Interconnection device based on active and passive device combination, control method and medium

Abstract

The embodiment of the invention discloses an interconnection device based on active and passive device combination, a control method and a medium, the device comprises a controller, an active interconnection unit and a passive interconnection unit, the controller is connected with the active interconnection unit and the passive interconnection unit, the active interconnection unit and the passive interconnection unit are connected in parallel, and the active interconnection unit is connected with the passive interconnection unit. The controller controls the active interconnection unit to be connected with the first power distribution network and the second power distribution network, and is also used for controlling the passive interconnection unit to be connected with the first power distribution network and the second power distribution network. The active interconnection unit and the passive interconnection unit are controlled to work cooperatively through the controller, the device cost is reduced, continuous changes of power distribution network source loads can be flexibly coped with by dynamically adjusting the working states of the active interconnection unit and the passive interconnection unit, economical, flexible and safe interconnection of the power distribution network is achieved, and the power distribution network interconnection efficiency is improved. The method has remarkable economical efficiency and control flexibility.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply, and in particular to an interconnection device, a control method and a medium based on a combination of active and passive components. Background Art

[0002] In recent years, with the advancement of the construction of new power systems, new sources and loads such as distributed photovoltaics, decentralized small wind power, electric vehicles, and electric tobacco have been connected to low-voltage distribution network stations in large quantities, resulting in inconsistent temporal and spatial characteristics of sources and loads in distribution network stations, and the original problems of heavy overload, extreme light load, and three-phase imbalance have become increasingly prominent. The voltage and current fluctuations caused by these connections have increased the flexibility of traditional passive devices in the application of low-voltage distribution network stations, and they cannot effectively adapt to changes in sources and loads. In order to cope with these problems, low-voltage flexible interconnection devices have been piloted in distribution network stations, which can address the above problems to a certain extent with significant results.

[0003] However, existing low-voltage flexible interconnection devices also have some problems. First, such devices mainly use power electronic devices, which are much more expensive than passive devices of the same capacity, increasing maintenance costs and field applicability, limiting the flexibility and economy of the devices in a wide range of applications. Secondly, when the distribution network is in a fault state, the large-capacity flexible interconnection device needs to transfer a large load, causing the device to be unable to operate normally, further increasing the economic cost. Finally, when the source and load of the distribution network change, the device has a high demand for capacity expansion, but actual capacity expansion is difficult, further limiting the expansion performance of the interconnection device. Summary of the invention

[0004] Based on this, it is necessary to propose an interconnection device, control method and medium based on a combination of active and passive devices to address the above problems.

[0005] An interconnection device based on a combination of active and passive devices, the device comprising: a controller, an active interconnection unit, and a passive interconnection unit, the controller is connected to the active interconnection unit and the passive interconnection unit, the active interconnection unit and the passive interconnection unit are connected in parallel, the controller controls the active interconnection unit to be connected to a first distribution network and a second distribution network, and is also used to control the passive interconnection unit to be connected to the first distribution network and the second distribution network.

[0006] Among them, the active interconnection unit specifically includes: a first converter and a second converter, the DC side of the first converter is connected to the DC side of the second converter, the AC side of the first converter is connected to the first distribution network, and the AC side of the second converter is connected to the second distribution network. The controller controls the first converter to output a power supply with a phase difference, voltage difference, and frequency difference consistent with the first distribution network, or controls the second converter to output a power supply with a phase difference, voltage difference, and frequency difference consistent with the second distribution network, thereby completing the first interconnection step.

[0007] Wherein, the active interconnection unit further includes: a first supporting capacitor, a second supporting capacitor, a first filter, and a second filter.

[0008] The first supporting capacitor is connected in parallel with the DC side of the first converter, and the second supporting capacitor is connected in parallel with the DC side of the second converter;

[0009] The first filter is connected to a first power distribution network, and the second filter is connected to a second power distribution network.

[0010] The passive interconnection unit specifically includes: an adjustable impedance, a first phase switch and a second phase switch,

[0011] The adjustable impedance is connected in series with a first split-phase switch and a second split-phase switch, the first split-phase switch is connected to a first distribution network, and the second split-phase switch is connected to a second distribution network;

[0012] On the basis of the first interconnection step, the controller controls the impedance value of the adjustable impedance, adjusts the impedance value to make the load rate of the first distribution network and the second distribution network equal, closes the first phase switch and the second phase switch, and completes the second interconnection step.

[0013] Among them, if the circulating current between the first distribution network, the second distribution network, the active interconnection unit, and the passive interconnection unit is greater than a first preset value, the controller controls the first converter and the second converter of the active interconnection unit to output reactive power to the first distribution network and the second distribution network, and adjusts the grid connection point voltage between the device and the first distribution network and the second distribution network until the circulating current between the first distribution network, the second distribution network, the active interconnection unit, and the passive interconnection unit is less than the first preset value.

[0014] Among them, when the passive interconnection unit fails after being put into operation, the controller controls the active interconnection unit to lock the output, disconnecting the first step of interconnection between the first distribution network and the second distribution network. When the first step of interconnection is disconnected, the passive interconnection unit does not perform the second step of interconnection.

[0015] Among them, if a fault occurs after the first step interconnection and the second step interconnection are performed, the controller controls the active interconnection unit to exit operation, the passive interconnection unit adjusts the impedance value of the adjustable impedance to zero, disconnects the first phase switch and the second phase switch, and the adjustable impedance exits operation, and the passive interconnection unit and the active interconnection unit cooperate with each other in the protection action timing.

