Coordinated configuration method and system for high-voltage direct-current frequency control and emergency power control

Abstract

The invention relates to the technical field of high-voltage direct-current operation control, in particular to a high-voltage direct-current frequency control and emergency power control coordinated configuration method and system, and the method comprises the steps: obtaining a current operation power instruction and a direct-current system frequency control adjustment variable; obtaining a direct current frequency controller starting value according to the direct current system frequency control adjusting quantity; obtaining a direct current emergency power modulation instruction, and determining a direct current emergency power control starting value according to the direct current emergency power modulation instruction; starting a direct-current power coordination control mechanism according to the direct-current frequency controller starting value and the direct-current emergency power control starting value; updating the current operation power instruction according to the adjusting quantity of the frequency controller in the time delay stage and the direct current emergency power modulation instruction to obtain a direct current system operation power updating instruction; and completing direct current active power modulation according to the direct current system operation power updating instruction. Dynamic coordination control over the power and frequency of the high-voltage direct-current power transmission system is achieved, and safe and reliable operation of a power grid is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage direct current operation control, and in particular to a method and system for coordinating configuration of high-voltage direct current frequency control and emergency power control. Background Art

[0002] In the power system, there is often a significant mismatch between the geographical distribution of energy resources and electricity consumption demand. Specifically, abundant new energy resources such as coal, hydropower, wind power and solar energy are mostly concentrated in remote areas, while power load centers are mainly concentrated in economically developed and densely populated urban areas. This uneven distribution of resources has prompted the development of inter-regional DC transmission technology to achieve optimal allocation and long-distance transmission of power resources. At present, major regional power grids have achieved inter-regional power transmission and interconnection through inter-regional DC asynchronous interconnection technology. Among them, the DC transmission system plays an important role in the power system due to its rapid controllability. It can provide frequency and power support by adjusting the DC operating power according to the operating requirements of the AC system. The active power control of the DC system mainly includes two types: frequency control and emergency power control. The DC frequency controller detects the changes in the commutation bus frequency and calculates and adjusts the DC power in real time to maintain the frequency stability of the power system.

[0003] However, although both active power control methods of DC systems act on the operating power of DC transmission, their driving mechanisms and positioning in the power system are different. In actual operation, there is a situation where both may act simultaneously to adjust the DC operating power, which leads to conflicting control objectives. For example, when a large disturbance occurs in the AC system at the DC receiving end, the safety control system starts the DC emergency power control to reduce the DC operating power. At this time, the AC system at the DC sending end has excess power, causing the system frequency to rise, triggering the DC frequency controller to increase the DC power, thereby weakening the effect of emergency power control and even endangering the stability of the AC system at the receiving end.

[0004] Therefore, how to effectively coordinate the functions of the DC frequency controller and the emergency power control to avoid conflicts in the DC power regulation requirements when the two operate at the same time, and ensure that the DC system can provide sufficient and appropriate active power regulation for the AC system under power system disturbances, thereby maintaining the safe and stable operation of the entire power system, is a problem that needs to be solved urgently. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method and system for coordinating and configuring high voltage direct current frequency control and emergency power control.

[0006] In a first aspect, the present invention provides a method for coordinating and configuring high voltage direct current frequency control and emergency power control, the method comprising the following steps:

[0007] Initializing the initial state flag of the high voltage direct current transmission system; the initial state flag includes a direct current emergency power control start initial value and a direct current frequency controller start initial value;

[0008] According to the current DC operation state of the HVDC transmission system, the current operation power instruction of the HVDC transmission system and the DC system frequency control adjustment amount are obtained;

[0009] Obtaining a DC frequency controller startup value according to the DC system frequency control adjustment amount and a preset DC frequency control action threshold;

[0010] Calculating a DC emergency power modulation instruction according to system disturbance monitoring data, and determining a DC emergency power control start value according to the DC emergency power modulation instruction;

[0011] Starting the DC power coordination control mechanism according to the DC frequency controller startup value and the DC emergency power control startup value, and determining the delay phase frequency controller adjustment amount according to the working state of the DC power coordination control mechanism;

[0012] The current operating power instruction is updated according to the delay phase frequency controller adjustment amount and the DC emergency power modulation instruction, and a DC system operating power update instruction is calculated;

[0013] The high-voltage direct current transmission system is controlled to operate according to the direct current system operating power update instruction to complete direct current active power modulation.

[0014] In a further embodiment, the step of obtaining the current operating power instruction of the high-voltage direct current transmission system and the DC system frequency control adjustment amount according to the current DC operating state of the high-voltage direct current transmission system comprises:

[0015] Collecting DC voltage data and DC current data of a high-voltage DC power transmission system, and calculating current DC power according to the DC voltage data and the DC current data;

[0016] Determining a current operating power instruction of the high-voltage direct current transmission system according to the power system dispatching demand, the current direct current power and the rated power of the high-voltage direct current transmission system;

[0017] Collecting AC system frequency measurement data, and comparing the AC system frequency measurement data with a preset frequency reference value to calculate a frequency deviation;

[0018] According to the frequency deviation, a frequency control adjustment amount is calculated using a proportional-integral controller.

