New energy power station and control method thereof

Abstract

The invention provides a new energy power generation station and a control method thereof, which are used for a communication abnormal state of a reactive voltage control system of the new energy power generation station, and the new energy power generation station comprises the reactive voltage control system and a power generation unit. The reactive voltage control system comprises a reactive power acquisition device, a reactive voltage controller and a reactive compensation unit. And controlling reactive power emitted by the reactive compensation unit and the active power of the power generation unit according to the size relationship between the initial value of the active power emitted by the power generation unit when the system communication is abnormal and an active power threshold Pthd, so as to maintain the stable operation of the system under the condition that the system communication is abnormal. The active power threshold Pthd represents an active power value which corresponds to the system short-circuit capacity value and is used for maintaining stable operation of the system. The control method is based on communication link exception handling, corresponding handling is adopted for exceptions of different communication links, and optimal control reliability and minimum risk are achieved.

Description

Technical Field

[0001] The present invention belongs to the field of renewable energy power generation, and in particular, relates to a renewable energy power generation station and a control method thereof. Background Art

[0002] As renewable energy generation is gradually replacing traditional energy, and its share in the power system is increasing, higher and higher requirements are placed on the grid-connected control performance of renewable energy power plants, among which the importance of reactive voltage control is more prominent. It is extremely important for the reactive voltage control system of renewable energy power plants to take necessary measures to reduce the impact on the power grid when the control is abnormal. In the past, renewable energy reactive voltage control systems often only considered the basic processing when the equipment was abnormal, and did not perform systematic communication abnormality processing from the perspective of communication abnormalities within the system of the entire renewable energy power plant. The influence of the system strength parameters of the renewable energy power plant itself on the control strategy and system stability is not considered, especially the safety threshold of active power or the system short-circuit capacity ratio is not considered in the control strategy. Summary of the invention

[0003] This summary is provided to introduce selected concepts in a simplified form, and these concepts are further described in the following detailed description. This summary is neither intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0004] The control method of reactive voltage control communication anomaly of the new energy power station of the present invention is mainly based on the perspective of communication link anomaly processing of the entire control system. When anomalies occur in different communication links, corresponding processing methods are adopted to achieve optimal control reliability and minimum risk.

[0005] According to one embodiment of the present invention, a control method for a new energy power station is provided, which is used for abnormal communication of a reactive voltage control system of a new energy power station, wherein the reactive voltage control system includes a reactive power acquisition device, a reactive voltage controller and a reactive power compensation unit. The control method includes: according to the initial value of the active power emitted by the power generation unit when the system communication is abnormal and the active power threshold P thd The reactive power generated by the reactive compensation unit and the active power of the power generation unit are controlled to maintain the stable operation of the system in the case of abnormal system communication, wherein the active power threshold P thd It indicates the active power value corresponding to the system short-circuit capacity value to maintain the stable operation of the system. When the reactive power acquisition device in the reactive power control system of the new energy power station has communication abnormality, it can effectively warn and make optimization adjustments to the power generation, thereby ensuring the continued operation of the system.

[0006] Optionally, the control method comprises: when the initial value of the active power generated by the power generation unit is higher than the active power threshold value P thd When the active power of the power generation unit is controlled to decrease from the initial value to the safety value, and the reactive power emitted by the reactive compensation unit is controlled to decrease to 0, wherein the safety value is lower than the active power threshold value P thd .

[0007] Optionally, the control method comprises: when the initial value of the active power generated by the power generation unit is not higher than the active power threshold value P thd Alternatively, after a predetermined time has passed since the active power of the power generation unit is controlled to decrease from an initial value to a safe value, the active power of the power generation unit is controlled to decrease to 0.

[0008] Optionally, the control method further includes: when the system short-circuit capacity ratio of the new energy power generation station is greater than a preset short-circuit capacity ratio threshold, the active power and the reactive power are not adjusted.

[0009] Optionally, the control method further includes: in response to identifying that communication between the reactive voltage controller and the power generation unit is interrupted, excluding the power generation unit with interrupted communication when the reactive voltage controller calculates the reactive power instruction, and recalculates and distributes the reactive power instruction.

[0010] Optionally, the control method further comprises: in response to the communication interrupted power generation unit not restoring communication after maintaining the last reactive power instruction for a predetermined time, when the initial value of the active power emitted by the communication interrupted power generation unit is higher than the active power threshold P thd When the communication is interrupted, the active power of the power generation unit with communication interruption is controlled to decrease from the initial value to the safety value, and the reactive power emitted by the power generation unit with communication interruption is controlled to decrease to 0, wherein the safety value is lower than the active power threshold value P thd ; or when the initial value of the active power emitted by the power generation unit whose communication is interrupted is not higher than the active power threshold P thd Alternatively, when a predetermined time has passed since the active power of the power generation unit whose communication is interrupted is controlled to decrease from an initial value to a safe value, the active power of the power generation unit is controlled to decrease to 0.