[0016] A control method for an interconnection device based on a combination of active and passive components, the method being applied to the interconnection device based on a combination of active and passive components as described above, the method comprising:

[0017] Measure the phase difference, voltage difference, and frequency difference between the first distribution network and the second distribution network, and output a power supply that is consistent with the phase difference, voltage difference, and frequency difference of the first distribution network, or output a power supply that is consistent with the phase difference, voltage difference, and frequency difference of the second distribution network, to complete the first interconnection step;

[0018] On the basis of the first interconnection step, the impedance value of the adjustable impedance is controlled to adjust the impedance value to make the load rate of the first distribution network and the second distribution network equal, and the first phase switch and the second phase switch are closed to complete the second interconnection step.

[0019] A control method for an interconnection device based on a combination of active and passive components, the method being applied to the interconnection device based on a combination of active and passive components as described above, the method comprising:

[0020] Measure the neutral line current and the A, B, C three-phase voltages of the first distribution network and the second distribution network, and control the active interconnection unit to output the regulating power to adjust the neutral line current and the A, B, C three-phase voltages of the first distribution network and the second distribution network, until the neutral line current of the first distribution network and the second distribution network is less than the second preset value, and the voltage of the first distribution network and the second distribution network is less than the value specified in the national standard.

[0021] The method further comprises: controlling the impedance value of the adjustable impedance, adjusting the impedance value to make the load rates of the first distribution network and the second distribution network equal, closing the first phase switch and the second phase switch, and completing the second step of interconnection;

[0022] Determine whether a fault occurs after the first step interconnection and the second step interconnection;

[0023] If a fault occurs after the first and second interconnections, the controller controls the active interconnection unit to exit operation, the passive interconnection unit adjusts the impedance value of the adjustable impedance to zero, disconnects the first phase-splitting switch and the second phase-splitting switch, the adjustable impedance exits operation, and the passive interconnection unit and the active interconnection unit cooperate with each other in the protection action timing;

[0024] If no fault occurs after the first interconnection and the second interconnection, measuring the circulating current between the first distribution network, the second distribution network, the active interconnection unit, and the passive interconnection unit;

[0025] Determining whether the circulation current is greater than a first preset value;

[0026] If the circulating current is greater than the first preset value, the first converter and the second converter of the active interconnection unit output reactive power to the first distribution network and the second distribution network, and adjust the grid connection point voltage between the device and the first distribution network and the second distribution network until the circulating current between the first distribution network, the second distribution network, the active interconnection unit, and the passive interconnection unit is less than the first preset value, and the device interconnection is normal at this time;

[0027] After the interconnection is normal, the controller calculates the power distribution between the active interconnection unit and the passive interconnection unit in the resonance mode of the passive interconnection unit, and determines whether the power flowing through the active interconnection unit exceeds the capacity of the active interconnection unit;

[0028] If the power flowing through the active interconnection unit does not exceed the capacity of the active interconnection unit, the reactance and capacitance of the passive interconnection unit are adjusted to make the passive interconnection unit resonate and work in a pure resistance mode to reduce the loss of the passive interconnection unit. At this time, the power between the active interconnection unit and the passive interconnection unit is redistributed according to the parallel resistance mode.

[0029] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the processor is caused to execute the steps of the method described above.

[0030] The embodiments of the present invention have the following beneficial effects:

[0031] The present invention controls the active interconnection unit and the passive interconnection unit to work together through a controller, thereby reducing the cost of the device. By dynamically adjusting the working states of the active interconnection unit and the passive interconnection unit, it can flexibly respond to the continuous changes in the source and load of the distribution network, avoiding the low operating efficiency caused by the traditional method due to the limited capacity and difficulty in expansion, delaying the expansion of the device, solving the problems of high cost and difficulty in expansion of traditional flexible interconnection devices, and realizing economic, flexible and safe interconnection of the distribution network, with significant economy and control flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] in:

[0034] Figure 1 A schematic structural diagram of an embodiment of an interconnection device based on a combination of active and passive components provided by the present invention;

[0035] Figure 2 A schematic structural diagram of another embodiment of an interconnection device based on a combination of active and passive components provided by the present invention;

[0036] Figure 3 A flow chart of an embodiment of a control method for an interconnection device based on a combination of active and passive components provided by the present invention;

[0037] Figure 4 A flow chart of another embodiment of a control method for an interconnection device based on a combination of active and passive components provided by the present invention;

[0038] Figure 5 A flow chart of another embodiment of a control method for an interconnection device based on a combination of active and passive components provided by the present invention;

[0039] Figure 6 A schematic structural diagram of an embodiment of the medium provided by the present invention. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] like Figure 1 As shown, Figure 1 A schematic diagram of the structure of an embodiment of an interconnection device based on a combination of active and passive devices provided by the present invention. An interconnection device 10 based on a combination of active and passive devices, the device comprises: a controller 11, an active interconnection unit 12, and a passive interconnection unit 13, the controller 11 is connected to the active interconnection unit 12 and the passive interconnection unit 13, the active interconnection unit 12 and the passive interconnection unit 13 are connected in parallel, the controller 11 controls the active interconnection unit 12 to connect to a first distribution network 14 and a second distribution network 15, and is also used to control the passive interconnection unit 13 to connect to the first distribution network 14 and the second distribution network 15.

