Power system cluster coordination control method, device and system

Abstract

The invention discloses a cluster coordination control method, device and system of a power system, and relates to the technical field of new energy. The method comprises the following steps: collecting the frequency and power of each electric power region from an inter-region tie line; adjusting a frequency reference value and a power reference value of each power region according to the frequency and the power of each power region; and according to the frequency reference value and the power reference value, performing frequency modulation on each power region. According to the invention, through frequency modulation of each power region, frequency modulation resource complementation of each region of the power system is realized, real-time adjustment of power interaction between the new energy power distribution network and the main network is realized, and reliable power supply of a non-fault region of the new energy power grid when the main network transiently breaks down can be ensured.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and in particular to a method, device and system for coordinated control of power system clusters. Background Art

[0002] At present, it will gradually become the norm for a large number of wind and solar power generation and new energy storage to be connected to the power grid through power electronic devices, which will have a great impact on the existing power system, especially the form, operation and control system of the distribution network. Traditional multi-unit frequency control cannot effectively achieve the complementary frequency regulation resources of various regions under the penetration of new energy, nor can it adjust the power interaction between the new energy distribution network and the main network in real time, nor can it guarantee the reliable power supply of the non-fault area of ​​the new energy distribution network when the main network fails temporarily. Summary of the invention

[0003] The purpose of the present application is to provide a cluster coordination control method, device and system for an electric power system, so as to solve the problems in the prior art that various power areas cannot achieve complementary frequency regulation resources, cannot adjust the power interaction between the distribution network and the main network in real time, and cannot ensure reliable power supply to non-fault areas of the new energy distribution network when the main network fails temporarily.

[0004] In a first aspect, in order to achieve the above-mentioned purpose, an embodiment of the present application provides a cluster coordination control method of a power system, comprising:

[0005] Collect the frequency and power of each power area from the inter-regional tie lines;

[0006] According to the frequency and power of each of the power areas, adjusting the frequency reference value and the power reference value of each of the power areas;

[0007] Frequency modulation is performed on each of the power areas according to the frequency reference value and the power reference value.

[0008] Optionally, adjusting the frequency reference value and the power reference value of each power area according to the frequency and the power of each power area includes:

[0009] When the frequency of the first power area is less than the frequency reference value of the first power area, and the frequency of the second power area is the same as the frequency reference value of the second power area, the frequency reference value and the power reference value of the first power area and the second power area are adjusted according to the power and the power setting value of the first power area and the capacity of the power system; wherein the first power area and the second power area are adjacent power areas.

[0010] Optionally, adjusting the frequency reference value and the power reference value of the first power area and the second power area according to the power and the power setting value of the first power area and the capacity of the power system includes:

[0011] calculating a frequency deviation between a frequency reference value and a frequency of the first power area;

[0012] calculating a power deviation between a power setting value and a power of the first power area;

[0013] According to the frequency deviation, the power deviation and the capacity of the power system, the frequency reference value and the power reference value of the first power area are reduced, and the frequency reference value and the power reference value of the second power area are increased.

[0014] Optionally, adjusting the frequency reference value and the power reference value of each power area according to the frequency and the power of each power area includes:

[0015] In the case where the power area includes a converter, the frequency reference value and the power reference value of each of the power areas are adjusted based on at least one of the following control objectives:

[0016] The angular frequency of the power system is maintained at the rated angular frequency of the power system;

[0017] Allocate active power among power areas according to the proportion of real-time power generation in each power area;

[0018] Within each power area, active power is allocated among the converters according to the active capacity of each distributed generation;

[0019] When the power system is connected to the grid, the power transmission power P of the inter-regional interconnection line connected to the main grid tie When the total system reserve capacity is sufficient, it is maintained at its set value P tie* .

[0020] Optionally, frequency modulation is performed on each of the power areas according to the frequency reference value and the power reference value, including:

[0021] In the case where the generator set of the target power area includes a converter, the dispatchable virtual oscillator dVOC of each of the converters generates a control variable according to a frequency reference value and a power reference value of the target power area, wherein the control variable includes one or more of a rated frequency, a rated active power, and a voltage reference value;

[0022] The dVOC controls the converter corresponding to the dVOC according to the control variable to adjust the operating frequency of the converter.

[0023] Optionally, the dVOC controls a converter corresponding to the dVOC according to the control variable to adjust the operating frequency of the converter, including:

[0024] By means of a distributed consensus algorithm, the frequency of the dVOC is adjusted, wherein the frequency of the dVOC is less than or equal to the rated frequency;

[0025] According to the voltage reference value and the frequency of the dVOC, a pulse width modulation (PWM) module is controlled to generate a switching signal for controlling the inverter.

[0026] Optionally, frequency modulation is performed on each of the power areas according to the frequency reference value and the power reference value, including:

[0027] In the case where the power generation unit in the target power generation area includes a gas turbine, primary frequency regulation and secondary frequency regulation are performed on the gas turbine based on a mathematical model of the gas turbine and the frequency reference value.

