Energy-feedback DC / DC test method and device

Abstract

The invention relates to an aging test equipment technology, and discloses an energy-feedback DC / DC test method and device, and the method comprises the steps: 1, an aging power supply provides a power supply for a voltage boosting module; step 2, the voltage boosting module boosts the input voltage through the DSP module, and transmits the boosted voltage to the tested DC / DC module; and step 3, the tested DC / DC module outputs voltage to the direct current energy feedback type electronic load module, the direct current energy feedback type electronic load module feeds back a direct current power supply to the voltage boosting module and the DSP module, and the step 2 is further executed. The output power of the aging power supply is reduced; and by adding the boosting module, the input voltage requirements of the high and low voltage DC / DC modules are met.

Description

Technical Field

[0001] The invention relates to an aging test equipment technology, and in particular to an energy-feedback DC / DC test method and device. Background Art

[0002] During the power aging test of the DC / DC power module, it is necessary to apply a load of rated output power to the DC / DC module within a specified time under specific environmental and input voltage conditions. In the traditional power aging test circuit, Vs is the input power supply, Vin is the input voltage, Vout is the output voltage, and RL is the power load (pure resistance load or programmable electronic load). It can be seen that the output power is converted into heat energy through the load RL and discharged into the air, causing waste.

[0003] For example, the existing technology adopts method 1: pure resistance aging, which consumes a lot of energy and generates a lot of heat. The resistance size needs to be adjusted each time the current is loaded, and it has been basically eliminated; Method 2: The electronic load is aging, consumes a lot of energy, and generates a lot of heat. Although the current can be adjusted by program control, it cannot save energy and will be gradually eliminated in the future. For the aging systems of the above-mentioned methods 1 and 2, all the electrical energy is converted into heat and dissipated into the environment, which not only wastes energy but also affects the ambient temperature. Summary of the invention

[0004] The present invention aims at the problem that the energy-feeding schemes adopted in the prior art have the difference in whether the load is energy-feeding or not, but the common point is that the high-voltage DC / DC power supply module and the low-voltage DC / DC power supply module cannot be used on the same aging system, and provides a novel energy-feeding DC / DC test method and device.

[0005] In order to solve the above technical problems, the present invention is solved by the following technical solutions: A power-feed type DC / DC test method comprises a power-feed type circuit unit and a DC / DC module to be tested, wherein the power-feed type circuit unit comprises a voltage boost module, a DC power-feed type electronic load module and a DSP module; the DC power-feed type electronic load module is connected to the voltage boost module, the DC power-feed type electronic load module feeds back energy to the voltage boost module, the voltage boost module is connected to the DC / DC module to be tested, the DC / DC module to be tested is connected to the DC power-feed type electronic load module, The energy-feedback DC / DC test method comprises: Step 1, the aging power supply provides power to the voltage boost module; Step 2, the voltage boosting module boosts the input voltage through the DSP module, and transmits the boosted voltage to the DC / DC module under test; Step 3, the DC / DC module under test outputs voltage to the DC energy-fed electronic load module, and the DC energy-fed electronic load module feeds back DC power to the voltage boost module and the DSP module, and further executes step 2.

[0006] Preferably, the voltage boost module includes a boost unit, a rectifier unit and a voltage sampling unit; the boost unit is used to boost the voltage output from the input aging power supply end, the rectifier unit is used to rectify and filter the boosted voltage, and transmit the rectified and filtered voltage to the DC / DC module under test; the voltage sampling unit collects the voltage output by the rectifier unit and feeds it back to the DSP end.

[0007] Preferably, the boost unit includes a first isolation driving unit, a second isolation driving unit, a MOS transistor Q5, a MOS transistor Q6 and a transformer unit T2, wherein the input end of the first isolation driving unit is connected to the ePWM2A signal provided by the DSP module, the output end of the first isolation driving unit is connected to the first end of the MOS transistor Q5, the second end of the MOS transistor Q5 is connected to the transformer unit T2, and the third end of the MOS transistor Q5 is grounded; The input end of the second isolation driving unit is connected to the ePWM2B signal provided by the DSP module, the output end of the second isolation driving unit is connected to the first end of the MOS tube Q6, the second end of the MOS tube Q6 is connected to the transformer unit T2, and the third end of the MOS tube Q6 is grounded.

