Method, device and equipment for calculating power delivered by direct current fault loss for stability control

Abstract

The application discloses a kind of stable control's DC fault loss transmission power calculation method: stable control device receives each valve group transmission power instruction value sent by DC control protection system, when detecting that the device meets starting condition, lock the transmission power instruction value of each valve group before preset time as each valve group steady-state DC transmission power instruction value, receive each pole post-accident power update mark and post-accident transmission power value sent by DC control protection when DC is locked converter due to fault, calculate the power loss amount of DC valve group after locking due to fault, equal to the sum of each valve group steady-state DC transmission power instruction value minus the sum of each pole post-accident transmission power value.The application also discloses corresponding stable control device.The method of the application improves the accuracy of lost transmission power calculation when DC is locked due to fault, which can effectively avoid the misoperation and refusal of power grid stability control system caused by DC fault loss transmission power calculation error.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of power system automation, and particularly relates to a DC fault loss power transmission calculation method for stability control in a power system, a stability control device adopting the method, and electronic equipment. BACKGROUND

[0002] A safety and stability control automatic device (hereinafter referred to as a "stability control device") is an indispensable second and third line of defense for maintaining the safe and stable and reliable operation of a power system, and is widely used in domestic power systems. High-voltage / ultra-high-voltage DC power transmission has a long distance and high economic benefits. The DC power transmission system has a large transmission power, and a fault or blocking of the DC system causes a large power transfer or system power imbalance, which seriously threatens the safe and stable operation of the power grid. The DC power transmission system is configured with a corresponding safety and stability automatic device for solving the stability problem of the power grid after a fault or blocking of the DC system, and for ensuring the safe and stable operation of the power grid. The stability control device is required to accurately calculate the DC fault loss power transmission, and to take corresponding control measures according to the loss amount, generally taking generator tripping control measures at the rectifier side and taking load shedding control measures at the inverter side. Whether the DC fault loss power transmission calculation is accurate is crucial for the correct operation of the safety and stability control system.

[0003] The calculation method of the DC fault loss power transmission used by the currently operating stability control device needs the stability control device to determine whether the remaining valve group after the valve group is blocked due to a fault can perform power transfer, according to the control mode of each pole of the DC, if the power transfer can be performed, it is determined that the transfer is successful, and the maximum operating capacity of the valve group sent by the DC control is taken as the operating capacity of the valve group after the accident; if the power transfer cannot be performed, it is determined that the corresponding valve group remains unchanged at the steady-state operating power. The main problem is that:

[0004] (1) The calculation method is complex. The stability control device needs to calculate according to the pre-accident power of each valve group, the maximum transferable power, and the pole control mode.

[0005] Table 1 Relationship between power transfer and pole power control mode

[0006]

[0007] When a valve group is blocked, the table is used to determine whether the healthy valve group can be transferred, and the valve group that can be transferred is determined to be successfully transferred. For example, if the DC double-pole four-valve group is operating before the accident, the high-end valve of pole 1 is blocked, the low-end valve of pole 1, the low-end valve of pole 2 can be transferred, and the high-end valve of pole 2 cannot be transferred, then the DC loss power PDC1 calculation method is:

[0008] PDC1=(Pdc1_+Pdc2_+Pdc3_+Pdc4_)–(Pdc2max+Pdc4max+Pdc3_)

[0009] Wherein: Pdc1_, Pdc2_, Pdc3_, Pdc4_ are the valve group transmission power before starting (the valve group operation power instruction value received by the steady control device from the DC control and protection system) of the high end of pole 1, the low end of pole 1, the high end of pole 2, and the low end of pole 2. Pdc1max, Pdc2max, Pdc3max, Pdc4max are the maximum transmission power of the valve group (the maximum operation power of the valve group sent by the DC control and protection system, when the valve group is locked due to failure, the maximum operation power of the remaining valve group is taken within 20ms before the last valve group is locked).

[0010] (2) The DC control and protection system sends the maximum transmission power of each valve group to the steady control device in real time, and the steady control device takes the information within 20ms before the last valve group is locked as the maximum operation capacity of the healthy valve group after the accident, which has a certain deviation and may cause a larger error in the calculation result of the DC fault loss transmission power, and there is a larger overcut or undercut capacity in the implementation result of the steady control strategy.

[0011] (3) For an ultra-high voltage hybrid DC power transmission project (conventional DC + flexible DC), the DC transmission capacity after failure is restricted by multiple factors, and the above method cannot be adapted. SUMMARY

[0012] The purpose of the present application is to provide a DC fault loss transmission power calculation method for stability control, to calculate the DC fault loss transmission power in time and accurately, and to prevent the misoperation and refusal of the power grid stability control system caused by the calculation error of the DC fault loss transmission power. The present application correspondingly provides a steady control device and electronic equipment using the method.

