 90% of HighLSVCv, it reverts to the normal function of stage 1: If in the stage 2 to stage 1 mode, then { HSVCV = HSVCv (minimum opening) LSVCV = VEXVCv - HSVCv if VEXVCv < 0.9 * HighLSVCv then { LSVCV = VEXVCv HSVCV = 0 Leave the stage 2 to stage 1 mode } } The LSV has an HSV combination selection

[0066] Based on the available real EXV and virtual EXVMax Cv parameters, many new virtual actuators with different LSV and HSV behaviors can be defined and created according to the HighLSVCv and LSVMinWeight parameters. Parameter examples of virtual EXV and real EXV.

[0067] The following are some examples of the creation of virtual EXVs with different and similar or identical real EXV situations. These examples illustrate system and controller embodiments, as well as embodiments of the development methods for developing system embodiments and controller embodiments.

[0068] In some embodiments, first, a development method is used to confirm the operation of a control system using a simulator and then to confirm it on a real unit for dynamic confirmation. In some embodiments, various rules are used to define parameters such as virtual EXV maximum Cv, low-level valve high Cv, low-level valve minimum weighted, and high-level valve minimum opening. Below, in tabular form, are the operating parameters for various exemplary real-world expansion valves from which virtual and real EXV models are developed according to some embodiments. Additionally, one of the following tables also shows an example of a user interface / service tool that may include various settings, commands, etc. This example table shows information for two example user interfaces, TD7 and TU. User interface / service tool

[0070] In various embodiments, examples of EXV models developed based on the above exemplary real-world EXVs are given for a refrigerant circuit system having a single, virtual EXV and multiple real EXVs and their control operations. The virtual EXV is developed based on the real EXV (see Figures 8A - 8C ), and the developed real EXV model (see Figure 7 ), the developed weighted model (see Figures 5A - 5C , 6, 8A - 8C), and the weighting combined with the real EXV model are mapped to the virtual EXV model (and vice versa). Then, the developed system or controller embodiments (see Figure 1 , 3 , 4) control the real EXV according to the virtual EXV model mapped to the real EXV model by weighting (see Figure 9 's flowchart). Exemplary expansion valves for a two-stage, dual EXV

[0071] Figure 7 Shows the operating values for two expansion valves in a refrigerant circuit system for some embodiments in tabular and graphical form. Specifically, the SEHI - 400Cv curve 102 and the SEHI - 175Cv curve 104 are shown (e.g., characteristic curves for a real refrigerant metering device), with the refrigerant flow rate and valve opening position range of 0 - 100% shown on the left, a dashed line at 10%, and the 0 - 50% low refrigerant flow rate range 106 or operating area (magnified) shown on the right. Although developed for a specific EXV in this embodiment, other embodiments with other specific EXVs or refrigerant metering devices can be easily developed according to the teachings herein.

[0072] For this example, the explanation of the refrigerant flow controllability is as follows. Consider the case of RTWF, where SEHI-400 has been selected, and the selection possibility is restricted between SEHI-175 and SEHI-400. Here is Figure 7 the Cv curves 102, 104 in

[0073] By examining the Cv curves 102, 104 of the two expansion valves, and in particular Figure 7 the low refrigerant flow rate range 106 in Figure 8A and 8B returning reference Figure 7 and

[0074] For the development of some embodiments (e.g., embodiments of manufacturing and using a specific control system or refrigerant circuit system), consider the SEHI-400 opening from 2% to 10% (8-point dynamic), which gives a Cv from 0.1 to 1.15 from the curve 102 in Figure 7 This indicates problems with refrigerant flow controllability such as linearity, reliability, repeatability, etc. However, for the same Cv range, when using SEHI-175, the opening is approximately 9% to 28% (19-point dynamic), and for this range, it indicates relatively more linear, reliable, and repeatable refrigerant flow controllability. Therefore, for better refrigerant flow controllability, some embodiments use SEHI-175 under conditions where the required Cv is low, and use SEHI-400 to achieve the highest Cv. Some embodiments use two SEHI-175s. Some embodiments use two SEHI-Ts. For example, based on the following description and illustration, it is easy to develop other embodiments with other refrigerant metering devices or expansion valves in various combinations. Example of two-stage, two-EXV development with SEHI-175 and SEHI-400

[0075] Figure 8AThe operating values for two expansion valves for some embodiments and an idealized target valve for modeling a virtual expansion valve are shown in tabular and graphical form. Specifically, the SEHI-175 Cv curve 107 for operating the "low-stage valve" (LSV), the SEHI-400 Cv curve 110 for operating the "high-stage valve" (HSV), and the idealized Cv curve 108 for operating the virtual or target expansion valve are shown. The idealized Cv curve 108 (or variations thereof) may be referred to as the target characteristic curve of the virtual refrigerant metering device.

[0076] In some embodiments with reference to Figure 8A the RTWF with SEHI-175 and SEHI-400, this principle is applied. In some embodiments, as follows, the two real EXVs are controlled by a control system based on the virtual valve. SEHI-175 is considered smaller, e.g., a low-volume expansion valve with a maximum flow rate lower than that of the larger, high-volume expansion valve, SEHI-400.

