Zero-voltage ride through type airplane static conversion power supply with photovoltaic function

Abstract

The invention discloses a zero-voltage ride-through type airplane static variable power supply with a photovoltaic function. The zero-voltage ride-through type airplane static variable power supply comprises a power grid access part, a photovoltaic access part, an energy storage access part, a direct-current bus system, an inversion output part and a control system, the control system is internally provided with a detection part for detecting the voltage drop of the power grid, the power grid access part, the photovoltaic access part and the energy storage access part are all connected with the direct-current bus system, and the direct-current bus system is connected with the inverter output part; the control system is respectively connected with the power grid access part, the photovoltaic access part and the energy storage access part, and the control system selectively accesses the power grid access part and / or the photovoltaic access part and / or the energy storage access part to the inversion output part according to the detection of the detection part on the power grid drop data; according to the scheme, when the voltage of the power grid drops or the power supply of the power grid is interrupted, the static variable power supply of the airplane can provide a 400Hz power supply for the airplane, and can provide 380V / 50Hz three-phase alternating current to the outside.

Description

Technical Field

[0001] The invention relates to the technical field of civil aviation power supply equipment, and in particular to a photovoltaic zero-voltage ride-through aircraft static variable power supply. Background Art

[0002] The existing aircraft ground static variable power supply generally adopts twelve-pulse rectification + PWM inverter technology. The DC bus voltage is not adjustable, and the power supply quality is affected by the grid wave. In particular, when the grid voltage drops by more than 40%, it will cause the static variable power supply to be interrupted, which cannot meet the requirements of aircraft power supply reliability. The existing solution to static variable power supply flashover is mainly to add capacitors to the static variable power supply bus, but the capacitor is large in size and high in cost, which is not conducive to promotion. Summary of the invention

[0003] The purpose of the present invention is to provide a zero voltage ride-through aircraft static variable power supply with photovoltaic power supply to address the above-mentioned deficiencies, thereby solving the problem in the prior art that the DC bus voltage of the aircraft ground static variable power supply cannot be adjusted, the power supply quality is affected by grid waves, and in particular, when the grid voltage drops by more than 40%, the static variable power supply will be interrupted, and the aircraft power supply reliability requirements cannot be met.

[0004] The present invention is achieved through the following scheme:

[0005] A zero voltage ride-through aircraft static variable power supply with photovoltaics, comprising the following steps:

[0006] At least including but not limited to a grid access unit, a photovoltaic access unit, an energy storage access unit, a DC bus system, an inverter output unit and a control system; the control system is provided with a detection unit for detecting grid voltage drop, the grid access unit, the photovoltaic access unit and the energy storage access unit are all connected to the DC bus system, and the DC bus system is connected to the inverter output unit; the control system is respectively connected to the grid access unit, the photovoltaic access unit and the energy storage access unit, and the control system selects to connect the grid access unit and / or the photovoltaic access unit and / or the energy storage access unit to the inverter output unit according to the detection of the grid drop data by the detection unit.

[0007] Based on the structure of the above-mentioned zero-voltage ride-through aircraft static variable power supply with photovoltaics, the grid access part includes a first line, a grid fast switching device, a reactor and a grid-side converter; the grid fast switching device, the reactor and the grid-side converter are arranged in sequence along the power input direction of the first line, and a first filter capacitor is also arranged between the grid fast switching device and the reactor; the control lines of the grid fast switching device and the grid-side converter are connected to the control system.

[0008] Based on the above-mentioned structure of a zero-voltage ride-through aircraft static variable power supply with photovoltaics, an external circuit is arranged between the grid fast switching device and the first filter capacitor; a soft start circuit is arranged between the grid fast switching device and the grid-side converter, and the control end of the soft start circuit is connected to the control system.

[0009] Based on the above-mentioned structure of a zero-voltage ride-through aircraft static variable power supply with photovoltaics, the photovoltaic access part includes a photovoltaic incoming line and a photovoltaic controller. The photovoltaic controller is arranged on the photovoltaic incoming line. The control line of the photovoltaic controller is connected to the control system. One end of the photovoltaic incoming line is connected to an external photovoltaic component, and the other end is connected to a DC bus system.

