JPH08111973A - How to operate the harmonic compensator - Google Patents

Abstract

(57) [Summary] [Purpose] To make it possible to evaluate the harmonic compensator easily and in a short period of time while operating, and to ensure safe operation. [Structure] System V voltage, current Is to system voltage distortion, correction amount such that the harmonic compensation content rate is within the suppression value, compensation values are corrected through converters 18 and 19 and comparators 14B and 14C. The current is controlled by the circuit 17, the output is introduced into the current control circuit 13 to control the current, and the voltage distortion, the harmonic compensation amount, etc. are determined by the signal synthesis circuit 21,
It can be monitored by the display 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a harmonic compensating apparatus for compensating a harmonic current flowing out from a load by connecting a harmonic compensating apparatus to a plurality of loads connected to a power system, and in particular to a method of operating the same. Regarding

[0002]

2. Description of the Related Art Generally, since it is known that a power converter can be used as a harmonic compensator, a harmonic compensator is connected to a plurality of loads connected to an electric power system line and a harmonic compensator is connected to the load. I try to deal with wave disturbances. By the way, there is a demand to know to what extent such a harmonic compensator actually performs harmonic compensation. Therefore, conventionally, for example, when operating the harmonic compensation device,
Measure harmonic current components with and without,
There is one that makes an evaluation by comparing the two.

[0003]

However, the above method has a problem that the evaluation method is complicated and takes time. It has also been pointed out that overcompensation does not affect the system very well. Therefore, an object of the present invention is to ensure the safety of the system by making it possible to easily and quickly evaluate the degree of compensation while performing the compensation by the harmonic compensator.

[0004]

In order to solve such a problem, according to the present invention, a harmonic compensating device is connected to a plurality of loads connected to a power system so that a harmonic current flowing out from the loads is detected. In compensating, the current and voltage of the power system are taken in, and at least the voltage distortion and harmonic content ratio are controlled to be within the suppression values, and the voltage distortion and harmonic content ratio can be displayed. .

[0005]

[Function] The harmonics are compensated by taking in the current and voltage of the system to be compensated, and the degree of compensation can be monitored to ensure the safety of the system.

[0006]

FIG. 1 is a block diagram showing an embodiment of the present invention,
FIG. 2 is a schematic configuration diagram showing the entire system to which the present invention is applied. First, FIG. 2 will be described. In FIG.
1 is a harmonic compensator (AF), 2 is a load, and the harmonic compensator 1 has a current I _L from the load 2 and a system current I.
_S and system voltage V _S are input. In addition, 3 and 5 show a current transformer (CT) and 4 shows a transformer (PT).

As shown in FIG. 1, the harmonic compensator 1 includes a voltage control circuit (AVR) 11, a load current detection circuit 12, a current control circuit (ACR) 13, and comparators (CP) 14A, 1
4B, 14C, carrier generator 15, pulse generator (P
G) 16, compensation value correction circuit (IF) 17, current converter (S / C) 18, voltage converter (S / C) 19, setter (SET) 20, signal synthesis circuit 21, display 22 and the like Composed.

That is, the DC component V _D of the output of the harmonic compensator 1 is input to the AVR 11, and control is performed here according to the DC component V _D. The output is added to the output from the load current detection circuit 12, and the ACR 13
Is input to and a current adjustment calculation is performed. The output of the ACR 13 and the output of the carrier generator 15 are introduced into the comparator 14A, and a pulse signal corresponding to the comparison result is generated from the pulse generator 16 and supplied to the switching device of the harmonic compensator 1 (not shown). As a result, the harmonic current flowing out to the electric power system due to the operation of the load 2 shown in FIG. 2 is compensated.

Although the above-mentioned configuration is similar to the conventional one, in the present invention, a portion indicated by a one-dot chain line is further added to these control circuits, and the following operation is performed here. The current converter 18 supplies the system current I _S and also the voltage converter 1
Reference numeral 9 converts the system voltage V _S into controllable DC level signals I _SC and V _SC , respectively. In the comparators 14B and 14C, I
_{The SC} and V _SC are compared with the suppression target value set in the setter 20, and a signal corresponding to the comparison result is output to output the ACR.
Input correction of 13 is performed.

As a result, the harmonic compensator can be efficiently operated within a range not exceeding the suppression value. The suppression target value is selected, for example, within 5% in the case of voltage distortion, and within 5% in the total content rate for outflow harmonic current. In the signal synthesizing circuit 21, the harmonic compensation rate, the voltage distortion of the system or the outflowing harmonic current amount, etc. are obtained from the system current I _S , the system voltage V _{S, the} signals I _SC , V _SC, etc. and displayed on the monitor 22.

[0011]

According to the present invention, not only is it possible to perform harmonic compensation control that matches the power system, but it is also possible to display the degree of compensation, and thus avoid overcompensation. The advantages such as

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing an entire system to which the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Harmonic compensation device (AF), 2 ... Load, 3, 5 ... Current transformer (CT), 4 ... Transformer (PT), 11 ... Voltage control circuit (AVR), 12 ... Load current detection circuit, 13 ... Current control circuit (ACR), 14A, 14B, 14C ... Comparator (C
P), 15 ... Carrier generator, 16 ... Pulse generator (P
G), 17 ... Compensation value correction circuit, 18 ... Current converter (S /
C), 19 ... Voltage converter (S / C), 20 ... Setting device (S
ET), 21 ... Signal combining circuit, 22 ... Indicator.

Claims (1)

[Claims] 1. When a harmonic compensator is connected to a plurality of loads connected to a power system to compensate a harmonic current flowing out from the load, at least voltage distortion is obtained by taking in the current and voltage of the power system. A method of operating a harmonic compensating device, characterized in that the harmonic content rate is controlled to be within a suppression value and the voltage distortion and the harmonic content rate can be displayed.