DC to AC inverter

U.S. Electricar built the lead-acid Electricar Prizm in Torrance, California, at Hughes Power Control Systems, a GM subsidiary that also designed the car s DC-to-AC inverter. Instead of a gas gauge there was a range meter. The batteries were in a covered tunnel underneath the car. Most electric vehicles have good low-end torque for excellent 0-60 acceleration, but the Prizm was a little sluggish initially but then picked up quickly. The car used a recharging paddle. 

In 2001, the authors of this chapter developed a 400-W, dc-to-ac inverter using SiC GTOs and p-/-n diodes for operation at case temperatures up to 150°C for driving three-phase, inductive loads up to 5 SOW. The inverter circuit was constructed to perform the first characterization of these SiC devices under significant electrical and thermal stresses, investigate the parametric operating space of the SiC devices, and uncover circuit-related failure modes. 

A quite different technique is the application of electronic ballasts, commonly a combination of a rectifier on the mains side followed by a DC to AC inverter. Its frequency on the output side is adjusted to values exceeding 20kcps. In this frequency range, the fluorescent lamps show an increased luminous efficiency compared with a 50 or 60cps supply. In parallel, the upper limit of the human hearing is passed avoiding undesirable whistle caused by the magnetostriction of inductive components. 

The Renault Scenic fuel cell vehicle (see the listed web site) has a specially developed high-efficiency squirrel cage induction motor for each road wheel, and is likely to have rivals in competing projects. However, at http //www.sustainability. renault.com/html/image.htm img=images/p/p.jpg, Renault shows a car layout with a front axle driven by one motor. There is a 48 VDC to DC converter followed by a DC to AC inverter. The hydrogen source is a petrol reformer. Evidently the project is still fluid. Setting out the options and alternatives is in hand. 

Clearly, a bond graph approach to FDI of systems modelled as a hybrid system is not limited to switched power electronic systems but may be applied to other engineering systems as well for which a hybrid model is appropriate. In the following, the case studies consider faults in a DC to DC boost-converter, in a three-phase DC to AC inverter and in a three-phase rectifier AC to DC. In some motor drives, a rectifier and an inverter are used back-to-back [8], Computations have been performed by means of the open source software program Scilab [21],... 

Figure8.36 shows the circuit schematic of an uncontrolled three-phase full bridge rectifier with a capacitor on the dc-side and a resistive load used, for instance, in variable voltage variable frequency dc to ac inverters as a front end, or for battery charger applications [34]. Figure8.37 displays the circuit diagram of a controlled three-phase rectifier.

The m-g UPS also can be built around a synchronous AC motor, as illustrated in Fig. 10.130. UtiHty AC energy is rectified and used to drive an inverter, which provides a regulated frequency source to power the synchronous motor. The output from the DC-to-AC inverter need not be a well-formed sine wave, nor a... 

An inductor/capacitor tank is driven by a DC-to-AC inverter, as illustrated in Fig. 10.144. The tank circuit acts to reconstruct the sine wave at the output of the system. Regulation is accomplished by varying the capacitance or the inductance to control partial resonance and/or power factor. Some systems of this... 

The direct current (DC) output of a fuel cell stack will rarely be suitable for direct connection to an electrical load, and so some kind of power conditioning is nearly always needed. This may be as simple as a voltage regulator, or a DCIDC converter. In CHP systems, a DC to AC inverter is needed, which is a significant part of the cost of the whole system. Electric motors, which drive the pumps, blowers, and compressors mentioned above, will nearly always be a vital part of a fuel cell system. Frequently also, the electrical power generated will be destined for an electric motor - for example, in motor vehicles. 

---