CN108183489B

CN108183489B - Load balance control method for tramcar engineering power supply system

Info

Publication number: CN108183489B
Application number: CN201711448845.7A
Authority: CN
Inventors: 张开波; 周才发; 向往; 刘卫东; 陈桁; 江安
Original assignee: China Railway Eryuan Engineering Group Co Ltd CREEC
Current assignee: China Railway Eryuan Engineering Group Co Ltd CREEC
Priority date: 2017-12-27
Filing date: 2017-12-27
Publication date: 2021-05-25
Anticipated expiration: 2037-12-27
Also published as: CN108183489A

Abstract

A load balance control method for a tramcar engineering power supply system relates to the technical field of rail transit and power supply control. The method comprises the following steps that 1) a monitoring substation judges whether a vehicle is rapidly charged with large current in a monitoring range, and reports monitoring information to a monitoring main station; 2) the monitoring master station judges whether overload is possible to occur in the range of the monitoring master station, if so, the charging circuit which is not subjected to large-current quick charging in the range of the monitoring master station is cut off according to the monitoring information reported by each monitoring substation; 3) when the monitoring substation detects that the large-current quick charging is completed, reporting the completion information to the monitoring main station; 4) and after the monitoring master station receives the completion information, the monitoring master station judges whether the monitoring master station exits from a possible overload state or not, and if so, the disconnected charging loop is released. The invention fully utilizes the cruising ability of the vehicle-mounted energy storage vehicle and ensures the safe and reliable operation of the power supply system.

Description

Load balance control method for tramcar engineering power supply system

Technical Field

The invention relates to the technical field of rail transit technology and power supply control.

Background

At present, modern tram engineering is more and more being popularized and applied at home, but now more cities because the view, plan and other reasons, the tram of on-vehicle energy storage mode power supply operation has been adopted, it does not set up the contact net at all or great district section scope does not set up the contact net at all to require the line, through facilities such as the rail that charges that set up in station or other local district section scopes, utilize the time of vehicle on the station time of getting on and off the bus that parks, carry out high-power quick charge to the energy memory of installing on the vehicle, provide the mode of traction electric energy for the vehicle operation through on-vehicle energy memory.

In the scheme of a power supply system of a modern tramcar, a distributed power supply mode is basically adopted, a plurality of loops of 10kV power supplies of a local power grid are introduced nearby, a medium-voltage power supply looped network structure in a single looped network and 'large looped string' connection mode is adopted, the introduced 10kV power supply points are fewer, the number of substations in the looped strings is larger, and each substation is responsible for providing power supplies for charging devices of a plurality of nearby stations or other stations.

The following problems exist in the prior art:

due to the fact that running density of the vehicle in driving planning is high, the number of the driving pairs set to be 20 pairs/hour or more is basically considered in the long term of engineering. Each station is divided into an ascending platform and a descending platform, when a vehicle runs to the station, the high-power quick charging of energy storage facilities such as a super capacitor and the like arranged on the vehicle is immediately started, the stopping time is short (generally within 30 seconds), the current and the power are large, the voltage can reach 500-900V generally, the current can reach more than 1000A, and the capacity configuration of the vehicle-mounted energy storage facilities is different, and even some vehicles can reach more than 2100A.

Due to the probability relation of vehicle operation, the situation that a plurality of rows of vehicles carry out high-power quick charging at a plurality of stations or a plurality of charging rails simultaneously may occur within a certain short time range, so that short-time overload occurs on substation equipment or a 10kV external power supply lead-in loop, impact is caused on a local power grid, the allowable load value is exceeded, and power supply accidents are caused under severe conditions or overcurrent protection tripping actions are caused, and the normal operation of a line is influenced.

In order to avoid this situation, the capacity of the substation equipment or the capacity of the power supply points is increased more, or the number of external power supply points is increased more, which will all cause serious influences on various aspects such as engineering investment and feasibility of implementation. Meanwhile, the vehicle operation charging is an intermittent working mode, the charging time of the vehicle on the main line at the station is generally more than 2 minutes and about 30 seconds, so that the power supply capacity of the power supply system and the cruising capacity of the vehicle-mounted energy storage device are not fully utilized under the normal condition of the facility of the power supply system, the resource sharing is not facilitated, and the energy-saving operation of the whole power supply system is also not facilitated.

Due to the fact that a certain probability exists, if overcurrent protection tripping of a protection device is caused by overload current frequently, a normal power supply source is lost in a large range of the whole engineering, the service life of equipment is influenced, and more seriously, the normal operation of the tramcar engineering is influenced, and even the serious consequence of outage occurs.

