JP2000184798A - Vscf converter and vscf power supply unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a VSCF power supply unit whose frequency is constant and which is capable of obtaining AC voltage with low harmonic percentage content. SOLUTION: A generator 2 is driven by an engine 1 for power generation. A VSCF converter 3 includes a rectifying circuit converting AC voltage outputted from the generator 2 into DC voltage, an inverter which outputs AC voltage consisting of cyclic pulses of fixed patterns through the rectifying circuit, and a filter which removes a harmonic component included in AC voltage obtained from the inverter and outputs it. A generator controller 4 controls the output voltage obtained from the filter so as to be constant by controlling the magnetic field voltage of the generator 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a VSCF converter and a VSCF power supply suitable for an aircraft power supply and the like.

[0002]

2. Description of the Related Art VSCF (Variable Speed Constant Fr)
Power supplies are expected to become the mainstream of aircraft power supplies in the future because of their high reliability and high quality output voltage.

The VSCF power supply receives an AC voltage from a generator directly driven by an aircraft engine or the like, and converts the AC voltage with frequency fluctuation into a VSCF.
This is a power supply device of a method of converting into an AC voltage of a predetermined frequency by an AC / AC conversion device called a converter. The VSCF converter used in the power supply device includes a cycloconverter type and a DC link type. Here, the cycloconverter type VS
The CF converter is a type that directly converts an AC voltage from a generator into an AC voltage having a predetermined frequency without converting the AC voltage into a DC voltage. On the other hand, a DC link type VSCF converter converts an AC voltage from a generator into a DC voltage and converts the DC voltage into an AC voltage having a predetermined frequency.

As shown in FIG. 5, this DC link type VSCF converter includes a rectifier circuit 11 and an inverter 1.
2 and an output filter 13. Here, the rectifier circuit 12 is a circuit that rectifies an AC voltage from the generator and outputs a DC voltage. And inverter 1
2, the DC voltage is pulsed by a switching pulse, and an AC voltage having a pulse waveform including a fundamental wave of a predetermined frequency and its harmonics is output. This inverter 12
Stands for PWM (Pulse Width Modulation)
In this case, the pulse width of a switching pulse used for switching the DC voltage is controlled by control means (not shown). The output filter 13 removes harmonics from the AC voltage output from the inverter 12,
An AC voltage having a predetermined frequency is output.

In the above configuration, the output AC voltage obtained from the output filter 13 is supplied to a load (not shown). However, the output AC voltage may fluctuate due to the load fluctuation. Therefore, in this VSCF converter,
The control unit (not shown) automatically adjusts the pulse width of the switching pulse so that the output AC voltage is always constant irrespective of the load fluctuation.

[0006]

The above-described conventional DC link type VSCF converter performs stabilization control of the output AC voltage by adjusting the pulse width of the switching pulse in the inverter 12. The pulse width of the AC voltage supplied to the output filter 13 fluctuates, and as a result, harmonics included in the AC voltage change moment by moment. The conventional VSCF converter requires the output filter 13 having a large-scale circuit configuration in order to remove such temporally unstable harmonics.

The present invention has been made in view of the above circumstances, and does not require an output filter having a large-scale circuit configuration, is stable in frequency, and has a high quality with a low harmonic content. An object is to provide a VSCF converter and a VSCF power supply device that can generate an AC voltage.