[0042] In a specific implementation scenario, the controller 11 is connected to the active interconnection unit 12 and the passive interconnection unit 13; the active interconnection unit 12 and the passive interconnection unit 13 are connected in parallel, and the controller 11 controls the active interconnection unit 12 to output a 360-degree adjustable power supply to realize the flexible interconnection of the first distribution network 14 and the second distribution network 15, and adjusts the phase difference, voltage difference, and frequency difference between the first distribution network 14 and the second distribution network 15, so as to provide conditions for the first distribution network 14 or the second distribution network 15 to be synchronously connected to the grid through the passive interconnection unit 13. The controller 11 also controls the passive interconnection unit 13 to realize the connection between the passive interconnection unit 13 and the first distribution network 14 and the second distribution network 15 by adjusting the distribution of power between the active interconnection unit 12 and the passive interconnection unit 13, thereby realizing the power mutual assistance of the first distribution network 14 and the second distribution network 15.

[0043] In addition, when a fault occurs after the passive interconnection unit 13 is put into operation, the controller 11 controls the active interconnection unit 12 to lock the output, disconnecting the first step of interconnection between the first distribution network 14 and the second distribution network 15. When the first step of interconnection is disconnected, the passive interconnection unit 13 does not meet the synchronous closing requirement and cannot perform the second step of interconnection.

[0044] If a fault occurs after the first and second steps of interconnection, the controller 11 controls the active interconnection unit 12 to exit operation, the passive interconnection unit 13 adjusts the impedance value of the adjustable impedance to zero, disconnects the first phase switch and the second phase switch, and the adjustable impedance exits operation. The passive interconnection unit 13 cooperates with the active interconnection unit 12 in the protection action timing, and the protection setting time of the passive interconnection unit 13 is any value between 1.3 times and 1.5 times the protection setting time of the active interconnection unit 12, thereby fully protecting the active interconnection unit 12 from being damaged by overcurrent impact.

[0045] When the first distribution network 14 or the second distribution network 15 fails, after the first distribution network 14 or the second distribution network 15 is isolated from the fault, when the load in the non-fault section is transferred to the first distribution network 14 or the second distribution network 15 by the interconnection device, the controller 11 controls the active interconnection unit 12 to output at the rated power. If the rated power of the active interconnection unit 12 is less than the power to be transferred, the remaining power is transferred by the passive interconnection unit 13, thereby avoiding load shedding of the first distribution network 14 or the second distribution network 15 due to insufficient capacity of the active interconnection unit 12, solving the problem that the flexible interconnection device is overloaded and cannot operate normally due to the transfer of a large amount of load in the distribution network fault state, and improving the power supply reliability.

[0046] From the above description, it can be seen that the present invention controls the active interconnection unit and the passive interconnection unit to work together through a controller, thereby reducing the cost of the device. By dynamically adjusting the working states of the active interconnection unit and the passive interconnection unit, it can flexibly respond to the continuous changes in the source and load of the distribution network, avoiding the low operating efficiency caused by the traditional method due to limited capacity and difficulty in expansion, delaying the expansion of the device, solving the problems of high cost and difficulty in expansion of traditional flexible interconnection devices, and realizing the economic, flexible and safe interconnection of the distribution network, with significant economy and control flexibility.

[0047] like Figure 2 As shown, Figure 2A schematic diagram of the structure of another embodiment of an interconnection device based on a combination of active and passive components provided by the present invention. An interconnection device 10 based on a combination of active and passive components, wherein an active interconnection unit 12 specifically comprises: a first converter CV1 and a second converter CV2, wherein the DC side of the first converter CV1 is connected to the DC side of the second converter CV2, the AC side of the first converter CV1 is connected to the first distribution network 14, and the AC side of the second converter CV2 is connected to the second distribution network 15, and the controller 11 controls the first converter CV1 to output a power supply having a phase difference, voltage difference, and frequency difference consistent with the first distribution network 14, or controls the second converter CV2 to output a power supply having a phase difference, voltage difference, and frequency difference consistent with the second distribution network 15, thereby completing the first step of interconnection.

[0048] In a specific implementation scenario, the DC side of the first converter CV1 is connected to the DC side of the second converter CV2 through a DC line, the AC side of the first converter CV1 is connected to the first distribution network 14, and the AC side of the second converter CV2 is connected to the second distribution network 15. Specifically, the active interconnection device 12 and the passive interconnection device 13 are connected through the first phase-splitting switch S1 to form a first distribution network access terminal, and the active interconnection device 12 and the passive interconnection device 13 are connected through the second phase-splitting switch S2 to form a second distribution network access terminal; the first distribution network access terminal is used to connect to the three-phase bus of the first distribution network 14 through the third phase-splitting switch S3, the second distribution network access terminal is used to connect to the three-phase bus of the second distribution network 15 through the fourth phase-splitting switch S4, the three-phase bus of the first distribution network 14 is connected to the first distribution network 14 through the fifth phase-splitting switch S5, and the second distribution network 15 is connected to the three-phase bus of the second distribution network 15 through the sixth phase-splitting switch S6.

[0049] The phase difference, voltage difference and frequency difference between the first distribution network 14 and the second distribution network 15 are measured. When the first distribution network 14 transmits power to the second distribution network 15, the controller 11 controls the second converter CV2 of the active interconnection unit 12 to output a power supply having the same phase difference, voltage difference and frequency difference as the second distribution network 15, thereby completing the first interconnection step.

