A protection system and method for a zero-loss deep current limiting device

Abstract

The invention relates to the technical field of reactors, and discloses a protection system and method for a zero-loss deep current limiting device. The method obtains the number of times the current limiting reactor is put into operation within a preset period by acquiring the switching-in state of the current limiting reactor, generates a switching-in state execution instruction according to a comparison result between the number of times the current limiting reactor is put into operation and a preset switching-in and switching-out number constant, thereby exiting the current limiting reactor and locking its input function, further obtains the operating temperature and the short-circuit current of the switch branch, generates a joint trip execution instruction according to a comparison result between the short-circuit current of the switch branch and a preset joint trip short-circuit current constant, so as to joint trip the current limiting reactor to a bus switch and a main transformer low-voltage switch, and generates a switching-in state execution instruction according to a comparison result between the operating temperature and a preset overheat protection temperature constant, so as to exit or lock the input function of the current limiting reactor when the temperature of the current limiting reactor of the zero-loss deep current limiting device is too high, thereby improving the operating stability of the current limiting reactor.

Description

Technical Field

[0001] The present invention relates to the technical field of reactors, and in particular to a protection system and method for a zero-loss deep current limiting device. Background Art

[0002] As the system capacity continues to grow, the short-circuit current exceeds the standard seriously when the 10kV busbars of the substation are running in parallel. If a short-circuit fault occurs near the busbar, the circuit breaker will not be able to interrupt the excessive short-circuit current, which may cause equipment damage, over-tripping and busbar pressure loss accidents, causing large-scale power outages in the power supply area, bringing significant economic losses and adverse social impacts.

[0003] Generally speaking, the system mainly limits the 10kV bus short-circuit current by selecting a high-impedance transformer or installing a fixed current-limiting reactor on the 10kV side of the low-impedance transformer. However, the increase in impedance brings about voltage drop and loss problems, which not only causes the 10kV bus voltage to decrease but also causes huge power loss in long-term operation.

[0004] To solve the above problems, some substations currently use zero-loss deep current limiting devices to replace existing conventional current limiting reactors. The zero-loss deep current limiting device is composed of a fast switch and a current limiting reactor in parallel, which is installed in series between the transformer and the 10kV busbar or in series on the 110kV line that needs current limiting. When the system is operating normally, the fast switch is in the closed position, and the device is in a "zero loss, zero voltage drop" working state; when a short-circuit fault occurs in the system, the device will put the current limiting reactor into operation within 20ms and enter the "current limiting" working state; after the system short-circuit fault is removed, the device will return within 35ms and restore the "zero loss, zero voltage drop" working state. The device can effectively reduce the impact of short-circuit current on the 10kV switch, ensure reliable power supply for 10kV users, and achieve the goal of "reliable short-circuit current limitation, safety, energy saving, and consumption reduction".

[0005] However, the current-limiting reactor of the zero-loss deep current limiting device works in a short-time mode and is only put into operation when a short-circuit fault occurs. When the zero-loss deep current limiting device is put into operation and withdrawn multiple times in a short period of time or the current-limiting reactor is put into operation for a long time due to reasons such as damage to the fast switch, jamming, and controller failure, the current-limiting reactor may heat up severely and may even be damaged due to excessive heat generation. Therefore, it is necessary to protect the current-limiting reactor from damage.

[0006] At present, in the prior art, the protection methods for the reactor include:

[0007] A Chinese invention patent with publication number CN103515924B discloses a method for protecting a series reactor. When the absolute value of the difference between the actual impedance ratio and the standard impedance ratio exceeds the set impedance ratio error value, an alarm signal is issued and the series reactor is withdrawn from the system circuit. However, the disclosed technology of this patent does not pay attention to the dynamic process of the current limiting reactor during the process of being put into and withdrawn from the system, and it is difficult to ensure the stability of the operation of the current limiting reactor. Summary of the invention

[0008] The present invention provides a protection system and method for a zero-loss deep current limiting device, which are used to solve the technical problem of poor stability in the operation of a current limiting reactor.

[0009] In view of this, the first aspect of the present invention provides a protection system for a zero-loss deep current limiting device, wherein the zero-loss deep current limiting device comprises a current limiting reactor and a fast switch connected in parallel therewith, wherein the zero-loss deep current limiting device is connected to a line between a transformer and a busbar, and wherein the protection system comprises: an input module, a counting module, a control module, a sampling module and an output module;

[0010] The switching-in module is used to obtain the switching-in state of the current-limiting reactor, wherein the switching-in state includes switching-in and switching-out, and is also used to generate a short-time pulse and send it to the counting module when the switching-in state of the current-limiting reactor is switching-out;

[0011] The counting module is used to count the number of short-time pulses received within a preset period to obtain the number of times the current-limiting reactor is put into operation within the preset period, and send the number of times the current-limiting reactor is put into operation to the control module;