[0019] In a further embodiment, the step of obtaining a DC frequency controller startup value according to the DC system frequency control adjustment amount and a preset DC frequency control action threshold comprises:

[0020] Compare the DC system frequency control adjustment amount with the DC frequency control action threshold, and if the DC system frequency control adjustment amount exceeds the DC frequency control action threshold, determine that the DC frequency controller starts before the emergency power control, and set the DC frequency controller start value to one;

[0021] If the DC system frequency control adjustment amount does not exceed the DC frequency control action threshold, it is determined that the emergency power control is started before the DC frequency controller, and the DC frequency controller startup value is set to zero.

[0022] In a further embodiment, the step of determining the DC emergency power control start value according to the DC emergency power modulation instruction includes:

[0023] Comparing the absolute value of the DC emergency power modulation instruction with a preset emergency power control action threshold, if the absolute value of the DC emergency power modulation instruction is greater than the emergency power control action threshold, determining to start emergency power control, and setting the DC emergency power control start value to one;

[0024] If the absolute value of the DC emergency power modulation instruction is equal to the emergency power control action threshold, it is determined that the emergency power control is locked and the DC emergency power control start value is set to zero.

[0025] In a further embodiment, the step of starting the DC power coordination control mechanism according to the DC frequency controller start value and the DC emergency power control start value comprises:

[0026] Obtaining a start-up timing flag sum according to the sum of the DC frequency controller start-up value and the DC emergency power control start-up value;

[0027] The start timing flag and the DC emergency power control start value are multiplied to obtain a DC power coordination control flag value, and the DC power coordination control mechanism is started according to the DC power coordination control flag value.

[0028] In a further embodiment, the step of determining the delay phase frequency controller adjustment amount according to the working state of the DC power coordinated control mechanism includes:

[0029] When the DC power coordination control mechanism starts working, the DC frequency controller startup value is assigned to the delay phase frequency controller adjustment value;

[0030] When the DC power coordination control mechanism is not started, the delay phase frequency controller adjustment amount is set to zero.

[0031] In a further embodiment, the step of updating the current operating power instruction according to the delay phase frequency controller adjustment amount and the DC emergency power modulation instruction to calculate the DC system operating power update instruction includes:

[0032] The current operating power instruction is added to the delay phase frequency controller adjustment amount and the DC emergency power modulation instruction to obtain a DC system operating power update instruction.

[0033] In a further embodiment, after the step of controlling the high voltage direct current transmission system to operate according to the direct current system operating power update instruction and completing the direct current active power modulation step, the method further comprises:

[0034] The delay time is determined according to the working state of the DC power coordination control mechanism, and after the delay time ends, the DC frequency controller locking state is released, the DC frequency controller and emergency power control functions are restored, and the high-voltage DC power transmission system is restored to normal operation.

[0035] In a further embodiment, the delay time is determined according to the DC frequency controller lockout duration of different DC power coordinated control mechanisms.

[0036] In a second aspect, the present invention provides a high voltage direct current frequency control and emergency power control coordinated configuration system, the system comprising:

[0037] A flag initialization module is used to initialize the initial state flag of the high-voltage direct current transmission system; the initial state flag includes a direct current emergency power control start initial value and a direct current frequency controller start initial value;

[0038] An operating frequency analysis module is used to obtain a current operating power instruction of the high-voltage direct current transmission system and a DC system frequency control adjustment amount according to the current DC operating state of the high-voltage direct current transmission system;

[0039] A frequency startup analysis module, used to obtain a DC frequency controller startup value according to the DC system frequency control adjustment amount and a preset DC frequency control action threshold;

[0040] The emergency power control module is used to calculate a DC emergency power modulation instruction according to the system disturbance monitoring data, and determine a DC emergency power control start value according to the DC emergency power modulation instruction;

[0041] A delay adjustment control module, used to start the DC power coordination control mechanism according to the DC frequency controller start value and the DC emergency power control start value, and determine the delay phase frequency controller adjustment amount according to the working state of the DC power coordination control mechanism;

[0042] An operating power update module, used to update the current operating power instruction according to the delay phase frequency controller adjustment amount and the DC emergency power modulation instruction, and calculate the DC system operating power update instruction;

[0043] The power coordination control module is used to control the high-voltage direct current transmission system to operate according to the direct current system operating power update instruction to complete direct current active power modulation.

[0044] The present invention provides a method and system for coordinating and configuring high-voltage direct current frequency control and emergency power control. The method initializes an initial state flag of a high-voltage direct current transmission system; obtains a current operating power instruction and a direct current system frequency control adjustment amount of the high-voltage direct current transmission system according to a current direct current operating state of the high-voltage direct current transmission system; obtains a direct current frequency controller startup value according to the direct current system frequency control adjustment amount and a preset direct current frequency control action threshold; calculates a direct current emergency power modulation instruction according to system disturbance monitoring data, and determines a direct current emergency power control startup value according to the direct current emergency power modulation instruction; starts a direct current power coordination control mechanism according to the direct current frequency controller startup value and the direct current emergency power control startup value, and determines a delay phase frequency controller adjustment amount according to a working state of the direct current power coordination control mechanism; updates the current operating power instruction according to the delay phase frequency controller adjustment amount and the direct current emergency power modulation instruction, and calculates a direct current system operating power update instruction; controls the high-voltage direct current transmission system to operate according to the direct current system operating power update instruction, and completes direct current active power modulation. Compared with the existing technology, this method flexibly adjusts the DC power output through the real-time status of the high-voltage DC transmission system, realizes dynamic coordinated control of the power and frequency of the high-voltage DC transmission system, ensures that the system can quickly return to a stable state when facing disturbances, and effectively improves the system stability and operating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a flow chart of a method for coordinating and configuring high-voltage direct current frequency control and emergency power control provided by an embodiment of the present invention;