[0011] Optionally, the control method further includes: in response to identifying a communication interruption between the reactive voltage controller and the reactive compensation unit, excluding the reactive compensation unit with the communication interruption when the reactive voltage controller calculates the reactive power instruction, and recalculating and distributing the reactive power instruction.

[0012] Optionally, the control method further comprises: in response to the reactive power compensation unit with interrupted communication not resuming communication after maintaining the last reactive power instruction for a predetermined period of time, controlling the reactive power emitted by the reactive power compensation unit to drop to 0.

[0013] Optionally, when the reactive compensation unit is a centralized reactive compensation device or a synchronous phase regulator, the reactive power emitted by the reactive compensation unit that controls the communication interruption gradually decreases to 0; when the reactive compensation unit is a switching reactive compensation device, the reactive power emitted by the reactive compensation unit that controls the communication interruption directly exits.

[0014] According to one embodiment of the present invention, a new energy power generation station is provided. The new energy power generation station includes a reactive voltage control system and a power generation unit. The reactive voltage control system includes: a reactive power acquisition device; a reactive power compensation unit; and a reactive voltage controller, which is configured to generate a reactive power output according to the initial value of the active power generated by the power generation unit and the active power threshold P. thd The reactive power generated by the reactive power compensation unit is controlled to control the active power of the power generation unit to achieve stable operation of the system, wherein the active power threshold P thd Indicates the active power value corresponding to the lower limit of the system short-circuit capacity to maintain stable operation of the system.

[0015] Optionally, the power generation unit includes a wind turbine and / or a photovoltaic module.

[0016] Optionally, the reactive voltage controller is further configured to: execute the control method of the new energy power generation station as described above.

[0017] According to one embodiment of the present invention, a computer-readable storage medium storing a computer program is provided, and when the computer program is executed by a processor, the control method of the new energy power station as described above is implemented.

[0018] According to one embodiment of the present invention, a computer device is provided, the computer device comprising: a processor; a memory storing a computer program, and when the computer program is executed by the processor, the control method of the new energy power station as described above is implemented.

[0019] From the overall perspective of the new energy power station, the present invention proposes a control method for abnormal communication of the reactive voltage control system. When abnormal communication occurs between the internal devices of the reactive voltage control system of the new energy power station, the system can be guaranteed to continue to operate, effectively warn, and optimize the power generation. The operating status of the system is evaluated for the interruption of communication in the internal system of the new energy power station, the interruption of communication between the power generation unit and the reactive compensation unit, and effective control measures are formulated, which greatly improves the stability of the system operation and minimizes the adverse effects on the system when the system control is abnormal.

[0020] Other features and aspects will be readily apparent from the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Shows the topology of a typical reactive voltage control system.

[0022] Figure 2 A flow chart showing a control method of a new energy power plant according to an embodiment.

[0023] Figure 3 A flow chart showing a control method for a new energy power generation station according to another embodiment.

[0024] Figure 4 A flow chart showing a control method for a new energy power generation station according to another embodiment.

[0025] Figure 5 A flow chart showing a control method for a new energy power generation station according to another embodiment.

[0026] Figure 6 is a flowchart of the internal processing of the reactive voltage control system according to the embodiment.

[0027] Figure 7 and Figure 8 The active power of the power generation unit is shown based on the set active power threshold P thd Graph for adjustment.

[0028] Fig. 9 It is a flow chart of reactive voltage control based on the regulation of system short-circuit capacity ratio of renewable energy power generation stations. DETAILED DESCRIPTION

[0029] The following specific embodiments are provided to help the reader gain a comprehensive understanding of the methods, devices and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be readily understood. For example, the order of operations described herein is merely an example and is not limited to the order set forth herein, but in addition to the operations that must occur in a particular order, changes that will be readily understood after understanding the disclosure of the present application may be made. In addition, in order to improve clarity and brevity, after understanding the disclosure of the present application, the description of known features may be omitted, and the omission of features and their descriptions is not intended to admit that they are common sense.

[0030] Definition of technical terms :

[0031] AVC (Automatic Voltage Control): Automatic voltage control system, which centrally monitors and analyzes the reactive voltage status of the entire network, and coordinates and optimizes the reactive devices of the widely dispersed power grid from a global perspective. It can not only realize automatic regulation of reactive voltage, but also has certain optimization functions. It is an important technical means to maintain system voltage stability, improve the quality of power grid voltage and the economic operation level of the entire system, and improve the level of reactive voltage management.

[0032] AGC (Automatic Generation Control): Automatic generation control is an important function in the energy management system EMS. It controls the output of the frequency-modulating units to meet the ever-changing power needs of users and keep the system in an economical operating state.

[0033] System impedance: The impedance seen from the power access point to the power supply side is the impedance of the power system, that is, the internal resistance of the power supply.

[0034] SVG (Static Var Generator): A static var generator, which consists of a voltage source converter connected in parallel to the system. Its output capacitive or inductive reactive current is continuously adjustable and is independent of the system voltage within the operating system voltage range.

