CN103427415A - Three-phase combined same-phase power supply and transformation structure - Google Patents

Abstract

The invention discloses a three-phase combined same-phase power supply and transformation structure which comprises a traction transformer and same-phase power supply devices. The traction transformer and the same-phase power supply devices are of single-phase structures, and each same-phase power supply device comprises a high-voltage matching transformer, an alternating-current, direct-current and alternating-current converter and a traction matching transformer; primary-side windings of the two high-voltage matching transformers and a primary-side winding of the traction transformer form a delta connection assembly. Secondary-side windings of the high-voltage matching transformers are connected with input ends of the alternating-current, direct-current and alternating-current converters, and output ends of the alternating-current, direct-current and alternating-current converters are connected with primary sides of the traction matching transformers. The amplitude and the phase of a voltage of a secondary-side winding of the traction transformer are identical to the amplitudes and the phases of voltages of secondary-side windings of the traction matching transformers, and the secondary-side winding of the traction transformer and the secondary-side windings of the traction matching transformers are connected with a traction bus. The three-phase combined same-phase power supply and transformation structure has the advantages that traction power supply resources can be optimally configured, construction investment can be reduced, and an energy conservation effect is obvious; the three-phase combined same-phase power supply and transformation structure not only brings convenience for same-phase power supply modification for Vv wiring or Vx wiring traction substations, but also is applicable to replacing traction transformers by a group of novel same-phase power supply devices to implement comprehensive same-phase power supply in the future.

Description

A three-phase combined same-phase power supply and transformation structure

technical field

The invention relates to the field of AC electrified railway power supply, in particular to a three-phase combined in-phase power supply and transformation structure.

Background technique

Electrified railways generally adopt the single-phase power frequency AC system powered by the public power system. In order to make the single-phase traction load be distributed as balanced as possible in the three-phase power system, the electrified railway often adopts the scheme of rotating phase sequence and separate phase and partition power supply. The adjacent power supply areas at the phase-splitting partitions are divided by phase-splitting insulators to form electrical split phases, also known as phase splits. In order to prevent electric locomotives from burning out catenary suspension components caused by arcing due to over-separation of phases, and even causing phase-to-phase short-circuit and other accidents, as the train speed continues to increase, when the driver cannot manually degrade, turn off auxiliary units, and disconnect the main circuit When over-phase splitting is completed by passing through the neutral section by the inertia of the train, closing the main circuit breaker, closing the auxiliary unit, and upgrading the traction power to restore the traction power, the automatic over-phase technology is adopted, mainly including the ground switch automatically switching over-phase, There are several types of on-vehicle automatic over-phase and pole-mounted automatic over-phase, but there is still a transient electrical process of train over-phase during switching, which is prone to large operating overvoltage or overcurrent, causing accidents such as traction network and on-board equipment burning. , and even lead to the failure of automatic over-phase operation, affecting the reliability of power supply and the safe operation of trains. Therefore, the phase separation link is the weakest link in the entire traction power supply system, and the excessive phase separation of trains has become the bottleneck of traction power supply for high-speed railways and even the entire electrified railway.

High-speed and heavy-duty railways have widely used high-power AC-DC electric locomotives or EMUs based on full-control devices such as IGBTs and IGCTs. The core is traction converters with multiple sets of four-quadrant PWM control and multiple control. The content is small, and the power factor is close to 1, but the traction power of AC-DC electric locomotives or EMUs is large. For example, the rated power of single-vehicle high-speed EMUs running in large formations can reach 25MW (equivalent to 5 trains of ordinary speed railways). The power quality problems caused by large-power single-phase loads on the three-phase grid, mainly caused by three-phase voltage unbalance (negative sequence), are becoming more and more serious, and must be paid attention to.

Both theory and practice have shown that the use of the same-phase power supply technology can effectively control the negative-sequence current while canceling the phase separation at the outlet of the traction substation, eliminating the power supply bottleneck, increasing the power supply capacity, and enhancing the energy-saving effect. The power quality requirements based on national standard limits are conducive to promoting the common and harmonious development of electric power and railways.