[0077] In some embodiments, the control system uses a virtual EXV (target) defined by an ideal Cv curve 108 (Cv = A × opening) from 0 to 100% opening (e.g., with a 5% interval selection, but other intervals can be used) based on the SEHI-400 maximum Cv (e.g., 14.5). Then, considering the installation of SEHI-175 as the low-stage valve (LSV) and SEHI-400 as the high-stage valve (HSV) with two real EXVs, the weight of the LSV is defined from 100% to 0% by considering a virtual position where, as the HSV weight (= 100 – LSV weight) ramps up, the LSV weight ramps down sensibly (here chosen as 50%). Using the defined weights, the Cv required for the LSV and HSV is calculated (= weight × virtual EXV Cv), and then it is converted to the LSV and HSV positions according to the corresponding weighted real EXV Cv curves 107, 110.

[0078] Thus, Figure 8A the development of a two-stage, two-EXV refrigerant circuit system or a controller for such a system is shown, where the two EXVs or refrigerant metering devices are different. The smaller EXV operates as the low-stage valve with one weighting function applied to the characteristic curve of the smaller EXV (e.g., Cv curve 106). The larger EXV operates as the high-stage valve with another weighting function applied to the characteristic curve of the larger EXV (e.g., Cv curve 110). The two EXVs are operated using two-stage control based on the target characteristic curve of the virtual refrigerant metering device (e.g., the ideal Cv curve 108). Example of a two-stage, two-EXV development with two SEHI-175s

[0079] Figure 8B The operating values for two expansion valves and for an idealized target valve used to model a virtual expansion valve are shown in tabular and graphical form for some embodiments that are alternatives to Figure 8A . Specifically, the SEHI-175 Cv curve 112 for operating a “low stage valve,” the SEHI-175 Cv curve 116 for operating a “high stage valve,” and the idealized Cv curve 114 for operating a virtual or target expansion valve are shown. Note that the two real-world EXVs are the same physical unit (e.g., physically identical components), but one operates as a low stage valve with one weighting function applied to the Cv curve 112 and the other operates as a high stage valve with another weighting function applied to the Cv curve 116, so the control of the unit in the system embodiment is different from Figure 8A the embodiment shown.

[0080] Thus, Figure 8B the development of a two-stage, dual EXV refrigerant circuit system or a controller for such a system is shown, where the two EXVs or refrigerant metering devices are the same (e.g., examples of the same or substantially the same specific expansion valve). One of the two identical EXVs operates as a low stage valve (see the left side of Figure 8B ), the two identical EXVs together operate as a high stage valve (see the right side of Figure 8B ), and there is a transition region in which the EXV operating as a low stage valve ramps down while the other EXV ramps up (see the middle of Figure 8B ).

[0081] Continuing with the example of Figure 8B , if the above principles are applied to an RTWF with dual SEHI-175 expansion valves, the dual SEHI-175 expansion valves can cover the SEHI-400 maximum Cv. That is, a system with two smaller expansion valves and a controller can achieve the expected maximum refrigerant flow rate obtainable with a single, larger expansion valve.

[0082] In some embodiments based on the above, the system defines a virtual EXV based on the SEHI-400 maximum Cv. The intention here is that the maximum refrigerant flow rate of the dual EXV system should match the maximum refrigerant flow rate obtainable in the case of using a larger EXV in a single EXV-based system. Then, considering a dual real EXV installation, with one SEHI-175 as the low-stage valve and the other as the high-stage valve, by considering the virtual position, the weight of the LSV is positioned from 100% to 50%, at which virtual position, when the HSV weight ramps up, the LSV weight is sensibly ramped down (chosen here as 50%). By stopping the ramp-down of the LSV weight and the ramp-up of the HSV weight at 50%, there is a point where the two EXVs follow the same opening until the 100% opening of the virtual EXV (see Figure 8B to the right). Dual-stage, dual EXV development example with two SEHI-Ts

[0083] Figure 8C The operating values for two expansion valves and for an idealized target valve used to model the virtual expansion valve are shown in tabular and graphical form, for some embodiments, as Figure 8A and Figure 8B alternatives. In one example, the above principles are applied to an RTHF product with a dual SEHI-T installed, which can be referred to as a large-tonnage unit. However, before applying the above (one or more) principles, the two SEHI-T expansion valves will be controlled with the same opening request, such that the opening position range of the valves for the two expansion valves simultaneously varies from 0 to 100%. As described above, when a low refrigerant flow rate is requested, this can (or may, and does) result in refrigerant flow control problems (one or more). In one embodiment, by using the dual-stage feature with the control further described below, it is possible to overcome this risk. Specifically, in Figure 8C is shown an SEHI-T Cv curve 118 with one weighting function for operating the "low-stage valve", an SEHI-T Cv curve 122 with another weighting function for operating the "high-stage valve", and an idealized Cv curve 120 for operating the virtual or target expansion valve. Note that the two real-world EXVs are the same physical unit (e.g., physically identical components), but one operates as the low-stage valve and the other as the high-stage valve, using different weighting functions, and thus the control of the units in the system is different.

