Spare power automatic switching control method and control system of new energy power system

Abstract

The embodiment of the invention relates to the technical field of power system relay protection, and provides a spare power automatic switching control method and control system for a new energy power system, and the method comprises the steps: splitting a local-side circuit breaker of a target new energy power system and calculating the power loss of a tie line when the target new energy power system is detected to be in an island operation state; adjusting the power deviation of the power generation side and the load side of the system based on the tie line power loss, and enabling the adjusted target new energy power system to enter an off-grid control mode; in the off-grid control mode, frequency indifference adjustment is carried out on controllable active resources of the system, and voltage indifference adjustment is carried out on controllable reactive resources of the system; and after adjustment, when it is detected that the island area of the system and the frequency and voltage of the system side meet stable conditions, switching on when it is judged that synchronous conditions exist according to the phase angle difference of the two sides of the circuit breaker. The spare power automatic switching control system is switched on under the voltage condition, the problem that spare power automatic switching cannot reliably act under the new energy background is solved, and the power supply reliability of the system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of relay protection for electric power systems, and in particular to a backup automatic switching control method and control system for a new energy electric power system. Background Art

[0002] As the scale of distributed power generation systems continues to expand, the "low-breakthrough" characteristics of new energy systems lead to residual pressure on the busbar when the system fails. This causes the traditional backup power supply automatic switching device (backup automatic switching device) to be unable to meet the "no pressure detection" condition, and thus lose its function and cannot ensure the continuous and reliable power supply of the system.

[0003] At present, in order to meet the "no-pressure detection" condition of the backup automatic start-up logic, the new energy is often disconnected. However, the removal of new energy will prolong the startup time of the backup automatic start-up, which will affect the coordination with the stability control system; at the same time, the long time spent on disconnecting new energy will lead to a large amount of load loss, reducing the utilization rate of new energy; in addition, it is difficult for new energy units to be connected to the grid again. In order to reduce the losses caused by disconnecting new energy, the resistance compensation technology can realize the voltage backup plan without disconnecting new energy, which can alleviate the harm caused by large impact current to a certain extent. However, this plan has the problems of high cost and long-term idle equipment, or when used for long-term period impact load compensation, the resistance heating cannot be effectively utilized for economic operation. Moreover, this plan can only reduce the impact current, and cannot ensure that the conditions for synchronous closing are met when the backup automatic start-up is closed. Summary of the invention

[0004] The present invention provides a control method and control system for a new energy power system, which are used to solve the defects in the prior art such as long start-up time of the standby automatic start-up, resulting in a large amount of load loss, low utilization rate of new energy, and great difficulty in re-grid connection of new energy units. The method can realize the reliable operation of the standby automatic start-up device under the condition of new energy access with pressure, thereby improving the power supply reliability of the system, and effectively avoiding the disconnection of new energy from the grid, thereby improving the utilization rate of new energy.

[0005] The present invention provides a method for controlling a backup automatic start-up of a new energy power system, comprising: When it is detected that the target new energy power system is in an island operation state, de-energizing the circuit breaker on the local side of the target new energy power system and calculating the tie line power loss of the target new energy power system; Based on the tie line power loss, the power deviation between the generation side and the load side of the target new energy power system is adjusted, and the adjusted target new energy power system enters an off-grid control mode; In the off-grid control mode, frequency difference-free regulation is performed on the controllable active resources of the target new energy power system, and voltage difference-free regulation is performed on the controllable reactive resources; After the frequency of the controllable active resources of the target new energy power system is adjusted without difference and the voltage of the controllable reactive resources is adjusted without difference, when it is detected that the frequency and voltage of the island area and the system side of the target new energy power system in the off-grid control mode meet the stability conditions, the circuit breaker is closed when it is judged that the synchronization conditions are met based on the phase angle difference on both sides of the circuit breaker.

[0006] In a possible implementation, the method further includes: Determining whether the main supply line is tripped based on the electrical quantity and switch position of the main supply line of the target new energy power system; When the main supply line trips, determining that the target new energy power system is in an island operation state, and de-energizing the local circuit breaker of the target new energy power system; The power of a preset time length before the main supply line trips is obtained as the interconnection line power loss of the target new energy power system.