[0012] The sampling module is used to obtain the operating temperature of the current limiting reactor and the short-circuit current of the switch branch, and send the operating temperature of the current limiting reactor and the short-circuit current of the switch branch to the control module;

[0013] The control module is used to generate an input state execution instruction based on a preset current limiting reactor throw-in and throw-out discrimination rule and a comparison result between the throw-in times of the current limiting reactor and a preset throw-in and throw-out times constant value, and send it to the output module. The input state execution instruction includes the exit current limiting reactor and the lock current limiting reactor throw-in function; it is also used to generate a joint jump execution instruction based on a preset joint jump rule and a comparison result between the short-circuit current of the switch branch and a preset joint jump short-circuit current constant value, and send it to the output module. The joint jump execution instruction includes joint jump to the bus switch and joint jump to the main transformer low switch; it is also used to generate an input state execution instruction based on a preset reactor temperature protection rule and a comparison result between the operating temperature and a preset overheat protection temperature constant value;

[0014] The output module is used to perform corresponding execution instruction operations on the current-limiting reactor according to the input state execution instruction and the joint jump execution instruction.

[0015] Preferably, the preset current limiting reactor switching judgment rule includes:

[0016] 101. Determine whether the number of times the current limiting reactor is put into operation is greater than or equal to a preset number of times of putting in and out. If the number of times the current limiting reactor is put into operation is greater than or equal to the preset number of times of putting in and out, execute the next step. If the number of times the current limiting reactor is put into operation is less than the preset number of times of putting in and out, execute step 104.

[0017] 102. Calculate the Nth time t corresponding to the current limiting reactor being put into operation N With current limiting reactor No. NN set+1 The input time corresponding to the input (N-Nset+1) The input time difference is: set+1 The next investment number for the preset investment and withdrawal number setting value is determined, and whether the investment time difference is greater than the preset short-time investment and withdrawal time setting value is determined. If the investment time difference is not greater than the preset short-time investment and withdrawal time setting value, the next step is executed. If the investment time difference is greater than the preset short-time investment and withdrawal time setting value, step 104 is executed.

[0018] 103. Generate an execution instruction including exiting the open-in state of the current limiting reactor;

[0019] 104. Calculate the long-term input detection time of the current-limiting reactor according to the time corresponding to the execution of the current step and the preset short-term input and output time constant;

[0020] 105. Detection input time t N Whether there is a current limiting reactor in operation within the short-time switching time setting value, if it is detected that there is a current limiting reactor in operation, the next step is executed; if it is not detected that there is a current limiting reactor in operation, step 107 is executed;

[0021] 106. Increase the number of times the current limiting reactor is put into operation, obtain the time of the current limiting reactor being put into operation for the N+1th time, and go to step 101;

[0022] 107. Determine whether the current limiting reactor has exited. If the current limiting reactor has not exited, generate an on-state execution instruction including a function of locking the current limiting reactor. If the current limiting reactor has exited, end the current cycle and wait for the next cycle to arrive.

[0023] Preferably, the preset joint jump rule includes:

[0024] 201. Determine whether the short-circuit current of the switch branch is greater than or equal to a preset joint short-circuit current setting value. If it is determined that the short-circuit current of the switch branch is greater than or equal to the preset joint short-circuit current setting value, execute the next step. If it is determined that the short-circuit current of the switch branch is less than the preset joint short-circuit current setting value, end.

[0025] 202. Generate a jump execution instruction for jump to the bus switch;

[0026] 203. Obtain the short-circuit current of the switch branch of the current-limiting reactor after being linked to the bus switch, and determine whether the short-circuit current of the switch branch of the current-limiting reactor after being linked to the bus switch is greater than or equal to a preset linked short-circuit current setting value. If it is determined that the short-circuit current of the switch branch of the current-limiting reactor after being linked to the bus switch is greater than or equal to the preset linked short-circuit current setting value, execute the next step. If it is determined that the short-circuit current of the switch branch of the current-limiting reactor after being linked to the bus switch is less than the preset linked short-circuit current setting value, end.

[0027] 204. Generate a jump execution instruction for jump to the main transformer low switch.

[0028] Preferably, the preset reactor temperature protection rule specifically includes:

[0029] 301. Determine whether the working temperature is greater than a preset overheat protection temperature setting value. If the working temperature is greater than the preset overheat protection temperature setting value, execute the next step;

[0030] 302. Detect whether the current limiting reactor is put into operation. If the current limiting reactor is put into operation, execute the next step; if the current limiting reactor is not put into operation, execute step 304;

[0031] 303. Generate an execution instruction including exiting the switch-in state of the current limiting reactor;

[0032] 304. Generate an input state execution instruction including a function of locking the current-limiting reactor.

