CN114966188B - Load start-stop identification method and system based on continuous power change - Google Patents

Abstract

The invention provides a load start-stop identification method and a system based on continuous power change, wherein the method comprises the following steps: the voltage and current signals are sampled synchronously at fixed time, and sampling data are stored; when judging transient load starting, the following steps are carried out: judging whether to jump to the working state by comparing the n second with the n-1 second active power or comparing the n second with the n-2 second active power; judging whether a load is started or not by further comparing the active power at the n+1th second and the n+2th second with the active power at the n-1 th second; when judging the slow-change load starting, the following steps are carried out: judging whether to jump to the working state by comparing the average value of the active power in the mth minute with the average value of the active power in the annular queue; by further comparing the average active power of the m+1th minute and the m+2th minute with the average active power in the annular queue, whether the load is started or not is judged.

Description

Load start-stop identification method and system based on continuous power change

Technical Field

The invention relates to the field of non-invasive load identification, in particular to a load start-stop identification method and system based on continuous change of power.

Background

The main object of non-intrusive load identification is household appliances. Traditional household appliances, such as electric kettles, electric heaters and the like, belong to transient loads, and the power of the traditional household appliances changes within tens of milliseconds. The frequency conversion technology is gradually and widely used in household appliances, such as a frequency conversion air conditioner, a frequency conversion washing machine and the like, the starting process is complicated and various, and the starting time is different from tens of milliseconds to minutes. In addition, the power change of the frequency conversion electric appliance in the starting process is not simple but only has two states of opening and closing, and the frequency conversion electric appliance has a plurality of power change modes such as continuous slow change, sudden increase and decrease, alternate change and the like.

The existing non-invasive load identification method for judging the load starting is generally to judge the load starting and stopping by adopting the power variation amplitude in fixed interval time, and the method is suitable for judging transient loads and loads operated in fixed cycle timing. For the change modes of slow load power change, sudden increase and decrease and the like, the method is difficult to reliably identify the start-stop state of the electric appliance, so that a method for judging transient and slow load start is required.

Disclosure of Invention

In order to solve the technical problems, the invention discloses a load start-stop identification method and a system based on continuous change of power, which are used for judging start-stop states of transient and variable frequency loads in non-invasive load identification, and solve the problem that the conventional method is difficult to reliably change modes such as slow change, sudden increase and sudden decrease of load power and the like.

In order to achieve the above purpose, the technical scheme of the invention provides a load start-stop identification method based on continuous power change, which comprises the following steps:

s1: the method comprises the steps of performing timing synchronous sampling on voltage and current signals, and storing sampling data into a ring queue, wherein:

S11: when judging transient load starting, taking T1 as a time interval to synchronously sample voltage and current signals at fixed time so as to calculate the current active power and store the current active power into a ring-shaped queue, wherein T1 is less than 1 second;

s12: when judging the starting of the slow-changing load, calculating an average value P '(m) of the continuous 60s active power P (m) every minute, and storing the average value P' (m) into a ring queue;

S2: judging whether to make the state machine module jump to the working state by comparing the data of the current state and the historical state, wherein:

s21: in making the determination of transient load start-up, it is determined whether to cause the state machine module to jump from the M1 state to the M3 state by comparing the n-th second with the n-1 th second active power or comparing the n-th second with the n-2 th second active power,

S22: when judging the starting of the slow-change load, judging whether to jump the state machine module from the M1 state to the M3 state by comparing the active power average value of the mth minute with the active power average value in the annular queue;

S3: if the state machine module enters the M3 state, further judging whether a load is started, wherein:

S31: when judging transient load starting, by further comparing the active power at n+1th and n+2th seconds with the active power at n-1 th seconds, whether or not load is started is judged,

S32: when judging the slow-change load starting, the average value of the active power in the (m+1) th minute and the (m+2) th minute is further compared with the average value of the active power in the annular queue to judge whether the load is started or not.

