春晨 JEHEH电机引接线 电机连接电缆

江苏春晨电缆有限公司生产春晨 JEHEH电机引接线 电机连接电缆，

继电保护装置是在电力网、发电厂、变电所及电气设备发生断线、短路、接地等故障，及过载、过热等不正常运行时及时发出信号，并使断路器自动跳闸，切断故障通路的一种自动装置。

Relay protection device is an automatic device that sends out signals in time when power network, power plant, substation and electrical equipment break, short circuit, grounding, overload, overheating and other abnormal operation, and makes circuit breaker trip automatically and cut off the fault path.

继电保护装置在大多数情况下是由几个继电器组成的自动装置、按其工作原理分有：过电流保护、电流速断保护，过（欠）电压保护、差动保护、瓦斯保护、单相接地保护等。对继电保护的基本要求是良好的选择性、反应故障的快速性、灵敏性、可靠性及投资维护的经济性。

In most cases, relay protection device is an automatic device consisting of several relays. According to its working principle, it can be divided into overcurrent protection, current quick-break protection, overvoltage protection, differential protection, gas protection, single-phase grounding protection, etc. The basic requirements of relay protection are good selectivity, fast response to faults, sensitivity, reliability and economy of investment and maintenance.

过电流保护装置

Overcurrent protection device

过电流保护是一种 基本的电流保护，用来反应短路故障及严重的过载故障。保护对象广泛：如线路、发电机、变压器和各种负载等。过电流保护一般带有动作时限，可分为定时限和反时限两种。春晨 JEHEH电机引接线 电机连接电缆

Overcurrent protection is one of the most basic current protection, which is used to respond to short-circuit fault and serious overload fault. The object of protection is extensive: such as lines, generators, transformers and various loads. Overcurrent protection usually has operation time limit, which can be divided into fixed time limit and inverse time limit.

所谓定时限过电流保护是不管故障电流超过整定值多少、其动作时间是一定的。若动作时间与故障电流成反比变化，即故障电流超过整定值越多，动作时间越快，则称为反时限过电流保护。下图所示是过电流保护的方框图。图中启动、时限、信号、出口各个环节分别是电流继电器、时间继电器、信号继电器、中间继电器。

The so-called fixed-time over-current protection is that no matter how much fault current exceeds the set value, its operation time is certain. If the action time is inversely proportional to the fault current, that is, the more the fault current exceeds the set value, the faster the action time is, it is called inverse time overcurrent protection. The following figure shows the block diagram of overcurrent protection.  The starting, time limit, signal and outlet links are current relay, time relay, signal relay and intermediate relay.

过电流保护

Overcurrent protection

当线路出现短路故障时，通过电流互感器TA，电流继电器检测出故障并启动，经过时间环节的延时后，再利用中间继电器使断路器QF跳闸，同时通过信号继电器发出灯光及音响信号。

When a short-circuit fault occurs in the circuit, the fault is detected and started by the current transformer TA and the current relay. After the delay of the time link, the QF of the circuit breaker is tripped by the intermediate relay. At the same time, the light and sound signals are sent out by the signal relay.

过电流保护的主要优点是结构简单、可靠、经济、缺点是随着电网延伸段数的增多，靠边电源的过载电流保护装置的时限将很长，有时长到不能允许的程度。此外，当负荷电流很大时，保护的灵敏度往往不能满足要求。

The main advantage of over-current protection is its simple structure, reliability, economy and disadvantage. With the increase of the number of extended sections of power grid, the time limit of overload current protection device of side power supply will be very long, sometimes to an unacceptable extent. In addition, when the load current is very large, the sensitivity of protection often can not meet the requirements.

电流速断保护

Current Quick Break Protection

这是另一种电流保护。这种保护没有延时性，是瞬时动作的，上右图去掉时限环节，即为速断保护框图。速断保护通常与过电流保护配合使用。构成所谓“两段式保护”。

This is another kind of current protection. This kind of protection has no delay, it is instantaneous action. The upper right figure removes the time-limit link, that is, the block diagram of quick-break protection. Quick-break protection is usually used in conjunction with over-current protection. It constitutes the so-called "two-stage protection".

电流速断保护突出优点是结构简单、动作迅速、可靠、经济，缺点是保护范围运行方式的影响很大，无时限的速断保护不能保护电路的全长。为了弥补这一缺陷，常采用略带时限的速断保护，即延时速断保护。

The outstanding advantages of current quick-break protection are simple structure, fast operation, reliability and economy. The disadvantage is that the operation mode of protection range has a great influence, and the full length of circuit can not be protected by time-limited fast-break protection. In order to remedy this defect, a slightly time-limited quick-break protection, i.e. delayed quick-break protection, is often used.