阅读说明：本技术 一种基于地面牵引供电的电气列车、供电系统及控制方法 (Electric train based on ground traction power supply, power supply system and control method ) 是由 吴波 王永建 何晓燕 李毅 于 2021-07-06 设计创作，主要内容包括：本发明提供一种基于地面牵引供电的电气列车,包括牵引电机和与所述牵引电机连接的无功补偿器,其中：所述牵引电机通过地面牵引变流器进行驱动控制；所述无功补偿器根据所述牵引电机的运行状态发出无功电流,为所述牵引电机提供励磁和无功补偿。本发明电气列车内的牵引电机由地面牵引变流器进行驱动控制,从而取消车载牵引变流器和车载牵引变压器,并在电气列车内设置为牵引电机提供励磁和无功补偿的无功补偿器,不仅可以有效减轻电气列车的轴重提升电气列车的有效空间,有利于提升电气列车的运行速度效率,还可以提高电气列车的功率因数和三相牵引网的输电距离。(The invention provides an electric train based on ground traction power supply, which comprises a traction motor and a reactive power compensator connected with the traction motor, wherein: the traction motor is driven and controlled through a ground traction converter; and the reactive compensator sends out reactive current according to the running state of the traction motor to provide excitation and reactive compensation for the traction motor. The traction motor in the electric train is driven and controlled by the ground traction converter, so that the vehicle-mounted traction converter and the vehicle-mounted traction transformer are eliminated, and the reactive compensator for providing excitation and reactive compensation for the traction motor is arranged in the electric train, so that the axle weight of the electric train can be effectively reduced, the effective space of the electric train is increased, the running speed efficiency of the electric train is favorably improved, and the power factor of the electric train and the power transmission distance of a three-phase traction network can be improved.)

1. An electric train based on ground traction power supply, characterized in that, includes traction motor (M), Reactive Power Controller (RPC) and reactive power compensator (SVG), wherein:

the traction motor (M) is driven and controlled by a ground Traction Converter (TC);

the Reactive Power Controller (RPC) sends a control signal to the reactive power compensator (SVG) according to the running state of the traction motor (M);

and the reactive compensator (SVG) sends out reactive current according to the received control signal to provide excitation and/or reactive compensation for the traction motor (M).

2. An electric train powered on ground traction according to claim 1, characterized in that it also comprises a three-phase Current Collector (CC) for taking three-phase power from a three-phase traction network (UVW) and supplying it to said traction motor (M), Reactive Power Controller (RPC) and reactive power compensator (SVG).

3. A ground traction power supply based electric train according to claim 2, characterized in that, after said reactive compensator (SVG) provides excitation and/or reactive compensation to said traction motor (M), the power factor at said three-phase Current Collector (CC) to said three-phase traction network (UVW) approaches 1 or equal to 1.

4. A ground traction power supply based electric train according to claim 3, characterized in that when the power factor at the three-phase Current Collector (CC) to the three-phase traction network (UVW) is equal to 1, the traction motor (M) does not absorb reactive power from the three-phase traction network (UVW).

5. The utility model provides an electric train ground traction power supply system, its characterized in that, including traction Transformer (TR), ground Traction Converter (TC), three-phase traction net (UVW) and electric train (LM), electric train (LM) inside is provided with traction motor (M), Reactive Power Controller (RPC) and reactive power compensator (SVG), wherein:

the primary side of the traction Transformer (TR) is connected with a high-voltage power Grid (GRD), and the secondary side of the traction Transformer (TR) is connected with the input port of a ground Traction Converter (TC);

the three-phase output ports of the ground Traction Converter (TC) are respectively connected with corresponding phase lines of the three-phase traction network (UVW);

the electric train (LM) is followed through three-phase Current Collector (CC) three-phase electricity is got to three-phase traction network (UVW) department to provide three-phase electricity traction motor (M), Reactive Power Controller (RPC) and reactive power compensator (SVG).

6. An electric train ground traction power supply system according to claim 5, characterized in that the traction motor (M) inside the electric train (LM) is drive controlled by the ground Traction Converter (TC).

7. An electric train ground traction power supply system according to claim 5, characterized in that the Reactive Power Controller (RPC) sends control signals to the reactive power compensator (SVG) according to the operating state of the traction motor (M); and the reactive compensator (SVG) sends out reactive current according to the received control signal to provide excitation and/or reactive compensation for the traction motor (M).

8. An electric train ground traction power supply system according to claim 7, characterised in that, after said reactive compensator (SVG) provides excitation and/or reactive compensation to said traction motor (M), the power factor at said three-phase Current Collector (CC) to said three-phase traction network (UVW) approaches 1 or equal to 1.

