A control method for a dual-channel power supply system integrating storage and generation

Abstract

The present invention discloses a storage-generation integrated dual-channel power supply system and a control method thereof. The system comprises a dual-winding generator, an energy storage device, an energy storage converter, a static excitation converter and a transformer. In a light load scenario, the energy storage device outputs electric energy to supply power to a distribution station area. When the amount of the energy storage device is lower than a preset value, the control winding supplies power to the distribution station area, and the control winding charges the energy storage device at the same time. Alternatively, the energy storage converter controls the energy storage device to output electric energy, which is boosted by a transformer to supply power to a distribution network. When the amount of the energy storage device is lower than a preset value, the power winding supplies power to the distribution network, and the control winding charges the energy storage device. In a medium load scenario, the control winding supplies power to the distribution station area alone, or the power winding supplies power to the distribution network alone. In a heavy load scenario, the energy storage device and the control winding supply power to the distribution station area at the same time, or the energy storage device and the power winding supply power to the distribution network at the same time. This solution can meet the requirements of non-stop operations in a variety of application scenarios.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply control, and in particular to a control method for a storage-generation integrated dual-channel power supply system. Background Art

[0002] With the continuous rise and development of high-end manufacturing, the electricity demand of high-tech enterprises is also increasing. High-quality non-stop operations are of great significance to enterprises with high power supply quality requirements. In order to improve the reliability of power supply, the demand for non-stop operations in distribution networks has increased significantly. Due to the limited number of live-line operators, non-stop operations are mainly supported by using emergency power supply vehicles. Emergency power supply vehicles mainly include diesel generators and energy storage generators. For example, patent text CN115987153A discloses a control method and device for a diesel engine-energy storage combined power generation system. In the diesel engine-energy storage combined power generation system, the diesel engine is connected to the rotor of the dual-winding generator through a rotating shaft, the energy storage is connected to the control winding of the dual-winding generator, and the power winding of the dual-winding generator is connected to the grid side. The control method includes: using the first control loop to control the rotor speed of the dual-winding motor driven by the diesel engine, and then controlling the output frequency through the power winding of the dual-winding generator; using the second control loop to control the energy storage output, and then indirectly controlling the output frequency of the power winding of the dual-winding generator through the control winding connected to the energy storage; the two frequency control loops are coupled to the output AC frequency of the power winding of the dual-winding generator through the magnetic field of the dual-winding generator. Patent text CN116365694A discloses a diesel generator vehicle based on a dual-stator winding motor, including: a battery module, a controller, a diesel engine, a clutch, and a dual-stator winding motor. The battery module is electrically connected to the DC bus side of the controller, the controller is electrically connected to the motor control winding, the diesel engine is mechanically connected to one end of the clutch through a shaft, the other end of the clutch is mechanically connected to the motor rotor through a shaft, the motor power winding is connected to the generator incoming switch, the generator incoming switch is respectively connected to the load side outgoing switch and the grid side outgoing switch, the load side outgoing switch is connected to the load side interface, and the grid side outgoing switch is connected to the grid side interface; based on the coupling characteristics of the power winding and the control winding, the controller realizes the isolated charging and discharging of the battery module by the grid by controlling the operating frequency of the diesel engine.

[0003] Traditional diesel generators have the disadvantages of fixed power generation voltage and low efficiency in low-load operation scenarios, while energy storage vehicles have short power supply duration and cannot support long-term operation. The method disclosed in the above patent text can only be applied to low-load operation scenarios and cannot meet actual needs. Summary of the invention

[0004] The present invention provides a control method for a storage-generation integrated dual-channel power supply system, which can meet the needs of non-stop operations in various application scenarios.

[0005] A storage-generation integrated dual-channel power supply system, comprising a dual-winding generator, an energy storage device, an energy storage converter, a static excitation converter and a transformer, wherein the dual-winding generator comprises a control winding and a power winding, wherein the control winding is connected to the static excitation converter and a distribution network, wherein the power winding is connected to a distribution network through the transformer, wherein the energy storage device is connected in parallel with the control winding and the power winding through the energy storage converter, and wherein the energy storage device is also connected to a DC side of the static excitation converter;

[0006] In a small load scenario, the energy storage converter is used to control the energy storage device to output electric energy to supply power to the distribution station area. When the power of the energy storage device is lower than a preset value, the static excitation converter is used to control the control winding to supply power to the distribution station area, and the energy storage converter controls the control winding to charge the energy storage device; or, the energy storage converter is used to control the energy storage device to output electric energy, and supply power to the distribution network after being stepped up by the transformer. When the power of the energy storage device is lower than a preset value, the static excitation converter controls the power winding to supply power to the distribution network, and the energy storage converter controls the control winding to charge the energy storage device;

[0007] In a medium load scenario, the static excitation converter is used to control the control winding to supply power to the distribution network alone or to control the power winding to supply power to the distribution network alone;

[0008] In a heavy load scenario, the energy storage converter and the static excitation converter are used to control the energy storage device and the control winding to simultaneously power the distribution station area, or to control the energy storage device and the power winding to simultaneously power the distribution network.

[0009] Furthermore, the energy storage device is connected to the DC side of the static excitation converter through a diode.

[0010] Furthermore, the voltage level of the distribution station area is 400V, the voltage level of the distribution network is 10KV, and the voltage levels output by the control winding and the power winding are the same.