[0008]

SUMMARY OF THE INVENTION The present invention provides an AC / DC converter for converting an AC voltage into a DC voltage, and a DC / DC converter for generating a periodic AC voltage comprising a fixed pattern of pulse trains from the DC voltage. AC conversion means;
A VSCF converter comprising: a filter that removes a harmonic component contained in an AC voltage obtained from an AC conversion unit and outputs the resultant signal. Also, the present invention provides a power generator driven by an engine to generate power, an AC / DC converter for converting an AC voltage output from the generator into a DC voltage, and a periodic pattern comprising a pulse train having a fixed pattern. DC / AC conversion means for generating a high AC voltage from the DC voltage, a filter for removing harmonic components contained in the AC voltage obtained from the DC / AC conversion means and outputting the same, and a field of the generator. An output voltage stabilization control means for controlling the output voltage obtained from the filter to be constant by controlling the output voltage stabilization control means is provided.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a VSCF power supply device 10 according to one embodiment of the present invention. As shown in FIG. 1, the VS according to the present embodiment
The CF power supply device 10 includes a generator 2, a VSCF converter 3, and a generator controller 4. Here, the generator 2 outputs an AC voltage by being directly driven by the engine 1 such as an aircraft. VSCF converter 3
Is means for converting an AC voltage obtained from the generator 2 into an AC voltage having a constant frequency and outputting the AC voltage. The generator controller 4 receives the output AC voltage of the VSCF converter 3 as a feedback voltage Vf, and controls a field voltage or a field voltage supplied to the generator 2 so that the output AC voltage maintains a constant target voltage value. It is a means to do.

FIG. 2 is a block diagram showing the configuration of the VSCF converter 3 in the present embodiment. As shown in FIG. 2, the VSCF converter 3 includes a rectifier circuit 31 for converting an AC voltage from the generator 2 to a DC voltage, an inverter 32 for converting the DC voltage to an AC voltage, and a harmonic from the AC voltage. And an output filter 33 that removes the noise.

Here, the inverter 32 is not of the PWM type used in the above-mentioned conventional VSCF converter, but has a fixed period corresponding to the target frequency of the AC voltage finally output from the VSCF converter 3. The switching of the DC voltage from the rectifier circuit 31 is performed according to the pattern.

FIG. 3 shows an inverter 32 according to this embodiment.
1 shows an example of the configuration. The inverter 32 includes a clock generation circuit 321, an address counter 322,
It has a ROM 323 and a switching circuit 324.

Here, the clock generation circuit 321 supplies a clock of a constant frequency to the address counter 322. The address counter 322 counts this clock, and uses the count value as a read address in the ROM 32.
Supply 3

The ROM 323 stores the counter 32 from address 0.
"0" or "1" is stored in a series of addresses up to the address corresponding to the maximum count value of 2. And RO
The M 323 receives the supply of the address from the address counter 322, and switches the fixed pattern of “0” / “1” stored in these series of addresses to the switching circuit 32.
4 repeatedly. The repetition period of the fixed pattern (that is, the time length of the fixed pattern) is the reciprocal of the target frequency of the AC voltage finally output from the VSCF converter 3. The content of the fixed pattern is determined so that the harmonic content of the AC voltage finally obtained from the VSCF converter 3 is minimized.

The switching circuit 324 includes a ROM 323
The DC voltage from the rectifier circuit 31 is supplied to the output filter 33 only during the period when “1” is supplied from. The switching circuit 324 includes an address counter 322
During the period in which the most significant bit of the address output from is "1", the function of inverting the polarity of the voltage supplied to the output filter 33 is provided. The above is the VSCF according to the present embodiment.
3 is a diagram illustrating details of a configuration of a power supply device.

Next, the operation of this embodiment will be described with reference to the waveform diagram shown in FIG. As already explained, the generator 1 is driven directly by the engine 1. Therefore, the frequency of the AC voltage supplied from the generator 1 to the VSCF converter 3 is not stable, as illustrated in FIG. 4A. In the VSCF converter 3, the AC voltage from the generator 2 is converted into a DC voltage by the rectifier circuit 31. This DC voltage is applied to the inverter 3
2 is switched according to the fixed pattern, and is output to the output filter 13 as an AC voltage having a periodic waveform corresponding to the fixed pattern. FIG. 4B illustrates an example of the waveform of the AC voltage output from the inverter 12. The waveform of the AC voltage for one cycle is represented by R
It is determined by the fixed pattern in OM323. This AC voltage is supplied to the output filter 13 to remove harmonics. As a result, an AC voltage composed of a sine wave from which harmonics have been removed as illustrated in FIG.
Obtained from 3. In FIG. 4C, in order to clarify the phase relationship between the AC voltage waveform and the output voltage waveform of the inverter 32, the latter waveform is indicated by a broken line.

