A Three-Phase PWM Inverter For Double Conversion UPS That Complies With the Standard IEC 62040-3

FERNANDO BOTTERÓN AND HUMBERTO PINHEIRO

Recife - Brasil

Congreso; PESC 2005; 2005

Abstract. — This paper proposes an improved digital voltage controller suitable for three-phase PWM inverters with output transformer for medium and high power uninterruptible power supplies (UPS). The proposed controller is derived from the internal model principle using a state-variable approach in stationary αβ frame. With this controller it is possible to obtain a high performance in both steady-state and load transients. In addition, with the selected internal model, dc components result from real circuit implementation nonidealities are not amplified avoiding in this way, the transformer saturation. The UPS output voltages have reduced total harmonic distortion (THD) for both balanced and unbalanced non-linear loads. Regarding the transient performance, load steps responses are improved with the proposed digital controller and as a result the UPS compliant with the Classification 1 of the international Standard IEC 62040-3. In order to validate the proposed digital controller and to demonstrate the steady-state and transient performance, experimental results from a 10kVA space vector modulated three-phase inverter, fully controlled by a DSP TMS320F241, are presented.