JP2001245433A - Measuring device for high harmonic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable dispersively and concurrently injecting in phase the output current of an injection frequency of each injection unit to a host-system side without transmitting a timing-control signal to each injection-control unit from a host device. SOLUTION: The device comprises a clock-circuit unit 12 that outputs a clock information to each injection-control unit 7a to 7c calculating a clock signal by a multistage counter, a GPS receiving unit 23 that receives a clock information and a pulse signal of every one second from GPS satellite 21, and a clock-correcting unit 24 that renews the clock information of the circuit unit 12 with the received clock information of the receiving unit 23 and resets a lower figure smaller than second of the multistage counter to zero with an edge of the received pulse signal of every one second of the receiving unit 23. A phase of the output current of the injection frequency of the injection units 6a to 6c is corrected by a timing control based on the clock information of the circuit unit 12 corresponding to a load condition of each lower-end system 5a to 5c. Then the current in sync. with the identical injection frequency is dispersively injected to the host-system 1 side from the systems 5a to 5c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an injection device which simultaneously injects a current obtained by multiplying the system fundamental frequency by a non-integer number from a plurality of lower systems to a higher system, and branches from the upper system or this higher system. More specifically, the present invention relates to a harmonic measurement device for measuring a harmonic characteristic by obtaining an equivalent circuit of an injection frequency of a lower system, and more particularly to a synchronous control of current injection.

[0002]

2. Description of the Related Art The applicant of the present invention is a transmission and distribution system (power system).
In order to accurately understand the harmonic characteristics of the power system and to reduce the harmonic level satisfactorily, the power system was multiplied by a non-integer multiple of the system fundamental frequency f _s above and below the measured harmonics (harmonics of interest). A frequency current (interharmonic current) is injected, and based on the measured results of the voltage and current at the injection frequency, an equivalent circuit for the injection frequency of the power system is obtained. From this equivalent circuit, the equivalent circuit of the harmonic of interest is determined. An invention in which an interpolation operation is determined and its harmonic characteristics are measured has already been filed in Japanese Patent Application No. 8-310192. (Hereinafter, this is referred to as the first already filed application.)

In the case of this harmonic measurement, current injection frequency is current having a frequency which is integral multiple original nonexistent system fundamental frequency f _s to the system, admittance of the equivalent circuit for the injection frequency is determined accurately by measurement Therefore, the characteristics of the harmonic of interest can be accurately grasped using this result.

However, in the harmonic measurement method described in the above-mentioned first application, since the injection point and the measurement point are set to the same point, the method is applied to an actual power system in which a plurality of lower systems branch from an upper system. For example, when measuring harmonics of a higher-order system of the 20 KV class, for example, the injection point must be set to the higher-order system, and the current of the above-mentioned interharmonics must be directly injected into the higher-order system. Because of the high voltage, the voltage class (insulation class) of the injection device must be sufficiently high, and sufficient protection measures must be taken, which makes the device large, complex and expensive.

Accordingly, the applicant of the present invention has already proposed an invention of a method for measuring higher harmonics in a power system which will be described below in Japanese Patent Application No. 9-19780.
No. 8 filed. (Hereinafter, this is referred to as the second already filed application.)

[0006] The harmonic measurement method of the second filed application is described above.
Injection points to multiple buses (sub-systems) branched from
Set, connect the injection device to each injection point, and from each injection device
The harmonics of interest (frequency nx
f_s) Sandwiching the system fundamental frequency f_eFrequency of non-integer multiple of
Number f₁, F_Two(F₁<Nxf_e<F_Two) Current of order
The current is injected as a wave current, and the
Frequency f ₁, F_TwoEach interharmonic of
Find the admittance of the equivalent circuit for
Equivalent circuit for higher harmonics of interest from mitance to higher system
Is determined by interpolation calculation, and the higher harmonics of interest are determined.
This is to measure the harmonic characteristics of.