In a further technical solution, in step S21:

when the nth second is performed, the current active power is P (n), the active power P (n-1) is taken out of the annular queue when the nth second is performed, and the absolute value |deltaP (n-1) | of the difference value of the active power P and the active power P (n-1) is calculated;

if the value of I deltaP (n-1) is greater than the decision threshold Pgate, the state machine module jumps from the M1 state to the M3 state, and records P (n-1) as the pre-steady state power value;

If the value of the absolute value of the difference between the active power P (n-2) and the active power P (n-2) is taken out of the annular queue for n-2 seconds and calculated if the value of the absolute value of the difference is less than or equal to the judging threshold Pgate is less than or equal to the absolute value judging threshold Pgate, the state machine module jumps from the M1 state to the M3 state, records that the active power P (n-2) is a former steady-state power value, and otherwise, the M1 state is maintained.

In a further technical solution, in step S22: in the M-th minute, assuming that k active power averages exist in the annular queue, wherein k is greater than 2, calculating a difference value between the current active power average value P ' (M) and the active power average value in the annular queue, setting deltaP ' (M-i) =P ' (M) -P ' (i), wherein i is greater than or equal to 0 and less than or equal to k, if |deltaP ' (M-i) | is greater than a judgment threshold Pgate, a state machine module jumps from an M1 state to an M3 state, and recording pre-steady state average active power values P ' (i) and P ' (M); otherwise, the M1 state is maintained.

In a further technical solution, in step S31:

Assuming that the state machine module enters the M3 state in the nth second, and the pre-steady state active power value is P (n-1), and after operating for T2 seconds, t2=2×t1, taking active power values P (n+1) and P (n+2) in the nth and n+2seconds from the annular queue, and respectively calculating the absolute values of the differences between the two powers and the pre-steady state active power value P (n-1): deltaP (n+1) | and deltaP (n+2) |;

if the two values of the I deltaP (n+1) I and the I deltaP (n+2) I are larger than Pgate < 1 >, and the signs of the three differences deltaP (n-1), deltaP (n+1) and deltaP (n+2) are the same, judging that the transient starting exists; if the three difference signs are different, no judgment is made, and the state machine module jumps to the M1 state and enters the next detection.

In a further technical solution, in step S32:

Assuming that the state machine module enters an M3 state at the M-th minute, calculating the difference between the average active power of m+1 and m+2 minutes and the average active power P '(i) at the moment i at the m+2 minute, namely deltaP' (m+1-i) and deltaP '(m+2-i), and judging that a load is started if the 2 value is the same as the sign of deltaP' (M-i) and the absolute value of the 2 value is larger than a judging threshold Pgate; if any absolute value of the 2 values is not more than Pgate < 2 >, the state machine module jumps to the M1 state; if the sign of this 2 value is not the same as the sign of deltaP' (M-i), the state machine module jumps to the M1 state.

The embodiment of the invention also provides a load start-stop identification system based on continuous power change, which comprises the following steps: the device comprises a timing synchronous sampling module, a ring queue module and a state machine module; wherein,

The timing synchronous sampling module performs timing synchronous sampling on the voltage and current signals and stores sampling data into the annular queue module, wherein: when judging transient load starting, taking T1 as a time interval to synchronously sample voltage and current signals at fixed time so as to calculate the current active power and store the current active power into a ring-shaped queue module, wherein T1 is less than 1 second; when judging the starting of the slow-changing load, calculating an average value P '(m) of continuous 60s active power P (m) every minute, and storing the average value P' (m) into a ring queue module;

Determining whether to cause the state machine module to jump to the operating state by comparing the data of the current state and the historical state, wherein: when judging transient load starting, comparing the n-th second with the n-1 th second active power or comparing the n-th second with the n-2 nd second active power to judge whether to jump the state machine module from the M1 state to the M3 state; when judging the starting of the slow-change load, judging whether to jump the state machine module from the M1 state to the M3 state by comparing the active power average value of the mth minute with the active power average value in the annular queue;

When the state machine module enters the M3 state, further judging whether a load is started, wherein: when judging transient load starting, further comparing the active power in the n+1th and n+2th seconds with the active power in the n-1 th second to judge whether the load is started or not; when judging the slow-change load starting, the average value of the active power in the (m+1) th minute and the (m+2) th minute is further compared with the average value of the active power in the annular queue to judge whether the load is started or not.

