Method for participating in power system demand response control by variable frequency temperature control load based on state queue

Abstract

The application provides a state queue-based variable frequency temperature control load participating in power system demand response control method, which comprises the following steps: proposing an application scenario and a control method of a state queue model in variable frequency temperature control load demand response; and realizing control of large-scale dispersed variable frequency temperature control loads based on state queue priority. A state queue algorithm for variable frequency temperature control load cluster demand response control is designed, and the variable frequency temperature control load is controlled based on queue priority to provide regulation capacity for a power system.

Description

Technical Field

[0001] This invention belongs to the field of power system technology, specifically relating to the application scenario of state queue model in variable frequency temperature-controlled load clusters, and the control method for demand response of large-scale distributed temperature-controlled loads under state queue. Background Technology

[0002] With socio-economic development and a significant improvement in residents' living standards, controllable temperature-controlled loads such as air conditioners account for over 50% of total loads in economically developed regions, and this proportion is increasing year by year, giving them a natural demand response advantage. First, the scale of temperature-controlled loads is enormous, with their share of total load increasing annually, indicating huge potential for demand response regulation. Second, the loads and their associated building environments possess a certain heat storage capacity, meaning that adjusting the temperature within a certain range will not excessively affect residents' comfort. Third, periods of high electricity consumption by temperature-controlled loads coincide with peak power system load times when system reserve capacity is insufficient, allowing the demand response of temperature-controlled loads to compensate for the shortfall in generator regulation capacity. Fourth, with the rapid development of information communication and intelligent control technologies, compared to traditional generator sets, the demand response speed of temperature-controlled loads is much faster, reaching the second level, fully meeting the frequency regulation requirements of the power system.

[0003] Previous research on demand response control for temperature-controlled loads has largely focused on the start-stop control of fixed-frequency temperature-controlled loads, using duty cycle as the control variable and incorporating load thermal dynamic comfort constraints to control demand response. With advancements in science, technology, and the economy, the market share of variable-frequency temperature-controlled loads has been steadily increasing; for example, variable-frequency air conditioners saw their market share rise from 57.9% in 2014 to 77.3% in 2019. Variable-frequency temperature-controlled loads, by adjusting compressor speed through inverters, can achieve flexible and continuous adjustment of operating frequency. Compared to the on / off start-stop mode of fixed-frequency temperature-controlled loads, they consume less energy, provide higher user thermal comfort, and further enhance the flexibility of the power system when participating in demand response. For variable-frequency temperature-controlled loads, coarse start-stop control not only affects equipment lifespan but also reduces user load performance; therefore, research on demand response for variable-frequency temperature-controlled loads has significant practical implications.

[0004] Existing variable frequency temperature-controlled load demand response technologies employ a stochastic control strategy for large-scale distributed temperature-controlled loads. This involves randomly defining demand response thresholds for these loads. When a system characteristic reaches the threshold, the load cluster randomly initiates demand response, providing regulation capabilities to the power system. While this method ensures an equal probability of demand response for each terminal load, the total number of load clusters responding based on the stochastic control strategy is relatively large, making it impossible to optimize the overall user comfort level.

[0005] Therefore, how to optimize the number of demand responses for variable frequency temperature-controlled loads and achieve a win-win situation for both demand response and user comfort is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to propose an application scenario and control method for the state queue model in demand response of variable frequency temperature-controlled loads, enabling control of large-scale distributed temperature-controlled loads based on state queue priorities. A state queue algorithm for demand response control of variable frequency temperature-controlled load clusters is designed to provide regulation capabilities for the power system.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] The application of the state queue model in demand response of variable frequency temperature-controlled loads includes the following steps:

[0009] (1) Establish a room thermal-electric equivalent model for typical temperature-controlled loads;

[0010] a. Use the first-order equivalent thermal parameter (ETP) model to describe the changes in indoor temperature of a building under the influence of indoor and outdoor heat sources such as indoor equipment and outdoor temperature;

[0011] b. Operating power P of a typical variable frequency temperature-controlled load IAC and cooling capacity Q IAC With the compressor operating frequency f IAC The fitted functional relationship describes the load power operation model.

