Electric power system comprising novel energy storage device

Abstract

The invention discloses a power system comprising a novel energy storage device. The power system comprises the novel energy storage device, a sensitive load, a distributed new energy power generation device, a first DC / DC converter, a first AC / DC converter, a first isolation transformer, a second DC / DC converter, a second AC / DC converter and a second isolation transformer, the novel energy storage device is connected in series with the sensitive load through the first DC / DC converter, the first AC / DC converter and the first isolation transformer, and is connected in parallel with the distributed new energy power generation device through the second DC / DC converter, the second AC / DC converter and the second isolation transformer. The problem that a traditional new energy storage device is single in wiring mode and wiring scheme, single in function and single in application scene is solved.

Description

Technical Field

[0001] The present invention relates to the field of new energy storage technologies, and particularly to a power system including a new energy storage device. Background Art

[0002] With the continuous growth of power demand and the increasing complexity of the power grid, traditional energy storage technologies have been difficult to meet the requirements of modern power systems. Therefore, new energy storage technologies have shown great application potential in power systems.

[0003] The wiring methods of traditional new energy storage devices mainly adopt a single series or parallel scheme. The series scheme and the parallel scheme have their own focuses. When connected in series, more attention is paid to providing customized power quality guarantee and power support for specific users; while when connected in parallel to the distribution network bus, more attention is paid to improving the stability of the power system, frequency regulation, and power support, etc. Once the traditional single series or single parallel method is wired, it can only achieve a single function and adapt to a single application scenario. For example: The single series method limits the new energy storage device to be connected to the power grid in series, and cannot achieve the related functions of parallel connection to the power grid. It is only applicable to power systems with sensitive loads, but not applicable to power systems with distributed new energy generation devices. The single parallel method limits the new energy storage device to be connected to the power grid in parallel, and cannot achieve the related functions of series connection to the power grid. It is only applicable to power systems with distributed new energy generation devices, but not applicable to power systems with sensitive loads. If the power grid contains both sensitive loads and distributed new energy generation devices, neither the single series scheme nor the single parallel scheme is applicable. Therefore, due to the single wiring scheme, the traditional wiring method of new energy storage devices has the disadvantages of single function and single applicable scenario. Summary of the Invention

[0004] The present invention provides a power system including a new energy storage device to solve the technical problems of single function and single applicable scenario of the traditional wiring method.

[0005] To solve the above technical problems, an embodiment of the present invention provides a power system including a new energy storage device, comprising: a new energy storage device, a sensitive load, a distributed new energy generation device, a first DC / DC converter, a first AC / DC inverter, a first isolation transformer, a second DC / DC converter, a second AC / DC inverter, and a second isolation transformer;

[0006] The new energy storage device is connected to the first end of the first DC / DC converter;

[0007] The second end of the first DC / DC converter is connected to the first end of the first AC / DC inverter;

[0008] The second end of the first AC / DC converter is connected to the first end of the first isolation transformer;

[0009] The second end of the first isolation transformer is connected to the distribution bus of the power system through a sensitive load feeder;

[0010] The third end of the first isolation transformer is connected to the sensitive load through a sensitive load power supply line;

[0011] The novel energy storage device is connected to the first end of the second DC / DC converter;

[0012] The second end of the second DC / DC converter is connected to the first end of the second AC / DC converter;

[0013] The second end of the second AC / DC converter is connected to the first end of the second isolation transformer;

[0014] The second end of the second isolation transformer is connected to the distribution bus.

[0015] As a preferred solution, the novel energy storage device is a high-temperature superconducting magnetic energy storage device.

[0016] As a preferred solution, the first DC / DC converter is a DC / DC chopper;

[0017] The first AC / DC converter is an AC / DC bidirectional MMC series converter;

[0018] The first isolation transformer is a series isolation transformer.

[0019] As a preferred solution, the second DC / DC converter is a DC / DC chopper;

[0020] The second AC / DC converter is an AC / DC bidirectional MMC parallel converter;

[0021] The second isolation transformer is a parallel isolation transformer.

[0022] As a preferred solution, the voltage level of the distribution bus is 10 kV.

[0023] As a preferred solution, the second end of the first isolation transformer is connected to the first end of the sensitive load feeder breaker; wherein, the second end of the sensitive load feeder breaker is connected to the distribution bus.

[0024] As a preferred solution, the second end of the second isolation transformer is connected to the first end of the feeder breaker; wherein, the second end of the feeder breaker is connected to the distribution bus.

[0025] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0026] The power system of the present invention includes: a new energy storage device, a sensitive load, a distributed new energy power generation device, a first DC / DC converter, a first AC / DC inverter, a first isolation transformer, a second DC / DC converter, a second AC / DC inverter, and a second isolation transformer; the new energy storage device is connected to the first end of the first DC / DC converter; the second end of the first DC / DC converter is connected to the first end of the first AC / DC inverter; the second end of the first AC / DC inverter is connected to the first end of the first isolation transformer; the second end of the first isolation transformer is connected to the distribution bus of the power system through a sensitive load feeder; the third end of the first isolation transformer is connected to the sensitive load through a sensitive load power supply line; the new energy storage device is connected to the first end of the second DC / DC converter; the second end of the second DC / DC converter is connected to the first end of the second AC / DC inverter; the second end of the second AC / DC inverter is connected to the first end of the second isolation transformer; the second end of the second isolation transformer is connected to the distribution bus.

