Power secondary equipment time information network system and fault-tolerant time synchronization method

Abstract

The invention discloses a power secondary equipment time information network system and a fault-tolerant time synchronization method. The system comprises a time information network sending module and a time information network receiving module. The time information network sending module comprises a B code selection unit which receives and selects an external electric B code or an optical B code; the B code decoding unit is used for decoding the selected B code; the millisecond counting unit generates millisecond information, and the millisecond information and the decoded time information form time information with milliseconds; the CRC calculation unit is used for performing cyclic redundancy check calculation; and the time synchronization sending unit is used for sending the time information data to each time synchronization receiving unit. The time information network receiving module comprises a time synchronization receiving unit used for receiving time information data; the CRC check unit is used for carrying out check calculation; the synchronous selection unit is used for making synchronous selection according to the verification result; and the local time keeping unit performs synchronous following or local time keeping according to the time synchronization information. The time information network disclosed by the invention adopts a simple non-redundant structure, so that the cost is lower.

Description

Technical Field

[0001] The present invention belongs to the technical field of clock calibration of power systems, and more specifically, relates to a time information network system for power secondary equipment and a fault-tolerant time calibration method. Background Art

[0002] During power operation, power secondary equipment is diverse and has a large number of plug-ins. Various measuring instruments, protection devices, and control equipment require precise time synchronization to function properly. Otherwise, errors or even accidents may occur. By establishing a high-precision time synchronization system, namely a time information network system, time synchronization between various devices can be achieved, thereby ensuring the stable operation of the power system.

[0003] In addition, the time information network system can also be used in the inspection and maintenance process of the power system. Through the time information network system, the entire power system can be remotely managed, thereby greatly improving maintenance efficiency and accuracy.

[0004] Prior art time information network systems typically consist of a high-precision clock source, communication data transmission, and a controller. GPS and other tools provide high-precision time signals, fiber-optic communications enable data transmission and synchronization, and a centralized controller manages data and synchronizes time. Time synchronization with higher precision is achieved through continuous comparison and fault-tolerance mechanisms between multiple servers. Multiple servers simultaneously receive GPS signals and record the time locally. The times recorded by each server are compared. If any discrepancies are found, the average is calculated and used as the final time. If a server fails, it is removed from the comparison and the average is recalculated.

[0005] In existing time information network systems, serial communication outputs time information as a serial data stream. Each automatic protection device receives this serial time information once per second for time synchronization. During this synchronization process, serial data transmission and reception utilize interrupts, which consumes time for both interrupt handlers. In serial communication, data is transmitted bit by bit at a specific baud rate, resulting in bus transmission delays.

[0006] Furthermore, the complex environment in which power secondary equipment and plug-ins operate makes hard pulse synchronization between multiple devices and plug-ins susceptible to errors caused by the complex electromagnetic environment, limiting the synchronization system's anti-interference capabilities. Existing technologies often employ redundant synchronization, which improves the synchronization system's anti-interference capabilities to a certain extent. However, the redundant design of the synchronization source complicates the synchronization system's structure and also results in high costs. Summary of the Invention

[0007] In order to address the deficiencies in the prior art, the present invention provides a time information network system for power secondary equipment and a fault-tolerant timing method. This system adopts a concise system structure to improve the timing and anti-interference performance of multiple devices and multiple plug-ins in complex electromagnetic environments, and to enhance the timing accuracy.

[0008] The present invention adopts the following technical solutions.

[0009] A first aspect of the present invention provides a power secondary equipment time information network system, comprising a time information network sending module and a plurality of time information network receiving modules.

