JP2014096904A - Harmonic absorption circuit and high voltage power receiving facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a harmonic absorption circuit and high voltage power receiving facility that appropriately suppress an outflow of harmonic current generated in a broadcasting transmitter or the like in a simple configuration.SOLUTION: A harmonic absorption circuit 101 is connected to a feed path 10 for a single phase or multiple phase AC voltage to a broadcasting transmitter 61. For example, the harmonic absorption circuit 101 includes: inductors 52, 72, 112 each corresponding to a phase, and having a first end electrically connected to the feed path 10 and a second end; and capacitors 51, 71, 111 each corresponding to the inductor 52, 72, 112, and having a first end electrically connected to the second end of the inductor 52, 72, 112 and a second end. At the frequency of the AC voltage, reactor ratios that are ratios of reactances of the inductors 52, 72, 112 to reactances of the capacitors 51, 71, 111 are each other than 6% and 13%.

Description

  The present invention relates to a harmonic absorption circuit and a high-voltage power receiving facility, and more particularly, to a harmonic absorption circuit and a high-voltage power receiving facility connected to a power feeding path to a broadcasting transmitter.

  “Guidelines for Harmonic Suppression for Consumers Receiving Power at High Voltage or Extra High Voltage”, established in January 2004, NISA (Non-Patent Document 1) (hereinafter also referred to as harmonic suppression guidelines) Harmonics generated by customers who receive high-voltage or extra-high voltage from the grid, using the electrical equipment based on the harmonic environmental target level of the commercial power system, while complying with technical standards based on the Electricity Business Law The technical requirements for suppressing the current are described.

  For example, a consumer who receives high-voltage power from a 6.6 kV system and whose total capacity exceeds 50 kVA in consideration of the harmonic generation rate for each type of harmonic generator installed in the facility is harmonic suppression. The guideline is applicable.

  Here, the equivalent capacity is the sum of the converted capacities of the respective harmonic generators by converting the capacity of the harmonic generators possessed by the consumer into a 6-pulse converter capacity.

“Guidelines for Harmonic Suppression Measures for Customers Receiving High Voltage or Extra High Voltage”, established in January 2004, NISA

  For example, when a broadcast transmitter used for television broadcasting transmits radio waves, the greater the power of the radio waves, the wider the area covered by the radio waves, so the number of households receiving the radio waves increases.

  Therefore, a broadcasting station including a broadcasting transmitter that transmits radio waves with high power is an important broadcasting station, and performs high-voltage power reception to supply large power to the broadcasting transmitter. The broadcast transmitter has a characteristic of generating a large amount of harmonic current.

  In general, an emergency generator and an uninterruptible power supply (UPS) are installed in an important broadcasting station. This makes it possible to transmit radio waves even when a power failure occurs in an important broadcasting station.

  In addition, since UPS has a characteristic of absorbing harmonic current, harmonic current generated in other devices electrically connected to UPS is absorbed by the UPS.

  That is, a broadcasting transmitter in an important broadcasting station receives power from the UPS. In this case, since the broadcast transmitter is electrically connected to the UPS, the harmonic current generated in the broadcast transmitter is absorbed by the UPS.

  Therefore, when important broadcasting stations do not take special measures to comply with the harmonic suppression guidelines because the UPS installed as a countermeasure for power outages will suppress the outflow of harmonic currents to the system. There are many.

  Also, broadcast transmitter manufacturers often manufacture broadcast transmitters on the assumption that UPS is used in the power supply equipment of the broadcasting station. That is, manufacturers of broadcast transmitters recognize that it is common sense that broadcast transmitters are used with UPS. For this reason, the countermeasure for suppressing generation | occurrence | production of a harmonic current is often not taken in the broadcast transmitter itself.

  On the other hand, in a broadcasting station in which a broadcasting transmitter that transmits radio waves with large electric power is installed, an emergency generator is installed, but a case in which a UPS is not installed is considered, unlike the above-described measures against power failure.

  In this case, for example, when the broadcast station receives a high voltage power of 6.6 kV and the total equivalent capacity of devices such as a broadcast transmitter installed in the broadcast station exceeds a predetermined upper limit value, the broadcast station Harmonic suppression guidelines are applicable. And in a broadcasting station, the countermeasure for suppressing the outflow to the system | strain of the harmonic current which generate | occur | produced in each apparatus is needed.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a harmonic that can appropriately suppress the outflow of harmonic current generated in a broadcasting transmitter or the like with a simple configuration. It is to provide an absorption circuit and a high-voltage power receiving facility.

  (1) In order to solve the above problems, a harmonic absorption circuit according to an aspect of the present invention is a harmonic absorption circuit connected to a power supply path of a single-phase or multiple-phase AC voltage to a broadcasting transmitter. One or a plurality of inductors provided corresponding to the phases and electrically connected to the power supply path and having a second end, and provided corresponding to the inductors, A reactor having a first end electrically connected to the second end of the inductor and a second end; and a reactor that is a ratio of a reactance of the inductor to a reactance of the capacitor at a frequency of the AC voltage The ratio is other than 6% and 13%.

  With such a configuration, an optimum reactor ratio can be selected from reactor ratios other than 6% and 13% without using standard inductors having reactor ratios of 6% and 13%.

  By using an inductor having a selected reactor ratio, the harmonic current generated in a broadcast transmitter or the like flows out through the power feeding path, and a simple configuration of a series circuit of an inductor and a capacitor appropriately Can be suppressed.

  (2) Preferably, the reactor ratio has an absorptivity of 50% or more, which is a ratio of the target harmonic current flowing into the harmonic absorption circuit to the target harmonic current generated in the broadcasting transmitter. The frequency of the target harmonic current is at least one of a frequency that is five times the frequency of the AC voltage and a frequency that is seven times the frequency of the AC voltage.

  With such a configuration, a high absorption rate can be achieved as compared with the case of using a standard inductor.

  The “target harmonic current” means a harmonic current of a specific order, and does not mean a harmonic current of all orders. Therefore, for example, when the target harmonic current is the fifth harmonic current, the reactor ratio may be a value at which the absorption factor of the fifth harmonic current is 50% or more, and all the orders The absorption rate of the harmonic current does not have to be 50% or more.

  (3) Preferably, the reactor ratio has an absorptivity of 30% or more as a ratio of the target harmonic current flowing into the harmonic absorption circuit with respect to the target harmonic current generated in the broadcasting transmitter. The frequency of the target harmonic current is at least one of 11 times and 13 times the frequency of the AC voltage.

  With such a configuration, a high absorption rate can be achieved as compared with the case of using a standard inductor.

  The “target harmonic current” means a harmonic current of a specific order, and does not mean a harmonic current of all orders. Therefore, for example, when the target harmonic current is the eleventh harmonic current, the reactor ratio may be a value at which the absorption ratio of the eleventh harmonic current is 30% or more, and all the orders The absorption rate of the harmonic current does not have to be 30% or more.

  (4) More preferably, the reactance of the inductor is larger than the reactance of the capacitor at the frequency of the target harmonic current.

  With this configuration, the series circuit of the inductor and the capacitor can be made inductive, so that excess current having a magnitude equal to or higher than the harmonic current generated in the broadcasting transmitter or the like flows into the series circuit. Can be prevented.

  Moreover, since it can prevent that an inductor and a capacitor form a resonance circuit, it can prevent that a short circuit current flows into the said series circuit.

  Therefore, it is possible to prevent the occurrence of fire due to heat generation due to excessive current or short-circuit current flowing through the series circuit of the inductor and capacitor, and damage to the inductor or capacitor.

  (5) More preferably, one or a plurality of the inductors and the capacitors are provided corresponding to the frequency of the target harmonic current.

  Thus, by providing a series circuit of an inductor and a capacitor for each frequency of the target harmonic current, the degree of freedom related to the design of the circuit can be increased.

  Moreover, each series circuit can be optimally designed according to the magnitude of the harmonic current of each frequency generated in a broadcast transmitter or the like.

  (6) More preferably, the impedance of the circuit constituted by the inductor and the capacitor viewed from the power supply path is the impedance in the direction of the AC voltage to the power supply viewed from the power supply path and the predetermined absorption. Less than the impedance determined based on the rate.

  With such a configuration, an upper limit value can be set for the impedance value of the series circuit for increasing the absorption rate above a predetermined value.

  (7) More preferably, the impedance of the circuit constituted by the inductor and the capacitor viewed from the power supply path is the impedance in the direction of the AC voltage to the power supply viewed from the power supply path and the predetermined absorption. Less than the product of the reciprocal of the rate minus one.

  With such a configuration, an appropriate upper limit value can be set for the impedance value of the series circuit for increasing the absorption rate above a predetermined value.

  (8) Preferably, the harmonic absorption circuit is further provided corresponding to the phase, and is one or a plurality of slow-phase inductors electrically connected to the power supply path in parallel with the inductor and the capacitor. Is provided.

  With such a configuration, even when a large-capacity capacitor is used to absorb a large amount of harmonic current, it is possible to prevent the power factor from being lowered by the capacitor.

  Thereby, since the increase in the apparent current resulting from the decrease in the power factor can be prevented, the capital investment for enhancing the power feeding path can be suppressed. Moreover, the power rate can be discounted by optimizing the power factor.

  (9) Preferably, the harmonic absorption circuit further includes a switch for switching whether or not to connect the power feeding path and the inductor, and the switch flows into the inductor from the power feeding path. When the target harmonic current generated in the transmitter exceeds a predetermined threshold value, the connection between the power supply path and the inductor is disconnected.

  Thus, the configuration in which the connection between the power supply path and the inductor is cut according to the magnitude of the harmonic current, for example, through the inductor or the capacitor, compared to the configuration in which the connection is cut according to the temperature in the inductor or the capacitor. Heat generation due to a large current can be suppressed early.

  Thereby, it is possible to prevent the occurrence of fire due to heat generation and the deterioration of the inductor or the capacitor.

  (10) Preferably, the electric power of the radio wave transmitted by the broadcast transmitter is 5 kilowatts or more.

  With such a configuration, it is possible to prevent outflow of harmonic current without using a UPS in a broadcasting transmitter that transmits radio waves with high power.

  Since inductors and capacitors are less expensive than UPS, the cost of equipment or maintenance can be reduced.

  Further, since the inductor and the capacitor are passive elements, it is possible to prevent the harmonic current from flowing out regardless of the operation state of the UPS.

  (11) In order to solve the above-described problem, a high-voltage power receiving facility according to another aspect of the present invention includes a power receiving unit that receives a single-phase or multiple-phase AC voltage, and an AC voltage corresponding to the AC voltage for broadcasting. A high-voltage power receiving facility including a power transmission unit that outputs to a transmitter via a power feeding path and a harmonic absorption circuit connected to the power feeding path, wherein the harmonic absorption circuit is provided corresponding to the phase. One or a plurality of inductors having a first end electrically connected to the power supply path and a second end, and provided corresponding to the inductor, and electrically connected to the second end of the inductor. The reactor ratio, which is the ratio of the reactance of the inductor to the reactance of the capacitor at the frequency of the AC voltage, is 6% and 13%. It is outside.

  With such a configuration, an optimum reactor ratio can be selected from reactor ratios other than 6% and 13% without using standard inductors having reactor ratios of 6% and 13%.

  By using an inductor having a selected reactor ratio, the harmonic current generated in a broadcast transmitter or the like flows out through the power feeding path, and a simple configuration of a series circuit of an inductor and a capacitor appropriately Can be suppressed.

  Moreover, even when a device having a high-voltage power receiving facility is subject to application of the harmonic suppression guideline by performing high-voltage power reception, the device can be made to comply with the harmonic suppression guideline.

  ADVANTAGE OF THE INVENTION According to this invention, the outflow of the harmonic current which generate | occur | produced in the transmitter for broadcasting etc. can be suppressed appropriately with a simple structure.

It is a figure which shows an example of a structure of the electric power feeding system for broadcasting which concerns on embodiment of this invention. It is a figure which shows an example of the specification relevant to the electric equipment in the broadcast electric power feeding system which concerns on embodiment of this invention. It is a figure which shows an example of the calculation regarding the harmonic current and outflow regulation value which flow out from the broadcasting apparatus which concerns on embodiment of this invention. It is a figure which shows the "Table 1 conversion coefficient" described in a harmonic suppression guideline. It is a figure which shows "1. Three-phase bridge" in "Table 2 Harmonic current generation amount of an individual apparatus" described in a harmonic suppression guideline. It is a figure which shows "Table 1 Harmonic outflow current upper limit per contract electric power 1kW" described in a harmonic suppression guideline. It is a figure which shows an example of a structure of the comparative example of the power supply system for broadcasting. It is a figure which shows another example of a structure of the comparative example of the electric power feeding system for broadcasting. It is a figure which shows another example of a structure of the comparative example of the electric power feeding system for broadcasting. FIG. 10 is a single-line diagram of an example of an SCSR circuit in the comparative example shown in FIG. 9. It is a single wire connection diagram of an example of the harmonic absorption circuit which concerns on embodiment of this invention. It is a double track connection diagram of an example of a harmonic absorption circuit according to an embodiment of the present invention. It is a figure which shows an example of the shunting of the harmonic current which generate | occur | produced in the broadcasting apparatus which concerns on embodiment of this invention to the transformer side and the harmonic absorption circuit side. It is a figure which shows an example of the equivalent circuit represented approximately in the case of designing the filter circuit for 5th harmonics concerning embodiment of this invention. It is a figure which shows an example of the value with respect to each harmonic of% impedance of the transformer and system electric wire which concerns on embodiment of this invention. It is a figure which shows an example of the value of% impedance of the trans | transformer which concerns on embodiment of this invention. It is a figure which shows an example of the value with respect to each harmonic of% impedance in the equivalent circuit 551 which concerns on embodiment of this invention. It is a figure which shows an example of the change of% impedance of the filter circuit for 5th harmonics with respect to the order of the harmonics in the equivalent circuit 551 which concerns on embodiment of this invention. It is a figure which shows the change of the absorption factor of the 5th harmonic current with respect to the reactor ratio in the equivalent circuit 551 which concerns on embodiment of this invention. It is a figure which shows an example of the equivalent circuit represented approximately in the case of designing the filter circuit for 7th harmonics concerning embodiment of this invention. It is a figure which shows an example of the value with respect to each harmonic of% impedance in the equivalent circuit 552 which concerns on embodiment of this invention. It is a figure which shows an example of the change of% impedance of the filter circuit for 7th harmonics with respect to the order of the harmonics in the equivalent circuit 552 which concerns on embodiment of this invention. It is a figure which shows the change of the absorption factor of the 7th harmonic current with respect to the reactor ratio in the equivalent circuit 552 which concerns on embodiment of this invention. It is a figure which shows an example of the equivalent circuit represented approximately in the case of designing the 11th harmonic filter circuit which concerns on embodiment of this invention. It is a figure which shows an example of the value with respect to each harmonic of% impedance in the equivalent circuit 553 which concerns on embodiment of this invention. It is a figure which shows an example of the change of% impedance of the filter circuit for 11th harmonics with respect to the order of the harmonics in the equivalent circuit 553 which concerns on embodiment of this invention. It is a figure which shows the change of the absorption factor of the 11th harmonic current with respect to the reactor ratio in the equivalent circuit 553 which concerns on embodiment of this invention. It is a single wire connection diagram of other examples of the harmonic absorption circuit which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Configuration and basic operation]
FIG. 1 is a diagram showing an example of a configuration of a broadcasting power supply system according to an embodiment of the present invention.

  With reference to FIG. 1, a broadcasting power supply system 401 includes a high-voltage power receiving facility 201 and a broadcasting device 301. The high-voltage power receiving facility 201 includes a power receiving unit 151, a transformer 171, a power transmission unit 181, and a harmonic absorption circuit 101. The broadcast device 301 includes broadcast transmitters 61A and 61B and air conditioners 41A and 41B.

  Hereinafter, each of the broadcast transmitters 61A and 61B may be referred to as a broadcast transmitter 61. Each of the air conditioners 41A and 41B may be referred to as an air conditioner 41.

  In FIG. 1, two broadcast transmitters 61 are representatively shown, but a larger or smaller number of broadcast transmitters 61 may be provided. In FIG. 1, two air conditioners 41 are representatively shown, but a larger number or a smaller number of air conditioners 41 may be provided.

  The power receiving unit 151 receives AC power from the commercial power system via the system wire 11 and outputs the received AC power to the transformer 171. At this time, the power receiving unit 151 receives the AC voltage of 6600 volts in three phases of the R phase, the S phase, and the T phase via the system electric wire 11. The frequency of the alternating voltage is, for example, 50 hertz.