Therefore, aiming at the medium-voltage power supply ring network structure adopting the connection mode of large ring strings and the charging mode of vehicle operation, a power supply system load balance control scheme based on the digital communication network technology is provided, the optimization of the power supply system scheme is realized, the phenomenon that excessive vehicles are out of line due to the fact that the excessive vehicles are charged quickly at high power at the same time is avoided, the power supply capacity of the power supply system and the cruising capacity of the vehicle-mounted energy storage type vehicles are fully utilized, one substation supplies power to the charging rails of a plurality of stations at the same time, and a 10kV external power supply can supply power to more substations; the charging time of each charging rail is reasonably distributed, and the installation capacity of a power supply system is optimized.

The system can reduce excessive occupation of power supply points and capacity of the urban power grid, reduce impact on the capacity of the urban power grid, reduce the implementation difficulty of engineering and reduce engineering construction and operation maintenance cost. The energy-saving, environment-friendly and economic effects of modern tramcar line engineering are realized, and the safe and reliable operation is ensured.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a load balance control method for a tramcar engineering power supply system, which can avoid short-time overload impact on the power supply system.

The technical scheme adopted by the invention for solving the technical problems is that the load balance control method of the tramcar engineering power supply system is characterized by comprising the following steps:

1) the monitoring substation judges whether a vehicle is carrying out large-current quick charging in the monitoring range, and reports monitoring information to the monitoring main station;

2) the monitoring master station judges whether overload is possible to occur in the range of the monitoring master station, if so, the charging circuit which is not subjected to large-current quick charging in the range of the monitoring master station is cut off according to the monitoring information reported by each monitoring substation;

3) when the monitoring substation detects that the large-current quick charging is completed, reporting the completion information to the monitoring main station;

4) and after the monitoring master station receives the completion information, the monitoring master station judges whether the monitoring master station exits from a possible overload state or not, and if so, the disconnected charging loop is released.

Further, the step 4) is as follows:

all the disconnected charging loops are released at one time.

The step 4) is as follows:

and gradually releasing the cut charging loop according to the sequence of cutting off first and releasing first according to a preset time interval.

Or, the step 1) is:

the monitoring substation collects the effective value of the current of the charging loop and the duration of the current reaching the effective value, if the effective value and the duration of the current reach a preset threshold value, the fact that a vehicle is rapidly charged with large current is indicated, and monitoring information is reported.

The step 2) is as follows:

the monitoring main station detects whether the current value of the input current of the substation equipment in which the monitoring main station is located exceeds a preset value and the duration time of exceeding the preset value, judges whether overload is likely to occur in the range of the monitoring main station, and cuts off a charging loop which is not subjected to large-current quick charging in the range of the monitoring main station according to the monitoring information reported by each monitoring substation if overload is likely to occur in the range of the monitoring main station.

The invention has the beneficial effects that:

1) the method provided by the invention does not influence the scheme and the scale of the existing power supply system.

2) In the method provided by the invention, the load balancing control system can automatically monitor and operate, and can avoid short-time overload impact on the equipment capacity of the power supply system and the capacity of an external power supply. The cruising ability of the vehicle-mounted energy storage vehicle is fully utilized, and the safe and reliable operation of the power supply system is ensured.

3) In the method provided by the invention, the data information is transmitted by adopting a digital communication network, and the scale of the load balancing control system can be easily adapted according to the quantity and scale of the field charging loops.

4) According to the method provided by the invention, different action logic schemes can be selected according to the field situation, and the logic criterion scheme is simple and reliable.

Drawings

Fig. 1 is a schematic view of a control system according to the present invention.

Fig. 2 is a schematic diagram of the operation logic of the load balancing control system.

Detailed Description

See fig. 1, 2. Firstly, a set of load balancing control system arranged in a substation and across substations is configured. The load balancing monitoring master station device sends and receives information of other load balancing monitoring substation devices arranged in the field charging loop based on a digital communication network technology, and load balancing control of the power supply system is achieved.

The invention provides a power supply system load balancing control scheme based on a digital communication network technology, wherein the digital communication network can be IEC 61850 GOOSE technology or other general digital communication networks.

Load currents of traction power supply equipment or a 10kV power supply loop are collected in a substation provided with a load balance monitoring main station device, and each field charging loop is provided with a load balance monitoring substation device for collecting charging currents of each charging facility and position states of a charging switch.

The load balance monitoring master station device judges whether overload conditions possibly exceeding the allowed conditions occur in power supply equipment or a 10kV power supply loop drawn by a substation or not by combining the acquired current data; the load balance monitoring substation device judges whether vehicles in the charging loop are rapidly charged with large current or not, and the charging state and the charging switch information are transmitted to the load balance monitoring main station device through the digital communication network.