[0033] Preferably, the system further comprises:

[0034] The alarm module is used to generate an alarm instruction to issue an alarm when an execution instruction for exiting the switching-in state of the current-limiting reactor or an execution instruction for locking the switching-in state of the current-limiting reactor is generated.

[0035] Preferably, the system further comprises:

[0036] The execution detection module is used to detect the execution status of the corresponding open-in state execution instruction and the joint jump execution instruction of the current limiting inductor. If it is detected that the current limiting inductor fails to execute the corresponding open-in state execution instruction and the joint jump execution instruction, an alarm is issued.

[0037] In a second aspect, the present invention further provides a protection method for a zero-loss deep current limiting device, wherein the zero-loss deep current limiting device comprises a current limiting reactor and a fast switch connected in parallel therewith, wherein the zero-loss deep current limiting device is connected to a line between a transformer and a busbar, and the protection method comprises the following steps:

[0038] Acquire the switching-in state of the current-limiting reactor, wherein the switching-in state includes switching-in and switching-out. When the switching-in state of the current-limiting reactor is switching-out, generate a short-time pulse;

[0039] Calculating the number of short-time pulses received within a preset period to obtain the number of times the current-limiting reactor is put into operation within the preset period;

[0040] Obtaining the operating temperature of the current limiting reactor and the short-circuit current of the switch branch;

[0041] Based on the preset current limiting reactor throw-in / out discrimination rule, an input state execution instruction is generated according to the comparison result of the number of times the current limiting reactor is thrown in and out and the preset throw-in / out number constant value, and the input state execution instruction includes the exit of the current limiting reactor and the locking of the current limiting reactor throw-in function; based on the preset joint trip rule, a joint trip execution instruction is generated according to the comparison result of the short-circuit current of the switch branch and the preset joint trip short-circuit current constant value, and the joint trip execution instruction includes joint trip to the bus switch and joint trip to the main transformer low switch; based on the preset reactor temperature protection rule, an input state execution instruction is generated according to the comparison result of the working temperature and the preset overheat protection temperature constant value;

[0042] According to the input state execution instruction and the joint jump execution instruction, corresponding execution instruction operation is performed on the current limiting reactor.

[0043] It can be seen from the above technical solutions that the present invention has the following advantages:

[0044] The present invention obtains the number of times the current limiting reactor is put into operation within a preset period by acquiring the switching-in state of the current limiting reactor, and based on the preset current limiting reactor throwing-in and pulling-out judgment rules, generates a switching-in state execution instruction according to the comparison result of the number of times the current limiting reactor is put into operation and the preset throwing-in and pulling-out number constant, thereby exiting the current limiting reactor and locking its input function, avoiding the reactor from passing the short-circuit fault current for a long time, and preventing the reactor from being damaged by heating. The present invention also obtains the operating temperature of the current limiting reactor and the short-circuit current of the switch branch, and generates a joint trip execution instruction according to the comparison result of the short-circuit current of the switch branch and the preset joint trip short-circuit current constant, so as to jump the current limiting reactor to the bus switch and the main transformer low switch to ensure power supply reliability. At the same time, the switching-in state execution instruction is generated according to the comparison result of the operating temperature and the preset overheat protection temperature constant, so as to exit or lock the input function of the current limiting reactor when the temperature of the current limiting reactor of the zero-loss deep current limiting device is too high, thereby improving the stability of the operation of the current limiting reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A schematic diagram of the connection of a zero-loss deep current limiting device provided by an embodiment of the present invention under a 10kV bus;

[0046] Figure 2 A schematic diagram of the connection of a zero-loss deep current limiting device provided by an embodiment of the present invention under a 110kV bus;

[0047] Figure 3 A schematic diagram of the structure of a protection system for a zero-loss deep current limiting device provided by an embodiment of the present invention;

[0048] Figure 4 A flow chart of a protection method for a zero-loss deep current limiting device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] like Figures 1-2 As shown, Figure 1 It shows the connection diagram of zero-loss deep current limiting device under 10kV bus. Figure 2The diagram shows the connection of the zero-loss deep current limiting device under the 110kV bus. The zero-loss deep current limiting device includes a current limiting reactor and a fast switch connected in parallel therewith. The zero-loss deep current limiting device is connected to the line between the transformer and the bus. Since the current limiting reactor of the zero-loss deep current limiting device works in a short-time mode, it is only put into operation when a short-circuit fault occurs. When the zero-loss deep current limiting device is repeatedly put into operation or put into operation for a long time in a short period of time due to damage, jamming of the fast switch, controller failure, etc., the current limiting reactor may heat up seriously, and may even be damaged due to excessive heat generation. Therefore, it is necessary to protect the current limiting reactor from damage.

