A method for evaluating the adjustable capacity of air-conditioning units participating in demand-side response

Abstract

The present invention discloses a method for evaluating the adjustable capacity of an air-conditioning unit participating in demand-side response, establishes an indoor thermodynamic model, calculates the operating time and standby time of a single air-conditioning unit according to the initial state of the single air-conditioning unit when the single air-conditioning unit participates in demand-side response and when the single air-conditioning unit does not participate in demand-side response, compares the operating time of the single air-conditioning unit that does not participate in demand-side response and is within the duration of demand-side response with the operating time of the single air-conditioning unit that participates in demand-side response and is within the duration of demand-side response, and then calculates the adjustable capacity of a single air-conditioning unit in combination with the cooling power and energy efficiency ratio of the air-conditioning unit, the sum of the adjustable capacities of all air-conditioning units in the air-conditioning unit is the total adjustable capacity, and the total adjustable capacity is regulated in the power grid control. The present application achieves the high efficiency of the air-conditioning unit participating in demand-side response by accurately evaluating the adjustable capacity of the air-conditioning unit.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution networks, and in particular to a method for evaluating the adjustable capacity of an air-conditioning unit participating in demand-side response. Background Art

[0002] In recent years, electricity consumption has continued to grow rapidly. Existing data shows that in 2019, the world's total electricity consumption reached 7486.61 billion kWh, and the peak-to-valley difference in load is also increasing rapidly, requiring more adjustable capacity to reduce the peak-to-valley difference. However, for environmental reasons, traditional generators are being phased out and cannot provide sufficient adjustable capacity for the power system. Therefore, it is becoming increasingly difficult to maintain a balance between supply and demand.

[0003] In order to relieve the pressure of power generation and transmission during peak load periods, demand response (DR) is a widely used peak load reduction method. Demand side response is to guide users to change their electricity consumption behavior by reducing peak power consumption or shifting peak loads to off-peak periods. Especially in the hot summer, the power consumption of air conditioners (ACs) has increased rapidly, accounting for more than 40% of the total power load. The huge power consumption has a great demand for energy. Considering the thermal inertia of indoor air, if the air conditioner is turned off for a short time, the indoor temperature will not change much. Based on this, the air conditioner is controlled by demand side response. However, how to accurately evaluate the adjustable capacity of the air conditioner unit to achieve the high efficiency of the air conditioner unit participating in demand side response is a problem that needs to be solved urgently. Summary of the invention

[0004] The purpose of the present invention is to provide a method for evaluating the adjustable capacity of an air-conditioning unit participating in demand-side response. The method analyzes the operating time and standby time of a single air-conditioner within a set time when the air-conditioner is not participating in demand-side response and in different initial states, and then compares the operating time and standby time of a single air-conditioner within a set time when the air-conditioner participates in demand-side response. The operating time participating in demand-side response is compared with the operating time not participating in demand-side response to obtain the adjustable capacity. The sum of the adjustable capacities of all single air-conditioners is the adjustable capacity of the power grid.

[0005] In the first aspect, the above-mentioned invention object of the present invention is achieved through the following technical solutions:

[0006] A method for evaluating the adjustable capacity of an air-conditioning unit participating in demand-side response is proposed. An indoor thermodynamic model is established. The operating time and standby time of a single air-conditioner are calculated according to its initial state when a single air-conditioner participates in demand-side response and when a single air-conditioner does not participate in demand-side response. The adjustable capacity of a single air-conditioning unit is calculated in combination with the cooling power and energy efficiency ratio of the air-conditioning unit. The sum of the adjustable capacities of all air-conditioners in the air-conditioning unit is the total adjustable capacity.

[0007] The present invention is further configured to establish an indoor thermodynamic model for describing the dynamic process of indoor real-time temperature, which is related to the heat capacity of the room, the heat resistance of the room, and the cooling capacity of the air conditioner, and is expressed by the following formula:

[0008]

[0009] Where, T A represents the indoor temperature, C represents the heat capacity of the room, Q gain It represents all the heat gained, including the cooling heat of the air conditioner, the heat exposed by sunlight, and the heat generated by various electrical appliances in the room. loss Indicates the amount of heat lost by a room, which is related to the room's heat resistance and indoor and outdoor temperatures.

[0010] The present invention is further configured as follows: when the air-conditioning unit does not participate in demand-side response and when it participates in demand-side response, the operating time and standby time of the air-conditioning unit within a set time in different initial states are calculated, and the operating time of the air-conditioning unit not participating in demand-side response and the operating time of the air-conditioning unit participating in demand-side response in the same initial state are compared to calculate the adjustable capacity.