[0013] In order to achieve the above purpose, the solution of the present application is:

[0014] As a first aspect of the present application, a DC fault loss transmission power calculation method for stability control is provided, comprising:

[0015] The steady control device receives the valve group transmission power instruction value sent by the DC control and protection system;

[0016] The steady control device detects that any power mutation or current mutation occurs at the AC side of the converter transformer, and sets the starting state of the steady control device;

[0017] Locking the valve group transmission power instruction value at the preset time before starting as the steady-state DC transmission power instruction value of each valve group, which is used to calculate the steady-state DC transmission power;

[0018] Detecting whether the valve group is locked due to failure;

[0019] The post-accident power update identifier and the post-accident transmission power value are triggered to be calculated by the DC control and protection system after a valve group in the DC system is blocked due to a fault, and are updated and sent to the stability control device in a pole unit.

[0020] The power loss calculation function is started: the power loss amount PLost = ∑P_ - ∑P' is calculated after the DC valve group is blocked due to a fault, where PLost is the power loss amount, ∑P_ is the sum of the steady-state DC transmission power instruction values of each valve group, and ∑P' is the sum of the post-accident transmission power values of each pole.

[0021] Preferably, when at least two valve groups in the DC power transmission system are blocked due to a fault, the update of the post-accident power update identifier and the post-accident transmission power value is triggered each time the blocking occurs.

[0022] Preferably, when at least two valve groups in the DC power transmission system are blocked due to a fault, if the interval between the two blockings is less than 20 ms, the DC control and protection system comprehensively considers the two valve group blocking conditions and only updates and sends the post-accident power update identifier and the post-accident transmission power value to the stability control device once, and the post-accident transmission power value is calculated according to the two valve group blocking conditions; if the interval between the two blockings is greater than 20 ms and less than 100 ms, the DC control and protection system will trigger the update of the post-accident power update identifier and the post-accident transmission power value again after an interval of at least 20 ms after the previous update and sending of the post-accident power update identifier and the post-accident transmission power value; if the interval between the two blockings is greater than 100 ms, the update of the post-accident power update identifier and the post-accident transmission power value is triggered each time.

[0023] Preferably, the stability control device receives multiple updates of the post-accident power update identifier and the post-accident transmission power value, and calculates the power loss amount of the DC valve group after a fault blocking multiple times, and takes control measures according to the maximum power loss amount.

[0024] Preferably, the stability control device collects three-phase voltages and three-phase currents on the AC side of the converter transformer for power calculation, and calculates the transmission power by pole, and blocks the power loss calculation function when the power direction on the AC side of any pole is inconsistent with the normal DC transmission power direction.

[0025] Preferably, the stability control device blocks the power loss calculation function if it only receives the post-accident power update identifier and the post-accident transmission power value updated and sent by the DC control and protection system, and does not detect that any valve group is blocked due to a fault.

[0026] Preferably, the stability control device detects that any valve group is closed due to failure, and only receives the update instruction of the post-accident power update identifier and the post-accident transmission power value, but does not receive the update instruction of the post-accident power update identifier and the post-accident transmission power value of the other pole. After waiting for a first preset time T1, if the post-accident power update identifier of the other pole is still not received, the post-accident power update identifier of the other pole is set, the post-accident transmission power value remains the last updated post-accident transmission power value of the other pole, and if the post-accident transmission power value of the other pole has never been received, the post-accident transmission power value is updated to the sum of the steady-state direct-current transmission power instruction values of all valve groups of the pole to calculate the direct-current power loss.

[0027] Preferably, the stability control device detects that any pole is closed due to failure, and automatically sets the post-accident power update identifier of the corresponding pole, and sets the post-accident transmission power value of the corresponding pole to zero. In the case where the post-accident power update identifier and the post-accident transmission power value of the healthy pole are not received, after waiting for a second preset time T2, the post-accident power update identifier of the healthy pole is set, the post-accident transmission power value of the healthy pole remains the last updated post-accident transmission power value of the pole, and if the post-accident transmission power value of the pole has never been received, the post-accident transmission power value is updated to the sum of the steady-state direct-current transmission power instruction values of all valve groups of the pole to calculate the direct-current power loss.

[0028] As a second aspect of the present application, a stability control device is provided, comprising: a first receiving unit, a start detection unit, a steady-state locking unit, a valve group closure detection unit, a second receiving unit, and a power loss calculation unit, wherein:

[0029] The first receiving unit is configured to receive the transmission power instruction value of each valve group sent by the direct-current control and protection system.

