Self-Contained Type (High Side Voltage Control) or PSS (Power System Stabilizer) Power System Voltage Vr(PU) 0.5 800 1000 1200 1400 1600 Transmission Power Pr(MW) Self-Contained Type or PSS unit unit Easy Installation PSS unit PSS without PSS Existing Excitation Panel Power 1.1 1.0 0.9 0.8 0.7 0.6 Conventional with PSS time (sec)
MITSUBISHI Self-Contained Type or PSS for Improving the Performance of Existing Excitation System Features of Self-Contained Type or PSS Improving Effect on Power System Stability & Features function and PSS function self-contained in independent units function and/or PSS function easily added to existing (excitation panel) Optional features for increased functionality and remote operation controllers for high performance and reliability Improved system stability and collapse prevention Low cost and easy installation Improved transient stability and voltage stability by controlling high side voltage and more efficient use of the reactive power supplying capability of each generator High side voltage measurement not needed ---only terminal voltage and current measurement (advanced line drop compensation) High control response of high side voltage within several seconds. For details, please refer to MITSUBISHI brochure SE-D735-A Power System Voltage Vr(PU) 1.1 1.0 0.9 0.8 0.7 0.6 Conventional 0.5 800 1000 1200 1400 1600 Transmission Power Pr(MW) Low operation and maintenance cost Configuration of or PSS Unit PSS Improved power system stability --- damping power system oscillations Integral of accelerating power type PSS For details, please refer to MITSUBISHI brochure SE-D779 Power without PSS Vi Xd,Ig G Pg, CT Load Circuit Breaker PT Step-up Transformer VH Network with PSS time (sec) Exciter Self-Contained Type /PSS Server...etc. Power Supply 125VDC Internet / Intranet Server...etc. Unit of other s Power Supply 125VDC "Control"(PSS on) Internet / Intranet PSS Unit of other s "Control"( on) Parallel "Operating" (Load circuit breaker "Close") Voltage Current Voltage Setter of Parallel CTs PTs CPU Human / Machine Interface Unit Configuration Alarms Control Signal to to Unit of Parallel Voltage Current G Shaft (toothed-wheel) CTs PTs Speed Detector CPU Human / Machine Interface PSS Unit Configuration Alarms Control Signal to BASIC
Mitsubishi Self-Contained Type (High Side Voltage Control) or PSS (Power System Stabilizer) Function of has many optional functions and these functions will be installed according to the customer VHref n Calculating function of control target voltage Reactive current compensation function (option) Compensation follow-up control function (option) Automatic XDR*1 compensation function by tap position (n) of step-up transformer ( option) Phase compensation function for stabilizing control loop Phase compensation function for damping angle oscillation (option) of voltage setter Compensation function of position of voltage setter of parallel generator Cross Current Compensation function (Option) Voltage Limiter VL To function diagram *1: Voltage Droop Rate for stable parallel operation Function of PSS or (option) stw1 1+sTw1 stw2 1+sTw2 1 1+sT6 Pa (1+sT8) N (1+sT9) M Ks1 1+sT1 1+sT2 1+sT3 1+sT4 Ks3 Pg stw3 1+sTw3 stw4 1+sTw4 Ks2 1+sT7 1+sT10 1 1+sT11 1+sT12 Limiter To Function diagram for accelerating power type ( IEEE PSS2A model ) In addition to integral of accelerating power type PSS, the following types of PSS are also available. (1) Active Power and Speed (frequency) type (2) Active Power type (3) Speed (frequency) type *1:Kinds of Speed signal (1) Frequency of terminal voltage --- only terminal voltage (2) Frequency of internal voltage calculated from terminal voltage and current (Vi= + xd Ig) --- (option) (3) Actual rotor speed --- required speed detector (option)
Specification of Hardware ITEM unit PSS unit Power Source CT/PT (burden) 125Vdc (77 to 144Vdc) / 60W (burden) CT (1 or 5A) PT (100 to 120V) Signal level less than 0.2VA less than 0.1VA +/- 10V Accuracy +/- 0.5% of 3 Phase Reactive Power Voltage Active Power Voltage Pg Frequency f of Other signal of voltage setter Speed signal (Option) from a parallel generator Signal level +/- 10V (External load resistance 5kOHM or greater) Accuracy +/- 0.5% output to PSS output signal to output to a unit of a parallel generator (For measurement) (For measurement) 24Vdc / 10mA Power supply for relay contacts Change signal of "Control" ( "on") None A signal of parallel generator "operating" (Load circuit breaker "close") Human-Machine Interface (HMI) Working Temperature Working Humidity Optional System & Speed detector & PC & Network SCADA Server Web Server Contact rating 200Vdc / 0.15A (Semiconductor relay) Alarm Power supply failure / Electrical failure (Self-diagnosis) Setting of parameters 0 to +50 C 10 to 90 %RH (without dewing) None For speed signal input Remote operation Data logger, Trend graph etc. Connection to Internet
Mitsubishi Self-Contained Type (High Side Voltage Control) or PSS(Power System Stabilizer) Scale of or PSS Unit MITSUBISHI Self-Contained Type or PSS is respectively offered as 1 module. This module is compact so that the user can built it into existing excitation cubicles.the or PSS application is for improving transient stability and voltage stability of the power system. 480mm 420mm HMI Status Function Value Run 149mm Error Control Value Lock Cancel Error Maintenance RS232-C (option) Check1 Check 2 Check 3 Check 4 Check 5 Check 6 220mm HEAD OFFICE: MITSUBISHI DENKI BLDG., MARUNOUCHI, TOKYO 100-8310. TELEX: J24532 CABLE: MELCO TOKYO Improper use of products can cause severe injury or death, and may result in damage to product and other property. Please read instruction manual before installing or using product. SE-D778-A(0202-1.0)MDOC New Publication, effective Sep. 2001. Specifications subject to change without notice.