Claims
- 1. In a method of controlling wicket gates of a pump-turbine upon removal of load from said pump-turbine, said pump-turbine being of the type having in the turbine operation area S-section where discharge per unit head (Q.sub.1) and speed per unit head (N.sub.1) satisfy the relationship, .differential.Q.sub.1 /.differential.N.sub.1 >0, the improvement which comprises the steps of slowly closing said wicket gates when the ratio (.differential.Q.sub.1 /.differential.N.sub.1) of variation of the discharge per unit head to the speed per unit head is reduced than a predetermined negative value, continuing the slow closure of said wicket gates while said pump-turbine operates tracing said S-section, and rapidly closing said wicket gates as soon as the ratio, .differential.Q.sub.1 /.differential.N.sub.1, is once reversed from a positive value out of said S-section to a negative value.
- 2. In a method of controlling wicket gates of a pump-turbine upon removal of load from said pump-turbine, said pump-turbine being or the type having in the turbine operation area S-section where discharge per unit head (Q.sub.1) and speed per unit head (N.sub.1) satisfy the relationship, .differential.Q.sub.1 /.differential.N.sub.1 >0, the improvement which comprises the steps of forcibly opening said wicket gates when the ratio (.differential.Q.sub.1 /.differential.N.sub.1) of variation of the discharge per unit head to the speed per unit head is reduced than a predetermined negative value, continuing the forcible opening of said wicket gates while said pump-turbine operates tracing said S-section, and rapidly closing said wicket gates as soon as the ratio, .differential.Q.sub.1 /.differential.N.sub.1, is once reversed from a positive value out of said S-section to a negative value.
- 3. In a method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area S-section where discharge per unit head (Q1) and speed per unit head (N.sub.1) satisfy the relationship, .differential.Q.sub.1 /.differential.N.sub.1 >0, the improvement which comprises the steps of opening said wicket gates when the turbine operation of said pump-turbine is effected on the S-section upon removal of load from said pump-turbine, and, when said pump-turbine operates outside said S-section, closing said wicket gates as rapidly as possible under condition that the hydraulic pressure variation caused by the rapid closure of said wicket gates becomes substantially equal to the hydraulic pressure variation caused in the S-section.
- 4. A method of controlling the wicket gates of a pump-turbine to prevent abnormal pressure rises when load carried by the pump-turbine is removed during the turbine operation, with respect to a turbine having wicket gates closable and openable to control the flow of fluid through the turbine impeller and having a S-section of its performance as a turbine defined by .differential.Q.sub.1 /.differential.N.sub.1 >0, wherein Q.sub.1 is the discharge fluid through the impeller per unit head and N.sub.1 is the impeller speed per unit head, comprising the steps of:
- upon removal of load from the pump-turbine, reducing Q.sub.1 and approaching the S-section;
- thereafter opening the wicket gates within the S-section; and
- thereafter closing the wicket gates.
- 5. The method of claim 4, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q.sub.1 is decreasing and conducting said step of opening when Q.sub.1 is decreasing.
- 6. The method of claim 5, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 7. The method of claim 4, wherein the turbine impeller speed N is detected, and said step of opening is conducted when the impeller speed with respect to time satisfies both of the relationships that dN/dt<0 and d.sup.2 N/dt.sup.2 <0, wherein t is time.
- 8. The method of claim 7, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 9. The method of claim 4, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 10. The method of claim 4, wherein the turbine further has the characteristic of operating either above its no load discharge line or below its no load discharge line, and said steps of opening and last mentioned closing are conducted in operation below said no load discharge line.
- 11. A method according to claim 4, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said closing step when dP/dt<0, and dN/dt<0, wherein t is time.
- 12. A method according to claim 4, further including the steps of:
- detecting the speed of rotation of the impeller N;
- detecting the torque T produced by turbine operation; and
- conducting said step of opening when dT/dt<0 and dN/dt<0.
- 13. The method of claim 4, further comprising the steps of:
- rapidly closing the wicket gates when it is detected that the ratio .differential.Q.sub.1 /.differential.N.sub.1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.