[0027] The new energy storage device of the present invention is connected to the sensitive load in series through the first DC / DC converter, the first AC / DC inverter, and the first isolation transformer, and is connected to the distributed new energy power generation device in parallel through the second DC / DC converter, the second AC / DC inverter, and the second isolation transformer. The power system containing the new energy storage device provided by the present invention is applicable not only to the scenario where the power system contains sensitive loads, but also to the scenario where the power system contains distributed new energy power generation devices. At the same time, it has the advantages of series access and parallel access of the new energy storage device, and solves the problems of single wiring scheme, single function, and single applicable scenario of the traditional new energy storage device wiring method. Description of the Drawings

[0028] Figure 1 is a schematic structural diagram of a power system containing a new energy storage device provided by an embodiment of the present invention;

[0029] Among them, the reference numerals in the specification drawings are as follows: new energy storage device 1, sensitive load 2, distributed new energy power generation device 3, first DC / DC converter 4, first AC / DC inverter 5, first isolation transformer 6, second DC / DC converter 7, second AC / DC inverter 8, and second isolation transformer 9. Detailed Embodiments

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] Embodiment 1

[0032] Please refer to Figure 1 , a power system including a new energy storage device 1 provided by an embodiment of the present invention, comprising: a new energy storage device 1, a sensitive load 2, a distributed new energy power generation device 3, a first DC / DC converter 4, a first AC / DC inverter 5, a first isolation transformer 6, a second DC / DC converter 7, a second AC / DC inverter 8, and a second isolation transformer 9;

[0033] The new energy storage device 1 is connected to the first end of the first DC / DC converter 4;

[0034] The second end of the first DC / DC converter 4 is connected to the first end of the first AC / DC inverter 5;

[0035] The second end of the first AC / DC inverter 5 is connected to the first end of the first isolation transformer 6;

[0036] The second end of the first isolation transformer 6 is connected to the distribution bus of the power system through the feeder line of the sensitive load 2;

[0037] The third end of the first isolation transformer 6 is connected to the sensitive load 2 through the power supply line of the sensitive load 2;

[0038] The new energy storage device 1 is connected to the first end of the second DC / DC converter 7;

[0039] The second end of the second DC / DC converter 7 is connected to the first end of the second AC / DC inverter 8;

[0040] The second end of the second AC / DC inverter 8 is connected to the first end of the second isolation transformer 9;

[0041] The second end of the second isolation transformer 9 is connected to the distribution bus.

[0042] In this embodiment, the new energy storage device 1 controls the DC-side voltage through the first DC / DC converter 4 circuit, connects to the first AC / DC inverter 5, converts it into alternating current corresponding to the voltage level of the distribution bus for output, and then is connected in series between the power supply line of the sensitive load and the feeder line of the sensitive load 2 in the distribution system through the first isolation transformer 6.

[0043] In a preferred embodiment, the novel energy storage device 1 is a high-temperature superconducting magnetic energy storage device.

[0044] It should be noted that the traditional novel energy storage device 1 has system losses and its efficiency needs to be improved. It is proposed to use a high-temperature superconducting magnetic energy storage device, which utilizes the "zero resistance" and "zero loss" effects of high-temperature superconducting magnetic energy storage technology and is applied to the power system more efficiently and with high density. As a novel energy storage technology, high-temperature superconducting magnetic energy storage stores electrical energy in the form of electromagnetic energy through superconducting coils and then outputs the electrical energy to the power grid or other loads when needed. It has extremely high energy conversion efficiency and an extremely fast response speed, can quickly adjust the power balance of the power system, improve the stability of the power grid and the quality of electrical energy, and shows great application potential in the power system.

[0045] Sensitive loads have high requirements for voltage stability. Once the voltage fluctuates too much, it may cause equipment failure or damage. The high-temperature superconducting magnetic energy storage device can provide stable voltage support for sensitive loads through its characteristics of fast response and high-efficiency energy storage. When the grid voltage fluctuates, the high-temperature superconducting magnetic energy storage device can quickly release or absorb electrical energy, thereby stabilizing the voltage, ensuring the normal operation of sensitive loads, providing voltage support for the power lines of sensitive loads, and improving the power supply quality.

[0046] In a preferred embodiment, the second end of the first isolation transformer 6 is connected to the first end of the feeder breaker of the sensitive load 2; wherein, the second end of the feeder breaker of the sensitive load 2 is connected to the distribution bus.

[0047] In a preferred embodiment, the first DC / DC converter 4 is a DC / DC chopper;

[0048] The first AC / DC converter 5 is an AC / DC bidirectional MMC series converter;

[0049] The first isolation transformer 6 is a series isolation transformer.