[0035] SVC (Static Var Compensator): Static Var Compensator, which is composed of reactors and capacitors controlled by thyristors. Since thyristors react very quickly to control signals and the number of on-off times is not limited, the reactive power output is related to the voltage.

[0036] The present invention proposes a control method for reactive voltage control communication anomalies of a new energy power generation station. Aiming at the processing of communication link anomalies of the control system, when communication anomalies occur in different links, corresponding processing methods are adopted to achieve optimal control reliability and minimum risk.

[0037] Figure 1 Shows the topology of a typical reactive voltage control system.

[0038] Reference Figure 1 The communication topology of the reactive voltage control system of a new energy power station may include a reactive voltage controller 100, a power generation unit (for example, a wind turbine 101, an energy storage device 105 and / or a photovoltaic module 106), a reactive compensation unit (for example, a switching reactive compensation device 102, a synchronous phase regulator 103, a centralized reactive compensation device 104), a reactive power collection device 107, and a network for communication between them. In addition, the reactive voltage controller 100 can be connected to a host computer workstation and a telecontrol device using the ModbusTCP protocol to achieve input and output. The reactive voltage controller 100 can be connected to a dispatching private network through vertical encryption using protocols such as IEC 104 and DNP 3.0, and then connected to the AVC system of a power grid company or the AGC system of a power grid company. The reactive voltage controller 100 can be connected to the wind turbine 101 and the photovoltaic module 106 via Modbus TCP, IEC 104, POCUA, DNP 3.0, etc., and can be connected to the reactive compensation unit and the energy storage device 105 via Modbus TCP, IEC 104, IEC61850, etc. The protocols used for the network connection are not limited to the above protocols.

[0039] According to an embodiment, a control method for a new energy power station is provided, which is used for abnormal communication state of reactive voltage control system of a new energy power station. The new energy power station includes a reactive voltage control system and a power generation unit; the reactive voltage control system includes a reactive power acquisition device, a reactive voltage controller and a reactive compensation unit. The control method includes: according to the initial value of the active power emitted by the power generation unit when the system communication is abnormal and the active power threshold P thd The reactive power generated by the reactive compensation unit and the active power of the power generation unit are controlled to maintain the stable operation of the system in the case of abnormal system communication, wherein the active power threshold P thd Indicates the active power value corresponding to the system short-circuit capacity value to maintain stable operation of the system.

[0040] In an embodiment, the active power threshold P thdThe setting is related to the renewable energy power station itself. In the early stage of the construction of renewable energy stations, the site selection and the strength of the access system will be analyzed, and the static stability analysis of the renewable energy power station will be carried out according to the actual situation of the access system and the wind farm, that is, the relationship between the active output and reactive output to ensure the stability of the system voltage, thereby obtaining the static stable operation range of the renewable energy power station. When the system short-circuit capacity ratio is less than the set threshold, the active power needs to be reduced, so the active power threshold P needs to be adjusted. thd Set the active power threshold P thd Affected by the actual situation of the static stability analysis of the system. In order to ensure the stability of the system voltage, the new energy power generation stations connected to the system have a minimum short-circuit capacity requirement. There are different standards for this short-circuit capacity requirement. Generally, the short-circuit capacity ratio SCR of a single machine cannot be lower than 1.5. The short-circuit capacity ratio SCR of the station-level access system is generally not lower than 4 to 6. Therefore, the active power threshold P can be set according to the safe and stable operation range corresponding to the system short-circuit capacity ratio SCR of 6. thd , combined with the actual project, the active power stability range corresponding to the short-circuit capacity ratio SCR of 6 is generally 0.2~0.3Pn, Pn is the rated active power of the station, considering P thd It is only a threshold value for adjusting active power, so the default value can be set to be slightly higher than the upper limit value, generally 0.4Pn, but the embodiment is not limited thereto. thd Both can be expressed as a proportional threshold value of the rated power and can be the same proportional value.

[0041] Figure 2 A flow chart showing a control method of a new energy power station according to an embodiment. As described above, the new energy power station may include a reactive power collection device, a reactive voltage controller, a power generation unit (including a wind turbine and / or a photovoltaic module) and a reactive compensation unit.

[0042] Reference Figure 2 According to the embodiment, the control method of the new energy power generation station includes the following steps.

[0043] In step 201, it is determined whether the communication of the reactive power collection device is interrupted. In response to the identification of the interruption of the communication of the reactive power collection device, step 202 is executed to block the control instruction of the reactive voltage controller. In step 203, it is determined whether the initial value of the active power generated by the power generation unit is higher than the active power threshold value P thd When the initial value of the active power generated by the power generation unit is higher than the active power threshold P thd When the active power of the power generation unit is reduced from the initial value to the safe value, step 204 is executed to control the active power of the power generation unit to be reduced from the initial value to the safe value, and the reactive power generated by the reactive compensation unit is controlled to be reduced to 0.

[0044] In the embodiment, the safety value P1 is a power value that can ensure the safe and stable operation of the system. Therefore, the P1 value range is generally set in the range of 0.2 to 0.3Pn. From an economic point of view (generating as much electricity as possible under safe conditions), P1 can be set to 0.3Pn, but the embodiment is not limited to this.

