KR101211815B1 - Single and muti channel regeneration type electronic load device for electric energy saving - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an electronic load, and more specifically, to various household machinery such as computers, TVs, refrigerators, microwave ovens, washing machines, air conditioners, as well as various industrial machinery, communication equipment, automobiles, aerospace equipment, and the like. An electronic load is used to test the load reliability of a DC power supply being used.
To this end, the present invention includes an AC / DC converter operating in the constant voltage mode, and converts the AC power input to the input terminal of the AC / DC converter into a stable DC power output to the output terminal, and receives the DC power input And a recirculating load section for driving a sample section for driving, a DC / DC converter operating in a constant current mode, and returning the power output from the sample section to an output terminal of the power supply section and an input terminal of the sample section; The feedback power is input, the power consumption is sensed by each of the sample unit and the recirculating load unit, and the insufficient power is calculated from the power required to drive the sample unit. An addition control unit for adding to the feedback power output from the supply unit and supplying the feedback power to the sample unit; To provide energy-saving electronic parts.
Therefore, according to the present invention, by returning 80% or more of the power consumed as heat to 100% in the electronic load according to the prior art to the input side of the sample to prevent unnecessary consumption of power, and dramatically reduce the heat of the electronic load By lowering the temperature, it is possible to fundamentally prevent the problem of building an additional air conditioning system due to the heat generation of the existing electronic load.

Description

SINGLE AND MUTI CHANNEL REGENERATION TYPE ELECTRONIC LOAD DEVICE FOR ELECTRIC ENERGY SAVING}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an electronic load, and more specifically, to various household machinery such as computers, TVs, refrigerators, microwave ovens, washing machines, and air conditioners, as well as various industrial machinery, communication equipment, automobiles, aerospace equipments, and the like. An electronic load is used to test the load reliability of a DC power supply being used.

In general, various DC power supplies are used to supply power not only to household appliances such as computers, TVs, refrigerators, microwave ovens, washing machines, air conditioners, but also various industrial machines, communication equipment, automobiles, and aerospace equipment. These DC power supplies require more diverse and accurate tests as they become increasingly high performance, high reliability, and large in capacity. To this end, loads capable of various tests are essential.

In order to evaluate the reliability and quality of the DC power supply, the most commonly used method is a passive resistive load method that supplies power to a DC power supply and connects a resistive load to an output. Resistance load is the most widely used as described above, but the load can not be arbitrarily varied, there is a disadvantage that can only be a linear load test. In addition, since the energy flowing into the load consumes the entire amount of heat, energy loss is severe in the case of a large capacity.

In order to improve the disadvantage of the resistance load, an electronic load (Electronics LOAD) has been developed and widely used. The electronic load is a method of controlling the load current by controlling the base current by operating the semiconductor transistor in the linear operating region.Although the load current can be continuously changed, various load currents in addition to the constant current load and the constant power load can be obtained. There is a limit to generating. In addition, like the resistive load, energy flowing into the load is consumed as heat in the transistor, and thus has the same disadvantage as the resistive load.

In fact, in the industrial field, the production line of DC power supply such as Uninterruptible Power Supply (UPC), DC power supply, generator, etc., burns in full load for more than 24 hours to check reliability before the product is shipped. Burn-in and aging tests are conducted. Most of these production lines use resistive loads, which consumes a great amount of power and requires a lot of space.

1 is a conceptual diagram illustrating a load test method of a general power supply.

Referring to FIG. 1, a general load tester includes a power supply unit 1, a sample unit 2, and a resistance load 3.

Referring to the load test method using the load tester, first supplying 110W of power through the power supply unit (1) to the sample unit (2). The 110W of power supplied to the sample unit 2 outputs 100W of power to the resistive load 3 after 10W of the power consumption of the sample unit 2 is consumed. Accordingly, the resistance load 3 takes 100W of power, and the power of 100W applied to the resistance load 3 consumes 100% of heat.

As described above, the load test method of the power supply according to the related art consumes 100% of the output power as heat at the resistive load 3, thereby inevitably causing power consumption. In particular, since the long-term reliability test of 12 hours, 24 hours or 48 hours or more must be performed with the sample 2 at full load, the power consumption is increased accordingly. In addition, the prior art has a disadvantage in that the power capacity of the power supply for input power supply must be designed large. In addition, there is an additional cost for dissipating heat generated from the resistance load (or the electronic load).