[0028] Optionally, the secondary frequency regulation control structure of the gas turbine can be expressed as:

[0029]

[0030]

[0031]

[0032]

[0033] Among them, ω g represents the gas turbine output speed, ω n Indicates the rated angular frequency of the inverter, R g represents the equivalent droop coefficient of the gas turbine governor, Indicates the secondary frequency modulation reference value of the gas turbine generator output active power, P g Indicates the active power output of the gas turbine generator, They represent the frequency recovery component and power sharing component of the gas generator respectively, Respectively represent the frequency recovery coefficient and power sharing coefficient, χ g represents the set of communication lines connected to the gas generator, a gk Indicates the strength coefficient of the communication line connected to the gas generator, a gk The larger the value, the stronger the connection. g represents the frequency gain of the connection between the gas turbine and the dispatch center, ω k represents the angular frequency of the converter in region k, is the system rated angular frequency, v ref represents the rated voltage of the converter in area k, η k represents the real-time dVOC design parameters of all converters in region k, P k represents the output power of the converter in area k.

[0034] Optionally, in the mathematical model of the gas turbine, the control system of the gas turbine is used to control one or more of speed, temperature, acceleration, upper and lower limits of fuel.

[0035] Optionally, the method further comprises:

[0036] Obtaining the rated capacity of each of the power areas;

[0037] When there is load fluctuation in the power area, the frequency of the power area is adjusted according to the rated capacity.

[0038] In a second aspect, in order to achieve the above-mentioned purpose, an embodiment of the present application further provides a cluster coordination control device of a power system, comprising:

[0039] A collection module, used to collect the frequency and power of each power area from the inter-regional tie lines;

[0040] An adjustment module, used for adjusting a frequency reference value and a power reference value of each of the power areas according to the frequency and power of each of the power areas;

[0041] The sending module is used to modulate the frequency of each of the power areas according to the frequency reference value and the power reference value.

[0042] In the third aspect, in order to achieve the above-mentioned purpose, an embodiment of the present application also provides a cluster coordination control system of an electric power system, including: a transceiver, a processor, a memory, and a program or instruction stored on the memory and executable on the processor; when the processor executes the program or instruction, the cluster coordination control method of the electric power system as described in the first aspect is implemented.

[0043] In a fourth aspect, in order to achieve the above-mentioned purpose, an embodiment of the present application further provides a readable storage medium, on which a program or instruction is stored, and when the program or instruction is executed by a processor, the cluster coordination control method of the power system as described in the first aspect is implemented.

[0044] The beneficial effects of the above technical solution of the present application are as follows:

[0045] The cluster coordination control method of the power system in the embodiment of the present application first collects the frequency and power of each power area from the inter-regional interconnection line; secondly, adjusts the frequency reference value and power reference value of each power area according to the frequency and power of each power area; finally, frequency modulation is performed on each power area according to the frequency reference value and the power reference value. In this way, on the one hand, the frequency modulation resources of each power area are complemented based on the actual situation, and on the other hand, the real-time adjustment of the power interaction between the distribution network and the main network is achieved. Based on the above two aspects, the reliable power supply of the non-fault area of ​​the new energy distribution network can be guaranteed when the main network has a short-term fault. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A flow chart of a cluster coordination control method for a power system according to an embodiment of the present application;

[0047] Figure 2 It is a schematic diagram of the structure of a typical twin-shaft gas turbine;

[0048] Figure 3 It is a schematic diagram of the dynamic model of a gas turbine with a governor;

[0049] Figure 4 A schematic diagram of a double-layer distributed communication topology of a distribution network when cluster control is adopted in an embodiment of the present application;

[0050] Figure 5 A schematic diagram of the topological structure of a distribution network including a gas turbine in an embodiment of the present application;

[0051] Figure 6 A schematic diagram of the structure of a cluster coordination control device for a power system according to an embodiment of the present application;

[0052] Figure 7 A schematic diagram of the structure of a cluster coordination control system of an electric power system according to an embodiment of the present application. DETAILED DESCRIPTION

[0053] In order to make the technical problems, technical solutions and advantages to be solved by the present application clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0054] It should be understood that the references to "one embodiment" or "an embodiment" throughout the specification mean that the specific features, structures, or characteristics associated with the embodiment are included in at least one embodiment of the present application. Therefore, the references to "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0055] In the various embodiments of the present application, it should be understood that the size of the serial numbers of the following processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0056] Additionally, the terms "system" and "network" are often used interchangeably herein.

[0057] In the embodiments provided in the present application, it should be understood that "B corresponding to A" means that B is associated with A, and B can be determined according to A. However, it should also be understood that determining B according to A does not mean determining B only according to A, and B can also be determined according to A and / or other information.

[0058] like Figure 1 As shown, an embodiment of the present application provides a cluster coordination control method for a power system, comprising:

[0059] Step 101, collecting the frequency and power of each power area from the inter-regional tie line; here, the frequency and power of the power area are the real-time frequency of power supply of each power area and the real-time external output power;

[0060] Step 102, adjust the frequency reference value and power reference value of each power area according to the frequency and power of each power area; here, the frequency reference value and power reference value are the expected frequency value and power expected value allocated to each power area based on factors such as the total capacity demand of the power system and the actual capacity of each power area, that is, the frequency and power that each power area is expected to achieve.

[0061] Step 103, frequency modulation is performed on each of the power areas according to the frequency reference value and the power reference value. For example, when the power area cannot reach the frequency reference value and the power reference value through self-regulation, the operating frequency of each power area can be coordinated and controlled to achieve frequency stability of the entire power system.

[0062] The cluster coordination control method of the power system in the embodiment of the present application first collects the frequency and power of each power area from the inter-regional interconnection line; secondly, adjusts the frequency reference value and power reference value of each power area according to the frequency and power of each power area; finally, frequency modulation is performed on each power area according to the frequency reference value and the power reference value. In this way, on the one hand, the frequency modulation resources of each power area are complemented based on the actual situation, and on the other hand, the real-time adjustment of the power interaction between the distribution network and the main network is achieved. Based on the above two aspects, the reliable power supply of the non-fault area of ​​the new energy distribution network can be guaranteed when the main network has a short-term fault.

