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Electrical Distribution Training Training for Sepam Series 20/40/80 Control and monitoring functions Load shedding principle Motor load shedding is done to reduce the load on the electrical system so as to keep the voltage within an acceptable range. Block diagram Sepam advanced control logic EN 2007_01.ppt 2 Load shedding implementation Setting the load shedding function The outputs for load shedding orders and inhibition of closing are part of the switchgear control function. Sepam advanced control logic EN 2007_01.ppt 3 Restart principle With this function, motors can be automatically restarted after a shutdown triggered by a voltage dip (load shedding). The restart function is to be associated with the load shedding function. It allows staggered restarting of process motors as long as the voltage dip that caused load shedding was brief. Sepam advanced control logic EN 2007_01.ppt 4 Restart implementation Setting the restart function The outputs for restart orders are part of the switchgear control function Sepam advanced control logic EN 2007_01.ppt 5 Generator shutdown and tripping Generator shutdown and tripping involve: tripping of the circuit breaker connecting the machine to the network (1) tripping of the excitation circuit breaker (2) shutdown of the prime mover (3). The combination of these three orders determines four types of shutdown and tripping orders: total shutdown (1,2,3), often referred to as simultaneous tripping generator tripping (1,2) generator separation (1) sequential tripping (1,2,3 sequentially). Sepam advanced control logic EN 2007_01.ppt 6 Generator shutdown and tripping Genset shutdown The genset shutdown function, only present in generator applications, is used for mechanical shutdown by shutting down the prime mover and electrical shutdown by tripping the generator. Genset shutdown is a control logic function which may be used to include or exclude protection function action in conjunction with genset shutdown. This operation may be disabled. Sepam advanced control logic EN 2007_01.ppt 7 Generator shutdown and tripping Genset shutdown Genset shutdown may be initiated in the following ways: by a shutdown order by delayed protection functions – protection functions unrelated to circuit breaker position:12, 21B, 24, 27TN, 32Q, 40, 51V, 64REF, 67, 67N, 81L, 87M, 87T – protection functions dependent on circuit breaker position: 50/51, 50N/51N, 59N. The time-delayed, non-memorized outputs of these protection functions trigger shutdown only if the circuit breaker is open by logic equations Sepam advanced control logic EN 2007_01.ppt 8 Generator shutdown and tripping Genset shutdown Participation in the function is to be set individually in the protection function setting tabs of the SFT2841 software for each protection unit that can take part in genset shutdown. Sepam advanced control logic EN 2007_01.ppt 9 Generator shutdown and tripping De-excitation The de-excitation function, only present in generator applications, is used to quickly cut off the power supply to an internal fault when the generator is disconnected from the network. De-excitation is a control logic function that may be used to include or exclude protection function action. This operation may be disabled. Sepam advanced control logic EN 2007_01.ppt 10 Generator shutdown and tripping De-excitation A de-excitation order may be initiated in the following ways: by a shutdown order by delayed protection functions – protection functions unrelated to circuit breaker position:12, 21B, 24, 27TN, 32Q, 40, 51V, 64REF, 67, 67N, 81L, 87M, 87T – protection functions dependent on circuit breaker position: 50/51, 50N/51N, 59N. The time-delayed, nonmemorized outputs of these protection functions trigger de-excitation only if the circuit breaker is open by logic equations Sepam advanced control logic EN 2007_01.ppt 11 Generator shutdown and tripping De-excitation Participation in the function is to be set individually in the protection function setting tabs of the SFT2841 software for each protection unit that can take part in genset shutdown. Sepam advanced control logic EN 2007_01.ppt 12 Generator shutdown and tripping Add the outputs for the genset shutdown and de-excitation functions to the control matrix. Sepam advanced control logic EN 2007_01.ppt 13 Automatic transfer Objectives Automatic transfer is used to increase the continuity of electrical power supply: to automatically replace a failing power