[0011] The present invention is further configured as follows: when the air-conditioning unit does not participate in the demand-side response, the initial state of the air-conditioning unit is running, and at the set time t DR The running time of the air conditioning unit is t′ on1 for:

[0012]

[0013] The standby time is: t′ off1 =t DR -t′ on1 (3);

[0014] In the formula, R represents the heat resistance of the room, C represents the heat capacity of the room, and T s represents the room starting temperature, T out Indicates the ambient temperature, T min Indicates the lowest temperature acceptable to the user, P cool Indicates the cooling power of the air conditioning unit.

[0015] The present invention is further configured as follows: when the air-conditioning unit does not participate in the demand-side response, the initial state of the air-conditioning unit is standby, and at the set time t DR The standby time of the air conditioner is t′ off2 for:

[0016]

[0017] The running time is: t′ on2 =tDR -t′ off2 (5);

[0018] Where, T set Indicates the air conditioning set temperature, T db The error range of the air conditioner set temperature.

[0019] The present invention is further configured as follows: when the air-conditioning unit participates in demand-side response, when the demand-side response is started, if the air-conditioning unit is in running state, it switches to standby state. During the demand-side response period, if the room temperature reaches the maximum temperature, the air-conditioning unit enters running state and gives up participating in demand-side response; if the air-conditioning unit is in standby state, it continues to maintain standby state.

[0020] The present invention is further configured as follows: the operating time t of the air conditioning unit on and standby time t off Respectively expressed as:

[0021]

[0022]

[0023] In the formula, set the time t DR Equal to the demand side response duration, T max Indicates the highest temperature acceptable to the user.

[0024] The present invention is further configured as follows: the adjustable capacity E of a single air conditioner DR It is related to the air conditioning power and standby time, as shown in the following formula:

[0025] E DR =P AC (t′ onj -t on ) (8);

[0026] Where P AC Represents the power of a single air conditioner, P AC =p cool / EER,P cool represents the cooling power of the air conditioner, EER represents the cooling efficiency of the air conditioner, and j is equal to 1 or 2, which represents the initial state of the air conditioner when it does not participate in the demand-side response.

[0027] The present invention is further configured as follows: the total adjustable capacity of n air conditioners is the sum of the adjustable capacities of all n individual air conditioners, which is expressed by the following formula:

[0028]

[0029] In a second aspect, the above-mentioned object of the present invention is achieved through the following technical solutions:

[0030] A terminal for evaluating the adjustable capacity of an air-conditioning unit participating in demand-side response comprises a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method described in the present application is implemented.

[0031] In a third aspect, the above-mentioned object of the present invention is achieved through the following technical solutions:

[0032] A computer-readable storage medium stores a computer program, and when the computer program is executed by the processor, the method described in the present application is implemented.

[0033] Compared with the prior art, the beneficial technical effects of this application are:

[0034] 1. This application calculates the adjustable capacity of a single air conditioner by calculating the operating time and standby time of the air conditioner in different initial states within a set time when the single air conditioner does not participate in the demand side response, and compares it with the operating time of the single air conditioner within a set time when the single air conditioner participates in the demand side response, so as to provide a basis for grid regulation;

[0035] 2. Further, the present application summarizes the adjustable capabilities of all air conditioners to obtain the adjustable capabilities of the power grid, which is used to adjust the power grid;

[0036] 3. Furthermore, the present application suppresses peak power consumption and regulates grid load by adjusting the operating hours of the air conditioner. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a timing diagram of the operating mechanism of the air conditioner;

[0038] Figure 2 It is a timing diagram of the air conditioner in operation when the demand side response starts;

[0039] Figure 3 It is a timing diagram of the air conditioner in standby state when the demand side response starts. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below in conjunction with the accompanying drawings. Specific embodiment 1

[0042] The present application provides a method for evaluating the adjustable capacity of an air-conditioning unit participating in demand-side response. The method first calculates the operating time and standby time of a single air-conditioner within a set time when the air-conditioner does not participate in the demand-side response and starts from different initial states; then calculates the operating time and standby time of the single air-conditioner within a set time, i.e., the demand-side response time, when the air-conditioner participates in the demand-side response; with respect to the initial state of the single air-conditioner, the adjustable operating time of the single air-conditioner is calculated, thereby calculating the adjustable power of the single air-conditioner, and summing up the adjustable powers of all n air-conditioners in the air-conditioning unit to obtain the total adjustable power of the air-conditioning unit.