In order to solve this problem, a technique for regenerating a power system without consuming energy of a load as heat is disclosed, for example, in Korean Patent Laid-Open Publication No. 2004-94552 (published on Nov. 10, 2004), Republic of Korea Utility Model No. 20- 0228970 (published date: July 19, 2001), Japanese Patent Application Laid-Open No. 09-325823 (published date: December 16, 1997) and the like have been proposed.

Korean Patent Laid-Open Publication No. 2004-94552 is configured to connect the DC side of two voltage source inverters in common and to face each other, one side of the AC side as a load input and the other side to be connected to a power system. It controls the input side inverter by switching by PWM (Pulse Width Modulation) to make the desired load current and the energy flowing into the load is regenerated into the system by the inverter connected to the power system.

The Republic of Korea Utility Model Registration No. 20-0228970 temporarily stores the electrical energy to be consumed as heat by the set load to the regenerative output including the inductor and supplies it to the external supply power, thereby operating the electronic load tester. Thus, by regenerating the energy to be consumed, it is possible to reduce the energy loss and also reduce the heat load of the electronic load tester.

Japanese Patent Laid-Open No. 09-325823 proposes a method of returning the test power to the input side or the original power source of a power supply under test while operating a constant current or a constant resistance as a load using an auxiliary power source or an inverter. Specifically, a power supply is connected to the input of the power supply under test, and an auxiliary power supply is connected to the output terminal side of the power supply under test in order to adjust the output current of the power supply under test when the power is returned by balancing the voltage with the power supply. The voltage difference between the power supply and the auxiliary power supply was connected to the impedance element. This can provide a load device that can reuse electricity because most of the power is regenerated at the input side or the original power source of the power device under test without consuming the test power of the power device under test.

However, the related arts proposed in these prior arts are connected to the input side because the final power output from the load device is an alternating current by returning the power supplied to the power source apparatus under test by using an inverter. In this case, access to commercial power is extremely limited because there are considerable risks (power rise, sudden fluctuation, tilting, etc.) in actual industrial sites. In fact, KEPCO has limited restrictions on access to commercial power and its connection regulations, so it is limited to commercialization.

In addition, Japanese Patent Application Laid-Open No. 09-325823 firstly returns power finally output from a power supply under test to an input using an inverter to boost the inverter or boost auxiliary power in order to assist power consumed by self-heating. Should be used. In addition, Japanese Patent Laid-Open No. 09-325823 discloses that a power supply under test that can be subjected to a load test using an AC / DC converter and an AC / AC inverter is determined according to an input voltage. In other words, when the input voltage is 220V, it is difficult to test loads on various power supplies because it is fixed to test only the power supply under test requiring the input voltage of 220V.

[Document 1] KR 10-2004-94552 A, 2004. 11.10. 4-6, drawing 1 [Document 2] KR 20-228970 Y1, July 19, 2001, p. 3-, drawing 3 [JP 3] JP H 09-325823 A, Dec. 16, 1997, pp. 2-3, drawings 1b-1e.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and has the following objectives.

First, the present invention, during the load test to check the load reliability of the power supply, while continuously supplying the stabilized power to the power supply to be tested to improve the efficiency of energy use and to prevent the rise of the ambient temperature due to heat generation heat emission It is an object of the present invention to provide single and multi-channel regenerative electronic loads for saving electric energy, which can also save additional costs such as air conditioners and ducts.

Second, the present invention is a single and multiple for saving the electrical energy that can be fed back to the power supply under test at the time of load test to check the load reliability of the power supply, the power output from the power supply under test without any risk stably. Another object is to provide a channel regenerative electronic load.

Third, when the load test to check the load reliability of the power supply unit (PSU), the various outputs output from the PSU, for example, 3.3V, 5V, 12V input such as multi-channel (Multi Channel) to be tested Another purpose is to provide single and multi-channel regenerative electronic loads for the reduction of electrical energy.