[0063] Here, it should be noted that the architecture of the cluster coordinated control method of the power system using the embodiment of the present application includes an inter-regional control layer, an intra-regional control layer and a circuit loop; wherein the inter-regional control layer is used to coordinate and control the power grids of each power area (such as the above steps 101 and 102), the intra-regional control layer is used to control the power grids of the corresponding power areas (such as step 103), and the power loop executes a specific power generation process according to the control parameters of the intra-regional control layer.

[0064] As an optional implementation, step 102, adjusting the frequency reference value and the power reference value of each power area according to the frequency and power of each power area, includes:

[0065] When the frequency of the first power area is less than the frequency reference value of the first power area, and the frequency of the second power area is the same as the frequency reference value of the second power area, the frequency reference value and the power reference value of the first power area and the second power area are adjusted according to the power and power setting value of the first power area and the capacity of the power system; wherein the first power area and the second power area are adjacent power areas.

[0066] Here, it should be noted that when a load is added to the first power area, the frequency of the first power area will decrease; therefore, when the frequency of the first power area is less than the frequency reference value of the first power area, it means that the load of the first power area has increased, and the first power area cannot adapt to the increased load by itself. At this time, other power areas are required to increase power to ensure that the frequency of the first power area reaches the frequency reference value.

[0067] In this optional implementation, the frequency of the second power area is the same as the frequency reference value of the second power area, indicating that the power generation power of the second power area can meet the power generation demand. Therefore, when the power generation power of the first power area cannot meet its power reference value, the frequency reference value and power reference value of the first power area and the second power area can be adjusted so that the first power area can meet the power generation demand and the power generation power of all power areas can meet the total capacity demand of the entire power system.

[0068] As a specific implementation, adjusting the frequency reference value and the power reference value of the first power area and the second power area according to the power and the power setting value of the first power area and the capacity of the power system includes:

[0069] calculating a frequency deviation between a frequency reference value and a frequency of the first power area;

[0070] calculating a power deviation between a power setting value and a power of the first power region;

[0071] According to the frequency deviation, the power deviation and the capacity of the power system, the frequency reference value and the power reference value of the first power area are reduced, and the frequency reference value and the power reference value of the second power area are increased.

[0072] In this specific implementation method, based on the power deviation and the frequency deviation, the power that needs to be additionally generated by the second power area in order to maintain the frequency of the first power area at the frequency reference value can be obtained; thereby further adjusting the frequency reference value and the power reference value of the first power area and the second power area to meet the capacity requirements of the entire power system.

[0073] In simple terms, as mentioned above, the control subject of the inter-regional control layer is the power grid of each power area. The inter-regional control layer collects the frequency data of each power area and the power data on the interconnection line, and calculates the deviation from the frequency reference value and the power reference value. After appropriately processing these data according to the total capacity of the power system, the inter-regional control layer sends control instructions to the control layer in each area, where the control instructions include the frequency reference value / power reference value. The control layer in the area controls the corresponding generator set in the circuit loop according to the received control instructions, in the hope that each power area can output the expected frequency and power.

[0074] Here, it should be noted that for new power systems with a high proportion of new energy access, it is generally expected that the new energy areas will transmit excess power to the main grid and actively participate in system frequency regulation when power generation is sufficient, and absorb power from the main grid when power generation is weak. It is expected that the new energy areas and the main grid will achieve resource complementarity by adjusting the power setting value (power reference value) of the inter-regional tie line, and the system with more power generation will participate in the frequency regulation of the system with less power generation.

[0075] Based on the above content, as a specific implementation, step 102, adjusting the frequency reference value and the power reference value of each power area according to the frequency and power of each power area, includes:

[0076] In the case where the power area includes a converter, the frequency reference value and the power reference value of each power area are adjusted based on at least one of the following control targets:

[0077] (1) The angular frequency of the power system is maintained at the rated angular frequency of the power system; wherein the angular frequency has a corresponding relationship with the frequency, and therefore, the control objective can also be described as maintaining the system frequency at its rated value;

[0078] (2) Active power is allocated among the power areas according to the proportion of real-time power generation in each power area. This control index can be expressed by the following formula:

[0079]

[0080] in, represents the active capacity of power area m, P Aream represents the power reference value of power area m, that is, the power allocated to power area m, P Area1 Indicates the power reference value of power area 1, P Area2 Indicates the power reference value of power area 1, represents the active capacity of power area 1, Indicates the active capacity of power area 2.

[0081] (3) Within each power area, the active power is allocated among the converters according to the active capacity of each distributed generation; wherein this control index can be expressed by the following formula:

[0082]

[0083] in, represents the active capacity of converter n, P DGn represents the power reference value of converter n, that is, the power allocated to converter n, P DG1 Indicates the power reference value of converter 1, P DG2 represents the power reference value of converter 2, represents the active capacity of converter 1, Indicates the active capacity of the converter 2.

[0084] (4) When the power system is connected to the grid, the power transmission power P of the inter-regional interconnection line connected to the main grid tie When the total system reserve capacity is sufficient, it is maintained at its set value P tie* .

[0085] Here, it should be noted that the inter-regional control layer in the embodiment of the present application can be a distributed inter-regional control layer based on virtual oscillator (dispatchable Virtual Oscillator Control, dVOC) control. As mentioned above, its main function is to ensure that the frequency of the entire interconnected system is maintained at its rated value (frequency reference value) under load disturbance when a large number of new energy devices with active support capabilities are connected to the multi-regional interconnected distribution network, and when the load in each region fluctuates, each region first increases or decreases the corresponding power according to the rated capacity to maintain the frequency. When the region cannot increase the corresponding power to maintain the frequency (the frequency of the power region is less than the corresponding frequency reference value), the adjacent region provides power to maintain the frequency stability of the entire system. In the above case, the distributed inter-regional control layer can complete the above-mentioned control objectives (1) and (2) of the virtual oscillator cluster control strategy. That is to say, when a power system detects load fluctuations, the power system will distribute the increased load to each converter in a certain proportion to increase its output power. However, each power generation area has a maximum output power limit and cannot generate electricity indefinitely. Therefore, when the power area itself cannot meet the power generation demand, it can supplement the power from other power areas through inter-regional interconnection lines.

[0086] The inter-regional control layer can be a combination of centralized proportional integral (PI) control and dVOC control. First, the set value (power reference value) of the rated system frequency and inter-regional tie line power determined by the operator is obtained, and the frequency reference value of each area is obtained in the distributed inter-regional control layer and sent to the (distributed) intra-regional control layer.

[0087] As an optional implementation, step 103, frequency modulation is performed on each power area according to the frequency reference value and the power reference value, including:

[0088] In the case where the generator set of the target power area includes a converter, the dispatchable virtual oscillator dVOC of each converter generates a control variable according to a frequency reference value and a power reference value of the target power area, and the control variable includes one or more of a rated frequency, a rated active power, and a voltage reference value;

[0089] Here, it should be noted that the intra-regional control layer includes multiple dVOCs, and each power area has a dVOC responsible for receiving the frequency reference signal (frequency reference value) of each power area generated by the inter-regional control layer. The dVOC exchanges information with its adjacent nodes to generate the control variable, and sends the generated control variable to the corresponding dVOC.

[0090] dVOC controls the converter corresponding to dVOC according to the control variable to adjust the operating frequency of the converter, and finally ensures that the output frequency and power of the converter can meet the expected value (frequency reference value / power reference value).

[0091] In combination with this optional implementation, it can be seen that the distributed regional control layer is based on the dispatchable virtual oscillator control. Its specific function is: when the regional power grid is operating in an islanded manner, the distributed regional control layer adds correction items based on the primary control of the virtual oscillator. These correction items will be based on a collaborative consistency algorithm, taking into account the frequency recovery and power sharing capabilities of each unit in the region, that is, each converter should increase the corresponding power according to its rated power to maintain frequency stability, and complete the control objectives (1) and (3) of the virtual oscillator cluster control strategy.

[0092] The distributed intra-regional control layer is a collection of distributed controllers and schedulable virtual oscillator controls based on a distributed consensus algorithm. The dVOC that has a communication link with the regional dispatch center will receive the frequency reference value of the region from the inter-regional control layer. Through the distributed consensus algorithm, each dVOC in the area hi The angular frequency ω hi Adjust to In its steady state, the reference values ​​of each region will converge to ω sys * To achieve the above control objective (1); the algorithm will also achieve objectives (2) and (3) by shifting the frequency-active power droop curves of each converter.

[0093] As a specific implementation method, dVOC controls the converter corresponding to dVOC according to the control variable to adjust the operating frequency of the converter, including:

[0094] The frequency of dVOC is adjusted through a distributed consensus algorithm, wherein the frequency of dVOC is less than or equal to the rated frequency;

[0095] According to the voltage reference value and the frequency of dVOC, a pulse width modulation (PWM) module is controlled to generate a switching signal for controlling the inverter.

[0096] That is, based on the circuit loop layer controlled by the schedulable virtual oscillator, each dVOC hi The angular frequency ω hi The voltage and voltage reference values ​​are sent to the voltage and current controllers, and finally generate switching signals through the PWM module to control the converter (such as the voltage source converter VSC), so that the frequency and power output by the converter meet the desired values, and can coordinate and simultaneously achieve the aforementioned multiple control objectives.

[0097] As an optional implementation, step 103, frequency modulation is performed on each power area according to the frequency reference value and the power reference value, including:

[0098] In the case where the power generation unit in the target power generation area includes a gas turbine, primary frequency regulation and secondary frequency regulation are performed on the gas turbine based on a mathematical model of the gas turbine and a frequency reference value.

[0099] Here, it should be noted that, since gas turbines have excellent performances such as being able to start quickly without external power supply, good mobility, being able to be used as emergency backup and being able to drive peak loads, gas turbines are bound to become an indispensable part of the new distribution network. Therefore, this application focuses on the dispatchable virtual oscillator control strategy with global stability under large disturbances, starting from the network control of the converter actively supporting the power grid, and conducting cluster control research on the distribution system including converters and flexible power generation resources, and proposes a dVOC cluster coordination control strategy considering flexible power generation resources.

[0100] like Figure 2 As shown, the gas turbine includes a starter 1, a gearbox accessory 2, a pump 3, a transmission shaft 4, an air inlet, a reduction gear 5, a compressor 6, a combustion chamber 7, a fuel control unit, a high-pressure turbine 8, a low-pressure turbine 9, a transmission shaft 10, a drive load unit, and an electrical control unit, wherein the high-pressure turbine 8 can also be called a gas turbine or a compressor turbine, which is used to provide the power required to drive the compressor and accessories; the low-pressure turbine 9 can also be called a power turbine, which is used to provide output power.

[0101] In the embodiment of the present application, when establishing the mathematical model of the gas turbine, white box modeling can be performed based on the traditional gas turbine model, and the model is established using mathematical equations about the system dynamics. The dynamic equations of these systems are usually coupled and nonlinear, and the system is linearized. The mathematical model of the gas turbine adopts a simplified mathematical model of a heavy-duty single-shaft gas turbine, such as Figure 3 The simplified dynamic model of a gas turbine with a speed governor is shown in Figure 1. This model is based on Rowen's model and further ignores the dynamic characteristics of the gas turbine, such as no-load loss, combustion delay, and transmission delay. These characteristics have little effect on the frequency modulation system. R represents the droop coefficient of the gas turbine, T1 is the mechanical time constant of the speed governor, T2 is the turbine power time constant, T3 is the turbine exhaust temperature time constant, AT represents the ambient temperature load limit, KT represents the temperature limiter gain coefficient, and V max With V minRepresent the maximum turbine output power and the minimum turbine output power respectively, and D represents the turbine damping coefficient. Among them, the model covers the entire structure of the gas turbine, appropriately reflects the characteristics of the turbine generator, and the established model includes parallel and isolated operation, gas and liquid fuel systems, and isochronous and droop governors.

[0102] Specifically, in the mathematical model of the gas turbine, the control system of the gas turbine is used to control one or more of the speed, temperature, acceleration, upper limit and lower limit of fuel.

[0103] Among them, speed control can represent droop or zero-difference control according to different speed regulator parameters. Its specific input is the difference between each unit speed and the digital set value, that is, the speed error formed between the reference and the actual system or rotor speed.

[0104] Temperature control is the normal means of limiting gas turbine output at a predetermined firing temperature independent of changes in ambient temperature or fuel properties. Since exhaust temperature is measured using a series of thermocouples with radiation shields, there is a small transient error due to the time constants associated with the measurement system. Under normal system conditions, gas turbine output power is determined by the slow rate of the digital set point and these time constants are not meaningful to the load limiting function. However, increases in gas turbine output are a result of a reduction in system frequency and therefore can occur quite rapidly and the exhaust temperature measurement system time constants will result in some transient overshoot in the load acquisition. Temperature controllers are designed to compensate for this transient behavior.

[0105] Acceleration control is mainly used during gas turbine startup to limit the acceleration of the rotor before reaching the governor speed, thereby improving the thermal stresses encountered during startup. Its function is to reduce the flow and limit the overspeed tendency when the turbine generator is separated from the system.

[0106] Fuel upper and lower limit control: Gas turbines require a significant portion of the rated fuel to support self-sustaining. This fuel flow range is maintained between 23-100% to be compatible with the thermodynamics of the turbine.

[0107] Based on the above content, in this optional implementation, the model of the speed governor used for primary frequency regulation of the gas turbine can be expressed by the following formula:

[0108]

[0109] Among them, ω g represents the output speed of the gas turbine generator, ω n Indicates the rated angular frequency of the converter in the power system. For example, if the rated angular frequency is 50Hz, R g represents the equivalent droop coefficient of the gas turbine generator governor, Indicates the secondary frequency modulation reference value of the gas turbine generator output active power, P g Indicates the active power output of the gas turbine generator.

[0110] As a specific implementation method, the secondary frequency regulation control structure of the gas turbine can be expressed as:

[0111]

[0112]

[0113]

[0114]

[0115] Among them, ω g represents the gas turbine output speed, ω n Indicates the rated angular frequency of the inverter, R g represents the equivalent droop coefficient of the gas turbine governor, Indicates the secondary frequency modulation reference value of the gas turbine generator output active power, P g Indicates the active power output of the gas turbine generator, They represent the frequency recovery component and power sharing component of the gas generator respectively, Respectively represent the frequency recovery coefficient and power sharing coefficient, χ g represents the set of communication lines connected to the gas generator, a gk Indicates the strength coefficient of the communication line connected to the gas generator, a gk The larger the value, the stronger the connection. g represents the frequency gain of the connection between the gas turbine and the dispatch center, ω k represents the angular frequency of the converter in region k, is the system rated angular frequency, v ref represents the rated voltage of the converter in area k, η k represents the real-time dVOC design parameters of all converters in region k, P k represents the output power of the converter in area k.

[0116] In this optional implementation, the gas turbine is subjected to primary and secondary frequency regulation based on the acquired frequency reference value. Based on the adjustment of the gas turbine, the complementarity of frequency regulation resources and power interaction of various regions such as the power area including the gas turbine and the power area of ​​the new energy distribution network can be achieved, so as to ensure that the power system can provide stable power supply in the event of a large disturbance, as well as the reliability of power supply of the power grid in the event of a power grid failure.

[0117] That is to say, the power system using the power system cluster coordinated control method of the embodiment of the present application may include a gas turbine and a converter; wherein the system may include nodes, buses, loads, transformers, converters, switch breakers, gas turbines, wind turbines, photovoltaic panels, etc.; its topological structure may be as follows Figure 5 As shown, specifically, the system has 5 nodes, of which nodes 1 to 4 are connected to the converter through a transformer, and node 5 is connected to a gas generator. Nodes 1 to 4 are all connected to the common bus with loads, and node 5 is not connected to loads. When cluster control is adopted, nodes 1 and 2 are divided into power area 1; nodes 3 and 4 are divided into power area 2; and node 5 is divided into power area 3.

[0118] Furthermore, as an optional implementation, the method further includes:

[0119] Obtaining the rated capacity of each power area; here, the rated capacity may be a preset capacity;

[0120] When there is load fluctuation in the power area, the frequency of the power area is adjusted according to the rated capacity.

[0121] That is to say, during the power supply process of the power system, each power area will first increase or reduce the corresponding power according to the rated capacity to maintain the rated frequency (frequency reference value). Only when the adjustment within the power area cannot maintain the frequency reference value, the inter-regional control layer can participate to increase the power of other adjacent power systems to compensate for the power reduction in this power area, and ultimately maintain the stability of the frequency of the entire system.

[0122] The power cluster coordinated control method of the embodiment of the present application, when considering cluster control, adopts a distribution network double-layer distributed communication topology including both gas turbines and new energy converters, including three categories, such as Figure 4 As shown, the first is to select the chain communication topology, the leading unit is the converter, and the gas turbine unit is the last link of the chain communication line ( Figure 4 (a) in the figure); the second is that the leading unit is the inverter, and a radial communication topology is adopted, and the gas turbine directly receives the communication signal of the "leading" inverter ( Figure 4 (b)); the third is that the leading unit is a gas turbine, using a chain communication topology, with the gas generator leading the converter unit ( Figure 4 (c) in the figure.

[0123] In the new distribution network, the cluster control strategy considering flexibility resources is of great significance for the future research on the penetration of new energy sources in the new distribution network. The power system cluster coordinated control method of the embodiment of the present application studies the excellent performance of gas turbines as emergency backup and driving peak loads in the absence of external power supply. By adding gas generators to the distribution network containing only converter clusters, a dVOC cluster control strategy considering flexibility resources is proposed. By improving the system frequency response characteristics through cluster coordinated control, flexible coordinated control of heterogeneous resources in the region can be achieved. Specifically, the power system cluster coordinated control method proposed in the present application is a cluster control strategy considering flexibility resources, including two control layers and one circuit layer. The cluster control strategy idea is to transmit the frequency of each region and the power value on the tie line to the inter-regional control layer. The inter-regional control layer calculates the deviation of the transmitted data from the reference value, and allocates power and frequency instructions to each region according to the total capacity requirements of the entire system. After receiving the instructions, each region transmits the information to each schedulable virtual oscillator as a control variable. The schedulable virtual oscillator controls the corresponding VSC of the circuit loop layer so that the output power and frequency meet the expected values.

[0124] like Figure 6 As shown, an embodiment of the present application provides a cluster coordination control device for a power system, comprising:

[0125] The acquisition module 601 is used to collect the frequency and power of each power area from the inter-regional tie line;

[0126] A first adjustment module 602, configured to adjust a frequency reference value and a power reference value of each of the power areas according to the frequency and power of each of the power areas;

[0127] The frequency modulation module 603 is used to modulate the frequency of each of the power areas according to the frequency reference value and the power reference value.

[0128] Optionally, the first adjustment module 602 includes:

[0129] An adjustment submodule is used to adjust the frequency reference value and the power reference value of the first power area and the second power area according to the power and the power setting value of the first power area and the capacity of the power system when the frequency of the first power area is less than the frequency reference value of the first power area and the frequency of the second power area is the same as the frequency reference value of the second power area; wherein the first power area and the second power area are adjacent power areas.

[0130] Optionally, the adjustment submodule includes:

[0131] a first calculation unit, configured to calculate a frequency deviation between a frequency reference value and a frequency of the first power area;

[0132] a second calculation unit, configured to calculate a power deviation between a power setting value and a power of the first power area;

[0133] An adjustment unit is used to reduce the frequency reference value and the power reference value of the first power area and increase the frequency reference value and the power reference value of the second power area according to the frequency deviation, the power deviation and the capacity of the power system.

[0134] Optionally, the first adjustment module 602 is specifically configured to:

[0135] In the case where the power area includes a converter, the frequency reference value and the power reference value of each of the power areas are adjusted based on at least one of the following control objectives:

[0136] The angular frequency of the power system is maintained at the rated angular frequency of the power system;

[0137] Active power is allocated among the regions according to the proportion of real-time power generation in each region;

[0138] Within each area, active power is allocated among the converters according to the active capacity of each distributed generation;

[0139] When the system is connected to the grid, the transmission power P of the inter-regional tie line connected to the main grid tie When the total system reserve capacity is sufficient, it is maintained at its set value P tie* .

[0140] Optionally, the frequency modulation module 603 includes:

[0141] A generating submodule, configured to generate control variables according to a frequency reference value and a power reference value of the target power area by a dispatchable virtual oscillator dVOC of each of the converters when the generator set of the target power area includes a converter, wherein the control variables include one or more of a rated frequency, a rated active power, and a voltage reference value;

[0142] The frequency modulation submodule is used for the dVOC to control the converter corresponding to the dVOC according to the control variable to adjust the operating frequency of the converter.

[0143] Optionally, the frequency modulation submodule includes:

[0144] an adjusting unit, configured to adjust the frequency of the dVOC by using a distributed consensus algorithm, wherein the frequency of the dVOC is less than or equal to the rated frequency;

[0145] The control unit is used to control a pulse width modulation (PWM) module to generate a switching signal for controlling the converter according to the voltage reference value and the frequency of the dVOC.

[0146] Optionally, the frequency modulation module 603 is specifically used for:

[0147] In the case where the power generation unit in the target power generation area includes a gas turbine, primary frequency regulation and secondary frequency regulation are performed on the gas turbine based on a mathematical model of the gas turbine and the frequency reference value.

[0148] Optionally, the secondary frequency regulation control structure of the gas turbine can be expressed as:

[0149]

[0150]

[0151]

[0152]

[0153] Among them, ω g represents the gas turbine output speed, ω n Indicates the rated angular frequency of the inverter, R g represents the equivalent droop coefficient of the gas turbine governor, Indicates the secondary frequency modulation reference value of the gas turbine generator output active power, P g Indicates the active power output of the gas turbine generator, They represent the frequency recovery component and power sharing component of the gas generator respectively, Respectively represent the frequency recovery coefficient and power sharing coefficient, χ g represents the set of communication lines connected to the gas generator, a gk Indicates the strength coefficient of the communication line connected to the gas generator, a gk The larger the value, the stronger the connection. g represents the frequency gain of the connection between the gas turbine and the dispatch center, ω k represents the angular frequency of the converter in region k, is the system rated angular frequency, v ref represents the rated voltage of the converter in area k, η k represents the real-time dVOC design parameters of all converters in region k, P k represents the output power of the converter in area k.

[0154] Optionally, in the mathematical model of the gas turbine, the control system of the gas turbine is used to control one or more of speed, temperature, acceleration, upper and lower limits of fuel.

[0155] Optionally, the device further comprises:

[0156] An acquisition module, used for acquiring the rated capacity of each of the power areas;

[0157] The second adjustment module is used to adjust the frequency of the power area according to the rated capacity when there is load fluctuation in the power area.

[0158] It should be noted that the cluster coordination control device of the above-mentioned power system provided in the embodiment of the present application can implement all the method steps implemented in the cluster coordination control method embodiment of the above-mentioned power system, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as those of the method embodiment will not be described in detail here.

[0159] like Figure 7 As shown, an embodiment of the present application also provides a cluster coordination control system of an electric power system, including a transceiver 710, a processor 700, a memory 720, and a program or instruction stored on the memory 720 and executable on the processor 700; when the processor 700 executes the program or instruction, the cluster coordination control method of the above-mentioned electric power system is implemented.

[0160] The transceiver 710 is used to receive and send data under the control of the processor 700.

[0161] Among them, Figure 7 In the embodiment, the bus architecture may include any number of interconnected buses and bridges, specifically one or more processors represented by processor 700 and various circuits of memory represented by memory 720 are linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The transceiver 710 may be a plurality of components, namely, a transmitter and a receiver, providing a unit for communicating with various other devices on a transmission medium. For different systems, the user interface 730 may also be an interface capable of externally and internally connecting required devices, and the connected devices include but are not limited to a keypad, a display, a speaker, a microphone, a joystick, and the like.

[0162] The processor 700 is responsible for managing the bus architecture and general processing, and the memory 720 can store data used by the processor 700 when performing operations.

[0163] A readable storage medium in an embodiment of the present application stores a program or instruction thereon. When the program or instruction is executed by a processor, the steps in the cluster coordinated control method of the power system as described above are implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0164] The processor is a processor in the cluster coordination control system of the power system described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0165] In the embodiment of the present application, module can be implemented with software so that it can be executed by various types of processors. For example, an executable code module of an identification can include one or more physical or logical blocks of computer instructions, for example, it can be constructed as an object, process or function. Nevertheless, the executable code of the identified module does not need to be physically located together, but can include different instructions stored in different positions, and when these instructions are logically combined together, it constitutes a module and realizes the specified purpose of the module.

[0166] In fact, an executable code module can be a single instruction or many instructions, and can even be distributed over multiple different code segments, distributed among different programs, and distributed across multiple memory devices.

[0167] When a module can be implemented by software, considering the level of existing hardware technology, a person skilled in the art can build a corresponding hardware circuit to implement the corresponding function of the module that can be implemented by software without considering the cost. The hardware circuit includes a conventional very large scale integration (VLSI) circuit or gate array and existing semiconductors such as logic chips, transistors, or other discrete components. The module can also be implemented by a programmable hardware device, such as a field programmable gate array, a programmable array logic, a programmable logic device, etc.

[0168] The above exemplary embodiments are described with reference to the accompanying drawings, and many different forms and embodiments are feasible without departing from the spirit and teachings of the present application. Therefore, the present application should not be constructed as a limitation of the exemplary embodiments proposed herein. More specifically, these exemplary embodiments are provided so that the present application will be perfect and complete, and the scope of the present application will be conveyed to those who are familiar with the technology. In these figures, the component sizes and relative sizes may be exaggerated for clarity. The terms used here are only based on the purpose of describing specific exemplary embodiments and are not intended to be limiting. As used herein, unless the text clearly indicates otherwise, the singular forms "one", "an" and "the" are intended to include these multiple forms. It will be further understood that the terms "comprising" and / or "including" when used in this specification indicate the presence of the features, integers, steps, operations, components and / or components, but do not exclude the presence or increase of one or more other features, integers, steps, operations, components, components and / or their groups. Unless otherwise indicated, when stated, a range of values ​​includes the upper and lower limits of that range and any subranges therebetween.

[0169] The above is a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles described in the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A cluster coordination control method for a power system, characterized in that: include: Collect the frequency and power of each power area from the inter-regional tie lines; According to the frequency and power of each of the power areas, adjusting the frequency reference value and the power reference value of each of the power areas; Frequency modulation is performed on each of the power areas according to the frequency reference value and the power reference value.

