WO2021184693A1

WO2021184693A1 - Power peak regulation system and method for railway traction substation

Info

Publication number: WO2021184693A1
Application number: PCT/CN2020/113130
Authority: WO
Inventors: 张敏; 周方圆; 田哲; 吕顺凯; 吴丽然; 胡前; 仇乐兵; 肖宇翔; 徐晓天; 张志学; 田华贵; 刘正雄; 何健明; 邹三红; 孙茂
Original assignee: 株洲中车时代电气股份有限公司
Priority date: 2020-03-16
Filing date: 2020-09-03
Publication date: 2021-09-23
Also published as: CN111313443A

Abstract

A power peak regulation system and method for a railway traction substation, wherein the system comprises a power transfer device, a control device and an energy scheduling management device. The power transfer device is arranged at a traction substation, and comprises an indirect AC converter and an energy storage device; the control device is used to regulate the operation state of the power transfer device; and the energy scheduling management device is used to acquire the current load power value of the traction substation, output a first command signal to the control device when the current load power value is less than the maximum preset power peak so as to control the power transfer device to absorb electric energy from a traction network to the energy storage device, and output a second command signal to the control device when the current load power value is greater than the maximum preset power peak so as to control the energy storage device to release electric energy to the traction network, thereby reducing the real-time output power of the traction substation. In the present application, a power peak of a traction substation is reduced by reducing peaks and filling valleys, thus reducing the maximum demand of the load of the substation and saving on the cost of railway operation.

Description

Power peak adjustment system and method for railway traction substation

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office on March 16, 2020, the application number is 202010182767.6, and the invention title is "A system and method for peak power regulation of railway traction substations", and its entire contents Incorporated in this application by reference.

Technical field

This application relates to the technical field of electrified railway traction power supply, and in particular to a power peak adjustment system and method of a railway traction substation.

Background technique

my country currently implements a two-part electricity price for large industrial power users with electricity capacity of 315kVA and above, that is, the calculation of electricity bills is divided into two parts: one is the electricity cost per kilowatt, which is charged according to the electricity consumption; the other is the basic electricity bill, according to The capacity of the transformer or the maximum demand of the load is billed.

The maximum peak power of the traction load is directly related to the rated capacity of the traction transformer and the maximum demand of the load. However, the problem of peak power imbalance in different traction network segments is common in the prior art, which not only affects the quality of power supply, but also increases the electricity bill. The cost.

In view of this, providing a solution to the above-mentioned technical problems has been urgently needed by those skilled in the art.

Summary of the invention

The purpose of this application is to provide a power peak adjustment system and method for a railway traction substation, so as to effectively reduce the power peak and save railway operating costs.

In order to solve the above technical problems, in the first aspect, this application discloses a power peak adjustment system for a railway traction substation, which includes:

A power fusion device installed in a traction substation for power conversion, including an AC-DC converter and an energy storage device connected to the DC side of the AC-DC converter;

A control device connected to the control end of the power fusion device, used to adjust the operating state of the power fusion device;

The energy dispatching management device is used to obtain the current load power value of the traction substation, and when the current load power value is less than the preset maximum power peak value, output a first command signal to the control device to control the substation The power integration device absorbs electric energy from the traction network to the energy storage device; when the current load power value is greater than the preset maximum power peak value, a second command signal is output to the control device to control the The energy storage device releases electrical energy to the traction network to reduce the real-time output power of the traction substation.

Optionally, the second instruction signal is specifically used to specify that the electric energy release power of the energy storage device is _PL- Pmax;

Among them, P _L is the current load power value; Pmax is the preset maximum power peak value.

Optionally, the energy scheduling management device is further configured to:

When the current load power value is less than the preset maximum power peak value and the energy storage device is full of electric energy, a third command signal is output to the control device to control the power integration device to transform the traction The output electric energy of the two power supply arms performs power transfer.

Optionally, the energy scheduling management device specifically includes:

A signal acquisition unit for acquiring the voltage signal and current signal of the traction substation;

A power calculation unit, configured to calculate the current load power value according to the voltage signal and the current signal;

The energy scheduling unit is configured to output the first instruction signal or the second instruction signal to the control device according to the current load power value and the preset maximum power peak value.

