WO2019128844A1

WO2019128844A1 - Non-invasive identification method of microwave oven operation based on hybrid criteria

Info

Publication number: WO2019128844A1
Application number: PCT/CN2018/122388
Authority: WO
Inventors: 邓士伟; 傅萌; 苗青; 耿树军; 冯燕钧; 何朝伟
Original assignee: 江苏智臻能源科技有限公司
Priority date: 2017-12-26
Filing date: 2018-12-20
Publication date: 2019-07-04
Also published as: CN108152574A; SG11201910685VA

Abstract

Provided is a non-invasive identification method of microwave oven operation based on hybrid criteria, wherein the method includes the following steps: sampling voltage and current signals of a main power inlet wire to form a voltage signal sampling sequence u and a current signal sampling sequence i; calculating active power variation delta P(i) and reactive power variation delta Q(i); determining the rising or falling of power through the power variation, and storing the active power rising value delta P_u(i), the reactive power rising value delta Q_u(i) and the rising time T_on(i) in a started electric appliance list, when reactive power rises; and recording the active power falling value delta P_d(i), the reactive power falling value delta Q_d (i) and the falling time T _off(i) when active power falls, and matching the load information in the started electric appliance list, and determining the operation of a microwave oven and calculating the similar rated power of the microwave oven according to the active power, reactive power and time characteristics of the load. By means of the method, the operation of the microwave oven can be accurately sensed, and technological support is provided for non-invasive identification of the microwave oven .

Description

Non-intrusive identification method for microwave oven operation based on mixing criterion

Technical field

The invention belongs to the technical field of intelligent electricity, and relates to a non-intrusive identification method for operating a microwave oven based on a mixing criterion.

Background technique

China's residential electricity currently presents the following characteristics: First, the growth rate is high. In 2016, the proportion of residents' newly-occupied electricity consumption is as high as 38%. Second, the behavior is complicated. Due to the large number of individuals, there are many types of household appliances, and the users are The use of electricity 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. Resident power load monitoring and decomposition technology is an emerging smart grid basic support technology. Unlike current smart meters, which measure only the total user power, it monitors and decomposes the startup time, working status and energy consumption of all electrical appliances in the household. Targeted to achieve more reliable and accurate electrical energy management. The power load monitoring and decomposition technology makes the user's electricity bill list like the telephone bill list, and the power consumption of various household appliances is clear at a glance, so that the user can know his power usage in time, and reasonably allocate the power consumption time of each appliance and the corresponding use. The power supply provides a reference, which can effectively reduce electricity expenses and waste of electricity. According to statistics, if household users can keep abreast of the detailed electricity consumption information of residential appliances, they can reduce monthly electricity bills by 5% to 15%. If half of the households in the United States save so much money each month, the reduction in carbon emissions is equivalent to reducing the use of 8 million cars.

At present, residential power load monitoring and decomposition technology is mainly divided into two categories: Intrusive Load Monitoring and Decomposition (ILMD) and Non-intrusive Load Monitoring and Decomposition (NILMD):

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

(2) Non-intrusive load monitoring and decomposition technology (NILMD): Install a sensor only at the user's entrance, and collect and analyze the total current, voltage and other information of the inlet to determine the power consumption and working status of each or every type of electrical appliance in the household. (For example, the washing machine has different working states such as washing, rinsing, dehydration, etc.), thereby obtaining the electricity consumption law of the residents. Compared with intrusive load decomposition, since only the sensor needs to be installed at the power inlet, the construction cost and post-maintenance difficulty of the non-intrusive load decomposition scheme are greatly reduced; in addition, the sensor installation position can be selected at the user meter box, and it will not Invade the residents to carry out construction. It can be considered that NILMD replaces the sensor network of ILMD system with decomposition algorithm, which has the advantages of simplicity, economy, reliability, data integrity and easy promotion and application. It is expected to develop into a new generation of core technology in advanced measurement system (AMI). The NILMD algorithm can also be integrated into the chip of a smart meter. It supports the advanced functions of smart power such as demand side management and custom power package, and is also suitable for temporary load power detail monitoring and investigation.