[0084] Define the virtual EXV based on the doubled SEHI-T maximum Cv (see Figure 8C at the lower left of Figure 8Cto the left), the weight is defined to operate only one SEHI-T as a low-level valve (see the left part of the SEHI-T Cv curve 118), while the other SEHI-T is "closed" or valve-closed (the left part of the SEHI-T Cv curve 122 is omitted but implied at "0" along the horizontal axis). The weighting of the LSV from 100% to 50% is defined by considering a virtual position at which the LSV weight is sensibly ramped down (chosen here as 45% so as not to request the LSV to reach 100% in the middle of the virtual curve), while the HSV weight ramps up (see Figure 8C in the middle). By stopping the ramp-down of the LSV weighting in the SEHI-T Cv curve 118 and the ramp-up of the HSV weighting in the SEHI-T Cv curve 122, at 50% there is a point where the EXV and the corresponding Cv curves 118, 122 follow the same expansion valve opening up to the virtual EXV 100% opening (see Figure 8C to the right) (in this example, at the virtual EXV 70% opening on the idealized Cv curve 120).

[0085] Figure 9 FIG. shows a flowchart of a method for operating a refrigerant circuit system according to some embodiments. The method can be implemented by an embodiment of a refrigerant circuit system, its controller, or a more general processor. The method can be implemented in a tangible, non-transitory computer-readable medium by instructions for execution by a processor. The virtual refrigerant metering device can be a virtual expansion valve or a virtual EXV. The refrigerant metering device can be an expansion valve or an EXV. The various specific real, non-virtual refrigerant metering devices and their variants described herein can be applied to the embodiments. The method can include algorithms and parameters as described herein in various examples and embodiments or their variants.

[0086] In operation 902, the system or its controller receives a control input that represents the directed flow rate of refrigerant through the virtual refrigerant metering device. Described herein are examples of various control inputs and their associated parameters, as well as various versions of the virtual refrigerant metering device and its associated parameters. In various embodiments, the refrigerant circuit system has a plurality of parallel-connected, real, non-virtual refrigerant metering devices that can be operated by the system according to the control input, as in the following operations 904, 906.

[0087] In operation 904, the system or its controller determines a separate control input for each refrigerant metering device of a plurality of refrigerant metering devices. For each refrigerant metering device, the separate control input is based on a control input representative of a directed flow rate and the refrigerant flow characteristics of the refrigerant metering device. In summary, with each of the plurality of refrigerant metering devices controlled to a separate control input, the refrigerant metering devices provide a total flow rate that is substantially equal to the directed flow rate. In various embodiments, the system or controller achieves this by simulating a virtual refrigerant metering device and the refrigerant flow characteristics of the refrigerant metering device, as described herein, which have various combinations or variations of weighting, Cv curves, bipolar operation, with or without hysteresis, and other features and aspects. As used herein, "substantially" refers to manufacturing, operating, tuning, wear, and / or measurement tolerances within the system and / or components.

[0088] In operation 906, the system or its controller sends the control input to the refrigerant metering device. In operation 904, the control input and its sending are based on determining the respective control inputs for the refrigerant metering devices. This operation 906 can be accomplished, for example, with its appropriate parameter(s) and value(s), and can be accomplished by, for example, a device driver, and / or other electrical, electronic, electromechanical, interface, or component, etc.

[0089] It should be understood that the methods described herein can be performed using a digital processing system, such as a conventional general-purpose computer system. A special-purpose computer is designed or programmed to perform only one function used in an alternative. Figure 10 is a diagram showing an exemplary computing device that can implement the embodiments described herein. Figure 10 The computing device can be used to perform the functions of a process according to some embodiments. The computing device includes a central processing unit (CPU) 1001, which can include one or more processors and is coupled via a bus 1005 to a memory 1003 and a mass storage device 1007. The mass storage device 1007 represents a permanent data storage device such as a floppy disk drive or a fixed disk drive, which in some embodiments can be local or remote. The memory 1003 can include read-only memory, random access memory, etc. In some embodiments, applications residing on the computing device can be stored in a computer-readable medium, such as the memory 1003 or the mass storage device 1007, or accessed via a computer-readable medium, such as the memory 1003 or the mass storage device 1007. The applications can also be accessed in a modulated form via a network modem or other network interface of the computing device in the form of a modulated electronic signal. It should be understood that in some embodiments, the CPU 1001 can be implemented in a general-purpose processor, a special-purpose processor, or a specially programmed logic device.

[0090] The display 1011 communicates with the CPU 1001, the memory 1003, and the mass storage device 1007 via the bus 1005. The display 1011 is configured to display any visualization tool or report associated with the systems described herein. The input / output device 1009 is coupled to the bus 1005 to communicate information in a command selection to the CPU 1001. It should be understood that data to and from external devices can be communicated through the input / output device 1009. The CPU 1001 can be defined as performing the functions described herein to implement the reference Figures 1 - 9 the functions described. In some embodiments, the code implementing the function can be stored in the memory 1003 or the mass storage device 1007 for execution by a processor, such as the CPU 1001. The operating system on the computing device can be MSDOSTM, MS-WINDOWSTM, OS / 2TM, UNIXTM, LINUXTM, or other known operating systems. It should be understood that the embodiments described herein can also be integrated with virtualized computing systems implemented using physical computing resources.