9. An electric train ground traction power supply system according to claim 8, characterized in that, when the power factor at said three-phase Current Collector (CC) to said three-phase traction network (UVW) is equal to 1, said ground Traction Converter (TC) supplies said traction motor (M) with active power only through said three-phase traction network (UVW).

10. A control method of an electric train ground traction power supply system is characterized by comprising the following steps:

detecting input voltage and input current of a traction motor (M), and calculating a rotor current vector of the traction motor (M) by combining parameters of the traction motor (M);

calculating a rotor flux vector of the traction motor (M) according to the rotor current vector of the traction motor (M);

calculating an excitation component and a moment component of a stator current of the traction motor (M) according to a rotor magnetic flux vector of the traction motor (M);

calculating the slip frequency of the rotor of the traction motor (M) according to the rotor flux vector of the traction motor (M) and the moment component of the stator current;

detecting the rotation frequency of a rotor of the traction motor (M), and calculating the synchronous frequency of the traction motor (M) according to the rotation frequency and the slip frequency of the rotor of the traction motor (M);

calculating active current and reactive current of the traction motor (M) based on synchronous rotation coordinate control according to the synchronous frequency of the traction motor (M);

and controlling a reactive power compensator (SVG) to perform reactive power current compensation on the traction motor (M) according to the active current and the reactive current of the traction motor (M).

Technical Field

The invention relates to the technical field of alternating current electrified railway power supply, in particular to an electric train based on ground traction power supply, a power supply system and a control method.

Background

The existing electric train is powered by a power frequency single-phase alternating current power supply system, and electric equipment plays an important role in electric locomotives and motor cars of the electric train, wherein the most important is an alternating current-direct current-alternating current traction transmission system. The AC-DC-AC traction transmission system is formed by connecting a vehicle-mounted traction transformer, a vehicle-mounted traction converter and a traction motor in series, drives the traction motor, and achieves the purposes of driving and speed-regulating operation of an electric train by changing the rotating speed of the traction motor through frequency modulation and voltage regulation, and the process is called electric train driving. Generally, in a real situation, the electric train driving is performed manually, and a few electric trains are driven automatically. There are some problems here: the traction transmission system occupies absolute components in electrical equipment on a main railway electric locomotive and a motor car, and has large weight and large volume; secondly, the axle weight is increased when the weight is large, the larger the axle weight is, the higher the line manufacturing cost is, the larger the volume is, more precious space of the electric locomotive and the motor car is occupied, and the power density and the efficiency are reduced.

Disclosure of Invention

In view of the above, a first aspect of the present invention is to provide an electric train based on ground traction power supply, in which a traction motor in the electric train is driven and controlled by a ground traction converter, so as to cancel a vehicle-mounted traction converter and a vehicle-mounted traction transformer, and a reactive compensator for providing excitation and reactive compensation to the traction motor is arranged in the electric train, so that not only can the axle weight of the electric train be effectively reduced, but also the effective space of the electric train is increased, which is beneficial to increasing the operating speed efficiency of the electric train, and also the power factor of the electric train and the power transmission distance of a three-phase traction network can be increased. The scheme is realized by the following technical means:

an electric train based on ground traction power supply, includes traction motor, reactive power controller and reactive power compensator, wherein:

the traction motor is driven and controlled through a ground traction converter;

the reactive power controller sends a control signal to the reactive power compensator according to the running state of the traction motor;

and the reactive compensator sends out reactive current according to the received control signal to provide excitation and/or reactive compensation for the traction motor.

The system further comprises a three-phase current receiving device, wherein the three-phase current receiving device is used for taking three-phase power from a three-phase traction network and providing the three-phase power to the traction motor, the reactive power controller and the reactive power compensator.

Further, after the reactive compensator provides excitation and/or reactive compensation for the traction motor, the power factor of the three-phase current receiving device to the three-phase traction network approaches to 1 or is equal to 1.

Further, when the power factor at the three-phase current-receiving device to the three-phase traction grid is equal to 1, the traction motor does not absorb reactive power from the three-phase traction grid.

The invention provides a ground traction power supply system of an electric train, which comprises a traction transformer, a ground traction converter, a three-phase traction network and the electric train, wherein a traction motor, a reactive power controller and a reactive power compensator are arranged in the electric train, wherein:

the primary side of the traction transformer is connected with a high-voltage power grid, and the secondary side of the traction transformer is connected with an input port of a ground traction converter;

the three-phase output ports of the ground traction converter are respectively connected with corresponding phase lines of the three-phase traction network;

and the electric train obtains three-phase power from the three-phase traction network through a three-phase current receiving device and provides the three-phase power for the traction motor, the reactive power controller and the reactive power compensator.

