Multi-source power grid control method, device, equipment, medium and program product

Abstract

The invention relates to a multi-source power grid control method, device and equipment, a medium and a program product. The multi-source power grid control method comprises the following steps: acquiring a power grid access state between an external alternating current power grid and a multi-source power grid; under the condition that the power grid access state is an abnormal state, a reference current value meeting the multi-source power grid load requirement is determined; and according to the reference current value, outputting a first control pulse to an energy supplementing device connected to the multi-source power grid, so that the energy supplementing device supplements energy to the multi-source power grid according to the first control pulse. By means of the method, energy supplementation is carried out according to the current multi-source power grid load requirement, the power supply requirement of the multi-source power grid is guaranteed, and the power supply stability of the multi-source power grid is improved.

Description

Technical Field

[0001] The present application relates to the field of power grid control technology, and in particular to a control method, device, equipment, medium and program product for a multi-source power grid. Background Art

[0002] As energy demand increases, multi-source grid technology has emerged. Multi-source grid refers to the physical network of the power system composed of various types of power equipment. The application of multi-source grid has significantly improved the power grid in terms of energy supply and dispatch flexibility.

[0003] However, in the traditional application of multi-source power grids, especially when some power equipment is abnormal, it is easy to have unstable power supply or power supply unable to meet the load, affecting normal use. Summary of the invention

[0004] Based on this, it is necessary to provide a control method, device, equipment, medium and program product for a multi-source power grid that can improve the stability of the multi-source power grid in response to the above technical problems.

[0005] In a first aspect, the present application provides a control method for a multi-source power grid, comprising:

[0006] Obtaining the grid access status between the external AC grid and the multi-source grid;

[0007] When the grid access state is abnormal, determining a reference current value that meets the multi-source grid load demand;

[0008] According to the reference current value, a first control pulse is output to an energy replenishment device connected to the multi-source power grid, so that the energy replenishment device replenishes energy to the multi-source power grid according to the first control pulse.

[0009] In one of the embodiments, if the abnormal state is a short-term abnormal state, the energy compensation device includes an energy storage power supply and a bidirectional converter; accordingly, according to the reference current value, a first control pulse is output to the energy compensation device connected to the multi-source power grid, including: according to the reference current value, obtaining a duty cycle corresponding to the bidirectional converter; according to the duty cycle, determining a first control pulse for the bidirectional converter; outputting the first control pulse to the bidirectional converter so that the bidirectional converter controls the energy storage power supply to output current to the multi-source power grid according to the first control pulse.

[0010] In one of the embodiments, a duty cycle corresponding to the bidirectional converter is obtained according to a reference current value, including: determining a minimum current error between a reference current value and an actual output current of the energy storage power supply according to a current value output interval of the energy storage power supply; and determining a duty cycle corresponding to the bidirectional converter according to the minimum current error.

[0011] In one embodiment, if the abnormal state is a long-term abnormal state, the energy replenishment device includes a fuel generator, a first transfer switch, and a bus converter; correspondingly, according to the reference current value, a first control pulse is output to the energy replenishment device connected to the multi-source power grid, including: adjusting the switch state of the first transfer switch to the on state; obtaining the actual three-phase current value output by the fuel generator; determining the first control pulse for the bus converter according to the reference current value and the actual three-phase current value; and outputting the first control pulse to the bus converter so that the bus converter controls the fuel generator to supply power to the multi-source power grid according to the first control pulse.

[0012] In one embodiment, determining the first control pulse for the bus converter according to the reference current value and the actual three-phase current value includes: determining the current difference between the reference current value and the actual three-phase current value; and determining the first control pulse for the bus converter according to the current difference.

[0013] In one embodiment, it further includes: when the grid access state is a normal state, respectively determining the second control pulses of at least one power electronic device connected to the multi-source power grid; and outputting the second control pulses to each power electronic device so that each power electronic device performs current and voltage control for the multi-source power grid according to the second control pulses.

[0014] In a second aspect, the present application further provides a control device for a multi-source power grid, including:

[0015] An acquisition module, configured to acquire the grid access state between an external AC power grid and the multi-source power grid;

[0016] A determination module, configured to determine a reference current value that meets the load demand of the multi-source power grid when the grid access state is an abnormal state;

[0017] An output module, configured to output a first control pulse to the energy replenishment device connected to the multi-source power grid according to the reference current value, so that the energy replenishment device performs energy replenishment for the multi-source power grid according to the first control pulse.

[0018] In a third aspect, the present application further provides a computer device, including a memory and a processor, where the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0019] Acquire the grid access state between an external AC power grid and the multi-source power grid;

[0020] When the grid access state is an abnormal state, determine a reference current value that meets the load demand of the multi-source power grid;

[0021] Output a first control pulse to an energy replenishment device connected to a multi-source power grid according to a reference current value, so that the energy replenishment device replenishes energy to the multi-source power grid according to the first control pulse.