[0045] In an embodiment, after the communication of the reactive power collection device is interrupted, the reactive voltage control system can execute the control instruction of the blocking reactive voltage controller and trigger the alarm information. After a predetermined time, the active power of the controlled power generation unit (which may include wind turbines, photovoltaic components and / or energy storage units) is adjusted. Specifically, the active power can be gradually reduced from the current active power P0 to P1, where the P1 value is a safe value of the system in the event of failure of the reactive voltage control system, and the P1 value can be within the operating range allowed by the grid-connected guidelines. At the same time, the controlled reactive compensation unit is adjusted to gradually reduce the reactive power to stop, that is, the reactive power is 0. When a communication abnormality occurs in the reactive power collection device inside the reactive voltage control system of a new energy power generation station, an effective alarm can be issued and the power generation power optimization adjustment can be made at the same time, thereby ensuring the continued operation of the system.

[0046] Figure 3 A flow chart showing a control method for a new energy power generation station according to another embodiment.

[0047] Reference Figure 3 According to another embodiment, the control method of the new energy power station further includes: when the initial value of the active power generated by the power generation unit is not higher than the active power threshold value P thd , or after the active power of the power generation unit is controlled to decrease from the initial value to the safe value, after a predetermined time, in step 301, the active power of the power generation unit is controlled to decrease to 0. Other steps are the same as those in reference Figure 2 The same as described. When the reactive power collection device has communication anomalies, the active power can be controlled to run at a safe value to reduce system fluctuations, and then gradually reduced to 0 after the system fully responds.

[0048] Figure 4 A flow chart showing a control method for a new energy power generation station according to another embodiment.

[0049] Reference Figure 4According to another embodiment, the control method of the new energy power station includes the following steps. In step 401, it is identified whether the communication of the power generation unit is interrupted. In response to identifying the interruption of communication of the power generation unit, in step 402, the power generation unit with the interrupted communication is excluded when the reactive voltage controller calculates the reactive power instruction, and the reactive power instruction is recalculated and allocated. After the communication is interrupted, the reactive voltage control system excludes the power generation unit with the interrupted communication from the scope of the controlled device, and excludes the power generation unit with the interrupted communication during the reactive instruction calculation and reactive instruction allocation, and recalculates and allocates the reactive power instruction. On the other hand, from the perspective of the power generation unit itself, in response to the power generation unit with the interrupted communication not resuming communication after maintaining the previous reactive power instruction for a predetermined time, in step 403, it is identified whether the initial value of the active power emitted by the power generation unit with the interrupted communication is higher than the active power threshold value P thd When the initial value of the active power generated by the power generation unit with communication interruption is higher than the active power threshold P thd , execute step 404, control the active power of the power generation unit with communication interruption to decrease from the initial value to the safe value, and control the reactive power emitted by the power generation unit with communication interruption to decrease to 0. Thus, when the power generation unit has communication abnormality, the active power can be controlled to operate at a safe value to reduce system fluctuations, and then gradually decrease to 0 after the system fully responds. When the initial value of the active power emitted by the power generation unit with communication interruption is not higher than the active power threshold P thd Or when the active power of the power generation unit whose communication is interrupted is reduced from the initial value to the safe value after a predetermined time, step 405 is executed to control the active power of the power generation unit to be reduced to 0. In this way, the reactive power can be slowly reduced to 0. After the communication is interrupted, the power generation unit whose communication is interrupted maintains the last reactive power instruction, and after the predetermined time of communication interruption, the controlled power generation unit reduces the active power from the current P0 to P1 or directly to 0.

[0050] Figure 5 A flow chart showing a control method for a new energy power generation station according to another embodiment.

[0051] Reference Figure 5, a control method for a new energy power station according to another embodiment includes the following steps. In step 501, a communication interruption of a reactive compensation unit is identified. In response to identifying the communication interruption of the reactive compensation unit, in step 502, the reactive compensation unit with the communication interruption is excluded when the reactive voltage controller calculates the reactive power instruction, and the reactive power instruction is recalculated and allocated. In the case of a communication interruption of the reactive compensation unit, some reactive compensation units with communication interruption can be temporarily exited to maintain the continued operation of the system. From the perspective of the reactive compensation unit itself, in step 503, in response to the reactive compensation unit with communication interruption not restoring communication after maintaining the previous reactive power instruction for a predetermined time, the reactive power emitted by the reactive compensation unit is controlled to be reduced to 0. The reactive compensation unit can be prevented from operating in an uncontrolled manner to avoid causing further secondary faults.

[0052] According to another embodiment, when the reactive compensation unit is a centralized reactive compensation device or a synchronous phase regulator, the reactive power emitted by the reactive compensation unit that controls the communication interruption gradually decreases to 0; when the reactive compensation unit is a switched reactive compensation device, the reactive power emitted by the reactive compensation unit that controls the communication interruption directly exits.