[0010] The time information network sending module includes: a B code selection unit, a B code decoding unit, a millisecond counting unit, a cyclic redundancy calculation unit and a time synchronization sending unit; each of the time information network receiving modules includes: a time synchronization receiving unit, a cyclic redundancy check unit, a synchronization selection unit and a local timekeeping unit;

[0011] The B code selection unit receives an external electrical B code or an optical B code and makes a selection, and transmits the selected B code to the B code decoding unit;

[0012] The B code decoding unit decodes the selected B code to obtain a second pulse signal and time information accurate to the second, and transmits the decoded time information to the millisecond counting unit;

[0013] The millisecond counting unit generates millisecond information, which is combined with the decoded time information to form the time information with milliseconds, and is passed to the cyclic redundancy calculation unit;

[0014] The cyclic redundancy calculation unit performs cyclic redundancy check calculation on the time information with milliseconds;

[0015] The time synchronization sending unit is connected to each time synchronization receiving unit, and the time synchronization sending unit sends time information data consisting of millisecond time information and cyclic redundancy check calculation results to each time synchronization receiving unit;

[0016] The time synchronization receiving unit sends the received time information data to the cyclic redundancy check unit for verification calculation;

[0017] The synchronization selection unit makes a synchronization selection based on the verification result, and the selected time synchronization information enters the local timekeeping unit;

[0018] The local timekeeping unit performs synchronization following or local timekeeping according to the time synchronization information.

[0019] Preferably, all devices or plug-ins in the power secondary equipment that require time synchronization are connected to the time information network system. The time information network system has only one time information network sending module, and the rest are time information network receiving modules.

[0020] Preferably, the electrical B code and the optical B code are de-jittered, and the B code selection unit receives the de-jittered electrical B code or optical B code.

[0021] Preferably, the B code selection unit uses the electrical B code by default, and selects to switch to the optical B code when detecting that the optical B code is connected, and selects to switch to the electrical B code when detecting that the optical B code is disconnected.

[0022] Preferably, in the cyclic redundancy calculation unit, the cyclic redundancy check calculation process is expressed by the following formula:

[0023] D(x)×x k ÷G(x)=Q(x)…R(x)

[0024] Where D(x) is the polynomial corresponding to the millisecond time information, x is the formal variable, k is the check code length of the cyclic redundancy check, G(x) is the generator polynomial, Q(x) is the quotient polynomial, and R(x) is the remainder polynomial.

[0025] Preferably, the generator polynomial G(x) is expressed as follows:

[0026] X 16 +X 13 +X 12 +X 11 +X 10 +X 8 +X 6 +X 5 +X 2 +1.

[0027] Preferably, in the time synchronization sending unit, the time information data sent is expressed by the following formula:

[0028] T(x)=D(x)×x k +R(x)

[0029] Where T(x) is the time information data sent by the time synchronization sending unit, D(x) is the polynomial corresponding to the time information with milliseconds, k is the check code length of the cyclic redundancy check, and R(x) is the remainder polynomial.

[0030] Preferably, the cyclic redundancy check unit uses the same generating polynomial as that in the time information network sending module to perform cyclic redundancy check calculation on the received time information data, and the calculation method is consistent with the cyclic redundancy check calculation unit in the time information network sending module. If the cyclic redundancy check result calculated by the cyclic redundancy check unit is consistent with the cyclic redundancy check calculation result in the received time information data, the check passes; if the cyclic redundancy check result calculated by the cyclic redundancy check unit is inconsistent with the cyclic redundancy check calculation result in the received time information data, the check fails.

[0031] Preferably, in the synchronization selection unit, the time synchronization information includes a synchronization follow instruction and a local timekeeping instruction, wherein if the verification passes, the synchronization follow instruction is generated, and if the verification fails, the local timekeeping instruction is generated;

[0032] In the local timekeeping unit, when the time synchronization information is a synchronous follow instruction, the time information with milliseconds received this time is used, otherwise the local time generated by the local timekeeping unit itself is used.