[0050] In addition, the circulating current between the first distribution network 14, the second distribution network 15, the active interconnection unit 12, and the passive interconnection unit 13 is measured, and the controller 11 determines whether the circulating current is greater than a first preset value. If the circulating current is greater than the first preset value, the active interconnection unit 12 is controlled to output reactive power to the second distribution network 15, and the voltage at the grid connection point between the regulating device and the second distribution network 15 is adjusted until the circulating current between the first distribution network 14, the second distribution network 15, the active interconnection unit 12, and the passive interconnection unit 13 is less than the first preset value IK.

[0051] In another specific implementation scenario, when the second distribution network 15 transmits power to the first distribution network 14, the controller 11 controls the first converter CV1 of the active interconnection unit 12 to output a power supply with the same phase difference, voltage difference and frequency difference as the first distribution network 14, thereby completing the first interconnection step.

[0052] In addition, the circulating current between the first distribution network 14, the second distribution network 15, the active interconnection unit 12, and the passive interconnection unit 13 is measured, and the controller 11 determines whether the circulating current is greater than a first preset value. If so, the active interconnection unit 12 is controlled to output reactive power to the first distribution network 14, and the voltage at the grid connection point between the device and the first distribution network 14 is adjusted until the circulating current between the first distribution network 14, the second distribution network 15, the active interconnection unit 12, and the passive interconnection unit 13 is less than the first preset value IK. At this time, the device interconnection is normal.

[0053] After the interconnection is normal, the controller 11 calculates the power distribution between the active interconnection unit 12 and the passive interconnection unit 13 in the resonance mode of the passive interconnection unit 13, and determines whether the power flowing through the active interconnection unit 12 exceeds the capacity of the active interconnection unit 12.

[0054] If the power flowing through the active interconnection unit 12 does not exceed the capacity of the active interconnection unit 12, the reactance and capacitance of the passive interconnection unit 13 are adjusted to make the passive interconnection unit 13 resonate and work in a pure resistance mode to reduce the loss of the passive interconnection unit 13. At this time, the power between the active interconnection unit 12 and the passive interconnection unit 13 is redistributed according to the parallel resistance mode.

[0055] The first converter CV1 and the second converter CV2 are both composed of six IGBTs with anti-parallel diodes.

[0056] Continue reading Figure 2 The active interconnection unit also includes: a first supporting capacitor C1, a second supporting capacitor C2, a first filter LC1, and a second filter LC1. The first supporting capacitor C1 is connected in parallel to the DC side of the first converter CV1, and the second supporting capacitor C2 is connected in parallel to the DC side of the second converter CV2; the first filter LC1 is connected to the first distribution network 14, and the second filter LC2 is connected to the second distribution network 15.

[0057] In a specific implementation scenario, the active interconnection unit 12 is composed of a first converter CV1, a second converter CV2, a first supporting capacitor C1, a second supporting capacitor C2, a first filter LC1, and a second filter LC2. The first supporting capacitor C1 is connected in parallel to the DC side of the first converter CV1, the second supporting capacitor C2 is connected in parallel to the DC side of the second converter CV2, the first converter CV1 is connected to the second converter CV2 through a DC line, the first converter CV1 is connected to the first distribution network 14 through the first filter LC1, and the second converter CV2 is connected to the second distribution network 15 through the second filter LC2. The circulating current among the first distribution network 14, the second distribution network 15, the active interconnection unit 12, and the passive interconnection unit 13 is measured. When the first distribution network 14 transmits power to the second distribution network 15, the controller 11 determines whether the circulating current is greater than a first preset value. If so, the second converter CV2 of the active interconnection unit 12 is controlled to output reactive power to the second distribution network 15, and the voltage at the grid connection point between the regulating device and the second distribution network 15 is adjusted until the circulating current among the first distribution network 14, the second distribution network 15, the active interconnection unit 12, and the passive interconnection unit 13 is less than the first preset value IK.

[0058] In another specific implementation scenario, when the second distribution network 15 transmits power to the first distribution network 14, the controller 11 determines whether the circulating current is greater than a first preset value. If so, the first converter CV1 of the active interconnection unit 12 is controlled to output reactive power to the first distribution network 14, and the voltage at the grid connection point between the regulating device and the first distribution network 14 is adjusted until the circulating current between the first distribution network 14, the second distribution network 15, the active interconnection unit 12, and the passive interconnection unit 13 is less than the first preset value IK.

[0059] Continue reading Figure 2 The passive interconnection unit 13 specifically includes: an adjustable impedance Z, a first phase switch S1 and a second phase switch S2, the adjustable impedance Z is connected in series with the first phase switch S1 and the second phase switch S2, the first phase switch S1 is connected to the first distribution network 14, and the second phase switch S2 is connected to the second distribution network 15;

[0060] On the basis of the first interconnection step, the controller 11 controls the impedance value of the adjustable impedance Z, adjusts the impedance value to make the load rate of the first distribution network 14 and the second distribution network 15 equal, closes the first phase switch S1 and the second phase switch S2, and completes the second interconnection step.

[0061] In a specific implementation scenario, the passive interconnection unit 13 is composed of an adjustable impedance Z, a first phase switch S1 and a second phase switch S2, the adjustable impedance Z is connected in series with the first phase switch S1 and the second phase switch S2, the first phase switch S1 is connected to the first distribution network 14, and the second phase switch S2 is connected to the second distribution network 15. On the basis of the first interconnection step, the controller 11 controls the passive interconnection unit 13 to adjust the impedance value of the adjustable impedance Z, adjust the power distribution between the active interconnection unit 12 and the passive interconnection unit 13, so as to realize the power mutual assistance of the first distribution network 14 and the second distribution network 15, and control the phase switches (the first phase switch S1 and the second phase switch S2) to realize the mutual connection of the first distribution network 14 and the second distribution network 15.

