Automatic voltage and reactive power control method and device

Abstract

An automatic voltage and reactive power control method and apparatus are disclosed. The method includes: acquiring the voltage of the AC side bus of the flexible DC power grid; determining the over-limit situation of the AC side bus voltage based on the target value and actual value of the AC side bus voltage of the flexible DC power grid; analyzing the over-limit situation of the conventional pumped-storage unit's terminal voltage based on the actual value, constraint threshold, and control dead zone of the conventional pumped-storage unit's terminal voltage; when the conventional pumped-storage unit's terminal voltage is not over-limit, automatically controlling the voltage and reactive power by adjusting the terminal voltage command of the conventional pumped-storage unit; when the conventional pumped-storage unit's terminal voltage is over-limit, analyzing the over-limit situation of the variable-speed pumped-storage unit's terminal voltage and reactive power based on the actual value and constraint threshold of the variable-speed pumped-storage unit's terminal voltage; when the variable-speed pumped-storage unit's terminal voltage and reactive power are not over-limit, adjusting the variable-speed pumped-storage unit's terminal voltage or reactive power through constant voltage control or constant reactive power control according to the variable-speed pumped-storage unit's control strategy to complete the automatic voltage and reactive power control.

Description

Technical Field

[0001] This invention relates to the field of power control and management, and more particularly to an automatic voltage and reactive power control method and apparatus. Background Technology

[0002] Flexible DC transmission technology has become an important means to solve the problem of large-scale renewable energy transmission being able to "send and connect" to the grid. Pumped storage technology, with its most mature technology and lowest cost, plays a crucial role in mitigating the impact of large-scale renewable energy grid connection. The combined operation of "flexible DC + pumped storage" has become an important scenario for solving the problem of renewable energy grid integration and absorption. Given that MMC (Multi-Mode Capable Transmission) can quickly and independently adjust reactive power output, MMC-based flexible DC converter stations have become a potential plant-level automatic voltage control (AVC) resource in the power system. Simultaneously, with the advancement of power electronics technology, pumped storage units have acquired the ability to change their operating state in a short time, possessing the potential to rapidly adjust system reactive power and voltage. If flexible DC converter stations and pumped storage units can participate in AVC, it will help avoid long-distance or multi-level transmission of reactive power, achieving hierarchical and local balancing, and improving the stability of the power grid voltage operation. However, both the flexible DC converter station and the pumped-storage unit employ constant reactive power control and constant AC voltage control methods. If they participate in AVC simultaneously, it involves coordination issues between the flexible DC converter station and the pumped-storage unit on steady-state long-term and transient short-term time scales. If the pumped-storage power station includes conventional pumped-storage units and variable-speed pumped-storage units, the regulation priority among the pumped-storage units must also be considered. Therefore, it is necessary to conduct research on the coordinated control of the flexible DC converter station and the pumped-storage unit when participating in AVC, and to fully utilize their reactive power and voltage regulation capabilities while considering equipment constraints.

[0003] A two-step voltage regulation method is provided in the existing technology to achieve AC bus voltage regulation by flexible DC converter. First, based on the initial value U0 of the AC bus voltage before regulation and the target value U after regulation, the flexible DC converter valve is controlled to generate reactive power to Q1, and the AC bus voltage U1 at this time is observed. Then, the reactive power Q2 required by the flexible DC converter is calculated based on U1 and U. This method calculates the final reactive power required to regulate the AC voltage through testing steps, is simple and practical, does not rely on complex power calculations, does not need to consider the converter station's operating mode, clearly defines the reference value of the generated reactive power, and avoids disturbances to the system caused by frequent on-site adjustments. However, this scheme studies the scenario where flexible DC converters participate in the system's AC voltage regulation, and involves the condition where pumped-storage units also participate in the system's AC voltage regulation.

[0004] Another approach proposes a coordinated fault ride-through method for a flexible DC system (DCS) comprising a pumped-storage power station and a wind farm when a fault occurs. When a fault occurs in the DCS system, the fault information is transmitted to the pumped-storage turbine (PST) via communication. Simultaneously, the power measurement link at the wind farm's PCC node also sends the measured power value to the PST. The PST determines its operating mode by analyzing the fault information and considering the wind farm's output power, and simultaneously determines the magnitude of the power command value. Through rapid power regulation, it reduces the power injected into the DCS system, achieving fault ride-through. However, this technology only studies the active power joint ride-through scheme of the PST and wind turbines during DCS faults, and does not consider the coordination between reactive power. Summary of the Invention

[0005] The purpose of this invention is to provide an automatic voltage and reactive power control method and device. This method addresses the reactive power and voltage coordination control scenario involving flexible DC converter stations and pumped-storage units participating in AVC (Automatic Voltage Control). Based on the reactive power and voltage adjustment margins of flexible DC converter stations, conventional pumped-storage units, and variable-speed pumped-storage units, a reasonable AVC control strategy is determined to achieve reactive power and voltage balance in the flexible DC power grid + pumped-storage unit scenario, reducing unreasonable reactive power flow and improving the safe and stable operation of the system.

