Fasa Tunggal Kuasa Analisis
Analisis beban kuasa kediaman dan komersial ringan. Kira profil tenaga keseluruhan melebihi wattan mudah.
Input Sistem
AC Fasa Tunggal
Keputusan dikemas kini secara masa nyata semasa anda memasukkan parameter.
Formula Segitiga Kuasa
Kuasa AC fasa tunggal mempunyai tiga komponen — nyata, reaktif, dan ketara — yang membentuk segitiga kuasa.
Kuasa Nyata (kW)
P = V × I × PF Kuasa yang benar-benar melakukan kerja — diukur dalam kilowatt. Inilah yang dicaj oleh bil elektrik anda.
Kuasa Reaktif (kVAR)
Q = V × I × sin(θ) Kuasa yang disimpan dan dilepaskan oleh beban induktif dan kapasitif. Ia menyebabkan arus tanpa melakukan kerja berguna, meningkatkan kehilangan kabel.
Kuasa Ketara (kVA)
S = V × I = √(P² + Q²) Jumlah kuasa yang mesti dibekalkan oleh bekalan — hasil tambah vektor kuasa nyata dan reaktif. Digunakan untuk menentukan saiz penjana dan transformer.
Understanding Single-Phase AC Power
Single-phase AC power is the standard supply for residential buildings and light commercial facilities. Unlike DC, AC voltage reverses direction periodically (50 or 60 times per second), which enables efficient voltage transformation but introduces the concept of power factor — the relationship between the voltage and current waveforms.
The Power Triangle
Real power (kW), reactive power (kVAR), and apparent power (kVA) form a right triangle. The angle θ between the apparent and real power vectors is the phase angle — and the cosine of this angle is the power factor. A PF of 1.0 means the triangle collapses to a straight line: all apparent power is real power.
What Causes Low Power Factor?
- Induction Motors: The most common cause. Motors use reactive power to build rotating magnetic fields. Lightly loaded motors have worse PF than fully loaded ones.
- Transformers at Light Load: The magnetizing current drawn by transformer cores is largely reactive.
- Fluorescent Lighting (older ballasts): Magnetic ballasts introduce significant reactive current. Electronic ballasts largely solve this.
- Variable Speed Drives: Can improve motor PF but introduce harmonic distortion which has its own effects on the supply.
Power Factor Correction
Low power factor can be corrected by adding capacitor banks in parallel with inductive loads. Capacitors supply reactive power locally, reducing the reactive current that must flow from the utility. This reduces cable losses, improves voltage regulation, and avoids utility penalties for industrial customers with PF below 0.9.