Phase‐shift modulation in double half‐bridge inverter with common resonant capacitor for induction heating appliances

Abstract

In this study, the application of the phase-shift modulation to a double half-bridge resonant inverter supplying inductive loads with a common resonant capacitor is analysed in order to control the output power provided to the load of each converter. This study is focused on the application of such modulation to a cost-effective solution for domestic induction heating appliances with at least two burners heating up simultaneously two pots. The burners, also called inductor-pot systems, are usually electrically modelled by their equivalent impedances, Z coil (ω). The proposed modulation is suitable to control the power provided to inductor-pot systems with different equivalent impedances. The control variables of each half-bridge inverter, that is, switching frequency, f sw o, and duty cycle, D, have been assumed identical to both inverters in order to simplify the analysis, but, a new control parameter, the phase-shift between inverters, j, is employed. In the analysis, it has been proved that the power dependence with respect to the phase-shift between the inverter is almost totally due to the first harmonic contribution of the current. Finally, the main results of the analysis are checked by means of experimental measurements.

Analysis of the Acoustic Noise Spectrum of Domestic Induction Heating Systems Controlled by Phase-Accumulator Modulators

“…Let us consider the following parameters for the power inverter: P max = 3500 W, Q ∈ [1,8], f sw ∈ [30 kHz, 70 kHz], and f o = 30 kHz. The relative power resolution P R r is defined as:…”

“…Operating in the frequency domain is convenient when f sw is the output variable of the controller that adjust the power delivered to the load [5], [6]; besides frequency and pulse width are set independently in the PAB-PWM; whereas the compare register must be changed accordingly to the period register in the CB-PWM in order to maintain D. Additionally, operating in the frequency domain is convenient when switching frequency modulation profiles are used as a spread spectrum technique to reduce conducted electromagnetic interferences in resonant inverters [7]. Furthermore, frequency and phase can be set independently what can be suitable when several PWM signals with the same frequency and duty cycle, that have constant phase relationships must be generated, such as in [8], [9].…”

“…The Spectral Flatness Measure (SFM) [27] will be used to quantify the noise-like or tone-like nature of the spectrum of i 2 L in the band [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. For tonal signals, SFM is close to 0; and it is close to 1 for noise signals.…”

A comprehensive overview of power converter topologies for induction heating applications

“…The main drawback is that even harmonics are injected in the source side. The phase shift control (PSC), 23,[47][48][49][50][51][52] asymmetrical voltage cancellation (AVC), 21,[53][54][55][56] and pulse density modulation (PDM) 46,[57][58][59][60][61] are constant frequency methods, which are used in IH converter topologies to control the output power. In PSC, the inverter pulses are generated in order to create a phase difference between voltage and current.…”

A Comparative Evaluation of SiC Power Devices for High-Performance Domestic Induction Heating

“…The former enabled the design of a family of softswitching converters with improved efficiency and EMC performance whereas the latter allowed the design of reliable and cost-effective implementations for the home appliance mass-market. These advances, together with new flexible architectures [9][10][11][12][13] and advanced control schemes [14][15][16][17], made possible a significant technological breakthrough which led to a market share higher than 50% in many European and Asian countries.…”