[0011] A storage-generation integrated dual-channel power supply control method applied to the above system comprises:

[0012] In a small load scenario, the energy storage converter controls the energy storage device to output electric energy to supply power to the distribution station area. When the power of the energy storage device is lower than a preset value, the static excitation converter controls the control winding to supply power to the distribution station area, and at the same time, the energy storage converter controls the control winding to charge the energy storage device; or, the energy storage converter controls the energy storage device to output electric energy, which is boosted by the transformer to supply power to the distribution network. When the power of the energy storage device is lower than a preset value, the static excitation converter controls the power winding to supply power to the distribution network, and at the same time, the energy storage converter controls the control winding to charge the energy storage device;

[0013] In a medium load scenario, the static excitation converter controls the control winding to supply power to the distribution network area alone or controls the power winding to supply power to the distribution network alone;

[0014] In a heavy load scenario, the energy storage converter and the static excitation converter respectively control the energy storage device and the control winding to simultaneously power the distribution station area, or control the energy storage device and the power winding of the dual-winding generator to simultaneously power the distribution network.

[0015] Furthermore, in a light load scenario, the energy storage converter controls the energy storage device to output electric energy, including:

[0016] Collect three-phase voltage at the common connection point;

[0017] Performing a dq transformation on the three-phase voltage at the common connection point to obtain a d-axis voltage component and a q-axis voltage component at the connection point;

[0018] Subtract the connection point d-axis voltage component and the connection point q-axis voltage component from the d-axis component given value and the q-axis component given value respectively to obtain the connection point d-axis voltage deviation and the connection point q-axis voltage deviation;

[0019] The d-axis voltage deviation and the q-axis voltage deviation of the connection point are calculated by a PI controller to obtain a given value of the d-axis current component and a given value of the q-axis current component of the connection point;

[0020] Collect the output side current of the energy storage converter and perform dq transformation to obtain the output side d-axis current component and the output side q-axis current component;

[0021] According to the given value of the d-axis current component at the connection point, the given value of the q-axis current component at the connection point, the d-axis current component at the output side, and the q-axis current component at the output side, a d-axis reference voltage component and a q-axis voltage reference component are calculated based on a PI controller;

[0022] A power supply control signal is generated according to the d-axis reference voltage component and the q-axis voltage reference component, and the energy storage converter controls the energy storage device to output electric energy according to the power supply control signal.

[0023] Furthermore, in a small load scenario, a medium load scenario, and a large load scenario, the static excitation converter controls the control winding to supply power to the distribution station area, including:

[0024] Collect the three-phase voltage on the output side of the control winding;

[0025] Performing dq transformation on the output side three-phase voltage of the control winding to obtain a d-axis voltage component of the control winding and a q-axis voltage component of the control winding;

[0026] Subtracting the control winding d-axis voltage component and the control winding q-axis voltage component from the distribution station area voltage and the starting power supply side voltage respectively to obtain the control winding d-axis voltage deviation and the control winding q-axis voltage deviation;

[0027] Calculating the control winding d-axis voltage deviation and the control winding q-axis voltage deviation by a PI controller to obtain a control winding d-axis current component given value and a control winding q-axis current component given value;

[0028] According to the given value of the d-axis current component of the control winding and the given value of the q-axis current component of the control winding, a PI controller is used to calculate and obtain a reference value of the control winding voltage;

[0029] A control winding drive signal is generated according to the control winding voltage reference value, and the static excitation converter controls the control winding to supply power to the power distribution station section according to the control winding drive signal.

[0030] Furthermore, in a small load scenario, a medium load scenario, and a large load scenario, the static excitation converter controls the power winding to supply power to the distribution network, including:

[0031] Collect the three-phase voltage on the output side of the power winding;

[0032] Performing dq transformation on the output side three-phase voltage of the power winding to obtain a d-axis voltage component of the power winding and a q-axis voltage component of the power winding;

[0033] Subtracting the power winding d-axis voltage component and the power winding q-axis voltage component from the power distribution network voltage and the starting power supply side voltage respectively to obtain the power winding d-axis voltage deviation and the power winding q-axis voltage deviation;

[0034] Calculating the power winding d-axis voltage deviation and the power winding q-axis voltage deviation through a PI controller to obtain a power winding d-axis current component given value and a power winding q-axis current component given value;

[0035] According to the given value of the power winding d-axis current component and the given value of the power winding q-axis current component, a PI controller is used to calculate and obtain a power winding voltage reference value;

[0036] A power winding drive signal is generated according to the power winding voltage reference value, and the static excitation converter controls the power winding to supply power to the power distribution network according to the power winding drive signal.

[0037] Furthermore, the energy storage converter controls the control winding to charge the energy storage device, including:

[0038] The given value of the q-axis current component of the control winding is set to 0, and the given value of the d-axis current component of the control winding is set to the charging current;

[0039] Calculate the initial value of the charging current according to the current discharge capacity and discharge constant of the energy storage device;

[0040] Calculate the charging current according to the initial value of the charging current, the current charge of the energy storage device, the maximum charge of the energy storage device, and the charging current acceptance ratio;

[0041] A charging control signal is generated according to the charging current, and the energy storage converter controls the control winding to charge the energy storage device according to the charging control signal.

[0042] Furthermore, the initial value of the charging current is calculated by the following formula:

[0043] ;

[0044] Among them, I0 represents the initial value of charging current, K represents the discharge constant, and C represents the discharge capacity of the energy storage device;

[0045] The charging current is calculated by the following formula:

[0046] ;

[0047] in, represents the charging current, α represents the charging current acceptance ratio, t represents the charging time, SOC represents the current charge of the energy storage device, SOC M Indicates the maximum charge of the energy storage device.

[0048] Furthermore, in a heavy load scenario, the energy storage current device controls the energy storage device to supply power to the distribution station area or the distribution network, including:

[0049] Collect load active power and load reactive power;

[0050] Collecting the active power and reactive power of the generator output by the control winding or the power winding;

[0051] Subtract the load active power from the generator active power, and the load reactive power from the generator reactive power to obtain a power compensation value;

[0052] According to the power compensation value, a PI controller is used to calculate and obtain a d-axis current component and a q-axis current component;

[0053] A power supply drive signal is generated according to the d-axis current component and the q-axis current component, and the energy storage current device controls the energy storage device to supply power to the distribution station area or the distribution network according to the power supply drive signal.