[0030] The start detection unit is configured to set the start state of the stability control device when detecting that any power mutation or current mutation occurs on the alternating side of the converter transformer.

[0031] The steady-state locking unit is configured to lock the transmission power instruction value of each valve group at a preset time before starting as the steady-state direct-current transmission power instruction value of each valve group, and is configured to calculate the steady-state direct-current transmission power.

[0032] The valve group closure detection unit is configured to detect whether the valve group is closed due to failure.

[0033] The second receiving unit is configured to receive the post-accident power update identifier and the post-accident transmission power value of each pole sent by the direct-current control and protection system. The post-accident power update identifier and the post-accident transmission power value are calculated by the direct-current control and protection system after the valve group is closed due to failure in the direct-current system, and are sent to the stability control device in units of poles.

[0034] The power loss amount calculation unit is configured to perform a power loss calculation function, and the power loss amount PLost of the DC valve group after being blocked due to a fault is calculated as PLost = ∑P_ - ∑P', wherein PLost is the power loss amount, ∑P_ is the sum of the steady-state DC transmission power instruction values of each valve group, and ∑P' is the sum of the post-fault transmission power values of each pole.

[0035] As a third aspect of the present application, an electronic device is provided, comprising a processor and a storage medium;

[0036] The storage medium is configured to store instructions.

[0037] The processor is configured to operate according to the instructions to perform the steps of the foregoing method.

[0038] The present application has the following beneficial effects: by locking the steady-state DC operating power, detecting the DC valve group blocked due to a fault, receiving the post-fault power update identifier and the post-fault transmission power value sent by the DC control and protection system, the accuracy of the loss transmission power calculation during the DC blocking fault is improved, and the misoperation and refusal of the power grid stability control system caused by the calculation error of the DC fault loss transmission power can be effectively avoided. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 Fig. 1 is a flowchart of a DC fault loss transmission power calculation method for stability control provided by an embodiment of the present application.

[0040] Figure 2 Fig. 2 is a block diagram of a stability control device provided by an embodiment of the present application.

[0041] Figure 3 Fig. 3 is a block diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0043] Figure 1 The DC fault loss transmission power calculation method for stability control provided by an embodiment of the present application is shown in the figure, which comprises the following steps:

[0044] S101, the stability control device receives the transmission power instruction value of each valve group sent by the DC control and protection system.

[0045] The stable control device establishes communication with the DC control and protection equipment based on the "GDW 11764-2017 High Voltage Direct Current Engineering DC Control and Protection and Stable Control Device Interface Technical Specification", and the communication includes receiving the valve group power transmission instruction value sent by the DC control and protection system.

[0046] In S102, the stable control device detects power mutation or current mutation of any converter transformer AC side, and sets the stable control device to start state.

[0047] In S102, the stable control device detects power mutation or current mutation of any converter transformer AC side, and sets the stable control device to start state.

[0048] In S103, the valve group power transmission instruction value at the preset time before starting is locked as the valve group steady-state DC power transmission instruction value, which is used to calculate the DC steady-state DC power transmission. In some embodiments, after the stable control device is set to start state, the valve group power transmission instruction value 200 ms before starting is locked as the valve group steady-state DC power transmission instruction value. The DC steady-state DC power transmission is equal to the sum of the valve group steady-state DC power transmission instruction values.

[0049] In S104, it is detected whether the valve group is locked due to failure.

[0050] In S104, it is detected whether the valve group is locked due to failure.

[0051] 1) The converter transformer power before starting is higher than the valve group running power set value Prun;

[0052] 2) The converter transformer power after starting is less than the valve group shutdown power set value Pstop;

[0053] 3) The converter transformer current after starting is less than the valve group shutdown current set value Istop;

[0054] 4) The valve group unlocking signal and no valve group locking signal are received before starting.

[0055] 5) The valve group abnormal shutdown signal sent by the DC control and protection system is received.

[0056] In addition, if the device receives a valve group abnormal shutdown signal, it opens for 100 ms to determine valve group locking; if it receives a valve group abnormal shutdown signal for more than 2 s, it locks the valve group locking determination function; if it receives a valve group unlocking or locking signal sent by the DC control protection system, it delays for 5 s and alarms and locks the valve group locking determination function.

[0057] S105, receiving the post-accident power update identifier and the post-accident transmission power value sent by the DC control protection system; the post-accident power update identifier and the post-accident transmission power value are calculated by the DC control protection system after the valve group is locked due to failure in the DC system, and are updated and sent to the stability control device in pole units.

