CN103457352A - BCD gear information collection method for intelligent substation - Google Patents

Abstract

The invention relates to a BCD gear information collection method for an intelligent substation. The method comprises the steps that idle contact signals participating in the composition of BCD are collected in real time at first; if the state of more than one idle contact signal changes within the set time T, the starting moment of the T is updated, the state changing moment of the last idle contact signal with the state changed is taken as the corresponding starting deflection moment t of the BCD value, the starting deflection moment t of the BCD value is taken as the shake disappearing moment to delay one shake disappearing time Tx, the states of the idle contact signals are confirmed after the shake disappearing time Tx is over, and then the BCD value is determined. According to the BCD gear information collection method for the intelligent substation, the BCD gear information is sent once through a GOOSE message only after the states of all the idle contact signals are stable, unnecessary network message transmission is avoided, and the burden of an upper-layer device is effectively reduced.

Description

BCD code stall information acquisition method for smart substation

technical field

The invention relates to a BCD code stall information collection device and a collection method for an intelligent substation.

Background technique

In the operation of the power system, the closing or opening of the circuit breaker, the position status of the isolating switch, the working conditions of the relay protection and the automatic device are all represented by the two remote signaling states of closing and opening. According to the IEC standard of the International Electrotechnical Commission: "0" means the open state, and "1" means the closed state. On the primary equipment side, this remote signaling state is usually provided to the secondary equipment in the form of an empty contact, and in order to prevent errors caused by poor contact and other reasons, a DC 220V or 110V voltage is added to the contact circuit, and When connecting to the secondary device, a photoelectric isolation device is introduced to avoid damage to the secondary device caused by the strong current impact in the substation. In the transformer, the corresponding gear position information is often provided by combining multiple empty contacts into BCD codes. For example, six empty contacts are commonly used as a group, and two of the empty contacts represent tens. The remaining four represent units, so that up to 39 fields of information can be provided. For the signal input by the empty contact, because there is a short-term mechanical jitter when it is turned on or off, it is usually required to perform necessary debounce processing (typically 10ms) to prevent the jitter of the signal from affecting the normal power supply. adverse effects caused.

In addition, in the current smart substation, the process layer device generally uses the GOOSE message to send the collected equipment status information to the Ethernet, and then transmits it to the upper layer device (in this application, it refers to the interval layer and station control layer device) , the same below). As shown in Figure 1, according to the IEC61850 standard, when the event state is stable, the GOOSE message is sent repeatedly at a longer time interval, and when the event state changes, it will enter a burst state, that is, within a short time interval, Send multiple frames in a row and then return to the steady state sending mode.

In view of this situation, for the BCD code gear position information composed of multiple empty contacts, in the process layer device, there are usually the following two methods to process the gear position information:

Method 1: remote synthesis of BCD code gear information. The details are as follows: Each empty contact is regarded as an independent remote signaling state. When it changes, after a certain debounce time is confirmed, it is encoded into the BOOL type of the GOOSE message according to the switch state and sent. When the value is "True", it corresponds to the closed state of the empty contact, and when the value is "False", it corresponds to the open state of the empty contact. For specific gear information, the upper device decodes the received GOOSE message, extracts the remote signaling status of each empty contact, and generates BCD code gear information according to the corresponding weight.

Method 2: In-situ synthesis of BCD code stall information. The details are as follows: The process layer device detects any change in the status of any empty contact, and after debounce confirmation, it synthesizes a new BCD code position, and then encodes it into the integer or short integer data in the GOOSE message, and changes according to the event The burst transmission of messages is performed according to the state of the time.

In the first method, the composition of the BCD code gear information is assigned to the upper-layer device, which will increase the CPU load of the upper-layer device to a certain extent, and the multiple empty contacts in one gear information will be unreasonable in a short period of time. During synchronous displacement, for mechanical contacts, when they are closed at the same time, there is generally a difference of several ms. As shown in Figure 2, the empty contacts "BCD-0-1" and "BCD-1-2" are displaced at _t1 and _t2 respectively, and after debounce time, they change at _t3 and _t4 respectively The status is confirmed. According to the GOOSE message transmission mechanism, this will cause the process layer device to activate the burst state of the GOOSE message at time _t3 and _t4 . For the BCD code position composed of six empty contacts, the worst case will be at During the debounce time, six GOOSE message bursts are generated, which not only increases the network traffic, but also enables the upper device to extract the BCD code gear information within a short time interval (t ₂ -t ₁ , less than the debounce Time), different gear information is extracted, so a certain delay confirmation mechanism must be implemented, otherwise it may cause continuous switching of protection strategies, which increases the complexity of the upper device; in method 2, although it is not necessary to The upper device synthesizes BCD code gear position information, but when the phenomenon shown in Figure 2 occurs, it will also cause the upper device to receive different gear information in a short time. Therefore, both of these two methods increase unnecessary network traffic and the burden on the upper device, and it is necessary to improve them.

