CN203352187U - Single-phase combined co-phased power supply and transformation device - Google Patents

Abstract

The utility model discloses a single-phase combined type in-phase power supply and transformation device, which mainly includes a traction transformer and a co-phase compensation device (CPD). In the same-phase compensation device: the primary side of the high-voltage matching transformer and the primary side of the traction transformer form a SCOTT connection group, the secondary winding is connected to the input end of the AC-DC converter, and the output end of the AC-DC converter is connected to the primary side of the traction matching transformer. The voltage amplitude and phase of the secondary winding of the traction transformer and the secondary winding of the traction matching transformer are the same and both are connected to the traction busbar; the calculated capacity of the traction load = the calculated capacity of the traction transformer + the calculated capacity of the same-phase compensation device, the traction transformer is responsible for the main power supply task, The calculation capacity of the same-phase compensation device is determined by the capacity of the traction load that causes the three-phase voltage imbalance to exceed the standard; the utility model can realize the optimal allocation of traction power supply resources and achieve better energy-saving effects.

Description

A single-phase combined in-phase power supply and transformation device

technical field

The utility model relates to the field of AC electrified railway power supply, in particular to a single-phase combined type in-phase power supply and transformation device. the

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 due to arcing through electric split-phase emission, 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 When the main circuit breaker is driven through the neutral section by the inertia of the train, the main circuit breaker is closed again, the auxiliary unit is closed, and the traction power is upgraded to restore the traction power to complete the over-phase separation, the automatic over-phase separation technology is adopted, mainly including the automatic switching of the ground switch. phase, on-board automatic over-phase, and pole-mounted automatic over-phase equalization, but there are still transient electrical processes in which the train passes through the electric phase during switching, which is easy to generate large operating overvoltage or overcurrent, causing damage to the traction network and on-board equipment. Accidents such as burnout may even lead to the failure of automatic over-phase separation operation, which affects the reliability of power supply and the safe operation of trains. Therefore, the electrical 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. the

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 on ordinary speed railways). The increasingly serious power quality problems caused by power single-phase loads on the three-phase grid, mainly caused by three-phase voltage unbalance (negative sequence), must be paid attention to. the

Theory and practice show that the use of the same-phase power supply technology can effectively control the negative-sequence current and achieve three-phase voltage imbalance while canceling the electrical phase separation at the exit 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. the

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. Considering that the simplest and most economical wiring method of various traction transformers in traction substations is single-phase traction transformers, then the wiring methods of traction substations used in the same-phase power supply system can be divided into two categories, namely one The traction transformer that can form the same phase power supply with the single-phase traction transformer belongs to the line voltage type, and the other type belongs to the non-line voltage type, mainly the phase voltage type. the

The main representative of the phase-voltage type is the traction substation with YNd11 connection, which is widely used on existing domestic ordinary-speed railways and can be a self-contained system, that is, transforming the two-phase power supply of the existing railways into the same-phase power supply. However, in the case where the three-phase voltage unbalance (negative sequence) does not meet the standard, it is necessary to install the same-phase (symmetrical) compensation device, which needs to be compensated at the three ports on the traction side, and the structure is more complicated. At the same time, compared with the minimum It is necessary to add 1/3 of the same-phase compensation capacity. In addition, when the three-phase voltage unbalance (negative sequence) meets the requirements and does not need the same-phase (symmetrical) compensation, using one of the phases for the same-phase power supply will cause YNd11 wiring traction transformers Large waste of capacity (up to 2/3), very uneconomical. Therefore, it is difficult to promote YNd11 wiring traction transformers to implement same-phase power supply on the whole line of new railways. the

In addition to the single-phase traction transformer, the same-phase power supply of the line voltage type can come from a three-phase-two-phase balanced wiring transformer, in which one port of most three-phase-two-phase balanced wiring is the line voltage, and the other port is the phase voltage, such as Scott, Leblanc, (variant) Wood-Bridge and YNvd, etc., among them, the line voltage can cooperate with the traction substation of the single-phase traction transformer to realize the same phase power supply of the whole line, which is an advantage, but the disadvantage is that the three-phase-two-phase balanced wiring traction transformer needs Special manufacturing will increase the cost of standard wiring transformers, and will cause part of the capacity of the traction backup transformer to be idle, which will affect the economy, and it is difficult to promote it on the whole line of the new railway. the