In this case, the injection points of the interharmonics are set in a plurality of branched lower systems on the low pressure side lower than the measurement point,
Since the interharmonic currents of the frequencies f ₁ and f ₂ required for the measurement are dispersedly injected from the injection points of the respective sub-systems, the voltage class of each injection device can be lowered and the current of each injection device can be reduced. Harmonic measurement can be performed using a small and simple device having a small voltage class and a small current capacity, as compared with a case where a single device can cover the capacity.

[0008]

In the case of the harmonic measurement method of the second application, even if the injection currents of the injection devices are simultaneously injected at the respective injection points in synchronization with each other, actually, each injection Depending on the condition of the lower system (injection system) to which the device is connected, that is, the load state, the phase of the current injected into the upper system is shifted for each injection device (for each lower system).

The phase shift (phase difference) is 18
When the angle reaches 0 °, the injection currents cancel each other, the amount of injection into the upper system decreases, and the effect of dispersion injection is weakened. In some cases, dispersion injection is performed from a large number of lower systems. Nevertheless, the injection is practically performed from one injection device of one of the lower systems, and a sufficient injection amount cannot be secured.

Therefore, the load state of each injection system is grasped in advance by some method, and at the time of measurement, the phase of the injection current by each injector is shifted in anticipation of a change based on the load state of each injection system, and It is conceivable that the injection currents of the injection devices at the measurement points on the system side have the same phase.

[0011] The load state of each injection system can be determined, for example, by examining the connected loads for the entire system to be measured in advance and creating a system diagram (single-line connection diagram). An equivalent circuit for the injection frequency of the system can be obtained and grasped.

Instead of conducting the above-mentioned investigation, before the measurement, each injection device is individually driven, and the current and voltage of the injection frequency flowing from each injection device to the load side of each connection system (injection system) are measured. It is also possible to determine the load state of each injection system by measuring and obtaining an equivalent circuit for the injection frequency of each injection system from this measurement result.

When the load state of each injection system is determined, the phase change in the upper system when the current of the injection frequency of each injector is injected into the upper system can be obtained by a simple equivalent circuit operation. At the time of measurement, if the phase of the output current of each injection device is shifted in the opposite direction of the obtained phase change and corrected, the output current of each injection device can be dispersedly injected at the measurement point on the upper system side in synchronization with the same phase. .

By the way, in this kind of harmonic measurement,
Since the target harmonics to be measured are 5th, 7th,..., In order to accurately synchronize the output currents of the interharmonics of each injection device so that they are in phase, their injection phases should be on the order of microseconds. Needs to be corrected with extremely high precision and made to match on the upper system side.

On the other hand, the operation timing of each injection device is usually individually controlled based on time information such as a built-in clock of a microcomputer of each injection control device. Not very expensive.

Therefore, conventionally, the phase of the output current of each injection device cannot be accurately corrected with high timing accuracy, and the current of the interharmonic of the injection frequency is increased from each injection system to the higher system side during measurement. There is a problem that distributed injection cannot be performed in synchronization with precision.

[0017] For example, a signal of some timing control is sent from a common host device to each injection control device by wire or wireless every time the measurement is started, and the phase of the output current by each injection device is shifted based on the timing of this signal. If the correction is made, it is possible to make the output current of each injection device in-phase on the upper system side, but in this case, the upper device is required, and the transmission / reception for transmitting / receiving the timing control signal is performed for each injection control device. It requires a communication cable such as a device and a telephone line, and is extremely complicated and expensive.

According to the present invention, at the time of measurement, the higher-order system outputs the output current of the inter-order harmonic of the same injection frequency from each injection device without transmitting a timing control signal from the higher-order device to each injection control device. It is an object of the present invention to simultaneously perform distributed injection so as to synchronize accurately.

[0019]

In order to solve the above-mentioned problems, in the harmonic measuring apparatus according to the present invention, a clock signal is counted by a multi-stage counter and time information of timing control is output to each injection control apparatus. Clock circuit and GP
G to receive time information of S satellite and pulse signal every second
The time information of the clock circuit is updated by the reception time information of the PS receiver and the GPS receiver, and the lower order than the second of the multi-stage counter is reset to zero by the edge of the reception pulse signal every second of the GPS receiver. And a timing correction unit based on the time information of the clock circuit unit of each injection control device, thereby controlling the phase of the output current of the injection frequency of each injection device, and the level of each lower system to which each injection device is connected. Correction is made according to the load state, and a current synchronized with the injection frequency is distributed and injected from the lower system to which the respective injection devices are connected to the upper system.