According to an aspect of the present invention, there is provided an AC / DC converter operating in a constant voltage mode, and converts AC power input to an input terminal of the AC / DC converter into a stable DC power and outputs the output terminal. A recirculation load including a power supply unit, a sample unit for receiving and driving the DC power, and a DC / DC converter operating in a constant current mode, and returning the power output from the sample unit to an output terminal of the power source unit and an input terminal of the sample unit; The unit receives the return power output from the recirculating load unit, detects power consumed by the sample unit and the recirculating load unit, and calculates insufficient power from the power required to drive the sample unit. The sample part by being added to the feedback power supplied from the power supply part and outputted from the recirculating load part; It provides for single and multi-channel electron-regenerative unit for supplying electric energy saving comprising a control unit for the addition.

Preferably, the AC / DC converter is a power factor correction converter, and may have a two-stage configuration in which a power factor correction (PFC) and a current control mode type DC / DC converter are connected in series.

Preferably, the sample unit may test a power supply for outputting a single voltage or a plurality of voltages.

Preferably, the power supply device for outputting the plurality of voltages may be a power supply unit (PSU).

Preferably, the DC / DC converter is composed of a multi-stage series connected converter, and the transformers constituting each stage are designed with different conversion ratios corresponding to a plurality of voltages output from the power supply unit (PSU), respectively. It can work as

As described above, according to the present invention, the following effects can be obtained.

First, according to the present invention, by returning 80% or more of the power consumed as heat to 100% in the electronic load according to the prior art to the input side of the sample to prevent unnecessary consumption of power, and dramatically reduce the heat of the electronic load By lowering the temperature, it is possible to fundamentally prevent the problem of building an additional air conditioning system due to the heat generation of the existing electronic load.

Second, according to the present invention, in the full load test using the electronic load according to the prior art, a product larger than the total capacity of the sample and the load should be used. As it only supplements the power for the excess and the loss, it is possible to design more than 1/3 of the capacity smaller than before.

Third, according to the present invention, in the prior art, there is a problem in regenerating to commercial power, but the electronic load device according to the present invention output power according to the input power standard of the sample when the power output from the sample is a low DC voltage. It converts into electric power corresponding to input voltage and supplies it to EUT. That is, when the input voltage of the sample is 110V, 220V, 380V, etc. or DC DC voltage, etc., the output power is converted into the power corresponding to the input voltage of the sample to supply the sample, and in particular, the returned power is commercial power. Since the power is fed back to the output of the AC / DC converter inside the electronic load, there is no problem with commercial power.

Fourth, according to the present invention, since the internal power supply of the electronic load is set at 300V, the AC / DC converter and the DC / DC converter can be driven. For example, when AC 220V is converted to DC, the voltage becomes 311V, so that the bridge diode portion including the filter part of the rectifier constituting the AC / DC converter can be removed and supplied with power. The DC / DC converter can be tested directly without any equipment.

1 is a conceptual diagram illustrating a load test method of a general DC / DC converter.
2 is a block diagram illustrating a single and multi-channel regenerative electronic load for reducing electrical energy according to an embodiment of the present invention.
3 is a configuration diagram showing the power supply unit 10 of the electronic load shown in FIG. 2 in detail.
FIG. 4 is a circuit diagram for explaining the internal circuit diagram of the PFC 11 shown in FIG.
FIG. 5 is a circuit diagram for explaining the internal circuit diagram of the DC / DC converter 12 shown in FIG.
FIG. 6 is a circuit diagram illustrating the internal circuit of the recirculating load unit 30 shown in FIG. 2.
7 is a view showing the front of the electronic load according to the present invention actually implemented.
8 is a block diagram illustrating the main control unit 50 according to the present invention.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms.

In this specification, the embodiments are provided so that the disclosure of the present invention may be completed and the scope of the present invention may be completely provided to those skilled in the art. And the present invention is only defined by the scope of the claims. Thus, in some embodiments, well known components, well known operations, and well-known techniques are not specifically described to avoid an undesirable interpretation of the present invention.

In addition, like reference numerals refer to like elements throughout the specification. In addition, the terms used (discussed) herein are for the purpose of describing the embodiments are not intended to limit the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. Also, components and acts referred to as " comprising (or comprising) " do not exclude the presence or addition of one or more other components and operations.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless they are defined.