- 14. The method of claim 4, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- conducting said opening step when dP/dt>0, and dN/dt<0, wherein t is time.
- 15. The method of claim 14, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said closing step when dP/dt<0, and dN/dt<0, wherein t is time.
- 16. The method of claim 4, including discontinuing said opening of the wicket gates when .differential.Q.sub.1 /.differential.N.sub.1 <0.
- 17. The method of claim 16, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q.sub.1 is decreasing and conducting said step of opening when Q.sub.1 is decreasing.
- 18. The method of claim 4, wherein said step of reducing partially closes the wicket gates.
- 19. The method of claim 18, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q.sub.1 is decreasing and conducting said step of opening when Q.sub.1 is decreasing.
- 20. The method of claim 19, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 21. The method of claim 18, wherein the turbine impeller speed N is detected, and said step of opening is conducted when the impeller speed with respect to time satisfies both of the relationships that dN/dt<0 and d.sup.2 N/dt.sup.2 <0, wherein t is time.
- 22. The method of claim 21, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 23. The method of claim 18, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 24. The method of claim 18, wherein the turbine further has the characteristic of operating either above its no load discharge line or below its no load discharge line, and said steps of opening and last mentioned closing are conducted in operation below said no load discharge line.
- 25. The method of claim 18, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said closing step when dP/dt<0, and dN/dt<0, wherein t is time.
- 26. The method of claim 18, further including the steps of:
- detecting the speed of rotation of the impeller N;
- detecting the torque T produced by turbine operation; and
- conducting said step of opening when dT/dt<0 and dN/dt<0.
- 27. The method of claim 18, further comprising the steps of:
- rapidly closing the wicket gates when it is detected that the ratio .differential.Q.sub.1 /.differential.N.sub.1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.
- 28. The method of claim 18, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said opening step when dP/dt>0, and dN/dt<0, wherein t is time.
- 29. The method of claim 28, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said closing step when dP/dt<0, and dN/dt<0, wherein t is time.
- 30. The method of claim 18, discontinuing opening of the wicket gates when .differential.Q.sub.1 /.differential.N.sub.1 <0.
- 31. The method of claim 30, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q.sub.1 is decreasing and conducting said step of opening when Q.sub.1 is decreasing.
- 32. The method of claim 21, wherein the turbine further has the characteristic of operating either above its no load discharge line or below its no load discharge line, and said steps of opening and last mentioned closing are conducted in operation below said no load discharge line.
- 33. The method of claim 32, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said closing step when dP/dt<0, and dN/dt<0, wherein t is time.
- 34. The method of claim 32, further comprising the steps of:
- rapidly closing the wicket gates when it is detected that the ratio .differential.Q.sub.1 /.differential.N.sub.1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.
- 35. The method of claim 32, including discontinuing said opening of the wicket gates when .differential.Q.sub.1 /.differential.N.sub.1 <0.
- 36. The method of claim 18, wherein said step of closing closes the wicket gates at a rate at least as great as said step of reducing.
- 37. The method of claim 36, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q.sub.1 is decreasing and conducting said step of opening when Q.sub.1 is decreasing.
- 38. The method of claim 37, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 39. The method of claim 36, wherein the turbine impeller speed N is detected, and said step of opening is conducted when the impeller speed with respect to time satisfies both of the relationships that dN/dt<0 and d.sup.2 N/dt.sup.2 <0, wherein t is time.
- 40. The method of claim 39, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 41. The method of claim 36, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 42. The method of claim 36, wherein the turbine further has the characteristic of operating either above its no load discharge line or below its no load discharge line, and said steps of opening and last mentioned closing are conducted in operation below said no load discharge line.
- 43. The method of claim 36, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said closing step when dP/dt<0, and dN/dt<0, wherein t is time.
- 44. The method of claim 36, further including the steps of:
- detecting the speed of rotation of the impeller N;
- detecting the torque T produced by turbine operation; and
- conducting said step of opening when dT/dt<0 and dN/dt<0.
- 45. The method of claim 36, further comprising the steps of:
- rapidly closing the wicket gates when it is detected that the ratio .differential.Q.sub.1 /.differential.N.sub.1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.
