JP5020010B2 - Generator power factor control device - Google Patents

Description

The present invention relates to power factor control in generator control.

The generator control mainly includes constant voltage control, constant frequency control, constant power control, constant power factor control, generator load sharing control, and power factor balance control. In general, constant power control and constant power factor control are performed during connection with commercial power supply, and in proportion to the rated capacity of each generator while connected to commercial power supply and when multiple generators are connected. Performs load sharing control and power factor balance control. Among the above controls, the generator power factor is controlled by changing the generator voltage.
JP-A-6-14466

In the generator power factor control, there is a method (reactive power control) in which a power factor is converted into reactive power and a control signal for the generator output voltage is generated in proportion to the deviation of the reactive power. (Deviation is the difference between the target value (set value) and the current value (measured value).) However, this control method has the following problems. If the deviation of the reactive power conversion value is the same regardless of the position of the power factor angle, an equal amount of generator output voltage control signal will be output. Even if it is an amount, the amount of change in power factor cannot be made equal.

Table 1 shows reactive power value changes and reactive power deviations due to power factor changes. As shown in Table 1, when the active power is 5 kW, the reactive power deviation A when the power factor is changed from 0.5 to 0.6 and the power factor is changed from 0.8 to 0.9. Compare the reactive power deviation B at the time.

Ａ＝無効電力値 Ｂ＝有効電力値
上記式により無効電力偏差Ａは、１．９９、無効電力偏差Ｂは１．３３となり、力率を同じ０．１変化させることに於いて、無効電力での変化では０．６６の差が生じてしまう。よって等量の発電機出力電圧の制御信号を出しても力率の角度によって力率の変化量に差が生じる問題が起こる。

A = Reactive power value B = Active power value According to the above equation, the reactive power deviation A is 1.99 and the reactive power deviation B is 1.33. A difference of 0.66 will occur in the change of. Therefore, even if an equal amount of generator output voltage control signal is output, there arises a problem that a difference in the amount of power factor change occurs depending on the angle of the power factor.

According to the invention of claim 1, in the power factor control of the generator, a power factor measuring device that outputs a power factor measurement value of the generator output, and a power factor setting device that outputs a power factor setting value of the generator A power unit that outputs a power factor deviation signal calculated from the power factor measurement value and the power factor setting value; a pulse pattern is generated based on the power factor deviation signal; and a voltage setting pulse is generated by the pulse pattern. A pulse pattern generator that outputs a signal, and a voltage regulator that outputs a control signal of the generator output voltage based on the voltage setting pulse signal, wherein the pulse pattern has a power factor deviation regardless of the power factor angle. On the other hand, a control signal of the generator output voltage that makes the power factor change amount of the generator constant is outputted .

In the power factor control of the generator, a pulse pattern generated in advance is generated based on the power factor deviation signal obtained by subtracting the power factor set value from the power factor measurement value of the generator output, and the generator output is based on the pulse pattern. A voltage control signal is output, and the power factor change amount of the generator is made constant.

It is not a control method that converts the power factor into reactive power and outputs a pulse signal of the generator output voltage proportional to the deviation, but outputs a pulse with a predetermined pulse width pattern as a control signal of the generator output voltage depending on the power factor deviation. Device.

Since the generator output voltage control signal according to the present invention outputs a pulse width determined by the pulse width pattern, the amount of change in the power factor per short time can be made substantially constant.

Takes the current value (measured value) and target value (set value), calculates the deviation from that value, and outputs the pulse width derived from the set pulse width pattern graph to the outside as a control signal for the generator output voltage , Perform stable power factor control.

FIG. 1 is a block diagram of a power factor control apparatus for implementing the method of the present invention. In FIG. 1, the power factor measurement value 1 ′ and the power factor setting value 2 ′ are taken into the calculator 3, and the power factor deviation amount 3 ′ between the power factor measurement value 1 ′ and the power factor setting value 2 ′ is determined in advance according to Table 2. Ask. (Here, the set values are described when the delay is 0.9 and the delay is 0.8.)

Table 2 shows a table of deviation amounts used in the power factor control of the present invention.

表２により求めた力率偏差量３’を偏差量／パルスパターン発生器４に取り込み、その力率偏差量３’からあらかじめ決められたパルス出力周期間に出すパルス出力幅と上げ、下げ出力方向を決める。偏差量／パルスパターン発生器４の内容を表３及び図２に記す。

The power factor deviation amount 3 ′ obtained from Table 2 is taken into the deviation amount / pulse pattern generator 4, and the pulse output width to be output from the power factor deviation amount 3 ′ during a predetermined pulse output cycle is increased and lowered, and the output direction is lowered. Decide. The contents of the deviation amount / pulse pattern generator 4 are shown in Table 3 and FIG.

Table 3 shows a table for replacing the deviation used in the power factor control of the present invention with an output pattern.

表３では、（１）矢印で示される偏差量より小さい時は、パルス出力幅はこの値で固定とする。（２）矢印で示される偏差量より大きい時は、パルス出力幅はこの値で固定とする。偏差量／パルスパターン発生器４で決められたパルスパターンを、すなわちパルス出力周期間、パルス出力幅、出力方向が決められた電圧設定パルス信号４’を電圧調整器５から発電機出力電圧制御信号５’として出力する。偏差量が“−”の時は電圧を下げる方向にパルス信号を出し、偏差量が“＋”の時は電圧を上げる方向にパルス信号を出力する。表３では、パルス出力周期を５秒、最大パルス幅を４秒として記す。パルス出力周期とパルス幅の関係を図３に記す。

In Table 3, (1) when the deviation amount is smaller than the arrow, the pulse output width is fixed at this value. (2) When the deviation is larger than the arrow, the pulse output width is fixed at this value. The pulse pattern determined by the deviation amount / pulse pattern generator 4, that is, the voltage setting pulse signal 4 ′ in which the pulse output period, the pulse output width, and the output direction are determined is output from the voltage regulator 5 to the generator output voltage control signal. Output as 5 '. When the deviation amount is “−”, a pulse signal is output in the direction of decreasing the voltage, and when the deviation amount is “+”, the pulse signal is output in the direction of increasing the voltage. In Table 3, the pulse output period is 5 seconds and the maximum pulse width is 4 seconds. The relationship between the pulse output period and the pulse width is shown in FIG.

This control device can also be used for voltage control, frequency control, and power control of other generator controls.

The block diagram which shows the power factor control of this invention. The figure which replaces the deviation used by power factor control of the present invention with an output pattern. Diagram of pulse output period and pulse width

Explanation of symbols

1 Power factor measuring device 1 'Power factor measurement value 2 Power factor setting device 2' Power factor setting value 3 Calculator 3 'Power factor deviation amount 4 Deviation amount / pulse pattern generator 4' Voltage setting pulse signal 5 Voltage regulator 5 '' Generator output voltage control signal

Claims (1)

In power factor control of a generator, a power factor measuring device that outputs a power factor measurement value of a generator output, a power factor setting device that outputs a power factor setting value of the generator, the power factor measurement value and the power A calculator that outputs a power factor deviation signal calculated from the rate setting value and a pulse pattern generator that generates a pulse pattern based on the power factor deviation signal and outputs a voltage setting pulse signal based on the pulse pattern. A voltage regulator that outputs a control signal of a generator output voltage based on the voltage setting pulse signal, and the pulse pattern is a power factor change amount of the generator with respect to a power factor deviation regardless of a power factor angle. A generator power factor control apparatus that outputs a control signal of a generator output voltage that keeps constant.

Images