[0062] Specifically, the phase difference, voltage difference and frequency difference between the first distribution network 14 and the second distribution network 15 are measured. When the first distribution network 14 transmits power to the second distribution network 15, the controller 11 controls the active interconnection unit 12 to output a power supply having the same phase difference, voltage difference and frequency difference as the second distribution network 15, so as to provide conditions for the first distribution network 14 or the second distribution network 15 to be synchronously connected to the grid through the passive interconnection unit 13, and the first distribution network 14 and the second distribution network 15 are interconnected in the first step; the controller 11 calculates the impedance value of the adjustable impedance of the passive interconnection unit 13, adjusts the impedance value of the adjustable impedance Z to make the load rate of the first distribution network 14 and the second distribution network 15 equal, closes the first phase switch S1 and the second phase switch S2, and realizes the second step of interconnection of the distribution networks. The circulating current among the first distribution network 14, the second distribution network 15, the active interconnection unit 12, and the passive interconnection unit 13 is measured, and the controller 11 determines whether the circulating current is greater than a first preset value. If so, the active interconnection unit 12 is controlled to output reactive power to the second distribution network 15, and the voltage at the grid connection point between the regulating device and the second distribution network 15 is adjusted until the circulating current among the first distribution network 14, the second distribution network 15, the active interconnection unit 12, and the passive interconnection unit 13 is less than the first preset value IK.

[0063] In another specific implementation scenario, when the second distribution network 15 transmits power to the first distribution network 14, the controller 11 controls the active interconnection unit 12 to output a power supply with a phase difference, voltage difference, and frequency difference consistent with the first distribution network 14, and the first distribution network 14 and the second distribution network 15 perform the first step of interconnection; the controller 11 calculates the impedance value of the adjustable impedance Z of the passive interconnection unit 13, adjusts the impedance value of the adjustable impedance Z to the same load rate as the first distribution network 14 and the second distribution network 15, closes the first phase switch S1 and the second phase switch S2, and realizes the second step of interconnection of the distribution networks. The circulating current among the first distribution network 14, the second distribution network 15, the active interconnection unit 12, and the passive interconnection unit 13 is measured, and the controller 11 determines whether the circulating current is greater than a first preset value. If so, the active interconnection unit 12 is controlled to output reactive power to the first distribution network 14, and the voltage at the grid connection point between the device and the first distribution network 14 is adjusted until the circulating current among the first distribution network 14, the second distribution network 15, the active interconnection unit 12, and the passive interconnection unit 13 is less than the first preset value IK. At this time, the device interconnection is normal.

[0064] After the interconnection is normal, the controller 11 calculates the power distribution between the active interconnection unit 12 and the passive interconnection unit 13 in the resonance mode of the passive interconnection unit 13, and determines whether the power flowing through the active interconnection unit 12 exceeds the capacity of the active interconnection unit 12.

[0065] If the power flowing through the active interconnection unit 12 does not exceed the capacity of the active interconnection unit 12, the capacitance and reactance of the adjustable impedance Z of the passive interconnection unit 13 are adjusted to make the passive interconnection unit 13 resonate and work in a pure resistance mode to reduce the loss of the passive interconnection unit 13. At this time, the power between the active interconnection unit 12 and the passive interconnection unit 13 is redistributed according to the parallel resistance mode.

[0066] In addition, the power output by the active interconnection unit 12 to the first distribution network 14 or the second distribution network 15 is adjusted in phase, so that the three-phase balance of the first distribution network 14 or the second distribution network 15 is achieved, and the adjustable impedance Z of the passive interconnection unit 13 is purely resistive, thereby reducing the loss of the passive interconnection unit 13.

[0067] From the above description, it can be seen that the active interconnection unit realizes flexible power allocation between distribution networks by adjusting the current phase, voltage and frequency difference, and combining the impedance adjustment function of the passive interconnection unit. It can not only adjust the state of the distribution network in real time, but also output the interconnection power that does not exceed its rated capacity through the active interconnection unit, so as to avoid overload or abnormality of the distribution network caused by high power output. The passive interconnection unit is adjusted through adjustable impedance and phase-splitting switches to realize real-time distribution of power and three-phase balance control between distribution networks. This device not only improves the economy, but also effectively alleviates the partial load demand of the distribution network and reduces the risk of overload during faults.

[0068] like Figure 3 As shown, Figure 3 A flow chart of an embodiment of a control method of an interconnection device based on a combination of active and passive components provided by the present invention. A control method of an interconnection device based on a combination of active and passive components is applied to the above-mentioned interconnection device based on a combination of active and passive components, and the method comprises:

[0069] S101: Measure the phase difference, voltage difference, and frequency difference between the first distribution network and the second distribution network, and output a power supply that is consistent with the phase difference, voltage difference, and frequency difference of the first distribution network, or output a power supply that is consistent with the phase difference, voltage difference, and frequency difference of the second distribution network, to complete the first interconnection step.

[0070] In a specific implementation scenario, refer to Figure 2 , measure the phase difference, voltage difference and frequency difference between the first distribution network 14 and the second distribution network 15. When the first distribution network 14 transmits power to the second distribution network 15, the controller 11 controls the second converter CV2 of the active interconnection unit 12 to output a power supply having the same phase difference, voltage difference and frequency difference as the second distribution network 15, and the first distribution network 14 and the second distribution network 15 are interconnected in the first step.