Further, a traction motor inside the electric train is driven and controlled by the ground traction converter.

Further, the reactive power controller sends a control signal to the reactive power compensator according to the running state of the traction motor; and the reactive compensator sends out reactive current according to the received control signal to provide excitation and/or reactive compensation for the traction motor.

Further, after the reactive compensator provides excitation and/or reactive compensation for the traction motor, the power factor of the three-phase current receiving device to the three-phase traction network approaches to 1 or is equal to 1.

Further, when the power factor at the three-phase current-receiving device to the three-phase traction network is equal to 1, the ground traction converter provides active power only to the traction motor through the three-phase traction network.

The third aspect of the present invention provides a method for controlling a ground traction power supply system of an electric train, including:

detecting input voltage and input current of a traction motor, and calculating a rotor current vector of the traction motor by combining traction motor parameters;

calculating a rotor flux vector of the traction motor according to the rotor current vector of the traction motor;

calculating an excitation component and a moment component of a stator current of the traction motor according to a rotor magnetic flux vector of the traction motor;

calculating slip frequency of a traction motor rotor according to a rotor magnetic flux vector of the traction motor and a moment component of a stator current;

detecting the rotation frequency of a traction motor rotor, and calculating the synchronous frequency of the traction motor according to the rotation frequency and the slip frequency of the traction motor rotor;

calculating active current and reactive current of the traction motor based on synchronous rotation coordinate control according to synchronous frequency of the traction motor;

and controlling the reactive compensator to perform reactive current compensation on the traction motor according to the active current and the reactive current of the traction motor.

The working principle of the invention is as follows: the traction transformer reduces the voltage of a high-voltage power grid, converts the voltage into three-phase power supply voltage with adjustable voltage amplitude and frequency through a ground traction converter, and directly drives an electric train traction motor through a three-phase traction network; the vehicle-mounted reactive compensator sends out reactive current to provide excitation and reactive compensation current for the traction motor so as to keep the power factor of the port of the electric train at 1; by controlling the power factor of the electric train to be 1, the voltage drop of the three-phase traction network caused by the reactive power of the electric train is reduced, the power supply distance of the three-phase traction network is prolonged, and the control complexity of the ground converter is simplified.

Drawings

Fig. 1 is a block diagram of a ground traction power supply system of an electric train according to an exemplary embodiment.

Fig. 2 is a flowchart of a method for controlling a ground traction power supply system of an electric train according to an exemplary embodiment.

Fig. 3 is a block diagram of an algorithm of a compensation control method of a reactive power compensator according to an exemplary embodiment.

Detailed Description

In order to make the technical solutions of the present invention better understood, those skilled in the art will further describe the present invention with reference to the accompanying drawings and the detailed description.

Example 1

As shown in fig. 1, the present embodiment provides an electric train based on ground traction power supply, including traction motor M, reactive power controller RPC and reactive power compensator SVG, wherein:

the traction motor M is driven and controlled through a ground traction converter TC;

the reactive power controller RPC sends a control signal to the reactive power compensator SVG according to the running state of the traction motor M;

and the SVG sends out reactive current according to the received control signal to provide excitation and/or reactive compensation for the traction motor M.

In the embodiment, a vehicle-mounted traction transformer and a vehicle-mounted traction converter are omitted, and the ground traction converter TC is used for driving and controlling the traction motor M, so that the axle weight of the electric train can be effectively reduced, the effective space of the electric train is improved, and the running speed efficiency of the electric train is favorably improved; meanwhile, considering that the distance between the ground traction converter TC and the traction motor M in the electric train changes all the time when the electric train operates, so that the line parameters between the traction motor M and the ground traction converter TC change all the time, the control difficulty of the ground traction converter TC is increased, and in order to realize more accurate control on the traction motor M, the embodiment is provided with the reactive power controller RPC and the reactive power compensator SVG on the electric train, and the reactive power controller RPC controls the reactive power compensator SVG to directly provide excitation and/or reactive power compensation for the traction motor M according to the operating state of the traction motor M, so that the control complexity of the ground traction converter TC can be simplified, the power factor of the traction motor can be improved, and the line voltage drop still meets the requirement during long-distance power transmission.

