The present invention relates to a station auxiliary power source apparatus that converts power supplied from an overhead cable to generate power to be supplied to a load in a station. The station auxiliary power source apparatus includes a first average calculation unit that calculates the average value of the overhead cable voltage for every predetermined time period; a second average calculation unit that calculates, two or more times, an average value of the overhead cable voltage that is larger than a first average value of the average value among the overhead cable voltages; a third average calculation unit that calculates an average value of the overhead cable voltage per day; and a comparator that selects any one of a second average value of the average value and a third average value of the average value and sets the selected value as the threshold value.

A railroad system includes a first vehicle and a second vehicle. The first vehicle includes a drive-part, an inverter, an electric storage device, and a control part. The control part controls feasibility of charge or discharge of the electric storage device based on a detection value of any of a charge accumulation amount of the electric storage device, a distance between the first vehicle and the second vehicle, or a voltage value of a power line. When it is assumed that the detection value when charge or discharge of the electric storage device is switched from an allowable state to a prohibited state is a first set value, and the detection value when charge or discharge of the electric storage device is switched from a prohibited state to an allowable state is a second set value, the first set value and the second set value are different from each other.

A railroad system includes a first vehicle and a second vehicle. The first vehicle includes a drive-part, an inverter, an electric storage device, and a control part. The control part controls feasibility of charge or discharge of the electric storage device based on a detection value of any of a charge accumulation amount of the electric storage device, a distance between the first vehicle and the second vehicle, or a voltage value of a power line. When it is assumed that the detection value when charge or discharge of the electric storage device is switched from an allowable state to a prohibited state is a first set value, and the detection value when charge or discharge of the electric storage device is switched from a prohibited state to an allowable state is a second set value, the first set value and the second set value are different from each other.

A station building power supply device includes a circuit breaker to disconnect a connection with a train side, a circuit breaker to disconnect a connection with the station load side, a power converter disposed between the circuit breaker and the circuit breaker to convert the regenerative power into the AC power, a housing that houses the circuit breaker, the power converter, and the circuit breaker, a voltage sensor that detects a charged state of the housing, and a control unit that controls operations of the circuit breaker, of the power converter, and of the circuit breaker based on a detection result from the voltage sensor.

A station building power supply device includes a circuit breaker to disconnect a connection with a train side, a circuit breaker to disconnect a connection with the station load side, a power converter disposed between the circuit breaker and the circuit breaker to convert the regenerative power into the AC power, a housing that houses the circuit breaker, the power converter, and the circuit breaker, a voltage sensor that detects a charged state of the housing, and a control unit that controls operations of the circuit breaker, of the power converter, and of the circuit breaker based on a detection result from the voltage sensor.

A station-building power-supply device includes: a detector that detects a ripple in an overhead line voltage and outputs information on the detected ripple and an overhead line voltage value; a determiner that compares the information with a threshold for determining whether a ripple is in the overhead line voltage, and outputs the overhead line voltage value obtained when a ripple is determined to be not in the overhead line voltage based on the comparison result; an estimator that estimates, based on the overhead line voltage value, a no-load voltage value of an overhead line in a no-load state; a controller that sets an additional value; and a calculator that adds the additional value to the no-load voltage value to calculate a regeneration determining voltage value for determining whether an electric vehicle performs regeneration, and outputs the regeneration determining voltage value to a circuit that utilizes energy generated by the regeneration.

A station-building power-supply device includes: a detector that detects a ripple in an overhead line voltage and outputs information on the detected ripple and an overhead line voltage value; a determiner that compares the information with a threshold for determining whether a ripple is in the overhead line voltage, and outputs the overhead line voltage value obtained when a ripple is determined to be not in the overhead line voltage based on the comparison result; an estimator that estimates, based on the overhead line voltage value, a no-load voltage value of an overhead line in a no-load state; a controller that sets an additional value; and a calculator that adds the additional value to the no-load voltage value to calculate a regeneration determining voltage value for determining whether an electric vehicle performs regeneration, and outputs the regeneration determining voltage value to a circuit that utilizes energy generated by the regeneration.

A voltage control device includes a fluctuation calculating unit that calculates voltage tolerance, which is a difference between a voltage measured by a voltage control apparatus and a proper voltage upper limit value or a proper voltage lower limit value, and voltage sensitivity, which is a ratio of a fluctuation amount of active power and a fluctuation amount of the voltage, a change-request-information generating unit that generates information for requesting a change of a limit value of a control target range of other voltage control devices, a change processing unit that performs a change of a limit value of a control target range of the voltage control device according to content of the change request information, and a communication processing unit that transmits the change request information to the voltage control devices other than the voltage control device. The change request information includes information indicating voltage tolerance and voltage sensitivity.

A voltage control device includes a fluctuation calculating unit that calculates voltage tolerance, which is a difference between a voltage measured by a voltage control apparatus and a proper voltage upper limit value or a proper voltage lower limit value, and voltage sensitivity, which is a ratio of a fluctuation amount of active power and a fluctuation amount of the voltage, a change-request-information generating unit that generates information for requesting a change of a limit value of a control target range of other voltage control devices, a change processing unit that performs a change of a limit value of a control target range of the voltage control device according to content of the change request information, and a communication processing unit that transmits the change request information to the voltage control devices other than the voltage control device. The change request information includes information indicating voltage tolerance and voltage sensitivity.

A renewable energy-based hybrid bi-directionally interactive DC traction power supply system includes two traction substations. Each substation includes transformers, rectifiers, bidirectional AC-DC converters, a DC bus, a catenary, a steel rail and a section post. A DC bus between two adjacent traction substations is provided with a DC renewable energy system constructed by an electric vehicle charging-discharging system, a distributed generation and more than one low voltage DC microgrid. The DC renewable energy system is connected to the DC bus between two adjacent traction substations through a high voltage DC bus, thus a DC circular microgrid being formed in a power supply section post. The electric vehicle charging-discharging system is formed by more than one bidirectional DC-DC charging-discharging equipments which are intended for in connection with the power batteries of the electric vehicle. The renewable energy-based hybrid bi-directionally interactive DC traction power supply system of the invention realizes effective usage of distributed generation and recycling of electric locomotive braking energy, reducing DC voltage fluctuation, thus improving reliability of the DC traction power supply system.