[0051] To do this, see Figure 3 The present invention provides a protection system for a zero-loss deep current limiting device, the protection system comprising: an input module 100, a counting module 200, a control module 300, a sampling module 400 and an output module 500;

[0052] The input module 100 is used to obtain the input state of the current limiting reactor, which includes input and output. When the input state of the current limiting reactor is output, a short-time pulse is generated and sent to the counting module 200.

[0053] The counting module 200 is used to count the number of short-time pulses received within a preset period to obtain the number of times the current-limiting reactor is put into operation within the preset period, and send the number of times the current-limiting reactor is put into operation to the control module 300;

[0054] The control module 300 can reset the count of the counting module 200 to obtain a complete cycle.

[0055] The sampling module 400 is used to obtain the operating temperature of the current limiting reactor and the short-circuit current of the switch branch, and send the operating temperature of the current limiting reactor and the short-circuit current of the switch branch to the control module 300;

[0056] The control module 300 is used to generate an input state execution instruction based on a preset current limiting reactor throw-in and throw-out discrimination rule and a comparison result between the number of throw-in and throw-out times of the current limiting reactor and a preset throw-in and throw-out number constant, and send it to the output module 500. The input state execution instruction includes the exit of the current limiting reactor and the locking of the current limiting reactor throw-in function; it is also used to generate a joint jump execution instruction based on a preset joint jump rule and a comparison result between the short-circuit current of the switch branch and a preset joint jump short-circuit current constant, and send it to the output module 500. The joint jump execution instruction includes joint jump to the bus switch and joint jump to the main transformer low switch; it is also used to generate an input state execution instruction based on a preset reactor temperature protection rule and a comparison result between the operating temperature and a preset overheat protection temperature constant;

[0057] The output module 500 is used to perform corresponding execution instruction operations on the current-limiting reactor according to the input state execution instruction and the joint jump execution instruction.

[0058] In addition, the system also includes a power module and a human-computer interaction module. The power module converts the externally connected DC110V (or DC220V) working power into the working power required by each module of the device;

[0059] The human-computer interaction module includes a touch screen, which is used to provide human-computer interaction scenarios such as parameter setting, function selection, and alarm information display.

[0060] Among them, the preset current limiting reactor switching judgment rules include:

[0061] 101. Determine whether the number of times the current limiting reactor is put into operation is greater than or equal to a preset number of times of putting in and out. If the number of times the current limiting reactor is put into operation is greater than or equal to the preset number of times of putting in and out, execute the next step. If the number of times the current limiting reactor is put into operation is less than the preset number of times of putting in and out, execute step 104.

[0062] It can be understood that, in the initial state, the number of inputs is 0 and the corresponding time is 0.

[0063] 102. Calculate the time t corresponding to the Nth time the current limiting reactor is put into operation N With current limiting reactor No. NN set+1 The input time corresponding to the input (N-Nset+1) The input time difference is: set+1 The next investment number for the preset investment and withdrawal number setting value is determined, and whether the investment time difference is greater than the preset short-time investment and withdrawal time setting value is determined. If the investment time difference is not greater than the preset short-time investment and withdrawal time setting value, the next step is executed. If the investment time difference is greater than the preset short-time investment and withdrawal time setting value, step 104 is executed;

[0064] Among them, if the time difference of input is not greater than the preset short-time input and output time value, the current limiting reactor is short-time input; if the time difference of input is greater than the preset short-time input and output time value, the current limiting reactor is long-time input.

[0065] 103. Generate an execution instruction including exiting the open-in state of the current limiting reactor;

[0066] 104. Calculate the long-term input detection time of the current-limiting reactor according to the time corresponding to the execution of the current step and the preset short-term input and output time constant;

[0067] 105. Detection input time t N Whether there is a current limiting reactor in operation within the short-time switching time setting value, if it is detected that there is a current limiting reactor in operation, the next step is executed; if it is not detected that there is a current limiting reactor in operation, step 107 is executed;

[0068] 106. Increase the number of times the current limiting reactor is put into operation, obtain the time of the current limiting reactor being put into operation for the N+1th time, and go to step 101;

[0069] 107. Determine whether the current limiting reactor has been exited. If the current limiting reactor has not been exited, generate an open state execution instruction including a function of locking the current limiting reactor. If the current limiting reactor has been exited, end the current cycle and wait for the next cycle to arrive.

[0070] It can be understood that through the current limiting reactor switching judgment rules, when the current limiting reactor is frequently switched on and off in a short period of time, the zero-loss deep current limiting device current limiting reactor can be shut down and its switching function can be locked to avoid multiple switching on and off in a short period of time, thereby effectively preventing damage to the reactor.

[0071] If the zero-loss deep current limiting device current limiting reactor is put into operation for a long time, the zero-loss deep current limiting device current limiting reactor will be shut down and its input function will be locked to prevent the reactor from passing short-circuit fault current for a long time and prevent the reactor from overheating and being damaged.