Hereinafter, the technical features of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram illustrating a single and multi-channel regenerative electronic load for reducing the electrical energy according to an embodiment of the present invention.

Referring to FIG. 2, the electronic load device according to the embodiment of the present invention includes a power supply unit 10, a power supply device under test (hereinafter referred to as a sample unit) 20, a recirculating load unit 30, and an addition control unit ( 40).

The power supply unit 10 includes an AC / DC converter which is a rectifier in a constant voltage mode, and converts the commercial power input (AC power) into a stable DC power and outputs it to the sample unit 20. For example, 220V commercial power is input and converted into DCVDC of 300VDC / 1A and output.

3 is a configuration diagram illustrating the power supply unit 10 of the electronic load illustrated in FIG. 2 in detail.

The power supply unit 11 includes a PFC (Power Factor Correction) 11 and a DC / DC converter 12 as shown in FIG. 3. That is, the PFC 11 and the DC / DC converter 12 are configured in two stages connected in series.

As is well known, the input of a switched power supply consists of a bridge diode and a filter capacitor to convert the input alternating current (AC) into a direct current voltage (DC) with some ripple, in which case the input is affected by the input capacitor. High peak current with narrow pulse width instead of sinusoidal current flows, resulting in low power factor of 0.5 ~ 0.65, increasing harmonic content of input current, generating a lot of noise and EMI, and distorting the AC line voltage waveform. It will adversely affect other electrical devices connected to the line, and the low power factor will increase the reactive power, causing a lot of current to flow.

In order to solve these problems, the AC / DC converter used in the power supply unit 10 according to the present invention uses a power factor correction AC / DC converter to improve the power factor and reduce the harmonic component of the input current. The AC / DC converter for power factor correction uses a diode bridge rectifier PFC 111 and a current control mode type DC / DC converter 112 to obtain a single power factor by controlling the input current to a sinusoidal wave in phase with the input voltage. .

In addition, the DC / DC converter 112 used in the AC / DC converter for power factor correction according to the present invention uses a boost converter, a buck and a boost, and a flyback converter, but controls current. Step-up converter is mainly used in consideration of the ease of use, noise and EMI generation characteristics, AC / DC converter according to the present invention used a step-up converter method.

FIG. 4 is a circuit diagram for explaining the internal circuit diagram of the PFC 11 shown in FIG.

Referring to FIG. 4, the PFC 11 used an active boost continuous current mode type (CCM) using an L4981 PFC chip (IC) released by ST. Looking at the operation characteristics, when the PFC chip turns on the transistors (MosFET, Q), a current flows through the inductor (L), thereby accumulating energy in the inductor (L). In this state, when the transistor Q is turned off, a boost up converter in which current flowing in the inductor L is output through the diode D to accumulate voltage in the capacitor Co is accumulated. It works. At this time, the diode (D) is preferably using a fast recovery diode (fast recovery diode) to perform a switching operation at a high speed when the transistor (Q) is a high-speed switching, thereby reducing the conversion efficiency and power factor reduction You can stop it.

Since the PFC 11 uses the full-wave rectified voltage as a reference waveform, the PFC 11 generates a current in the form of a sine wave. First, when the transistor Q is turned on, the current flowing in the inductor L increases linearly. In this case, when the increased current is detected through the sensing resistor Rsense and the reference sine wave is reached, the transistor Q is turned off.

Before and after switching of the transistor Q, the current flowing through the inductor L must be continuous, so that the output terminal voltage of the inductor L is raised to turn on the diode D. Accordingly, a voltage is charged in the capacitor Co through the diode D, and the current of the inductor L is linearly discharged. The sense resistor Rsense senses the moment when all the current in the inductor L is discharged, and when the current in the inductor L is all discharged, the transistor Q becomes the zero value of the inductor L. Is turned on. Due to this operation, the current flowing through the inductor L draws a sine wave.

Advantages of the PFC 11 according to the present invention can be greatly reduced switching loss by soft switching zero voltage switching (ZVS), high power factor of 0.99, low distortion of less than 5%, low noise detection (Low) Various functions such as noise sensitivity, over voltage protection, and over current protection are added.