[0071] In another specific implementation scenario, when the second distribution network 15 transmits power to the first distribution network 14, the controller 11 controls the first converter CV1 of the active interconnection unit 12 to output a power supply having a phase difference, a voltage difference, and a frequency difference consistent with the first distribution network 14, thereby providing conditions for the first distribution network 14 or the second distribution network 15 to be synchronously connected to the grid through the passive interconnection unit 13, and the first distribution network 14 and the second distribution network 15 perform the first step of interconnection.

[0072] S102: Based on the first interconnection step, the impedance value of the adjustable impedance is controlled to adjust the impedance value to make the load rates of the first distribution network and the second distribution network equal, and the first phase switch and the second phase switch are closed to complete the second interconnection step.

[0073] In a specific implementation scenario, refer to Figure 2 On the basis of the first interconnection step, the controller 11 calculates the impedance value of the adjustable impedance Z of the passive interconnection unit 13, adjusts the impedance value of the adjustable impedance Z to make the load rates of the first distribution network 14 and the second distribution network 15 equal, closes the first phase switch S1 and the second phase switch S2, and realizes the second interconnection of the distribution networks.

[0074] The impedance value of the adjustable impedance Z of the passive interconnection unit 13 can be determined by using the following formula:

[0075]

[0076] in, Zt is the impedance value of the adjustable impedance, I y is the current passing through the active interconnection unit, Ih is the current to be transmitted from the first distribution network to the second distribution network or from the second distribution network to the first distribution network, Z y is the impedance value of the active interconnect unit.

[0077] From the above description, it can be seen that the present invention realizes real-time power distribution and three-phase balance control between distribution networks by dynamically adjusting the impedance value of the adjustable impedance under the condition of adjusting the phase difference, voltage difference and frequency difference of the first distribution network or the second distribution network, thereby reducing the overall impedance loss and being able to flexibly respond to the continuous changes in the source and load of the distribution network, thereby avoiding the low operating efficiency of traditional methods due to problems such as limited capacity and difficulty in capacity expansion.

[0078] like Figure 4 As shown, Figure 4 A flow chart of another embodiment of a control method for an interconnection device based on a combination of active and passive components provided by the present invention. A control method for an interconnection device based on a combination of active and passive components, the method comprising:

[0079] S201: Measure the phase difference, voltage difference, and frequency difference between the first distribution network and the second distribution network, and output a power supply that is consistent with the phase difference, voltage difference, and frequency difference of the first distribution network, or output a power supply that is consistent with the phase difference, voltage difference, and frequency difference of the second distribution network, to complete the first interconnection step.

[0080] S202: Based on the first interconnection step, the impedance value of the adjustable impedance is controlled to adjust the impedance value to make the load rates of the first distribution network and the second distribution network equal, and the first phase switch and the second phase switch are closed to complete the second interconnection step.

[0081] It should be noted that steps S201-S202 are Figure 3 This has been discussed in detail in the implementation scenario shown and will not be repeated here.

[0082] S203: Determine whether a fault occurs after the first interconnection step and the second interconnection step.

[0083] S204: If a fault occurs after the first and second interconnections, the controller controls the active interconnection unit to exit operation, the passive interconnection unit adjusts the impedance value of the adjustable impedance to zero, disconnects the first phase switch and the second phase switch, and the adjustable impedance exits operation. The passive interconnection unit and the active interconnection unit cooperate with each other in the protection action timing.

[0084] In a specific implementation scenario, it is determined whether a fault occurs after the first interconnection step and the second interconnection step. If a fault occurs after the first interconnection step and the second interconnection step, the controller 11 controls the active interconnection unit 12 to exit operation, and the passive interconnection unit 13 adjusts the impedance value of the adjustable impedance to zero, disconnects the first phase switch and the second phase switch, and the adjustable impedance exits operation. The passive interconnection unit 13 cooperates with the active interconnection unit 12 in the protection action timing, and the protection setting time of the passive interconnection unit 13 is any value between 1.3 times and 1.5 times the protection setting time of the active interconnection unit 12, thereby fully protecting the active interconnection unit 12 from being damaged by overcurrent impact.

[0085] S205: If no fault occurs after the first interconnection step and the second interconnection step, the circulating current among the first distribution network, the second distribution network, the active interconnection unit, and the passive interconnection unit is measured.

[0086] S206: Determine whether the circulation current is greater than a first preset value.

[0087] S207: If the circulating current is greater than the first preset value, the first converter and the second converter of the active interconnected unit output reactive power to the first distribution network and the second distribution network, and adjust the voltage of the connection point between the device and the first distribution network and the second distribution network, until the circulating current between the first distribution network, the second distribution network, the active interconnected unit, and the passive interconnected unit is less than the first preset value. At this time, the device interconnection is normal.

[0088] In a specific implementation scenario, when the first distribution network 14 transmits power to the second distribution network 15, the circulating current between the first distribution network 14, the second distribution network 15, the active interconnection unit 12, and the passive interconnection unit 13 is measured, and the controller 11 determines whether the circulating current is greater than a first preset value. If so, the active interconnection unit 12 is controlled to output reactive power to the second distribution network 15, and the grid connection point voltage between the device and the second distribution network 15 is adjusted until the circulating current between the first distribution network 14, the second distribution network 15, the active interconnection unit 12, and the passive interconnection unit 13 is less than the first preset value IK. At this time, the device interconnection is normal.