[0007] In a possible implementation, the method further includes: If the tie line power loss is within the preset cooperative control range, the target new energy power system enters the off-grid control mode; If the tie line power loss is not within the preset cooperative control range, the load or unit is removed based on the tie line power loss and the preset cooperative control adjustment margin; When the power loss of the interconnection line after the load or unit is removed is within the preset cooperative control range, the target new energy power system enters the off-grid control mode.

[0008] In a possible implementation, the method further includes: Acquire an island system frequency and an island system voltage of the target new energy power system in the off-grid control mode; Calculating an island system frequency difference based on the island system frequency and a preset target system frequency; Determining an active power compensation amount based on the island system frequency difference; Based on the active power compensation amount, frequency-free regulation is performed on the controllable active resource; Calculating an island system voltage difference based on the island system voltage and a preset target system voltage; Determining a reactive power compensation amount based on the island system voltage difference; The voltage of the controllable reactive resource is regulated without difference based on the reactive power compensation amount.

[0009] In a possible implementation, the method further includes: After the frequency of the controllable active resources of the target new energy power system is adjusted without difference and the voltage of the controllable reactive resources is adjusted without difference, when it is detected that the frequency and voltage of the island area and the main grid side system of the target new energy power system in the off-grid control mode meet the stability conditions, closing the circuit breaker when it is judged that the synchronization conditions are met according to the phase angle difference between the two sides of the circuit breaker, including: Determine whether the phase angle difference between the two sides of the circuit breaker is less than a preset phase angle; If yes, it is determined that the phase angle difference between the two sides of the circuit breaker meets the synchronization condition; When it is determined that the phase angle difference between the two sides of the circuit breaker meets the synchronization condition, a closing command is sent to the circuit breaker.

[0010] In a possible implementation, the method further includes: If it is determined that the phase angle difference between the two sides of the circuit breaker is greater than or equal to the preset phase angle, it is determined that the phase angle difference between the two sides of the circuit breaker does not meet the synchronization condition; When it is determined that the phase angle difference between the two sides of the circuit breaker does not meet the synchronization condition, the frequency of the island system is adjusted based on the phase angle difference between the two sides of the circuit breaker until the phase angle difference between the two sides of the circuit breaker meets the synchronization condition.

[0011] The present invention also provides a new energy power system standby automatic control system, comprising: The cooperative control system is used to disconnect the circuit breaker on the local side of the target new energy power system when it is detected that the target new energy power system is in an island operation state; A stabilization control system, used for calculating the tie line power loss of the target new energy power system, and adjusting the power deviation between the generation side and the load side of the target new energy power system based on the tie line power loss, so that the adjusted target new energy power system enters an off-grid control mode; The cooperative control system is further used to perform frequency error-free regulation on the controllable active resources of the target new energy power system and voltage error-free regulation on the controllable reactive resources in the off-grid control mode; The cooperative control system is also used to perform frequency error-free regulation of the controllable active resources of the target new energy power system and voltage error-free regulation of the controllable reactive resources, and when it is detected that the frequency and voltage of the island area and the system side of the target new energy power system in the off-grid control mode meet the stability conditions, close the circuit when it is judged that the synchronization conditions are met according to the phase angle difference on both sides of the circuit breaker.

[0012] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, a standby automatic start-up control method for a new energy power system as described in any one of the above-described methods is implemented.

[0013] The present invention also provides a non-transitory computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the method for controlling the backup automatic start-up of a new energy power system as described in any one of the above is implemented.

[0014] The present invention also provides a computer program product, comprising a computer program, which, when executed by a processor, implements any of the above-described methods for controlling the backup and automatic switching on of a new energy power system.