[0006] To achieve the above objectives, the automatic voltage and reactive power control method provided by this invention is applicable to power systems including flexible DC converter stations and pumped-storage units, and specifically includes the following: acquiring the AC bus voltage of the flexible DC power grid; determining the over-limit status of the AC bus voltage based on the target value and actual value of the AC bus voltage of the flexible DC power grid; when the AC bus voltage of the flexible DC power grid exceeds the limit, analyzing the over-limit status of the conventional pumped-storage unit's terminal voltage based on the actual value, constraint threshold, and control dead zone; when the conventional pumped-storage unit's terminal voltage exceeds the limit, analyzing the over-limit status of the variable-speed pumped-storage unit's terminal voltage and reactive power based on the actual value and constraint threshold of the variable-speed pumped-storage unit's terminal voltage; when the variable-speed pumped-storage unit's terminal voltage and reactive power do not exceed the limit, adjusting the variable-speed pumped-storage unit's terminal voltage or reactive power through a constant voltage control mode or a constant reactive power control mode according to the variable-speed pumped-storage unit's control strategy to complete automatic voltage and reactive power control.

[0007] In the above-mentioned automatic voltage and reactive power control method, preferably, the method further includes: when the terminal voltage of the conventional pumped-storage unit does not exceed the limit, adjusting the terminal voltage of the conventional pumped-storage unit according to the actual value of the terminal voltage and the adjustment step size to complete the automatic voltage and reactive power control.

[0008] In the above-mentioned automatic voltage and reactive power control method, the preferred method, based on the actual value of the conventional pumped-storage unit's terminal voltage, constraint threshold, and control dead zone, analyzes the following situations regarding the excessive voltage of the conventional pumped-storage unit's terminal voltage:

[0009] The following formula is used to calculate the over-limit situation of the terminal voltage of a conventional pumped-storage unit:

[0010] V pump1_min -Err_V pump1≤ V pump1≤ V pump1_max +Err_V pump1 ;

[0011] In the above formula, V pump1 V pump1_max V pump1_min Err_V pump1 These are the actual value of the generator terminal voltage of a conventional pumped-storage unit, the upper limit of the constraint, the lower limit of the constraint, and the control dead zone.

[0012] In the above-mentioned automatic voltage and reactive power control method, preferably, the method further includes: when the terminal voltage and reactive power of the variable speed pumped-storage unit exceed the limit, obtaining the over-limit status of the flexible DC reactive power; when the flexible DC reactive power exceeds the limit, controlling the flexible DC converter station and the pumped-storage unit to maintain the current operating conditions.

[0013] In the above-mentioned automatic voltage reactive power control method, preferably, the method further includes: when the reactive power of the flexible DC converter does not exceed the limit, and the flexible DC converter station adopts a constant reactive power control mode or a constant AC voltage control mode, adjusting the reactive power or AC voltage command of the flexible DC converter station according to a preset model to obtain reactive power parameters or AC voltage parameters; and completing automatic voltage reactive power control according to the reactive power parameters or the AC voltage parameters.

[0014] In the above-mentioned automatic voltage and reactive power control method, preferably, the analysis of the over-limit situation of the variable speed pumped storage unit's terminal voltage and reactive power based on the actual value of the terminal voltage and the constraint threshold includes: calculating the over-limit situation of the variable speed pumped storage unit's terminal voltage and reactive power using the following formula:

[0015] V pump2_min -Err_V pump2≤ V pump2≤ V pump2_max +Err_V pump2 ;

[0016] Q pump2_min -Err_Q pump2≤ Q pump2≤ Q pump2_max +Err_Q pump2 ;

[0017] In the above formula, V pump2 V pump2_max V pump2_min Err_V pump2These represent the actual value, upper and lower limits of the constraint, control dead zone, and adjustment step size of the variable-speed pumped-storage unit's terminal voltage, respectively. pump2 Q pump2_max Q pump2_min Err_Q pump2 These are the actual reactive power value, upper and lower limits of the constraint, and control dead zone of the variable speed pumped storage unit.

