阅读说明：本技术 一种热泵系统控制方法及装置 (Heat pump system control method and device ) 是由 房亮 于 2021-08-27 设计创作，主要内容包括：本发明提供一种热泵系统控制方法及装置,应用于系统控制技术领域,该方法在获取控制参数向量的当前控制值、系统状态向量的当前状态值和目标状态值之后,首先确定与当前状态值对应的控制参数计算矩阵,并根据当前状态值、目标状态值以及控制参数计算矩阵,确定控制参数调节向量,最后基于当前控制值和控制参数调节向量调节控制参数向量,以使系统状态向量达到目标状态值。本发明提供的热泵系统控制方法,能够替代现有技术中的人工调节方式,并同时对热泵系统中的多个控制参数进行调节,与现有技术相比,能够有效缩短调节耗时,显著提高热泵系统的调节效率。(The invention provides a heat pump system control method and a device, which are applied to the technical field of system control. The heat pump system control method provided by the invention can replace a manual regulation mode in the prior art, and can regulate a plurality of control parameters in the heat pump system at the same time.)

1. A heat pump system control method, characterized by comprising:

acquiring a current control value of a control parameter vector, a current state value of a system state vector and a target state value of the system state vector; wherein the control parameter vector comprises a plurality of control parameters of the heat pump system and the system state vector comprises a plurality of state parameters of the heat pump system;

determining a control parameter calculation matrix corresponding to the current state value; the control parameter calculation matrix is obtained based on the corresponding relation between the control parameter vector and the system state vector;

determining a control parameter adjustment vector according to the current state value, the target state value and the control parameter calculation matrix; wherein the control parameter adjustment vector comprises an adjustment value of each control parameter in the control parameter vector;

adjusting the control parameter vector based on the current control value and the control parameter adjustment vector to bring the system state vector to the target state value.

2. The heat pump system control method of claim 1, wherein said adjusting the control parameter vector based on the current control value and the control parameter adjustment vector to bring the system state vector to the target state value comprises:

determining an intermediate control value of the control parameter vector based on the current control value and the control parameter adjustment vector;

acquiring an intermediate state value of the system state vector after the heat pump system operates according to the intermediate control value and is in a stable state;

if the deviation of the intermediate state value and the target state value is not within a first preset range, adjusting the control parameter vector based on the intermediate control value and the intermediate state value to enable the system state vector to reach the target state value;

and if the deviation of the intermediate state value and the target state value is within the first preset range, controlling the heat pump system to operate according to the intermediate control value.

3. The heat pump system control method of claim 2, wherein said adjusting the control parameter vector based on the intermediate control value and the intermediate state value to bring the system state vector to the target state value comprises:

if the deviation between the intermediate state value and the current state value is within a second preset range, updating the current control value to the intermediate control value, and updating the current state value to the intermediate state value;

returning to the step of executing the calculation matrix according to the current state value, the target state value and the control parameter and determining a control parameter adjustment vector;

if the deviation between the intermediate state value and the current state value is not within the second preset range, updating the current control value to the intermediate control value, and updating the current state value to the intermediate state value;

and returning to execute the step of determining the control parameter calculation matrix corresponding to the current state value.

4. The heat pump system control method of claim 2, wherein said determining an intermediate control value of the control parameter vector based on the current control value and the control parameter adjustment vector comprises:

acquiring a preset attenuation coefficient;

calculating the product of the control parameter adjusting vector and the preset attenuation coefficient to obtain a single adjusting value of the control parameter adjusting vector;

and taking the sum of the current control value and the single adjustment value as a middle control value of the control parameter vector.

5. The heat pump system control method of claim 4, wherein said calculating a product of the control parameter adjustment vector and the predetermined attenuation factor to obtain a single adjustment value of the control parameter adjustment vector comprises:

if the control parameter adjusting vector is larger than a preset adjusting threshold value, reducing the control parameter adjusting vector according to a preset proportion;

and calculating the product of the reduced control parameter adjustment vector and the preset attenuation coefficient to obtain a single adjustment value of the control parameter adjustment vector.

6. The heat pump system control method according to claim 1, wherein said determining a control parameter calculation matrix corresponding to said current state value comprises:

respectively adjusting the current control value of each control parameter in the control parameter vector;

respectively obtaining reference state values of the system state vectors of the heat pump system in a stable state after adjusting the current control values of the control parameters;

respectively calculating the difference between each reference state value and the current state value to obtain corresponding state change values;

taking the set of the state change values as a state parameter change matrix;

and calculating an inverse matrix of the state parameter change matrix to obtain the control parameter calculation matrix.

7. The heat pump system control method according to claim 6, wherein the obtaining of the reference state value of the system state vector at which the heat pump system is in a steady state after the current control value for adjusting each of the control parameters includes:

taking each control parameter in the control parameter vector as a target control parameter in turn;

adjusting the current control value of the target control parameter, and controlling the heat pump system to operate according to the adjusted current control value;

after the heat pump system operates for a first preset time, acquiring a plurality of groups of state reference values of the system state vector within a second preset time;

determining a system state fitting function according to the state reference values;

and determining the reference state value of the system state vector of the heat pump system in a stable state according to the system state fitting function.