[0015] The automatic standby control method and control system of the new energy power system provided by the present invention are as follows: when it is detected that the target new energy power system is in an island operation state, the circuit breaker on the local side of the target new energy power system is de-listed and the interconnection line power loss of the target new energy power system is calculated; based on the interconnection line power loss, the power deviation between the generation side and the load side of the target new energy power system is adjusted, and the adjusted target new energy power system enters an off-grid control mode; in the off-grid control mode, the frequency of the controllable active resources of the target new energy power system is adjusted without difference, and the voltage of the controllable reactive resources is adjusted without difference; after the frequency of the controllable active resources of the target new energy power system is adjusted without difference, and the voltage of the controllable reactive resources is adjusted without difference, when it is detected that the frequency and voltage of the island area of ​​the target new energy power system in the off-grid control mode meet the stability conditions with the main grid side system frequency and voltage, closing is performed when it is judged that the synchronization conditions are met according to the phase angle difference on both sides of the circuit breaker. Compared with the existing defects of long startup time of new energy standby automatic start-up, resulting in large load losses, low utilization rate of new energy, and great difficulty in re-connecting new energy units to the grid, or the resistance compensation scheme has the problems of high cost and long-term idle equipment, or when used for long-term period impact load compensation, the resistance heat cannot be effectively utilized for economic operation, and the condition of synchronous closing cannot be ensured when the standby automatic start-up is closed. This scheme realizes the frequency and voltage control of the isolated island system through a collaborative control system, and uses the frequency difference adjustment of the cooperative control system to further adjust the phase difference to meet the island synchronization condition, so as to realize the closing of the standby automatic start-up device under pressure, solves the problem of unreliable operation of the standby automatic start-up device under the background of new energy, and improves the power supply reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1It is a flow chart of the automatic backup control method of the new energy power system provided by the present invention.

[0018] Figure 2 It is a structural schematic diagram of the backup automatic control system of the new energy power system provided by the present invention.

[0019] Figure 3 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] To facilitate understanding of the embodiments of the present invention, specific embodiments will be further explained below in conjunction with the accompanying drawings. The embodiments do not constitute a limitation on the embodiments of the present invention.

[0022] Figure 1 It is one of the flow charts of the automatic backup control method of the new energy power system provided by the present invention, such as Figure 1 As shown, the method includes the following: S11. When it is detected that the target new energy power system is in an island operation state, the circuit breaker on the local side of the target new energy power system is decoupled and the interconnection line power loss of the target new energy power system is calculated.

[0023] In an embodiment of the present invention, whether the main supply line of the target new energy power system is tripped is determined based on the electrical quantity and switch position of the main supply line of the target new energy power system; when the main supply line is tripped, it is determined that the target new energy power system is in an island operation state, and the circuit breaker of the target new energy power system is de-listed; the power of a preset time length before the main supply line trips is obtained as the interconnection line power loss of the target new energy power system.

[0024] Specifically, the cooperative control system detects the island operation of the system. The island operation of the power system refers to an operation mode in which the generator is not connected to the external power grid and the output power is only transmitted to the factory power supply. In this state, a part of the power system is disconnected from the main power grid and is completely powered by the local power supply. This operation mode is called island operation or power island. When the system is in the island operation state, the circuit breaker on this side is de-energized, the safety and stability control system (stability control system) calculates the power loss of the interconnection line, controls the power deviation between the generation side and the load side within the adjustment range of the cooperative control system, and starts the off-grid control mode of the cooperative control system.

[0025] Specifically, the coordinated control system can determine whether the main power supply line is normal by collecting the electrical quantities of the main power supply line and the switch positions. When the main power supply line trips, it determines whether the system is operating in an islanded mode. When the system is operating in an islanded mode, the coordinated control system disconnects the circuit breaker on its own side.

[0026] S12. Adjust the power deviation between the power generation side and the load side of the target new energy power system based on the power loss of the tie line. After the adjustment, the target new energy power system enters the off-grid control mode.

[0027] If the power loss of the system tie line is within the preset coordinated control range, it enters the off-grid control mode; if the power loss of the system tie line is not within the preset coordinated control range, load or units are cut based on the power loss of the system tie line and the preset coordinated control adjustment margin; when the power loss of the tie line after cutting the load or units is within the preset coordinated control range, the target new energy power system enters the off-grid control mode.