[0010] Based on the above-mentioned structure of a zero-voltage ride-through aircraft static variable power supply with photovoltaics, the energy storage access part includes an energy storage incoming line and an energy storage controller. The energy storage controller is arranged on the energy storage incoming line. The control line of the energy storage controller is connected to the control system. One end of the energy storage incoming line is connected to an external energy storage battery, and the other end is connected to a DC bus system.

[0011] Based on the structure of the above-mentioned zero-voltage ride-through aircraft static variable power supply with photovoltaics, the inverter output unit includes an inverter, a transformer, a second filter capacitor and an output contactor; the inverter is connected to the control system, and the inverter, transformer, second filter capacitor and output contactor are arranged in sequence along the power transmission direction.

[0012] Based on the structure of the above-mentioned zero voltage ride-through aircraft static variable power supply with photovoltaic, a supporting capacitor is provided in the DC bus system.

[0013] This solution provides a control method for a zero voltage ride-through aircraft static variable power supply with photovoltaic, which at least includes the following steps:

[0014] Step 1: Connect the AC grid, photovoltaic modules and energy storage batteries to the first line, photovoltaic feeder line and energy storage feeder line respectively;

[0015] Step 2: The internal detection unit of the control system detects the grid drop value of the AC grid, and selects to switch on and off the AC grid according to predetermined rules, or cooperates with photovoltaic modules and / or energy storage batteries to output the inverter output unit, and finally supplies a stable current to the aircraft static variable power supply.

[0016] In step 2, the pre-set regulations are as follows:

[0017] When the detection unit detects that the grid drops by less than 20%, the control system decouples the active and reactive power of the grid-side converter, controls the grid to provide power to the aircraft, and gives priority to absorbing photovoltaic power generation;

[0018] When the detection unit detects a grid drop of 20% ≤ <40%, the control system controls the grid-side converter, photovoltaic controller and energy storage controller to achieve power supply balance. The electricity from photovoltaic, grid and energy storage is used to power the aircraft through the inverter.

[0019] When the detection unit detects a grid drop of 40% or less, the control system controls the grid fast cut-off device to disconnect the grid-side converter from the grid, and controls the energy storage and photovoltaic power to power the aircraft through the inverter;

[0020] When the detection unit detects that the power grid drops by ≥40% until the power grid returns to normal, the soft start circuit first controls the power grid to gradually supply power to the DC bus, and then closes the fast switching device to restore power supply to the power grid.

[0021] When the PV module parameters have a lot of electric energy, the control system sends the PV power to the grid through the grid-side converter, and other equipment in the airport consumes the PV power, making it more efficient. When 50Hz AC power is required externally, the control system controls the grid fast-cut device to disconnect the grid-side converter from the grid, and the grid-side converter inverts 50Hz three-phase AC power. The entire system is powered by energy storage and photovoltaics.

[0022] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0023] 1) When the grid voltage drops or the grid power supply is interrupted, the aircraft static variable power supply can provide 400Hz power to the aircraft and can provide AC380V / 50Hz three-phase AC power to the outside;

[0024] 2) Restoring power after a grid power outage can avoid the impact of the aircraft's static variable power supply on the grid, and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural flow chart of the whole invention;

[0026] Markings in the figure: 1. Grid access part; 2. Photovoltaic access part; 3. Energy storage access part; 4. DC bus system; 5. Inverter output part; 6. Control system; 11. First line; 12. Grid fast switching device; 13. Reactor; 14. Grid-side converter; 15. First filter capacitor; 16. External line; 17. Soft start circuit; 21. Photovoltaic input line; 22. Photovoltaic controller; 31. Energy storage input line; 32. Energy storage controller; 51. Inverter; 52. Transformer; 53. Second filter capacitor; 54. Output contactor; 55. Support capacitor. DETAILED DESCRIPTION

[0027] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0028] Any feature disclosed in this specification (including any additional claims and abstract), unless otherwise stated, may be replaced by other equivalent or alternative features having similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0029] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a predetermined direction, be constructed and operated in a predetermined direction, and therefore cannot be understood as a limitation on the present invention.