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 to achieve the elimination of the electrical substation at the exit of the traction substation. The goal is to eliminate power supply bottlenecks and control the negative sequence to meet the power quality requirements of the three-phase voltage unbalance (negative sequence) limit, so as to achieve the best match between the wiring mode of the traction substation and the capacity of the power supply device. Best choice for in-phase power supply. the

For this reason, the inventor once proposed a single-phase three-phase combined in-phase power supply and transformation device (invention application number: 201210583674.X), that is, through the line voltage of the single-phase traction transformer and the phase voltage of the YNd11 three-phase transformer Combination with AC-DC-AC converter to achieve the best matching of the same phase power supply, suitable for neutral point large current grounding system and/or occasions that need to output three-phase self-consumption power, but YNd11 three-phase transformer is used for single-phase The load makes its winding capacity not fully utilized. In this regard, a combination of single-phase traction transformer and AC-DC-AC converter is proposed, which is suitable for occasions that do not require large-current grounding of the neutral point and do not need to output three-phase self-consumption electricity. Compared with the single-phase three-phase combined in-phase power supply and transformation device, the same-phase power supply and transformation device realized by the best matching, its main wiring is simpler, and the investment can be further reduced. the

Utility model content

The purpose of this utility model is to provide a single-phase combined in-phase power supply and transformation device, which can effectively realize the technical and economic optimization of the same-phase power supply for electrified railways, and at the same time, can eliminate the load of the three-phase system caused by the single-phase load of electrified railways. Sequence (voltage imbalance) problems. the

The purpose of this utility model is achieved by the following technical solutions: a co-phase power supply and transformation device includes a traction transformer (TT), a traction backup transformer (TB) and a co-phase compensation device (CPD); a co-phase compensation device (CPD); Composed of high-voltage matching transformer (HMT), AC-DC converter (ADA) and traction matching transformer (TMT); traction transformer (TT), traction backup transformer (TB) and co-phase compensation device (CPD) are all single-phase structures; One end T0 of the primary winding of the matching transformer (HMT) is respectively connected to the middle points of the primary windings of the traction transformer (TT) and the traction standby transformer (TB); the primary winding of the traction transformer (TT) and the primary winding of the traction standby transformer (TB) The winding is connected to the same line voltage of the power system, that is, it is connected between the same two phases of the three phases, and the other end T1 of the primary winding of the high voltage matching transformer (HMT) is connected to the other phase of the three phases; the high voltage matching transformer (HMT) The secondary winding is connected to the input terminal of the AC-DC converter (ADA); the output terminal of the AC-DC converter (ADA) is connected to the primary side of the traction matching transformer (TMT) to generate a voltage with the same phase and frequency as the traction transformer (TT); The transformer (TT) secondary winding, the traction backup transformer (TB) secondary winding and the traction matching transformer (TMT) secondary winding have the same voltage amplitude and phase and are all connected to the traction bus; when the traction transformer (TT) fails or During the planned maintenance, the traction backup transformer (TB) was put into operation. the

If equipped with high-voltage matching backup transformer HMTB, it can follow the operation mode of traction transformer (TT) failure or maintenance; if high-voltage matching transformer HMT and traction transformer TT are assembled in one box, high-voltage matching backup transformer HMTB and traction backup transformer TB are assembled in If it is inside a box, it should exit or run as a whole. the

The working principle of the utility model is:

The traction transformer (TT) and the traction backup transformer (TB) respectively form a unequal SCOTT connection group with the high voltage matching transformer (HMT), which constitutes a special three-way power supply with unequal power supply capacity, unequal voltage amplitude, and vertical voltage phase. Phase-to-two-phase balancing transformer. the