8. The heat pump system control method according to claim 1, wherein said determining a control parameter calculation matrix corresponding to said current state value comprises:

acquiring a plurality of preset control parameter calculation matrixes of the heat pump system, wherein each preset control parameter calculation matrix corresponds to a state reference value of one system state vector;

respectively calculating deviation amounts of the current state value and each state reference value;

and taking a preset control parameter calculation matrix with the minimum deviation amount and the deviation amount within a preset deviation range as a control parameter calculation matrix corresponding to the current state value.

9. The heat pump system control method according to any one of claims 1-8, wherein said determining a control parameter adjustment vector based on said current state value and said target state value and said control parameter calculation matrix comprises:

calculating the difference between the target state value and the current state value to obtain a state parameter deviation vector;

and calculating the product of the control parameter calculation matrix and the state parameter deviation vector to obtain a control parameter adjustment vector.

10. A heat pump system control apparatus, characterized by comprising:

the device comprises an acquisition unit, a processing unit and a control unit, wherein the acquisition unit is used for acquiring a current control value of a control parameter vector, a current state value of a system state vector and a target state value of the system state vector; wherein the control parameter vector comprises a plurality of control parameters of the heat pump system and the system state vector comprises a plurality of state parameters of the heat pump system;

the first determining unit is used for determining a control parameter calculation matrix corresponding to the current state value;

the control parameter calculation matrix is obtained based on the corresponding relation between the control parameter vector and the system state vector; the second determining unit is used for determining a control parameter adjusting vector according to the current state value, the target state value and the control parameter calculation matrix;

wherein the control parameter adjustment vector comprises an adjustment value of each control parameter in the control parameter vector; a control unit for adjusting the control parameter vector based on the current control value and the control parameter adjustment vector to bring the system state vector to the target state value.

Technical Field

The invention belongs to the technical field of system control, and particularly relates to a heat pump system control method and device.

Background

The heat pump system is widely applied to various devices such as an air conditioner, a refrigerator and a thermodynamic test bed, is one of key systems which can normally run and realize a set function, and in practical application, system state parameters such as evaporation pressure, condensation pressure, degree of superheat in front of a compressor and the like of the heat pump system are often required to be accurately controlled, so that the heat pump system is ensured to exert good performance.

In the prior art, control and adjustment of a heat pump system are mostly dependent on experience and are manually completed, and because the heat pump system has the characteristics of strong nonlinearity, long delay time, numerous control parameters and state parameters and the like, adjustment of a single control parameter often causes changes of a plurality of state parameters, so that the adjustment efficiency is low because each control parameter of the heat pump system is manually adjusted until the state parameter of the heat pump system reaches an expected value, and long adjustment time is often needed.

Disclosure of Invention

In view of the above, the present invention provides a method and an apparatus for controlling a heat pump system, which automatically implement adjustment of multiple control parameters simultaneously, shorten adjustment time, and improve adjustment efficiency, and the specific scheme is as follows:

in a first aspect, the present invention provides a heat pump system control method, including:

acquiring a current control value of a control parameter vector, a current state value of a system state vector and a target state value of the system state vector; wherein the control parameter vector comprises a plurality of control parameters of the heat pump system and the system state vector comprises a plurality of state parameters of the heat pump system;

determining a control parameter calculation matrix corresponding to the current state value; the control parameter calculation matrix is obtained based on the corresponding relation between the control parameter vector and the system state vector;

determining a control parameter adjustment vector according to the current state value, the target state value and the control parameter calculation matrix; wherein the control parameter adjustment vector comprises an adjustment value of each control parameter in the control parameter vector;

adjusting the control parameter vector based on the current control value and the control parameter adjustment vector to bring the system state vector to the target state value.

Optionally, the adjusting the control parameter vector based on the current control value and the control parameter adjustment vector to make the system state vector reach the target state value includes:

determining an intermediate control value of the control parameter vector based on the current control value and the control parameter adjustment vector;

acquiring an intermediate state value of the system state vector after the heat pump system operates according to the intermediate control value and is in a stable state;

if the deviation of the intermediate state value and the target state value is not within a first preset range, adjusting the control parameter vector based on the intermediate control value and the intermediate state value to enable the system state vector to reach the target state value;

and if the deviation of the intermediate state value and the target state value is within the first preset range, controlling the heat pump system to operate according to the intermediate control value.

Optionally, the adjusting the control parameter vector based on the intermediate control value and the intermediate state value to make the system state vector reach the target state value includes:

if the deviation between the intermediate state value and the current state value is within a second preset range, updating the current control value to the intermediate control value, and updating the current state value to the intermediate state value;

returning to the step of executing the calculation matrix according to the current state value, the target state value and the control parameter and determining a control parameter adjustment vector;

if the deviation between the intermediate state value and the current state value is not within the second preset range, updating the current control value to the intermediate control value, and updating the current state value to the intermediate state value;

and returning to execute the step of determining the control parameter calculation matrix corresponding to the current state value.