[0072] The preset joint jump rules include:

[0073] 201. Determine whether the short-circuit current of the switch branch is greater than or equal to a preset joint short-circuit current setting value. If it is determined that the short-circuit current of the switch branch is greater than or equal to the preset joint short-circuit current setting value, execute the next step. If it is determined that the short-circuit current of the switch branch is less than the preset joint short-circuit current setting value, end.

[0074] 202. Generate a jump execution instruction for jump to the bus switch;

[0075] 203. Obtain the short-circuit current of the switch branch of the current-limiting reactor after being linked to the bus switch, and determine whether the short-circuit current of the switch branch of the current-limiting reactor after being linked to the bus switch is greater than or equal to a preset linked short-circuit current setting value. If it is determined that the short-circuit current of the switch branch of the current-limiting reactor after being linked to the bus switch is greater than or equal to the preset linked short-circuit current setting value, execute the next step. If it is determined that the short-circuit current of the switch branch of the current-limiting reactor after being linked to the bus switch is less than the preset linked short-circuit current setting value, end.

[0076] 204. Generate a jump execution instruction for jump to the main transformer low switch.

[0077] In one example, it is necessary to delay a set time before the joint tripping. However, this system has a joint tripping function. After the zero-loss deep current limiting device current limiting reactor is automatically returned after a long time of input, if the short-circuit current in the switch branch still exists, it will be joint tripped to the bus switch and the main transformer low-voltage switch within the set time to cut off the permanent fault and ensure power supply reliability.

[0078] The preset reactor temperature protection rules specifically include:

[0079] 301. Determine whether the working temperature is greater than a preset overheat protection temperature setting value. If the working temperature is greater than the preset overheat protection temperature setting value, execute the next step;

[0080] 302. Detect whether the current limiting reactor is put into operation. If the current limiting reactor is put into operation, execute the next step; if the current limiting reactor is not put into operation, execute step 304;

[0081] 303. Generate an execution instruction including exiting the switch-in state of the current limiting reactor;

[0082] 304. Generate an input state execution instruction including a function of locking the current-limiting reactor.

[0083] It can be understood that when the temperature of the zero-loss deep current limiting device current limiting reactor is too high, the zero-loss deep current limiting device current limiting reactor input function is locked; when the zero-loss deep current limiting device current limiting reactor is put into operation, the current limiting reactor is first exited and then the zero-loss deep current limiting device current limiting reactor input function is locked.

[0084] In a specific embodiment, the system further includes:

[0085] The alarm module is used to generate an alarm instruction to issue an alarm when an execution instruction for exiting the switching-in state of the current-limiting reactor or an execution instruction for locking the switching-in state of the current-limiting reactor is generated.

[0086] In a specific embodiment, the system further includes:

[0087] The execution detection module is used to detect the execution status of the corresponding open-in state execution instruction and the joint jump execution instruction of the current limiting inductor. If it is detected that the current limiting inductor fails to execute the corresponding open-in state execution instruction and the joint jump execution instruction, an alarm is issued.

[0088] It can be understood that after the "execution" command is issued, it is detected whether the current limiting reactor of the zero-loss deep current limiting device has exited. If the current limiting reactor of the zero-loss deep current limiting device has not exited, a "fast switch fault" alarm is issued.

[0089] The present embodiment provides a protection system for a zero-loss deep current limiting device, which obtains the number of times the current limiting reactor is put into operation within a preset period by acquiring the switching-in state of the current limiting reactor, and generates a switching-in state execution instruction based on the comparison result of the number of times the current limiting reactor is put into operation and the preset switching-in and switching-out number constant value based on the preset current limiting reactor throwing-in and pulling-out judgment rules, thereby exiting the current limiting reactor and locking its input function, avoiding the reactor from passing the short-circuit fault current for a long time, and preventing the reactor from being damaged by heating. The operating temperature of the current limiting reactor and the short-circuit current of the switch branch are also obtained, and a joint trip execution instruction is generated based on the comparison result of the short-circuit current of the switch branch and the preset joint trip short-circuit current constant value, so as to joint trip the current limiting reactor to the bus switch and the main transformer low-voltage switch to ensure power supply reliability. At the same time, the switching-in state execution instruction is generated based on the comparison result of the operating temperature and the preset overheat protection temperature constant value, so as to exit or lock the input function of the current limiting reactor when the temperature of the current limiting reactor of the zero-loss deep current limiting device is too high, thereby improving the stability of the operation of the current limiting reactor.

[0090] The above is a detailed description of an embodiment of a protection system of a zero-loss deep current limiting device provided by the present invention. The following is a detailed description of an embodiment of a protection method of a zero-loss deep current limiting device provided by the present invention.