[0018] In the above-mentioned automatic voltage reactive power control method, preferably, obtaining reactive power parameters or AC voltage parameters by adjusting the reactive power or AC voltage command of the flexible DC converter station according to the preset model includes:

[0019] The reactive power parameters or AC voltage parameters can be calculated using the following formula:

[0020] V HVDC =V HVDC ±△V HVDC ;

[0021] Q HVDC =Q HVDC ±△Q HVDC ;

[0022] In the above formula, Q HVDC V HVDC These are the reactive power parameters and AC voltage parameters, ΔV. HVDC For flexible DC fixed voltage control, the voltage adjustment step size is ΔQ. HVDC The reactive power adjustment step size for the flexible DC power constant reactive power control is ±, which is determined by the over-limit direction of the flexible DC AC side bus voltage. When it is higher than the upper limit, it takes a negative sign, and when it is lower than the lower limit, it takes a positive sign.

[0023] In the above-mentioned automatic voltage and reactive power control method, preferably, the automatic voltage and reactive power control is achieved by adjusting the terminal voltage or reactive power of the variable speed pumped storage unit according to the control strategy of the variable speed pumped storage unit through constant voltage control or constant reactive power control, which includes:

[0024] The adjustment parameters corresponding to constant voltage control mode or constant reactive power control mode are calculated using the following formulas. Automatic voltage and reactive power control is then achieved by adjusting the terminal voltage or reactive power of the variable speed pumped-storage unit according to these adjustment parameters.

[0025] V pump2 =V pump2 ±△V2;

[0026] Q pump2 =Q pump2 ±△Q pump2 ;

[0027] In the above formula, V pump2 Q pump2These are the adjustment parameters for constant voltage control and constant reactive power control, respectively: ΔV2 and ΔQ. pump2 These are the voltage regulation step size and reactive power regulation step size of the variable speed pumped storage unit, respectively. ± is determined according to the over-limit direction of the AC bus voltage on the flexible DC side. When it is higher than the upper limit, it takes a negative sign, and when it is lower than the lower limit, it takes a positive sign.

[0028] This invention also provides an automatic voltage and reactive power control device, applicable to power systems including flexible DC converter stations and pumped-storage units. The device includes a data acquisition module, a conventional pumped-storage unit analysis module, a variable-speed pumped-storage unit analysis module, and a regulation module. It acquires the AC bus voltage of the flexible DC converter station and determines the over-limit status of the AC bus voltage based on the target and actual values ​​of the AC bus voltage of the flexible DC converter station. When the AC bus voltage of the flexible DC converter station exceeds the limit, it analyzes the over-limit status of the conventional pumped-storage unit's terminal voltage based on the actual value, constraint threshold, and control dead zone. When the terminal voltage of the conventional pumped-storage unit exceeds the limit, it analyzes the non-over-limit status of the variable-speed pumped-storage unit's terminal voltage and reactive power based on the actual value and constraint threshold of the variable-speed pumped-storage unit's terminal voltage. When the terminal voltage and reactive power of the variable-speed pumped-storage unit exceed the limit, it adjusts the terminal voltage or reactive power of the variable-speed pumped-storage unit through constant voltage control or constant reactive power control according to the variable-speed pumped-storage unit's control strategy to complete automatic voltage and reactive power control.

[0029] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described method.

[0030] The present invention also provides a computer-readable storage medium storing a computer program for performing the above-described method.

[0031] The beneficial technical effects of this invention are as follows: when there is a need for reactive power voltage regulation in the system, the reactive power voltage of the system is regulated according to the priority order of conventional pumped-storage units, variable-speed pumped-storage units, and flexible DC converter stations. Under the premise of considering capacity constraints, the reactive power voltage regulation potential of the equipment is fully utilized. It can fully take into account the characteristics of mature conventional pumped-storage excitation technology, rapid regulation of variable-speed pumped-storage units, and flexible control of flexible DC converter stations, thereby improving the regional reactive power voltage stability operation level. Attached Figure Description

[0032] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, are not intended to limit the scope of the invention. In the drawings:

[0033] Figure 1 This is a flowchart illustrating an automatic voltage reactive power control method according to an embodiment of the present invention.

[0034] Figure 2This is a schematic diagram of the analysis process for over-limit situations of a variable-speed pumped-storage unit provided in an embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of the processing flow when a variable-speed pumped-storage unit does not exceed the limit, according to an embodiment of the present invention.

[0036] Figure 4 This is a schematic diagram of the processing flow for flexible direct current reactive power exceeding the limit according to an embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of the process for obtaining reactive power parameters according to an embodiment of the present invention;

[0038] Figure 6 This is a schematic diagram of the process for obtaining AC voltage parameters according to an embodiment of the present invention;

[0039] Figure 7 This is a schematic diagram of the control logic of an automatic voltage reactive power control method provided in an embodiment of the present invention;

[0040] Figure 8 This is a schematic diagram of the structure of an automatic voltage reactive power control device provided in an embodiment of the present invention;

[0041] Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0042] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings and examples, so that the process of how the present invention uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that, as long as there is no conflict, the various embodiments and features in the various embodiments of the present invention can be combined with each other, and the resulting technical solutions are all within the protection scope of the present invention.