[0053] The reactive voltage control system can exclude the centralized reactive compensation equipment with interrupted communication from the controlled equipment, and recalculate and distribute the reactive power command after considering the exclusion of the centralized reactive compensation equipment with interrupted communication during reactive power command calculation and reactive power command distribution. On the other hand, after the communication is interrupted, the centralized reactive compensation equipment (SVC, SVG) keeps running, and if the communication is not restored after a certain period of time, the reactive power is gradually reduced to 0.

[0054] The reactive voltage control system can exclude the switched reactive compensation equipment (parallel capacitors, reactors, etc.) with interrupted communication from the controlled equipment, and recalculate and distribute the reactive power command after considering the excluded switched reactive compensation equipment (parallel capacitors, reactors, etc.) with interrupted communication when calculating the reactive power command and distributing the reactive power command. On the other hand, after the communication is interrupted, the switched reactive compensation equipment (parallel capacitors, reactors, etc.) keeps running. If the communication is not restored after a certain period of time, it will exit the operation (i.e. disconnect the circuit breaker connected to the system side) to make the reactive power of the equipment to the primary system zero.

[0055] The reactive voltage control system can exclude the synchronous condenser equipment with interrupted communication from the controlled equipment, and recalculate and distribute the reactive power command after considering the exclusion of the synchronous condenser equipment with interrupted communication during reactive power command calculation and reactive power command distribution. On the other hand, after the communication is interrupted, the synchronous condenser equipment keeps running, and if the communication is not restored after a certain period of time, the reactive power is gradually reduced to 0.

[0056] In addition, since the synchronous condenser has the function of improving the short-circuit capacity of the system and enhancing the stability of the system, once the communication with the synchronous condenser is interrupted, the reactive voltage control system will lose control of the synchronous condenser, so it is necessary to adjust the active and reactive power of the whole field. The specific adjustment can be made according to the actual active power of the current system and the strength of the system. The explanation of the strength of the system will be described later.

[0057] The control method of the new energy power station according to the embodiment includes two aspects of processing: processing inside the reactive voltage control system and processing of each controlled device itself, wherein the controlled device itself can also store the corresponding control method to spontaneously execute processing when communication is interrupted.

[0058] Figure 6 is a flowchart of the internal processing of the reactive voltage control system according to the embodiment.

[0059] Reference Figure 6 ,The processing flow inside the reactive voltage control system specifically includes the following steps.

[0060] In step 610, the reactive voltage control system detects whether the communication status of the collection device set at the primary system control point of the new energy power generation station is normal. When the communication data of the collection device set at the primary system control point is normal, the reactive voltage control system reads the data of the collection device regularly, the overall control is carried out normally, and in step 611, the reactive voltage control target calculation is performed. On the contrary, in step 610, if the communication is interrupted or the data is abnormal, step 612 is executed, the command control of the reactive voltage can be locked, and the alarm information is triggered to notify the operating personnel, and if the communication is still not restored after the communication interruption t1 seconds, it is regarded as a long-term system interruption event, and safety and stability measures need to be taken. Specifically, an emergency control instruction can be issued to the controlled active source to reduce the active power from the current P0 to P1 (the P1 value is the safe active power value considered by the system after the reactive voltage control system fails. The value can be the operating range allowed by the grid-connected guide, or it can be to stop issuing active power, that is, the active power is 0), and a reactive power instruction is issued to other controlled reactive source devices to slowly reduce the reactive power to 0. If the system communication is automatically restored within t1, the emergency control command will not be executed. The specific time t1 can be set according to the actual situation.

[0061] In step 620, it is determined whether there is a centralized reactive power compensation device in the system. If there is a reactive power compensation device, then in step 621, it is determined whether the communication between the reactive voltage control system and the centralized reactive power compensation device (SVC, SVG) is normal. When the communication between the centralized reactive power compensation device is normal, the system operates normally. For example, the reactive voltage control system reads the data of the centralized reactive power compensation device (SVC, SVG) at regular intervals and issues reactive power instructions to the centralized reactive power compensation device (SVC, SVG) according to the instruction cycle. On the contrary, in step 621, if the communication status between the reactive voltage control system and the centralized reactive power compensation device (SVC, SVG) is abnormal, step 622 is executed to exclude the centralized reactive power compensation device from the controlled devices, control other devices normally, and trigger an alarm message to notify the operator.

[0062] In step 630, it is determined whether there is a switching type reactive compensation device in the system. If there is a switching type reactive compensation device, then in step 631, it is determined whether the communication between the reactive voltage control system and the switching type reactive compensation device (parallel capacitor, reactor, etc.) is normal. When the communication of the switching type reactive compensation device is normal, the system operates normally. On the contrary, in step 631, when the communication is interrupted, in step 632, the switching type reactive compensation device is excluded from the controlled device, and other devices are normally controlled, and an alarm message is triggered to notify the operator.