[0046] Figure 2 It is a block diagram of the coordinated configuration process of high voltage direct current frequency control and emergency power control provided by an embodiment of the present invention;

[0047] Figure 31 is a schematic diagram comparing the effects of the coordinated configuration method provided by an embodiment of the present invention under a non-operating condition of a DC frequency controller;

[0048] Figure 4 1 is a schematic diagram comparing the effects of the coordinated configuration method under the operating condition of the DC frequency controller provided by an embodiment of the present invention;

[0049] Figure 5 It is a block diagram of a high-voltage direct current frequency control and emergency power control coordinated configuration system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] The following specifically illustrates the implementation mode of the present invention in conjunction with the accompanying drawings. The embodiments are provided for illustrative purposes only and cannot be understood as limiting the present invention. The accompanying drawings are provided for reference and illustration only and do not constitute a limitation on the scope of patent protection of the present invention, because many changes can be made to the present invention without departing from the spirit and scope of the present invention.

[0051] refer to Figure 1 The embodiment of the present invention provides a method for coordinating and configuring high-voltage direct current frequency control and emergency power control, such as Figure 1 As shown, the method comprises the following steps:

[0052] S1. Initialize the initial state flag of the high-voltage direct current transmission system; the initial state flag includes the initial value of starting the direct current emergency power control and the initial value of starting the direct current frequency controller.

[0053] S2. According to the current DC operation state of the HVDC transmission system, obtain the current operation power instruction of the HVDC transmission system and the DC system frequency control adjustment amount.

[0054] In this embodiment, the step of obtaining the current operating power instruction of the high-voltage direct current transmission system and the DC system frequency control adjustment amount according to the current DC operating state of the high-voltage direct current transmission system includes:

[0055] Collecting DC voltage data and DC current data of a high-voltage DC power transmission system, and calculating current DC power according to the DC voltage data and the DC current data;

[0056] Determining a current operating power instruction of the high-voltage direct current transmission system according to the power system dispatching demand, the current direct current power and the rated power of the high-voltage direct current transmission system;

[0057] Collecting AC system frequency measurement data, and comparing the AC system frequency measurement data with a preset frequency reference value to calculate a frequency deviation;

[0058] According to the frequency deviation, a frequency control adjustment amount is calculated using a proportional-integral controller.

[0059] Specifically, Figure 2 As shown, in the control process of the high-voltage direct current transmission system, the present embodiment defines two flag variables, namely, the start-up state of the direct current emergency power control and the start-up state of the direct current frequency controller. Initially, the present embodiment may set the two flag variables to 0 according to the system design requirements and the safety operation standards, which indicates that the corresponding control function is not started. Then, the present embodiment collects the direct current voltage data V and the direct current current data I of the high-voltage direct current transmission system in real time through sensors. According to the collected direct current voltage and direct current data, the current direct current power P is calculated by using the formula P=V×I. Meanwhile, the current required direct current power dispatching demand value is obtained from the power system dispatching center, and the current direct current power is compared with the direct current power dispatching demand value. If the current power is lower than the dispatching demand power, the power value to be increased is calculated according to the regulation capability and safety margin of the system, and the power value is added to the current power to obtain a new operating power instruction. If the current power is higher than the dispatching demand power, the power value to be reduced is calculated, and the power value is subtracted from the current power to obtain a new operating power instruction. The rated power limit of the high-voltage direct current transmission system is considered to ensure that the current operating power instruction does not exceed the rated power, thereby determining the current operating power instruction of the high-voltage direct current transmission system.

[0060] For the frequency control adjustment amount, in this embodiment, the frequency data of the AC system is collected in real time by the AC system frequency measurement device, the collected frequency data is compared with the preset frequency reference value, the frequency deviation is calculated, and then the parameters of the proportional integral (PI) controller are set. The parameters of the proportional integral controller include a proportional coefficient and an integral coefficient. The frequency deviation is input into the PI controller, and the frequency control adjustment amount is calculated according to the PI control algorithm. Specifically, the frequency deviation α is multiplied by the proportional coefficient K p and the integral coefficient K i , and then add the results of the two to get the frequency control adjustment amount. The specific formula is: Frequency control adjustment amount Here, t represents time.

[0061] S3. Obtain a DC frequency controller startup value according to the DC system frequency control adjustment amount and a preset DC frequency control action threshold.

[0062] In this embodiment, the step of obtaining a DC frequency controller startup value according to the DC system frequency control adjustment amount and a preset DC frequency control action threshold comprises:

[0063] Compare the DC system frequency control adjustment amount with the DC frequency control action threshold, and if the DC system frequency control adjustment amount exceeds the DC frequency control action threshold, determine that the DC frequency controller starts before the emergency power control, and set the DC frequency controller start value to one;

[0064] If the DC system frequency control adjustment amount does not exceed the DC frequency control action threshold, it is determined that the emergency power control is started before the DC frequency controller, and the DC frequency controller startup value is set to zero.