[0091] The present invention provides a protection method for a zero-loss deep current limiting device, wherein the zero-loss deep current limiting device comprises a current limiting reactor and a fast switch connected in parallel therewith, and the zero-loss deep current limiting device is connected to the line between the transformer and the busbar, see Figure 4 , the protection method includes the following steps:

[0092] S1. Obtain the switching-in state of the current-limiting reactor. The switching-in state includes switching-in and switching-out. When the switching-in state of the current-limiting reactor is switching-out, a short-time pulse is generated.

[0093] S2. Calculate the number of short-time pulses received within a preset period to obtain the number of times the current-limiting reactor is put into operation within the preset period;

[0094] S3, obtaining the operating temperature of the current limiting reactor and the short-circuit current of the switch branch;

[0095] S4, based on the preset current limiting reactor throw-in / out discrimination rule, according to the comparison result of the throw-in / out times of the current limiting reactor and the preset throw-in / out times constant value, generate the switch-in state execution instruction, the switch-in state execution instruction includes the exit of the current limiting reactor and the locking of the throw-in function of the current limiting reactor; based on the preset joint trip rule, according to the comparison result of the short-circuit current of the switch branch and the preset joint trip short-circuit current constant value, generate the joint trip execution instruction, the joint trip execution instruction includes the joint trip to the bus switch and the joint trip to the main transformer low switch; based on the preset reactor temperature protection rule, according to the comparison result of the working temperature and the preset overheat protection temperature constant value, generate the switch-in state execution instruction;

[0096] S5. Perform corresponding execution instruction operations on the current limiting reactor according to the input status execution instruction and the joint jump execution instruction.

[0097] Among them, the preset current limiting reactor switching judgment rules include:

[0098] 101. Determine whether the number of times the current limiting reactor is put into operation is greater than or equal to a preset number of times of putting in and out. If the number of times the current limiting reactor is put into operation is greater than or equal to the preset number of times of putting in and out, execute the next step. If the number of times the current limiting reactor is put into operation is less than the preset number of times of putting in and out, execute step 104.

[0099] It can be understood that, in the initial state, the number of inputs is 0 and the corresponding time is 0.

[0100] 102. Calculate the time t corresponding to the Nth time the current limiting reactor is put into operation N With current limiting reactor No. NN set+1 The input time corresponding to the input (N-Nset+1) The input time difference is: set+1 The next investment number for the preset investment and withdrawal number setting value is determined, and whether the investment time difference is greater than the preset short-time investment and withdrawal time setting value is determined. If the investment time difference is not greater than the preset short-time investment and withdrawal time setting value, the next step is executed. If the investment time difference is greater than the preset short-time investment and withdrawal time setting value, step 104 is executed;

[0101] Among them, if the time difference of input is not greater than the preset short-time input and output time value, the current limiting reactor is short-time input; if the time difference of input is greater than the preset short-time input and output time value, the current limiting reactor is long-time input.

[0102] 103. Generate an execution instruction including exiting the open-in state of the current limiting reactor;

[0103] 104. Calculate the long-term input detection time of the current-limiting reactor according to the time corresponding to the execution of the current step and the preset short-term input and output time constant;

[0104] 105. Detection input time t N Whether there is a current limiting reactor in operation within the short-time switching time setting value, if it is detected that there is a current limiting reactor in operation, the next step is executed; if it is not detected that there is a current limiting reactor in operation, step 107 is executed;

[0105] 106. Increase the number of times the current limiting reactor is put into operation, obtain the time of the current limiting reactor being put into operation for the N+1th time, and go to step 101;

[0106] 107. Determine whether the current limiting reactor has been exited. If the current limiting reactor has not been exited, generate an on-state execution instruction including a function of locking the current limiting reactor. If the current limiting reactor has been exited, end the current cycle and wait for the next cycle to arrive.

[0107] It can be understood that through the current limiting reactor switching judgment rules, when the current limiting reactor is frequently switched on and off in a short period of time, the zero-loss deep current limiting device current limiting reactor can be switched off and its switching function can be locked to avoid its multiple switching on and off in a short period of time, thereby effectively preventing damage to the reactor.

[0108] If the zero-loss deep current limiting device current limiting reactor is put into operation for a long time, the zero-loss deep current limiting device current limiting reactor will be shut down and its input function will be locked to prevent the reactor from passing short-circuit fault current for a long time and prevent the reactor from overheating and being damaged.

[0109] The preset joint jump rules include:

[0110] 201. Determine whether the short-circuit current of the switch branch is greater than or equal to a preset joint short-circuit current setting value. If it is determined that the short-circuit current of the switch branch is greater than or equal to the preset joint short-circuit current setting value, execute the next step. If it is determined that the short-circuit current of the switch branch is less than the preset joint short-circuit current setting value, end.