A microwave oven is a cooking appliance that uses food to absorb microwave energy in a microwave field to heat itself. The microwave generated by the microwave generator in the microwave oven establishes a microwave electric field in the cavity of the microwave oven, and takes certain measures to make the microwave electric field be evenly distributed in the furnace cavity, put the food into the microwave electric field, and control the cooking time by the control center. And microwave electric field strength to carry out a variety of cooking processes. The power range of a microwave oven is generally 800 to 1500 watts.

In summary, 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 in the whole society. However, the research on NILMD technology is still in the theoretical research stage, and key technologies such as intermittent operation load, especially the decomposition identification method of microwave oven, have yet to be broken.

Therefore, there is a need for a non-invasive identification method for microwave oven operation to solve the above problems.

Summary of the invention

SUMMARY OF THE INVENTION It is an object of the present invention to provide a non-invasive identification method for operation of a microwave oven based on a mixing criterion in order to solve the above problems.

The present invention achieves the above objects by the following technical solutions:

A non-intrusive identification method for microwave oven operation based on a hybrid criterion includes the following steps:

1), under the sampling frequency f, the voltage and current signals at the power supply total line are sampled to form a voltage signal sampling sequence u(i) and a current signal sampling sequence i(i), where i is a sampling point number;

2) scanning the collected voltage signal sampling sequence u(i) and the current signal sampling sequence i(i) within the first time window, and calculating the real-time average active power sequence P(k) and the real-time average reactive power sequence Q (k), the first time window includes m power frequency periods, each power frequency period includes n sampling points, and k is a sampling point number of the average power sequence;

3) scanning the real-time average active power sequence P(k) and the real-time average reactive power sequence Q(k) in the second time window, and calculating the active power variation ΔP(k) and the reactive power variation ΔQ(k) ;

4) Detecting the reactive power change sequence ΔQ(t) in the tth time window, and if ΔQ(t)>700, determining the power uplift, the lifting time is T _on (i), and the active power lifting value is ΔP _u , the rise value of reactive power is recorded as ΔQ _u , and ΔP _u , ΔQ _u and _Ton (i) are recorded in the starter appliance table, go to step 5), otherwise go to step 2);

5) Detecting the active power change amount ΔP(t). If ΔP(t) <-1200, determine the power drop, the drop time is T _off (i), the active power drop value is ΔP _d , and the reactive power falls. The value is ΔQ _d , go to step 6), otherwise, go to step 2);

6) traversing the starter electrical meter, when |ΔP _d | / | ΔP _u | > 3 and | ΔQ _u | / | ΔQ _d | > 2, go to step 7), otherwise go to step 2);

7) Calculate the interval duration ΔT _i =T _off (i)-T _on (i) of the two power changes, and if 10s<ΔT _i <30s, determine that the microwave oven is running, otherwise return to step 2).

Further, the sampling frequency f in the step 1) ranges from 0.5 kHz to 2 kHz.

Further, the real-time average active power sequence P(k) and the real-time average reactive power sequence Q(k) in step 2) are calculated by the following formula:

Where m is the number of power frequency periods included in the first time window, i is the sampling point number, and n is the number of sampling points included in one power frequency period.

Further, the time length of the second time window in step 3) is n×T, where n is the number of sampling points included in one power frequency period, and T is a power frequency period.

Further, n = 1000 × (f / 50).

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

Further, the active power change amount ΔP(k) and the reactive power change amount ΔQ(k) in the step 3) are calculated by the following formula: ΔP(k)=P(k+1)-P(k), ΔQ (k) = Q(k + 1) - Q(k).