[0030] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0031] Example 1

[0032] like Figure 1 As shown, the present invention provides a technical solution:

[0033] A zero voltage ride-through aircraft static variable power supply with photovoltaics, which at least includes but is not limited to a power grid access unit 1, a photovoltaic access unit 2, an energy storage access unit 3, a DC bus system 4, an inverter output unit 5 and a control system 6; a detection unit for detecting a power grid voltage drop is provided in the control system 6, the power grid access unit 1, the photovoltaic access unit 2, and the energy storage access unit 3 are all connected to the DC bus system 4, and the DC bus system 4 is connected to the inverter output unit 5; the control system 6 is respectively connected to the power grid access unit 1, the photovoltaic access unit 2 and the energy storage access unit 3, and the control system 6 selects to connect the power grid access unit 1 and / or the photovoltaic access unit 2 and / or the energy storage access unit 3 to the inverter output unit 5 according to the detection of the power grid drop data by the detection unit.

[0034] Based on the above structure, one end of the grid access part 1 is connected to the AC grid, and the other end is connected to the DC bus system 4. The AC grid is directly connected to the DC bus system 4 after being processed through the grid access part 1, and the aircraft power supply is powered by the inverter output part 5. One end of the photovoltaic access part 2 is connected to the photovoltaic component, and the other end is connected to the DC bus system 4. The photovoltaic component is connected to the power supply structure through corresponding conditions, and the aircraft static variable power supply is powered alone or in combination. One end of the energy storage access part 3 is connected to the energy storage battery, and the other end is connected to the DC bus system 4. The energy storage battery is connected to the power supply structure through corresponding conditions, and the aircraft static variable power supply is powered alone or in combination. Through this solution, energy can be supplied to the aircraft static variable power supply more efficiently, flexibly and safely, ensuring the data and power safety in the aircraft and its attached components. At the same time, the power supply is restored after the power supply of the grid is interrupted, which can avoid the impact of the grid on the aircraft static variable power supply.

[0035] As an example, the grid access unit 1 may include a first line 11, a grid fast switching device 12, a reactor 13 and a grid-side converter 14; the grid fast switching device 12, the reactor 13 and the grid-side converter 14 are arranged in sequence along the power input direction of the first line 11, and a first filter capacitor 15 may also be arranged between the grid fast switching device 12 and the reactor 13; the control lines of the grid fast switching device 12 and the grid-side converter 14 are connected to the control system 6.

[0036] Based on the above structure, in this scheme, the grid fast switching device 12 is used to realize the fast switching or connection of the grid, and the grid passing through its line can be filtered by setting the inductor 13; by setting the first filter capacitor 15 between the grid fast switching device 12 and the inductor 13, it is mainly for filtering voltage and current harmonics; by setting the grid-side converter 14: the AC power of the grid can be converted into DC power or the DC power can be converted into AC power, and the grid access part 1 can realize the switching in and out of the grid, and at the same time, the AC and DC of the grid can be converted, and the input circuit can be filtered and processed, so that the electrical signal entering the inverter output part 5 is more stable.

[0037] As an example, the grid fast cutting device can specifically be a thyristor and its driving circuit, a fast circuit breaker or a contactor, which has a fast switching function and a breaking time of less than 20ms to ensure stability after switching.

[0038] As an example, the grid-side converter 14 may specifically be a three-phase half-bridge circuit.

[0039] As an example, an external line 16 may be provided between the grid fast switching device 12 and the first filter capacitor 15. The external line 16 may be used to supply power to external devices.

[0040] As an example, a soft start circuit 17 may be provided between the grid fast switching device 12 and the grid-side converter 14 , and a control end of the soft start circuit 17 is connected to the control system 6 .

[0041] Based on the above structure, the present solution can reduce the starting current impact and protect the system circuit through the soft start circuit 17; the soft start circuit 17 can specifically be a thyristor and its driving circuit. When the power grid returns to normal, the soft start circuit 17 first controls the power grid to gradually supply power to the output end, and then closes the fast switching device to restore the power supply of the power grid, so that the power supply can be more safely carried out.