Therefore, each injection control device controls the time information of each clock circuit unit based on the time information of the GPS satellite and the pulse signal of each second so as to synchronize with the time of the time information of the GPS satellite every second. Calibrated.

According to this calibration, even if the time information of the operation timing of each injection control device is a clock circuit having a very low accuracy such as a built-in clock of a microcomputer, there is almost no error, and Synchronous matches with the following precision:

For this reason, the timing control based on the time information of each injection control device accurately corrects the phase of the interharmonic current of the same injection frequency by each injection device, and the injection frequency from each lower system to the upper system is adjusted. Can be dispersedly injected synchronously in phase with no phase shift.

Since the so-called time adjustment of each injection control device is performed using the time information of the GPS satellites, it is necessary to transmit timing control information and the like by wire or wireless from a host device common to each injection control device. In addition, it is possible to simply and inexpensively inject the current having the synchronized injection frequency into the upper system side at low cost.

In the case of the present invention, a clock circuit for counting clock signals by a multi-stage counter and outputting time information for timing control, and receiving time information for receiving standard radio waves to each injection control device. And a standard radio receiver for demodulating and outputting the received second signal, and updating the time information of the clock circuit with the received time information, and
A time correction unit that performs feedback control of the frequency of the clock signal based on an edge timing error with a count pulse signal of seconds, and performs timing control based on time information of a clock circuit unit of each injection control device to control each injection device. The phase of the output current at the injection frequency is corrected according to the load state of each lower system to which each injection device is connected, and the current synchronized with the injection frequency is transferred from each lower system to which each injection device is connected to the upper system. Is dispersedly injected.

Therefore, in this case, the time information of the clock circuit of each injection control device is calibrated so as to be synchronized with the time of the time information of the standard radio wave, and each second of the clock circuit is converted to one second of the standard radio wave. The frequency (phase) of the clock signal supplied to the clock circuit unit of each injection control device is feedback-controlled so as to coincide with

Therefore, the time information serving as the reference for the operation timing of each injection control device matches the time of the time information of the standard radio wave with high accuracy, and the same precision as in the case of using the time information of the GPS satellite according to claim 1 is used. Can be synchronized with the injection.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. (One Embodiment) First, one embodiment using time information of a GPS satellite will be described with reference to FIGS. FIG.
Is a single-line diagram of the distribution system showing the overall configuration, in which the primary side of the transformer 3 is connected to the distribution main line 2 of the upper system 1, and the secondary side is connected via the transformers 4 a, 4 b, 4 c, for example. 6
The lower systems 5a, 5b and 5c of the KV are branched.

Then, the injection points P are added to the lower systems 5a to 5c.
a, Pb and Pc are set, and these injection points Pa to Pc are set.
Are connected to injection devices 6a, 6b and 6c, each of which comprises an inverter or the like.

[0029] These injection devices 6a~6c Each injection control device 7a, 7b, is driven and controlled by 7c, and outputs the interharmonic current of the same injection frequency was non-integer multiple lineage fundamental frequency f _s.

Then, the same injection is performed by the injection devices 6a to 6c.
The output current at the input frequency is phase θ₁, Θ_Two, Θ_ThreeCurrent I
₁(θ₁), I_Two(θ_Two), I_Three(θ_Three), These output power
Style I₁(θ₁), I_Two(θ_Two), I_Three(θ_Three) Indicates that the injection point P
a, Pb, Pc to upper system 1 side₁’,
θ_Two’, Θ_Three’ Current I₁’(Θ₁’), I_Two’(Θ_Two’), I_Three’
(θ_Three′) And the rest are injected at the injection points Pa, Pb, P
c, the loads 8a, 8b, 8 of the respective systems 5a to 5c
phase θ in c₁”, Θ_Two”, Θ_ThreeCurrent I₁”(Θ₁”),
I_Two”(Θ _Two"), I_Three”(Θ_Three)).