[0012] (2) Establish a demand response control model for variable frequency temperature-controlled loads under an equal-duration control strategy:

[0013] a. Define the demand response state variable for variable frequency temperature-controlled load clusters as follows:

[0014]

[0015] b. Determine the operating frequency of the variable frequency temperature-controlled load cluster during demand response based on the equal-duration control strategy:

[0016] b1. Select the fixed demand response control duration Δt for the load cluster;

[0017] b2. Calculate the adjustable indoor temperature ΔT based on the operating status of the load cluster. in :

[0018]

[0019] b3. The cooling capacity during the controlled stage of the demand response of variable frequency temperature-controlled loads is calculated based on the differential equation of the first-order ETP model.

[0020] b4. The operating frequency of the variable frequency temperature-controlled load compressor is calculated based on the load power operation model.

[0021] c. Determine the operating frequency during the demand response recovery phase of variable frequency temperature-controlled loads:

[0022] c1. Select a fixed demand response control duration of 2Δt for the load cluster;

[0023] c2. Set the target value for indoor temperature recovery ΔT in :

[0024] ΔT in =T up -T down

[0025] c3. Calculate the cooling capacity during the demand response recovery phase of variable frequency temperature-controlled loads based on the differential equation of the first-order ETP model.

[0026] c4. The operating frequency of the variable frequency temperature-controlled load compressor is calculated based on the load power operation model.

[0027] (3) Establish a state queue model for the variable frequency temperature control load cluster.

[0028] a. Determine the upper and lower limits (T) of indoor temperature for comfort constraints in rooms with typical temperature control loads. up and T down Temperature setpoint T set ;

[0029] b. Define the state sequence of the thermal dynamic behavior of variable frequency temperature-controlled loads based on the state division method with equal temperature step size:

[0030] b1. Based on the range of indoor temperature variation under the constraints of room comfort under load, the thermal dynamic isotemperature step during the room temperature rise phase under load is divided into 1-5 states.

[0031] b2. Divide the thermal dynamic isothermal step of the indoor temperature reduction phase into 6-20 states;

[0032] b3. Define the load state sequence in a stable operating state as -21.

[0033] c. Calculate the real-time status sequence of the load cluster based on the temperature change status of the load room and the indoor temperature:

[0034] c1. Temperature step T of the load cluster in a temperature rise state rise for:

[0035]

[0036] Based on the current indoor temperature T of the load a Calculate the real-time state sequence S i for:

[0037]

[0038] c2. Temperature step T of the load cluster in a temperature drop state fall for:

[0039]

[0040] Based on the current indoor temperature T of the load a Calculate the real-time state sequence S i for:

[0041]

[0042] c3. The state sequence S of the load cluster in a stable operating state. i It is -21.

[0043] A demand response control method for large-scale distributed temperature-controlled loads under a state queue includes the following steps:

[0044] (1) In the building corresponding to the target power system, the variable frequency temperature control load whose current state is demand response state 1 is identified as the target variable frequency temperature control load;

[0045] (2) Determine the real-time variable frequency temperature control load operating status sequence;

[0046] (3) Determine the priority of variable frequency temperature control loads in demand response:

[0047] a. In the temperature rise state sequence 1-5, the priority level increases sequentially, with the load cluster in sequence 5 having the highest priority;

[0048] b. In the temperature drop state sequence 6-20, the priority level increases sequentially, with the load cluster in sequence 20 having the highest priority;

[0049] c. In the stable operation state - 21 sequence clusters, the adjustment power is ranked according to the first-order ETP model, with the one with the greater capacity having the highest priority.

[0050] (4) Determine the priority of response to the withdrawal of variable frequency temperature control loads:

[0051] a. In the temperature rise state sequence 1-5, the priority level decreases sequentially, with the load cluster in sequence 1 having the highest priority;

[0052] b. In the temperature drop state 6-20 sequence, the priority level decreases sequentially, and the load cluster in sequence 6 has the highest priority;

[0053] c. In the stable operation state - 21 sequence clusters, the adjustment power is ranked according to the first-order ETP model, with the lowest capacity having the highest priority.