Optionally, the AC-DC converter specifically includes a first AC-DC converter, a DC support capacitor, and a second AC-DC converter connected in sequence;

The power fusion device further includes:

A first transformer or a first reactor connected between the first AC terminal of the AC-DC converter and the first power supply arm of the traction substation; and,

A second transformer or a second reactor connected between the second AC terminal of the AC-DC converter and the second power supply arm of the traction substation.

Optionally, it also includes:

A first switch connected between the power fusion device and the first power supply arm of the traction substation; and,

A second switch connected between the power fusion device and the second power supply arm of the traction substation.

In the second aspect, this application also discloses a power peak adjustment method of a railway traction substation, which includes:

Obtain the current load power value of the traction substation;

Judging whether the current load power value is less than a preset maximum power peak value;

If so, control the power fusion device installed in the traction substation and used for power conversion to absorb electric energy from the traction network to the energy storage device; the power fusion device includes an AC-DC converter and an AC-DC converter. The energy storage device connected to the DC side of the converter;

If not, determine whether the current load power value is greater than the preset maximum power peak value;

If the current load power value is greater than the preset maximum power peak value, the energy storage device is controlled to release electric energy to the traction network to reduce the real-time output power of the traction substation.

Optionally, after the control is provided in the traction substation and the power fusion device for power conversion absorbs electric energy from the traction network to the energy storage device, the method further includes:

After the energy storage device is full of electrical energy, the power fusion device is controlled to perform power transfer on the output electrical energy of the two power supply arms of the traction substation.

It can be seen that this application uses the power fusion device installed in the traction substation to realize the power interaction between the traction substation and the energy storage device, which not only improves the power supply capacity of the traction network, but also can work without affecting the normal operation of the train. In order to reduce the peak power of the power output of the traction substation, the maximum load demand of the substation is reduced, the railway operation cost is saved, and the economic efficiency of the railway is greatly improved. The power peak adjustment method of the railway traction substation provided by the present application also has the above-mentioned beneficial effects.

Description of the drawings

In order to more clearly explain the prior art and the technical solutions in the embodiments of the present application, the following will briefly introduce the prior art and the drawings that need to be used in the description of the embodiments of the present application. Of course, the following drawings related to the embodiments of the present application describe only a part of the embodiments of the present application. For those of ordinary skill in the art, without creative work, other examples can be obtained according to the provided drawings. The drawings and other drawings obtained also belong to the protection scope of this application.

Figure 1 is a schematic structural diagram of a peak power adjustment system of a railway traction substation disclosed in an embodiment of the application;

2 is a schematic structural diagram of another peak power adjustment system of a railway traction substation disclosed in an embodiment of the application;

Fig. 3 is a flowchart of a method for adjusting peak power of a railway traction substation disclosed in an embodiment of the application.

Detailed ways

The core of this application is to provide a power peak adjustment system and method for a railway traction substation, so as to effectively reduce the power peak of the traction substation and save railway operating costs.

In order to describe the technical solutions in the embodiments of the present application more clearly and completely, the technical solutions in the embodiments of the present application will be introduced below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of this application.

At present, my country currently implements a two-part electricity price for large industrial power users with electricity capacity of 315kVA and above, that is, the calculation of electricity bills is divided into two parts: one is the electricity cost per kilowatt, which is charged according to the electricity consumption; the other is the basic electricity bill , Billing is based on the capacity of the transformer or the maximum demand of the load.

The maximum peak power of the traction load is directly related to the rated capacity of the traction transformer and the maximum demand of the load. However, the problem of peak power imbalance in different traction network segments is common in the prior art, which not only affects the quality of power supply, but also increases the electricity bill. The cost. In view of this, the present application provides a power peak adjustment solution for railway traction substations, which can effectively solve the above-mentioned problems.