[0065] In the power system, DC frequency control is one of the important means to maintain the stability of the system frequency. Especially after the access of large-scale renewable energy, the system frequency fluctuations are more frequent and violent. In order to effectively manage such fluctuations, this embodiment needs to determine the start-up time of the DC frequency controller according to the DC system frequency control adjustment amount and the preset DC frequency control action threshold. Specifically, this embodiment defines the DC system frequency control adjustment amount to represent the amount that needs to be adjusted that is automatically calculated by the DC system according to the current frequency deviation; the DC frequency control action threshold is used to determine whether the DC frequency controller needs to be started. The DC frequency control action threshold can generally be 0. This embodiment obtains the DC system frequency control adjustment amount P FC Compared with the preset DC frequency control action threshold ε, if |P FC |>ε, that is, the absolute value of the DC system frequency control adjustment amount exceeds the preset DC frequency control action threshold, which means that the frequency deviation of the current system is large enough and the DC frequency controller needs to intervene immediately to stabilize the system frequency. In this case, this embodiment determines that the DC frequency controller starts before the emergency power control, and at the same time sets the DC frequency controller startup value D FC is 1, indicating that the DC frequency controller should be activated and put into operation. It should be noted that emergency power control is usually the last line of defense for system frequency and is only started when the DC frequency controller cannot effectively stabilize the frequency. FC |≤ε, that is, the DC system frequency control adjustment amount does not exceed the preset DC frequency control action threshold, which means that the frequency deviation of the current system is still within the acceptable range, and the DC frequency controller does not need to be started immediately. In this case, it is determined that the emergency power control starts before the DC frequency controller, and the DC frequency controller startup value D FC Set to 0, which means that under the current conditions, the DC frequency controller does not need to be activated. Its mathematical expression is:

[0066]

[0067] In the formula, when D FC =1, indicating that the frequency controller starts before the emergency power control; when DFC =0, it means that the emergency power control starts before the frequency controller.

[0068] This embodiment sends corresponding startup or standby state instructions to the DC frequency controller through the control system according to the set DC frequency controller startup value. This embodiment ensures that the DC frequency controller is started at an appropriate time by continuously monitoring the frequency state of the system and the actual operation of the DC frequency controller, effectively supports the frequency stability control of the power system, and improves the reliability and safety of the system.

[0069] S4. Calculate a DC emergency power modulation instruction based on the system disturbance monitoring data, and determine a DC emergency power control start value based on the DC emergency power modulation instruction.

[0070] In this embodiment, the step of determining the DC emergency power control start value according to the DC emergency power modulation instruction includes:

[0071] Comparing the absolute value of the DC emergency power modulation instruction with a preset emergency power control action threshold, if the absolute value of the DC emergency power modulation instruction is greater than the emergency power control action threshold, determining to start emergency power control, and setting the DC emergency power control start value to one;

[0072] If the absolute value of the DC emergency power modulation instruction is equal to the emergency power control action threshold, it is determined that the emergency power control is locked and the DC emergency power control start value is set to zero.

[0073] The security control system monitors the voltage, current and other electrical quantities of the system in real time, obtains the real-time operating status of the system using the state estimation method, and then uses the transient stability analysis method (such as time domain simulation method or direct method, etc.) to calculate the DC emergency power modulation instruction P required to ensure the safe and stable operation of the system according to the preset disturbance type (such as short circuit fault, load mutation, etc.) and the transient stability constraint conditions of the system. mod Then, according to the DC emergency power modulation instruction P mod To determine the DC emergency power control start value D mod In the power system, DC emergency power control is an important regulation method, which is mainly used to quickly adjust the DC transmission power when the system has serious frequency deviation or power imbalance to maintain the stable operation of the system. In this embodiment, an emergency power control action threshold is set to determine whether the DC emergency power control needs to be started. In this embodiment, the emergency power control action threshold is preferentially set to 0, and then the calculated DC emergency power modulation instruction P is used. mod The absolute value of the preset emergency power control action threshold T mod Compare, if |Pmod |>T mod , that is, the absolute value of the DC emergency power modulation instruction is greater than the emergency power control action threshold, which means that the current system needs to urgently adjust the DC power to maintain stability. In this case, this embodiment determines to start the emergency power control, and the emergency power control will be based on P mod The DC system power output is adjusted according to the indication, and the DC emergency power control start value D mod Set to 1, indicating that emergency power control should be activated and put into operation; if |P mod |=T mod , that is, the absolute value of the DC emergency power modulation instruction is equal to the emergency power control action threshold, which means that the current state of the system is at the critical point of emergency power control, but has not yet reached the level where emergency power control must be started. In this case, this embodiment determines to lock the emergency power control. Locking means that even if the emergency power modulation instruction is issued, the system will not execute the emergency power control action because the instruction value is equal to the threshold. At the same time, this embodiment sets the DC emergency power control start value D mod Set to 0, which is used to indicate that under the current conditions, emergency power control does not need to be activated. The specific mathematical expression is:

[0074]

[0075] In the formula, when D mod =1, indicating that emergency power control is started; when D mod =0, indicating emergency power control is locked.