[0089] When the second distribution network 15 transmits power to the first distribution network 14, the circulating current among the first distribution network 14, the second distribution network 15, the active interconnection unit 12, and the passive interconnection unit 13 is measured, and the controller 11 determines whether the circulating current is greater than a first preset value. If so, the active interconnection unit 12 is controlled to output reactive power to the first distribution network 14, and the grid connection point voltage between the device and the first distribution network 14 is adjusted until the circulating current among the first distribution network 14, the second distribution network 15, the active interconnection unit 12, and the passive interconnection unit 13 is less than the first preset value IK. At this time, the device interconnection is normal.

[0090] S208: After the interconnection is normal, the controller calculates the power distribution between the active interconnection unit and the passive interconnection unit in the resonance mode of the passive interconnection unit, and determines whether the power flowing through the active interconnection unit exceeds the capacity of the active interconnection unit.

[0091] S209: If the power flowing through the active interconnection unit does not exceed the capacity of the active interconnection unit, the reactance and capacitance of the passive interconnection unit are adjusted to make the passive interconnection unit resonate and work in a pure resistance mode to reduce the loss of the passive interconnection unit. At this time, the power between the active interconnection unit and the passive interconnection unit is redistributed according to the parallel resistance mode.

[0092] In a specific implementation scenario, after the interconnection is normal, the controller 11 calculates the power distribution between the active interconnection unit 12 and the passive interconnection unit 13 in the resonance mode of the passive interconnection unit 13, and determines whether the power flowing through the active interconnection unit 12 exceeds the capacity of the active interconnection unit 12.

[0093] If the power flowing through the active interconnection unit 12 does not exceed the capacity of the active interconnection unit 12, the reactance and capacitance of the passive interconnection unit 13 are adjusted to make the passive interconnection unit 13 resonate and work in a pure resistance mode to reduce the loss of the passive interconnection unit 13. At this time, the power between the active interconnection unit 12 and the passive interconnection unit 13 is redistributed according to the parallel resistance mode.

[0094] like Figure 5 As shown, Figure 5 A flow chart of another embodiment of a control method for an interconnection device based on a combination of active and passive components provided by the present invention. A control method for an interconnection device based on a combination of active and passive components, the method comprising:

[0095] S301: Measure the neutral line current and the A, B, and C three-phase voltages of the first distribution network and the second distribution network.

[0096] S302: Control the active interconnection unit to output the regulating power for regulating the neutral line current and the A, B, and C three-phase voltages of the first distribution network and the second distribution network, so that the neutral line current of the first distribution network and the second distribution network is less than a second preset value, and the voltage of the first distribution network and the second distribution network is less than the value specified by the national standard.

[0097] In a specific implementation scenario, the neutral line current and the three-phase voltages A, B, and C of the first distribution network 14 and the second distribution network 15 are measured, and the active interconnection unit 12 is controlled to output a regulating power for regulating the neutral line current and the three-phase voltages A, B, and C of the first distribution network 14 and the second distribution network 15, so that the neutral line current of the first distribution network 14 and the second distribution network 15 is less than a second preset value, and the voltage of the first distribution network 14 and the second distribution network 15 is less than the value specified in the national standard.

[0098] like Figure 6 As shown, Figure 5 The structure diagram of an embodiment of the medium provided by the present invention is shown in FIG. The medium 20 stores at least one computer program 21, which is executed by a processor to implement the following Figure 3 , Figure 4 and Figure 5 In one embodiment, the medium 20 may be a storage chip, a hard disk, a mobile hard disk, a USB flash drive, an optical disk, or other readable and writable storage tools, or a server, etc.

[0099] The above describes specific embodiments of the present specification, and other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily have to be performed in the specific order or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0100] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device, equipment, and non-volatile computer-readable storage medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0101] The apparatus, device, non-volatile computer-readable storage medium and method provided in the embodiments of this specification correspond to each other, and therefore, the apparatus, device, and non-volatile computer storage medium also have similar beneficial technical effects as the corresponding methods. Since the beneficial technical effects of the methods have been described in detail above, the beneficial technical effects of the corresponding apparatus, device, and non-volatile computer storage medium will not be repeated here.

[0102] The systems, devices, modules or units described in the above embodiments may be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0103] For the convenience of description, the above device is described by being divided into various units according to their functions and described separately. Of course, when implementing this specification, the functions of each unit can be implemented in one or more software and / or hardware. It should be understood by those skilled in the art that this specification embodiment can be provided as a method, system, or computer program product. Therefore, this specification embodiment can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, this specification embodiment can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0104] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0105] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0106] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. An interconnection device based on a combination of active and passive components, characterized in that: The device includes: a controller, an active interconnection unit, and a passive interconnection unit. The controller is connected to the active interconnection unit and the passive interconnection unit. The active interconnection unit and the passive interconnection unit are connected in parallel. The controller controls the active interconnection unit to be connected to a first distribution network and a second distribution network, and is also used to control the passive interconnection unit to be connected to the first distribution network and the second distribution network.

2. The interconnection device based on a combination of active and passive components according to claim 1, characterized in that: The active interconnection unit specifically includes: a first converter and a second converter, the DC side of the first converter is connected to the DC side of the second converter, the AC side of the first converter is connected to a first distribution network, and the AC side of the second converter is connected to a second distribution network. The controller controls the first converter to output a power supply with a phase difference, voltage difference, and frequency difference consistent with the first distribution network, or controls the second converter to output a power supply with a phase difference, voltage difference, and frequency difference consistent with the second distribution network, thereby completing the first interconnection step.