In a further technical solution, when determining that the transient load is started, determining whether to cause the state machine module to jump to the operating state includes:

when the nth second is performed, the current active power is P (n), the active power P (n-1) is taken out of the annular queue when the nth second is performed, and the absolute value |deltaP (n-1) | of the difference value of the active power P and the active power P (n-1) is calculated;

if the value of I deltaP (n-1) is greater than the decision threshold Pgate, the state machine module jumps from the M1 state to the M3 state, and records P (n-1) as the pre-steady state power value;

If the value of the absolute value of the difference between the active power P (n-2) and the active power P (n-2) is taken out of the annular queue for n-2 seconds and calculated if the value of the absolute value of the difference is less than or equal to the judging threshold Pgate is less than or equal to the absolute value judging threshold Pgate, the state machine module jumps from the M1 state to the M3 state, records that the active power P (n-2) is a former steady-state power value, and otherwise, the M1 state is maintained.

In a further technical solution, when determining that the ramp load is started, determining whether to make the state machine module jump to the operating state includes:

In the M-th minute, assuming that k active power averages exist in the annular queue, wherein k is greater than 2, calculating a difference value between the current active power average value P ' (M) and the active power average value in the annular queue, setting deltaP ' (M-i) =P ' (M) -P ' (i), wherein i is greater than or equal to 0 and less than or equal to k, if |deltaP ' (M-i) | is greater than a judgment threshold Pgate, a state machine module jumps from an M1 state to an M3 state, and recording pre-steady state average active power values P ' (i) and P ' (M); otherwise, the M1 state is maintained.

In a further technical solution, when determining that the transient load is started, if the state machine module enters the M3 state, further determining whether there is a load start includes:

Assuming that the nth second enters an M3 state and the pre-steady state active power value is P (n-1), after operating for T2 seconds again, wherein t2=2×t1, taking active power values P (n+1) and P (n+2) at the nth+1 and n+2 seconds from the annular queue, and respectively calculating absolute values of differences between the two power values and the pre-steady state active power value P (n-1): deltaP (n+1) | and deltaP (n+2) |;

if the two values of the I deltaP (n+1) I and the I deltaP (n+2) I are larger than Pgate < 1 >, and the signs of the three differences deltaP (n-1), deltaP (n+1) and deltaP (n+2) are the same, judging that the transient starting exists; if the three difference signs are different, no judgment is made, and the state machine module jumps to the M1 state and enters the next detection.

In a further technical solution, when determining that the load is started slowly, if the state machine module enters the M3 state, further determining whether the load is started includes:

Assuming that the state machine module enters an M3 state at the M-th minute, calculating the difference between the average active power of m+1 and m+2 minutes and the average active power P '(i) at the moment i at the m+2 minute, namely deltaP' (m+1-i) and deltaP '(m+2-i), and judging that a load is started if the 2 value is the same as the sign of deltaP' (M-i) and the absolute value of the 2 value is larger than a judging threshold Pgate; if any absolute value of the 2 values is not more than Pgate < 2 >, the state machine module jumps to the M1 state; if the sign of this 2 value is not the same as the sign of deltaP' (M-i), the state machine module jumps to the M1 state.

Drawings

FIG. 1 is a schematic diagram of a transient load start decision process according to the present invention;

fig. 2 is a schematic diagram of a decision flow for slow load start according to the present invention.

Detailed Description

The technical scheme of the present invention will be further described with reference to specific examples, but the present invention is not limited to these examples.

The technical scheme of the invention provides a load start-stop identification method based on continuous power change, which comprises the following steps:

s1: the method comprises the steps of performing timing synchronous sampling on voltage and current signals, and storing sampling data into a ring queue, wherein:

S11: when judging transient load starting, taking T1 as a time interval to synchronously sample voltage and current signals at fixed time so as to calculate the current active power and store the current active power into a ring-shaped queue, wherein T1 is less than 1 second;

s12: when judging the starting of the slow-changing load, calculating an average value P '(m) of the continuous 60s active power P (m) every minute, and storing the average value P' (m) into a ring queue;

S2: judging whether to make the state machine module jump to the working state by comparing the data of the current state and the historical state, wherein:

s21: in making the determination of transient load start-up, it is determined whether to cause the state machine module to jump from the M1 state to the M3 state by comparing the n-th second with the n-1 th second active power or comparing the n-th second with the n-2 th second active power,

S22: when judging the starting of the slow-change load, judging whether to jump the state machine module from the M1 state to the M3 state by comparing the active power average value of the mth minute with the active power average value in the annular queue;

S3: if the state machine module enters the M3 state, further judging whether a load is started, wherein:

S31: when judging transient load starting, by further comparing the active power at n+1th and n+2th seconds with the active power at n-1 th seconds, whether or not load is started is judged,

S32: when judging the slow-change load starting, the average value of the active power in the (m+1) th minute and the (m+2) th minute is further compared with the average value of the active power in the annular queue to judge whether the load is started or not.