[0043] Furthermore, the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0044] Please refer to Figure 1 As shown, the automatic voltage and reactive power control method provided by this invention is applicable to power systems including flexible DC converter stations and pumped-storage units, and specifically includes the following:

[0045] S101 acquires the AC bus voltage of the flexible DC power grid and determines the over-limit situation of the AC bus voltage based on the target value and actual value of the AC bus voltage of the flexible DC power grid.

[0046] S102 When the voltage of the flexible DC AC side bus exceeds the limit, the voltage exceeding the limit of the conventional pumped storage unit is analyzed based on the actual value of the terminal voltage of the conventional pumped storage unit, the constraint threshold, and the control dead zone.

[0047] S103 When the terminal voltage of the conventional pumped storage unit exceeds the limit, analyze the over-limit situation of the terminal voltage and reactive power of the variable speed pumped storage unit based on the actual value of the terminal voltage and the constraint threshold.

[0048] S104 When the terminal voltage and reactive power of the variable speed pumped storage unit do not exceed the limits, the terminal voltage or reactive power of the variable speed pumped storage unit is adjusted according to the control strategy of the variable speed pumped storage unit through constant voltage control mode or constant reactive power control mode to complete automatic voltage and reactive power control.

[0049] Specifically, the following formula can be used to determine whether the voltage of the AC side bus of the flexible DC power grid exceeds the limit, based on the target value and the actual value:

[0050] |V ref -V t |>V err (1);

[0051] In the above formula, V ref V t V err This refers to the target value, actual value, and control dead zone of the AC bus voltage in the flexible DC power grid. If the AC bus voltage of the flexible DC power grid does not exceed the limit, the judgment continues; if the AC bus voltage exceeds the limit, AVC control begins and the subsequent process commences. Overall, given the relatively mature excitation control technology of conventional pumped storage, and the poor transient response of variable-speed pumped storage and flexible DC power grids due to their power electronic power supply attributes, the above-mentioned embodiment provided by this invention uses the AC bus voltage as the control target. Under the constraints of conventional pumped storage, variable-speed pumped storage generator terminal voltage, and reactive power not exceeding the limit, control is performed according to the priority order of conventional pumped storage, variable-speed pumped storage, and flexible DC power grids. That is, conventional pumped storage units are controlled first, then variable-speed pumped storage units, and finally flexible DC power grids. During each control operation, the same type of unit can operate simultaneously. Regarding the selection of control methods, given that the excitation control technology of conventional pumped storage is relatively mature, only the constant generator terminal voltage control method is adopted; variable speed pumped storage and flexible DC can adopt constant reactive power or constant voltage control methods. Among them, the constant reactive power control method has poor response capability under transient conditions. As a steady-state control method, constant voltage control is more closely related to the grid mode. It can be used as a steady-state regulation means, and can also autonomously respond to reactive power support needs during transients. The specific implementation method will be described in detail in the subsequent embodiments.

[0052] In one embodiment of the present invention, the method may further include: when the terminal voltage of the conventional pumped-storage unit is not exceeded, adjusting the terminal voltage of the conventional pumped-storage unit according to the actual value of the terminal voltage and the adjustment step size to complete automatic voltage and reactive power control. The analysis of the limit-exceeding situation of the conventional pumped-storage unit terminal voltage based on the actual value of the terminal voltage, the constraint threshold, and the control dead zone includes:

[0053] The following formula is used to calculate the over-limit situation of the terminal voltage of a conventional pumped-storage unit:

[0054] V pump1_min -Err_V pump1≤ V pump1≤ V pump1_max +Err_V pump1 (2);

[0055] In the above formula, V pump1 V pump1_max V pump1_min Err_V pump1 These are the actual value, upper limit, lower limit, and control dead zone of the conventional pumped-storage unit's terminal voltage, respectively. Therefore, formula (2) is used to determine whether the conventional pumped-storage unit's terminal voltage exceeds the limit and whether it can participate in AVC. If the conventional pumped-storage unit can participate in AVC, the terminal voltage of the conventional pumped-storage unit is adjusted using the following formula:

[0056] V pump1 =V pump1 ±△V1 (3);

[0057] In the above formula, △V1 is the step size of the voltage regulation at the generator terminal of the conventional pumped-storage unit, and "±" is determined according to the direction of the voltage exceeding the limit on the flexible DC AC side bus. When it is higher than the upper limit, it takes a negative sign, and when it is lower than the lower limit, it takes a positive sign. If the conventional pumped-storage unit cannot participate in AVC, another method is used to determine whether the variable-speed pumped-storage unit can participate in AVC. Please refer to the subsequent embodiments for details of this method, which will not be described in detail here.

