JPH0445613A - Synchronous signal circuit - Google Patents

Abstract

PURPOSE:To obtain a control signal synchronously with a power supply voltage in power feeding by outputting the control signal in response to one of the output signal of 1st and 2nd BPFs connected to an AC power supply, and having frequency around 50 or 60Hz. CONSTITUTION:Suppose that the frequency of an AC power supply 1 is 60Hz, the output of a 2nd absolute value circuit 11 via a 2nd BPF is larger than an input to a 1st absolute value circuit 10 via a 1st BPF 8. A comparator 12 discriminates the quantity and allows a changeover switch 13 to select an output signal from the BPF 9. Thus, a sinusoidal wave signal W2 whose frequency is 60Hz is outputted to a waveform shaping circuit 3, from which a rectangular control signal W3 is obtained. When the frequency of the AC power supply 1 is 50Hz, the output of the 1st absolute value circuit 10 is larger conversely and an output signal from the BPF 8 is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a circuit that is connected to an AC power source that generates a commercial frequency voltage of 50 Hz or 60 Hz and outputs a synchronization signal according to the frequency.

[Conventional technology]

Figure 3 is a block diagram showing a synchronous signal circuit used, for example, in Japan National Railways limited express type AC trains. In Figure 0, (1) is an AC power supply that generates a 50Hz commercial frequency voltage, and (2) is a 50Hz (3) is a waveform shaping circuit that shapes and converts the output waveform from the bandpass filter (2) into a rectangular wave.

When controlling the speed of a vehicle electric motor using control rectifiers such as thyristors, a control signal synchronized with the power supply voltage is required to control the ignition of these control rectifiers.

However, normally, the power supply voltage contains harmonic components based on the switching operation of the control rectifying element (see voltage waveform W1 in Figure 3). Therefore, this harmonic component is removed by a bandpass filter (■) to create a waveform. A sine waveform as shown in W2 is used, and based on this waveform, a waveform shaping circuit L3+ is used to obtain a voltage of a rectangular wave W3 that is accurately synchronized with the fundamental wave component of the power supply voltage.

[Problem to be solved by the invention]

Since the conventional synchronization signal circuit is configured as described above, it is fine when the AC power supply has only a single frequency such as 50Hz, but it is not suitable when both the 50H7 power supply and the 60Hz power supply are present. , cannot be applied when power is supplied at 60Hz. In theory, if this circuit is configured with a 60Hz constant, it will no longer be applicable to 50Hz power supply.

This invention was made to solve the above-mentioned problems, and it is possible to obtain a control signal synchronized with the power supply voltage being applied even at a frequency of 50 Hz or 60) 1 z. This is what I did.

[Means and effects for solving the problem] The synchronizing signal circuit according to the present invention is connected to an AC power source and has a frequency of 50 Hz or more.
A band-pass filter that passes voltages with frequency components below 0 Hz, a phase comparator that detects the phase difference between the output signal from this band-pass filter and a comparison signal, and outputs a signal corresponding to this phase difference, and this phase comparator. a voltage controlled oscillator that outputs a sine wave signal with a frequency proportional to the output signal from the loop filter to the phase comparator as the comparison signal; It is equipped with a waveform shaping circuit that shapes the ratio i signal into a rectangular wave and outputs it as a control signal.

In this case, if the frequency of the AC power supply voltage changes from, for example, 50 Hz to 60 Hz, a phase shift will occur between the output signal of the bandpass filter and the comparison signal from the voltage controlled oscillator, and the phase shift based on this will occur. The output of the comparator is input to a voltage controlled oscillator via a loop filter, and the frequency of the comparison signal that is its output is increased. This change stops when the comparison signal synchronizes with the output signal from the bandpass filter, and the signal is reshaped and output as a control signal.

In addition, the second aspect of the present invention provides a second band-pass filter connected to an AC power supply, and first and second band-pass filters that rectify the output signals of the first and second band-pass filters, respectively.
absolute value circuit, a selector that compares the magnitude of the output signals from both absolute value circuits and selects and outputs the output signal of the bandpass filter with the larger frequency, and converts the output signal from this selector into a rectangular wave. It is equipped with a waveform shaping circuit that shapes the signal and outputs it as a control signal.

In this case, if the frequency of the AC power supply voltage is, for example, 50Hz, the first
Since the output of the first band-pass filter is a dog, the selector selects the output signal of the first band-pass filter and sends it to the waveform shaping circuit, and a rectangular wave signal synchronized with the 50 Hz AC power supply voltage is output as a control signal. be done.

〔Example〕

FIG. 1 is a block diagram showing a synchronizing signal circuit according to an embodiment of the present invention. In FIG. 8, (1) and (3) are the same as the conventional one. (2) is 50Hz or more 60H
A bandpass filter (5) that passes voltages with frequency components below z detects the phase difference between the output signal from the bandpass filter (2) and a comparison signal S from the voltage controlled oscillator (6), which will be described later. A phase comparator that outputs a signal according to the phase difference, (7) a loop filter that removes harmonic components of the output signal from the phase comparator (5), and a voltage controlled oscillator (6) that outputs an output from the loop filter. A sine wave signal with a frequency proportional to the signal is output as a comparison signal S.

