Digital protective devices shall satisfy the following requirements.(1) The protective devices shall be capable of automatically detectingchanges of system operation states based on input current and voltageas much as possible so as to reduce relevant ext...[继续阅读]

    3.16.1 For 200 MW and above generators with possible excitationvoltage increase under low rotation speed and subject to statorearthing faults or inter-phase short-circuit faults, generator start-upand shutdown protection shall be provided to initiate a ge...[继续阅读]

    15.3.1 Secondary circuits of CTs shall have one and only one pointearthed and generally is earthed at local earthed terminal box viaterminal board. Protective devices consisting of severalinterconnecting CTs shall be earthed at protection panel via termin...[继续阅读]

    The motor-generators operating in motor-mode may be subject toabnormal condition such as power loss and shall be equipped withunder-frequency protection to initiate a unit shutdown....[继续阅读]

    5.8.1 For excessive transformer temperature and tank pressure,abnormal oil level, and cooling system faults, protective devices thatactivate an alarm or a trip may be equipped in compliance withcurrent power transformer standards.5.8.2 Temperature protect...[继续阅读]

    Generators shall be provided with overvoltage protection, of whichthe setting values are determined according to the insulationcondition of stator winding. The overvoltage protection shouldinitiate a unit shutdown or a disconnection and deexcitation....[继续阅读]

    15.2.1 The configuration of voltage transformers (VTs) shallensure that protective devices do not lose voltage in case of operationmode change of primary system.15.2.2 Protective VTs shall be able to correctly transform theprimary voltage to the secondary...[继续阅读]

    5.5.1 Zero-sequence current protection shall be provided forovercurrent at the external single-phase earthing in case transformerneutral is directly earthed in the power system of 100 kV and abovewith a directly-earthed neutral.(1) The 110 kV and 220 kV s...[继续阅读]

    3.2.1 Generators with a unit capacity of 6 MW and above shall beprovided with longitudinal differential protection as the primaryprotection against inter-phase short circuit of stator windings andleads.The protection shall initiate the unit shutdown insta...[继续阅读]

    3.10.1 Generators shall be provided with loss-of-excitationprotection that initiates disconnection with time-delay.3.10.2 The loss-of-excitation protective device shall not misoperatein such cases as external short-circuit, power system oscillation,genera...[继续阅读]