[0033] A second aspect of the present invention provides a fault-tolerant time synchronization method for power secondary equipment, based on the power secondary equipment time information network system, comprising the following steps:

[0034] Step 1: Select one of all the power secondary devices that need time synchronization as the master device, and the rest are slave devices. The master device is equipped with a time information network sending module, and the B code selection unit receives the external electrical B code or optical B code signal and makes a selection;

[0035] Step 2: The B code decoding unit decodes the selected B code, and the millisecond counting unit combines the decoded time information and the millisecond information into time information with milliseconds;

[0036] Step 3: The cyclic redundancy calculation unit performs a cyclic redundancy check calculation on the time information with milliseconds, and the time transmission unit sends the cyclic redundancy check calculation result and the time information with milliseconds to each slave device;

[0037] Step 4: The slave device sets a time information network receiving module, the cyclic redundancy check unit performs a check calculation on the cyclic redundancy check calculation result and the time information with milliseconds received by the time synchronization receiving unit, and the synchronization selection unit performs synchronization selection to generate time synchronization information;

[0038] Step 5: The local timekeeping unit performs synchronization following or local timekeeping according to the time synchronization information.

[0039] Compared with the prior art, the beneficial effects of the present invention include at least:

[0040] 1) The time information network system and time synchronization method proposed in the present invention perform CRC calculation and verification on millisecond time information, and perform synchronous following or local timekeeping based on time synchronization information, thereby improving the system's time synchronization and anti-interference performance, and occasional communication errors do not affect the time synchronization accuracy.

[0041] 2) The time information network system and time synchronization method proposed in the present invention are applied to the time synchronization of multiple devices and multiple plug-ins of power secondary equipment. The B code selection unit selects a B code with better quality, which significantly improves the time synchronization accuracy.

[0042] 3) The time information network system and time synchronization method proposed in the present invention adopt a simple non-redundant structure and are less costly.

[0043] 4) The time information network system and time synchronization method proposed in the present invention can achieve time synchronization between various devices, improve the reliability and safety of the power system, thereby ensuring the stable operation of the power system, and at the same time improve the management efficiency and maintenance accuracy of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a structural diagram of a power secondary equipment time information network system provided in accordance with an embodiment of the present invention;

[0045] Figure 2 This is a schematic diagram of a time information network system provided according to an application example of the present invention applied to a multi-device scenario of power secondary equipment;

[0046] Figure 3 This is a schematic diagram of a time information network system provided according to an application example of the present invention applied to a multi-plug-in scenario of power secondary equipment;

[0047] Figure 4 This is a schematic diagram of a time information network system provided according to an application example of the present invention applied to a multi-device and multi-plug-in scenario of power secondary equipment.

[0048] The reference numerals in the figure are: 1-time information network sending module; 11-B code selection unit; 12-B code decoding unit; 13-millisecond counting unit; 14-CRC calculation unit; 15-time synchronization sending unit; 2-time information network first receiving module; 21-time synchronization receiving unit; 22-CRC check unit; 23-synchronization selection unit; 24-local timekeeping unit; 3-time information network second receiving module. DETAILED DESCRIPTION

[0049] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. The embodiments described in this application are only part of the embodiments of the present invention, not all of them. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0050] like Figure 1 As shown, embodiment 1 of the present invention provides a time information network system for power secondary equipment, including a time information network sending module 1 and a time information network receiving module.

[0051] Preferably, all devices or plug-ins in the power secondary equipment that require time synchronization are connected to the time information network system. Each time information network sending module and receiving module are interconnected to form a high-precision time information network. The system contains only one time information network sending module, and the remaining modules are time information network receiving modules. In one exemplary but non-limiting embodiment, the time information network system utilizes a first time information network receiving module 2 and a second time information network receiving module 3 with identical structures.

[0052] The time information network sending module specifically includes: a B code selection unit 11, a B code decoding unit 12, a millisecond counting unit 13, a CRC (Cyclic Redundancy Check) calculation unit 14 and a time synchronization sending unit 15, and each unit is connected in sequence; the time information network receiving module specifically includes: a time synchronization receiving unit 21, a CRC check unit 22, a synchronization selection unit 23 and a local timekeeping unit 24, and each unit is connected in sequence; the time synchronization receiving unit 21 of each time information network receiving module is connected to the time synchronization sending unit 15 of the time information network sending module.