  Here, the system | strain electric wire 11 is an electric wire from the substation in an electric power company to the power receiving part 151, for example.

  When the transformer 171 receives AC power from the power reception unit 151, the transformer 171 outputs the received AC power to the power transmission unit 181. At this time, the transformer 171 steps down the three-phase 6600 volt AC voltage received from the power receiving unit 151 to, for example, three-phase 220 volt, and outputs the three-phase 220 volt voltage to the power transmitting unit 181.

  Note that the transformer 171 can output, for example, a single-phase AC voltage or a multi-phase AC voltage other than three phases to the power transmission unit 181. The input terminal of the transformer 171 is, for example, the power receiving unit 151.

  When the power transmission unit 181 receives AC power from the transformer 171, the power transmission unit 181 outputs the received AC power to the broadcasting device 301 via the power feeding path 10. Specifically, power transmission unit 181 is an output terminal of transformer 171, for example.

  Here, the power feeding path 10 is an electric wire from the power transmission unit 181 to the air conditioner 41 and the broadcasting transmitter 61.

  The broadcast device 301 receives AC power from the power transmission unit 181 through the power supply path 10. The AC power received by the broadcasting device 301 is consumed by devices included in the broadcasting device 301, such as the air conditioner 41 and the broadcasting transmitter 61.

  The air conditioner 41 consumes AC power by operating a compressor, for example. The broadcast transmitter 61 consumes AC power by transmitting radio waves that are high-frequency signals, for example. The electric power of the radio wave is, for example, 5 kilowatts or more.

  More specifically, the air conditioner 41 and the broadcast transmitter 61 receive a three-phase 220-volt AC voltage from the power transmission unit 181. The air conditioner 41 receives a three-phase AC voltage of 220 volts and a current corresponding to the load of the air conditioner 41. The broadcasting transmitter 61 is supplied with a current corresponding to the three-phase 220-volt AC voltage and the load of the broadcasting transmitter 61.

  For example, when the load is composed of a linear element, a current having no distortion, that is, a fundamental wave current having a frequency of 50 Hz flows through the load. On the other hand, when the load includes a non-linear element such as a commutator, a strained current, that is, a distorted wave current flows through the load.

  More specifically, the distorted wave current is a current including a fundamental current and a harmonic current having a frequency that is an integral multiple of the fundamental frequency. Hereinafter, a harmonic current having a frequency n times the frequency of the fundamental wave is referred to as an nth harmonic current. For example, a harmonic current having a frequency five times the frequency of the fundamental wave is referred to as a fifth harmonic current.

  In addition, since the distorted wave current in this case is a symmetric wave current, the distorted wave current does not include a harmonic current having a frequency that is an even multiple of the fundamental frequency. Therefore, the distortion wave current in this case includes the third harmonic current, the fifth harmonic current, the seventh harmonic current, the ninth harmonic current, the eleventh harmonic current, and the like. .

[Problems caused by outflow of harmonic current]
For example, when a harmonic current is generated in the air conditioner 41 or the broadcasting transmitter 61, the harmonic current flows out from the broadcasting power supply system 401 via the high-voltage power receiving equipment 201 and the system electric wire 11.

  Since the system wire 11 is inductive, the impedance of the system wire 11 is increased with respect to a harmonic current having a high frequency. For this reason, for example, when another device is electrically connected to the system cable 11 from the broadcasting power supply system 401 to the substation, a harmonic current may flow into the other device. . In a device into which a harmonic current flows, problems such as abnormal noise, vibration, or damage occur.

  For example, a device including a phase advance capacitor (Static Capacitor, SC) for power factor improvement (hereinafter referred to as a power factor improvement device) has a high frequency because the phase advance capacitor, that is, the capacitor is capacitive. The impedance of the power factor correction device becomes small.

  For this reason, harmonic current tends to flow into the power factor correction apparatus. When a large harmonic current flows into the power factor corrector, Joule heat is generated in the power factor corrector. This Joule heat may cause a fire in the power factor correction apparatus.

  As a countermeasure, a series reactor (Series Reactor, SR) that is an inductor is connected in series with a phase advance capacitor. As a result, inductivity can be imparted to the power factor correction apparatus, so that the impedance to the harmonics can be increased.

  Specifically, the series reactor for preventing burning of the phase advance capacitor is a 6% series reactor or a 13% series reactor. 6% series reactor and 13% series reactor are standard products by JIS, for example, and are generally marketed as a phase advance capacitor with a 6% series reactor or a phase advance capacitor with a 13% series reactor. There are many.

  Here, in the circuit configuration in which the inductor and the capacitor are connected in series, the ratio of the reactance at the fundamental frequency of the inductor to the reactance at the fundamental frequency of the capacitor is defined as the reactor ratio.

  “6%” in the 6% series reactor indicates a reactor ratio. Accordingly, the reactance at the fundamental frequency of the 6% series reactor corresponds to 6% of the reactance at the fundamental frequency of the phase advance capacitor connected in series with the 6% series reactor.

  Similarly, the reactance at the fundamental wave frequency of the 13% series reactor corresponds to 13% of the reactance at the fundamental wave frequency of the phase advance capacitor connected in series with the 13% series reactor.

  A phase-advancing capacitor with a series reactor can prevent the capacitor from being burned out, but the series reactor has been burned out frequently. This is considered to be caused by an increase in the harmonic current in the system electric wire 11 due to an increase in the use of thyristor power converters such as inverters and home appliances such as televisions.

  On the other hand, measures are taken to prevent the occurrence of burnout accidents in the series reactor by replacing it with a series reactor having a resistance of 55%, which is greater than 35%, which is a general resistance of the series reactor.

  Thus, when the harmonic electric current is contained in the system | strain electric wire 11, the bad effect to the apparatus electrically connected with the system | strain electric wire 11 increases. For this reason, the harmonic suppression guidelines indicate technical requirements for suppressing harmonic currents flowing out of electrical equipment.

  Harmonic absorption circuit 101 is electrically connected to power supply path 10 via node A. The harmonic absorption circuit 101 suppresses the harmonic current flowing out from the broadcasting power supply system 401 to the grid side via the grid line 11 by absorbing the harmonic current generated in the broadcasting device 301 via the node A. To do. A detailed configuration of the harmonic absorption circuit 101 will be described later.

[Harmonic current generation]
FIG. 2 is a diagram showing an example of specifications related to the electrical equipment in the broadcasting power supply system according to the embodiment of the present invention.

  Referring to FIG. 2, broadcasting power supply system 401 is disposed, for example, in an area east of Kanto, and high-voltage power receiving facility 201 receives a three-phase AC voltage having a frequency of 50 Hz and a voltage of 6.6 kilovolts. . The contract power is, for example, 105 kilowatts.

  Note that the case where the broadcasting power supply system 401 is arranged in an area west of Fujikawa, for example, Kansai, is the same as the case where it is arranged in an area east of Kanto, except that the frequency is 60 Hz.

  The transformer 171 is, for example, a mold type, and the transformer capacity is 150 KVA. There are two broadcast transmitters 61, and the output is 7.5 kilowatts. Two air conditioners 41 are provided corresponding to the broadcasting transmitter, and the output is 10.0 HP.

  System side% Z (% impedance) from power reception unit 151 is, for example, 6.70%. The grid side% Z is obtained, for example, by referring to an electric power company. This 6.70% is a value when the% impedance reference capacity is 10 MVA. The% impedance and the% impedance reference capacity will be described later.

  FIG. 3 is a diagram showing an example of the calculation of the harmonic current generated in the broadcast apparatus according to the embodiment of the present invention.

  FIG. 4 is a diagram showing the “Table 1 conversion coefficient” described in the harmonic suppression guideline.

  FIG. 5 is a diagram showing “1. Three-phase bridge” in “Table 2 Harmonic current generation amount of individual devices” described in the harmonic suppression guideline.

  FIG. 6 is a diagram showing “Table 1 Upper limit value of harmonic outflow current per 1 kW of contract power” described in the harmonic suppression guideline.

  Referring to FIGS. 3 and 4, the circuit type of broadcast transmitter 61 is classified into “10. Others” in “Table 1” shown in FIG. For this reason, the conversion coefficient Ki, that is, the conversion coefficient K10 is a declared value. Here, i is a value indicating the conversion circuit type that combines the circuit classification and the circuit type. The conversion circuit type in this case is 10. The conversion coefficient K10 reported by the manufacturer of the broadcast transmitter 61 is, for example, 1.00.

  Further, the circuit type of the air conditioner 41 is classified into “6-pulse conversion device” in “1. Three-phase bridge” shown in FIG. For this reason, the conversion coefficient Ki, that is, the conversion coefficient K11 is 1. The conversion circuit type in this case is 11.

  2 and 3, the rated capacity, that is, the rated capacity defined in the harmonic suppression guideline, is a value obtained by dividing the output of each device shown in FIG. 2 by the power factor of each device. Specifically, the rated capacity of the broadcast transmitter 61 is 31.95 KVA. The rated capacity of the air conditioner 41 is 10.3 KVA. The value of the power factor is a value obtained by dividing the active power by the apparent power. In other words, the value of the power factor is a cosine value of the difference between the phase of the AC voltage and the phase of the AC current.

  Referring to FIG. 3, since there are two broadcast transmitters 61 and two air conditioners 41, the number n of broadcast transmitters 61 and air conditioners 41 is two. Accordingly, the total capacity P10 of the broadcast transmitter 61 is 63.9 KVA obtained by multiplying 31.95 KVA by 2. The total capacity P11 of the air conditioner 41 is 20.6 KVA obtained by multiplying 10.3 KVA by 2.

  The equivalent capacity P0 (hereinafter simply referred to as equivalent capacity P0) when converted to a 6-pulse converter is a value obtained by multiplying the conversion coefficient Ki and the total capacity Pi. Specifically, the equivalent capacity P0 of the broadcast transmitter 61 is 63.9 KVA obtained by multiplying 1.00 and 63.9. The equivalent capacity P0 of the air conditioner 41 is 20.6 KVA obtained by multiplying 1.00 and 20.6.

  In this case, the high-voltage power receiving equipment 201 receives power from the system at 6.6 kilovolts, and the total equivalent capacity is 84.5 KVA, which exceeds 50 KVA. Therefore, the broadcasting power supply system 401 is subject to application of the harmonic suppression guidelines. Become.

  The received voltage converted rated current value is a value obtained by dividing the equivalent capacity P0 by the received voltage, that is, a value obtained by multiplying by √3 and 6600 because there are three phases in this case. Specifically, the received current equivalent rated current value of the broadcasting transmitter 61 is 5590 mA (milliamperes). Moreover, the received voltage conversion rated current value of the air conditioner 41 is 1802 mA.

  The equipment maximum operating rate is the ratio of the capacity at which an actually operating apparatus is maximum to the total capacity of the apparatus that generates harmonics. Since the broadcast transmitter 61 and the air conditioner 41 are continuously operated, for example, at 100% of the rated capacity, the equipment maximum operating rate of the broadcast transmitter 61 and the air conditioner 41 is 100%.

  Referring to FIGS. 3 and 5, the harmonic current flowing out by order is a value obtained by multiplying the received voltage converted rated current value, the operation rate, and the amount of harmonic current generated. Since the harmonic current generation amount of the broadcast transmitter 61 is not described in the harmonic suppression guideline, the value given by the manufacturer of the broadcast transmitter 61 is used.

  Specifically, the harmonic current generation amount of the broadcasting transmitter 61 is 28%, 16%, 5th order, 7th order, 11th order, 13th order, 17th order, 19th order, 23rd order and 25th order, respectively. 4.5%, 3.0%, 1.5%, 1.25%, 0.75% and 0.75%.

  Therefore, the harmonic outflow currents by order of the broadcast transmitter 61 are 1565 mA, 894 mA, 252 mA, 168 mA, 5th order, 7th order, 11th order, 13th order, 17th order, 19th order, 23rd order and 25th order, 84 mA, 70 mA, 42 mA and 42 mA.

  The harmonic current generation amount of the air conditioner 41 uses the value given in the harmonic suppression guideline, that is, the value corresponding to the 6-pulse converter in “Table 2” shown in FIG. Specifically, the harmonic current generation amount of the air conditioner 41 is 17.5%, 11.0 in the 5th, 7th, 11th, 13th, 17th, 19th, 23rd and 25th orders, respectively. %, 4.5%, 3.0%, 1.5%, 1.25%, 0.75% and 0.75%.

  Therefore, the harmonic outflow current according to the order of the air conditioner 41 is 315 mA, 198 mA, 81 mA, 54 mA, 27 mA in the fifth, seventh, eleventh, thirteenth, seventeenth, nineteenth, twenty-third, and twenty-fifth orders, respectively. 23 mA, 14 mA and 14 mA.

  As described above, the ratio of the fifth harmonic current and the seventh harmonic current in the harmonic current generated in the broadcast transmitter 61 is, for example, the fifth harmonic in the harmonic current generated in the inverter circuit included in the air conditioner 41. Larger than the ratio of the harmonic current and the seventh harmonic current.

  In addition, the sum of harmonic outflow currents by order of the broadcast transmitter 61 and the air conditioner 41 is 1880 mA for the fifth, seventh, eleventh, thirteenth, seventeenth, nineteenth, twenty-third, and twenty-fifth orders, respectively. 1092 mA, 333 mA, 222 mA, 111 mA, 93 mA, 56 mA and 56 mA.

  With reference to FIGS. 2, 3, and 6, it is necessary to calculate the allowable upper limit value of the harmonic outflow current flowing out to the system electric wire 11, that is, the outflow regulation value, for each order of the harmonic current. More specifically, the power reception voltage in “Table 1” shown in FIG. 6 is a value obtained by multiplying the value of each order corresponding to 6.6 kV by 105 kW, which is the contract power.

  Specifically, the outflow regulation value for each order is, for example, 368 mA, which is a value obtained by multiplying 3.5 mA / kW by 105 kW in the fifth order. Similarly, when the outflow restriction values are calculated in the seventh, eleventh, thirteenth, seventeenth, nineteenth, twenty-third, and twenty-fifth orders, the outflow restriction values are 263 mA, 168 mA, 137 mA, 105 mA, 95 mA, 80 mA, and 74 mA, respectively. It becomes.

  Therefore, for example, the sum of the fifth-order harmonic outflow current is 1880 mA, whereas the fifth-order outflow regulation value is 368 mA, so that the total of the fifth-order harmonic outflow current is less than or equal to the outflow regulation value. It is necessary to take preventive measures.

  As in the case of the fifth order, for the seventh, eleventh, thirteenth and seventeenth orders, the sum of harmonic outflow currents exceeds the outflow regulation value, and thus the same suppression measures are required. On the other hand, for the 19th, 23rd and 25th orders, the sum of the harmonic outflow currents does not exceed the outflow regulation value, so the same suppression measures are not necessary.

  As will be described later, harmonic currents of orders of multiples of 3 such as third order, sixth order, ninth order, twelfth order, fifteenth order, eighteenth order, twenty-first order, and twenty-fourth order include, for example, coils connected in a circular connection. It cannot pass through the transformer 171. For this reason, harmonic currents of orders of multiples of 3 are not subject to suppression of outflow from the power supply path 10 to the system side.

  Moreover, the value which calculated the ratio of the harmonic outflow current with respect to the excess electric current value which is the difference of a harmonic outflow current and an outflow regulation value for every order is defined as a target absorption factor. Specifically, the ratio of 1880 mA that is a harmonic outflow current to the excess current value 1512 mA in the fifth order, that is, the fifth-order target absorption rate is 0.804, that is, 80.4%.

  Similarly, the target absorption rates in the 7th, 11th, 13th, 17th, 19th, 23rd and 25th orders are 75.9%, 49.5%, 38.3%, 5.4%, -2.0%, -43.0% and -32.0%.

  The target absorption rate is a ratio of the harmonic current that should not be allowed to flow out from the broadcasting power supply system 401 to the system side with respect to the harmonic current generated in the broadcasting device 301. In other words, the target absorption rate is the ratio of the harmonic current to be consumed in the broadcasting power supply system 401 to the harmonic current generated in the broadcasting device 301. Specifically, it is the ratio of the harmonic current to be consumed in the harmonic absorption circuit 101 to the harmonic current generated in the broadcast transmitter 61.