Meanwhile, Fairchild's KA5L0380 can be used to further configure a flyback converter circuit as an auxiliary power source for driving a PFC driver, and through this, MIC502 is used to drive a fan that is actively operated according to temperature change. When the temperature of the product exceeds 40 ℃, it can be started and the speed of rotation can be changed in three stages.

FIG. 5 is a circuit diagram illustrating the internal circuit diagram of the DC / DC converter 12 shown in FIG. 3.

Referring to FIG. 5, the DC / DC converter 12 uses a phase shifted full-bridge converter. Phase-shifted full-bridge converters allow zero voltage switching (ZVS) using the resonance of the transformer's leakage inductance, capacitance, and the switch's output capacitance without additional circuitry. Accordingly, the switching loss is small, so that the high frequency switching operation is possible, and thus the power density and the efficiency can be greatly improved, and thus, a large capacity isolated DC / DC converter has been applied.

Zero-voltage switching (ZVS) operation in a phase-shifted full bridge converter requires accurate switching timing between the leading and ground legs and accurate phase shift timing of the leading and ground legs. Conventional PWM controllers with built-in zero-voltage switching (ZVS) functions do not meet these zero-voltage switching (ZVS) requirements due to effects such as frequency, load and input voltage variations, and device characteristics. Done. This shortcoming can be improved by using high speed switching with accurate timing using a digital controller using a digital processor.

Specifically, the phase shift full bridge converter includes a digital controller including a full bridge stage, an output stage, and a digital signal processor (DSP) as shown in FIG. 5.

Referring to the circuit operation of the phase shift full bridge converter, first, the gate signal of the transistor required for zero voltage switching (ZVS) is generated through a digital controller, so that the forward leg (Q1 or Q3) and the ground leg (Q2 or Q4) is controlled.

The digital controller receives an output voltage (Voltage) and an output current (Current) output from the output stage, performs an algorithm for controlling the output voltage (Voltage) and output current (Current), and correspondingly DSP and driver Generate a gate signal through. The DSP includes an A / D converter for feedback of the output voltage (Voltage) and output current (Current).

Then, zero voltage switching (ZVS) is performed by resonance of energy to charge / discharge the leakage inductance of the transformer L2, the parasitic capacitance, and the output capacitances of the transistors Q1 to Q4. For example, one fastening leg Q1 or Q3 is turned off so that the output capacitance charges and the other fastening leg Q3 or Q1 discharges. At this time, the parallel diodes D1 to D4 connected to the transistors Q1 to Q4 are connected to each other by the leakage inductance of the transformer L2 and the secondary energy transfer, so that the voltage at both ends thereof becomes 0V, and zero voltage switching (ZVS) is performed. .

To control the phase-shifted full bridge converter, a pulse width modulation (PWM) signal is generated that facilitates phase shifting between dead time and legs. Conventional analog PWM chips are difficult to meet zero voltage switching (ZVS) characteristics under various load conditions.

Therefore, in the present invention, the gate signal is generated using an EV (Event Manager) built in the DSP to control the phase between the dead time and the leg by programming.

In addition, a digital controller can be configured using a phase shift PWM controller and a Micom AVR128 using a phase shift full bridge converter UCC3895, which is a commercial IC for low cost products. In the UCC3895 PWM controller, an algorithm is generated to generate the gate signal required for zero voltage switching (ZVS) and to control the output voltage and output current. In addition, microcomputer has built-in A / D converter, and feeds back output voltage and output current by using this A / D converter.

In addition, in the present invention, various protection circuits having respective protection functions may be mounted for stable operation of the rectifier. For example, OVP (Over Voltage Protection), OCP (Over Current Protection), and OTP (Over Temperature Protection) And short protection of a power transistor (power MosFET). In addition, a flyback converter circuit may be further mounted as an auxiliary power supply for supplying power to the UCC3895 PWM driver chip. These protection circuits and the UCC3895 PWM controller and driver chip are mounted together on the board.

As shown in FIG. 2, the recirculating load unit 30 includes a DC / DC converter functioning as an energy-saving load, and serves as a load consuming power coming from the output of the sample unit 20. The output value of the preset sample unit 20 is always kept constant. In addition, the recirculation load unit 30 outputs the power input from the sample unit 20 to the output, so that this power is introduced again to the input of the sample unit 20.

FIG. 6 is a circuit diagram illustrating the internal circuit of the recirculating load unit 30 shown in FIG. 2.

Referring to FIG. 6, the recirculating load unit 30 according to the present invention has a four-stage structure in which four DC / DC converters are connected in series, and operates in a constant current mode.

The recirculating load unit 30 according to the present invention is designed in a phase shift full bridge converter method similarly to the DC / DC converter 12 of the power supply unit 10 described above, and a specific matter is to input a low voltage from the sample unit 20. In this case, if a circuit is composed of one module, a lot of voltage or current may be generated, which may cause instability of the power supply device. Accordingly, in the present invention, as described above, four DC / DC converters are connected in series to form a four-stage structure to obtain stable output.

The recirculating load unit 30 configures a DC / DC converter to convert a low voltage into a high voltage. However, unlike the DC / DC converter 12 of the power supply unit 10 is controlled in the constant current mode.

Since the recirculating load unit 30 converts a low voltage and a high current into a high voltage low current, heat generation and loss may be higher than that of the AC / DC converter used in the power supply unit 10. Therefore, care must be taken in the design of the heat dissipation problem and the balance of each module because the output is output at high voltage by connecting the outputs in series. To this end, as shown in FIG. 7, heat sinks and four DC fans are mounted on a board to radiate heat, and an output value is sensed and controlled in real time so that the balance between each DC / DC converter is not disturbed.

Actually, in the embodiment of the present invention, since the current capacity of the four DC / DC converter module constituting the recirculating load unit 30 is relatively large, about 100A, the bus bar was used. TDK's Fairlight E150 was used as the main transformer, and the DC / DC converter used a phase shifted full bridge converter UCC3895. What is different from the DC / DC converter 12 of the power supply unit 10 is to drive four DC / DC converters with one chip. That is, four DC / DC converters are controlled by one UCC3895, which not only ensures uniformity of output of each DC / DC converter, but is also easy to control and easy to maintain.

The recirculating load unit 30 may be designed to operate in a single channel or in multiple channels according to the output voltage of the power supply device, which is a sample. If the output voltage of the power supply being a specimen is a single voltage, it shall be designed to operate in a single channel, and if the output voltage of the power supply is multiple voltages, it shall be designed to operate in multiple channels. In other words, the DC / DC converter has to design the transformer of each stage in the same way to operate in a single channel, and the conversion ratio (step-up ratio) may be designed differently in order to operate in the multi-channel.

In the case of short-channel operation, for example, as shown in FIG. 3, assuming that the output of the power supply used as the sample is 12V and the DC / DC converter of the recirculating load unit 30 outputs 300VDC, the recirculating load The four DC / DC converters of the unit 30 each receive 12V, convert the same to 75V, and output the same. The output voltage is added and 300VDC is output.

Power Supply Units (PSUs), as is well known, are power supplies that provide stable power to computers. The output voltage of the PSU is 12V, which is the main voltage, and 5V, 3.3V, which is the sub-power. For example, two of the four-stage series-connected DC / DC converters are designed with the same conversion ratio in response to the same input voltage, and the other two are designed with different conversion ratios in response to the input voltage. That is, since the voltage output from the PSU, which is a power supply, is four, and the DC / DC converter is composed of four stages, two stages of the DC / DC converters are designed with the same conversion ratio in response to the input voltage to match them. do.

As such, by adjusting the conversion ratio of the transformer of the 4-stage series-connected DC / DC converter, short-channel or multi-channel operation may be implemented according to the output voltage of the power supply which is a sample. Of course, when the sample is used as a PSU, the conversion ratio of each transformer of a four-stage series-connected DC / DC converter is also fixed, so a replacement operation must be performed for a power supply that outputs another single voltage.