[0091] This document shows how to develop virtual "ideal" EXV control characteristics using virtual EXVs based on the use of two real EXVs. In some embodiments, the two real EXVs are physically identical to each other and have the same refrigerant flow capacity and operating characteristics, and in some embodiments, the two real EXVs have different refrigerant flow capacities, sizes, and / or operating characteristics. This can be extended to further EXV development because it is possible to create multiple new virtual EXVs from further dual EXV combinations with matching EXVs and different EXVs or different sizes, as well as multiple EXV combinations with matching and different EXVs and / or sizes, refrigerant flow capacities, and operating characteristics.

[0092] Clause 1. A method of operating a refrigerant circuit system, comprising: receiving a control input that represents a directed flow rate of refrigerant through a virtual refrigerant metering device; for each refrigerant metering device of a plurality of parallel-connected, real, non-virtual refrigerant metering devices of the refrigerant circuit system, determining a separate control input for the refrigerant metering device at least in part based on the control input representing the directed flow rate and the refrigerant flow characteristics of the refrigerant metering device to produce a plurality of separate flow rates through the plurality of refrigerant metering devices, the plurality of separate flow rates providing a total flow rate that is substantially equal to the directed flow rate; and based on the determination of the separate control inputs for the plurality of refrigerant metering devices, sending a plurality of control inputs to the plurality of refrigerant metering devices.

[0093] Clause 2. Any method among the clauses listed herein, wherein the sending includes: sending a first control input among a plurality of control inputs to a first refrigerant metering device among a plurality of refrigerant metering devices; and sending a second control input among the plurality of control inputs to a second refrigerant metering device among the plurality of refrigerant metering devices, wherein the refrigerant flow characteristics of the refrigerant metering device include a control characteristic curve, which controls the refrigerant flow rate of the refrigerant through the refrigerant metering device, the refrigerant flow characteristics of the first refrigerant metering device include a first characteristic curve, which controls the first refrigerant flow rate of the refrigerant through the first refrigerant metering device, the refrigerant flow characteristics of the second metering device include a second characteristic curve, which controls the second refrigerant flow rate of the refrigerant through the second refrigerant metering device, and determining a separate control input for the first refrigerant metering device and a separate control input for the second refrigerant metering device such that the total flow rate includes a combination of the first refrigerant flow rate and the second refrigerant flow rate.

[0094] Clause 3. Any method among the clauses listed herein, wherein the separate control input for the first refrigerant metering device according to the first characteristic curve and the separate control input for the second refrigerant metering device according to the second characteristic curve are determined to follow the target characteristic curve of a virtual refrigerant metering device.

[0095] Clause 4. Any method among the clauses listed herein, wherein the first characteristic curve is a first flow coefficient versus refrigerant metering device set curve, the second characteristic curve is a second flow coefficient versus refrigerant metering device set curve, and determining the separate control input for the first refrigerant metering device at least in part by: determining a first refrigerant metering device setting at least in part based on a first weighting function, the first characteristic curve, and the target characteristic curve of the virtual refrigerant metering device, and determining the separate control input for the second refrigerant metering device at least in part by: determining a second refrigerant metering device setting at least in part based on a second weighting function, the second characteristic curve, and the target characteristic curve of the virtual refrigerant metering device.

[0096] Clause 5. Any method among the clauses listed herein, wherein the first refrigerant metering device is a first electronic expansion valve, the second refrigerant metering device is a second electronic expansion valve, the first refrigerant metering device setting is a first valve opening percentage, and the second refrigerant metering device setting is a second valve opening percentage.

[0097] Clause 6. Any method among the clauses listed herein, wherein for points on the target characteristic curve of the virtual refrigerant metering device, the first weighting function and the second weighting function transition between a first stage and a second stage with respect to the first characteristic curve and the second characteristic curve.

[0098] Clause 7. Any method among the clauses listed herein, wherein a first weighting function and a second weighting function provide hysteresis in the operation of a refrigerant metering device with respect to a first characteristic curve and a second characteristic curve.

[0099] Clause 8. Any method among the clauses listed herein, wherein, since the characteristic curves of refrigerant metering devices are different among multiple refrigerant metering devices, separate control inputs for the refrigerant metering devices are different among the multiple refrigerant metering devices.

[0100] Clause 9. Any method among the clauses listed herein, wherein each refrigerant metering device is a corresponding refrigerant metering device type such that the characteristic curve of each of the multiple refrigerant metering devices is different from that of at least one other refrigerant metering device among the multiple refrigerant metering devices.

[0101] Clause 10. Any method among the clauses listed herein, wherein the corresponding refrigerant metering device type is selected from the group consisting of a low volume expansion valve and a high volume expansion valve; and wherein the maximum flow rate of the low volume expansion valve is lower than the maximum flow rate of the high volume expansion valve.

[0102] Clause 11. Any method among the clauses listed herein, further comprising determining a directional flow rate based on a control input; and encoding the directional flow rate in the separate control inputs for the refrigerant metering devices for each of the multiple refrigerant metering devices.