[0076] This embodiment sends corresponding start or lock instructions to the DC emergency power control module through the control system according to the set DC emergency power control start value, continuously monitors the power status of the system and the actual operation of the DC emergency power control module, and can ensure that the DC emergency power control is started or locked at an appropriate time, effectively supporting the stable operation and power balance regulation of the power system.

[0077] S5. Start the DC power coordination control mechanism according to the DC frequency controller startup value and the DC emergency power control startup value, and determine the delay phase frequency controller adjustment amount according to the working state of the DC power coordination control mechanism.

[0078] In this embodiment, the step of starting the DC power coordination control mechanism according to the DC frequency controller starting value and the DC emergency power control starting value includes:

[0079] Obtaining a start-up timing flag sum according to the sum of the DC frequency controller start-up value and the DC emergency power control start-up value;

[0080] The start timing flag and the DC emergency power control start value are multiplied to obtain a DC power coordination control flag value, and the DC power coordination control mechanism is started according to the DC power coordination control flag value.

[0081] The step of determining the adjustment amount of the frequency controller in the delay phase according to the working state of the DC power coordinated control mechanism includes:

[0082] When the DC power coordination control mechanism starts working, the DC frequency controller startup value is assigned to the delay phase frequency controller adjustment value;

[0083] When the DC power coordination control mechanism is not started, the delay phase frequency controller adjustment amount is set to zero.

[0084] In a specific embodiment, the DC frequency controller startup value and the DC emergency power control startup value are both binary variables, which are used to indicate whether the DC frequency controller is started and whether the DC emergency power control is started. Specifically, the startup of the DC power coordination control mechanism is based on the startup conditions of the two strategies of the DC frequency controller and the DC emergency power control. When D FC =1 and D mod =1, that is, the DC frequency controller and the DC emergency power control are both started, and the DC power coordinated control is started at this time. The setting of this judgment condition is to ensure that in the case of a conflict between the two control strategies, coordination measures are taken in time to avoid unreasonable adjustment of the DC operating power and ensure the safe and stable operation of the power system. In this embodiment, the DC frequency controller startup value and the DC emergency power control startup value are added to obtain the startup timing flag sum, and then the startup timing flag sum is multiplied by the DC emergency power control startup value to obtain the DC power coordinated control flag value, and its mathematical expression is:

[0085] S cod =D mod ×(D mod +D FC )

[0086] This embodiment starts the DC power coordination control mechanism only when at least one controller is started and the emergency power control is also started. If the emergency power control is not started, even if the frequency controller is started, we do not start the coordination control mechanism. This embodiment determines whether the DC power coordination control mechanism is started. If the DC power coordination control flag value is non-zero, the DC power coordination control mechanism is started; if the DC power coordination control flag value is zero, the DC power coordination control mechanism is not started. When the DC power coordination control mechanism starts working, the DC frequency controller startup value is assigned to the delay stage frequency controller adjustment amount. When the DC power coordination control mechanism is not started, the delay stage frequency controller adjustment amount is set to zero. This means that without the support of the DC power coordination control mechanism, the frequency controller does not perform any adjustment in the delay stage. Its mathematical expression is:

[0087]

[0088] At the same time, this embodiment determines the delay time S according to the working state of the DC power coordination control mechanism. delay :

[0089]

[0090] In the formula, NP FC is the frequency controller adjustment amount in the delay phase. When the DC power coordination control mechanism starts working, it is used to indicate the adjustment amount of the frequency controller in the delay phase. FC is the frequency control regulation of the DC system; S cod is the DC power coordination control flag value. Its values ​​0, 1, and 2 represent no coordination, coordination mode 1, and coordination mode 2, respectively. Its value is determined according to the sequence of starting the DC frequency controller and the emergency control and the current operating status of the system. FC = 0 and D mod =1, that is, the emergency power control starts first, at this time S cod = 0, no coordinated control is performed, because emergency power control takes priority and will not conflict with the frequency controller; when D FC =1 and D mod =1, further judge the system frequency change trend and the size of the emergency power control instruction. If the system frequency rises slowly and the power adjustment required by the emergency power control instruction is small, S cod =1, using coordination mode 1; if the system frequency rises rapidly and the power adjustment required by the emergency power control command is large, S cod =2, using coordination mode 2; S delay is the delay time, which is expressed as codThe DC frequency controller lockout duration is determined, and the delay time is determined according to the DC frequency controller lockout duration of different DC power coordinated control mechanisms; t1 and t2 are the DC frequency controller lockout durations corresponding to coordination mode 1 and coordination mode 2, respectively, which can be usually 1800s and 30s respectively according to the system stability control requirements.

[0091] This embodiment adjusts the regulation amount of the frequency controller in the delay phase in real time according to the working state of the DC power coordination control mechanism, and monitors the frequency and power state of the system, thereby effectively supporting the frequency stability and power balance regulation of the power system.

[0092] S6. The current operating power instruction is updated according to the delay phase frequency controller adjustment amount and the DC emergency power modulation instruction, and a DC system operating power update instruction is calculated.