[0111] 202. Generate a jump execution instruction for jump to the bus switch;

[0112] 203. Obtain the short-circuit current of the switch branch of the current-limiting reactor after being linked to the bus switch, and determine whether the short-circuit current of the switch branch of the current-limiting reactor after being linked to the bus switch is greater than or equal to a preset linked short-circuit current setting value. If it is determined that the short-circuit current of the switch branch of the current-limiting reactor after being linked to the bus switch is greater than or equal to the preset linked short-circuit current setting value, execute the next step. If it is determined that the short-circuit current of the switch branch of the current-limiting reactor after being linked to the bus switch is less than the preset linked short-circuit current setting value, end.

[0113] 204. Generate a jump execution instruction for jump to the main transformer low switch.

[0114] In one example, it is necessary to delay a set time before the joint tripping. However, this system has a joint tripping function. After the zero-loss deep current limiting device current limiting reactor is automatically returned after a long time of input, if the short-circuit current in the switch branch still exists, it will be joint tripped to the bus switch and the main transformer low-voltage switch within the set time to cut off the permanent fault and ensure power supply reliability.

[0115] The preset reactor temperature protection rules specifically include:

[0116] 301. Determine whether the working temperature is greater than a preset overheat protection temperature setting value. If the working temperature is greater than the preset overheat protection temperature setting value, execute the next step;

[0117] 302. Detect whether the current limiting reactor is put into operation. If the current limiting reactor is put into operation, execute the next step; if the current limiting reactor is not put into operation, execute step 304;

[0118] 303. Generate an execution instruction including exiting the switch-in state of the current limiting reactor;

[0119] 304. Generate an input state execution instruction including a function of locking the current-limiting reactor.

[0120] It can be understood that when the temperature of the zero-loss deep current limiting device current limiting reactor is too high, the zero-loss deep current limiting device current limiting reactor input function is locked; when the zero-loss deep current limiting device current limiting reactor is put into operation, the current limiting reactor is first exited and then the zero-loss deep current limiting device current limiting reactor input function is locked.

[0121] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the method described above can refer to the corresponding process in the aforementioned system embodiment, and will not be repeated here.

[0122] In the several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0123] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0124] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0125] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A protection system of a zero-loss deep current limiting device, wherein the zero-loss deep current limiting device comprises a current limiting reactor and a fast switch connected in parallel therewith, wherein the zero-loss deep current limiting device is connected to a line between a transformer and a busbar, and is characterized in that: Its protection system includes: input module, counting module, control module, sampling module and output module; The switching-in module is used to obtain the switching-in state of the current-limiting reactor, wherein the switching-in state includes switching-in and switching-out, and is also used to generate a short-time pulse and send it to the counting module when the switching-in state of the current-limiting reactor is switching-out; The counting module is used to count the number of short-time pulses received within a preset period to obtain the number of times the current-limiting reactor is put into operation within the preset period, and send the number of times the current-limiting reactor is put into operation to the control module; The sampling module is used to obtain the operating temperature of the current limiting reactor and the short-circuit current of the switch branch, and send the operating temperature of the current limiting reactor and the short-circuit current of the switch branch to the control module; The control module is used to generate an input state execution instruction based on a preset current limiting reactor throw-in and throw-out discrimination rule and a comparison result between the throw-in times of the current limiting reactor and a preset throw-in and throw-out times constant value, and send it to the output module. The input state execution instruction includes the exit current limiting reactor and the lock current limiting reactor throw-in function; it is also used to generate a joint jump execution instruction based on a preset joint jump rule and a comparison result between the short-circuit current of the switch branch and a preset joint jump short-circuit current constant value, and send it to the output module. The joint jump execution instruction includes joint jump to the bus switch and joint jump to the main transformer low switch; it is also used to generate an input state execution instruction based on a preset reactor temperature protection rule and a comparison result between the operating temperature and a preset overheat protection temperature constant value; The output module is used to perform corresponding execution instruction operations on the current-limiting reactor according to the input state execution instruction and the joint jump execution instruction.

2. The protection system of the zero-loss deep current limiting device according to claim 1, characterized in that: The preset current limiting reactor switching judgment rules include:

101. Determine whether the number of times the current limiting reactor is put into operation is greater than or equal to a preset number of times of putting in and out. If the number of times the current limiting reactor is put into operation is greater than or equal to the preset number of times of putting in and out, execute the next step. If the number of times the current limiting reactor is put into operation is less than the preset number of times of putting in and out, execute step 104.

102. Calculate the Nth time t corresponding to the current limiting reactor being put into operation N With current limiting reactor No. NN set+1 The input time corresponding to the input (N-Nset+1) The input time difference is: set+1 The next investment number for the preset investment and withdrawal number setting value is determined, and whether the investment time difference is greater than the preset short-time investment and withdrawal time setting value is determined. If the investment time difference is not greater than the preset short-time investment and withdrawal time setting value, the next step is executed. If the investment time difference is greater than the preset short-time investment and withdrawal time setting value, step 104 is executed.