A key to realize the same-phase power supply at this stage is the voltage phase of the traction network, which is determined by the traction port of the traction transformer with a certain wiring mode. Among them, the simplest and most economical wiring mode of various traction transformers in the traction substation is single-phase Traction transformers, and single-phase wiring or Vv and Vx wiring developed from it are widely used in high-speed railways and passenger dedicated lines in my country. Obviously, based on the simplest and most economical single-phase traction transformer in the traction transformer wiring mode of the traction substation, if necessary, it is equipped with an appropriate amount of in-phase (symmetrical) compensation device, so as to achieve the elimination of phase separation at the exit of the traction substation. In order to eliminate the power supply bottleneck and control the negative sequence to meet the power quality requirements of the three-phase voltage unbalance degree (negative sequence) limit, it is the preferred choice to achieve the same phase power supply with a good match between the wiring mode of the traction substation and the capacity of the power supply device.

For this reason, the present inventor has proposed a single-phase three-phase combined in-phase power supply and transformation device (Chinese invention application number: 201210583674.X) and a single-phase combined in-phase power supply and transformation structure (Chinese invention application number: 201310227591.1), the former is suitable for the neutral point large current grounding system and/or the occasions that need to output three-phase self-consumption power, the latter is suitable for the occasions where the midpoint of the primary side of the single-phase traction transformer can be extracted, and a three-phase combination is proposed The same-phase power supply and transformation structure is suitable for occasions where the neutral point is not required for high-current grounding and the primary side midpoint of the single-phase traction transformer cannot be extracted. Especially for the transformation of the existing Vv and Vx wiring traction substations, a new option is added. .

Contents of the invention

The purpose of the present invention is to provide a three-phase combined in-phase power supply and transformation structure, cancel the phase separation at the outlet of the traction substation, optimize the technical and economic indicators of the electrified railway in-phase power supply, and eliminate the three-phase system failure caused by the single-phase load of the electrified railway. Negative sequence (voltage unbalance) effect provides more options for the implementation of the same phase power supply.

The purpose of the present invention is achieved by the following technical solutions:

A three-phase combined in-phase power supply and transformation structure, including a traction transformer TT, a backup traction transformer TB, a first in-phase power supply device CPD1 and a second in-phase power supply device CPD2; the first in-phase power supply device CPD1 is composed of a first high-voltage matching transformer HMT1, the first AC-DC-AC converter ADA1 and the first traction matching transformer TMT1; the second in-phase power supply device CPD2 is composed of the second high-voltage matching transformer HMT2, the second AC-DC-AC converter ADA2 and the second traction matching transformer TMT2; The traction transformer TT, the backup traction transformer TB, the first common-phase power supply device CPD1 and the second common-phase power supply device CPD2 are all single-phase structures; the primary winding of the traction transformer TT, the primary winding of the first high-voltage matching transformer HMT1 and the second high-voltage matching The primary windings of the transformer HMT2 are respectively connected to three sets of line voltages of the power system to form a delta connection group; the primary windings of the traction transformer TT and the primary windings of the backup traction transformer TB are connected to the same set of line voltages of the power system; the first and second high-voltage matching transformers The secondary side windings of the first and second AC-DC converters are respectively connected to the input terminals; the output terminals of the first and second AC-DC converters are respectively connected to the primary sides of the first and second traction matching transformers, generating and traction The voltage of the same phase and frequency of the transformer TT; the voltage amplitude and phase of the secondary winding of the traction transformer TT, the secondary winding of the backup traction transformer TB and the secondary windings of the two traction matching transformers are the same and are all connected to the traction busbar. When the traction transformer TT fails or is overhauled as planned, the backup traction transformer TB is put into operation.

A first standby high-voltage matching transformer HMTB1 with the same structure as the first high-voltage matching transformer HMT1 can be equipped, and a second standby high-voltage matching transformer HMTB2 with the same structure as the second high-voltage matching transformer HMT2 can be equipped; the first high-voltage matching transformer HMT1, the second The high-voltage matching transformer HMT2 and the single core of the traction transformer TT form a three-core traction transformer TG; the first standby high-voltage matching transformer HMTB1, the second standby high-voltage matching transformer HMTB2 and the single core of the standby traction transformer TB form a standby three-core traction transformer TGB. When the three-core traction transformer TG fails or is overhauled as planned, the spare three-core traction transformer TGB is put into operation.