As shown in Fig. 1, an embodiment of the present application discloses a power peak adjustment system of a railway traction substation, which mainly includes:

The power fusion device 100 installed in the traction substation and used for power conversion includes an AC-DC converter and an energy storage device connected to the DC side of the AC-DC converter;

The control device 200 connected to the control end of the power fusion device 100 is used to adjust the operating state of the power fusion device 100;

The energy dispatch management device 300 is used to obtain the current load power value of the traction substation, and when the current load power value is less than the preset maximum power peak value, output a first command signal to the control device 200 to control the power integration device 100 from The traction network absorbs electrical energy to the energy storage device; when the current load power value is greater than the preset maximum power peak value, the second command signal is output to the control device 200 to control the energy storage device to release electrical energy to the traction network to reduce the traction substation Real-time output power.

Specifically, in the field of locomotive power supply, a traction substation is a place where the electric energy sent from the power plant via the power transmission line is converted into a voltage suitable for the rolling stock and distributed to the contact network or contact rail.

The power peak adjustment system of the railway traction substation provided by this application aims to reduce the power peak adjustment of the traction substation. Specifically, the present application provides a power fusion device 100 connected in parallel with the traction substation, that is, one end of the power fusion device 100 is connected to a power supply arm (power supply arm α) of the traction substation, and the power fusion device 100 The other end is connected with another power supply arm (power supply arm β) of the traction substation.

The power fusion device 100 specifically includes an AC-DC converter and an energy storage device. The on and off of the power switch in the AC-DC-AC converter is controlled by the control device 200, so that the working state of the AC-DC-AC converter can be adjusted, and the energy storage device can be used to store or discharge energy. The energy storage device is specifically connected to the DC side of the AC-DC converter, and can store or discharge energy by means of the power conversion of the AC-DC converter.

As a specific embodiment, the energy storage device may specifically include a hybrid energy storage unit composed of a single or several types of energy storage devices among supercapacitors, lithium batteries, and flywheels, and the hybrid energy storage unit is connected through a bidirectional DC/DC converter. The DC bus to the power fusion device 100 realizes energy interaction with the traction network.

The control device 200 specifically adjusts the operating state of the power integration device 100 according to the instruction signal sent by the energy scheduling management device 300. The energy dispatch management device 300 specifically detects the current load power value of the traction substation and compares it with the preset maximum power peak value, and then generates the corresponding command signal according to the specific working conditions. Suppose P _L is the current load power value and Pmax is the preset maximum power peak value, then the following specific working conditions exist:

(1) P _L <Pmax. That is, the current load power value is less than the preset maximum power peak value. At this time, it can be determined that the traction substation is in a low-load operation state or in a regenerative braking state, and the first command signal can be used to control the AC-DC-AC converter to work in In the rectified state, electric energy is absorbed from the traction network and stored in the energy storage device.

(2) P _L >Pmax. That is, the current load power value is greater than the preset maximum power peak value. At this time, it can be determined that the traction substation is in a high-load operation state. Therefore, the second command signal can be used to control the AC-DC-AC converter to work in the inverter state to save the power. The electric energy in the energy device is released to the traction network.

Further, as a specific embodiment, the second command signal may also specify the electric energy release power of the energy storage device, for example, it may be _PL- Pmax. It is easy to understand that at this time, the traction load of the traction substation is specifically borne by the electric energy output by the traction substation itself and the electric energy released by the energy storage device, that is, the current load power value is equal to the real-time output power of the traction substation itself. The sum of the value and the power released by the energy storage device.

It can be seen that this application uses the power fusion device provided in the traction substation to realize the power interaction between the traction substation and the energy storage device, which not only improves the power supply capacity of the traction network, but also can work without affecting the normal operation of the train. In order to reduce the peak power of the power output of the traction substation, the maximum load demand of the substation is reduced, the railway operation cost is saved, and the economic efficiency of the railway is greatly improved.

As a specific embodiment, on the basis of the above content, the power peak adjustment system of the railway traction substation provided by the embodiment of the present application, in the above-mentioned (1) working condition, that is, P _L <Pmax (current load power If the value is less than the preset maximum power peak value), after the energy storage device is instructed to perform energy storage by using the first command signal, the energy scheduling management device 300 is further configured to:

When the energy storage device is full of electrical energy, the third command signal is output to the control device 200 to control the power fusion device 100 to transfer the output electrical energy of the two power supply arms of the traction substation.