2 and 3, the addition control unit 40 combines the output of the power supply unit 10, the input of the sample unit 20, and the output of the recirculating load unit 30 into a circuit. During the load test, power fluctuations occur due to power lost in the sample part 20 and the recirculating load part 30 and the external environment. Such fluctuations in power may prevent stable starting of the sample part 20. have. Therefore, the addition control unit 40 detects the voltage and current output from the sample unit 20 and the recirculating load unit 30 to calculate the insufficient power for stable starting of the sample unit 20, and calculates the insufficient power, and supplies the insufficient power to the power supply unit. By receiving from the supply (10) to the sample unit 20 to supply a constant and stable power to the sample unit 20 at all times during the load test.

7 is a photograph of the front surface of the electronic load according to the present invention actually implemented. Referring to FIG. 7, the front display of the electronic load according to the present invention is driven using ATMGA128. The input voltage and current, the output voltage and current of the AC / DC converter, which is the power supply unit 10, and the recirculating load unit 30. It consists of six FNDs indicating input voltage and current of DC / DC converter, and one LDC window for displaying and setting the detected value and inputting numerical values.

It consists of 6 input keys, consisting of direction keys for numeric input, "ESC Key" for exiting to the previous stage, and "ENT Key" for execution, and additionally green to indicate the normal state of the system (NORM). Red LED diodes are disposed to check LED diodes, various protections (OV (Over Voltage), OC (Over Current), and OT (Over Temperature)). In addition, two RS-485 terminals (Termianl) are installed as a communication port for parallel connection of multiple devices, and a Data Link Terminal (Data Link Terminal) for uploading data to the Main Controller (50) is added. have.

As shown in FIG. 8, the main controller 50 receives data input through a data link terminal that provides an interface with a user, and the AC / DC converter of the power supply unit 10 and the DC / DC of the sample unit 20. The DC converter and the DC / DC converter of the recirculating load unit 30 are controlled. For this purpose, the main controller 50 used a 32-bit AT91SAM7S (LQPF) ARM controller, and additionally used two 8-bit ATMGA Micom to collect and process the sensed data. The main controller 50 controls the DC / DC converter of the recirculating load unit 30 by using a selection key, that is, controls the constant voltage, constant current, constant resistance, constant power, dynamic mode, and the like of the DC / DC converter to output necessary power. can do.

Hereinafter, an operation effect of the electronic load according to the present invention will be described with reference to FIG. 2. Here, the sample unit 20 (DUT (Device Under Test)) will be described by taking a DC / DC converter as an example.

Referring to FIG. 2, when the electronic load according to the present invention supplies the starting power for operating the first DUT in the AC / DC converter operating in the constant voltage mode, the DUT outputs and recycles most of the power except for its own heat consumption. Output to DC / DC converter which is load part.

The recirculating load, the DC / DC converter, operates in constant current mode, returning most of its power to the DUT input, except for its thermal power. That is, the power output from the DUT is subtracted from its own thermal power consumption and the remaining power is returned to the input terminal of the DUT.

The addition control unit 40 detects its own loss of the DUT and the DC / DC converter, which is the recirculating load unit, calculates insufficient power, receives the insufficient power from the AC / DC converter, and supplies it to the DUT to always be constant and stable during the load test. Power will be supplied to the DUT.

For example, as shown in FIG. 2, when the 100W DC / DC converter is fully loaded, the self-heat consumption by the DUT is 10%, and the self-heat consumption by the DC / DC converter of the recirculating load is 10. Assuming%, the power output through the recycle load is 80W.

Therefore, the electronic load machine of the present invention prevents unnecessary power consumption by returning 80% or more of the power consumed as heat to 100% of the existing electronic load to the input side of the sample and breaks down the heat of the electronic load. By lowering the temperature, it is possible to fundamentally prevent the problem of building an additional air conditioning system due to the heat generation of the existing electronic load.

In addition, since the AC / DC converter only covers the loss lost in the DC / DC converter, which is a sample and a recirculating load, it is possible to obtain an effect of designing a capacity smaller than 1/3 by weight. That is, in the full load test using the existing electronic load device, a product larger than the total capacity of the sample and the load should be used. However, in the electronic load according to the present invention, the AC / DC converter supplements only the initial driving power and the power for the loss. Because it plays a role, it is possible to obtain the effect of designing capacity smaller than 1/3 compared with existing.