[0063] In step 640, it is determined whether there is a synchronous condenser device in the system. If there is a synchronous condenser device, then in step 641, it is determined whether the communication between the reactive voltage control system and the synchronous condenser is normal. When the communication of the synchronous condenser is normal, the system operates normally. For example, the reactive voltage control system reads the synchronous condenser data regularly and sends reactive power instructions to the synchronous condenser according to the instruction cycle. On the contrary, in step 641, when the communication is interrupted, step 642 is executed. After the communication status between the reactive voltage control system and the synchronous condenser is abnormal, the synchronous condenser device with abnormal communication is excluded from the controlled device, and other controlled devices are controlled normally, and an alarm message is triggered to notify the operator. When the communication interruption lasts for more than t3 time and is not restored, an emergency control instruction is sent to the controlled power generation unit to reduce the active power from the current P0 to P1, where P1 is the safe active power considered by the system after the reactive voltage control system fails. This value can be the operating range allowed by the grid-connected guidelines, or it can be to stop generating active power, that is, the active power is 0), and the reactive power is reduced to 0. If the communication is restored to normal within the predetermined t3 time, the above emergency control will not be performed.

[0064] Step 650, determine whether there is a power generation unit in the system. If there is a power generation unit, then in step 651, determine whether the communication between the reactive voltage control system and the controlled power generation unit (wind turbine, energy storage, photovoltaic) is normal. When the communication of the power generation unit is normal, the system operates normally. On the contrary, in step 651, when the communication is interrupted, step 652 is executed to exclude the power generation unit from the controlled equipment, control other equipment normally, and trigger an alarm message to notify the operator.

[0065] In step 660, the reactive voltage control system calculates and executes the overall adjustment strategy according to the above situation. The above steps are executed cyclically.

[0066] Figure 7 and Figure 8 The active power of the power generation unit is shown based on the set active power threshold P thd Graph for adjustment.

[0067] According to another embodiment, the control method of the new energy power station further includes: setting the active power threshold P of the power generation unit based on the system stability of the new energy power station. thd In response to identifying a communication interruption, when the active power of the new energy power generation station is not higher than the active power threshold P thd When the active power of the whole field of the new energy power station is higher than the active power threshold P thd When the active power is reduced from the initial value to the safe value, the reactive power is slowly reduced to zero, where the safe value is lower than the active power threshold P thd .

[0068] Reference Figure 7 and Figure 8 For the sake of system stability, in the regulation of the active power of the controlled power generation unit, an active power threshold P can be set. thd When the active power is lower than this threshold, the active power and reactive power are urgently controlled, that is, the current active power P0 of the active power and the current value of the reactive power Q0 are all reduced to 0, and an alarm message is triggered to notify the operator. On the contrary, when the actual system active power is higher than P thd When the active power is reduced from the current active power P0 to P1, P1 is slightly lower than P thd , the reactive power directly and slowly drops to zero. At the same time, an alarm message is triggered to notify the operator. If it is not handled for a long time, the active power will drop to zero. thd Processing, that is, reducing the active power to 0. The reactive power is slowly reduced from the current value to reactive power, so no illustration is given here.

[0069] According to another embodiment, the control method of the new energy power station may further include not adjusting the active power and reactive power when the system short-circuit capacity ratio of the new energy power station is greater than a preset short-circuit capacity ratio threshold, so as to avoid a significant reduction in system power and resulting in system instability when the system short-circuit capacity ratio is too large.

[0070] In addition, whether to adjust the active power can also be determined according to the actual strength of the system, such as by setting a parameter value that can characterize the strength of the system, such as the short-circuit capacity ratio. Here, the system short-circuit capacity ratio SCR is taken as an example, but the parameters of the system strength are not limited to this. When the actual short-circuit capacity ratio SCR of the system is greater than the short-circuit capacity ratio threshold thdSCR, since the system short-circuit capacity ratio SCR is large, the station control has little effect on the grid connection point voltage, so no emergency adjustment is made to the active power and reactive power of the entire field. The strength of the access system is directly related to the system short-circuit capacity ratio SCR. It is generally believed that if the SCR is greater than 10, the station access system is a very strong system. A strong access system means that the static stable operation range of the system is also large, so the system's output acceptance capacity for active power and reactive power is also high. In this case, the active output and reactive output of the system can be adjusted. According to engineering experience, the short-circuit capacity ratio threshold thdSCR value can be set to a general value range of 8 to 15. For example, the short-circuit capacity ratio threshold thdSCR can be set to 10, but the embodiment is not limited to this.

[0071] For the enabling logic of active power adjustment of the controlled power generation unit, refer to Fig. 9 .

[0072] Fig. 9 This is a flowchart of reactive voltage control based on the short-circuit capacity ratio adjustment of the system in the renewable energy power station. Fig. 9 As shown, in step 901, it is determined that SCR < thdSCR. When SCR < thdSCR, step 902 is executed to determine whether the active power P0 is greater than the active power threshold P thd When P0>P thd When P0<P thd When the voltage is 0, step 904 is executed to slowly reduce both active power and reactive power to 0. The active power safety threshold can be set according to factors such as the system environment, and the active power safety threshold can be referred to during the reactive voltage control process to avoid unexpected fluctuations in the system and increase system stability.