Optionally, the determining an intermediate control value of the control parameter vector based on the current control value and the control parameter adjustment vector includes:

acquiring a preset attenuation coefficient;

calculating the product of the control parameter adjusting vector and the preset attenuation coefficient to obtain a single adjusting value of the control parameter adjusting vector;

and taking the sum of the current control value and the single adjustment value as a middle control value of the control parameter vector.

Optionally, the calculating a product of the control parameter adjustment vector and the preset attenuation coefficient to obtain a single adjustment value of the control parameter adjustment vector includes:

if the control parameter adjusting vector is larger than a preset adjusting threshold value, reducing the control parameter adjusting vector according to a preset proportion;

and calculating the product of the reduced control parameter adjustment vector and the preset attenuation coefficient to obtain a single adjustment value of the control parameter adjustment vector.

Optionally, the determining a control parameter calculation matrix corresponding to the current state value includes:

respectively adjusting the current control value of each control parameter in the control parameter vector;

respectively obtaining reference state values of the system state vectors of the heat pump system in a stable state after adjusting the current control values of the control parameters;

respectively calculating the difference between each reference state value and the current state value to obtain corresponding state change values;

taking the set of the state change values as a state parameter change matrix;

and calculating an inverse matrix of the state parameter change matrix to obtain the control parameter calculation matrix.

Optionally, after obtaining and adjusting the current control value of each control parameter, the obtaining a reference state value of the system state vector of the heat pump system in a steady state includes:

taking each control parameter in the control parameter vector as a target control parameter in turn;

adjusting the current control value of the target control parameter, and controlling the heat pump system to operate according to the adjusted current control value;

after the heat pump system operates for a first preset time, acquiring a plurality of groups of state reference values of the system state vector within a second preset time;

determining a system state fitting function according to the state reference values;

and determining the reference state value of the system state vector of the heat pump system in a stable state according to the system state fitting function.

Optionally, the determining a control parameter calculation matrix corresponding to the current state value includes:

acquiring a plurality of preset control parameter calculation matrixes of the heat pump system, wherein each preset control parameter calculation matrix corresponds to a state reference value of one system state vector;

respectively calculating deviation amounts of the current state value and each state reference value;

and taking a preset control parameter calculation matrix with the minimum deviation amount and the deviation amount within a preset deviation range as a control parameter calculation matrix corresponding to the current state value.

Optionally, the determining a control parameter adjustment vector according to the current state value, the target state value, and the control parameter calculation matrix includes:

calculating the difference between the target state value and the current state value to obtain a state parameter deviation vector;

and calculating the product of the control parameter calculation matrix and the state parameter deviation vector to obtain a control parameter adjustment vector.

In a second aspect, the present invention provides a heat pump system control apparatus comprising:

the device comprises an acquisition unit, a processing unit and a control unit, wherein the acquisition unit is used for acquiring a current control value of a control parameter vector, a current state value of a system state vector and a target state value of the system state vector; wherein the control parameter vector comprises a plurality of control parameters of the heat pump system and the system state vector comprises a plurality of state parameters of the heat pump system;

the first determining unit is used for determining a control parameter calculation matrix corresponding to the current state value;

the control parameter calculation matrix is obtained based on the corresponding relation between the control parameter vector and the system state vector; the second determining unit is used for determining a control parameter adjusting vector according to the current state value, the target state value and the control parameter calculation matrix;

wherein the control parameter adjustment vector comprises an adjustment value of each control parameter in the control parameter vector; a control unit for adjusting the control parameter vector based on the current control value and the control parameter adjustment vector to bring the system state vector to the target state value.

After the current control value of the control parameter vector, the current state value of the system state vector and the target state value are obtained, the control parameter calculation matrix corresponding to the current state value is determined, the control parameter adjustment vector is determined according to the current state value, the target state value and the control parameter calculation matrix, and finally the control parameter vector is adjusted based on the current control value and the control parameter adjustment vector so that the system state vector reaches the target state value. The heat pump system control method provided by the invention can replace a manual regulation mode in the prior art, and can regulate a plurality of control parameters in the heat pump system at the same time.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a flowchart of a heat pump system control method according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a heat pump system according to the prior art;

FIG. 3 is a flow chart of another method of controlling a heat pump system according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a simulation result of controlling a heat pump system by applying the heat pump system control method according to the embodiment of the present invention;

fig. 5 is a schematic diagram of a simulation result of controlling a heat pump system by applying the heat pump system control method according to the embodiment of the present invention;

fig. 6 is a block diagram of a heat pump system control device according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, fig. 1 is a flowchart of a heat pump system control method provided in an embodiment of the present invention, where the method may be applied to a controller in a heat pump system, and may also be applied to other controllers in an application scenario to which the heat pump system itself belongs, and obviously, in some cases, the method may also be implemented by using a server on a network side; referring to fig. 1, a flow of a heat pump system control method provided in an embodiment of the present invention may include:

s100, acquiring a current control value of the control parameter vector, a current state value of the system state vector and a target state value of the system state vector.