[0058] In addition to establishing communication between the stability control device and the DC control protection equipment based on the “GDW 11764-2017 High Voltage DC Project DC Control Protection and Stability Control Device Interface Technical Specification”, the stability control device also receives the post-accident power update identifier and the post-accident transmission power value information. The DC control protection system triggers the sending of the post-accident power update identifier and the post-accident DC transmission power value to the stability control device in pole units after the valve group is locked due to failure in the DC system (regardless of how many valve groups are locked). Taking single locking as an example, the rectifier side sends the post-accident power update identifier and the post-accident transmission power value to the stability control device 80 ms after the locking ESOF signal appears, and the inverter side sends the post-accident power update identifier and the post-accident transmission power value to the stability control device 90 ms after the locking ESOF signal appears. In some embodiments, in order to ensure the stability of the signal, the stability control receives the post-accident power update identifier in pole units using continuous 5 frames (4 ms) confirmation, with a 5 ms expansion; the post-accident transmission power value is received using continuous 3 frames (2.5 ms) confirmation, with a 5 ms expansion.

[0059] S106, starting the power loss calculation function: calculating the power loss PLost = ∑P_ - ∑P' after the DC valve group is locked due to failure, where PLost is the power loss, ∑P_ is the sum of the steady-state DC transmission power command values of each valve group, and ∑P' is the sum of the post-accident transmission power values of each pole.

[0060] In some embodiments, when at least two valve groups in the DC transmission system are locked due to failure, the post-accident power update identifier and the post-accident transmission power value are updated each time the locking occurs.

[0061] In some embodiments, when at least two valve groups of the DC power transmission system are blocked due to faults, if the interval between the two times of blocking is less than 20 ms, the DC control and protection system comprehensively considers the two times of valve group blocking, and only sends the post-accident power update identifier and the post-accident transmission power value to the stability control device once, wherein the post-accident transmission power value is calculated according to the two times of valve group blocking; if the interval between the two times of blocking is greater than 20 ms and less than 100 ms, the DC control and protection system will trigger the update of the post-accident power update identifier and the post-accident transmission power value again after an interval of at least 20 ms after the previous update; if the interval between the two times of blocking is greater than 100 ms, the update of the post-accident power update identifier and the post-accident transmission power value is triggered twice. Because the DC control and protection system needs 80-90 ms to calculate the post-accident transmission power value, the use of this method can reduce the calculation workload.

[0062] In some embodiments, if the stability control device receives multiple updates of the post-accident power update identifier and the post-accident transmission power value, the stability control device calculates the power loss amount after the blocking of the DC valve group due to faults multiple times, and takes control measures according to the maximum power loss amount.

[0063] In some embodiments, to prevent the DC control and protection device from sending false signals and causing the stability control device to malfunction, if the stability control device only receives the post-accident power update identifier and the post-accident transmission power value updated and sent by the DC control and protection system, and does not detect any valve group blocked due to faults, the blocking power loss calculation function is disabled.

[0064] In some embodiments, the stability control device collects three-phase voltages and three-phase currents on the AC side of the converter transformer for power calculation, and calculates the transmission power according to the polarity. When the sampling power direction on the AC side of any pole is inconsistent with the normal DC transmission power direction, the blocking power loss calculation function is disabled. Therefore, when the DC pole is in the ice blocking mode, the stability control device will not determine the DC power loss amount.

[0065] When the DC control and protection system has abnormal inter-pole communication, the pole control device of the DC bipolar cannot distinguish the operation and fault state of the other pole. When a pole has valve group lockout or pole lockout, only the fault pole can send the post-accident power update identifier and post-accident power transmission value information, and the sound pole will not send the corresponding information. Therefore, in some embodiments, when the stability control device detects that any valve group is locked due to failure, only the post-accident power update identifier and the update instruction of the post-accident power transmission value of one pole are received, but the update instruction of the post-accident power update identifier and the post-accident power transmission value of the other pole is not received. After waiting for a first preset time T1, if the update instruction of the post-accident power update identifier and the post-accident power transmission value of the other pole is still not received, the post-accident power update identifier of the other pole is set, the post-accident power transmission value of the other pole remains the post-accident power transmission value updated last time, and if the post-accident power transmission value of the other pole has never been updated, the post-accident power transmission value is updated to the sum of the steady-state DC power transmission power instruction values of all valve groups of the pole to calculate the DC power loss.