The invention has the beneficial effects that the non-intrusive identification method of the microwave oven operation based on the hybrid criterion of the invention fully considers the characteristics of the active power, the reactive power change and the running time characteristic when the microwave oven starts and stops, thereby accurately distinguishing the microwave oven and the inductive Working appliances (such as rice cookers, etc.) increase the accuracy of non-invasive identification of microwave ovens.

DRAWINGS

Figure 1 is a schematic flow chart of the present invention;

2 is a calculation result of real-time average active power of a non-intrusive identification method of a microwave oven based on a mixing criterion;

FIG. 3 is a graph showing calculation results of real-time average reactive power of a microwave oven non-intrusive identification method based on a mixing criterion.

Detailed ways

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

As shown in FIG. 1 , the non-intrusive identification method of the microwave oven based on the power phase change characteristic of the present invention has the following specific steps:

(1) taking the sampling frequency f=0.8 kHz, using the current sensor and the voltage sensor to sample the voltage and current of the total power incoming line, forming a voltage signal sampling sequence u(i) and a current signal sampling sequence i(i), i is Sample point number.

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

The formula for calculating P(k) is

The formula for calculating Q(k) is

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

As shown in Figure 2, the power of the microwave oven has been changing during operation. The active power and reactive power intermittently appear two step changes. The first stage of active power is raised by 220W, and the reactive power is raised by about 800Var. The second stage The active power is raised by 1020W; the reactive power is reduced by about 500Var, then the active power is stabilized at about 1300W, and the reactive power is stabilized at about 300Var. The values of ΔP(k) and ΔQ(k) are obtained according to the calculation formula.

(4) Detect the reactive power change sequence ΔQ(t) in the tth time window. If ΔQ(t)>700 is satisfied, the power rise is determined. The rise time is T _on (i), and the rise value of active power is recorded. For ΔP _u , the rise value of reactive power is recorded as ΔQ _u , and ΔP _u , ΔQ _u , T _on (i) are recorded in the startup appliance table, otherwise go to step (2);

Specifically, it is determined whether the load is power uplift by detecting the magnitude of ΔQ(t). If the power is not up, return to step (2). Otherwise, the lifting time is recorded as T _on (i), and the active increment is recorded as ΔP _u , reactive power. The increment is recorded as ΔQ _u .

As shown in Fig. 2 and Fig. 3, the microwave power rises 845Var instantaneously at the starting time, which is greater than the threshold value of 700Var in the criterion, so it can be judged that the power is raised, and the lifting time is recorded as T _on (1), ΔP _u ( 1) = 400W, ΔQ _u (1) = 845Var.

(5) Detect whether the active power change amount ΔP(t) satisfies ΔP(t)<-1200, if it is satisfied, record the drop time T _off (i), the active power drop value ΔP _d , and the reactive power drop value ΔQ _d Traversing the appliance table when the following criteria are met: |ΔP _d |/|ΔP _u |>3, |ΔQ _u |/|ΔQ _d |>2, going to step (6);

Specifically, it is determined whether the load is a power drop by detecting the ΔP(t) value, and if not, returning to step (2); otherwise, the change time is recorded as T _off (i), and the active increment is recorded as ΔP _d , and the power is increased. The amount is recorded as ΔQ _d , and ΔP _d , ΔQ _d , and T _off (i) are added to the starter meter.

As shown in Fig. 2 and Fig. 3, the active power at time T _off (1) drops by 1360W, while the reactive power at the same time drops by 295Var, and the active gain ΔP _d (1) = -1360W, the reactive power increment ΔQ _d (1)=-295Var, available |ΔP _d (1)|/|ΔP _u (1)|≈3.4>3,|ΔQ _u (1)|/|ΔQ _d (1)|≈2.86>2, The criterion is satisfied: |ΔP _d |/|ΔP _u |>3, |ΔQ _u |/|ΔQ _d |>2, and the process proceeds to step (6).

(6) Calculate the interval duration ΔT _i =T _off (i)-T _on (i), if 10s<ΔT _i <30s is satisfied, ΔT ₁ ≈ΔT ₂ ≈...≈ΔT _n determine the microwave oven operation and calculate the approximation of the microwave oven Rated power, otherwise return to step (2).