[0054] The control method of the storage-generation integrated dual-channel power supply system provided by the present invention has at least the following beneficial effects:

[0055] (1) The integrated power supply architecture makes up for the shortcomings of traditional generators in low efficiency and high power generation cost in low-load operation scenarios. At the same time, the energy storage battery can also play the role of a range-extending generator, and cooperate with the dual-winding generator to realize power supply in various scenarios and different voltage levels, meeting the needs of non-stop operation;

[0056] (2) The solution can support 400V and 10kV power generation operations, solving the problem of the single operation scenario of traditional diesel generators;

[0057] (3) Based on the coordinated control of the energy storage converter and the static excitation converter, the energy storage battery and the dual-winding generator can be connected in parallel to achieve flexible power distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 A schematic structural diagram of an embodiment of the storage-generation integrated dual-channel power supply system provided by the present invention.

[0059] Figure 2 A flowchart of an embodiment of the storage-generation integrated dual-channel power supply control method provided by the present invention.

[0060] Figure 3 A control schematic diagram of an embodiment of an energy storage converter in a 400V distribution station area scenario in the storage-generation integrated dual-channel power supply system provided by the present invention.

[0061] Figure 4 A control schematic diagram of an embodiment of a double-winding generator in a 400V distribution station area scenario in the storage-generation integrated dual-channel power supply system provided by the present invention.

[0062] Figure 5 A control schematic diagram of an embodiment of an energy storage converter in a 10KV distribution network scenario in the storage-generation integrated dual-channel power supply system provided by the present invention.

[0063] Figure 6A control schematic diagram of an embodiment of a double-winding generator in a 10KV distribution network scenario in the storage-generation integrated dual-channel power supply system provided by the present invention. DETAILED DESCRIPTION

[0064] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0065] refer to Figure 1 In some embodiments, a storage-generation integrated dual-channel power supply system is provided, comprising a dual-winding generator 1, an energy storage device 2, an energy storage converter 3, a static excitation converter 4 and a transformer 5, wherein the dual-winding generator 1 comprises a control winding and a power winding, the control winding is connected to the static excitation converter and the distribution network, the power winding is connected to the distribution network through the transformer 5, the energy storage device 2 is connected in parallel with the control winding and the power winding through the energy storage converter 3, and the energy storage device 2 is also connected to the DC side of the static excitation converter 4;

[0066] In a small load scenario, the energy storage converter 3 is used to control the energy storage device 2 to output electric energy to supply power to the distribution station area. When the power of the energy storage device 2 is lower than a preset value, the static excitation converter 4 is used to control the control winding to supply power to the distribution station area, and at the same time, the energy storage converter 3 controls the control winding to charge the energy storage device 2; or, the energy storage converter 3 is used to control the energy storage device 2 to output electric energy, and after being stepped up by the transformer 5, it supplies power to the distribution network. When the power of the energy storage device 2 is lower than a preset value, the static excitation converter 4 controls the power winding to supply power to the distribution network, and at the same time, the energy storage converter 3 controls the control winding to charge the energy storage device;

[0067] In the medium load scenario, the static excitation converter 4 is used to control the control winding to supply power to the distribution network area alone or to control the power winding to supply power to the distribution network alone;

[0068] In a heavy load scenario, the energy storage converter 3 and the static excitation converter 4 are used to control the energy storage device 2 and the control winding to simultaneously supply power to the distribution network area, or to control the energy storage device 2 and the power winding to simultaneously supply power to the distribution network.

[0069] Among them, the large load scenario, medium load scenario and small load scenario are determined relative to the rated power of the energy storage device and the dual-winding generator. The rated power of the dual-winding generator is greater than the rated power of the energy storage device. If the load power is less than 50% of the rated power of the dual-winding generator, it is a small load scenario. If the load power is between 50% and 100% of the rated power of the dual-winding generator, it is a medium load scenario. If the load power is greater than the rated power of the dual-winding generator and less than the sum of the rated powers of the dual-winding generator and the energy storage device, it is a large load scenario. For example, the rated power of the energy storage device is 500kW, and the rated power of the dual-winding generator is 1000kW. The small load scenario is less than 50% of the rated power of the dual-winding generator, that is, the load power is 0-500kW. The medium load scenario is the load power between 50% and 100% of the rated power of the dual-winding generator, that is, the load power is 500kW-1000kW. The high-power scenario is greater than the rated power of the dual-winding generator and less than the sum of the rated powers of the dual-winding generator and the energy storage device, that is, the load power is 1000kW-1500kW.

[0070] In some embodiments, the energy storage device 2 is connected to the DC side of the static excitation converter through a diode.

[0071] In some embodiments, the voltage level of the distribution station area is 400V, the voltage level of the distribution network is 10KV, and the voltage levels output by the control winding and the power winding are the same.

[0072] refer to Figure 1 and Figure 2 In some embodiments, a storage-generation integrated dual-channel power supply control method using the above system is provided, comprising:

[0073] S1. In a small load scenario, the energy storage converter 3 controls the energy storage device 2 to output electric energy to supply power to the distribution station area. When the power of the energy storage device 2 is lower than a preset value, the static excitation converter 4 controls the control winding to supply power to the distribution station area, and at the same time, the energy storage converter 3 controls the control winding to charge the energy storage device 2; or, the energy storage converter 3 controls the energy storage device 2 to output electric energy, which is boosted by the transformer 5 to supply power to the distribution network. When the power of the energy storage device 2 is lower than a preset value, the static excitation converter 4 controls the power winding to supply power to the distribution network, and at the same time, the energy storage converter 3 controls the control winding to charge the energy storage device 2;

[0074] S2. In a medium load scenario, the static excitation converter 4 controls the control winding to supply power to the distribution network area alone or controls the power winding to supply power to the distribution network alone;

[0075] S3. In a heavy load scenario, the energy storage converter 3 and the static excitation converter 4 respectively control the energy storage device 2 and the control winding to simultaneously supply power to the distribution station area, or control the energy storage device 2 and the power winding of the dual-winding generator 1 to simultaneously supply power to the distribution network.

