CN107247201A - Electric oven non-intruding discrimination method based on power and time response - Google Patents

Abstract

The invention discloses a non-invasive identification method for an electric oven based on power and time characteristics, which comprises the following steps: sampling the voltage and current signals of the incoming line of the total power supply to form a voltage signal sampling sequence u(k) and a current signal sampling sequence i(k); calculate real-time average active power sequence P(i) and real-time average reactive power sequence Q(i); calculate active power variation ΔP(i) and reactive power ΔQ(i); detect active power variation ΔP(i) and electrical operating time ΔT(i) determine the operation of the electric oven, and calculate the approximate rated power of the electric oven. The present invention solves the problems that current household appliances have many loads of intermittent operation, the steady-state characteristics of electric ovens are similar to other electrical appliances, and have no obvious transient characteristics. state, and provide the approximate rated power of the electric oven to realize the non-invasive identification of the electric oven.

Description

Non-invasive identification method of electric oven based on power and time characteristics

technical field

The invention belongs to the technical field of intelligent electricity utilization, and in particular relates to a non-invasive identification method for an electric oven based on power and time characteristics.

Background technique

Residential electricity consumption in my country presents the following characteristics: first, the growth rate is high, and residents accounted for 38% of the newly added electricity consumption in 2016; second, the behavior is complex, due to the large number of individuals and the variety of household appliances, the The behavior of electricity consumption is very complicated; third, the comprehensive energy consumption is high, and the comprehensive energy consumption of residential users is much higher than that of developed countries such as Japan. Residential power load monitoring and decomposition technology is an emerging smart grid basic support technology. Unlike the current smart meter that only measures the total power of users, it monitors and decomposes the start-up time, working status, and energy consumption of all electrical appliances in the household. As the goal, so as to achieve more reliable and accurate electric energy management. The power load monitoring and decomposition technology makes the user's electricity bill list like a telephone bill list, and the power consumption of various household appliances is clear at a glance, so that users can know their own electricity consumption in a timely manner, and provide a reasonable allocation of the electricity consumption time of each appliance and the corresponding consumption. The power supply provides a reference, and ultimately can effectively reduce electricity bills and waste of electricity. According to statistical data, if household users can keep abreast of the detailed electricity consumption information of residential electrical appliances, the monthly electricity bill can be reduced by 5% to 15%. If half the households in the United States save this much each month, the reduction in carbon emissions is equivalent to reducing the use of 8 million cars.

Currently, residential power load monitoring and decomposition technologies are mainly divided into two categories: Intrusive Load Monitoring and decomposition (ILMD) and Non-intrusive Load Monitoring and decomposition (NILMD):

(1) Intrusive Load Monitoring Decomposition Technology (ILMD): Intrusive load monitoring installs sensors with digital communication functions at the interface between each electrical appliance and the grid, which can accurately monitor the operating status and power consumption of each load. However, the installation of a large number of monitoring sensors results in high construction and maintenance costs. The most important thing is that intrusive load monitoring needs to be installed and debugged in residents' homes, which is likely to cause resistance from users.

(2) Non-intrusive load monitoring and decomposition technology (NILMD): only one sensor is installed at the user entrance, and the power consumption and working status of each or each type of electrical appliance in the room can be judged by collecting and analyzing information such as the total current and voltage of the entrance (For example, air conditioners have different working states such as cooling, heating, and standby), so as to obtain the electricity consumption rules of residents. Compared with intrusive load splitting, since only one monitoring sensor needs to be installed, the construction cost and subsequent maintenance difficulty of the non-intrusive load splitting scheme are greatly reduced; in addition, the sensor installation location can be selected at the user's meter box, which will not invade residents at all Construction is carried out indoors. It can be considered that NILMD uses a decomposition algorithm to replace the sensor network of the ILMD system, which has the advantages of simplicity, economy, reliability, data integrity, and easy rapid promotion and application. It is expected to develop into a new generation of core technology in the advanced measurement system (AMI) The NILMD algorithm can also be integrated into the chip of the smart meter), which supports advanced functions of smart power consumption such as demand side management and customized power, and is also suitable for temporary monitoring and investigation of load power consumption details.