[0053] B-code (B-type code) refers to the IRIG-B serial time code, which has a frame rate of 1 frame / s and can transmit 100 bits of information. As a widely used time code, B-type code has the following characteristics: 1) It carries a large amount of information. After decoding, it can obtain pulse signals of 1, 10, 100, and 1000 c / s, as well as BCD-encoded time information and control function information; 2) It has high resolution; and 3) the bandwidth of the modulated B-code is suitable for long-distance transmission.

[0054] The B code selection unit 11 of the time information network sending module receives external electrical B code or optical B code, selects a B code with better quality and outputs it to the B code decoding unit 12 .

[0055] In a preferred but non-limiting embodiment of the present invention, the electrical B code and optical B code that are jittered due to external interference are de-jittered, and jitter less than 128ns is ignored. The B code selection unit receives the de-jittered electrical B code or optical B code.

[0056] In a preferred but non-limiting embodiment of the present invention, the B code selection unit block uses the electrical B code by default, switches to the optical B code when the optical B code is detected, and switches to the electrical B code when the optical B code is detected to be disconnected.

[0057] Understandably, because the electrical B code, as an electrical signal, is susceptible to electromagnetic interference and signal attenuation when transmitted over twisted-pair or coaxial cables, it is generally suitable for short-distance applications. However, the complex electromagnetic environments of substations and industrial sites can cause signal distortion or errors due to interference, resulting in poor signal quality. Therefore, the optical B code, which has stronger electromagnetic interference resistance and better signal quality, is preferred. In complex electromagnetic environments, the B code selection unit 11 selects the external electrical B code or optical B code, improving the system's anti-interference capability. The higher-quality B code also contributes to improved time synchronization accuracy.

[0058] The B code decoding unit 12 decodes the B code output by the B code selecting unit 11 . The decoded information includes second pulses and time information (year, day, hour, minute, and second). The decoded time information is passed to the millisecond counting unit 13 .

[0059] The millisecond counting unit 13 is reset at the second pulse, and the counter accumulates the millisecond information. The millisecond information and the decoded time information form the time information with milliseconds, which is communicated in short intervals and passed to the CRC calculation unit 14.

[0060] It can be understood that the time information network system of the present invention adopts a short-interval communication method, which increases the serial transmission rate based on the one-second-one-frame interrupt transmission method of the B code, sends one frame every 1ms, and adds millisecond information to the time information parsed from the B code through the millisecond counting unit, thereby increasing the time resolution.

[0061] The time information with milliseconds passes through the CRC calculation unit 14 to obtain a CRC calculation result, and the time information with milliseconds and the CRC calculation result are input together into the time synchronization sending unit 15. The time synchronization sending unit 15 is connected to the time synchronization receiving unit 21 in each time information network receiving module. The time synchronization sending unit 15 sends the time information data consisting of the time information with milliseconds and the CRC calculation result to the time synchronization receiving unit 21 of each time information network receiving module.

[0062] In a preferred but non-limiting embodiment of the present invention, the time information with milliseconds is represented by the corresponding polynomial D(x), G(x) is the generator polynomial, Q(x) is the quotient polynomial, and R(x) is the remainder polynomial. The CRC calculation process is expressed as follows:

[0063] D(x)×x k ÷G(x)=Q(x)…R(x)

[0064] In the formula, x is a formal variable used to construct a polynomial structure to represent the positional relationship of each bit in the binary data; k is the number of bits of the generating polynomial G(x) minus 1, that is, the length of the CRC check code; each term in the generating polynomial G(x) corresponds to a bit in the binary, and the generating polynomial G(x) is manually set according to a pre-agreed rule. It is preset in the CRC calculation unit and the CRC check unit and is not transmitted with the time information data.