[0076] The following is an explanation of the 400V distribution area power supply and the 10KV distribution network power supply.

[0077] For the small load scenario of the 400V distribution station area, the energy storage device 2 is first powered separately to provide voltage and frequency support for the distribution station area. The control method used at this time is as follows: Figure 3 As shown in part A of the figure, the outer loop is the voltage loop, which collects the three-phase voltage U of the common connection point PCC. pcc , the three-phase voltage U pcc Perform dq transformation to obtain the d-axis voltage component U of the connection point pcc_d and the q-axis voltage component U at the connection point pcc_q , and use it as feedback to make a difference between the d-axis component set value and the q-axis component set value, where the d-axis component set value is the grid voltage target value U ref1 , the q-axis component given value is 0, the d-axis voltage deviation and the q-axis voltage deviation of the connection point are calculated, and the d-axis current component given value I of the connection point is obtained by calculating the d-axis voltage deviation and the q-axis voltage deviation of the connection point through the PI controller. ref_d1 and the connection point q-axis current component given value I ref_q1 , the calculation formula is as follows:

[0078] ; (1)

[0079] Among them, I ref_d1 is the given value of the d-axis current component of the connection point, I ref_q1 is the given value of the q-axis current component of the connection point, K p1 , K p2 , K s1 , K s2 is the parameter of PI controller, U ref1 is the target value of grid voltage, U pcc_d is the d-axis voltage component of the connection point, U pcc_q is the q-axis voltage component of the connection point, s is the Laplace operator.

[0080] Furthermore, the output current of the energy storage converter is collected and dq transformed to obtain the output d-axis current component I L_d and the output side q-axis current component I L_q , according to the given value I of the d-axis current component of the connection point ref_d1 , connection point q-axis current component given value I ref_q1, output side d-axis current component I L_d and the output side q-axis current component I L_q , based on the PI controller, the d-axis reference voltage component U is calculated d and the q-axis voltage reference component U q , the calculation formula is as follows:

[0081] ; (2)

[0082] Among them, U d Represents the d-axis reference voltage component, U q Represents the q-axis voltage reference component, K p3 , K p4 , K s3 , K s4 is the parameter of the PI controller, I ref_d1 is the given value of the d-axis current component of the connection point, I ref_q1 is the given value of the q-axis current component of the connection point, I L_d is the d-axis current component on the output side, I L_q is the q-axis current component on the output side.

[0083] Further, according to the d-axis reference voltage component U d and the q-axis voltage reference component U q A power supply control signal is generated, and the energy storage converter 3 controls the energy storage device 2 to output electric energy according to the power supply control signal to supply power to the distribution station area.

[0084] Furthermore, when the power of the energy storage device 2 is lower than the preset value, the control winding of the dual-winding generator 1 is switched to supply power to the distribution station area alone and charge the energy storage device 2. At this time, the dual-winding generator 1 provides voltage and frequency support. The control method is as follows: Figure 4 As shown, the instantaneous reactive power control method is adopted, the outer loop is the voltage loop, and the three-phase voltage u on the output side of the control winding is collected. c_abc , the three-phase voltage u on the output side c_abc Perform dq transformation to obtain the d-axis voltage component U of the control winding cd and the control winding q-axis voltage component U cq , the distribution station area voltage U p As the d-axis voltage given, the starting power supply side voltage U dc As the q-axis voltage given, the d-axis voltage component U of the control winding is cd and the control winding q-axis voltage component U cq Respectively with the distribution station area voltage U p And starting power supply side voltage U dcThe d-axis voltage deviation and the q-axis voltage deviation of the control winding are obtained by performing a difference, and the d-axis voltage deviation and the q-axis voltage deviation of the control winding are calculated by a PI controller to obtain a given value I of the d-axis current component of the control winding. ref_cd1 and the given value I of the q-axis current component of the control winding ref_cq1 , the calculation formula is as follows:

[0085] ; (3)

[0086] Among them, I ref_cd1 is the given value of the d-axis current component of the control winding, I ref_cq1 K is the given value of the q-axis current component of the control winding, p7 , K p8 , K s7 , K s8 is the parameter of PI controller, U p is the distribution station area voltage, U dc is the starting power supply voltage, U cd To control the winding d-axis voltage component, U cq is the q-axis voltage component of the control winding.

[0087] The inner loop is a current loop, which also uses a PI controller to calculate a control winding voltage reference value; a control winding drive signal is generated according to the control winding voltage reference value, and a static excitation converter controls the control winding to supply power to the distribution station area according to the control winding drive signal.

[0088] At this time, the energy storage device 2 switches to the charging state, and the control structure switches to the single current loop control. The control structure is as follows: Figure 3 As shown in part C of the figure, the given value of the q-axis current component of the control winding is set to 0, and the given value of the d-axis current component of the control winding is set to the charging current; first, the initial value of the charging current is calculated according to the discharge capacity and discharge constant of the energy storage device:

[0089] ; (4)

[0090] Among them, I0 represents the initial value of charging current, K represents the discharge constant, and C represents the discharge capacity of the energy storage device;

[0091] Furthermore, the charging current is calculated according to the initial value of the charging current, the current charge of the energy storage device, the maximum charge of the energy storage device and the charging current acceptance ratio:

[0092] ; (5)

[0093] in, represents the charging current, α represents the charging current acceptance ratio, t represents the charging time, SOC represents the current charge of the energy storage device, SOCM Indicates the maximum charge of the energy storage device.

[0094] Furthermore, a charging control signal is generated according to the charging current, and the energy storage converter 3 controls the control winding to charge the energy storage device 2 according to the charging control signal.