[0058] Please refer to Figure 2 As shown, in one embodiment of the present invention, analyzing the over-limit conditions of the variable-speed pumped-storage unit's terminal voltage and reactive power based on the actual value of the terminal voltage and the constraint threshold includes: calculating the over-limit conditions of the variable-speed pumped-storage unit's terminal voltage and reactive power using the following formula:

[0059] V pump2_min -Err_V pump2≤ V pump2≤ V pump2_max +Err_V pump2 (4);

[0060] Q pump2_min-Err_Q pump2≤ Q pump2≤ Q pump2_max +Err_Q pump2 (5);

[0061] In the above formula, V pump2 V pump2_max V pump2_min Err_V pump2 These represent the actual value, upper and lower limits of the constraint, control dead zone, and adjustment step size of the variable-speed pumped-storage unit's terminal voltage, respectively. pump2 Q pump2_max Q pump2_min Err_Q pump2 These are the actual reactive power value, upper and lower limits of the constraint, and the control dead zone of the variable-speed pumped-storage unit, respectively. Based on this embodiment, if the variable-speed pumped-storage unit can participate in AVC (Automatic Voltage and Reactive Power Control), in another embodiment of the invention, automatic voltage and reactive power control is achieved by adjusting the terminal voltage or reactive power of the variable-speed pumped-storage unit according to the control strategy of the unit using either constant voltage control or constant reactive power control. This includes: calculating the adjustment parameters corresponding to the constant voltage control or constant reactive power control method using the following formula, and adjusting the terminal voltage or reactive power of the variable-speed pumped-storage unit according to the adjustment parameters to achieve automatic voltage and reactive power control.

[0062] V pump2 =V pump2 ±△V2 (6);

[0063] Q pump2 =Q pump2 ±△Q pump2 (7);

[0064] In the above formula, V pump2 Q pump2 These are the adjustment parameters for constant voltage control and constant reactive power control, respectively: ΔV2 and ΔQ. pump2 These are the voltage regulation step size and reactive power regulation step size of the variable speed pumped storage unit, respectively. ± is determined according to the over-limit direction of the AC bus voltage on the flexible DC side. When it is higher than the upper limit, it takes a negative sign, and when it is lower than the lower limit, it takes a positive sign.

[0065] If the variable-speed pumped-storage unit cannot participate in AVC, please refer to... Figure 3 As shown, in one embodiment of the present invention, the method may further include:

[0066] S301 When the terminal voltage and reactive power of the variable speed pumped storage unit exceed the limits, obtain the limit-exceeding status of the flexible DC reactive power.

[0067] S302 When the reactive power limit of the flexible DC converter exceeds the limit, the flexible DC converter station and the pumped storage unit shall be controlled to maintain the current operating conditions.

[0068] Therefore, based on whether the flexible DC-DC power supply exceeds its limits, it is determined whether it can participate in AVC. Based on the determination result, S302 is executed. If the flexible DC-DC power supply and pumped storage maintain their current operating conditions, other reactive power and voltage regulation resources in the system participate in AVC; or, subsequent actions are executed. Figure 4 The process. Specifically, when flexible and linear reactive power can participate in AVC, please refer to... Figure 4 As shown, the method further includes:

[0069] S401 When the reactive power of the flexible DC converter does not exceed the limit, and the flexible DC converter station adopts a constant reactive power control mode or a constant AC voltage control mode, the reactive power or AC voltage parameters of the flexible DC converter station are obtained by adjusting the reactive power or AC voltage command according to the preset model.

[0070] S402 performs automatic voltage and reactive power control based on the reactive power parameters or the AC voltage parameters.

[0071] The process of obtaining reactive power or AC voltage parameters by adjusting the reactive power or AC voltage of the flexible DC converter station according to the preset model includes:

[0072] The reactive power parameters or AC voltage parameters can be calculated using the following formula:

[0073] V HVDC =V HVDC ±△V HVDC (8);

[0074] Q HVDC =Q HVDC ±△Q HVDC (9);

[0075] In the above formula, Q HVDC V HVDC These are the reactive power parameters and AC voltage parameters, ΔV. HVDC For flexible DC fixed voltage control, the voltage adjustment step size is ΔQ. HVDC The reactive power adjustment step size for the flexible DC power constant reactive power control is ±, which is determined by the over-limit direction of the flexible DC AC side bus voltage. When it is higher than the upper limit, it takes a negative sign, and when it is lower than the lower limit, it takes a positive sign.