2. The cluster coordination control method of the power system according to claim 1, characterized in that: According to the frequency and power of each of the power areas, adjusting the frequency reference value and the power reference value of each of the power areas comprises: When the frequency of the first power area is less than the frequency reference value of the first power area, and the frequency of the second power area is the same as the frequency reference value of the second power area, the frequency reference value and the power reference value of the first power area and the second power area are adjusted according to the power and power setting value of the first power area and the capacity of the power system; wherein the first power area and the second power area are adjacent power areas.

3. The cluster coordinated control method of the power system according to claim 2, characterized in that: According to the power and the power setting value of the first power area and the capacity of the power system, adjusting the frequency reference value and the power reference value of the first power area and the second power area includes: calculating a frequency deviation between a frequency reference value and a frequency of the first power area; calculating a power deviation between a power setting value and a power of the first power area; According to the frequency deviation, the power deviation and the capacity of the power system, the frequency reference value and the power reference value of the first power area are reduced, and the frequency reference value and the power reference value of the second power area are increased.

4. The cluster coordinated control method of the power system according to claim 1, characterized in that: According to the frequency and power of each of the power areas, adjusting the frequency reference value and the power reference value of each of the power areas comprises: In the case where the power area includes a converter, the frequency reference value and the power reference value of each of the power areas are adjusted based on at least one of the following control objectives: The angular frequency of the power system is maintained at the rated angular frequency of the power system; Allocate active power among power areas according to the proportion of real-time power generation in each power area; Within each power area, active power is allocated among the converters according to the active capacity of each distributed generation; When the power system is connected to the grid, the power transmission power P of the inter-regional interconnection line connected to the main grid tie When the total system reserve capacity is sufficient, it is maintained at its set value P tie* .

5. The cluster coordination control method of the power system according to claim 1, characterized in that: According to the frequency reference value and the power reference value, frequency modulation is performed on each of the power areas, including: In the case where the generator set of the target power area includes a converter, the dispatchable virtual oscillator dVOC of each of the converters generates a control variable according to a frequency reference value and a power reference value of the target power area, wherein the control variable includes one or more of a rated frequency, a rated active power, and a voltage reference value; The dVOC controls the converter corresponding to the dVOC according to the control variable to adjust the operating frequency of the converter.

6. The cluster coordinated control method of the power system according to claim 5, characterized in that: The dVOC controls a converter corresponding to the dVOC according to the control variable to adjust the operating frequency of the converter, including: By means of a distributed consensus algorithm, the frequency of the dVOC is adjusted, wherein the frequency of the dVOC is less than or equal to the rated frequency; According to the voltage reference value and the frequency of the dVOC, a pulse width modulation (PWM) module is controlled to generate a switching signal for controlling the inverter.

7. The cluster coordination control method of the power system according to claim 1, characterized in that: According to the frequency reference value and the power reference value, frequency modulation is performed on each of the power areas, including: In the case where the power generation unit in the target power generation area includes a gas turbine, primary frequency regulation and secondary frequency regulation are performed on the gas turbine based on a mathematical model of the gas turbine and the frequency reference value.

8. The cluster coordination control method of the power system according to claim 7, characterized in that: The secondary frequency modulation control structure of the gas turbine is expressed as: Among them, ω g represents the gas turbine output speed, ω n Indicates the rated angular frequency of the inverter, R g represents the equivalent droop coefficient of the gas turbine governor, Indicates the secondary frequency modulation reference value of the gas turbine generator output active power, P g Indicates the active power output of the gas turbine generator, They represent the frequency recovery component and power sharing component of the gas generator respectively, Respectively represent the frequency recovery coefficient and power sharing coefficient, χ g represents the set of communication lines connected to the gas generator, a gk Indicates the strength coefficient of the communication line connected to the gas generator, a gk The larger the value, the stronger the connection. g represents the frequency gain of the connection between the gas turbine and the dispatch center, ω k represents the angular frequency of the converter in region k, is the system rated angular frequency, v ref represents the rated voltage of the converter in area k, η k represents the real-time dVOC design parameters of all converters in region k, P k represents the output power of the converter in area k.

9. The cluster coordination control method of the power system according to claim 7, characterized in that: In the mathematical model of the gas turbine, the control system of the gas turbine is used to control one or more of speed, temperature, acceleration, upper and lower fuel limit controls.

10. The cluster coordination control method of the power system according to claim 1, characterized in that: The method further comprises: Obtaining the rated capacity of each of the power areas; When there is load fluctuation in the power area, the frequency of the power area is adjusted according to the rated capacity.

11. A cluster coordination control device for a power system, characterized in that: include: A collection module, used to collect the frequency and power of each power area from the inter-regional tie lines; An adjustment module, used for adjusting a frequency reference value and a power reference value of each of the power areas according to the frequency and power of each of the power areas; The sending module is used to modulate the frequency of each of the power areas according to the frequency reference value and the power reference value.

12. A cluster coordination control system for an electric power system, comprising: A transceiver, a processor, a memory, and a program or instruction stored in the memory and executable on the processor; characterized in that when the processor executes the program or instruction, the cluster coordination control method of the power system as described in any one of claims 1 to 10 is implemented.

13. A readable storage medium having a program or instruction stored thereon, characterized in that: When the program or instruction is executed by a processor, a cluster coordinated control method for a power system according to any one of claims 1 to 10 is implemented.

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