- 46. The method of claim 36, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said opening step when dP/dt>0, and dN/dt<0, wherein t is time.
- 47. The method of claim 46, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said closing step when dP/dt<0, and dN/dt<0, wherein t is time.
- 48. A method of controlling the wicket gates of a pump-turbine to prevent abnormal pressure rises when load carried by the pump-turbine is removed during the turbine operation, with respect to a turbine having wicket gates closable and openable to control the flow of fluid through the turbine impeller and having an S-section of its performance as a turbine defined by .differential.Q.sub.1 /.differential.N.sub.1 >0, wherein Q.sub.1 is the discharge fluid through the impeller per unit head and N.sub.1 is the impeller speed per unit head, comprising the steps of:
- detecting the removal of load from the turbine and in response to detecting the load removal, closing the wicket gates upon removal of load from the pump-turbine to reduce Q.sub.1 and approach the S-section without completely closing the wicket gates;
- thereafter detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q.sub.1 is decreasing and discontinuing said step of closing when Q.sub.1 is decreasing; and
- thereafter detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and closing the wicket gates in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 49. The method of claim 48, wherein the turbine speed and the lapsed time is detected, and said step of discontinuing is conducted when the impeller speed with respect to time satisfies both of the relationships that dN/dt<0 and d.sup.2 N/dt.sup.2 <0.
- 50. The method of claim 48, wherein both said steps of discontinuing and last mentioned closing are conducted when the turbine is operating below its no load discharge line.
- 51. The method of claim 48, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said last mentioned closing step when dP/dt<0, and dN/dt<0, wherein t is time.
- 52. The method of claim 48, further including the steps of:
- detecting the speed of rotation of the impeller N;
- detecting the torque T produced by turbine operation; and
- conducting said step of discontinuing when dT/dt<0 and dN/dt<0.
- 53. The method of claim 48, further comprising the steps of:
- rapidly closing the wicket gates when it is detected that the ratio .differential.Q.sub.1 /.differential.N.sub.1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.
- 54. A method of controlling the wicket gates of a pump-turbine to prevent abnormal pressure rises when load carried by the pump-turbine is removed during the turbine operation, with respect to a turbine having wicket gates closeable and openable to control the flow of fluid through the turbine impeller under the control of a regular controller, such as a speed governor, and having an S-section of its performance as a turbine defined by .differential.Q.sub.1 /.differential.N.sub.1 >0, wherein Q.sub.1 is the discharge fluid through the impeller per unit head and N.sub.1 is the impeller speed per unit head, comprising the steps of:
- upon removal of load from the pump-turbine, reducing Q.sub.1 and approaching the S-section with the wicket gates being closed under control from the regular controller;
- thereafter putting the wicket gates under an overriding control within the S-section which allows only closing speed substantially stopping and very slow closing or opening signals from said regular controller and, for any faster closing signals from said regular controller outside said closing speed range, gives an overriding signal for substantially holding at the current wicket gate position; and
- thereafter closing the wicket gates.
- 55. The method of claim 54, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q.sub.1 is decreasing and conducting said overriding control when Q.sub.1 is decreasing.
- 56. The method of claim 55, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 57. The method of claim 54, wherein the turbine impeller speed N is detected, and said overriding control is conducted when the impeller speed with respect to time satisfies both of the relationships that dN/dt<0 and d.sup.2 N/dt.sup.2 <0, wherein t is time.
- 58. The method of claim 57, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 59. The method of claim 54, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 60. The method of claim 54, wherein the turbine further has the characteristic of operating either above its no load discharge line or below its no load discharge line, and said overriding control and last mentioned closing are conducted in operation below said no load discharge line.
- 61. A method according to claim 54, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said closing step when dP/dt<0, and (dN/dt)<0, wherein t is time.
- 62. A method according to claim 54, further including the steps of:
- detecting the speed of rotation of the impeller N;
- detecting the torque T produced by turbine operation; and
- conducting said overriding control when dT/dt<0 and dN/dt<0.
- 63. The method of claim 54, further comprising the steps of:
- rapidly closing the wicket gates when it is detected that the ratio .differential.Q.sub.1 /.differential.N.sub.1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.