[0022] In a fourth aspect, the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0023] Obtain the grid access status between an external AC power grid and a multi-source power grid;

[0024] When the grid access status is an abnormal state, determine a reference current value that meets the load demand of the multi-source power grid;

[0025] Output a first control pulse to an energy replenishment device connected to a multi-source power grid according to the reference current value, so that the energy replenishment device replenishes energy to the multi-source power grid according to the first control pulse.

[0026] In a fifth aspect, the present application further provides a computer program product, including a computer program. When the computer program is executed by a processor, the following steps are implemented:

[0027] Obtain the grid access status between an external AC power grid and a multi-source power grid;

[0028] When the grid access status is an abnormal state, determine a reference current value that meets the load demand of the multi-source power grid;

[0029] Output a first control pulse to an energy replenishment device connected to a multi-source power grid according to the reference current value, so that the energy replenishment device replenishes energy to the multi-source power grid according to the first control pulse.

[0030] The above control method, device, equipment, medium and program product of the multi-source power grid obtain the grid access status between the external AC power grid and the multi-source power grid, so as to facilitate the immediate acquisition of abnormal situations in the multi-source power grid connection, providing a prerequisite for rapid response and decision-making processing. By determining a reference current value that meets the load demand of the multi-source power grid when the grid access status is an abnormal state, data support and a control basis are provided for the control strategy of the multi-source power grid; by outputting a first control pulse to an energy replenishment device connected to the multi-source power grid according to the reference current value, so that the energy replenishment device replenishes energy to the multi-source power grid according to the first control pulse, energy replenishment is realized for the current load demand of the multi-source power grid, ensuring the power supply demand of the multi-source power grid and improving the power supply stability of the multi-source power grid. Description of the Drawings

[0031] To more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments of the present application or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0032] Figure 1 It is an application environment diagram of the control method for a multi-source power grid in an embodiment;

[0033] Figure 2 It is a schematic flowchart of the control method for a multi-source power grid in an embodiment;

[0034] Figure 3A It is a schematic flowchart of the output step of the first control pulse in an embodiment;

[0035] Figure 3B It is a schematic diagram of the determination process of the power supply control pulse in an embodiment;

[0036] Figure 4A It is a schematic flowchart of the output step of the first control pulse in another embodiment;

[0037] Figure 4B It is a schematic diagram of the determination process of the first bus control pulse in an embodiment;

[0038] Figure 5 It is a schematic diagram of the determination process of the charging control pulse in an embodiment;

[0039] Figure 6 It is a schematic diagram of the determination process of the second bus control pulse in an embodiment;

[0040] Figure 7 It is a schematic diagram of the determination process of the stator-side control pulse in an embodiment;

[0041] Figure 8 It is a schematic diagram of the determination process of the rotor-side control pulse in an embodiment;

[0042] Figure 9 It is a schematic diagram of the determination process of the rotor-side control pulse in another embodiment;

[0043] Figure 10 It is a schematic diagram of the determination process of the grid-side control pulse in an embodiment;

[0044] Figure 11 It is a schematic diagram of the determination process of the boost control pulse in an embodiment;

[0045] Figure 12Schematic diagram of the step-down control pulse determination process in an embodiment;

[0046] Figure 13 Flow schematic diagram of the control method for a multi-source power grid in another embodiment;

[0047] Figure 14 Structural block diagram of the control device for a multi-source power grid in an embodiment;

[0048] Figure 15 Internal structure diagram of a computer device in an embodiment. Detailed implementation manners

[0049] To make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0050] The control method for a multi-source power grid provided by the embodiments of the present application can be applied to an application environment as shown in Figure 1 . Among them, the multi-source power grid may include an AC bus and a DC bus, and the AC bus and the DC bus are interconnected through a bus converter ILC. The external AC power grid can be connected to the DC bus through a grid-side converter GSC. The energy storage power supply can be connected to the DC bus through a bidirectional converter BDC. The fuel generator DG can be connected to the AC bus through a first transfer switch DSTS n . Among them, the first transfer switch DSTS n can be a solid-state transfer switch.

[0051] Among them, the multi-source power grid may also include clean energy. Continuing to refer to Figure 1 , the stator of the doubly-fed induction generator DFIG n can be connected to the AC bus through a second transfer switch SSTS n , and the rotor can be connected to the AC bus through a rotor-side converter RSC n , a stator-side converter SSC n , and a step-up transformer TF n . The photovoltaic array can be connected to the DC bus through a step-up converter BTC m . Among them, the second transfer switch SSTS n can be a solid-state transfer switch.

[0052] Among them, the loads of the multi-source power grid may include at least one of a low-voltage DC load, a medium-voltage DC load, and an AC load, etc. The low-voltage DC load can be connected to the DC bus through a step-down converter BKC, the medium-voltage DC load is connected to the DC bus, and the AC load is connected to the AC bus.

[0053] Continuing to refer toFigure 1 When the external AC power grid is off-grid or experiences a voltage sag, power supply instability or inability to meet the required load will occur, thus affecting the normal operation of the load. In response to this, the present application obtains the grid connection status between the external AC power grid and the multi-source power grid; in the case where the grid connection status is an abnormal state, determines a reference current value that meets the load demand of the multi-source power grid; and according to the reference current value, outputs a first control pulse to the energy supplement device connected to the multi-source power grid, so that the energy supplement device supplements energy to the multi-source power grid according to the first control pulse. Thus, energy supplementation is achieved for the current load demand of the multi-source power grid, ensuring the power supply demand of the multi-source power grid and improving the stability of the power supply of the multi-source power grid.