The working principle of the present invention is:

In normal operation, the traction transformer TT, together with the first in-phase power supply device CPD1 and the second in-phase power supply device CPD2, supplies power to the traction load of the traction network. The traction transformer TT is responsible for the main power supply task. The first in-phase power supply device CPD1 and the second in-phase power supply The power supply device CPD2 is responsible for the secondary power supply task, the active power calculation capacity of the traction transformer TT + the calculation transfer capacity of the first AC-DC-AC converter ADA1 + the calculation transfer capacity of the second AC-DC-AC converter ADA2 = the traction active load calculation capacity; the first AC-DC-AC converter The calculated transfer capacity of the converter ADA1 = the calculated transfer capacity of the second AC-DC converter ADA2; the calculated transfer capacity of the first AC-DC converter ADA1 and the second AC-DC converter ADA2 is caused by the excess of the three-phase voltage unbalance The capacity of the traction active load is determined; the calculated active power capacity of the traction transformer is greater than the calculated transfer capacity of a single AC-DC-AC converter.

That is to say, in the normal working process, when the traction active load power is less than or equal to three times the calculated transfer capacity of a single AC-DC-AC converter (the first AC-DC-AC converter ADA1, the second AC-DC-AC converter ADA2) , the traction transformer TT, the first AC-DC-AC converter ADA1, and the second AC-DC-AC converter ADA2 are respectively responsible for 1/3 of the traction active load power P, denoted as p. At this time, the traction active power carried by the traction transformer TT is The negative sequence power generated by the load power p, combined with the traction active load power p borne (transmitted) by the first AC-DC-AC converter ADA1 and the traction active load power p borne (transmitted) by the second AC-DC-AC converter ADA2 The sequence power is offset, that is, the synthetic negative sequence power of the traction substation is zero, and the resulting three-phase voltage unbalance is also zero; when the active power of the traction load is greater than the first AC-DC-AC converter ADA1 or the second AC-DC When the calculated transfer capacity of the AC converter ADA2 is three times, the first AC-DC converter ADA1 and the second AC-DC converter ADA2 are supplied according to their calculated transfer capacity, and the excess part is supplied by the traction transformer TT. At this time, there is a surplus Negative-sequence power flows and causes voltage unbalance, but the three-phase voltage unbalance it produces meets the requirements of the national standard and will not exceed the standard.

When the traction is converted to regenerative feedback, the active power delivered by the first AC-DC-AC converter ADA1 and the second AC-DC-AC converter ADA2 is reversed.

High-speed and heavy-duty railways have widely used high-power AC-DC electric locomotives or EMUs based on full-control devices such as IGBTs and IGCTs. The power factor is close to 1, and generally only the active load is considered. The load is perceptual and its magnitude is so small that it can be ignored. However, when the traction reactive load cannot be ignored, such as for AC-DC electric locomotives, a certain amount of capacitive reactive power can be absorbed by the output of the first AC-DC-AC converter ADA1 or the second AC-DC-AC converter ADA2 to compensate ; and vice versa when traction is switched to regenerative feedback.

When necessary, the first AC-DC converter ADA1 and the second AC-DC converter ADA2 can also provide harmonic compensation current.

Due to the characteristics of fully-controlled devices such as IGBT and IGCT used in the AC-DC-AC converter in the same-phase power supply device, the overload capacity of the AC-DC-AC converter is generally not considered, while the high-voltage matching transformer HMT and traction matching transformer in the same-phase power supply device The rated capacity of the TMT can be determined by referring to the rated capacity of the input and output terminals of the corresponding AC-DC-AC converter and its own overload capacity. The capacity of the backup traction transformer should be determined mainly according to the failure conditions and maintenance requirements of the traction transformer TT and the same-phase power supply device, and at the same time, the influence of the corresponding three-phase voltage imbalance should be considered. Generally, the capacity of the traction transformer TT can be selected to be the same as that of the traction transformer TT or a capacity level can be increased or decreased. traction transformer.

The beneficial effect of the present invention compared with prior art is:

1. The present invention can greatly reduce the capacity and proportion of the AC-DC-AC converter in the expensive in-phase power supply device, thereby greatly reducing the one-time investment.

