CN106786641A - High ferro is powered and is compensated with single-phase MMC_STATCOM methods for designing - Google Patents

Abstract

Compensation is powered with single-phase MMC_STATCOM methods for designing the invention discloses a kind of high ferro, is comprised the following steps：Single-phase MMC_STATCOM converter topologies structure list bridge arm Mathematical Modeling is set up, wherein each submodule is made up of two insulated gate bipolar transistor IGBTs connected and DC capacitor parallel connection；According to upper and lower two bridge arm voltages, the single-phase equivalent output voltage of MMC_STATCOM converter output terminals mouthful is calculated；Calculate the MMC_STATCOM upper and lower bridge arm reference voltages of converter list bridge arm；Single-phase MMC_STATCOM converters under to the topology carry out power frequency analysis of components；The secondary undulate quantity that dc bus side voltage is produced is calculated, secondary LC filter circuits are set；Many cars access electrical quantity fluctuation and the lower Traction networks electrical quantity distribution of MMC_STATCOM converters compensation that Traction networks trigger in the case of comparing uncompensated device；The present invention can make electrified railway compensating device fast response time low, can effectively suppress many cars and access the voltage pulsation problem that tractive power supply system triggers.

Description

High ferro is powered and is compensated with single-phase MMC_STATCOM methods for designing

Technical field

The present invention relates to high-speed railway dynamic passive compensation field, and in particular to a kind of high ferro is powered to compensate and uses single-phase MMC_ STATCOM methods for designing.

Background technology

Typical nonlinear-load, preferably overcomes that power factor is relatively low to be lacked after using " AC-DC-AC " mode Point；But a large amount of electric locomotives life bows take stream when reorganizing and outfit so that Traction networks net presses larger fluctuation, causes locomotive relay equipment to move Make, self-locking occurs in insulated gate bipolar transistor IGBT, or even triggers transport paralysis；Scene is by the gradual raw bow of power train Mode suppresses the problem, but cannot tackle the problem at its root；The indemnifying measure for using at present has：Phase sequence rotation, balance become Depressor, passive filtration unit, reactive power compensator SVC and passive filter mixed method；But the exclusive use of the above method Or be used in mixed way and be limited by scene, cause the big heavy discount of actual effect；Such as use SVC and the passive filter mixed method can be with Preferably solve that asymmetric, power factor is low and harmonic problem, but SVC device harmonic wave is larger in itself, loss is big, floor space Greatly, operating cost is high；With Development of Power Electronic Technology, active power compensator shows wide in tractive power supply system Prospect；Wherein STATCOM STATCOM, remote procedure call protocol RPC partly come into operation, but due to electric power The limitation of electronic component stress levels, compensation device could need to be connected by step-down transformer with traction, the increase of input cost Limit promoting the use of for such device.

The content of the invention

The present invention provides one kind can make electrified railway compensating device while reduces cost, and floor space is small, phase Answer the high ferro that speed is fast, the small, integrated cost of loss is low to power to compensate with single-phase MMC_STATCOM methods for designing.

The technical solution adopted by the present invention is：A kind of high ferro powers compensation with single-phase MMC_STATCOM methods for designing, including Following steps：

Single-phase MMC_STATCOM converter topologies structure list bridge arm Mathematical Modeling is set up, wherein each submodule is by connecting Two insulated gate bipolar transistor IGBTs and DC capacitor is in parallel constitutes；

According to upper and lower two bridge arm voltages, the single-phase equivalent output voltage of MMC_STATCOM converter output terminals mouthful is calculated；

Calculate the MMC_STATCOM upper and lower bridge arm reference voltages of converter list bridge arm；

Single-phase MMC_STATCOM converters under to the topology carry out CIRCULATION ANALYSIS；

The secondary undulate quantity that dc bus side voltage is produced is calculated, setting meets the secondary LC filtered electricals of the topological circuit Road；

Many cars access electrical quantity fluctuation and the MMC_STATCOM converters that Traction networks trigger in the case of comparing uncompensated device The lower Traction networks electrical quantity distribution of compensation.

Further, it is further comprising the steps of：Checking method for designing feasibility, specially using FFT FFT carries out spectrum analysis to supply conductor voltage, electric current.

Further, it is described according to upper and lower two bridge arm voltages, the equivalent output voltage in port of converter is calculated, specifically Method is as follows：

Assume initially that alternating current i_sIt is evenly distributed in upper and lower bridge arm, it is as follows for j phase current relations：

According to Kirchhoff's second law KVL laws, upper and lower bridge arm voltage is calculated：

Single-phase MMC_STATCOM converter output terminals button equivalent voltage u is：

In formula：i_zIt is the total current that single bridge arm is flowed through, i_LIt is ac output end electric current, i_PIt is upper arm electric current, i_NIt is underarm Electric current, L_LIt is ac output end inductance, R_LIt is ac output end resistance, R₀、L₀Respectively upper and lower bridge arm resistance sense value, V_dcIt is centre DC voltage, u_LIt is AC power, u_VIt is AC port voltage, u_P、u_NIt is upper and lower bridge arm total voltage.

Further, the upper and lower bridge arm reference voltage specific method of the calculating MMC_STATCOM converter list bridge arms is such as Under：

The connection inductance of the upper and lower bridge arm of MMC_STATCOM converters and internal resistance are equivalent to exchange one that tie point resists Point, nominal value is original half, institute above bridge arm reference voltage u_P, lower bridge arm reference voltage u_NFor：

In formula：V_dzIt is i_zThe unbalance voltage produced in bridge arm resistance sense.

Further, the single-phase MMC_STATCOM converters under the described pair of topology carry out CIRCULATION ANALYSIS, and specific method is such as Under：

Assume initially that DC capacitor, voltage are constant, single-phase MMC_STATCOM transducer loops stream expression formula is as follows：

In formula：M is the index of modulation, I_LmIt is ac-side current maximum,It is power-factor angle, ω is frequency, i_zd、i_zqPoint Wei not each shaft current component under dq coordinate systems.

Further, it is described to calculate the secondary undulate quantity that dc bus side voltage is produced, secondary LC filter circuits, tool are set Body method is as follows：

In formula：i_dIt is DC side electric current, S is AC input power, P_dIt is dc bus side power output, U_LmIt is exchange Voltage max.

Assuming that DC current is in mean allocation between phase and phase, the reactive component superposition of single-phase circulation is not zero, and has two Harmonic, sets secondary LC filter circuits, there is following relation：

In formula：L=1/4C ω², C, L are respectively electric capacity, inductance in secondary filtering circuit.

The beneficial effects of the invention are as follows：

(1) present invention can make electrified railway compensating device while reduces cost, and floor space is small, corresponding speed Hurry up, that small, integrated cost is lost is low；

(2) present invention eliminates special step-down transformer compared with conventional dead compensator STATCOM, reduces input Cost；

(3) present invention can effectively suppress many cars access Traction networks and trigger power train traction block phenomenon.

Brief description of the drawings

Fig. 1 is the compensation tractive power supply system structure charts of MMC_STATCOM in the present invention.

Fig. 2 is the mono- bridge arm Mathematical Modelings of single-phase MMC_STATCOM.

Fig. 3 is that many cars access the voltage wave cardon that Traction networks trigger.

Fig. 4 is that many cars access the current wave cardon that Traction networks trigger

Fig. 5 is the Traction networks electrical quantity oscillogram under MMC_STATCOM is introduced.

Fig. 6 is the Traction networks electrical quantity histogram under MMC_STATCOM is introduced.

Specific embodiment

MMC_STATCOM refers to the direct hanging type dynamic passive compensation converter based on multimode combining structure in the present invention；This Invention accesses Traction networks and triggers power train traction block phenomenon to launch for many cars, and access effect is as shown in figure 1, without special Single-phase MMC_STATCOM is directly effectively applied in traditional tractive power supply system under transformer.

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

A kind of high ferro powers compensation with single-phase MMC_STATCOM methods for designing, comprises the following steps：

Single-phase MMC_STATCOM converter topologies structure list bridge arm Mathematical Modeling is set up, wherein each submodule is by connecting Two insulated gate bipolar transistor IGBTs and DC capacitor is in parallel constitutes；

According to upper and lower two bridge arm voltages, the single-phase equivalent output voltage of MMC_STATCOM converter output terminals mouthful is calculated；

Calculate the MMC_STATCOM upper and lower bridge arm reference voltages of converter list bridge arm；

Single-phase MMC_STATCOM converters under to the topology carry out CIRCULATION ANALYSIS；

The secondary undulate quantity that dc bus side voltage is produced is calculated, setting meets the secondary LC filtered electricals of the topological circuit Road；

Many cars access electrical quantity fluctuation and the MMC_STATCOM converters that Traction networks trigger in the case of comparing uncompensated device The lower Traction networks electrical quantity distribution of compensation；

As shown in figure 1, cascading main circuit structure of 8 single-phase invertors of submodule as compensation part per phase bridge arm； Each submodule is made up of two insulated gate bipolar transistor IGBTs connected and DC capacitor parallel connection；Different IGBT switches Under combination, the exportable U of submodule_CWith 0 two kinds of voltages, output voltage (n+1) U after n cascade_C, to obtain maximum DC voltage rate With galvanic current pressure, it is desirable to the submodule complementary duty of upper and lower bridge arm；The submodule of obvious any time each bridge arm work Quantity is n, and output voltage range is 0~nU_C。

Further, it is further comprising the steps of：Checking method for designing feasibility, specially using FFT FFT carries out spectrum analysis to supply conductor voltage, electric current.

Further, it is described according to upper and lower two bridge arm voltages, the equivalent output voltage in port of converter is calculated, specifically Method is as follows：

Assume initially that alternating current i_sIt is evenly distributed in upper and lower bridge arm, according to Fig. 2 as can be seen that being directed to a phase current Relation is as follows：

According to Kirchhoff's second law KVL laws, upper and lower bridge arm voltage is calculated：

Single-phase MMC_STATCOM converter output terminals mouthful equivalent voltage u is：

In formula：i_zIt is the total current that single bridge arm is flowed through, i_LIt is ac output end electric current, i_PIt is upper arm electric current, i_NIt is underarm Electric current, L_LIt is ac output end inductance, R_LIt is ac output end resistance, R₀、L₀Respectively upper and lower bridge arm resistance sense value, V_dcIt is centre DC voltage, u_LIt is AC power, u_VIt is AC port voltage, u_P、u_NIt is upper and lower bridge arm total voltage.

Further, the upper and lower bridge arm reference voltage specific method of the calculating MMC_STATCOM converter list bridge arms is such as Under：

The connection inductance of the upper and lower bridge arm of MMC_STATCOM converters and internal resistance are equivalent to exchange one that tie point resists Point, nominal value is original half, institute above bridge arm reference voltage u_P, lower bridge arm reference voltage u_NFor：

Further, the single-phase MMC_STATCOM converters under the described pair of topology carry out CIRCULATION ANALYSIS, and specific method is such as Under：

Assume initially that DC capacitor, voltage are constant, single-phase MMC_STATCOM transducer loops stream expression formula is as follows：

In formula：M is the index of modulation, I_LmIt is ac-side current maximum,It is power-factor angle, ω is frequency, i_zd、i_zqPoint Wei not each shaft current component under dq coordinate systems.

Further, it is described to calculate the secondary undulate quantity that dc bus side voltage is produced, secondary LC filter circuits, tool are set Body method is as follows：

In formula：i_dIt is DC side electric current, S is AC input power, P_dIt is dc bus side power output, U_LmIt is exchange Voltage max.

Assuming that DC current is in mean allocation between phase and phase, the reactive component superposition of single-phase circulation is not zero, and has two Harmonic, sets secondary LC filter circuits, there is following relation：

In formula：L=1/4C ω², C, L are respectively electric capacity, inductance in secondary filtering circuit.

Many cars access electrical quantity fluctuation and the MMC_STATCOM converters that Traction networks trigger in the case of comparing uncompensated device The lower Traction networks electrical quantity distribution of compensation；Be can be seen that by Fig. 3, Fig. 4 when being introduced without MMC_STATCOM converters, supply conductor voltage Current envelope curve shows the cyclic fluctuation of 5.1Hz；Fig. 5 shows, when introducing MMC_STATCOM converters, fluctuates obvious Suppress, Traction networks net work voltage stable is in 25kV；As can be seen from Figure 6 in the absence of the secondary lobe radio-frequency component of 5.1Hz, the party near power frequency Case effectively inhibits many cars to access the voltage pulsation problem for triggering.

The present invention by deriving single-phase MMC_STATCOM converter topologies structure list bridge arm Mathematical Modeling first；Secondly it is right Single-phase MMC_STATCOM converters under the topology carry out CIRCULATION ANALYSIS；Finally derive dc bus side voltage and produce secondary wave Momentum, and the secondary LC filter circuits for meeting the topological circuit are set；It is experimentally confirmed and traditional STATCOM, the present invention Special step-down transformer is eliminated, input cost is reduced；Many cars access Traction networks can effectively be suppressed triggers power train to lead Draw block phenomenon.

Presently preferred embodiments of the present invention is the foregoing is only, is not intended to limit the invention, it is all in essence of the invention Any modification, equivalent and improvement made within god and principle etc., should be included within the scope of the present invention.

Claims (6)

1. a kind of high ferro is powered and is compensated with single-phase MMC_STATCOM methods for designing, it is characterised in that comprised the following steps：

Set up single-phase MMC_STATCOM converter topologies structure list bridge arm Mathematical Modeling, wherein each submodule by connect two Individual insulated gate bipolar transistor IGBT and DC capacitor composition in parallel；

According to upper and lower two bridge arm voltages, the single-phase equivalent output voltage of MMC_STATCOM converter output terminals mouthful is calculated；

Calculate the MMC_STATCOM upper and lower bridge arm reference voltages of converter list bridge arm；

Single-phase MMC_STATCOM converters under to the topology carry out CIRCULATION ANALYSIS；

The secondary undulate quantity that dc bus side voltage is produced is calculated, secondary LC filter circuits are set；

Many cars access electrical quantity fluctuation and the compensation of MMC_STATCOM converters that Traction networks trigger in the case of comparing uncompensated device Lower Traction networks electrical quantity distribution.

2. a kind of high ferro according to claim 1 powers compensation with single-phase MMC_STATCOM methods for designing, and its feature exists In further comprising the steps of：Checking method for designing feasibility, specially using FFT FFT to supply conductor voltage, Electric current carries out spectrum analysis.

3. a kind of high ferro according to claim 1 powers compensation with single-phase MMC_STATCOM methods for designing, and its feature exists In described to calculate the equivalent output voltage in port of converter according to upper and lower two bridge arm voltages, specific method is as follows：

Assume initially that alternating current i_sIt is evenly distributed in upper and lower bridge arm, it is as follows for j phase current relations：

$\left\{\begin{array}{c}{i}_z=\frac{1}{2}(i_P+i_N)\\ i_L=i_N-i_P\end{array}\right.$

According to Kirchhoff's second law KVL laws, upper and lower bridge arm voltage is calculated：

$\left\{\begin{array}{c}{u}_L=R_L\·i_L+L_L\frac{{\mathrm{di}}_L}{dt}-R_o{i}_P-L_o\frac{{\mathrm{di}}_P}{dt}-u_P+\frac{V_{dc}}{2}\\ u_L=R_L\·i_L+L_L\frac{{\mathrm{di}}_L}{dt}+R_o{i}_N+L_o\frac{{\mathrm{di}}_N}{dt}+u_N-\frac{V_{dc}}{2}\end{array}\right.$

Single-phase MMC_STATCOM converter output terminals mouthful equivalent voltage u is：

$\left\{\begin{array}{c}{u}_v=u+\frac{R_o}{2}\·i_L+\frac{L_o}{2}\frac{{\mathrm{di}}_L}{dt}\\ u=\frac{u_N-u_P}{2}\end{array}\right.\→\begin{array}{c}u=u_L-(R_L+\frac{R_o}{2})\·i_L-(L_L+\frac{L_o}{2})\frac{{\mathrm{di}}_L}{dt}\\ =u_L-R_L\·i_L-L_L\frac{{\mathrm{di}}_L}{dt}\end{array}$

In formula：i_zIt is the total current that single bridge arm is flowed through, i_LIt is ac output end electric current, i_PIt is upper arm electric current, i_NIt is underarm electric current, L_LIt is ac output end inductance, R_LIt is ac output end resistance, R₀、L₀Respectively upper and lower bridge arm resistance sense value, V_dcIt is intermediate dc electricity Pressure, u_LIt is AC power, u_VIt is AC port voltage, u_P、u_NIt is upper and lower bridge arm total voltage.

4. a kind of high ferro according to claim 3 powers compensation with single-phase MMC_STATCOM methods for designing, and its feature exists In the calculating MMC_STATCOM upper and lower bridge arm reference voltage specific methods of converter list bridge arm are as follows：

The connection inductance of the upper and lower bridge arm of MMC_STATCOM converters and internal resistance are equivalent to exchange the anti-part of tie point, mark Value is called original half, institute above bridge arm reference voltage u_P, lower bridge arm reference voltage u_NFor：

$\left\{\begin{array}{c}{u}_P=\frac{V_{dc}}{2}-u-V_{dz}\\ u_N=\frac{V_{dc}}{2}+u-V_{dz}\end{array}\right.$

In formula：V_dzIt is i_zThe unbalance voltage produced in bridge arm resistance sense.

5. a kind of high ferro according to claim 4 powers compensation with single-phase MMC_STATCOM methods for designing, and its feature exists In the single-phase MMC_STATCOM converters under the described pair of topology carry out CIRCULATION ANALYSIS, and specific method is as follows：

Assume initially that DC capacitor, voltage are constant, single-phase MMC_STATCOM circulation expression formula is as follows：

In formula：M is the index of modulation, I_LmIt is ac-side current maximum,It is power-factor angle, ω is frequency, i_zd、i_zqRespectively Each shaft current component under dq coordinate systems.

6. a kind of high ferro according to claim 5 powers compensation with single-phase MMC_STATCOM methods for designing, and its feature exists In, it is described to calculate the secondary undulate quantity that dc bus side voltage is produced, secondary LC filter circuits are set, specific method is as follows：

In formula：i_dIt is DC side electric current, S is AC input power, P_dIt is dc bus side power output, U_LmIt is alternating voltage Maximum.

Assuming that DC current is in mean allocation between phase and phase, the reactive component superposition of single-phase circulation is not zero, and there are two frequencys multiplication Component, sets secondary LC filter circuits, there is following relation：

$\frac{U_{Lm}{I}_{Lm}}{2{\mathrm{C\ωV}}_{dc}}\≤V_{dc}\·10\%\→C\≥\frac{5U_{Lm}{I}_{Lm}}{{\mathrm{\ωV}}_{dc}^2}$

In formula：L=1/4C ω², C, L are respectively electric capacity, inductance in secondary filtering circuit.