[0008] Preferably, the rectifying unit comprises a MOS transistor Q7, a MOS transistor Q8, a MOS transistor Q9 and a MOS transistor Q10; the first ends of the MOS transistor Q7 and the MOS transistor Q10 provide an ePWM3A signal through the DSP module, and the first ends of the MOS transistor Q8 and the MOS transistor Q9 provide an ePWM3B signal through the DSP module; the rectified output signals of the MOS transistors Q7, Q8, Q9 and Q10 are filtered by capacitor C3 and then transmitted to the DC / DC module under test.

[0009] Preferably, the voltage sampling unit includes a DA sampling chip and an optocoupler isolator, wherein the DA sampling chip is connected to the filter capacitor C3 to collect the voltage output by the rectifier unit; and the collected voltage is fed back to the DSP module via the optocoupler isolator.

[0010] Preferably, the DC energy-fed electronic load module includes a MOS tube Q1, a MOS tube Q2, and a transformer unit T1; the negative electrode of the output end of the measured DC / DC module voltage is connected to the third end of the MOS tube Q1 and the third end of the MOS tube Q2, the second end of the MOS tube Q1 and the second end of the MOS tube Q2 are connected to one side of the transformer unit T1, the first end of the MOS tube Q1 provides an ePWM1B signal through the DSP module, and the first end of the MOS tube Q2 provides an ePWM1A signal through the DSP module; the other side of the transformer unit T1 is connected to the rectification and filtering unit, and is connected to the output end of the aging power supply through the rectification and filtering unit.

[0011] Preferably, the DC energy-fed electronic load module also includes a relay K1 and a relay K2; the relay K1 and the relay K2 can be connected in series or in parallel, and are controlled by the DSP module, one side of the relay K1 and the relay K2 is connected to the rectifier and filter unit, and the other side is connected to the aging power supply output end.

[0012] In order to solve the above technical problem, the present invention also provides a feed-back DC / DC test device, characterized in that it is a device for implementing the feed-back DC / DC test method.

[0013] The present invention has significant technical effects due to the adoption of the above technical solution: The present invention takes the feedback load module as the core to achieve the purpose of energy recycling and energy saving and emission reduction. The energy of the feedback electronic load is fed back to the output end of the aging power supply to reduce the output power of the aging power supply; for example, when the feedback efficiency is 90%, when aging a 10kw power module, only the aging power supply needs to provide more than 1kw.

[0014] The present invention meets the input voltage requirements of high and low voltage DC / DC modules by adding a boost module. When aging a low voltage DC / DC module, it is only necessary to set the boost module to 1 times. When aging a high voltage DC / DC module, the boost multiple is controlled according to the DC / DC input voltage specification, so that the input voltage requirements of the high and low voltage DC / DC modules are met, and the aging power requirements are also met.

[0015] The present invention solves the problem of compatibility between input power selection and input voltage selection of aging products for DC / DC power supply manufacturers, and can be achieved with a low-power low-voltage power supply. Products with low-voltage and high-voltage inputs can be tested and aged on the aging system equipment, which greatly improves the utilization rate of the aging cabinet and saves the cost of investing in aging system equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of an energy-fed DC / DC experiment performed by pure resistance aging or electronic load aging in Example 1 of the present invention.

[0017] Figure 2 It is a schematic diagram of the energy-feedback type in which the energy-saving load is combined with the inverter in Embodiment 1 of the present invention.

[0018] Figure 3 It is a schematic diagram of Example 2 of the present invention.

[0019] Figure 4 It is a schematic diagram of the present invention.

[0020] Figure 5 This is a circuit diagram of an energy-feedback constant-current electronic load of the present invention.

[0021] Figure 6 It is a circuit diagram of a voltage boost module of the present invention. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Example 1

[0023] exist Figure 1 In the experiment, pure resistance aging or electronic load aging is used to conduct energy-feed DC / DC experiments. The aging power supply is directly connected to the DC / DC power module, and the DC / DC power module is connected to the energy-consuming load. In this way, it consumes a lot of energy and generates a lot of heat. The resistance needs to be adjusted each time the current is loaded. For the electronic load mode, it consumes a lot of energy and generates a lot of heat. Although the current can be adjusted by programmable control, it cannot save energy.

[0024] exist Figure 2 In the process, it adopts the combination of energy-saving load and inverter. The aging power supply is directly connected to the DC / DC power supply module, the DC / DC power supply module is connected to the energy-fed load, and the DC energy-fed load is directly connected to the DCAC inverter.

[0025] for Figure 1 and Figure 2 In addition to the difference in whether the load can be fed back, the common point is that high-voltage DC / DC power modules and low-voltage DC / DC power modules cannot be used on the same aging system. Low-voltage input DC / DC modules are generally <60V, such as typical voltages: DC-24V, DC-48V; high-voltage input DC / DC modules are generally 100V< input voltage <600V, typical voltages: DC-270V, DC-400V, DC-550V.