When the load balance monitoring function is put into operation, when the load balance monitoring master station device judges that the situation of exceeding the allowed overload current is possible, a control command is sent out, other charging loops which are not subjected to large-current quick charging temporarily in the range of the power supply subarea are cut off, the charging current superposition of other vehicles in the next time interval is prevented, and the large-capacity impact of the charging load is avoided.

When the overload signal disappears, the charging circuit which is cut off before is released, and the charging circuit is allowed to be charged normally.

Further, the method comprises the steps of:

the first step is as follows: system device configuration

And (3) configuring the load balancing monitoring master station equipment, the load balancing monitoring substation equipment and the digital communication network facility according to the power supply system scheme of the actual engineering, and completing the wiring diagram and equipment configuration relation of the load balancing control system scheme.

Generally, a set of load balancing control system includes a load balancing monitoring master station device, a plurality of load balancing monitoring slave station devices, and a digital communication network facility for implementing data communication between them.

The second step is that: system state quantity and setting value setting

1) Setting a system setting value:

load balancing monitoring master station: and setting a current reference value Izdset of the system overload current, and detecting overload delay time Tzdset.

Load balancing monitoring substation: and setting a charging current minimum detection reference value Icdset of the charging loop and a charging current detection delay time Tcdset.

2) Setting the system running state quantity:

load balancing monitoring master station: load balancing control function on/off status bit Y (1)

Load balancing monitoring substation: charging loop switch load balance control enable/disable state signal B (2)

Load balancing monitoring master station: load balance control start control state bit G (3)

Load balancing monitoring substation: charging loop charging status bit: c (4)

Load balancing monitoring substation: charging circuit switch position state: k (5)

(1) Load balancing control function on/off status bit: y is

Load balancing monitors the main station apparatus: load balancing control function input: y is 1. The load balancing control function exits: y is 0.

(2) Charge circuit switch load balancing control enable/disable status signal: b is

Load balancing monitoring substation equipment:

the charging loop switch allows the load balance to control the switch-off and switch-on control state position: b is 1.

The charging loop switch forbids the load balance control to switch off and switch on the control state position: and B is 0.

(3) Load balancing control start control status bit: g

The load balance monitoring master station equipment performs actual overload current detection: and detecting the delay time (duration) Tf according to the effective value If of the current acquired on line.

If is greater than or equal to Izdset, Tf is greater than or equal to Tzdset, the system detects that an overload condition occurs, and the load balancing control charging loop cut-off control information G is equal to 1.

If is less than Izdset, Tf is more than or equal to Tzdset and represents that no overload condition occurs, the load balancing control charging loop releases control information G which is 0.

(4) Charging loop charging status bit: c

The load balance monitoring substation equipment performs actual charging current detection: and the charging current detection value Icd and the charging current detection delay time Tcd are acquired on line.

And if the Icd is larger than or equal to the Icdset, the Tcd is larger than or equal to the Tcdset and represents normal charging, the circuit is in a high-current quick charging state, and charging state information C is sent to be 1.

If Icd is less than Icdset, Tcd is more than or equal to Tcdset, the circuit is not subjected to high-current quick charging temporarily, the charging state information C is sent to be 0, and the cut-off operation is allowed.

(5) Charging circuit switch position state: k

The load balance monitoring substation equipment performs actual charging switch state detection: the switch is in the on position: k is 1. The switch is in the opening position: k is 0.

(6) Time T1 when the charge circuit switch is in the off state, and release operation interval time T2 between the charge circuit switches.

The third step: selecting load balancing control implementation logic

For disconnecting and releasing the charging loop in the power supply range, there are two control logics:

1) the control logic one:

when cutting off: and cutting off other charging loops which are not subjected to large-current quick charging temporarily at one time.

When releasing: all the disconnected charging loops are released at one time.

2) And the control logic II:

When releasing: and gradually releasing the cut-off charging loop at certain time intervals. The releasing sequence is in the order relation of cutting off first and releasing first. If the time is the same, the release is performed randomly.

The fourth step: the load balance control system carries out logic judgment according to the field condition

1) The load balance monitoring master station equipment performs actual overload current detection:

2) Each load balance monitoring substation device performs actual charging current detection:

3) The system judges the input/exit state bit Y of the load balancing control function, the load balancing control permission/prohibition state signal B of each charging loop switch, the load balancing control starting control state bit G, the charging loop charging state bit C and the charging loop switch position state K through combination, and controls the output after comprehensive judgment.

Time T1 when the charge circuit switch is in the off state, and release operation interval time T2 between the charge circuit switches.