[0043] In order to maintain a relatively stable indoor temperature, the indoor heat exchange capacity determines whether the air conditioner operates or not. Figure 1 As shown, the indoor temperature fluctuates within the set temperature range, and the temperature range depends on the dead zone.

[0044] When the air conditioner is running, the indoor temperature decreases over time until it is lower than the boundary temperature Tset-Tdb, at which point the power of the air conditioner (ACs) reaches the rated power Prated. Once the temperature is lower than the boundary temperature, the AC will switch to standby mode. When the air conditioner is in standby mode, the power of the air conditioner is close to 0, and the cooling stops. The indoor temperature will slowly rise, and the rate of increase is mainly related to the heat exchange capacity of the room. The air conditioner will remain in standby mode until the temperature exceeds Tset+Tdb. Therefore, during the entire working process of the air conditioner, the air conditioner is in a cyclic switching between the running and standby states, where Tset represents the set temperature of the air conditioner, and Tdb represents the error interval value of the set temperature of the air conditioner.

[0045] An indoor thermodynamics (ETP) model is established to evaluate the heat exchange capacity of the room and describe the real-time temperature dynamic process of the room.

[0046] The indoor thermodynamic (ETP) model is expressed as follows:

[0047]

[0048] Q gain =Q AC +Q sun +Q loads (2);

[0049] Q loss =(T A -T out ) / R (3);

[0050] In the formula, C is the heat capacity of the room, which indicates the room's heat storage capacity. If the room's heat capacity is larger, the room's temperature is more difficult to change. R represents the room's heat resistance, which is the room's insulation capacity.

[0051] Qgain Indicates all the heat obtained, including the cooling heat of the air conditioner, the heat exposed to sunlight, and the heat generated by various electrical appliances in the room; Q loss Indicates the amount of heat lost by a room, which is related to the room's heat resistance and indoor and outdoor temperatures.

[0052] Q AC Indicates the cooling capacity of the air conditioner, which is related to the rated power of the air conditioner and the cooling energy efficiency ratio (EER); Q sun is the heat of sunlight exposure; Q loads Indicates the heat generated by various electrical appliances in the room.

[0053] T A Indicates the indoor temperature, T out Indicates the ambient temperature.

[0054] At the beginning of a set time, the initial state of a single air conditioner can be divided into two states: running state and standby state. When a single air conditioner does not participate in the demand side response, in these two different cases, the running time and standby time of the air conditioner within a set time are calculated as follows:

[0055] The initial state of a single air conditioner is running. At the set time t DR The running time of the air conditioning unit is t′ on1 for:

[0056]

[0057] The standby time is: t′ off1 =t DR -t′ on1 (5);

[0058] In the formula, R represents the heat resistance of the room, C represents the heat capacity of the room, and T s represents the room starting temperature, T out Indicates the ambient temperature, T min Indicates the lowest temperature acceptable to the user, P cool Indicates the cooling power of the air conditioning unit.

[0059] When the initial state of a single air conditioner is in standby mode, it will be turned off after the set time t DR The standby time of the air conditioner is t′ off2 for:

[0060]

[0061] The running time is: t′ on2 =t DR -t′ off2 (7);

[0062] Where, Tset Indicates the air conditioning set temperature, T db The error range of the air conditioner set temperature.

[0063] When a single air conditioner participates in demand-side response, when a single air conditioner receives a demand-side response instruction, no matter it is in running state or standby state, the air conditioner needs to switch to standby state. The standby time at this time is related to the initial indoor temperature T s 、The maximum temperature acceptable to users T max , environmental heat exchange and other parameters, and is also related to the time point of ending the demand side response. However, considering that the time point of ending the demand side response is difficult to determine, the corresponding indoor temperature at the end of the demand response is also difficult to determine. Therefore, during the demand side response time t DR The air conditioner running time is t DR Minus the standby time.

[0064] When demand-side response is started, if the air conditioner is running, it will switch to standby mode and the power will quickly drop from P to 0; if the indoor temperature reaches the maximum temperature acceptable to the user, but demand-side response (DR) is still continuing, to ensure user comfort, the air conditioner will enter the running state and lower the room temperature instead of continuing to participate in demand-side response.