The output AC voltage obtained from the output filter 13 is supplied to a load. Also in the present embodiment, the output voltage stabilization control is performed so that the output AC voltage does not fluctuate due to the load fluctuation. However, this stabilization control is performed by adjusting the field voltage and the like for the generator 2, and the switching control of the DC voltage in the inverter 32 is always performed according to a fixed pattern. Therefore, by using a fixed pattern corresponding to a waveform having a low harmonic content, a high-quality AC voltage having a constant frequency and a low voltage and having a low harmonic content is output to the output filter 33. Can be obtained from

[0018]

As described above, the V according to the present invention is
According to the SCF converter, an AC / DC converter for converting an AC voltage to a DC voltage, and an AC voltage having a periodic pulse waveform and a constant pulse waveform for each cycle are generated from the AC / DC converter. DC / AC conversion means,
A filter that removes and outputs harmonic components included in the AC voltage obtained from the DC / AC conversion means, so that the frequency is constant without using a large-scale filter; An AC voltage with a small content can be obtained. Further, according to the VSCF power supply device of the present invention, a generator driven by the engine to generate power, an AC / DC converter for converting an AC voltage output from the generator into a DC voltage, DC / AC converting means for generating, from the AC / DC converting means, an AC voltage having a pulse waveform and a constant pulse waveform for each cycle;
A filter that removes and outputs harmonic components included in the AC voltage obtained from the DC / AC conversion means, and an output that controls the output voltage obtained from the filter by controlling the field of the generator. Since the voltage stabilization control means is provided, an AC voltage having a constant frequency and voltage and a low harmonic content can be obtained without using a large-scale filter.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a VSCF power supply device according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a VSCF converter according to the first embodiment.

FIG. 3 is a block diagram showing a configuration example of an inverter in the VSCF converter.

FIG. 4 is a waveform chart showing the operation of the embodiment.

FIG. 5 is a block diagram showing a configuration of a conventional VSCF converter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Generator, 3 ... VSCF converter, 4 ... Generator controller, 31 ... Rectifier circuit, 32 ...
... fixed pattern output type inverter, 33 ... output filter.

Continued on the front page F term (reference) 5H590 AA17 CA07 CC01 CD01 CD03 CD05 DD64 EA13 EB02 EB07 EB21 FA06 FA08 GA03 HA02 JA19 JB01 JB02 JB14 JB15

Claims (3)

[Claims] An AC / DC converter for converting an AC voltage into a DC voltage; a DC / AC converter for generating a periodic AC voltage composed of a pulse train having a fixed pattern from the DC voltage; A VSCF converter comprising: a filter that removes and outputs a harmonic component included in the AC voltage obtained from the AC converter. 2. A generator, which is driven by an engine to generate power, an AC / DC converter for converting an AC voltage output from the generator into a DC voltage, and a periodic pattern comprising a fixed pattern of pulse trains. DC / AC conversion means for generating an AC voltage from the DC voltage; a filter for removing harmonic components contained in the AC voltage obtained from the DC / AC conversion means for output; and controlling a field of the generator. Output voltage stabilization control means for controlling the output voltage obtained from the filter to be constant. 3. The DC / AC conversion means includes: a memory storing a fixed pattern; a reading means for repeatedly reading the fixed pattern from the memory in synchronization with a clock of a fixed frequency; and an output from the AC / DC conversion means. 3. The VSCF power supply device according to claim 2, further comprising: a switching circuit that intermittently outputs the applied DC voltage according to a fixed pattern read from the memory.