[0065] Further preferably, the polynomial for generating the check sequence code in the national standard GB / T 20840.8-2007 for mutual inductors is selected as the generating polynomial G(x) for CRC calculation, which is expressed as the following formula:

[0066] X 16 +X 13 +X 12 +X 11 +X 10 +X 8 +X 6 +X 5 +X 2 +1

[0067] The CRC generator polynomial G(x) is expressed as follows:

[0068] X 16 +X 13 +X 12 +X 11 +X 10 +X 8 +X 6 +X 5 +X 2 +1

[0069] The time information with milliseconds sent by the time synchronization sending unit 15 and the CRC calculation result are recorded as T(x) and expressed by the following formula:

[0070] T(x)=D(x)×x k +R(x)

[0071] It can be understood that the present invention uses CRC check to replace the redundant time synchronization method of the existing technology. CRC check can be implemented through a simple logic circuit. The calculation process does not require complex operations. The anti-interference ability of the existing redundant time synchronization method can be achieved by using lower memory and computing resources.

[0072] The time information data received by the time synchronization receiving unit 21 of the time information network receiving module is checked and calculated by the CRC check unit 22. Specifically, the CRC check unit 22 uses the same generating polynomial in the time information network sending module to perform CRC calculation on the received time information data. The calculation method is consistent with the CRC calculation unit 14 in the time information network sending module. If the CRC check result calculated by the CRC check unit 22 is consistent with the CRC calculation result in the received time information data, the check passes. If the CRC check result calculated by the CRC check unit 22 is inconsistent with the CRC calculation result in the received time information data, the check fails.

[0073] The synchronization selection unit 23 makes a synchronization selection based on the verification result and generates time synchronization information. In an exemplary but non-limiting embodiment of the present invention, if the verification passes, a synchronization follow instruction is generated; if the verification fails, synchronization follow is not performed and a local timekeeping instruction is generated. The synchronization follow instruction and the local timekeeping instruction constitute the time synchronization information.

[0074] It is worth noting that those skilled in the art may also set other instructions as needed, and all instructions together constitute the time synchronization information, which, based on the spirit of the present invention, falls within the protection scope of the present invention.

[0075] The time synchronization information selected by the synchronization selection unit 23 enters the local timekeeping unit 24 for synchronization following or local timekeeping. In an exemplary but non-limiting embodiment of the present invention, when the time synchronization information is a synchronization following instruction, the local timekeeping unit 24 uses the time information with milliseconds received this time. When the time synchronization information is a local timekeeping instruction, the local timekeeping unit 24 does not use the time information with milliseconds received this time, but uses the local time generated by the local timekeeping unit 24.

[0076] Preferably, the local timekeeping unit 24 uses a local counter to accumulate the generated time, and each time the synchronization selection unit 23 selects synchronization following, the local counter is reset to zero and then accumulated again.

[0077] It is understandable that CRC calculation and verification are performed on the time information with milliseconds. The selected time synchronization information can make the timing system fault-tolerant. Even if occasional communication errors occur in a complex electromagnetic environment, the timing accuracy will not be affected, further improving the anti-interference ability and timing accuracy of the timing system.

[0078] Embodiment 2 of the present invention provides a fault-tolerant time synchronization method for power secondary equipment, based on the power secondary equipment time information network system described in embodiment 1, including the following steps:

[0079] Step 1: Select one of all the power secondary devices that need time synchronization as the master device, and the rest are slave devices. The master device sets up a time information network sending module, and the B code selection unit receives the external electrical B code or optical B code signal and makes a selection.

[0080] Step 2: The B code decoding unit decodes the B code selected in step 1, and the millisecond counting unit combines the decoded time information and the millisecond information into time information with milliseconds.

[0081] Step 3: The CRC calculation unit performs CRC calculation on the time information with milliseconds in step 2, and the time synchronization sending unit sends the CRC calculation result and the time information with milliseconds to each slave device.