Electric oven is a kitchen appliance that uses the radiant heat emitted by electric heating elements to bake food. The effective volume ranges from 13 liters to 34 liters, and the power is between 1000W-2000W. However, the oven is not always powered on when it is working, so high-power ovens do not It must consume more electricity than a low-power oven. The heating methods of the electric oven can be divided into three types: upper heat, lower heat alone, and upper and lower simultaneous heating. The temperature can generally be adjusted within the range of 50-250 °C.

To sum up, NILMD technology has gradually become a research hotspot, and the breakthrough and industrialization of related technologies are of great significance to the goal of energy conservation and emission reduction of the whole society. However, the current research on NILMD technology is still at the stage of theoretical research, and key technologies such as the decomposition and identification method of intermittent operating loads, especially hair dryers, have yet to be broken through.

Therefore, urgently need to solve the above-mentioned problem.

Contents of the invention

Purpose of the invention: The purpose of the invention is to provide a non-invasive identification method for an electric oven based on power and time characteristics that can accurately sense the operating state and rated power of the hair dryer.

Technical solution: To achieve the above objectives, the present invention discloses a non-invasive identification method for an electric oven based on power and time characteristics. The identification method includes the following steps:

(1) Within a certain sampling frequency range, the voltage and current signals of the main power supply line are sampled to form a voltage signal sampling sequence u(k) and a current signal sampling sequence i(k), where k is the sampling point number;

(2) Scan the collected voltage signal sampling sequence u(k) and current signal sampling sequence i(k), and calculate the real-time average active power sequence P(i) and real-time average reactive power sequence Q(i);

(3) Scan real-time average active power sequence P(i) and real-time average reactive power sequence Q(i) within a certain calculation time window, and calculate active power variation ΔP(i) and reactive power ΔQ(i);

(4) Detect whether the active power variation ΔP(i) is greater than 1000. If ΔP( _i )>1000, it is determined that the power has increased. The time of the increase is t _on (i). The lift value of ΔQ u is recorded as ΔQ _u , and ΔP _u , ΔQ _u , t _on (i) are recorded in the starter table;

(5) Detect whether the active power variation ΔP(i) is less than -1000, if ΔP(i)<-1000, then determine the power drop, record the drop time t _off (i), the drop value of active power ΔP _d , reactive power The drop value ΔQ _d of , traverse the starting electric meter, when the following criteria are met: |ΔP _u |≈|ΔP _d |>1000, |ΔQ _u |≈|ΔQ _d |≈0, go to step (6)

(6) Calculate the running time of the electrical appliance ΔT(i)=t _off (i)-t _on (i), if it satisfies 60s<ΔT<70s, ΔT ₁ ≈ΔT ₂ ≈...≈ΔT _n , it is determined that the electric oven is running, and Calculate the approximate rated power of the electric oven, otherwise return to step (2).

Wherein, the range of sampling frequency in the step (1) is f=0.5kHz～2kHz.

Preferably, the calculation formulas of the real-time average active power sequence P(i) and the real-time average reactive power sequence Q(i) in the step (2) are respectively

Among them, m is the number of power frequency cycles contained in the calculation time window, m=5, k is the number of sampling points, N is the number of sampling points contained in one power frequency cycle, N=1000×(f/50).

Furthermore, the calculation formulas of active power variation ΔP(i) and reactive power ΔQ(i) in the step (3) are respectively: ΔP(i)=P(i+1)-P(i), ΔQ (i)=Q(i+1)-Q(i), where i=1, 2, 3 . . .

Further, in the step (1), a voltage sensor and a current sensor are respectively used to sample the voltage and current signals of the main power incoming line.

Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The present invention provides a non-invasive identification method for electric ovens based on power and time characteristics, which solves the problem of the current intermittent operation load of household appliances, such as hair dryers. , electric ovens, microwave ovens, etc. The steady-state characteristics of electric ovens are similar to other electrical appliances, and there are no obvious transient characteristics and other problems. Through power changes and calculation time, the operation and state of electric ovens can be accurately sensed, and electric ovens can be provided. The approximate rated power provides technical support for the non-invasive identification of electric ovens.

Description of drawings

Fig. 1 is a schematic flow sheet of the present invention;

Fig. 2 is a calculation result diagram of real-time average active power in the non-intrusive identification method of electric oven operation based on load intermittent operation;

Fig. 3 is a diagram of the calculation results of real-time average reactive power in the non-intrusive identification method of electric oven operation based on intermittent load operation.

detailed description

The technical solution of the present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1 and Figure 2, the present invention discloses a non-invasive identification method for an electric oven based on power and time characteristics, and the specific process steps are as follows:

(1) Take the sampling frequency f=0.8kHz, use the current sensor and the voltage sensor to sample the voltage and current of the total power supply line, and form a voltage signal sampling sequence u(k) and a current signal sampling sequence i(k), where k is Sample point number.

(2) Take the calculation time window m=5 power frequency cycles, the number of sampling points contained in one power frequency cycle N=16, and calculate the real-time average active power sequence P(i) and reactive power sequence Q at the incoming line of the total power supply (i), where

The calculation formula of P(i) is

The formula for calculating Q(i) is

As shown in Figure 2, the operation mode of the electric oven is intermittent operation, and the operation time of each section is roughly equal, and the operation time of one operation is about 60s to 70s. There are multiple intermittent operation processes during the entire working process of the electric oven.

(3) Scan real-time average active power sequence P(i) and real-time average reactive power sequence Q(i) within a certain calculation time window, and calculate active power variation ΔP(i) and reactive power ΔQ(i), ΔP (i) is calculated as ΔP(i)=ΔP(i+1)-ΔP(i), and ΔQ(i) is calculated as ΔQ(i)=ΔQ(i+1)-ΔQ(i), where i=1,2,3...

As shown in Figure 2, the power of the electric oven is constantly changing during operation, and the active power intermittently appears a step-type start-stop process. The change of active power is about 1080W, while the reactive power fluctuates within 0 to -12W. The formula finds the values of ΔP(i) and ΔQ(i).

(4) Check whether the active power variation ΔP(i) is greater than 1000. If ΔP( _i )>1000, it is determined that the power has increased. The time of the increase is t _on (i). The lift value of ΔQ u is recorded as ΔQ _u , and ΔP _u , ΔQ _u , t _on (i) are recorded in the starter table;

Specifically, by detecting the value of ΔP(i) to identify whether the load is a power increase, if it is not a power increase, go to step (5), otherwise, record the time of increase as t _on (i), and record the active power increase value as ΔP _u , The reactive power rise value is recorded as ΔQ _u , and ΔP _u , ΔQ _u , t _on (i) are recorded in the starter table.

As shown in Figure 2 and Figure 3, the ΔP value of the electric oven at the step-up moment during operation is 1080W, which is greater than the threshold value of 1000W in the criterion, so it can be judged as a power rise, and the rise time is recorded as t _on (i), For t _on (1) and t _on (2) shown in the figure, the rising value of active power is recorded as ΔP _u (i), the rising value of reactive power is recorded as ΔQ _u (i), and ΔP _u (i ), ΔQ _u (i), t _on (i) are recorded in the starting electrical table.