Therefore, the control parameter vector described in the embodiment of the present invention includes a plurality of control parameters corresponding to the heat pump system, and the system state vector includes a plurality of state parameters of the heat pump system.

Based on the basic knowledge of the heat pump system, it is known that each state parameter of the heat pump system often has a strong coupling relationship, and a change of any state parameter may cause a change of other state parameters, and correspondingly, a strong coupling relationship also exists between control parameters directly corresponding to the state parameters, and it is difficult to define a corresponding relationship between the control parameters and the state parameters, and in practical applications, there are often situations where a plurality of control parameters affect one state parameter, or one control parameter affects a plurality of state parameters.

Therefore, when selecting the parameters in the control parameter vector and the system state parameter vector, the coupling and function repetition between the control parameters should be reduced as much as possible to reduce the difficulty of the adjustment process, for example, the coolant-side inlet temperature and the flow rate cannot be simultaneously selected as the control parameters, and the coolant-side inlet temperature rather than the flow rate should be selected as the control parameters in consideration of the influence of the coolant-side inlet temperature and the influence that the adjustment range is much larger than the flow rate. The present invention is not limited to the specific parameters included in the control parameter vector and the system state vector.

Specifically, the current control value of the control parameter vector may be an initial value after the system is started, or may be another specified value, and in practical application, the current control value may be flexibly selected according to the control requirement; for the current state value of the system state vector, the current state value corresponds to the current control value of the control parameter vector, and the heat pump system is in the value of each state parameter in a stable state; the target state value is the value of each state parameter finally reached by the heat pump system after the heat pump system is regulated and controlled by the method.

And S110, determining a control parameter calculation matrix corresponding to the current state value.

The control parameter calculation matrices described in this embodiment and the following embodiments are obtained based on the correspondence between the control parameter vector and the system state vector, and it can be further seen based on the following contents that the control parameter calculation matrices may be subjected to multiple corrections or replacements in the whole control process, and are not expanded here.

As for the control parameter calculation matrix corresponding to the current state value, there are roughly two methods available, the first method is to select one of a plurality of preset control parameter calculation matrices as the control parameter calculation matrix used in the current control process, and the second method is to calculate a control parameter calculation matrix corresponding to the current state value according to the current control value of the control parameter vector of the heat pump system and the current state value of the system state vector.

The embodiment is first developed and described in the first method, and for the second method, the manner of the embodiment will be developed in the following, which will not be described in detail herein.

For the first method, a plurality of preset control parameter calculation matrices of the heat pump system are first obtained, and in the plurality of preset control parameter calculation matrices, each preset control parameter calculation matrix corresponds to a state reference value of a system state vector, which can also be understood as that one preset control parameter calculation matrix is obtained based on a corresponding and determined system state.

Then, deviation amounts of the current state value of the heat pump system and the state reference value corresponding to each preset control parameter calculation matrix are calculated respectively, and the preset control parameter calculation matrix with the minimum deviation amount and the deviation amount within the preset deviation range is used as the control parameter calculation matrix corresponding to the current state value. Namely, one control parameter calculation matrix which is closest to the current state value and is used in the control process is selected from a plurality of preset control parameter calculation matrices.

It is conceivable that the first approach is presented for a mature, repetitive use heat pump system, and would not be applicable for heat pump systems outside of this case. Further, the preset deviation range may be set based on a specific control precision requirement, and the specific value is not limited in the present invention.

And S120, determining a control parameter adjusting vector according to the current state value, the target state value and the control parameter calculation matrix.

In this and subsequent embodiments, the control parameter adjustment vector includes an adjustment value of each control parameter in the control parameter vector. It should be noted that the adjustment value obtained in this step may be understood as a total expected variation of each control parameter, as to whether the adjustment value corresponding to each control parameter needs to be adjusted, and a specific process of the adjustment, flexible control needs to be performed in combination with a variation situation of a state parameter of the heat pump system, and this process will also be developed in the following.

Optionally, the control parameter adjustment vector may be obtained specifically based on the following process:

and calculating the difference between the target state value and the current state value to obtain a state parameter deviation vector, and calculating the product of the control parameter calculation matrix and the state parameter deviation vector, wherein the product is the control parameter adjustment vector.

And S130, adjusting the control parameter vector based on the current control value and the control parameter adjusting vector so as to enable the system state vector to reach the target state value.

After the control parameter adjustment vector is obtained, the value of each control parameter in the control parameter vector can be adjusted based on the current control value and the control parameter adjustment vector obtained in the previous step, and then the value of each system parameter in the system state vector is changed until the system state vector reaches the target state value.

In summary, the heat pump system control method provided by the invention can replace a manual adjustment mode in the prior art, and can adjust a plurality of control parameters in the heat pump system at the same time.

The second method for determining the control parameter calculation matrix corresponding to the current state value in S110 is described below with reference to a specific example.