[0054] It should be noted that the above multi-source power grid is only used for illustration, and those skilled in the art can increase or decrease the corresponding electrical power equipment according to actual needs. The present application does not make any limitations on the type, quantity, and connection method of the electrical power equipment in the multi-source power grid.

[0055] In an exemplary embodiment, as Figure 2 shown, a control method for a multi-source power grid is provided. Taking the application of this method to a controller as an example, it includes the following steps:

[0056] S210. Obtain the grid connection status between the external AC power grid and the multi-source power grid.

[0057] Among them, the grid connection status refers to the connection status between the external AC power grid and the multi-source power grid. The grid connection status can include an abnormal state and a normal state. The abnormal state can include a long-term abnormal state and a short-term abnormal state. The long-term abnormal state can be understood as the abnormal time in the abnormal state being greater than the first preset time; the short-term abnormal state can be understood as the abnormal time in the abnormal state not being greater than the first preset time.

[0058] Exemplarily, the situation where the grid connection status is an abnormal state can include at least one of the following: the external AC power grid is off-grid; the output voltage of the external AC power grid is lower than the preset output voltage. Among them, the preset output voltage can be set by technicians according to needs or experience, and the present application does not make any limitations on this.

[0059] Exemplarily, the situation where the grid connection status is a normal state can include: the external AC power grid is grid-connected and the output voltage is not lower than the preset output voltage.

[0060] S220. In the case where the grid connection status is an abnormal state, determine a reference current value that meets the load demand of the multi-source power grid.

[0061] Among them, the reference current value can be understood as the reference or benchmark current value that needs to be provided to meet the load demand of the multi-source power grid.

[0062] Exemplarily, for the DC bus of a multi-source power grid, a reference current value can be determined based on the reference DC parameters and the actual DC parameters of the DC bus. Among them, the reference DC parameters may include the reference DC voltage, and the actual DC parameters may include the actual DC voltage.

[0063] Exemplarily, for the AC bus of a multi-source power grid, a reference current value can be determined based on the reference power supply parameters of the energy replenishment device and the actual AC parameters of the AC bus. Among them, the reference power supply parameters may include the reference active power, and the actual AC parameters may include the sine component of the voltage and the voltage amplitude, etc.

[0064] It should be noted that this application does not make any limitations on the specific parameter types and values of the above-mentioned reference DC parameters, actual DC parameters, reference power supply parameters, and actual AC parameters.

[0065] S230. Output a first control pulse to the energy replenishment device connected to the multi-source power grid according to the reference current value, so that the energy replenishment device replenishes energy to the multi-source power grid according to the first control pulse.

[0066] Among them, the energy replenishment device can be understood as a device that can provide or replenish energy to the power grid. Exemplarily, the energy replenishment device may include at least one of a fuel generator and an energy storage power supply, etc. The fuel generator may specifically be a fuel oil generator.

[0067] Among them, the first control pulse is used to perform current closed-loop control on the energy replenishment device according to the reference current value, so that the actual output current of the energy replenishment device matches the reference current value.

[0068] In the embodiments of this application, by obtaining the grid access status between the external AC power grid and the multi-source power grid, it is convenient to immediately obtain abnormal situations in the multi-source power grid connection, providing a premise for rapid response and decision-making processing. By determining the reference current value that meets the load demand of the multi-source power grid when the grid access status is an abnormal state, data support and a control basis are provided for the control strategy of the multi-source power grid; by outputting a first control pulse to the energy replenishment device connected to the multi-source power grid according to the reference current value, so that the energy replenishment device replenishes energy to the multi-source power grid according to the first control pulse, energy replenishment is realized for the current load demand of the multi-source power grid, ensuring the power supply demand of the multi-source power grid and improving the power supply stability of the multi-source power grid.

[0069] Based on the technical solutions of the above embodiments, this application also provides an optional embodiment. In this optional embodiment, if the abnormal state is a short-term abnormal state, the energy replenishment device includes an energy storage power supply and a bidirectional converter. Accordingly, the output step of the first control pulse is refined.

[0070] See Figure 3A The output step of the first control pulse shown in the figure includes:

[0071] S310. Obtain the duty ratio corresponding to the bidirectional converter according to the reference current value.

[0072] In an optional embodiment, the energy storage power supply is connected to the DC bus of the multi-source power grid through a bidirectional converter. Correspondingly, the reference current value can be determined through the following steps: obtain the reference DC voltage and the actual DC voltage of the DC bus; determine the voltage deviation between the reference DC voltage and the actual DC voltage; determine the reference current value according to the voltage deviation.

[0073] Among them, the reference DC voltage of the DC bus can be set by those skilled in the art according to needs, and the present application does not make any limitation on the specific value of the reference DC voltage.