2. The present invention is especially convenient for the in-phase power supply transformation of Vv wiring or Vx wiring traction substations widely used in high-speed railways and passenger dedicated lines;

3. The present invention can further enhance the energy-saving effect of the traction power supply system. After the implementation of the same-phase power supply, the combination of the upper and lower power supply arms of the traction substation is more conducive to the utilization of regenerative train electric energy by the traction trains running in it. The power system sends out excess and up-to-standard electric energy, which greatly increases the energy saving effect.

Four, the first high-voltage matching transformer HMT1 of the present invention and the secondary side winding of the second high-voltage matching transformer HMT2 form a V connection, which can provide three-phase self-consumption electricity;

5. In addition to traction substations and traction networks suitable for direct power supply, it is also suitable for traction substations and traction networks powered by AT.

6. The technology of the present invention is advanced, reliable and easy to implement.

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is a schematic diagram of the same-phase power supply and transformation structure of the traction substation of the embodiment.

Fig. 2 is a schematic diagram of the connection of the AC-DC-AC converter in the same-phase power supply device of the present invention.

Fig. 3 is a connection schematic diagram of the present invention for the 2×27.5kV AT traction power supply system.

Fig. 4 is a schematic diagram of the same-phase power supply and transformation structure with a backup high-voltage matching transformer of the present invention.

Fig. 5 is a schematic diagram of the same-phase power supply and transformation structure for a 2×27.5kV AT traction power supply system with a spare high-voltage matching transformer of the present invention.

Detailed ways

Example

As shown in Figure 1, a three-phase combined in-phase power supply and transformation structure includes a traction transformer TT, a backup traction transformer TB, a first in-phase power supply device CPD1 and a second in-phase power supply device CPD2; the first in-phase power supply device CPD1 It is composed of the first high-voltage matching transformer HMT1, the first AC-DC-AC converter ADA1 and the first traction matching transformer TMT1; the second non-phase power supply device CPD2 is composed of the second high-voltage matching transformer HMT2, the second AC-DC-AC converter ADA2 and the second The traction matching transformer TMT2 is composed; the traction transformer TT, the backup traction transformer TB, the first in-phase power supply device CPD1 and the second in-phase power supply device CPD2 are all of single-phase structure; the primary side winding of the traction transformer TT and the primary side of the first high-voltage matching transformer HMT1 The winding and the primary winding of the second high-voltage matching transformer HMT2 are respectively connected to the three sets of line voltages of the high-voltage bus H-Bus of the power system to form a delta connection group; the primary winding of the traction transformer TT and the primary winding of the backup traction transformer TB are connected to the high voltage of the power system The same group of line voltages of the bus H-Bus, the primary winding of the traction transformer TT and the primary winding of the spare traction transformer TB in the figure are connected to the line voltage BC of the high-voltage bus H-Bus of the power system, the primary winding of the first high-voltage matching transformer HMT1 and the primary winding of the second The primary windings of the two high-voltage matching transformers HMT2 are respectively connected to the line voltages AB and CA of the high-voltage bus H-Bus of the power system; the secondary windings of the first and second high-voltage matching transformers are respectively connected to the first and second AC-DC-AC converters input terminals; the output terminals of the first and second AC-DC-AC converters are respectively connected to the primary sides of the first and second traction matching transformers to generate a voltage with the same phase and frequency as the traction transformer TT; the secondary side winding of the traction transformer, the backup traction transformer The transformer secondary winding and the secondary windings of the two traction matching transformers have the same voltage amplitude and phase and are connected to the traction bus T-Bus. In the figure, T is catenary, G is rail, K1, K2, K3, K4, K5, K6, K7, K8, K9 circuit breakers, K1, K3, K5, K7 are two-phase circuit breakers, K2, K4 , K6, K8, and K9 are single-phase circuit breakers.

The voltage level of the secondary winding of the high-voltage matching transformer and the input terminal of the AC-DC-AC converter should weigh the primary voltage level of the high-voltage matching transformer, the primary-secondary transformation ratio, the capacity of the AC-DC-AC converter, and the cascade connection of the input terminal. It is suitable to be in the range of 6kV to 10kV.