[0103] Clause 12. Any method among the clauses listed herein, wherein the refrigerant is a metered refrigerant, the multiple control inputs are of a single signal type, and the single signal type is one of an electrical signal or a mechanical signal.

[0104] Clause 13. Any method among the clauses listed herein, wherein the multiple refrigerant metering devices are of a single metering device type, and the single metering device type includes one of an electronic expansion valve, a thermal expansion valve, an externally equalized expansion valve, or an internally equalized expansion valve.

[0105] Clause 14. The controller includes one or more processors, wherein the controller is configured to receive a control input that represents a directed flow rate of refrigerant through a virtual refrigerant metering device; one or more outputs that are coupled to the one or more processors and are configured to be communicatively coupled to a plurality of parallel-connected, real, non-virtual refrigerant metering devices; and a computer-readable storage medium that is coupled to the one or more processors, the computer-readable storage medium including program instructions that, when executed by the one or more processors, cause the controller to: receive a control input that represents a directed flow rate of refrigerant through the virtual refrigerant metering device; for each refrigerant metering device of the plurality of refrigerant metering devices, determine a separate control input for the refrigerant metering device based at least in part on the control input representing the directed flow rate and the refrigerant flow characteristics of the refrigerant metering device to produce a plurality of separate flow rates through the plurality of refrigerant metering devices, the plurality of separate flow rates providing a total flow rate that is substantially equal to the directed flow rate; and based on the determined separate control inputs for the plurality of refrigerant metering devices, send one or more control inputs to the plurality of refrigerant metering devices via the one or more outputs.

[0106] Clause 15. Any controller as listed herein, wherein the program instructions for sending one or more control signals further include program instructions that cause the controller to send a first control input of the one or more control inputs to a first refrigerant metering device of the plurality of refrigerant metering devices; and send a second control input of the one or more control inputs to a second refrigerant metering device of the plurality of refrigerant metering devices, wherein the refrigerant flow characteristics of the refrigerant metering device include a characteristic curve that controls the refrigerant flow rate of the refrigerant through the refrigerant metering device, the characteristics of the first refrigerant metering device include a first characteristic curve that controls the first refrigerant flow rate of the refrigerant through the first refrigerant metering device, the characteristics of the second refrigerant metering device are described by a second characteristic curve that controls the second refrigerant flow rate of the refrigerant through the second refrigerant metering device, and determine the separate control input for the first refrigerant metering device and the separate control input for the second refrigerant metering device such that the total refrigerant flow rate includes a combination of the first refrigerant flow rate and the second refrigerant flow rate.

[0107] Clause 16. For any one of the controllers in the clauses listed herein, wherein a separate control input for a first refrigerant metering device according to a first characteristic curve and a separate control input for a second refrigerant metering device according to a second characteristic curve are determined to follow a target characteristic curve of a virtual refrigerant metering device, the first characteristic curve is a first flow coefficient versus a refrigerant metering device set curve, the second characteristic curve is a second flow coefficient versus a refrigerant metering device set curve, the separate control input for the first refrigerant metering device is determined at least in part by: determining a first refrigerant metering device set at least in part based on a first weighting function, the first characteristic curve, and the target characteristic curve of the virtual refrigerant metering device, and the separate control input for the second refrigerant metering device is determined at least in part by: determining a second refrigerant metering device set at least in part based on a second weighting function, the second characteristic curve, and the target characteristic curve of the virtual refrigerant metering device.

[0108] Clause 17. For any one of the controllers in the clauses listed herein, wherein the first refrigerant metering device is a first electronic expansion valve, the second refrigerant metering device is a second electronic expansion valve, the first refrigerant metering device set is a first valve opening percentage, and the second refrigerant metering device set is a second valve opening percentage.

[0109] Clause 18. For any one of the controllers in the clauses listed herein, wherein for points on the target characteristic curve of the virtual refrigerant metering device, the first weighting function and the second weighting function transition between a first stage and a second stage with respect to the first characteristic curve and the second characteristic curve, and the first weighting function and the second weighting function provide hysteresis in the operation of the refrigerant metering device with respect to the first characteristic curve and the second characteristic curve.

[0110] Clause 19. For any one of the controllers in the clauses listed herein, wherein due to the characteristic curves of the refrigerant metering devices being different among multiple refrigerant metering devices, the separate control inputs for the refrigerant metering devices are different among the multiple refrigerant metering devices, and the characteristics of the refrigerant metering devices include the maximum flow rate of the refrigerant metering devices.

[0111] Clause 20. For any one of the controllers in the clauses listed herein, wherein each refrigerant metering device is a corresponding refrigerant metering device type such that the characteristic curve of each one of the multiple refrigerant metering devices is different from at least one other refrigerant metering device among the multiple refrigerant metering devices, the corresponding refrigerant metering device type is selected from the group consisting of a low volume expansion valve and a high volume expansion valve; and wherein the maximum flow rate of the low volume expansion valve is lower than the maximum flow rate of the high volume expansion valve.

[0112] Clause 21. Any one of the controllers as listed in the terms herein, wherein the controller is in a system that includes another controller, the controllers are communicatively coupled to receive a control input from the other controller, and the other controller is configured to determine a directed flow rate, the directed flow rate encoded in the control input, and to send the control input to the controller.