In a further technical solution, in step S21:

when the nth second is performed, the current active power is P (n), the active power P (n-1) is taken out of the annular queue when the nth second is performed, and the absolute value |deltaP (n-1) | of the difference value of the active power P and the active power P (n-1) is calculated;

if the value of I deltaP (n-1) is greater than the decision threshold Pgate, the state machine module jumps from the M1 state to the M3 state, and records P (n-1) as the pre-steady state power value;

If the value of the absolute value of the difference between the active power P (n-2) and the active power P (n-2) is taken out of the annular queue for n-2 seconds and calculated if the value of the absolute value of the difference is less than or equal to the judging threshold Pgate is less than or equal to the absolute value judging threshold Pgate, the state machine module jumps from the M1 state to the M3 state, records that the active power P (n-2) is a former steady-state power value, and otherwise, the M1 state is maintained.

In a further technical solution, in step S22: in the M-th minute, assuming that k active power averages exist in the annular queue, wherein k is greater than 2, calculating a difference value between the current active power average value P ' (M) and the active power average value in the annular queue, setting deltaP ' (M-i) =P ' (M) -P ' (i), wherein i is greater than or equal to 0 and less than or equal to k, if |deltaP ' (M-i) | is greater than a judgment threshold Pgate, a state machine module jumps from an M1 state to an M3 state, and recording pre-steady state average active power values P ' (i) and P ' (M); otherwise, the M1 state is maintained.

In a further technical solution, in step S31:

Assuming that the state machine module enters the M3 state in the nth second, and the pre-steady state active power value is P (n-1), and after operating for T2 seconds, t2=2×t1, taking active power values P (n+1) and P (n+2) in the nth and n+2seconds from the annular queue, and respectively calculating the absolute values of the differences between the two powers and the pre-steady state active power value P (n-1): deltaP (n+1) | and deltaP (n+2) |;

if the two values of the I deltaP (n+1) I and the I deltaP (n+2) I are larger than Pgate < 1 >, and the signs of the three differences deltaP (n-1), deltaP (n+1) and deltaP (n+2) are the same, judging that the transient starting exists; if the three difference signs are different, no judgment is made, and the state machine module jumps to the M1 state and enters the next detection.

In a further technical solution, in step S32:

Assuming that the state machine module enters an M3 state at the M-th minute, calculating the difference between the average active power of m+1 and m+2 minutes and the average active power P '(i) at the moment i at the m+2 minute, namely deltaP' (m+1-i) and deltaP '(m+2-i), and judging that a load is started if the 2 value is the same as the sign of deltaP' (M-i) and the absolute value of the 2 value is larger than a judging threshold Pgate; if any absolute value of the 2 values is not more than Pgate < 2 >, the state machine module jumps to the M1 state; if the sign of this 2 value is not the same as the sign of deltaP' (M-i), the state machine module jumps to the M1 state.

The embodiment of the invention also provides a load start-stop identification system based on continuous power change, which comprises the following steps: the device comprises a timing synchronous sampling module, a ring queue module and a state machine module; wherein,

The timing synchronous sampling module performs timing synchronous sampling on the voltage and current signals and stores sampling data into the annular queue module, wherein: when judging transient load starting, taking T1 as a time interval to synchronously sample voltage and current signals at fixed time so as to calculate the current active power and store the current active power into a ring-shaped queue module, wherein T1 is less than 1 second; when judging the starting of the slow-changing load, calculating an average value P '(m) of continuous 60s active power P (m) every minute, and storing the average value P' (m) into a ring queue module;

Determining whether to cause the state machine module to jump to the operating state by comparing the data of the current state and the historical state, wherein: when judging transient load starting, comparing the n-th second with the n-1 th second active power or comparing the n-th second with the n-2 nd second active power to judge whether to jump the state machine module from the M1 state to the M3 state; when judging the starting of the slow-change load, judging whether to jump the state machine module from the M1 state to the M3 state by comparing the active power average value of the mth minute with the active power average value in the annular queue;

When the state machine module enters the M3 state, further judging whether a load is started, wherein: when judging transient load starting, further comparing the active power in the n+1th and n+2th seconds with the active power in the n-1 th second to judge whether the load is started or not; when judging the slow-change load starting, the average value of the active power in the (m+1) th minute and the (m+2) th minute is further compared with the average value of the active power in the annular queue to judge whether the load is started or not.

