阅读说明：本技术 一种断路器分合闸线圈电流录波的触发方法 (Trigger method for current recording of opening and closing coil of circuit breaker ) 是由 赵勇 宋昕 杨本初 于 2020-08-07 设计创作，主要内容包括：一种断路器分合闸线圈电流录波的触发方法,采用FPGA可编程逻辑门阵列对经AD转换后的分合闸线圈电流数据进行周期采集,采用硬件逻辑电路实现滑动窗口数据过阈值统计与辅助开关状态变化相结合的数据录波触发方式,确保分合闸线圈电流波形监测装置精准录波,提高智能化断路器的可靠性。(A trigger method for current recording of a switching-on and switching-off coil of a circuit breaker is characterized in that an FPGA (field programmable gate array) is adopted to periodically collect current data of the switching-on and switching-off coil after AD (analog-to-digital) conversion, a data recording trigger mode combining sliding window data threshold value passing statistics and auxiliary switch state change is realized by adopting a hardware logic circuit, accurate recording of a current waveform monitoring device of the switching-on and switching-off coil is ensured, and the reliability of an intelligent circuit breaker is improved.)

1. A trigger method for current recording of a circuit breaker opening and closing coil is characterized by comprising the following steps:

1) a hardware logic circuit is adopted to construct a sliding window of a dual-port queue, the head of the queue is the last entering data point of the current window, the tail of the queue is the first entering data point of the sliding window, each time the window is slid, the newly entering data point is added into the head of the queue and the tail of the queue is popped up, the average value of the whole queue data point is calculated to be used as the current threshold value of the sliding window, and the size of the sliding window is dynamically settable;

2) in the translation process of the sliding window, if the amplitude of a newly entered data point is greater than the threshold of the sliding window, counting the data point which passes the threshold, otherwise, resetting the counting of the data point which passes the threshold; when the number of data points continuously larger than the threshold value of the sliding window exceeds half of the length of the sliding window, triggering data wave recording;

3) and judging whether the state of the auxiliary switch is changed or not, if so, triggering data recording if the state is changed and the duration time reaches the length of the sliding window.

2. The method for triggering current recording of the opening and closing coil of the circuit breaker according to claim 1, characterized by comprising the following steps:

1) setting the length n of a data sliding window, wherein an initial threshold value is the maximum value;

2) collecting data points and writing the data points into an RAM memory;

3) collecting data points and entering a sliding window queue memory;

4) calculating the average value of all data points of the sliding window as the current threshold value of the sliding window;

5) judging whether the amplitude of a newly entered data point of the sliding window exceeds a threshold value;

6) if the threshold value is exceeded, performing threshold value statistics; if the threshold value is not exceeded, the threshold value is crossed for counting and clearing, and the step 9 is switched;

7) judging whether the data point passing threshold value statistics continuous number exceeds half of the length of the sliding window;

8) if the length of the sliding window is more than half, starting the RAM memory to record waves at the front fixed length data points and the rear fixed length data points, and clearing the auxiliary switch state trigger wave recording mark;

9) otherwise, judging whether the state of the auxiliary switch is changed;

10) starting the auxiliary switch to keep counting when the state of the auxiliary switch changes, and turning to the step 2;

11) the state of the auxiliary switch is not changed, the state change of the auxiliary switch keeps the counting not to reach the length of the sliding window, and the step 2 is switched;

12) otherwise, after the state of the auxiliary switch changes, the state keeping count reaches the length of a sliding window, the front fixed-length wave recording and the rear fixed-length wave recording of the RAM are started, and the state change keeping count of the auxiliary switch is reset;

13) and (5) after the wave recording is finished, storing the wave recording file.

3. The method for triggering current recording of the opening and closing coil of the circuit breaker according to claim 1, wherein the length of the data sliding window can be set, the opening and closing time of the circuit breaker is usually more than 15mS, the length of the sliding window can be reliably triggered by 1/2 mS, and the set value is about 7.5mS at minimum; the trigger threshold varies with the sliding window data mean, separated by 1 data point time.