[0042] As an example, the photovoltaic access part 2 may include a photovoltaic incoming line 21 and a photovoltaic controller 22. The photovoltaic controller 22 is arranged on the photovoltaic incoming line 21. The control line of the photovoltaic controller 22 is connected to the control system 6. One end of the photovoltaic incoming line 21 is connected to an external photovoltaic component, and the other end is connected to a DC bus system.

[0043] In this solution, the photovoltaic controller 22 can track the maximum power point of the photovoltaic cell in real time and transfer the photovoltaic power to the DC bus. The photovoltaic controller 22 can adopt a Boost / Buck circuit.

[0044] Based on the above structure, the output power of this solution can be a photovoltaic module. In places where there is sufficient light energy, light energy can be used to charge the aircraft static variable power supply first, which can reduce the load on the power grid.

[0045] As an example, the energy storage access unit 3 may include an energy storage incoming line 31 and an energy storage controller 32. The energy storage controller 32 is arranged on the energy storage incoming line 31. The control line of the energy storage controller 32 is connected to the control system 6. One end of the energy storage incoming line 31 is connected to an external energy storage battery, and the other end is connected to the DC bus system.

[0046] In this solution, the energy storage battery can realize bidirectional power flow and voltage step-up and step-down, charging the electric energy of the DC bus into the battery, and also discharging the electricity in the battery to the DC bus. The energy storage controller 32 can adopt the Boost / Buck bidirectional step-up and step-down circuit.

[0047] Based on the above structure, the output power supply of this solution can be an energy storage battery. In places where solar energy is insufficient, the aircraft static variable power supply can be charged by the energy storage battery, which can also reduce the load on the power grid.

[0048] As an example, the inverter output unit 5 may include an inverter 51, a transformer 52, a second filter capacitor 53 and an output contactor 54; the inverter 51 is connected to the control system 6, and the inverter 51, the transformer 52, the second filter capacitor 53 and the output contactor 54 are arranged in sequence along the power transmission direction.

[0049] Based on the above structure, the inverter 51 can be controlled by the control system 6, the circuit is converted by the inverter 51, and power is sent to the aircraft static power supply through the transformer 52, the second filter capacitor 53 and the output contactor 54.

[0050] In this solution, the inverter 51 converts DC power into 400Hz AC power, and a three-phase full-bridge circuit can be used; the transformer 52 has filtering and voltage conversion functions; the output contactor 54 is developed for 400Hz power supply output; the second filter capacitor 53 can filter out voltage and current harmonics; control system 6: the control system 6 controls the DC bus voltage, controls the dispatching of electric energy and the switching of the grid fast cutting device, and ensures the stability of the 400Hz power supply.

[0051] As an example, a support capacitor 55 may be provided in the DC bus system 4. The support capacitor 55 can provide power supply for the entire system when a power outage occurs, so that relevant personnel can have sufficient time to carry out safety processing when a power outage occurs.

[0052] Example 2

[0053] Based on the structure of the above embodiment 1, this solution provides a technical solution;

[0054] A control method for a photovoltaic zero voltage ride-through aircraft static variable power supply comprises at least the following steps:

[0055] Step 1: Connect the AC grid, photovoltaic modules and energy storage batteries to the first line 11, the photovoltaic feeder line 21 and the energy storage feeder line 31 respectively;

[0056] Step 2: The internal detection unit of the control system 6 detects the grid drop value of the AC grid, and selects to switch on and off the AC grid according to predetermined rules, or cooperates with photovoltaic components and / or energy storage batteries to output the inverter output unit 5, and finally supplies a stable current to the aircraft static variable power supply.