103. Generate an execution instruction including exiting the open-in state of the current limiting reactor; 104. Calculate the long-term input detection time of the current-limiting reactor according to the time corresponding to the execution of the current step and the preset short-term input and output time constant; 105. Detection input time t N Whether there is a current limiting reactor in operation within the short-time switching time setting value, if it is detected that there is a current limiting reactor in operation, the next step is executed; if it is not detected that there is a current limiting reactor in operation, step 107 is executed; 106. Increase the number of times the current limiting reactor is put into operation, obtain the time of the current limiting reactor being put into operation for the N+1th time, and go to step 101; 107. Determine whether the current limiting reactor has exited. If the current limiting reactor has not exited, generate an on-state execution instruction including a function of locking the current limiting reactor. If the current limiting reactor has exited, end the current cycle and wait for the next cycle to arrive.

3. The protection system of the zero-loss deep current limiting device according to claim 2, characterized in that: The preset joint jump rules include:

201. Determine whether the short-circuit current of the switch branch is greater than or equal to a preset joint short-circuit current setting value. If it is determined that the short-circuit current of the switch branch is greater than or equal to the preset joint short-circuit current setting value, execute the next step. If it is determined that the short-circuit current of the switch branch is less than the preset joint short-circuit current setting value, end.

202. Generate a jump execution instruction for jump to the bus switch; 203. Obtain the short-circuit current of the switch branch of the current-limiting reactor after being linked to the bus switch, and determine whether the short-circuit current of the switch branch of the current-limiting reactor after being linked to the bus switch is greater than or equal to a preset linked short-circuit current setting value. If it is determined that the short-circuit current of the switch branch of the current-limiting reactor after being linked to the bus switch is greater than or equal to the preset linked short-circuit current setting value, execute the next step. If it is determined that the short-circuit current of the switch branch of the current-limiting reactor after being linked to the bus switch is less than the preset linked short-circuit current setting value, end.

204. Generate a jump execution instruction for jump to the main transformer low switch.

4. The protection system of the zero-loss deep current limiting device according to claim 3, characterized in that: The preset reactor temperature protection rule specifically includes:

301. Determine whether the working temperature is greater than a preset overheat protection temperature setting value. If the working temperature is greater than the preset overheat protection temperature setting value, execute the next step; 302. Detect whether the current limiting reactor is put into operation. If the current limiting reactor is put into operation, execute the next step; if the current limiting reactor is not put into operation, execute step 304; 303. Generate an execution instruction including exiting the switch-in state of the current limiting reactor; 304. Generate an input state execution instruction including a function of locking the current-limiting reactor.

5. The protection system of the zero-loss deep current limiting device according to claim 4, characterized in that: Also includes: The alarm module is used to generate an alarm instruction to issue an alarm when an execution instruction for exiting the switching-in state of the current-limiting reactor or an execution instruction for locking the switching-in state of the current-limiting reactor is generated.

6. The protection system of the zero-loss deep current limiting device according to claim 1, characterized in that: Also includes: The execution detection module is used to detect the execution status of the corresponding open-in state execution instruction and the joint jump execution instruction of the current limiting inductor. If it is detected that the current limiting inductor fails to execute the corresponding open-in state execution instruction and the joint jump execution instruction, an alarm is issued.

7. A protection method for a zero-loss deep current limiting device, wherein the zero-loss deep current limiting device comprises a current limiting reactor and a fast switch connected in parallel therewith, wherein the zero-loss deep current limiting device is connected to a line between a transformer and a busbar, characterized in that: The protection method includes the following steps: Acquire the switching-in state of the current-limiting reactor, wherein the switching-in state includes switching-in and switching-out. When the switching-in state of the current-limiting reactor is switching-out, generate a short-time pulse; Calculating the number of short-time pulses received within a preset period to obtain the number of times the current-limiting reactor is put into operation within the preset period; Obtaining the operating temperature of the current limiting reactor and the short-circuit current of the switch branch; Based on the preset current limiting reactor throw-in / out discrimination rule, an input state execution instruction is generated according to the comparison result of the number of times the current limiting reactor is thrown in and out and the preset throw-in / out number constant value, and the input state execution instruction includes the exit of the current limiting reactor and the locking of the current limiting reactor throw-in function; based on the preset joint trip rule, a joint trip execution instruction is generated according to the comparison result of the short-circuit current of the switch branch and the preset joint trip short-circuit current constant value, and the joint trip execution instruction includes joint trip to the bus switch and joint trip to the main transformer low switch; based on the preset reactor temperature protection rule, an input state execution instruction is generated according to the comparison result of the working temperature and the preset overheat protection temperature constant value; According to the input state execution instruction and the joint jump execution instruction, corresponding execution instruction operation is performed on the current limiting reactor.

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