When the traction transformer TT fails or is overhauled as planned, the backup traction transformer TB is put into operation.

The working principle of the present invention is:

In normal operation, the traction transformer TT, together with the first in-phase power supply device CPD1 and the second in-phase power supply device CPD2, supplies power to the traction load of the traction network. The traction transformer TT is responsible for the main power supply task. The first in-phase power supply device CPD1 and the second in-phase power supply The power supply device CPD2 is responsible for the secondary power supply task, the active power calculation capacity of the traction transformer TT + the calculation transfer capacity of the first AC-DC-AC converter ADA1 + the calculation transfer capacity of the second AC-DC-AC converter ADA2 = the traction active load calculation capacity; the first AC-DC-AC converter The calculated transfer capacity of the converter ADA1 = the calculated transfer capacity of the second AC-DC converter ADA2; the calculated transfer capacity of the first AC-DC converter ADA1 and the second AC-DC converter ADA2 is caused by the excess of the three-phase voltage unbalance The capacity of the traction active load is determined.

That is to say, in the normal working process, when the traction active load power is less than or equal to three times the calculated transfer capacity of the first AC-DC-AC converter ADA1 or the second AC-DC-AC converter ADA2, the traction transformer TT and the first AC-DC converter The AC converter ADA1 and the second AC-DC-AC converter ADA2 are respectively responsible for 1/3 of the traction active load power P, denoted as p. At this time, the negative sequence power generated by the traction active load power p borne by the traction transformer TT is the same as the first The traction active load power p borne (transmitted) by the first AC-DC-AC converter ADA1 and the traction active load power p borne (transmitted) by the second AC-DC-AC converter ADA2 are offset by the negative sequence power generated jointly, that is, the traction substation The combined negative sequence power is zero, and the resulting three-phase voltage imbalance is also zero; when the active power of the traction load is greater than the calculated transfer capacity of the first AC-DC-AC converter ADA1 or the second AC-DC-AC converter ADA2 3 times, the first AC-DC-AC converter ADA1 and the second AC-DC-AC converter ADA2 are supplied according to their calculated transfer capacity, and the excess part is supplied by the traction transformer TT. At this time, there is residual negative-sequence power flowing and causing voltage imbalance , but the three-phase voltage unbalance it produces meets the national standard requirements and will not exceed the standard.

When the traction is converted to regenerative feedback, the active power delivered by the first AC-DC-AC converter ADA1 and the second AC-DC-AC converter ADA2 is reversed.

High-speed and heavy-duty railways have widely used high-power AC-DC electric locomotives or EMUs based on full-control devices such as IGBTs and IGCTs. The power factor is close to 1, and generally only the active load is considered. The load is perceptual and its magnitude is so small that it can be ignored.

Take an actual traction substation as an example, power factor = 1, traction active load calculation capacity = 48MVA, the traction load capacity that meets the national standard requirements for three-phase voltage unbalance is 18MVA, regardless of the overload capacity of the AC-DC-AC converter , then the calculated transfer capacity of the first AC-DC-AC converter ADA1 in the same-phase power supply device = the calculated transfer capacity of the second AC-DC-AC converter ADA2 = (48MVA-18MVA)/3=10MVA; the high-voltage matching transformer and traction in the same-phase power supply device The rated capacity of the matching transformer can be determined by referring to the rated capacity of the input and output terminals of the corresponding AC-DC-AC converter and its own overload capacity. It should be 10/1.2MVA=8.33MVA, and a single-phase transformer with a rated capacity of 8MVA standard grade can be selected; the active power calculation capacity of the traction transformer=48-20=28MVA, when the overload capacity is not considered, the rated capacity can be selected to be 31.5MVA Standard-grade single-phase traction transformers and standby traction transformers, and when considering the 1.5 times overload capacity of traction transformers, the calculated capacity of traction transformers = 28/1.5 = 18.67MVA, then a single-phase traction transformer with a rated capacity of 20MVA standard grades can be selected .

The capacity of the backup traction transformer should be determined mainly according to the fault conditions and maintenance requirements of the traction transformer and the same-phase power supply device, and at the same time, the influence of the corresponding three-phase voltage unbalance should be considered. Generally, the traction transformer with the same capacity as the traction transformer or one capacity level increased or decreased should be selected. . In this example, a single-phase traction transformer with a rated capacity of 20MVA standard grade is selected as the standby traction transformer.