- 64. The method of claim 54, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said overriding control when dP/dt>0, and (dN/dt)<0, wherein t is time.
- 65. The method of claim 64, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said closing step when dP/dt<0, and (dN/dt)<0, wherein t is time.
- 66. The method of claim 54, including discontinuing said overriding control of the wicket gates when .differential.Q.sub.1 /.differential.N.sub.1 <0.
- 67. The method of claim 66, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q.sub.1 is decreasing and conducting said overriding control when Q.sub.1 is decreasing.
- 68. The method of claim 54, wherein said step of reducing partially closes the wicket gates.
- 69. The method of claim 68, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q.sub.1 is decreasing and conducting said overriding control when Q.sub.1 is decreasing.
- 70. The method of claim 69, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 71. The method of claim 68, wherein the turbine impeller speed N is detected, and said overriding control is conducted when the impeller speed with respect to time satisfies both of the relationships that dN/dt<0 and d.sup.2 N/dt.sup.2 <0, wherein t is time.
- 72. The method of claim 71, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 73. The method of claim 68, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 74. The method of claim 68, wherein the turbine further has the characteristic of operating either above its no load discharge line or below its no load discharge line, and said overriding control and last mentioned closing are conducted in operation below said no load discharge line.
- 75. The method of claim 68, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said closing step when dP/dt<0, and (dN/dt)<0 wherein t is time.
- 76. The method of claim 68, further including the steps of:
- detecting the speed of rotation of the impeller N;
- detecting the torque T produced by turbine operation; and
- conducting said overriding control when dT/dt<0 and dN/dt<0.
- 77. The method of claim 68, further comprising the steps of:
- rapidly closing the wicket gates when it is detected that the ratio .differential.Q.sub.1 /.differential.N.sub.1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.
- 78. The method of claim 68, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said overriding control when dP/dt>0, and (dN/dt)<0, wherein t is time.
- 79. The method of claim 78, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said closing step when dP/dt<0, and (dN/dt)<0, wherein t is time.
- 80. The method of claim 68, discontinuing said overriding control of the wicket gates when .differential.Q.sub.1 /.differential.N.sub.1 <0.
- 81. The method of claim 80, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q.sub.1 is decreasing and conducting said overriding control when Q.sub.1 is decreasing.
- 82. The method of claim 71, wherein the turbine further has the characteristic of operating either above its no load discharge line or below its no load discharge line, and said overriding control and last mentioned closing are conducted in operation below said no load discharge line.
- 83. The method of claim 82, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said closing step when dP/dt<0, and (dN/dt)<0, wherein t is time.
- 84. The method of claim 82, further comprising the steps of:
- rapidly closing the wicket gates when it is detected that the ratio dQ.sub.1 /dN.sub.1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.
- 85. The method of claim 82, including discontinuing said overriding control of the wicket gates when .differential.Q.sub.1 /.differential.N.sub.1 <0.
- 86. The method of claim 68, wherein said step of closing closes the wicket gates at a rate at least as great as said step of reducing.
- 87. The method of claim 86, including the further steps of detecting when the pump-turbine is operating within the S-section so that the discharge per unit head Q.sub.1 is decreasing and conducting said overriding control when Q.sub.1 is decreasing.
- 88. The method of claim 87, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 89. The method of claim 86, wherein the turbine impeller speed N is detected, and said overriding control is conducted when the impeller speed with respect to time satisfies both of the relationships that dN/dt<0 and d.sup.2 N/dt.sup.2 <0, wherein t is time.
- 90. The method of claim 89, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 91. The method of claim 86, further including the step of detecting when the discharge per unit head Q.sub.1 is increasing within the S-section and conducting said last mentioned step of closing in the S-section when the discharge per unit head Q.sub.1 is increasing.
- 92. The method of claim 86, wherein the turbine further has the characteristic of operating either above its no load discharge line or below its no load discharge line, and said overriding control and last mentioned closing are conducted in operation below said no load discharge line.
- 93. The method of claim 86, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said closing step when dP/dt<0, and (dN/dt)<0, wherein t is time.