[0028] Specifically, the stability control system calculates the power loss of the tie line, PLoss. PLoss can take the power in the 200 ms before the tie line trips, and the power direction is positive when flowing out of the islanded area. It determines whether the current working condition is within the control range of the coordinated control system.

[0029] When PLoss > 0, PLoss < Pup satisfies the coordinated control range, otherwise it does not satisfy the coordinated control range. Pup is the upper limit of the adjustable margin of the coordinated control system, including the amount that the power generation resources such as photovoltaic and wind power in the islanded area can be reduced, the maximum chargeable power when the energy storage turns to the charging state, and the amount that the adjustable load can be increased, etc.

[0030] When PLoss < 0, |PLoss| < Pdown satisfies the coordinated control range, otherwise it does not satisfy the coordinated control range. Pdown is the lower limit of the adjustable margin of the coordinated control system, including the amount that the power generation resources such as photovoltaic and wind power in the islanded area can be increased, the maximum dischargeable power when the energy storage turns to the discharging state, and the amount that the adjustable load can be reduced, etc.

[0031] If it is within the control range of the coordinated control system, the stability control system does not act, starts the off-grid control mode of the coordinated control system, and executes the steps of performing frequency droop control on the controllable active resources and voltage droop control on the controllable reactive resources of the target new energy power system in the off-grid control mode.

[0032] If it is not within the control range of the coordinated control system, the stability control system acts, cuts some load or units, and the cut amount is Pcut, so that the system is stabilized within the control range of the coordinated control system, and the off-grid control mode of the coordinated control system is started. The calculation formula for the cut amount Pcut is as follows: Among them, when PLoss>0, the cooperative control system adjusts the margin P=Pup, and the stabilization control system cuts off the unit according to the power Pcut; when PLoss<0, the cooperative control system adjusts the margin P=Pdown, and the stabilization control system cuts off the load according to the power Pcut.

[0033] S13. In the off-grid control mode, frequency difference-free regulation is performed on controllable active resources of the target new energy power system, and voltage difference-free regulation is performed on controllable reactive resources.

[0034] Obtain the island system frequency and island system voltage of the target new energy power system in the off-grid control mode; calculate the island system frequency difference based on the island system frequency and the preset target system frequency; determine the active power compensation amount based on the island system frequency difference; and perform frequency error-free regulation of controllable active resources based on the active power compensation amount.

[0035] Specifically, the cooperative control system enters the off-grid control mode, and the cooperative control master station uses the PI algorithm to continuously coordinate and adjust the frequency f0 as the target, and calculates the frequency difference △f of the isolated island system. The formula is as follows: Among them, f is the frequency of the isolated grid system, f0=50Hz.

[0036] Furthermore, the cooperative control master station calculates the power compensation amount △PX through the frequency difference, and sends the target control instruction PT to the cooperative control substation according to the control period △Ta. The calculation formula of △PX is as follows: Among them, k is the power frequency response coefficient in the system; P0 is the actual value of the active power of the cooperative control system at the current moment; h is the control factor, which is -1 for power generation resources and 1 for load resources. △Ta is 50ms.

[0037] Furthermore, the cooperative control substation distributes the adjustment target value Pi to the control terminal in proportion to realize the closed-loop continuous adjustment control of the periodic control △Tb. The terminal includes adjustable resources such as thermal power units, energy storage, photovoltaic and electric loads.

[0038] Among them, Pi,0 is the active power of the control terminal at the current moment, and X is the adjustment ratio, which is obtained by calculating the proportion of adjustable resources of the control terminal in the area. △Tb is taken as 10ms.

[0039] The voltage difference of the island system is calculated based on the voltage of the island system and the preset target system voltage; the reactive power compensation amount is determined based on the voltage difference of the island system; and the voltage of the controllable reactive resources is adjusted without difference based on the reactive power compensation amount.