[0026] Assume that when aging a 10kw product, the 24V input voltage requires the aging power supply to provide about 420A current. Under the same aging power condition, for a module with a 550V input voltage, the aging power supply must be configured with at least 550V*420A = 231kw to meet the 420A current requirement of the low-voltage module. However, only 10kw of power is actually used, which is less than 5%. This configuration is a huge waste for the equipment, and the output current of a general high-voltage power supply is generally not high, so it is difficult to match a suitable aging power supply.

[0027] It can be seen that because the input voltage span of high and low voltage DC / DC is too large, the existing energy-feedback aging solutions are difficult to be compatible on the same device. Some systems are also configured with two sets of aging power supplies to force compatibility with high and low voltage products, and they are manually replaced during use. This not only wastes resources, but also is troublesome to operate. During the operation, the aging power supply may be damaged due to mistakes. Example 2

[0028] Different from Example 1, a feed-type DC / DC test method in this embodiment includes a feed-type circuit unit and a DC / DC module under test, wherein the feed-type circuit unit includes a voltage boost module, a DC feed-type electronic load module and a DSP module; the DC feed-type electronic load module is connected to the voltage boost module, the DC feed-type electronic load module feeds back energy to the voltage boost module, the voltage boost module is connected to the DC / DC module under test, and the DC / DC module under test is connected to the DC feed-type electronic load module. The energy-feedback DC / DC test method comprises: Step 1, the aging power supply provides power to the voltage boost module; Step 2, the voltage boosting module boosts the input voltage through the DSP module, and transmits the boosted voltage to the DC / DC module under test; Step 3, the DC / DC module under test outputs voltage to the DC energy-fed electronic load module, and the DC energy-fed electronic load module feeds back DC power to the voltage boost module and the DSP module, and further executes step 2.

[0029] In this embodiment, only one device is needed to meet the aging requirements of high and low voltage DC / DC modules; energy is fed back to the output end of the aging power supply, which reduces the output power of the aging power supply, and at the same time, the power loss of the aging power supply is also reduced, thereby increasing the energy feedback efficiency. Figure 2 Figure 3Two schemes, assuming that the two aging schemes have the same efficiency, aging power supply efficiency = 90%, DC / DC module efficiency = 90%, inverter efficiency = 85%, where A = AC power supply power, B = aging power supply output power, C = DC / DC module output power, D = feedback power. When aging the same 10kw power DC / DC module, the efficiency values ​​are as follows. It can be seen from the calculation that under the same conditions, the new scheme is more energy-efficient; C=10kw×90%, D=C×85%, B=10kw / 90%, A=B / 90%, Figure 2 The power consumption of the scheme = A–D = 4.7kW.

[0030] C=10kw×90%, D=C×85%, B=10kw / 90%-D, A=B / 90%, the power consumption is A, Figure 3 The scheme consumes electric energy A=3.8kW.

[0031] For the energy-feedback circuit unit, the system uses the TMS320F28335 chip produced by TI for control, with a main frequency of up to 150MHz, a high-performance 32-bit CPU, single-precision floating-point operation (FPU), and 18 PWM outputs, including 6 groups of 12 enhanced ePWMs, each of which consists of two channels, namely ePWMxA and ePWMxB, which can be configured as two independent single-edge PWM outputs, or two independent but mutually symmetrical double-edge PWM outputs. This solution uses 3 pairs of complementary and symmetrical ePWM waveforms for control, namely ePWM1A / ePWM1B, ePWM2A / ePWM2B, and ePWM3A / ePWM3B. Figure 5 As shown in the circuit principle block diagram, the DSP controls the energy-fed load to perform constant current. At the same time, the load feeds back part of the energy to the output end of the aging power supply. The DSP controls the boost multiple so that the voltage meets the input voltage of the DC / DC module for aging.

[0032] The voltage boost module includes a boost unit, a rectifier unit and a voltage sampling unit; the boost unit is used to boost the voltage output from the input aging power supply end, the rectifier unit is used to rectify the boosted voltage and transmit the rectified voltage to the DC / DC module under test; the voltage sampling unit collects the voltage output by the rectifier unit and feeds it back to the DSP end.