[0113] Detailed exemplary embodiments are disclosed herein. However, the specific functional details disclosed herein are representative only for the purpose of describing embodiments. However, the embodiments may be embodied in many alternative forms and should not be construed as limited to the embodiments set forth herein.

[0114] It should be understood that although the terms first, second, etc. may be used herein to describe various steps or calculations, these steps or calculations should not be limited by these terms. These terms are only used to distinguish one step or calculation from another. For example, a first calculation may be referred to as a second calculation, and similarly, a second step may be referred to as a first step, without departing from the scope of the present disclosure. As used herein, the terms "and / or" and the " / " symbol include any and all combinations of one or more of the associated listed items.

[0115] As used herein, the singular forms "a", "an", and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that when the terms "comprises", "comprising", "includes", and / or "including" are used herein, they specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof. Thus, the terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting.

[0116] It should also be noted that in some alternative implementations, the indicated functions / actions may not occur in the order indicated in the figures. For example, depending on the functions / actions involved, two consecutively shown figures may actually be executed substantially simultaneously, or sometimes in the reverse order.

[0117] Considering the above embodiments, it should be understood that these embodiments may employ various computer-implemented operations involving data stored in a computer system. These operations are those that require physical manipulation of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. Additionally, the operations performed are often referred to in terms such as generating, identifying, determining, or comparing. Any operations forming part of the embodiments described herein are performed using machine operations. The embodiments also relate to apparatus or devices for performing these operations. The device may be specially constructed for the required purpose, or the device may be a general-purpose computer selectively activated or configured by a computer program stored in the computer. Specifically, various general-purpose machines may be used with a computer program written in accordance with the teachings herein, or it may be more convenient to construct a more specialized device to perform the required operations.

[0118] Modules, applications, layers, agents, or other entities operable by a method may be implemented as hardware, firmware, or a processor executing software, or a combination thereof. It should be understood that in cases where software-based embodiments are disclosed herein, the software may be implemented in a physical machine, such as a controller. For example, the controller may include a first module and a second module. The controller may be configured to perform various actions, such as methods, applications, layers, or agents.

[0119] These embodiments may also be implemented as computer-readable code on a tangible non-transitory computer-readable medium. The computer-readable medium is any data storage device capable of storing data that can thereafter be read by a computer system. Examples of computer-readable media include hard disk drives, network-attached storage (NAS), read-only memory, random access memory, CD-ROMs, CD-Rs, CD-RWs, magnetic tapes, and other optical and non-optical data storage devices. The computer-readable medium may also be distributed over network connections and computer connections such that the computer-readable code is stored and executed in a distributed manner. The embodiments described herein may be practiced with various computer system configurations, including handheld devices, tablet computers, microprocessor systems, microprocessor-based or programmable consumer electronics, minicomputers, mainframe computers, etc. These embodiments may also be practiced in a distributed computing environment where tasks are performed by remote processing devices linked through a wired or wireless network.

[0120] Although the method operations are described in a particular order, it should be understood that other operations may be performed between the described operations, the described operations may be adjusted so that they occur at slightly different times, or the described operations may be distributed across a system that allows the processing operations to occur at various intervals associated with the processing.

[0121] In various embodiments, one or more portions of the methods and mechanisms described herein may form part of a cloud computing environment. In such an embodiment, resources may be provided as services over the Internet according to one or more different models. Such models may include infrastructure as a service (IaaS), platform as a service (PaaS), and software as a service (SaaS). In IaaS, computer infrastructure is delivered as a service. In this case, the computing equipment is typically owned and operated by the service provider. In the PaaS model, the software tools and underlying equipment used by developers to develop software solutions may be provided as a service and hosted by the service provider. SaaS typically includes service provider licensed software as an on-demand service. The service provider may host the software or may deploy the software to the customer for a given time period. Many combinations of the above models are possible and are contemplated.

[0122] Various units, circuits, or other components may be described or claimed as “configured to” or “configurable to” perform one or more tasks. In such a context, the phrase “configured to” or “configurable to” is used to imply structure by indicating that the unit / circuit / component includes a structure (e.g., circuitry) that performs one or more tasks during operation. Thus, even when the specified unit / circuit / component is not currently operative (e.g., not turned on), the unit / circuit / component can be said to be configured to perform the task, or configurable to perform the task. Units / circuits / components used in conjunction with “configured to” or “configurable to” language include hardware—such as, circuitry, a memory storing program instructions executable to implement the operations, etc. For a unit / circuit / component, reiterating that the unit / circuit / component is “configured to” perform one or more tasks, or is “configurable to” perform one or more tasks, is expressly intended not to trigger the provisions of 35 U.S.C. § 112, ¶ 6. Additionally, “configured to” or “configurable to” can include a general structure (e.g., a general-purpose circuit) that is manipulated by software and / or firmware (e.g., an FPGA or a general-purpose processor executing software) so as to operate in a manner capable of performing the task(s) being discussed. “Configured to” can also include adapting a manufacturing process (e.g., a semiconductor manufacturing facility) to fabricate a device (e.g., an integrated circuit) suitable for implementing or performing one or more tasks. “Configurable to” is expressly intended not to apply to a blank medium, an unprogrammed processor, or an unprogrammed general-purpose computer, or an unprogrammed programmable logic device, programmable gate array, or other unprogrammed device, unless accompanied by a programmed medium that imparts to the unprogrammed device the ability to perform the disclosed function(s).