(1) With action logic scheme one:

when the state conditions of the load balance monitoring master station Y being 1 and the state conditions of the load balance monitoring master station G being 1 are all present at the same time, each load balance monitoring slave station satisfies the charging switch loop of the control conditions of B being 1, C being 0 and K being 1, and the operation exit is uniformly cut off.

And when the state conditions that the load balance monitoring main station Y is equal to 1 and G is equal to 0 exist simultaneously, the charging switch loops of all the load balance monitoring sub-stations meeting the control conditions that B is equal to 1 and K is equal to 0 release the action outlets, and the state which can be charged is recovered.

(2) When the action logic scheme II is adopted:

And when the state conditions that the load balance monitoring main station Y is 1 and the G is 0 exist simultaneously, each load balance monitoring substation meets the control conditions that the B is 1 and the K is 0, comparing the charging loop switches which are in an off state, and when the time T1 when the loop switches are in the off state is the maximum, meeting the control conditions of the release of the charging loop, and the release action of the charging loop is exported to restore the state of being capable of being charged.

When the load balance monitoring master station continuously detects that Y is 1 and G is 0, the load balance monitoring slave station meets the control conditions that B is 1 and K is 0 at a certain time interval T2, compares the time T1 when the rest of the charging circuit switches are in the cut-off state, and releases each cut-off charging switch circuit one by one to the maximum.

Example (b):

fig. 1 is a specific application scenario of the method of the present invention: a power supply subarea, an external incoming line power supply and two substations. The power supply scheme adopts a 10kV single-ring network power supply mode, each transformer substation is provided with a return incoming line, a return outgoing line and three charging feed outgoing line loops, and each set of charging device supplies power to a charging rail of a station. And each power supply partition is provided with a set of load balancing control system. The system consists of a load balance monitoring main station arranged at a 10kV incoming line power supply, load balance monitoring substations arranged in each set of charging device at a station and a digital communication network facility.

The description is given by taking fig. 1 as an example:

the first step is as follows:

the load balancing control system in the figure comprises a set of load balancing monitoring master station FK0 and 6 sets of load balancing monitoring sub-stations FK1\ FK2\ FK3\ FK4\ FK5\ FK6 and digital communication network facilities.

The load balance monitoring master station FK0 collects the current of a 10kV incoming line power supply as a judgment basis of overload, and receives the charging current of the current sensor CT in the charging loop and the position state information of the charging loop switch K which are respectively collected by the load balance monitoring sub-stations FK1\ FK2\ FK3\ FK4\ FK5\ FK6 through a digital communication network facility. And issues a command to turn off or release the charge circuit switch depending on the condition of the overload current.

The load balance monitoring substation FK1\ FK2\ FK3\ FK4\ FK5\ FK6 respectively receives a command of cutting off or releasing a charging loop switch K sent by a load monitoring master station FK0 through a digital communication network facility.

The second step is that: state quantity and setting value setting

1) Load balancing monitoring master station: a current reference value Izdset of the overload current is set, and the overload detection delay time Tzdset is set.

Load balancing monitoring substation: setting a charging current minimum detection reference value Icdset, and detecting a charging current delay time Tcdset.

2) The current data acquisition and related state quantities of each device operated by the system are set and shown in table 1.

Table 1 load balancing control system data acquisition and status information table corresponding to each relevant device

The third step: selecting load balancing control implementation logic

1) the control logic one:

When releasing: all the disconnected charging loops are released at one time.

2) And the control logic II:

1) First, the load balancing monitoring master FK0 determines whether the load balancing control function corresponding to the system is activated, that is, the status bit Y, and if Y is equal to 1, the function is activated, and if Y is equal to 0, the function is deactivated, the load balancing control function of the entire system is deactivated.

2) And judging whether the load balancing control function corresponding to the load balancing monitoring substation FK1\ FK2\ FK3\ FK4\ FK5\ FK6 is put into use or not, namely judging the state bit B. If B is 1, the corresponding load balancing control function is put into use; and if B is 0, the corresponding load balancing control function exits.

3) Current detection:

firstly, the load balance monitoring master station equipment carries out actual overload current detection:

if is greater than or equal to Izdset, Tf is greater than or equal to Tzdset, the system detects that an overload condition occurs, and the load balancing control charging loop cut-off control information G is equal to 1. Otherwise, G is 0.

Secondly, each load balance monitoring substation device performs actual charging current detection:

and if the Icd is larger than or equal to the Icdset, the Tcd is larger than or equal to the Tcdset and represents normal charging, the circuit is in a high-current quick charging state, and charging state information C is sent to be 1. Otherwise, C is 0.