[0093] In this embodiment, the step of updating the current operating power instruction according to the delay phase frequency controller adjustment amount and the DC emergency power modulation instruction to calculate the DC system operating power update instruction includes:

[0094] The current operating power instruction is added to the delay phase frequency controller adjustment amount and the DC emergency power modulation instruction to obtain a DC system operating power update instruction.

[0095] Specifically, in this embodiment, the current operating power instruction P ref The delay phase frequency controller adjustment amount NP FC and DC emergency power modulation command P mod Add them together to get the updated DC system operating power command NP ref , its mathematical expression is:

[0096] NP ref =P ref +P mod +NP FC

[0097] This embodiment sends the calculated DC system operating power update instruction to the DC system's actuator, such as the control system of the DC converter station, to adjust the DC system's operating power, monitor the actual operating power of the DC system, and compare it with the updated power instruction to ensure that the DC system operates correctly according to the instruction. If there is a deviation between the actual operating power and the instruction, this embodiment can further adjust the control strategy.

[0098] S7. Control the high-voltage direct current transmission system to operate according to the direct current system operating power update instruction to complete direct current active power modulation.

[0099] Specifically, in this embodiment, after calculating the DC system operating power update instruction NP ref Afterwards, the power command is changed from the current operating power command P to ref Updated to DC system operating power update instruction NP ref , the DC system receives the DC system operating power update instruction NP ref After that, the output power is adjusted to match the new command value, such as adjusting the trigger angle of the converter, the DC voltage and other parameters, so as to achieve fast and accurate power regulation and complete the DC active power modulation. Then, after the modulation is completed, the DC emergency power control start value D is set. mod Clear, DC emergency power control start value D mod Clearing to zero indicates that the emergency state has been lifted, and the DC power coordination control flag value S cod Clear to prepare for the next emergency control, and at the same time set the delay phase frequency controller adjustment amount NP FC Clear to avoid interference with subsequent control; after the delay ends, the DC frequency controller starts at value D FC Clear to restore the normal function of the DC frequency controller, the mathematical expression is:

[0100]

[0101] After the clearing operation, this embodiment needs to confirm that the relevant flag bits and status codes have been correctly cleared to ensure the consistency of the system state, and delay After the end, the DC frequency controller blocking state is released through the control system operation. After the blocking state is released, the DC frequency controller and emergency power control functions are gradually restored to restore the high-voltage DC transmission system to normal operation. After completing the power modulation and zeroing operations, you can continue to wait for the next pre-delay time S delay This delay is used to ensure the stability of the system state and avoid frequent control switching from causing adverse effects on the system. Through the above steps, this embodiment can ensure that the high-voltage direct current transmission system operates stably according to the new power command, while restoring the normal control function of the system, providing strong support for the stable operation of the power grid.

[0102] This embodiment takes the example of the Southwest Power Grid transmitting electric energy to the East China Power Grid through several DC transmission lines, and realizes the interconnection of the two major power grid areas. In order to analyze the coordinated configuration method of DC frequency control and emergency power control, this embodiment takes the Binjin DC as an example for example discussion. In the example setting, this embodiment simulates the emergency action of the safety control system (security control system), requiring the Binjin DC power to be urgently reduced by 3000 MW. At the same time, it is assumed that the Binjin DC has been put into use. The frequency controller function, the dead zone of the controller is set to ±0.07 Hz, and the adjustment limit is ±800 MW. In order to intuitively demonstrate the effect of the coordination method, this embodiment draws a comparison chart of the power change of the Binjin DC under the two working conditions of the DC frequency controller (FC) not acting and acting, and whether the proposed coordination method is adopted or not, as shown in FIG. Figure 3 , Figure 4 As shown, from Figure 3 , Figure 4 It can be clearly seen that after adopting the proposed coordination method between DC frequency controller and DC emergency power control, the Bingin DC can accurately adjust its power output according to the requirements of emergency power control. This result fully verifies the effectiveness and practicality of the proposed method.

[0103] An embodiment of the present invention provides a method for coordinating and configuring high-voltage direct current frequency control and emergency power control. The method initializes an initial state flag of a high-voltage direct current transmission system; obtains a current operating power instruction and a direct current system frequency control adjustment amount of the high-voltage direct current transmission system according to a current direct current operating state of the high-voltage direct current transmission system; obtains a direct current frequency controller startup value according to the direct current system frequency control adjustment amount and a preset direct current frequency control action threshold; calculates a direct current emergency power modulation instruction according to system disturbance monitoring data, and determines a direct current emergency power control startup value according to the direct current emergency power modulation instruction; starts a direct current power coordination control mechanism according to the direct current frequency controller startup value and the direct current emergency power control startup value, and determines a delay phase frequency controller adjustment amount according to a working state of the direct current power coordination control mechanism; updates the current operating power instruction according to the delay phase frequency controller adjustment amount and the direct current emergency power modulation instruction, and calculates a direct current system operating power update instruction; controls the high-voltage direct current transmission system to operate according to the direct current system operating power update instruction, and completes direct current active power modulation. Compared with the existing technology, this method flexibly adjusts the DC power output through the real-time status of the high-voltage DC transmission system, realizes dynamic coordinated control of the power and frequency of the high-voltage DC transmission system, ensures that the system can quickly return to a stable state when facing disturbances, and effectively improves the system stability and operating efficiency.