At this time, the phases θ ₁ , θ ₂ , and θ ₃ are determined by the phase angles θ according to the load state (load amount) of each of the lower systems 5a to 5c.
₁ ′ (θ ₁ ″), θ ₂ ′ (θ ₂ ″), and θ ₃ ′ (θ ₃ ″).

Therefore, before the measurement, the injection devices 6a to 6c
Are individually driven, and the current transformers 9a, 9b, 9c,
The measurement signals of the currents 10a, 10b, and 10c and the measurement signals of the voltages of the instrumentation transformers 11a, 11b, and 11c are taken into the injection control devices 7a to 7c, and subjected to frequency analysis by DFT and FFT dental processing to determine the injection frequency. When the current and the voltage are obtained, the loads 8a to 8c are obtained, and the load states of the lower systems (injection systems) 5a to 5c can be grasped.

Each of the injection control devices 7a to 7c is formed as shown in FIG. 2 using a microcomputer or the like.

FIG. 2 shows the configuration of the injection control device 7a. A clock signal of, for example, several hundred MHz of the clock circuit unit 12 is supplied as an operation clock to various parts in the device. , The timing controller 13 controls the A / D converter 14 and the frequency analyzer 1
5. Control the operations of the operation unit 16 and the injection control unit 17.

Based on this control, the A / D converter 14 converts the measurement signals of the current transformers 9a to 9c, 10a to 10c and the transformers 11a to 11c into digital signals before measurement, and performs frequency analysis. The unit 15 converts these digital signals into D
Frequency analysis is performed by digital processing of FT or FFT to extract currents and voltages of interharmonics of the injection frequency.

Then, based on the analysis result of the frequency analysis unit 15, the calculation unit 16 calculates the injection system 5 for the interharmonic.
a to 5c calculate the admittance (or impedance) of each of the loads 8a to 8c to obtain an equivalent circuit, calculate the phase change of the output current of the same injection frequency by the injection devices 6a to 6c using the equivalent circuit, and The phase correction amount is determined as an amount that cancels out this phase change.

Further, the injection controller 17 controls the clock circuit 12
Before the measurement, for example, the injection start phase is set to the reference phase of 0 ° to drive the injectors 6a to 6c before the measurement, and the injection start phase is calculated from the reference phase at the time of measurement by the timing control of the timing control unit 13 based on the time information. Each of the injection devices 6a to 6c is driven by shifting the correction amount determined by the unit 16.

At this time, the injection phase at the time of measurement of each of the injection devices 6a to 6c is corrected by shifting the injection start phase or the injection start time by the above-mentioned correction amount.

Then, as described later, each injection control device 7
Since the time information of a to 7c is accurate, the phases of the output currents of the injection devices 6a to 6c simultaneously injected at the time of measurement are changed by the timing control based on the time information to change the load state of each of the lower systems 5a to 5c. Corrected to be accurate,
The phases θ ₁ ′, θ ₂ ′, and θ ₃ ′ of the respective output currents injected into the upper system 1 through the transformers 4 a to 4 c and 3 become equal, and the lower systems 5 a to 5 c move to the upper system 1. Currents of harmonics between orders of the injection frequency are dispersed and injected accurately and synchronously without phase shift.

Next, the clock circuit section 12 will be described. The clock circuit section 12 is similar to a clock circuit section of a so-called built-in clock of a personal computer. For example, a clock signal of several hundred MHz of the free-running oscillation output of the crystal oscillator 18 is output. It is counted by the counter unit 19.

The counter section 19 includes counters 20a, 20b, 20c, 20d, 20e,..., 20m for date, hour, minute, second, 1/10 second,.
Are connected in cascade to count clock signals and output time information whose minimum unit is microseconds or less.

Further, this time information is stored in the injection control devices 7a to 7a.
In this embodiment, a GPS satellite 21 is used in order to make the coincidence between 7c exactly.

That is, the GPS receiver unit 23 receives the time information of the GPS satellites 21 and the pulse signal every one second synchronized with the Coordinated Universal Time (UTC) via the antenna 22 of each of the injection control devices 7a to 7c. .