[0076] In the above embodiments, the specific control logic for automatic voltage and reactive power control based on the reactive power parameters or the AC voltage parameters can be found in [reference needed]. Figure 5 and Figure 6 As shown:

[0077] Flexible DC control methods are divided into three types: system-level control, converter-level control, and trigger-level control. For converter station system-level control, reactive power control methods include reactive power control and AC voltage control, but these are incompatible control objectives, and only one can be controlled at a time.

[0078] Among them, reactive power control can be referred to Figure 5 As shown, the reactive power control module receives the reactive power dispatch command Q. HVDC Reactive power modulation or fast reactive power control signal Q m They generate a reactive power reference signal Q through the reactive power command regulation stage. ref The reactive power is transmitted to the converter-level control system. Reactive power modulation and rapid reactive power change can be used to improve system voltage stability, suppress flicker, and improve power quality.

[0079] AC voltage control can be referenced. Figure 6 As shown, the control objective of the flexible DC converter station is to adjust the AC voltage on a certain bus (usually the connection point bus); the AC voltage control module receives the command V from the upper level. HVDC Within the capacity limits of the converter station, based on information such as system operating conditions, an AC voltage reference signal V is generated through the AC voltage command regulation stage. HVDC_ref And transmit it to the converter-level control system.

[0080] In conjunction with the above embodiments, the control logic of the automatic voltage and reactive power control method provided by this invention in actual operation can be referred to... Figure 7 As shown, the specific application methods of each module have been described in detail in the foregoing embodiments, and will not be described in detail here.

[0081] Please refer to Figure 8 As shown, this invention also provides an automatic voltage and reactive power control device, applicable to power systems including flexible DC converter stations and pumped-storage units. The device includes a data acquisition module, a conventional pumped-storage unit analysis module, a variable-speed pumped-storage unit analysis module, and a regulation module. It acquires the AC bus voltage of the flexible DC converter station and determines the over-limit status of the AC bus voltage based on the target and actual values ​​of the AC bus voltage of the flexible DC converter station. When the AC bus voltage of the flexible DC converter station exceeds the limit, it analyzes the over-limit status of the conventional pumped-storage unit's terminal voltage based on the actual value, constraint threshold, and control dead zone. When the terminal voltage of the conventional pumped-storage unit exceeds the limit, it analyzes the over-limit status of the variable-speed pumped-storage unit's terminal voltage and reactive power based on the actual value and constraint threshold of the variable-speed pumped-storage unit's terminal voltage. When the terminal voltage and reactive power of the variable-speed pumped-storage unit do not exceed the limit, it adjusts the terminal voltage or reactive power of the variable-speed pumped-storage unit through constant voltage control or constant reactive power control according to the control strategy of the variable-speed pumped-storage unit to complete automatic voltage and reactive power control.

[0082] The beneficial technical effects of this invention are as follows: when there is a need for reactive power voltage regulation in the system, the reactive power voltage of the system is regulated according to the priority order of conventional pumped-storage units, variable-speed pumped-storage units, and flexible DC converter stations. Under the premise of considering capacity constraints, the reactive power voltage regulation potential of the equipment is fully utilized. It can fully take into account the characteristics of mature conventional pumped-storage excitation technology, rapid regulation of variable-speed pumped-storage units, and flexible control of flexible DC converter stations, thereby improving the regional reactive power voltage stability operation level.

[0083] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described method.

[0084] The present invention also provides a computer-readable storage medium storing a computer program for performing the above-described method.

[0085] like Figure 9 As shown, the electronic device 600 may also include: a communication module 110, an input unit 120, an audio processing unit 130, a display 160, and a power supply 170. It is worth noting that the electronic device 600 does not necessarily need to include these components. Figure 9 All components shown; in addition, the electronic device 600 may also include Figure 9 For components not shown, please refer to existing technologies.

[0086] like Figure 9 As shown, the central processing unit 100, sometimes also referred to as a controller or operating control, may include a microprocessor or other processor device and / or logic device. The central processing unit 100 receives inputs and controls the operation of various components of the electronic device 600.

[0087] The memory 140 may be, for example, one or more of a cache, flash memory, hard drive, removable media, volatile memory, non-volatile memory, or other suitable devices. It may store the aforementioned failure-related information, and also store a program for executing that information. The central processing unit 100 may execute the program stored in the memory 140 to perform information storage or processing, etc.

[0088] Input unit 120 provides input to central processing unit 100. Input unit 120 may be, for example, a keypad or touch input device. Power supply 170 provides power to electronic device 600. Display 160 displays images and text. Display may be, for example, an LCD display, but is not limited thereto.