[0095] In some embodiments, in order to shorten the charging time and maximize the service life of the battery in the energy storage device, multi-stage constant current charging is adopted, and the charging current value is set to change every time the SOC increases by 20%.

[0096] For the medium load scenario of the 400V distribution station area, the static excitation converter 4 controls the control winding to supply power to the distribution station area alone. At this time, the control structure is as follows: Figure 4 As shown, the instantaneous reactive power control method is adopted, the outer loop is the voltage loop, and the three-phase voltage u on the output side of the control winding is collected. c_abc , the three-phase voltage u on the output side c_abc Perform dq transformation to obtain the d-axis voltage component U of the control winding cd and the control winding q-axis voltage component U cq , the distribution station area voltage U p As the d-axis voltage given, the starting power supply side voltage U dc As the q-axis voltage given, the d-axis voltage component U of the control winding is cd and the control winding q-axis voltage component U cq Respectively with the distribution station area voltage U p And starting power supply side voltage U dc The d-axis voltage deviation and the q-axis voltage deviation of the control winding are obtained by performing a difference, and the d-axis voltage deviation and the q-axis voltage deviation of the control winding are calculated by a PI controller to obtain a given value I of the d-axis current component of the control winding. ref_cd1 and the given value I of the q-axis current component of the control winding ref_cq1 , the calculation formula is as follows:

[0097] ; (3)

[0098] Among them, I ref_cd1 is the given value of the d-axis current component of the control winding, I ref_cq1 K is the given value of the q-axis current component of the control winding, p7 , K p8 , K s7 , K s8 is the parameter of PI controller, U p is the distribution station area voltage, U dc is the starting power supply voltage, U cd To control the winding d-axis voltage component, U cqis the q-axis voltage component of the control winding.

[0099] The inner loop is a current loop, which also uses a PI controller to calculate a control winding voltage reference value; a control winding drive signal is generated according to the control winding voltage reference value, and a static excitation converter controls the control winding to supply power to the distribution station area according to the control winding drive signal.

[0100] Furthermore, in the case of a large load in a 400V distribution station area, the load has exceeded the maximum output power of the dual-winding generator 1, and the energy storage device needs to be coordinated with the dual-winding generator for power supply. At this time, the dual-winding generator 1 provides voltage and frequency support, and the control structure is as follows: Figure 4 As shown, the instantaneous reactive power control method is adopted, the outer loop is the voltage loop, and the three-phase voltage u on the output side of the control winding is collected. c_abc , the three-phase voltage u on the output side c_abc Perform dq transformation to obtain the d-axis voltage component U of the control winding cd and the control winding q-axis voltage component U cq , the distribution station area voltage U p As the d-axis voltage given, the starting power supply side voltage U dc As the q-axis voltage given, the d-axis voltage component U of the control winding is cd and the control winding q-axis voltage component U cq Respectively with the distribution station area voltage U p And starting power supply side voltage U dc The d-axis voltage deviation and the q-axis voltage deviation of the control winding are obtained by performing a difference, and the d-axis voltage deviation and the q-axis voltage deviation of the control winding are calculated by a PI controller to obtain a given value I of the d-axis current component of the control winding. ref_cd and the given value I of the q-axis current component of the control winding ref_cq , the calculation formula is as follows:

[0101] ; (3)

[0102] Among them, I ref_cd1 is the given value of the d-axis current component of the control winding, I ref_cq1 K is the given value of the q-axis current component of the control winding, p7 , K p8 , K s7 , K s8 is the parameter of PI controller, U p is the distribution station area voltage, U dc is the starting power supply voltage, U cd To control the winding d-axis voltage component, U cq is the q-axis voltage component of the control winding.

[0103] The inner loop is a current loop, which also uses a PI controller to calculate a control winding voltage reference value; a control winding drive signal is generated according to the control winding voltage reference value, and a static excitation converter controls the control winding to supply power to the distribution station area according to the control winding drive signal.

[0104] Energy storage device 2 supplements the remaining power, and the control structure is as follows Figure 3 As shown in part B of the figure, the control method is dual-loop control, the outer loop is the power loop, and the load active power P is collected. ref and load reactive power Q ref , collect the generator active power P of the control winding G and generator reactive power Q G , the load active power P ref and the generator active power P G , load reactive power Q ref and generator reactive power Q G The power compensation value is obtained by making a difference respectively, and the d-axis current component I is calculated by using the PI controller. ref_d2 and the q-axis current component I ref_q2 , the calculation formula is as follows:

[0105] ; (6)

[0106] Among them, I ref_d2 represents the d-axis current component, I ref_q2 represents the q-axis current component, K p5 , K p6 , K s5 , K s6 is the PI controller parameter, P ref is the load active power, Q ref is the load reactive power, P G is the active power of the generator, Q G is the reactive power of the generator.

[0107] A power supply drive signal is generated according to the d-axis current component and the q-axis current component. The energy storage current controller controls the energy storage device to output electric energy according to the power supply drive signal. The energy storage device and the control winding output electric energy of the dual-winding generator jointly supply power to the distribution station area.

[0108] Furthermore, for the small load scenario of the 10KV distribution network, the energy storage device 2 is first powered separately to provide voltage and frequency support for the distribution network. The control method used at this time is as follows: Figure 5 As shown in part A of the figure, the outer loop is the voltage loop, which collects the three-phase voltage U of the common connection point PCC. pcc , the three-phase voltage U pccPerform dq transformation to obtain the d-axis voltage component U of the connection point pcc_d and the q-axis voltage component U at the connection point pcc_q , and use it as feedback to make a difference between the d-axis component set value and the q-axis component set value, where the d-axis component set value is the grid voltage target value U ref1 , the q-axis component given value is 0, the d-axis voltage deviation and the q-axis voltage deviation of the connection point are calculated, and the d-axis current component given value I of the connection point is obtained by calculating the d-axis voltage deviation and the q-axis voltage deviation of the connection point through the PI controller. ref_d1 and the connection point q-axis current component given value I ref_q1 , the calculation formula is as follows:

[0109] ; (1)

[0110] Among them, I ref_d1 is the given value of the d-axis current component of the connection point, I ref_q1 is the given value of the q-axis current component of the connection point, K p1 , K p2 , K s1 , K s2 is the parameter of PI controller, U ref1 is the target value of grid voltage, U pcc_d is the d-axis voltage component of the connection point, U pcc_q is the q-axis voltage component of the connection point.