[0066] When the DC control and protection system has a double-pole control dead machine (double-pole control dead machine) of one pole, the DC control and protection system sends the abnormal shutdown signal of each valve group of the pole to the stability control device through the pole backup interface device, but the fault pole cannot send the post-accident power update identifier and post-accident power transmission value information at this time. Meanwhile, the sound pole also needs to obtain the double-pole control dead machine information of the fault pole from the pole backup interface device, and the sending time of the post-accident power update identifier and post-accident power transmission value information of the pole is slightly later than that in normal operation. Tests show that when the double-pole control dead machine occurs on the same side, the sound pole sends the post-accident power update identifier and post-accident power transmission value information of the pole about 100 ms after the accident; when the double-pole control dead machine occurs on the opposite side, the sound pole sends the post-accident power update identifier and post-accident power transmission value information of the pole about 110 ms after the accident (if the distance between the sending end and the receiving end is far, the required time may increase by 20 ms to 30 ms). Based on this, some embodiments further include the following scheme: when the stability control device detects that any pole is locked due to failure, the pole lock here refers to that all running valve groups of the pole are locked, the post-accident power update identifier of the corresponding pole is automatically set, and the post-accident power transmission value of the corresponding pole is set to zero; in the case where the update instruction of the post-accident power update identifier and the post-accident power transmission value of the sound pole is not received, the post-accident power update identifier of the sound pole is set after waiting for a second preset time T2, the post-accident power transmission value of the sound pole remains the post-accident power transmission value updated last time, and if the post-accident power transmission value of the sound pole has never been updated, the post-accident power transmission value is updated to the sum of the steady-state DC power transmission power instruction values of all valve groups of the pole to calculate the DC power loss.

[0067] The above schemes are specifically introduced below in combination with a UHV DC power transmission project with a rated power transmission capacity of 8000 MW.

[0068] An embodiment provided by the application assumes that a certain UHV DC transmission project rated transmission power is 8000 MW, bipolar four valve groups operate at 7200 MW, and the high valve of pole 1 is blocked due to a fault, and the healthy valve group performs power transfer and operates at full power. The stability control device detects that the corresponding commutation current and power meet the sudden variable starting condition in the high valve blocking fault of pole 1, the device enters the starting state, and simultaneously locks the valve group transmission power instruction value of 200 ms before starting as the steady-state DC transmission power instruction value of each valve group. The steady-state DC transmission power is equal to the sum of the steady-state DC transmission power instruction values of each valve group, which is 7200 MW. The stability control device discriminates whether the valve group is blocked due to a fault according to the pole 1 high valve unlocking, blocking, and abnormal shutdown signals sent by the DC control and protection system and the pole 1 high valve current and power collected by the stability control device. After 90 ms (inverter side) of the fault, the post-fault power update identifier and the post-fault transmission power value P' of pole 1 are received, which are 2000 MW, and after 100 ms of the fault, the post-fault power update identifier and the post-fault transmission power value P' of pole 2 are received, which are 4000 MW. Then, the stability control device discriminates the power loss PLost=∑P_-∑P' = 7200 MW-(2000 MW+4000 MW)=1200 MW at 100 ms after the fault.

[0069] An embodiment provided by the application assumes that the DC operates in the ice blocking mode of pole 1 positive sending and pole 2 reverse sending, and the inverter side stability control device collects the power direction of each valve group of pole 1 commutation transformer alternating current side as the DC flow direction of the alternating current grid, and the power direction of each valve group of pole 2 commutation transformer alternating current side as the alternating current grid flow direction of the DC. In this working condition, the DC fault will not cause the stability problem of the power grid. The stability control device detects that the power transmission direction of pole 2 is opposite to the normal DC transmission direction, blocks the power loss calculation function, and does not calculate the DC fault loss transmission power.

[0070] An embodiment provided by the application assumes that the DC control and protection system occurs inter-pole communication interruption when the DC normally operates, and then the high valve of pole 1 is blocked due to a fault. The stability control device receives the post-fault power update identifier and the post-fault transmission power value P' of pole 1 after 90 ms of the fault, which are 2000 MW, and does not receive the post-fault power update identifier and the post-fault transmission power value P' of pole 2. Then, the stability control device discriminates that pole 2 does not perform post-fault power transfer at 90 ms+T1 (25 ms) after the fault, i.e., 115 ms after the fault, and the power loss PLost=∑P_-∑P' = 7200 MW-(2000 MW+3600 MW)=1600 MW.