[0074] Optionally, the voltage deviation between the reference DC voltage and the actual DC voltage can be minimized through a PI controller, so as to obtain the reference current value.

[0075] In an optional embodiment, the minimum current error between the reference current value and the actual output current of the energy storage power supply can be determined according to the current value output interval of the energy storage power supply; the duty ratio corresponding to the bidirectional converter is determined according to the minimum current error. Among them, the duty ratio corresponding to the bidirectional converter is determined through the minimum current error, so that the actual output current of the bidirectional converter matches the reference current value, thereby enabling energy supplementation for the current multi-source power grid load demand.

[0076] Optionally, the current deviation between the reference current value and the actual output current of the energy storage power supply can be minimized through a PI controller, so as to obtain the duty ratio corresponding to the bidirectional converter.

[0077] S320. Determine the first control pulse for the bidirectional converter according to the duty ratio.

[0078] Optionally, the first control pulse can be modulated according to the duty ratio through PWM (Pulse Width Modulation).

[0079] S330. Output the first control pulse to the bidirectional converter, so that the bidirectional converter controls the energy storage power supply to output current to the multi-source power grid according to the first control pulse.

[0080] The following combines Figure 3B , to illustrate the determination process of the first control pulse of the bidirectional converter. For the convenience of distinction, the first control pulse of the bidirectional converter is denoted as the power supply control pulse S BDC1 , and the reference current value is denoted as the energy storage reference current value I *bdc The duty cycle is expressed as the energy storage duty cycle d bdc1 .

[0081] Reference Figure 3B , the power supply control pulse S BDC1 The determination steps may include: determining the actual DC voltage V of the DC bus dc and the reference DC voltage V * dc The voltage deviation between them; the PI controller obtains the energy storage reference current value I by minimizing the voltage deviation * bdc ; determining the current deviation between the energy storage reference current value I * bdc and the actual output current I of the bidirectional converter bdc ; the PI controller obtains the energy storage duty cycle d by minimizing the current deviation bdc1 ; performing PWM modulation on the energy storage duty cycle d bdc1 to obtain the power supply control pulse S BDC1 .

[0082] In the above embodiment, by obtaining the duty cycle corresponding to the bidirectional converter according to the reference current value, and determining the first control pulse for the bidirectional converter according to the duty cycle, energy supplement to the multi-source power grid is realized through the energy storage power supply in the case of short-time abnormal state, ensuring the power supply demand of the multi-source power grid.

[0083] Based on the technical solutions of the above embodiments, the present application also provides an optional embodiment. In this optional embodiment, if the abnormal state is a long-time abnormal state, the energy supplement device includes a fuel generator, a first transfer switch, and a bus converter. Correspondingly, the output steps of the first control pulse are refined.

[0084] Referring to Figure 4A the output steps of the first control pulse shown, including:

[0085] S410. Adjust the switch state of the first transfer switch to the on state.

[0086] S420. Obtain the actual three-phase current value output by the fuel generator.

[0087] S430. Determine the first control pulse for the bus converter according to the reference current value and the actual three-phase current value.

[0088] S440. Output the first control pulse to the bus converter so that the bus converter controls the fuel generator to supply power to the multi-source power grid according to the first control pulse.

[0089] In an alternative embodiment, a current difference between a reference current value and an actual three-phase current value may be determined; based on the current difference, a first control pulse for the bus converter is determined. Exemplarily, the first control pulse may be modulated based on CHBPWM (Current Hysteresis Band PWM).

[0090] In an alternative embodiment, the fuel generator is connected to the AC bus through a first switch, and the AC bus is interconnected with the DC bus through a bus converter. Correspondingly, the reference current value may be determined through the following steps: based on the voltage amplitude of the AC bus and the actual active power of the fuel generator, the output current reference weight of the fuel generator is determined; based on the sinusoidal component of the voltage of the AC bus and the output current reference weight, the reference current value is determined.

[0091] Exemplarily, the output current reference weight may be determined through the following formula:

[0092] ;

[0093] where w * dg represents the output current reference weight; P * dg represents the actual active power of the fuel generator; V lpk represents the voltage amplitude of the AC bus.

[0094] where the actual active power P * dg of the fuel generator may be set to 90% of the rated power to obtain the maximum fuel consumption efficiency.

[0095] Exemplarily, the reference current of the fuel generator is a three-phase current, that is, including the phase A current, the phase B current, and the phase C current. For the sake of distinction, the reference current value is represented as the generator reference current value i * da , i * db , i * dc . The following three-phase current or three-phase voltage involved may be represented in this way, and will not be elaborated here. Among them, the generator reference current value i * da , i * db , i * dc may be determined through the following formula:

[0096] ;

[0097] where ula and u lb and u lc represent the sine component of the voltage of the AC bus, and w * dg represents the reference weight of the output current.

[0098] Next, in combination with Figure 4B , the determination process of the first control pulse of the bus converter will be described. At the same time, for the convenience of distinction, the first control pulse of the bus converter is denoted as the first bus control pulse S ILC , and the actual three-phase current value is denoted as i da 、i db 、i dc .