[0073] The control method for reactive voltage control communication anomaly proposed in the present invention requires coordinated control with the controlled reactive compensation equipment and the power generation unit in addition to the reactive voltage control system itself. Specifically, when the communication between the controlled power generation unit and the reactive voltage control system is interrupted, from the perspective of the controlled power generation unit, the active power and reactive power can be slowly reduced to 0 at a fixed rate or in other ways according to the current active power and reactive power, and the specific adjustment can be made according to the actual project situation. The coordination of reactive compensation equipment (centralized reactive compensation equipment, switching reactive compensation equipment, synchronous phase regulator, energy storage equipment) can use a fixed rate or other methods to slowly reduce the reactive power to 0, and the specific adjustment can be made according to the actual project situation. It should be noted that the switching reactive compensation equipment is slightly different from the centralized reactive compensation equipment and the synchronous phase regulator. The reactive power adjustment of the switching reactive compensation equipment refers to the switching on and off of the equipment, and does not have the nature of slow adjustment. However, the overall concept needs to achieve the purpose of the reactive power value being 0, so the same process can be used with other reactive compensation equipment.

[0074] In addition, in the present invention, in the link of abnormal communication state, it is necessary to adjust the active power of the controlled power generation unit, and in normal operation, the active power control of the power generation unit is controlled by the active power control system. This is related to the actual project. The active power control system and the reactive power control system of the new energy power generation station can be the same device or system, but it is not limited to this. The active power control system and the reactive power control system of the new energy power generation station can also be separated. The active power regulation involved in the present invention needs to lock the instructions of the active power control system to achieve the effect of the communication abnormality coordination control method. The specific implementation can be sent to the active power control system by the reactive power control system. The locking state flag can also be sent to the controlled power generation unit by sending the abnormal state control flag. Each power generation unit locks the execution of the active power instruction issued to each power generation unit by the active power control system according to the flag bit, and then executes the active power instruction strategy agreed by the abnormal control. For the reactive power instruction when the communication is abnormal, each power generation unit and the controlled reactive equipment can be executed according to the agreed instruction strategy.

[0075] Furthermore, in the process of reducing the active power, a fixed slope power reduction method can be used to reduce the active power to 0 within a certain period of time, which can be set according to the actual needs of the system. The speed of reactive power reduction needs to match the active power.

[0076] The basis for judging the communication interruption may be based on communication layer information or application layer information, or even data information itself, but is not limited thereto.

[0077] According to one embodiment of the present invention, a new energy power generation station is provided. The new energy power generation station includes a reactive voltage control system and a power generation unit. The reactive voltage control system includes: a reactive power acquisition device; a reactive power compensation unit; and a reactive voltage controller, which is configured to generate a reactive power output according to the initial value of the active power generated by the power generation unit and the active power threshold P. thd The reactive power generated by the reactive power compensation unit is controlled to control the active power of the power generation unit to achieve stable operation of the system, wherein the active power threshold P thd Indicates the active power value corresponding to the lower limit of the system short-circuit capacity to maintain stable operation of the system.

[0078] The power generation unit includes a wind turbine and / or a photovoltaic module. In addition, the power generation unit may also include an energy storage unit.

[0079] Furthermore, the reactive voltage controller according to the embodiment may be configured to execute the control method of the renewable energy power plant as described above.

[0080] The present invention proposes a control method for a new energy power station, which can effectively give an alarm when communication anomalies occur between internal devices of the reactive voltage control system of the new energy power station, and make optimization adjustments to the power generation, thereby ensuring the continued operation of the system. The present invention evaluates the operating status of the system from different angles, such as communication interruption of the subsystems within the station, communication interruption between the controlled power generation unit and the reactive compensation unit, or equipment anomalies, and formulates effective operation control measures, which greatly improves the stability of the system operation, and reduces the adverse effects on the system when the system control is abnormal.

[0081] According to an exemplary embodiment of the present invention, there is also provided a computer-readable storage medium storing a computer program. The computer-readable storage medium stores a computer program that, when executed by a processor, causes the processor to execute a control method for a new energy power generation station according to the present invention. The computer-readable recording medium is any data storage device that can store data read out by a computer system. Examples of computer-readable recording media include: read-only memory, random access memory, read-only optical disc, magnetic tape, floppy disk, optical data storage device, and carrier wave (such as data transmission over the Internet via a wired or wireless transmission path).

[0082] According to an exemplary embodiment of the present invention, a computer device is also provided. The computer device includes a processor and a memory. The memory is used to store a computer program. The computer program is executed by the processor so that the processor executes the computer program of the control method of the new energy power station according to the present invention.

[0083] Although the present invention includes specific examples, it will be readily understood by those skilled in the art after understanding the disclosure of the present application that various changes in form and detail may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein will be considered to be descriptive only, not for the purpose of limitation. The description of the features or aspects in each example will be considered to be applicable to similar features or aspects in other examples. If the described techniques are performed in different orders, and / or if the components in the described system, architecture, device or circuit are combined in different ways, and / or the components in the described system, architecture, device or circuit are replaced or added by other components or their equivalents, suitable results can be obtained. Therefore, the scope of the present invention is not limited by specific embodiments, but by claims and their equivalents, and all variations within the scope of claims and their equivalents will be interpreted as being included in the present invention.