[0065] When the demand side response starts, if the air conditioner is in standby mode, the air conditioner load cannot be reduced. However, since the indoor temperature will reach the maximum temperature acceptable to the user (the maximum temperature acceptable to the user T max Greater than (T set +T db ), so the standby time will be extended.

[0066] According to the working characteristics of air conditioners, the main potential of air conditioners participating in demand-side response comes from extending the standby state of the air conditioner to reduce the running time of the air conditioner during peak hours. The adjustable capacity of the air conditioner to participate in demand-side response is equal to the response power of the air conditioner multiplied by the duration. If the air conditioner is in working state, the response power is equal to the rated power of the air conditioner. If the air conditioner is in standby state, the response power is equal to 0, but the standby time will be extended.

[0067] After the room and air conditioner parameters are determined, the air conditioner will exit the demand side response after reaching the maximum temperature, so the duration of the standby state and the running state depends on the maximum temperature rise. Figure 2 and Figure 3 As shown, when the demand-side response begins, the initial state of the air conditioner, whether it is running or standby, will switch to standby. That is to say, for the air conditioner participating in demand response, the adjustable capacity only needs to consider the situation where the initial state is standby.

[0068] According to the indoor thermodynamics (ETP) model, the real-time indoor temperature T air (t) is shown in the following formula:

[0069]

[0070] Where, T air (t) represents the indoor temperature at time t, T air (t-Δt) represents the room temperature at time t-Δt, P cool represents the cooling power of the air conditioner, and Δt represents the calculation period.

[0071] When participating in demand-side response, the operating time of a single air conditioner is t on and standby time t off Respectively expressed as:

[0072]

[0073]

[0074] In the formula, for the convenience of analysis, the time t is set DR Equal to the demand side response duration, T max Indicates the highest temperature acceptable to the user.

[0075] Regardless of whether the air conditioner participates in demand-side response, the power of the air conditioner is equal to the cooling power divided by the energy efficiency ratio (EER), which represents the cooling efficiency of the air conditioner.

[0076] The operating time of a single air conditioner participating in demand-side response is compared with the operating time of a single air conditioner not participating in demand-side response to obtain the adjustable capacity E of a single air conditioner. DR As shown below:

[0077] E DR =P AC (t′ onj -t on ) (11);

[0078] P AC =P coll / EER (12);

[0079] Where P AC Represents the power of a single air conditioner, P coll represents the cooling power of the air conditioner, EER represents the cooling efficiency of the air conditioner, and j is equal to 1 or 2, which represents the initial state of the air conditioner when it does not participate in the demand-side response.

[0080] Assume that the air conditioning unit includes n air conditioners, then the sum of the adjustable capacities of all n air conditioners is the total adjustable capacity of the air conditioning unit.

[0081] Specific embodiment 2

[0083] An embodiment of the present invention provides a terminal device for evaluating the adjustable capacity of an air-conditioning unit that participates in demand-side response. The terminal device of this embodiment includes: a processor, a memory, and a computer program stored in the memory and executable on the processor, such as a program for calculating the adjustable capacity of each air conditioner. When the processor executes the computer program, the method in Example 1 is implemented.

[0084] Exemplarily, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of completing specific functions, which are used to describe the execution process of the computer program in the air-conditioning unit adjustable capacity evaluation terminal device participating in the demand-side response. For example, the computer program may be divided into multiple modules to perform calculations on each air conditioner separately, and the specific functions of the modules are as follows:

[0085] Multiple calculation modules are used to calculate the adjustable capacity of each air conditioner.

[0086] The terminal device for evaluating the adjustable capacity of the air-conditioning unit participating in the demand-side response may be a computing device such as a desktop computer, a notebook, a PDA, and a cloud server. The terminal device for evaluating the adjustable capacity of the air-conditioning unit participating in the demand-side response may include, but is not limited to, a processor and a memory. Those skilled in the art will appreciate that the above examples are merely examples of the terminal device for evaluating the adjustable capacity of the air-conditioning unit participating in the demand-side response, and do not constitute a limitation on the terminal device for evaluating the adjustable capacity of the air-conditioning unit participating in the demand-side response. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal device for evaluating the adjustable capacity of the air-conditioning unit participating in the demand-side response may also include input and output devices, network access devices, buses, etc.

[0087] The processor may be a central processing unit (CPU), or other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the air-conditioning unit adjustable capacity evaluation terminal device participating in the demand-side response, and uses various interfaces and lines to connect the various parts of the air-conditioning unit adjustable capacity evaluation terminal device participating in the demand-side response.