[0089] The memory 140 can be a solid-state memory, such as a read-only memory (ROM), random access memory (RAM), a SIM card, etc. It can also be a memory that retains information even when power is off, can be selectively erased, and contains more data; examples of this type of memory are sometimes referred to as EPROMs. The memory 140 can also be some other type of device. The memory 140 includes a buffer memory 141 (sometimes referred to as a buffer). The memory 140 may include an application / function storage unit 142 for storing application programs and function programs or processes for executing the operation of the electronic device 600 via the central processing unit 100.

[0090] The memory 140 may also include a data storage unit 143 for storing data, such as contacts, digital data, pictures, sounds, and / or any other data used by the electronic device. The driver storage unit 144 of the memory 140 may include various drivers for the electronic device's communication functions and / or for performing other functions of the electronic device (such as messaging applications, address book applications, etc.).

[0091] The communication module 110 is a transmitter / receiver 110 that transmits and receives signals via antenna 111. The communication module (transmitter / receiver) 110 is coupled to the central processing unit 100 to provide input signals and receive output signals, which can be the same as in a conventional mobile communication terminal.

[0092] Based on different communication technologies, multiple communication modules 110 can be configured in the same electronic device, such as cellular network modules, Bluetooth modules, and / or wireless LAN modules. The communication module (transmitter / receiver) 110 is also coupled to a speaker 131 and a microphone 132 via an audio processor 130 to provide audio output via the speaker 131 and receive audio input from the microphone 132, thereby enabling typical telecommunications functions. The audio processor 130 may include any suitable buffer, decoder, amplifier, etc. Additionally, the audio processor 130 is coupled to a central processing unit 100, enabling on-device recording via the microphone 132 and on-device playback of stored audio via the speaker 131.

[0093] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0094] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0095] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0096] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0097] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An automatic voltage and reactive power control method, applicable to power systems including flexible DC converter stations and pumped-storage units, characterized in that, The method includes: Obtain the AC bus voltage of the flexible DC power grid, and determine the over-limit situation of the AC bus voltage based on the target value and actual value of the AC bus voltage of the flexible DC power grid. When the voltage of the AC bus on the flexible DC-DC converter exceeds the limit, the reactive power regulation capability of each device is judged in the order of priority of conventional pumped storage units, variable speed pumped storage units, and flexible DC-DC converter stations, and the priority level devices that have not exceeded the limit are controlled to make adjustments. Among them, the over-limit situation of the terminal voltage of conventional pumped-storage units is analyzed based on the actual value of the terminal voltage, constraint threshold and control dead zone; When the terminal voltage of the conventional pumped storage unit exceeds the limit, the over-limit situation of the terminal voltage and reactive power of the variable speed pumped storage unit is analyzed based on the actual value of the terminal voltage and the constraint threshold. When the terminal voltage and reactive power of the variable speed pumped storage unit do not exceed the limits, the terminal voltage or reactive power of the variable speed pumped storage unit is adjusted through constant voltage control or constant reactive power control according to the control strategy of the variable speed pumped storage unit to complete automatic voltage and reactive power control.

2. The automatic voltage reactive power control method according to claim 1, characterized in that, The method further includes: When the terminal voltage of the conventional pumped-storage unit does not exceed the limit, the terminal voltage of the conventional pumped-storage unit is adjusted according to the actual value of the terminal voltage and the adjustment step size to complete the automatic voltage and reactive power control.

3. The automatic voltage reactive power control method according to claim 1 or 2, characterized in that, Based on the actual value, constraint threshold, and control dead zone of the terminal voltage of conventional pumped-storage units, the following exceedance scenarios of the terminal voltage of conventional pumped-storage units are analyzed: The following formula is used to calculate the over-limit situation of the terminal voltage of a conventional pumped-storage unit: V pump1_min -Err_ V pump1≤ V pump1≤ V pump1_max + Err_ V pump1 ; In the above formula, V pump1 , V pump1_max , V pump1_min Err_ V pump1 These are the actual value of the generator terminal voltage of a conventional pumped-storage unit, the upper limit of the constraint, the lower limit of the constraint, and the control dead zone.

4. The automatic voltage reactive power control method according to claim 1, characterized in that, The method further includes: When the terminal voltage and reactive power of the variable speed pumped storage unit exceed the limits, the over-limit situation of flexible DC reactive power is obtained; When the reactive power limit of the flexible DC converter exceeds the limit, the flexible DC converter station and pumped storage unit are controlled to maintain the current operating conditions.

5. The automatic voltage reactive power control method according to claim 4, characterized in that, The method further includes: When the reactive power of the flexible DC converter does not exceed the limit, and the flexible DC converter station adopts a constant reactive power control mode or a constant AC voltage control mode, the reactive power parameters or AC voltage parameters are obtained by adjusting the reactive power or AC voltage command of the flexible DC converter station according to the preset model. Automatic voltage and reactive power control is performed based on the reactive power parameters or the AC voltage parameters.