Under normal conditions, the traction transformer and the same-phase power supply device work, and the standby traction transformer does not work; when the traction transformer is out, the standby traction transformer is put into operation; when the same-phase power supply device is out of operation, the traction transformer can work alone for a short time, and the standby traction transformer can also replace the traction The transformer works.

Fig. 2 is the connection diagram of the AC-DC-AC converter ADA in the same-phase power supply device of the present invention. ) single-phase PWM (pulse width modulation) converter, that is, an AC-DC-AC conversion device connected through a DC energy storage capacitor. The leakage reactance of the transformer and the traction matching transformer are considered together.

It should be noted that since the AC-DC-AC converter in the same-phase power supply device uses modern power electronic semiconductor devices with excellent performance such as integrated gate commutation thyristor IGCT or insulated gate bipolar transistor IGBT, its manufacturing cost is relatively high, and at the same time due to the " The traction transformer is responsible for the main power supply task, and the same-phase power supply device is responsible for the secondary power supply task". Generally, the 100% backup method like the traction transformer is not adopted, but the module-level backup is used after weighing the cost and reliability to reduce costs. And ensure reliability.

Fig. 3 is a schematic diagram of the connection of the present invention for AT (autotransformer) traction power supply system, in which the connection mode of the high-voltage bus H-Bus is the same as that of Fig. 1, and the voltage of the traction bus T-Bus is 2×27.5kV, F , T are the negative feeder and contact line in the AT traction network TS respectively, and G is the rail. Obviously, in the same-phase power supply and transformation structure of 2×27.5kVAT power supply mode, the midpoints of the secondary windings of the traction transformer TT and the standby traction transformer TB are drawn out to ground, and when the midpoints of the secondary windings of the traction transformer TT and the standby traction transformer TB When neither is drawn out, it is a 55kV AT power supply method. Generally, the middle points of the secondary windings of the first traction matching transformer TMT1 and the second traction matching transformer TMT2 are not extracted. In the figure, K1, K2, K3, K4, K5, K6, K7, K8, and K9 are all two-phase circuit breakers.

Fig. 4 is a schematic diagram of the same-phase power supply and transformation structure with a backup high-voltage matching transformer of the present invention. In the figure, in order to save space and further reduce costs, the first high-voltage matching transformer HMT1, the second high-voltage matching transformer HMT2 and the single core of the traction transformer TT form a three-core traction transformer TG; the first standby high-voltage matching transformer HMTB1, the second The spare high-voltage matching transformer HMTB2 and the single core of the spare traction transformer TB form a spare three-core traction transformer TGB. In order to facilitate the connection between the secondary windings of the high-voltage matching transformer HMT and the backup high-voltage matching transformer HMTB and the input end of the AC-DC-AC converter ADA, set up low-voltage (such as 10kV) compensation buses L-Bus1, L-Bus2 and corresponding circuit breakers; in the figure , T is catenary, G is rail, K1, K2, K3, K4, K5, K6, K7, K8, K9, K10, K11, K12, K13 circuit breakers, K1, K9 are three-phase circuit breakers, others A single-phase circuit breaker.

When the three-core traction transformer TG fails or is overhauled as planned, the spare three-core traction transformer TGB is put into operation.

