3. INTRODUCTION & OBJECTIVES
Our design project is mainly based on the simulation of power quality problems. We are designing a device that will simulate these power quality problems. The number of the power quality problems we can actually simulate are very limited because of the required voltage and current requirements. Our approach to the design of this piece of test equipment that simulates power quality problems is using a voltage amplifier that will amplify a 5Vrms (7.07Vp-p), 10mArms (14.14mAp-p) AC sinusoidal signal from a function generator to 120Vrms (169.71Vp-p), 7.07Arms (10 Ap-p) AC sinusoidal signal. Our test equipment will have an interface to which we can connect equipment and appliances to be tested. This device will be very useful to the manufacturers of consumer electronics, in testing how their products hold up under adverse power quality situations.
The design constraints for the voltage amplifier are as follows:
3.1. Design Input: Input will be a 5Vrms (7.07Vp-p), 10mArms (14.14mAp-p) AC Sinusoidal signal from a function generator.
Design Output: Output will be the amplified input signal at 120Vrms |(169.71Vp-p), 7.07Arms (10 Ap-p) AC sinusoidal signal. This should be sufficient to test many different consumer appliances.
3.3 Efficiency: Efficiency of the circuit will be kept to 90% or greater. A less
efficient design would cause problems when the amplifier is attempting to boost the output and the power supply cannot provide much more than what is to be amplified.
3.4. Temperature/Heat: Transistor circuit temperature must be kept below 200F as measured from each transistor’s heat sink. This will ensure that the circuitry does not break down due to excess heat.
3.5. Harmonic Distortion: A perfect output waveform is not possible, but the
total harmonic distortion (THD) must be kept 0.1% or less. This will ensure accurate simulation in testing power quality problems.
3.6.Safety & Short Circuit Protection: The project requires safety and
circuit protection measures to be integrated into the design. Fuses, and a sleep switch will be used to protect the amplifier as well as the input device from excess current. GFI receptacles will be used to protect against short circuit on the output.
3.7. Self Test & Maintenance: The circuit will have a function to
determine when it is ready for use and to indicate malfunctions. This will allow the user to detect when the device is functional and when it needs to be serviced.