[0040] Specifically, the cooperative control master station uses the PI algorithm to continuously coordinate and adjust the line rated voltage U0 as the target, and the voltage difference △U of the island system is calculated as follows: Among them, U is the island system voltage and U0 is the line rated voltage.

[0041] Furthermore, the cooperative control master station calculates the reactive power compensation amount △Q through the voltage difference, and sends the target control instruction QT to the cooperative control substation according to the control period △Ta; Among them, kQ is the adjustment coefficient of reactive power in the system; Q0 is the actual value of reactive power of the cooperative control substation at the current moment.

[0042] The cooperative control substation distributes the adjustment target value Qi to the control terminal in proportion to realize the closed-loop continuous adjustment control of periodic control △Tb.

[0043] Among them, Qi,0 is the reactive power of the control terminal at the current moment, XQ is the reactive power adjustment ratio, and the proportion of the adjustable reactive power of the control terminal in the total adjustable reactive power in the region is calculated.

[0044] S14. After performing frequency difference-free regulation on the controllable active resources of the target new energy power system and voltage difference-free regulation on the controllable reactive resources, when it is detected that the frequency and voltage of the island area and the system side of the target new energy power system in the off-grid control mode meet the stability conditions, closing the circuit breaker is performed when it is judged that the synchronization conditions are met based on the phase angle difference on both sides of the circuit breaker.

[0045] Determine whether the phase angle difference on both sides of the circuit breaker is less than a preset phase angle degree; if so, determine that the phase angle difference on both sides of the circuit breaker meets the synchronization condition; when it is determined that the phase angle difference on both sides of the circuit breaker meets the synchronization condition, close the circuit breaker.

[0046] Optionally, if it is determined that the phase angle difference on both sides of the circuit breaker is greater than or equal to a preset phase angle degree, it is determined that the phase angle difference on both sides of the circuit breaker does not meet the synchronization condition; when it is determined that the phase angle difference on both sides of the circuit breaker does not meet the synchronization condition, the frequency of the island system is adjusted based on the phase angle difference on both sides of the circuit breaker until the phase angle difference on both sides of the circuit breaker meets the synchronization condition.

[0047] Specifically, the cooperative control system detects that the frequency and voltage of the island area and the system side meet the stability conditions. The stability conditions include that the frequency deviation on both sides of the circuit breaker is within the range of ±0.2Hz, the voltage on both sides of the circuit breaker is within the range of 0.95~1.08Un, and the state lasts for 20s.

[0048] Furthermore, the synchronization control is started to determine whether the phase angle difference meets the synchronization conditions. When the synchronization conditions are not met, the cooperative control system quickly tracks the main grid phase by adjusting the frequency.

[0049] Specifically, the cooperative control system detects whether the phase angle difference on both sides of the circuit breaker meets the synchronization condition, that is, the phase angle difference on both sides is less than 2 degrees.

[0050] If the phase angle difference meets the synchronization conditions, the backup supply line will be directly closed.

[0051] If the phase angle difference does not meet the synchronization conditions, the frequency is adjusted to quickly track the main grid phase so that the island system meets the synchronous closing conditions. According to the control period △Tc, the target control instruction △PF is sent to the cooperative control substation to adjust the frequency of the island system. The phase angle difference is adjusted using the frequency difference between the main grid and the island system. When the phase angle difference is less than 2 degrees and the frequency deviation is within ±0.02Hz, the synchronous closing conditions are met and a closing instruction is sent to the backup supply line.

[0052] Among them, fsys is the system frequency, KF is the frequency adjustment coefficient, and △Tc is 30ms.

[0053] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention realizes a self-investment scheme with pressure standby under the background of new energy access, effectively solves the difficulty of re-connecting new energy to the grid caused by traditional new energy decoupling technology, and improves the utilization rate of new energy.

[0054] 2. The method of the present invention realizes synchronous closing of the standby automatic switch through the cooperative control system, which effectively solves the problem of large impact current during asynchronous closing.

[0055] 3. The present invention fully mobilizes the adjustable and controllable resources in the system through the cooperative control system, so that the isolated island system can quickly meet the synchronous closing conditions, thereby improving the economy and reliability.