[0111] Furthermore, the output current of the energy storage converter is collected and dq transformed to obtain the output d-axis current component I L_d and the output side q-axis current component I L_q , according to the given value I of the d-axis current component of the connection point ref_d1 , connection point q-axis current component given value I ref_q1 , output side d-axis current component I L_d and the output side q-axis current component I L_q , based on the PI controller, the d-axis reference voltage component U is calculated d and the q-axis voltage reference component U q , the calculation formula is as follows:

[0112] ; (2)

[0113] Among them, U d Represents the d-axis reference voltage component, U q Represents the q-axis voltage reference component, K p3 , K p4 , K s3 , K s4 is the parameter of the PI controller, I ref_d1is the given value of the d-axis current component of the connection point, I ref_q1 is the given value of the q-axis current component of the connection point, I L_d is the d-axis current component on the output side, I L_q is the q-axis current component on the output side.

[0114] Further, according to the d-axis reference voltage component U d and the q-axis voltage reference component U q A power supply control signal is generated, and the energy storage converter 3 controls the energy storage device 2 to output electric energy according to the power supply control signal, and the electric energy is boosted to 10KV electric energy through the transformer to supply power to the distribution network.

[0115] When the energy storage device is insufficient, the power winding of the dual-winding generator is switched to supply power. At this time, the control structure of the dual-winding generator is as follows: Figure 6 As shown, at this time, the system control winding is controlled, and the power winding is indirectly controlled through the magnetic field coupling property. The control method adopts vector control, sampling dual-loop control, the outer loop is the voltage loop, and the output side three-phase voltage u of the power winding is collected. p_abc , the three-phase voltage u on the output side of the power winding p_abc Perform dq transformation to obtain the d-axis voltage component U of the power winding pd and the power winding q-axis voltage component U pq , the distribution network voltage U ref2 As the d-axis given value, the starting power supply side voltage U dc As the q-axis given value, the d-axis voltage component U pd and the power winding q-axis voltage component U pq Respectively with the distribution network voltage U ref2 And starting power supply side voltage U dc The power winding d-axis voltage deviation and the power winding q-axis voltage deviation are calculated by the PI controller to obtain the power winding d-axis current component given value I ref_cd2 and the given value of the q-axis current component of the power winding I ref_cq2 :

[0116] ; (7)

[0117] Among them, I ref_cd2 is the given value of the d-axis current component of the power winding, I ref_cq2 is the given value of the q-axis current component of the power winding, K p9 , K p10 , K s9 , K s10 is the parameter of PI controller, U ref2 is the distribution network voltage, U dcis the starting power supply voltage, U pd is the d-axis voltage component of the power winding, U pq is the q-axis voltage component of the power winding.

[0118] The inner loop is a current loop. According to the given value of the d-axis current component of the power winding and the given value of the q-axis current component of the power winding, a PI controller is used to calculate a power winding voltage reference value; a power winding drive signal is generated according to the power winding voltage reference value, and the static excitation converter controls the power winding to output electric energy according to the power winding drive signal, and supplies power to the distribution network after being stepped up by a transformer.

[0119] At this time, the energy storage device 2 switches to the charging state, and the control structure switches to the single current loop control. The control structure is as follows: Figure 3 As shown in part C of the figure, the given value of the q-axis current component of the control winding is set to 0, and the given value of the d-axis current component of the control winding is set to the charging current; first, the initial value of the charging current is calculated according to the discharge capacity and discharge constant of the energy storage device:

[0120] ; (4)

[0121] Among them, I0 represents the initial value of charging current, K represents the discharge constant, and C represents the discharge capacity of the energy storage device;

[0122] Furthermore, the charging current is calculated according to the initial value of the charging current, the current charge of the energy storage device, the maximum charge of the energy storage device and the charging current acceptance ratio:

[0123] ; (5)

[0124] in, represents the charging current, α represents the charging current acceptance ratio, t represents the charging time, SOC represents the current charge of the energy storage device, SOC M Indicates the maximum charge of the energy storage device.

[0125] Furthermore, a charging control signal is generated according to the charging current, and the energy storage converter 3 controls the control winding to charge the energy storage device 2 according to the charging control signal.

[0126] For the medium load scenario of 10KV distribution network, the power winding of the double-winding generator supplies power to the distribution network alone. The control structure is as follows: Figure 6 As shown, at this time, the system control winding is controlled, and the power winding is indirectly controlled through the magnetic field coupling property. The control method adopts vector control, sampling dual-loop control, the outer loop is the voltage loop, and the output side three-phase voltage u of the power winding is collected. p_abc , the three-phase voltage u on the output side of the power winding p_abcPerform dq transformation to obtain the d-axis voltage component U of the power winding pd and the power winding q-axis voltage component U pq , the distribution network voltage U ref2 As the d-axis given value, the starting power supply side voltage U dc As the q-axis given value, the d-axis voltage component U pd and the power winding q-axis voltage component U pq Respectively with the distribution network voltage U ref2 And starting power supply side voltage U dc The power winding d-axis voltage deviation and the power winding q-axis voltage deviation are calculated by the PI controller to obtain the power winding d-axis current component given value I ref_cd2 and the given value of the q-axis current component of the power winding I ref_cq2 :

[0127] ; (7)

[0128] Among them, I ref_cd2 is the given value of the d-axis current component of the power winding, I ref_cq2 is the given value of the q-axis current component of the power winding, K p9 , K p10 , K s9 , K s10 is the parameter of PI controller, U ref2 is the distribution network voltage, U dc is the starting power supply voltage, U pd is the d-axis voltage component of the power winding, U pq is the q-axis voltage component of the power winding.

