This paper introduces a novel control strategy for shunt-type active power filters (APF) using a cascaded H-bridge (CHB) topology in a delta connection. The control is tailored particularly for low-cost microcontrollers with limited computation power and resources. The control combines the modified instantaneous active-reactive power (PQ) theory for power grid control and subordinated opti-mized (two-step) finite control set model predictive control (FCS-MPC) for control of CHB converters. The power grid control gener-ates setpoints for CHB converters, i.e., grid compensation currents and current references securing active power delivery for dc-links of CHB converters of the APF. The two-step FCS-MPC controls the particular CHBs, generates phase grid compensation currents, and balances the dc-link capacitors of the CHBs. The proposed control is validated by extensive simulations and experiments on the developed 60kW prototype of APF. The results show that the control quality is comparable to the full-state FCS-MPC while its com-putation time and complexity are notably reduced.