[0033] The boost unit includes a first isolation driving unit, a second isolation driving unit, a MOS transistor Q5, a MOS transistor Q6 and a transformer unit T2, wherein the input end of the first isolation driving unit is connected to the ePWM2A signal provided by the DSP module, the output end of the first isolation driving unit is connected to the first end of the MOS transistor Q5, the second end of the MOS transistor Q5 is connected to the transformer unit T2, and the third end of the MOS transistor Q5 is grounded; The input end of the second isolation driving unit is connected to the ePWM2B signal provided by the DSP module, the output end of the second isolation driving unit is connected to the first end of the MOS tube Q6, the second end of the MOS tube Q6 is connected to the transformer unit T2, and the third end of the MOS tube Q6 is grounded.

[0034] The rectifier unit includes MOS tube Q7, MOS tube Q8, MOS tube Q9, and MOS tube Q10; the first ends of the MOS tube Q7 and the MOS tube Q10 provide ePWM3A signals through the DSP module, and the first ends of the MOS tube Q8 and the MOS tube Q9 provide ePWM3B signals through the DSP module; the output signals after rectification by the MOS tube Q7, the MOS tube Q8, the MOS tube Q9, and the MOS tube Q10 are filtered by the capacitor C3 and then sent to the DC / DC module under test.

[0035] The voltage sampling unit includes a DA sampling chip and an optocoupler isolator. The DA sampling chip is connected to the filter capacitor C3 and is used to collect the voltage output by the rectifier unit; and the collected voltage is fed back to the DSP module via the optocoupler isolator.

[0036] DSP outputs ePWM2A and ePMW2B, which control MOS tubes Q5 and Q6 respectively, convert the DC voltage of the aging power supply into AC voltage, and then transmit energy through transformer unit T2. The output end of transformer unit T2 uses MOS tubes Q7, Q8, Q9, and Q10 for rectification, converting the AC voltage output by the transformer into DC voltage, and at the same time feeds back the voltage value sampled by the output DA chip to the DSP end, and controls the duty cycle of ePWM2A and ePWM2B through software algorithm comparison, so that the output voltage meets the input voltage requirements of the DC / DC module. Here, the output end of transformer unit T2 uses MOS tubes for rectification instead of traditional diode rectification, which uses the low on-resistance of MOS tubes to reduce energy loss and increase recovery efficiency. MOS tubes Q7 / MOS tubes Q10 and MOS tubes Q8 / MOS tubes Q9 are controlled by ePWM3A and ePWM3B output by DSP respectively.

[0037] The DC energy-fed electronic load module includes a MOS tube Q1, a MOS tube Q2, and a transformer unit T1; the negative electrode of the output end of the DC / DC module voltage is connected to the third end of the MOS tube Q1 and the third end of the MOS tube Q2, the second end of the MOS tube Q1 and the second end of the MOS tube Q2 are connected to one side of the transformer unit T1, the first end of the MOS tube Q1 provides an ePWM1B signal through a DSP module, and the first end of the MOS tube Q2 provides an ePWM1A signal through the DSP module; the other side of the transformer unit T1 is connected to the rectifier unit, and the output voltage end of the rectifier unit is connected to the output end of the aging power supply.

[0038] The DSP sends out ePWM1A and PWM1B pulse signals, and adjusts the duty cycle by reading back the DA current sampling value, so that the current reaches a constant current state; when the MOS tube Q1 is turned on, the MOS tube Q2 is turned off; when the MOS tube Q1 is turned off, the MOS tube Q2 is turned on. The working time of each cycle of the MOS tube Q1 and the MOS tube Q2 is less than 50%, which reduces the heat generated by the MOS tube.

[0039] Transformer unit T1 feeds back part of the energy on the load to the output end of the aging power supply. Since most DC / DC modules are step-down modules, that is, input voltage>output voltage, when the electronic load feeds back energy, in order to achieve the output voltage of the aging power supply (<60V), transformer T1 is set as a step-up transformer, and the ratio of the number of turns of the primary side of transformer T1 to the number of turns of the secondary side of transformer T1 is 1:8; the ratio of the primary side turns to the secondary side = 1*8, which can meet the input-output voltage ratio of most DC / DCs. At the same time, relays K1 and K2 are introduced. When the ratio of individual input-output voltage exceeds 8 times, the common terminal 2 of K1 and K2 can be switched from 3 to 1. At this time, the secondary side of transformer T1 is equivalent to series connection, which can be amplified by 16 times. Under normal conditions, relays K1 and K2 are short-circuited 2 / 3 to form a parallel state. This ratio increases the energy feedback efficiency under the condition of meeting most DC / DC step-down ratios; when relays K1 / relays K2 are short-circuited 2 / 1 to form a series connection, the ratio of the primary side turns is increased, making the feedback voltage higher. Example 3

[0040] Based on Example 2, this example is a power-feed DC / DC test device, which is a device for implementing the power-feed DC / DC test method.

Claims

1. A power-feed type DC / DC test method, comprising a power-feed type circuit unit and a DC / DC module to be tested, characterized in that: The energy-feeding circuit unit includes a voltage boosting module, a DC energy-feeding electronic load module and a DSP module; the DC energy-feeding electronic load module is connected to the voltage boosting module, the DC energy-feeding electronic load module feeds back energy to the voltage boosting module, the voltage boosting module is connected to the DC / DC module under test, the DC / DC module under test is connected to the DC energy-feeding electronic load module, The energy-feedback DC / DC test method comprises: Step 1, the aging power supply provides power to the voltage boost module; Step 2, the voltage boosting module boosts the input voltage through the DSP module, and transmits the boosted voltage to the DC / DC module under test; Step 3, the DC / DC module under test outputs voltage to the DC energy-fed electronic load module, and the DC energy-fed electronic load module feeds back DC power to the voltage boost module and the DSP module, and further executes step 2.

2. The energy-fed DC / DC test method according to claim 1, characterized in that: The voltage boost module includes a boost unit, a rectifier unit and a voltage sampling unit; the boost unit is used to boost the voltage output from the input aging power supply end, the rectifier unit is used to rectify and filter the boosted voltage, and transmit the rectified and filtered voltage to the DC / DC module under test; The voltage sampling unit collects the voltage output by the rectifying unit and feeds it back to the DSP end.

3. The energy-fed DC / DC test method according to claim 1, characterized in that: The boost unit includes a first isolation driving unit, a second isolation driving unit, a MOS transistor Q5, a MOS transistor Q6 and a transformer unit T2, wherein the input end of the first isolation driving unit is connected to the ePWM2A signal provided by the DSP module, the output end of the first isolation driving unit is connected to the first end of the MOS transistor Q5, the second end of the MOS transistor Q5 is connected to the transformer unit T2, and the third end of the MOS transistor Q5 is grounded; The input end of the second isolation driving unit is connected to the ePWM2B signal provided by the DSP module, the output end of the second isolation driving unit is connected to the first end of the MOS tube Q6, the second end of the MOS tube Q6 is connected to the transformer unit T2, and the third end of the MOS tube Q6 is grounded.

4. The energy-fed DC / DC test method according to claim 1, characterized in that: The rectifier unit includes MOS tube Q7, MOS tube Q8, MOS tube Q9, and MOS tube Q10; the first ends of the MOS tube Q7 and the MOS tube Q10 provide ePWM3A signals through the DSP module, and the first ends of the MOS tube Q8 and the MOS tube Q9 provide ePWM3B signals through the DSP module; the output signals after rectification by the MOS tube Q7, the MOS tube Q8, the MOS tube Q9, and the MOS tube Q10 are filtered by the capacitor C3 and then sent to the DC / DC module under test.

5. The energy-fed DC / DC test method according to claim 1, characterized in that: The voltage sampling unit includes a DA sampling chip and an optocoupler isolator. The DA sampling chip is connected to the filter capacitor C3 and is used to collect the voltage output by the rectifier unit; and the collected voltage is fed back to the DSP module via the optocoupler isolator.

6. The energy-fed DC / DC test method according to claim 1, characterized in that: The DC energy-fed electronic load module includes a MOS tube Q1, a MOS tube Q2, and a transformer unit T1; the negative electrode of the output end of the measured DC / DC module voltage is connected to the third end of the MOS tube Q1 and the third end of the MOS tube Q2, the second end of the MOS tube Q1 and the second end of the MOS tube Q2 are connected to one side of the transformer unit T1, the first end of the MOS tube Q1 provides an ePWM1B signal through a DSP module, and the first end of the MOS tube Q2 provides an ePWM1A signal through the DSP module; the other side of the transformer unit T1 is connected to a rectifier and filter unit, and is connected to the output end of the aging power supply through the rectifier and filter unit.

7. The energy-fed DC / DC test method according to claim 1, characterized in that: The DC energy-fed electronic load module also includes a relay K1 and a relay K2; the relay K1 and the relay K2 can be connected in series or in parallel, and are controlled by the DSP module. One side of the relay K1 and the relay K2 is connected to the rectifier and filter unit, and the other side is connected to the output end of the aging power supply.

8. A power-feed type DC / DC test device, characterized in that: A device for implementing the energy-fed DC / DC test method described in any one of claims 1-7.

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