[0104] It should be noted that the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0105] In one embodiment, Figure 5 As shown, an embodiment of the present invention provides a high-voltage direct current frequency control and emergency power control coordinated configuration system, the system comprising:

[0106] The flag initialization module 101 is used to initialize the initial state flag of the high voltage direct current transmission system; the initial state flag includes the initial value of starting the direct current emergency power control and the initial value of starting the direct current frequency controller;

[0107] The operating frequency analysis module 102 is used to obtain the current operating power instruction of the high-voltage direct current transmission system and the DC system frequency control adjustment amount according to the current DC operating state of the high-voltage direct current transmission system;

[0108] The frequency startup analysis module 103 is used to obtain a DC frequency controller startup value according to the DC system frequency control adjustment amount and a preset DC frequency control action threshold;

[0109] The emergency power control module 104 is used to calculate a DC emergency power modulation instruction according to the system disturbance monitoring data, and determine a DC emergency power control start value according to the DC emergency power modulation instruction;

[0110] The delay adjustment control module 105 is used to start the DC power coordination control mechanism according to the DC frequency controller startup value and the DC emergency power control startup value, and determine the delay phase frequency controller adjustment amount according to the working state of the DC power coordination control mechanism;

[0111] An operating power update module 106 is used to update the current operating power instruction according to the delay phase frequency controller adjustment amount and the DC emergency power modulation instruction, and calculate the DC system operating power update instruction;

[0112] The power coordination control module 107 is used to control the high voltage direct current transmission system to operate according to the direct current system operating power update instruction to complete direct current active power modulation.

[0113] For the specific limitations of a high-voltage direct current frequency control and emergency power control coordinated configuration system, please refer to the above-mentioned limitations on a high-voltage direct current frequency control and emergency power control coordinated configuration method, which will not be repeated here. A person of ordinary skill in the art will appreciate that the various modules and steps described in conjunction with the embodiments disclosed in this application can be implemented in hardware, software, or a combination of both. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0114] The embodiment of the present invention provides a high-voltage direct current frequency control and emergency power control coordination configuration system, wherein the system initializes an initial state flag of a high-voltage direct current transmission system through a flag initialization module; an operating frequency analysis module obtains a current operating power instruction and a direct current system frequency control adjustment amount of the high-voltage direct current transmission system according to the current direct current operating state of the high-voltage direct current transmission system; a frequency startup analysis module obtains a direct current frequency controller startup value according to the direct current system frequency control adjustment amount and a preset direct current frequency control action threshold; an emergency power control module calculates a direct current emergency power modulation instruction according to system disturbance monitoring data, and determines a direct current emergency power control startup value according to the direct current emergency power modulation instruction; a delay adjustment control module starts a direct current power coordination control mechanism according to the direct current frequency controller startup value and the direct current emergency power control startup value, and determines a delay phase frequency controller adjustment amount according to the working state of the direct current power coordination control mechanism; an operating power update module updates the current operating power instruction according to the delay phase frequency controller adjustment amount and the direct current emergency power modulation instruction, and calculates a direct current system operating power update instruction; and a power coordination control module controls the high-voltage direct current transmission system to operate according to the direct current system operating power update instruction to complete direct current active power modulation. Compared with the existing technology, this system flexibly adjusts the DC power output through the real-time status of the high-voltage DC transmission system, realizes dynamic coordinated control of the power and frequency of the high-voltage DC transmission system, ensures that the system can quickly return to a stable state when faced with disturbances, and effectively improves the system stability and operating efficiency.

[0115] The above-mentioned embodiments only express several preferred implementation modes of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in the technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be regarded as the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be based on the protection scope of the claims.

Claims

1. A method for coordinating and configuring high-voltage direct current frequency control and emergency power control, characterized in that: The following steps are involved: Initializing the initial state flag of the high voltage direct current transmission system; the initial state flag includes a direct current emergency power control start initial value and a direct current frequency controller start initial value; According to the current DC operation state of the HVDC transmission system, the current operation power instruction of the HVDC transmission system and the DC system frequency control adjustment amount are obtained; Obtaining a DC frequency controller startup value according to the DC system frequency control adjustment amount and a preset DC frequency control action threshold; Calculating a DC emergency power modulation instruction according to system disturbance monitoring data, and determining a DC emergency power control start value according to the DC emergency power modulation instruction; Starting the DC power coordination control mechanism according to the DC frequency controller startup value and the DC emergency power control startup value, and determining the delay phase frequency controller adjustment amount according to the working state of the DC power coordination control mechanism; The current operating power instruction is updated according to the delay phase frequency controller adjustment amount and the DC emergency power modulation instruction, and a DC system operating power update instruction is calculated; The high-voltage direct current transmission system is controlled to operate according to the direct current system operating power update instruction to complete direct current active power modulation.