(5) Detect whether the active power variation ΔP(i) is less than -1000, if ΔP(i)<-1000, then determine the power drop, record the drop time as t _off (i), the active power drop value is ΔP _d , the reactive power The power drop value is ΔQ _d , traverse the starting electric meter, when the following criteria are met: |ΔP _u |≈|ΔP _d |>1000, |ΔQ _u |≈|ΔQ _d |≈0, go to step (6);

Specifically, by detecting the value of ΔP(i) to identify whether the load is a power drop, if it is not a power drop, return to step (2), otherwise, record the drop time as t _off (i), and record the active power drop value as ΔP _d , The drop value of reactive power is recorded as ΔQ _d , and ΔP _d and ΔQ _d are recorded in the starter table.

As shown in Figure 2 and Figure 3, the active power increase value at t _on (1) is recorded as ΔP _u (1), the reactive power increase value is recorded as ΔQ _u (1), and the active power at t _off (1) The drop value is recorded as ΔP _d (1), and the reactive power drop value is recorded as ΔQ _d (1); the active power rise value at time t _on (2) is marked as ΔP _u (2), and the reactive power rise value is recorded as ΔQ _u (2), the active power drop value at t _off (2) is recorded as ΔP _d (1), and the reactive power drop value is recorded as ΔQ _d (1), and |ΔP _u (1)|≈|ΔP _d (1)|>1000, |ΔP _u (2)|≈|ΔP _d (2)|>1000, while the reactive power fluctuation is very small and can be approximately equal to 0, satisfying the criterion: |ΔP _u |≈|ΔP _d | >1000, |ΔQ _u |≈|ΔQ _d |≈0, go to step (6).

(6) Calculate the running time of the electrical appliance ΔT(i)=t _off (i)-t _on (i), if it satisfies 60s<ΔT<70s, ΔT ₁ ≈ΔT ₂ ≈...≈ΔT _n , it is determined that the electric oven is running, and Calculate the approximate rated power of the electric oven, otherwise return to step (2).

Specifically, calculate the operating time of the electric oven according to the formula, as shown in Figure 2 and Figure 3, ΔT(1)=t _off (1)-t _on (1), ΔT(2)=t _off (2)-t _on (2) If the electric appliance operates at approximately equal intervals, and the duration of each intermittent operation is 60s to 70s, it can be judged that the electric oven is operating, and the approximate rated power P _ss of the electric oven can be obtained.

As shown in Figure 2 and Figure 3, if 60s≤ΔT ₁ =ΔT ₂ ...=ΔT _n ≤70s, it can be considered that there is an electric oven running, and the approximate rated electric power of the electric oven is 1080W.

It should be pointed out that those skilled in the art can make some improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention. All components that are not specified in this embodiment can be realized by existing technologies.

Claims (5)

1. a kind of electric oven non-intruding discrimination method based on power and time response, it is characterised in that：The discrimination method includes Following steps：

(1) in the range of certain sample frequency, the voltage and current signal of general supply inlet wire is sampled, voltage signal is formed Sample sequence u (k) and current signal sample sequence i (k), k is sampling point number；

(2) the voltage signal sampling sequence u (k) that scanning collection is arrived and current signal sample sequence i (k), calculating averagely has in real time Work(power sequence P (i) and real-time average reactive power sequence Q (i)；

(3) necessarily calculating in time window, scanning real-time average active power sequence P (i) and real-time average reactive power sequence Q (i) is arranged, active power variation delta P (i) and reactive power Δ Q (i) is calculated；

(4) whether detection active power variation delta P (i) is more than 1000, if Δ P (i)>1000 judgement power liftings, lifting Moment is t_on(i), the lifting value of active power is designated as Δ P_u, the lifting value of reactive power is designated as Δ Q_u, and by Δ P_u、ΔQ_u、t_on (i) startup electrical equipment table is charged to；

(5) whether detection active power variation delta P (i) is less than -1000, if Δ P (i)<- 1000 judgement power fall downs, Record falls moment t_off(i), active power falls value Δ P_d, reactive power falls value Δ Q_d, traversal startup electrical equipment table, when Meet following criterion：|ΔP_u|≈|ΔP_d|>1000, | Δ Q_u|≈|ΔQ_d| ≈ 0, go to step (6)

(6) electric operation duration Δ T (i)=t is calculated_off(i)-t_on(i), if meeting 60s<ΔT<70s, Δ T₁≈ΔT₂≈… ≈ΔT_n, then judgement electric oven is run, and calculates the approximate rated power of electric oven, otherwise return to step (2).