[0056] The method for controlling a standby automatic switching on of a new energy power system provided by the present invention comprises the following steps: when it is detected that the target new energy power system is in an island operation state, the circuit breaker on the local side of the target new energy power system is de-listed and the power loss of the interconnection line of the target new energy power system is calculated; based on the power loss of the interconnection line, the power deviation between the generation side and the load side of the target new energy power system is adjusted, and the adjusted target new energy power system enters an off-grid control mode; in the off-grid control mode, the frequency of the controllable active resources of the target new energy power system is adjusted without difference, and the voltage of the controllable reactive resources is adjusted without difference; after the frequency of the controllable active resources of the target new energy power system is adjusted without difference, and the voltage of the controllable reactive resources is adjusted without difference, when it is detected that the frequency and voltage of the island area and the main grid side system of the target new energy power system in the off-grid control mode meet the stability conditions, closing the circuit breaker is performed when it is judged that the synchronization conditions are met according to the phase angle difference on both sides of the circuit breaker. Compared with the existing defects of long startup time of new energy standby automatic start-up, resulting in large-scale load loss, low utilization rate of new energy, and great difficulty in re-connecting new energy units to the grid, or the resistance compensation scheme has the problems of high cost and long-term idle equipment, or when used for long-term period impact load compensation, the resistance heat generation cannot be effectively utilized for economic operation, and the condition of synchronous closing cannot be ensured when the standby automatic start-up is closed. This method realizes frequency and voltage control of the isolated island system through a collaborative control system, and uses the frequency difference adjustment of the cooperative control system to further adjust the phase difference to meet the island synchronization condition, so as to realize the closing of the standby automatic start-up device under pressure, solves the problem of unreliable operation of the standby automatic start-up device under the background of new energy, and improves the power supply reliability of the system.

[0057] The following describes the automatic standby control system of the new energy power system provided by the present invention. The automatic standby control system of the new energy power system described below and the automatic standby control method of the new energy power system described above can be referred to each other.

[0058] Figure 2 It is a structural diagram of the automatic backup control system of the new energy power system provided by the present invention, which specifically includes: The cooperative control system 201 is used to disconnect the circuit breaker of the target renewable energy power system when it is detected that the target renewable energy power system is in an island operation state. Detailed descriptions refer to the relevant descriptions corresponding to the above method embodiments, which will not be repeated here.

[0059] The stabilization control system 202 is used to calculate the tie line power loss of the target new energy power system, and adjust the power deviation of the power generation side and the load side of the target new energy power system based on the tie line power loss, and the adjusted target new energy power system enters the off-grid control mode. For detailed description, please refer to the relevant description corresponding to the above method embodiment, which will not be repeated here.

[0060] The cooperative control system 201 is also used to perform frequency error-free regulation on the controllable active resources of the target new energy power system and voltage error-free regulation on the controllable reactive resources in the off-grid control mode. Detailed descriptions refer to the relevant descriptions corresponding to the above method embodiments, which will not be repeated here.

[0061] The cooperative control system 201 is also used to perform frequency difference-free regulation on the controllable active resources of the target new energy power system and voltage difference-free regulation on the controllable reactive resources, and when it is detected that the frequency and voltage of the island area and the system side of the target new energy power system in the off-grid control mode meet the stability conditions, close the circuit breaker when it is judged that the synchronization conditions are met according to the phase angle difference on both sides of the circuit breaker. For detailed description, please refer to the relevant description corresponding to the above method embodiment, which will not be repeated here.

[0062] Figure 3 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 3 As shown, the electronic device may include: a processor (processor) 810, a communication interface (Communications Interface) 820, a memory (memory) 830 and a communication bus 840, wherein the processor 810, the communication interface 820, and the memory 830 communicate with each other through the communication bus 840. The processor 810 can call the logic instructions in the memory 830 to execute the backup automatic control method of the new energy power system, which includes: when it is detected that the target new energy power system is in an island operation state, de-listing the circuit breaker on the local side of the target new energy power system and calculating the interconnection line power loss of the target new energy power system; based on the interconnection line power loss, adjusting the power deviation on the generation side and the load side of the target new energy power system, and the adjusted target new energy power system enters the off-grid control mode; in the off-grid control mode, the controllable active resources of the target new energy power system are frequency-free regulated and the controllable reactive resources are voltage-free regulated; after the controllable active resources of the target new energy power system are frequency-free regulated and the controllable reactive resources are voltage-free regulated, when it is detected that the frequency and voltage of the island area and the main grid side system of the target new energy power system in the off-grid control mode meet the stability conditions, closing the circuit breaker when it is judged that the synchronization conditions are met according to the phase angle difference on both sides of the circuit breaker.

[0063] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0064] On the other hand, the present invention also provides a computer program product, which includes a computer program, which can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the backup automatic control method of the new energy power system provided by the above methods, the method comprising: when it is detected that the target new energy power system is in an island operation state, decoupling the circuit breaker of the target new energy power system and calculating the interconnection line power loss of the target new energy power system; based on the interconnection line power loss, adjusting the power deviation on the generation side and the load side of the target new energy power system, and the adjusted target new energy power system enters an off-grid control mode; in the off-grid control mode, the controllable active resources of the target new energy power system are frequency-free regulated and the controllable reactive resources are voltage-free regulated; after the controllable active resources of the target new energy power system are frequency-free regulated and the controllable reactive resources are voltage-free regulated, when it is detected that the frequency and voltage of the island area and the system side of the target new energy power system in the off-grid control mode meet the stability conditions, closing the circuit breaker when it is judged that the synchronization conditions are met according to the phase angle difference on both sides of the circuit breaker.

[0065] On the other hand, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it is implemented to execute the backup automatic control method of the new energy power system provided by the above methods, the method comprising: when it is detected that the target new energy power system is in an island operation state, de-listing the circuit breaker on the local side of the target new energy power system and calculating the interconnection line power loss of the target new energy power system; based on the interconnection line power loss, adjusting the power deviation on the generation side and the load side of the target new energy power system, and the adjusted target new energy power system enters an off-grid control mode; in the off-grid control mode, the controllable active resources of the target new energy power system are frequency-free regulated and the controllable reactive resources are voltage-free regulated; after the controllable active resources of the target new energy power system are frequency-free regulated and the controllable reactive resources are voltage-free regulated, when it is detected that the frequency and voltage of the island area and the main grid side system of the target new energy power system in the off-grid control mode meet the stability conditions, closing the circuit breaker when it is judged that the synchronization conditions are met according to the phase angle difference on both sides of the circuit breaker.

[0066] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative work.

[0067] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for controlling the automatic switching on of a new energy power system, characterized in that: include: When it is detected that the target new energy power system is in an island operation state, de-energizing the circuit breaker on the local side of the target new energy power system and calculating the tie line power loss of the target new energy power system; Based on the tie line power loss, the power deviation between the generation side and the load side of the target new energy power system is adjusted, and the adjusted target new energy power system enters an off-grid control mode; In the off-grid control mode, frequency difference-free regulation is performed on the controllable active resources of the target new energy power system, and voltage difference-free regulation is performed on the controllable reactive resources; After the frequency of the controllable active resources of the target new energy power system is adjusted without difference and the voltage of the controllable reactive resources is adjusted without difference, when it is detected that the frequency and voltage of the island area and the system side of the target new energy power system in the off-grid control mode meet the stability conditions, the circuit breaker is closed when it is judged that the synchronization conditions are met based on the phase angle difference on both sides of the circuit breaker.

2. The method according to claim 1, characterized in that When it is detected that the target new energy power system is in an island operation state, decoupling the circuit breaker of the target new energy power system and calculating the tie line power loss of the target new energy power system comprises: Determining whether the main supply line is tripped based on the electrical quantity and switch position of the main supply line of the target new energy power system; When the main supply line trips, determining that the target new energy power system is in an island operation state, and de-energizing the local circuit breaker of the target new energy power system; The power of a preset time length before the main supply line trips is obtained as the interconnection line power loss of the target new energy power system.