[0050] S21. When the power system contains a distributed new energy power generation device 3, connect the novel energy storage device 1 to the first end of the second DC / DC converter 7.

[0051] S22. Connect the second end of the second DC / DC converter 7 to the first end of the second AC / DC converter 8.

[0052] S23. Connect the second end of the second AC / DC converter 8 to the first end of the second isolation transformer 9.

[0053] S24. Connect the second end of the second isolation transformer 9 to the distribution bus of the power system.

[0054] In this embodiment, the novel energy storage device 1 controls the DC-side voltage through the second DC / DC converter 7, connects to the second AC / DC converter 8, is converted into alternating current corresponding to the distribution bus voltage level for output, and then is connected to the distribution bus through the second isolation transformer 9.

[0055] It should be noted that the distributed new energy power generation device 3, due to the intermittency and uncertainty of its power generation power, will affect the stability of the power grid. The superconductor of the high-temperature superconducting magnetic energy storage device has the "zero resistance effect", can achieve high-density and high-efficiency energy storage with a fast response in milliseconds. When there are power fluctuations or imbalances in the power grid, the high-temperature superconducting magnetic energy storage device can use its fast response ability to track and compensate these power fluctuations in real time. The device can respond quickly, release or absorb electric energy, thereby effectively balancing the power changes in the power grid and balancing the impact of distributed power sources on the power grid stability.

[0056] In a preferred embodiment, the second end of the second isolation transformer 9 is connected to the first end of the feeder circuit breaker; wherein, the second end of the feeder circuit breaker is connected to the distribution bus.

[0057] In a preferred embodiment, the voltage level of the distribution bus is 10 kV.

[0058] In a preferred embodiment, the second DC / DC converter 7 is a DC / DC chopper;

[0059] The second AC / DC converter 8 is an AC / DC bidirectional MMC parallel converter;

[0060] The second isolation transformer 9 is a parallel isolation transformer.

[0061] In the preferred embodiment of the present invention, the high-temperature superconducting magnetic energy storage device is respectively connected in parallel to the 10 kV distribution bus feeder interval and in series to the 10 kV sensitive load feeder through parallel and series transformers. The high-temperature superconducting magnetic energy storage device uses the series connection to improve the power supply quality of sensitive loads, and uses the parallel connection to balance the impact of distributed power sources on the power grid stability, realizing the "multi-purpose in one body, time-sharing multiplexing" of the high-temperature superconducting magnetic energy storage device, and further realizing the flexible control of the power flow direction and the diversification of functions of the high-temperature superconducting magnetic energy storage device for the 10 kV distribution system.

[0062] It should be noted that in view of the problem of single regulation and function caused by the traditional novel energy storage device adopting a single parallel or single series connection to the distribution network, the present invention proposes a wiring design scheme for a novel energy storage device in a power system that combines parallel and series hybrid coupling. It solves the problems of single wiring scheme, single function and single applicable scenario of the traditional new energy storage device wiring method.

Claims

1. A power system with a new energy storage device, characterized in that, Comprising: A new energy storage device, a sensitive load, a distributed new energy power generation device, a first DC / DC converter, a first AC / DC inverter, a first isolation transformer, a second DC / DC converter, a second AC / DC inverter, and a second isolation transformer; The new energy storage device is connected to the first end of the first DC / DC converter; The second end of the first DC / DC converter is connected to the first end of the first AC / DC inverter; The second end of the first AC / DC inverter is connected to the first end of the first isolation transformer; The second end of the first isolation transformer is connected to the distribution bus of the power system through a sensitive load feeder; The third end of the first isolation transformer is connected to the sensitive load through a sensitive load power supply line; The new energy storage device is connected to the first end of the second DC / DC converter; The second end of the second DC / DC converter is connected to the first end of the second AC / DC inverter; The second end of the second AC / DC inverter is connected to the first end of the second isolation transformer; The second end of the second isolation transformer is connected to the distribution bus.

2. The power system according to claim 1, wherein, The new energy storage device is a high-temperature superconducting magnetic energy storage device.

3. The power system according to claim 1, characterized in that, The first DC / DC converter is a DC / DC chopper; The first AC / DC inverter is an AC / DC bidirectional MMC series inverter; The first isolation transformer is a series isolation transformer.

4. The power system according to claim 1, characterized in that, The second DC / DC converter is a DC / DC chopper; The second AC / DC inverter is an AC / DC bidirectional MMC parallel inverter; The second isolation transformer is a parallel isolation transformer.

5. The power system according to claim 1, characterized in that, The voltage level of the distribution bus is 10 kV.

6. The power system according to claim 1, wherein The second end of the first isolation transformer is connected to the first end of a sensitive load feeder circuit breaker; wherein, the second end of the sensitive load feeder circuit breaker is connected to the distribution bus.

7. The power system according to claim 1, characterized in that, The second end of the second isolation transformer is connected to the first end of a feeder circuit breaker; wherein, the second end of the feeder circuit breaker is connected to the distribution bus.

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