[0057] In step 2, the pre-set regulations are as follows:

[0058] When the detection unit detects that the grid drops less than 20%, the control system 6 decouples the active and reactive power of the grid-side converter 14, controls the grid to provide power to the aircraft, and preferentially consumes photovoltaic power generation;

[0059] When the detection unit detects that the grid drop is 20%≤40%, the control system 6 controls the grid-side converter 14, the photovoltaic controller 22 and the energy storage controller 32 to achieve power supply balance, and the electricity from the photovoltaic, grid and energy storage is used to power the aircraft through the 400Hz inverter 51;

[0060] When the detection unit detects that the grid drops by 40% ≤, the control system 6 controls the grid fast cutting device to disconnect the grid-side converter 14 from the grid, and controls the energy storage and photovoltaic power to supply power to the aircraft through the 400Hz inverter 51;

[0061] When the detection unit detects that the grid drops by ≥40% until the grid returns to normal, the soft start circuit 17 first controls the grid to gradually supply power to the DC bus, and then closes the fast switching device to restore grid power supply.

[0062] Based on the above rules, since photovoltaics are energy that is not easy to store, it is necessary to give priority to the use of energy generated by photovoltaic modules, so as to reduce the load on the power grid; when the detection unit detects that the power grid drops by less than 20%, the AC power grid fluctuation value is calculated with 380V AC power, and the AC power grid fluctuation value is between 304 and 380V, that is, the AC power grid voltage fluctuation is small. At this time, the AC power grid can be used to directly transform and supply power to the aircraft static transformer circuit; when photovoltaics are present, photovoltaics are used for power supply; the allocation principle at this time is that the AC power grid output voltage + the photovoltaic module output voltage = the predetermined voltage to be inverted. After the voltage to be inverted is inverted, it can continuously output a voltage of predetermined parameters for the aircraft static transformer power supply. The voltage of the predetermined parameters is usually 115V or 200V, 400Hz.

[0063] When the detection unit detects that 20%≤grid drop<40%, the AC grid fluctuation value is measured at 380V AC power and is between 228V and 304V, that is, the AC grid voltage is reduced. Therefore, it is necessary to connect at least two energy supply units to supply energy to the inverter output unit 5. At this time, the AC grid output voltage+the photovoltaic component output voltage+the energy storage battery output power=the predetermined voltage to be inverted. After the voltage to be inverted is inverted, it can continuously output a voltage of predetermined parameters for the aircraft static power supply; the voltage of the predetermined parameters is usually 115V or 200V, 400Hz.

[0064] When the grid drops by ≥40% (including grid power outage), the AC grid supply is no longer available, so the control system 6 controls the grid fast cutting device to disconnect the grid-side converter 14 from the grid, and controls the energy storage and photovoltaic power to power the aircraft through the 400Hz inverter 51. At this time, the output voltage of the photovoltaic component + the output power of the energy storage battery = the predetermined voltage to be inverted. After the voltage to be inverted is inverted, it can continuously output a voltage of a predetermined parameter for the aircraft static power supply; the voltage of the predetermined parameter is usually 115V or 200V, 400Hz voltage.

[0065] When the photovoltaic component parameters have a large amount of electrical energy, the control system 6 can send the photovoltaic electrical energy to the power grid through the grid-side converter 14, and other equipment in the airport will consume the photovoltaic electricity, so that it can be used more efficiently.

[0066] When 50Hz AC power is needed externally, the control system 6 controls the grid fast cut-off device to disconnect the grid-side converter 14 from the grid, and the grid-side converter 14 inverts 50Hz three-phase AC power. The entire system is powered by energy storage and photovoltaics, making the use of this power supply more flexible. Energy can be used externally through an external line 16, making it more efficient.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A zero voltage ride-through aircraft static variable power supply with photovoltaic, characterized in that: At least including but not limited to a grid access unit, a photovoltaic access unit, an energy storage access unit, a DC bus system, an inverter output unit and a control system; the control system is provided with a detection unit for detecting grid voltage drop, the grid access unit, the photovoltaic access unit and the energy storage access unit are all connected to the DC bus system, and the DC bus system is connected to the inverter output unit; the control system is respectively connected to the grid access unit, the photovoltaic access unit and the energy storage access unit, and the control system selects to connect the grid access unit and / or the photovoltaic access unit and / or the energy storage access unit to the inverter output unit according to the detection of the grid drop data by the detection unit.

