Search

Recently, low wattage HID lamps are developed and used steadily for an indoor illumination such as offices or stores. The ballast for the lamps is required to be in smaller size and lighter weight, and moreover it is required to have excellent function with good controllability. If the simulation model of the HID lamps is given for the behavior in transient such as in starting period, it is very useful for analysis and design of the ballast. In the paper, a simulation model for high pressure mercury lamps is proposed by means of state variable method. The equations are taken account of the state of each portion such as pressure, temperature and mercury vapor density, etc. The coefficient values of the equations are investigated physically and determined referred to experiment. The calculated results are in good agreement with the experimental results. Then, it is verified that the simulation model is available for the high pressure mercury lamps.

For the design of an “electronic” discharge lamp operating circuit, the accommodation to the variety of circuit’s configuration, the accurate calculation and the economic constraint are to be taken into account. The adaptation of CAD (Computer-Aided Design) may be most suitable for these situations. But achieving the CAD, there are a few troublesome problems to be solved, such as the simulation of the discharge lamp and the CAD techniques, etc. In this paper, the establishment of the basic design procedure is described through the development of a CAD program for an electronic operating circuit. The results are as follows; (1) the way of establishment of a criterion function and the procedure of optimum design have been proposed, (2) it has been reconfirmed that the simulation model of discharge lamps should be chosen case by case, (3) SUMT method has been introduced for calculation treatment. The usefulness of the CAD is verified by a good agreement between calculated and experimental results of a design example.

The analytical program of a voltage source inverter (VSI)-fed permanent magnet synchronous motor (PMSM) with a half-controlled bridge converter and an LC filter is developed. The input voltage of the inverter, that is the capacitor voltage, has a ripple of double frequency of the source due to the phase control of the thyristor. The performance of the motor is significantly influenced by the ripple in the capacitor voltage. This influence can be evaluated by the analytical program.

A generalized analytical model is presented for thyristor- controlled variable inductors. The proposed model can represent the performance of various types of thyristor phase-controlled variable inductors (VI's), e. g., conventional, UM-concept, magnetically coupled reactor, and asymmetrically firing control types, by introducing two parameters: m and ?By means of numerical computation using this model, the characteristics of variable inductors can be clarified, and their characteristics can be compared with ease. This analytical model is very useful for deciding circuit configuration and design.

A circuit controlled by thyristors and having series RLC elements gives rise to a step-up phenomenon. The term step-up is defined with respect to the capacitance voltage on steady state operation, i.e., the ratio of the maximum peak value when controlled by thyristers to the peak amplitude when thyristors are short-circuited exceeds unity. The domain of possible step-up voltage is determined by the angle of displacement between current and voltage and damping factor. The step-up voltages appear across each element, i.e., not only across the capacitance, inductance, and resistance but also across the thyristors. The control characteristic has a distinctive hump phenomenon. The interrupted current results in waveform distortion, phase lag, and improved power factor. The difference of characteristics between the peak and rms values of voltages, particularly of inductance and thyristors, is large. The response time, which is evaluated by numbers of half cycles, is large when the step-up ratio becomes large. The output voltage when the circuit is used as a voltage source has a drooping characteristic.

In the previous paper, the authors treated “Discharge Lamp Operation by Means of a Step-up Voltage Circuit by Back to Back Thyristor Pair.” The advantages of the new lamp operating system are based on the performance characteristics of this step-up voltage circuit, which depends delicately on the constants of the circuit and the phase control angle of thyristors. The obscurity of this dependability is an obstacle to the design calculation, together with the nonlinearity of the discharge lamp's own resistance.Thus, in this paper, with a view to investigate the step-up circuit, the analysis of the discharge lamp operating circuit has been carried out, assumed that both discharge lamp and L-ballast are replaced by a lumped, linearized equivalent load, that is, R-L load. The calculated results have revealed quantitatively the whole mechanism of the lamp operating circuit and provided the characteristics about output, power factor and efficiency that are the foundamental informations to design, and then given the prospects of the practical circuit design method.

Most of the existing papers have dealt with the torque pulsation of an inverter-fed AC motor caused by the behaviour of the inverter. In industrial applications the DC source is achieved by rectifying the AC supply. Therefore the behaviour of this rectifier also influences the torque pulsation. This paper describes analytically the influences of not only the behaviour of the inverter but also the behaviour of the rectifier on the motor torque. The torque pulsation is estimated by using three estimation methods. The selection of filter constants is also discussed.