JPH05333077A - Switching type simulated load device - Google Patents

Abstract

PURPOSE:To enable controlling a current flowing on a load to an arbitrary wave shape, reduce the danger due to heating and minimize the electric loss for saving energy. CONSTITUTION:Provided are a load circuit for converting the alternating current input from an alternating current power source for testing to direct current with a step-up converter circuit 3, smoothing this with a capacitor 4 and then converting to alternating current with an inverter circuit 5 and returning to the alternating current power source side, and a PLL circuit 11 for generating a clock synchronizing to the input signal of the step-up converter circuit 3. Also provided are an ROM 15 for forming wave shape which stores current wave shape data corresponding to a period of input current to be phase adjustable for a synchronizing signal and outputs wave shape data when address is specified by a clock, a D/A converter 16 which analog-converts this wave shape data and can control the gain of the wave shape, and a PWM modulator 17 which PWM-modulates the output signal of this converter and produces gate signals for on-off controlling the switching element in the step-up converter 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching type simulated load device capable of controlling a current flowing through a load to have an arbitrary waveform.

[0002]

2. Description of the Related Art Generally, in order to test a power supply device (CVCF or UPS) at a factory or the like, various data are taken by using a resistance whose load can be easily switched as a load and a power supply characteristic test is performed. In this case, since a resistor is used as the load, the current flowing through the load when the power source outputs a sine wave also has a sine wave.

[0003]

However, since the load actually connected to the power supply after the test is a computer or other equipment, even if the power output is a sine wave, the current flowing through the load is a clean sine wave. Does not mean Therefore, the test result of the power supply device is different from the actual waveform, which causes various problems.

Further, if a resistor is used as a load, all the electric power supplied from the power source is consumed as heat, so not only is the resistor itself at a high temperature, which is dangerous and the electric power is wasted, resulting in effective use of energy. It is not preferable from the viewpoint of

An object of the present invention is to provide a switching type simulated load device capable of controlling a current flowing through a load to an arbitrary waveform, reducing the risk of heat generation, and reducing power loss to a necessary minimum for energy saving. To provide.

[0006]

In order to achieve the above object, the present invention converts an alternating current input from a test alternating current power source into a direct current by a step-up converter circuit, smoothes this by a capacitor, and then an alternating current by an inverter circuit. A load circuit which constitutes a main circuit which is converted into a main circuit for regeneration to the side of the AC power source, clock generation means for generating a clock synchronized with the input signal of the boost converter circuit, and one cycle of the input current of the AC power source. A waveform generation ROM which outputs current waveform data corresponding to a minute portion so that the phase of the current waveform data can be adjusted with respect to a synchronizing signal, and when the address is designated by the clock generated by the clock generating means.
And a D / A converting means having a function of converting the waveform data output from the waveform creating ROM into an analog signal and outputting it as a reference signal and adjusting the gain of the waveform, and the D / A converting means. And a gate signal generation means for PWM-modulating the output signal of 1 to generate a gate signal for controlling on / off of the switching element of the boost converter.

[0007]

In the switching type simulated load device having such a configuration, the clock generating means generates a clock synchronized with the input current, and when the clock specifies the address of the waveform data generating ROM, the waveform is generated. Current waveform data corresponding to one cycle of the input current stored in the ROM for data creation so that the phase can be adjusted with respect to the synchronization signal is output. The current waveform data is converted into an analog signal by the D / A conversion means. The gain of the waveform is adjusted by the gain adjusting function and taken into the gate signal generating means.
In this gate signal generating means, the analog-converted current waveform is PWM-modulated to create a gate signal, and the switching element of the boost converter is turned on / off by this gate signal. Therefore, the input current of the boost converter of the main circuit can be controlled to have an arbitrary current waveform according to the reference signal.

Further, since the output current of the step-up converter is regenerated by the inverter circuit to the AC power source on the regeneration side, the efficiency of the device is low due to internal loss, heat generation is low, and the safety is high. You can do it.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a configuration example of a main circuit of an AC / DC common type as a switching type simulated load device according to the present invention. Here, an AC input case will be described.
The main circuit of this device is an input filter circuit 1 to which an AC power source (not shown) is connected as shown in FIG. 1, and an AC current is input from the input filter circuit 1 through a reactor 2.
A step-up converter circuit 3 for converting this into a direct current, a direct current output from the step-up converter circuit 3 is smoothed by a capacitor 4, then converted into an alternating current, and is converted through a current suppressing reactor 6 and a transformer 7 to a regeneration side (not shown). The inverter circuit 5 that regenerates the AC power supply is configured as a load circuit. In this case, the boost converter 3 and the inverter circuit 5 are those in which semiconductor switching elements are bridge-connected.