[0054] This invention provides a state queue model for the application and control method of demand response for variable frequency temperature-controlled loads. It uses the operating frequency of the variable frequency temperature-controlled load as the control parameter and fixes the controlled duration before and after demand response of the load cluster. This achieves state segmentation with a fixed operating frequency before and after demand response of the variable frequency temperature-controlled load cluster, laying the foundation for the application of the state queue model in variable frequency temperature-controlled loads. The provided demand response control method for large-scale distributed temperature-controlled loads based on state queues prioritizes load cluster demand response capabilities, optimizing the total number of load cluster demand responses and achieving a win-win situation for both user comfort and demand response to a certain extent. Attached Figure Description

[0055] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0056] Figure 1 A schematic diagram of an equivalent thermodynamic parameter model provided for an embodiment;

[0057] Figure 2 A fitting graph showing the relationship between operating frequency, electrical power, and cooling capacity is provided for an embodiment.

[0058] Figure 3 A flowchart of a demand response control method for a variable frequency temperature-controlled load is provided as an example.

[0059] Figure 4 This is a schematic diagram of the operating frequency of a variable frequency temperature-controlled load under the control method.

[0060] Figure 5 This is a schematic diagram of the operating power of a variable frequency temperature-controlled load under the control method.

[0061] Figure 6 A schematic diagram of indoor temperature under the control method for variable frequency temperature control loads;

[0062] Figure 7 A state queue model diagram of a variable frequency temperature-controlled load is provided for an embodiment.

[0063] Figure 8 A schematic diagram of the state queue demand response priority for a variable frequency temperature-controlled load is provided for an embodiment.

[0064] Figure 9 A flowchart of a variable frequency temperature-controlled load demand response control method based on a state queue is provided for an embodiment.

[0065] Figure 10 For variable frequency temperature-controlled loads to participate in the power system frequency response under state queue priority control, the output change curve is adjusted.

[0066] Figure 11 The curve showing the change in grid frequency for variable frequency temperature-controlled loads participating in the power system frequency response under state queue priority control. Detailed Implementation

[0067] The embodiments of the present invention are implemented based on the technical solutions and detailed implementation methods are given, but the protection scope of the present invention is not limited to the following embodiments.

[0068] The application of the state queue model proposed in this invention in demand response of variable frequency temperature-controlled loads includes the following steps:

[0069] (1) Establish a room thermal-electric equivalent model for typical variable frequency temperature control loads;

[0070] The thermodynamic dynamic model of a room with variable frequency temperature control load is described using a first-order equivalent thermodynamic parameter (ETP) model. A simplified model of the indoor temperature change in the room under the influence of indoor equipment, outdoor temperature, and other indoor and outdoor heat sources is shown below. Figure 1 As shown. Write the first-order differential equation of the equivalent thermal parameter model:

[0071]

[0072] In the formula, Let t be the indoor temperature, in °C; Let t be the outdoor temperature at time t, in °C; R be the equivalent thermal resistance of the room, in °C / W; and C be the equivalent heat capacity of the indoor air, in J / °C. Let W be the cooling capacity of the air conditioner at time t.

[0073] make If dt = Δt, then the indoor temperature at time t + Δt is:

[0074]

[0075] like Figure 2As shown, the variable frequency air conditioner's power operation model uses the compressor's operating frequency as the control variable. During normal operation, room temperature control is achieved by adjusting the compressor's operating frequency. The air conditioner's operating power P... IAC and cooling capacity Q IAC With the compressor operating frequency f IAC The fitted functional relationship is:

[0076] P IAC =k P *f IAC +μ P

[0077] Q IAC =k q *f IAC +μ q

[0078] Where, k p k q μ p μ q This is the power coefficient.

[0079] (2) Establish a demand response control model for variable frequency temperature-controlled loads under an equal-duration control strategy:

[0080] Set the demand response status variable for the variable frequency temperature-controlled load cluster as follows:

[0081]

[0082] like Figure 3 The flow chart of the demand response control method for variable frequency temperature-controlled loads is as follows: Step 1: When the variable frequency temperature-controlled load cluster participates in demand response, it adopts equal-duration control and asynchronous input method.