Contents of the invention

The purpose of the present invention is to provide a BCD code stall information collection method for intelligent substations, which is used to solve the problems of frequent sending of messages and unstable stall information in the network caused by the existing BCD code stall information collection method.

In order to achieve the above object, the present invention provides a method for collecting BCD code stall information for smart substations, the steps are as follows:

(1) Real-time collection of each empty contact signal that participates in the BCD code composition;

(2) Within the set time T, whenever more than one state of the empty contact signal changes, the starting time of T is updated, and the state change time of the last state of the empty contact signal is The start shift time t of the corresponding BCD code value;

(3) Delay a debounce time Tx with the start time t of the BCD code value as the debounce start time, and confirm the signal status of each empty contact after the debounce time Tx ends to determine the BCD code value .

After the BCD code value is determined, the BCD code gear position information is sent through the GOOSE message.

In step (1), the empty contact signals are collected in real time by means of scanning, and the current BCD code value is recorded for each collection, and the scanning period T _S <T.

In step (2), within the time T, by comparing whether the BCD code values of two adjacent collections have changed, it is judged whether there is a displacement of the empty contact point, and each time the displacement occurs, the time at which the displacement starts is reset t.

The set time T in step (2) is a sliding time window, and its starting time is updated with the starting time of each empty contact signal state change.

In the operating system, set a query task and a debounce task, set a debounce queue and a debounce queue in the debounce task, the operating system checks the status of each empty contact signal every other query cycle, and according to The state of the empty contact signal in the last query cycle is used to judge whether the state of the space-time contact signal has changed in this query, and to judge whether to update the BCD code value at the time of this query, until all the empty contact signal states are no longer When changing, the BCD code value updated during this query is sent to the debounce queue to prepare for debounce, and when the debounce task time slice arrives, the corresponding BCD code value is sent to the debounce queue and starts changing according to it Debounce it at all times. During the debounce process, if it is found to be a jitter signal, exit the debounce; otherwise, after the end of debounce, activate the GOOSE message and send the corresponding BCD code gear information.

The beneficial effects achieved by the present invention: in the process of collecting BCD code stall information, when the CPU inquires that the state of the empty contact signal changes at time _t1 , the BCD code value is updated, and the BCD code signal is simultaneously Send it to the debounce queue to prepare for debounce. When the state of another empty contact signal that makes up the BCD code changes at time t ₂ (less than the debounce time Tx), re-update the BCD code value and use time t ₂ as the new The starting time of the debounce, so that when the multiple empty contact signals that make up it change in a short period of time, the shift occurrence time of the last one in the group of changing contacts that enters a stable state can be used as the start of the gear value The bit change time, and then the acquisition device synthesizes its BCD code value on the spot, and activates the corresponding GOOSE message group to enter the burst state, avoiding unnecessary network message transmission and effectively reducing the burden on the upper device.

Description of drawings

Figure 1 is the GOOSE message event transmission mechanism;

Figure 2 is the debounce process of the open contact signal opening;

Fig. 3 is a structural diagram of a collection device applying the method of the present invention;

Fig. 4 is the determination process of BCD code value in a query period of the present invention;

Fig. 5 is the working flow chart of CPU inquiry module of the present invention;

Fig. 6 is a working flow chart of the CPU debounce module of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

As shown in Figure 3, it is a device applying the collection method of the present invention, including CPU, FPGA chip and network chip, and each input port of FPGA is respectively connected to an empty contact for collecting the state of each empty contact, each empty contact and There is also an optocoupler device between the input ports of the FPGA chip, BCD-1-2 and BCD-1-1 are the ten digits of the BCD code, BCD-0-1, BCD-0-2, BCD-0-4 and BCD-0-8 is the unit digit of the BCD code, and the weights represented by each empty contact state are shown in Table 1. For example, the empty contact corresponding to BCD-0-1 represents the unit digit of the BCD code, and its weight is 1, namely: 000001, the empty contact corresponding to BCD-1-2 represents the ten digit of the BCD code, and its weight is 20, namely: 100000.