[0123] For purposes of explanation, the foregoing description has been made with reference to specific embodiments. However, the above illustrative discussion is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in light of the above teachings. The embodiments were chosen and described in order to best explain the principles of the embodiments and their practical application, thereby enabling others skilled in the art to best utilize the embodiments and various modifications suitable for the particular use contemplated. Accordingly, the embodiments of the invention are considered to be illustrative rather than restrictive, and the invention is not limited to the details given herein but may be modified within the scope of the appended claims and their equivalents.

Claims

1. A method of operating a refrigerant circuit system, comprising: receiving a control input representing a directional flow rate of refrigerant through a virtual refrigerant metering device; For each refrigerant metering device of a plurality of real, non-virtual refrigerant metering devices connected in parallel of the refrigerant circuit system, determining individual control inputs for the refrigerant metering devices based at least in part on the control inputs representing the directional flow rates and refrigerant flow characteristics of the refrigerant metering devices to produce a plurality of individual flow rates through the plurality of refrigerant metering devices, the plurality of individual flow rates providing a total flow rate substantially equal to the directional flow rate; as well as Based on the determination of the individual control inputs for the plurality of refrigerant metering devices, a plurality of control inputs are sent to the plurality of refrigerant metering devices.

2. The method according to claim 1, characterized in that The sending includes: sending a first control input of the plurality of control inputs to a first refrigerant metering device of the plurality of refrigerant metering devices; and sending a second control input of the plurality of control inputs to a second refrigerant metering device of the plurality of refrigerant metering devices, wherein: The refrigerant flow characteristic of the refrigerant metering device includes a control characteristic curve, and the characteristic curve controls the refrigerant flow rate of the refrigerant passing through the refrigerant metering device. The refrigerant flow characteristic of the first refrigerant metering device comprises a first characteristic curve, the first characteristic curve controlling a first refrigerant flow rate of the refrigerant passing through the first refrigerant metering device, the refrigerant flow characteristic of the second refrigerant metering device comprises a second characteristic curve, the second characteristic curve controlling a second refrigerant flow rate of the refrigerant through the second refrigerant metering device, and The determining of the separate control input for the first refrigerant metering device and the separate control input for the second refrigerant metering device is performed such that the total flow rate includes a combination of the first refrigerant flow rate and the second refrigerant flow rate.

3. The method according to claim 2, characterized in that The individual control input for the first refrigerant metering device according to the first characteristic curve and the individual control input for the second refrigerant metering device according to the second characteristic curve are determined to follow a target characteristic curve of the virtual refrigerant metering device.

4. The method according to claim 3, characterized in that: The first characteristic curve is a curve of the first flow coefficient versus the refrigerant metering device setting. The second characteristic curve is a curve of the second flow coefficient versus the refrigerant metering device setting. The separate control input for the first refrigerant metering device is determined at least in part by: determining a first refrigerant metering device setting based at least in part on a first weighting function, the first characteristic curve, and the target characteristic curve of the virtual refrigerant metering device, and The separate control input for the second refrigerant metering device is determined at least in part by: A second refrigerant metering device setting is determined based at least in part on a second weighting function, the second characteristic curve, and the target characteristic curve of the virtual refrigerant metering device.

5. The method according to claim 4, characterized in that The first refrigerant metering device is a first electronic expansion valve, The second refrigerant metering device is a second electronic expansion valve, The first refrigerant metering device is set to a first valve opening percentage, and The second refrigerant metering device is set to a second valve opening percentage.

6. The method according to claim 4, characterized in that For a point on the target characteristic curve of the virtual refrigerant metering device, the first weighting function and the second weighting function transition between a first stage and a second stage with respect to the first characteristic curve and the second characteristic curve.

7. The method according to claim 6, characterized in that The first weighting function and the second weighting function provide a hysteresis in the operation of the refrigerant metering device relative to the first characteristic curve and the second characteristic curve.

8. The method according to claim 1, characterized in that Since the characteristic curves of the refrigerant metering devices differ between the plurality of refrigerant metering devices, individual control inputs for the refrigerant metering devices differ between the plurality of refrigerant metering devices.

9. The method according to claim 1, characterized in that Each refrigerant metering device is of a respective refrigerant metering device type such that the characteristic curve of each of the plurality of refrigerant metering devices is different from at least one other refrigerant metering device of the plurality of refrigerant metering devices.

10. The method according to claim 9, characterized in that The corresponding refrigerant metering device type is selected from the group consisting of a low volume expansion valve and a high volume expansion valve; and wherein, The maximum flow rate of the low volume expansion valve is lower than the maximum flow rate of the high volume expansion valve.

11. The method according to claim 1, characterized in that Also includes: determining the directional flow rate based on the control input; as well as For each of the plurality of refrigerant metering devices, the directional flow rate is encoded in the individual control input for the refrigerant metering device.