- 94. The method of claim 86, further including the steps of:
- detecting the speed of rotation of the impeller N;
- detecting the torque T produced by turbine operation; and
- conducting said overriding control when dT/dt<0 and dN/dt<0.
- 95. The method of claim 86, further comprising the steps of:
- rapidly closing the wicket gates when it is detected that the ratio .differential.Q.sub.1 /.differential.N.sub.1 changes from a positive value to a negative value indicating that operation within the S-section has terminated.
- 96. The method of claim 86, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure P within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said overriding control when dP/dt>0, and (dN/dt)<0, wherein t is time.
- 97. The method of claim 96, wherein the turbine has a penstock providing fluid under pressure to the wicket gates, further comprising the steps of:
- detecting the hydraulic pressure p within the penstock;
- detecting the speed of rotation N of the impeller;
- and
- conducting said closing step when dP/dt<0, and (dN/dt)<0, wherein t is time.
- 98. In a method of controlling wicket gates of a pump-turbine of the type showing during turbine operation the performance that discharge per unit head (Q.sub.1) and speed per unit head (N.sub.1) satisfy the relationship, .differential.Q.sub.1 /.differential.N.sub.1 >0, comprising the steps of:
- slowly opening said wicket gates upon removal of load from said pump-turbine;
- temporarily increasing the opening speed of said wicket gates during said slowly opening step when the pump-turbine is operated tracing the S-section in the Q.sub.1 -reducing direction (dQ.sub.1 /dt is negative).
- 99. A method of controlling wicket gates as set forth in claim 98, wherein said opening speed increasing step is carried out when a fixed time period has elapsed after the removal of load.
- 100. A method of controlling wicket gates as set forth in claim 98, wherein said opening speed increasing step is carried out when number of rotation (N) of said pump-turbine and time lapse (t) after the removal of load satisfy the relationships, dN/dt<0 and d.sup.2 N/dt.sup.2 <0.
- 101. A method of controlling wicket gates as set forth in claim 4, wherein said wicket gates temporarily opening step is engaged when number of rotation of said pump-turbine attains a maximum value.
- 102. A method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area an S-section where discharge per unit head (Q.sub.1) and speed per unit head (N.sub.1) satisfy the relationship .differential.Q.sub.1 /.differential.N.sub.1 >0, comprising the steps of:
- detecting a condition where said pump-turbine is operating tracing said S-section in the Q.sub.1 -reducing direction; and
- when said detecting step detects said condition, putting said wicket gates under an overriding control which allows only opening signals of a faster rate than a fixed rate from a regular controller (such as a speed-governor) and, for any slower rate, opening signals or closing signals from said regular controller gives an overriding opening signal of faster than or equal to said fixed rate.
- 103. A method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area an S-section where discharge per unit head (Q.sub.1) and speed per unit head (N.sub.1) satisfy the relationship .differential.Q.sub.1 /.differential.N.sub.1 >0, comprising the steps of:
- detecting a condition where said pump-turbine is operating tracing said S-section in the Q.sub.1 -increasing direction; and
- when said detecting step detects said condition, putting said wicket gates under an overriding control which allows only closing signals of faster rate than a fixed rate from a regular controller (such as a speed-governor) and, for any slower rate closing signals or opening signals from said regular controller gives an overriding closing signal of faster than or equal to said fixed rate.
- 104. A method of controlling wicket gates as set forth in claim 102, further comprising the steps of:
- detecting a second condition where said pump-turbine is operating tracing said S-section in the Q.sub.1 -increasing direction, and when said detecting step detects said second condition, putting said wicket gates under a second overriding control which allows only closing signals of faster rate than a second fixed rate from said regular controller and, for any slower rate closing signals or opening signals from said regular controller, gives an overriding closing signal of faster than or equal to said second fixed rate.
