Tmeic Corporation

Toshiba Mitsubishi-Electric Industrial Systems Corporation

Haiqing Li

Masakazu Okayasu

Kouki Morisaki

A PI controller that calculates a PI control value for charge limitation, which is a PI control value for a deviation between a DC voltage applied to an inverter circuit and a charge limiter operating voltage when the DC voltage is higher than the charge limiter operating voltage, and calculates a PI control value for discharge limitation, which is a PI control value for a deviation between the DC voltage and a discharge limiter operating voltage when the DC voltage is lower than the discharge limiter operating voltage. A limiter regulator increases a limitation on a charging power command value from a host device by a command value limiter in accordance with the PI control value for charge limitation and increases a limitation on a discharging power command value from the host device by the command value limiter in accordance with the PI control value for discharge limitation.

Power conditioner and power conversion system

A power conditioning subsystem (PCS) includes an inverter circuit configured to mutually covert direct current (DC) power of a storage battery and alternating current (AC) power, a command value acquiring portion configured to acquire a command value from a higher-level apparatus to charge or discharge the storage battery, a DC voltage acquiring portion configured to acquire a DC voltage on the storage battery side, and a limiter processing portion configured to perform a process of setting to limit each of an upper limit and a lower limit of the command value acquired by the command value acquiring portion on the basis of the DC voltage acquired by the DC voltage acquiring portion.

Power conditioning subsystem

A power conversion device with a three-level TNPP circuit, includes: a voltage detection unit; a test pulse output unit that outputs a test pulse to an inner switching device connected in a forward direction from the DC neutral point to an AC output terminal when the voltages detected by the voltage detection unit rise and exceed a predetermined threshold; and a determination unit that determines, when the test pulse output unit outputs a test pulse to the inner switching device connected in the forward direction from the DC neutral point to the AC output terminal, upon drop in the voltage between the DC neutral point and the DC negative electrode detected by the voltage detection unit, that an outer switching device connected to the DC negative electrode has a short circuit failure.

Power conversion device and method of diagnosing failures of switching devices

An electrical power system includes: a solar battery panel; a first electrical power conversion device; a secondary battery; and a second electrical power conversion device. The first electrical power conversion device and the second electrical power conversion device selectively execute a first mode in which the first electrical power conversion device performs MPPT control on the solar battery panel and the second electrical power conversion device performs the charging-discharging control and a second mode in which the first electrical power conversion device performs output limit control to restrict output electrical power from exceeding a predetermined output limiter value and the second electrical power conversion device performs MPPT control on the solar battery panel.

Electrical power system

A power system includes a photovoltaic cell panel, a first power conversion device converting the DC power from the photovoltaic cell panel into AC power, and outputting the AC power to an electric power grid, a DC-side switch device provided between the photovoltaic cell panel and the first power conversion device and opening upon a trouble, a storage battery, and a second power conversion device connected to a connection point between the photovoltaic cell panel and the DC-side switch device and controlling charging and discharging of the storage battery. The second power conversion device includes a normal charging control mode for charging the storage battery based on a command signal from the system host monitor. Disconnection charging control mode may be executed when the DC voltage of the connection point exceeds a predetermined threshold value even if the command signal does not instructs the normal charging control mode.

Growing community of inventors

Tokyo, Japan

Haiqing Li