[0099] Referring to Figure 4B , the determination steps of the bus control pulse S ILC may include: determining the generator reference current values i * dg and i la 、i lb 、i lc according to the reference weight w * da 、i * db 、i * dc of the output current of the fuel generator and the sine components u da 、i db 、i dc of the voltage of the AC bus; performing CHBPWM modulation on the actual three-phase current values i * da 、i * db 、i * dc and the reference current values i ILC to obtain the bus control pulse S

[0100] In the above embodiment, by obtaining the actual three-phase current values output by the fuel generator and determining the first control pulse for the bus converter according to the reference current values and the actual three-phase current values, energy supplementation of the multi-source power grid by the fuel generator is achieved under long-term abnormal conditions, further ensuring the power supply demand of the multi-source power grid.

[0101] In an alternative embodiment, the control method of the multi-source power grid further includes: when the grid access state is normal, respectively determining the second control pulses of at least one power electronic device accessing the multi-source power grid; outputting the second control pulses to each power electronic device so that each power electronic device performs current and voltage control for the multi-source power grid according to the second control pulses.

[0102] In some embodiments, when the grid access state is normal, the second control pulse of the bidirectional converter of the energy storage power supply can be determined, and the corresponding second control pulse is output to the bidirectional converter so that the multi-source grid charges the energy storage power supply.

[0103] The following combines Figure 5 , and the determination process of the second control pulse of the bidirectional converter is described. At the same time, for the convenience of distinction, the second control pulse of the bidirectional converter is denoted as the charging control pulse S BDC2 , the reference current value is denoted as the energy storage reference current value I * bdc , the duty cycle is denoted as the charging duty cycle d bdc2 .

[0104] Referring to Figure 5 , the determination steps of the charging control pulse S BDC2 may include: determining the actual DC voltage V of the DC bus dc and the reference DC voltage V * dc ; the PI controller obtains the charging reference current value I by minimizing the voltage deviation * bc ; determining the current deviation between the charging reference current value I * bc and the actual charging current value I of the energy storage power supply bc ; the PI controller obtains the charging duty cycle d by minimizing the current deviation bdc2 ; performing PWM modulation on the charging duty cycle d bdc2 to obtain the charging control pulse S BDC2 .

[0105] In some embodiments, when the grid access state is normal, the second control pulse of the bus converter can be determined, and the corresponding second control pulse is output to the bus converter. For the convenience of distinction, the second control pulse of the bus converter is denoted as the second bus control pulse.

[0106] The following combines Figure 6 , and the determination process of the second bus control pulse is described. Referring to Figure 6 , the determination process of the second bus control pulse may include: adjusting the switch state of the first switch to the off state; determining the reference bus voltage v of the AC bus * la , v * lb , v * lc and the actual bus voltage v of the AC bus la , v lb , vlc The voltage deviation between; the PI controller obtains the reference current value i of the bus converter by minimizing the voltage deviation * lca 、i * lcb 、i * lcc ; The reference current value i of the bus converter * lca 、i * lcb 、i * lcc and the actual three-phase current i of the bus converter lca 、i lcb 、i lcc are modulated by CHBPWM to obtain the second bus control pulse.

[0107] Exemplarily, the reference bus voltage v * pk and the reference frequency f * can be determined to determine the reference bus voltage v * la 、v * lb 、v * lc . Specifically, it can be determined by the following formula:

[0108]

[0109]

[0110]

[0111] where V * pk represents the reference voltage amplitude of the AC bus, and f * represents the reference frequency.

[0112] In some embodiments, as already mentioned above, the stator of the DFIG wind turbine n can be connected to the AC bus through the second transfer switch SSTS n , and the rotor can be connected to the AC bus through the rotor side converter RSC n , the stator side converter SSC n , and the step-up transformer TF n .

[0113] Optionally, in the case where the grid connection state is normal, the stator side converter SSC n and the rotor side converter RSC nThe corresponding second control pulse. For the convenience of distinction, the second control pulse of the stator-side converter SSC n is denoted as the stator-side control pulse S SSCn ; the second control pulse of the rotor-side converter RSC n is denoted as the rotor-side control pulse S RSCn .

[0114] Reference Figure 7 , the determination process of the stator-side control pulse S SSCn may include: filtering the sine components u wan , u wbn , u wcn (shown in a simplified form u wabcn in the figure) of the terminal voltage of the wind turbine and the stator currents i san , i sbn , i scn (shown in a simplified form i sabcn in the figure) of the wind turbine to determine the stator single-phase current weights w san , w sbn , w scn ; taking the average of the phase weights of the stator single-phase current weights to obtain the weight average w savgn ; obtaining the inherent DC capacitor voltage V n between the rotor-side converter RSC n and the stator-side converter SSC * dcn and the actual DC capacitor voltage V dcn ; adjusting the actual DC capacitor voltage V * dcn through a PI controller according to the inherent DC capacitor voltage V dcn to obtain the DC capacitor voltage weight w dcn ; taking the sum of the DC capacitor voltage weight w dcn and the weight average w savgn as the electronic current reference weight w * wn ; taking the product of the electronic current reference weight w * wn and the sine components u wan , u wbn , u wcn of the terminal voltage as the terminal reference currents i * wan , i * wbn , i * wcn ; taking the terminal reference currents i * wan , i * wbn, i * wcn and the actual machine-terminal current i wan , i wbn , i wcn After CHBPWM modulation, the stator-side control pulse S is obtained SSCn .

