JP6135201B2 - Control device and control method for DC feeding substation - Google Patents

Description

  The present invention relates to a control device and a control method for a DC feeder substation including a rectifier and a DC power storage device connected in parallel.

  It is generally well known that the load of an electric railway substation is a short-time high-power load that varies greatly with time. Therefore, except in the case of small-scale railway business such as trams, the receiving voltage of railway substations is received from a power supply system with a large back power of 66 kV or higher, such as a high voltage distribution system of 6.6 kV. When receiving power from the power supply, the received power is limited and the output of the rectifier is also limited.

  Because of such output restrictions, a 6.6 kV power receiving substation cannot output a large amount of power, which may hinder train operation.

  For example, those disclosed in Patent Documents 1 and 2 have been proposed as DC feeding systems to which an electric power storage medium is applied as a countermeasure against regenerative invalidation and a voltage drop countermeasure.

JP 2007-210513 A JP 2009-67205 A

  As mentioned above, the power substation output for 6.6 kV power reception is regulated to 2000 kW or less due to the power company's output restrictions, and so far it has been applied to small substations by small railway operators. It was only possible.

  In addition, the power feeding system provided with the power storage medium described in Patent Documents 1 and 2 has been applied as a regenerative invalidation countermeasure when installed in a substation, and has been applied as a voltage drop countermeasure when installed in the middle of a substation. It was. As a result of charging and discharging these devices, it was possible to expect a certain level of effect to suppress the peak of the received power, but a large-capacity output is expected when applied to a 6.6 kV power feeding substation. It is not possible.

  The present invention solves the above-described problems, and the object of the present invention is to achieve a hybrid power storage medium and power receiving power source that does not interfere with train operation due to the power restrictions even in 6.6 kV power receiving. It is an object to provide a control device and a control method for a DC feeding substation.

The DC feeder substation control device according to claim 1 for solving the above-mentioned problem is a rectifier that converts AC power into DC power and supplies the electric power to the electric wire, and is connected in parallel to the rectifier, DC power substation control device comprising a DC power storage device having a power conversion unit for controlling charging and discharging of the power storage medium, and detecting a rectifier output capacity according to an output voltage fluctuation of the rectifier The rectifier output capacity detection unit, and a rectifier output characteristic determined by the rated voltage, rated capacity, and overall voltage fluctuation rate of the rectifier, the discharge start of the DC power storage device in which the rectifier output capacity does not exceed the set power calculating a voltage, a DC power storage device by the discharge starting voltage and discharge control of the calculated, the rectifier output capacitance rectifier output capacitance detected by the detection unit, Do exceeds the power set It is characterized by comprising a control unit for controlling the output power of the DC power storage device as.

The method for controlling a DC feeder substation according to claim 4 includes a rectifier that converts AC power into DC power and supplies the electric power to the electric wire, and is connected in parallel to the rectifier, the power storage medium and charging of the power storage medium, A DC feeding substation control method comprising a DC power storage device having a power conversion unit for controlling discharge, wherein the rectifier output capacity detection unit has a rectifier output capacity corresponding to the output voltage fluctuation of the rectifier. The rectifier output capacity detection step to detect, and the control unit, from the rectifier output characteristics determined by the rated voltage, rated capacity, and overall voltage fluctuation rate of the rectifier, the rectifier output capacity does not exceed the set power calculates a discharge start voltage of the storage device, the method comprising discharging controlling the DC power storage device by the discharge starting voltage of the calculated, the control unit, is detected by the rectifier output capacitance detector Rectifier output capacity has been characterized by comprising the steps of: controlling the output power of the DC power storage device so as not to exceed the power set.

  According to a second aspect of the present invention, there is provided a control device for a DC feeder substation according to the first aspect, wherein the rectifier output capacity detector detects a rectifier output capacity from a voltage and current on the DC feeder side. .

The DC feeder substation control method according to claim 5 is characterized in that, in claim 4 , the rectifier output capacity detection step detects the rectifier output capacity from the voltage and current on the DC feeder side. .

  According to a third aspect of the present invention, there is provided a control apparatus for a DC feeder substation according to the first aspect, wherein the rectifier output capacity detector detects a rectifier output capacity from a voltage, current and power factor on the AC power receiving side. It is said.

According to a sixth aspect of the present invention, there is provided the DC feeding substation control method according to the fourth aspect , wherein the rectifier output capacity detecting step detects the rectifier output capacity from the voltage, current and power factor on the AC power receiving side. It is said.

According to the above configuration, the output power of the rectifier does not exceed the set power, for example, the power receiving contract power, and the output power as a substation can be increased by the output power of the DC power storage device. In addition, according to the above configuration, since the discharge start voltage of the DC power storage device can be changed according to the magnitude of the overall voltage fluctuation rate of the rectifier, even if the overall voltage fluctuation rate of the rectifier fluctuates, the output of the rectifier The power can be surely suppressed below the set power.

(1) According to the inventions described in claims 1 to 6 , the output power of the rectifier does not exceed the set power, for example, the high voltage receiving output limit of the power company, and hinders the train operation under the feeder line. Never come. Also, since the discharge start voltage of the DC power storage device can be changed according to the overall voltage fluctuation rate of the rectifier, even if the overall voltage fluctuation rate of the rectifier fluctuates, the output power of the rectifier The following can be reliably suppressed.

The block diagram of the DC feeding substation which shows one embodiment of this invention. Explanatory drawing showing the control method in the embodiment of this invention, and showing the relationship between DC bus-line voltage and the output electric power of a substation. Explanatory drawing showing the control method in the embodiment of this invention, and showing the relationship between DC bus-line voltage and the output electric power of a substation. The output characteristic figure of a rectifier for demonstrating the control method in the embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. The DC feeding hybrid substation according to the embodiment of the present invention is configured such that the rectifier and the chopper (power conversion unit) output of the electric double layer capacitor (power storage medium) are connected in parallel, and the chopper output voltage is appropriately controlled. High-capacity output is possible without exceeding the high voltage receiving output limit of the electric power company.

  FIG. 1 shows the configuration of a DC feed hybrid substation according to an embodiment of the present invention. In FIG. 1, reference numeral 10 denotes a transformer 11 that receives an AC voltage of 6.6 kV from the AC bus 20 via an AC circuit breaker 52-1 and transforms it to 1500 V, and rectifies the output voltage of the transformer 11 into a DC voltage. It is a rectification part provided with the rectifier 12 to perform.

  The output side of the rectifier 12 is connected to the feeder 31 and the rail 32 via a positive high-speed circuit breaker 54P and a negative disconnector 89N.

  40 is a capacitor post (registered trademark) connected in parallel to the rectifier 12 via a high-speed circuit breaker 54CP and a disconnector 89CN (this capacitor post 40 is a regenerative power storage device, and the DC power of the present invention Storage device).

  The capacitor post 40 includes an electric double layer capacitor 41 as a power storage medium, semiconductor switches 42a and 42b and a reactor 42L that constitute a step-up / step-down chopper 42 (power conversion unit), a filter reactor 43L, and a filter capacitor 43C. It has. The semiconductor switches 42a and 42b are connected in parallel with diodes that enable reverse conduction.

  The step-up / step-down chopper 42 performs control to step up and step down the electric wire voltage (DC bus voltage) according to the voltage of the feeder 31. That is, when the feeder voltage exceeds, for example, the upper limit of the rated voltage range, the semiconductor switch 42a is controlled to switch from the feeder 31 to the electric double layer capacitor through the high-speed circuit breaker 54CP, the filter reactor 43L, the semiconductor switch 42a, and the reactor 42L. A charging current is caused to flow through 41, thereby lowering the feeder 31.

  Further, when the feeder voltage falls below, for example, the lower limit of the rated voltage range, the semiconductor switch 42b is controlled to switch the electromagnetic energy stored in the reactor 42L by the electric double layer capacitor 41 during the ON period of the semiconductor switch 42b. During the OFF period, the feeder 31 is discharged via the diode (not shown) connected to the semiconductor switch 42a, the filter reactor 43L and the high-speed circuit breaker 54CP, thereby boosting the feeder 31 (suppressing voltage drop). To do.

  A controller for controlling the step-up / step-down chopper 42 is not shown.

  The capacity of the cap post 40 is DC 1500 V, 2000 KW, and the discharge capacity is 30 MW · s.

  The charging voltage of the step-up / step-down chopper 42 is in the range of 1550 to 1620V, the discharging voltage is in the range of 1380V to 1500V, and the current is 3626A (maximum) to 1333A (at 1500V).

  The rating of the electric double layer capacitor 41 is 170V, 4.8F, 8SS × 64P, 30 MW · s.

  The transformer 11 is configured for kW and 6.6 kV / 1200 V × 2 for 1000 kW.

  The rectifier 12 is a small-capacity rectifier, and its rating is DC 1500 V, 1000 kW, Class D, 667A.

  Further, an instrument transformer and a current transformer for detecting voltage and current on the feeder side of the rectifier 12, and an instrument transformer and current transformer for detecting voltage and current on the AC power receiving side of the rectifier 12, respectively. The rectifier output capacity detector for obtaining (detecting) the output capacity of the rectifier based on the detection outputs of the instrument transformer and the current transformer is not shown.

  Next, the control method in the present embodiment will be described with reference to FIGS. 2 and 3 show the relationship between the power capacity of the DC feeder hybrid substation of FIG. 1 and the voltage of the electric wire 31 (DC bus voltage).

  First, the case where the power reception from the electric power company is suppressed to 1000 kW and the discharge capacity of the capacity post 40 is set to 2000 kW will be described with reference to FIG.

  When the DC bus voltage is in the range of 1590 to 1620 V, the rectifier 12 feeder load and the capacitor post 40 are charged.

  When the DC bus voltage is in the range of 1590 to 1500 V, power is supplied to the rectifier 12 feeder line load.

  When the DC bus voltage is 1500 V, the rated capacity of 1000 kW is output from the rectifier 12, and the current that outputs the DC bus voltage to 1500 V is output from the capacitor post 40 (that is, the discharge start voltage of the capacitor post 40 is 1500 V). .

  The maximum current is from rectifier 12 to 667A and capacity post 40 to 1333A, and a maximum of 2000A is output as a substation.

  When the electric double layer capacitor 41 finishes discharging, the capacity post 40 stops, and the substation output voltage is at least 1260 V when the load current is 2000 A.

  Therefore, the substation maximum output in the case of FIG. 2 is 3000 kW.

  The received power from the power company can be adjusted by the discharge voltage of the capacitor post 40. Therefore, the discharge start voltage of the capacitor post 40 is set to 1380 V as shown in FIG. 3, for example, and the output control of the capacitor post 40 is performed by the control unit.

  In FIG. 3, the rectifier 12 feeder load and the capacitor post 40 are charged when the DC bus voltage is in the range of 1590 to 1620V.

  When the DC bus voltage is in the range of 1590 to 1380V, power is supplied to the rectifier 12 feeder line load.

  When the DC bus voltage is 1380V, the capacitor post 40 starts to discharge, and a current that makes the DC bus voltage constant 1380V is output. Therefore, the rectifier 12 is suppressed at a maximum of 1333A (1840 kW), and the contract power is 2000 kW or less.

  Further, since the capacity post 40 outputs up to 1333A, the substation maximum output can be output up to a maximum output current of 2666A and a maximum output power of 3680 kW.

  In the present embodiment, as described above, the output power of the capacitor post 40 is controlled so as not to exceed the contract power 2000 kW (set power) of the rectifier 12, but the output voltage of the rectifier 12 is the received voltage. And the total voltage fluctuation rate which is a characteristic of the rectifier 11.

  For this reason, it is necessary to change the charge / discharge start voltage of the capacitor post 40 in accordance with the variation. Specifically, for example, when the output limiting capacity from a rectifier with a rated 1500 V, a rated capacity 1000 kW, and an overall voltage fluctuation rate 5% is 2000 kW, the no-load output voltage of the rectifier is 1500 × 1.05 = 1575 V, and the rectifier output 2000 kW. In this case, the rectifier output voltage is 1500-1500 × 0.05 = 1425V.

  From the above, the charging start voltage to the capacitor post 40 is set to 1550V or more, and the discharging start voltage is set to 1425V. In this case, the output voltage of the rectifier may fluctuate due to fluctuations in the received voltage, and there may be cases where the rectifier's output capacity of 2000 kW or less cannot be strictly maintained. It is necessary to do.

  Therefore, in order to protect the output capacity of 2000 kW of the rectifier 12, for example, the voltage and current on the DC side are constantly monitored (by the rectifier output capacity detection unit), and output from the capacity post 40 so as not to exceed the contracted power of 2000 kW. Specifically, the output is output from the capacitor post 40 so as to satisfy DC voltage × DC current ≦ rectifier output 2000 kW.

  For example, in order to set the rectifier output to 2000 kW or less, a current threshold is provided according to the DC output voltage, and power is output from the electric double layer capacitor 41 so as not to exceed this current.

  As another method, the output capacity of the rectifier 12 is calculated from the received voltage, current, and power factor (φ) (by the rectifier output capacity detector), and output from the capacitor post 40 so as not to exceed the contract power 2000 kW. To do. Specifically, the output is output from the capacitor post 40 so as to satisfy the following condition: received voltage × received current × √3 × φ ≦ 2000 kW.

  For example, in order to set the output of the rectifier to 2000 kW or less, a threshold value is provided for the received current according to the received voltage, and power is output from the electric double layer capacitor 41 so as not to exceed this current.

  Further, the discharge start voltage of the capacitor post 40 is changed according to the difference in the overall voltage fluctuation rate. That is, for example, the discharge start voltage (1425 V) of the capacitor post 40 at 5% is the capacitor post at 8% as in the rectifier output characteristics of 5% and 8% of the total voltage fluctuation rate of the rectifier shown in FIG. It becomes higher than the discharge start voltage (1380V) of 40.

  Note that the ratings, capacities, and the like of the transformer 11, the rectifier 12, and the electric double layer capacitor 41 and the step-up / step-down chopper 42 constituting the rectifier 10 are not limited to those in the above-described embodiment.

DESCRIPTION OF SYMBOLS 10 ... Rectification part 11 ... Transformer 12 ... Rectifier 20 ... AC bus 31 ... Feed wire 32 ... Rail 40 ... Capa post (regenerative power storage device)
41 ... Electric double layer capacitor 42 ... Step-up / step-down chopper 42a, 42b ... Semiconductor switch 42L ... Reactor 43c ... Filter capacitor 43L ... Filter reactor

Claims (6)

A rectifier that converts AC power into DC power and supplies the rectifier to the electric wire; and a DC power storage device that is connected in parallel to the rectifier and includes a power storage medium and a power conversion unit that controls charging and discharging of the power storage medium. A control device for a DC feeder substation,
A rectifier output capacity detector for detecting a rectifier output capacity corresponding to the output voltage fluctuation of the rectifier;
From the rectifier output characteristics determined by the rated voltage, rated capacity, and overall voltage fluctuation rate of the rectifier, the discharge start voltage of the DC power storage device in which the rectifier output capacity does not exceed the set power is calculated. A control unit for controlling the output power of the DC power storage device so that the DC power storage device is controlled to discharge according to a discharge start voltage, and the rectifier output capacity detected by the rectifier output capacity detection unit does not exceed a set power; ,
A control device for a DC feeder substation characterized by comprising:   The DC rectifier substation control device according to claim 1, wherein the rectifier output capacity detector detects the rectifier output capacity from a voltage and current on a DC feeder side.   The control device for a DC feeder substation according to claim 1, wherein the rectifier output capacity detection unit detects the rectifier output capacity from the voltage, current and power factor on the AC power receiving side. A rectifier that converts AC power into DC power and supplies the rectifier to the electric wire; and a DC power storage device that is connected in parallel to the rectifier and includes a power storage medium and a power conversion unit that controls charging and discharging of the power storage medium. A control method for a DC feeder substation,
A rectifier output capacity detection unit detects a rectifier output capacity corresponding to the output voltage fluctuation of the rectifier, and a rectifier output capacity detection step;
The controller calculates the discharge start voltage of the DC power storage device from which the rectifier output capacity does not exceed the set power from the rectifier output characteristics determined by the rated voltage, rated capacity, and overall voltage fluctuation rate of the rectifier. And controlling the discharge of the DC power storage device with the calculated discharge start voltage;
A step control unit, the rectifier output capacitance rectifier output capacitance detected by the detection unit, to control the output power of the DC power storage device so as not to exceed the power set,
A control method for a DC feeder substation characterized by comprising: 5. The DC feeder substation control method according to claim 4 , wherein the rectifier output capacity detection step detects the rectifier output capacity from the voltage and current on the DC feeder side. 5. The method of controlling a DC feed substation according to claim 4 , wherein the rectifier output capacity detection step detects the rectifier output capacity from the voltage, current and power factor on the AC power receiving side.

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