3. The method according to claim 1 or 2, characterized in that: The step of adjusting the power deviation between the power generation side and the load side of the target new energy power system based on the tie line power loss, so that the adjusted target new energy power system enters an off-grid control mode, includes: If the tie line power loss is within the preset cooperative control range, the target new energy power system enters the off-grid control mode; If the tie line power loss is not within the preset cooperative control range, the load or unit is removed based on the tie line power loss and the preset cooperative control adjustment margin; When the power loss of the interconnection line after the load or unit is removed is within the preset cooperative control range, the target new energy power system enters the off-grid control mode.

4. The method according to claim 3, characterized in that In the off-grid control mode, frequency difference-free regulation is performed on the controllable active resources of the target new energy power system and voltage difference-free regulation is performed on the controllable reactive resources, including: Acquire an island system frequency and an island system voltage of the target new energy power system in the off-grid control mode; Calculating an island system frequency difference based on the island system frequency and a preset target system frequency; Determining an active power compensation amount based on the island system frequency difference; Based on the active power compensation amount, frequency-free regulation is performed on the controllable active resource; Calculating an island system voltage difference based on the island system voltage and a preset target system voltage; Determining a reactive power compensation amount based on the island system voltage difference; The voltage of the controllable reactive resource is regulated without difference based on the reactive power compensation amount.

5. The method according to claim 4, characterized in that The stability condition includes that the frequency deviation on both sides of the circuit breaker is within a preset frequency range, the voltage on both sides of the circuit breaker is within a preset voltage range, and the state lasts for a preset time length; After the frequency of the controllable active resources of the target new energy power system is adjusted without difference and the voltage of the controllable reactive resources is adjusted without difference, when it is detected that the frequency and voltage of the island area and the main grid side system of the target new energy power system in the off-grid control mode meet the stability conditions, closing the circuit breaker when it is judged that the synchronization conditions are met according to the phase angle difference between the two sides of the circuit breaker, including: Determine whether the phase angle difference between the two sides of the circuit breaker is less than a preset phase angle; If yes, it is determined that the phase angle difference between the two sides of the circuit breaker meets the synchronization condition; When it is determined that the phase angle difference between the two sides of the circuit breaker meets the synchronization condition, a closing command is sent to the circuit breaker.

6. The method according to claim 5, characterized in that The method further comprises: If it is determined that the phase angle difference between the two sides of the circuit breaker is greater than or equal to the preset phase angle, it is determined that the phase angle difference between the two sides of the circuit breaker does not meet the synchronization condition; When it is determined that the phase angle difference between the two sides of the circuit breaker does not meet the synchronization condition, the frequency of the island system is adjusted based on the phase angle difference between the two sides of the circuit breaker until the phase angle difference between the two sides of the circuit breaker meets the synchronization condition.

7. A new energy power system automatic backup control system, characterized in that: include: The cooperative control system is used to disconnect the circuit breaker on the local side of the target new energy power system when it is detected that the target new energy power system is in an island operation state; A stabilization control system, used for calculating the tie line power loss of the target new energy power system, and adjusting the power deviation between the generation side and the load side of the target new energy power system based on the tie line power loss, so that the adjusted target new energy power system enters an off-grid control mode; The cooperative control system is further used to perform frequency error-free regulation on the controllable active resources of the target new energy power system and voltage error-free regulation on the controllable reactive resources in the off-grid control mode; The cooperative control system is also used to perform frequency error-free regulation of the controllable active resources of the target new energy power system and voltage error-free regulation of the controllable reactive resources, and when it is detected that the frequency and voltage of the island area and the system side of the target new energy power system in the off-grid control mode meet the stability conditions, close the circuit when it is judged that the synchronization conditions are met according to the phase angle difference on both sides of the circuit breaker.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the backup automatic switching control method of the new energy power system as described in any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the backup automatic switching control method of the new energy power system as described in any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the backup automatic switching control method of the new energy power system as described in any one of claims 1 to 6 is implemented.

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