In a further technical solution, when determining that the transient load is started, determining whether to cause the state machine module to jump to the operating state includes:

when the nth second is performed, the current active power is P (n), the active power P (n-1) is taken out of the annular queue when the nth second is performed, and the absolute value |deltaP (n-1) | of the difference value of the active power P and the active power P (n-1) is calculated;

if the value of I deltaP (n-1) is greater than the decision threshold Pgate, the state machine module jumps from the M1 state to the M3 state, and records P (n-1) as the pre-steady state power value;

If the value of the absolute value of the difference between the active power P (n-2) and the active power P (n-2) is taken out of the annular queue for n-2 seconds and calculated if the value of the absolute value of the difference is less than or equal to the judging threshold Pgate is less than or equal to the absolute value judging threshold Pgate, the state machine module jumps from the M1 state to the M3 state, records that the active power P (n-2) is a former steady-state power value, and otherwise, the M1 state is maintained.

In a further technical solution, when determining that the ramp load is started, determining whether to make the state machine module jump to the operating state includes:

In the M-th minute, assuming that k active power averages exist in the annular queue, wherein k is greater than 2, calculating a difference value between the current active power average value P ' (M) and the active power average value in the annular queue, setting deltaP ' (M-i) =P ' (M) -P ' (i), wherein i is greater than or equal to 0 and less than or equal to k, if |deltaP ' (M-i) | is greater than a judgment threshold Pgate, a state machine module jumps from an M1 state to an M3 state, and recording pre-steady state average active power values P ' (i) and P ' (M); otherwise, the M1 state is maintained.

In a further technical solution, when determining that the transient load is started, if the state machine module enters the M3 state, further determining whether there is a load start includes:

Assuming that the nth second enters an M3 state and the pre-steady state active power value is P (n-1), after operating for T2 seconds again, wherein t2=2×t1, taking active power values P (n+1) and P (n+2) at the nth+1 and n+2 seconds from the annular queue, and respectively calculating absolute values of differences between the two power values and the pre-steady state active power value P (n-1): deltaP (n+1) | and deltaP (n+2) |;

if the two values of the I deltaP (n+1) I and the I deltaP (n+2) I are larger than Pgate < 1 >, and the signs of the three differences deltaP (n-1), deltaP (n+1) and deltaP (n+2) are the same, judging that the transient starting exists; if the three difference signs are different, no judgment is made, and the state machine module jumps to the M1 state and enters the next detection.

In a further technical solution, when determining that the load is started slowly, if the state machine module enters the M3 state, further determining whether the load is started includes:

Assuming that the state machine module enters an M3 state at the M-th minute, calculating the difference between the average active power of m+1 and m+2 minutes and the average active power P '(i) at the moment i at the m+2 minute, namely deltaP' (m+1-i) and deltaP '(m+2-i), and judging that a load is started if the 2 value is the same as the sign of deltaP' (M-i) and the absolute value of the 2 value is larger than a judging threshold Pgate; if any absolute value of the 2 values is not more than Pgate < 2 >, the state machine module jumps to the M1 state; if the sign of this 2 value is not the same as the sign of deltaP' (M-i), the state machine module jumps to the M1 state.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The invention is composed of three modules, namely a timing synchronous sampling module, a ring queue module and a state machine module.

The timing synchronous sampling module is responsible for timing sampling voltage and current signals, and synchronous sampling can reduce phase errors of the voltage and current signals and improve the calculation accuracy of power.

The annular queue module is responsible for storing sampling data for data comparison of the current state and the historical state, and meanwhile limited RAM resources can be fully utilized.

The state machine module is responsible for managing and judging the working state of the electric appliance to be tested, so that the condition branch judgment is clearer, the entering condition of each working state is definitely specified, the task completed in the current working state and the condition of jumping to the next working state are completed.

The judging flow of transient load starting is shown in fig. 1, and the specific flow is as follows:

1) Taking T1 (T1 <1 second) as a time interval to sample voltage and current, calculating current active power P, and storing the current active power P in a ring queue;

2) At the nth second, the current active power P (n), the active power P (n-1) at the nth-1 second is taken out from the annular queue, and the absolute value |deltaP (n-1) | of the difference value of the current active power P (n) and the active power P (n-1) is calculated.

3) If the value of I deltaP (n-1) is larger than the decision threshold Pgate, jumping from the M1 state to the M3 state, and recording P (n-1) as a former steady-state power value;

4) If the value of deltaP (n-1) is less than or equal to the decision threshold Pgate1, the active power P (n-2) at the n-2 th second is taken out of the circular queue, the absolute value of the difference between the active power P (n-2) and P (n) is calculated, if the value of deltaP (n-2) is greater than decision threshold Pgate, then jump from M1 state to M3 state, record P (n-2) as the previous steady state power value, otherwise maintain M1 state.

5) Assuming that the nth second enters the M3 state and the pre-steady state active power value is P (n-1), after the system operates for T2 (t2=2× t1) seconds again, taking active power values P (n+1) and P (n+2) at the nth+1 and n+2 seconds from the annular queue, and calculating absolute values of differences between the 2 powers and the pre-steady state active power value P (n-1), respectively: deltaP (n+1) | and deltaP (n+2) |.

6) If both values of |deltaP (n+1) | and |deltaP (n+2) | are greater than Pgate < 1 >, and the three differences deltaP (n-1), deltaP (n+1) and deltaP (n+2) are the same sign, then a transient start is determined. If the three difference signs are different, no decision is made. At this time, the system will jump to the M1 state and enter the next detection.

The judging flow of the slow load starting is shown in fig. 2, and the specific flow is as follows:

1) The average value P' (m) of the continuous active power P (m) for 60s is calculated every minute and is saved to the annular queue.

2) In the M-th minute, assuming that k active power averages (k > 2) exist in the annular queue, calculating difference values between the current active power average value P ' (M) and the active power average value in the annular queue, setting deltaP ' (M-i) =P ' (M) -P ' (i), wherein i is more than or equal to 0 and less than or equal to k, if |deltaP ' (M-i) | is more than Pgate < 2 >, jumping from M1 to M3, and recording the pre-steady state average active power values P ' (i) and P ' (M); otherwise, the M1 state is maintained.

3) Assuming that the system has entered the M3 state at the mth minute and the mth+2th minute, calculating the difference between the average active power at the m+1 and m+2 times and the average active power at the i time P '(i), namely deltaP' (m+1-i) and deltaP '(m+2-i), and judging that the load is started if the 2 value is the same as the deltaP' (M-i) in sign and the absolute value of the 2 value is larger than Pgate 2; if any of the absolute values of the 2 values is not greater than Pgate < 2 >, the system jumps to M1; if the sign of this 2 value is not the same as the sign of deltaP' (M-i), the system jumps to M1.

The invention discloses a method for identifying start and stop of a load based on continuous change of power, which is used for judging start and stop states of transient and variable frequency loads in non-invasive load identification and solves the problem that the conventional method is difficult to reliably change modes such as slow change of load power, sudden increase and sudden decrease and the like.

The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and improvements could be made by those skilled in the art without departing from the inventive concept, which falls within the scope of the present invention.

Claims (10)

1. The load start-stop identification method based on continuous power change is characterized by comprising the following steps of:

s1: the method comprises the steps of performing timing synchronous sampling on voltage and current signals, and storing sampling data into a ring queue, wherein:

S11: when judging transient load starting, taking T1 as a time interval to synchronously sample voltage and current signals at fixed time so as to calculate the current active power and store the current active power into a ring-shaped queue, wherein T1 is less than 1 second;

s12: when judging the starting of the slow-changing load, calculating an average value P '(m) of the continuous 60s active power P (m) every minute, and storing the average value P' (m) into a ring queue;