2. the electric oven non-intruding discrimination method according to claim 1 based on power and time response, it is characterised in that： Sample frequency scope in the step (1) is f=0.5kHz~2kHz.

3. the electric oven non-intruding discrimination method according to claim 1 based on power and time response, it is characterised in that： The calculating of real-time average active power sequence P (i) and real-time average reactive power sequence Q (i) described in the step (2) is public Formula is respectively

<mrow> <mi>P</mi> <mrow> <mo>(</mo> <mi>i</mi> <mo>)</mo> </mrow> <mo>=</mo> <mfrac> <mn>1</mn> <mrow> <mi>m</mi> <mi>N</mi> </mrow> </mfrac> <munderover> <mo>&amp;Sigma;</mo> <mi>k</mi> <mrow> <mi>k</mi> <mo>+</mo> <mi>m</mi> <mi>N</mi> </mrow> </munderover> <mi>u</mi> <mrow> <mo>(</mo> <mi>k</mi> <mo>)</mo> </mrow> <mo>*</mo> <mi>i</mi> <mrow> <mo>(</mo> <mi>k</mi> <mo>)</mo> </mrow> </mrow>

<mrow> <mi>Q</mi> <mrow> <mo>(</mo> <mi>i</mi> <mo>)</mo> </mrow> <mo>=</mo> <mfrac> <mn>1</mn> <mrow> <mi>m</mi> <mi>N</mi> </mrow> </mfrac> <msqrt> <mrow> <munderover> <mo>&amp;Sigma;</mo> <mi>k</mi> <mrow> <mi>k</mi> <mo>+</mo> <mi>m</mi> <mi>N</mi> </mrow> </munderover> <mi>u</mi> <msup> <mrow> <mo>(</mo> <mi>k</mi> <mo>)</mo> </mrow> <mn>2</mn> </msup> <mo>*</mo> <munderover> <mo>&amp;Sigma;</mo> <mi>k</mi> <mrow> <mi>k</mi> <mo>+</mo> <mi>m</mi> <mi>N</mi> </mrow> </munderover> <mrow> <mi>i</mi> <msup> <mrow> <mo>(</mo> <mi>k</mi> <mo>)</mo> </mrow> <mn>2</mn> </msup> </mrow> <mo>-</mo> <msup> <mrow> <mo>(</mo> <munderover> <mo>&amp;Sigma;</mo> <mi>k</mi> <mrow> <mi>k</mi> <mo>+</mo> <mi>m</mi> <mi>N</mi> </mrow> </munderover> <mi>u</mi> <mo>(</mo> <mi>k</mi> <mo>)</mo> <mo>*</mo> <mi>i</mi> <mo>(</mo> <mi>k</mi> <mo>)</mo> <mo>)</mo> </mrow> <mn>2</mn> </msup> </mrow> </msqrt> </mrow>

Wherein, m is calculates the number of power frequency period contained by time window, and it is sampling point number to take m=5, k, and N is a power frequency week The sampled point number that phase includes, N=1000 × (f/50).

4. the electric oven non-intruding discrimination method according to claim 1 based on power and time response, it is characterised in that： Active power variation delta P (i) and reactive power Δ Q (i) calculation formula is respectively in the step (3)：Δ P (i)=P (i + 1)-P (i), Δ Q (i)=Q (i+1)-Q (i), wherein i=1,2,3 ....

5. the electric oven non-intruding discrimination method according to claim 1 based on power and time response, it is characterised in that： Voltage sensor and current sensor is respectively adopted in the step (1) to adopt the voltage and current signal of general supply inlet wire Sample.