  When the air conditioner 41 is connected to the broadcast transmitter 61, the sum of the harmonic current generated in the air conditioner 41 and the harmonic current generated in the broadcast transmitter 61 is used as the broadcast transmission. The target absorption rate may be calculated as the harmonic current in the machine 61.

  Further, for example, when a device that generates a harmonic current in addition to the air conditioner 41 is connected to the power supply path 10, a harmonic current generated in the air conditioner 41 and the device and a harmonic generated in the broadcasting transmitter 61. The target absorption rate may be calculated using the sum of the wave currents as the harmonic current in the broadcast transmitter 61.

  Further, the harmonic current to be consumed in the harmonic absorption circuit 101 may be rephrased as a harmonic current flowing into the harmonic absorption circuit 101.

[Harmonic current absorption by UPS]
FIG. 7 is a diagram illustrating an example of a configuration of a comparative example of a broadcasting power supply system.

  Referring to FIG. 7, a broadcast power supply system 402 is a broadcast power supply system that takes measures against outflow of harmonic current by UPS 162 as compared to the broadcast power supply system 401. The contents other than those described below are the same as those of the broadcasting power supply system 401.

  The broadcast power supply system 402 includes a high-voltage power reception facility 202 instead of the high-voltage power reception facility 201 as compared with the broadcast power supply system 401. The high-voltage power receiving facility 202 includes a UPS 162 connected between the power transmission unit 181 and the broadcasting device 301 instead of the harmonic absorption circuit 101.

  Since the UPS 162 has a characteristic of absorbing harmonic current, the harmonic current generated in the broadcasting device 301 electrically connected to the UPS 162 is absorbed by the UPS 162.

  The UPS 162 absorbs approximately 95% of the harmonic current generated in the broadcast device 301 when performing inverter operation. As a result, the broadcast device 301 is excluded from the harmonic suppression guideline device, and thus it is not necessary to take measures against outflow of harmonic currents to the broadcast device 301.

  Further, the broadcasting power supply system 402 can be made to comply with the harmonic suppression guidelines.

  However, when a failure or the like of the UPS 162 occurs, the UPS 162 transitions to a bypass mode in which, for example, the power transmission unit 181 and the broadcasting device 301 are electrically connected directly. Since the UPS 162 does not absorb the harmonic current in the bypass mode, the harmonic current generated in the broadcasting device 301 flows out to the system side.

  Further, the UPS 162 has a large shape, so that the installation space is excessive and expensive. Also, UPS 162 does not contribute to power factor improvement.

[Harmonic current absorption by active filter]
FIG. 8 is a diagram illustrating another example of the configuration of the comparative example of the broadcasting power supply system.

  Referring to FIG. 8, the broadcast power supply system 403 is a broadcast power supply system in which the active filter 163 takes measures against outflow of harmonic current, compared to the broadcast power supply system 401. The contents other than those described below are the same as those of the broadcasting power supply system 401.

  The broadcast power supply system 403 includes a high-voltage power reception facility 203 instead of the high-voltage power reception facility 201 as compared with the broadcast power supply system 401. The high-voltage power receiving equipment 203 includes an active filter 163 instead of the harmonic absorption circuit 101.

  The active filter 163 monitors the harmonic current flowing through the power supply path 10. When the active filter 163 detects that the harmonic current flows in the power feeding path 10, the active filter 163 outputs a current that cancels the harmonic current to the power feeding path 10.

  Thereby, since the harmonic current flowing out from the power supply path 10 to the system side can be suppressed, the broadcasting power supply system 403 can be made to comply with the harmonic suppression guidelines.

  Further, for example, when the capacity of the active filter 163 is appropriate, the harmonic current flowing out from the power supply path 10 to the system side can be suppressed almost completely.

  However, since the harmonic current generated in the broadcast transmitter 61 is very large, an active filter 163 having a capacity approximately twice that of the broadcast transmitter 61 is required. For this reason, the price of the active filter 163 becomes very expensive.

  Since the active filter 163 has a large shape, the installation space becomes excessive. The active filter 163 does not contribute to power factor improvement.

[Harmonic current absorption by SCSR method]
FIG. 9 is a diagram illustrating another example of the configuration of the comparative example of the broadcasting power supply system.

  Referring to FIG. 9, broadcast power supply system 404 is a broadcast power supply system in which harmonic current outflow countermeasures are performed by SCSR circuit 164 as compared with broadcast power supply system 401. The contents other than those described below are the same as those of the broadcasting power supply system 401.

  The broadcast power supply system 404 includes a high-voltage power reception facility 204 instead of the high-voltage power reception facility 201 as compared with the broadcast power supply system 401. High-voltage power receiving facility 204 includes an SCSR circuit 164 instead of harmonic absorption circuit 101.

  FIG. 10 is a single-line diagram of an example of the SCSR circuit in the comparative example shown in FIG.

  Referring to FIG. 10, SCSR circuit 164 includes phase advance capacitors 501A and 501B and 6% series reactors 502A and 502B.

  Hereinafter, each of the phase advance capacitors 501A and 501B may be referred to as a phase advance capacitor 501. In addition, each of the 6% series reactors 502A and 502B may be referred to as a 6% series reactor 502.

  In FIG. 10, two phase advance capacitors 501 are representatively shown. However, a larger number or a smaller number of phase advance capacitors 501 may be provided. In FIG. 10, two 6% series reactors 502 are representatively shown, but a larger number or a small number of 6% series reactors 502 may be provided.

  Three 6% series reactors 502A are provided corresponding to the R phase, the S phase, and the T phase, and have a first end connected to the power supply path 10 of the corresponding phase, and a second end.

  Three phase advance capacitors 501A are provided corresponding to 6% series reactors 502A, and each has a first end connected to a second end of the corresponding 6% series reactor 502A, and a second end. The second end of each phase advance capacitor 501A is, for example, delta-connected.

  Three 6% series reactors 502B are provided corresponding to the R phase, the S phase, and the T phase, and have a first end connected to the power supply path 10 of the corresponding phase, and a second end.

  Three phase advance capacitors 501B are provided corresponding to the 6% series reactor 502B, and each of the phase advance capacitors 501B has a first end connected to a second end of the corresponding 6% series reactor 502B, and a second end. The second end of each phase advance capacitor 501B is, for example, delta-connected.

  The withstand capacity of the 6% series reactor 502 is, for example, 55%. The capacity of the phase advance capacitor 501 is, for example, 30 Kvar.

  The absorption rate of the SCSR circuit 164 is approximately 40% according to a calculation method described later. This means that approximately 40% of the harmonic current generated in the broadcasting device 301 is absorbed. For this reason, the broadcasting power supply system 404 cannot comply with the harmonic suppression guidelines.

  In addition, since approximately 40% of the harmonic current generated in the broadcasting device 301 flows into the SCSR circuit 164, the phase-advancing capacitor 501 has an unnecessarily large capacity of 30 Kvar in order to prevent the series reactor from burning out.

  Since the phase advance capacitor 501 and the 6% series reactor 502 are small in shape, installation space can be saved. Further, the phase advance capacitor 501 and the 6% series reactor 502 are commercially available and thus are inexpensive.

  Note that the SCSR circuit 164 is configured by the 6% series reactor 502, but may be configured by, for example, a 13% series reactor. However, the absorption rate of the SCSR circuit in this case is much lower than 40%, which is not preferable as compared with the case where the 6% series reactor 502 is used.

  As described above, since the UPS 162 and the active filter 163 sufficiently absorb the harmonic current generated in the broadcasting device 301, the harmonic current flowing out to the system side is set to be equal to or less than the outflow regulation value defined in the harmonic suppression guideline. be able to.

  However, the UPS 162 and the active filter 163 are expensive and have a problem that the installation space is large. Further, the UPS 162 has a problem that harmonic current flows out to the system side in the bypass mode.

  On the other hand, the SCSR circuit 164 is inexpensive and space-saving, but has a problem that the harmonic current flowing out to the system side cannot be made equal to or less than the outflow regulation value defined in the harmonic suppression guideline because of its low absorption rate. .

  Moreover, the impedance of the transformer 171 is greatly different depending on whether the transformer 171 is an oil-filled transformer or a mold-type transformer. This means that the absorption rate of the SCSR circuit 164 differs depending on whether the transformer 171 is an oil-filled transformer or a mold-type transformer.

  Therefore, it is necessary to design an optimum combination of a capacitor and an inductor in consideration of the type of the transformer 171 and the harmonic current generated in the broadcasting device 301.

  Therefore, in the harmonic absorption circuit 101 according to the embodiment of the present invention, with the following configuration, the harmonic current flowing out to the system side is made less than or equal to the outflow regulation value stipulated in the harmonic suppression guideline with low cost and space saving. Make it possible.

[Harmonic current absorption by LC hybrid system]
FIG. 11 is a single-line connection diagram of an example of the harmonic absorption circuit according to the embodiment of the present invention.

  Referring to FIG. 11, the harmonic absorption circuit 101 includes a fifth harmonic filter circuit 50, a seventh harmonic filter circuit 70, an eleventh harmonic filter circuit 110, and a delay phase filter. A circuit 20 and a fuse 31 are included.

  The fifth harmonic filter circuit 50 uses the fifth harmonic current as an object of absorption. The seventh harmonic filter circuit 70 absorbs the seventh harmonic current. The eleventh harmonic filter circuit 110 uses the eleventh harmonic current as an absorption target.

  The fifth harmonic filter circuit 50 includes a capacitor 51, an inductor 52, a switch unit 53, a manual switch control unit HS1, and an automatic switch control unit AS1.

  The switch unit 53 includes a circuit breaker MCCB1 and a magnetic conductor MC1. The automatic switch control unit AS1 includes a harmonic meter relay HfMR1, a harmonic relay HfR1, a temperature sensor TS1 whose measurement target is the inductor 52, and a shape sensor DS1 whose measurement target is the capacitor 51.

  The circuit breaker MCCB1 for wiring has a first end connected to the power supply path 10 and a second end connected to the first end of the electromagnetic contactor MC1. The magnetic contactor MC1 has a first end connected to the second end of the circuit breaker MCCB1 for wiring, and a second end connected to the first end of the inductor 52.

  Inductor 52 has a first end connected to the second end of electromagnetic contactor MC <b> 1 and a second end connected to the first end of capacitor 51. Capacitor 51 has a first end connected to the second end of inductor 52, and a second end.

  The harmonic meter relay HfMR1 and the harmonic relay HfR1 measure the current flowing from the power supply path 10 to the capacitor 51 via the circuit breaker MCCB1, the magnetic contactor MC1, and the inductor 52.

  The seventh harmonic filter circuit 70 includes a capacitor 71, an inductor 72, a switch unit 73, a manual switch control unit HS2, and an automatic switch control unit AS2.

  Switch unit 73 includes a circuit breaker MCCB2 for wiring and an electromagnetic contactor MC2. The automatic switch control unit AS2 includes a harmonic meter relay HfMR2, a harmonic relay HfR2, a temperature sensor TS2 whose measurement target is the inductor 72, and a shape sensor DS2 whose measurement target is the capacitor 71.

  The circuit breaker MCCB2 for wiring has a first end connected to the power supply path 10 and a second end connected to the first end of the electromagnetic contactor MC2. The magnetic contactor MC2 has a first end connected to the second end of the circuit breaker MCCB2 for wiring and a second end connected to the first end of the inductor 72.

  Inductor 72 has a first end connected to the second end of electromagnetic contactor MC <b> 2 and a second end connected to the first end of capacitor 71. Capacitor 71 has a first end connected to the second end of inductor 72, and a second end.

  The harmonic meter relay HfMR2 and the harmonic relay HfR2 measure the current flowing from the power supply path 10 to the capacitor 71 via the circuit breaker MCCB2, the magnetic contactor MC2, and the inductor 72.

  The eleventh harmonic filter circuit 110 includes a capacitor 111, an inductor 112, a switch unit 113, a manual switch control unit HS3, and an automatic switch control unit AS3.

  Switch part 113 includes circuit breaker MCCB3 for wiring and electromagnetic contactor MC3. The automatic switch controller AS3 includes a harmonic meter relay HfMR3, a harmonic relay HfR3, a temperature sensor TS3 whose measurement target is the inductor 112, and a shape sensor DS3 whose measurement target is the capacitor 111.

  The circuit breaker MCCB3 for wiring has a first end connected to the power supply path 10 and a second end connected to the first end of the electromagnetic contactor MC3. The magnetic contactor MC3 has a first end connected to the second end of the circuit breaker MCCB3 for wiring, and a second end connected to the first end of the inductor 112.

  Inductor 112 has a first end connected to the second end of electromagnetic contactor MC3, and a second end connected to the first end of capacitor 111. Capacitor 111 has a first end connected to the second end of inductor 112, and a second end.

  The harmonic meter relay HfMR3 and the harmonic relay HfR3 measure the current flowing from the power supply path 10 to the capacitor 111 via the circuit breaker MCCB3, the magnetic contactor MC3, and the inductor 112.

  The delay phase circuit 20 includes a delay phase inductor 22, a switch unit 23, and a harmonic meter relay HfMR0. The switch unit 23 includes a circuit breaker MCCB4 and a magnetic contactor MC4.

  The circuit breaker MCCB4 for wiring has a first end connected to the power supply path 10 and a second end connected to the first end of the electromagnetic contactor MC4. The magnetic contactor MC4 has a first end connected to the second end of the wiring breaker MCCB4 and a second end connected to the first end of the slow-phase inductor 22.

  Slow phase inductor 22 has a first end connected to the second end of electromagnetic contactor MC4, and a second end.

  The harmonic meter relay HfMR0 supplies the current flowing from the power supply path 10 to the fifth harmonic filter circuit 50, the seventh harmonic filter circuit 70, the eleventh harmonic filter circuit 110, and the slow phase circuit 20. Measured.

  Hereinafter, each of the harmonic meter relays HfMR1, HfMR2, and HfMR3 may be referred to as a harmonic meter relay HfMR. Further, each of the harmonic relays HfR1, HfR2, and HfR3 may be referred to as a harmonic relay HfR.

  In addition, each of the circuit breakers MCCB1, MCCB2, MCCB3, and MCCB4 may be referred to as a circuit breaker MCCB. In addition, each of the magnetic contactors MC1, MC2, and MC3 may be referred to as an electromagnetic contactor MC. Each of the manual switch control units HS1, HS2, and HS3 may be referred to as a manual switch control unit HS.

  In addition, each of the temperature sensors TS1, TS2, TS3 may be referred to as a temperature sensor TS. Each of the shape sensors DS1, DS2, DS3 may be referred to as a shape sensor DS.

  The magnetic contactor MC includes the inductor 52, 72, or 112 corresponding to the power supply path 10 in accordance with the logical sum of abnormal signals indicating abnormality from the harmonic meter relay HfMR, the harmonic relay HfR, the temperature sensor TS, and the shape sensor DS. Open and close the connection.

  More specifically, in the magnetic contactor MC, when the logical sum of the abnormal signals is true, that is, at least one of the harmonic meter relay HfMR, the harmonic relay HfR, the temperature sensor TS, and the shape sensor DS outputs an abnormal signal. The electrical connection between the power supply path 10 and the corresponding inductor 52, 72 or 112 is cut off.

  The magnetic contactor MC corresponds to the power supply path 10 when the logical sum of the abnormal signals is false, that is, when none of the harmonic meter relay HfMR, the harmonic relay HfR, the temperature sensor TS, and the shape sensor DS outputs an abnormal signal. The inductor 52, 72 or 112 is electrically connected.

  The manual switch control unit HS fixes the electrical connection between the power supply path 10 and the corresponding inductor 52, 72, or 112 in the electromagnetic contactor MC to either the connected state or the disconnected state regardless of the logical sum of the abnormal signals. To do.

  The circuit breaker MCCB for wiring disconnects the electrical connection between the power supply path 10 and the corresponding inductor 52, 72, or 112 when the current flowing through the circuit breaker MCCB exceeds a predetermined threshold value.

  The harmonic meter relay HfMR outputs an abnormal signal to the magnetic contactor MC according to the current to be measured. More specifically, the harmonic meter relay HfMR outputs an abnormal signal to the magnetic contactor MC when the magnitude of the harmonic current included in the current to be measured exceeds a predetermined threshold value.

  Specifically, for example, the harmonic meter relay HfMR1 outputs an abnormal signal to the electromagnetic contactor MC1 when the magnitude of the harmonic current included in the current to be measured exceeds a predetermined threshold value.

  When receiving an abnormal signal from the harmonic meter relay HfMR1, the magnetic contactor MC1 disconnects the electrical connection between the power supply path 10 and the inductor 52. Thereby, it is possible to prevent the inductor 52 and the capacitor 51 from being damaged by the harmonic current.

  Further, since the magnetic contactor MC1 can receive an abnormal signal from the harmonic meter relay HfMR1 before the temperature of the inductor 52 and the capacitor 51 rises due to the harmonic current, damage to the inductor 52 and the capacitor 51 is minimized. Can be suppressed.

  The harmonic meter relay HfMR0 outputs an open signal to the electromagnetic contactor MC4 according to the current to be measured. More specifically, the magnitude of the harmonic current when the broadcast transmitters 61A and 61B operate is larger than the harmonic current when either one of the broadcast transmitters 61A and 61B operates.

  Further, when the broadcast transmitters 61A and 61B operate, the power factor is large without providing the slow phase inductor 22. On the other hand, when either one of the broadcast transmitters 61A and 61B operates, the capacity of the capacitors 51, 71, and 11 is large, so that there is a problem that the power factor is lowered due to the phase of the alternating current being excessively advanced with respect to the alternating voltage. To do. On the other hand, the slow phase inductor 22 delays the phase of the alternating current, which contributes to the improvement of the power factor.

  Therefore, the harmonic meter relay HfMR0 transmits an open signal when the magnitude of the harmonic current included in the current to be measured is larger than a predetermined threshold, that is, when the broadcast transmitters 61A and 61B operate. Output to contactor MC4.

  When receiving the open signal from the harmonic meter relay HfMR0, the magnetic contactor MC4 disconnects the electrical connection between the power supply path 10 and the slow-phase inductor 22. On the other hand, when the electromagnetic contactor MC4 does not receive an open signal from the harmonic meter relay HfMR0, the magnetic contactor MC4 electrically connects the power feeding path 10 and the slow phase inductor 22. Thereby, even when one of the broadcasting transmitters 61A and 61B operates, the power factor can be increased.

  Since the apparent current can be reduced when the power factor is improved, the power company can save on the cost of equipment such as electric wires and substations. For this reason, an electric power company may discount the electricity bill charged with respect to the customer who improved the power factor.

  The harmonic meter relay HfMR and the harmonic meter relay HfMR0 output, for example, an alarm when outputting an abnormal signal or an open signal, and turn on a warning lamp or sound an alarm sound installed in the housing. Further, the harmonic meter relay HfMR and the harmonic meter relay HfMR0 display the ratio of the harmonic current contained in the current to be measured in units of “%”, for example.

  The harmonic relay HfR outputs an abnormal signal to the electromagnetic contactor MC when the magnitude of the harmonic current of the target order included in the current to be measured exceeds a predetermined threshold value.

  Specifically, for example, the harmonic relay HfR1 outputs an abnormal signal to the electromagnetic contactor MC1 when the magnitude of the fifth harmonic current exceeds a predetermined threshold value.

  When receiving an abnormal signal from the harmonic relay HfR1, the magnetic contactor MC1 disconnects the electrical connection between the power supply path 10 and the inductor 52. Thereby, it is possible to prevent the inductor 52 and the capacitor 51 from being damaged by the harmonic current.

  Further, since the magnetic contactor MC1 can receive an abnormal signal from the harmonic relay HfR1 before the temperature of the inductor 52 and the capacitor 51 rises due to the harmonic current, damage to the inductor 52 and the capacitor 51 is minimized. Can be suppressed.

  The temperature sensor TS measures the temperature of the target inductor 52, 72, or 112, and outputs an abnormal signal to the magnetic contactor MC when the measured temperature exceeds a predetermined threshold value.

  Specifically, for example, when the temperature of the inductor 52 exceeds a predetermined threshold value, the temperature sensor TS1 outputs an abnormal signal to the electromagnetic contactor MC1.

  When receiving an abnormal signal from the temperature sensor TS1, the magnetic contactor MC1 disconnects the electrical connection between the power supply path 10 and the inductor 52. This can prevent the inductor 52 from being further damaged by heat.

  The shape sensor DS measures a change in the shape of the casing when the casing that stores the target capacitor 51, 71, or 111 expands due to heat generated by a current flowing in the capacitor 51, 71, or 111. When exceeds a predetermined threshold, an abnormal signal is output to the magnetic contactor MC.

  Specifically, for example, when the change in the shape of the capacitor 51 exceeds a predetermined threshold, the shape sensor DS1 outputs an abnormal signal to the electromagnetic contactor MC1.

  When receiving an abnormal signal from the shape sensor DS1, the magnetic contactor MC1 disconnects the electrical connection between the power supply path 10 and the inductor 52. Thereby, the capacitor 51 can be prevented from being damaged by heat.

  When the current supplied to the harmonic meter relay HfMR0, the harmonic meter relay HfMR1, and the harmonic relay HfR1 exceeds a predetermined threshold, the fuse 31 is melted and stops supplying the current.

  Thereby, for example, when a short circuit failure occurs in the harmonic meter relay HfMR0, the harmonic meter relay HfMR1, and the harmonic relay HfR1, it is possible to prevent the occurrence of a fire due to the short circuit failure.

  FIG. 12 is a double-line connection diagram of an example of the harmonic absorption circuit according to the embodiment of the present invention.

  Referring to FIG. 12, fifth harmonic filter circuit 50 includes switches 55R, 55S, and 55T corresponding to wiring circuit breaker MCCB1 shown in FIG. 11, and a switch corresponding to electromagnetic contactor MC1 shown in FIG. 54R, 54S, 54T, inductors 52R, 52S, 52T corresponding to the inductor 52 shown in FIG. 11, and capacitors 51A, 51B, 51C corresponding to the capacitor 51 shown in FIG.

  Switches 55R, 55S, 55T, switches 54R, 54S, 54T, inductors 52R, 52S, 52T and capacitors 51A, 51B, 51C are provided corresponding to the R phase, S phase, and T phase, respectively.

  Switch 55R has a first end connected to power supply path 10R corresponding to the R phase, and a second end. Switch 54R has a first end connected to the second end of switch 55R, and a second end.

  Inductor 52R has a first end connected to the second end of switch 54R, and a second end. Capacitor 51A has a first end connected to the second end of inductor 52R and a second end connected to the second end of inductor 52S.

  Switch 55S has a first end connected to power supply path 10S corresponding to the S phase, and a second end. Switch 54S has a first end connected to the second end of switch 55S, and a second end.

  Inductor 52S has a first end connected to the second end of switch 54S, and a second end. Capacitor 51B has a first end connected to the second end of inductor 52S and a second end connected to the second end of inductor 52T.

  Switch 55T has a first end connected to power supply path 10T corresponding to the T phase, and a second end. Switch 54T has a first end connected to the second end of switch 55T, and a second end.

  Inductor 52T has a first end connected to the second end of switch 54T, and a second end. Capacitor 51C has a first end connected to the second end of inductor 52T and a second end connected to the second end of inductor 52R.

  The capacitors 51A, 51B, and 51C are delta-connected, but are not limited to this. Capacitors 51A, 51B, and 51C may be star-connected, for example.

  The seventh harmonic filter circuit 70 includes switches 75R, 75S, and 75T corresponding to the circuit breaker MCCB2 shown in FIG. 11, switches 74R, 74S, and 74T corresponding to the electromagnetic contactor MC2 shown in FIG. Inductors 72R, 72S, 72T corresponding to inductor 72 shown in FIG. 11 and capacitors 71A, 71B, 71C corresponding to capacitor 71 shown in FIG. 11 are included.

  Switches 75R, 75S, 75T, switches 74R, 74S, 74T, inductors 72R, 72S, 72T and capacitors 71A, 71B, 71C are provided corresponding to the R phase, S phase, and T phase, respectively.

  Switch 75R has a first end connected to power supply path 10R corresponding to the R phase, and a second end. Switch 74R has a first end connected to the second end of switch 75R, and a second end.

  Inductor 72R has a first end connected to the second end of switch 74R, and a second end. Capacitor 71A has a first end connected to the second end of inductor 72R and a second end connected to the second end of inductor 72S.

  Switch 75S has a first end connected to power supply path 10S corresponding to the S phase, and a second end. Switch 74S has a first end connected to the second end of switch 75S, and a second end.

  Inductor 72S has a first end connected to the second end of switch 74S, and a second end. Capacitor 71B has a first end connected to the second end of inductor 72S, and a second end connected to the second end of inductor 72T.

  Switch 75T has a first end connected to power supply path 10T corresponding to the T phase, and a second end. Switch 74T has a first end connected to the second end of switch 75T, and a second end.

  Inductor 72T has a first end connected to the second end of switch 74T, and a second end. Capacitor 71C has a first end connected to the second end of inductor 72T and a second end connected to the second end of inductor 72R.

  The capacitors 71A, 71B, 71C are delta-connected, but are not limited to this. Capacitors 71A, 71B, 71C may be star-connected, for example.

  The eleventh harmonic filter circuit 110 includes switches 115R, 115S, 115T corresponding to the circuit breaker MCCB3 shown in FIG. 11, switches 114R, 114S, 114T corresponding to the electromagnetic contactor MC3 shown in FIG. Inductors 112R, 112S, and 112T corresponding to inductor 112 shown in FIG. 11 and capacitors 111A, 111B, and 111C corresponding to capacitor 111 shown in FIG. 11 are included.

  Switches 115R, 115S, and 115T, switches 114R, 114S, and 114T, inductors 112R, 112S, and 112T, and capacitors 111A, 111B, and 111C are provided corresponding to the R phase, the S phase, and the T phase, respectively.

  Switch 115R has a first end connected to power supply path 10R corresponding to the R phase, and a second end. Switch 114R has a first end connected to the second end of switch 115R, and a second end.

  Inductor 112R has a first end connected to the second end of switch 114R, and a second end. Capacitor 111A has a first end connected to the second end of inductor 112R and a second end connected to the second end of inductor 112S.

  Switch 115S has a first end connected to power supply path 10S corresponding to the S phase, and a second end. Switch 114S has a first end connected to the second end of switch 115S, and a second end.

  Inductor 112S has a first end connected to the second end of switch 114S, and a second end. Capacitor 111B has a first end connected to the second end of inductor 112S and a second end connected to the second end of inductor 112T.

  Switch 115T has a first end connected to power supply path 10T corresponding to the T phase, and a second end. Switch 114T has a first end connected to the second end of switch 115T, and a second end.

  Inductor 112T has a first end connected to the second end of switch 114T, and a second end. Capacitor 111C has a first end connected to the second end of inductor 112T and a second end connected to the second end of inductor 112R.

  The capacitors 111A, 111B, and 111C are delta-connected, but are not limited to this. Capacitors 111A, 111B, and 111C may be star-connected, for example.

  The phase delay circuit 20 includes switches 25R, 25S, and 25T corresponding to the circuit breaker MCCB4 shown in FIG. 11, switches 24R, 24S, and 24T corresponding to the electromagnetic contactor MC4 shown in FIG. And slow phase inductors 22R, 22S, and 22T corresponding to the slow phase inductor 22.

  The switches 25R, 25S, 25T, the switches 24R, 24S, 24T and the slow-phase inductors 22R, 22S, 22T are provided corresponding to the R phase, the S phase, and the T phase, respectively.

  Switch 25R has a first end connected to power supply path 10R corresponding to the R phase, and a second end. Switch 24R has a first end connected to the second end of switch 25R, and a second end. Delay phase inductor 22R has a first end connected to the second end of switch 24R, and a second end.

  Switch 25S has a first end connected to power supply path 10S corresponding to the S phase, and a second end. Switch 24S has a first end connected to the second end of switch 25S, and a second end. The slow phase inductor 22S has a first end connected to the second end of the switch 24S, and a second end.

  Switch 25T has a first end connected to power supply path 10T corresponding to the T phase, and a second end. Switch 24T has a first end connected to the second end of switch 25T, and a second end. The slow-phase inductor 22T has a first end connected to the second end of the switch 24T, and a second end. The second ends of the slow-phase inductors 22R, 22S, and 22T are connected to each other.

  The slow-phase inductors 22R, 22S, and 22T are star-connected, but are not limited to this. The slow-phase inductors 22R, 22S, and 22T may be delta-connected, for example.

  FIG. 13 is a diagram illustrating an example of the branching of the harmonic current generated in the broadcasting apparatus according to the embodiment of the present invention to the transformer side and the harmonic absorption circuit side.

  Referring to FIG. 13, the sum of the nth harmonic currents generated in broadcasting transmitters 61A and 61B and air conditioners 41A and 41B in broadcasting apparatus 301 is defined as ih (n).

  ih (n) is a harmonic current ihs (n) that flows to the power supply side of the AC voltage, that is, the transformer 171 side, and ihc (n) that is a harmonic current that flows to the harmonic absorption circuit 101 side at the node A. Divide.

  Here, the ratio of ihc (n) to ih (n) is defined as the absorption rate of the harmonic absorption circuit 101. The ratio of ihc (n) to ih (n) is based on the impedance Zs in the direction toward the transformer 171 as viewed from the node A and the impedance Zc in the direction toward the harmonic absorption circuit 101 as viewed from the node A. Calculated.

  That is, the absorption rate of the harmonic absorption circuit 101 can be calculated based on the impedance Zs and the impedance Zc.

  The reciprocal of impedance Zs is admittance Ys. The reciprocal of impedance Zc is admittance Yc.

  The ratio of ihc (n) to ih (n), ie (ihc (n) / ih (n)) is equal to Yc / (Ys + Yc). Therefore, the absorption rate is approximately proportional to the admittance Yc.

  Further, the admittance Yc includes the admittance Yc5 in the fifth harmonic filter circuit 50, the admittance Yc7 in the seventh harmonic filter circuit 70, the admittance Yc11 in the eleventh harmonic filter circuit 110, and the slow phase. It is represented by the sum of the admittance Yc20 in the circuit 20 for use.

  Here, the following approximation is performed. That is, when designing the circuit constants of the fifth harmonic filter circuit 50, the admittance Yc5 is designed to be large. At this time, the admittance Yc7, the admittance Yc11, and the admittance Yc20 are treated as small enough to be ignored with respect to the admittance Yc5.

  Thereby, the admittance Yc can be approximated to the admittance Yc5. The absorptance is expressed by Yc5 / (Ys + Yc5). Thus, the absorptance can be expressed by a simple expression such as Zs / (Zs + Zc5) using impedance. The above approximation is considered a good approximation as long as no resonance occurs.

  In other words, when designing the fifth harmonic filter circuit 50, it is approximated that the seventh harmonic filter circuit 70, the eleventh harmonic filter circuit 110, and the slow phase circuit 20 are not provided.

  Similarly, when designing the seventh harmonic filter circuit 70, it is approximated that the fifth harmonic filter circuit 50, the eleventh harmonic filter circuit 110, and the slow phase circuit 20 are not provided.

  Similarly, when designing the eleventh-order harmonic filter circuit 110, it is approximated that the fifth-order harmonic filter circuit 50, the seventh-order harmonic filter circuit 70, and the slow-phase circuit 20 are not provided.

  In addition, harmonic currents of orders of multiples such as the third harmonic current, the sixth harmonic current, and the ninth harmonic current cannot pass through the transformer including the coils connected in a circular connection. This is because the harmonic current flows back in the annularly connected coil.

  In the transformer 171, for example, the primary coil is star-connected and the secondary coil is circular-connected. As a result, it is possible to prevent harmonic currents of orders of multiples of 3 included in ih (n) from passing through the transformer 171 and flowing out to the system side.

  Therefore, a filter circuit that absorbs harmonic currents of orders of multiples of 3 is unnecessary. On the other hand, if the transformer 171 does not include, for example, an annularly connected coil, a filter circuit that absorbs harmonic currents of orders of multiples of 3 is required.

  FIG. 14 is a diagram showing an example of an approximately equivalent circuit when designing the fifth harmonic filter circuit according to the embodiment of the present invention.

  Referring to FIG. 14, as described above, for example, when designing the fifth harmonic filter circuit 50, the seventh harmonic filter circuit 70, the eleventh harmonic filter circuit 110, and the delay circuit. It approximates that there is no phase circuit 20.

  Therefore, the equivalent circuit 551 represented approximately is configured by the fifth harmonic filter circuit 50 including the inductor 52 and the capacitor 51, the transformer 171 and the system electric wire 11 from the substation to the power receiving unit 151. .

  Moreover, it is convenient to calculate the impedance in the equivalent circuit 551 including the transformer 171 using% impedance. The% impedance converted into the same% impedance reference capacity can be calculated in the same manner as the impedance. Hereinafter, calculation is performed based on% impedance.

  The% impedance in the direction from the node A toward the harmonic absorption circuit 101 is% Zc1 (n) that is the% impedance of the fifth harmonic filter circuit 50. % Zc1 (n) is represented by the sum of jn (X1) which is the% impedance of the inductor 52 and −j (XC1) / n which is the% impedance of the capacitor 51. Here, j represents an imaginary unit.

  Here, n represents the order of the harmonic current. X1 represents the magnitude of% impedance with respect to the fundamental wave of the inductor 52. Since the magnitude of the% impedance and the magnitude of the impedance are in a proportional relationship, X1 can be regarded as the reactance of the inductor 52.

  XC1 represents the magnitude of% impedance with respect to the fundamental wave of the capacitor 51. Since the magnitude of the% impedance and the magnitude of the impedance are in the same proportional relationship as described above, XC1 can be regarded as the reactance of the capacitor 51.

  In this case, the reactor ratio is the ratio of X1 to XC1, that is, X1 / XC1.

  The% impedance in the direction from the node A toward the transformer 171 is% Zs (n). Here, n represents the order of the harmonic current. % Zs (n) is represented by the sum of jn (XT) which is the% impedance of the transformer 171 and jn (XS) which is the% impedance of the system electric wire 11.

[% Impedance% Zs (n) of system wire and transformer]
The% impedance of the inductor 52, the capacitor 51, the transformer 171 and the system wire 11 included in the equivalent circuit 551 is expressed as follows when the% impedance reference capacity is converted to, for example, 150 KVA.

  That is, referring to FIG. 2 again, the power source side% Z, that is, the% impedance of the system wire 11 is 6.70%. In this case, the% impedance reference capacity is 10 MVA.

  FIG. 15 is a diagram illustrating an example of values for each harmonic of the% impedance of the transformer and the system electric wire according to the embodiment of the present invention.

  Referring to FIG. 15, the% impedance magnitude of system electric wire 11 is a value obtained by dividing 6.70% and 150 KVA by 10 MVA when converted to a 150 KVA% impedance reference capacity, that is, 0.101. %.

  0.101% in this case corresponds to XS shown in FIG. Therefore, the% impedance of the system wire 11 with respect to the fundamental wave is j0.101%.

  The% impedance of the system electric wire 11 with respect to the n-th harmonic is represented by n · j 0.101%. Specifically, the% impedance of the system electric wire 11 in the case of the fundamental wave to the 19th harmonic is a value shown in FIG. 15 obtained by multiplying j0.101% by the harmonic order. For example, the% impedance of the system electric wire 11 with respect to the fifth harmonic is j0.505%.

  FIG. 16 is a diagram illustrating an example of the value of% impedance of the transformer according to the embodiment of the present invention.

  Referring to FIGS. 2 and 16, transformer 171 is, for example, a mold type and has a transformer capacity of 150 KVA. The frequency of the power supply is 50 hertz.

  Since the transformer capacity and the% impedance reference capacity are the same 150 KVA, the% impedance of the transformer 171 is 1.59% + j4.81%. This represents the% impedance of the transformer 171 with respect to the fundamental wave.

  The% impedance of the transformer 171 with respect to the nth harmonic is represented by 1.59% + n · j4.81%. Further, the magnitude of the% impedance of the transformer 171 with respect to the nth harmonic is given by Sqrt ((% R) ^ 2 + (n ·% X) ^ 2). Here, “Sqrt (*)” represents calculating the square root of *. Further, “* ^ 2” represents calculating the square of *.

  Therefore, the magnitude of the% impedance of the transformer 171 with respect to the fundamental wave is Sqrt ((1.59) ^ 2 + (1 · 4.81) ^ 2), that is, 5.07. Here, the phase angle of% impedance of the transformer 171 is 72 degrees.

  Further, the magnitude of the% impedance of the transformer 171 with respect to the fifth harmonic is Sqrt ((1.59) ^ 2 + (5 · 4.81) ^ 2), that is, 24.1. Here, the phase angle of the% impedance of the transformer 171 is 86 degrees.

  Here, the following approximation is performed. Since the inductor 52 and the system wire 11 are inductive, the% impedance of the inductor 52 and the system wire 11 is an imaginary number. Further, since the capacitor 51 is capacitive, the% impedance of the capacitor 51 is an imaginary number.

  Therefore, the calculation can be simplified by setting the% impedance of the transformer 171 to an imaginary number.

  Specifically, since the% impedance of the transformer 171 is highly inductive, the% impedance of the transformer 171 approximates that represented by a value obtained by multiplying the magnitude of the% impedance of the transformer 171 by j.

  Since the magnitude of the% impedance of the transformer 171 is smaller than the sum of the real component and the imaginary component in the complex% impedance of the transformer 171, the harmonic current flowing out to the system side when calculated by this approximation is strictly calculated. In this case, it becomes larger than the harmonic current flowing out to the system side.

  Therefore, the calculation by this approximation is considered to be a good approximation because the calculation result is on the safe side.

  As a specific% impedance of the transformer 171, for example, the% impedance of the transformer 171 with respect to the fundamental wave is j5.07% as shown in FIG. Further, for example, the% impedance of the transformer 171 with respect to the fifth harmonic is j24.10% as shown in FIG.

  Further, the% impedance% Zs (n) in the direction toward the transformer 171 as viewed from the node A with respect to the n-th harmonic is obtained by calculating the sum of the% impedance of the system wire 11 and the% impedance of the transformer 171. .

  As a specific% Zs (n), for example,% Zs (1) with respect to the fundamental wave is j5.2% as shown in FIG. Further, for example,% Zs (5) for the fifth harmonic is j24.6% as shown in FIG. It can be seen that the contribution of% impedance of the transformer 171 is large in% Zs (n).

[% Impedance of capacitor 51]
FIG. 17 is a diagram showing an example of values for each harmonic of% impedance in the equivalent circuit 551 according to the embodiment of the present invention.

  Referring to FIG. 17, the capacitance of capacitor 51 is determined based on the amount of absorption of harmonic current. Specifically, the effective value of the current passing through the capacitor 51 is obtained by calculating the square root of the sum of the squares of the harmonic currents of the respective orders passing through the capacitor 51. The harmonic current of each order passing through the capacitor 51 is calculated based on, for example, FIG.

  The capacity of the capacitor 51 is set to 35 KVA, for example, in consideration of the calculated effective value and the calorific value.

  The size of the% impedance of the capacitor 51 having a capacity of 35 KVA is a value obtained by dividing the value obtained by multiplying 100% by 150 KVA by 35 KVA, that is, 428.57%, when converted to a 150 KVA% impedance reference capacity.

  428.57% in this case corresponds to XC1 shown in FIG. Therefore, the% impedance of the capacitor 51 with respect to the fundamental wave is -j428.57%.

  The% impedance of the capacitor 51 in the case of the fundamental wave to the 19th harmonic is a value obtained by dividing the harmonic order with respect to -j428.57%. For example, the% impedance of the capacitor 51 with respect to the fifth harmonic is -j85.71% as shown in FIG.

[Calculation of% impedance of inductor 52 by reactor ratio]
The% impedance of the inductor 52 with respect to the fundamental wave is determined by the reactor ratio. The reactor ratio in this case is specifically a value obtained by dividing the reactance at the fundamental frequency of the inductor 52 by the reactance at the fundamental frequency of the capacitor 51.

  As described above, since the magnitude of the% impedance can be regarded as reactance, the reactor ratio is obtained by changing the% impedance magnitude at the fundamental frequency of the inductor 52 and the% impedance magnitude at the fundamental frequency of the capacitor 51. It is also the value divided by the size. In other words, the magnitude of the% impedance with respect to the fundamental wave of the inductor 52 is a value obtained by multiplying the magnitude of the% impedance with respect to the fundamental wave of the capacitor 51 by the reactor ratio.

  Specifically, the magnitude of the% impedance with respect to the fundamental wave of the inductor 52 is, for example, 18.00% obtained by multiplying 428.57%, which is the magnitude of the% impedance with respect to the fundamental wave of the capacitor 51, by 4.2%, for example. Become.

  In this case, 18.00% corresponds to X1 shown in FIG. Therefore, the% impedance of the inductor 52 with respect to the fundamental wave is j18.00%.

  The% impedance of the inductor 52 in the case of the fundamental wave to the 19th harmonic is a value obtained by multiplying j18.00% by the harmonic order. For example, the% impedance of the inductor 52 with respect to the fifth harmonic is j90.00% as shown in FIG.

[% Impedance% Zc1 (n) of fifth harmonic filter circuit]
FIG. 18 is a diagram illustrating an example of a change in% impedance of the fifth harmonic filter circuit with respect to the harmonic order in the equivalent circuit 551 according to the embodiment of the present invention.

  Referring to FIG. 18,% Zc1 (n), which is the% impedance of fifth harmonic filter circuit 50, is represented by the sum of% impedance of capacitor 51 and% impedance of inductor 52 in each order. Here, n represents the order of the harmonic current.

  % Zc1 (n) is smaller than zero when the harmonic order n is 1 and 3. In this case,% Zc1 (n) has a capacitive property. % Zc1 (n) is greater than zero when the harmonic order n is 5 or more. In this case,% Zc1 (n) is inductive.

[Design Guidelines for Circuit Constants of 5th Harmonic Filter Circuit]
As described above, the absorptance in the fifth harmonic filter circuit 50 is represented by Zs / (Zs + Zc5). Here, Zs represents the impedance in the direction from the node A toward the transformer 171. Zc5 represents the impedance of the fifth harmonic filter circuit 50.

  Since% Zs (n) and% Zc1 (n) can be calculated in the same manner as the impedance, the absorption factor in the fifth harmonic filter circuit 50 for the nth harmonic current is% Zs (n). / (% Zs (n) +% Zc1 (n)).

  Specifically, the absorption factor for the fifth harmonic current is 85.0% obtained from% Zs (5) / (% Zs (5) +% Zc1 (5)).

  FIG. 19 is a diagram showing a change in the absorption factor of the fifth harmonic current with respect to the reactor ratio in the equivalent circuit 551 according to the embodiment of the present invention.

  Referring to FIG. 19, Rc1 (5) indicating the change in absorption rate is, for example, the absorption rate for the fifth harmonic current when the reactor ratio is changed from 3.5% to 6.0%, that is, % Zs (5) / (% Zs (5) +% Zc1 (5)). T5 indicates a target absorption rate of 80.4%.

  Further, the ratio of the nth harmonic current flowing out to the system side with respect to the nth harmonic current generated in the broadcasting device 301 is defined as the outflow rate for the nth harmonic current.

  For example, the outflow rate for the fifth harmonic current is represented by ihs (5) / ih (5) in the equivalent circuit 551 shown in FIG. ihs (5) / ih (5) is (ih (5) -ihc (5)) / ih (5) or 1- (ihc (5) / ih (5)). Here, (ihc (5) / ih (5)) represents the absorption rate for the fifth harmonic current.

  Ec1 (5) indicating the change in the outflow rate is, for example, from the outflow rate for the fifth harmonic current when the reactor ratio is changed from 3.5% to 6.0%, that is, from 100% to Rc1 (5). Is the value obtained by subtracting.

  Rc1 (5) is 100% when the reactor ratio is 4.00%. In this case, Ec1 (5) is 0%. This means that the inductor 52 and the capacitor 51 are in a resonance state when the reactor ratio is 4.00%.

  That is, since the% impedance of the inductor 52 and the% impedance of the capacitor 51 just cancel each other,% Zc1 (5) becomes zero, that is, a short circuit state.

  For this reason, all the fifth harmonic current generated in the broadcasting device 301 flows into the fifth harmonic filter circuit 50, so the fifth harmonic current does not flow out to the system side.

  However, since there is a high possibility that a short-circuit current flows unexpectedly in the fifth harmonic filter circuit 50, considering the protection of the inductor 52 and the capacitor 51, the reactor ratio is set to 4.00% at which resonance occurs. That is not preferable.

  For example, when the reactor ratio is smaller than 4.00%, Rc1 (5) exceeds 100%. Moreover, Ec1 (5) is less than 0%. This means that a current other than the fifth harmonic current generated in the broadcasting device 301 further flows into the fifth harmonic filter circuit 50.

  The cause is considered as follows. That is, when the reactor ratio is smaller than 4.00%,% Zs (5) on the transformer 171 side is inductive, whereas% Zc1 (5) on the inductor 52 and capacitor 51 side is capacitive. .

  For this reason, weak resonance occurs between the transformer 171 and the system wire 11 and the inductor 52 and the capacitor 51.

  The fifth harmonic current generated in the broadcasting device 301 and the resonance current flow into the fifth harmonic filter circuit 50, so that Rc1 (5) exceeds 100%.

  Therefore, when the reactor ratio is made smaller than 4.00%, current other than the fifth harmonic current generated in the broadcasting device 301 flows in the inductor 52 and the capacitor 51, so that% Zc1 (5) is capacity. It is not preferable to make it sex.

  On the other hand, by making the reactor ratio larger than 4.00%, current other than the fifth harmonic current generated in the broadcasting device 301 without short-circuiting the% impedance of the fifth harmonic filter circuit 50. Can be prevented from further flowing into the fifth harmonic filter circuit 50.

  That the reactor ratio is larger than 4.00% means that the combined% impedance of the inductor 52 and the capacitor 51 is inductive at the fifth harmonic. This is synonymous with the fact that the% impedance magnitude of the inductor 52 is larger than the% impedance magnitude of the capacitor 51 in the fifth harmonic.

  In other words, the reactance of the inductor 52 is larger than the reactance of the capacitor 51 at the frequency of the fifth harmonic. This is because the magnitude of% impedance can be regarded as reactance as described above.

  For example, when a commercially available 6% series reactor is used as an inductor, Rc1 (5) is 36.5% as shown in FIG. Although not shown in FIG. 19, when a commercially available 13% series reactor is used as an inductor, Rc1 (5) is 11.3%.

  Therefore, even if any of the 6% series reactor and the 13% series reactor is used as the inductor, it is much lower than the target absorption rate T5. For this reason, the fifth harmonic current cannot be sufficiently absorbed by the SCSR circuit including the phase advance capacitor 501 and the 6% series reactor 502 or the 13% series reactor as shown in FIG.

  Further, it is considered that the absorption rate when the SCSR circuit 164 is used can be improved to about 40% by optimizing the% impedance of the transformer, for example.

  Here, when the reactor ratio is set to 5.72%, for example, as shown in FIG. 19, Rc1 (5) becomes 40%. Therefore, it is preferable to set the reactor ratio to less than 5.72%.

  Further, when the reactor ratio is set to 5.15%, for example, as shown in FIG. 19, Rc1 (5) becomes 50%. As a result, the fifth harmonic current can be absorbed at an absorption rate higher than 40%, which is the absorption rate of the optimized SCSR circuit 164.

  Referring to FIG. 3 again, for example, when one air conditioner 41 and one broadcast transmitter 61 are operated and each other is stopped, the fifth harmonic outflow current is determined when two units are simultaneously operated. Is 940 mA, which is half of 1880 mA.

  Since the outflow regulation value is 368 mA, the magnitude of the current to be absorbed in this case is 572 mA which is the difference between 940 mA and 368 mA. Therefore, the target absorption rate is 60.9%, which is the ratio of 572 mA to 940 mA.

  Referring to FIG. 19 again, for example, when the reactor ratio is set to 4.49%, Rc1 (5) becomes 70% as shown in FIG. Thereby, for example, when each of the air conditioner 41 and the broadcasting transmitter 61 is operated and each of the other ones is stopped, the fifth harmonic is obtained with an absorption rate of 60.9% or more which is a target absorption rate. Current can be absorbed.

  For example, when the reactor ratio is set to 4.29%, Rc1 (5) is 80% as shown in FIG. On the other hand, when the air conditioner 41 and the two broadcast transmitters 61 are simultaneously operated, the target absorption rate is 80.4%, and thus the reactor ratio needs to be further reduced from 4.29%.

  More specifically, as described above, σ (5), which is the absorption factor for the fifth harmonic current, is σ (5) =% Zs (5) / (% Zs (5) +% Zc1 (5) ). Solving this equation for% Zc1 (5) yields% Zc1 (5) = (1 / σ (5) −1) ×% Zs (5).

  As for% Zs (5), j24.60 is obtained from FIG. Assuming that σ (5) is the target absorption rate of 80.4%,% Zc1 (5) becomes (1 / 0.804-1) × j24.60, that is, j6.00. In other words, the product of j24.60 which is the% impedance in the direction toward the transformer 171 viewed from the power feeding path 10 and the value obtained by subtracting 1 from the reciprocal of 80.4% which is the target absorption rate is j6.00. is there. Then,% Zc1 (5) is made smaller than j6.00.

  For example, calculating% Zc1 (5) when the reactor ratio is 4.25% and 4.30%, the% Zc1 (5) becomes j5.36 and j6.43, respectively.

  Referring to FIG. 19 again, for example, when the reactor ratio is 4.25%, the absorption rate is 82.1%, and when the reactor ratio is 4.30%, the absorption rate is 79.3%. .

  Therefore, by setting the reactor ratio to 4.28% or less, an absorption rate of 80.4% or more, which is a target absorption rate, can be achieved. Thereby, about the 5th harmonic, the electric power feeding system 401 for broadcasting can be made to comply with a harmonic suppression guideline.

[7th harmonic filter circuit% impedance% Zc2 (n)]
FIG. 20 is a diagram showing an example of an equivalent circuit approximately expressed when designing the seventh harmonic filter circuit according to the embodiment of the present invention.

  Referring to FIG. 20, as described above, for example, when designing the seventh harmonic filter circuit 70, the fifth harmonic filter circuit 50, the eleventh harmonic filter circuit 110, and the delay circuit. It approximates that there is no phase circuit 20.

  Therefore, the equivalent circuit 552 represented approximately is configured by the seventh harmonic filter circuit 70 including the inductor 72 and the capacitor 71, the transformer 171, and the system electric wire 11 from the substation to the power receiving unit 151. .

  Further, the calculation of the impedance in the equivalent circuit 552 is performed based on the% impedance hereinafter.

  The% impedance in the direction from the node A toward the harmonic absorption circuit 101 is% Zc2 (n) which is the% impedance of the seventh harmonic filter circuit 70. % Zc2 (n) is represented by the sum of jn (X2) which is the% impedance of the inductor 72 and −j (XC2) / n which is the% impedance of the capacitor 71.

  Here, n represents the order of the harmonic current. X2 represents the magnitude of% impedance with respect to the fundamental wave of the inductor 72. Since the magnitude of% impedance and the magnitude of impedance are in a proportional relationship, X2 can be regarded as the reactance of the inductor 72.

  XC2 represents the magnitude of% impedance with respect to the fundamental wave of the capacitor 71. Since the magnitude of the% impedance and the magnitude of the impedance are in the same proportional relationship as described above, XC2 can be regarded as the reactance of the capacitor 71.

  In this case, the reactor ratio is the ratio of X2 to XC2, that is, X2 / XC2.

  Since the% impedance of transformer 171 and system electric wire 11 included in equivalent circuit 552 is the same as that shown in FIG. 14, detailed description will not be repeated. Therefore, the% impedance in the direction from the node A toward the transformer 171 is the same as% Zs (n) shown in FIG.

  The% impedance of the inductor 72 and the capacitor 71 is expressed as follows when the% impedance reference capacitance is converted to, for example, 150 KVA.

[% Impedance of capacitor 71]
FIG. 21 is a diagram showing an example of values for each harmonic of% impedance in the equivalent circuit 552 according to the embodiment of the present invention.

  Referring to FIG. 21, the capacitance of capacitor 71 is determined based on the amount of absorption of harmonic current. Specifically, the effective value of the current passing through the capacitor 71 is obtained by calculating the square root of the sum of the squares of the harmonic currents of the respective orders passing through the capacitor 71. The harmonic current of each order passing through the capacitor 71 is calculated based on, for example, FIG.

  The capacity of the capacitor 71 is set to 20 KVA, for example, in consideration of the calculated effective value and the calorific value.

  The amount of% impedance of the capacitor 71 having a capacity of 20 KVA is a value obtained by dividing 100% multiplied by 150 KVA by 20 KVA, that is, 750.00%, when converted to a 150 KVA% impedance reference capacity.

  750.00% in this case corresponds to XC2 shown in FIG. Therefore, the% impedance of the capacitor 71 with respect to the fundamental wave is −j750.00%.

  The% impedance of the capacitor 71 in the case of the fundamental wave to the 19th harmonic is a value obtained by dividing the harmonic order with respect to -j750.00%. For example, the% impedance of the capacitor 71 with respect to the seventh harmonic is -j107.14% as shown in FIG.

[Calculation of% impedance of inductor 72 by reactor ratio]
The% impedance of the inductor 72 with respect to the fundamental wave is determined by the reactor ratio. The reactor ratio in this case is specifically a value obtained by dividing the reactance at the fundamental frequency of the inductor 72 by the reactance at the fundamental frequency of the capacitor 71.

  As described above, since the magnitude of the% impedance can be regarded as the reactance, the reactor ratio is defined as the% impedance magnitude at the fundamental frequency of the inductor 72 and the% impedance magnitude at the fundamental frequency of the capacitor 71. It is also the value divided by the size. In other words, the magnitude of the% impedance with respect to the fundamental wave of the inductor 72 is a value obtained by multiplying the magnitude of the% impedance with respect to the fundamental wave of the capacitor 71 by the reactor ratio.

  Specifically, the magnitude of the% impedance with respect to the fundamental wave of the inductor 72 is, for example, 16.50% obtained by multiplying 750.00%, which is the magnitude of the% impedance with respect to the fundamental wave of the capacitor 71, by 2.2%. Become.

  16.50% in this case corresponds to X2 shown in FIG. Therefore, the% impedance of the inductor 72 with respect to the fundamental wave is j16.50%.

  The% impedance of the inductor 72 in the case of the fundamental wave to the 19th harmonic is a value obtained by multiplying j16.50% by the harmonic order. For example, the% impedance of the inductor 72 with respect to the seventh harmonic is j115.50% as shown in FIG.

[7th harmonic filter circuit% impedance% Zc2 (n)]
FIG. 22 is a diagram illustrating an example of a change in% impedance of the seventh harmonic filter circuit with respect to the harmonic order in the equivalent circuit 552 according to the embodiment of the present invention.

  Referring to FIG. 22,% Zc2 (n), which is the% impedance of the seventh harmonic filter circuit 70, is represented by the sum of the% impedance of capacitor 71 and the% impedance of inductor 72 in each order. Here, n represents the order of the harmonic current.

  % Zc2 (n) is smaller than zero when the harmonic order n is 1, 3, and 5. In this case,% Zc2 (n) has a capacitive property. % Zc2 (n) is greater than zero when the harmonic order n is 7 or more. In this case,% Zc2 (n) is inductive.

  As can be seen from the fact that% Zc2 (5) shown in FIG. 21 is −j67.5, the seventh harmonic filter circuit 70 is capacitive with respect to the fifth harmonic. Therefore, it is assumed that the fifth harmonic current due to resonance flows into the seventh harmonic filter circuit 70.

  In the fifth harmonic filter circuit 50 shown in FIG. 17, j4.3, which is% Zc1 (5), is sufficiently smaller than −j67.5, which is% Zc2 (5). The fifth harmonic current flowing into the harmonic filter circuit 70 is considered to be negligibly small.

  Therefore, it is considered that the influence of the seventh harmonic filter circuit 70 on the absorption rate of the fifth harmonic current absorbed in the fifth harmonic filter circuit 50 is small.

[Design guidelines for circuit constants of the 7th harmonic filter circuit]
As described above, the absorptance in the seventh harmonic filter circuit 70 is represented by Zs / (Zs + Zc7). Here, Zs represents the impedance in the direction from the node A toward the transformer 171. Zc7 represents the impedance of the seventh harmonic filter circuit 70.

  Since% Zs (n) and% Zc2 (n) can be calculated in the same manner as the impedance, the absorption factor in the seventh harmonic filter circuit 70 for the nth harmonic current is% Zs (n). / (% Zs (n) +% Zc2 (n)).

  Specifically, 80.0% is obtained from% Zs (7) / (% Zs (7) +% Zc2 (7)) as the absorptance for the seventh harmonic current.

  FIG. 23 is a diagram showing a change in the absorption factor of the seventh harmonic current with respect to the reactor ratio in the equivalent circuit 552 according to the embodiment of the present invention.

  Referring to FIG. 23, Rc2 (7) indicating the change in absorption rate is, for example, the absorption rate for the seventh harmonic current when the reactor ratio is changed from 1.5% to 4.0%. % Zs (7) / (% Zs (7) +% Zc2 (7)). T7 indicates a target absorption rate of 75.9%.

  For example, the outflow rate for the seventh harmonic current is represented by ihs (7) / ih (7) in the equivalent circuit 552 shown in FIG. ihs (7) / ih (7) is (ih (7) -ihc (7)) / ih (7) or 1- (ihc (7) / ih (7)). Here, (ihc (7) / ih (7)) represents the absorption rate for the seventh harmonic current.

  Ec2 (7) indicating a change in the outflow rate is, for example, an outflow rate for the seventh harmonic current when the reactor ratio is changed from 1.5% to 4.0%, that is, from 100% to Rc2 (7). Is the value obtained by subtracting.

  Rc2 (7) is 100% when the reactor ratio is 2.04%. In this case, Ec2 (7) is 0%. This means that the inductor 72 and the capacitor 71 are in a resonance state when the reactor ratio is 2.04%.

  That is, since the% impedance of the inductor 72 and the% impedance of the capacitor 71 just cancel each other,% Zc2 (7) becomes zero, that is, a short circuit state.

  For this reason, all the seventh harmonic current generated in the broadcasting device 301 flows into the seventh harmonic filter circuit 70, and therefore the seventh harmonic current does not flow out to the system side.

  However, since there is a high possibility that a short-circuit current flows unexpectedly in the seventh harmonic filter circuit 70, considering the protection of the inductor 72 and the capacitor 71, the reactor ratio is set to 2.04% at which resonance occurs. That is not preferable.

  For example, when the reactor ratio is smaller than 2.04%, Rc2 (7) exceeds 100%. Ec2 (7) is less than 0%. This means that a current other than the seventh harmonic current generated in the broadcasting device 301 further flows into the seventh harmonic filter circuit 70.

  As in the case of FIG. 19, this is because% Zs (7) is inductive, whereas% Zc2 (7) becomes capacitive, so that the transformer 171 and the system wire 11, inductor 72, and capacitor This is because a weak resonance is generated with respect to 71.

  Therefore, when the reactor ratio is made smaller than 2.04%, current other than the seventh harmonic current generated in the broadcasting device 301 flows in the inductor 72 and the capacitor 71, so that% Zc2 (7) is stored in the capacity. It is not preferable to make it sex.

  On the other hand, by making the reactor ratio larger than 2.04%, current other than the seventh harmonic current generated in the broadcasting device 301 without short-circuiting the% impedance of the seventh harmonic filter circuit 70. Can be prevented from further flowing into the seventh harmonic filter circuit 70.

  That the reactor ratio is larger than 2.04% means that the combined% impedance of the inductor 72 and the capacitor 71 is inductive at the seventh harmonic. This is synonymous with the fact that the magnitude of the% impedance of the inductor 72 is larger than the magnitude of the% impedance of the capacitor 71 in the seventh harmonic.

  In other words, the reactance of the inductor 72 is larger than the reactance of the capacitor 71 at the frequency of the seventh harmonic. This is because the magnitude of% impedance can be regarded as reactance as described above.

  Although not shown in FIG. 23, for example, when a commercially available 6% series reactor is used as an inductor, Rc2 (7) is 14.2%. For example, when a commercially available 13% series reactor is used as an inductor, Rc2 (7) is 5.6%.

  Therefore, even if any of the 6% series reactor and the 13% series reactor is used as the inductor, it is much lower than the target absorption rate T7. For this reason, the SCSR circuit including the phase advance capacitor 501 and the 6% series reactor 502 or the 13% series reactor as shown in FIG. 10 cannot sufficiently absorb the seventh harmonic current.

  Further, it is considered that the absorption rate when the SCSR circuit 164 is used can be improved to about 40% by optimizing the% impedance of the transformer, for example.

  Here, when the reactor ratio is set to 3.02%, for example, as shown in FIG. 23, Rc2 (7) becomes 40%. Therefore, it is preferable to set the reactor ratio to less than 3.02%.

  Further, when the reactor ratio is set to 2.70%, for example, as shown in FIG. 23, Rc2 (7) becomes 50%. As a result, the seventh harmonic current can be absorbed with an absorption rate higher than 40%, which is the absorption rate of the optimized SCSR circuit 164.

  Referring to FIG. 3 again, when one air conditioner 41 and one broadcasting transmitter 61 are operated, for example, and the other one is stopped, the seventh harmonic outflow current is determined when two units are simultaneously operated. This is 546 mA, which is half of 1092 mA.

  Since the outflow regulation value is 263 mA, the magnitude of the current to be absorbed in this case is 283 mA which is the difference between 546 mA and 263 mA. Therefore, the target absorption rate is 51.8%, which is a ratio of 283 mA to 546 mA.

  Again referring to FIG. 23, for example, when the reactor ratio is set to 2.32%, Rc2 (7) becomes 70% as shown in FIG. Thereby, for example, when each of the air conditioner 41 and the broadcasting transmitter 61 is operated and each of the other ones is stopped, the seventh harmonic wave is absorbed at a target absorption rate of 51.8% or more. Current can be absorbed.

  Moreover, when the air conditioner 41 and the two broadcast transmitters 61 operate simultaneously, the target absorption rate is 75.9%. On the other hand, for example, when the reactor ratio is set to 2.21%, Rc2 (7) becomes 80% as shown in FIG. Thereby, in the case where two air conditioners 41 and two broadcast transmitters 61 are simultaneously operated, the seventh harmonic current can be absorbed with an absorption rate of 75.9% or more which is a target absorption rate.

  More specifically, as described above, σ (7), which is an absorptance for the seventh harmonic current, is σ (7) =% Zs (7) / (% Zs (7) +% Zc2 (7) ). Solving this equation for% Zc2 (7) yields% Zc2 (7) = (1 / σ (7) −1) ×% Zs (7).

  Also, as for% Zs (7), j34.40 is obtained from FIG. If σ (7) is 75.9%, which is the target absorption rate,% Zc2 (7) is (1 / 0.7559-1) × j34.40, that is, j10.92. In other words, the product of j34.40 which is the% impedance in the direction toward the transformer 171 viewed from the power feeding path 10 and the value obtained by subtracting 1 from the reciprocal of the target absorption rate of 75.9% is j10.92. is there. Then,% Zc2 (7) is made smaller than j10.92.

  For example, calculating% Zc2 (7) when the reactor ratio is 2.20% and 2.25%, the% Zc2 (7) becomes j8.36 and j10.98, respectively.

  Referring to FIG. 23 again, for example, when the reactor ratio is 2.20%, the absorption rate is 80.5%, and when the reactor ratio is 2.25%, the absorption rate is 75.8%. .

  Therefore, by setting the reactor ratio to 2.249% or less, an absorption rate of 75.9% or more, which is a target absorption rate, can be achieved. Thereby, about the 7th harmonic, the electric power feeding system 401 for broadcasting can be made to comply with a harmonic suppression guideline.

[% Impedance% Zc3 (n) of 11th harmonic filter circuit]
FIG. 24 is a diagram showing an example of an approximately equivalent circuit when designing the eleventh harmonic filter circuit according to the embodiment of the present invention.

  Referring to FIG. 24, as described above, for example, when designing the eleventh harmonic filter circuit 110, the fifth harmonic filter circuit 50, the seventh harmonic filter circuit 70, and the delay circuit. It approximates that there is no phase circuit 20.

  Therefore, the equivalent circuit 553 represented approximately is configured by the eleventh harmonic filter circuit 110 including the inductor 112 and the capacitor 111, the transformer 171, and the system wire 11 from the substation to the power reception unit 151. .

  The calculation of the impedance in the equivalent circuit 553 is performed based on the% impedance hereinafter.

  The% impedance in the direction from the node A toward the harmonic absorption circuit 101 is% Zc3 (n) which is the% impedance of the eleventh harmonic filter circuit 110. % Zc3 (n) is represented by the sum of jn (X3), which is the% impedance of the inductor 112, and -j (XC3) / n, which is the% impedance of the capacitor 111.

  Here, n represents the order of the harmonic current. X3 represents the magnitude of% impedance with respect to the fundamental wave of the inductor 112. Since the magnitude of% impedance is proportional to the magnitude of impedance, X3 can be regarded as the reactance of the inductor 112.

  XC3 represents the magnitude of% impedance with respect to the fundamental wave of the capacitor 111. Since the magnitude of% impedance and the magnitude of impedance are in the same proportional relationship as described above, XC3 can be regarded as the reactance of the capacitor 111.

  In this case, the reactor ratio is the ratio of X3 to XC3, that is, X3 / XC3.

  Since the% impedance of transformer 171 and system electric wire 11 included in equivalent circuit 553 is the same as that shown in FIG. 14, detailed description will not be repeated. Therefore, the% impedance in the direction from the node A toward the transformer 171 is the same as% Zs (n) shown in FIG.

  The% impedance of the inductor 112 and the capacitor 111 is expressed as follows when the% impedance reference capacitance is converted to, for example, 150 KVA.

[% Impedance of capacitor 111]
FIG. 25 is a diagram showing an example of values for each harmonic of% impedance in the equivalent circuit 553 according to the embodiment of the present invention.

  Referring to FIG. 25, the capacitance of capacitor 111 is determined based on the absorption amount of the harmonic current. Specifically, the effective value of the current passing through the capacitor 111 is obtained by calculating the square root of the sum of the squares of each order of harmonic current passing through the capacitor 111. The harmonic current of each order passing through the capacitor 111 is calculated based on, for example, FIG.

  The capacity of the capacitor 111 is set to 15 KVA, for example, in consideration of the calculated effective value and the amount of heat generated.

  The amount of% impedance of the capacitor 111 having a capacitance of 15 KVA is a value obtained by dividing 100% multiplied by 150 KVA by 15 KVA, that is, 1000.00%, when converted to a 150 KVA% impedance reference capacitance.

  1000.00% in this case corresponds to XC3 shown in FIG. Therefore, the% impedance of the capacitor 111 with respect to the fundamental wave is −j1000.00%.

  The% impedance of the capacitor 111 in the case of the fundamental wave to the 19th harmonic is a value obtained by dividing the harmonic order with respect to −j1000.00%. For example, the% impedance of the capacitor 111 with respect to the 11th harmonic is -j90.91% as shown in FIG.

[Calculation of% impedance of inductor 112 based on reactor ratio]
The% impedance of the inductor 112 with respect to the fundamental wave is determined by the reactor ratio. The reactor ratio in this case is specifically a value obtained by dividing the reactance at the fundamental frequency of the inductor 112 by the reactance at the fundamental frequency of the capacitor 111.

  As described above, since the magnitude of the% impedance can be regarded as reactance, the reactor ratio is obtained by changing the magnitude of the% impedance at the fundamental frequency of the inductor 112 to the percentage of the% impedance at the fundamental frequency of the capacitor 111. It is also the value divided by the size. In other words, the magnitude of the% impedance with respect to the fundamental wave of the inductor 112 is a value obtained by multiplying the magnitude of the% impedance with respect to the fundamental wave of the capacitor 111 by the reactor ratio.

  Specifically, the magnitude of the% impedance with respect to the fundamental wave of the inductor 112 is 12.00% obtained by multiplying 1000.00%, which is the magnitude of the% impedance with respect to the fundamental wave of the capacitor 111, by 1.2%, for example. Become.

  In this case, 12.00% corresponds to X3 shown in FIG. Therefore, the% impedance of the inductor 112 with respect to the fundamental wave is j12.00%.

  The% impedance of the inductor 112 in the case of the fundamental wave to the 19th harmonic is a value obtained by multiplying j12.00% by the harmonic order. For example, the% impedance of the inductor 112 with respect to the 11th harmonic is j132.00% as shown in FIG.

[% Impedance% Zc3 (n) of 11th harmonic filter circuit]
FIG. 26 is a diagram illustrating an example of a change in% impedance of the eleventh harmonic filter circuit with respect to the harmonic order in the equivalent circuit 553 according to the embodiment of the present invention.

  Referring to FIG. 26,% Zc3 (n) which is the% impedance of the eleventh harmonic filter circuit 110 is represented by the sum of the% impedance of capacitor 111 and the% impedance of inductor 112 in each order. Here, n represents the order of the harmonic current.

  % Zc3 (n) is smaller than zero when the harmonic order n is from 1 to 9. In this case,% Zc3 (n) has a capacitive property. % Zc3 (n) is greater than zero when the harmonic order n is 11 or more. In this case,% Zc3 (n) is inductive.

  As can be seen from the fact that% Zc3 (5) shown in FIG. 25 is −j140.0, the eleventh harmonic filter circuit 110 is capacitive with respect to the fifth harmonic. Therefore, it is assumed that the fifth harmonic current due to resonance flows into the eleventh harmonic filter circuit 110.

  In the fifth harmonic filter circuit 50 shown in FIG. 17, j4.3 which is% Zc1 (5) is sufficiently smaller than −j140.0 which is% Zc3 (5). The fifth harmonic current flowing into the harmonic filter circuit 110 is considered to be negligibly small.

  Therefore, it is considered that the influence of the eleventh harmonic filter circuit 110 on the absorption rate of the fifth harmonic current absorbed in the fifth harmonic filter circuit 50 is small.

  As can be seen from the fact that% Zc3 (7) shown in FIG. 25 is −j58.9, the eleventh harmonic filter circuit 110 is capacitive with respect to the seventh harmonic. Therefore, it is assumed that the seventh harmonic current due to resonance flows into the eleventh harmonic filter circuit 110.

  In the seventh harmonic filter circuit 70 shown in FIG. 21, j8.4, which is% Zc2 (7), is sufficiently smaller than −j58.9, which is% Zc3 (7). It is considered that the seventh harmonic current flowing into the harmonic filter circuit 110 is small enough to be ignored.

  Therefore, it is considered that the influence of the eleventh harmonic filter circuit 110 on the absorption rate of the seventh harmonic current absorbed in the seventh harmonic filter circuit 70 is small.

[Design Guidelines for Circuit Constants of 11th Harmonic Filter Circuit]
As described above, the absorptance in the eleventh harmonic filter circuit 110 is represented by Zs / (Zs + Zc11). Here, Zs represents the impedance in the direction from the node A toward the transformer 171. Zc11 represents the impedance of the eleventh harmonic filter circuit 110.

  Since% Zs (n) and% Zc3 (n) can be calculated in the same manner as the impedance, the absorption factor in the eleventh harmonic filter circuit 110 for the nth harmonic current is% Zs (n) / (% Zs (n) +% Zc3 (n)).

  Specifically, 57.0% is obtained from% Zs (11) / (% Zs (11) +% Zc3 (11)) as the absorption factor for the 11th harmonic current.

  FIG. 27 is a diagram showing a change in the absorption rate of the 11th harmonic current with respect to the reactor ratio in the equivalent circuit 553 according to the embodiment of the present invention.

  Referring to FIG. 27, Rc3 (11) indicating the change in absorption rate is, for example, the absorption rate for the 11th harmonic current when the reactor ratio is changed from 0.5% to 3.0%. % Zs (11) / (% Zs (11) +% Zc3 (11)). T11 indicates the target absorption rate of 49.5%.

  Further, for example, the outflow rate for the eleventh harmonic current is represented by ihs (11) / ih (11) in the equivalent circuit 553 shown in FIG. ihs (11) / ih (11) is (ih (11) -ihc (11)) / ih (11), that is, 1- (ihc (11) / ih (11)). Here, (ihc (11) / ih (11)) represents the absorption rate for the 11th harmonic current.

  Ec3 (11) indicating the change in the outflow rate is, for example, the outflow rate for the 11th harmonic current when the reactor ratio is changed from 0.5% to 3.0%, that is, from 100% to Rc3 (11). Is the value obtained by subtracting.

  Rc3 (11) is 100% when the reactor ratio is 0.83%. In this case, Ec3 (11) is 0%. This means that the inductor 112 and the capacitor 111 are in a resonance state when the reactor ratio is 0.83%.

  That is, since the% impedance of the inductor 112 and the% impedance of the capacitor 111 just cancel each other,% Zc3 (11) becomes zero, that is, a short circuit state.

  For this reason, all the 11th harmonic current generated in the broadcasting device 301 flows into the 11th harmonic filter circuit 110, so that the 11th harmonic current does not flow out to the system side.

  However, since there is a high possibility that a short-circuit current flows unexpectedly in the eleventh harmonic filter circuit 110, considering the protection of the inductor 112 and the capacitor 111, the reactor ratio is set to 0.83% at which resonance occurs. That is not preferable.

  For example, when the reactor ratio is smaller than 0.83%, Rc3 (11) exceeds 100%. Ec3 (11) is less than 0%. This means that a current other than the 11th harmonic current generated in the broadcasting device 301 further flows into the 11th harmonic filter circuit 110.

  As in the case of FIG. 19, this is because% Zs (11) is inductive, whereas% Zc3 (11) is capacitive, so that the transformer 171 and the system wire 11, inductor 112, and capacitor This is because a weak resonance occurs between the magnetic field 111 and the substrate 111.

  Therefore, when the reactor ratio is made smaller than 0.83%, current other than the 11th harmonic current generated in the broadcasting device 301 flows in the inductor 112 and the capacitor 111, so% Zc3 (11) is stored in the capacity. It is not preferable to make it sex.

  On the other hand, by making the reactor ratio larger than 0.83%, current other than the 11th harmonic current generated in the broadcasting device 301 without short-circuiting the% impedance of the 11th harmonic filter circuit 110. Can be prevented from further flowing into the eleventh harmonic filter circuit 110.

  That the reactor ratio is greater than 0.83% means that the combined impedance of inductor 112 and capacitor 111 is inductive at the 11th harmonic. This is synonymous with the fact that the% impedance magnitude of the inductor 112 is larger than the% impedance magnitude of the capacitor 111 in the eleventh harmonic.

  In other words, the reactance of the inductor 112 is greater than the reactance of the capacitor 111 at the eleventh harmonic frequency. This is because the magnitude of% impedance can be regarded as reactance as described above.

  Although not shown in FIG. 27, for example, when a commercially available 6% series reactor is used as an inductor, Rc3 (11) is 8.7%. For example, when a commercially available 13% series reactor is used as an inductor, Rc3 (11) is 3.9%.

  Therefore, even if any of the 6% series reactor and the 13% series reactor is used as the inductor, it is much lower than the target absorption rate T11. Therefore, the SCSR circuit including the phase advance capacitor 501 and the 6% series reactor 502 or the 13% series reactor as shown in FIG. 10 cannot sufficiently absorb the 11th harmonic current.

  Here, when the reactor ratio is set to 1.97%, for example, as shown in FIG. 27, Rc3 (11) becomes 30%. Therefore, by setting the reactor ratio to less than 1.97%, the eleventh harmonic with a higher absorptance than that in the case of using either the 6% series reactor or the 13% series reactor as the inductor. Current can be absorbed.

  Further, it is considered that the absorption rate when the SCSR circuit 164 is used can be improved to about 40% by optimizing the% impedance of the transformer, for example.

  Here, when the reactor ratio is set to 1.56%, for example, as shown in FIG. 27, Rc3 (11) becomes 40%. Therefore, it is preferable to set the reactor ratio to less than 1.56%.

  Further, when the reactor ratio is set to 1.32%, for example, as shown in FIG. 27, Rc3 (11) becomes 50%. As a result, the 11th harmonic current can be absorbed with an absorption rate higher than 40%, which is the absorption rate of the optimized SCSR circuit 164.

  Referring to FIG. 3 again, when two air conditioners 41 and two broadcast transmitters 61 are operated simultaneously, the target absorption rate is 49.5%.

  As described above, σ (11), which is the absorption factor for the 11th harmonic current, is expressed by σ (11) =% Zs (11) / (% Zs (11) +% Zc3 (11)). . Solving this equation for% Zc3 (11) yields% Zc3 (11) = (1 / σ (11) −1) ×% Zs (11).

  As for% Zs (11), j54.00 is obtained from FIG. When σ (11) is 49.5%, which is the target absorption rate,% Zc3 (11) becomes (1 / 0.495-1) × j54.00, that is, j55.09. In other words, the product of j54.00 which is the% impedance in the direction toward the transformer 171 viewed from the power feeding path 10 and the value obtained by subtracting 1 from the reciprocal of 49.5% which is the target absorption rate is j55.09. is there. Then,% Zc3 (11) is made smaller than j55.09.

  For example, calculating% Zc3 (11) when the reactor ratio is 1.30% and 1.35%,% Zc3 (11) becomes j52.09 and j57.59, respectively.

  Referring to FIG. 27 again, for example, when the reactor ratio is 1.30%, the absorption rate is 50.9%, and when the reactor ratio is 1.35%, the absorption rate is 48.4%. .

  Therefore, by setting the reactor ratio to 1.33% or less, an absorption rate of 49.5% or more, which is the target absorption rate, can be achieved. Thereby, about the 11th harmonic, the electric power feeding system 401 for broadcasting can be made to comply with a harmonic suppression guideline.

  For example, when the reactor ratio is set to 0.95% and 1.04%, as shown in FIG. 27, Rc3 (11) becomes 80% and 70%, respectively.

[Measures for 13th harmonic current and 17th harmonic current]
Referring to FIG. 3 again, as shown in the necessity determination of countermeasures corresponding to the 13th and 17th orders, it is necessary to take measures against outflow of harmonic currents for the 13th harmonic current and the 17th harmonic current. .

  However, the magnitudes of the thirteenth harmonic current and the seventeenth harmonic current are smaller than the magnitudes of the fifth harmonic current, the seventh harmonic current, and the eleventh harmonic current. For this reason, the fifth harmonic filter circuit 50, the seventh harmonic filter circuit 70, and the eleventh harmonic filter circuit 110 described above are used for the thirteenth harmonic current and the seventeenth harmonic current. The harmonics can be absorbed to such an extent that the excess current value becomes zero or less.

  Therefore, even if the harmonic absorption circuit 101 in the embodiment of the present invention does not include a filter circuit designed to efficiently absorb the 13th harmonic current and the 17th harmonic current, The power supply system 401 can be made to comply with harmonic suppression guidelines.

[Harmonic absorption circuit with simple circuit configuration]
As described above, the harmonic absorption circuit 101 has a configuration in which the target harmonic current is the fifth harmonic current, the seventh harmonic current, and the eleventh harmonic current. However, the present invention is not limited to this. is not. The harmonic absorption circuit may be configured such that the target harmonic current is the fifth harmonic current and the seventh harmonic current as follows.

  FIG. 28 is a single-line connection diagram of another example of the harmonic absorption circuit according to the embodiment of the present invention.

  Referring to FIG. 28, the harmonic absorption circuit 101M is a harmonic absorption circuit that does not use the eleventh harmonic current as a target harmonic current, as compared with the harmonic absorption circuit 101. The contents other than those described below are the same as those of the harmonic absorption circuit 101.

  The harmonic absorption circuit 101M does not include the eleventh harmonic filter circuit 110 as compared with the harmonic absorption circuit 101.

  That is, the harmonic absorption circuit 101M has a simple configuration as compared with the harmonic absorption circuit 101.

  For example, referring again to FIG. 3, when the air conditioner 41 and the broadcasting transmitter 61 are operated, for example, one each, and the other one is stopped, the eleventh harmonic outflow current is two at the same time. This is 167 mA, which is half of 333 mA during operation.

  Since the outflow regulation value is 168 mA, the eleventh harmonic outflow current is within the outflow regulation value. Therefore, for example, when each of the air conditioner 41 and the broadcasting transmitter 61 is operated and each of the other ones is stopped, the eleventh harmonic filter having the eleventh harmonic current as the target harmonic current. Even when the circuit 110 is not provided, the broadcasting power supply system 401 can be compliant with the harmonic suppression guidelines.

  That is, the fifth harmonic filter circuit 50, the seventh harmonic filter circuit 70, and the eleventh harmonic filter circuit 110 according to the magnitude of the harmonic current of each order generated in the broadcasting device 301. It is possible to appropriately select a filter circuit to be used from among them and to perform an appropriate design for each filter circuit.

  Incidentally, the UPS 162 and the active filter 163 are expensive and have a problem of a large installation space. Further, the UPS 162 has a problem that harmonic current flows out to the system side in the bypass mode.

  On the other hand, the SCSR circuit 164 is inexpensive and space-saving, but has a problem that the harmonic current flowing out to the system side cannot be made equal to or less than the outflow regulation value defined in the harmonic suppression guideline because of its low absorption rate. .

  In contrast, in the harmonic absorption circuit according to the embodiment of the present invention, inductors 52R, 52S, 52T, 72R, 72S, 72T, 112R, 112S, and 112T correspond to the R phase, the S phase, and the T phase, respectively. And having a first end electrically connected to the power supply path 10 and a second end. The capacitors 51A, 51B, 51C, 71A, 71B, 71C, 111A, 111B, 111C are provided corresponding to the inductors 52R, 52S, 52T, 72R, 72S, 72T, 112R, 112S, 112T, respectively, and the inductors 52R, 52S. , 52T, 72R, 72S, 72T, 112R, 112S, 112T, respectively, and a first end electrically connected to a second end, and a second end. Then, at the frequency of the fundamental wave of the AC voltage, the inductors 52R, 52S, 52T, 72R, 72S, 72T, 112R, 112S, and the reactance of the capacitors 51A, 51B, 51C, 71A, 71B, 71C, 111A, 111B, 111C The reactor ratio, which is the reactance ratio of 112T, is other than 6% and 13%, respectively.

  With such a configuration, an optimum reactor ratio can be selected from reactor ratios other than 6% and 13% without using standard inductors having reactor ratios of 6% and 13%.

  By using the inductor having the selected reactor ratio, the harmonic current generated in the broadcasting transmitter 61 and the like flows out via the power feeding path 10 by a simple configuration of a series circuit of an inductor and a capacitor. It can be suppressed appropriately.

  In the harmonic absorption circuit according to the embodiment of the present invention, the reactor ratio is the ratio of the target harmonic current flowing into the harmonic absorption circuit 101 to the target harmonic current generated in the broadcast transmitter 61. Is a value at which the absorptance is 50% or more. In this case, the frequency of the target harmonic current that is the target of the harmonic absorption circuit 101 is at least one of a frequency that is five times and a frequency that is seven times the frequency of the AC voltage.

  With such a configuration, a high absorption rate can be achieved as compared with the case of using a standard inductor.

  Preferably, the reactor ratio in the harmonic absorption circuit 101 is an absorptance that is a ratio of a target harmonic current flowing into the harmonic absorption circuit 101 to a target harmonic current generated in the broadcast transmitter 61. The value is 70% or more. In this case, the frequency of the target harmonic current that is the target of the harmonic absorption circuit 101 is at least one of a frequency that is five times and a frequency that is seven times the frequency of the AC voltage.

  With such a configuration, a higher absorption rate can be achieved as compared with the case of using a standard inductor.

  More preferably, the reactor ratio in the harmonic absorption circuit 101 is an absorptance that is a ratio of a target harmonic current flowing into the harmonic absorption circuit 101 to a target harmonic current generated in the broadcast transmitter 61. Is a value that becomes 80% or more. In this case, the frequency of the target harmonic current that is the target of the harmonic absorption circuit 101 is at least one of a frequency that is five times and a frequency that is seven times the frequency of the AC voltage.

  With such a configuration, an extremely high absorption rate can be achieved as compared with the case of using a standard inductor.

  In the harmonic absorption circuit according to the embodiment of the present invention, the reactor ratio is the ratio of the target harmonic current flowing into the harmonic absorption circuit 101 to the target harmonic current generated in the broadcast transmitter 61. Is a value at which the absorptance is 30% or more. In this case, the frequency of the target harmonic current that is the target of the harmonic absorption circuit 101 is at least one of a frequency that is 11 times and a frequency that is 13 times the frequency of the AC voltage.

  With such a configuration, a high absorption rate can be achieved as compared with the case of using a standard inductor.

  Preferably, the reactor ratio in the harmonic absorption circuit 101 is an absorptance that is a ratio of a target harmonic current flowing into the harmonic absorption circuit 101 to a target harmonic current generated in the broadcast transmitter 61. The value is 40% or more. In this case, the frequency of the target harmonic current that is the target of the harmonic absorption circuit 101 is at least one of a frequency that is 11 times and a frequency that is 13 times the frequency of the AC voltage.

  With such a configuration, a higher absorption rate can be achieved as compared with the case of using a standard inductor.

  More preferably, the reactor ratio in the harmonic absorption circuit 101 is an absorptance that is a ratio of a target harmonic current flowing into the harmonic absorption circuit 101 to a target harmonic current generated in the broadcast transmitter 61. Is a value that is 50% or more. In this case, the frequency of the target harmonic current that is the target of the harmonic absorption circuit 101 is at least one of a frequency that is 11 times and a frequency that is 13 times the frequency of the AC voltage.

  With such a configuration, an extremely high absorption rate can be achieved as compared with the case of using a standard inductor.

  In the harmonic absorption circuit according to the embodiment of the present invention, the reactances of the inductors 52, 72, and 112 are larger than the reactances of the capacitors 51, 71, and 111, respectively, at the target harmonic current frequency.

  With this configuration, the series circuit of the inductor and the capacitor can be made inductive, so that excess current having a magnitude equal to or higher than the harmonic current generated in the broadcasting transmitter or the like flows into the series circuit. Can be prevented.

  Moreover, since it can prevent that an inductor and a capacitor form a resonance circuit, it can prevent that a short circuit current flows into the said series circuit.

  Therefore, it is possible to prevent the occurrence of fire due to heat generation due to excessive current or short-circuit current flowing through the series circuit of the inductor and capacitor, and damage to the inductor or capacitor.

  In the harmonic absorption circuit according to the embodiment of the present invention, one or a plurality of inductors and capacitors are provided corresponding to the frequency of the target harmonic current.

  Thus, by providing a series circuit of an inductor and a capacitor for each frequency of the target harmonic current, the degree of freedom related to the design of the circuit can be increased.

  In addition, each series circuit can be optimally designed according to the magnitude of the harmonic current of each frequency generated in the broadcast transmitter 61 or the like.

  Further, in the harmonic absorption circuit according to the embodiment of the present invention,% Zc1 (n),% Zc2 (n) and% Zc which are% impedances of circuits of respective orders composed of inductors and capacitors viewed from the power supply path 10 % Zc3 (n) is smaller than the impedance determined based on% Zs (n) which is the impedance of the AC voltage in the direction to the power supply source viewed from the power supply path 10 and a predetermined absorption rate.

  With such a configuration, an upper limit value can be set for the impedance value of the series circuit for increasing the absorption rate above a predetermined value.

  Further, in the harmonic absorption circuit according to the embodiment of the present invention,% Zc1 (n),% Zc2 (n) and% Zc which are% impedances of circuits of respective orders composed of inductors and capacitors viewed from the power supply path 10 % Zc3 (n) is smaller than the product of% Zs (n), which is the impedance of the AC voltage in the direction to the power supply as seen from the power supply path 10, and a value obtained by subtracting 1 from the reciprocal of the predetermined absorption rate.

  With such a configuration, an appropriate upper limit value can be set for the impedance value of the series circuit for increasing the absorption rate above a predetermined value.

  In the harmonic absorption circuit according to the embodiment of the present invention, the slow-phase inductors 22R, 22S, and 22T are provided corresponding to the R-phase, S-phase, and T-phase, respectively, and are fed in parallel with the inductor and the capacitor. It is electrically connected to the path 10.

  With such a configuration, even when a large-capacity capacitor is used to absorb a large amount of harmonic current, it is possible to prevent the power factor from being lowered by the capacitor.

  Thereby, since the increase in the apparent current resulting from the decrease in the power factor can be prevented, the capital investment for enhancing the power feeding path can be suppressed. Moreover, the power rate can be discounted by optimizing the power factor.

  In the harmonic absorption circuit according to the embodiment of the present invention, the switch units 53, 73, 113 are the harmonics of the target generated in the broadcast transmitter 61 that flows into the inductors 52, 72, 112 from the power supply path 10, respectively. When the wave current exceeds a predetermined threshold value, the connection between the power supply path 10 and the inductor is disconnected.

  In this way, the configuration in which the connection between the power supply path 10 and the inductor is disconnected according to the magnitude of the harmonic current is larger through the inductor or the capacitor than the configuration in which the connection is disconnected according to the temperature in the inductor or the capacitor, for example. Heat generation due to current flow can be suppressed early.

  Thereby, it is possible to prevent the occurrence of fire due to heat generation and the deterioration of the inductor or the capacitor.

  Moreover, in the harmonic absorption circuit according to the embodiment of the present invention, the power of the radio wave transmitted by the broadcast transmitter 61 is 5 kilowatts or more.

  With such a configuration, it is possible to prevent outflow of harmonic current without using a UPS in a broadcasting transmitter that transmits radio waves with high power.

  Since inductors and capacitors are less expensive than UPS, the cost of equipment or maintenance can be reduced.

  Further, since the inductor and the capacitor are passive elements, it is possible to prevent the harmonic current from flowing out regardless of the operation state of the UPS.

  In the high-voltage power receiving facility according to the embodiment of the present invention, power receiving unit 151 receives R-phase, S-phase, and T-phase AC voltages. The power transmission unit 181 outputs an AC voltage corresponding to the AC voltage to the broadcasting transmitter 61 via the power feeding path 10. The harmonic absorption circuit 101 is connected to the power supply path 10. The harmonic absorption circuit 101 includes inductors 52R, 52S, 52T, 72R, 72S, 72T, 112R, 112S, 112T and capacitors 51A, 51B, 51C, 71A, 71B, 71C, 111A, 111B, 111C. Inductors 52R, 52S, 52T, 72R, 72S, 72T, 112R, 112S, and 112T are provided corresponding to the R phase, the S phase, and the T phase, respectively, and are connected to the feeding path 10 and electrically connected to the first end. And a second end. The capacitors 51A, 51B, 51C, 71A, 71B, 71C, 111A, 111B, 111C are provided corresponding to the inductors 52R, 52S, 52T, 72R, 72S, 72T, 112R, 112S, 112T, respectively, and the inductors 52R, 52S. , 52T, 72R, 72S, 72T, 112R, 112S, 112T, respectively, and a first end electrically connected to a second end, and a second end. Then, at the frequency of the fundamental wave of the AC voltage, the inductors 52R, 52S, 52T, 72R, 72S, 72T, 112R, 112S, and the reactance of the capacitors 51A, 51B, 51C, 71A, 71B, 71C, 111A, 111B, 111C The reactor ratio, which is the reactance ratio of 112T, is other than 6% and 13%, respectively.

  With such a configuration, an optimum reactor ratio can be selected from reactor ratios other than 6% and 13% without using standard inductors having reactor ratios of 6% and 13%.

  By using the inductor having the selected reactor ratio, the harmonic current generated in the broadcasting transmitter 61 and the like flows out via the power feeding path 10 by a simple configuration of a series circuit of an inductor and a capacitor. It can be suppressed appropriately.

  Moreover, even when a device having a high-voltage power receiving facility is subject to application of the harmonic suppression guideline by performing high-voltage power reception, the device can be made to comply with the harmonic suppression guideline.

  Although the harmonic absorption circuit according to the embodiment of the present invention is configured to include three series circuits of an inductor and a capacitor connected to a three-phase AC voltage feeding path, the present invention is limited to this. is not. The harmonic absorption circuit 101 may be configured to be connected to a power supply path for a single-phase or multiple-phase AC voltage other than three phases and include a series circuit of an inductor and a capacitor for each phase.

  Moreover, although the broadcast power supply system according to the embodiment of the present invention is configured to be supplied with an AC voltage having a frequency of 50 Hertz, the present invention is not limited to this. Even if the broadcasting power supply system 401 is configured to supply an AC voltage having a frequency other than 50 Hertz, for example, an AC voltage having a frequency of 60 Hertz, the capacitor, the inductor, and the slow-phase inductor in the harmonic absorption circuit 101. Each effect as described above can be obtained by changing the constant.

  The broadcast power supply system according to the embodiment of the present invention classifies the conversion circuit type of the air conditioner 41 into “6-pulse conversion device” in the “three-phase bridge” shown in FIG. Although the harmonic generation current according to the order at is calculated, the present invention is not limited to this. For example, by classifying the conversion circuit type of the air conditioner into “reactor present (DC side)” in “three-phase bridge (capacitor smoothing)” shown in FIG. May be. In this case, the harmonic generation current by order generated in the broadcasting apparatus 101 increases. Even in such a case, by appropriately setting the constants of the capacitor, the inductor, and the slow-phase inductor in the harmonic absorption circuit 101, the harmonic current flowing out from the broadcasting power supply system to the system side is within the outflow regulation value. Can be suppressed.

  The above embodiment should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 10 Power supply path 11 System | strain electric wire 22 Inductor for slow phases 24, 25 Switch 41 Air conditioner 51,71,111 Capacitor 52,72,112 Inductor 54,55,74,75,114,115 Switch 61 Broadcast transmitter 101 Harmonic wave Absorption circuit 151 Power receiving unit 171 Transformer 181 Power transmitting unit 201 High voltage power receiving equipment 301 Broadcasting device 401 Power supply system for broadcasting

Claims (11)

A harmonic absorption circuit connected to a single-phase or multiple-phase AC voltage feeding path to a broadcast transmitter,
One or more inductors provided corresponding to the phases and having a first end electrically connected to the power supply path and a second end;
A capacitor provided corresponding to the inductor and having a first end electrically connected to a second end of the inductor and a capacitor having a second end;
A harmonic absorption circuit in which a reactor ratio, which is a ratio of reactance of the inductor to reactance of the capacitor at a frequency of the AC voltage, is other than 6% and 13%. The reactor ratio is a value at which an absorptance that is a ratio of the target harmonic current flowing into the harmonic absorption circuit with respect to the target harmonic current generated in the broadcasting transmitter is 50% or more,
2. The harmonic absorption circuit according to claim 1, wherein a frequency of the target harmonic current is at least one of a frequency five times and a frequency seven times the frequency of the AC voltage. The reactor ratio is a value at which an absorptance that is a ratio of the target harmonic current flowing into the harmonic absorption circuit with respect to the target harmonic current generated in the broadcasting transmitter is 30% or more,
3. The harmonic absorption circuit according to claim 1, wherein a frequency of the target harmonic current is at least one of a frequency that is 11 times and a frequency that is 13 times the frequency of the AC voltage.   4. The harmonic absorption circuit according to claim 2, wherein a reactance of the inductor is larger than a reactance of the capacitor at a frequency of the target harmonic current.   5. The harmonic absorption circuit according to claim 2, wherein one or a plurality of the inductors and the capacitors are provided corresponding to the frequency of the target harmonic current. 6.   The impedance of the circuit configured by the inductor and the capacitor viewed from the power supply path is determined based on the impedance of the AC voltage to the power supply source viewed from the power supply path and the predetermined absorption rate. The harmonic absorption circuit according to any one of claims 2 to 5, wherein the harmonic absorption circuit is smaller than a certain impedance.   The impedance of the circuit constituted by the inductor and the capacitor viewed from the power supply path is obtained by subtracting 1 from the impedance of the AC voltage to the power supply source viewed from the power supply path and the reciprocal of the predetermined absorption rate. The harmonic absorption circuit according to claim 6, wherein the harmonic absorption circuit is smaller than a product of the value and the value. The harmonic absorption circuit further includes:
8. The device according to claim 1, further comprising one or a plurality of slow-phase inductors provided corresponding to the phases and electrically connected to the power supply path in parallel with the inductor and the capacitor. Harmonic absorption circuit described in 1. The harmonic absorption circuit further includes:
A switch for switching whether to connect the power supply path and the inductor;
The switch disconnects the connection between the power supply path and the inductor when a target harmonic current generated in the broadcasting transmitter flowing into the inductor from the power supply path exceeds a predetermined threshold value. The harmonic absorption circuit according to any one of claims 1 to 8.   The harmonic absorption circuit according to any one of claims 1 to 9, wherein electric power of a radio wave transmitted by the broadcasting transmitter is 5 kilowatts or more. A power receiving unit for receiving a single-phase or multiple-phase AC voltage;
A power transmission unit that outputs an AC voltage corresponding to the AC voltage to a broadcasting transmitter via a power feeding path;
A high-voltage power receiving facility comprising a harmonic absorption circuit connected to the power feeding path,
The harmonic absorption circuit is
One or more inductors provided corresponding to the phases and having a first end electrically connected to the power supply path and a second end;
A capacitor provided corresponding to the inductor and having a first end electrically connected to a second end of the inductor and a second end;
A high-voltage power receiving facility in which a reactor ratio, which is a ratio of reactance of the inductor to reactance of the capacitor at a frequency of the AC voltage, is other than 6% and 13%.

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