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CH1 常用低压电器 专业英语 Language Points
[1] Power semiconductor devices constitute the heart of modern power electronic apparatus. They are used in power electronic conversion in the form of a matrix of on-off switches. And the switching mode power conversion gives high efficiency.
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CH1 常用低压电器 专业英语 Language Points
[11]GTOs are available with asymmetric and symmetric voltage-blocking capabilities which are used in voltage-fed and currentfed converters, respectively． [12]GTOs are used in motor drives, static VAR compensators (SVCs), and AC/DC power supplies with high power ratings. When large-power GTOs became available they ousted the force-commutated, voltage-fed thyristor inverters.
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CH1 常用低压电器 专业英语 Language Points
[4] If the reverse voltage exceeds a threshold value, called the breakdown voltage, the device goes through avalanche breakdown, which is when reverse current becomes large and the diode is destroyed by heating due to large power dissipation in the junction.
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CH1 常用低压电器 专业英语 Language Points
[7] Basically, thyristor is a three-junction P-N-P-N device, where P-N-P and N-P-N component transistors are connected in regenerative feedback mode. The device blocks voltage in both the forward and reverse direction (symmetric blocking).
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CH1 常用低压电器 专业英语 Language Points
[6] Often, it is a family name that includes SCR, TRIAC, GTO,MCT, and IGCT. Thyristors can be classified as standard, or slow phase-control-type and fastswitching, voltage-fed inverter-type. The inverter-type has recently become obsolete.
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CH1 常用低压电器 专业英语 Language Points
[5] Thyristors, or silicon-controlled rectifiers (SCRs) have been the traditional workhorses for bulk power conversion and control in industry. The modern era of solid-state power electronics started due to the introduction of this device in the late 1950s.
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CH1 常用低压电器 专业英语 Language Points
[15] The introduction of insulated gate bipolar transistors in the mid-1980s was an important milestone in the history of power semiconductor devices．They are extremely popular devices in power electronics up to medium power range and are applied extensively in DC/AC drives and power supply systems. They ousted BJTs in the upper range, and are currently ousting GTOs in the lower power range.
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CH1 常用低压电器 专业英语 Language Points
[9] A well-designed RC snubber is essential for a triac circuit. Triacs are used in light dimming, heating control, alliancetype motor drives, and solid-state relays with typically 50/60 Hz supply frequency.
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CH1 常用低压电器 专业英语 Language Points
[16] An IGBT is basically a hybrid MOSgated turn-on/off bipolar transistor that combines the advantages of both a MOSFET and BJT. Its architecture is essentially similar to that of a MOSFET, except an additional P+ layer has been added at the collector over the N+ drain layer of the MOSFET.
Complement
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CH1 常用低压电器 专业英语
New Words and Expressions
converter n. 转换器，换流器，变流器 matrix n. 模型，矩阵 diode n. 二极管，半导体二极管 thyristor n. 晶闸管 triac n. 三端双向晶闸管 GTO 门极可关断晶闸管 BJT 双极结型晶体管 power MOSFET 电力MOS场效应晶体 管 SIT 静态感应晶体管
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CH1 常用低压电器 专业英语
New Words and Expressions
IGBT 绝缘栅双极型晶体管 MCT MOS控制晶闸管 IGCT 集成门极换向晶闸管 rectification n. 整流 feedback n. 反馈 freewheeling n. 单向传动 snubber n. 缓冲器，减震器 intrinsic adj. 固有的，体内的，本征
CH1 常用低压电器 专业英语
PART 1 Electrical and Electronic Engineering Basics
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CH1 常用低压电器 专业英语
Section 4 Power Semiconductor Devices
New Words and Expressions Language points
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CH1 常用低压电器 专业英语
New Words and Expressions
forward biased 正向偏置 conduction n. 导电,传导 reverse biased 反向偏置 leakage current 漏电流 threshold n. 门限，阈限，极限 breakdown n. 击穿，雪崩 recovery n. 恢复 schottky diode 肖基特二极管
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CH1 常用低压电器 专业英语 Language Points
[3] They are also used in feedback and the freewheeling functions of converters and snubbers. A typical power diode has P-I-N structure, that is, it is a P-N junction with a near intrinsic semiconductor layer (I-layer) in the middle to sustain reverse voltage.