Table 1

empty contact Weight BCD-0-1 1 BCD-0-2 2 BCD-0-4 4 BCD-0-8 8 BCD-1-1 10 BCD-1-2 20

In order to meet the requirements of the device for the input resolution of the input signal not greater than 1ms, the FPGA collects the input signal in real time and stores it in the corresponding register. The input signals collected by the device include ordinary input signals, namely: empty contact signals that do not participate in the composition of BCD codes, such as knife switch position, knife switch close position, etc., which are only provided in the state of "0" and "1". For protection and measurement and control devices, it also includes BCD code signals composed of empty contact states.

The concrete steps of the inventive method are as follows:

(1) Real-time collection of each empty contact signal that participates in the BCD code composition;

(2) Within the set time T, whenever there is more than one state change of the empty contact signal, the starting time of T is updated, and the state change time of the last state change of the empty contact signal is The start shift time t of the corresponding BCD code value;

(3) delaying a debounce time Tx with the start displacement time t of the BCD code value as the debounce start time, and confirming the state of each empty contact signal after the debounce time Tx ends, to determine the BCD code value .

As shown in Figure 4, t1, t3, t5, t7, t9, and t11 are the state change moments of each empty contact, and the change time t11 of the last empty contact BCD-1-2 is the beginning change of the corresponding BCD code value. At the bit time, the BCD code value at the current moment is determined at t12 after a debounce time starting at t11.

In this embodiment, the CPU is provided with a query module, which reads the registers of the FPGA through the bus every 0.25 ms, so as to obtain the current status of each empty contact. In the CPU, a state database is established for all input signals for management. For common input signals, each item in the database corresponds to an empty contact signal, and the state and state change of the empty contact can be recorded. Time, it is 0 at the time of initialization, and it records the on-off state of the empty contact; for BCD code signals, multiple empty contact signals that make up the BCD code correspond to one item in the database, and the corresponding database item records the specific The BCD code value of the BCD code value, the database item corresponding to the BCD code value and the database item corresponding to the ordinary input signal are all consistent except for the information reflected by the state value, so it can be regarded as a virtual empty contact open entry.

There is also a debounce module in the CPU to implement ms-level debounce tasks. The CPU calls the debounce module every 1ms. Debounce queue, among them, the debounce queue is used to store the state change information of the input signal detected by the CPU query module, such as the empty contact number, state change time, change value, etc., and the debounce queue is used to store the debounce state The input signal information, such as the number of empty contacts, the start time of debounce, the time required for debounce, and the status value when debounce is turned on, etc.

Therefore, the present invention completes the collection, synthesis, debounce confirmation, database update and activation of the GOOSE burst state of the specific BCD code gear value through the cooperation of the query module and the debounce module in the CPU, thereby reducing network traffic and upper device purpose of burden.

As shown in Figure 5, in the query module, for ordinary input signals, when the CPU inquires that there is a signal state at the current time that is inconsistent with the state at the time of the last query, it will send the state value of the signal and the time of this query to the queue to be debounced , wait for the time slice of the debounce task to arrive, and then process it; for the BCD code gear information, when it is found that the current state of the empty contact contained in the gear is inconsistent with the last query, it is not directly sent to the Waiting for the debounce queue, but first update the current BCD code value according to the BCD code value at the time of the last query, and when the status of all empty contacts in this query is confirmed, the BCD code value at the current moment is generated , and then compare it with the BCD code value generated during the last query. If the two are inconsistent, the code value will be sent as a status value together with the time of this query to the queue to be debounced, waiting for debounce processing.

As shown in Figure 6, in the debounce module, the queue to be debounced is first traversed, and each signal to be debounced needs to be cleared from the queue to be debounced, and then it is judged whether it is in the debounced state, This can be judged by checking whether it is already in the debounce queue. If it is already in the debounce queue, it means that the signal is in a state of jitter at the current moment. It is necessary to further judge whether the normal input signal or BCD code signal is consistent with the corresponding item in the database. The state values are consistent, and the empty contact compares the on and off state values, while the BCD code signal compares its BCD code value. If they are consistent, it means that the signal state has not changed effectively, and exit the debounce. If they are inconsistent, you need to Use the latest state change time as the debounce start time to debounce again. At this time, it is only necessary to update the debounce start time in the debounce queue. If it is not in the debounce queue, it will be cleared out of the debounce queue, and directly sent into the debounce queue as a new debounce item, so as to start the debounce process.

Once the traversal of the queue to be debounced is completed, the traversal process of the debounced queue begins. For each debounce signal, it is necessary to confirm whether it has completed debounce according to the difference between the current system time and the debounce start time. If it has been completed, it will be cleared from the debounce queue and updated in the database. The state change time and state value of the corresponding item. At the same time, activate the GOOSE event change flag of the corresponding item to send the state of the input signal. For the BCD code signal, directly send the BCD code value; 0", "1" status value. Among them, the state change time should be the start time of debounce, not the current time when debounce ends, so as to ensure that in the subsequent GOOSE message, the time information can truly reflect the state change time of the empty contact corresponding to the project, satisfying The system requires 1ms resolution for a single hard switch. If it has not been completed, wait for the next call to continue the above debounce processing.