Specifically, although P _L <Pmax at this time, the energy storage device has full capacity. Therefore, the present application controls the power fusion device 100 to perform power transfer between the two power supply arms, that is, the power supply arm with less current output increases the power output And transfer to another power supply arm. Since the unbalanced fault of the two power supply arms will cause negative sequence current and affect the power supply safety of the traction grid, the power peak adjustment system provided by the embodiment of the present application has the above beneficial effects and can also use the power fusion device 100 The power conversion balances the output power of the two power supply arms to achieve the purpose of negative sequence control, improvement of terminal network voltage drop, and improvement of power quality.

As a specific embodiment, the power peak adjustment system of a railway traction substation provided by the embodiment of the present application is based on the above content, and the energy dispatching management device 300 specifically includes:

The signal acquisition unit is used to acquire the voltage signal and current signal of the traction substation;

The power calculation unit is used to calculate the current load power value according to the voltage signal and the current signal;

The energy scheduling unit is configured to output the first command signal or the second command signal to the control device 200 according to the current load power value and the preset maximum power peak value.

As a specific embodiment, the power peak adjustment system of the railway traction substation provided by the embodiment of the present application is based on the above content. Modified structure, MMC structure or cascade structure, etc.

Refer to FIG. 2, which is a schematic structural diagram of another power peak adjustment system of a railway traction substation disclosed in an embodiment of the application.

The power peak adjustment system shown in Figure 2 is based on the above content. The AC-DC converter specifically includes a first AC-DC converter, a DC support capacitor C, and a second AC-DC converter connected in sequence; the first AC-DC converter The AC-DC converter and the second AC-DC converter share the DC support capacitor C to form a back-to-back structure, and the power switches in both are controlled by the control device 200.

In addition, the power peak adjustment system shown in FIG. 2 is based on the above content. The power fusion device 100 also includes a first AC terminal connected to the AC-DC converter and the first power supply arm (power supply arm α) of the traction substation. ) Between the first transformer or the first reactor; and, the second transformer or the first reactor connected between the second AC terminal of the AC-DC converter and the second power supply arm (power supply arm β) of the traction substation Two reactors.

Among them, the first AC terminal is the AC side of the first AC-DC converter, and the second AC terminal is the AC side of the second AC-DC converter. The first transformer and the second transformer may specifically be an oil-immersed or dry-type structure.

Further, on the basis of the above content, the power peak adjustment system shown in FIG. 2 also includes a first switch F1 connected between the power fusion device 100 and the first power supply arm of the traction substation; and, connected to the power The second switch F2 between the fusion device 100 and the second power supply arm of the traction substation.

Among them, the first switch F1 and the second switch F2 may specifically be a circuit breaker or an isolating switch.

Referring to FIG. 3, the embodiment of the present application discloses a method for adjusting the peak power of a railway traction substation, which mainly includes:

S301: Obtain the current load power value of the traction substation.

S302: Determine whether the current load power value is less than the preset maximum power peak value; if yes, go to S303; if not, go to S304.

S303: Control the power fusion device installed in the traction substation and used for power conversion to absorb electric energy from the traction network to the energy storage device; the power fusion device includes an AC-DC converter and a DC side connection with the AC-DC converter Energy storage device.

S304: Determine whether the current load power value is greater than the preset maximum power peak value; if yes, go to S305.

S305: Control the energy storage device to release electrical energy to the traction network to reduce the real-time output power of the traction substation.

It can be seen that the power peak adjustment method of the railway traction substation disclosed in the embodiments of the present application utilizes the power fusion device provided in the traction substation to realize the power interaction between the traction substation and the energy storage device, which not only improves The power supply capacity of the traction network, and without affecting the normal operation of the train, the power output of the traction substation can be cut and filled to reduce the peak power, thereby reducing the maximum load demand of the substation and saving railway operations The cost has greatly improved the economic efficiency of the railway.

As a specific embodiment, the power peak adjustment method of the railway traction substation disclosed in the embodiment of the present application is based on the above content, and then controls the power fusion device connected in parallel with the traction substation for power conversion. After absorbing electric energy from the traction network to the energy storage device, it also includes:

Regarding the specific content of the peak power adjustment method of the above-mentioned railway traction substation, please refer to the detailed introduction of the power peak adjustment system of the railway traction substation, which will not be repeated here.

The various embodiments in this application are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant information can be referred to the description of the method section.

It should also be noted that in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and are not necessarily required Or it implies that there is any such actual relationship or sequence between these entities or operations. In addition, the terms "including", "including" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements includes not only those elements, but also those that are not explicitly listed Other elements of, or also include elements inherent to this process, method, article or equipment. If there are no more restrictions, the element defined by the sentence "including a..." does not exclude the existence of other identical elements in the process, method, article, or equipment that includes the element.

The technical solutions provided by this application are described in detail above. Specific examples are used in this article to describe the principles and implementations of the application, and the descriptions of the above examples are only used to help understand the methods and core ideas of the application. It should be pointed out that for those of ordinary skill in the art, without departing from the principles of this application, several improvements and modifications can be made to this application, and these improvements and modifications also fall within the protection scope of this application.

Claims

A power peak adjustment system of a railway traction substation, which is characterized in that it comprises:

A power fusion device installed in a traction substation for power conversion, including an AC-DC converter and an energy storage device connected to the DC side of the AC-DC converter;

A control device connected to the control end of the power fusion device, used to adjust the operating state of the power fusion device;

The energy dispatching management device is used to obtain the current load power value of the traction substation, and when the current load power value is less than the preset maximum power peak value, output a first command signal to the control device to control the substation The power integration device absorbs electric energy from the traction network to the energy storage device; when the current load power value is greater than the preset maximum power peak value, a second command signal is output to the control device to control the The energy storage device releases electrical energy to the traction network to reduce the real-time output power of the traction substation.
The power peak adjustment system according to claim 1, wherein the second command signal is specifically used to specify that the electric energy release power of the energy storage device is PL- Pmax;

Among them, P L is the current load power value; Pmax is the preset maximum power peak value.
The power peak adjustment system according to claim 1, wherein the energy scheduling management device is further configured to:

When the current load power value is less than the preset maximum power peak value and the energy storage device is full of electric energy, a third command signal is output to the control device to control the power integration device to transform the traction The output electric energy of the two power supply arms performs power transfer.
The power peak adjustment system according to claim 1, wherein the energy scheduling management device specifically comprises:

A signal acquisition unit for acquiring the voltage signal and current signal of the traction substation;

A power calculation unit, configured to calculate the current load power value according to the voltage signal and the current signal;

The energy scheduling unit is configured to output the first instruction signal or the second instruction signal to the control device according to the current load power value and the preset maximum power peak value.
The power peak adjustment system according to claim 1, wherein the AC-DC converter specifically comprises a first AC-DC converter, a DC supporting capacitor, and a second AC-DC converter connected in sequence;

The power fusion device further includes:

A first transformer or a first reactor connected between the first AC terminal of the AC-DC converter and the first power supply arm of the traction substation; and,

A second transformer or a second reactor connected between the second AC terminal of the AC-DC converter and the second power supply arm of the traction substation.
The power peak adjustment system according to any one of claims 1 to 5, further comprising:

A first switch connected between the power fusion device and the first power supply arm of the traction substation; and,

A second switch connected between the power fusion device and the second power supply arm of the traction substation.
A method for adjusting the peak power of a railway traction substation, which is characterized in that it comprises:

Obtain the current load power value of the traction substation;

Judging whether the current load power value is less than a preset maximum power peak value;

If so, control the power fusion device installed in the traction substation and used for power conversion to absorb electric energy from the traction network to the energy storage device; the power fusion device includes an AC-DC converter and an AC-DC converter. The energy storage device connected to the DC side of the converter;

If not, determine whether the current load power value is greater than the preset maximum power peak value;

If the current load power value is greater than the preset maximum power peak value, the energy storage device is controlled to release electric energy to the traction network to reduce the real-time output power of the traction substation.
The power peak adjustment method according to claim 7, characterized in that, after the control is set in the traction substation and used for power conversion, the power fusion device for power conversion absorbs electric energy from the traction network to the energy storage device, further comprising: :

After the energy storage device is full of electrical energy, the power fusion device is controlled to perform power transfer on the output electrical energy of the two power supply arms of the traction substation.