[0115] Exemplarily, the filter can adopt a logarithmic hyperbolic cosine filter LHCF; the stator single-phase current weight is determined by the following formula:

[0116]

[0117]

[0118] where r represents a certain moment; w s represents the stator single-phase current weight; e s represents the error signal; u w represents the sine component of the machine-terminal voltage; i s represents the stator current.

[0119] Reference Figure 8 , when the second transfer switch SSTS n is in the conducting state, the determination process of the rotor-side control pulse S RSCn can include: according to different wind speeds V w , determining the reference rotor speed ω of the wind turbine n * ; adjusting the actual rotor speed ω n * according to the reference rotor speed ω n to obtain the first quadrature-axis reference current I * rqnc ; determining the first direct-axis reference current I of the wind turbine according to the rotor-side magnetizing current I Rn of the wind turbine * rdnc ; determining the rotor-side current reference values i * rqnc and the first direct-axis reference current I * rdnc ; determining the rotor-side current reference values i ran * , i rbn * , i rcn * ; for the rotor-side current reference values i ran * , i rbn * , i rcn * and the actual rotor-side current value iran 、 i rbn 、 i rcn Perform CHBPWM modulation to obtain the rotor-side control pulse S RSCn .

[0120] Among them, the reference rotor speed ω can be determined by using the maximum power point tracking MPPT or the optimal tip speed ratio n * . The first quadrature-axis reference current I * rqnc and the first direct-axis reference current I * rdnc are subjected to Park transformation to obtain the rotor-side current reference values i ran * 、 i rbn * 、 i rcn * . The rotor-side magnetizing current I can be determined according to the stator voltage amplitude and magnetizing inductance of the wind turbine Rn .

[0121] Reference Figure 9 , when the second transfer switch SSTS n is in the off state, the determination process of the rotor-side control pulse S RSCn can include: determining the amplitude difference between the stator voltage amplitude V spkn of the wind turbine and the terminal voltage amplitude V wpkn ; the PI controller determines the second direct-axis reference current I * rdnd by minimizing the amplitude difference; determining the phase angle difference between the stator voltage phase angle θ stn of the wind turbine and the terminal voltage phase angle θ wn ; the PI controller determines the second quadrature-axis reference current I * rqnd by minimizing the phase angle difference; according to the second quadrature-axis reference current I * rqnd and the second direct-axis reference current I * rdnd , determine the rotor-side current reference values i ran * 、 i rbn * 、 i rcn * ; for the rotor-side current reference values i ran * 、 i rbn * 、 i rcn * and the actual rotor-side current values i ran 、 i rbn, i rcn Perform CHBPWM modulation to obtain the rotor-side control pulse S RSCn .

[0122] Among them, the second quadrature-axis reference current I * rqnd and the second direct-axis reference current I * rdnd can be subjected to Park transformation to obtain the rotor-side current reference values i ran * , i rbn * , i rcn * .

[0123] In some embodiments, the external AC power grid can be connected to the DC bus through the grid-side converter GSC. When the grid connection state is normal, the second control pulse corresponding to the grid-side converter GSC can be determined. For the sake of distinction, the second control pulse of the grid-side converter GSC is denoted as the grid-side control pulse S GSC .

[0124] Reference Figure 10 , the determination process of the grid-side control pulse S GSC can include: obtaining the active reference weight w * gA and the reactive reference weight w * gR of the injected current of the external AC power grid; determining the first grid reference current values i gpa , u gpb , u gpc and the active reference weight w * gA ; determining the second grid reference current values i * gaA , i * gbA , i * gcA ; according to the voltage in-phase sine components u gqa , u gqb , u gqc and the reactive reference weight w * gR ; determining the grid reference current values i * gaR , i * gbR , i * gcR ; according to the first grid reference current values and the second grid reference current values, determining the grid reference current values i * ga , i* gb and i * gc ; For the grid reference current value i * ga and i * gb and i * gc and the actual three-phase current values i of the external AC grid ga and i gb and i gc are subjected to CHBPWM modulation to obtain the grid-side control pulse S GSC .

[0125] Exemplarily, the grid reference current values i * ga and i * gb and i * gc can be determined by the following formula:

[0126]

[0127]

[0128] .

[0129] Exemplarily, the active reference weight w * gA and the reactive reference weight w * gR can be determined by the following formula:

[0130]

[0131]

[0132] where V gpk represents the voltage amplitude of the external AC grid; P * g represents the preset active power; Q * g represents the preset reactive power.

[0133] In some embodiments, the photovoltaic array can be connected to the DC bus through a boost converter BTC m . In the case where the grid access state is normal, the second control pulse corresponding to the boost converter BTC m can be determined. For the sake of distinction, the second control pulse corresponding to the boost converter BTC m is denoted as the boost control pulse S BTCm .