Table 1 is a table showing the actual input power requirements of the AC / DC converter when the DC / DC converter is a DUT unit unit capacity of 12V / 10A, Table 2 is a single rack capacity, DC / DC converter is a DUT The table shows the actual input power requirements when up to 100 units are mounted.

division DUT output capacity Recirculating Load Capacity Actual input demand power Volume 120 W (12 V / 10 A) 100 W (η = 90%) 24 W (η = 90%)

division DUT output capacity Recirculating Load Capacity Actual input demand power Volume 120W * 100EA = 12KW 100W * 100EA = 10KW 24W * 100 = 2.4KW

As shown in the above table, when the efficiency of the load is 90%, 100 W of power is consumed in the conventional electronic load, whereas 24 W of power is consumed in the electronic load according to the present invention. The power consumption can be prevented by about 80W, and the power efficiency can be greatly improved when the number of DUTs is increased.

The electronic load device according to the present invention can stably return the power output from the sample to the power under test without any risk during the load test for checking the load reliability of the sample. As described above, in the prior art, there is a problem in regenerating to commercial power, but the electronic load according to the present invention meets the input power standard of the DUT when the power output from the DUT is a DC voltage, that is, the input voltage is AC 110V, 220V. , 380V etc. or DC DC voltage, it converts the output power into the power corresponding to the input voltage of the DUT and supplies it to the DUT. Especially, the return power is not connected to the commercial power, but the AC inside the electronic load Since the power is returned by being connected to the output terminal of the / DC converter, there is no problem with commercial power.

In addition, the electronic load according to the present invention can test a variety of samples as the power supply unit for supplying power to the sample is made of an AC / DC converter. That is, various direct current (rectifier and DC / DC converter) load devices can be tested without being affected by the input voltage. For example, when testing AC / DC converters for 110V and 220V, when AC is converted to DC because a bridge diode is built-in and converts AC to DC after passing a line filter inside the circuit. The peak value of is converted into "AC 110V * √2 = DC 155V" and "AC 220V * √v2 = DC 311V". Therefore, if the corresponding DC power source is inputted, no problem occurs in the test drive of the specimen.

As described above, the technical spirit of the present invention has been described in detail in the preferred embodiments, but the above-described preferred embodiments are for the purpose of description and not of limitation. As such, those skilled in the art may understand that various embodiments are possible through the combination of the embodiments of the present invention within the scope of the technical idea of the present invention.

10: power supply
20: sample part
30: recirculation load
40: addition control unit

Claims (5)

A power supply unit including an AC / DC converter operating in a constant voltage mode, and converting AC power input to the input terminal of the AC / DC converter into a stable DC power and outputting the output to an output terminal;
A sample unit configured to receive and drive the DC power;
A recirculating load unit including a DC / DC converter operating in a constant current mode and returning power output from the sample unit to an output terminal of the power supply unit and an input terminal of the sample unit; And
After receiving the return power output from the recirculating load unit, sensing the power consumed by the sample unit and the recirculating load unit to calculate the insufficient power from the power required to drive the sample unit, and calculating the insufficient amount from the power supply unit. Single and multi-channel regenerative electronic load for electric energy savings including an addition control unit for receiving and adding to the feedback power output from the recirculating load unit to supply to the sample unit.
The method of claim 1,
The AC / DC converter is a power factor correction converter, and includes a single-stage and multi-channel regenerative electronic load for electric energy saving, which consists of a two-stage configuration in which a power factor correction (PFC) and a current control mode type DC / DC converter are connected in series.
The method of claim 1,
Single and multi-channel regenerative electronic load for the electrical energy saving to test the power supply for outputting a single voltage or a plurality of voltages to the sample portion.
The method of claim 3, wherein
The power supply device for outputting a plurality of voltages is a power supply unit (PSU) single and multi-channel regenerative electronic load for electrical energy saving.
The method of claim 4, wherein
The DC / DC converter is composed of a multi-stage series connected converter, and the transformers constituting each stage are designed to have different conversion ratios corresponding to a plurality of voltages output from the power supply unit (PSU) to operate in multiple channels. Single and multichannel regenerative electronic loads for saving electrical energy.

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