CN106684892B - A kind of alternating supercurrent custom power system - Google Patents

Abstract

The invention discloses a superconducting alternating current customized power system with high power supply quality, which is mainly applied to a new energy system. The conduction branch corresponds to the connected AC load. Since the first superconducting busbar, the second superconducting bus and the superconducting branch are connected in parallel with corresponding superconducting energy storage devices, the first superconducting bus, the second superconducting The fluctuation of AC power on the conducting busbar and superconducting branch can be quickly responded by the corresponding superconducting energy storage device, which improves the response speed and power supply quality of the system. The capacity requirements of the superconducting energy storage device on the conducting bus bar and the superconducting branch are smaller, which reduces the total device development cost.

Description

A Superconducting AC Customized Power System

technical field

The invention relates to the technical field of customized electric power, in particular to a superconducting alternating current customized electric power system.

Background technique

In recent years, a variety of natural energy sources, including wind energy and solar energy, have been directly used for large-capacity grid-connected or off-grid power generation. Due to the technical problems of intermittency and instability of natural energy, the output power and voltage of natural energy power stations have relatively severe dynamic fluctuations. It is often necessary to add additional power storage equipment, and operate through dynamic energy absorption or compensation. In order to complete the continuous and stable power supply. Existing power energy storage devices are mainly battery energy storage devices, but their dynamic response speed is slow and cannot achieve rapid energy absorption or compensation. Superconducting magnetic energy storage with fast dynamic response and high operating efficiency can make up for the technical defects of battery energy storage, but its energy density is low and the development cost is expensive.

According to the different requirements of electric power load on power supply reliability and power supply quality, in order to make the power supply and distribution system achieve technically reasonable and economical savings, the electric power load is often subjected to hierarchical power supply processing. AC power loads with different power quality requirements can be classified into primary loads, secondary loads, tertiary loads, quaternary loads, etc. At present, custom power systems often use conventional power electronics technology and distribution automation technology, limited by the response speed of battery energy storage and the conduction loss of conventional copper or aluminum conductors. Slow, low operating efficiency and other issues. Although superconducting power devices such as superconducting AC cables, conventional superconducting transformers, superconducting magnetic energy storage devices, and superconducting fault current limiters prepared by using high-temperature superconducting wires have been gradually applied to AC power transmission and distribution systems to replace conventional However, in the field of customized power technology, due to the low energy density of superconducting magnetic energy storage devices, and in the case that the AC load requires high power supply quality, large-capacity superconducting magnetic energy storage devices are required. This greatly increases the cost of device development. At the same time, due to the influence of the length of the transmission line, once the installation position of the superconducting magnetic energy storage device is determined, it can only quickly respond to the power fluctuation generated on the transmission line with a short distance, but cannot quickly respond to the power fluctuation generated on the transmission line with a long distance. Therefore, the use of superconducting power devices in the field of customized power technology still has great limitations.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the technical problems of high device development cost, slow overall response speed and low overall power supply quality when applying superconducting power devices in customized power technology.

In order to achieve the above purpose of the invention, the present invention provides the following technical solutions: a superconducting AC customized power system, which is applied to a new energy system with a wind power station and/or a photovoltaic power station, and the new energy system uses the generated The alternating current power is transmitted to the first superconducting busbar, the first superconducting busbar is connected in series with the superconducting cable through a circuit breaker and a superconducting current limiting transformer, and then the alternating current power is transmitted to the second superconducting cable through the superconducting cable. On the superconducting bus, the second superconducting bus is connected with a plurality of superconducting branches, wherein each superconducting branch is routed by a circuit breaker, a conventional superconducting transformer or a superconducting current limiting transformer and a superconducting branch The cables are connected in series, each superconducting branch cable is connected with the corresponding AC load, and provides AC power for the AC load;

In addition, each of the first superconducting busbar, the second superconducting busbar and at least one superconducting branch with a superconducting current limiting transformer is connected in parallel with a superconducting energy storage device, and the corresponding superconducting energy storage device is connected in parallel. The device maintains the stability of the alternating current power on the first superconducting busbar, the second superconducting busbar and the superconducting branch.