2. A method for coordinating and configuring high voltage direct current frequency control and emergency power control as claimed in claim 1, characterized in that: The step of obtaining the current operating power instruction of the high-voltage direct current transmission system and the DC system frequency control adjustment amount according to the current DC operating state of the high-voltage direct current transmission system comprises: Collecting DC voltage data and DC current data of a high-voltage DC power transmission system, and calculating current DC power according to the DC voltage data and the DC current data; Determining a current operating power instruction of the high-voltage direct current transmission system according to the power system dispatching demand, the current direct current power and the rated power of the high-voltage direct current transmission system; Collecting AC system frequency measurement data, and comparing the AC system frequency measurement data with a preset frequency reference value to calculate a frequency deviation; According to the frequency deviation, a frequency control adjustment amount is calculated using a proportional-integral controller.

3. A method for coordinating and configuring high voltage direct current frequency control and emergency power control as claimed in claim 1, characterized in that: The step of obtaining a DC frequency controller startup value according to the DC system frequency control adjustment amount and a preset DC frequency control action threshold comprises: Compare the DC system frequency control adjustment amount with the DC frequency control action threshold, and if the DC system frequency control adjustment amount exceeds the DC frequency control action threshold, determine that the DC frequency controller starts before the emergency power control, and set the DC frequency controller start value to one; If the DC system frequency control adjustment amount does not exceed the DC frequency control action threshold, it is determined that the emergency power control is started before the DC frequency controller, and the DC frequency controller startup value is set to zero.

4. A method for coordinating and configuring high voltage direct current frequency control and emergency power control as claimed in claim 1, characterized in that: The step of determining the DC emergency power control start value according to the DC emergency power modulation instruction comprises: Comparing the absolute value of the DC emergency power modulation instruction with a preset emergency power control action threshold, if the absolute value of the DC emergency power modulation instruction is greater than the emergency power control action threshold, determining to start emergency power control, and setting the DC emergency power control start value to one; If the absolute value of the DC emergency power modulation instruction is equal to the emergency power control action threshold, it is determined that the emergency power control is locked and the DC emergency power control start value is set to zero.

5. A method for coordinating and configuring high voltage direct current frequency control and emergency power control as claimed in claim 1, characterized in that: The step of starting the DC power coordination control mechanism according to the DC frequency controller starting value and the DC emergency power control starting value comprises: Obtaining a start-up timing flag sum according to the sum of the DC frequency controller start-up value and the DC emergency power control start-up value; The start timing flag and the DC emergency power control start value are multiplied to obtain a DC power coordination control flag value, and the DC power coordination control mechanism is started according to the DC power coordination control flag value.

6. A method for coordinating and configuring high voltage direct current frequency control and emergency power control as claimed in claim 1, characterized in that: The step of determining the adjustment amount of the frequency controller in the delay phase according to the working state of the DC power coordinated control mechanism includes: When the DC power coordination control mechanism starts working, the DC frequency controller startup value is assigned to the delay phase frequency controller adjustment value; When the DC power coordination control mechanism is not started, the delay phase frequency controller adjustment amount is set to zero.

7. A method for coordinating and configuring high voltage direct current frequency control and emergency power control as claimed in claim 1, characterized in that: The step of updating the current operating power instruction according to the delay phase frequency controller adjustment amount and the DC emergency power modulation instruction to calculate and obtain the DC system operating power update instruction comprises: The current operating power instruction is added to the delay phase frequency controller adjustment amount and the DC emergency power modulation instruction to obtain a DC system operating power update instruction.

8. A method for coordinating and configuring high voltage direct current frequency control and emergency power control as claimed in claim 1, characterized in that: After the step of controlling the high-voltage direct current transmission system to operate according to the direct current system operating power update instruction and completing the direct current active power modulation step, the method further includes: The delay time is determined according to the working state of the DC power coordination control mechanism, and after the delay time ends, the DC frequency controller locking state is released, the DC frequency controller and emergency power control functions are restored, and the high-voltage DC transmission system is restored to normal operation.

9. A method for coordinating and configuring high voltage direct current frequency control and emergency power control as claimed in claim 8, characterized in that: The delay time is determined according to the DC frequency controller locking duration of different DC power coordinated control mechanisms.

10. A high voltage direct current frequency control and emergency power control coordinated configuration system, characterized in that: The system comprises: A flag initialization module is used to initialize the initial state flag of the high-voltage direct current transmission system; the initial state flag includes a direct current emergency power control start initial value and a direct current frequency controller start initial value; An operating frequency analysis module is used to obtain a current operating power instruction of the high-voltage direct current transmission system and a DC system frequency control adjustment amount according to the current DC operating state of the high-voltage direct current transmission system; A frequency startup analysis module, used to obtain a DC frequency controller startup value according to the DC system frequency control adjustment amount and a preset DC frequency control action threshold; The emergency power control module is used to calculate a DC emergency power modulation instruction according to the system disturbance monitoring data, and determine a DC emergency power control start value according to the DC emergency power modulation instruction; A delay adjustment control module, used to start the DC power coordination control mechanism according to the DC frequency controller start value and the DC emergency power control start value, and determine the delay phase frequency controller adjustment amount according to the working state of the DC power coordination control mechanism; An operating power update module, used to update the current operating power instruction according to the delay phase frequency controller adjustment amount and the DC emergency power modulation instruction, and calculate the DC system operating power update instruction; The power coordination control module is used to control the high-voltage direct current transmission system to operate according to the direct current system operating power update instruction to complete direct current active power modulation.

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