- 105. A method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area an S-section where discharge per unit head (Q.sub.1) and speed per unit head (N.sub.1) satisfy the relationship .differential.Q.sub.1 /.differential.N.sub.1 >0, comprising the steps of:
- detecting a condition where said pump-turbine is operating tracing said S-section in the Q.sub.1 -reducing direction,
- and
- when said detecting step detects said condition, putting said wicket gates under an overriding control which allows only substantially stopping or opening signals from a regular controller (such as a speed-governor) and, for any faster closing signals from said regular controller, gives an overriding signal for substantially holding at the current wicket gate position.
- 106. A method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area an S-section where discharge per unit head (Q.sub.1) and speed per unit head (N.sub.1) satisfy the relationship, .differential.Q.sub.1 /.differential.N.sub.1 >0, comprising the steps of:
- detecting a second condition where said pump-turbine is operating tracing said S-section in the Q.sub.1 -increasing direction, and
- when said detecting step detects said second condition, putting said wicket gates under an overriding control which allows only substantially stopping or closing signals from a regular controller (such as a speed-governor) and, for any faster opening signals from said regular controller, gives an overriding signal for substantially holding at the current wicket gate position.
- 107. A method of controlling wicket gates as set forth in claim 106, further comprising the steps of:
- detecting a second condition where said pump-turbine is operating tracing said S-section in the Q.sub.1 -increasing direction, and
- when said detecting step detects said second condition, putting said wicket gates under a second overriding control which allows only substantially stopping or closing signals from said regular controller and, for any faster opening signals from said regular controller, gives a second overriding signal for substantially holding at the current wicket gate position.
- 108. A method of controlling wicket gates as set forth in claim 102, further comprising the steps of:
- detecting a second condition where said pump-turbine is operating tracing said S-section in the Q.sub.1 -increasing direction, and
- when said detecting step detects said second condition, putting said wicket gates under a second overriding control which allows only substantially stopping or closing signals from said regular controller and, for any faster opening signals from said regular controller, gives a second overriding signal for substantially holding at the current wicket gate position.
- 109. A method of controlling wicket gates as set forth in claim 105, further comprising the steps of:
- detecting a second condition where said pump-turbine is operating tracing said S-section in the Q.sub.1 -increasing direction, and
- when said detecting step detects said second condition, putting said wicket gates under a second overriding control which allows only closing signals of faster rate than a fixed rate from said regular controller and, for any slower rate closing signals or opening signals from said regular controller, gives an overriding closing signal of faster than or equal to said fixed rate.
- 110. A method of controlling wicket gates as set forth in claim 102, 104 or 108, wherein said first overriding control for opening is carried out when it is detected that both number of rotation (N) of said pump-turbine and hydraulic flow rate (Q) through said pump-turbine reduce with the lapse of time.
- 111. A method of controlling wicket gates as set forth in claim 102, 104 or 108, wherein said first overriding control for opening is carried out when it is detected that, with the lapse of time, number of rotation (N) of said pump-turbine reduces and hydraulic pressure (P) in a penstock increases.
- 112. A method of controlling wicket gates as set forth in claim 102, 104 or 108, wherein said first overriding control for opening is carried out when it is detected that both pump-turbine torque (T) and number of rotation (N) of said pump-turbine reduce with the lapse of time.
- 113. A method of controlling wicket gates as set forth in claim 102, 104 or 108, wherein said first overriding control for opening is carried out when it is detected that number of rotation (N) of said pump-turbine and time lapse (t) satisfy the relationships, dN/dt<0 and d.sup.2 N/dt.sup.2 <0.
- 114. A method of controlling wicket gates as set forth in claim 102, 104 or 109, wherein said overriding control for closing is carried out when it is detected that hydraulic flow rate (Q) through said pump-turbine increases sharply with the lapse of time.
- 115. A method of controlling wicket gates as set forth in claim 102, 104 or 109, wherein said overriding control for closing is carried out when it is detected that, with the lapse of time, hydraulic pressure (P) in a penstock sharply reduces.
- 116. A method of controlling wicket gates as set forth in claim 98, further comprising the step of closing said wicket gates when it is detected that said pump-turbine operation tracing said S-section in the Q.sub.1 -reducing direction is terminated.
- 117. A method of controlling wicket gates as set forth in claim 105, 107 or 109, wherein said first overriding control is carried out when it is detected that both number of rotation (N) of said pump-turbine and hydraulic flow rate (Q) through said pump-turbine reduce with the lapse of time.