According to a specific embodiment, in the superconducting AC customized power system with high power supply quality of the present invention, the superconducting energy storage device includes a superconducting magnetic energy storage device, and the superconducting magnetic energy storage device is powered by a transformer. The current transformer is connected in parallel with the external AC power transmission line.

Further, the superconducting energy storage device further includes a battery energy storage device, and the battery energy storage device is connected in parallel with an external AC power transmission line through another converter.

According to a specific embodiment, in the superconducting energy storage device of the present invention, when the superconducting energy storage device responds to the power fluctuation of the alternating current electric energy on the line, the response line of the superconducting magnetic energy storage device is first activated The AC power on the line fluctuates, and after the duration of the AC power fluctuation exceeds a set time, the battery energy storage is activated, and the battery energy storage responds to the AC power fluctuation on the line.

According to a specific embodiment, in the superconducting AC customized power system with high power supply quality of the present invention, the superconducting current limiting transformer further has a non-inductive superconducting coil for limiting the superconducting cable and superconducting Short-circuit fault current on the branch.

Compared with the prior art, the beneficial effects of the present invention:

1. In the present invention, the new energy system transmits AC power to the AC load corresponding to each superconducting branch through the first superconducting busbar and the second superconducting busbar, because the first superconducting busbar and the second superconducting busbar Corresponding superconducting energy storage devices are connected in parallel with the superconducting branch respectively. Therefore, the fluctuation of AC power on the first superconducting busbar, the second superconducting busbar and the superconducting branch can all be passed through the corresponding superconducting energy storage device. The energy storage device can respond quickly, which improves the response speed and power supply quality of the system. At the same time, the capacity requirements of the superconducting energy storage devices installed on the first superconducting busbar, the second superconducting busbar and the superconducting branch are smaller, which reduces the total capacity of the energy storage device. device development cost.

2. In the present invention, the superconducting current limiting transformer used has a non-inductive superconducting coil, which has the function of limiting the short-circuit fault current on the superconducting cable and the superconducting branch. Therefore, when the short-circuit fault current occurs, the voltage on the line drops, and the superconducting energy storage device needs to compensate the AC voltage power. Since the non-inductive coil of the superconducting current-limiting transformer has the function of limiting the short-circuit fault current, the superconducting energy storage device The AC power fluctuation that needs to be compensated becomes smaller, that is, the capacity requirement of the superconducting energy storage device is smaller, thereby further reducing the development cost of the superconducting energy storage device. At the same time, because the superconducting energy storage device has the function of compensating for the fluctuation of AC power, the short-circuit fault current that needs to be limited by the non-inductive superconducting coil in the superconducting current-limiting transformer becomes smaller, that is, the capacity of the superconducting current-limiting transformer is reduced. The requirements are smaller, thereby reducing the development cost of superconducting current-limiting transformers. Moreover, combining the functions of the superconducting energy storage device and the superconducting current limiting transformer can effectively alleviate the voltage drop problem on the line, improve the overall power supply quality of the system, and enable the new energy system to safely complete the low-voltage ride-through operation to avoid large currents. Equipment damage to the new energy subsystem.

3. In the present invention, since the superconducting energy storage device is composed of a battery energy storage device and a superconducting magnetic energy storage device, and the superconducting magnetic energy storage device with a smaller energy storage capacity is used to respond quickly, The AC power fluctuation is suppressed for the first time, and then when the duration of the AC power fluctuation exceeds the set time, the battery energy storage with larger energy storage capacity continues to suppress the AC power fluctuation, thereby improving the operating efficiency of the system and the quality of the AC power supply.

Description of drawings:

FIG. 1 is a schematic structural diagram of an embodiment of a superconducting AC customized power system with high power supply quality according to the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with test examples and specific embodiments. However, it should not be construed that the scope of the above-mentioned subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

The present invention has a superconducting AC customized power system with high power supply quality, and is applied to a new energy system having a wind power station and/or a photovoltaic power station. The quality of the AC power supplied.

In the superconducting AC customized power system with high power supply quality of the present invention, the new energy system transmits the AC power generated by the new energy system to the first superconducting busbar, and the first superconducting busbar passes through a circuit breaker and a superconductor The current limiting transformer is connected in series with the superconducting cable, and then the AC power is transmitted to the second superconducting busbar through the superconducting cable, and the second superconducting busbar is connected with a plurality of superconducting branches, wherein each superconducting branch The conduction branch consists of a circuit breaker, a conventional superconducting transformer or a superconducting current limiting transformer and a superconducting branch cable connected in series. Each superconducting branch cable is connected to the corresponding AC load and provides the AC load. AC power.