[0083] The equal-duration control uses the load compressor frequency as the regulation parameter. The demand response control duration of the load cluster is a fixed value Δt. Under the condition of ensuring that the pre-set upper and lower temperature limits are met, it operates at a fixed frequency higher than the minimum frequency. The adjustable value of the indoor temperature is set as follows:

[0084] ΔT in =T max -T set

[0085] The cooling capacity Q during the controlled phase of the demand response of variable frequency temperature-controlled loads can be calculated using the first-order ETP model. IAC (Δt):

[0086]

[0087] Based on the load power operation model, the frequency and operating power of the compressor for variable frequency temperature-controlled loads can be obtained:

[0088]

[0089]

[0090] This provides the system with adjustment capabilities, such as Figure 4 , 5 The curve for the controlled demand response stage is shown in section 6.

[0091] Step 2: When exiting demand response, control the room temperature recovery phase of the fixed load for 2Δt, so that the variable frequency load resumes normal operation at a fixed frequency lower than the highest frequency.

[0092] After a cluster of variable frequency (VFD) temperature-controlled loads responds, the system frequency gradually recovers, and the number of loads requiring regulation gradually decreases. However, when participating in power system demand response, VFD loads, due to their frequency-varying characteristics directly related to ambient temperature, experience a significant difference between the indoor temperature and the original set temperature after their participation ends. This causes the VFD loads to operate at full power to recover to the set temperature, resulting in a power rebound. This rebound characteristic leads to substantial power aggregation and rebound when a large cluster of VFD loads participates in power system demand response, easily generating new frequency fluctuations.

[0093] Therefore, by utilizing the adjustable operating frequency of variable frequency temperature-controlled loads, and by limiting the specific operating frequency of each temperature-controlled load during the demand response recovery period, the rebound power of each variable frequency temperature-controlled load can be effectively reduced. This avoids the power rebound effect of temperature-controlled load clusters and is easier to implement in practical engineering applications. The control duration for the load demand response recovery phase is set to 2Δt, and the indoor temperature change is:

[0094] ΔT in =T max -T min

[0095] Similarly, the cooling load Q of the air conditioning load after the adjustment is removed can be calculated using the first-order ETP formula. IAC (2Δt):

[0096]

[0097] Q IAC Substituting (2Δt) into the power operation model, the operating frequency f of the variable frequency temperature-controlled load during the recovery period after the demand response ends can be calculated. IAC (2Δt),

[0098]

[0099] f IACSubstituting (2Δt) into the power operation model, we can obtain the operating power P of the variable frequency temperature-controlled load during the recovery period after the demand response ends. IAC (Δt) is as follows:

[0100]

[0101] During the demand response recovery phase, the operating frequency of the variable frequency temperature control load is f. IAC (2Δt). The operating power of each temperature-controlled load is P. IAC (2Δt), the control effect under this control method is as follows: Figure 4 , 5 As shown in section 6, the demand response and recovery phase.

[0102] (3) Establish a state queue model for the variable frequency temperature control load cluster.

[0103] Set the thermal state sequence of variable frequency temperature control loads as follows: Figure 7 As shown in the figure. The vertical axis T up and T down T represents the upper and lower limits of indoor temperature based on room comfort constraints according to the load, respectively. set Set the temperature value for the user's room.

[0104] Based on the thermal dynamic behavior of variable frequency temperature-controlled loads, a load cluster state queue sequence is set. Considering the differences in the working nature of variable frequency temperature-controlled loads, the compressors of variable frequency temperature-controlled loads can flexibly adjust and change their operating frequency. Unlike the equal-duration division method in previous studies of fixed frequency temperature-controlled loads, this invention proposes to adopt an equal-temperature-step state division method. The thermal dynamics of variable frequency temperature-controlled loads are divided into different states such as -21 and 1-20 according to the difference between the upper and lower limits of room temperature for different loads, i.e., the range of indoor temperature variation under user comfort constraints. When determining the current state of the load cluster, it is first determined whether the load is in a temperature rise state, a temperature fall state, or a stable operating state of the variable frequency temperature-controlled load.