The reception time information of the receiver unit 23 is transmitted to the counter unit 12 via the time correction unit 24 of the clock circuit unit 12.
To the counters 20a to 20d of these date, time,
Update the minutes and seconds to the respective values of the reception time information.

The reception pulse signal of the receiver unit 23 for each second is supplied to the reset terminal r of the flip-flop 25 of the time correction unit 24 and the AND gate 26, and the counter unit 1
9 supplied from the counter 20e to the counter 20d.
The second count pulse signal is supplied to the set terminal s of the flip-flop 25.

Then, the flip-flop 25 is set at the rising edge of the one-second counting pulse signal of the counter section 19 to turn on the AND gate 26, and immediately thereafter, at the rising edge of the receiving pulse signal of the receiver section 23. Counter part 1
The counters 20e to 20m lower than the seconds of 9 are instantaneously reset to zero.

Due to this repetition, the time information of the counter unit 19 is calibrated every second, and the time information of the GPS satellite 21 coincides with the time information of the GPS satellite 21 very accurately with an error precision of microsecond or less. Timing control based on time information is performed synchronously with an accuracy of microseconds or less.

Therefore, without transmitting a timing control signal to each of the injection control devices 7a to 7c from a common host device by wire or wirelessly, each of the injection control devices 7a to 7c can be set before and during the measurement. In particular, at the time of measurement (timing), it is possible to accurately drive the phase of the output current of the interharmonic having the same injection frequency by the injection devices 6a to 6c at the time of measurement. In this way, it is possible to simultaneously dispersely inject the current of the interharmonic of the injection frequency into the upper system 1 side synchronously without phase shift.

[0049] Then, the same as the second supra Application harmonic measuring methods, etc., interharmonic attention harmonic injection frequency (frequency n × f _s) sandwiching the second frequency f _1, f ₂ (f ₁ <N
× f _s <f ₂ ), and repeat the measurement while changing the same injection frequency by the injection devices 6a to 6c to f ₁ and f ₂ in order.

At this time, a measurement point is provided in the upper system 1 and the currents and voltages of the two frequencies f ₁ and f ₂ at this measurement point are measured. As described above, the injection frequencies f ₁ and f ₂ are added to the system. Since the frequency does not originally exist, an equivalent circuit of the upper system 1 for each of the two frequencies f ₁ and f ₂ is obtained from the measurement result, and the equivalent of the higher system 1 for the target harmonic is determined from the impedance or admittance of both equivalent circuits. The circuit can be obtained by performing an interpolation operation, and the harmonic characteristics of the upper system 1 can be measured.

As shown in FIG. 1, the lower system 5a to the lower system 5a
In the case where the lower system 16 in which an injection device of the same voltage class as 5c is not installed is branched, harmonics between orders of the injection frequencies f ₁ and f ₂ dispersedly injected from the injection devices 6a to 6c to the upper system 1 side. If the current of the wave is sufficiently large, a measurement point is provided in the lower system 16 and the current of the two frequencies f ₁ and f ₂ at this measurement point is
By measuring the voltage, the equivalent circuit of the lower system 16 for each of the two frequencies f ₁ and f ₂ is obtained, and the equivalent circuit of the lower system 16 for the target harmonic is interpolated to obtain the harmonic characteristics of the lower system 16. Can also be measured. In addition,
8d in the figure indicates the load of the lower system 16.

The measuring device of the measuring point also has a clock circuit unit and a GPS receiver unit similar to the clock circuit unit 12 and the receiver unit 23 of the injection control devices 7a to 7c. , Measurement can be started with accurate timing control.

By the way, in the actual measurement, a plurality of harmonics of interest are set, and for each of the harmonics of interest, current of two frequencies f ₁ and f ₂ is injected to measure the harmonic characteristics. Will be

In this case, the drive control of each of the injection devices 6a to 6c by the injection control devices 7a to 7c before and during the measurement is actually performed, for example, as shown in FIG. 3 or FIG.

Firstly, in the case of FIG. 3, the control of the previous measurement step S ₁ to S _3, per each injection device 6 a to 6 c, obtains a phase correction amount in advance all injection frequency.

