Hydro Turbine-Generator Package Provided As Part of Conduit Energy System for Hartford County, Conn.
Sorensen Systems received the selection to provide the turbine control systems for the Barkhamsted Transmission Hydro project near Hartford, Connecticut. This project included the induction generator, inlet expansion box, and the hydraulic power pack system, turbine inlet valve, and the main transmission by-pass valve. The project scope also encompassed the turbine control panel, circuit breaker panel, and UPS panel.
John Ford, Project Manager at Sorensen Systems, reported approval for the construction of a qualifying Conduit Hydropower Facility. This approval came as part of a comprehensive $2.1 billion clean water improvement project aimed at the 30 billion-gallon Barkhamsted Reservoir. According to John, “The conduit portion of the project involves the installation of a 250kW turbine to replace the currently unused booster pump in the Puddletown booster pump station.” This setup is expected to generate an estimated annual capacity of 1,475 megawatt-hours. The electricity is generated while water is in transit from the reservoir to MDC (Metropolitan District Commission) customers.
Turbine-Generator
The Sorensen Systems engineering project team, in collaboration with its strategic partner James Leffel & Co, undertook the design and construction of a Francis turbine-generator. They handled key sub-assemblies of the system. This comprised of the Inlet Expansion Box, the Stay Ring/Spiral Case, the Stainless Steel Runner, the Front and Rear Stainless Steel Covers, the Wicket Gate Mechanism, the Discharge Draft Tube, and the Marelli-Motori induction generator.
Hydraulic Power Pack
The Sorensen Systems engineering team designed and constructed a Hydraulic Power Pack System to operate the turbine wicket gates. The team then designed the turbine inlet valve (36 inches), and the main transmission by-pass valve (48 inches). They also incorporated other essential components. This included a full containment drip pan base with a level switch alarm and dual premium efficiency 480VAC, 3PH, 60HZ electric motor-driven hydraulic pumps, with one in operation and one on standby.
The design provided a control manifold to provide for normal operation and failsafe emergency close operation. Other components included four-inch stainless steel pressure gauges with gauge isolators and flow control valves. The valves limit the maximum closure rate of the wicket gate. Which then prevents pressure spikes in the water system. A stainless-steel motor starter enclosure was mounted to the HPU (hydraulic power unit) base. This provided for manual operation of the HPP (high pressure pump) motors. Other components included a lockable flanged disconnect switch and enclosure intrusion alarm switch. The entire power pack system weighed approximately 1,200 lbs.
Turbine Generator Control Panel
Sorensen Systems developed and validated the control scheme for the turbine/generator including PLC and HMI programming. The stainless steel free-standing turbine generator control panel contains an Allen-Bradley SLC500 PLC system, an Allen-Bradley Panel View HMI color touch-screen, PLC programming, a 24 VDC redundant power supply with loss of power detection and control power circuit breakers/fusing. In addition to the stainless steel enclosure, significant sub-assemblies and components include redundant power supplies, PLC programming, Ethernet communications, hardwired I/O interface to existing SCADA system, and enclosure intrusion alarm switch.
Circuit Breaker/Switchgear Panel
This panel weighs nearly 1,000 lbs and contains a custom 480VAC, 3PH, 4W, 60 HZ switchboard. Other components include metering, control switches, multifunction protection relay, modbus communications, and an intrusion alarm switch.
Uninterruptible Power Supply (UPS)
The UPS panel, enclosed in stainless steel, has a capacity to provide four hours of backup power to the control system in associated panels, as well as the miscellaneous solenoids and valves. Additionally, the panel features a maintenance bypass switch and incorporates status and alarms to transmit data to the existing SCADA system.
Facility Start-up and Commissioning
Sorensen Systems provided facility start-up and commissioning as well as operator training. The detailed test and commissioning procedures included:
- Factory Acceptance Test
- Turbine/Generator Operational Readiness Test
- Turbine/Generator Field Operations Test
- 30 Day Demonstration Test