4) The system is described by taking the following working conditions as examples:

the load balancing monitoring master station FK0 load balancing control function inputs Y equal to 1.

② the load balance control function input B which corresponds to each load balance monitoring substation FK1\ FK2\ FK3\ FK4\ FK5\ FK6 is 1.

③ the charging loop corresponding to the monitoring substation FK1\ FK3\ FK5 is charging, namely:

icd1 is more than or equal to Icdset, and Tcd1 is more than or equal to Tcdset; the result is C1 ═ 1 and K1 ═ 1.

Icd3 is more than or equal to Icdset, and Tcd3 is more than or equal to Tcdset; the result is C3 ═ 1 and K3 ═ 1.

Icd5 is more than or equal to Icdset, and Tcd5 is more than or equal to Tcdset; the result is C5 ═ 1 and K5 ═ 1.

Fourthly, the load balance monitoring substation FK2\ FK4\ FK6 is not charged and the switch is in the closed position, namely:

icd2 is less than Icdset, and Tcd2 is more than or equal to Tcdset; c2 ═ 0 and K2 ═ 1 were obtained.

Icd4 is less than Icdset, and Tcd4 is more than or equal to Tcdset; c4 ═ 0 and K4 ═ 1 were obtained.

Icd6 is less than Icdset, and Tcd6 is more than or equal to Tcdset; c6 ═ 0 and K6 ═ 1 were obtained.

Adopting different action logic schemes

I, adopting an action logic scheme one:

A. when an overload condition occurs, namely the current detection of the FK0 main station is monitored by load balancing:

if is not less than Izdset, Tf is not less than Tzdset, and G is 1.

The load balance monitoring master station FK0 switches off the charging circuit meeting the state conditions of C0 and K1 in all the load balance monitoring substations FK1\ FK2\ FK3\ FK4\ FK5\ FK6 at the uniform disconnection action outlet, sends an disconnection command to the load balance monitoring substation and disconnects each charging circuit switch K.

The working condition is that all the charging loop switches K2\ K4\ K6 corresponding to the FK2\ FK4\ FK6 of the load balance monitoring substation are turned off at one time.

B. When the overload condition disappears, namely the current detection of the FK0 main station is monitored by load balance:

if is less than Izdset, Tf is more than or equal to Tzdset, and G is 0.

The load balance monitoring master station FK0 enables all the load balance monitoring substations FK1\ FK2\ FK3\ FK4\ FK5\ FK6 to meet the charging loop switch K with the condition that K is 0, releases the action outlet uniformly, and restores the chargeable state.

The working condition releases all the FK 2/FK 4/FK 6 and other charging circuit switches K2/K4/K6 which are correspondingly disconnected at one time, and the chargeable state is recovered.

II, when an action logic scheme II is adopted:

if is not less than Izdset, Tf is not less than Tzdset, and G is 1.

if is less than Izdset, Tf is more than or equal to Tzdset, and G is 0.

The load balance monitoring master station FK0 compares the charging circuit switches K1\ K2\ K3\ K4\ K5\ K6 of all the load balance monitoring substations FK1\ FK2\ FK3\ FK4\ FK5\ FK6 which satisfy the condition that K is 0, and preferentially releases the charging circuit switch which is in the cut-off state and has the maximum time T2, so as to restore the chargeable state.

In this release process, when it is continuously detected that G is 0, the circuit having the maximum time T2 in the shut-off state is released with priority at a constant time T1, and the chargeable state is restored.

In this case, when the overload condition disappears, the load balance monitoring substations FK2\ FK4\ FK6 and the time T2 when the corresponding charging switches K2\ K4\ K6 are in the off state are compared, and the circuit with the maximum time T2 in the off state is preferentially released to restore the chargeable state.

If the charging circuit switch K4 corresponding to the load balancing monitoring substation FK4 is turned off for the maximum time T2, it is preferentially restored to a chargeable state. At a certain time T1, the charging circuit switches K2 and K6 corresponding to the FK2 and FK6 of the load balance monitoring substation are compared, and the time T2 in the off state is the maximum, and the charging circuit switches are released successively, and similarly, the judgment processing is performed until the end of the entire state.

Claims

1. The load balance control method of the tramcar engineering power supply system is characterized by comprising the following steps of:

2. The load balancing control method for the tram engineering power supply system according to claim 1, wherein the step 4) is:

all the disconnected charging loops are released at one time.

3. The load balancing control method for the tram engineering power supply system according to claim 1, wherein the step 4) is:

4. The load balancing control method for the tram engineering power supply system according to claim 1, wherein the step 1) is:

5. The load balancing control method for the tram engineering power supply system according to claim 1, wherein the step 2) is: