PT Interface Generator Speed Sensor

Hydroelectric Turbine Control Equipment
Click here: Hydroelectric Speed Sensing With PT Interface video Back Story
	2021 - The Model ATE-32-15V PT Interface improves noise immunity by increasing the input threshold level from the standard 0.07 VAC to 15 VAC. Originally designed to amplify the low-level residual magnetism signal from a generator, it has been learned that most applications do not use this feature. Low level amplification allows spurious small noise signals to become false pulses in the speed signal. The new adjustable input threshold takes care of this. The input threshold can be increased from the normal 0.07 VAC up to 100% of the input signal amplitude to block unwanted noise. Complaints of noise “blips” getting through the ATE-32 to disturb speed stability have been received. Further investigation found the source to be low-level (8 to 10 volt) noise. Raising the threshold level to > 10 V will block them. The customer wanted the PT Interface output pulses only when the generator's exciter was energized. Field measurements found that the generator output was 1.8kV with minimum excitation stepped down to 20 VAC on the PT Wires. The threshold at 15V was chosen to split the difference between the highest noise and the lowest PT Signal when the unit is running with minimum excitation. The ATE-32 is certified in accordance with I.E.C. 60255-5; 1977. Full text of test report is at this link/ To buy, call (815) 335-1143 to place order.
	2011 - The Model ATE-32 PT Interface Module is a signal conditioner that converts the output of the Potential Transformer of a hydroelectric generator to a 24 Volt pulse train suitable for input to a PLC-based frequency counter. Input amplitude range is 0.2 VRMS to 180 VRMS. Input frequency range is from 6 Hz to 120 Hz. Over 2000 VDC isolation between the input and output circuits protects the governor PLC. Noise Immunity is enhanced by a hysteresis circuit on the input side. Input threshold voltage can be adjusted from 0.015VP-P up to to 1.0 VP-P amplitude to block spurious noise input signals and prevent unwanted output responses. ATE-32 Data Sheet Link The ATE-32 is certified in accordance with I.E.C. 60255-5; 1977. Full text of test report is at this link/
	The ATE-31 introduced in 2003 has the same electronic circuit and functionality as the ATE-30. Redesign into the Phoenix Contact enclosure offered several advantages that made this alternate package design modification desirable. The enclosure provides more room inside for additional or alternate circuitry and an optional magnetic shield that can be added to suppress EMI/RFI from the AD-210 switching power supply. An optional "spring cage" connector provides an alternative to traditional screw-terminal connectors. ATE-31 Data Sheet Link This model is obsolete. It has been supercededby the ATE-32 which offers significant improvements over the ATE-31 and ATE-30. The ATE-32 and ATE-32-15V are fit, form and function direct replacements forthe ATE-30 and ATE-31.
	The ATE-30 PT Interface signal conditioner was introduced in 2001 as a replacement upgrade for magnetic and proximity pickups and toothed wheel gears for speed sensing of hydroelectric turbines. The ATE-3X signal conditioner converts the electrical output of a generator into a pulse train suitable for digital counters to measure rotating speeds down to 10% speed (6Hz) with no excitation. Residual voltage output of an unexcited generator is typically > (0.2 AC VRMS) at 10% speed. This is beneficial during off-line startup when precise governor speed control is required for rapid synchronization of the generator to the electrical grid before closing the breaker contacts and for precise control of unit braking during shutdown. Original Data Sheet Link
Knock-off of ATE-30 and 31 is at:	http://www.americangovernor.com/woodward-governor-parts/pt-interface/
	2006- The ATE-36 was designed as a 4-20 mA input high power current driver for Voith (R) voice coil force motors. Two were sold to North American Phoenix for use in a governor upgrade at Newfoundland Hydro. After 13+ years of service, they are still working just fine. In 2007 BC Hydro bought a few ATE-36 to test for their new self-designed Francis governor system. Unit 3 at Mica Dam was the first to recieve this upgrade. The Data Cut Sheet has the specific engineering details. ATE-36 Data Sheet Link
	2019 ATE-37 BC Hydro requested a new higher power amplfier to drive Woodward Mod II and NYERPIC TR-10 electro/hydraulic servovalves for the G.M. Schrum Generatintng Station governor upgrades. The Woodward servovalve requires +750 mA of current to open the pilot valve all the way. A new switcher power supply was located that outputs up to +1,250mA at +24 VDC. The power amplifier IC can output up to 5A at +40 VDC but is held-back by the Current Limiter sense resistor. See OPA541AP Datasheet for more information.
	2019 For programming and setup work while developing governor software and hardware on the test bench a handy table-top electronic replacement for the ATE-37 was developed. The electronic amplifier circuit is exactly the same as the ATE-37 in the Phoenix Contact module. Inputs can be 4-20 mA or any standard DC Voltage range centered at 0 Volts or with an offset. Output is +21 VDC at up to +750 mA.
	2020 The ATE-40 was designed to augment a PLC 4-20mA output to drive a 0 to +20V, 10A output into a 2-Ohm force motor. Power supply is typical powerplant backup power of 24 to 30V DC. The ATE-40 is capable of much higher outputs with a larger HEXFET output transistor and heat sink. This configuration will sustain 10A at 20V indefinately. Gain and offset trimpots allow calibrating the 4-20mA setpoint input to get the desired output voltage span.
BC Hydro ATE-32, ATE-36 and ATE-37 used in governor upgrade projects at Mica and WAC Bennett Dams. PT Interface Description PT_Interface_Synchronizer PT_Interface_Back_Story 2016-02-06_Dave_PT-Interfacer_Pitch-to_Manitoba_Hydro

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