S2: judging whether to make the state machine module jump to the working state by comparing the data of the current state and the historical state, wherein:

s21: in making the determination of transient load start-up, it is determined whether to cause the state machine module to jump from the M1 state to the M3 state by comparing the n-th second with the n-1 th second active power or comparing the n-th second with the n-2 th second active power,

S22: when judging the starting of the slow-change load, judging whether to jump the state machine module from the M1 state to the M3 state by comparing the active power average value of the mth minute with the active power average value in the annular queue;

S3: if the state machine module enters the M3 state, further judging whether a load is started, wherein:

S31: when judging transient load starting, by further comparing the active power at n+1th and n+2th seconds with the active power at n-1 th seconds, whether or not load is started is judged,

S32: when judging the slow-change load starting, the average value of the active power in the (m+1) th minute and the (m+2) th minute is further compared with the average value of the active power in the annular queue to judge whether the load is started or not.

2. The method according to claim 1, characterized in that in step S21:

when the nth second is performed, the current active power is P (n), the active power P (n-1) is taken out of the annular queue when the nth second is performed, and the absolute value |deltaP (n-1) | of the difference value of the active power P and the active power P (n-1) is calculated;

if the value of I deltaP (n-1) is greater than the decision threshold Pgate, the state machine module jumps from the M1 state to the M3 state, and records P (n-1) as the pre-steady state power value;

If the value of the absolute value of the difference between the active power P (n-2) and the active power P (n-2) is taken out of the annular queue for n-2 seconds and calculated if the value of the absolute value of the difference is less than or equal to the judging threshold Pgate is less than or equal to the absolute value judging threshold Pgate, the state machine module jumps from the M1 state to the M3 state, records that the active power P (n-2) is a former steady-state power value, and otherwise, the M1 state is maintained.

3. The method according to claim 1, characterized in that in step S22: in the M-th minute, assuming that k active power averages exist in the annular queue, wherein k is greater than 2, calculating a difference value between the current active power average value P ' (M) and the active power average value in the annular queue, setting deltaP ' (M-i) =P ' (M) -P ' (i), wherein i is greater than or equal to 0 and less than or equal to k, if |deltaP ' (M-i) | is greater than a judgment threshold Pgate, a state machine module jumps from an M1 state to an M3 state, and recording pre-steady state average active power values P ' (i) and P ' (M); otherwise, the M1 state is maintained.

4. The method according to claim 1, characterized in that in step S31:

Assuming that the state machine module enters the M3 state in the nth second, and the pre-steady state active power value is P (n-1), and after operating for T2 seconds, t2=2×t1, taking active power values P (n+1) and P (n+2) in the nth and n+2seconds from the annular queue, and respectively calculating the absolute values of the differences between the two powers and the pre-steady state active power value P (n-1): deltaP (n+1) | and deltaP (n+2) |;

if the two values of the I deltaP (n+1) I and the I deltaP (n+2) I are larger than Pgate < 1 >, and the signs of the three differences deltaP (n-1), deltaP (n+1) and deltaP (n+2) are the same, judging that the transient starting exists; if the three difference signs are different, no judgment is made, and the state machine module jumps to the M1 state and enters the next detection.

5. The method according to claim 1, characterized in that in step S32:

Assuming that the state machine module enters an M3 state at the M-th minute, calculating the difference between the average active power of m+1 and m+2 minutes and the average active power P '(i) at the moment i at the m+2 minute, namely deltaP' (m+1-i) and deltaP '(m+2-i), and judging that a load is started if the 2 value is the same as the sign of deltaP' (M-i) and the absolute value of the 2 value is larger than a judging threshold Pgate; if any absolute value of the 2 values is not more than Pgate < 2 >, the state machine module jumps to the M1 state; if the sign of this 2 value is not the same as the sign of deltaP' (M-i), the state machine module jumps to the M1 state.