6. The automatic voltage reactive power control method according to claim 4 or 5, characterized in that, The analysis of the over-limit situations of variable-speed pumped-storage unit terminal voltage and reactive power based on the actual value of the terminal voltage and constraint threshold includes: The following formulas are used to calculate the over-limit conditions of the generator terminal voltage and reactive power of the variable-speed pumped-storage unit: V pump2_min -Err_ V pump2≤ V pump2≤ V pump2_max +Err_ V pump2 ; Q pump2_min -Err_ Q pump2≤ Q pump2≤ Q pump2_max + Err_ Q pump2 ; In the above formula, V pump2 , V pump2_max , V pump2_min Err_ V pump2 These are the actual value, upper and lower limits of the constraint, and control dead zone of the variable speed pumped-storage unit's terminal voltage. Q pump2 , Q pump2_max , Q pump2_min Err_ Q pump2 These are the actual reactive power value, upper and lower limits of the constraint, and control dead zone of the variable speed pumped storage unit.

7. The automatic voltage reactive power control method according to claim 5, characterized in that, The reactive power parameters or AC voltage parameters obtained by adjusting the reactive power or AC voltage of the flexible DC converter station according to the preset model include: The reactive power parameters or AC voltage parameters can be calculated using the following formula: V HVDC= V HVDC ±△ V HVDC ； Q HVDC= Q HVDC ±△ Q HVDC ； In the above formula, Q HVDC 、V HVDC These are the reactive power parameters and AC voltage parameters, respectively, Δ V HVDC For flexible DC fixed voltage control, the voltage adjustment step size is Δ Q HVDC The reactive power adjustment step size for the flexible DC power constant reactive power control is ±, which is determined by the direction of the over-limit of the flexible DC AC side bus voltage. When it is higher than the upper limit, it takes a negative sign, and when it is lower than the lower limit, it takes a positive sign.

8. The automatic voltage reactive power control method according to claim 1, characterized in that, Automatic voltage and reactive power control, based on the control strategy of the variable-speed pumped-storage unit, is achieved by adjusting the unit's terminal voltage or reactive power through constant voltage control or constant reactive power control. This includes: The adjustment parameters corresponding to constant voltage control mode or constant reactive power control mode are calculated using the following formulas. Automatic voltage and reactive power control is then achieved by adjusting the terminal voltage or reactive power of the variable speed pumped-storage unit according to these adjustment parameters. V pump2= V pump2 ±△ V 2； Q pump2= Q pump2 ±△ Q pump2 ； In the above formula, V pump2 , Q pump2 These are the adjustment parameters corresponding to constant voltage control mode and constant reactive power control mode, respectively, Δ V 2. △ Q pump2 These are the voltage regulation step size and reactive power regulation step size of the variable speed pumped storage unit, respectively. ± is determined according to the over-limit direction of the AC bus voltage on the flexible DC side. When it is higher than the upper limit, it takes a negative sign, and when it is lower than the lower limit, it takes a positive sign.

9. An automatic voltage and reactive power control device, applicable to power systems including flexible DC converter stations and pumped-storage units, characterized in that, The device includes a data acquisition module, a conventional pumped-storage unit analysis module, a variable-speed pumped-storage unit analysis module, and a regulation module. Obtain the AC bus voltage of the flexible DC power grid, and determine the over-limit situation of the AC bus voltage based on the target value and actual value of the AC bus voltage of the flexible DC power grid. When the voltage of the AC bus of the flexible DC converter exceeds the limit, the reactive power regulation capability of each device is judged in the order of priority of conventional pumped-storage units, variable-speed pumped-storage units, and flexible DC converter stations, and the priority level devices that have not exceeded the limit are controlled to make adjustments; among them, the over-limit situation of the conventional pumped-storage unit terminal voltage is analyzed based on the actual value of the terminal voltage of the conventional pumped-storage unit, the constraint threshold, and the control dead zone. When the terminal voltage of the conventional pumped storage unit exceeds the limit, the over-limit situation of the terminal voltage and reactive power of the variable speed pumped storage unit is analyzed based on the actual value of the terminal voltage and the constraint threshold. When the terminal voltage and reactive power of the variable speed pumped storage unit do not exceed the limits, the terminal voltage or reactive power of the variable speed pumped storage unit is adjusted through constant voltage control or constant reactive power control according to the control strategy of the variable speed pumped storage unit to complete automatic voltage and reactive power control.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 1 to 8.

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that enables a computer to execute the method of any one of claims 1 to 8.

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