Optionally, referring to fig. 2, fig. 2 is a schematic structural diagram of a heat pump system in the prior art, and the heat pump system provided in this embodiment belongs to a typical thermodynamic experiment table for measuring evaporation and heat exchange characteristics of an experimental heat exchanger under different working conditions, and for this heat pump system, the heat pump system mainly includes: the system comprises a compressor, a condenser, a liquid storage tank, an expansion valve, a front heat exchanger, an experimental heat exchanger, a rear heat exchanger, a connecting pipeline and other components, and is characterized in that various state parameters of the system, including the regulation and control of the inlet and outlet states of the experimental heat exchanger, are realized by controlling the temperature of the secondary refrigerant of each heat exchanger.

Based on this heat pump system, the state parameters in the system state vector include: inlet pressure P of experimental heat exchanger^eAnd the inlet dryness x of the experimental heat exchangerⁱⁿAnd the outlet dryness x of the experimental heat exchanger^outMass flow rate m of experimental heat exchanger and superheat degree T in front of compressor^shCondensing pressure P^cSix in total; correspondingly, six control parameters, specifically the rotation speed omega of the compressor, the opening degree X of the expansion valve and the temperature T of the secondary refrigerant at the condenser side, are selected from the control parameter vector^wcThe temperature T of the secondary refrigerant at the side of the preheater^wpTemperature T of external secondary refrigerant of experimental heat exchanger^weRear heater side coolant temperature T^wa。

And inputting the current control value corresponding to each control parameter in the control parameter vector as an initial value into the heat pump system, and taking the current value of each state parameter after the heat pump system enters a stable state as the current state value of the system state vector.

Based on the above, it is assumed that the current control value of the heat pump system control parameter vector is expressed as follows:

wherein the subscript "cal" represents the current state; accordingly, the current state value of the system state vector can be expressed as:

firstly, respectively adjusting the current control value of each control parameter in the control parameter vector, and obtaining the reference state value of the system state vector of the heat pump system in a stable state after the current control value of each control parameter is adjusted.

Taking the adjustment of the rotation speed of the compressor as an example, if the rotation speed of the compressor is adjusted by a certain amount Δ ω, the control parameter vector of the heat pump system is changed to:

where Δ ω is a small variation that enables the heat pump system to produce measurable system state changes while still operating stably, and for a typical compressor, it can be tens of revolutions per minute.

After the heat pump system is in a stable state, recording a state reference value corresponding to the system state vector at the moment, and calculating as follows:

and traversing each control parameter in the control parameters, and executing the same control operation to correspondingly obtain the state reference value of the corresponding system state vector.

Then, the difference between each reference state value and the current state value is calculated respectively to obtain the corresponding state change value.

Use the previous example, use S_Δω-S_calThe obtained result is the state change value of the system state vector corresponding to the control parameter of adjusting the rotating speed of the compressor, which can be expressed as follows:

by analogy, the state change values of the system state vectors corresponding to the control parameters can be obtained, and then the obtained state change values are sorted to obtain the state parameter change matrix.

It should be noted that, in general, after obtaining a state reference value corresponding to a system state vector corresponding to a certain control parameter after adjusting the control parameter, the control parameter is directly restored, and a change of a next control parameter is controlled, and how a system state vector corresponding to a steady state of the heat pump system changes into a current state value corresponding to a current control value when the previous control parameter is adjusted is not concerned, until each control parameter completes the above adjusting process.

And finally, calculating an inverse matrix of the obtained state parameter change matrix to obtain a control parameter calculation matrix.

It is conceivable that the calculation matrix for each preset control parameter in the first method mentioned in S110 may also be obtained according to the method provided in the above embodiment.

Further, based on the process of obtaining the control parameter calculation matrix, it can be seen that each time a specific value of a control parameter is adjusted, a change in the value of the state parameter is caused, and each adjustment is performed until the heat pump system is in a stable state, and then the parameter value of each state parameter of the system can be obtained.

Optionally, each control parameter in the control parameter vector is sequentially used as a target control parameter, a current control value of the target control parameter is adjusted, and the heat pump system is controlled to operate according to the adjusted current control value, which is consistent with the process provided in the foregoing embodiment and is not described again.

Aiming at the adjusting process of each target control parameter, after the heat pump system runs for a first preset time period, the heat pump system passes through a stage of violent change of the system state, a plurality of groups of state reference values of the system state vector are obtained within a second preset time period, and then a system state fitting function is determined according to each state reference value.

Specifically, the system state fitting function can be expressed as:

y＝a+b·e^-ct

wherein y represents a state reference value, a value a of the obtained state fitting function is a reference state value of the system state vector of the heat pump system in a stable state, b is an initial value of the state parameter after the state parameter enters a second preset time period, t is a timing time period of the state parameter after the state parameter enters the second preset time period, and c is a fitting parameter which can be an empirical value or a calibration value. It should be noted that all variables and constants in the system state fitting function are dimensionless values.