[0082] Step 4: The slave device sets up a time information network receiving module. The CRC check unit verifies the CRC calculation result and the millisecond time information received by the time synchronization receiving unit. The synchronization selection unit performs synchronization selection and generates time synchronization information. The time synchronization information includes a synchronization follow instruction and a local timekeeping instruction. Specifically, if the verification passes, the synchronization follow instruction is generated. If the verification fails, the local timekeeping instruction is generated.

[0083] Step 5, the local timekeeping unit performs synchronous following or local timekeeping according to the time synchronization information. Specifically, when the time synchronization information is a synchronous following instruction, the decoded information received from the device this time is used for local timekeeping. When the time synchronization information is a local timekeeping instruction, that is, asynchronous following, the local time generated by the slave device itself continues to be used for local timekeeping.

[0084] To further clarify the technical solution of the present invention and the beneficial technical effects it brings, the following application examples are introduced. The power secondary equipment time information network system and fault-tolerant time synchronization method of the present invention have a wide range of application scenarios, including multi-device time synchronization, multi-plug-in time synchronization, and multi-device multi-plug-in time synchronization application scenarios.

[0085] like Figure 2As shown, in a multi-device time synchronization application scenario, device 1 requiring time synchronization uses a time information network transmission module, while the remaining devices requiring time synchronization use a time information network receiving module to achieve time synchronization for all devices requiring time synchronization. The B-code selection unit of the time information network transmission module in device 1 receives an external electrical B-code or optical B-code. In complex electromagnetic environments, the B-code selection unit selects the B-code with the external electrical B-code or optical B-code, selecting the higher-quality B-code and sending it to the B-code decoding unit. The B-code decoding unit decodes the B-code in the B-code selection unit. The decoded time information is combined with the millisecond information from the millisecond counting unit to form millisecond-containing time information. This millisecond-containing time information passes through the CRC calculation unit, along with the CRC calculation result, and enters the time synchronization transmission unit. The time synchronization sending unit of device 1 is connected to the time synchronization receiving unit in each time information network receiving module of devices such as device 2 or device 3. Taking device 2 as an example, the time synchronization receiving unit in device 2 receives the time synchronization sending unit in the time information network sending module of device 1. The received data of the time synchronization receiving unit enters the CRC check unit, and the CRC check unit performs check calculation. The synchronization selection unit makes a synchronization selection based on the check result, and the selected time information enters the local timekeeping unit for local timekeeping of device 2.

[0086] like Figure 3 As shown, in a multi-plug-in time synchronization application scenario, plug-in 1 with time synchronization requirements uses the time information network sending module, while the remaining plug-ins with time synchronization requirements use the time information network receiving module to achieve time synchronization for each plug-in with time synchronization requirements. The B-code selection unit of the time information network sending module in plug-in 1 receives an external electrical B-code or optical B-code. In a complex electromagnetic environment, the B-code selection unit makes a selection based on the external electrical B-code or optical B-code, and selects the B-code with better quality to enter the B-code decoding unit. The B-code decoding unit decodes the B-code in the B-code selection unit. The time information obtained by decoding and the millisecond information of the millisecond counting unit are combined to form the time information with milliseconds. The time information with milliseconds passes through the CRC calculation unit and, together with the CRC calculation result, enters the time synchronization sending unit. The time synchronization sending unit of plug-in 1 is connected to the time synchronization receiving unit in each time information network receiving module of plug-in 2 or plug-in 3. Taking plug-in 2 as an example, the time synchronization receiving unit in plug-in 2 receives the time synchronization sending unit in the time information network sending module of plug-in 1. The received data of the time synchronization receiving unit enters the CRC check unit, and the CRC check unit performs check calculation. The synchronization selection unit makes a synchronization selection based on the check result, and the selected time information enters the local timekeeping unit for the local timekeeping of plug-in 2.