supply, or to temporarily transfer the load to another branch of the power supply system for maintenance operations. An operating configuration is chosen as of the design of the installation according to technical and economic criteria. The chosen transfer principle calls for the installation of breaking cubicles and voltage sensors. A ladder diagram is created to control the transfer of breaking devices (circuit breakers, contactors or switches) and checking is done to help with the manual return to the usual operating position. The coupling of power supplies (parallel-connected) is a technical improvement which reduces disturbances for users at the time of the return to normal operation. Generally speaking, the coupling operation, when possible, only lasts for a short time. Sepam advanced control logic EN 2007_01.ppt 14 Automatic transfer Description The Sepam series 80 substation, transformer, busbars and generator applications contain preprogrammed logic schemes that cover the majority of configurations found in MV or LV installations. 1 out of 2 sources is closed: There are 2 possible power supplies (one normal and one backup) on the same busbars. Just one of them supplies the busbars. Transfer consists of switching completely to the other source. 2 out of 3 circuit breakers are closed: 2 power supplies are connected to 2 separate busbars, which may or may not be coupled by a coupling circuit breaker. Each source is capable of supplying on its own all of the loads of both busbars. This is why there are some installations with just one power supply and coupling closed and others with 2 power supplies and coupling open. An automatic load shedding system is sometimes associated with the «backup» power supply. When there are 2 independent sources, a synchro-check device (ANSI 25 function) is required to enable parallel connection (coupling of sources). This function is only used for the return-to-normal operation. Sepam advanced control logic EN 2007_01.ppt 15 Automatic transfer: «One out of two» transfer (no coupling breaker) Operating position Transfer After transfer ! NO normally open circuit breaker Sepam advanced control logic EN 2007_01.ppt NO normally open circuit breaker NO normally open circuit breaker 16 Automatic transfer: «One out of two» transfer (no coupling breaker) Operating position Manual return Return of source with or without coupling Coupling with or without ANSI 25 ! 25 25 NO Sepam advanced control logic EN 2007_01.ppt 17 Automatic transfer: «Two out of three» with coupling open After transfer Operating position Transfer ! NO Sepam advanced control logic EN 2007_01.ppt NO NO 18 Automatic transfer: «Two out of three» with coupling open Operating position Manual return with or without coupling Coupling with or without ANSI 25 Return of source ! 25 25 NO Sepam advanced control logic EN 2007_01.ppt 19 Automatic transfer: «Two out of three» with coupling closed After transfer Operating position Transfer ! NO Sepam advanced control logic EN 2007_01.ppt NO NO 20 Automatic transfer: «Two out of three» with coupling closed Operating position Manual return Return of source with or without coupling Coupling with or without ANSI 25 ! 25 25 NO Sepam advanced control logic EN 2007_01.ppt 21 Automatic transfer Implementation in SFT2841 First operation: activation of predefined control logic Tr Latching of close order Stabilization of the difference between the 2 sources Acknowledgment of the Type of transfer “close enable (ANSI 25)” input Sepam advanced control logic EN 2007_01.ppt 22 Automatic transfer Implementation in SFT2841 Description of standard assignments - compulsory ____ - optional ------- To record input and output numbers Sepam advanced control logic EN 2007_01.ppt 23 Automatic transfer Implementation in SFT2841 Second operation: standard assignment and activation of the use of output relays This input can be connected to one of the outputs of the MCS025 synchro-check module Third operation: add, cancel or reassign inputs according to the configuration, habits and operating requirements. Example: - no coupling, - manual control…. Sepam advanced control logic EN 2007_01.ppt 24 Automatic transfer Implementation in SFT2841 Fourth operation: confirm and set the thresholds of the protection functions used by the transfer function. Example: 27-1 (20%Un) to activate transfer 59-1 (90%Un) to enable a correct return to normal voltage No latching No tripping of CB Sepam advanced control logic EN 2007_01.ppt 25 Automatic transfer Implementation in SFT2841 N.B. No latching or tripping Sepam advanced control logic EN 2007_01.ppt 26 Automatic transfer Implementation in SFT2841 N.B. No latching or tripping Delete standard «overvoltage» messages Sepam advanced control logic EN 2007_01.ppt 27 Automatic transfer Implementation in SFT2841 Fifth operation: assign logic to outputs for interconnection with other cubicles and indications. Sepam advanced control logic EN 2007_01.ppt 28 Automatic transfer Implementation in SFT2841 Sixth operation: Delete the standard «overvoltage» messages for 59 -1 Sepam advanced control logic EN 2007_01.ppt 29 Automatic transfer A few comments Installations are symmetrical, so ladder diagrams in Sepam units may be identical, The selector designating the «NO» normally open circuit breaker is used to create the usual operating configuration and therefore differentiate the operation of automatic transfer ladder diagrams. Not all controls are compulsory. The inputs (compulsory or optional) have a default value in the ladder diagrams. This must be taken into account since when they are declared in Sepam, they become active in the ladder diagrams. Internal variables (for example: V-trans-on_flt, V_close_NO_ord...) are available for «remote control» of transfer and the creation of partially or totally specific ladder diagrams. The «equation editor» and «Logipam» tools provide this adaptation flexibility. Sepam advanced control logic EN 2007_01.ppt 30 Capacitor bank switchgear control Objective The control logic embedded in the Sepam C86 may be used to protect and control a circuit breaker and 1 to 4 capacitor bank switches. The capacitors banks may be star-connected or delta-connected. Sepam advanced control logic EN 2007_01.ppt In the case of star-connection, Sepam provides short-circuit protection of the link to the capacitor bank steps and monitors each link between the 2 stars of each step (fault = unbalance current). In the case of delta connection of each capacitor bank, the Sepam C86 mainly protects against short-circuits (there is no need for a link between capacitor banks). Voltage and frequency monitoring, as well as adaptive thermal overload protect the capacitors against the destructive effects of overvoltage and harmonic frequencies (number 13). 31 Capacitor bank switchgear control Description Circuit breaker control is linked to capacitor bank control voluntary manual control triggers, first of all, the staggered opening of capacitor bank step switches, followed by the opening of the circuit breaker. When a fault occurs, the circuit breaker opens the circuit and then orders the simultaneous opening of all the capacitor step switches. Position matching is monitored for each breaking device. In «automatic control» mode, an external reactive-energy regulator can control the use of the capacitor bank steps. Sepam advanced control logic EN 2007_01.ppt 32 Capacitor bank switchgear control Implementation in SFT2841 First operation: Set the number of capacitor steps according to the installation, the connection and capacitor step ratios* Sepam advanced control logic EN 2007_01.ppt 33 Capacitor bank switchgear control Implementation in SFT2841 Second operation: select circuit breaker control and capacitor step control. This is the capacitor discharge time (given by the manufacturer) These times are used to stagger the opening of the steps. To adapt control* to different breaking devices. Sepam advanced control logic EN 2007_01.ppt 34 Capacitor bank switchgear control Implementation in SFT2841 The outputs dedicated to capacitor bank control are set up as «latched». (i.e. not pulse) Third operation: assign the inputs and confirm the outputs. e.g. 3 steps and manual or automatic control possible by external reactive-energy regulator. Sepam advanced control logic EN 2007_01.ppt 35 Capacitor bank switchgear control Implementation in SFT2841 Fourth operation: confirm and set the protection functions. Change the messages when required. Sepam advanced control logic EN 2007_01.ppt 36 Capacitor bank switchgear control Implementation in SFT2841 Fifth operation: assign the outputs to control logic and indication. Sepam advanced control logic EN 2007_01.ppt 37 Capacitor bank switchgear control A few comments Internal variables are available for «remote control» and the creation of partially or totally specific ladder diagrams. The «equation editor» and «Logipam» tools provide some adaptation flexibility. Sepam advanced control logic EN 2007_01.ppt 38