Optionally, referring to fig. 3, fig. 3 is a flowchart of another heat pump system control method according to an embodiment of the present invention, and based on the embodiment shown in fig. 1, this embodiment provides a specific implementation manner for adjusting the control parameter vector based on the current control value and the control parameter adjustment vector to make the system state vector reach the target state value.

It should be noted that, since the embodiment shown in fig. 3 is provided on the basis of the embodiment shown in fig. 1, for a specific process related to each execution step in the embodiment shown in fig. 1, the specific process will not be expanded in this embodiment, and specifically, reference may be made to corresponding contents in the embodiment shown in fig. 1. And only new additions will be introduced in this section.

And S200, determining a middle control value of the control parameter vector based on the current control value and the control parameter adjusting vector.

Based on the foregoing, it can be seen that the current control value is a control parameter value for controlling the operation of the heat pump system at the current time, the adjustment amount corresponding to each control parameter is recorded in the control parameter adjustment vector, and when the intermediate control value of the control parameter vector is determined, the current control value and the control parameter adjustment vector are mainly superimposed, and in order to ensure stable operation of the heat pump system, the specific value of the control parameter cannot be changed greatly, and at the same time, the change of the system state needs to be caused, which is the key point of this step.

Optionally, a preset attenuation coefficient may be set, and of course, the preset attenuation coefficient is smaller than 1, for example, the preset attenuation coefficient may be selected from 0.1 to 0.4, and the product of the control parameter adjustment vector and the preset attenuation coefficient is calculated to obtain the single adjustment value of the control parameter adjustment vector, it is conceivable that, since the preset attenuation coefficient is smaller than 1, the obtained single adjustment value is definitely smaller than the relative adjustment value in the control parameter adjustment vector, and then, the sum of the current control value and the single adjustment value is taken as the intermediate control value of the control parameter vector.

The method can be used in each adjusting process, so that the condition that the intermediate control value of the control parameter vector is not too large in each adjusting process is ensured, and the condition that the heat pump system is unstable is avoided.

Optionally, a preset adjustment threshold may be further set, the size of the control parameter adjustment vector is generally controlled by the preset adjustment threshold, specifically, if the control parameter adjustment vector is greater than the preset adjustment threshold, the control parameter adjustment vector is reduced according to a preset proportion to avoid the control parameter adjustment vector from being generally too large, and then the product of the reduced control parameter adjustment vector and the preset attenuation coefficient is calculated to obtain a single adjustment value of the control parameter adjustment vector.

And S210, acquiring an intermediate state value of a system state vector after the heat pump system operates according to the intermediate control value and is in a stable state.

The process of controlling the operation of the heat pump system according to the intermediate control value and the process of obtaining the intermediate state value after the heat pump system is in the stable state can be realized by referring to the foregoing contents, and details are not repeated here.

S220, judging whether the deviation between the intermediate state value and the target state value is in a first preset range, if not, executing S230, and if so, executing S260.

In this step, the first preset range is set based on the target condition value in order to finally control the heat pump system within a range close to the target condition value, and of course, it is most desirable that the intermediate condition value is equal to the target condition value. The selection of the first preset range can be set according to specific control precision requirements.

If the deviation between the intermediate state value and the target state value is not in the first preset range, adjusting the control parameter vector based on the intermediate control value and the intermediate state value to enable the system state vector to reach the target state value, wherein the specific adjusting process is shown as S230-S250; if the deviation of the intermediate state value from the target state value is within the first preset range, S260 is performed.

And S230, judging whether the deviation between the intermediate state value and the current state value is in a second preset range, if so, executing S240, and if not, executing S250.

When the deviation between the intermediate state value and the target state value of the heat pump system is not within the first preset range, it is necessary to determine whether the deviation between the intermediate state value and the current state value is within the second preset range.

As mentioned above, the system state change of the heat pump system is nonlinear, and it is often difficult to accurately express the corresponding relationship between the control parameters and the state parameters in the whole control process of the heat pump system through a control parameter calculation matrix, so that it is necessary to determine whether to update the control parameter calculation matrix, and if the deviation between the intermediate state value and the current state value is within the second preset range, it indicates that the currently applicable control parameter calculation matrix can also measure or express the corresponding relationship between the control parameters and the state parameters, and conversely, if the deviation between the intermediate state value and the current state value is not within the second preset range, it indicates that the currently applicable control parameter calculation matrix is difficult to measure or express the corresponding relationship between the control parameters and the state parameters, and it is necessary to update.

The setting of the second preset range can also be selected based on the requirement of control accuracy, and is not described in detail herein.

And S240, updating the current control value to an intermediate control value, and updating the current state value to an intermediate state value.

Referring to fig. 2, when the deviation between the intermediate state value and the current state value is within the second preset range, the current control value needs to be updated to the intermediate control value, and the current state value needs to be updated to the intermediate state value, that is, the result after the last adjustment is used as the initial value of the next adjustment, and then the step S120 is executed again and again, and the process is repeated until the deviation between the intermediate state value and the target state value is within the first preset range.