3. The interconnection device based on a combination of active and passive components according to claim 2, characterized in that: The active interconnection unit further includes: a first supporting capacitor, a second supporting capacitor, a first filter, and a second filter. The first supporting capacitor is connected in parallel with the DC side of the first converter, and the second supporting capacitor is connected in parallel with the DC side of the second converter; The first filter is connected to a first power distribution network, and the second filter is connected to a second power distribution network.

4. The interconnection device based on a combination of active and passive components according to claim 2, characterized in that: The passive interconnection unit specifically includes: an adjustable impedance, a first phase-splitting switch and a second phase-splitting switch, The adjustable impedance is connected in series with a first split-phase switch and a second split-phase switch, the first split-phase switch is connected to a first distribution network, and the second split-phase switch is connected to a second distribution network; On the basis of the first interconnection step, the controller controls the impedance value of the adjustable impedance, adjusts the impedance value to make the load rate of the first distribution network and the second distribution network equal, closes the first phase switch and the second phase switch, and completes the second interconnection step.

5. The interconnection device based on a combination of active and passive components according to claim 3, characterized in that: If the circulating current among the first distribution network, the second distribution network, the active interconnection unit, and the passive interconnection unit is greater than a first preset value, the controller controls the first converter and the second converter of the active interconnection unit to output reactive power to the first distribution network and the second distribution network, and adjusts the grid connection point voltage between the device and the first distribution network and the second distribution network until the circulating current among the first distribution network, the second distribution network, the active interconnection unit, and the passive interconnection unit is less than the first preset value.

6. The interconnection device based on the combination of active and passive components according to claim 3 or 4, characterized in that: When the passive interconnection unit fails after being put into operation, the controller controls the active interconnection unit to lock the output, disconnecting the first step of interconnection between the first distribution network and the second distribution network. When the first step of interconnection is disconnected, the passive interconnection unit does not perform the second step of interconnection.

7. The interconnection device based on the combination of active and passive components according to claim 6, characterized in that: If a fault occurs after the first and second steps of interconnection, the controller controls the active interconnection unit to exit operation, the passive interconnection unit adjusts the impedance value of the adjustable impedance to zero, disconnects the first phase switch and the second phase switch, the adjustable impedance exits operation, and the passive interconnection unit and the active interconnection unit cooperate with each other in the protection action timing.

8. A control method for an interconnection device based on a combination of active and passive components, the method being applied to the interconnection device based on a combination of active and passive components as claimed in any one of claims 1 to 7, characterized in that: The method comprises: Measure the phase difference, voltage difference, and frequency difference between the first distribution network and the second distribution network, and output a power supply that is consistent with the phase difference, voltage difference, and frequency difference of the first distribution network, or output a power supply that is consistent with the phase difference, voltage difference, and frequency difference of the second distribution network, to complete the first interconnection step; On the basis of the first interconnection step, the impedance value of the adjustable impedance is controlled to adjust the impedance value to make the load rate of the first distribution network and the second distribution network equal, and the first phase switch and the second phase switch are closed to complete the second interconnection step.

9. A control method for an interconnection device based on a combination of active and passive components, the method being applied to the interconnection device based on a combination of active and passive components as claimed in any one of claims 1 to 7, characterized in that: The method comprises: Measure the neutral line current and the three-phase voltages A, B, and C of the first distribution network and the second distribution network, and control the active interconnection unit to output a regulating power for regulating the neutral line current and the three-phase voltages A, B, and C of the first distribution network and the second distribution network, until the neutral line current of the first distribution network and the second distribution network is less than a second preset value, and the voltage of the first distribution network and the second distribution network is less than the value specified in the national standard.

10. The interconnection method based on active and passive device combination according to claim 8, characterized in that: The step of controlling the impedance value of the adjustable impedance, adjusting the impedance value to make the load rate of the first distribution network and the second distribution network equal, closing the first phase switch and the second phase switch, and completing the second step of interconnection further includes: Determine whether a fault occurs after the first step interconnection and the second step interconnection; If a fault occurs after the first and second interconnections, the controller controls the active interconnection unit to exit operation, the passive interconnection unit adjusts the impedance value of the adjustable impedance to zero, disconnects the first phase-splitting switch and the second phase-splitting switch, the adjustable impedance exits operation, and the passive interconnection unit and the active interconnection unit cooperate with each other in the protection action timing; If no fault occurs after the first interconnection and the second interconnection, measuring the circulating current between the first distribution network, the second distribution network, the active interconnection unit, and the passive interconnection unit; Determining whether the circulation current is greater than a first preset value; If the circulating current is greater than the first preset value, the first converter and the second converter of the active interconnection unit output reactive power to the first distribution network and the second distribution network, and adjust the grid connection point voltage between the device and the first distribution network and the second distribution network until the circulating current between the first distribution network, the second distribution network, the active interconnection unit, and the passive interconnection unit is less than the first preset value, and the device interconnection is normal at this time; After the interconnection is normal, the controller calculates the power distribution between the active interconnection unit and the passive interconnection unit in the resonance mode of the passive interconnection unit, and determines whether the power flowing through the active interconnection unit exceeds the capacity of the active interconnection unit; If the power flowing through the active interconnection unit does not exceed the capacity of the active interconnection unit, the reactance and capacitance of the passive interconnection unit are adjusted to make the passive interconnection unit resonate and work in a pure resistance mode to reduce the loss of the passive interconnection unit. At this time, the power between the active interconnection unit and the passive interconnection unit is redistributed according to the parallel resistance mode.

11. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor is caused to execute the steps of the method according to any one of claims 8 to 10.

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