[0071] In an embodiment provided by the application, it is assumed that the DC control protection system sends the abnormal stop signal of each valve group of pole 2 to the stability control device through the pole backup interface device when the pole 2 bipolar control is dead, and sends the post-fault power update identifier and the post-fault power value P' of 4000 MW of pole 1 to the stability control device through the pole 1 control protection device 100 ms after the fault. The stability control device receives the abnormal stop signal of each valve group of pole 2 sent by the pole backup interface device, and determines that all the running valve groups of pole 2 are blocked due to the fault in combination with the pole 2 current and power of each valve group, and then immediately sets the post-fault power update identifier of pole 2 and the post-fault power value P' of pole 2 to zero. When the post-fault power update identifier and the post-fault power instruction value P' of pole 1 are received by the stability control device from the pole 1 control protection device 100 ms after the fault, the power loss PLost is calculated as 3200 MW, i.e., PLost = ∑P - ∑P' = 7200 MW - (0 MW + 4000 MW) = 3200 MW. It is assumed that the pole 1 control protection device does not send the post-fault power update identifier and the post-fault power instruction value P' to the stability control device due to some abnormality of the DC control protection system after the fault, and then the stability control device determines that pole 1 does not occur power transfer after the time T2 (150 ms) after determining that pole 2 is blocked, and pole 1 keeps the pre-start steady-state power operation, and the power loss PLost is calculated as 3600 MW, i.e., PLost = ∑P - ∑P' = 7200 MW - (0 MW + 3600 MW) = 3600 MW.

[0072] In an embodiment provided by the application, it is assumed that the DC control protection system sends the abnormal stop signal of each valve group of pole 2 to the stability control device through the pole backup interface device when the pole 2 bipolar control is dead, and sends the post-fault power update identifier and the post-fault power value P' of 4000 MW of pole 1 to the stability control device through the pole 1 control protection device 100 ms after the fault. The stability control device receives the abnormal stop signal of each valve group of pole 2 sent by the pole backup interface device, and determines that all the running valve groups of pole 2 are blocked due to the fault in combination with the pole 2 current and power of each valve group, and then immediately set the post-fault power update identifier of pole 2 and the post-fault power value P' of pole 2 to zero. When the post-fault power update identifier and the post-fault power instruction value P' of pole 1 are received by the stability control device from the pole 1 control protection device 100 ms after the fault, the power loss PLost is calculated as 3200 MW, i.e., PLost = ∑P - ∑P' = 7200 MW - (0 MW + 4000 MW) = 3200 MW. It is assumed that the pole 1 control protection device does not send the post-fault power update identifier and the post-fault power instruction value P' to the stability control device due to some abnormality of the DC control protection system after the fault, and then the stability control device determines that pole 1 does not occur power transfer after the time T2 (150 ms) after determining that pole 2 is blocked, and pole 1 keeps the pre-start steady-state power operation, and the power loss PLost is calculated as 3600 MW, i.e., PLost = ∑P - ∑P' = 7200 MW - (0 MW + 3600 MW) = 3600 MW.

[0073] The technical scheme of the embodiment of the application realizes the calculation of the loss of transmission power of the DC fault by the stability control device, fully considers the processing scheme under various operation modes and abnormal conditions of the DC control protection, meets the requirements of the reliability, rapidity, sensitivity and selectivity of the relay protection device, and can effectively reduce the risk of over-tripping or under-tripping control objects of the power grid stability control system caused by the inaccurate calculation of the loss of transmission power of the DC fault.

[0074] Figure 2 The stability control device provided by the embodiment of the application includes a first receiving unit, a start detection unit, a steady-state locking unit, a valve group locking detection unit, a second receiving unit and a power loss calculation unit, wherein:

[0075] The first receiving unit is configured to receive the transmission power instruction value of each valve group sent by the DC control protection system.

[0076] The start detection unit is configured to set the start state of the stability control device when detecting that the power or current of any AC side of the converter transformer suddenly changes.

[0077] The steady-state locking unit is configured to lock the transmission power instruction value of each valve group at the preset time before the start as the steady-state DC transmission power instruction value of each valve group.

[0078] The valve group locking detection unit is configured to detect whether the valve group is locked due to a fault.

[0079] The second receiving unit is configured to receive the post-accident power update identifier and the post-accident transmission power value of each pole sent by the DC control protection system. The post-accident power update identifier and the post-accident transmission power value are calculated by the DC control protection system after the valve group is locked due to a fault in the DC system, and are updated and sent to the stability control device in the form of a pole.

[0080] The power loss calculation unit is configured to perform the power loss calculation function. After the DC valve group is locked due to a fault, the power loss PLost = ∑P_ - ∑P', wherein PLost is the power loss, ∑P_ is the sum of the steady-state DC transmission power instruction values of each valve group, and ∑P' is the sum of the post-accident transmission power values of each pole.

[0081] The stability control device performs similar functions to the method provided above, and other functions can be referred to the foregoing description, which will not be described here again.

[0082] Figure 3 A block diagram of an electronic device according to an example embodiment is shown.

[0083] The electronic device 300 according to this embodiment of the application will be described below with reference to Figure 3 Figure 3 ​The electronic device 300 shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0084] like Figure 3 As shown, the electronic device 300 is presented in the form of a general-purpose computing device. The components of the electronic device 300 may include, but are not limited to: at least one processing unit 310, at least one storage unit 320, a bus 330 connecting different system components (including storage unit 320 and processing unit 310), a display unit 340, etc.

