Handbook of Energy Storage for Transmission or ... - W2agz.com

More documents

Recommendations

Info

EPRI Proprietary Licensed Material distribution feeders, acting on post-disturbance voltage to assist in returning the voltage and frequency to an equilibrium status within one second. The advantages of the electrochemical capacitor-based storage system over conventional lead-acid battery are relatively high-power density and cycle life as well as inherently lower maintenance and tolerance to temperature. Currently the main disadvantage is cost. The potential advantage of EC capacitors over SMES, a technology that has been used successfully in grid stabilization, is likely to be modularity in size selection and lower cost. Electrochemical Capacitors DSP Controller DC DC DC AC Bi-directional Multi- Level Converters Figure 23 Concept of Electrochemical capacitor-Based Mini-FACTS controllers Coupled to Utility Grid Uninterrupted Power for Critical Substation Loads Utility Grid Problem Description The need to protect substation equipment during momentary power disturbances and longer-term outages depends on the equipment sensitivity, function, and exposure to power disturbance events at the location. Currently, most substations have control and protection equipment that are identified as critical to station functions. By far the most common practice to protect this equipment is the installation of 48-, 125- and 250-Vdc stationary batteries sized for several days of outage protection. These station batteries require a significant amount of real estate often in the control house of modern transmission and distribution stations. Sixty to 120 cells of large 100- to 400-AH batteries on several battery racks are not uncommon. These typically require environmental space conditioning and periodic maintenance. In some cases, without space conditioning, the expected battery life and its capacity are less. Replacing the batteries with a smaller power protection system that can be installed outdoors is of interest to many utility planners and substation engineers. One concept that will accomplish this is to provide short-term energy storage with some form of back up generation. The system is designed for a few seconds of bridging power to transfer from the primary supply to on site back up generator. Today most practical generators are internal combustion engines, however new types of generators such as micro turbines and fuel cells, as well as advanced fuels, such as hydrogen and bio diesel are evolving. Short-term energy storage products are currently available and could be applied. As of this writing no such application has been installed and tested in substations, although a number of utilities are investigating possible demonstrations. These same Electrochemical Capacitors 44
EPRI Proprietary Licensed Material systems have proven to be reliable in many power quality applications. In the future short-term energy storage such as flywheels, high-energy capacitors, or low-cost cranking batteries, may replace station batteries as a bridge to a fast-start alternate source, such as an engine generator. The options for alternate generators are getting to be more interesting with the possibility of fuel cells, micro-turbines or even hydrogen-fueled IC engines 3 . And the high output power characteristic of many short-term storage technology is particularly complementary to new generation technologies that, when operating alone lack overload capability. Before any application of power protection equipment is attempted the expected electrical environment should be identified. Monitoring and studies of electric power systems have shown that nearly all locations are exposed to power disturbances such as faults on distribution feeders and momentary or sustained loss of the primary power feed. In the case of substations, the low-voltage power service bus is likely to be affected by all events that take place on the transmission lines serving the station and from all the faults on feeders originating from the station. EPRI’s distribution power quality study has defined the typical electrical environment in terms of number and duration of expected events. Figure 24 shows typical interruption and sag rates from the study [3]. These results are based on monitoring events at 277 locations for 28 months, with 326,000-recorded events. Monitor locations were utility feeders selected to be representative of typical quality of power in the US. The average at each location was 74.6 per year. The proposed application is Uninterruptible Power for Critical Substation Equipment that will replace existing station lead acid batteries. This is accomplished by a short-term storage device (e.g., high energy capacitor) incorporated into a bridging power system, as described below, to enable seamless transfer to an alternate feeder or power source. The technical criteria for this application will be substation specific but likely will fall within these parameters: • Application – Uninterruptible Power for Critical Substation Equipment • Power Rating – 25 kW (32 kVA) • Energy Storage Capacity – 139 Wh (not including generator output) • Duration – 20 seconds, or until start of back up generator • Response Time – 5 milliseconds Events per Site per Year 25 20 3 15 When considering short-term energy storage for bridging power the best storage technology depends heavily on the required discharge time. For a few seconds electrochemical or for systems less 50.00% than 50-kW electrochemical capacitors are interesting, from 10 to 20 seconds flywheels are more cost competitive, and 10 40.00% for the longer times that may be required to start new technology generators the conventional lead-acid cranking batteries are very competitive. 30.00% 5 20.00% Electrochemical Capacitors 45 0 Feeder Substations Feeder Middle Feeder End Feeder Mean Interruptions Voltage 10% and
Page 1:
Handbook of Energy Storage for Tran
Page 4 and 5:
DISCLAIMER OF WARRANTIES AND LIMITA
Page 7:
EPRI Proprietary Licensed Material
Page 10 and 11:
Vanadium Redox Battery 2
Page 12 and 13:
Page 14 and 15:
Page 16 and 17:
Page 18 and 19:
Page 20 and 21:
Page 22 and 23:
Page 24 and 25:
Page 26 and 27:
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Regenesys Electricity Storage Techn
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73:
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
The status of sodium sulfur batteri
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Page 145:
Page 149 and 150:
Page 151:
Page 154 and 155:
Page 156 and 157:
Page 158 and 159:
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Page 180 and 181:
Page 182 and 183:
Page 184 and 185:
Page 186 and 187:
Page 188 and 189:
Page 190 and 191:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
Page 209 and 210:
Page 211 and 212:
Page 213 and 214:
Page 215 and 216:
Page 217 and 218:
Page 219 and 220:
Page 221 and 222:
Page 223 and 224: EPRI Proprietary Licensed Material
Page 273: EPRI Proprietary Licensed Material
Page 300: About EPRI EPRI creates science and
show all

Handbook of Energy Storage for Transmission or ... - W2agz.com

Create successful ePaper yourself

Delete template?

Save as template?