FIG. 2 shows an example of a block circuit of a control device for controlling the boost converter circuit 3 of the main circuit to obtain a load current having an arbitrary waveform. In FIG. 2, 11 is a PLL circuit to which an AC signal is inputted as a synchronizing signal from an AC input terminal ti through a transformer 12 and a low-pass filter 13 for noise removal. The PLL circuit 11 receives the synchronizing signal as shown in FIG. Phase Detector (Phase Detector) 11-1, Low Pass Filter 11-2 and Oscillator 1
1 to 3, and generates a clock signal synchronized with the input signal of the boost converter circuit 3.

Numeral 14 is a counter for storing the clock signal generated by the PLL circuit 11, which gives a feedback signal to the phase detector 11-1 of the PLL circuit 11 when the count value of the clock signal reaches a predetermined value.

Reference numeral 15 stores current waveform data corresponding to one cycle of the input current, and when an address is designated according to the count value of the clock signal counted by the counter 14, the waveform data of the corresponding address is output. Waveform creation ROM
As shown in FIG. 4, the phase adjusting volume 15-1 and the A / D for switching the phase of the reference waveform by digitally converting the output of the phase adjusting volume 15-1 are stored in the waveform forming ROM 15. The converter 15-2 is provided.

Reference numeral 16 is a multiplication type D / A converter which converts the waveform data output from the waveform generating ROM 15 into an analog signal and outputs the analog signal as a reference signal. The D / A converter 16 has a gain adjustment. The control volume 16-1 is provided, and the gain of the waveform can be adjusted.

Reference numeral 17 is an input of the reference signal output from the D / A converter 16 and the detection signal of the actual current input to the boost converter circuit 3, and an error amplifier (PI adjuster) for comparing these to correct the waveform. ), 18 is a PWM modulator that PWM-modulates the output signal of the PI adjuster 17 with a carrier wave generated by a carrier signal generator 19 to generate a gate signal of a switching element of the boost converter circuit 3. The gate signal output from the booster converter circuit 3 is output via the gate drive interface 20.
Is supplied as an on / off control signal to the switching element.

Next, the operation of the switching type simulated load device configured as described above will be described. Now, when a power supply device such as CVCF or UPS is connected as a test power supply to the AC input terminal ti and an AC current is input, this current is supplied to the PLL circuit 11 as a synchronization signal through the transformer 12 and the low pass filter 13 for noise removal. Given. The PLL circuit 11 generates a clock synchronized with the input signal, and when this clock is given to the counter 14, the waveform creation ROM 15 is designated with an address according to the count value of the clock of the counter 14, and the current of the corresponding address is specified. The reference waveform data is sequentially output. In this case, since waveform data corresponding to one cycle of the input current is stored in the waveform creating ROM 15, a current waveform as shown in FIG. 5, for example, is created and output.

When the waveform data output from the waveform generating ROM 15 is input to the multiplication type D / A converter 16, the waveform data is converted into an analog signal by the D / A converter 16 and used as a reference signal. Then, it is added to the PI adjuster 17.

Here, the phase adjusting volume 15-1 provided in the waveform forming ROM 15 is adjusted, and the output thereof is passed through the A / D converter 15-2 to form the waveform forming RO.
When input to M15, the address of the waveform generating ROM 15 is switched, and the phases of the reference signal and the synchronizing signal can be changed as shown in FIG.

Further, when the data output from the waveform generating ROM 15 is converted into an analog signal by the multiplication type D / A converter 16, the gain adjusting volume 16-1.
By adjusting, the gain of the waveform can be changed as shown in FIG.

Therefore, the D / A converter 16 can obtain a reference signal whose phase and gain can be changed in synchronization with the input waveform.

When such a reference signal is given to the PI adjuster 17, the PI adjuster 17 compares the detection signal of the actual input current flowing into the boost converter circuit 3 with the reference signal to correct the waveform. , P with the PWM modulator 18
The gate signal of the switching element is created by the WM modulation. Then, when this gate signal is given to the gate drive interface 19, the gate of the switching element of the boost converter circuit 3 is controlled. That is,
The switching element of the boost converter circuit 3 is repeatedly turned on and off so as to have a reference current waveform by comparing with a carrier wave as shown in FIG.

In this case, when the switching element of the boost converter circuit 3 is on / off controlled, the input current waveform is superimposed on the reference current waveform, and a harmonic ripple is generated.
Since the filter 1 for removing harmonics is provided on the input side of the boost converter circuit 3, these harmonic ripples are removed.

Therefore, the input current becomes a load current whose current waveform and magnitude are controlled, and the regenerative side inverter circuit 5
Flow to.