[0085] The storage unit stores program code, which can be executed by the processing unit 310, causing the processing unit 310 to perform the methods described in this specification according to various exemplary embodiments of this application.

[0086] Storage unit 320 may include readable media in the form of volatile storage units, such as random access memory (RAM) 3201 and / or cache memory 3202, and may further include read-only memory (ROM) 3203.

[0087] Storage unit 320 may also include a program / utility 3204 having a set (at least one) program module 3205, such program module 3205 including but not limited to: operating system, one or more application programs, other program modules and program data, each or some combination of these examples may include an implementation of a network environment.

[0088] Bus 330 can represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of the various bus structures.

[0089] The electronic device 300 can also communicate with one or more external devices 300' such as a keyboard or a pointing device, a Bluetooth device, etc., and can also communicate with one or more devices that enable a user to interact with the electronic device 300 and / or one or more devices (e.g., a router, a modem, etc.) that enable the electronic device 300 to communicate with one or more other computing devices. Such communication can occur via Input / Output (I / O) interface 350. Still yet, the electronic device 300 can communicate with one or more networks (such as one or more local area networks (LANs), wide area networks (WANs), and / or the Internet) via network adapter 360. The network adapter 360 can communicate with the other components of the electronic device 300 via bus 330. It should be understood that, although not shown explicitly, other hardware and / or software components could be used in conjunction with the electronic device 300. These include, but are not limited to, microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data archival storage systems, etc.

[0090] Those skilled in the art will readily understand that the example embodiments described herein can be implemented by software and / or by software in combination with the necessary hardware. The technical solutions according to the embodiments of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB, a mobile hard disk, etc.) or a network, and includes a number of instructions to enable a computing device (which can be a personal computer, a server, or a network device, etc.) to perform the above-mentioned methods according to the embodiments of the present application.

[0091] The software product can adopt any combination of one or more readable media. The readable media can be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or apparatus, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include an electrical connection having one or more wires, a portable disc, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0092] A computer readable storage medium can include a data signal traveling in a baseband or other transmission in which the data is modulated onto a carrier wave. The data signal can travel in any suitable form of transmission, including but not limited to analog signals, digital signals, optical signals, or any suitable combination. The computer readable storage medium can be any medium that can be read by a machine, including but not limited to read-only memory (ROM), random access memory (RAM), volatile memory, non-volatile memory, blue-ray discs, DVDs, CD-ROMs, flash memory, or any suitable combination. The program code contained on the computer readable storage medium can be transmitted in any suitable form before, during, or after transmission, including but not limited to electromagnetic signals, optical signals, or any suitable combination.

[0093] The program code for carrying out operations of the present application can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, C++, or the like, and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computing device, partly on the user's computing device, as a stand-alone software package, partly on the user's computing device and partly on a remote computing device or entirely on the remote computing device or server. In the latter scenario, the remote computing device can be connected to the user's computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computing device, such as through the Internet using an Internet Service Provider.

[0094] Those skilled in the art will understand that the modules described above can be distributed in the apparatus as described in the embodiments, or can be changed correspondingly and only one or more apparatuses different from the embodiments. The modules of the above embodiments can be combined into one module, or can be further split into a plurality of sub-modules.

[0095] The exemplary embodiments of this application are specifically illustrated and described herein. But it is to be understood that the application is not limited to the precise details described herein; rather, various modifications and equivalents can be resorted to by those skilled in the art, and such modifications and equivalents are meant to fall within the scope of the application as defined by the appended claims.

Claims

1. A method for calculating power delivered by a DC fault loss in a stability control, characterized by, The method comprises the following steps: The stability control device receives the power instruction value of each valve group sent by the DC control and protection system; When the stability control device detects that power or current of any AC side of the converter transformer suddenly changes, the stability control device is set to the starting state; The power instruction value of each valve group at the preset time before starting is locked as the steady-state DC power instruction value of each valve group for calculating the steady-state DC power of the DC system; It is detected whether the valve group is closed due to failure; The post-accident power update identifier and post-accident power value of each pole sent by the DC control and protection system are received; the post-accident power update identifier and post-accident power value are calculated by the DC control and protection system after the valve group is closed due to failure in the DC system, and are updated and sent to the stability control device in units of poles; Start power loss calculation function: calculate the power loss amount of the DC valve group after failure blocking PLost= ∑P_- ∑ P' , wherein PLost is the power loss amount, ∑P_ is the sum of the steady-state DC transmission power command values of each valve group, ∑P' is the sum of the post-incident transmission power values of each pole.