Technical Field

The invention belongs to the technical field of current waveform monitoring, and particularly relates to a trigger method for current recording of a circuit breaker opening and closing coil.

Background

The current waveform of a circuit breaker opening and closing coil is an important monitoring parameter of circuit breaker intellectualization, a monitoring device generally adopts a method of fixing a threshold value, and wave recording is started when current data exceeds the threshold value; however, false triggering or missed triggering is easily generated due to strong electric field environment interference of a transformer substation site and different magnitudes of working currents of opening and closing coils of circuit breakers of various manufacturers, so that the phenomenon that current waveform of the opening and closing coils is recorded in an empty mode or a missed mode exists in a monitoring device of the circuit breaker, a false alarm or a missed alarm is generated through analysis, and the reliability of the intelligent circuit breaker is reduced.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a trigger method for current recording of a switching-on and switching-off coil of a circuit breaker, which adopts an FPGA (field programmable gate array) to periodically acquire current data of the switching-on and switching-off coil after AD (analog-to-digital) conversion, and adopts a data recording trigger mode of combining sliding window data threshold value passing statistics and auxiliary switch state change by adopting a hardware logic circuit, so that accurate recording of a current waveform monitoring device of the switching-on and switching-off coil is ensured, and the reliability of an intelligent circuit breaker is improved.

In order to achieve the purpose, the invention adopts the technical scheme that:

a trigger method for current recording of a circuit breaker opening and closing coil is characterized by comprising the following steps:

1) a sliding window of a dual-port queue is constructed by adopting a hardware logic circuit, the head of the queue is the last entering data point of the current window, the tail of the queue is the first entering data point of the sliding window, each time the window is slid, the newly entering data point is added into the head of the queue and the tail of the queue is popped up, the average value of the whole queue data point is calculated to be used as the current threshold value of the sliding window, and the size of the sliding window is dynamically settable.

2) In the translation process of the sliding window, if the amplitude of a newly entered data point is greater than the threshold of the sliding window, counting the data point which passes the threshold, otherwise, resetting the counting of the data point which passes the threshold; and when the number of data points continuously larger than the threshold value of the sliding window exceeds half of the length of the sliding window, triggering data wave recording.

3) And judging whether the state of the auxiliary switch is changed or not, if so, triggering data recording if the state is changed and the duration time reaches the length of the sliding window.

The length of the data sliding window can be set, the opening and closing time of the circuit breaker is usually more than 15mS, the length of the sliding window can be reliably triggered by 1/2 time, and the set value is about 7.5mS at minimum; the trigger threshold varies with the sliding window data mean, separated by 1 data point time.

The invention has the beneficial effects that:

the method can ensure the accurate wave recording of the opening and closing coil current waveform monitoring device and improve the reliability of the intelligent circuit breaker.

Drawings

FIG. 1 is a diagram of an embodiment of a data over-threshold statistical triggering method according to the present invention.

Fig. 2 is a diagram of an embodiment of an auxiliary switch state change triggering method according to the present invention.

Detailed Description

The present invention will be further described with reference to the following examples and accompanying drawings.

1) A sliding window of a dual-port queue is constructed by adopting a hardware logic circuit, the head of the queue is the last entering data point of the current window, the tail of the queue is the first entering data point of the sliding window, each time the window is slid, the newly entering data point is added into the head of the queue and the tail of the queue is popped up, the average value of the whole queue data point is calculated to be used as the current threshold value of the sliding window, and the size of the sliding window is dynamically settable.

2) In the translation process of the sliding window, if the amplitude of a newly entered data point is greater than the threshold of the sliding window, counting the data point which passes the threshold, otherwise, resetting the counting of the data point which passes the threshold; and when the number of data points continuously larger than the threshold value of the sliding window exceeds half of the length of the sliding window, triggering data wave recording.

3) And judging whether the state of the auxiliary switch is changed or not, if so, triggering data recording if the state is changed and the duration time reaches the length of the sliding window.

The length of the data sliding window can be set, the opening and closing time of the circuit breaker is usually more than 15mS, the length of the sliding window can be reliably triggered by 1/2 time, and the set value is about 7.5mS at minimum; the trigger threshold varies with the sliding window data mean, separated by 1 data point time.

The invention specifically realizes the following steps:

1) setting the length n of a data sliding window, wherein an initial threshold value is the maximum value;

2) collecting data points and writing the data points into an RAM memory;

3) collecting data points and entering a sliding window queue memory;

4) calculating the average value of all data points of the sliding window as the current threshold value of the sliding window;

5) judging whether the amplitude of a newly entered data point of the sliding window exceeds a threshold value;

6) if the threshold value is exceeded, performing threshold value statistics; if the threshold value is not exceeded, the threshold value is crossed for counting and clearing, and the step 9 is switched;

7) judging whether the data point passing threshold value statistics continuous number exceeds half of the length of the sliding window;

8) if the length of the sliding window is more than half, starting the RAM memory to record waves at the front fixed length data points and the rear fixed length data points, and clearing the auxiliary switch state trigger wave recording mark;

9) otherwise, judging whether the state of the auxiliary switch is changed;

10) starting the auxiliary switch to keep counting when the state of the auxiliary switch changes, and turning to the step 2;

11) the state of the auxiliary switch is not changed, and the state of the auxiliary switch keeps counting and does not reach the length of the sliding window, and then the step 2 is carried out;

12) otherwise, after the state of the auxiliary switch changes, the state duration reaches the length of a sliding window, the front fixed-length wave recording and the rear fixed-length wave recording of the RAM are started, and the state change of the auxiliary switch keeps counting and zero clearing;

13) and (5) after the wave recording is finished, storing the wave recording file.

As shown in fig. 1, the size of the sliding window is set to 5, the initial threshold is 32767, when the sliding window crosses the array each time, the average value of the data points in the current sliding window is calculated, and the threshold counting and wave recording triggering judgment are performed at the same time, which specifically includes the following steps:

1) 5 data points enter a sliding window, the head of line data point is 5, the mean value is 2, the threshold value passing count is 1, and the wave recording trigger signal level is 0;

2) the sliding window is shifted to the right by one data point, the data point at the head of the queue is 10, the mean value is 3, the count of the threshold is 2, and the level of the recording trigger signal is 0;

3) shifting a sliding window by one data point to the right, wherein the data point at the head of the queue is-10, the average value is 1, counting by a threshold value and clearing, and the level of a recording trigger signal is 0;

4) the sliding window is shifted to the right by one data point, the data point at the head of the queue is 10, the mean value is 3, the count of the threshold is 1, and the level of the recording trigger signal is 0;

5) the sliding window is shifted to the right by one data point, the data point at the head of the queue is 20, the mean value is 7, the count of the threshold is 2, and the level of the recording trigger signal is 0;

6) moving a sliding window by one data point to the right, wherein the data point at the head of the queue is 30, the mean value is 12, the count of the threshold value is 3, the level of the wave recording trigger signal is 1, and starting wave recording;

as shown in fig. 2, the size of the sliding window is set to 5, when the state of the auxiliary switch changes, counting is started, and meanwhile, wave recording triggering judgment is performed, specifically including the following steps:

1) the state of the auxiliary switch is unchanged, the count is kept to be 0, and the level of the recording trigger signal is 0;

2) starting counting when the state of the auxiliary switch is changed, keeping the counter plus 1, the value of 1 and the level of the recording trigger signal to be 0;

3) the auxiliary switch maintains the changed state, the counter is kept to be added with 1, the numerical value is 2, 3 and 4, and the level of the recording trigger signal is 0;

4) and (3) maintaining the changed state of the auxiliary switch, adding 1 to the counter, setting the value to be 5, setting the level of the recording trigger signal to be 1, starting recording, and resetting the counter.