[0105] Assuming the temperature-controlled load is operating in cooling mode under normal conditions, then Figure 7 State sequences 1-5 represent low-frequency load operation with rising room temperature. Variable frequency temperature-controlled compressors operate at a lower frequency. When the system frequency recovers and downward adjustment is needed, the compressor frequency can be increased. Air conditioners in state 5 have the highest priority. The temperature step size T for each state is... rise for:

[0106]

[0107] Since variable frequency temperature control loads do not have on / off states to track, a state queue setting algorithm is proposed to set state variables based on the indoor temperature change trend. If an increase in indoor temperature is detected at a certain moment, the increase in indoor temperature is set to T. aThen the current load state sequence variable S i for:

[0108]

[0109] State sequence 6-20 represents a state where the load is running at high frequency and the room temperature is gradually decreasing. When the system frequency recovery requires upward adjustment capability, the compressor operating frequency can be reduced. Among these, the air conditioner in state 20 has the highest priority, with a temperature step size T. fall for:

[0110]

[0111] The real-time state sequence variable S of the load i for:

[0112]

[0113] Variable frequency temperature control loads operating in a stable state, i.e., loads whose indoor temperature is maintained around the set temperature value, have the highest demand response capability. Therefore, regardless of whether the system frequency recovery requires upward or downward adjustment capability, the priority of loads participating in demand response in this state should be the highest. Therefore, in the state coding, a special state number -21 is assigned to it. In the algorithm, the load cluster in this state is always kept under limited adjustment.

[0114] A demand response control method for large-scale distributed temperature-controlled loads under a state queue includes the following steps:

[0115] like Figure 8 The flowchart shown is for a variable frequency temperature-controlled load demand response control method based on a state queue.

[0116] Step 1: Upon receiving a disturbance, before the variable frequency temperature-controlled load cluster participates in the system demand response control, system initialization is performed. This includes determining the equivalent thermal resistance and capacity of the load building, the temperature setpoint and upper and lower limits, detecting the ambient temperature, and setting the load-side controller parameters. The number of variable frequency temperature-controlled load clusters available to participate in the power system demand response is also determined.

[0117] Step 2: Based on the thermal dynamics of the temperature-controlled load cluster, determine the real-time state queue sequence of the load cluster according to the method of dividing by equal temperature step size;

[0118] Step 3: The load-side control center receives real-time characteristic values ​​of power system demand. When the received system characteristic value exceeds the threshold for variable frequency temperature-controlled load clusters to participate in power system demand response regulation, the center begins to select variable frequency temperature-controlled loads to participate in demand response in response to the power demand required for the system to return to stable operation.

[0119] Step 4: Determine the demand response priority of variable frequency temperature-controlled load clusters. If the system requires load clusters to provide upward adjustment capability, assuming the variable frequency temperature-controlled loads are operating normally in cooling mode, then load clusters with state sequences of -21 and 6-20 should be selected. Among them, the load clusters in stable operation (state sequence -21) have the highest priority. Stable operation means that the variable frequency temperature-controlled loads maintain the indoor temperature around the set temperature. The priority of load clusters in the 6-20 state sequence increases sequentially, with state 20 having the highest priority. If the system requires load clusters to provide downward adjustment capability, assuming the variable frequency temperature-controlled loads are operating normally in cooling mode, then load clusters with state sequences of -21 and 1-5 should be selected. Similarly, the load clusters in stable operation (state sequence -21) have the highest priority; the priority of load clusters in the 1-5 state sequence increases sequentially, with state 5 having the highest priority. In particular, for load clusters in the stable operation state sequence, considering that the equivalent thermal resistance R and equivalent heat capacity C of different room loads are different, and that equivalent heat capacity and thermal resistance will affect the load demand response adjustment capability. Therefore, based on the maximum temperature control load demand response capability ΔP IAC_max Prioritize investments based on ranking, with those having greater adjustment capabilities being invested first. ΔP IAC_max To ensure the maximum load demand response capability while maintaining user comfort, a fixed demand response control duration for the load cluster is selected, and the temperature change is determined as ΔT. in =1 is calculated. The priority allocation of variable frequency temperature-controlled load clusters in demand response is illustrated as follows: Figure 9 As shown.