[0087] like Figure 4As shown, in a multi-device, multi-plug-in time synchronization application scenario, plug-in 1 in device 1 with time synchronization requirements uses a time information network sending module, while plug-ins in other devices with time synchronization requirements use a time information network receiving module, thereby achieving time synchronization for multiple devices and multiple plug-ins with time synchronization requirements. The B-code selection unit of the time information network sending module of plug-in 1 in device 1 receives an external electrical B-code or optical B-code. In a complex electromagnetic environment, the B-code selection unit makes a selection based on the external electrical B-code or optical B-code, and selects a B-code with better quality to enter the B-code decoding unit. The B-code decoding unit decodes the B-code in the B-code selection unit. The time information obtained by decoding and the millisecond information of the millisecond counting unit form the time information with milliseconds. The time information with milliseconds passes through the CRC calculation unit and, together with the CRC calculation result, enters the time synchronization sending unit. The time synchronization sending unit of plug-in 1 in device 1 is connected to the time synchronization receiving unit in the time information network receiving module in the plug-ins with time synchronization requirements in other devices. Taking plug-in 1 in device 2 as an example, the time synchronization receiving unit of plug-in 1 in device 2 receives the time synchronization sending unit in the time information network sending module of plug-in 1 in device 1. The received data of the time synchronization receiving unit enters the CRC check unit, and the CRC check unit performs check calculation. The synchronization selection unit makes a synchronization selection based on the check result, and the selected time information enters the local timekeeping unit for the local timekeeping of plug-in 1 in device 2.

[0088] Compared with the prior art, the beneficial effects of the present invention include at least:

[0089] 1) The time information network system and time synchronization method proposed in the present invention perform CRC calculation and verification on millisecond time information, and perform synchronous following or local timekeeping based on time synchronization information, thereby improving the system's time synchronization and anti-interference performance, and occasional communication errors do not affect the time synchronization accuracy.

[0090] 2) The time information network system and time synchronization method proposed in the present invention are applied to the time synchronization of multiple devices and multiple plug-ins of power secondary equipment. The B code selection unit selects a B code with better quality, which significantly improves the time synchronization accuracy.

[0091] 3) The time information network system and time synchronization method proposed in the present invention adopt a simple non-redundant structure and are less costly.

[0092] 4) The time information network system and time synchronization method proposed in the present invention can achieve time synchronization between various devices, improve the reliability and safety of the power system, thereby ensuring the stable operation of the power system, and at the same time improve the management efficiency and maintenance accuracy of the power system.

[0093] The present disclosure may be a system, method and / or computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A power secondary equipment time information network system, comprising a time information network sending module and a plurality of time information network receiving modules, characterized in that: The time information network sending module includes: a B code selection unit, a B code decoding unit, a millisecond counting unit, a cyclic redundancy calculation unit and a time synchronization sending unit; each of the time information network receiving modules includes: a time synchronization receiving unit, a cyclic redundancy check unit, a synchronization selection unit and a local timekeeping unit; The B code selection unit receives an external electrical B code or an optical B code and makes a selection, and transmits the selected B code to the B code decoding unit; The B code decoding unit decodes the selected B code to obtain a second pulse signal and time information accurate to the second, and transmits the decoded time information to the millisecond counting unit; The millisecond counting unit generates millisecond information, which is combined with the decoded time information to form the time information with milliseconds, and is passed to the cyclic redundancy calculation unit; The cyclic redundancy calculation unit performs cyclic redundancy check calculation on the time information with milliseconds; The time synchronization sending unit is connected to each time synchronization receiving unit, and the time synchronization sending unit sends time information data consisting of millisecond time information and cyclic redundancy check calculation results to each time synchronization receiving unit; The time synchronization receiving unit sends the received time information data to the cyclic redundancy check unit for verification calculation; The synchronization selection unit makes a synchronization selection based on the verification result, and the selected time synchronization information enters the local timekeeping unit; The local timekeeping unit performs synchronization following or local timekeeping according to the time synchronization information.