In addition, each of the first superconducting busbar, the second superconducting busbar and at least one superconducting branch with a superconducting current limiting transformer is connected in parallel with a superconducting energy storage device, and the corresponding superconducting energy storage device is connected in parallel. The device maintains the stability of the alternating current power on the first superconducting busbar, the second superconducting busbar and the corresponding superconducting branch. Specifically, the superconducting energy storage device maintains the stability of the AC power on the line by storing the excess AC power on the line, or compensating for the insufficient AC power on the line.

In the present invention, a superconducting current-limiting transformer is arranged between the first superconducting busbar and the superconducting cable, and the superconducting current-limiting transformer can limit the short-circuit fault current on the superconducting cable. The energy storage device compensates the AC voltage dropped on the first superconducting bus, so that the new energy system can safely complete the low voltage ride-through operation and avoid equipment damage to the new energy subsystem caused by the high current.

Moreover, the new energy system transmits AC power to the AC loads corresponding to each superconducting branch through the first superconducting busbar and the second superconducting busbar. Corresponding superconducting energy storage devices are connected in parallel on the roads. Therefore, the fluctuation of the AC power on the first superconducting busbar, the second superconducting busbar and the superconducting branch can be quickly carried out by the corresponding superconducting energy storage devices. The response speed and power supply quality of the system are improved, and the capacity requirements of the superconducting energy storage devices installed on the first superconducting busbar, the second superconducting busbar and the superconducting branch are smaller, and the total device development cost is reduced. .

In the present invention, the superconducting magnetic energy storage device directly adopts the superconducting magnetic energy storage device, but since the capacity of the general superconducting magnetic energy storage device is relatively small, if the first superconducting busbar, the second superconducting busbar and the superconducting support If the fluctuation of AC power on the road is serious or lasts for a long time, the superconducting magnetic energy storage device must be composed of a superconducting magnetic energy storage device and a battery energy storage device, and the superconducting magnetic energy storage device and the battery energy storage device pass through respectively. A converter is connected in parallel with the first superconducting busbar or the second superconducting busbar or superconducting branch.

Specifically, in a superconducting energy storage device composed of a superconducting magnetic energy storage device and a battery energy storage device, when AC power fluctuations occur on the line, firstly, the superconducting magnetic energy storage device provided on the line is used for the circuit. After the AC power fluctuation time on the line exceeds the set value, it switches to the battery energy storage set on the line to respond to the AC power fluctuation on the line. . It not only ensures that the AC power fluctuations on the line can be quickly absorbed/compensated, but also can continuously maintain the stability of the AC power on the line.

At the same time, the superconducting current limiting transformer used in the present invention has a non-inductive superconducting coil, which has the function of limiting the short-circuit fault current on the superconducting cable and the superconducting branch cable. Therefore, when the short-circuit fault current occurs, the voltage on the line drops, and the superconducting energy storage device needs to compensate the AC voltage power. Since the non-inductive coil of the superconducting current-limiting transformer has the function of limiting the short-circuit fault current, the superconducting energy storage device The AC power fluctuation that needs to be compensated becomes smaller, that is, the capacity requirement of the superconducting energy storage device is smaller, thereby further reducing the development cost of the superconducting energy storage device. At the same time, because the superconducting energy storage device has the function of compensating for the fluctuation of AC power, the short-circuit fault current that needs to be limited by the non-inductive superconducting coil in the superconducting current-limiting transformer becomes smaller, that is, the capacity of the superconducting current-limiting transformer is reduced. The requirements are smaller, thereby reducing the development cost of superconducting current-limiting transformers.

During implementation, the circuit breaker in the present invention completes the operation of cutting off the line when the duration of the short-circuit fault on the line to which it is connected exceeds a threshold value. That is, after the duration of the short-circuit fault on the superconducting cable exceeds a certain time, the first superconducting busbar cuts off the power supply to the superconducting cable through the circuit breaker connected to it. After the duration of the short-circuit fault of the superconducting branch circuit cable exceeds a certain time, the second superconducting busbar cuts off the power supply to the superconducting branch circuit through the corresponding circuit breaker.

