Bipolar Power Supply Inverter

A "bipolar power supply inverter" isn't a standard single device butrefers to the use of a bipolar power supply in conjunction with an inverter circuit for applications requiring both DC and AC power control. A bipolar power supply provides both positive and negative DC voltages and can source or sink current, operating in all four quadrants of the voltage-current system. This is crucial for testing inverters and converters, which convert DC to AC power, as the bipolar supply can simulate the loads and varying conditions that an inverter will encounter in its operating environment.

1、 Working principle

-Dual battery input creates a potential difference: two sets of batteries, one connected in the positive direction and the other connected in the reverse direction, thus forming a power source with positive and negative potentials between the battery pack connection points. For example, a positively connected battery pack provides positive voltage, while a negatively connected battery pack provides negative voltage. With the intermediate connection point as the reference potential, there are relative positive and negative voltage outputs.

Usually, a full bridge (H-bridge) topology structure is used to achieve inversion. Two pairs of bridge arms are composed of four switching transistors (such as IGBT or MOSFET), and the upper and lower switching transistors of the same bridge arm conduct complementarily. By controlling the on and off sequence and time of the switching transistor, the input positive and negative DC voltages are converted into AC voltage output. If pulse width modulation (PWM) technology is used, when the amplitude of the modulation wave is greater than the carrier wave, the relevant switching devices are controlled to output a positive voltage; On the contrary, outputting a negative voltage causes the output voltage waveform to switch between positive and negative polarities, forming an alternating current similar to a sine wave.

2、 Characteristics

① Good output voltage characteristics: able to output complete AC waveforms including positive and negative half cycles, closer to ideal sine waves, with relatively low harmonic content. For loads that require high quality power waveform, such as precision electronic equipment, motors, etc., it can provide more stable and reliable power supply, reducing equipment heating, noise, and increased losses caused by waveform distortion.

② High power utilization efficiency: Two sets of batteries provide positive and negative voltages respectively. During the inverter process, the electrical energy of the battery pack can be fully utilized. Compared to inverters with single battery inputs, with the same battery capacity, it is possible to achieve higher output power and improve energy utilization efficiency.

③ Strong flexibility: The connection method and quantity of the battery pack can be flexibly adjusted according to actual needs to adapt to different output voltage and power requirements. For example, when a higher output voltage is required, the number of batteries in series can be increased; When a larger output power is required, the number of parallel battery packs can be increased.

3、 Application scenarios

① In the field of industrial automation, it provides stable AC power supply for various motor drives, programmable logic controllers (PLCs), sensors and other equipment in industrial production, ensuring precise operation and control of the equipment.

② Communication base station: Ensure stable power supply for communication equipment, provide high-quality AC power for transceivers, switches, monitoring equipment, etc. in the base station, and reduce the impact of power fluctuations and interference on communication signals.

③ Medical equipment, such as medical imaging devices (CT, MRI, etc.), medical monitoring devices, etc., require extremely high stability and waveform quality of the power supply. This inverter can provide reliable power support for these devices, ensuring the accuracy and safety of medical diagnosis and treatment.

④ Aerospace: In aerospace equipment such as airplanes and satellites, stable AC power is provided for various electronic instruments, control systems, communication equipment, etc., meeting the high reliability and stability requirements of aerospace equipment for power supply.