[0120] Step 5: Based on the power restoration requirements after system disturbance, select N according to the priority of the variable frequency temperature control load status queue. IAC Variable frequency temperature-controlled loads participate in demand response. The regulation capacity calculation follows the demand response control method for variable frequency temperature-controlled loads described earlier. Relying on information communication and intelligent control technologies, control commands are issued, and the load cluster participates in demand response, contributing system regulation power ΔP. IAC .

[0121] The load cluster status queue is continuously updated and iterated according to the control calculation cycle.

[0122] In addition, during the response process, the indoor temperature of the variable frequency temperature-controlled load is monitored in real time to see if it exceeds the upper or lower temperature limits set according to user comfort. If it does not exceed these limits, the temperature-controlled load continues to participate in providing system regulation; otherwise, the regulation ends and it returns to normal operation. Similarly, if the system characteristic value does not reach the demand response threshold, or if it recovers to stable operation after regulation, the load cluster operates normally.

[0123] This analysis takes the scenario of a variable frequency temperature-controlled load cluster participating in the frequency response of a power system under state queue control as an example.

[0124] Suppose that the power system is suddenly subjected to a power disturbance of 0.025 pu at t = 1s, causing a drop in system frequency. The power system urgently needs upward regulation capability. When the system frequency deviation reaches the response threshold, traditional generator sets and variable frequency temperature-controlled load clusters begin to respond, providing regulation capability for system frequency recovery. The regulation power curves of generator sets and variable frequency temperature-controlled load clusters are as follows: Figure 10 As shown.

[0125] It is evident that variable frequency temperature-controlled load clusters have shorter activation times and can respond flexibly and quickly to changes in system frequency. Therefore, variable frequency temperature-controlled load clusters can replace traditional generator sets to provide regulation capabilities for system frequency response. However, because load clusters under state queue strategy control must maintain the indoor temperature within the upper and lower limits to ensure user comfort, the demand response duration is limited. The demand response capability provided to the system in the subsequent stages of the response gradually decreases over time. In contrast, traditional generator sets can respond for a longer period, and while the output of the load cluster decreases, its regulation capability continuously increases, compensating for the power deficit caused by system disturbances.

[0126] The dynamic results of system frequency deviation after temperature-controlled load clusters participate in the power system frequency response are as follows: Figure 11 As shown, compared with the case where only traditional generator sets participate in the system frequency response, the simulation results show that when the regulation capacity required after a system disturbance is entirely provided by traditional generator sets, the maximum drop in system frequency deviation Δf is... nadir = -0.125Hz, the time t to reach the lowest frequency point nadir =5.0s; When the temperature-controlled load cluster participates in the power system frequency response with a 50% allocation ratio of regulation capacity, the maximum frequency deviation change of the system is Δf nadir = -0.090Hz, the time to reach the lowest point is shortened to t nadir =4.2s. It can be seen that the participation of temperature-controlled load clusters in the system frequency response under the state queue strategy can effectively reduce the maximum drop in power system frequency deviation, shorten the frequency regulation time, and the load clusters have less regulation inertia, enabling the system frequency to recover to a stable value more quickly.