2. The method of claim 1, wherein: ###0001### ###0002### When at least two valve groups are closed due to failure in the DC power transmission system, the update of the post-accident power update identifier and post-accident power value is triggered each time the valve group is closed.

3. The method for calculating DC fault loss transmission power for stable control according to claim 1, characterized in that: When at least two valve groups are closed due to failure in the DC power transmission system, if the interval time between the two closings is less than 20 ms, the DC control and protection system comprehensively considers the two valve group closing conditions and only updates and sends the post-accident power update identifier and post-accident power value to the stability control device once; if the interval time between the two closings is greater than 20 ms and less than 100 ms, the DC control and protection system will trigger the update of the post-accident power update identifier and post-accident power value again after at least 20 ms after updating and sending the post-accident power update identifier and post-accident power value the first time; if the interval time between the two closings is greater than 100 ms, the update of the post-accident power update identifier and post-accident power value is triggered both the first time and the second time.

4. The method for calculating DC fault loss transmission power for stable control according to claim 1, characterized in that: If the stability control device receives multiple updates of the post-accident power update identifier and post-accident power value, the power loss amount of the DC valve group after being closed due to failure is calculated multiple times, and the control measures are taken according to the maximum power loss amount.

5. The method for calculating DC fault loss transmission power for stable control according to claim 1, characterized in that: The stability control device collects three-phase voltage and three-phase current of the AC side of the converter transformer for power calculation, and calculates the power loss of the closed valve group when the power direction of any AC side is inconsistent with the normal DC transmission power direction.

6. The method of claim 1, wherein: ###0001### ###0002### If the stability control device only receives the post-accident power update identifier and post-accident power value updated and sent by the DC control and protection system and does not detect that any valve group is closed due to failure, the power loss calculation function is closed.

7. The method for calculating DC fault loss transmission power for stable control according to claim 1, characterized in that: After the stability control device detects that any valve group is closed due to failure, only the update instruction of the post-accident power update identifier and post-accident power value of one pole is received, but the update instruction of the post-accident power update identifier and post-accident power value of the other pole is not received, the stability control device waits for a first preset time T1, and if the update instruction of the post-accident power update identifier and post-accident power value of the other pole is still not received after the first preset time T1, the post-accident power update identifier of the other pole is set, the post-accident power value remains the post-accident power value updated the last time for the other pole, and if the post-accident power value of the other pole has never been updated, the post-accident power value is updated to the sum of the steady-state DC power instruction values of all valve groups of the pole to calculate the DC power loss amount.

8. The method for calculating DC fault loss transmission power for stable control according to claim 1, characterized in that: The stability control device detects any pole fault pole blockage, and automatically sets the corresponding pole post-accident power update identifier, and sets the corresponding pole post-accident transmission power value to zero; in the case where no intact pole post-accident power update identifier and post-accident transmission power value update instruction is received, waiting for a second preset time T2, then setting the intact pole post-accident power update identifier, and the intact pole post-accident transmission power value remains the last time the pole is updated post-accident transmission power value, if the pole has never received the post-accident transmission power value update, the post-accident transmission power value is updated to the sum of the steady-state DC transmission power instruction value of all valve groups of the pole to calculate the DC power loss.

9. A stability control device characterized by comprising: Comprise: A first receiving unit, a start detection unit, a steady-state locking unit, a valve group blockage detection unit, a second receiving unit and a power loss calculation unit, wherein: The first receiving unit is configured to receive the valve group transmission power instruction value sent by the DC control and protection system; The start detection unit is configured to set the stability control device to a start state when detecting any power mutation or current mutation on the AC side of the converter transformer; The steady-state locking unit is configured to lock the valve group transmission power instruction value at a preset time before starting as the steady-state DC transmission power instruction value of each valve group for calculating the steady-state DC transmission power; The valve group blockage detection unit is configured to detect whether the valve group is blocked due to failure; The second receiving unit is configured to receive the post-accident power update identifier and the post-accident transmission power value sent by the DC control and protection system; the post-accident power update identifier and the post-accident transmission power value are calculated by the DC control and protection system after the valve group is blocked due to failure in the DC system, and are updated and sent to the stability control device by pole unit; The power loss amount calculation unit is configured to execute a power loss calculation function, and the power loss amount after the DC valve group is blocked due to a fault PLost= ∑P_- ∑P' wherein PLost is the power loss amount, ∑P_ is the sum of the steady-state DC transmission power command values of the valve groups, ∑P' is the sum of the post-fault transmission power values of the poles.

10. An electronic device, comprising: Comprise a processor and a storage medium; The storage medium is configured to store instructions; The processor is configured to operate according to the instructions to perform the steps of the method according to any one of claims 1-8.

Images