Method and apparatus for control of a turbine generator

A water turbine generating system comprising,

• a turbine having an input connected to a source of water supply and an output connected to a distribution system,
• a generator connected to be driven by the turbine,
• a set of generator contactors for connecting the generator to an electrical load,
• a control valve connected in the flow path of said turbine to control flow of water through the turbine, and,
• control means for operating the control valve and the contactors, said control means comprising
• a start circuit having a start relay coil (32) and a plurality of contacts connected to be operated thereby, the start circuit including a valve position switch (44) for energizing said start relay coil,
• a switch operator on said control valve for driving said valve switch to open and closed positions respectively as the valve moves to open and closed positions,
• a contactor control relay having a relay coil (36) and a plurality of relay contacts connected to be operated thereby, one of said start relay coil contacts (32-3) being connected in circuit with said control relay coil,
• a control circuit, including a first one of said control relay contacts (36-1) and including said valve switch in open position for energizing said control relay coil (36) and for maintaining energization thereof,
• a maintain circuit independent of said valve position switch and including a second set of said start relay coil contacts (32-2) for maintaining energization of said start relay coil (32),
• a pilot valve solenoid (60) connected in said maintain circuit for opening said control valve, and
• a motor contactor circuit having one of said control relay coil contacts (36-2) connected therein and including a generator contactor coil (34) for operating said generator contactors (34-2, 34-3, 34-4) to connect the generator to a user electrical system.

The method of generating electricity comprising the steps of

• connecting a turbine in the flow path of water flowing from a water supply to a water user system,
• connecting a generator to be driven by the turbine,
• connecting the generator to a power circuit,
• connecting a control valve to control flow of water through the turbine,
• connecting a relief valve to flow water past the turbine when water pressure exceeds a predetermined value,
• starting turbine and generator operation by initiating opening of the control valve and connecting the generator to an electrical load, and
• preventing starting of said turbine and generator and disabling said connection of said generator and power circuit when said control valve is open.

In combination with a water system in which water flows from a water supply at relatively high pressure to a water receiving system at relatively low pressure, a controlled power generating system comprising

• a first turbine generator and a first control valve connected in a flow path between said supply and a junction point connected to feed said receiving system, said turbine generator being sized for handling a predetermined minimum flow rate at optimum efficiency,
• a bypass valve connected in a second flow path between said water supply and said junction point,
• a second turbine generator and a second control valve connected in a third flow path parallel with said first and second paths between said water supply and said junction point,
• a flow meter connected to sense flow to said water receiving system at a point downstream of said junction point, said flow meter including means for generating a start signal in response to measured flow that exceeds said predetermined minimum by a first amount,
• means (356a) responsive to said start signal for opening said second control valve and starting operation of said second turbine generator,
• a first control circuit for operating said first turbine generator and control valve,
• a second control circuit for operating said second turbine generator and control valve, and
• first and second contactor means operable between closed and open conditions for respectively coupling said first and second generators to a power circuit,
• each said control circuit including start circuit means for operating the corresponding contactor means to closed condition and for initiating operation of the corresponding control valve to open position, and each said control circuit including means responsive to its corresponding valve for disabling the start circuit means when the control valve is in its open position, said means (356a) responsive to the start signal comprising means for initiating operation of said start circuit means of said second control circuit.