2. According to claim 1, a photovoltaic zero voltage ride-through aircraft static variable power supply, characterized in that: The grid access unit includes a first line, a grid fast switching device, a reactor and a grid-side converter; the grid fast switching device, the reactor and the grid-side converter are arranged in sequence along the power input direction of the first line, and a first filter capacitor is also arranged between the grid fast switching device and the reactor; the control lines of the grid fast switching device and the grid-side converter are connected to the control system.

3. According to claim 2, a photovoltaic zero voltage ride-through aircraft static variable power supply, characterized in that: An external circuit is arranged between the grid fast switching device and the first filter capacitor; a soft start circuit is arranged between the grid fast switching device and the grid-side converter, and a control end of the soft start circuit is connected to a control system.

4. According to claim 3, a photovoltaic zero voltage ride-through aircraft static variable power supply, characterized in that: The photovoltaic access part includes a photovoltaic incoming line and a photovoltaic controller. The photovoltaic controller is arranged on the photovoltaic incoming line. The control line of the photovoltaic controller is connected to the control system. One end of the photovoltaic incoming line is connected to an external photovoltaic component, and the other end is connected to a DC bus system.

5. The photovoltaic zero voltage ride-through aircraft static variable power supply according to claim 4, characterized in that: The energy storage access part includes an energy storage inlet line and an energy storage controller. The energy storage controller is arranged on the energy storage inlet line. The control line of the energy storage controller is connected to the control system. One end of the energy storage inlet line is connected to an external energy storage battery, and the other end is connected to a DC bus system.

6. The photovoltaic zero voltage ride-through aircraft static variable power supply according to claim 5, characterized in that: The inverter output unit includes an inverter, a transformer, a second filter capacitor and an output contactor; the inverter is connected to a control system, and the inverter, the transformer, the second filter capacitor and the output contactor are arranged in sequence along the power transmission direction.

7. The photovoltaic zero voltage ride-through aircraft static variable power supply according to claim 6, characterized in that: A supporting capacitor is provided in the DC bus system.

8. The photovoltaic zero voltage ride-through aircraft static variable power supply according to claim 7, characterized in that: A control method is provided; the control method comprises at least the following steps: Step 1: Connect the AC grid, photovoltaic modules and energy storage batteries to the first line, photovoltaic feeder line and energy storage feeder line respectively; Step 2: The internal detection unit of the control system detects the grid drop value of the AC grid, and selects to switch on and off the AC grid according to predetermined rules, or cooperates with photovoltaic modules and / or energy storage batteries to output the inverter output unit, and finally supplies a stable current to the aircraft static variable power supply.

9. The photovoltaic zero voltage ride-through aircraft static variable power supply according to claim 8, characterized in that: In step 2, the pre-set regulations are as follows: When the detection unit detects that the grid drops by less than 20%, the control system decouples the active and reactive power of the grid-side converter, controls the grid to provide power to the aircraft, and gives priority to absorbing photovoltaic power generation; When the detection unit detects a grid drop of 20% ≤ <40%, the control system controls the grid-side converter, photovoltaic controller and energy storage controller to achieve power supply balance. The electricity from photovoltaic, grid and energy storage is used to power the aircraft through the inverter. When the detection unit detects a grid drop of 40% or less, the control system controls the grid fast cut-off device to disconnect the grid-side converter from the grid, and controls the energy storage and photovoltaic power to power the aircraft through the inverter; When the detection unit detects that the power grid drops by ≥40% until the power grid returns to normal, the soft start circuit first controls the power grid to gradually supply power to the DC bus, and then closes the fast switching device to restore power supply to the power grid.

10. The photovoltaic zero voltage ride-through aircraft static variable power supply according to claim 9, characterized in that: When the PV module parameters have a lot of electric energy, the control system sends the PV power to the grid through the grid-side converter, and other equipment in the airport consumes the PV power, making it more efficient. When 50Hz AC power is required externally, the control system controls the grid fast-cut device to disconnect the grid-side converter from the grid, and the grid-side converter inverts 50Hz three-phase AC power. The entire system is powered by energy storage and photovoltaics.

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