[0088] The memory can be used to store the computer program and / or module, and the processor realizes various functions of the air conditioner unit adjustable capacity evaluation terminal device participating in demand side response by running or executing the computer program and / or module stored in the memory, and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area can store data created according to the use of the mobile phone (such as audio data, a phone book, etc.), etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (SecureDigital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices. Specific embodiment three

[0090] The module / unit integrated in the terminal device for evaluating the adjustable capacity of the air-conditioning unit participating in the demand-side response, if implemented in the form of a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on such an understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal and software distribution medium, etc.

[0091] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, all equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for evaluating the adjustable capacity of an air-conditioning unit participating in demand-side response, characterized in that: An indoor thermodynamic model is established. The operating time and standby time of a single air conditioner are calculated according to its initial state when a single air conditioner participates in demand-side response and when a single air conditioner does not participate in demand-side response. The adjustable capacity of a single air conditioner is calculated by combining the cooling power and energy efficiency ratio of the air conditioner unit. The sum of the adjustable capacities of all air conditioners in the air conditioner unit is the total adjustable capacity. An indoor thermodynamic model is established to describe the dynamic process of indoor real-time temperature, which is related to the heat capacity of the room, the heat resistance of the room, and the cooling capacity of the air conditioner, and is expressed as follows: Q gain =Q AC +Q sum +Q loads (2); Q loss =(T A -T out ) / R (3); Where, T A represents the indoor temperature, C represents the heat capacity of the room, Q gain It represents all the heat gained, including the cooling heat of the air conditioner, the heat exposed by sunlight, and the heat generated by various electrical appliances in the room. loss It indicates the heat loss of the room, which is related to the heat resistance of the room and the indoor and outdoor temperatures. R indicates the heat resistance of the room; When the air-conditioning unit does not participate in the demand-side response, the initial state of the air-conditioning unit is running. DR The running time of the air conditioning unit is t′ on1 for: The standby time is: t′ off1 =t DR -t′ on1 (5); In the formula, R represents the heat resistance of the room, C represents the heat capacity of the room, and T s represents the room starting temperature, T out Indicates the ambient temperature, T min Indicates the lowest temperature acceptable to the user, P cool Indicates the cooling power of the air conditioning unit; When the air conditioner unit does not participate in the demand side response, the initial state of the air conditioner unit is standby. DR The standby time of the air conditioner is t′ off2 for: The running time is: t′ on2 =t DR -t′ off2 (7); Where, T set Indicates the air conditioning set temperature, T db The error interval of the air conditioner set temperature; the running time of the air conditioner unit t on and standby time t off Respectively expressed as: In the formula, set the time t DR Equal to the demand side response duration, T max Indicates the maximum temperature acceptable to the user; Adjustable capacity of a single air conditioner E DR It is related to the air conditioning power and standby time, as shown in the following formula: E DR =P AC (t′ onj -t on ) (10); Where P AC Represents the power of a single air conditioner, P AC =p cool / EER,p cool represents the cooling power of the air conditioner, EER represents the cooling efficiency of the air conditioner, and j is equal to 1 or 2, which represents the initial state of the air conditioner when it does not participate in the demand-side response.

2. The method for evaluating the adjustable capacity of air-conditioning units participating in demand-side response according to claim 1 is characterized in that: The operating time and standby time of the air-conditioning unit within the set time are calculated in different initial states when the air-conditioning unit does not participate in demand-side response and when it participates in demand-side response. The operating time of the air-conditioning unit not participating in demand-side response and the operating time of the air-conditioning unit participating in demand-side response under the same initial state are compared to calculate the adjustable capacity.

3. The method for evaluating the adjustable capacity of air-conditioning units participating in demand-side response according to claim 2 is characterized in that: When the air-conditioning unit participates in demand-side response, when the demand-side response starts, if the air-conditioning unit is in running state, it will switch to standby state. During the demand-side response period, if the room temperature reaches the maximum temperature, the air-conditioning unit will enter the running state and give up participating in the demand-side response; if the air-conditioning unit is in standby state, it will continue to remain in standby state.

4. The method for evaluating the adjustable capacity of air-conditioning units participating in demand-side response according to claim 1 is characterized in that: The total adjustable capacity of n air conditioners is the sum of the adjustable capacities of all n individual air conditioners, expressed as follows:

5. An air conditioning unit adjustable capacity evaluation terminal participating in demand-side response, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 4 is implemented.

6. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

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