12. The method according to claim 1, characterized in that The refrigerant is a metered refrigerant. The plurality of control inputs are of a single signal type, and The single signal type is one of an electrical signal or a mechanical signal.

13. The method according to claim 11, characterized in that The plurality of refrigerant metering devices are of a single metering device type, and The single metering device type includes one of an electronic expansion valve, a thermal expansion valve, an externally balanced expansion valve, or an internally balanced expansion valve.

14. A controller, comprising: One or more processors, wherein The controller is configured to receive a control input representing a directional flow rate of refrigerant through a virtual refrigerant metering device; one or more outputs coupled to the one or more processors and configured to be communicatively coupled to a plurality of parallel-connected real, non-virtual refrigerant metering devices; and a computer-readable storage medium coupled to the one or more processors, the computer-readable storage medium comprising program instructions that, when executed by the one or more processors, cause a controller to: receiving a control input representing the directional flow rate of the refrigerant through the virtual refrigerant metering device; For each refrigerant metering device of the plurality of refrigerant metering devices, determining individual control inputs for the refrigerant metering devices based at least in part on the control inputs representing the directional flow rates and refrigerant flow characteristics of the refrigerant metering devices to produce a plurality of individual flow rates through the plurality of refrigerant metering devices, the plurality of individual flow rates providing a total flow rate substantially equal to the directional flow rate; and Based on the determined individual control inputs for the plurality of refrigerant metering devices, one or more control inputs are sent to the plurality of refrigerant metering devices via the one or more outputs.

15. The controller according to claim 14, characterized in that The program instructions for sending the one or more control signals further include program instructions that cause the controller to: sending a first control input of the one or more control inputs to a first refrigerant metering device of the plurality of refrigerant metering devices; and sending a second control input of the one or more control inputs to a second refrigerant metering device of the plurality of refrigerant metering devices, wherein: The refrigerant flow characteristic of the refrigerant metering device comprises a characteristic curve, the characteristic curve controlling the refrigerant flow rate of the refrigerant passing through the refrigerant metering device, The characteristic of the first refrigerant metering device comprises a first characteristic curve, the first characteristic curve controlling a first refrigerant flow rate of the refrigerant through the first refrigerant metering device, The characteristic of the second refrigerant metering device is described by a second characteristic curve, which controls a second refrigerant flow rate of the refrigerant through the second refrigerant metering device, and The separate control input for the first refrigerant metering device and the separate control input for the second refrigerant metering device are determined such that a total refrigerant flow rate comprises a combination of the first refrigerant flow rate and the second refrigerant flow rate.

16. The controller according to claim 15, characterized in that the individual control input for the first refrigerant metering device according to the first characteristic curve and the individual control input for the second refrigerant metering device according to the second characteristic curve are determined to follow a target characteristic curve of the virtual refrigerant metering device, The first characteristic curve is a first flow coefficient versus refrigerant metering device setting curve, The second characteristic curve is a second flow coefficient versus refrigerant metering device setting curve, The separate control input for the first refrigerant metering device is determined at least in part by: determining a first refrigerant metering device setting based at least in part on a first weighting function, the first characteristic curve, and the target characteristic curve of the virtual refrigerant metering device, and The separate control input for the second refrigerant metering device is determined at least in part by: A second refrigerant metering device setting is determined based at least in part on a second weighting function, the second characteristic curve, and the target characteristic curve of the virtual refrigerant metering device.

17. The controller according to claim 16, characterized in that The first refrigerant metering device is a first electronic expansion valve, The second refrigerant metering device is a second electronic expansion valve, The first refrigerant metering device is set to a first valve opening percentage, and The second refrigerant metering device is set to a second valve opening percentage.

18. The controller according to claim 16, characterized in that For a point on the target characteristic curve of the virtual refrigerant metering device, the first weighting function and the second weighting function transition between a first stage and a second stage with respect to the first characteristic curve and the second characteristic curve, and The first weighting function and the second weighting function provide a hysteresis in the operation of the refrigerant metering device relative to the first characteristic curve and the second characteristic curve.

19. The controller according to claim 14, characterized in that Since the characteristic curves of the refrigerant metering devices differ between the plurality of refrigerant metering devices, the individual control inputs for the refrigerant metering devices differ between the plurality of refrigerant metering devices, and The characteristic of the refrigerant metering device includes a maximum flow rate of the refrigerant metering device.

20. The controller according to claim 14, characterized in that each refrigerant metering device is of a respective refrigerant metering device type such that the characteristic curve of each of the plurality of refrigerant metering devices is different from at least one other refrigerant metering device of the plurality of refrigerant metering devices, The corresponding refrigerant metering device type is selected from the group consisting of a low volume expansion valve and a high volume expansion valve; and wherein, The maximum flow rate of the low volume expansion valve is lower than the maximum flow rate of the high volume expansion valve.

21. The controller according to claim 14, characterized in that The controller is in a system, the system comprising another controller, The controller is communicatively coupled to receive the control input from the other controller, and The other controller is configured to: Determine the directional flow rate, the directional flow rate encoded in the control input, and The control input is sent to the controller.

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