Next, the operation will be explained. By passing the voltage of the AC power supply (1) through the bandpass filter 4, frequency components below 50 Hz and above 60 Hz are significantly suppressed, and the voltage waveform is improved to that shown by WIA in the figure. This output signal is then processed by a so-called phase-locked loop (PLL) composed of (5) and (5). That is, now, after the voltage of the AC power supply (1) has been in a steady state at 50Hz, 60H
z, it is determined that the output signal from the phase comparator (manufactured by Bandpass Filter Co., Ltd.) is ahead in phase with respect to the comparison signal S, and its output is increased.This output signal is passed through the loop. Voltage controlled oscillator (6) via filter ■
and the voltage controlled oscillator (6) increases the frequency of the output signal S in response to an increase in this input. It becomes a steady state at a value of 60 Hz). The comparison signal S obtained in this way has a frequency of 60Hz.
This is a sine wave signal whose output is taken out as a rectangular wave control signal indicated by W3 in the figure through a waveform shaping circuit (3).

The voltage frequency of AC power supply (1) is from 60)1z to 5°H
z, the same operation occurs in the opposite direction to the above, and after a predetermined response time, a control signal synchronized with the 50Hz AC power supply (1) is output from the waveform shaping circuit (3). become.

FIG. 2 is a block diagram showing a synchronization signal circuit according to another embodiment. In the figure, (8) and (9) are the first and second band-pass filters, respectively, and each
Hz and 60Hz are set as the center frequencies.

(10) and (1) are first and second absolute value circuits, respectively, which rectify the output signals from the first and second bandpass filters (81+91).
(12) is the first and second absolute value circuit (10) (1
)), a comparator (13) is a changeover switch operated by the output of the comparator (12), and a selector (14) is operated by the comparator (12) and changeover switch (13). It consists of

In this case, for example, the voltage frequency of the AC power supply (1) is 60)
1z, the output of the second absolute value circuit (1) which has passed through the second band pass filter (9) is the input of the first absolute value circuit (1o) which has passed through the first band pass filter (8). Become bigger. The comparator (12) determines this magnitude relationship and operates the contact of the changeover switch (13) to the illustrated position, that is, the position for selecting the output signal from the second bandpass filter (9). As a result, the 60 Hz sine wave signal W2 is output to the waveform shaping circuit (3), and a rectangular wave control signal W3 is obtained.

When the AC power supply (1) is generating a voltage of 50Hz, the output of the first absolute value circuit (10) becomes large, contrary to the above, and the output signal from the first bandpass filter 6 becomes selected.

As mentioned above, the voltage frequency of the AC power supply (1) is 5゜Hz.
or 60 Hz, it is automatically determined within the synchronization signal circuit and a control signal synchronized with the power supply voltage at that time is obtained.

It should be noted that each of the above embodiments has been described for the case where it is applied to the ignition control of a control rectifier mounted on a train.
The present invention is not limited to this, and can similarly be applied to various types of electrical equipment that use commercial frequencies in different areas, and produce similar effects.

〔Effect of the invention〕

Since this invention is configured as described above, whether the frequency of the AC power supply is 50Hz or 60Hz, it is automatically determined internally, and a signal synchronized with the power supply voltage at the time can be obtained. .

[Brief explanation of drawings]

Section 1 is a block diagram showing a synchronizing signal circuit according to one embodiment of the present invention, FIG. 2 is a block diagram showing another embodiment, and Section 3 [E] is a block diagram showing a conventional synchronizing signal circuit. . In the figure, (1) is an AC power supply, (3) is a waveform shaping circuit, (41B (91 is a band pass filter, (5) is a phase comparator, (6) is a voltage controlled oscillator, (7) is a loop filter, (10) (1)) is an absolute value circuit, and (14) is a selector. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent: Patent Attorney Masuo Oiwa 1st)! 1 1Q, /ノ I Otsu 1 Susakuguchi pay! Figure 3

Claims (2)

[Claims] (1) In a device that is connected to an AC power source that generates a commercial frequency voltage of 50 Hz or 60 Hz and outputs a control signal synchronized with the generated AC power voltage, A bandpass filter that passes component voltages, a phase comparator that detects the phase difference between the output signal from this bandpass filter and a comparison signal, and outputs a signal according to this phase difference, and an output signal from this phase comparator. a loop filter that removes harmonic components of the loop filter, a voltage controlled oscillator that outputs a sine wave signal with a frequency proportional to the output signal from the loop filter to the phase comparator as the comparison signal, and shapes the comparison signal into a rectangular wave. A synchronous signal circuit comprising a waveform shaping circuit that outputs the above-mentioned control signal as the control signal. (2) In a device that is connected to an AC power source that generates a commercial frequency voltage of 50 Hz or 60 Hz and outputs a control signal synchronized with the generated AC power voltage, a first band-pass filter having a center frequency of 60 Hz, a second band-pass filter having a center frequency of 60 Hz, first and second absolute value circuits rectifying the output signals of the first and second band-pass filters, respectively; A selector that compares the magnitude of the output signal from the absolute value circuit and selects and outputs the output signal of the bandpass filter with the higher frequency, and the output signal from this selector is shaped into a rectangular wave and outputted as the above-mentioned control signal. A synchronous signal circuit characterized by comprising a waveform shaping circuit that outputs as follows.