REX010 HESG324426R0001 接地故障保护是基于编码信号的注入

接地故障保护是基于编码信号的注入。由此产生的偏置电压用于计算地电阻(Rf)。
注油信号在注油单元REX010中产生，通过变压器单元REX011作用于发电机。对于与保护单元的耦合，使用电阻(RE, RP)。对于转子接地故障保护，还需要增加两个电容。
接地故障保护的测量信号分别由REG216或REG316*4处理。
所描述的设备可以100%保护发电机定子绕组。应用了两个独立的保护功能:一个用于95%，另一个使用不同的算法，用于100%的定子绕组。100%函数是计算接地电阻，95%函数是测量发电机的中性电压位移。
a) 100%功能在Rf = 0, I0max = 15a时保护35%的定子绕组不受中性点影响
b) 95%功能(U>)保护95%的发电机定子绕组免受端子的伤害。这导致重叠(冗余)的两个保护功能，如图1所示。
100%函数的灵敏度随接地故障电阻的增大和接地故障电流的减小而增大。

保护设备由以下部件组成(图4 – 8):REG216/316*4:数字发生器保护REX010:注液单元REX011:带辅助接触器的注液变压器单元此外还需要以下部件:
-发电机中性点(REs, RPs)和励磁电路(REr, RPr)中的接地电阻
-转子励磁电路中的耦合电容器
-电压互感器
注入单元(REX010)与注入变压器(REX011)一起产生频率为fN/4的三个编码方波信号(Uis, Uir, Ui)。这些方波信号通过耦合元件注入被保护对象。三个方波有不同的振幅:Uis(定子注入信号)，Uir(转子注入信号)和Ui (REG216/316*4参考信号)。注入单元REX010连接到电站电池，注入信号电压由电池或内部DC/DC转换器产生。

REX010

The earth fault protection is based on the injection of a coded signal. The resulting offset voltage is utilized to calculate the earth resistance (Rf).
The injection signal is produced in the injection unit REX010 and applied to the generator through the transformer unit REX011. For the coupling to the protected unit resistors (RE, RP) are used. For the rotor earth fault protection two capacitors are required in addition.
The measurement signals for earth fault protection are processed by the REG216 or the REG316*4 respectively.
The equipment described protects 100% of the generator stator winding. Two independent protection functions are applied: one for 95% and one, using a different algorithm, for 100% of the stator winding. The 100% function is calculating the earth resistance and the 95% function is measuring the neutral voltage displacement of the generator.
a) The 100% function protects 35% of the stator windings from the neutral point for Rf = 0 and I0max = 15 A
b) The 95% function (U>) protects 95% of the generator stator winding from the terminals. This results in an overlap (redundancy) of the two protection functions as seen in Fig. 1.
The 100% function increases in sensitivity with increasing earth fault resistance and decreasing earth fault current.

The protection equipment consists of the following units (Figures 4 – 8): REG216/316*4: Numerical generator protection REX010: Injection unit REX011: Injection transformer unit with auxiliary contactor In addition the following components are required:
– Earthing resistors in the generator neutral point (REs, RPs) and in the excitation circuit (REr, RPr)
– Coupling capacitors in the excitation circuit of the rotor
– Voltage transformers
The injection unit (REX010) together with the injection transformer (REX011) produces three coded square wave signals (Uis, Uir, Ui) with a frequency fN/4. These square wave signals are injected into the protected object via the coupling components. The three square waves have different amplitudes: Uis (Injection signal for the stator), Uir (Injection signal for the rotor) and Ui (reference signal for the REG216/316*4). The injection unit REX010 is connected to the station battery and the injection signal voltage is generated either by the battery or by an internal DC/DC converter.