Fig. 5 is a schematic diagram of the same-phase power supply and transformation structure for a 2×27.5kV AT traction power supply system with a spare high-voltage matching transformer according to the present invention. In the figure, in order to save space and further reduce costs, the first high-voltage matching transformer HMT1, the second high-voltage matching transformer HMT2 and the single core of the traction transformer TT form a three-core traction transformer TG; The high-voltage matching transformer HMTB2 and the single core of the backup traction transformer TB form a backup three-core traction transformer TGB. The voltage of the traction bus T-Bus is 2×27.5kV, F and T are the negative feeder and contact line in the AT traction network TS respectively, and G is the rail. Obviously, in the same-phase power supply and transformation structure of 2×27.5kV AT power supply mode, the midpoints of the secondary windings of the traction transformer TT and the standby traction transformer TB are drawn out to ground, and when the secondary windings of the traction transformer TT and the standby traction transformer TB When the points are not pulled out, it is a 55kV AT power supply mode. Generally, the middle points of the secondary windings of the first traction matching transformer TMT1 and the second traction matching transformer TMT2 are not extracted. In order to facilitate the connection of the secondary windings of the high-voltage matching transformer HMT and the backup high-voltage matching transformer HMTB to the input terminal of the AC-DC-AC converter ADA, set up low-voltage (such as 10kV) compensation buses L-Bus1, L-Bus2 and corresponding circuit breakers. Among the circuit breakers of K1, K2, K3, K4, K5, K6, K7, K8, K9, K10, K11, K12 and K13, K1 and K9 are three-phase circuit breakers, and K2, K6, K8, K10 and K13 are two-phase circuit breakers. Phase circuit breakers, K3, K4, K5, K7, K11, K12 are single-phase circuit breakers.

Claims (4)

1. a three phase combined cophase supply power transformation structure, comprise that traction transformer TT, standby traction transformer TB, the first cophase supply device CPD1 and the second cophase supply device CPD2 form; Wherein: the first cophase supply device CPD1 consists of the first high pressure matching transformer HMT1, the first AC-DC-AC converter ADA1 and the first traction matching transformer TMT1; The second cophase supply device CPD2 consists of the second high pressure matching transformer HMT2, the second AC-DC-AC converter ADA2 and the second traction matching transformer TMT2; Traction transformer TT, standby traction transformer TB, the first cophase supply device CPD1 and the second cophase supply device CPD2 are phase structure; It is characterized in that: the former limit of traction transformer TT winding, the first high pressure matching transformer HMT1 former limit winding and the second former limit of high pressure matching transformer HMT2 winding are connected to three groups of line voltages of electric power system, form triangle connection group; The former limit of traction transformer TT winding is connected same group of line voltage of electric power system with the former limit of standby traction transformer TB winding; The inferior limit winding of first and second high pressure matching transformer connects respectively the end that enters of first and second AC-DC-AC converter; The first and second AC-DC-AC converter go out the former limit that end connects respectively the first and second traction matching transformers, produce the voltage with traction transformer TT same phase and frequency; The voltage magnitude of the inferior limit winding of TT limit winding of traction transformer, TB limit winding of standby traction transformer and two traction matching transformers identical with phase place and all with the traction bus join.

2. a kind of three phase combined cophase supply power transformation according to claim 1 is constructed, it is characterized in that: in described cophase supply power transformation structure, the traction burden with power calculated capacity=meritorious calculated capacity of traction transformer TT+first AC-DC-AC converter ADA1 calculates transfer capacity+second AC-DC-AC converter ADA2 and calculates transfer capacity; The first AC-DC-AC converter ADA1 calculates transfer capacity=second AC-DC-AC converter ADA2 and calculates transfer capacity; Two AC-DC-AC converter are calculated transfer capacity by causing that the exceed standard capacity of traction burden with power of part of imbalance of three-phase voltage degree determines; The meritorious calculated capacity of traction transformer TT is greater than the calculating transfer capacity of single AC-DC-AC converter.

3. a kind of three phase combined cophase supply power transformation according to claim 1 is constructed, it is characterized in that: in described cophase supply power transformation structure, when traction is converted to Regenerative feedback, the active power that the first AC-DC-AC converter ADA1 and the second AC-DC-AC converter ADA2 transmit is all reverse.

4. a kind of three phase combined cophase supply power transformation according to claim 1 is constructed, it is characterized in that: being that the first high pressure matching transformer HMT1 is equipped with the first standby high pressure matching transformer HMTB1 of same structure with it, is that the second high pressure matching transformer HMT2 is equipped with the second standby high pressure matching transformer HMTB2 of same structure with it; The singlecore of the first high pressure matching transformer HMT1, the second high pressure matching transformer HMT2 and traction transformer TT forms three traction transformer TG unshakable in one's determination; The singlecore of the first standby high pressure matching transformer HMTB1, the second standby high pressure matching transformer HMTB2 and standby traction transformer TB forms standby three traction transformer TGB unshakable in one's determination.

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