Then, at the measurement time, step S ₇
The control of measurements to S _11, the injection frequency of the injection device 6a~6c every predetermined several seconds while sequentially changing the frequency of each interharmonic, determined before measuring the phase of the respective output currents The upper system 1 synchronizes by shifting the correction amount.

On the other hand, in the case of FIG. 4, steps Q _{1 to} Q ₄ are controls before measurement, steps Q _{5 to} Q ₇ are controls during measurement, and step Q ₈ changes the injection frequency while changing the injection frequency. ₁ to Q ₇ repeatedly executes the, repeating the measuring seeking correction amount of the phase for each injection frequency.

(Other Embodiment) Next, another embodiment using the time information of the standard radio wave will be described with reference to FIG. In FIG. 5, the reference numerals with a dash (') indicate the same or corresponding ones as those in FIGS.

In this embodiment, each of the injection controllers 7a to 7c is provided with a standard radio receiver 27 for receiving and demodulating a standard radio instead of the GPS receiver 23 of the first embodiment.
Is provided, a standard radio wave is received by the receiver unit 27 via the antenna 28, and based on the transmission format of the standard radio wave,
The reception time information and the reception second signal are output intermittently.

Then, the counter unit 1 receives the reception time information.
The date, hour, minute, and second of 9 'are updated, and the flip-flop 25' set by the rising edge of the counting pulse signal every second of the counter unit 19 'is reset by the rising edge of the received signal, An error signal having the pulse width of the phase difference between the two signals is output from the amplifier 25 '.

Further, the error signal is converted to a time correction unit 24 '.
To form a feedback control signal, and the signal is used to feedback control the oscillation frequency of the crystal oscillator 18 'so that the error becomes zero.

By repeating this control, after an appropriate time, the time of the time information of the clock circuit section 12 'coincides with the time of the time information of the standard radio wave, and each of the injection control devices 7a to 7a.
7d operates based on the same time information.

Therefore, after that, for example, FIG.
By performing the above processing, the same effect as in the case of the first embodiment can be obtained.

The configurations of the clock circuit sections 12 and 12 'and the time correction sections 24 and 24' are not limited to those of the above-mentioned embodiments, and each of them is realized by software processing of a microcomputer. Of course, it is good.

The number of sub-systems to which the injection device is connected, the capacity of the injection device, and the like are arbitrary.

Also, instead of injecting currents of the same injection frequency from the injection devices 6a to 6c, a voltage is injected (applied).
However, since current distortion is larger than voltage distortion, it is practical and preferable to inject current.

[0067]

The present invention has the following effects. First, in the case of claim 1, each of the injection control devices 7a to 7
c, based on the time information of the GPS satellites 21 and the pulse signal every second, the GP
Calibration can be performed so as to be synchronized with the time of the time information of the S satellite 21.

By this calibration, even if the clock circuit section 12 of each of the injection control devices 7a to 7c is a clock circuit section having a not so high accuracy such as a built-in clock of a microcomputer, errors in the operation timings (shifts) of the clock circuit sections 12a to 7c. ), And the control of each of the injection control devices 7a to 7c is synchronized with an accuracy of microsecond or less.

Therefore, based on the control of each of the injection control devices 7a to 7c, the injection devices 6a to 6c output the currents of the interharmonics of the same injection frequency without deviation in timing before and during the measurement. The required amount of phase correction previously obtained can be accurately performed, and each of the lower systems 5a to 5a
From 5c, it is possible to dispersely inject the harmonic current between the orders of the injection frequency into the upper system 1 side in synchronism in phase with no phase shift.

Then, in order to perform so-called time adjustment of each of the injection control devices 7a to 7c using the clock information of the GPS satellite 21, information on timing control and the like is transmitted from a higher-level device common to each of the injection control devices 7a to 7c. Therefore, it is possible to measure the harmonic characteristics by simply and inexpensively injecting the current having the synchronized injection frequency into the upper system.

Further, in the case of claim 2, it is possible to calibrate the time information of the clock circuit unit 12 'of each of the injection control devices 7a to 7c so as to be synchronized with the time of the time information of the standard radio wave.
Based on the calibration of the time, the same effect as that of the first aspect can be obtained.