1 is a schematic structural diagram of an embodiment of the superconducting AC customized power system with high power supply quality according to the present invention; wherein, the new energy system is composed of a wind power station and a photovoltaic power station. A superconducting busbar is connected, and the photovoltaic power station is connected with the first superconducting busbar through a converter.

Specifically, the wind power station and the photovoltaic power station transmit the AC power generated by each of them to the first superconducting busbar, and the first superconducting busbar is connected in series with the superconducting cable through a circuit breaker and a superconducting current limiting transformer, and then passes through a circuit breaker and a superconducting current limiting transformer. The superconducting cable transmits AC power to the second superconducting busbar, and the second superconducting busbar is connected with four superconducting branches, and each superconducting branch corresponds to AC loads with different power supply quality levels.

The first superconducting branch is composed of a circuit breaker, a superconducting current limiting transformer and a first superconducting branch cable, and a superconducting energy storage device is connected in parallel with the first superconducting branch cable. It is composed of superconducting magnetic energy storage and battery energy storage, and the first superconducting branch corresponds to the primary load. The second superconducting branch is composed of a circuit breaker, a superconducting current limiting transformer and a second superconducting branch cable. A superconducting energy storage device is connected in parallel with the second superconducting branch cable. The superconducting energy storage device directly adopts In the superconducting magnetic energy storage device, the second superconducting branch corresponds to the secondary load. The third superconducting branch is composed of a circuit breaker, a superconducting current limiting transformer and a third superconducting branch cable, and the third superconducting branch corresponds to a three-level load. The fourth superconducting branch is composed of a circuit breaker, a conventional superconducting transformer and a fourth superconducting branch cable, and the fourth superconducting branch corresponds to a four-level load.

In the field of customized power technology, in the technical solution disclosed in the present invention, the structure of each superconducting branch is adjusted to meet the different demands of customers on the quality of the AC power of the load.

Claims (5)

1. a superconducting alternating current customized power system, applied to the new energy system with wind power station and/or photovoltaic power station, it is characterized in that, described new energy system transmits the alternating current electric energy it produces to the first superconducting busbar Above, the first superconducting busbar is connected in series with the superconducting cable through a circuit breaker and a superconducting current-limiting transformer, and then the AC power is transmitted to the second superconducting busbar through the superconducting cable, and the second superconducting busbar is connected in series. There are multiple superconducting branches connected to the superconducting bus, wherein each superconducting branch is formed by a circuit breaker, a conventional superconducting transformer or a superconducting current limiting transformer and a superconducting branch cable connected in series. The branch circuit cable is connected with the corresponding AC load, and provides AC power for the AC load; In addition, each of the first superconducting busbar, the second superconducting busbar and at least one superconducting branch with a superconducting current limiting transformer is connected in parallel with a superconducting energy storage device, and the corresponding superconducting energy storage device is connected in parallel. The device maintains the stability of the alternating current power on the first superconducting busbar, the second superconducting busbar and the superconducting branch. 2 . The superconducting AC customized power system according to claim 1 , wherein the superconducting energy storage device comprises a superconducting magnetic energy storage device, and the superconducting magnetic energy storage device is connected to an external device through a converter. 3 . The AC power transmission lines are connected in parallel. 3. The superconducting AC customized power system according to claim 2, wherein the superconducting energy storage device further comprises a battery energy storage device, and the battery energy storage device is connected to an external energy storage device through another converter. The AC power transmission lines are connected in parallel. 4. The superconducting AC customized power system according to claim 3, wherein when the superconducting energy storage device responds to the power fluctuation of the AC electric energy on the line, the superconducting magnetic energy storage device is first activated to respond to the power fluctuation on the line. The AC electric energy power fluctuates, and after the duration of the AC electric energy power fluctuation exceeds the set time, the battery energy storage device is started, and the battery energy storage device responds to the AC electric energy power fluctuation on the line. 5. The superconducting AC customized power system according to claim 1, wherein the superconducting current limiting transformer also has a non-inductive superconducting coil for limiting short circuits on the superconducting cables and superconducting branches fault current.