Specifically, the running time of the electrical appliance is calculated according to the formula, as shown in FIG. 2, ΔT ₁ =T _off (1)-T _on (1), ΔT ₂ =T _off (2)-T _on (2), and the electrical appliances are operated at approximately equal intervals. Each time the running time is 10s to 30s, it can be judged that the microwave oven is running, and the approximate rated power P _{s of the} microwave oven can be obtained _.

As shown in Fig. 2 and Fig. 3, 10s ≤ ΔT ₁ = ΔT ₂ ... = ΔT _n ≤ 30 s, it can be considered that there is a microwave oven operation, and the approximate electric power of the microwave oven is 1300 W.

Claims

A non-intrusive identification method for operating a microwave oven based on a hybrid criterion, comprising the steps of:

1), under the sampling frequency f, the voltage and current signals at the power supply total line are sampled to form a voltage signal sampling sequence u(i) and a current signal sampling sequence i(i), where i is a sampling point number;

2) scanning the collected voltage signal sampling sequence u(i) and the current signal sampling sequence i(i) within the first time window, and calculating the real-time average active power sequence P(k) and the real-time average reactive power sequence Q (k), the first time window includes m power frequency periods, each power frequency period includes n sampling points, and k is a sampling point number of the average power sequence;

3) scanning the real-time average active power sequence P(k) and the real-time average reactive power sequence Q(k) in the second time window, and calculating the active power variation ΔP(k) and the reactive power variation ΔQ(k) ;

4) Detecting the reactive power change sequence ΔQ(t) in the tth time window, and if ΔQ(t)>700, determining the power uplift, the lifting time is T on (i), and the active power lifting value is ΔP u , the rise value of reactive power is recorded as ΔQ u , and ΔP u , ΔQ u and Ton (i) are recorded in the starter appliance table, go to step 5), otherwise go to step 2);

5) Detecting the active power change amount ΔP(t). If ΔP(t) <-1200, determine the power drop, the drop time is T off (i), the active power drop value is ΔP d , and the reactive power falls. The value is ΔQ d , go to step 6), otherwise, go to step 2);

6) traversing the starter electrical meter, when |ΔP d | / | ΔP u | > 3 and | ΔQ u | / | ΔQ d | > 2, go to step 7), otherwise go to step 2);

7) Calculate the interval duration ΔT i =T off (i)-T on (i) of the two power changes, and if 10s<ΔT i <30s, determine that the microwave oven is running, otherwise return to step 2).
The method according to claim 1, wherein the sampling frequency f in the step 1) ranges from 0.5 kHz to 2 kHz.
The non-intrusive identification method for operating a microwave oven based on a hybrid criterion according to claim 1, wherein the real-time average active power sequence P(k) and the real-time average reactive power sequence Q(k) in step 2) are Calculated by the following formula:

Where m is the number of power frequency periods included in the first time window, i is the sampling point number, and n is the number of sampling points included in one power frequency period.
The non-intrusive identification method for operating a microwave oven based on a hybrid criterion according to claim 1, wherein the length of the second time window in step 3) is n×T, wherein n is a power frequency cycle. The number of sampling points included, T is the power frequency period.
A non-invasive identification method for operating a microwave oven based on a mixing criterion according to claim 3 or 4, wherein n = 1000 × (f / 50).
The non-intrusive identification method for operating a microwave oven based on a hybrid criterion according to claim 1, wherein the voltage sensor and the current sensor are used in step 1) to sample the voltage and current signals of the total power supply line.
The non-intrusive identification method for operating a microwave oven based on a hybrid criterion according to claim 1, wherein the active power change amount ΔP(k) and the reactive power change amount ΔQ(k) in the step 3) are calculated by the following formula: It is obtained that: ΔP(k)=P(k+1)-P(k), ΔQ(k)=Q(k+1)-Q(k).