[0129] The inner loop is a current loop. According to the given value of the d-axis current component of the power winding and the given value of the q-axis current component of the power winding, a PI controller is used to calculate a power winding voltage reference value; a power winding drive signal is generated according to the power winding voltage reference value, and the static excitation converter controls the power winding to output electric energy according to the power winding drive signal, and supplies power to the distribution network after being stepped up by a transformer.

[0130] In the heavy load scenario of the 10KV distribution network, the load has exceeded the maximum output power of the dual-winding generator 1, and the energy storage device and the dual-winding generator need to be powered together. At this time, the dual-winding generator 1 provides voltage and frequency support. The control structure is as follows: Figure 6 As shown, at this time, the system control winding is controlled, and the power winding is indirectly controlled through the magnetic field coupling property. The control method adopts vector control, sampling dual-loop control, the outer loop is the voltage loop, and the output side three-phase voltage u of the power winding is collected. p_abc, the three-phase voltage u on the output side of the power winding p_abc Perform dq transformation to obtain the d-axis voltage component U of the power winding pd and the power winding q-axis voltage component U pq , the distribution network voltage U ref2 As the d-axis given value, the starting power supply side voltage U dc As the q-axis given value, the d-axis voltage component U pd and the power winding q-axis voltage component U pq Respectively with the distribution network voltage U ref2 And starting power supply side voltage U dc The power winding d-axis voltage deviation and the power winding q-axis voltage deviation are calculated by the PI controller to obtain the power winding d-axis current component given value I ref_cd2 and the given value of the q-axis current component of the power winding I ref_cq2 :

[0131] ; (7)

[0132] Among them, I ref_cd2 is the given value of the d-axis current component of the power winding, I ref_cq2 is the given value of the q-axis current component of the power winding, K p9 , K p10 , K s9 , K s10 is the parameter of PI controller, U ref2 is the distribution network voltage, U dc is the starting power supply voltage, U pd is the d-axis voltage component of the power winding, U pq is the q-axis voltage component of the power winding.

[0133] The inner loop is a current loop, and a PI controller is used to calculate a power winding voltage reference value according to a given value of the power winding d-axis current component and a given value of the power winding q-axis current component; a power winding drive signal is generated according to the power winding voltage reference value, and the static excitation converter controls the power winding to output electrical energy according to the power winding drive signal.

[0134] Energy storage device 2 supplements the remaining power, and the control structure is as follows Figure 5 As shown in part B of the figure, the control method is dual-loop control, the outer loop is the power loop, and the load active power P is collected. ref and load reactive power Q ref , collect the active power P of the generator of the power winding G and generator reactive power Q G , the load active power P refand the generator active power P G , load reactive power Q ref and generator reactive power Q G Make a difference respectively to obtain the power compensation value, and use the PI controller to calculate the d-axis current component and the q-axis current component. The calculation formula is as follows:

[0135] ; (6)

[0136] Among them, I ref_d2 represents the d-axis current component, I ref_q represents the q-axis current component, K p5 , K p6 , K s5 , K s6 is the PI controller parameter, P ref is the load active power, Q ref is the load reactive power, P G is the active power of the generator, Q G is the reactive power of the generator.

[0137] A power supply drive signal is generated according to the d-axis current component and the q-axis current component. The energy storage current controller controls the energy storage device to output electric energy according to the power supply drive signal. The electric energy output by the energy storage device and the power winding of the dual-winding generator is input into the distribution network after being stepped up by the transformer.

[0138] The storage-generation integrated dual-channel power supply system and control method thereof provided in the above embodiments have at least the following beneficial effects:

[0139] (1) The integrated power supply architecture makes up for the shortcomings of traditional generators in low efficiency and high power generation cost in low-load operation scenarios. At the same time, the energy storage battery can also play the role of a range-extending generator, and cooperate with the dual-winding generator to realize power supply in various scenarios and different voltage levels, meeting the needs of non-stop operation;

[0140] (2) The solution can support 400V and 10kV power generation operations, solving the problem of the single operation scenario of traditional diesel generators;

[0141] (3) Based on the coordinated control of the energy storage converter and the static excitation converter, the energy storage battery and the dual-winding generator can be connected in parallel to achieve flexible power distribution.

[0142] Although preferred embodiments of the present invention have been described, additional changes and modifications may be made to these embodiments by those skilled in the art once the basic inventive concepts are known. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A control method for a dual-channel power supply system with storage and generation, characterized in that: The storage-generation integrated dual-channel power supply system comprises a dual-winding generator, an energy storage device, an energy storage converter, a static excitation converter and a transformer, the dual-winding generator comprises a control winding and a power winding, the control winding is connected to the static excitation converter and a distribution station, the power winding is connected to a distribution network through the transformer, the energy storage device is connected in parallel with the control winding and the power winding through the energy storage converter, and the energy storage device is also connected to the DC side of the static excitation converter; the method comprises: In a small load scenario, the energy storage converter controls the energy storage device to output electric energy to supply power to the distribution station area. When the power of the energy storage device is lower than a preset value, the static excitation converter is used to control the control winding to supply power to the distribution station area, and the energy storage converter controls the control winding to charge the energy storage device; or, the energy storage converter is used to control the energy storage device to output electric energy, which is boosted by the transformer to supply power to the distribution network. When the power of the energy storage device is lower than a preset value, the static excitation converter controls the power winding to supply power to the distribution network, and the energy storage converter controls the control winding to charge the energy storage device; In a medium load scenario, the static excitation converter controls the control winding to supply power to the distribution network area alone or controls the power winding to supply power to the distribution network alone; In a heavy load scenario, the energy storage converter and the static excitation converter control the energy storage device and the control winding to simultaneously supply power to the distribution network area, or control the energy storage device and the power winding to simultaneously supply power to the distribution network; The energy storage converter controls the control winding to charge the energy storage device, including: The given value of the q-axis current component of the control winding is set to 0, and the given value of the d-axis current component of the control winding is set to the charging current; Calculate the initial value of the charging current according to the current discharge capacity and discharge constant of the energy storage device; Calculate the charging current according to the initial value of the charging current, the current charge of the energy storage device, the maximum charge of the energy storage device and the charging current acceptance ratio; Generate a charging control signal according to the charging current, and the energy storage converter controls the control winding to charge the energy storage device according to the charging control signal; The initial value of the charging current is calculated by the following formula: ； Among them, I0 represents the initial value of charging current, K represents the discharge constant, and C represents the discharge capacity of the energy storage device; The charging current is calculated by the following formula: ； in, represents the charging current, α represents the charging current acceptance ratio, t represents the charging time, SOC represents the current charge of the energy storage device, SOC M Indicates the maximum charge of the energy storage device; If the load power is lower than 50% of the rated power of the dual-winding generator, it is a small load scenario. If the load power is between 50% and 100% of the rated power of the dual-winding generator, it is a medium load scenario. If the load power is greater than the rated power of the dual-winding generator and less than the sum of the rated powers of the dual-winding generator and the energy storage device, it is a large load scenario.

2. The method according to claim 1, characterized in that The energy storage device is connected to the DC side of the static excitation converter through a diode.

3. The method according to claim 1, characterized in that The voltage level of the distribution station area is 400V, the voltage level of the distribution network is 10KV, and the voltage levels output by the control winding and the power winding are the same.

4. The method according to claim 1, characterized in that: In a light load scenario, the energy storage converter controls the energy storage device to output electric energy, including: Collect three-phase voltage at the common connection point; Performing a dq transformation on the three-phase voltage at the common connection point to obtain a d-axis voltage component and a q-axis voltage component at the connection point; Subtract the connection point d-axis voltage component and the connection point q-axis voltage component from the d-axis component given value and the q-axis component given value respectively to obtain the connection point d-axis voltage deviation and the connection point q-axis voltage deviation; The d-axis voltage deviation and the q-axis voltage deviation of the connection point are calculated by a PI controller to obtain a given value of the d-axis current component and a given value of the q-axis current component of the connection point; Collect the output side current of the energy storage converter and perform dq transformation to obtain the output side d-axis current component and the output side q-axis current component; According to the given value of the d-axis current component at the connection point, the given value of the q-axis current component at the connection point, the d-axis current component at the output side, and the q-axis current component at the output side, a d-axis reference voltage component and a q-axis voltage reference component are calculated based on a PI controller; A power supply control signal is generated according to the d-axis reference voltage component and the q-axis voltage reference component, and the energy storage converter controls the energy storage device to output electric energy according to the power supply control signal.

5. The method according to claim 1, characterized in that In a small load scenario, a medium load scenario, and a large load scenario, the static excitation converter controls the control winding to supply power to the distribution station area, including: Collect the three-phase voltage on the output side of the control winding; Performing dq transformation on the output side three-phase voltage of the control winding to obtain a d-axis voltage component of the control winding and a q-axis voltage component of the control winding; Subtracting the control winding d-axis voltage component and the control winding q-axis voltage component from the distribution station area voltage and the starting power supply side voltage respectively to obtain the control winding d-axis voltage deviation and the control winding q-axis voltage deviation; Calculating the control winding d-axis voltage deviation and the control winding q-axis voltage deviation by a PI controller to obtain a control winding d-axis current component given value and a control winding q-axis current component given value; According to the given value of the d-axis current component of the control winding and the given value of the q-axis current component of the control winding, a PI controller is used to calculate and obtain a reference value of the control winding voltage; A control winding drive signal is generated according to the control winding voltage reference value, and the static excitation converter controls the control winding to supply power to the power distribution station section according to the control winding drive signal.

6. The method according to claim 1, characterized in that In a small load scenario, a medium load scenario, and a large load scenario, the static excitation converter controls the power winding to supply power to the distribution network, including: Collect the three-phase voltage on the output side of the power winding; Performing dq transformation on the output side three-phase voltage of the power winding to obtain a d-axis voltage component of the power winding and a q-axis voltage component of the power winding; Subtracting the power winding d-axis voltage component and the power winding q-axis voltage component from the power distribution network voltage and the starting power supply side voltage respectively to obtain the power winding d-axis voltage deviation and the power winding q-axis voltage deviation; Calculating the power winding d-axis voltage deviation and the power winding q-axis voltage deviation by a PI controller to obtain a power winding d-axis current component given value and a power winding q-axis current component given value; According to the given value of the power winding d-axis current component and the given value of the power winding q-axis current component, a PI controller is used to calculate and obtain a power winding voltage reference value; A power winding drive signal is generated according to the power winding voltage reference value, and the static excitation converter controls the power winding to supply power to the power distribution network according to the power winding drive signal.

7. The method according to claim 1, characterized in that In a heavy load scenario, the energy storage current device controls the energy storage device to supply power to the distribution station area or the distribution network, including: Collect load active power and load reactive power; Collecting the active power and reactive power of the generator output by the control winding or the power winding; Subtract the load active power from the generator active power, and the load reactive power from the generator reactive power to obtain a power compensation value; According to the power compensation value, a PI controller is used to calculate and obtain a d-axis current component and a q-axis current component; A power supply drive signal is generated according to the d-axis current component and the q-axis current component, and the energy storage current device controls the energy storage device to supply power to the distribution station area or the distribution network according to the power supply drive signal.

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