Claims

1. A control method for a new energy power station, used for abnormal communication state of reactive voltage control system of a new energy power station, wherein: The new energy power generation station includes a reactive voltage control system and a power generation unit; The reactive voltage control system includes a reactive power collection device, a reactive voltage controller and a reactive compensation unit. Characterized in that the control method comprises: According to the initial value of the active power generated by the power generation unit when the system communication is abnormal and the active power threshold P thd The reactive power generated by the reactive compensation unit and the active power of the power generation unit are controlled to maintain the stable operation of the system in the case of abnormal system communication. Among them, the active power threshold P thd Indicates the active power value corresponding to the system short-circuit capacity value to maintain stable operation of the system.

2. The control method according to claim 1, characterized in that: The control method comprises: When the initial value of the active power generated by the power generation unit is higher than the active power threshold P thd When the active power of the power generation unit is controlled to decrease from the initial value to the safety value, and the reactive power emitted by the reactive compensation unit is controlled to decrease to 0, wherein the safety value is lower than the active power threshold value P thd .

3. The control method according to claim 1, characterized in that: The control method comprises: When the initial value of the active power generated by the power generation unit is not higher than the active power threshold P thd Alternatively, after a predetermined time has passed since the active power of the power generation unit is controlled to decrease from an initial value to a safe value, the active power of the power generation unit is controlled to decrease to 0.

4. The control method according to claim 1, characterized in that: The control method further includes: when the system short-circuit capacity ratio of the new energy power generation station is greater than a preset short-circuit capacity ratio threshold, the active power and the reactive power are not adjusted.

5. The control method according to claim 1, characterized in that: The control method further comprises: In response to identifying that the communication between the reactive voltage controller and the power generation unit is interrupted, the power generation unit with the communication interruption is excluded when the reactive voltage controller calculates the reactive power command, and the reactive power command is recalculated and distributed.

6. The control method according to claim 5, characterized in that: The control method further comprises: In response to the communication interruption, the power generation unit does not resume communication after maintaining the last reactive power instruction for a predetermined time, When the initial value of the active power generated by the communication interrupted power generation unit is higher than the active power threshold P thd When the communication is interrupted, the active power of the power generation unit with communication interruption is controlled to decrease from the initial value to the safety value, and the reactive power emitted by the power generation unit with communication interruption is controlled to decrease to 0, wherein the safety value is lower than the active power threshold value P thd ;or When the initial value of the active power generated by the power generation unit with communication interruption is not higher than the active power threshold P thd Alternatively, when a predetermined time has passed since the active power of the power generation unit whose communication is interrupted is controlled to decrease from an initial value to a safe value, the active power of the power generation unit is controlled to decrease to 0.

7. The control method according to claim 1, characterized in that: The control method further comprises: In response to identifying that the communication between the reactive voltage controller and the reactive compensation unit is interrupted, the reactive compensation unit with the interrupted communication is excluded when the reactive voltage controller calculates the reactive power command, and the reactive power command is recalculated and distributed.

8. The control method according to claim 7, characterized in that: The control method further comprises: In response to the communication interruption, the reactive power compensation unit does not resume communication after maintaining the last reactive power instruction for a predetermined time, The reactive power generated by the reactive power compensation unit is controlled to drop to 0.

9. The control method according to claim 8, characterized in that: When the reactive compensation unit is a centralized reactive compensation device or a synchronous phase regulator, the reactive power emitted by the reactive compensation unit that controls the communication interruption gradually decreases to 0; when the reactive compensation unit is a switching reactive compensation device, the reactive power emitted by the reactive compensation unit that controls the communication interruption directly exits.

10. A new energy power generation station, wherein: The new energy power generation station includes a reactive voltage control system and a power generation unit; Characterized in that the reactive voltage control system comprises: Reactive power collection device; Reactive power compensation unit; and The reactive voltage controller is configured to adjust the active power generated by the power generation unit according to the initial value of the active power and the active power threshold P thd The reactive power generated by the reactive power compensation unit is controlled, and the active power of the power generation unit is controlled to achieve stable operation of the system. Among them, the active power threshold P thd Indicates the active power value corresponding to the lower limit of the system short-circuit capacity to maintain stable operation of the system.

11. The new energy power generation station according to claim 10, characterized in that: The power generation unit includes a wind turbine and / or a photovoltaic module.

12. The new energy power generation station according to claim 10, characterized in that: The reactive voltage controller is further configured to: Execute the control method of the new energy power station as described in any one of claims 2 to 9.

13. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the control method of the new energy power station as described in any one of claims 1 to 9 is implemented.

14. A computer device, characterized in that: The computer device comprises: processor; A memory storing a computer program, which, when executed by a processor, implements the control method for a new energy power station as claimed in any one of claims 1 to 9.

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