And S250, updating the current control value to an intermediate control value, and updating the current state value to an intermediate state value.

Under the condition that the deviation between the intermediate state value and the current state value is not within the second preset range, the control parameter calculation matrix needs to be updated, so that the current control value also needs to be updated to the intermediate control value, and the current state value is updated to the intermediate state value, that is, the result after the last adjustment is taken as the initial value of the next adjustment, and then the step returns to execute S110 to obtain a new control parameter calculation matrix.

It should be noted that the operations performed in S240 and S250 are the same and may be performed before performing S230, and the operations corresponding to both of the operations in this embodiment are placed after S230, and are divided into two steps for description, mainly to facilitate the implementation process of the solution.

And S260, controlling the heat pump system to operate according to the intermediate control value.

In case the deviation of the intermediate state value from the target state value is within a first predetermined range, it may be assumed that the desired adjustment objective has been reached, i.e. the operation of the heat pump system may be controlled according to the intermediate control value.

In summary, the control method provided in the embodiments of the present invention can not only simultaneously adjust a plurality of control parameters to finally achieve a target state value of the heat pump system, but also convert the nonlinear characteristics of the heat pump system into one or more linear equations (i.e., control parameter calculation matrices) for expression, so as to simplify the control process, shorten the time consumption of the entire control process, improve the control efficiency, and achieve automation of the control process on the premise of meeting the control accuracy requirement.

Furthermore, the control parameter calculation matrix can be corrected according to actual conditions, so that the system has adaptivity to system pipelines and device characteristic parameters, can be multiplexed on different systems, and can realize stable control on the system under the condition that the system pipelines and the device characteristic parameters are changed or unclear.

Optionally, in practical application of any of the above embodiments, the refrigerant is mostly used in the heat pump system, considering that the refrigerant has three forms of gas, two-phase and liquid, the superheat degree, the supercooling degree and the dryness degree cannot separately and completely represent the refrigerant state, and the superheat degree, the supercooling degree and the dryness degree can be combined into one state to represent the refrigerant state. The synthesis method comprises the following steps:

s＝T^sh+x*K-T^sc

where s is the resultant state value, T^shIs the degree of superheat, x is the degree of dryness, T^scThe degree of supercooling is K, and K is a proportionality coefficient and can be approximately taken as the numerical ratio of the phase change latent heat of the saturated liquid to the specific heat capacity of the saturated gas near the working temperature of the used refrigerant. For R134a refrigerant working at 0-40 ℃, K is 140. And then, replacing the superheat degree, the supercooling degree and the dryness degree with the refrigerant state s as the state parameters of the system to be regulated in the control algorithm. In practical applications, the refrigerant refers to a refrigerant circulating in the main line and performing phase-change heat exchange, and generally includes R134a, R410a, and the like, and the secondary refrigerant refers to a fluid for performing heat exchange with the refrigerant in the main line and performing no phase change, and generally includes water or glycol.

According to the example shown in fig. 2, the heat pump system shown in fig. 2 is subjected to simulation verification by using the control method provided by the embodiment of the invention, the whole control process lasts 45000 seconds totally, the set target values of the superheat degree and the condensing pressure of the refrigerant before the compressor are set in the whole process are kept unchanged, the set target values of the inlet pressure of the experimental heat exchanger, the mass flow rate of the experimental heat exchanger, the inlet dryness of the experimental heat exchanger and the outlet dryness of the experimental heat exchanger are respectively adjusted once at 9000 seconds, 21000 seconds and 33000 seconds, and the parameters of the heat pump system are controlled by using the control algorithm provided by the embodiment of the invention, if the target value of the inlet pressure of the experimental heat exchanger is gradually increased from 3.15bar to 4.2 bar.

Taking the superheat degree of the refrigerant before the compressor and the inlet pressure of the experimental heat exchanger as an example, the corresponding simulation results can be seen in fig. 4 and 5, wherein the dashed line represents the set target value of the system, and the solid line represents the actual state value of the system. It can be seen from the combination of the graphs that in the whole adjusting process, after the set target value of the system state is changed every time, the front superheat degree of the compressor and the inlet pressure of the experimental heat exchanger are gradually stabilized to the set target value, and meanwhile, the mass flow rate, the inlet dryness of the experimental heat exchanger and the outlet dryness of the experimental heat exchanger are also changed at the plurality of time nodes. In the process, when the set target value is changed, the control method provided by the embodiment of the invention can effectively adjust the actual state value of the system to the set target value, can effectively realize the accurate adjustment of the state parameter at the same time, and enables the system state to change along with the change of the set target value.

The heat pump system control device provided in the embodiment of the present invention is described below, and the heat pump system control device described below may be regarded as a functional module architecture that needs to be provided in the central device to implement the heat pump system control method provided in the embodiment of the present invention; the following description may be cross-referenced with the above.