In normal operation, the traction transformer (TT) and the same-phase compensation device (CPD) together supply power to the traction load of the traction network. The traction transformer (TT) is responsible for the main power supply task, and the common-phase compensation device (CPD) is responsible for the secondary power supply task. The traction transformer ( TT) calculation capacity + common phase compensation device (CPD) calculation capacity = traction load calculation capacity; common phase compensation device (CPD) calculation capacity is the capacity of the traction load that causes the three-phase voltage imbalance to exceed the standard (beyond the national standard limit value) Sure. the

That is to say, in the normal working process, when the traction load power is less than or equal to twice the rated capacity of the same-phase compensation device (CPD), the traction transformer (TT) and the same-phase compensation device (CPD) respectively bear 1/1 of the traction load power 2. At this time, the negative sequence current can be fully compensated, and the resulting three-phase voltage unbalance is zero; when the traction load power is greater than twice the rated capacity of the same-phase compensation device (CPD), the same-phase compensation device (CPD) will The rated capacity is supplied, and the excess part is supplied by the traction transformer (TT). At this time, the residual negative sequence current flows and causes voltage unbalance, but the three-phase voltage unbalance produced by it meets the national standard requirements, that is, it will not exceed the standard. the

If necessary, the common phase compensation device (CPD) can also provide the reactive power and harmonic compensation current required by the traction load. the

Regardless of the overload capacity of the AC-DC-AC converter (ADA) in the same-phase compensation device (CPD), the calculation capacity of the non-phase compensation device (CPD) = the rated capacity of the AC-DC-AC converter (ADA), and the high-voltage matching transformer ( HMT) and the rated capacity of the traction matching transformer (TMT) can be determined by referring to the rated capacity of the AC-DC converter (ADA) and its own overload capacity. The capacity of the traction backup transformer (TB) should be determined mainly according to the failure conditions and maintenance requirements of the traction transformer (TT) and the common-phase compensation device (CPD), while considering the influence of the corresponding three-phase voltage unbalance. ) Traction transformers with the same capacity or one capacity level increased or decreased. the

The beneficial effects of the utility model compared with the prior art are:

1. The utility model can minimize the capacity and proportion of the AC-DC-AC converter (ADA) in the expensive common-phase compensation device (CPD), and effectively reduce the one-time investment of the same-phase power supply and transformation device. the

2. The utility model proposes a new combination of traction transformer and co-phase compensation device (CPD), which further simplifies the main wiring structure of the traction substation while canceling the electric phase separation link at the exit of the traction substation. the

3. The utility model can improve the power supply resource and equipment utilization rate of the traction substation. The utilization rate of winding (copper material) of single-phase traction transformer is 1, and the load in the same-phase compensation device (CPD) will occupy a certain amount of additional weight in the primary winding of the traction transformer, but usually this weight is small and will only affect the winding Utilization has an impact of several percentage points, even so, its winding utilization is still higher than that of existing three-phase-two-phase traction transformers, and higher than that of Vv wiring and Vx wiring traction transformers used for the same phase supply. the

4. The utility model 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 mutual utilization of the traction and regenerative power of multiple trains running in it, reducing the power consumption of the power system, and the working condition of the same-phase compensation device (CPD) When the train in the traction power supply system is in regenerative condition, it can also send the standard electric energy to the power system, which greatly increases the energy saving effect. the

5. The utility model is not only suitable for traction substations and traction networks with direct power supply, but also applicable to traction substations and traction networks with AT power supply. the

Six, the utility model is advanced in technology, reliable and easy to implement. the

The utility model can be equipped with the same high-voltage matching transformer HM as the high-voltage matching standby transformer HMTB. The high-voltage matching transformer HMT and the traction transformer TT are assembled in one box, and the high-voltage matching standby transformer HMTB and the traction standby transformer TB are assembled in one box, which reduces the occupied area. area. the

Below in conjunction with accompanying drawing and specific embodiment, the utility model is further described. the

Description of drawings

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

Fig. 2 is a schematic diagram of the connection of the AC-DC-AC converter in the same-phase compensation device (CPD) of the present invention. the

Fig. 3 is a schematic diagram of the same-phase power supply and transformation device equipped with a high-voltage matching backup transformer of the present invention. the

Fig. 4 is a connection schematic diagram of the utility model used in a 2×27.5kV AT traction power supply system. the

Fig. 5 is a schematic diagram of an in-phase power supply and transformation device for a 2×27.5kV AT traction power supply system equipped with a high-voltage matching backup transformer of the present invention. the

Detailed ways

Example

As shown in Figure 1, a schematic diagram of a common-phase power supply and transformation device, including a traction transformer (TT), a traction backup transformer (TB) and a common-phase compensation device (CPD); the common-phase compensation device (CPD) consists of a high-voltage matching transformer (HMT), Composed of AC-DC converter (ADA) and traction matching transformer (TMT); traction transformer (TT), traction backup transformer (TB) and common-phase compensation device (CPD) are all single-phase structures; the primary side of high-voltage matching transformer (HMT) One end T0 of the winding is respectively connected to the midpoint of the primary winding of the traction transformer (TT) and the traction backup transformer (TB); the primary winding of the traction transformer (TT) and the primary winding of the traction backup transformer (TB) are connected to the high-voltage bus H of the power system -The same line voltage of the Bus, the figure is the AB line voltage (the secondary side is the ab line voltage), that is, it is connected between the A and B phases of the three phases, and the other end of the primary winding of the high voltage matching transformer (HMT) is T1 Connect to the other phase of the three phases, the figure is C phase (the secondary side is c phase); the secondary side winding of the high voltage matching transformer (HMT) is connected to the input end of the AC-DC converter (ADA); the AC-DC converter (ADA) ) is connected to the primary side of the traction matching transformer (TMT) to generate a voltage with the same phase and frequency as the traction transformer (TT); the secondary winding of the traction transformer (TT), the secondary winding of the traction backup transformer (TB) and the traction matching transformer ( TMT) The voltage amplitude and phase of the secondary winding are the same and are all connected to the traction bus T-Bus; in the figure, T is the catenary, G is the rail, and K1, K2, K3, K4, K5, K6, K7 are open circuits Devices, of which K1 and K5 are three-phase circuit breakers. the

The voltage level of the secondary winding of the high-voltage matching transformer (HMT) and the input terminal of the AC-DC-AC converter (ADA) should balance the voltage level of the primary side of the high-voltage matching transformer, the transformation ratio of the primary side, the capacity of the AC-DC-AC converter and the cascading of the input terminal At present, it is generally advisable to choose in the range of 6kV to 10kV. the

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

The working principle of the utility model is:

The traction transformer (TT) and the traction backup transformer (TB) are respectively connected with the high-voltage matching transformer (HMT) to form a unequal SCOTT connection group, that is, to form a special SCOTT connection group with unequal power supply capacity, unequal voltage amplitude, and vertical voltage phase. Three-phase - two-phase balanced transformer. the

In normal operation, the traction transformer (TT) and the same-phase compensation device (CPD) supply power to the traction load of the traction network together. The traction transformer (TT) is responsible for the main power supply task, and the common-phase compensation device (CPD) is responsible for the secondary power supply task. The traction transformer ( TT) calculation capacity + common phase compensation device (CPD) calculation capacity = traction load calculation capacity; common phase compensation device (CPD) calculation capacity is determined by the traction load capacity of the part that causes the three-phase voltage unbalance to exceed the standard; traction backup transformer (TB) Calculation capacity = calculation capacity of traction transformer (TT); the overload capacity of AC-DC-AC converter (ADA) in the same-phase compensation device (CPD) is not considered, therefore, the calculation capacity of the same-phase compensation device (CPD) = AC-DC-AC converter can be selected (ADA) rated capacity, and the rated capacity of the high-voltage matching transformer (HMT) and traction matching transformer (TMT) can be determined by referring to the rated capacity of the AC-DC converter (ADA) and its own overload capacity. the

That is to say, during normal operation, when the traction load power is less than or equal to twice the rated capacity of the same-phase compensation device (CPD), the traction transformer (TT) and the same-phase compensation device (CPD) respectively supply 1/1 of the traction load power 2. At this time, the negative sequence current is fully compensated, and the three-phase voltage unbalance caused by it is zero; Capacity supply, and the excess part is supplied by the traction transformer (TT). At this time, there is a residual negative sequence current flowing and causing three-phase voltage unbalance, but the three-phase voltage unbalance produced by it meets the requirements of the national standard. the

Taking an actual traction substation as an example, the traction load calculation capacity = 38MVA, and the traction load capacity meeting the national standard for three-phase voltage unbalance is 18MVA, regardless of the overload capacity of the same-phase compensation device (CPD), the same-phase compensation device (CPD) calculation capacity = (38MVA-18MVA)/2=10MVA, choose the same phase compensation device (CPD) rated capacity = 10MVA, traction transformer (TT) calculation capacity = 38-10=28MVA, select the rated capacity as 31.5MVA standard single-phase traction transformer and traction backup transformer; when considering the 1.5 times overload capacity of the traction transformer, the calculated capacity of the traction transformer (TT) = 28/1.5 = 18.7MVA, then you can choose a single-phase rated capacity of 20MVA standard level Traction transformer. the

The capacity of the traction backup transformer (TB) should be determined mainly according to the failure conditions and maintenance requirements of the traction transformer (TT) and the common-phase compensation device (CPD), while considering the influence of the corresponding three-phase voltage unbalance. ) Traction transformers with the same capacity or one capacity level increased or decreased. In this example, a single-phase traction transformer with a rated capacity of 20MVA standard grade is selected as the traction backup transformer. the

If necessary, the same-phase compensation device (CPD) can also compensate the reactive power and harmonic current of the traction load. the

In Figure 1, a combination of the line voltage of the primary side AB (secondary side ab) of the traction transformer and the phase voltage of the primary side C (secondary side c) of the high-voltage matching transformer is taken as an example to form a SCOTT connection with unequal voltage amplitudes and vertical voltage phases group, that is, a special three-phase-two-phase balanced transformer, of course, there is also a combination of the line voltage of the primary side BC (secondary side bc) of the traction transformer and the phase voltage of the primary side A (secondary side a) of the high-voltage matching transformer, and the traction transformer Combination of transformer primary side CA (secondary side ca) line voltage and high voltage matching transformer primary side B (secondary side b) phase voltage. the

Under normal conditions, the traction transformer TT, the high voltage matching transformer HMT and its co-phase compensation device (CPD) work, and the traction backup transformer TB does not work; when the traction transformer TT exits, the traction backup transformer TB starts working; when the co-phase compensation device (CPD) exits , the traction transformer TT can work alone for a short time, and the traction backup transformer TB can also work instead of the traction transformer TT. the

Figure 2 is the connection diagram of the AC-DC-AC converter in the same-phase compensation device (CPD) of the present invention. The AC-DC-AC converter (ADA) adopts high-power power electronic semiconductor devices (such as integrated gate Bipolar transistor IGBT) single-phase PWM (pulse width modulation) converter, that is, an AC-DC-AC conversion device connected through a DC energy storage capacitor, the reactance value of the reactor Li and the reactor Lo connected in series at both ends It can be considered together with the leakage reactance of the high-voltage matching transformer and the traction matching transformer respectively. the

It should be noted that since the AC-DC converter (ADA) in the non-phase compensation device (CPD) uses modern power electronic semiconductor devices with excellent performance such as integrated gate commutated thyristor IGCT or insulated gate bipolar transistor IGBT, its manufacturing cost At the same time, due to the division of labor that "the traction transformer (TT) is responsible for the main power supply task, and the co-phase compensation device (CPD) is responsible for the secondary power supply task", the 100% backup method like the traction transformer is generally not used, but is in the balance of cost and After reliability, module-level backup is used to reduce costs and ensure reliability. the

Fig. 3 is a schematic diagram of the same-phase power supply and transformation device equipped with a high-voltage matching backup transformer of the present invention. In the figure, the high-voltage matching transformer HMT and the traction transformer TT are assembled in a box, and the high-voltage matching backup transformer HMTB and the traction backup transformer TB are assembled in a box. When the traction transformer TT or the high-voltage matching transformer HMT has a failure or needs to be repaired, then It should be withdrawn as a whole, put into the assembly of the traction backup transformer TB and the high-voltage matching backup transformer HMTB; in order to facilitate the connection of the secondary winding of the high-voltage matching transformer HMT and the high-voltage matching backup transformer HMTB with the input terminal of the AC-DC-AC converter ADA, a low-voltage transformer can be set. Compensation busbar L-Bus and corresponding switches; in the figure, T is catenary, G is rail, K1, K2, K3, K4, K5, K6, K7, K8, K9 are circuit breakers, of which K1 and K6 are three-phase Circuit breakers, others are single-phase circuit breakers; others are the same as in Figure 1. the

Fig. 4 is a connection schematic diagram of the utility model used in AT (autotransformer) traction power supply system, wherein 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 and T are the negative feeder and contact line in the AT traction network TS respectively. Obviously, in the same-phase power supply and transformation device of the AT power supply mode, the traction transformer (TT), traction backup transformer (TB) and traction matching transformer (TMT) The midpoints of the secondary windings are drawn out to ground, and the voltage is 2×27.5kV. When the midpoints of the secondary windings of the traction transformer (TT), traction standby transformer (TB) and traction matching transformer (TMT) are not drawn out, It is a 55kV AT power supply mode; in the figure, T is catenary, G is rail, K1, K2, K3, K4, K5, K6, K7 are circuit breakers, of which K1 and K5 are three-phase circuit breakers, and others It is a two-phase circuit breaker. the

Fig. 5 is a schematic diagram of an in-phase power supply and transformation device for a 2×27.5kV AT traction power supply system equipped with a high-voltage matching backup transformer of the present invention. In the figure, the high-voltage matching transformer HMT and the traction transformer TT are assembled in a box, and the high-voltage matching backup transformer HMTB and the traction backup transformer TB are assembled in a box. When the traction transformer TT or the high-voltage matching transformer HMT has a failure or needs to be repaired, then It should be withdrawn as a whole, and put into the assembly of the traction backup transformer TB and the high-voltage matching backup transformer HMTB; in order to facilitate the connection of the high-voltage matching transformer HMT, the secondary winding of the high-voltage matching backup transformer HMTB and the input terminal of the AC-DC-AC converter ADA, a low-voltage Compensation busbar L-Bus and corresponding switches K3, K4, K8; in the figure, T is catenary, F is negative feeder, G is rail, K1, K2, K3, K4, K5, K6, K7, K8, K9 are Circuit breakers, of which K1 and K6 are three-phase circuit breakers, K2, K5, K7, and K9 are two-phase circuit breakers, and K3, K4, and K8 are single-phase circuit breakers; others are the same as in Figure 4. the

Claims (2)

1. a single-phase composite type cophase supply transformation device, comprise traction transformer TT, traction spare transformer TB and same-phase compensation device CPD; Same-phase compensation device CPD consists of high pressure matching transformer HMT, AC-DC-AC converter ADA and traction matching transformer TMT; Traction transformer TT, traction spare transformer TB and same-phase compensation device CPD are phase structure; It is characterized in that: an end T0 of the former limit of high pressure matching transformer HMT winding joins with traction transformer TT and the traction former limit of spare transformer TB winding mid point respectively; The former limit of traction transformer TT winding is connected the same line voltage of electric power system with the traction former limit of spare transformer TB winding, is connected between the identical two-phase in three-phase, and the other end T1 of the former limit of high pressure matching transformer HMT winding connects another phase in three-phase; HMT limit winding of high pressure matching transformer connects AC-DC-AC converter ADA and enters end; AC-DC-AC converter ADA goes out end and connects the traction former limit of matching transformer TMT, produces the voltage with traction transformer TT same phase and frequency; The voltage magnitude of TT limit winding of traction transformer, traction spare transformer TB limit winding and TMT limit winding of traction matching transformer identical with phase place and all with draw bus and join.

2. a kind of single-phase composite type cophase supply transformation device according to claim 1 is characterized in that: described high pressure matching transformer HMT is equipped with identical high pressure coupling spare transformer HMTB; High pressure matching transformer HMT and traction transformer TT are assembled in a casing, and high pressure coupling spare transformer HMTB and traction spare transformer TB are assembled in a casing.

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