[Brief description of the drawings]

FIG. 1 is a system diagram of one embodiment of the present invention.

FIG. 2 is a block diagram of the injection control device of FIG.

FIG. 3 is a flowchart of an example of the operation of FIG. 1;

FIG. 4 is a flowchart of another example of the operation of FIG. 1;

FIG. 5 is a block diagram of an injection control device according to another embodiment of the present invention.

[Explanation of symbols]

 1 Upper system 5a, 5b, 5c, 16 Lower system 6a, 6b, 6c Injection device 7a, 7b, 7c Injection control device 8a, 8b, 8c, 8d Load 12, 12 'Clock circuit unit 23 GPS receiver unit 24, 24 '' Time correction unit 27 Standard power receiver unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masakazu Tsukamoto 1 Higashi-Shinmachi, Higashi-ku, Nagoya-shi Inside Chubu Electric Power Company (72) Inventor Toshihiko Shikata 47-47 Umezu Takaune-cho, Ukyo-ku, Kyoto-shi Nissin Electric Co., Ltd. (72) Inventor Ikusen Natsuta 47, Takaune-cho, Umezu, Ukyo-ku, Kyoto-shi F-term of Nissin Electric Co., Ltd. (reference) 5G066 EA03

Claims (2)

[Claims] 1. A plurality of injectors respectively connected to a plurality of lower systems branched from an upper system, and a current of the same injection frequency obtained by multiplying an output current of each of the injectors by a non-integer multiple of a system fundamental frequency. And a plurality of injection control devices for controlling and dispersing and injecting the current of the injection frequency from each of the lower systems to the upper system side, wherein the lower system is not provided with an injection device branched from the upper system or the upper system. A harmonic measurement device that measures a current and a voltage of the injection frequency in a system and obtains an equivalent circuit for the injection frequency in the upper system or a lower system to which the injection device is not connected and measures harmonic characteristics. A clock circuit for counting the clock signal by a multi-stage counter and outputting time information; and receiving time information of a GPS satellite and a pulse signal every second. The GPS receiver unit updates the time information of the clock circuit unit with the reception time information of the GPS receiver unit, and updates the time of the multi-stage counter by the edge of the received pulse signal every second of the GPS receiver unit. A time correction unit that resets the lower order to zero, and by performing timing control based on time information of the clock circuit unit of each of the injection control devices, the phase of the output current of the injection frequency of each of the injection devices, Correction is made in accordance with the load state of each of the lower systems to which the injection devices are connected, and the current synchronized with the injection frequency is dispersedly injected from each of the lower systems to which each of the injection devices is connected to the upper system. A harmonic measuring device, characterized in that: 2. A plurality of injection devices respectively connected to a plurality of lower systems branched from an upper system, and an injection current of the same injection frequency as a non-integer multiple of a system fundamental frequency of an output current of each of the injection devices. A plurality of injection controllers for controlling the current and dispersing and injecting the current of the injection frequency from each of the lower systems to the upper system, and an injection device branched from the upper system or the upper system is provided. Harmonic measurement for measuring the current and voltage of the injection frequency in a non-existing lower system and obtaining an equivalent circuit for the injection frequency of the upper system or a lower system in which the injection device is not installed and measuring harmonic characteristics. A clock circuit for counting clock signals by a multi-stage counter and outputting time information; and receiving time information and a reception second signal by receiving a standard radio wave. A standard wave receiver for demodulating and outputting, and updating the time information of the clock circuit unit with the reception time information, wherein the error of the edge timing between the reception second signal and the one-second count pulse signal of the clock circuit unit is used. And a time correction unit that performs feedback control of the frequency of the clock signal.By timing control based on time information of the clock circuit unit of each of the injection control devices, the phase of the output current of the injection frequency of each injection device is Correction is made in accordance with the load state of each of the lower systems to which each of the injectors is connected, and the current synchronized with the injection frequency is dispersedly injected from each of the lower systems to which each of the injectors is connected into the upper system. A harmonic measuring device, characterized in that: