Water flow rate and electric power combined decomposition method for electric water heater facing polymerization regulation

Abstract

A water flow rate and electric power joint decomposition method for electric water heaters facing aggregation regulation, the specific steps are as follows: step one, collecting individual water heater information; step two, receiving the aggregation regulation instruction of the scheduling unit; step three, electric water heater water flow rate decomposition; step four, electric water heater power decomposition; step five, control instruction issuing. The present application proposes a water flow rate and electric power joint decomposition method for electric water heaters facing aggregation regulation, on the basis of obtaining the aggregation regulation instruction and collecting individual water heater information, fully considering the water heater water time shift characteristic, realizing the water flow rate and electric power joint decomposition and instruction issuing of the water heater.

Description

Technical Field

[0001] This invention specifically relates to the field of electric water heater control and scheduling, and specifically designs a method for the joint decomposition of water flow rate and electrical power in electric water heaters for aggregated regulation. Background Technology

[0002] Electric water heaters can participate in electricity demand response by utilizing their heat storage capacity. In this process, it's necessary to optimize the aggregated regulation commands for the water heaters by incorporating external information, and to jointly decompose and distribute these aggregated regulation commands (water flow rate and electrical power) to individual water heaters. This patent addresses the problem of jointly decomposing and distributing aggregated regulation commands for electric water heaters. Based on collected information about individual water heaters, the total water flow rate issued by the scheduling unit is used as a basis to decompose the available water flow rate of water heaters at various times. The corresponding electrical power is then equivalently calculated based on the decomposed water flow rate information. Finally, using the total electrical power as a basis, the electrical power of water heaters available at various times is decomposed, providing a basis for distributing the joint water flow rate and electrical power commands to individual water heaters. This patent, based on comprehensive collection of individual water heater information and focusing on aggregated regulation commands, fully considers the shiftable nature of water usage time, achieving the joint decomposition and command distribution of water flow rate and electrical power for water heaters.

[0003] High penetration rates of renewable energy grid integration have exacerbated the volatility and uncertainty of power system operation. Against this backdrop, demand response technology has become a key strategy for improving the flexibility and stability of the power system.

[0004] Electric water heaters can utilize their heat storage capacity to participate in demand response, adjusting their own power consumption according to the needs of the power system, thereby achieving peak shaving and valley filling of the power system load.

[0005] To enable a large number of water heaters to participate in demand response, it is necessary to combine and decompose the water flow rate and power of individual water heaters and issue commands based on optimized scheduling and aggregated adjustment instructions.

[0006] However, most existing studies focus on electrical power, neglecting the joint decomposition of water flow rate and electrical power in water heaters and the issue of command issuance.

[0007] The differences compared to existing technologies are as follows:

[0008] In comparison with the technology of patent CN104482654A "Demand-Side Response Control Method and System for Electric Water Heaters Based on Temperature Control Load"

[0009] 1. Patent CN104482654A only collects the water usage status information of the water heater and does not consider the impact on the water flow rate of the water heater. In contrast, this invention takes into account the importance of water flow rate, and decomposes and issues commands for water flow rate and electrical power together, providing a basis for scheduling the water flow rate and electrical power of the water heater. Its advantage is that it can be applied to scenarios that require simultaneous adjustment of water flow rate and electrical power.

[0010] 2. In patent CN104482654A, the water usage status of the electric water heater at that moment is collected upon receiving a load adjustment command. Its drawback is that it fails to consider the variable nature of water usage time. In contrast, this invention collects the variable range of water heater usage time within a day, providing greater flexibility in water heater scheduling.

[0011] 3. In patent CN104482654A, the method aims to control the upper and lower limits of temperature and the on / off status of each electric water heater device, but it does not consider that in actual application scenarios, water heaters are difficult to control their on / off status in real time according to temperature changes. This invention, however, decomposes and issues commands to the water flow rate and electrical power of the water heater, making the adjustment of water flow rate and electrical power more practical in daily life.

[0012] In comparison with the technology of patent CN114200845A "Strategy for Cluster Consumption of New Energy by Electric Water Heaters Based on Smart Home Energy Consumption"

[0013] 1. Patent CN114200845A uses the electric power of the water heater as the scheduling quantity, considering only water consumption and other factors as influencing factors. In contrast, this invention fully considers the importance of regulating the water flow rate of the water heater, calculates the corresponding electric power under different water flow rates based on an equivalent model, and finally realizes the joint decomposition and command issuance of water flow rate and electric power, which can cope with scenarios that require simultaneous adjustment of water flow rate and electric power.

[0014] 2. In patent CN114200845A, the load group is clustered based on the dispatchable status, operating status, adjustable duration, and equipment comfort temperature difference information of the electric water heater, and overall control is performed based on the clustering results. This method cannot fully reflect the heterogeneity of water heaters. In contrast, this invention, based on obtaining aggregated scheduling instructions and collecting information from individual water heaters, enables the issuance and control of instructions to each individual water heater, achieving more precise scheduling. Summary of the Invention

[0015] To address the aforementioned technical problems, this invention proposes a method for the joint decomposition of water flow rate and power in electric water heaters for aggregated regulation. Based on obtaining aggregated regulation commands and collecting individual water heater information, this method fully considers the shiftable nature of water usage time in water heaters, thereby achieving the joint decomposition and command issuance of water flow rate and power in water heaters.

[0016] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0017] The specific steps of the method for jointly decomposing water flow rate and electrical power in an electric water heater for aggregate regulation are as follows:

[0018] Step 1: Collect individual water heater information;

[0019] Collect individual water heater information, including the individual water heater's tank volume V. tank,i The equivalent thermal resistance R of an individual water heater i The original faucet flow rate B of an individual water heater within a day tap0,i (t), the initial time of water use before translation t s0,i and the start time of water use t s,i The range of translational movement within a day [t] s,min,i ,t s,max,i ];

[0020] Step 2: Receive the aggregation and adjustment instructions from the scheduling unit;

[0021] Receive aggregated adjustment instructions for the electric water heater cluster from the scheduling unit, including the total water flow rate B of the electric water heaters. tap_agg (t) and total electric power P e_agg (t), serving as the basis for decomposing the water flow rate and electrical power of an individual electric water heater;

[0022] Step 3: Decompose the water flow rate of the electric water heater;

[0023] Assume the sum of the flow velocities of the individual electric water heaters after decomposition is B. tap_agg *(t) iterates through each time period within the scheduling period, with the sampling time t* gradually increasing from the starting time until the entire time window is traversed;

[0024] Step 4: Decompose the power consumption of the electric water heater;

[0025] Assume the sum of the electrical power of the individual electric water heaters after decomposition is P. e_agg *(t). Iterate through each time period within the scheduling period, with the sampling time t* gradually increasing from the starting time until the entire time window has been traversed;

[0026] Step 5: Issuance of control commands;

[0027] The B calculated in step three tap,i (t) and P calculated in step four e,i (t) The instructions are issued to each individual electric water heater, which then uses water and electricity according to the instructions, thereby achieving a total water flow rate of approximately B. tap_agg (t), the total electric power is approximately P e_agg The effect of (t).

[0028] As a further improvement to the present invention, the specific steps of step three are as follows;

[0029] a) Initialize B tap_agg *(t) and t*, B tap_agg *(t) is set to 0, and t* is set to the start time of the time window;

[0030] b) Filter available EWHs, i.e., t s,min,i ,t s,max,i The condition t*∈[t is satisfied s,min,i ,t s,max,i Assume that N are selected at time t*. a For each available individual electric water heater, perform the following operations:

[0031] c) Change the water usage start time of individual electric water heaters from t s0,i The flow velocity after translation is denoted as B. tap,i (t);

[0032] d) The corresponding flow rate B tap,i (t) is accumulated to B tap_agg Above *(t), the calculation formula is as follows:

[0033] B tap_agg *(t)=B tap_agg *(t)+B tap,i (t) (1)

[0034] e) Repeat steps c)-d) until condition B is met. tap_agg *(t*)>B tap_agg (t*), or the number of iterations reaches N. a ;

[0035] f)t* Proceed to the next moment;

[0036] g) Repeat b)-f) until t* has traversed the entire time window;

[0037] h) Record the current B tap,i (t) represents the flow rate of the individual water heater as a component.

[0038] As a further improvement to the present invention, step four is specifically as follows;

[0039] a) First initialize P e_agg * and t*, P e_agg *(t) is set to 0, and t* is set to the start time of the time window.

[0040] b) Count the number of electric water heaters for which the power decomposition results have not yet been obtained, and denote it as N. r Based on the water usage start time t of these electric water heaters s,i Sort them. Then, for each available individual electric water heater, perform the following operations:

[0041] c) B calculated based on step three tap,i (t) Calculate the equivalent water power P use,i (t), the calculation formula is:

[0042] P use,i (t)=cρB tap.i (t)(T exp,i -T inlet,i (2)

[0043] Where c is the specific heat capacity of water, ρ is the density of water, and T exp,i For the user's desired water temperature, T inlet,i The water temperature entering the water tank is the same as the temperature of the external cold water entering the tank.

[0044] d) Order and P e,i (t*)=P N,i P was calculated using a thermodynamic model of an individual electric water heater. e,i (t);

[0045] e) and add it to P e_agg Above *(t), the calculation formula is as follows:

[0046] P e_agg *(t)=P e_agg *(t)+P e,i (t) (3)

[0047] f) Repeat steps c)-e) until condition P is satisfied. e_agg *(t*)>P e_agg (t*) or the number of iterations reaches N. r ;

[0048] g)t* Proceed to the next moment;

[0049] h) Repeat b)-g) until t* has traversed the entire time window;

[0050] i) Record the current P e,i (t) represents the flow rate of the individual water heater as a component.

[0051] This patent provides a method for the combined decomposition of water flow rate and electrical power in an electric water heater for aggregate regulation. Compared with traditional methods, its main advantages include:

[0052] 1) The model fully collected information on individual water heaters and considered the characteristic that water usage time can be shifted, thus improving the accuracy of the model.

[0053] 2) It takes into account the joint decomposition and command issuance of water flow rate and power of water heater, and can cope with scenarios that require simultaneous adjustment of water flow rate and power. Attached Figure Description

[0054] Figure 1 Flowchart of the method for joint decomposition of water flow rate and electrical power in an electric water heater for aggregate regulation provided by the present invention;

[0055] Figure 2 This is a schematic diagram showing the breakdown of the water flow rate in the electric water heater in step three of this invention.

[0056] Figure 3 This is a schematic diagram showing the breakdown of the power consumption of the electric water heater in step four of this invention. Detailed Implementation

[0057] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0058] To enable those skilled in the art to more clearly understand the purpose, technical solution, and advantages of the invention, the invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0059] This invention aims to provide a method for the combined decomposition of water flow rate and electrical power in an electric water heater for aggregate regulation. Specifically, Figure 1 This invention provides a flowchart of a method for the combined decomposition of water flow rate and electrical power in an electric water heater for aggregate regulation. Figure 2 This is a schematic diagram illustrating the decomposition of water flow rate in the electric water heater in step three of this invention. Figure 3 This is a schematic diagram showing the breakdown of the power consumption of the electric water heater in step four of this invention.

[0060] The method includes the following steps:

[0061] Step 1: Collect individual water heater information;

[0062] Collect individual water heater information, including the individual water heater's tank volume V. tank,i The equivalent thermal resistance R of an individual water heater i The original faucet flow rate B of an individual water heater within a day tap0,i(t), the initial time of water use before translation t s0,i and the start time of water use t s,i The range of translational movement within a day [t] s,min,i ,t s,max,i ].

[0063] Step 2: Receive the aggregation and adjustment instructions from the scheduling unit;

[0064] Receive aggregated adjustment instructions for the electric water heater cluster from the scheduling unit, including the total water flow rate B of the electric water heaters. tap_agg (t) and total electric power P e_agg (t) serves as the basis for analyzing the water flow rate and electrical power of an individual electric water heater. For example... Figure 2 and Figure 3 The curve shown, Figure 2 and Figure 3 The total water flow rate B of the electric water heater is given respectively. tap_agg (t) and total electric power P e_agg Example of (t).

[0065] Step 3: Decompose the water flow rate of the electric water heater;

[0066] Assume the sum of the flow velocities of the individual electric water heaters after decomposition is B. tap_agg *(t) iterates through each time period within the scheduling period, with the sampling time t* gradually increasing from the starting time until the entire time window has been traversed.

[0067] Figure 2 The given instructions specify the operations to be performed when sampling time t* reaches a specific time, assuming that N samples are selected at time t*. a There are available individual electric water heaters, including the i-th electric water heater (satisfying the condition t*∈[t]). s,min,i ,t s,max,i When the i-th electric water heater is reached, the water usage start time of each individual electric water heater is changed from t. s0,i The flow velocity after translation is denoted as B. tap,i (t), and according to formula (1), the corresponding flow velocity B tap,i (t) is accumulated to B tap_agg Above *(t). If condition B is satisfied. tap_agg *(t*)>B tap_agg (t*) or the number of iterations reaches N. a If the condition is not met, proceed to the next time step; if not, perform the same operation on the next selected electric water heater.

[0068] The obtained B tap,i (t) represents the flow rate of the individual water heater after decomposition.

[0069] Step 4: Break down the power consumption of the electric water heater;

[0070] Assume the sum of the electrical power of the individual electric water heaters after decomposition is P. e_agg *(t). Iterates through each time period within the scheduling period, with the sampling time t* gradually increasing from the starting time until the entire time window has been traversed.

[0071] Figure 3 The operation to be executed when sampling time t* reaches a specific point is given. Assume that the number of electric water heaters for which the power decomposition result has not yet been obtained at sampling time t* is N. r The electric water heaters are categorized according to the start time t of water usage. s,i Sort the data. When the i-th electric water heater is reached, calculate B in step three. tap,i Based on (t), the equivalent water power P is calculated using formula (2). use,i (t). Based on this, let... and P e,i (t*)=P N,i And P was calculated using a thermodynamic model of an individual electric water heater. e,i (t). Accumulate it to P according to formula (3). e_agg Above *(t). If condition P is satisfied. e_agg *(t*)>P e_agg (t*) or the number of iterations reaches N. r If the condition is not met, proceed to the next time step; if not, perform the same operation on the next water heater.

[0072] The obtained P e,i (t) represents the flow rate of the individual water heater.

[0073] Step 5: Issuance of control commands;

[0074] The B calculated in step three tap,i (t) and P calculated in step four e,i (t) The instructions are issued to each individual electric water heater, which then uses water and electricity according to the instructions, thereby achieving a total water flow rate of approximately B. tap_agg (t), the total electric power is approximately P e_agg The effect of (t).

[0075] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any modifications or equivalent changes made based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

Claims

1. A method for the joint decomposition of water flow rate and electrical power in an electric water heater for aggregate regulation, characterized in that, The specific steps are as follows: Step 1: Collect individual water heater information; Collect individual water heater information, including the individual water heater's tank volume V. tank,i The equivalent thermal resistance R of an individual water heater i The original faucet flow rate B of an individual water heater within a day tap0,i (t), the initial time of water use before translation t s0,i and the start time of water use t s,i The range of translational movement within a day [t] s,min,i , t s,max,i ]; Step 2: Receive the aggregation and adjustment instructions from the scheduling unit; Receive aggregated adjustment instructions for the electric water heater cluster from the scheduling unit, including the total water flow rate B of the electric water heaters. tap_agg (t) and total electric power P e_agg (t), serving as the basis for decomposing the water flow rate and electrical power of an individual electric water heater; Step 3: Decompose the water flow rate of the electric water heater; Assume the sum of the flow velocities of the individual electric water heaters after decomposition is B. tap_agg *(t) iterates through each time period within the scheduling period, with the sampling time t* gradually increasing from the starting time until the entire time window is traversed; The specific steps of step three are as follows; a) Initialize B tap_agg *(t) and t*, B tap_agg *(t) is set to 0, and t* is set to the start time of the time window; b) Filter available EWHs, i.e., t s,min,i , t s,max,i The condition t*∈[t is satisfied s,min,i , t s,max,i Assume that N are selected at time t*. a For each available individual electric water heater, perform the following operations: c) Change the water usage start time of individual electric water heaters from t s0,i The flow velocity after translation is denoted as B. tap,i (t); d) The corresponding flow rate B tap,i (t) is accumulated to B tap_agg Above *(t), the calculation formula is as follows: （1） e) Repeat steps c)-d) until condition B is met. tap_agg *(t*)> B tap_agg (t*), or the number of iterations reaches N. a ; f) t* Proceed to the next moment; g) Repeat b)-f) until t* has traversed the entire time window; h) Record the current B tap,i (t) represents the flow rate of the individual water heater as a decomposed unit; Step 4: Decompose the power consumption of the electric water heater; Assume the sum of the electrical power of the individual electric water heaters after decomposition is P. e_agg *(t) iterates through each time period within the scheduling period, with the sampling time t* gradually increasing from the starting time until the entire time window is traversed; The specific steps of step four are as follows; a) First initialize P e_agg * and t*, P e_agg *(t) is set to 0, and t* is set to the start time of the time window; b) Count the number of electric water heaters for which the power decomposition results have not yet been obtained, and denote it as N. r Based on the water usage start time t of these electric water heaters s,i Sort them, and then perform the following operations for each available individual electric water heater: c) B calculated based on step three tap,i (t) Calculate the equivalent water power P use,i (t), the calculation formula is: （2） Where c is the specific heat capacity of water, ρ is the density of water, and T exp,i For the user's desired water temperature, T inlet,i The water temperature entering the water tank is the same as the temperature of the external cold water entering the tank. d) Let P e,i (t) = 0 for all t < t*, and P e,i (t*) = P N,i , and calculate P e,i (t) using the thermodynamic model of the individual electric water heater; e) and add it to P e_agg Above *(t), the calculation formula is as follows: （3） f) Repeat steps c)-e) until condition P is satisfied. e_agg *(t*)> P e_agg (t*) or the number of iterations reaches N. r ; g) t* Proceed to the next moment; h) Repeat b)-g) until t* has traversed the entire time window; i) Record the current P e,i (t) represents the flow rate of the individual water heater as a decomposed unit; Step 5: Issuance of control commands; The B calculated in step three tap,i (t) and P calculated in step four e,i (t) The instructions are issued to each individual electric water heater, which then uses water and electricity according to the instructions, thereby achieving a total water flow rate of approximately B. tap_agg (t), the total electric power is approximately P e_agg The effect of (t).

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