Next, the operation of regenerating the above-mentioned load current to the AC power source on the regeneration side will be described. FIG. 9 shows an equivalent circuit of the input / output unit including the boost converter circuit 3. Now, the switching element S of the boost converter circuit 3
When is turned on, short-circuit current flows through the reactor 2,
At this time, energy is stored in the reactor 2. When the switching element S is turned off in this state, the reactor 2
The energy stored in the capacitor 4 flows to the capacitor 4 through the diode D, and the voltage across the terminals of the capacitor 4 rises. Therefore, when this voltage exceeds the set value, the inverter circuit 5 operates and power is regenerated to the AC power source on the regeneration side.

In this case, the regenerative operation of the inverter circuit 5 is performed as follows. In the initial state, the regenerative inverter circuit 5 is boosted to charge the capacitor 4 of the main circuit. This is to prevent current from flowing from the test device to the capacitor 4 of the main circuit before the boost converter circuit 3 operates. Next, when the voltage across the terminals of the capacitor 4 exceeds a certain set level by the operation of the boost converter circuit 3, the regenerative operation is started and a voltage higher than the regenerative side power supply voltage synchronized with the regenerative side AC power supply is output. The current flowing at this time is limited by the current limiting reactor 6.

As described above, in this embodiment, the boost converter circuit 3 and the inverter circuit 5 are provided as load circuits in the main circuit to which the AC power source is connected as the test power source, and the input current is previously input to the control system of the boost converter circuit 3. Waveform data generating ROM 15 which stores current waveform data for one cycle and is capable of outputting waveform data having a phase different from that of the synchronizing signal by switching the address, when the input current of the AC power supply is inputted as the synchronizing signal, this input A PLL circuit 11 for generating a clock signal synchronized with the signal, a counter 14 for counting the clock signal generated by the PLL circuit 11 and designating an address of the waveform data creating ROM 15 by the count value, and an address by the counter 14. Then, the waveform data creation ROM 15 outputs the corresponding addresses sequentially. A D / A converter 16 with adjustable gain for converting waveform data serving as a flow reference into an analog signal is provided, and a reference signal output from the D / A converter 16 flows to the boost converter 3 by the PI adjuster 17. The waveform is corrected by comparing with the actual current, and this is corrected by the PWM modulator 1.
The step-up converter 3 is switching-controlled via the gate drive interface 19 by the gate signal obtained by PWM modulation in 8.

Therefore, the phase of the waveform data serving as the current reference output from the waveform generating ROM 15 is appropriately changed with respect to the synchronizing signal, and the waveform gain is appropriately changed by the D / A converter 16 to make the boost converter circuit 3
Input current can be controlled to an arbitrary waveform (current shape, magnitude, power factor). As a result, even a computer or other device in which the current flowing through the load connected to the power supply device does not have a sine wave can flow a current with a waveform peculiar to that load, effectively testing various power supply characteristics. It can be carried out.

The output of the boost converter circuit 3 can be regenerated to the AC power source on the regeneration side by the regeneration operation of the inverter circuit 5 when the voltage across the terminals of the main circuit capacitor 4 exceeds its set level, so that the output is low. The loss and high efficiency can be achieved, the risk of heat generation is small, and the size of the entire apparatus can be reduced.

Next, another embodiment of the present invention will be described with reference to FIG.

FIG. 10 is a block diagram showing a control device of a step-up converter circuit applied when a DC power source is used as a test power source. The same parts as those in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted. Now let's talk about the differences. In addition,
The configuration of the main circuit is the same as that of FIG. 1 except that a DC power source is connected to the input terminal as a test power source.

In the case of a DC power source as shown in FIG.
Since it is not necessary to synchronize with the input current, the transformer 12, the low pass filter 13, and the PLL circuit 1 having the configuration shown in FIG.
1 and the counter 14, a new reference voltage generator 21, an oscillator 22 that oscillates at a frequency proportional to the input voltage when a reference voltage output from the reference voltage generator 21 is input, and this oscillator 22 The output clock signal is counted, and the waveform shaping RO is calculated according to the counted value.
A counter 23 for designating the address of M15 is provided. The waveform data stored in the waveform shaping ROM 15 is stored as, for example, waveform data in which an AC waveform for one period is biased in a DC manner. In this case, the reason why the AC waveform is biased and input to the waveform shaping ROM 15 is that if the AC waveform itself is input to the ROM 15, current will flow from the load device to the DC power supply.

In the control device for the boost converter circuit having such a configuration, when the reference voltage generator 21 is appropriately adjusted to generate the reference voltage, the oscillator 22 oscillates a clock signal at a frequency proportional to the input voltage, This clock signal is given to the counter 23. When the address of the waveform shaping ROM 15 is designated by the counter 23 according to the count value, the waveform data of the corresponding address is sequentially output from the waveform shaping ROM 15. In this case, the counter 23 returns to the initial state when the clock signal input from the oscillator 22 counts up, and the clock signal is continuously counted again.

