外文翻譯--設(shè)計的反饋式直流電子負載硬件電路采用智能功率模塊（英文）

1、DESIGN OF THE FEEDBACK TYPE DC ELECTRONIC LOAD HARDWARE CIRCUIT USING IPM Lu Haiying1, Wu Jing2, Huang Songling1, Zhao Wei1 1. Department of Electrical Engineering, Tsinghua University, Beijing, China; 2. School of Autom

2、ation Science and Electrical Engineering, Beihang University, Beijing, China ABSTRACT Firstly, the paper shows the comparison between the traditional resistance load and the new electronic load. And then it suggests th

3、e implementation scheme of the feedback type DC electronic load, which features feeding back energy to the public grid. Furthermore, the structure of the inverter, which is the kernel module of the feedback type elect

4、ronic load, is introduced. Finally, an excellent functional and reliable single-phase grid-connected inverter is developed, using IPM to constitute its main circuit. The driving circuit, as well as the snubber circui

5、t and protection circuit, is designed. With advantages of energy saving and high efficiency, the feedback type DC electronic load possesses extensive application foreground and pretty well economic benefit. Index Ter

6、ms— feedback type DC electronic load, energy saving and high efficiency, inverter, IPM 1. INTRODUCTION As the common testing equipment, load plays a very important role in many kinds of power tests, which performance

7、has a direct effect on the test results. The traditional resistance load refers to the slide rheostat and the resistance box, which has a bad accuracy because of the thermal noise while going through the high current

8、[1]. Meanwhile, the resistance load has to be fitted with a set of large cooling equipments to bring down the temperature which rises because of the thermal energy transformed. The electronic load is a new kind of lo

9、ad consists of electronic components, which usually refer to the Power MOS or IGBT, and power resistance [2]. It can not only works as a fixed impedance, but also simulate some special load waveform to test the dynam

10、ic and transient characteristics of the power equipment [3], which is impossible for the resistance load. Besides, it has numerous advantages for its simple structure, high precision, adjustable range and high reliabi

11、lity [4]. This kind of electronic load is called energy dissipation type electronic load for its wasteful energy consumption. And it still needs to be fitted with a set of large cooling equipments. Therefore, the fee

12、dback type electronic load is proposed. To replace the power resistance by inverter module, it can feed back the testing energy to the utility grid, with a high efficiency more than 80% generally. Its losses only con

13、tain the power semiconductor switching losses and the line losses. And the cooling equipment is no longer needed cause this type of the electronic load don't generate large quantity of thermal energy. In addition,

14、 most of the electric energy is recycled, so we don't need equip the experimental site with large power capacity [5]. Making use of the advanced power electronic technology, the feedback type electronic load caus

15、es the widespread public concerns and has a wide use prospect for its advantages of energy saving and high efficiency. 2. FEEDBACK TYPE DC ELECTRONIC LOAD Fig. 1. Topology of the feedback type DC electronic load Accor

16、ding to the property of input power, the feedback type electronic load is classified into DC type, which is designed to test the DC power equipment, and AC type. IEEE CCECE 2011 - 000156????????????????????????????????

17、??????? ???????????????????????????????????make full use of the fault signal FO, an extra protection circuit is still needed to enhance the reliability of the whole system. Designs of the driving circuit, snubber circu

18、it and protection circuit are presented below. 4.1. Driving Circuit Because IPM's has a built-in driving module, its periphery driving circuits as two parts including power supply circuit and optocoupler circuit.

19、4.1.1. Power Supply Circuit IPM's power supply must be separated from each other, not grounded together and meet the power need. Three independent power sources are needed, two of which supply power to the two IG

20、BTs of IPM's up-bridge respectively, as well as the other of which is shared by the other two IGBTs of IPM's down-bridge. The typical voltage of the control sector is 15V, and the maximum current is 18mA. Ther

21、efore the power source should at least provide 0.27W to one IGBT while driving it alone, and 0.54W to the two IGBTs while driving them both. To obtain three independent isolation 15V DC power sources, three MORNSUN B

22、1215S-2W modules are selected, which can provide 2W, not only meet the power needs but also is enough for the future development. 4.1.2. Optocoupler Circuit To avoid the strong electrical interference from power sup

23、ply, the control signals from DSP should be isolated by optocouplers. The high-speed optocoupler HCPL4504 is selected for the driving signals, because the SPWM frequency is high and the driving waveform should meet t

24、he conditions as follows: tPLH?0.8 μ s, tPHL?0.8 μ s, CMR>10kV/ μ s. The low-speed optocoupler TLP521 is selected for the fault signal, because its signal cycle is measured in milliseconds and it requests CTR>1

25、00%. Firstly the SPWM signals from control circuit are current limited, and isolated and amplified by the high-speed optocouplers, then they are transmitted to the IPM's internal driving circuit to control the IGB

26、Ts. The fault signals FO are isolated and output through low-speed optocouplers. 4.2. Snubber Circuit The snubber circuit can control IGBT's turn-off surge voltage and reverse surge voltage of freewheel diodes, r

27、educe switching losses and protect IGBTs while the short circuit happens. RCD snubber circuit is selected. The transient voltage will be clamped by the diodes D, thus parasitical oscillation generated by bus parasiti

28、c inductors will be restrained. Values of the resistance and capacitance are given according to experiences and experiments. The maximum voltage pressure endurance of the capacitance should be 1.1-1.5 times of IGBT. T

29、he power of resistance is calculated according to P=fCU2/2, in which U is the peak voltage and f is the switching frequencies of IGBT. To ensure the capacitance initial voltage is zero, the RC time constant should b

30、e calculated according to the formula /3 1/3 RC T f τ = ≤ = . 20?/20W cement resistor, 0.1uF/1200V non-inductive capacitor and DSEI30-12A fast recovery diode are selected and packaged as a module in order to red

31、uce the wire inductance. 4.3. Protection Circuit 4.3.1 Hardware Protection Circuit Fig. 4. Interlock Circuit for SPWM First of all, an interlock circuit carrying on logical operation is designed for the SPWM impulse si

32、gnals which are output from DSP to avoid the two power semiconductors of the same bridge arm short circuit when DSP works abnormally. This circuit is composed of 74ALS04 NOT gate and 74ALS08 AND gate, as is shown in

33、Fig.4. Secondly, the output signals are connected to the IPM's input terminals of driving circuit through 74HC245 tri-stat transceiver. After the fault signals Fo from IPM's optocoupler circuit go through CD

34、4012B NOT-AND gate, the output result is given to the OE enable terminal of the transceiver. The circuit mentioned above can be seen in Fig.5. IPM has the active-low fault output which remains high when IPM runs corr

35、ectly, therefore the transceiver works in the strobe mode and the SPWM signals are output correctly. When something wrong happens, OE is set to be high, which results in a high impedance condition of transceiver, mak