Claims

1. The application of the state queue model in demand response of variable frequency temperature-controlled loads includes the following steps: (1) Establish a room thermo-electric equivalent model for typical variable frequency temperature control loads; a. Use the first-order equivalent thermal parameter (ETP) model, i.e., the first-order ETP model, to describe the changes in indoor temperature of a building under the influence of indoor and outdoor heat sources such as indoor equipment and outdoor temperature. b. Electric power used by a typical variable frequency type temperature controlled load P IAC and refrigeration capacity Q IAC and compressor operating frequency f IAC The fitted function describes the load power operating model; (2) Establish a demand response control model for variable frequency temperature-controlled loads under an equal-duration control strategy: a. Define the demand response state variable for variable frequency temperature-controlled load clusters as follows: b. Determine the operating frequency of the variable frequency temperature-controlled load cluster during demand response based on the equal-duration control strategy: b1. Selecting a load cluster fixed demand response control duration ; b2、According to the load cluster operation state, calculate the indoor temperature adjustable amount : in, T in Indoor temperature, T up This indicates the upper limit of indoor temperature based on the comfort constraints of the room where the load is located. T set Set the temperature value for the user's room; b3. The cooling capacity during the controlled stage of the demand response of variable frequency temperature-controlled loads is calculated based on the differential equation of the first-order ETP model. b4. Calculate the operating frequency of the variable frequency temperature-controlled load compressor based on the load power operation model; c. Determine the operating frequency during the demand response recovery phase of variable frequency temperature-controlled loads: c1. Select the fixed demand response control duration for the load cluster. ; c2. Set the target amount for indoor temperature recovery. : in, T down This indicates the lower limit of indoor temperature based on the comfort constraints of the room where the load is located; c3. Calculate the cooling capacity during the demand response recovery phase of variable frequency temperature-controlled loads based on the differential equation of the first-order ETP model. c4. Calculate the operating frequency of the variable frequency temperature-controlled load compressor based on the load power operation model; (3) Establish a state queue model for the variable frequency temperature control load cluster; a. Determine the upper and lower limits of indoor temperature for comfort constraints in rooms with typical temperature control loads. T up and T down Temperature setpoint T set ; b. Define the state sequence of the thermal dynamic behavior of variable frequency temperature-controlled loads based on the state division method with equal temperature step size: b1. Based on the range of indoor temperature variation under the constraints of room comfort under load, the thermal dynamic isotemperature step during the room temperature rise phase under load is divided into 1-5 states. b2. Divide the thermal dynamic isothermal step of the indoor temperature reduction phase into 6-20 states; b3. Define the load state sequence in a stable operating state as -21; c. Based on the load room temperature change status and the current indoor temperature T a Real-time status sequence of computing load cluster S i : c1. Temperature step size of the load cluster in a temperature rise state T rise for: Based on the current indoor temperature and load T a Calculate its real-time state sequence S i for: c2. Temperature step size of the load cluster in a temperature drop state T fall for: Based on the current indoor temperature and load T a Calculate its real-time state sequence S i for: c3. When the load is in a stable operating state, its real-time state sequence S i The value is set to -21, where each temperature rise and temperature fall sequence is based on the current indoor temperature. T a The isothermal step range is determined.

2. The application of the state queue model according to claim 1 in demand response of variable frequency temperature-controlled loads, characterized in that: Establish a first-order equivalent thermodynamic parameter model for variable frequency temperature-controlled loads and a power operation model based on linear function fitting; Using an equal-duration control strategy, the demand response control and recovery time of variable frequency temperature control load clusters are fixed, and the target amount of indoor temperature change is set. Based on the dynamic behavior of indoor temperature of the load cluster under the equal duration control strategy, and according to the equal temperature step size division method, the state queue sequence of the variable frequency temperature control load cluster is defined. The regulation capacity during the controlled phase of demand response and the operating power during the recovery phase are calculated using an equivalent thermodynamic parameter model and a power operation model.

3. A demand response control method for large-scale distributed temperature-controlled loads under a state queue, comprising the following steps: (1) Obtain the time of each frequency converter-type temperature control load in the building corresponding to the target power system at time. t Demand response state variables S IAC ( t ), in, S IAC ( t )=0 indicates normal operation. S IAC ( t )=1 indicates participation in demand response. S IAC ( t )=2 indicates the recovery phase after exiting the demand response; the demand response state variable S IAC ( t The variable frequency temperature control load with a value of 1 is identified as the target variable frequency temperature control load, and the current indoor temperature of each target variable frequency temperature control load is obtained. T a Indoor temperature limit T up Indoor temperature limit T down Temperature setpoint T set And the trend of indoor temperature change; the variable frequency temperature control load with the current demand response status of 1 is identified as the target variable frequency temperature control load; (2) The application of the state queue model according to claim 1 in the demand response of variable frequency temperature-controlled loads, based on the indoor temperature change trend and the current indoor temperature. T a Determine the real-time state sequence of each target variable frequency temperature control load. S i ; a. When the indoor temperature is rising, T down to T up The range of indoor temperature variation can be determined by the temperature rise step size. T rise Divide into 5 equal temperature rise ranges, and according to... T down to T up The five temperature rise intervals are sequentially numbered 1 to 5 according to the direction, based on the current indoor temperature. T a The temperature rise range determines the real-time state sequence. S i ; b. When the indoor temperature is dropping, T up to T down The range of indoor temperature variation can be determined by the temperature drop step size. T fall Divided into 15 equal temperature drop ranges, and according to... T up to T down The 15 temperature drop state intervals are sequentially numbered from 6 to 20 according to the direction, based on the current indoor temperature. T a The temperature drop range determines the real-time state sequence. S i ; c. When the compressor operating frequency of a variable frequency temperature control load maintains the indoor temperature at the set temperature value... T set When the location is nearby, determine that the variable frequency temperature control load is in a stable operating state and record its real-time status sequence. S i The value is determined to be -21; where i is the target variable frequency temperature control load number; (3) The load-side control center receives the power system demand response characteristic value in real time. When the power system demand response characteristic value exceeds the threshold for variable frequency temperature-controlled loads to participate in demand response regulation, the priority of the target variable frequency temperature-controlled loads to participate in demand response is determined according to the regulation direction required for the system to restore stable operation. a. When the system requires the target variable frequency temperature-controlled load to provide upward regulation capability, the load power consumption is reduced by decreasing the compressor operating frequency, and a real-time state sequence is selected. S i For target variable frequency temperature control loads of -21°C and 6-20°C, the real-time status sequence is as follows: S i The highest priority is given to variable frequency temperature control loads with a target temperature of -21°C; for real-time status sequences... S i For target variable frequency temperature control loads with a state sequence of 6 to 20, the larger the state sequence value, the higher the priority for participating in demand response. Target variable frequency temperature control loads with a state sequence of 20 have the highest priority. b. When the system requires downward regulation capability from the target variable frequency temperature-controlled load, the load power consumption is increased by increasing the compressor operating frequency, and a real-time state sequence is selected. S i For target variable frequency temperature control loads of -21 and 1 to 5, the real-time status sequence is as follows: S i The highest priority is given to variable frequency temperature control loads with a target temperature of -21°C; for real-time status sequences... S i For target variable frequency temperature control loads with a state sequence of 1 to 5, the larger the state sequence value, the higher the priority of participating in demand response. Target variable frequency temperature control loads with a state sequence of 5 have the highest priority. c. For real-time state sequences S i For the target variable frequency temperature control load of -21, the loads are sorted from largest to smallest according to their maximum demand response capability. The larger the maximum demand response capability, the higher the priority of participating in demand response. (4) When the indoor temperature exceeds T up and T down Within a defined comfort range, control the corresponding target variable frequency temperature-controlled load to exit demand response and resume normal operation, and determine the priority of variable frequency temperature-controlled load exiting demand response: a. For real-time state sequences S i For target variable frequency temperature control loads with a state sequence of 1 to 5, the smaller the state sequence value, the higher the priority for exiting the demand response. Target variable frequency temperature control loads with a state sequence of 1 have the highest priority for exiting the demand response. b. For real-time state sequences S i For target variable frequency temperature control loads with a state sequence of 6 to 20, the smaller the state sequence value, the higher the priority for exiting the demand response. Target variable frequency temperature control loads with a state sequence of 6 have the highest priority for exiting the demand response. c. For real-time state sequences S i For the target variable frequency temperature control load of -21, the loads are sorted from smallest to largest according to their maximum load demand response capability. The smaller the maximum load demand response capability, the higher the priority of exiting demand response.

4. The demand response control method for large-scale distributed temperature-controlled loads under state queues according to claim 3, characterized in that: Based on the operating status of variable frequency temperature control loads, establish the demand response status variables for temperature control load clusters; The state queue sequence of the temperature control load cluster is calculated in real time based on the state queue model of the variable frequency temperature control load cluster. Determine the priority of load cluster demand response based on the status queue sequence of variable frequency temperature control load clusters; Based on the priority of the variable frequency temperature-controlled load cluster status queue, the power demand for stable system operation, and the indoor temperature comfort range requirements, the variable frequency temperature-controlled load is controlled to participate in or withdraw from demand response.

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