The waveform data output from the waveform shaping ROM 15 is converted into an analog signal by the D / A converter 16 and the PW is adjusted by the PI adjuster 17 as in the above embodiment.
By M-modulating, the gate signal of the switching element of the boost converter 3 is created. FIG. 11 shows an example of the clock signal output from the oscillator 22 and the output signal of the D / A converter 16.

Therefore, with such a configuration, even when a DC power source is connected as a test power source, a load current whose current waveform and magnitude are controlled is supplied to the regenerative side inverter 5 through the boost converter circuit 3 in the same manner as described above. be able to.

In the configuration shown in FIG. 2, the reference voltage generator 21, the oscillator 22 and the counter 23 shown in FIG. 10 are provided in parallel with the PLL circuit 11, and whether the test power source connected to the input terminal is an AC power source. Alternatively, these may be switched and used depending on whether they are DC power supplies. Further, in this case, the oscillator 11-3 included in the PLL circuit 11 of FIG. 2 can be shared as the oscillator 22 of FIG. 10 and the counter 14 can be shared as the counter 23 of FIG.

[0036]

As described above, according to the present invention, the current flowing through the load can be controlled to have an arbitrary waveform, the risk of heat generation is small, and the power loss can be minimized to save energy. A switching type simulated load device capable of being provided can be provided.

[Brief description of drawings]

FIG. 1 is a main circuit configuration diagram showing an embodiment of a switching type simulated load device according to the present invention.

FIG. 2 is a block diagram showing a control device of the boost converter circuit in the embodiment.

FIG. 3 is a block diagram showing the internal configuration of the PLL circuit of FIG.

FIG. 4 is a block diagram showing the waveform data ROM of FIG. 2 and its input / output unit.

FIG. 5 is a diagram showing an example of waveform data similarly stored in a waveform data generation ROM.

FIG. 6 is a diagram showing an example of a phase change state between waveform data serving as a current reference and a synchronization signal, which are also output from the waveform data generation ROM.

FIG. 7 is a waveform diagram showing changes in gain adjusted by the D / A changer of FIG.

FIG. 8 is a waveform diagram for producing a gate signal for controlling on / off of a switching element of the boost converter circuit in the embodiment.

FIG. 9 is an equivalent circuit diagram of an input / output unit that also includes a boost converter circuit.

FIG. 10 is a block diagram of a control device for a boost converter showing another embodiment of the present invention.

FIG. 11 is a diagram showing the relationship between the clock signal output from the oscillator and the output waveform of the D / A converter in the embodiment.

[Explanation of symbols]

1 ... Input filter circuit, 2 ... Reactor, 3 ... Boost converter circuit, 4 ... Capacitor, 5 ... Inverter circuit, 6 ... Current limiting reactor, 7 ... Transformer, 11 ... PLL circuit, 12 …… Trance, 13 ……
Low-pass filter, 14 ... Counter, 15 ... ROM for creating waveform data, 16 ... Multiplying D / A converter, 17
... PI adjuster, 18 ... PWM modulator, 19 ... Carrier signal generator, 20 ... Gate drive interface. 21 ... Reference voltage generator, 22 ... Oscillator, 23 ...
…counter.

Claims (3)

[Claims] 1. A main circuit for converting alternating current input from a test alternating-current power supply to direct current by a boost converter circuit, smoothing this by a capacitor and then converting it to alternating current by an inverter circuit, and regenerating it to the alternating current power supply side. And a clock generating means for generating a clock synchronized with the input signal of the step-up converter circuit, and the current waveform data corresponding to one cycle of the input current of the AC power supply is phase-adjusted with respect to the synchronizing signal. A waveform generation ROM which is stored as possible and outputs the waveform data of the address when the address is designated by the clock generated by the clock generating means.
And D / A converting means for converting the waveform data output from the waveform generating ROM to analog and adjusting the gain of the waveform, and the output signal of the D / A converting means for P
A switching type simulated load device, comprising: a gate signal generating means for performing WM modulation to generate a gate signal for controlling ON / OFF of a switching element of the boost converter. 2. A main circuit for controlling a direct current input from a test direct current power source by a step-up converter circuit, smoothing this by a capacitor, converting it to an alternating current by an inverter circuit, and regenerating it to the alternating current power source side. Load circuit, a waveform creation ROM in which current waveform data is stored so that the phase can be adjusted, and the waveform data output from this waveform creation ROM is converted into an analog signal and output as a reference signal, and the gain of the waveform is obtained. Of the D / A conversion means having an adjustable function and the output signal of the D / A conversion means
A switching type simulated load device, comprising: a gate signal generating unit that performs WM modulation to generate a gate signal for controlling ON / OFF of a switching element of the boost converter. 3. A waveform correction means for comparing the output signal of the D / A conversion means with the actual current input to the boost converter circuit to correct the waveform, and providing this to the gate signal generation means. The switching type simulated load device according to claim 1 or 2.