[0134] Reference Figure 11 , the boost control pulse S BTCm The determination process may include: according to the actual photovoltaic voltage V of the photovoltaic array pvn and the actual photovoltaic current I pvn , determine the reference photovoltaic voltage V refn ; the proportional difference between the reference photovoltaic voltage V refn and the actual DC voltage V of the DC bus dc is used as the duty cycle d m of the boost converter BTC btcn ; perform PWM modulation on the duty cycle d m of the boost converter BTC btcn to obtain the boost control pulse S BTCm , thus ensuring that the photovoltaic array is in the full-power generation state. Among them, the reference photovoltaic voltage V can be determined by the maximum power point tracking method MPPT refn .

[0135] In some embodiments, the low-voltage DC load can be connected to the DC bus through a buck converter BKC. When the grid access state is normal, the second control pulse corresponding to the buck converter BKC can be determined. For the sake of distinction, the second control pulse corresponding to the buck converter BKC is denoted as the buck control pulse S BKC .

[0136] Reference Figure 12 , the buck control pulse S BKC The determination process may include: minimizing the voltage deviation between the actual voltage V olv at the low-voltage DC load terminal and the reference voltage V * olv at the low-voltage DC load terminal through a PI controller, so as to determine the duty cycle d bkc of the buck converter BKC bkc ; perform PWM modulation on the duty cycle d BKC of the buck converter BKC to obtain the buck control pulse S

[0137] In an exemplary embodiment, as Figure 13 shown, a control method for a multi-source power grid is also provided, including:

[0138] S1301. Obtain the grid access state between the external AC power grid and the multi-source power grid.

[0139] S1302. When the grid access state is normal, respectively determine the second control pulses of at least one power electronic device connected to the multi-source power grid;

[0140] S1303. Output a second control pulse to each power electronic device so that each power electronic device performs current and voltage control for the multi-source power grid according to the second control pulse.

[0141] S1304. When the grid access state is an abnormal state, determine a reference current value that meets the load demand of the multi-source power grid.

[0142] S1305. If the abnormal state is a short-term abnormal state, obtain the duty cycle corresponding to the bidirectional converter according to the reference current value.

[0143] S1306. Determine a first control pulse for the bidirectional converter according to the duty cycle.

[0144] S1307. Output the first control pulse to the bidirectional converter so that the bidirectional converter controls the energy storage power supply to output current to the multi-source power grid according to the first control pulse.

[0145] S1308. If the abnormal state is a long-term abnormal state, adjust the switch state of the first transfer switch to the on state.

[0146] S1309. Obtain the actual three-phase current value output by the fuel generator.

[0147] S1310. Determine a first control pulse for the bus converter according to the reference current value and the actual three-phase current value.

[0148] S1311. Output the first control pulse to the bus converter so that the bus converter controls the fuel generator to supply power to the multi-source power grid according to the first control pulse.

[0149] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are sequentially shown according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same moment, but can be executed at different moments. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0150] Based on the same inventive concept, an embodiment of the present application further provides a control method device for a multi-source power grid for implementing the control method of the multi-source power grid involved above. The solution provided by this device for solving problems is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the control device for the multi-source power grid provided below can refer to the limitations on the control method of the multi-source power grid in the above text, and will not be repeated here.

[0151] In an exemplary embodiment, as Figure 14 shown, a control device for a multi-source power grid is provided, including: an acquisition module 1410, a first determination module 1420, and a first output module 1430, where:

[0152] The acquisition module 1410 is configured to acquire the grid access status between an external AC power grid and the multi-source power grid;

[0153] The first determination module 1420 is configured to determine a reference current value that meets the load demand of the multi-source power grid when the grid access status is an abnormal state;

[0154] The first output module 1430 is configured to output a first control pulse to an energy replenishment device connected to the multi-source power grid according to the reference current value, so that the energy replenishment device replenishes energy to the multi-source power grid according to the first control pulse.

[0155] In an embodiment, if the abnormal state is a short-term abnormal state, the energy replenishment device includes an energy storage power supply and a bidirectional converter; the first output module 1430 includes: a first acquisition unit, configured to acquire the duty cycle corresponding to the bidirectional converter according to the reference current value; a first determination unit, configured to determine a first control pulse for the bidirectional converter according to the duty cycle; and a first output unit, configured to output the first control pulse to the bidirectional converter, so that the bidirectional converter controls the energy storage power supply to output current to the multi-source power grid according to the first control pulse.

[0156] In an embodiment, the acquisition unit includes: a first determination subunit, configured to determine the minimum current error between the reference current value and the actual output current of the energy storage power supply according to the current value output range of the energy storage power supply; and a second determination subunit, configured to determine the duty cycle corresponding to the bidirectional converter according to the minimum current error.