Through the above processing, if the situation shown in Figure 2 occurs, for example: at time _t1 , the empty contact "BCD-0-1" is switched on, and the BCD code gear value is updated to 1 (the rest of the bits are assumed to be disconnected, and the BCD code The gear value is initialized to 0), therefore, the change of the BCD code gear value will be detected, and the corresponding virtual empty contact item will be sent to the debounce queue. When the debounce module is running, it will be removed from the debounce queue. Take it out from the queue, and start the debounce process with t ₁ as the debounce start time; at t ₂ , the empty contact "BCD-1-2" is put in, and the BCD code gear value is updated to 21, so the virtual empty The contact item is sent to the queue to be debounced. When the system schedules the debounce module again, it is found that it is already in the debounce queue, and the debounce start time is updated from t ₁ to t ₂ to start debounce again. It is ensured that the system only generates a database update and activates a GOOSE message burst state at the end of the debounce confirmation time of the empty contact "BCD-1-2", that is, at time _t4 . is t ₂ , so that the messages in the network are relatively stable, and at the same time, there is no need for the upper-layer device to delay confirmation of the specific gear information, which reduces the burden on the upper-layer device and makes it unnecessary to delay the confirmation of the gear information. If the empty contact "BCD-1-2" is only a jitter at the time t2, and it returns to its original position at a certain time t5 before _t4 , then take _the time _t5 as the starting time of debounce, until "t ₅ + debounce time", and then send the code value at time _t1 , which is equivalent to delaying confirmation of the gear position information on the process layer device.

Claims (6)

1. a binary-coded decimal gear information acquisition method for intelligent substation, is characterized in that, step is as follows:

(1) Real-time Collection participates in each dumb contact signal that binary-coded decimal forms;

(2) in the time T of setting, when the state that an above dumb contact signal is arranged changes, upgrade the initial time of T, the state variation of the dumb contact signal that last state changes of take is the beginning displacement of corresponding binary-coded decimal value t constantly constantly;

(3) with the beginning displacement of described binary-coded decimal value constantly t tremble for disappearing and postpone one the zero hour and disappear and tremble time T x, and disappear tremble time T x and finish after described each dumb contact signal condition of confirmation, to determine the binary-coded decimal value.

2. binary-coded decimal gear information acquisition method for intelligent substation according to claim 1, is characterized in that, after determining described binary-coded decimal value, the binary-coded decimal gear information sent by the GOOSE message.

3. binary-coded decimal gear information acquisition method for intelligent substation according to claim 1, it is characterized in that, in step (1), with described each dumb contact signal of mode Real-time Collection of scanning, and all record current binary-coded decimal value while gathering, scan period TS<T at every turn.

4. binary-coded decimal gear information acquisition method for intelligent substation according to claim 1, it is characterized in that, in step (2), in time T, whether the binary-coded decimal value by more adjacent twice collection changes, judged whether dumb contact generation displacement, each displacement occurs, and described beginning displacement t constantly resets.

5. binary-coded decimal gear information acquisition method for intelligent substation according to claim 1, is characterized in that, the setting-up time T in step (2) is a time slip-window, and the initial time that its initial time changes with each dumb contact signal condition upgrades.

6. binary-coded decimal gear information acquisition method for intelligent substation according to claim 1, it is characterized in that, in operating system, a query task and the task of trembling that disappears are set, arranging one in the task of trembling that disappears disappears and trembles queue and one and wait to disappear and tremble queue, operating system is inquired about the once state of each dumb contact signal every a polling cycle, and according to last polling cycle the hollow contact signal state judge whether the state of this time inquiring about the space-time contact signal changes, and judge whether to upgrade the binary-coded decimal value while this time inquiring about with this, until all dumb contact signal conditions are while all no longer changing, the binary-coded decimal value of upgrading when this is inquired about is sent into to wait to disappear and is trembled queue and prepare to disappear to tremble, and disappearing while trembling that task time, sheet arrived, corresponding binary-coded decimal value is sent into to disappear to tremble queue and start displacement according to it and constantly it is disappeared and trembles, in the process of trembling that disappears, if the dither signal of being found to be, exiting disappears trembles, otherwise, after disappearing and trembling end, excite the GOOSE message, send corresponding binary-coded decimal gear information.

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