In this embodiment, the electric train refers to a train driven by electric power, the ground traction converter TC refers to a traction converter disposed outside the electric train, the ground traction converter TC may be disposed in a traction substation or other ground places considered reasonable by a technician, and the ground traction converter TC of this embodiment may be a traction converter of an AC-DC-AC structure; the reactive power compensator SVG may be a static var generator; the traction motor M is a three-phase asynchronous motor; the reactive power controller RPC sends a control signal to the reactive power compensator SVG according to the operating state of the traction motor M, which may mean that the reactive power controller RPC sends a corresponding control signal to the reactive power compensator SVG by acquiring parameters such as input voltage, input current, and rotor speed of the traction motor M and using the parameters as control input quantity, thereby controlling the reactive power compensator SVG to send reactive current to provide excitation and/or reactive power compensation for the traction motor M.

Preferably, the present embodiment may further comprise a three-phase current collector CC for taking three-phase power from the three-phase traction network UVW and providing the three-phase power to the traction motor M, the reactive power controller RPC and the reactive power compensator SVG.

Here, the three-phase traction network UVW may be three steel rails laid on the ground, and the three-phase current receiving device CC may be a power receiving device capable of taking three-phase power from the three-phase traction network UVW, such as a train power receiving plough or other conductive power transmission device proposed by the yun group of transportation university in southwest.

Preferably, after the reactive power compensator SVG provides excitation and/or reactive power compensation for the traction motor M, the power factor at the three-phase current collector CC to the three-phase traction network UVW approaches 1 or equals 1.

Here, the control objective of the reactive power compensator SVG is to make the power factor of the port of the electric train (at the three-phase current receiving device CC) approach 1 to 1, so that on one hand, the voltage drop of the traction network caused by the reactive power of the electric train can be reduced, the power supply distance of the traction network can be extended, and on the other hand, the control complexity of the ground traction converter TC can be simplified.

Preferably, when the power factor at the three-phase current collector CC to the three-phase traction network UVW is equal to 1, the traction motor M does not absorb reactive power from the three-phase traction network UVW.

Example 2

As shown in fig. 1, the present embodiment provides a ground traction power supply system, which includes a traction transformer TR, a ground traction converter TC, and a three-phase traction network UVW, wherein:

the primary side of the traction transformer TR is connected with a high-voltage power grid GRD, and the secondary side of the traction transformer TR is connected with the input port of the ground traction converter TC;

the three-phase output port of the ground traction converter TC is respectively connected with the corresponding phase line of the three-phase traction network UVW;

the three-phase traction network UVW is used for providing three-phase power for the electric train, and the ground traction converter TC is used for driving and controlling a traction motor M in the electric train through the three-phase traction network UVW.

In this embodiment, the traction transformer TR and the ground traction converter TC are both disposed outside the motor vehicle, for example, in a traction substation or in another ground location considered reasonable by a technician, and the ground traction converter TC is electrically connected to the traction motor M through the three-phase traction network UVW, thereby implementing driving control of the traction motor M.

Preferably, the ground traction converter TC provides active power only for the traction motor M via the three-phase traction network UVW.

Here, considering that the distance between the ground traction converter TC and the traction motor M in the electric train is changed at any time when the electric train is running, and thus the line parameter between the traction motor M and the ground traction converter TC is changed at any time, in order to simplify the control complexity of the ground traction converter TC, the ground traction converter TC can only provide active power for the traction motor M, and the reactive power required by the traction motor M is provided by the reactive power compensator SVG in the electric train, so that the control of the traction motor M is more accurate.

Example 3

As shown in fig. 1, this embodiment provides an electric train ground traction power supply system, including traction transformer TR, ground traction converter TC, three-phase traction net UVW and electric train LM, inside traction motor M, reactive power controller RPC and the reactive power compensator SVG of being provided with of electric train LM, wherein:

the primary side of the traction transformer TR is connected with a high-voltage power grid GRD, and the secondary side of the traction transformer TR is connected with an input port of a ground traction converter TC;

the three-phase output port of the ground traction converter TC is respectively connected with the corresponding phase line of the three-phase traction network UVW;

the electric train LM is driven by a three-phase current receiving device CC to obtain three-phase power from the three-phase traction network UVW and provide the three-phase power for the traction motor M, the reactive power controller RPC and the reactive power compensator SVG.

Preferably, the traction motor M in the electric train LM is driven and controlled by the ground traction converter TC.

Preferably, the reactive power controller RPC sends a control signal to the reactive power compensator SVG according to the operating state of the traction motor M; and the SVG sends out reactive current according to the received control signal to provide excitation and/or reactive compensation for the traction motor M.

Preferably, after the reactive power compensator SVG provides excitation and/or reactive power compensation for the traction motor M, the power factor at the three-phase current collector CC to the three-phase traction network UVW approaches 1 or equals 1.