6. A load start-stop identification system based on continuous power variation, comprising: the device comprises a timing synchronous sampling module, a ring queue module and a state machine module; wherein,

The timing synchronous sampling module performs timing synchronous sampling on the voltage and current signals and stores sampling data into the annular queue module, wherein: when judging transient load starting, taking T1 as a time interval to synchronously sample voltage and current signals at fixed time so as to calculate the current active power and store the current active power into a ring-shaped queue module, wherein T1 is less than 1 second; when judging the starting of the slow-changing load, calculating an average value P '(m) of continuous 60s active power P (m) every minute, and storing the average value P' (m) into a ring queue module;

Determining whether to cause the state machine module to jump to the operating state by comparing the data of the current state and the historical state, wherein: when judging transient load starting, comparing the n-th second with the n-1 th second active power or comparing the n-th second with the n-2 nd second active power to judge whether to jump the state machine module from the M1 state to the M3 state; when judging the starting of the slow-change load, judging whether to jump the state machine module from the M1 state to the M3 state by comparing the active power average value of the mth minute with the active power average value in the annular queue;

When the state machine module enters the M3 state, further judging whether a load is started, wherein: when judging transient load starting, further comparing the active power in the n+1th and n+2th seconds with the active power in the n-1 th second to judge whether the load is started or not; when judging the slow-change load starting, the average value of the active power in the (m+1) th minute and the (m+2) th minute is further compared with the average value of the active power in the annular queue to judge whether the load is started or not.

7. The system of claim 6, wherein in making the determination of transient load start-up, determining whether to cause the state machine module to jump to an operational state comprises:

when the nth second is performed, the current active power is P (n), the active power P (n-1) is taken out of the annular queue when the nth second is performed, and the absolute value |deltaP (n-1) | of the difference value of the active power P and the active power P (n-1) is calculated;

if the value of I deltaP (n-1) is greater than the decision threshold Pgate, the state machine module jumps from the M1 state to the M3 state, and records P (n-1) as the pre-steady state power value;

If the value of the absolute value of the difference between the active power P (n-2) and the active power P (n-2) is taken out of the annular queue for n-2 seconds and calculated if the value of the absolute value of the difference is less than or equal to the judging threshold Pgate is less than or equal to the absolute value judging threshold Pgate, the state machine module jumps from the M1 state to the M3 state, records that the active power P (n-2) is a former steady-state power value, and otherwise, the M1 state is maintained.

8. The system of claim 6, wherein in making the determination of the ramp load start, determining whether to cause the state machine module to jump to an operational state comprises:

In the M-th minute, assuming that k active power averages exist in the annular queue, wherein k is greater than 2, calculating a difference value between the current active power average value P ' (M) and the active power average value in the annular queue, setting deltaP ' (M-i) =P ' (M) -P ' (i), wherein i is greater than or equal to 0 and less than or equal to k, if |deltaP ' (M-i) | is greater than a judgment threshold Pgate, a state machine module jumps from an M1 state to an M3 state, and recording pre-steady state average active power values P ' (i) and P ' (M); otherwise, the M1 state is maintained.

9. The system of claim 6, wherein in making the determination of transient load starts, if the state machine module enters the M3 state, further determining whether there is a load start comprises:

Assuming that the nth second enters an M3 state and the pre-steady state active power value is P (n-1), after operating for T2 seconds again, wherein t2=2×t1, taking active power values P (n+1) and P (n+2) at the nth+1 and n+2 seconds from the annular queue, and respectively calculating absolute values of differences between the two power values and the pre-steady state active power value P (n-1): deltaP (n+1) | and deltaP (n+2) |;

if the two values of the I deltaP (n+1) I and the I deltaP (n+2) I are larger than Pgate < 1 >, and the signs of the three differences deltaP (n-1), deltaP (n+1) and deltaP (n+2) are the same, judging that the transient starting exists; if the three difference signs are different, no judgment is made, and the state machine module jumps to the M1 state and enters the next detection.

10. The system of claim 6, wherein in making the determination of the slow-change load start, if the state machine module enters the M3 state, further determining whether there is a load start comprises:

Assuming that the state machine module enters an M3 state at the M-th minute, calculating the difference between the average active power of m+1 and m+2 minutes and the average active power P '(i) at the moment i at the m+2 minute, namely deltaP' (m+1-i) and deltaP '(m+2-i), and judging that a load is started if the 2 value is the same as the sign of deltaP' (M-i) and the absolute value of the 2 value is larger than a judging threshold Pgate; if any absolute value of the 2 values is not more than Pgate < 2 >, the state machine module jumps to the M1 state; if the sign of this 2 value is not the same as the sign of deltaP' (M-i), the state machine module jumps to the M1 state.