2. The power secondary equipment time information network system according to claim 1, characterized in that: All devices or plug-ins that need to be synchronized in the power secondary equipment are connected to the time information network system. There is only one time information network sending module in the time information network system, and the rest are time information network receiving modules.

3. The power secondary equipment time information network system according to claim 1, characterized in that: The electrical B code and the optical B code are de-jittered, and the B code selection unit receives the de-jittered electrical B code or the optical B code.

4. The power secondary equipment time information network system according to claim 1, characterized in that: The B code selection unit uses the electrical B code by default. When it detects that the optical B code is connected, it switches to the optical B code. When it detects that the optical B code is disconnected, it switches to the electrical B code.

5. The power secondary equipment time information network system according to claim 1, characterized in that: In the cyclic redundancy calculation unit, the cyclic redundancy check calculation process is expressed as follows: D(x)×x k ÷G(x)=Q(x)…R(x) Where D(x) is the polynomial corresponding to the millisecond time information, x is the formal variable, k is the check code length of the cyclic redundancy check, G(x) is the generator polynomial, Q(x) is the quotient polynomial, and R(x) is the remainder polynomial.

6. The power secondary equipment time information network system according to claim 5, characterized in that: The generating polynomial G(x) is expressed as follows: X 16 +X 13 +X 12 +X 11 +X 10 +X 8 +X 6 +X 5 +X 2 +1。 7. The power secondary equipment time information network system according to claim 1, characterized in that: In the time synchronization sending unit, the time information data sent is expressed as follows: T(x)=D(x)×x k +R(x) Where T(x) is the time information data sent by the time synchronization sending unit, D(x) is the polynomial corresponding to the time information with milliseconds, k is the check code length of the cyclic redundancy check, and R(x) is the remainder polynomial.

8. The power secondary equipment time information network system according to claim 1, characterized in that: In the cyclic redundancy check unit, a cyclic redundancy check calculation is performed on the received time information data using the same generating polynomial as that in the time information network sending module. The calculation method is consistent with that of the cyclic redundancy check calculation unit in the time information network sending module. If the cyclic redundancy check result calculated by the cyclic redundancy check unit is consistent with the cyclic redundancy check calculation result in the received time information data, the check passes; if the cyclic redundancy check result calculated by the cyclic redundancy check unit is inconsistent with the cyclic redundancy check calculation result in the received time information data, the check fails.

9. The power secondary equipment time information network system according to claim 1, characterized in that: In the synchronization selection unit, the time synchronization information includes a synchronization follow instruction and a local timekeeping instruction, wherein if the verification passes, the synchronization follow instruction is generated, and if the verification fails, the local timekeeping instruction is generated; In the local timekeeping unit, when the time synchronization information is a synchronous follow instruction, the time information with milliseconds received this time is used, otherwise the local time generated by the local timekeeping unit itself is used.

10. A fault-tolerant timing method for power secondary equipment, implemented based on the power secondary equipment time information network system according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: Select one of all the power secondary devices that need time synchronization as the master device, and the rest are slave devices. The master device is equipped with a time information network sending module, and the B code selection unit receives the external electrical B code or optical B code signal and makes a selection; Step 2: The B code decoding unit decodes the selected B code, and the millisecond counting unit combines the decoded time information and the millisecond information into time information with milliseconds; Step 3: The cyclic redundancy calculation unit performs a cyclic redundancy check calculation on the time information with milliseconds, and the time transmission unit sends the cyclic redundancy check calculation result and the time information with milliseconds to each slave device; Step 4: The slave device sets a time information network receiving module, the cyclic redundancy check unit performs a check calculation on the cyclic redundancy check calculation result and the time information with milliseconds received by the time synchronization receiving unit, and the synchronization selection unit performs synchronization selection to generate time synchronization information; Step 5: The local timekeeping unit performs synchronization following or local timekeeping according to the time synchronization information.

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