[0157] In one embodiment, if the abnormal state is a long-term abnormal state, the energy replenishment device includes a fuel generator, a first transfer switch, and a bus converter; the first output module 1430 includes: an adjustment unit configured to adjust the switch state of the first transfer switch to the on state; a second acquisition unit configured to acquire the actual three-phase current value output by the fuel generator; a second determination unit configured to determine a first control pulse for the bus converter according to a reference current value and the actual three-phase current value; and a second output unit configured to output the first control pulse to the bus converter, so that the bus converter controls the fuel generator to supply power to the multi-source power grid according to the first control pulse.

[0158] In one embodiment, the second determination unit includes: a third determination subunit configured to determine a current difference between the reference current value and the actual three-phase current value; and a fourth determination subunit configured to determine a first control pulse for the bus converter according to the current difference.

[0159] In one embodiment, it further includes: a second determination module configured to respectively determine second control pulses for at least one power electronic device connected to the multi-source power grid when the grid access state is normal; and a second output module configured to output the second control pulses to each power electronic device, so that each power electronic device performs current and voltage control for the multi-source power grid according to the second control pulses.

[0160] Each module in the above control device for the multi-source power grid can be implemented in whole or in part by software, hardware, and their combination. The above-mentioned modules can be embedded in or independent of a processor in a computer device in the form of hardware, or stored in a memory in a computer device in the form of software, so as to facilitate the processor to call and execute the operations corresponding to the above-mentioned modules.

[0161] In an exemplary embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as Figure 15As shown in the figure. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit, and an input device. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface, the display unit, and the input device are connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, near field communication (NFC), or other technologies. When the computer program is executed by the processor, it implements a control method for a multi-source power grid. The display unit of the computer device is used to form a visually visible picture, which can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer covering the display screen, or a button, a trackball, or a touchpad provided on the computer device housing, or an external keyboard, touchpad, or mouse, etc.

[0162] Those skilled in the art can understand that Figure 15 the structure shown in the figure is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0163] In one embodiment, a computer device is further provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, the steps in the above method embodiments are implemented.

[0164] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by the processor, the steps in the above method embodiments are implemented.

[0165] In one embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by the processor, the steps in the above method embodiments are implemented.

[0166] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in the present application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in the present application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logic devices, data processing logics based on quantum computing, artificial intelligence (AI) processors, etc., without limitation.

[0167] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in the present application.

[0168] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A control method for a multi-source power grid, characterized in that: The method comprises: Obtaining the grid access status between the external AC grid and the multi-source grid; When the grid access state is an abnormal state, determining a reference current value that meets the load demand of the multi-source grid; According to the reference current value, a first control pulse is output to an energy replenishment device connected to the multi-source power grid, so that the energy replenishment device replenishes energy to the multi-source power grid according to the first control pulse.

2. The method according to claim 1, characterized in that: If the abnormal state is a short-term abnormal state, the energy replenishment device includes an energy storage power supply and a bidirectional converter; Correspondingly, the outputting a first control pulse to the energy compensation device connected to the multi-source power grid according to the reference current value includes: According to the reference current value, obtaining a duty cycle corresponding to the bidirectional converter; Determining a first control pulse for the bidirectional converter according to the duty cycle; A first control pulse is output to the bidirectional converter, so that the bidirectional converter controls the energy storage power source to output current to the multi-source power grid according to the first control pulse.

3. The method according to claim 2, characterized in that The step of obtaining a duty cycle corresponding to the bidirectional converter according to the reference current value includes: Determining a minimum current error between the reference current value and an actual output current of the energy storage power supply according to the current value output interval of the energy storage power supply; A duty cycle corresponding to the bidirectional converter is determined according to the minimum current error.

4. The method according to claim 1, characterized in that: If the abnormal state is a long-term abnormal state, the energy replenishment equipment includes a fuel generator, a first conversion switch and a bus converter; Correspondingly, the outputting a first control pulse to the energy compensation device connected to the multi-source power grid according to the reference current value includes: Adjusting the switch state of the first conversion switch to an on state; Obtaining actual three-phase current values ​​output by the fuel generator; Determining a first control pulse for the bus converter according to the reference current value and the actual three-phase current value; A first control pulse is output to the bus converter, so that the bus converter controls the fuel generator to supply power to the multi-source power grid according to the first control pulse.

5. The method according to claim 4, characterized in that The step of determining a first control pulse for the bus converter according to the reference current value and the actual three-phase current value comprises: Determining a current difference between the reference current value and the actual three-phase current value; A first control pulse for the bus converter is determined according to the current difference.

6. The method according to any one of claims 1 to 5, characterized in that The method further comprises: When the grid access state is a normal state, respectively determining a second control pulse of at least one power electronic device connected to the multi-source grid; A second control pulse is output to each of the power electronic devices, so that each of the power electronic devices performs current and voltage control on the multi-source power grid according to the second control pulse.

7. A control device for a multi-source power grid, characterized in that: The device comprises: An acquisition module, used to acquire the grid access status between the external AC grid and the multi-source grid; A determination module, configured to determine a reference current value that satisfies the load demand of the multi-source power grid when the power grid access state is an abnormal state; The output module is used to output a first control pulse to an energy replenishment device connected to the multi-source power grid according to the reference current value, so that the energy replenishment device replenishes energy to the multi-source power grid according to the first control pulse.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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