- 118. A method of controlling wicket gates as set forth in claim 105, 107 or 109, wherein said first overriding control is carried out when it is detected that, with the lapse of time, number of rotation (N) of said pump-turbine reduces and hydraulic pressure (P) in a penstock increases.
- 119. A method of controlling wicket gates as set forth in claim 105, 107 or 109, wherein said first overriding control is carried out when it is detected that both the pump-turbine torque (T) and number of rotation (N) of said pump-turbine reduce with the lapse of time.
- 120. A method of controlling wicket gates as set forth in claim 105, 107 or 109, wherein said first overriding control is carried out when it is detected that number of rotation (N) of said pump-turbine and time lapse (t) satisfy the relationships, dN/dt<0 and d.sup.2 N/dt.sup.2 <0.
- 121. A method of controlling wicket gates as set forth in claim 102, 103 or 104, wherein said wicket gates closing and opening steps are carried out by forcibly controlling a hydraulic distributing valve of servomotors for the wicket gates.
- 122. In a method of controlling wicket gates of a pump-turbine upon removal of load from said pump-turbine, said pump-turbine being of the type having in the turbine operation area an S-section where discharge per unit head (Q.sub.1) and speed per unit head (N.sub.1) satisfy the relationship, .differential.Q.sub.1 /.differential.N.sub.1 >0, the improvement which comprises the steps of slowly closing said wicket gates when the ratio (.differential.Q.sub.1 /.differential.N.sub.1) of variation of the discharge per unit head to the speed per unit head is reduced than a predetermined negative value or turns to positive, continuing the slow closure of said wicket gates while said pump-turbine operates tracing said S-section, and rapidly closing said wicket gates as soon as the ratio, .differential.Q.sub.1 /.differential.N.sub.1, is once reversed from a positive value to a negative value, out of said S-section.
- 123. In a method of controlling wicket gates of a pump-turbine upon removal of load from said pump-turbine, said pump-turbine being of the type having in the turbine operation area an S-section where discharge per unit head (Q.sub.1) and speed per unit head (N.sub.1) satisfy the relationship, .differential.Q.sub.1 /.differential.N.sub.1 >0, the improvement which comprises the steps of forcibly opening said wicket gates when the ratio (.differential.Q.sub.1 /.differential.N.sub.1) of variation of the discharge per unit head to the speed per unit head is reduced than a predetermined negative value or turns to positive, continuing the forcible opening of said wicket gates while said pump-turbine operates tracing said S-section, and rapidly closing said wicket gates as soon as the ratio, .differential.Q.sub.1 /.differential.N.sub.1, is once reversed from a positive value to a negative value, out of said S-section.
- 124. In a method of controlling wicket gates of a pump-turbine of the type which has in the turbine operation area an S-section where discharge per unit head (Q.sub.1) and speed per unit head (N.sub.1) satisfy the relationship, .differential.Q.sub.1 /.differential.N.sub.1 >0, the improvement which comprises the steps of opening said wicket gates when the turbine operation of said pump-turbine is effected in the Q.sub.1 -reducing direction in the S-section upon removal of load from said pump-turbine, and, when said pump-turbine operates outside said S-section, or tracing the S-section in the Q.sub.1 -increasing direction, closing said wicket gates as rapidly as possible under condition that the hydraulic pressure variation caused by the rapid closure of said wicket gates becomes substantially equal to the hydraulic pressure variation caused in the S-section.
Priority Claims (3)
Number |
Date |
Country |
Kind |
52-59213 |
May 1977 |
JPX |
|
52-59214 |
May 1977 |
JPX |
|
52-122449 |
Oct 1977 |
JPX |
|
Parent Case Info
This is a continuation, of application Ser. No. 908,202, filed May 22, 1978, now abandoned.
US Referenced Citations (11)
Foreign Referenced Citations (1)
Number |
Date |
Country |
1503261 |
May 1970 |
DEX |
Continuations (1)
|
Number |
Date |
Country |
Parent |
908202 |
May 1978 |
|