Preferably, when the power factor at the three-phase current collector CC to the three-phase traction network UVW is equal to 1, the ground traction converter TC provides active power only to the traction motor M through the three-phase traction network UVW.

Example 4

As shown in fig. 2, the present embodiment provides a method for controlling a ground traction power supply system of an electric train, including:

step 1: detecting input voltage and input current of a traction motor M, and calculating a rotor current vector of the traction motor M by combining parameters of the traction motor M;

step 2: calculating a rotor flux vector of the traction motor M according to the rotor current vector of the traction motor M;

and step 3: calculating an excitation component and a moment component of a stator current of the traction motor M according to a rotor magnetic flux vector of the traction motor M;

and 4, step 4: calculating slip frequency of a rotor of the traction motor M according to a rotor magnetic flux vector of the traction motor M and a moment component of a stator current;

and 5: detecting the rotation frequency of a rotor of a traction motor M, and calculating the synchronous frequency of the traction motor M according to the rotation frequency and the slip frequency of the rotor of the traction motor M;

step 6: calculating active current and reactive current of the traction motor M based on synchronous rotation coordinate control according to the synchronous frequency of the traction motor M;

and 7: and controlling a reactive compensator SVG to perform reactive current compensation on the traction motor M according to the active current and the reactive current of the traction motor M.

The method provided by the embodiment can be applied to the reactive power controller RPC.

Specifically, in step 1, equation (2) is obtained according to equation (1), and traction is calculated according to equation (2)

Rotor current vector of motor M:

in the step 2, an equation (4) is obtained according to the equation (3), and a magnetic flux vector of the M rotor of the traction motor is obtained through calculation according to the equation (4):

in step 3, the excitation component and the moment component of the stator current of the traction motor M are calculated according to equation (5):

in step 4, calculating the slip frequency of the rotor of the traction motor M according to the equation (6):

in step 5, the synchronous frequency of the traction motor M is calculated according to equation (7):

wherein u is_αsSpecifying the sub-voltage alpha component, u_βsSpecifying the sub-voltage beta component, i_αsSpecifying the sub-current alpha component, i_βsSpecifying the sub-current beta component, R_sSpecifying the sub-resistance parameter, L_sSpecifying the sub-inductance parameter, L_mParameter of excitation inductance of finger motor i_αrAlpha component of rotor current, i_βrFinger rotor current beta component psi_αγAlpha component, psi, of the rotor magnetic field_βγBeta component of finger rotor magnetic field, i_msSpecifying the sub-current excitation component, i_tsSpecifying the sub-current power component, R_rIs a parameter of rotor resistance, L_rFinger rotor inductance parameter, omega_eRotor slip frequency, omega_γRefers to the mechanical rotational speed of the rotor, and ω refers to the synchronous rotational speed.

In step 6, as shown in fig. 3, the voltage is applied to the stator of the traction motor based on the synchronous frequency ω calculated in step 5Stator currentAnd reactive compensator port current [ i ]_α，i_β]Synchronous rotation coordinate transformation is carried out to respectively obtain the stator voltage direct current quantityStator current dc componentAnd DC amount of port current of reactive compensatorThen passing through the stator voltage DC componentAnd stator current DC componentCalculating to obtain the input active power and reactive power [ P, Q ] of the traction motor]. Controlling the reactive compensator to respectively carry out direct current quantity on ports of the reactive compensator under a rotating coordinate systemD component ofAnd q component is subjected to closed-loop control, and meanwhile, reactive compensator direct current bus outer ring control is added to stabilize the direct current side voltage. Reactive compensator current settingFrom a target power [ P^*,Q^*]The target active power target is an active instruction regulated by a bus voltage ring, and the reactive power target is a negative value of input reactive power of the motor, namely Q^*Q. The current inner loop introduces grid-connected reactive induced voltage [ Uid _ FF, Uiq _ FF]And AC voltage feedforward [ Ud _ FF, Uq _ FF [ ]]To accelerate the current regulation speed, the regulation signals [ Md, Mq ] under the rotating coordinate]Obtaining three-phase modulation signals [ Ma, Mb, Mc ] through inverse transformation]And the three-phase modulation signal generates a PWM signal by adopting a space vector modulation (SVPWM) mode to control the inverter bridge of the reactive power compensator.

The above is only a preferred embodiment of the present invention, and it should be noted that the above preferred embodiment should not be considered as limiting the present invention, and the protection scope of the present invention should be subject to the scope defined by the claims. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the spirit and scope of the invention, and these modifications and adaptations should be considered within the scope of the invention.