Optionally, referring to fig. 6, fig. 6 is a block diagram of a heat pump system control device according to an embodiment of the present invention, where the heat pump system control device according to the embodiment of the present invention includes:

an obtaining unit 10, configured to obtain a current control value of a control parameter vector, a current state value of a system state vector, and a target state value of the system state vector; the control parameter vector comprises a plurality of control parameters of the heat pump system, and the system state vector comprises a plurality of state parameters of the heat pump system;

a first determining unit 20, configured to determine a control parameter calculation matrix corresponding to the current state value;

the control parameter calculation matrix is obtained based on the corresponding relation between the control parameter vector and the system state vector;

a second determining unit 30, configured to determine a control parameter adjustment vector according to the current state value, the target state value, and the control parameter calculation matrix;

the control parameter adjusting vector comprises adjusting values of all control parameters in the control parameter vector;

and the control unit 40 is used for adjusting the control parameter vector based on the current control value and the control parameter adjusting vector so as to enable the system state vector to reach the target state value.

Optionally, the control unit 40 is configured to adjust the control parameter vector based on the current control value and the control parameter adjustment vector, so that when the system state vector reaches the target state value, the method specifically includes:

determining a middle control value of the control parameter vector based on the current control value and the control parameter adjustment vector;

acquiring an intermediate state value of a system state vector after the heat pump system operates according to the intermediate control value and is in a stable state;

if the deviation of the intermediate state value and the target state value is not within a first preset range, adjusting the control parameter vector based on the intermediate control value and the intermediate state value so as to enable the system state vector to reach the target state value;

and if the deviation of the intermediate state value and the target state value is within a first preset range, controlling the heat pump system to operate according to the intermediate control value.

Optionally, the control unit 40 is configured to adjust the control parameter vector based on the intermediate control value and the intermediate state value, so that when the system state vector reaches the target state value, the method specifically includes:

if the deviation between the intermediate state value and the current state value is within a second preset range, updating the current control value into the intermediate control value, and updating the current state value into the intermediate state value;

the second determination unit 30 is triggered back;

if the deviation between the intermediate state value and the current state value is not in a second preset range, updating the current control value into the intermediate control value, and updating the current state value into the intermediate state value;

the return triggers the first determination unit 20.

Optionally, the control unit 40 is configured to, when determining the intermediate control value of the control parameter vector based on the current control value and the control parameter adjustment vector, specifically include:

acquiring a preset attenuation coefficient;

calculating the product of the control parameter adjusting vector and a preset attenuation coefficient to obtain a single adjusting value of the control parameter adjusting vector;

and taking the sum of the current control value and the single adjustment value as a middle control value of the control parameter vector.

Optionally, the control unit 40 is configured to calculate a product of the control parameter adjustment vector and a preset attenuation coefficient, and when a single adjustment value of the control parameter adjustment vector is obtained, the method specifically includes:

if the control parameter adjusting vector is larger than a preset adjusting threshold, reducing the control parameter adjusting vector according to a preset proportion;

and calculating the product of the reduced control parameter adjustment vector and a preset attenuation coefficient to obtain a single adjustment value of the control parameter adjustment vector.

Optionally, the first determining unit 20 is configured to, when determining the control parameter calculation matrix corresponding to the current state value, specifically include:

respectively adjusting the current control value of each control parameter in the control parameter vector;

respectively obtaining reference state values of system state vectors of the heat pump system in a stable state after adjusting the current control values of the control parameters;

respectively calculating the difference between each reference state value and the current state value to obtain corresponding state change values;

taking the set of each state change value as a state parameter change matrix;

and calculating an inverse matrix of the state parameter change matrix to obtain a control parameter calculation matrix.

Optionally, the first determining unit 20 is configured to, after the current control value of each control parameter is adjusted, when the heat pump system is in a reference state value of a system state vector in a steady state, specifically include:

taking each control parameter in the control parameter vector as a target control parameter in turn;

adjusting the current control value of the target control parameter, and controlling the heat pump system to operate according to the adjusted current control value;

after the heat pump system operates for a first preset time, acquiring a plurality of groups of state reference values of a system state vector within a second preset time;

determining a system state fitting function according to each state reference value;

and determining the reference state value of the system state vector of the heat pump system in the stable state according to the system state fitting function.

Optionally, the first determining unit 20 is configured to, when determining the control parameter calculation matrix corresponding to the current state value, specifically include:

acquiring a plurality of preset control parameter calculation matrixes of the heat pump system, wherein each preset control parameter calculation matrix corresponds to a state reference value of a system state vector;

respectively calculating the deviation amount of the current state value and each state reference value;

and taking the preset control parameter calculation matrix with the minimum deviation amount and the deviation amount within the preset deviation range as the control parameter calculation matrix corresponding to the current state value.

Optionally, the second determining unit 30 is configured to determine the control parameter adjustment vector according to the current state value, the target state value, and the control parameter calculation matrix, and specifically includes:

calculating the difference between the target state value and the current state value to obtain a state parameter deviation vector;

and calculating the product of the control parameter calculation matrix and the state parameter deviation vector to obtain a control parameter adjustment vector.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in Random Access Memory (RAM), memory, Read Only Memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.