1. ParamedicDad

    Wind-up generators and Li-ion batteries

    Tl;dr: Are putting Li-ion batteries in a Wind-up flashlight a thing? If not, what options are there for a more reliable, renewable light source? Hello, I'm a Paramedic, husband and father of a small family of 3. We don't make much money and live in an area where we are often heavily impacted...
  2. Lambo Av

    Voltage Magnitude, Phases, Current for Bus (Load Flow)

    Say there are 3 buses of: Bus 1: Slack bus with a voltage source of E=1.0 and phase of 0° Bus 2: a generator and a load. Bus 3: a load. The line impedance are given below: z12 = 0.05 + j0.1 z13 = 0.02 + j0.05 z23 = j0.05 z11 = -j100 z22 = infinity z33 = -j40 The generators and loads are given...
  3. Lambo Av

    Generator at Slack Bus Reliability and Mean Time Before Failure

    Say, a generator at a slack bus with a voltage source of 1 V with phase of 0° with a hazard rate of 0.083. What's the reliability of the generator in 1 year and the Mean Time Before Failure? I have worked it out and got an illogical answer. Here are my workings, can anyone be kind enough to...
  4. Lambo Av

    Given 3 buses with line impedance, generators and loads provided, where must the protection circuit be allocated?

    The 3 buses are Bus 1: Slack bus with a voltage source of E=1.0 and phase of 0° Bus 2: a generator and a load. Bus 3: a load. The line impedance are given below: z12 = 0.05 + j0.1 z13 = 0.02 + j0.05 z23 = j0.05 z11 = -j100 z22 = infinity z33 = -j40 The generators and loads are given below...
  5. A

    How can a AC source be regulated to specific DC?

    Currently I am trying to power an Arduino project with a mechanical battery. I am using a stepper motor (NEMA23) as generator for it only needs low RPM to reach full potential (Around 600 RPM). Output of the stepper was determined at 1.8A AC @ 33V. This should be enough power for all the...
  6. Frequently.Modulated

    Does the Bombardier/DHC Q400 Auxiliary Power Unit Include a DC Generator? If it does, what kind of winding does it use?

    Good day! I am currently writing a short report on DC machines and I intended to use the generator onboard the Bombardier/DHC Dash 8 Q400's Auxiliary Power Unit as a focal topic. Upon searching through several documentation (both from Bombardier themselves and some airlines like AirBaltic) I...
  7. Lambo Av

    Two plants connected by a transmission line, load at plant 2, power loss included. Find the required generation for each plant and the power received

    A system consists of two plants connected by a transmission line. The only load is located at plant 2. When 200 MW is transmitted from plant 1 to plant 2 power loss in the line is 16 MW. Find the required generation for each plant and the power received by the load when lambda for the system is...
  8. Lambo Av

    3-bus system, finding Ybus and Gauss-Seidal method

    A 3-bus system data is as shown below. If the base is 200MWA, i) Find the Ybus admittance ii) Find the voltage at bus 2 and 3 after first iteration using Gauss-Seidal method For this, where do I start?
  9. Lambo Av

    Generator protection, calculating resistance for protection

    A 20kV, 100VA generator is protected by differential protection. 70% of the winding will be protected against the phase. What is the value of resistance to be located at the "Neutral to Ground" protection if the relay operates 30% out of the balance current? Below are my steps to the solution...
  10. Lambo Av

    Star-connected, 3-phase, synchronous generator with armature resistance, reactance, leakage resistance. Calculate rated load and unity power factor

    If a 100 KVA star-connected 400 V three-phase, 60 Hz synchronous generator with armature resistance 0.35Ω/phase and 3.5Ω reactance and leakage resistance given is 1Ω/phase. Calculate at rated load and unity power factor at i) No load e.m.f ii) Internal e.m.f. iii) percentage of regulation at...
  11. Lambo Av

    2 Generators connected to bus. Maximum, minimum voltage across light, peak voltage, pulsation

    2 generators are connected to the bus below. Given V1 = 300V, 50Hz V2 = 400V, 60Hz When the switch is opened, calculate i) the maximum and minimum voltage across both light 1 and 2. ii) peak voltage across both lights iii) maximum number of light pulsation How do I solve the issue above? Any...
  12. Theo_KVA

    Generator at low RPM for a non-chemical battery - What to look for?

    Hello! I’m in the process of trying to build a non-chemical battery. I sick a bit of guidance as I tend to go down an engineer rabit hole, because of the complexity that the project is aiming. My goal is to make some kind of object that could store enough energy to charge a smartphone’s...
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